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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 10/057,223 filed Jan. 25, 2002, now U.S. Pat. No. 6,774,300, which claims the benefit of provisional application Ser. No. 60/287,205 filed Apr. 27, 2001.
TECHNICAL FIELD
The present invention is directed to low cost, high efficiency solar cell technology. More specifically, the present invention is related to a method and apparatus for producing photovoltaic energy using solid-state devices.
BACKGROUND OF THE INVENTION
Conventional photovoltaic cells convert sunlight directly into electricity by the interaction of photons and electrons within the semiconductor material. Most solid-state photovoltaic devices rely on light energy conversion to excite charge carriers (electrons and holes) within a semiconductor material and charge separation by a semiconductor junction producing a potential energy barrier. To create a typical photovoltaic cell, a material such as silicon is doped with atoms from an element with one more or less electrons than occurs in its matching substrate (e.g., silicon). A thin layer of each material is joined to form a junction. Photons, striking the cell, transfer their energy to an excited electron hole pair that obtains potential energy. The junction promotes separation of the electrons from the holes thereby preventing recombinations thereof. Through a grid of physical connections, the electrons are collected and caused to flow as a current. Various currents and voltages can be supplied through series and parallel arrays of cells. The DC current produced depends on the electronic properties of the materials involved and the intensity of the solar radiation incident on the cell.
Conventional solar cell technologies are based largely on single crystal, polycrystalline, or amorphous silicon. The source for single crystal silicon is highly purified and sliced into wafers from single-crystal ingots or is grown as thin crystalline sheets or ribbons. Polycrystalline cells are another alternative which is inherently less efficient than single crystal solar cells, but also cheaper to produce. Gallium arsenide cells are among the most efficient solar cells available today, with many other advantages, however they are also expensive to manufacture.
In all cases of conventional solid-state photovoltaic cells, photon (light) absorption occurs in the semiconductor with both majority and minority charge carriers transported within the semiconductor; thus, both electron and hole transport must be allowed and the band gap must be sufficiently narrow to capture a large part of the visible spectrum yet wide enough to provide a practical cell voltage. For the solar spectrum the ideal band gap has been calculated to be approximately 1.5 eV. Conventionally, expensive material and device structures are required to achieve cells that provide both high efficiency and low recombination probability and leakage.
A conventional solid-state solar cell, such as the one shown in FIG. 1 , may include structures such as a semiconductor junction, heterojunction, interface, and thin-film PV's, which may be made from organic or inorganic materials. In all of these devices the necessary elements of these types of devices are a) photon absorption in the semiconductor bulk, b) majority and minority charge carrier transport in the semiconductor bulk, c) a semiconductor band-gap chosen for optimal absorption of the light spectrum and large photovoltages, and d) ideal efficiency limited by open circuit voltages less than the semiconductor band-gap. The photon absorption occurs within the bulk semiconductor and both majority and minority carriers are generated and transported in the bulk. For adequate absorbency, relatively thick, high quality semiconductors are needed. However, defect free, thick, narrow band-gap, materials are limited in numbers and expensive to fabricate. In heterostructures a limited number of acceptable compatible materials are available. Schottky barrier based devices have been proposed in this class that rely, again, on absorption of photons in the semiconductor bulk and use the Schottky barrier for charge separation.
Another class of conventional solar cells are the dye-sensitized photoelectrochemical solar cells as shown in FIG. 2 . These devices were derived from work on photoelectrochemical electron transfer and are cathode/electrolyte/anode systems in which a photoactive molecule is light activated and oxidized (or reduced) by electron (or hole) transfer to the adjacent semiconductor electrode. The charge transfer agents which replace the transferred charge in the photoactive molecule are typically molecules or atoms dissolved in a liquid electrolyte such that the molecules or atoms receive charges from an electrode. Reduction is performed by an electron donor in the liquid electrolyte. This device is limited in its power output by the relative free energies of electrons in the electrolyte and the semiconductor which limit the photovoltage. The maximum photovoltage is limited by the difference between the bottom of the conduction band edge and the liquid electrolyte chemical potential. Additional inefficiencies result from the required molecular diffusion of the donors to the electrode as well as overpotential losses at the electrode/electrolyte interface.
Another solid-state solar cell is the dye-sensitized Schottky barrier solar cell as described in U.S. Pat. Nos. 4,105,470 and 4,190,950 by Dr. Skotheim. The Skotheim device is similar to the above-mentioned photoelectrochemical cell except the liquid electrolyte is replaced by a “reducing agent” layer, the property of which is not precisely identified in either the '470 nor the '950 patent. Purportedly, as a means of removing the band-gap restrictions of conventional PV's, an invention was reported by Skotheim who proposed a solid-state Schottky barrier device whereby a) photon absorption occurs in a photosensitive dye deposited on the surface of a semiconductor, b) majority charge carriers are injected directly into the conducting bands of the adjacent semiconductor, c) the ionized photosensitizer is neutralized by charges delivered by a reducing agent, d) a conductor provides charge to the reducing agent, and e) the Schottky barrier height will determine the device's ideal efficiency and its height is determined by the interaction of the dye and the semiconductor. However, as previously mentioned, neither patent suggests the physical properties of the reducing agent, and it is unclear whether the proposed devices disclosed in the '470 and '950 patents can indeed yield the purported results. In the proposed cell three separate molecular oxidation/reduction electron transfer steps are required (one from the excited dye to the adjacent semiconductor, one from the reducing agent to the dye, and one from the conductor to the reducing agent). Thus an electron must move from/to a conduction band to/from a molecular orbit twice and from one molecular orbit to another one. An implementation of the device was published using an organic hole transport material, however, the performance and longevity were poor [ref: U. Bach, et al., Nature, Vol. 395, October 1998, pg. 583-585].
Experimental work by the present inventor has demonstrated that low energy molecular energy transfer at conducting surfaces can lead to excited charge carriers that can be efficiently transported through a conductor without energy loss (via ballistic transport) and captured by an electrical barrier device wherein the barrier height is determined in part by the electronic interactions between the surface conductor and the barrier material.
Accordingly, a fundamentally different type of photovoltaic device is provided by the present invention which can be easily manufactured from a wide variety of inexpensive material, and which may be, in practice, more efficient, the various embodiments of which will be described in more detail below.
SUMMARY OF THE INVENTION
The preferred embodiment of the present invention described herein is a multilayer solid-state structure wherein light absorption occurs in photosensitive layer (molecules or nanostructures) and the energetic charge carriers produced by the absorption are transported ballistically, without significant energy loss, through an ultra-thin conductor, to and over an adjacent potential energy barrier that separates and stores the charge for use as electrical power. The potential energy barrier largely determines the device efficiency and can be optimized by choice of the device materials.
In accordance with the preferred embodiment, a photoexcitable molecular species or absorbing nanostructure is deposited on an ultra-thin conductor, and following photoexcitation excited charges are ballistically transported through the conductor to the potential energy barrier (Schottky barrier) created at the interface between the conductor and the charge collection layer (a semiconductor). The ultra-thin conductor has, inter alia, three specific functions: I) allows efficient ballistic transport of charge carriers from the photosensitizer to the potential barrier at the interface, II) directly provides replacement charges of the opposite sign to the ionized photosensitizer, and III) influenced, in part, by its interaction with the charge separation layer, the magnitude of the potential energy barrier which determines, in part, the maximum device power.
The essential components (e.g., layers) of the preferred embodiment of the present invention include: 1) a photosensitive layer where light energy is converted to electron and/or hole excitation, 2) an adjacent ultra-thin conducting layer that provides a pathway for ballistic transport of charges using high efficiency conduction bands, and as a source of replacement charges to the photosensitive layer; and 3) a charge separation and collection layer such as an inorganic or organic semiconductor affixed with a back side ohmic contact opposite the ultra-thin conducting layer. The ohmic contact collects the charges transported across the barrier. The addition of an anti-reflection coating on top of the device is a highly practical embodiment of the invention.
The present invention is advantageous over the aforementioned dye-sensitized Schottky barrier solar cell structure in that it has the advantage of potentially greater photovoltages due to the ability to influence the barrier height by the choice of a high (for n-type semiconductors) or low (for p-type semiconductors) work function conductors at the surface, by the choice of the semiconductor (type and doping level), and by the surface treatment of the semiconductor prior to disposition of the conductor to maximize the barrier height by affecting the interface. Additional advantages of the present invention include eliminating the need for a specific reducing agent or a minority charge carrier transport material, and providing the ability to choose from among a broad choice of charge separation layer material to include both wide band-gap n and p type semiconductors. In contrast to the prior art U.S. Pat. Nos. 4,105,470 and 4,190,950 by Skotheim, only two transfers of electrons to/from conduction bands are required and no intermolecular charge transfer is necessarily required.
It is an object of the present invention to: 1) eliminate the need for electrolytes and/or molecular reducing agents and/or minority carrier conductors, 2) allow for a wider choice of the conductor and charge separation layer, and 3) maximize by design of the open circuit photovoltage.
It is another object of the present invention to increase the efficiency of photovoltaic energy generation. More specifically, light absorption can be optimized since a single band-gap is not required for light absorption and a large number and variety of materials with selectable spectral properties of photoabsorbing molecules or structures can be utilized without the need for compatibility with an electrolyte. Without the overpotential losses of the electrochemical redox reactions (both at the electrodes in the photoelectrochemical cell and by the reducing agent charge transfer), higher efficiencies are also possible. The ultra-thin conductor is used as an efficient ballistic transport channel and to maximize the photovoltage as determined by its effect on the barrier. The interaction between the conductor and charge separation layer to influence the barrier height, can be optimized by the choice of the conductor, charge separation material, and interface preparation.
It is yet another object of the present invention to lower the cost of generating photovoltaic energy. More specifically, present solid-state P.V. systems are expensive due to the need for high purity low defect silicon or other semiconductors with the required band-gap, which have high manufacturing costs. The liquid containing photoelectrochemical cells have reliability and efficiency limits as well as restrictions on the dye stability and reducing agent in solution, thus increasing their in-use costs. Frequently, reactive species such as iodine must be used.
In is yet another object of the present invention to increase the longevity of the solar cell devices by using stable components. In the case of photoelectrochemical cells, most types of feasible electrolytes are reactive and can erode or dissolve the adjacent semiconductor or react with the dye, causing the device to be unstable. By eliminating the need to use reactive components, the present invention promotes the longevity of solar cells.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be had by reference to the following Detailed Description when taken in connection with the accompanying Drawings, wherein:
FIG. 1 is a graphic illustration of a conventional solid-state solar cell;
FIG. 2 is an illustration of a conventional dye-sensitized photoelectrochemical cell;
FIG. 3 is an illustration of the present invention in accordance with the preferred embodiment;
FIG. 4 is an illustration of the present invention in accordance with an alternative embodiment;
FIG. 5 is an illustration of the present invention in accordance with another alternative embodiment;
FIG. 6 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 7 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 8 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 9 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 10 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 11 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 12 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 13 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 14 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 15 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 16 is an illustration of the present invention in accordance with yet another alternative embodiment;
FIG. 17 is an illustration of the present invention in accordance with yet another alternative embodiment; and
FIG. 18 is a current versus voltage plot of a device made in accordance with the preferred embodiment of the present invention.
DETAILED DESCRIPTION
Various embodiments of the present invention will be described with reference to FIGS. 3-11 . Although only a limited number of embodiments of the invention are described hereinafter, it shall be understood that the detailed discussion of the embodiments is not intended to limit the present invention to those particular embodiments.
FIG. 3 illustrates a photosensitized solid-state device in accordance with the preferred embodiment of the present invention. More specifically, the photosensitized solid-state device includes a photosensitive layer 10 , a front conducting layer 31 , a charge separation layer 39 , a back conducting layer. 30 , and a load 32 . The front conducting layer 31 is preferably an ultra-thin metal film (preferably in the nanometer range), while the back conducting layer 30 is preferably an ohmic conducting layer. The charge separation layer 39 has a determinable conduction band energy level 38 and a determinable valence band energy level 37 . In an alternative embodiment as shown in FIG. 14 , the metal film may be chemically treated to: 1) allow improved bonding of the photoactive materials, and 2) provide partial isolation of the photoreceptor from the conductor to optimize ballistic charge transfer compared to other pathways to de-excitation of the excited photoreceptor. In another alternative embodiment as shown in FIG. 16 , the surface of the device consisting of the photosensitive layer/metal film/charge separation layer is highly contoured, porous, or otherwise shaped to maximize the surface area and maximize the absorbance of photons.
The front conducting layer 31 and the back conducting layer 30 preferably have determinable work function levels 34 and 33 , respectively. It is preferable that the material chosen to make up the front conducting layer 31 has a higher work function (more negative) than the Fermi level of the charge separation layer 39 if the charge separation layer 39 is of an n-type semiconductor, or if the charge separation layer 39 is of a p-type semiconductor, a lower work function to facilitate formation of a Schottky barrier 25 .
It is preferable that the front conducting layer 31 is of the type of material that forms a Schottky barrier with the charge separation layer 39 so as to maximize the power output of the solid-state device. Such material (for an n-type barrier) may include metals such as gold or platinum, or a non-metal material such as organic conductor polythiophene or a metal oxide. For a p-type barrier, such as one shown in FIG. 8 , materials include low work function conductors including aluminum and titanium. In accordance with the preferred embodiment, the front conducting layer 31 acts as a donor to the photo-oxidized surface species and thereby eliminates the need for a redox active electrolyte, which causes losses in the production of photovoltaic energy and typically has mass transport limitations for current flow.
The charge separation layer 39 is preferably made of a semiconductor material, or multiple semiconductors. Either inorganic semiconductor materials (e.g., titanium dioxide, zinc oxide, other metal and mixed metal oxides, moly sulfide, zinc sulfide, other metal mixed and mixed metal sulfides, silicon carbide, etc.) or organic semiconductor materials, either hole conducting (e.g., triphenyldiamine (TPD), poly(p-phenylene vinylene) (PPV), poly (vinyl carbazole) (PVC), and their derivatives, etc.), or electron conducting (e.g., conjugated oligothiophenes, oxadiazole derivatives, etc.) may be used. In an alternative embodiment as shown in FIG. 17 , the charge separation layer 39 is made of an insulator or insulator-semiconductor composite structure with the key feature being alignment of the majority carrier bands with the absorber donor level (in FIG. 3 , 36 for n-type or in FIG. 8 , 84 for p-type). The photosensitizer layer 10 can be a dye or any energy absorbing material or structure, and may include light absorbing atomic or molecular species on a surface (e,g,. cis-di(thiocyanato)-N,N-bis-(2,2-bipyridyl-4,4-dicarboxylic acid)-Ru(II), phthalocyanines, carbocyanines, merbromin, o-phenylxanthene, iron cyanate, etc.), or quantum structures (e.g., nanoparticles of CdS, CdSe, or other semiconductors, or metals, or nanolayers of absorbing material). Additionally, multiple types and/or layers of different photoactive species can be used on the photosensitizer layer 10 to maximize the spectrum capture of incident light. In an alternative embodiment, the photoactive species may be imbedded in the front conductive layer to make a single composite layer.
In fabricating the above-described structure, the photosensitizer layer, the front and back conducting layers, and the charge separation layer can be deposited by vapor deposition, electrochemical deposition, deposition from solution or colloidal suspension, or be produced by evaporative, extrusion, or other conventional polymer manufacturing techniques. With specific regard to the charge separation layer 39 , it may be created with high surface area using organic template molecules, or it can be nano-, meso-, or macro-porous to increase the surface area. The conductor and photoactive layers would then follow the contoured surface (see FIG. 16 ).
In a specific fabrication example comprising the preferred embodiment of the invention, a charge separation layer 39 of titanium dioxide is deposited onto titanium foil (the ohmic back contact 30 ). The charge separation layer 39 has a thickness ranging between 100 nm and 500 nm and is deposited by electron beam evaporation and/or by electroanodization of the titanium metal. Gold is then deposited to the composite layer to a thickness of 10 nm to form the ultra-thin conductor.
The operation of the preferred embodiment will now be discussed with reference to FIG. 3 . The preferred embodiment of FIG. 3 produces electrical power from a photon energy source based on light energy conversion to charge excitation in a layer containing photosensitive molecules or structures. More specifically, a photon energy source 35 with energy hν, such as sunlight, is incident upon the photosensitive layer 10 . The energy source excites electrons 36 located in the photosensitive layer 10 causing the electrons 36 to rise to a higher energy state. In accordance with the preferred embodiment, electrons having an energy level above the barrier height 25 (or slightly below if tunneling occurs) pass through the front conducting layer 31 via ballistic transport (ballistic transport refers to the transfer of electrons through a medium in which there is a low or zero scattering cross-section between the electrons and the medium through which they are transferred). The process of charge (electron) emission from the photoexcited absorber into and ballistically across the conduction bands of the conductor and charge separation layer is termed “Internal Charge Emission”.
Once the electrons travel through the front conducting layer 31 , they travel through the charge separation layer 39 towards the back ohmic conducting layer 30 where they are stored with photon derived excess potential energy for later use (dissipation) in passing through the load 32 . After losing their energy in the load 32 the electrons are returned to the front conducting layer 31 . The maximum photovoltage of the device, or open circuit voltage, is determined by the potential barrier height between the front conducting layer 31 and the charge separation layer 39 . In conventional Schottky solar cells (where the photons are absorbed in the semiconductor band-gap) the same maximum voltage is possible as determined by the barrier height, however, in the present invention the choice of semiconductors is not limited to those with solar spectrum absorbance. The voltage can be optimized or influenced by selecting appropriate materials for the front conducting layer 31 and the charge separation layer 39 , and by specific treatments of the interface. For example, on clean silicon the Schottky barrier varies from approximately 0.4 eV to 0.8 eV as the conductor work function increases from approximately −2.5 eV (Ca) to −5.0 eV (Au) and on GaAs from 0.6 eV (for Mg) to 1 eV (for Pt). Preparation of the interface and metal can also be used to increase the barrier for Pd on titanium dioxide where treatment of the metallic conductor Pd with oxygen causes an increase in the barrier of nearly 0.5 eV. The design approach is to maximize the barrier and still allow efficient carrier transport across the barrier and efficient replacement of photosensitizer (PS) charge by the conductor.
In accordance with an alternative embodiment, the charge separation layer 39 may be a thin insulating layer (PS-MIM configuration) wherein the conduction band edge and thickness of the insulator are chosen to allow charge carriers from the photoexcited state of the photosensitizer 10 to move to the back contact and prevent current flow in the opposite direction.
In accordance with another alternative embodiment of the present invention an additional layer of semiconductor is included between the charge separation layer 39 and the back metal contact (PS-MIS configuration). The conduction band edge and thickness of the charge separation layer and the semiconductor type are chosen to allow charge carriers from the photoexcited state of the photosensitizer to move to the back contact and prevent current flow in the opposite direction.
In accordance with another alternative embodiment as shown in FIG. 4 , the photosensitizer layer 10 is replaced with a layer of photoactive material 40 comprising of clusters of atoms or molecules, including doped or quantum structures (quantum wells, nanoparticles, quantum dots, etc.), with dimensions engineered to maximize light absorbency and ballistic electron transfer. One advantage of this alternative embodiment is that the charged electrons transferred need not move into or out of an atomic or molecular system, which is the case when using a photosensitive dye. Rather, the electrons travel in and out of degenerate levels with less hindrance due to quantum state restrictions. A specific example would be the deposition of CdSe or CdS nanoparticles (˜5 nm in dimension) on the conductor surface. These semiconductor particles have been shown to have efficient capture and efficient transfer to semiconductors. Interposing the conductor ballistic transport will still allow charge transfer; however, the particle can now be supplied with compensation charge directly from the conductor.
In accordance with another alternative embodiment of the present invention as shown in FIG. 5 , the electrons 36 of the photosensitizer layer 10 do not ballistically transport through the front conducting layer 31 . Rather, as the excited electrons 36 relax back to lower energy states, energy released from electrons 36 excites electrons 50 that reside in the front conducting layer 31 . The excited electrons 50 may thereafter rise above the conduction energy band 38 and flow towards the back conducting layer 30 .
In yet another alternative embodiment as shown in FIG. 6 , the front conducting layer 31 is selected from among either conductors that have transparency characteristics, such as indium tin oxide, or semi-transparent conductors (e.g., ultra-thin metal). In this embodiment the photosensitizer layer can be deposited between the front conducting layer 31 and the charge separation layer 39 , thereby eliminating the need for ballistic transport of the electrons 36 , while still maintaining the tenability of the barrier height.
In accordance with another alternative embodiment of the present invention as shown in FIG. 7 , a doped semiconducting layer 70 having a doping type opposite that of the charge separation layer 39 is placed between the front conducting layer 31 and the charge separation layer 39 . This particular embodiment effectively increases the Schottky barrier level and thus the open circuit voltage of the photovoltaic device as has been demonstrated in conventional Schottky Barrier Solar Cells.
FIG. 8 shows yet another alternative embodiment of the present invention wherein the charge carriers are ballistic holes rather than electrons. The above-described operating principles of the preferred embodiment (shown in FIG. 3 ) are symmetrically applied in this instance.
FIG. 9 shows yet another alternative embodiment of the present invention wherein the charge separation layer 39 is made of a material having a narrow band-gap energy level (i.e., the conduction band energy level is close to the valence band energy level). The narrow band-gap property of the charge separation layer allows for excitation of additional electrons 90 from the underlying semiconductor material (as in a conventional Schottky diode solar cell). The internal emission supplements the photoexcitation of the photosensitizer layer 10 and thereby produces additional energy.
FIG. 10 shows yet another alternative embodiment of the present invention wherein an anti-reflection coating (ARC) layer 100 is added to the photosensitizer layer so as to increase the absorbency of the photosensitizer layer and reduce the reflection of incident light by keeping the photons within the structures. The detailed design of these coatings is well-established technology.
FIG. 11 shows a multilayer structure wherein multiple structures of the preferred embodiment as shown in FIG. 3 is deposited in a parallel fashion, separated by transparent spacer 112 , to produce a superstructure that provides increased absorbency and efficiency in producing photovoltaic energy. Although FIG. 11 shows a parallel combination of the preferred embodiment, it should be noted that a serial combination is also possible and feasible.
FIG. 12 shows an alternative embodiment where the absorption of photo energy and injection of electrons may be performed with different molecules or structures. More specifically, the photons are absorbed in one or more photoactive molecules or structures 120 and relay their charge carriers 122 to a second layer or structure 121 with more efficient injection properties. This mimics natural photosynthetic processes whereby multiple pigments are used to more efficiently capture sunlight and relay the excited charges to common collectors for further transport.
FIG. 13 shows an alternative embodiment where absorption occurs in a quantum well 131 deposited on the surface. The dimensions of the quantum well and the properties of the material are chosen to optimally inject the charges.
FIG. 14 shows an embodiment where absorption occurs in structure or molecule partially isolated from the conductor to reduce coupling for optimal charge transfer. Examples include metal oxides, silicon dioxide, titanium dioxide, aluminum dioxide, organic chains and self-assembled monolayers deposited on the surface prior to the photoabsorber. For example, a thin layer of titanium dioxide (˜1-5 nm) is deposited on the conductor (Au). The photoactive merbromin is applied and forms a covalent linkage through its active carboxylate moiety to the titanium (C—O—Ti).
As previously discussed, in fabricating a device in accordance with the preferred embodiment, a charge separation layer 39 of titanium dioxide is deposited onto titanium foil (the ohmic back contact 30 ). The charge separation layer 39 has a thickness ranging between 100 nm and 500 nm and is deposited by electron beam evaporation and/or by electroanodization of the titanium metal. Gold is then deposited to the composite layer to a thickness of 10 nm to form the ultra-thin conductor. The resulting current voltage curves of the Schottky contact are shown in FIG. 18 . Also shown in FIG. 18 for comparison are devices using nickel instead of gold as the ultra-thin conducting layer 31 . An approximately 0.8 eV barrier results.
In accordance with the alternative embodiment of FIG. 14 , 2 nm of titanium dioxide is deposited onto the above-mentioned metal conductor 31 as a partial isolation layer. Photoactive merbromin is then applied and bonded covalently through its active carboxylate moiety to the titanium (C—O—Ti) to complete the active device.
FIG. 15 shows an alternative embodiment comprising a polymer based device wherein a ballistic hole is injected into an ultra-thin hole carrier. Polymer A in FIG. 15 , (e.g., poly(p-phenylene vinylene), PPV) with its highest occupied molecular orbital (HOMO) level lower in energy than the HOMO of a second polymer (B in FIG. 15 ) hole conductor layered behind it. The PPV provides a barrier to reverse hole transport serving the same role as the Schottky barrier. More traditional Schottky barrier devices have also been fabricated from polymer semiconductors and would be configured as in the above embodiments.
Although preferred embodiments of the invention are illustrated in the Drawings and described in the Detailed Description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous modifications and rearrangements of parts and elements without departing from the spirit of the invention. | An apparatus and method for solar energy production comprises a multi-layer solid-state structure including a photosensitive layer, a thin conductor, a charge separation layer, and a back ohmic conductor, wherein light absorption occurs in a photosensitive layer and the charge carriers produced thereby are transported through the thin conductor through the adjacent potential energy barrier. The open circuit voltage of the solar cell can be manipulated by choosing from among a wide selection of materials making up the thin conductor, the charge separation layer, and the back ohmic layer. |
FIELD OF THE INVENTION
The present invention relates generally to an automatic latching device for securing the door of a railroad passenger car when the car is in motion and more specifically to latching means that does not have to be operated manually.
BACKGROUND OF TITLE INVENTION
Drastic changes in the transportation industry have occurred in the past forty years. Passengers that formerly depended on the railroad for long distance transportation are now traveling by air and the personal automobile is used by those who must make shorter trip. The railroad today moves freight that is not handled by trucks. Car trains, observation cars and other promotions encourage travelers who are not in a particular hurry to "relax and take the train", but thc method of securing the doors on railroad passenger cars has not changed during these many years.
The passenger train remains a series of passenger cars pulled over the tracks by the locomotive one behind the other. Each passenger car has seats so accommodate passengers on both sides of the car and a vestibule at the front and rear of the car. Entry and exit from the car is provided by a door that opens into the vestibule. The door or doors may he at either end and on either side of the car.
Railroad car doors are mounted on hinges to the front door jam in a manner that permits the rear edge of the door to swing inwardly and forward into the vestibule. This hinge mounting prevents the door of a passenger car from opening toward the outside of the train.
Over the years a number of passengers have been killed or injured due to leaving the car while the train is in motion. Apparently passengers were exiting the car doors thinking they were entering the bathroom. These tragedies generally end up it litigation against the railroad. While this problem could be solved by having the conductor locking all doors with a key before the train is in motion and unlocking the doors after the train is stopped, this procedure would be extremely time consuming because of the number of doors and the distance between doors, disrupting the schedule and increasing the time taken to reach the destination.
My invention solves; these problems by automatically latching the doors that exit a passenger car when the car reaches a speed of 10-15 miles per hour. When the train stops, the lock is released.
DESCRIPTION OF THE PRIOR ART
Over the years a substantial number of devices have been developed which will automatically fix a gate or door against movement from its closed position until some specific action is taken by the operator. U.S. Pat. No. 128,075 which issued to Sharp in 1872, describes a simple latch which is manually activated (by shutting the gate or door) and hold the gate or door in a closed position until manually released. It would not be desirable to install such a device on the door of a railroad passenger car because this latch could easily be activated by the passenger to open the door of the car while the train was in motion.
A later U.S. Pat. No. 2,683,049 issued in 1954 to Van der Spek describes a fastening device that may be shifted in a simple manner from its latching function to its locking function and vice versa, but at the same time, avoids any likelihood of the door being locked inadvertently. Again this device would permit the passenger to over ride the lock and open the door of the car while the train was in motion.
Most vehicle doors provided on automobiles and trucks, include vertically shiftable door latch lock activators shiftable between upper and lower inactive and active positions respectively. Lawrence J. Register, in his U.S. Pat. No. 3,990,531 describes an inertia activated locking mechanism having a weight that is responsive to sudden deceleration of a vehicle in a forward direction automatically shifting the conventional door latch lock activator to its active position in response to inertia forces.
U.S. Pat. No. 3,719,248 issued to Baeitschwerdt et al also describe a door lock for motor vehicles that will remain in the locked position if a vehicle accident occurs and U.S. Pat. No. 4,536,021 describes a locking system for the door of an automobile that will react to rapid deceleration by automatically and reliably unlocking the door in case of an emergency.
Thus there is a controversy between those who believe that the doors should remain closed following impact to prevent ejecting the occupants and those who believe that the doors should be easily opened from the outside following impact to facilitate removing from the automobile those passengers who may be unconscious.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to an automatic latching device that may be installed on the door of a railroad passenger car. When the passenger car is not moving, a rigid bar assumes a position that is parallel with the edge of the door. When the passenger car is moving, this rigid bar rotates to a position extending beyond the edge of the door and effectively prevents the door from being opened.
Accordingly, one object of the invention is to provide a automatic latching device that may be installed on the door of a passenger car that will prevent that door from opening when the passenger car is in motion.
Another object of the present invention is to provide an automatic latching device which may be installed on the door of a passenger car that will unlock that door when the passenger car is not moving.
A further object of this invention is to provide an automatic latching device which may be easily and economically manufactured using readily available hardware.
Yet another object of the invention is to provide an automatic latching device that can be easily and quickly installed on the door of a railroad passenger car in fifteen minutes or less without the necessity of removing the passenger car from service.
Still another object of the invention is to improve the safety of passengers traveling on the National railroad system and to improve the safety record of those traveling by train.
An additional object of the invention is to provide an automatic latching device for the door of a railroad passenger car that cannot be unlocked when the car is in motion.
Yet another object of this invention is to provide an automatic latching device that will lock the door of a railroad passenger car when the train is moving forward or backward.
Another object of my invention is to provide an automatic latching device the parts of which are interchangeable for installation on the left side or the right side of railroad passenger cars.
It is also an object of the invention to provide an automatic latching device that is adaptable to the thickness of doors.
A final object of the invention is to provide an improved automatic latching device for the purpose described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the drawings in which corresponding numerals refer to the same parts and in which:
FIG. 1 is a plan view of an elongated bar that functions as the latching component of the present invention and illustrates an air foil fastened to thc bar.
FIG. 2 is a side elevation of this latching component and air foil along line 2--2 of FIG. 1.
FIG. 3 is a side elevation of the automatic latching device of my invention installed on the door of a rail road passenger car.
FIG. 4 is an exploded view of the automatic latching device of the present invention. The air foil is not present.
FIG. 5 is a side elevation of the automatic latching device of my invention and illustrates a smaller air foil fastened to the elongated bar.
FIG. 6 is a plan view of the latching device of my invention and indicates the movement of the latching component upon movement of the railroad passenger car.
FIG. 7 is the door of a passenger car as viewed from inside the car.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1, 2 and 3 of the drawings, the present invention will be seen to relate to an automatic latching device which may be installed on the door of a railroad passenger car. The lock comprises an elongated bar 1 the first end 6 and the second end at of which may be rounded to facilitate passage over a door jam. A hole 2 is drilled centered on the longitudinal axis of the bar perpendicular to the outer surface 3 and the inner surface 4 of the bar to receive a 1/4th inch bolt 5. The hole 2 is riot centered between the ends of the bar but Ls drilled closer to the first end than to the second end.
The bar is bifurcated at 20 from the second end of the bar in the direction of the hole to receive an air foil 8. The air foil is fastened to the bar by means of two 1/8th inch roll pins 9 and 10 that are driven through the circular openings 11 and 12 which extend through the bar.
Referring now to FIG. 3, there is shown the automatic latching device of my invention installed on a door 13 of a railroad passenger car. The bar and air foil freely rotate on the bolt and a bearing 14 separates the bar from the outer surface of the door.
A tubular sleeve 15 extends through the door, and about 1/2 inch beyond the inside surface of the door, washers 16, 17 and 18 separate the various components of my lock and the nut 19 adjusts the tension against the bearing and regulates the freedom of rotation of the bar and air foil around the bolt. When the tension is properly adjusted, the bar and air foil will assume the position shown in FIG. 3 pointing toward the ground and parallel to the edge of the door when the railroad passenger car is not in motion.
FIG. 4 illustrates various components of the automatic latching device of my invention. The spring 21 and the ice breaking strap 22 are not essential for the satisfactory operation of my automatic locking device. However, during the winter months rain, sleet and snow can freeze between the latching bar and the side of the railroad passenger cir preventing the lock from falling to it's unlocked position when the train stops. Under these conditions the latching bar may be released by striking that end of the bolt which extends through the door inside of the railroad passenger car. The spring, when present facilitates adjusting the tension holding the latching member against the bearing surface and the ice breaking strap, if present makes it more comfortable to exert pressure against the bolt or bolt and spring. The component parts of the automatic latching device of my invention are interchangeable in that the lock maybe installed on a door that is on the left side of a railroad passenger car or the right side of the railroad passenger car.
The bar is held in the position shown in FIG. 3 by the force of gravity. As all components of the automatic latching device of my invention, except the bar, are symmetrical around the bolt, the center of gravity would be at the axis of rotation if the hole in the bar were equidistant from both ends. However, the hole is not equidistant from both ends of the bar but is closer to the first end of the bar than to the second end of the bar. As the hole is shifted from the center of the bar toward the first end of the bar, the center of gravity of the bar will shift in the opposite direction. The bar is free to rotate about its axis and will shift to a position with its canter of gravity directly beneath the bolt as shown in FIG. 3.
The force holding the bar in the position illustrated in FIG. 3 is dependent upon three factors, namely the density of the material from which the bar is manufactured, the weight of the air foil and the location of the hole in the bar. The force maintaining the bar in the unlocked position will increase as the density of the bar and the weight of the air foil increases, but by far, the largest factor Contributing to this force is the location of the hole with respect to the first end of the bar.
As best shown in FIG. 6, forward movement of the railroad passenger car through the air will generate a relative wind toward the rear of the passenger car thereby exerting a force against the air foil. As the velocity of the passenger car increases, so does the velocity of the wind and the force moving the bar into its locked position.
Referring now to FIG. 3 and FIG. 6, the automatic locking device of my invention illustrated in FIG. 3 will rotate as indicated by the arrow in FIG. 6 to the locking position shown by the dotted lines when the speed of the railroad passenger car reaches 10-15 miles per hour and will remain in the locked position until the railroad passenger car slows below 10 miles per hour.
Again, many different factors effect the movement of the bar from the unlocked position to the locked position as the railroad passenger car moves forward. Thus the tension holding the bar against the bearing surface, the density of the locking bar, the weight and location of the air foil, the temperature and density of the air and the different areas of the bar exposed to the wind on either side of the axis of rotation, will all have a slight effect on the rotation of the locking bar. The main factor however effecting movement of the locking bar into the locked position are the exposed area of the air foil, the location of the airfoil with respect to the axis of rotation and the distance from the axis of rotation to the first end of the locking bar and the second end of the locking bar. It follows that the speed at which the locking bar will shift between the locked and unlocked position may be changed by varying one or more of these factors.
I have found through the trial and error method of experimentation that the automatic locking device of my invention will rotate to the locked position when the railroad passenger car accelerates to 10-15 miles per hour and will rotate to the unlocked position when the speed decreases to about 10 miles per hour under the following conditions:
1. The locking bar is 6 inches in length and the hole is 2.44 inches from the first end (3.56 inches from the second end).
2. The air foil has an exposed area of 15.4 square inches.
I have noted under these conditions (6 inch locking bar and 15.4 square inch air foil) that when the bolt around which the locking bar rotates is 11/2 inches from the edge of the passenger car door the locking bar will move into the locking position at 10-15 miles per hour when the train is moving forward. When the train is moving backward under these same conditions (bolt holding the lock assembly of the present invention 11/2 inches from the edge of the door) the locking bar will rotate in the opposite direction and lock the door when the train reaches a speed of 10-15 miles an hour.
It should be noted that the automatic latching device of my invention cannot he unlocked when the train is moving forward or backward at 10-15 miles per hour.
It must be recognized that I have described a specific automatic latching device and its method of operation. My invention is not limited to the specific dimensions of the preferred example but include other locking devices wherein a locking bar responsive to the force of gravity and the relative wind shifts between the unlocked and locked position.
As taught above, the air foil and the position of the hole in the locking bar are the primary factors effecting the operation of the automatic lock of th(e present invention. Thus, the locking bar may be 10 inches in length instead of 6 inches and the hole may be located 4.07 inches from the first end of the bar instead of 2.44 inches. The exposed area and location of the airfoil may be varied to obtain the desired speed at which the locking bar will shift between its unlocked and locked position. I have found that the locking bar illustrated in FIG. 5 the air foil of which has an exposed area of 6 square inches on a six inch locking bar will shift between the locking and unlocked position at 15-20 miles per hour. Such smaller air foil may be desirable to compensate for local winds through out the country.
As indicated above it is an advantage of the automatic locking device of my invention that many of it's components are readily available commercially at low cost. Thus a 1/4 inch×4 inch steel bolt, 1/4 inch flat washers, and a 1/4 inch locking nut is available from the local hardware store. The 5/16 inch steel sleeve is readily available and may be flared if desired. The bearing is a standard item used in automobiles to provide an air Light fitting for air lines and is available from any local automobile parts store. The ice breaking strap may be cut and formed from sheet aluminum. I prefer to manufacture the locking bar from aluminum because aluminum is inexpensive, resists corrosion, has a low coefficient of friction and a density of 2.707.
I prefer to use 1/16th inch ABS plastic (acetate butadiene styrene) to form the air foil as it is easy to cut into the desired shape and is flexible (will not easily bend as sheet metal would). It is also an advantage Dt ABS plastic that it will not shatter at low temperatures.
The location of the automatic lock of my invention is best shown in FIG. 7. The locking bar is positioned on the outside surface of the door and sufficiently close to the trailing edge of the door that it will lock the door from the outside when the locking bar moves in the direction of the dotted arrow. The preferred position, as stated above, is 1 and 1/2 inches from the edge of the door. It will be rioted that the lock described may be adapted to the thickness of the door, if necessary by simply changing the length of the bolt. During inclement weather driving rain, snow and sleet may freeze on the lock when the train is in motion and prevent it from returning to the unlocked position when the train stops. The door may be easily unlocked under these conditions by simply pressing outward against the nut and bolt in opposition to the spring tension (if a spring is in place). This will break the locking bar lose from the side of the railroad passenger car and permit return to the unlocked position. Or the lock may be manually returned to it's unlocked position from inside the car if need be by opening the window to gain access to the lock.
It is apparent that many modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terns of the appended claims. | The doors of railroad passenger cars swing inward and toward the front of the car when opened for entry or exit by the passenger. An automatic locking device is described which may be mounted on the exterior surface of the door close to its trailing edge. When the railroad car is in motion, the pressure of the relative wind on an air foil acts to rotate the locking device to a position that prevents the door from opening. When the train slows and stops, the relative wind decreases and the locking mechanism returns to it's original position permitting the door to be opened. |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of pending U.S. Ser. No. 07/231,411 filed on Aug. 12, 1988, and entitled TOY FLASHLIGHT now abandoned.
BACKGROUND OF THE INVENTION
This invention is directed to a novel amusement device and, in particular, to a toy flashlight that emits light of different colors and provides distinct types of play value.
Over the years, flashlights have been used for a variety of purposes. One such purpose is as an amusement device for capturing the imagination of children. Although children will use a flashlight as a toy, the novelty of a standard flashlight will wear off quickly due, in large measure, to the absence of uses that are meaningful to a child. Toy manufacturers have developed several modifications of household flashlights. One such flashlight is disclosed in U.S. Pat. No. 3,877,171.
However, it is known that children enjoy toys that contain colors, make noises and can be used for a variety of different games. These type of toys allow a child to use his imagination and create games from a single device. Accordingly, an improved toy flashlight that emits color, sound and light and, hence, provides enhanced play value is desired.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the instant invention, a toy flashlight is provided. The toy flashlight includes a handle housing for receiving a power supply. A light source is mechanically mounted to the handle housing and is adapted to be electrically coupled to the power supply for the purpose of selectively emitting a beam of light. A filter mechanism is supported by the handle housing. The filter mechanism contains at least two distinct color filters. A transparent enclosure is mounted to the handle housing so that light is emitted through either the first or second color filter to permit distinct colored light to be emitted through the transparent enclosure.
A plurality of opaque objects in a variety of colors and shapes are disposed in the transparent enclosure. In a preferred embodiment, the objects are silver and gold shaped moons and stars. A movement of the handle housing causes the opaque objects to move in a random direction thereby causing the colored light to be reflected and scattered in a multiplicity of directions.
Accordingly, it is an object of the instant invention to provide an improved amusement device in the form of a toy flashlight.
A further object of the instant invention is to provide an amusement device which enables a child to have a lighting toy which can provide distinct colors, shapes, generates sounds and provides a distinct play value.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompany drawings, in which:
FIG. 1 is a perspective view of a flashlight constructed in accordance with the preferred embodiment;
FIG. 2 is a sectional view taken along line 2--2 of the toy flashlight of FIG. 1;
FIG. 3 is a sectional view taken along line 3--3 of FIG.
FIG. 4 is a sectional view taken along line 4--4 of FIG.
FIG. 5 is a perspective view of a toy flashlight constructed in accordance with a further embodiment of the instant invention;
FIG. 6 is a sectional view taken along line 6--6 of FIG.
FIG. 7 is a sectional view taken along line 6--6 of FIG.
FIG. 8 is a perspective view of a toy flashlight constructed in accordance with still a further embodiment of the instant invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first made to FIG. 1, wherein a toy flashlight, generally indicated as 10, is depicted. Flashlight 10 includes a handle assembly 12 including a displaceable on-off switch assembly generally indicated as 14. Handle assembly 12 supports a filter housing assembly generally indicated as 30, which assembly supports a transparent globe 40 having translucent or opaque balls 42 disposed therein.
Referring now to FIGS. 1-4, handle assembly 12 includes a cylindrical housing 13 for receiving and positioning therein batteries 15. In particular, handle housing 13 includes an end wall 16 and a cylindrical wall 17. A lead plate 18 is disposed against the inside of end wall 16 and extends along cylindrical wall 17 to the switch assembly 14. A conductive spring 19 is disposed against lead plate 18 to position the batteries 15 in the housing and couple the negative terminal of battery 15 to the lead plate 18.
Switch assembly 14 is conventional and includes a switch plate 23 and an elongated bent conductive lead 24 secured thereto by inserting a projection 25 on switch plate 23 into an opening 26 in conductive lead 24. Conductive lead 24 includes a contact portion 27 which extends toward the open end 28 of the cylindrical housing 13. At the open end 28 of the cylindrical housing 17 are threads 29 angularly disposed about the open end of housing for releasably receiving filter assembly 30.
Filter assembly 30 includes a housing 31 having a light bulb supporting wall 32 and a filter supporting wall 33. Bulb support wall 32 includes threads 34 on the inner surface thereof to permit filter assembly 30 to be releasably secured to housing 13. An inwardly radially disposed wall 35 having an opening 36 therein is adapted to support a conductive light bulb reflector 37, which reflector is adapted to secure therein a conventional flashlight bulb 38. In an alternative embodiment, flashlight bulb 38 is a focus light bulb. The focus bulb focusses the beam light thereby increasing the light that reflects against the objects in the globe 40. Seated in the reflector 37 and holding bulb 38 in position is a collar 39, which extends into handle housing 13 and positions the bulb in contact with positive terminal of battery 15 in a conventional manner.
Accordingly, bulb 38 is maintained in electrical contact with conductive reflector 37 and is also in electrical contact with the positive terminal of battery 15. When switch 14 is moved in the direction of globe 40, contact portion 27 of lead 24 is placed in electrical contact with reflector 37 to define a closed circuit, thus turning on the light 38 in a conventional manner.
Referring specifically to FIGS. 3 and 4, filter supporting wall 33 supports therein a filter assembly, generally indicated as 50. Filter assembly 50 includes a color wheel 51 that is rotatably mounted to support wall 33 by a screw 53 anchored into a threaded opening 54 Color wheel 53 includes four panels 54a, 54b, 54c and 54d, each formed of a translucent or transparent material for permitting light of different colors to be projected toward globe 40 In an exemplary embodiment, panel 54a is red, panel 54b is yellow, panel 54c is blue and panel 54d is green. However, one of these panels could be transparent or of any other color.
Color wheel 51 includes four notches 55a, 55b, 55c and 55d, each of which correspond to panels 54a, 54b, 54c and 54d, respectively. Notches 55a, 55b, 55c and 55d cooperate with indexing lever 56 to position the color wheel at one of four positions so that the color panels are in alignment with bulb 38. Indexing lever 56 includes a collar 57 which is interference fit on a post 58 that is formed on support wall 33. Indexing lever 56 also includes a rounded indexing projection 59. Projection 59 should be either round, cylindrical or tear-dropped to permit projection 59 to easily ride into and out of notches 55a, 55b, 55c and 55d when color wheel 51 is rotated.
In order to facilitate rotation of color wheel 51, color wheel 51 is positioned off center with respect to the axis of the cylindrical handle housing 17 and projects through upper and lower walls 61 and 62, respectively. Accordingly, color wheel 51 projects beyond walls 61 and 62 to permit a thumb to be used to rotate the color wheel and index the wheel to one of the four positions defined by notches 55a through 55d and the indexing lever 56.
At the end of the housing 33 that connects with globe 40 is a cylindrical wall 66 that supports an inwardly directing wall 64 defining an opening 65. A lens 68 is secured against wall 64 and projects into opening 68. Lens 68 includes projecting dome 69 that radiates the light throughout the globe 40. Also, within dome 69, at the apex thereof, the thickness is increased at 70 to assure that additional light is diffused thereby. Finally, globe 40 is secured to housing wall 33 by screws 72 which are inserted into threaded blind holes 73 molded into the globe 40 to permit the globe to be anchored to the filter housing 33.
In a first embodiment illustrated in FIGS. 1 through 4, balls 42 are placed in globe 40 before the globe is anchored to filter housing 33. In a preferred embodiment, balls 42 are made of an iridescent plastic resin that is reflective.
In operation, balls 42 cause toy flashlight 10 to make noise when the flashlight is moved around. Also, by turning on the light by displacing on-off switch 14 to an on position, the light emanating from the globe is randomly scattered by the balls in the dome. Thus, the scattering of light off the balls 42 causes a random light scattering effect that provides still additional play value.
Also, by rotating color wheel 51, a third play value is obtained, namely different colors of light can be selected. Thus, when turned on, and when a particular color such as red is selected, the red color will emanate from the globe and will be scattered by balls 42 in a random fashion.
Reference is now made to FIGS. 5 through 7 wherein an alternate embodiment of the toy flashlight of the instant invention, generally identified as 80, is depicted. The only difference between the embodiment depicted in FIGS. 5 through 7 and the embodiment depicted in FIGS. 1-4 is the replacement of balls 42 with MYLAR® chips 82 having a dimension on the order of 1/4" square. The shape of chips 82 can be square, trapezoidal, round or otherwise and can be die cast from sheets of MYLAR®. The chips cause the colored light beams 32 to reflect in a greater amount of directions in a faster and more random manner. In all other respects, the embodiment of FIGS. 5 through 7 are identical to the embodiment of FIGS. 1 through 4, and like reference numerals are utilized to denote like elements.
Referring to FIG. 8, still another embodiment is generally shown as 90. The only difference between the embodiment depicted in FIGS. 1-4 and the embodiment depicted in FIGS. 5-7 with that of the new embodiment is the replacement of balls 42 and MYLAR® chips 82 with MYLAR® objects of a variety of colors and shapes. In the preferred embodiment, the objects are silver and gold shaped moons 94 and stars 96. The silver and gold moons 94 and stars 96 continue to cause the colored light beams 32 to reflect therefrom. In addition, the colors and shapes provide added light dispersion by toy flashlight 90. Further, globe 40 in the embodiments previously disclosed is shaped in the form of a head 92 as shown in the embodiment of FIGS. 8.
Accordingly, the instant invention is characterized by a toy flashlight that is capable of imparting several distinct types of play value. In a first embodiment, scattered light of different colors and a noisemaker is provided. In a second embodiment, scattered light in different colors is rapidly and more randomly dispersed. In a third embodiment, the addition of a variety of colors and shapes to the objects within the globe enhances the color dispersion while maintaining the rapid movement of the objects.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the spirit and the scope of the invention, it is intended that all matters contained in the above description or shown in the accompanying drawings shall be interpreted as illustrated and not in a limiting sense.
It is also understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, is a matter of language, might be said to fall therebetween. | A toy flashlight includes a color filter assembly that is releasably mounted to a handle housing and contains at least two distinct color filters. Light beams are transmitted through the colored filters. A globe is included as part of the color filter assembly and includes reflective objects in a variety of colors and shapes therein. By moving the flashlight, color beams of light are scattered off the reflective objects to provide a random color light display. |
BACKGROUND OF THE INVENTION
The invention relates to a goal frame for soccer or other games which require a goal mounted at ground level assembled of light metal sections. The bar profile and post profiles are formed of mitered hollow sections firmly interconnected by corner pieces which are disposed and retained, in the area of the miters, within the hollow sections. The corner pieces are generally formed from double T-sections, and have fastened, in the corner area of the assembled sections, holding devices for the support of the net. The goal frames are generally further provided, in the longitudinal direction of the section walls pointing towards the backside of the goal, a slot in which are disposed mutually spaced hooks to fasten the net, the ends of the post sections generally being insertable into ground sockets of the same material.
Goal frames of the kind described above are known. The corner angles are connected to the posts and to the bar by several cap screws after insertion in the hollow sections. To accommodate the cap screws, the bar and post sections have holes and corner angle tapped holes. However, assembling the post and bar takes a great deal of time and effort because the tapped holes do not always align when the section corners have been moved together. In addition, the screws are easily lost. Moreover, the stability of the corner connection made in the known manner is not high.
In the known designs, a net yoke with a brace is used as a holding device for the net. The assembly of the net holding device is cumbersome because the components must be fastened in a guide rail on the main sections by means of screws and U-washers.
The guide rail in the known goal frames is a C-slot which extends through the bar and post sections and serves to seat slot nuts in which individual hooks are screwed to hold the net. Apart from the fact that the slot weakens the goal frame sections because it must be very deep, it is very time-consuming and complicated to fasten the various net hooks. About 70 to 80 hooks and slot nuts must be assembled and distributed evenly over the entire perimeter of the goal frame. Furthermore, the hooks are usually spaced no closer than about 300 mm apart, resulting in the net sagging in many places.
Then, after the hook screws are tightened, the hook openings are oriented in different directions, which make hanging the net difficult.
Another disadvantage is that the net hooks so fastened project beyond the goal frame contour. This may readily result in injuries to the players.
To erect the goals, the post ends are inserted into sockets anchored in concrete foundations so that the goal post ends can be removed again from the ground sockets, particularly in winter, and disassembled. In practice, grains of sand and small stones, etc. tend to get between the walls of the inserted post ends and the inside walls of the sockets preventing removal of the posts. The post ends are very tightly seated in the sockets in order to keep the frame in an upright position. The small clearance has the further disadvantage that when erecting or removing the goal, the two post ends must always be moved evenly and vertically to prevent their jamming in the sockets. Therefore, once a goal has been erected, it is hardly possible to take it out of its sockets again.
It is an object of the invention to provide a goal frame which is easy to assemble and disassemble, has great stability and is designed to reduce accident hazards.
BRIEF DESCRIPTION OF THE INVENTION
According to the invention, there is provided a supporting tube joined to the mitered and welded-together double T-sections of the corner angles perpendicular to the web plane, at their respective miter center, a supporting tube to support the net, or a short pipe nipple, extending through an opening in the bar and post sections, after they were placed on the corner angle, so as to project in the direction of the goal backside, its free end being supported against the bar and post sections by means of braces in the form of tubular hollow sections disposed in pairs, said braces being joined at one end to the supporting tube or pipe nipple by joining preferably, a screw bolt disposed in transverse direction to the latter, while they have at their other end, ends which are bent at an angle to the bar and post sections and are inserted in matching openings in the bar and post sections and in the corner angle, being retained therein by exerting tension forces in the direction of the bar and post section miters.
Due to the inventive design of the corner connection of the goal frame with supporting tube or pipe nipple and braces, its assembly and disassembly are simplified and accelerated. Only a single fastening means is required to secure the corner connection, namely the fastening means to join the brace ends to the supporting tube or pipe nipple. The corner connections can be assembled effortlessly. In addition, the supporting tube advantageously offers a support for the net.
The corner connection, according to the invention, provides a supporting tube or pipe nipple which is securely supported in all directions with its angularity to the goal frame as well as the stability of the corner connection being assured. Additionally, the connection effects especially good stiffening of the entire goal frame. Moreover, the lever effect of the stiffening braces assures that the bar and post sections are held together at the miter edges with great force, leaving no gaping joints.
It is also advantageous that the supporting tube according to the invention is suited for the attachment of another long, downwardly bent holding yoke supported by the ground so that a goal frame for soccer league games can be made simply and effortlessly.
In a further advantageous embodiment of the invention, the walls of the bar and post sections pointing towards the goal backside are provided over their entire length with a slot which is covered by a profiled strip arched convexly on the outside, in which hooks and eyes to hold the edge of the net are stamped out so that they are integrated with the outside wall of the profiled strip.
The profiled strip with the integrated hooks, designed according to the invention, is inserted by the factory in the continuous slot in the bar and post sections and locked, thus requiring no further assembly work when erecting the goal.
Threading a muliplicity of slot nuts with net hooks into the slot of the goal frame, which required much time and effort, is thus eliminated. Beyond this, the elimination of the slot nuts brings with it the advantage of a simplification of the section profile of the seating slot integrated in the wall of the goal frame sections (elimination of the C-profiling of the slot due to elimination of its C-profile and shallower slot depth), contributing to greater stability of the sections.
Since the hooks according to the invention, are integrated into the contour of the goal frame, the advantage is obtained, among others, that the hazard of injuries is reduced because no hooks project from the slot in the goal frame.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated schematically in the drawings by way of two embodiment examples.
FIG. 1 shows the rear view of a goal frame designed in accordance with the invention and inserted in ground sockets,
FIG. 2 shows the side view of the goal frame designed according to FIG. 1,
FIG. 3 shows the three-dimensional part view of the goal frame from the rear,
FIG. 4 shows the rear view of a corner of the goal frame, with a view of the supporting tube with the braces, in larger scale,
FIG. 5 shows a vertical section of the corner of the goal frame with corner angle and the supporting tube with brace according to line I--I in FIG. 4,
FIG. 6 shows a vertical section of the goal frame profile and of the profiled strip inserted in the slot, with hooks bent inwardly at the ends, without retaining projections according to line II--II in FIG. 4,
FIG. 7 shows a partial view of the rear of the goal frame with a view of the profiled strip inserted in the slot, with hooks bent inwardly at the ends, without retaining projection, in larger scale,
FIG. 8 shows a vertical section of the goal frame profile and of another embodiment of the profiled strip inserted in the slot, with retaining projections disposed on the hooks,
FIG. 9 shows a partial view of the rear of the goal frame with the profiled strip according to the embodiment in FIG. 8,
FIG. 10 shows the three-dimensional part view of another embodiment of the goal frame according to the invention, with short pipe nipple,
FIG. 11 shows a vertical section of the corner of the goal frame with corner angle and pipe nipple with brace according to the embodiment in FIG. 10,
FIG. 12 shows a vertical section of a ground socket with post end shown in -·- lines inserted, and
FIG. 13 shows a horizontal section of the ground socket with post end inserted according to line III--III in FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
In a further advantageous embodiment of the invention, the braces are provided at their one end with holding cups which, opposite each other, are in contact with the supporting tube or pipe nipple, and mutually corresponding holes are disposed in the walls of the holding cups and supporting tube or pipe nipple through which a screw bolt is pushed.
The supporting tube or pipe nipple is supported and retained securely in all directions, the fastening requiring only a single screw bolt.
It is advantageous, furthermore, that, at their ends bent at right angles to the bar or post sections, the braces each have locking bolts disposed transverse to the direction of the braces, with ends projecting beyond the outer tubular walls of the braces, which ends are retained against the web walls after insertion through appropriately shaped recesses in the respective corner angle leg and turned by 90° into their final position.
According to another advantageous embodiment of the invention, the braces may have, in their outer wall areas pointing to the corners of the goal frame in the area of their point of penetration of the corner angle leg, a transversely extending notch each which hooks into the wall of the associated corner angle leg after the insertion and assembly of the brace.
These two alternative measures prevent, with certainty, lift out of the braces.
According to another advantageous embodiment of the invention, the braces supporting the short pipe nipple are shaped so as to run parallel to the bar or post sections. This alternative makes possible the use of the corner connection according to the invention in goal designs without provision for the support of the net.
Advantageously, as viewed in cross-section, the profiled strip to support the net has, on its long edges, short legs which are bent outwardly and engage slot shaped recesses formed by strips at the slot edges, after insertion of the profiled strip. This provides secure hold of the profiled strip in its seating slot and its integration in the outer contour of the main section without requiring expensive profiling of the seating slot. The bent legs of the profiled strip as well as the slot shaped recesses in the slot need only be of small dimensions so that weakening of the section is avoided.
It is preferred that the hooks are stamped out of the profiled strip in transverse direction of the latter, alternating in their orientation relative to each other, and that, furthermore, all hooks eyes are disposed on the center axis of the profiled strip.
Due to the fact that the hooks point alternately in the opposite direction, it becomes more difficult for the net retaining rope to unhook itself.
Due to the fact that the profiled strip including the hook and eye components is pre-arched in convex shape and adapted to the surface contour of the bar and post sections, the hook parts are readily accessible, rendering the suspension of the net much easier and avoiding the danger of accidents. It is also advantageous that the hooks of the design according to the invention are always oriented in one direction, namely in the transverse direction of the profiled strip so that the openings are readily accessible when hooking up the net.
The hook ends are advantageously bent slightly towards the interior of the profiled strip. This helps prevent unhooking of the net holding rope and, at the same time reduces the danger of accidents.
According to another embodiment of the invention, the hook ends may be provided with two retaining projections each, opposite to each other and oriented in the longitudinal direction of the profiled strip. This, too, helps prevent the net holding rope from unhooking itself.
Due to the fact that 11 hook eyes are arranged in the direction of the longitudinal center line of the strip, the net suspension rope always runs in one direction which also facilitates hooking it up.
A preferred embodiment of the profiled strip according to the invention provides for spacing of the hooks at roughly 60 mm. intervals. The close hooking assures tight seating of the net everywhere on the goal frame without sagging.
According to another preferred embodiment of the invention, the bottom of the ground sockets which receive the ends of the post sections are each closed by a bottom plate and are provided with two mutually parallel, annular constrictions, one just under the opening and the other above the bottom plate, said constrictions making close contact with the outer wall of the post section after its insertion in the ground socket so that annular spaces are formed between the inner wall of the ground socket and the outer wall of the post sections.
This embodiment increases the inside diameter of the ground socket in such a manner that an annular space interrupted only by the constrictions is formed between the inner wall of the ground socket and the outer wall of the inserted post end of the frame section. This has the advantage that lifting the post ends is not hindered by dirt particles, grains of sand, or the like, because there is always adequate clearance. However, the linear support of the post ends by means of the constrictions provides for good seating of the inserted goal frame.
The spacing of the constrictions provides good guidance for inserting the post ends and assures that the goal can be taken out more easily when disassembling it. Due to the length of the post end inserted in the socket, relative to the lower construction, the post end has more freedom of motion when being pulled out so that it does not necessarily have to be evenly and vertically removed as required with known socket designs.
The embodiment example of the invention shown schematically in the drawings by way of a soccer goal consists of a goal frame assembled of a bar section 1 and post sections 2. Used as sections are hollow light-metal sections of identical profile, mitered at the corners and interconnected by means of corner angles 3 (FIG. 5), disposed and retained in the hollow sections, in the form of mitered double T-sections welded together. However, hollow box-type sections may also be employed as corner angles.
Welded to the miter center, in the web area of the corner angles 3 formed of double T-sections, at right angles to said web area, is a supporting tube 4. In an embodiment not shown in the drawings, where the corner angles are formed of box-type hollow sections, the end of the supporting tube 4 penetrates both section walls and is welded to them. This provides particularly great stability for the supporting tube/corner angle connection.
Disposed in each mitered bar and post section 1, 2, in the walls pointing to the backside of the goal and likewise in the miter center area, are mutually opposite recesses which, after the sections are joined, leave free an opening 5 of the diameter of the supporting tube 4. After insertion of the corner angle 3 including the welded-on supporting tube 4 into the hollow portion of the bar and post sections 1, 2 and after their assembly, the supporting tube 4 projects out of the opening 5 horizontally towards the backside of the goal.
The supporting tubes 4 are supported against the bar section 1 and post sections 2, respectively, by means of braces 6 in the form of tubular hollow sections arranged in pairs. The one end 7 of the braces 6 are bent at an angle towards the goal frame and pass through matching openings 8, 9 provided in the walls of the bar and post sections 1, 2 as well as the corner angles 3 and fastened in the corner angle 3 by means of a lock bolt 10. The lock bolt 10, pentrates the brace 6 transversely, has short ends 11 which project beyond the outer wall of the brace 6 and are passed through corresponding, matching recesses 12 provided on the openings 8, 9 in the bar and post sections 1, 2 and in the corner angle 3 during assembly. After turning the braces 6 into their final position, the lock bolts 10 are retained by the wall of the corner angle 3.
In place of a lock bolt 10, there may also be provided in the area of pentration of the corner angle leg, on the respective outer tube wall of brace 6 pointing to the miter, a notch, not shown in the drawings, which runs transverse to the brace 6 and hooks into the corner angle after the assembly of brace 6.
The other ends of the braces 6 are provided with holding cups 13 so arranged and shaped that, after the assembly of the braces 6, they are opposite each other and grip the end of supporting tube 4 in close contact. Provided in the walls of the holding cups 13 and the supporting tube 4, are matching holes 14 and 15, respectively, through which a screw bolt 16 can be passed transverse to the supporting tube 4 so that everything is joined into a sturdy connection by the counternut 17. In this way, the supporting tubes 4 serves to support the net on the one hand and at the same time, they also serve to secure the corner connection of the goal frame according to the invention.
If supporting tube 4 is not required to hold the net, a short pipe nipple 18 may be provided instead, according to another embodiment of the invention (see FIG. 10), where the braces 19 are shaped so as to extend not obliquely, but parallel to the support and bar sections 2 and 1, respectively. The fastening mode is the same as for the braces 6.
The walls of the bar and post sections 1, 2 pointing towards the backside of the goal frame contain a slot 20 which extends over their entire length and is covered by an outwardly convexly arched, profiled strip 21 into which are worked the hooks 22 and eyes 23 which hold the edge of the net. The hooks and eyes are stamped out of the profiled wall.
As viewed in cross-section, the profiled strip 21 has, on its long edges, short legs 24 bent outwardly at an angle. After the assembly of the profiled strip 21, these legs engage slot shaped recesses 26 formed by strips 25 on the edges of the slot 20.
The hooks 22 of the profiled strip 21 are arranged so as to point alternately in mutually opposite directions in the transverse direction of the profiled strip 21. The ends of the hooks 22 may be provided, each with retaining projections 27 (FIG. 8), which point in the longitudinal direction of the profiled strip 21 and are oriented in mutually opposite direction. The hooks may have no retaining projections and their ends 33 can be slightly bent towards the interior of the profile strip 21 (FIG. 7). The hooks 22 and eyes 23 are provided over the entire length of the profiled strip 21 at an insertion pattern of about 60 mm. In a preferred further development of the invention, the ends of the hooks 22 including the retaining projections 27 may also be bent inwardly.
The whole goal frame is erected by plugging the ends of the two post sections 2 into ground sockets 28 anchored in the ground. Due to the preferred design of the ground sockets, it is possible to remove the goal frame again from the ground sockets 28 by simply lifting its post ends out of the ground sockets 28, even if the latter are contaminated by small stones or grains or sand.
As shown in FIG. 12, each ground socket 28 has a bottom plate 29 and two annular constrictions 30 disposed parallel to each other, one just below the opening 31 and the other above the bottom plate 29. These constrictions make contact with the post section 2, supporting it. In this way, annular spaces of relatively great width are formed between the inner wall of the ground sleeve 28 and the outer wall of the post section 2 so that binding due to sand or small stones cannot happen when removing the post sections.
All single and combination features disclosed in the specification and/or the drawings are considered essential to the invention. | A goal frame for soccer or similar games comprising hollow bar and post sections, mitered at the corners and rigidly joined to each other by internally located corner pieces. Joined to each corner piece is a supporting tube which projects horizontally from the bar and post toward the back of the goal. The supporting tube is braced against the bar and post sections by braces. The backside of the goal frame has a continuous slot which retains a profiled strip with hooks and eyes for supporting the net. The post sections are supported in ground sockets having annular constrictions. |
This application is a continuation-in-part of Ser. No. 08/454,437, filed May 30, 1995, still pending, which is a continuation of Ser. No. 08/212,811, filed Mar. 15, 1994, now abandoned.
FIELD OF INVENTION
The invention relates to equipment which is used in commerce and industry. The equipment is used for handling liquids, and specifically is used for filling of tanks or containers with liquids. The equipment is designed and intended for use in situations in which the filling process must be stopped before the internal volume of the tank is completely filled with liquid. The equipment is also intended for use in situations in which there is no communication between the interior of the tank and the surrounding atmosphere. The liquid is handled in contact with its own only, or in contact with a gas at a specified pressure. Filling of tanks or containers under such conditions requires specialized techniques. The techniques currently known to those skilled in the art have deficiencies, especially in such applications as filling of fuel tanks of motor vehicles which utilize propane or liquefied petroleum gas (PG) as fuel. The present invention provides an improved apparatus and an improved method for filling of tanks or containers in this application and in related applications.
BACKGROUND
The invention relates to the handling of liquids in industrial and commercial processes. More specifically the invention relates to filling of tanks with liquids. One example of a case where tanks must be filled is the refueling of a motor vehicle which is powered by a fuel which is dispensed to the vehicle in liquid form.
Any liquid expands when it is warmed. Consider a completely closed tank which is nearly filled with a liquid. Suppose the tank is warmed, for example by the sun shining on it. The liquid in the tank expands, and may come to completely fill the available internal volume of the tank. If there is further warming, and the liquid has no further available space within the tank into which it can expand, the liquid develops extremely large forces against the tank walls and the tank may split apart, releasing the liquid in an uncontrolled manner. Such a release is obviously undesirable, especially if the liquid is toxic or flammable.
Every liquid has associated with it a "vapor pressure" which is a function of temperature. The phrase "vapor pressure" has a very specific meaning well known to those skilled in the arts of chemistry and chemical engineering. Vapor pressure is an intrinsic property of a given liquid at a given temperature and can be thought of as an outward force exerted on the surroundings, by the liquid.
If a liquid to be stored in a tank has a vapor pressure higher than atmospheric pressure, at temperatures to which the tank is exposed in normal use, the tank must be kept closed. Otherwise the material stored in the tank would be continuously lost to the surrounding atmosphere. In this type of situation it is important to understand that there is no air in the tank. Part of the tank internal volume is occupied by a given material in liquid form. The other part of the tank interior is occupied by the vapor form of the same material. The liquid is in contact only with its own vapor. The pressure in the tank is equal to the vapor pressure of the liquid, at the temperature of the liquid in the tank.
If a liquid is to have a specified gas pressure applied to it all times, such as when nitrogen or carbon dioxide is used to blanket a liquid subject to oxidation, and if that specified gas pressure is higher than atmospheric pressure, then again the tank must be kept closed. Otherwise the required nitrogen or carbon dioxide pressure could not be maintained. In this case part of the internal volume of the tank is occupied by the material in liquid form. In the other part of the interior of the tank, one finds a mixture of the gas which is used to pressurize or blanket the liquid material, and vapor of the same material. To shorten the following discussion, in this situation there will be reference simply to "gas", which will be understood to be in fact a mixture of gas and vapor. Again it must be understood that typically there is no air in the tank. The pressure in the tank is equal to the specified gas pressure to which it is desired to subject the liquid.
In any of the situations described above, the factor which could create a dangerous pressure build-up in the tank is the internal volume of the tank becoming completely filled with liquid. As long as there is a part of the interior tank volume which is filled with vapor or gas, pressure typically cannot become excessive. With further reference to any of the situations described above, the tank could be equipped with a "blow-off" valve, a "boil-off valve", or a pressure relief valve. If such a valve is present, and if the pressure in the tank becomes excessive for any reason, such as the internal volume of the tank becoming completely filled with liquid, material can be released through the valve, so that there is no danger of tank failure.
However in some applications it would be very undesirable to have to release material from the tank or container. Therefore in these situations extreme care must be taken to ensure that the internal volume of the tank never becomes completely filled with liquid. The maximum allowable amount of liquid in the tank is expressed in terms of a "filling ratio". A typical filling ratio limitation is that the volume of liquid in the tank is not allowed to exceed 80% of the total internal volume of the tank. This filling ratio limitation applies at the time the tank is filled, and is intended to take into account possible warming of the tank which may occur after the tank is filled, such as due to exposure to the rays of the sun. The idea is that if the tank is filled to no more than 80%, then the likely warming which may occur later will not result in the expansion of the liquid volume to more than, for example, 95% of the internal volume of the tank.
The vapor pressure of a liquid at typical temperatures of operation could be less than atmospheric pressure, and it may be desired to handle the liquid in contact with its own vapor only. Under this condition also, the tank must be kept closed. Otherwise air would enter. Similarly, it may be desired to keep a liquid under a specified gas pressure, using, for example, nitrogen or carbon dioxide, and this specified gas pressure may be less than atmospheric pressure. Again the tank must be kept closed to exclude air.
Under these sub-atmospheric pressure conditions it may again be desired to fill a tank up to a specified filling ratio.
The situation inside a tank containing a liquid in contact with its own vapor only, and with no air or other gas present, is a situation which is not met in everyday life. Failure to understand the behavior of this type of system is the root cause of the Three Mile Island Nuclear Power Plant disaster in 1979. In this case the material in the container was liquid water at very high temperature and pressure in contact with water vapor only. Also in 1979 there was a railroad accident in Mississauga, Ontario, involving cars containing chlorine. Failure of the authorities to understand the behavior of liquid chlorine in a tank in contact with its own vapor only resulted in hundreds of thousands of people being unnecessarily kept away from their homes, and thousands of businesses being unnecessarily closed, for a lengthy period.
The behavior of a liquid contained in a sealed tank, in contact with its own vapor only, must be fully understood in order to understand the apparatus and method of the present invention. Especially, it must always be kept in mind that there is no air inside the tank.
The apparatus and the method of the present invention apply to situations where a liquid is maintained in contact with its own vapor only, and to situations where a liquid is maintained under a specified gas pressure. Since the case of contact of a liquid with its own vapor only is more complex, the following discussion primarily relates to this case.
In industrial practice, typically there is a supply tank from which liquid is drawn. This liquid is moved by pump or by other means to a tank which is to be filled. While the tank to be filled may initially be essentially empty, there usually would be some liquid and therefore some vapor in the tank. When at least a portion of the internal volume of the tank is occupied by vapor, it is possible to force further liquid into the tank, which results in vapor in the tank being condensed into the liquid phase in the tank. However in order to proceed more easily and more rapidly with the filling process, vapor from the tank to be filled can be returned to the supply tank, during the filling process. The Vapor flows from the tank being filled, to the supply tank, via a "vapor return line".
The volume of vapor being returned is essentially equal to the volume of liquid entering the tank which is being filled. This condition defines a true or full-fledged vapor return system.
The apparatus and the method of the present invention rely on and require use of a very small flow of vapor from the tank being filled, back to the supply tank, during the filling process. The volume of vapor which returns to the supply tank is a very small fraction of the volume that would return in a full-fledged vapor return system. This very small vapor flow, for example, is not significant in terms of allowing further liquid to flow into the tank. Further liquid can be supplied to the tank by forcing significant quantities of vapor to condense into the liquid, as well as by forcing a small flow of vapor to leave the tank as described above.
In the case of a liquid maintained under a specified gas pressure, gas in the tank cannot be forced into the liquid phase without limit. Therefore the flow of gas out of the tank being filled must be larger.
The small flow of vapor, or the somewhat larger flow of gas, out of the tank being filled, can be referred to as a bleed flow or auxiliary flow. It can be regarded as a signal flow, or an information-carrying flow. The small-diameter hose or tubing which carries this flow can be regarded as a signal line which carries information about the liquid level within the tank being filled.
The allowable filling ratio is different for different liquids. For a liquid with a higher coefficient of thermal expansion, the maximum allowable filling ratio would be lower, a typical value being 50%. In addition, if, at the time a tank is filled, the liquid that is being fed to the tank is unusually cold, the allowed filling ratio or filling density properly should be less than the normal value.
Various methods are currently in use to stop the process of filling a tank with liquid, at the correct point, so that the tank is not overfilled. These methods include:
a. A mechanical valve is permanently installed inside the tank. This valve is on the inlet line or feed line. The valve senses the liquid level and closes when the correct liquid level has been reached in the tank.
b. A liquid level sensor can be placed inside the tank. When the correct liquid level is reached, a signal is sent to a controller, which in turn stops the flow of liquid to the tank.
c. To quote from "Handbook--Butane-Propane Gases", Third Edition, 1942, page 104, in a method which is applied to "tank trucks", "there is a fixed outage tube in each tank, that extends from the top of the shell to the correct point to indicate when loading is finishing, this tube having a valve through which vapor will vent until the liquid reaches the bottom of the tube. The valves are then shut and the liquid and vapor hose disconnected . . . ".
d. If the tank is removable from its usual place of use, and if it is not too large, it can be placed on a scale during filling. The maximum allowable weight of tank and contents is known. The weight of the tank and contents is observed on the scale during the filling operation. When the correct weight has been reached, the filling process is stopped.
There are various disadvantages and deficiencies to the above methods, including:
a. The mechanical valve could malfunction, and allow a larger than correct amount of liquid to enter the tank. It would be very difficult for the user of this method to be aware that the tank is being overfilled.
b. Some sensors would require an electrical connection to the tank. To make this connection each time the tank is filled adds to the complexity of the filling process, and to the hazard, if the liquid being handled is flammable. Again in case of malfunction, the tank might be overfilled without the user being aware of it.
c. The method as described in the reference does not provide automatic operation and therefore is only suitable for use with a trained operator in attendance. In filling of large tanks, which is the subject under discussion in the quoted reference, the feed rate is small relative to the tank volume and there is time for the operator to take action to stop the fill. In filling smaller tanks where the total filling time may be only 1 to 2 minutes, a delay of even a few seconds could result in an overfilled tank. Therefore the described manual method could not be used.
d. This method is only applicable to relatively small tanks, and to tanks that can readily be removed from any equipment with which they are used.
Any method which utilizes a valve or other mechanical equipment on the liquid feed line suffers from adverse effects of contaminants in the liquid feed. Because all the liquid goes through said valve or other mechanical equipment, contaminants tend to build up and this accumulation may in time cause a malfunction.
In view of these deficiencies, the various industries which deal with filling of tanks under the conditions described above are seeking improved methods of controlling the filling of tanks. The ideal control method would have the following attributes:
The control method would automatically stop the fill at the correct point, without supervision by human operators or observers, and would automatically take into account normal and abnormal operating conditions.
The control method would be self-supervising so that in case of malfunction of one of the components of the control system a warning is given and the system automatically shuts down. If the malfunction is such that the tank currently being filled may be overfilled, or has been overfilled, a warning to that effect is given. In any case, the control system automatically refuses to fill further tanks until repairs have been made and the system has been reset by authorized service and repair personnel.
The equipment required to put the control method into practice would not be unduly expensive, and the use of the equipment would not complicate the tank filling process.
Usually the number of tanks to be filled is relatively large. Therefore to put the control method into use the component(s) required on or in each tank should in particular be very simple and inexpensive and should require little or no maintenance.
Any hardware should not have to handle all the liquid which is supplied to the tank, and therefore, because the hardware is handling relatively little or no liquid, there would be a reduced tendency to suffer malfunctions due to contaminants in the liquid.
SUMMARY OF THE INVENTION
The present invention provides automatic control of the filling of tanks with liquids. The filling operation is automatically stopped when the amount of liquid in the tank has reached a specified filling ratio, i.e., when the volume of liquid in the container has reached but has not exceeded a specified percentage of the total internal volume of the tank or container. The apparatus and the method of the present invention have the following attributes:
1. There is no mechanical valve or other apparatus or appurtenance on the feed line to the tank being filled, with the following exception. The apparatus and the method of the present invention involve a microprocessor. The microprocessor receives information indicating when the tank has been correctly filled. At this time the microprocessor shuts off the flow of liquid to the tank, by closing a simple on/off valve which is located outside the tank, and well upstream of the tank, typically upstream of the fill hose which is connected to the tank during the filling process, or by shutting off the feed pump.
2. In different embodiments of the invention, different types of apparatus are permanently installed within the tank to be filled. In all cases, said apparatus is simple, inexpensive, and extremely reliable.
3. The microprocessor contains suitable programming and receives information from sensors located in the dispensing system. There are no sensors in or on the tank which is being filled. On the basis of the information from the sensors, the microprocessor controls, monitors, and supervises the filling process. A filling process is started by a human operator or user of the filling equipment. The microprocessor stops the fill automatically when the tank has been filled to the correct level. The microprocessor stops the filling process immediately if an abnormal condition is indicated, on the basis of the information provided by the sensors, and utilizing the programming with which the microprocessor is equipped. Abnormal conditions which would cause the microprocessor to refuse to start or to immediately stop a filling process include but are not limited to an attempt to fill a tank which is already correctly filled, or sensor failure.
A suitable warning is given in each case, and the control system does not allow further fills to occur until the problem has been investigated .and repaired, and the system reset by authorized personnel.
BRIEF DESCRIPTION OF THE DRAWINGS
A schematic of the present invention is presented in FIG. 1. A float valve is used inside the tank being filled. Two embodiments of the float valve are shown in FIGS. 2 and 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the tank 5 is to be filled with a liquid. The dispenser or other filling equipment 3 is supplied with liquid from supply tank 1 by pump 2. The pump could be within the dispenser 3 or could be at a different location. Various other liquid-handling appurtenances which are needed in the type of system sketched in FIG. 1 are well known to those skilled in the art and are not included in FIG. 1.
A key component in the apparatus and method of the present invention is a microprocessor or computer 30, which contains appropriate programming. The microprocessor 30 can be located within the dispenser 3 or elsewhere. The microprocessor receives information from sensors to be described later. The microprocessor performs all functions of the present invention and also performs various Other functions, thus providing complete control, monitoring, and supervision of all aspects of the filling equipment and the filling process.
The liquid is supplied to tank 5 by fill hose 4 or by a fill pipe which takes the place of fill hose 4. There is a very small flow of vapor from the tank 5 which is being filled, back to the supply tank 1, during the filling process. This small flow of vapor can be termed the bleed, auxiliary, or signal flow. This vapor returns via line 6 from the tank 5. For clarity, the auxiliary hose 6 and the components attached to it are shown separate from the dispenser 3 in FIG. 1. However for convenience in installation these components may be placed within the dispenser 3 or at another suitable location in the supply/dispensing system.
If the vapor or gas flowing out of the tank 5 via the auxiliary line 6 is not harmful, toxic or flammable, and if the pressure in tank 5 is greater than atmospheric pressure, the vapor or gas does not have to be returned to the supply tank 1, but can be released to the atmosphere.
The lines or hoses 4 and 6 could be combined into one package for ease of handling. A coaxial arrangement, a side by side arrangement, or other arrangement could be used. Or, the two lines 4 and 6 could be handled separately.
If the vapor or gas is to be returned to the supply tank, an additional length 7 of hose, tubing, or piping is utilized for this purpose.
During the filling process, there must be flow in the line 6 from the tank 5 which is being filled, ultimately to the atmosphere or to supply tank 1.
In order for there to be flow, the pressure in tank 5 must be higher than the pressure in tank 1, if the vapor or gas is to be returned to tank 1, or, as noted above, must be higher than atmospheric pressure, if the vapor or gas is to be released to the atmosphere.
In a given application of the apparatus and method of the present invention, if the pressure in tank 5 is not adequate to ensure flow, then a tank 27 must be used, as shown in FIG. 1. The pressure in the tank 27 is kept below the pressure in the tank 5 which is being filled. The required difference between the pressure in tank 5 and the pressure in tank 27 depends on the properties of the liquid being handled. Typically the pressure in tank 27 is maintained at a value which is on the order of one-half of the pressure in the tank 5.
In many applications the pressure in the tank 27 is higher than atmospheric but for ease of reference the tank is referred to as the vacuum tank. The compressor 24 takes vapor or gas from the vacuum tank 27 and compresses it to the pressure in the supply tank 1, or to atmospheric pressure, so as to dispose of vapor or gas from tank 27, and allow continuing flow from tank 5, through hose 6, to tank 27.
The pressure sensor 26 supplies information via the control wiring 31 to the microprocessor 30. The microprocessor operates the compressor 24 as necessary, via the control wiring 35, to maintain the required pressure in the vacuum tank 27.
In most applications the microprocessor has no direct information on the pressure in tank 5. Instead, in the case of a liquid being handled under its own vapor pressure, the microprocessor receives information on ambient temperature, and/or temperature of the liquid in the feed line 4, and estimates the pressure in tank 5 on the basis of pre-programmed information on the vapor pressure behavior of the liquid being handled.
In the case of a liquid being handled under a specified gas pressure, the required pressure in the tank 5 is pre-programmed into the microprocessor.
In the remainder of the description of the present invention, it is assumed that the vacuum tank 27 and the compressor 24 must be used. If there is adequate pressure difference driving force without these components, the description to be presented below still applies, with very minor modifications that will be obvious to those skilled in the art.
The check valve 23 allows vapor or flow only in the normal direction, i.e., away from the tank 5.
To begin a fill, the hoses or lines 4 and 6 are connected to the tank 5 which is to be filled. The method of connection of hose 6 is such that as soon as it is physically connected there is communication between the interior of hose 6 and the interior of tank 5. Equipment is commercially available for this purpose, as is well known to those skilled in the art, and is represented as the two mating halves 53 and 54 in FIG. 1. When the hose 6 is not connected to the tank 5, a device which is part of the mating half 53 which is permanently attached to tank 5, and a device which is part of the mating half 54 which is permanently attached to the end of hose 6, automatically close off the respective openings, so that there is no communication with the open air.
Mating halves similar in principle are used for hose 4 but are not shown in FIG. 1.
There are various possible sequences of events which follow upon connection of hose 4 to the tank 5. Regardless of which sequence of events occurs, the operation of the apparatus and method of the present invention is the same.
As one example of the sequence of events, a human operator may connect hose 4 to tank 5, and then open a valve (not shown in FIG. 1) at the end of hose 4. The human operator also connects hose 6 to tank 5. Or, there may be one filling connection which incorporates both lines 4 and 6.
Then the human operator operates a switch which in turn signals the microprocessor 30 to start the filling process. During a delay period of 1 to 2 seconds, the microprocessor carries out certain procedures to be described below. If all conditions are normal, the microprocessor activates the feed pump 2 to begin the fill, or otherwise starts the flow of liquid to the tank 5, via the hose 4.
The flow of liquid to the tank is automatically stopped by the microprocessor, by stopping via the control wiring 32 the liquid feed pump 2, or by similarly closing an electrically-operated on/off valve (not shown), located upstream of the hose 4, when either the liquid in the tank reaches the maximum allowable level, or an abnormal condition is detected by the microprocessor.
The human operator then removes the hoses 4 and 6 from the tank 5. In the typical sequence previously described, the human operator at this point closes the valve at the end of hose 4. Upon removal of hose 6 from the tank 5, the said devices within the components 53 and 54 of the connection system automatically close, so that no material from the interior of either hose 6 or tank 5 is released to ambient.
The key aspect of the apparatus and the method of the present invention is how the microprocessor determines when the liquid in the tank has reached the maximum allowable level.
The maximum allowable liquid level 8 in the tank 5 is indicated in FIG. 1. At some time during a typical filling operation, the liquid level may be at the intermediate position 9.
As already noted, the auxiliary hose 6 is in no sense a full-fledged vapor return line. The auxiliary hose 6 has a very small inside diameter, typically 3 mm or 1/8 inch, and in addition there is a restrictor 28b in the flow path. The restrictor can be described in terms of the Cv concept which is well known to those skilled in the art. The Cv of a valve or other fitting is a number which expresses the resistance to flow offered by that fitting. A smaller number indicates that the fitting is more restrictive.
The Cv of restrictor 28b is typically within the range 0.005 to 0.2. These values describe fittings which are extremely restrictive, in comparison with fittings which are met in everyday life, such as fittings in building water supply systems.
Due to the presence of the restrictor 28b, the flow capacity of the auxiliary hose 6 is negligible in relation to the flow capacity of the fill hose 4, and in relation to the amount of material in tank 5. Furthermore, for the same reasons the flow capacity of the hose 6 is very small in relation to the flow capacity of a full-fledged vapor return line.
A float valve, as shown in either FIG. 2 or FIG. 3, is installed within the tank 5. There may be an inlet tube 10, and the float valve 14,15,16 is attached to the outlet or exit tube 11 and is so positioned within the tank 5 that when the liquid level rises to the maximum allowable value 8, the float 15 which is within the cage 14 rises to seal against the seat 16.
During the filling operation, while the liquid level is still at an intermediate level 9, below the maximum allowable level 8, vapor or gas flows through the float valve assembly, through the exit tube 11, through the mating halves 53 and 54 of the connection system, and on to the auxiliary hose 6.
Continuing along the flow path of the auxiliary hose 6, there is a hose pressure sensor 21, the restrictor 28b, and a sensor 36 which provides a signal via control wiring 33 indicating whether liquid or vapor is flowing in the line. As already noted, information from all sensors goes to a microprocessor or computer 30 which uses the information generally to monitor and control the tank filling operation and specifically to stop the filling operation when the tank 5 has been correctly filled.
Sensor 36 can operate on the basis of capacitance, conductivity, or other property to provide the required indication. If the liquid being handled is a liquid in contact with its own vapor only, the liquid when passing through restrictor 28b may flash, with a resulting cooling effect. In this situation the sensor 36 can be a temperature sensor.
The hose 6 can be several meters or more in length, so that the component 21, the restrictor 28b, and component 36 are all several meters or more away from the tank which is being filled. The latter three components can be placed within the dispensing system 3 or at another convenient location.
During the filling operation, the pressure in the hose 6 is essentially equal to the pressure in the tank 5, because the float valve assembly 14, 15, 16, and the exit tube 11, offer little or no resistance to flow, while the flow restrictor 28b at the downstream end of the hose 6 offers significant resistance to flow. The pressure in tank 27 is maintained at a lower pressure and therefore there is flow through the restrictor 28b. The vapor or gas flows continuously to the vacuum tank 27. The compressor 24 then provides the motive power to move the vapor or gas intermittently from the tank 27 and to keep its pressure significantly below the pressure in the tank 5.
When the liquid level rises to the maximum value 8, and the float 15 seals against the seat 16, the supply of vapor or gas to the hose 6 is cut off and the pressure in hose 6 drops precipitously. The drop in pressure is sensed by the pressure sensor 21. The pressure information is conveyed via the control wiring 34 to the microprocessor 30, and the microprocessor immediately stops the fill.
The sensor 21 can also be a flow meter. The reduced flow of vapor or gas into the hose 6 can be sensed by a change in flow rate, as well as by a change in pressure.
It is important to emphasize that the apparatus and the method of the present invention do not require the entrance of liquid into the hose 6. In the intended and normal functioning of the present invention, liquid rises no higher than the maximum allowable level 8 in tank 5, and specifically does not enter the exit tube 11. As soon as the liquid reaches the maximum allowable level 8, the float valve closes, the hose pressure drops, and on the basis of this drop in pressure the microprocessor immediately stops the filling operation.
Between filling operations, if all equipment is in good condition, there is no leakage into hose 6 and, as a result, for long periods operation of the compressor is not necessary.
When a new filling operation starts, as already noted there is a delay period while the microprocessor makes various system checks, before starting the flow of liquid to tank 5. The most important of these checks is to ascertain that the hose 6 has been properly connected to the tank 5 which is to be filled. When the hose 6 is connected, the hose pressure immediately rises to a level above the value which existed between filling operations. This behaviour occurs because upon connection to the tank 5 the hose 6 immediately begins to receive a steady flow of vapor or gas, and because of the presence of the restrictor 28b. In this way the microprocessor determines that the hose 6 has been connected, and that it is permissible to start the fill.
Abnormal Conditions
In the apparatus and the method as described to this point, there are many possibilities for malfunctions which could result in the supply of liquid to the tank 5 continuing, after the liquid has reached the maximum allowable level 8, with the result being an overfill. The apparatus and the method of the present invention include provision for detection of an overfill. When an overfill is detected, an alarm is sounded and the dispensing system shuts down. The human operator or user of the system is alerted that the dispensing system, the tank and the float valve within the tank must be examined to determine and correct the cause of the malfunction.
The apparatus and the method Of the present invention thus are self-monitoring. A potential overfill is detected while the tank being filled is still on the filling station premises. In existing technology, there is no such self-monitoring feature. In the event of a malfunction, tanks could be overfilled repeatedly and the operator or user of the system would not be aware of the hazard thus created.
The heart of the self-monitoring feature in the apparatus and method of the present invention is that the float 15 is purposely designed not to fit absolutely tightly into the seat 16, in either FIG. 2 or FIG. 3. Another key aspect of the apparatus and method of the present invention is that the float 15 contacts the seat 16 before the liquid level reaches the level of the seat 16.
In any case a tight seal is not necessary to obtain the normal operation of the apparatus and the method of the present invention. If the opening at the seat 16 into the exit tube 11 is only partially closed when the float 15 rises to contact the seat, so that vapor or gas volumetric flow rate drops to, for example, 20 to 30% of the value which obtained while the liquid level was well below the maximum allowable level 8, the result will still be a strong drop of pressure in the hose 6, which will be sensed by pressure sensor 21.
If a malfunction then occurs so that liquid continues to flow into the tank 5, despite the pressure change in the hose 6, the liquid level will continue to rise and liquid will ultimately contact the seat 16.
If the operation involves a liquid in contact with its own vapor only, the liquid tends to flash or evaporate explosively as it flows through the relatively small gaps between the float 15 and the seat 16, into the lower pressure region represented by the hose 6. There is a resulting large new supply of vapor to hose 6, and the hose pressure rises again. This increase of pressure following a drop in pressure provides a strong signal that there is a potential for overfill.
If the operation involves a liquid under a specified gas pressure, the liquid flows through the gaps between the float 15 and the seat 16 and is ultimately detected by the liquid detector 36. The result is again a signal of a potential for overfill.
One possible malfunction is that the on/off valve upstream of the feed hose 4 fails to close despite being given a signal to do so. Protection against this malfunction is afforded in the scenario described above.
The float 15 could become lodged in the cage 14 or the whole float valve assembly could be at an incorrect angle so that there is no seating action at all. In this case liquid will freely enter the exit tube 11 and the hose 6 and will be detected by the liquid detector 36.
The pressure sensor 21 could fail and therefore the information on pressure change in hose 6 would not be transmitted to the microprocessor 30. This malfunction is guarded against by use of two pressure sensors, with monitoring of the difference between the outputs of the sensors. In the event of a significant difference developing, indicating that one sensor has failed, the system is automatically shut down for repair. Programming is also provided in the microprocessor which causes the microprocessor to shut down the system if a sensor signal goes out of range, a frequent indication of sensor failure.
Also in the event of failure of the pressure sensor, liquid would enter the hose 6, which would ultimately be noted by the liquid sensor 36. Thus the sensor 36 provides a backup to the sensor 21, the latter sensor being the basis for normal operation.
Provision to prevent overfill in the event of microprocessor failure can include two microprocessors operating in parallel, with a third microprocessor monitoring for any differences in the operation of the two microprocessors.
If a tank is presented for filling and the tank is already full, the pressure in hose 6 does not rise sufficiently for the microprocessor to allow the fill to start. Or, liquid enters the hose 6 and is detected by the liquid detector 36. In either case, there is no further supply of liquid to the tank.
The float valve is a very simple device and there is very little if any potential for failure to operate due to mechanical reasons. As discussed above, the float valve is not intended to be a precise device offering a leak-proof seal. Therefore there is little potential for failure due to fouling.
An override is used to accommodate a brand new tank which is completely empty. When handling a liquid which is in contact with its own vapor only, when the hose 6 is connected the hose pressure does not rise. Without the override, the microprocessor would not allow the fill to begin.
The override is operable by authorized personnel only and allows dispensing of a small quantity of liquid, typically 1 L. This small fill is completed and then a new fill is started. The standard procedure is followed in this new fill.
Temperature Compensation
The float 15 in FIG. 3 is elongated in the vertical direction. The float is a relatively long hollow tube, maintained in a vertical or nearly vertical position.
Any type of float rides higher with respect to the surface of the liquid, if the liquid is denser. The relatively long hollow tube used as a float in FIG. 3 provides a relatively greater movement with respect to the surface of the liquid, as the liquid density changes, as compared to a float with a smaller total height. This fact is taken advantage of in the following way.
As described earlier, the concern is that if the liquid in a sealed tank becomes warmer it expands and may fill the tank completely. Any further expansion would develop tremendous forces within the tank which would cause its catastrophic failure.
If the liquid which is supplied to a tank is already warm, there is less chance of a large thermal expansion which would fill the tank. Therefore, when the liquid is warm, the allowable liquid level in the tank is higher. As already noted, any float rides higher when the liquid is denser and lower when the liquid is less dense. Any float used in the apparatus shown in FIG. 2 or FIG. 3 thus contacts the seat 16 sooner when the liquid is denser and later when the liquid is less dense, as the liquid level rises in the tank. Therefore the tendency of the apparatus shown in the said Figures is to allow a higher liquid level when the liquid is less dense, which is exactly the behavior that is wanted.
It can be shown from elementary principles of physics that the increase in projection of the top of the float above the liquid surface, for a given change in density, is directly proportional to the total height of the float. By appropriate selection of the total height of the float 15 of FIG. 3, it is possible to approach the ideal behavior which is that the tank filling process is stopped when the mass of liquid in the tank reaches a pre-determined value, this value being independent of the temperature of the liquid in the tank.
General Comments and Summary
The present invention requires a pressure difference so that there is an auxiliary or bleed flow in hose 6. In most applications the pressure difference is created by maintaining, through use of vapor compressor 24, a lower pressure in the vacuum tank 27.
In some applications, the action of the feed pump 2 boosts the pressure in the vapor space in tank 5 so that it is greater than the pressure in tank 1. Then the vacuum tank 27 and compressor 24 are not needed.
Generally, in the very rare and unusual circumstance that the computer misses the change in pressure in hose 6, when the tank has become correctly filled, the filling operation continues and liquid flows through hose 6 and reaches the vapor/liquid sensor 36. Upon receiving a signal that liquid is present, the computer stops the filling operation.
Thus there is a backup or second detection method to determine when the tank has been correctly filled. Because of the small internal volume of hose 6, only 2 to 3 seconds are required for liquid to reach sensor 36. Therefore, the delay before the filling procedure is stopped is minimal.
There may be a length of hose or tubing between the tank 5 and the mating half 53 in FIG. 1. This length of hose or tubing could contain liquid, even if the tank, when presented for filling, contains very little liquid. At the start of the fill this liquid moves through hose 6 and while much of it may evaporate some liquid could still contact sensor 36. The microprocessor is programmed to disregard during the first few seconds of the fill any indication of liquid. The amount of liquid can be minimized by ensuring that any hose or tubing upstream of the mating half 53 has a very small inside diameter, and that the length of this hose or tubing is no greater than absolutely necessary.
After the first few seconds of the fill, the microprocessor shuts off the flow of liquid to tank 5, if liquid is still being sensed by sensor 36. This observation indicates that the tank presented for filling already contains the maximum allowable amount of liquid or may indicate a malfunction.
Test Results
The apparatus and the method of the present invention were tested repeatedly, using water and air, in a manner which simulates the behaviour of the float valve of FIG. 2 or of FIG. 3. In the test work, the pressure in the city water system, rather than a liquid feed pump, provided the motive force for liquid flow to the test tank. Downstream of the restrictor 28b, the air, and water if any, were released to ambient. The restrictor 28b had a Cv value of approximately 0.02.
At the start of a typical test, city water was supplied to the tank 5. Air was forced out of tank 5 and flowed through the restrictor 28b and then to ambient. The pressure in the hose 6 was typically 45 psia. When the water level in the tank reached the maximum allowable value, a device which simulates the behaviour of the float valve of FIG. 2 or of FIG. 3 closed off the flow of air from the tank 5 into the hose 6. The hose pressure (pressure in hose 6) immediately dropped to 15 psia (essentially ambient pressure). This typical observation supports the basic theory of operation of the apparatus and method of the present invention.
In the test work, the water supply to the tank 5 was not stopped at this time. Water flow was allowed to continue, in order to observe all aspects of system behaviour. After a few seconds, hose pressure rose again to about 40 psia, and soon after water was seen to issue from the downstream end of the restrictor 28b. This observation supports the theory of operation of the backup aspect of the invention, i.e., how the apparatus and method of the present invention would cope with an abnormal situation such as a malfunction. | The invention described in the patent is an automatic control system which provides monitoring, supervision, and control of the process of filling of a tank or container with a liquid. The invention is applicable to cases where the liquid is handled in contact with its own vapor only, or where the liquid must be maintained at all times under a specified gas pressure. The invention provides an improved method of carrying out the process of filling of tanks or containers with liquids such as ammonia, chlorine, propane, liquefied petroleum gas, or with liquids such as carbonated beverages. The main advantage provided by the apparatus and method of the present invention is that an improved means is included for automatically stopping the filling process at the correct point, so as to avoid a possibly hazardous overfilled condition. One of the methods currently in use requires a mechanical valve which senses liquid level in the tank and is supposed to close so as to stop flow to the tank when the liquid has reached the maximum allowable level. The mechanical valve may malfunction and allow overfilling of the tank, and the fact that the valve is malfunctioning may not be readily apparent. The present invention does not require a mechanical valve of the type described above. Further, there is a self-checking and self-monitoring capability so that users of the apparatus and method are warned of any malfunction. |
TECHNICAL FIELD
[0001] Embodiments of the present invention relate to a Rankine cycle system for vehicle, and more specifically, to a structure for mounting a Rankine cycle system on a vehicle.
BACKGROUND
[0002] Patent Literature 1 discloses a technology regarding a Rankine cycle system mounted on a vehicle. In this Rankine cycle system, a liquid-phase fluid is boiled with waste heat of an engine into a gas-phase fluid. Work is taken out by allowing the gas-phase fluid to expand. The gas-phase fluid after the expansion is condensed and returned to the liquid-phase fluid.
[0003] Following is a list of patent literatures which the applicant has noticed as related arts of embodiments the present invention.
[0004] Patent Literature 1: JP 2015-94271 A
[0005] Patent Literature 2: JP 2002-316530 A
[0006] Patent Literature 3: JP 2011-189824 A
SUMMARY
[0007] The Rankine cycle system has a structure in which its constituents are connected to one another with pipes and the like. In particular, to a gas-liquid separator, which is one of the constituents of the Rankine cycle system, pipes are provided which allow transfer of a refrigerant from/to system's constituents including an internal combustion engine. Therefore, in the case where the gas-liquid separator is fixed, for example, to the vehicle side, vibration of the internal combustion engine is caused to be transmitted to the vehicle via the pipe connecting the internal combustion engine to the gas-liquid separator. The aforementioned technology can be still improved in view of suppression of vibration of the vehicle since, in this technology, the Rankine cycle system is not sufficiently considered on a structure for mounting it on a moving object such as a vehicle.
[0008] The present invention is devised in view of the aforementioned problem and an object thereof is to provide a Rankine cycle system for vehicle capable of suppressing vibration of an internal combustion engine from being directly transmitted from a gas-liquid separator to a vehicle.
[0009] In order to achieve the aforementioned object, there is provided a Rankine cycle system for vehicle according to a first embodiment of the present invention, including: a boiler configured to apply waste heat to refrigerant circulating in an internal-combustion engine to vaporize the refrigerant; a gas-liquid separator configured to separate gas-liquid two-phase refrigerant, sent from the boiler, into gas phase fluid and liquid phase fluid; a superheater configured to superheat the gas phase fluid, sent from the gas-liquid separator, through heat exchange with exhaust gas of the internal-combustion engine; an expander configured to expand the gas phase fluid, passing through the superheater, to recover thermal energy; and a condenser configured to condense the gas phase fluid, passing through the expander, to return the gas phase fluid to liquid phase fluid, wherein the gas-liquid separator is connected to the internal combustion engine via a refrigerant pipe, the internal combustion engine is fixed onto an engine mount of a vehicle, and the gas-liquid separator is fixed to the internal combustion engine via a bracket.
[0010] According to a second embodiment of the present invention, in the first embodiment, the gas-liquid separator is connected to the superheater via a refrigerant pipe, and the superheater is fixed to the internal combustion engine.
[0011] According to a third embodiment of the present invention, in the second embodiment, the superheater is connected to the expander via a refrigerant pipe, and the expander is fixed to the internal combustion engine.
[0012] According to a fourth embodiment of the present invention, in the second embodiment, the superheater is integrally configured with an exhaust gas manifold fixed to the internal combustion engine.
[0013] According to the first embodiment, the internal combustion engine is fixed to the engine mount, and the gas-liquid separator is fixed to the internal combustion engine via the bracket. Vibration of the internal combustion engine is transmitted to the gas-liquid separator via the refrigerant pipe. Therefore, according to this embodiment, vibration of the internal combustion engine can be prevented from being directly transmitted from the gas-liquid separator to the vehicle since the gas-liquid separator is fixed to the internal combustion engine.
[0014] According to the second embodiment, the superheater connected to the gas-liquid separator with the refrigerant pipe is fixed to the internal combustion engine. Therefore, according to this embodiment, vibration transmitted to the superheater via the refrigerant pipe can be prevented from being directly transmitted to the vehicle.
[0015] According to the third embodiment, the expander connected to the superheater with the refrigerant pipe is fixed to the internal combustion engine. Therefore, according to this embodiment, vibration transmitted to the expander via the refrigerant pipe can be prevented from being directly transmitted to the vehicle.
[0016] According to the fourth embodiment, the superheater is integrally configured with the exhaust gas manifold fixed to the internal combustion engine. Therefore, according to this embodiment, vibration of the internal combustion engine can be prevented from being directly transmitted from the superheater to the vehicle.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a diagram illustrating a configuration of a Rankine cycle system of a first embodiment of the present invention;
[0018] FIGS. 2A and 2B are schematic diagrams for explaining a structure for fixing a gas-liquid separator;
[0019] FIG. 3 is a diagram for explaining a structure for mounting the Rankine cycle system having the gas-liquid separator fixed to an engine on a vehicle; and
[0020] FIG. 4 is a diagram for explaining a structure for mounting the Rankine cycle system having the gas-liquid separator fixed to the vehicle on the vehicle.
DESCRIPTION OF EMBODIMENTS
[0021] Hereafter, embodiments of the present invention are described with reference to the drawings. Common elements across the drawings are given the same reference signs and duplicated description of those is omitted. In the following embodiments, when numerical values are mentioned such as the quantity of each element, the number thereof, the amount thereof and the range thereof, any of the mentioned numerical values does not limit the invention except that it is particularly explicitly presented or it is definitely specified so in principle. Any of the following structures described in the embodiments is not always necessary for the invention except that it is particularly explicitly presented or it is definitely specified so in principle.
First Embodiment
[0022] 1. Configuration of Rankine Cycle System
[0023] FIG. 1 is a diagram illustrating a configuration of a Rankine cycle system 100 of a first embodiment. The Rankine cycle system 100 of the first embodiment is a Rankine cycle system for vehicle which includes an internal combustion engine (engine) 10 and is mounted on a vehicle. The engine 10 is not limited in its type and structure except that the engine 10 has, at its cylinder blocks and cylinder heads, a refrigerant flow channel 12 which a refrigerant circulated in the engine 10 flows through. The refrigerant flow channel 12 includes a water jacket surrounding the cylinders. The engine 10 is cooled through heat exchange with the refrigerant flowing through the refrigerant flow channel 12 . In the present embodiment, water is used as the refrigerant.
[0024] The refrigerant flowing through the refrigerant flow channel 12 is boiled with waste heat of the engine 10 and a part thereof is vaporized. The engine 10 is thus cooled. Namely, the refrigerant flow channel 12 serves as a boiler which boils the liquid-phase refrigerant flowing therethrough with the heat of the engine 10 . The configuration of the refrigerant flow channel 12 is not specially limited as long as the refrigerant can pass through inside the engine 10 . The refrigerant, which passes through the refrigerant flow channel 12 , is not limited to water but may be a liquid-phase fluid at ambient temperature that is boiled into a gas-phase fluid with heat of the engine 10 .
[0025] The refrigerant flow channel 12 of the engine 10 is connected to a gas-liquid separator 16 via a refrigerant pipe 14 . After the refrigerant is boiled with heat of the engine 10 , a liquid-phase fluid and a gas-phase fluid are ejected from the refrigerant flow channel 12 . The gas-liquid separator 16 separates the refrigerant in gas-liquid two phases which flows into the gas-liquid separator 16 , into the liquid-phase fluid and the gas-phase fluid. The gas-liquid separator 16 is connected to a first water pump 20 via a refrigerant pipe 18 . The liquid-phase fluid separated by the gas-liquid separator 16 flows into the first water pump 20 through the refrigerant pipe 18 and is sent to the refrigerant flow channel 12 by the first water pump 20 .
[0026] The Rankine cycle system 100 includes an exhaust gas heat recovery unit 13 . The refrigerant flow channel 12 is also connected to the exhaust gas heat recovery unit 13 via a refrigerant pipe 11 . Into the exhaust gas heat recovery unit 13 , the liquid-phase fluid is introduced from the refrigerant flow channel 12 . The introduced liquid-phase fluid is superheated through heat exchange with exhaust gas flowing through an exhaust gas passage 22 to be boiled, and a part thereof is vaporized. The vaporized gas-phase fluid is introduced into the gas-liquid separator 16 via a refrigerant pipe 15 .
[0027] The gas-liquid separator 16 is connected to a superheater 30 via a refrigerant pipe 28 . The superheater 30 is provided upstream of the exhaust gas heat recovery unit 13 on the exhaust gas passage 22 of the engine 10 . More in detail, the superheater 30 circumferentially covers an exhaust gas manifold 26 and is integrated with the exhaust gas manifold 26 . A space surrounded by the inner wall surface of the superheater 30 and the outer wall surface of the exhaust gas manifold 26 is a flow channel which the gas-phase fluid sent from the gas-liquid separator 16 flows through. In the gas-liquid separator 16 , the gas-phase fluid is saturated vapor since the gas-phase fluid is present along with the liquid-phase fluid. The gas-phase fluid entering the superheater 30 becomes superheated vapor after absorbing exhaust gas heat transmitted through the wall surface of the exhaust gas manifold 26 .
[0028] The superheater 30 is connected to a turbine 34 which is an expander via a refrigerant pipe 32 . In the turbine 34 , thermal energy is recovered by allowing the gas-phase fluid (superheated vapor) sent from the superheater 30 to expand. A not-shown supersonic nozzle is provided at a connection between the refrigerant pipe 32 and the turbine 34 . The gas-phase fluid is ejected into the turbine 34 from the supersonic nozzle to rotate the turbine 34 . The rotation of the turbine 34 is transmitted to an output shaft of the engine 10 via a not-shown reduction gear. Namely, the thermal energy recovered through the turbine 34 assists the engine 10 . The turbine 34 may drive a generator instead to store the generated electricity in a power storage.
[0029] The gas-phase fluid expanded in the turbine 34 is sent to a condenser 40 via a refrigerant pipe 36 . A liquid-phase fluid, which can be generated through condensation of the gas-phase fluid in the middle of the refrigerant pipe 36 , is temporarily stored in a condensed water tank 38 provided in the middle of the refrigerant pipe 36 . The condensed water tank 38 is connected to a catch tank 44 mentioned later via a refrigerant pipe 39 . The gas-phase fluid sent to the condenser 40 is cooled and condensed by the condenser 40 to be returned to a liquid-phase fluid. The liquid-phase fluid generated through the condensation of the gas-phase fluid is sent to the catch tank 44 from the condenser 40 via a refrigerant pipe 42 , and is temporarily stored in the catch tank 44 . The catch tank 44 is connected to the first water pump 20 via a refrigerant pipe 46 . A second water pump 48 is provided on the refrigerant pipe 46 . The second water pump 48 sends the liquid-phase fluid stored in the catch tank 44 to the first water pump 20 . A not-shown check valve is provided between the second water pump 48 and the gas-liquid separator 16 to prevent the liquid-phase fluid from flowing back from the gas-liquid separator 16 side to the catch tank 44 side. The refrigerant pipe 46 may connect the catch tank 44 to the middle of refrigerant pipe 18 instead. In this configuration, drive of the second water pump 48 sends the liquid-phase fluid stored in the catch tank 44 to the gas-liquid separator 16 and the engine 10 . The lower end of the catch tank 44 is connected to the lower end of a refrigerant tank 52 via a refrigerant pipe 50 . To the upper end of the refrigerant tank 52 , a refrigerant pipe 54 is connected whose end is connected to the upper end of the condenser 40 .
[0030] The Rankine cycle system 100 includes an electronic control unit (ECU) 70 as a controller. The ECU 70 at least includes an I/O interface, a memory and a processor (CPU). The I/O interface is provided for taking in sensor signals from sensors attached to the Rankine cycle system 100 or the engine 10 having the same mounted, and for outputting operation signals to actuators included in the Rankine cycle system 100 . The memory stores control programs, maps and the like. The CPU reads and executes the control program or the like from the memory, and generates the operation signals for the actuators on the basis of the taken-in sensor signals.
[0031] 2. Structure for Mounting Rankine Cycle System on Vehicle
[0032] The Rankine cycle system 100 is mounted inside an engine compartment of a vehicle for accommodating the engine 10 . The engine 10 is fixed onto an engine mount in the engine compartment. The engine mount absorbs the vibration of the engine 10 , and can suppress the vibration from being transmitted from the engine 10 to the vehicle side.
[0033] There are various restrictions in arranging the constituents of the Rankine cycle system 100 due to the limited space in the engine compartment for mounting them. Meanwhile, the gas-liquid separator 16 , which is one of the constituents of the Rankine cycle system 100 , needs a relatively large volume for stably supplying the vapor. Only in view of the space for mounting the gas-liquid separator 16 , it should be disposed at a place apart from the engine 10 . As a result, it is also supposed that the gas-liquid separator 16 be fixed onto the vehicle body side.
[0034] Vibration of the engine 10 is caused to be transmitted to the vehicle via the refrigerant pipe 14 when the gas-liquid separator 16 is directly fixed to a member constituting the vehicle framework since the gas-liquid separator 16 is connected to the refrigerant flow channel 12 of the engine 10 via the refrigerant pipe 14 as mentioned above. In particular, there is typically used a metal-made, large-diameter pipe to pass a gas-phase fluid (vapor) as well as a liquid-phase fluid, such as the refrigerant pipe 14 , for its heat resistance and pressure resistance. Use of such a pipe increases vibration transmitted from the engine 10 to the gas-liquid separator 16 , which results in large vibration to be transmitted to the vehicle.
[0035] Therefore, the inventors in the present application have been intensively studying structures for mounting the gas-liquid separator 16 on the vehicle in order to suppress vibration transmitted, not via the engine mount, from the engine 10 to the vehicle. The inventors in the present application have eventually found the structure for mounting the gas-liquid separator 16 on the vehicle, which structure will be described below.
[0036] 2-1. Structure for Fixing Gas-Liquid Separator
[0037] FIGS. 2A and 2B are schematic diagrams for explaining a structure for fixing the gas-liquid separator. FIG. 2A is a diagram of the Rankine cycle system in plan view above the vehicle. FIGS. 2B is a diagram of the Rankine cycle system mounted on the vehicle in elevation view beside the vehicle. In FIGS. 2A and 2B , elements other than the main constituents of the Rankine cycle system 100 are omitted. As illustrated in FIGS. 2A and 2B , the Rankine cycle system 100 is mounted inside an engine compartment 1 of the vehicle. The engine 10 is mounted on the engine mount (not shown) provided in the engine compartment 1 .
[0038] Reference sign S 1 in FIG. 2A denotes a plane which includes center axes L 1 of cylinders 104 and is parallel to the direction of the cylinders 104 lining up which are provided in series along the longitudinal direction of a cylinder block 102 . Reference sign S 2 in FIG. 2B denotes a plane on which a cylinder head 101 meets the cylinder block 102 . In the following description, “exhaust side” designates the exhaust side, of the engine 10 relative to the plane S 1 , on which the exhaust gas passage 22 is provided, and “air intake side” designates the air intake side of the engine 10 relative to the plane S 1 .
[0039] In the fixing structure illustrated in FIG. 2 , a transmitter 103 is fixed onto a lateral face of the cylinder block 102 . The gas-liquid separator 16 is disposed in a space which is on the exhaust side (that is, the side of the exhaust gas passage 22 of the engine 10 ) above the transmitter 103 , and is fixed to the engine 10 via brackets 2 a and 2 b. More in detail, one end of the bracket 2 a is fixed to the upper part of the gas-liquid separator 16 and the other end thereof is fixed onto the upper face of the cylinder head 101 of the engine 10 . Moreover, one end of the bracket 2 b is fixed to the lower part of the gas-liquid separator 16 and the other end thereof is fixed onto a lateral face of the cylinder block 102 of the engine 10 . The brackets 2 a and 2 b are formed by processing metal plates, and each of them has a shape which can secure strength needed for fixing the gas-liquid separator 16 . With bolts, the brackets 2 a and 2 b are fixed to the engine 10 and the brackets 2 a and 2 b are fixed to the gas-liquid separator 16 .
[0040] According to the aforementioned structure for fixing the gas-liquid separator 16 , the gas-liquid separator 16 is fixed to the engine 10 . This can prevent direct transmission of the vibration to the vehicle, the vibration having been transmitted to the gas-liquid separator 16 via the refrigerant pipe 14 . Hence, vibration of the vehicle can be suppressed. Moreover, the gas-liquid separator 16 can be effectively suppressed from shaking since the gas-liquid separator 16 is fixed at its upper part and lower part with the brackets 2 a and 2 b.
[0041] A method of fixing the brackets, the number thereof and the shape thereof are not limited as long as the brackets 2 a and 2 b can be fixed to the engine 10 . The material of the brackets 2 a and 2 b is not limited to metal. The material preferably has high strength since they fix the gas-liquid separator 16 , which is typically heavy.
[0042] 2-2. Structure for Fixing Superheater
[0043] As mentioned above, transmission of the vibration to the vehicle can be suppressed since the gas-liquid separator 16 is fixed to the engine 10 in the Rankine cycle system 100 of the first embodiment. Now, as illustrated in FIG. 2 , refrigerant pipes other than the refrigerant pipe 14 are also connected to the gas-liquid separator 16 . For example, the refrigerant pipe 28 connects the gas-liquid separator 16 and the superheater 30 together. Via the refrigerant pipe 28 , the vibration transmitted to the gas-liquid separator 16 is transmitted also to the superheater 30 . Depending on a structure for fixing the superheater 30 , vibration of the vehicle can be further suppressed.
[0044] With this point being in mind, the superheater 30 is integrated with the exhaust gas manifold 26 in the Rankine cycle system 100 of the first embodiment. The exhaust gas manifold 26 is fixed to the engine 10 . The vibration, of the gas-liquid separator 16 , transmitted to the superheater 30 via the refrigerant pipe 28 is not directly transmitted to the vehicle. According to the aforementioned structure for fixing the superheater 30 , vibration of the vehicle can be further suppressed.
[0045] The shape or the structure of the superheater 30 is not limited as long as it can be fixed to the engine 10 . Namely, the superheater 30 may be integrated, for example, with another portion which can absorb the exhaust gas heat, such as a catalyst, not limited to the structure of being integrated with the exhaust gas manifold 26 . Otherwise, it may also be fixed to the engine 10 at any place where it can absorb the exhaust gas heat.
[0046] 2-3. Structure for Fixing Turbine
[0047] As mentioned above, transmission of the vibration to the vehicle can be suppressed since the gas-liquid separator 16 and the superheater 30 are fixed to the engine 10 in the Rankine cycle system 100 of the first embodiment. Now, as illustrated in FIG. 2 , the superheater 30 is connected to the turbine 34 via the refrigerant pipe 32 . Via the refrigerant pipe 32 , the vibration transmitted from the gas-liquid separator 16 to the superheater 30 is transmitted to the turbine 34 . Depending on a structure for fixing the turbine 34 , vibration of the vehicle can be further suppressed.
[0048] With this point being in mind, the turbine 34 is fixed to the engine 10 in the Rankine cycle system 100 of the first embodiment. According to such a structure, the vibration transmitted to the turbine 34 from the superheater 30 through the refrigerant pipe 32 is not directly transmitted to the vehicle. According to the aforementioned structure for fixing the turbine 34 , vibration of the vehicle can be further suppressed. The structure for fixing the turbine 34 is not limited as long as it can be fixed to the engine 10 .
[0049] 3. Example of Structure for Mounting Rankine Cycle System 100 on Vehicle
[0050] Next, the structure for mounting the Rankine cycle system 100 of the first embodiment on the vehicle is described along with a comparative example. FIG. 3 is a diagram for explaining a structure for mounting a Rankine cycle system in which a gas-liquid separator is fixed to an engine on a vehicle. FIG. 4 is a diagram for explaining a structure for mounting a Rankine cycle system in which a gas-liquid separator is fixed to a vehicle, on the vehicle. FIG. 3 corresponds to the structure for mounting the Rankine cycle system 100 of the first embodiment of the present invention on the vehicle. FIG. 4 corresponds to a comparative example of the Rankine cycle system 100 of the first embodiment of the present invention. Each of FIG. 3 and FIG. 4 schematically illustrates an arrangement of the constituents of the Rankine cycle system in side view beside the vehicle. Moreover, in FIG. 3 and FIG. 4 , elements other than the main constituents of the Rankine cycle system are omitted.
[0051] 3-1. Discussion of Comparative Example
[0052] In the comparative example illustrated in FIG. 4 , the gas-liquid separator 16 is fixed to the vehicle while the superheater 30 and the turbine 34 are fixed to the engine 10 . In such a structure, the vibration of the engine 10 , which vibration is further transmitted to the gas-liquid separator 16 via the refrigerant pipes 14 , 28 and 18 , is caused to be transmitted, not via the engine mount, to the vehicle, which results in larger vibration of the vehicle.
[0053] 3-2. Discussion of Vehicle Mounting Structure of First Embodiment
[0054] On the contrary, in the vehicle mounting structure illustrated in FIG. 3 , the gas-liquid separator 16 is fixed to the engine 10 . In such a structure, there is no path through which the vibration is directly transmitted from the gas-liquid separator 16 to the vehicle body. The Rankine cycle system of the embodiment can reduce paths through which the vibration is transmitted between the engine 10 and the vehicle more than the Rankine cycle system of the comparative example. Therefore, vibration of the vehicle can be effectively suppressed. | A Rankine cycle system includes a boiler configured to apply waste heat to refrigerant circulating in an internal-combustion engine to vaporize the refrigerant; a gas-liquid separator configured to separate gas-liquid two-phase refrigerant, sent from the boiler, into gas phase fluid and liquid phase fluid; a superheater configured to superheat the gas phase fluid, sent from the gas-liquid separator, through heat exchange with exhaust gas of the internal-combustion engine; an expander configured to expand the gas phase fluid, passing through the superheater, to recover thermal energy, and a condenser configured to condense the gas phase fluid, passing through the expander, to return the gas phase fluid to liquid phase fluid. The gas-liquid separator is connected to the internal combustion engine via a refrigerant pipe. The internal combustion engine is fixed onto an engine mount of a vehicle. The gas-liquid separator is fixed to the internal combustion engine via a bracket. |
RELATED DOCUMENT
This application is related to and based upon provisional disclosure Number 60/044,455 filed on Apr. 12, 1996 under the same title, “Automated Quarry Operation with Communication Interface” and by the same inventors.
BACKGROUND
This invention relates to method devices and system for automated quarry operation. More particularly it relates to automatically shutting of an unmanned liquid jet cutting system upon encountering unforseen, unusual or abnormal technical problems and circumstances.
SUMMARY
An automated quarry robotic system comprising a power unit, a balanced oscillator, a communication interface, a plurality of sensors and transducers, an optional mobile system, multiple intensifiers, one or more nozzles with diamond or sapphire orifice and a PLC (programmable logic controller which is a micro-controller with a control panel for programming and controlling rise and fall, indexer and oscillator system.
The system also includes means for automatically communicating via phone or wireless the status of the system to the responsible party so that the problem can be solved and the system restarted at the earliest opportunity. The system also includes means for automatically and safely shutting off the operation upon encountering unforseen, unusual or abnormal technical problems and circumstances such as unworkable hard spots, unusual water pressure etc.
PRIOR ART
Notwithstanding the inventors are intimately familiar with the prior art in their industry, a prior art search was nonetheless conducted and the following pertinent U.S. prior art patents were uncovered arranged in reverse chronological order.
a) U.S. Pat. No. 5,568,030 awarded to Nishikawa et al on Oct. 22, 1996 for, “Travel Control Method, Travel Control Device and Mobile Robot for Mobile Robot Systems”
b) U.S. Pat. No. 5,436,903 bestowed upon Young et al on Jul. 15, 1995 for “Method and Apparatus for Use in a Network of the Ethernet Type to Improve Fairness by Controlling Collision Backoff Times and Using Stopped Backoff Timing in the Event of Channel Capture”
c) U.S. Pat. No. 5,411,432 honorably conferred upon Wyatt et al on May 2, 1995 for “Programmable Oscillating Liquid Jet Cutting System”
d) U.S. Pat. No. 5,257,743 issued to Charles K Brown Jr. on Nov. 2, 1993 for “Quarry Pulverizer”
e) U.S. Pat. No. 5,124,620 honorably given to Kurebayashi et al on Jun. 23, 1992 for, “Control Method for Robots”
f) U.S. Pat. No. 4,872,293 issued to Yasukawa et al on Oct. 10, 1989 for “Abrasive Water Jet Cutting System”
g) U.S. Pat. No. 4,637,017 earned by Assaal et al on Jan. 13, 1987 for “Monitoring of Input Backoff in Time Division Multiple Access Communication Satellites.”
h) U.S. Pat. No. 4,176,883 issued to Daniel Liesveld on Dec. 4, 1979 for “Oscillating Liquid Jet System and Method for Cutting Granite and the Like”
i) U.S. Pat. No. 4,135,762 earned by Vito Biancale on Jan. 23, 1979 for “Quarry Operation”
Prior art fluid jet cutting systems are not suitable for unmanned operation without serious risk and concomitant liability. Prior art system also do not include a fail safe or even fail soft way of shutting the system automatically when problems are encountered. Lastly prior art quarry systems lack communication interface to inform a remotely located human being the status of the system.
In summary the prior art systems do not meet singly or even in combination the following objectives for this system.
OBJECTIVES
1) It is an objective of this invention to provide an automated quarry operation.
2). Another objective of this invention is to provide a fail soft and even fail safe way of shutting the system automatically when problems are encountered.
3) Another objective of this invention is to provide a communication interface for automatically communicating the status of the system to a remote supervisor.
4) Another objective of this invention is to provide a programmable interface such that the system can be reprogrammed for varied applications readily.
5) Another objective of this invention is to provide a hard spot interface to limit the effect of a small hard area of a given material on the average cutting rate of the material.
6) Another objective of this invention is to increase the efficiency of cut by working around a hard spot according to a preprogrammed algorithm.
7) Another objective of this invention is to provide multiple water jet cutting nozzles driven and powered by the same power unit on the same crawler to increase the cut rate efficiency and cost effectiveness on-site at a quarry.
8) Another objective of this invention is to provide an environmentally friendly system.
9) Another objective of this invention is to provide safer, quicker method of cutting stone on site at a quarry.
10) Another objective of this invention is to provide a system that is reliable and easy to maintain.
11) Another objective of this invention is to provide a system that is intuitive and easy to use such that it requires little training or retraining.
12) Another objective of this invention is that the thickness of the cut, the pitch, the rise and fall speed and the jet cut path be all coordinated and computer controlled such that the operator needs to enter or reset only the minimum set of parameters for each new programmable automatic unattended cut.
13) Another objective of this invention is that it provide all of the above mentioned objectives concurrently in high horse power (Q*P*N), wherein Q=Flow; P=Pressure and N=A constant factor.
14) Another objective of this invention is to provide a means for adjusting the balance of the balanced oscillator incorporated in this invention.
15) Another objective of this invention is to pretension the oscillator or high pressure tubing so as to alter the position and/or dwell of the nozzle as it moves to and fro.
16) Another objective of this invention is to automatically maximize the productivity of the cut under various pressures and positions of the stone being aut.
17) Another objective of this invention is to provide a means for automatically and readily fine tuning the shape of the cut under differing quarry conditions.
18) Another objective is to reduce the liability of the owners and operators of the quarry.
19) Another objective is to reduce accidents, noise, dust from blasting.
20) Other objectives of this invention reside in its simplicity, design elegance, ease of manufacture, ease of training and the like as will become apparent from the following brief description of the drawing and detailed description of the preferred and various alternate embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features, and advantages of the present invention and its application will be more readily appreciated when read in conjunction with the accompanying drawing, in which:
a) FIG. 1 ( a ) is a front elevation of the quarry robotic arm of this invention.
b) FIG. 1 ( b ) 2 is a top elevation thereof.
c) FIG. 1 ( c ) is a side elevation thereof.
d) FIG. 2 is a flow chart of the overall operation of the unmanned quarry operation of this invention.
e) FIG. 3 is a flow chart of the automated quarry operation in the manual mode.
f) FIG. 4 is a flow chart of the feed flow algorithm of the automated quarry operation of this invention.
g) FIG. 5 shows the flow-chart for the automatic shutdown when the quarry robot encounters unworkable difficulties.
h) FIG. 6 flow-chart depicts the hard spot stage 0 algorithm.
i) FIG. 7 flow-chart depicts the hard spot stage 1 algorithm.
j) FIG. 8 flow-chart depicts the hard spot stage 2 algorithm.
k) FIG. 9 flow-chart depicts the hard spot stage 3 algorithm.
l) FIG. 10 shows the protocol for the feed/jam cycle of the hard spot stage 3 algorithm.
m) FIG. 11 shows a 3 D perspective view of Automatic Quarry Operation System with Communication Interface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the drawings wherein like numerals represent like parts throughout the several views, there is generally disclosed in FIG. 1 a robotic member 100 with rise and fall assembly 110 including feed and retract means. FIGS. 1 ( a,b,c ) are front top and side elevations thereof respectively. At the top of the robotic mast vertical member 100 is mounted the rise and fall motor 101 and at the bottom of the robotic mast vertical member 100 is mounted a counter balance motor 199 to balance the motor 101 at the top.
The computer controlled robotic member 100 has an arm 110 with rise and fall and feed and retract control also includes a PLC (programmable logic controller) a boom leveling system for tilt, dump and swing, tilting system for chain feed to level and position in travel mode and E Chain containing extendible, flexible high pressure hose as well as means for disengaging the oscillator from the high pressure tubing without breaking any fittings for centering purposes.
FIG. 2 is a computer program flow chart of the overall operation of the unattended quarry operation with communication interface of this invention delineating both the manual mode and the automatic mode operations.
FIG. 3 shows the logic of the manual mode operation wherein the decision blocks are diamond shape and operational blocks are rectangular and shut down sequence circular.
FIG. 4 shows the feed flow chart wherein the decision blocks are diamond shape and operational blocks are rectangular and shut down sequence circular.
FIG. 5 shows the shutdown sequence in the manual mode. FIG. 6 shows the flow-chart for the pre hard spot stage 0 ( 600 ) wherein the decision blocks are diamond shape and operational blocks are rectangular and shut down sequence circular.
FIGS. 7 through 9 show the logic of the computer program for the automatic mode for hard spot stages one ( 700 ). two ( 800 ) and three ( 900 ) respectively in the flow-chart format, wherein the decision blocks are diamond shape and operational blocks are rectangular and shut down sequence circular.
FIG. 10 shows the logic of the feed/jam cycle of the hard spot stage 3 in the automatic mode in flow-chart format wherein the decision blocks are diamond shape and operational blocks are rectangular and shut down sequence circular.
The following sensors and transducers are also integral part of the system.
a) Rise & Fall Encoder 120 such as Dynapar series H20 records position and speed along the rise & fall axis. Top limit, bottom limit, home for manned & unmanned mode, hard spot top, and hard spot bottom are stored based on material and cut considerations.
b) Feed & Retract Encoder 130 such as Dynapar series H20 records position on horizontal axis. Manned & unmanned mode index value, end cut position, hard spot index value, and hard spot retract value are stored based on material and cut considerations.
c) Balanced Oscillator Speed Sensor 140 such as a magnetoresistive sensor by Rechner records speed in rpm's of the balanced oscillator. Max and Min speed limits are stored and if either are reached an output will initiate a shut down.
d) High Pressure Water Sensor 160 such as sensotec model TJE records pressures up to 50,000 psi. Max and Min pressures are stored and if either are reached an output will initiate a shut down. The high pressure water sensor 160 also acts as an alarm to shut the system down in the proper manner. A high and low pressure alarms is set by the operator in the manual mode but in the automatic mode it is pre-programmed.
These alarms reduce the risk of equipment damage in unmanned operation.
e) The main output sensor is the communication interface 150 such as a cellular phone or a pager. In the preferred embodiment the inventors used Zetron Model 1516 from Milbank Communications of South Dakota. The communication interface 150 upon meeting a predefined criteria automatically dials the remote location. The cellular phone communication interface allows the operator to spend less time on the quarry site which not only reduces the employee exposure to the hazards of the occupation but also reduces the operating cost of cutting slots in quarries. In the automatic mode after a shut down the cell phone calls the various beeper numbers to notify reason for shut down.
In addition there are proximity sensors (not shown) to obviate accidental bumping or travel beyond safe limits of the robot arm.
OPERATION
The balanced oscillator assembly 110 moves up and down (also known as rise and fall) under the control of a PLC (Programmable Logic Controller) 175 .
The balanced oscillator speed is function of many variables including the rise and fall, the grain of the stone being cut. In the preferred embodiment the oscillator speed was 1200 cycles per minute.
The rise and fall motor 101 IS assisted and counter balanced by motor 199 to reduce the strength of the system in the downward direction in order to protect the nozzle 185 and the high pressure fittings. The wand 180 is mounted on the rise and fall assembly which is also capable of moving in and out, towards and away from the cut respectively. The high pressure water jet sapphire nozzle 185 is mounted on this wand 180 . The distance of the travel is determined by positioning of the top and bottom proximity sensors (not shown). This motion is repeated over and over again unless in the unlikely event the oscillator or some other related component jams, in which case the automatic shut down procedure takes over if in automatic mode or if in manual mode the operator initiates the shut down 999 sequence.
The horizontal travel (also known as indexer) moves a programmable predetermined amount which is normally activated when the bottom proximity sensor is activated. It is also possible to index at top only or top and bottom both.
Feed & Retract is the horizontal axis. The Feed Retract encoder is fixed to the Feed Retract motor shaft, if the Feed Retract motor is actuated the Feed Retract motor turns and moves the chain which moves the wand forward into the cut or backward away from the cut. The Feed Retract encoder relays position information to the PLC. This axis is actuated in automatic mode when either top ,bottom or both are on and when index on the jog/index switch is actuated.
Even in the manual mode if an obstruction causes the oscillator or the rise and fall to slow down or stop, the computer 95 senses a change of speed and shuts down automatically. This is a very effective safety feature for the unexpected in the quarries.
AUTOMATIC MODE
When actuated in automatic mode the wand moves into the cut by the index amount stored in the computer monitor. This index value is entered by the operator based on the stone characteristics. The operator may choose to index either at the top of the cut or the bottom of the cut or both top or bottom.
The “hard spot” cycle initiates repeated cutting in the hard area without wasting time over the complete cut. The hard spot stage 0 ( 600 ) merely ascertains whether or not any hard spot is involved before making a logic decision to enter manual or automatic mode.
To understand the operation of the stage 1 ( 700 ) of hard spot cycle, assume the wand 180 is jammed while falling. The wand 180 would rise until the top “hardspot position” is reached (usually 12″ unless top limit is reached first).
At this point the system enters into hard spot stage 2 ( 800 ) of hard spot cycle. The PLC 175 will send one signal to the feed/retract motor until the hard spot retract (2″ usually) value is reached.
Once this position is reached the system enters the hard spot stage 3 ( 900 ). At stage 3 the wand 110 begins falling, the wand passes by the actual point of jamming and travel to the bottom until the “hardspot position” is reached (usually 12″ unless bottom limit is reached first).
Hard spot stage three ( 900 ) is actually a mini automatic cycle without a hard spot cycle within it. When approaching the bottom limit the wand indexes into the cut as it does in automatic cycle except the index value corresponds to the “hard spot” index value.
This “hard spot” index value is entered by the operator based on the stone characteristics. The wand 180 will continue to Rise, index at top “hard spot position” and fall and continue until the current index position is one index less than the index value when hard spot cycle was started. At that point the PLC 175 jumps back into Automatic cycle referencing the auto cycle's top bottom and index values.
The benefits of the system are better efficiency using the plc to work out of hard spots rather than by manual operation. Unmanned operation also reduces the operating cost of equipment, which in turn leads to better productivity and cost. Furthermore in the automatic mode there is less exposure to occupational hazards for the employee which reduces accidents, noise, dust from blasting. All of this leads to lower, reduced or negligible liability.
To use this system the inventors recommend the following steps:
a) Initialize the system
b) Position the system at proper coordinates.
c) Program the coordinates of the location of the system
d) Program the coordinates of the object to be cut.
e) Define and enter the thickness of the cut
f) Define and enter the pitch (the distance between the zig zags). It should be noted that the optimum pitch is defined by the stone structure and its strength in tension. As a rule of thumb the larger the grain structure the higher the pitch.
g) Enter the desired balanced oscillator speed if not already preprogrammed.
h) Program the nozzle jet cutting tool path or load in the program from a preprogrammed computer readable media.
i) Program automatic shut off cycle.
j) Enter phone number of the remote supervisor in the communication interface for remote automatic message after shutdown.
k) Push auto cycle start and oscillator on when ready.
l) If in manual mode monitor the control panel for any problems.
m) If in automatic mode the operator may leave site.
n) Travel back to site upon intimation from the system that it has shut down or notification of other problem that need operator attention.
o) Repeat steps a through n for the next cut or next program as necessary.
The inventor has given a non-limiting description of the concept. Many changes may be made to this design without deviating from the spirit of the concept of this invention. Examples of such contemplated variations include the following.
a) a different combination of input sensor and output transducers may be used.
b) The hard spot algorithm may be modified.
c) The communication interfaced may be varied.
d) A different means may be used to initiate the hard spot cycle for example in hydraulic drive systems one could also measure hydraulic pressure and as resistance increases hydraulic pressure would rise. From the pressure change one could use the plc to initiate “hard spot” or use hydraulic valving to start a hard spot sequence.
Similarly in electric drive systems one could also measure current draw which could signal the plc to initiate hard spot.
e) Instead of the hard spot cycle taught here one could develop a sensor or some sort of limit switch, or Video camera system that could record the cut profile, which could be used to effectively predict the obstruction and hence the initiation of the hard spot cycle.
f) The crawler may be obviated or substituted by a mobile unit.
g) The PLC may be replaced by a general purpose personal computer.
h) The cutting methodology and embodiment may be adapted for other related applications such as in mining or for cutting other materials.
i) A different permutation and combination of the parts disclosed here may be used to fine tune the cut.
j) Additional features such as a automatic display, automatic safety features may be incorporated.
k) The programming may be further simplified such that it is user programmable.
Other changes such as aesthetic and substitution of newer materials as they become available which substantially perform the same function in substantially the same manner with substantially the same result without deviating from the spirit of this invention.
Following is a listing of the components used in this embodiment arranged in ascending order of the reference numerals for ready reference of the reader.
010 —Quarry stone
100 —Quarry Robot drilling member generally
101 —Rise and Fall Motor
110 —Rise and Fall Assembly
120 —Rise/Fall Encoder
125 —Rail
126 —Feed Retract Index Chain
130 —Feed and Retract Encoder
132 —Feed Retract Motor Socket
135 —Feed Retract Motor
136 —V Wheels
140 —Balanced Oscillator Speed sensor
145 —Hydraulic System
146 —Triplex Plunger Pump Hydraulic Intensifier
150 —Communication interface for phone
160 —High pressure water sensor
170 —Balanced Oscillator
180 —Wand
199 —Counter Balance Motor
210 —Decision Logic to ascertain Manual Auto Mode
220 —Decision Logic to ascertain Auto Mode On Off
230 —Decision Logic to ascertain Oscillator On Off
240 —Decision Logic to ascertain Jog Index Mode
250 —Automatic mode operation
290 —Manual mode operation
310 —Decision Logic to ascertain Rise/fall i manual mode
311 —Decision logic to ascertain if top limit has been reached in manual mode.
312 —Decision Logic to ascertain if bottom limit has been reached in manual mode
321 —Decision Logic to ascertain feed at top in manual mode
322 —Decision Logic to ascertain feed at bottom in manual mode
330 —Decision Logic to ascertain Rise Fall Speed
331 —Speed Too Low to enter Hard Spot Mode operation
332 —Speed Too High to prepare for immediate but safe shutdown
340 —Decision Logic to ascertain if oscillator speed is within safe range
350 —Decision Logic to ascertain if high water pressure is within safe range
351 —Water Pressure Alarm
400 —Feed Output On operation
410 —Decision Logic to ascertain feed speed
411 —Feed Problems
420 —Decision Logic to ascertain feed response
421 —No response from Feed. Prepare for shutdown
430 —Decision Logic to ascertain if new index location has been reached.
432 —Turn off feed output operation
440 —Decision Logic to ascertain if “End of Cut” is reached
442 —Single box feed operation
444 —Cut complete
450 —Decision logic to ascertain if low speed for a predetermined length of time
510 —Turn off outputs to Rise/Fall, Feed Retract and balanced oscillator
520 —Turn off water pressure
530 —Idle engine for 5 minutes
540 —Shut down the engine
550 —Computer footage cut
560 —Alert operator
570 —Engage normal shut down
580 —Emergency Stop
600 —Automatic Mode Hard Spot Stage 0
610 —Decision logic to ascertain if system is in hard spot mode
612 —Operation in single hard spot mode
620 —Decision logic to ascertain if nth hard spot of the session has been reached.
622 —Too many hard spots—Prepare for shut down
650 —Store location data
660 —Decision logic to ascertain Rise Fall in automatic mode in hard spot stage 0 (1st hard spot stage)
662 —Robot Arm Falling
664 —Robot Arm Rising
700 —Automatic Mode Hard Spot Mode Stage 1
710 —Decision logic to ascertain Rise Fall in automatic mode in hard spot stage 1 (2nd hard spot stage)
711 —Decision logic to ascertain if robot arm jam has occurred or top limit has been reached in automatic mode hard spot stage one.
712 —Decision Logic to ascertain if robot arm jam is jammed or bottom limit has been reached in automatic mode hard spot stage 1
730 —Decision logic to ascertain if Rise Fall speed is within safe range in automatic mode hard spot stage 1
732 —Speed unacceptable—Enter automatic shutdown sequence
740 —Decision logic to ascertain if balanced oscillator speed is within safe range in automatic mode hard spot stage 1
742 —Speed unacceptable—Enter automatic shut down sequence
750 —Decision Logic to ascertain if high water pressure is within safe range in automatic mode hard spot stage 1
752 —Water Pressure Problem—Enter automatic shut down sequence
800 —Automatic Mode Hard Sport Stage 2
810 —Retract operation
820 —Decision Logic to ascertain if retract speed is normal within safe range
825 —Retract speed problem—Enter automatic shut down sequence
830 —Decision logic to ascertain retract position and whether or not the goal is reached.
835 —Continued retraction till goal is reached and shut down sequence initiated
840 —Compute uncut length footage
850 —Decision logic to ascertain if limit is reached
900 —Automatic Mode Hard Spot Stage 3
910 —Decision logic to ascertain Rise & Fall in automatic mode in hard spot stage 3
911 —Decision logic to ascertain if robot arm has jammed or top limit has been reached in automatic mode hard spot stage three.
912 —Decision Logic to ascertain if robot arm has jammed or bottom limit has been reached in automatic mode hard spot stage 1
921 —Decision Logic to ascertain feed at top in automatic mode hard spot stage 3
922 —Decision Logic to ascertain feed at bottom in automatic mode stage 3
930 —Decision logic to ascertain if Rise Fall speed is within safe range in automatic mode hard spot stage 3
931 —Rise & Fail Speed Too Low—Enter automatic shutdown sequence
933 —Rise Fail Speed Too High—Enter automatic shutdown sequence
940 —Decision logic to ascertain if balanced oscillator speed is within safe range in automatic mode hard spot stage 3
942 —Balanced Oscillator Speed unacceptable—Enter automatic shutdown sequence
950 —Decision logic to ascertain if balanced oscillator speed is within safe range in automatic mode hard spot stage 3
952 —Speed unacceptable—Enter automatic shut down sequence
999 —Manual or automatic Shutdown
1000 —Automatic ode Hard Spot Stage 3 Feed Jam Cycle
1100 —Decision logic to ascertain if feed speed within safe range
1110 —Feed Problems—Enter automatic shutdown sequence
1120 —Decision logic to ascertain feed response
1125 —No response from feed—Enter automatic shut down sequence
1150 —Decision logic to ascertain if feed speed low for a predetermined period of time
1155 —Feed Speed Too Low for a predetermined period of time—Enter automatic shut down sequence
1200 —Decision logic to ascertain if “End of Jam” cycle is reached
1210 —End of Jam cycle reached—Turn off feed output automatically
1240 —Decision logic to ascertain if “End of Cut” reached
1244 —End of cut reached—Enter automatic shut down sequence
1250 Hard Spot Stage 3 automatic feed operation.
DEFINITIONS
While exacting care has been taken to avoid terms of art and use words with their conventional dictionary meaning the following definitions are included for clarification of the specification and its interpretation.
CPU—Central processing unit of a computer capable of performing all the timing, control, logic associated with running a computer program.
Hard Spot Stage—A particular hard spot in a quarry which is solved or circumvented by a particular algorithm.
Interface—Matching or two or more dissimilar entities however realized
Program—A computer program executable in a given computing environment.
PLC—Programmable Logic Controller
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention will be apparent to person skilled in the art upon reference to this description. It is therefore contemplated that the appended claims cover any such modifications, embodiments as fall within the true scope of the invention. | In an automated quarry operation an unmanned high pressure computer controlled liquid jet cutting system particularly adopted for cutting granite on-site with device for automatically and safely shutting off the operation upon encountering unforeseen, unusual or abnormal technical problems and circumstances such as unworkable hard spots, unusual water pressure etc. The system also includes automatic communication of the status of the system. The system includes a power unit, a balanced oscillator, a communication interface, a plurality of sensors and transducers, an optional mobile system, multiple intensifiers, one or more nozzles with diamond or sapphire orifice and a micro-controller with a control panel for programming and controlling rise and fall, indexer and oscillator system. |
PRIORITY REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. Provisional Application No. 60/933,793, entitled COMMUNICATION CARD WITH THREE OPERATIONAL STATES, filed on Jun. 8, 2007 by inventors Itay Sherman, Itay Cohen and Yaron Segalov.
FIELD OF THE INVENTION
The present invention relates to communication cards that may be connected to electronic devices and to shells, and that may also operate in a standalone mode.
BACKGROUND OF THE INVENTION
Prior art communication cards include cards with connectors that enable them to interface with different types of electronic devices that serve as hosts. These cards generally include a radio modem, a CPU with ancillary memories, a power source and possibly data storage.
SUMMARY OF THE DESCRIPTION
The present invention provides a novel communication card (i) that may operate in a standalone mode, (ii) that may be connected to a shell that is not an independent device and that cannot operate without the communication card being connected thereto, and (iii) that may be connected to an electronic device that serves as the card's host. In state (ii) the communication card functions as a master, and in state (iii) the communication card functions as a slave.
There is thus provided in accordance with an embodiment of the present invention a communication card with three operational states, including a controller, a battery, a flash storage unit, a wireless modem, and a connector for connecting the communication card to a shell host and to an electronic device host, wherein the communication card (i) operates in a standalone mode when the connector is not connected to a device, (ii) functions as a master when the connector is connected to the shell host, and (iii) functions as a slave when the connector is connected to the electronic device host.
There is additionally provided in accordance with an embodiment of the present invention a method for determining the operational state of a communication card, including providing a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III), monitoring a first signal on the communication card, and if the first signal has a voltage level lower than a first designated threshold, then concluding that the communication card is in State I, otherwise, concluding that the communication card is connected to a device, and monitoring a second signal on the communication card, and if the second signal has a voltage level lower than a second designated threshold, then concluding that the communication card is in State II, otherwise, concluding that the communication card is in State III.
There is moreover provided in accordance with an embodiment of the present invention a computer readable storage medium storing program code for causing a computing device to determine the state of a communication card that has three operational states, namely, (i) the communication card in a standalone mode (State I), (ii) the communication card connected to a shell (State II), and (iii) the communication card connected to a host (State III), by monitoring a first signal on the communication card, and if the first signal has a voltage level lower than a designated threshold, then concluding that the communication card is in State I, otherwise, concluding that the communication card is connected to a device, and monitoring a second signal on the communication card, and if the second signal has a voltage level lower than the designated threshold, then concluding that the communication card is in State II, otherwise, concluding that the communication card is in State III.
There is further provided in accordance with an embodiment of the present invention a communication card with three operational states, including a card connector for connecting a communication card to a shell and to an electronic device, including a connector for incoming and outgoing audio signals, a connector for a power supply, a universal serial bus (USB) connector, and a communication bus, wherein (i) no signals are routed to the communication bus when the card operates in a standalone mode (State I), (ii) secure digital (SD) card signals are routed to the communication bus when the card is connected to a shell (State II), with the card functioning as master, and (iii) SD card signals are routed to the communication bus when the card is connected to an electronic device (State III), with the card functioning as a slave, and circuitry for automatically detecting whether the card is operating in State I, State II or State III.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which:
FIG. 1 is a simplified block diagram of a communication card with three operational states, in accordance with a first embodiment of the present invention; and
FIG. 2 is a simplified flowchart of a method for a communication card to detect the type of device it is connected to, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The present invention relates to a communication card that is operable in three states; namely, (I) a standalone state, (II) a state connected to a simple host, and (III) a state connected to a complex host. In State II the simple host is a shell. The communication card operates as a master and the shell operates as a slave. Conversely, in State III the complex host is a consumer electronics (CE) device. The communication card operates as a slave and the CE device operates as a master.
In State I as a standalone, the card has its own user interface and provides communication data and voice over radio technology, in addition to other services including inter alia MP3 playing.
In State II connected to a simple host, the shell is not an independent device and cannot operate without the communication card being connected thereto. The shell may include only a display, a keyboard and a simple non-volatile EEPROM storage chip. Optionally, the shell may further include speakers, a microphone and a secondary power source. The communication card supplies power to the shell's keyboard, display speakers and microphone, and to the card's own internal circuitry. The communication card uses the shell's secondary power source to charge the card's internal power source.
In State III connected to a complex host, the CE device is an independent device that operates independently of the communication card, such as an MP3/MPP player or a digital camera. Commands and information are shared, and sent over an SD control bus during operation. The CE device includes its own CPU, user interface and power source. The user interface for both the device functionality and the communication card functionality operates through the CE device. The interface to the CE device is via the communication card connector, where pins on the connector have specifically assigned functionalities and use specific protocols.
It will thus be appreciated by those skilled in the art that the interface to the shell is via the same communication card connector as is the interface to the CE device, but the pins on the connector generally have different functionalities and use different protocols with the shell than those used with the CE device.
The three operational states of the communication card are summarized in TABLE I hereinbelow.
TABLE I
Three Operation States of a Communication Card
State I
Standalone
Card uses its own interface
State II
Connected to a
Card is master; Shell is slave
simple host
Shell cannot operate without card
Card provides shell with screen shots, in the
form of bitmap images, for display information
Communication is through SD bus
State III
Connected to a
Card is slave; CE device is master
complex host
CE device operates independently of card
Card provides CE device with screen shots, in
the form of bitmap images, for display
information
Communication is through SD bus
Reference is now made to FIG. 1 , which is a simplified block diagram of a communication card with three operational states, in accordance with a first embodiment of the present invention. As shown in FIG. 1 , a communication card 100 includes a connector 105 , a controller 110 , a flash storage unit 115 , a battery subsystem 120 , a USB connector 125 and a modem & applications processor 130 . Modem 130 includes a radio frequency (RE) interface 135 and an audio player 140 . Modem 130 is coupled with an input device 145 , which is a small keyboard, and an output device 150 , which is a small display.
Also shown in FIG. 1 is a host device 160 with a host connector 165 that may be connected to the communication card connector 105 . In accordance with an embodiment of the present invention, device 160 may be a shell and may be a CE device.
It will be appreciated by those skilled in the art that communication card 100 supports the three operational states in TABLE I. Components 105 - 150 enable communication card 100 to function as a standalone device. When host 160 is connected to communication card 100 , communication card 100 may operate as a master or as a slave, and the SD communication between connectors 105 and 165 flows accordingly. Specifically, in State II communication card 100 is the master and host 160 is the slave, and in State III communication card 100 is the slave and host 160 is the master.
In accordance with an embodiment of the present invention communication card 100 automatically detects its operational environment by monitoring the voltage on designated pins on the connector. I.e., communication card 100 distinguishes between States I-III based on voltage. CE devices and shells generally drive the voltage on these pins differently, which enables communication card 100 to discriminate whether or not it is connected to device 160 , and to detect the type of device 160 it is connected to.
In this regard, reference is made to FIG. 2 , which is a simplified flowchart of a method for communication card 100 to detect the type of host 160 it is connected to, in accordance with an embodiment of the present invention. At step 210 controller 105 monitors the connector signal VBat_host, shown in FIG. 1 . If the VBat_host signal has a voltage level higher than logical zero (i.e., 0.5V or higher), as determined at step 220 , then controller 105 concludes that communication card 100 is connected to host 160 . Otherwise, if VBat_host is logical zero (i.e., below 0.5V), then at step 230 controller 105 concludes that communication card 100 is not connected to a host. As such, it will be appreciated by those skilled in the art that when host 160 is attached to communication card 100 , controller 105 detects this by monitoring VBat_host.
In order to detect which type of host 160 is connected to communication card 100 , controller 105 monitors the HOST_INT/TYPE signal, shown in FIG. 1 . When connection to a host is detected, the HOSTANT/TYPE signal is sampled at step 240 . If HOST_INT/TYPE is a logical zero (i.e., below 0.5V), as determined at step 250 , then at step 260 the controller concludes that host 160 is a simple shell. Otherwise, if HOST_INT/TYPE is higher than logical zero (i.e., 0.5V or higher), then at step 270 the controller concludes that host 160 is a CE device.
The functionality of HOST_INT/TYPE for detecting the type of host 160 , is used wheft at the time host 160 is attached to communication card 100 . Afterwards, the signal HOST_INT/TYPE is used as an interrupt signal.
In an alternative embodiment of the present invention, the SD_Vdd signal, shown in FIG. 1 , may be monitored at step 210 instead of or in addition to the VBat_host signal. Whereas the VBat_host signal generally indicates whether or not communication card 100 is connected to host 160 , the SD_Vdd signal generally indicates whether or not host 160 is turned on.
It will be appreciated by those skilled in the art that the threshold of 0.5V used in the above discussion is merely indicative of a general pre-designated threshold that is used to detect attachment of the host to the communication card, and to detect the type of the host.
When communication card controller 105 detects connection to a CE device or a shell, the internal user interface of communication card 100 is disabled at step 280 . For CE devices, communication card controller 105 receives user interface inputs, and provides feedback as bitmap graphics BMP screen shots, or as single messages, via the secure digital (SD) card bus. The CE device controls the device's display and keyboard. For shell devices, the communication card controller receives direct keyboard strokes on the shell keyboard over an SD bus, and provides the displayed image pixels/characters directly to the shell display over the SD bus.
In an embodiment of the present invention, in order to be powered, shells connect their internal circuitry to the Vbat_CC signal that connects to connector 105 . If a shell 160 has a secondary battery, then the secondary battery is connected to Vbat_Host, which connects to communication card's battery subsystem 120 and is used to charge the communication card's internal battery.
Similarly, the internal circuitry of a CE device 160 is powered by connecting its internal power source to Vbat_Host. CE device 160 does not use the Vbat_CC signal as a power source, but may monitor it to detect when communication card 100 is connected thereto, or to monitor the communication card's battery level.
In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will, however, be evident that various modifications and changes may be made to the specific exemplary embodiments without departing from the broader spirit and scope of the invention as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | A communication card with three operational states, including a controller, a battery, a flash storage unit, a wireless modem, and a connector for connecting the communication card to a shell host and to an electronic device host, wherein the communication card (i) operates in a standalone mode when the connector is not connected to a device, (ii) functions as a master when the connector is connected to the shell host, and (iii) functions as a slave when the connector is connected to the electronic device host. A method and a computer-readable storage medium are also described and claimed. |
TECHNICAL FIELD
The present invention relates to a method of designing devices, and in particular to a method of designing devices that allows the material thereof to be recycled in a favorable fashion.
BACKGROUND OF THE INVENTION
Japanese patent laid open (kokai) publication No. 11-348855 discloses a method of recycling discarded automobiles by transporting each automobile with a loop-type carrier suspended from a hanger, removing components from the automobile while the automobile is transported among different work stations at low speed, sorting the components into those that can be recycled and those that cannot be recycled, storing them in corresponding bins, and pressing and shredding those that cannot be recycled.
However, considerations for recycling are mostly absent in the presently adopted vehicle structures. For instance, components are often made by inseparably combining different materials such as metallic material and plastic material. Therefore, when disposing an automobile, the weight of the waste material that cannot be recycled and is required to be disposed of by landfill or the like typically amounts to about 25% of that of the automobile itself.
The method proposed in the aforementioned Japanese patent publication is no more than an introduction of a flow process into the work of disassembling discarded automobiles in place of pure manual work, and failed to meet the social need to more efficiently utilize resources and reduce waste material.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art, a primary object of the present invention is to provide a method of designing devices that allows larger parts of the components to be recycled as useful resources.
To achieve such an object, the present invention provides a method of designing a device, comprising the steps of: determining a disposing process for each component of the device, the disposing process being selectable from a melting process, a shredding process and a renovating process; and designing a connecting part for joining two of the components of the device that would be determined to be disposed by different disposing processes in the determining step so as to allow them to be easily separated from each other. Thereby, the amount of work for dismantling the device and separating and sorting the components can be substantially reduced, and the component parts can be disposed simultaneously in most part.
It is desirable if the method further comprises the step of forming a module with a plurality of components so as to allow the components to be removed from the vehicle body simultaneously as a single module. Thereby, the small components are not required to be removed from narrow spaces in the engine room or the like, and the work efficiency of dismantling the device is improved.
It is preferable if the method comprises the step of selecting the material for individual components such that a component or components that are to be disposed jointly consist of a single material. For instance, because an automotive floor mat conventionally consisted of a polyester surface skin and a PVC back lining which cannot be easily separated from each other, the floor mat was required to be disposed as wholly waste material. However, if these two parts are made of a same material, it becomes easier to recycle the floor mat as a useful resource.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the present invention is described in the following with respect to an application to the disposal of automobiles that cover a wide range of industrial technologies, including mechanical, electric and electronic technologies, with reference to the appended drawings, in which:
FIG. 1 is a block diagram showing the step of determining the disposal process;
FIG. 2 is a perspective view of an engine module;
FIG. 3 is a sectional side view showing the relationship between the engine module and vehicle body;
FIG. 4 is a side view showing the relationship between the door module and door as seen from inside the passenger compartment;
FIG. 5 is a perspective view, partly seen through, showing the relationship between the instrument panel and vehicle body;
FIG. 6 is a layout view of the lock device arrangement for the instrument panel;
FIG. 7 is a view showing the structure of the lock device for the instrument panel;
FIG. 8 is a perspective view, partly seen through, showing the instrument panel and related parts;
FIG. 9 is a side view of the lock device for the instrument panel and related parts;
FIG. 10 is a fragmentary side view of the lock device for the instrument panel and related parts;
FIG. 11 is a side view of the lock device for the control panel and related parts;
FIG. 12 is a fragmentary plan view of the lock device for the control panel and related parts;
FIG. 13 is an overall perspective view of the floor mat;
FIG. 14 is a fragmentary sectional view taken along line XIV—XIV of FIG. 13 ;
FIG. 15 is a fragmentary sectional view taken along line XV—XV;
FIG. 16 is a fragmentary sectional view taken along line XVI—XVI;
FIG. 17 is a fragmentary sectional view of part XVII;
FIG. 18 is a fragmentary sectional view of part XVIII;
FIG. 19 is a fragmentary perspective view of the floor mat;
FIG. 20 is a block diagram for the engine module;
FIG. 21 is a block diagram for the door module; and
FIG. 22 is a block diagram for the instrument panel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the first step of the design method according to the present invention, it is determined how each component part of the device consisting of an automobile in this case should be processed. The components essentially made of metallic material are assigned to a melting process 1 and heated and melted so as to be separated into aluminum, iron and residues. The components essentially made of plastic material and thin pieces of metal are assigned to a shredding process 2 and shredded into chips so as to be separated into metallic parts and non-metallic parts. The components that are provided with individual functions and can be repaired are assigned to a renovation process 3 and overhauled or otherwise renovated by parts manufacturers. (the processing method determining step.)
Components such as engines 4 , transmissions 5 , wheel suspension systems 6 and vehicle bodies 7 that are made of metallic material and destined for the melting process 1 are brought together as a group. Components such as instrument panels 8 , seats 9 , linings 10 , floor mats 11 and bumpers 12 are brought together as another group. Electric equipment 13 , audio units 14 and meters 15 that are destined for the renovation process 3 are brought together as yet another group. See FIG. 1 .
In the second step, the connecting parts that connect various parts to the vehicle body or to each other are constructed so as to be easily broken apart. (the easily separable structure designing step).
For instance, the instrument panel 8 may be adapted to retain the audio unit 14 , the control unit for the air conditioner and various meters 15 each provided with a lock device using a suitable snap fit arrangement that can be readily released. The instrument panel 8 may be adapted to be readily detached from the vehicle body 7 by using a lock mechanism that uses an eccentric cam.
The floor mat 11 may be provided with a readily breakable part extending through the parts joining the seat 9 to the vehicle body 7 so that the floor mat 11 may be removed from the vehicle body 7 by tearing apart the readily breakable parts without requiring the seats to be removed.
The electric components are adapted for flat harnesses and quick couplers so that the cables may be detached without any difficulty.
In the third step, various components are given with a modular structure using a common member for supporting a plurality of components so that the various components may be removed from the vehicle body as a single group and, thereafter, separated into individual components outside the vehicle body. (the modular structure design step.)
For instance, the engine and related units may be formed as an engine module 21 as illustrated in FIGS. 2 and 3 . More specifically, the engine 4 and related units such as the transmission 5 , wheel suspension systems 6 and radiator 23 are attached to the vehicle body 7 via a front sub frame 22 forming a part of the vehicle body 7 and attached to the vehicle body 7 by using fastening means suited for repeated use, such as threaded bolts/nuts 24 , so that the engine 4 and related units may be removed from the vehicle body 7 simply by separating the front sub frame 22 from the vehicle body 7 .
The doors may also be formed as door modules as illustrated in FIG. 4 . More specifically, the side glass pane 33 and the wind regulator motor 38 are attached to a module frame 32 made of aluminum alloy or the like so that the components that cannot be processed together with the vehicle body 7 can be removed from the door 39 simply by removing the door lining 10 and detaching the module frame 32 from the door 39 .
Additionally, as opposed to the conventional practice to construct each component by combining a plurality of different materials without any special considerations, each component is made of a single material as much as possible. (the material selecting step).
For instance, because the conventional floor mat consisted of a back lining made of coarse cotton felt and a surface skin layer made of PET non-woven fabric, it could not be simply removed from the vehicle and turned into pellets. According to the present invention, the back lining and surface skin layer are both made of olefin based material (mono-material) so that the removed floor mat can be readily converted into pellets.
Also, a plurality of components that are made of a same material and/or that are to be processed together are integrally formed with each other. For instance, the cooling water sub tank and window washer fluid tank may be integrally molded with the radiator fan shroud, and the casing for the electronic control unit may be integrally formed with the air cleaner case.
The present invention is now described with respect to specific embodiments with reference to the appended drawings.
Referring to FIGS. 2 and 3 , the engine module 21 includes a front sub frame 22 forming a part of the vehicle body 7 and supporting the engine main body 4 , transmission 5 , wheel suspension system 6 and radiator 23 . The front sub frame 22 is fixedly attached to the vehicle body 7 by using threaded bolts/nuts 24 so that the engine main body 4 and related units can be removed from the vehicle body 7 all at the same time simply by detaching the front sub frame 22 from the vehicle body 7 . As a result, the dismantling of the engine and related units can be conducted outside the engine room, and this facilitates the removable of electric units 13 such as the alternator, starter motor and wire harnesses and non-metallic components such as an air cleaner 25 , washer fluid tank 26 and rubber hoses 27 from the engine main body 4 .
Referring to FIG. 4 , the door module 31 comprises a module frame 32 consisting of a first frame member 32 a and a second frame member 32 b which extend substantially linearly in the fore-and-aft direction parallel to each other as seen from the side, and a substantially U-shaped third frame member 32 c which are integrally joined to each other by welding. These frame members are, for instance, made of continuously extruded aluminum alloy. The first and second frame members 32 a and 32 b are formed by cutting a continuously extruded member into prescribed lengths and the third frame member 32 c is formed by bending a linear extruded member.
The module frame 32 is provided with guide members 34 a and 34 b for guiding the front and rear edges of the side glass pane 33 , a support member 35 supporting the lower edge of the side glass pane 33 , lock means 37 for locking the door with respect to the vehicle body 7 and a window regulator motor 38 .
The door 39 forming a part of the vehicle body 7 and having the module frame 32 fixedly attached thereto comprises a door inner panel 39 a and a door outer panel 39 b which are joined to each other by welding. A window frame 39 c for supporting the side glass pane 33 in its fully closed state is fixedly attached to an upper part of the door 39 . The door 39 is provided with a receiving portion 40 between the inner and outer panels 39 a and 39 b for receiving the side glass pane 33 therein, and the inner panel 39 a is provided with an opening 41 for introducing the side glass pane 33 attached to the door module 31 into the receiving portion 40 .
The door module 31 and door 39 are attached to each other by registering mounting holes 42 formed in the door module 31 and mounting holes 43 formed in the door inner panel 39 a to each other and passing plastic clip fasteners (not shown in the drawing) through these mounting holes 42 and 43 .
Thus, the door 39 and door module 31 can be readily separated from each other simply by removing the lining 10 (not shown in the drawing) and unfastening the clip fasteners. Once the door module 31 is separated from the door 39 , the various components and accessory units such as the side glass pane 33 and window regulator motor 38 can be removed from the door 39 all at the same time, individually and without requiring the worker to take any uncomfortable posture.
Referring to FIG. 5 , the instrument panel 8 is placed on the vehicle body 7 above the dashboard 51 . Opposite to the upper surface of the dashboard 51 is provided a front beam 52 that extends between the inner surfaces of front side panel inners (not shown in the drawing). To the front beam 52 are fixedly secured an instrument panel support bracket 53 , a control panel support bracket 54 , an air conditioner duct 55 and an air bag system 56 for the passenger seat. The front side panel inners connected to either lateral ends of the front beam 52 are provided with connecting brackets 57 which are in turn provided with lock mechanisms 58 for fixedly securing the instrument panel 8 . The control panel support bracket 54 fixedly attached to a middle part of the front beam 52 is provided with an operation handle 59 for actuating the lock mechanisms 58 . The operation handle 59 is connected to each lock mechanism 58 via a Bowden cable 60 serving as a member for transmitting force.
A plurality of locator pins 61 are provided in suitable parts of the upper part of the dashboard 51 and members attached to the front beam 52 for positioning the instrument panel 8 .
After the instrument panel 8 is removed, those members that are integral with the vehicle body 7 are subjected to the melting process together with the vehicle body
The instrument panel 8 is entirely made of an integrally molded single-piece member, and is provided with a mounting opening 62 for a meter panel on the right hand side thereof and another mounting opening 63 for an audio unit 14 and a control panel for the air conditioner in the middle part thereof. The back side of the instrument panel 8 that opposes the dashboard 51 is provided with bosses 65 each formed with a hole for receiving the corresponding locator pin 61 .
Referring to FIGS. 6 and 7 , each lock mechanism 58 consists of a holder 66 fixedly attached to the corresponding end of the front beam 52 and a latch 67 received in the holder 66 so as to be slidable laterally with respect to the vehicle body. The operating handle 59 is incorporated with a rotation/linear motion converting mechanism 68 using an eccentric cam or the like. By turning the operating handle 59 , the Bowden cable 60 extending from each side of the rotation/linear motion converting mechanism 68 is actuated in both pushing and pulling directions according to the rotational direction of the operation handle 59 , and the transmitted force causes the front end of the latch 67 to project out of and retract into the holder 66 .
When installing the instrument panel 8 constructed as described above onto the dashboard 51 (vehicle body 7 ), with the operation handle 59 turned to the locking position, the dashboard 51 is pushed against the instrument panel 8 . This causes the locating pins 61 provided on the dashboard 51 to fit into the holes of the bosses 65 provided on the back side of the instrument panel 8 , and the instrument panel 8 is properly positioned with respect to the dashboard 51 .
As the instrument panel 8 is pushed even further, edges of receiving portions 69 provided on the back side of the instrument panel 8 push the tapered front ends of the latches 67 , thereby causing the latches 67 to retract. Once the front ends of the latches 67 are received in the receiving portions 69 , the latches 67 are prevented from retracting and the locked state is maintained unless the operating handle 59 is turned in the unlocking direction and the Bowden cables 60 are pulled.
Once the instrument panel 8 is fixedly attached to the dashboard 51 , the central mounting opening 63 for gaining access to the operating handle 59 is closed by the audio unit 14 or the like in its installed state. Therefore, the unlocking operation is not possible under normal condition.
Referring to FIG. 8 , when the instrument panel 8 is fixedly attached to the dashboard 51 , the control panel support bracket 54 and meter panel support bracket 53 are located inside the mounting hole 62 formed on the right hand side of the instrument panel 8 and the mounting hole 63 formed in the middle part of the instrument panel 8 , respectively.
The meter panel support bracket 53 comprises a front wall 53 a on the front side with respect to the vehicle body and a pair of side walls 53 b . The middle part of the front wall 53 a is provided with a striker opening 71 for engaging a latch mechanism which is described hereinafter and a connector 72 for connecting signal lines, one above the other. To the inner side of each side wall 53 b is fixedly attached a guide member 74 provided with a groove 73 extending in the fore-and-aft direction.
The meter panel 75 comprises a liquid crystal display 75 a , a cover 75 b and a frame 76 . To either side of the frame 76 are fixedly attached a pair of key members 77 extending in the fore-and-aft direction so as to correspond to the grooves 73 of the guide members 74 provided in the support bracket 53 . The upper surface of the frame 76 is provided with a latch mechanism 78 which is adapted to engage the striker opening 71 provided in the support bracket 53 .
Referring to FIGS. 9 and 10 , the latch mechanism 78 of the meter panel is provided with a lever member 79 having an intermediate part thereof pivotally supported by a laterally extending shaft so as to be tiltable like a see-saw. The front end of the lever member 79 is provided with a claw 80 adapted to fit into and engaged by the striker opening 71 , and the rear end of the lever member 79 is provided with an operation knob 81 . The lever member 79 is normally urged by a torsion coil spring or the like in the direction to raise the end of the operation knob 81 or in the direction to engage the claw 80 with the striker opening 71 .
The control panel support bracket 54 comprises a front wall 54 a on the front side with respect to the vehicle body and a pair of side walls 54 b . The middle part of the front wall 54 a is provided with a connector 82 for connecting signal lines. To the inner side of each side wall 54 b is fixedly attached a guide member 84 provided with a groove 83 extending in the fore-and-aft direction and a striker member 86 having a striker opening 85 formed therein, one above the other.
The control panel 87 comprises a liquid crystal display 87 a , a cover 87 b and a frame 88 . To either side of the frame 88 are fixedly attached a pair of key members 89 extending in the fore-and-aft direction so as to correspond to the groove 83 of the guide member 84 provided in the support bracket 54 . The upper part of the frame 88 is provided with a latch mechanism 90 on each side thereof which is adapted to engage a striker opening 85 of a striker member 86 provided in the corresponding side of the support bracket 53 .
Referring to FIGS. 11 and 12 , the latch mechanism 90 of the control panel 87 is provided with a lever member 91 having an intermediate part thereof pivotally supported by a laterally extending shaft so as to be tiltable. The front end of the lever member 91 is provided with a claw 92 adapted to be engaged by the striker opening 85 , and the rear end of the lever member 91 is provided with an operation knob 93 . The lever member 93 is normally urged by a torsion coil spring or the like in the direction to urge the end of the operation knob 93 outward or in the direction to engage the claw 92 with the striker opening 85 .
The meter panel 75 and control panel 87 are attached to the corresponding support brackets 53 and 54 both from outside the instrument panel 8 . When mounting each of these panels on the corresponding support bracket 53 or 54 , the front end of the key member 77 or 89 is aligned with the rear end of the groove 73 or 83 of the corresponding guide member 74 or 84 , and is then pushed forward until the claw 80 or 92 of the lever member 79 or 91 fits into the corresponding striker opening 71 or 85 . Because the lever member 79 or 91 is biased by the spring, the claw 80 or 92 is engaged by the peripheral edge of the striker opening 71 or 85 so that the meter panel 75 or the control panel 87 , as the case may be, is fixedly attached to the corresponding support bracket 53 or 54 . At the same time, the plug (not shown in the drawing) provided on the backside of each of the meter panel 75 and control panel 87 fits into the corresponding connector 72 or 82 so that the required electric connection is established.
When removing the meter panel 75 or the control panel 87 from the corresponding bracket 63 or 54 , the operation knob 81 or 93 of the corresponding lever member 79 or 91 urged in the locking direction is pushed downward in the case of the meter panel 75 or inward in the case of the control panel 87 so that the claw 80 or 92 is disengaged from the corresponding striker opening 71 or 85 and the meter panel 75 or the control panel 87 , as the case may be, is allowed to be pulled rearward in this state.
An embodiment related to the floor mat 11 is described in the following with reference to FIGS. 13 to 19 . The floor mat 11 is contoured so as to conform to the irregular shape of the vehicle body floor not shown in the drawing, and is provided with fastener receiving holes 101 for securing the floor mat 11 to the vehicle body floor with plastic fasteners and threaded bolt receiving holes 102 for passing threaded bolts for securing the seats 9 (only one of the front seats is shown in the drawing) to the floor.
Referring to FIG. 14 , stud bolts 103 are fixedly attached to the vehicle body floor 7 f . The front part of the floor mat 11 is positioned with respect to the vehicle body floor 7 f by passing these stud bolts 103 through the fastener receiving holes 101 in the front part of the floor mart 11 . A plastic flanged cap 104 or the like is fitted onto each of the stud bolts 103 . The front part of the floor mat 11 is therefore interposed between the flanges 104 a of the flanged caps 104 and the vehicle body floor 7 f and the screw thread of each stud bolt 103 engages the inner circumferential surface of the corresponding flanged cap 104 so that the front part of the floor mat 11 is fixedly secured to the vehicle body floor 7 f.
Referring to FIG. 15 , the rear part of the floor mat 11 is fixedly attached to the vehicle body floor 7 f by passing a leg portion 105 b of a plastic clip 105 having an enlarged head 105 a through each of the fastener receiving holes 101 and resiliently forcing it into a corresponding through hole 106 provided in the vehicle body floor 7 f.
Referring to FIG. 16 , each side fringe of the floor mat 11 is contoured so as to conform to the cross sectional shape of the passenger compartment side of the corresponding side sill 107 , and is retained thereat by engaging hooks 108 tacked to the upper end of an upright portion of the floor mat 11 with mating flanges 107 a extending upright from the upper end of the side sill 107 . The part of the floor mat 11 thus engaged to the side sill 107 is covered by a plastic garnish 109 .
Referring to FIGS. 17 and 18 , front and rear parts of each of the seats 9 (front seats) are attached to the vehicle body floor 7 f via seat rails 110 . Each seat rail 110 is fixedly attached to the bottom surface of the corresponding seat 9 in such a manner that a front bracket 111 provided in the front end thereof is fixedly attached to a cross member 112 integrally formed with the vehicle body floor 7 f with threaded bolts 113 , and a rear bracket 114 formed in the rear end thereof is fixedly attached to the vehicle body floor 7 f with threaded bolts 113 .
The mounting positions of the threaded bolts 113 for attaching the brackets to the cross member 112 of the vehicle body 7 f are arranged along a straight line extending laterally across the vehicle body. The threaded bolt receiving holes 102 formed in the floor mat 11 are located so as to correspond to the threaded bolts 113 for attaching the brackets. Thus, these threaded bolt receiving holes 102 are also arranged along the same straight line L extending laterally across the vehicle body.
Referring to FIG. 19 , a plurality of slots 114 each having a prescribed length are arranged along the straight line L on which the threaded bolt receiving holes 102 of the floor mat 111 are formed. The threaded bolt receiving holes 102 and adjoining slots 114 are arranged in such a manner as to define a broken line along the straight line L. Therefore, the floor mat 11 can be easily torn apart along the straight line L. Also, the threaded bolt receiving holes 102 may be provided with a notch 115 so that stress concentration may occur in this part, and the dismantling work may be even further facilitated.
According to the illustrated embodiment, because three parting lines L are defined by the threaded bolt receiving holes 102 and slots 114 , when dismantling the vehicle body, after removing the fasteners attaching the floor mat 11 to the vehicle body floor 7 f , with the seats 9 still left mounted, the floor mat 11 can be separated into four parts by tearing the floor mat 11 along the parting lines L. Therefore, without requiring the seats 9 to be removed, the floor mart 11 can be easily torn away from the vehicle body floor 7 f.
The process of dismantling an automobile given as an example of the device designed and manufactured according to the present invention is described in the following with reference to FIGS. 20 to 22 .
Liquids such as fuel, lubricant, air conditioner refrigerant and coolant are recovered from the vehicle, and the engine module 21 , door modules 31 , instrument panel 8 and seats 9 are removed from the vehicle body 7 by releasing fasteners or the like.
The engine module 21 is charged into a melting furnace 121 after non-metallic components such as the electric components 13 , air cleaner 25 and hoses 27 are removed therefrom. The door modules 31 are also charged into the melting furnace 121 after the side glass panes 33 and window regulator motors 38 are removed. The meter panel 75 and control panel 87 are removed from the instrument panel 8 , and the instrument panel 8 is then removed from the dashboard 51 . The removed instrument panel 8 is charged into a shredder 128 .
After all the component parts and accessories are removed, the vehicle body 7 is pressed, and is charged into the melting furnace 121 , along with the metallic components of the engine module 21 and door modules 31 , so as to be eventually separated into aluminum 122 , iron 123 and residue 124 . The aluminum 122 is refined further, and used as the material 125 for casting engine blocks. The iron 124 is recycled by steel makers as the material for concrete reinforcing steel and shape steel. The residues containing inorganic substances are recycled by mixing them with bricks and pavement material 127 .
The components such as the dashboard 51 that are essentially made of plastic material and may include thin pieces of metal are, along with glass, charged into the shredder 128 and shredded into small pieces. The obtained small pieces are separated into different materials by using known means such as centrifugal force, wind force or magnetic force, and delivered to corresponding material supplies.
The engine module 21 , door modules 31 and electric components including the meters 15 , audio unit 14 and window regulator motors 38 are processed by electric component makers 129 . Those that can be overhauled are utilized as spare parts, and the remaining units are processed for recycling the material. Even when the electric appliances and other forms of onboard electric equipment are composed of materials of different kinds, if they are designed and manufactured according to the present invention, the processing by the electric component makers 129 can be simplified.
INDUSTRIAL APPLICABILITY
By selecting the various materials that make up each particular device according to the anticipated processes for disposing them, mounting a plurality of components onto a common base as an independent module, and adapting the various components destined for different disposing processes to be readily separated from each other, the materials which conventionally involved serious difficulties in separating and recycling are allowed to be recycled, and metals can be recycled as high quality materials. In particular, by using a common material for associated parts as much as possible, and integrating various members made of a common material or materials that are suited to be disposed by a same process into an independent module, a simultaneous disposal of such components becomes possible. Therefore, what was previously considered as waste material which is fit only for landfill can now be used as a useful resource. Therefore, the amount of waste can be minimized, and the present invention provides a high level of industrial utility. | Provided is a method of designing a device, comprising the steps of determining a disposing process for each component of the device, the disposing process being selectable from a melting process, a shredding process and a renovating process, and designing a connecting part for joining two of the components of the device that would be determined to be disposed by different disposing processes in the determining step so as to be easily separated from each other. Thereby, the amount of work for dismantling the device and separating the components can be substantially reduced, and the component parts can be disposed simultaneously in most part. |
BACKGROUND OF THE INVENTION
The present invention generally relates to a method and apparatus for controlling or reducing the growth of zebra mussels.
The zebra mussel, Dreissena Polymorpha, is believed to have been introduced into the Great Lakes of North America in the mid 1980's. The zebra mussel is native to Europe and is thought to have been transported to the Great Lakes watershed in the fresh water ballast of a trans-oceanic ship.
Most transplanted species are rather benign and have little apparent effect on the ecology of the new host system. Some are even beneficial. However, in this case, the introduced zebra mussel, has had negative impacts on the environment and constructions of man. The zebra mussel can clog water intakes and distribution pipelines for industrial and water supply facilities while also increasing the corrosion potential of the pipelines. Further, the mussel may encrust hulls of ships and populate the interiors of watercraft engines.
Particular structures that have problems with zebra mussels infestations are water intake structures, such as drinking water, industrial and power generating plants. These facilities usually have submerged pipelines that bring water to the plant from a water source such as a lake or stream. Water intakes of small diameter, 60 to 180 centimeters, and great length (over several hundred meters) are particularly vulnerable to mussel infestation. Most water intakes are disposed within a crib designed to prevent large debris from being suctioned into the intake.
Normally, water flows through the crib and intake, to a shore side pumping station. Adult zebra mussels easily clog and close the gaps in the crib and decrease the volume of water drawn to the pumping station. Depending upon the depth of the crib, a secondary problem may be increased likelihood of icing about the crib due to the zebra mussel infestation since the relative water intake velocity is drastically increased (i.e. the frazil effect).
In the water intake itself, zebra mussels reduce the amount of water the pipe can carry while increasing the friction and turbulence of the flow by increasing the roughness of the pipe surface. With larger zebra mussel infestations, additional problems occur such as the fowling of filters and pumps as clusters of mussels break off from the pipe and travel downstream. Rotting flesh of dead zebra mussels present in the water intake may increase odor, taste and bacteria levels in the water.
Other structures commonly infested by zebra mussels are industrial and power generation cooling systems. A problem with heating and cooling systems, that magnifies the harm of zebra mussels, is of scale that normally forms on heat exchange surfaces. This scale creates an opportunity for the zebra mussels to settle and attach, particularly into the cracks and crevices in the scale. At times, the mussels cause quantities of scale to separate from the heat exchange surfaces, causing fouling and other problems downstream in the system.
Current methods of treating zebra mussel infestations include mechanical, chemical or non-chemical methods. Mechanical cleaning is the most conventional treatment for reducing zebra mussel numbers. Typical mechanical cleaning agents include filters to strain the mussels from the water or mechanical "pigs" or scrubbers to scrape mussels and other debris from the interior of the pipelines. Mechanical filtering of water is effective but at certain times in the zebra mussel life span, the mussels are able to pass through the filter and survive behind the filter. Mechanical filtration or scraping cause problems in that when the filters become clogged, additional service is needed to clean the filters while the industrial plants or water feed systems may need to be taken off line for such maintenance.
Another current treatment is that of chemical killing agents such as chlorine, ozone, and other oxidizing chemicals added to the infested waters. Chlorine has been used for years in Europe to control zebra mussel infestations. A major advantage offered by chemical treatments is that they can be engineered to protect the entire water system from the water intake to the end of the system. Other types of treatment include the use of a hot water bath (i.e. thermal treatment), electric shock, and ultraviolet light.
A number of problems have persisted with the previous chemical treatment methods. The most common chemicals, chlorine and ozone, have a disadvantage in that they are toxic materials to most lifeforms. Various government agencies are looking at new discharge limits to reduce or eliminate the release of these chemicals into the water supply and environment. Further, these toxic chemicals may kill off beneficial animals. Additionally, treatment costs are not constant because various uncontrollable environmental factors affect the toxicity of the chemicals, particularly water temperature, pH, dilution and organic or inorganic compounds present in the source of water, such as the reducing agents, S 2- FE 2+ , MN 2+ and NO 2- . Thermal treatment, while effective, may be prohibited by new government regulations on thermal water release, while some facilities have no capacity to generate or backflush with the large quantities of hot water needed to kill zebra mussels.
The present invention is directed to overcoming the aforementioned problems associated with prior methods of zebra mussel growth control.
SUMMARY OF THE INVENTION
The present invention overcomes the problems and disadvantages of the prior art by providing an apparatus and method for controlling the growth of zebra mussels by treating their habitat with water that has been passed through a magnetic field. In accordance with the apparatus and method of the present invention, zebra mussel growth may be controlled or reduced in structures such as water intake pipes, industrial and domestic water handling facilities such as power plants, utilities and municipal drinking water stations.
Generally, the invention provides a method and apparatus to reduce the growth of zebra mussels by providing a first volume of water containing zebra mussels and treating a portion of the volume of water by passing it through a magnetic field. The magnetically treated portion is then mixed back into the first volume of water where growth of the zebra mussels is reduced. The greater the flux or density the magnetic field the water is passed through, along with a greater ratio of treated water to untreated water, the greater the effectiveness of treatment.
Types of treatments to which water having zebra mussel infestations may be categorized are batch treatments or injection treatments. Batch treatment (or sometimes called a feedback treatment) takes a portion of the water out of the zebra mussel environment, treats it magnetically through the magnetic water treatment unit, and replaces it back into the host environment. Examples of this type of treatment may be a water tank to which a pump and magnetic water unit are connected in series. Other types of batch treatments may be utilized as in a water jacket of an engine, a boat bilge area or numerous other industrial and domestic systems.
An injection treatment occurs in the system when a separate source of water is treated and injected into the zebra mussel host environment. Examples of this may include industrial water intakes from a raw water source such as a lake or stream, utility cooling towers or the outside of a boat hull. Injection treatment may be utilized to treat both the inside of a water intake pipe and alternatively treat the volume of water around the pipe opening.
An advantage of the magnetic water treatment of the present invention is that it reduces growth of zebra mussels without adding chemicals to the water. The effectiveness of the magnetically treated water is time dependent, the effectiveness decreasing with time. No pollution or permanent change to the water supply is created since the water reverts to its original state and condition after an amount of time.
A further advantage of the magnetic water treatment of the present invention is that the effect on zebra mussels is noticeable almost instantly. Although not entirely understood, the magnetic water treatment appears to interfere with the zebra mussels ability to extract needed nutrients from the water. During treatment, the zebra mussels "clam up" or close, while upon dissection, noticeable biological changes of the mussels are evident.
The invention, in one form thereof, provides a method for treating water to reduce the growth of zebra mussels. A volume of water containing zebra mussels is provided, with at least a portion of the water treated by passing it through a magnetic field. The treated portion is then mixed back into the original volume of water, whereby the growth of zebra mussels is reduced. The treatment may include passing the portion of water through a plurality of magnetic fields having alternating polarity.
In another form of the invention, an apparatus is provided for reducing the growth of zebra mussels in water within a containment zone. The apparatus includes a water conduit having an inlet and outlet in communication with the containment zone. A pump is connected to the water conduit for pumping water from the containment zone through the water conduit and back to the zone. A water treatment unit is disposed in the water conduit including a magnet for creating a magnetic field through which water in the water line is subjected, so magnetically treated water may enter the containment zone and reduce the growth of zebra mussels. The magnetic water treatment unit may comprise a plurality of permanent magnets having a sleeve means for shielding each permanent magnet from the others. This shielding sleeve collects the lines of magnetic force produced by the magnet to maximize the magnetic lines of force that perpendicularly intersect the direction of water flow through the water line.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an elevational view of one embodiment of the present invention;
FIG. 2 is an elevational view of another embodiment of the present invention;
FIG. 3 is a longitudinal section view of a magnetic treatment unit utilized in one form of the present invention;
FIG. 4 is a sectional view of one embodiment of the present invention utilized to treat water at a submerged water intake;
FIG. 5 is a diagrammatic view of another embodiment of the present invention utilized to treat water within a water cooled engine;
FIG. 6 is a diagrammatic view of another embodiment of the present invention utilized to treat water within a boat;
FIG. 7 is a partial sectional view of one form of the magnetic treatment unit of the present invention utilizing a plurality of magnetic units; and
FIG. 8 is a sectional view of the magnetic treatment unit of FIG. 7 taken along line 8--8 and viewed in the direction of the arrows.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the invention is shown in FIG. 1. There is shown a generic batch treatment unit 20 having a tank 22 filled with a volume of water 24 in which initially, zebra mussels are growing. Unit 20 includes a water line 26 having both an inlet 28 and an outlet 30. A water pump 32 is disposed in water line 26 for pumping water from water inlet 28 through pipe 26 and out water outlet 30. As shown in FIG. 1, a magnetic water treatment unit 40 is disposed within water line 26 for magnetically treating water flowing through water line 26. Downstream from water stream unit 40 is located a hydrocyclone 34 for removing entrained sludge or other insoluble particles within water line 26. For proper operation of the invention, a hydrocyclone is not required but may increase the effectiveness of the treatment. The particulars of the magnetic water treatment unit 40 will be discussed below.
FIG. 2 is another embodiment showing use of injection treatment, reducing the growth of zebra mussels in a volume of water. As shown in FIG. 2, a containment tank 42 includes a volume of zebra mussel infested water 44. In regards to the injection treatment, a second supply of water 46, as shown in tank 48, is connected by a water line 50 to tank 42. Water line 50 includes an inlet 52 communicating with tank 48 and an outlet 54 in communication with tank 42. Pump 56 is disposed within water line 50 to control the flow of water 46 into tank 42. A magnetic water treatment unit 40 is disposed downstream of pump 56 within water line 50 so that water 46 pumped from tank 48 will be magnetically treated and injected into zebra mussel infested water 44 within tank 42. Tank 42 further includes a drain valve 58 to remove dead zebra mussels and other settled debris within tank 42. Although the previous two embodiments show the magnetic treatment unit 40 downstream from pumps 32 and 56, alternatively, units 40 may be disposed upstream.
Both FIGS. 1 and 2 show tank style embodiments in which volumes of water have been infested with zebra mussels. The present method and apparatus operate without regard to the shape of the volume of water treated. Pipes, vessels, boilers, containment and even open water may be equivalently treated with the disclosed method and apparatus.
The key to the water treatment system of the present invention is that of creating a magnetic field through which water may pass. The magnetic water treatment unit 40 as shown in FIG. 3 is similar to the magnetic water treatment units shown in any one of the following U.S. Patents hereby incorporated by reference: U.S. Pat. Nos. 3,951,807, 4,050,426, 4,153,559, 4,299,700, 4,320,003, 4,357,237 and 4,430,785.
FIG. 3 discloses a single magnetic core unit 60 useful in low volume magnetic treatment of water. A single core unit includes an outer casing 62 made of non-magnetic material such as copper and fittings 64 and 66 made of non-magnetic materials such as brass. For purposes of the present description, "non-magnetic" means materials having a very low magnetic permeability and virtually no ferromagnetic characteristics, such as copper, brass, PVC, nylon and Delrin, for example. "Magnetic" materials are those exhibiting high magnetic permeability such as iron and steel.
Inner casing 68 is a threaded galvanized 1/2 inch steel pipe with an inner diameter of approximately 0.633 inches. Casing 68 is made of a ferromagnetic material having a high magnetic permeability such as preferably galvanized iron or steel, although other materials may be used. Inner casing 68 has an outside diameter less than the inside diameter of outer casing 62 and is uniformly spaced therefrom by threaded attachment to fittings 64 and 66.
Positioned within inner casing 68 is a tube 70 of non-magnetic material such as copper, which is open at both ends and has a pair of apertures 72, 74 and 76, 78 therein. Tube 70 within inner casing 68 forms an annular chamber 79. Apertures 72 and 74 are transversely aligned along an axis which is rotated 90° from the axis along which the apertures 76 and 78 are aligned. This causes the water which enters one end of unit 60 to make a 90° turn upon the longitudinal axis before it exits from the opposite end. Tube 70 has an outer diameter, in a preferred embodiment, of approximately 0.500 inches and inner diameter of 0.400 inches.
Magnetic 80 is disposed within tube 70 and is preferably approximately 0.375 inches in diameter, 6.0 inches in length and with a pole spacing of approximately 2.0 inches. The elongated permanent magnet 80, preferably having a composition of cobalt, nickel, aluminum, copper and iron, is magnetized along its longitudinal axis to have a plurality of longitudinally spaced apart poles of alternating polarity represented by the symbols "N" and "S". Magnet 80 is substantially homogeneous in composition and in the embodiment illustrated, comprises three magnetic domains extending transversely throughout the magnet, having their magnet moments oppositely aligned such that alternate north and south poles exist along the length of the magnet 80. A magnet such as this may be produced by imposing on a bar of magnetic material two longitudinally displaced static magnetic fields of opposite polarity. The number of poles for a particular magnet depends to a great extent on the size of the device and the gallon per hour capacity desired, so that in the case of a very small capacity device, a magnet having only 3 dipoles may be most efficient. Magnets with a different number of dipoles may also be used.
Magnet 80 may be provided with a pair of resilient plastic end caps which are compressed against tube 70 so as to frictionally retain magnet 80 in place as in known in the art. Alternatively, other ways of attaching magnet 80 in tube 70 may be used, such as epoxy or interference fitting.
The structure of magnetic core unit 60 is designed to concentrate the magnetic field produced by magnet 80 in the annular chamber 79 immediately adjacent thereto, and at the same time, insulate this field from the supporting structure to external ferromagnetic objects which may come in contact with the device. Due to the high permeability of tube 70, the flux produced by magnet 80 will extend radially outward therefrom, pass through tube 70 and return to magnet 80 without straying from chamber 79. Inner casing 68 located about magnet 80 assists in containing the magnetic field. By thus containing the magnetic field, maximum efficiency of subjecting the water flowing through the device to the magnetic field is achieved. Containment of the magnetic field is further enhanced through use of non-magnetic materials for outer casing 62, fitting 64 and 66 (as described in U.S. Pat. No. 4,299,700). Because single magnetic core unit 60 is a low capacity device, a magnetic water treatment unit 40 of the present device, as shown in FIG. 7, includes a plurality of such units 60 to increase the amount of treated water. As shown in FIG. 7, it is possible to arrange a plurality of single magnetic core units 60 together. Although the magnetic water treatment unit 40, shown in FIGS. 7 and 8, includes (12) magnetic core units 60, depending upon the demand for treated water, this number may vary. Unit 40 includes a 82 to hold core units 60 parallel to each other. A top flange 84 is bolted to housing 82 and connected to a source of water. A bottom flange 86 is connected to a water return line to the area of Zebra mussel infestation.
The embodiments in which the present invention may be utilized are quite diverse ranging from marine applications, to those for water tanks, water intakes, utility and industrial cooling towers, municipal water treatment plants and even open water systems. An embodiment as shown in FIG. 4 discloses a water intake 90, disposed in a lake or river bed 92, utilizing water 94 which may be infested with zebra mussels.
As shown in FIG. 4, water intake suctions water 94 through water line 91 to an onshore facility (not shown). Arrows 96 indicate the flow of water 94 into intake 90. For the proper growth control of zebra mussels, treated water is pumped back to water intake 90 via a treated water line 98. Treated water line 98 contains water treated with a magnetic water treatment unit 40 located in the onshore facility. A collar 100 is disposed about water intake 90 and connected to treated water line 98. Collar 100 includes a plurality of exit ports 102 through which the magnetically treated water flows back around water intake 90. Arrows 104 show the flow of treated water out of collar 100 through exit ports 102 and back around bed 92 and intake 90. This treatment of the water about water intake 90 will prevent zebra mussel infiltration and maintain a clear space about water intake 90 without growth of a zebra mussel colony. Alternatively and equivalently, magnetically treated water may be sprayed directly into the water intake 90 to thereby directly treat all areas downstream within water intake 90. Other variations of injecting the magnetically treated water in the intake may also be utilized.
Another embodiment of the invention is shown in FIG. 5 in which an engine, such as a marine engine 110, is protected from zebra mussel infestation by means of the present invention. Marine engine 110 includes a cold water intake 112 that utilizes untreated water containing zebra mussels as coolant. Box 114 is used to generically identify standard portions of a marine engine such as a piston-cylinder combination, crankshaft, and associated electronics without detail. These conventional portions of marine engine 110 are not part of the present invention. The important portion of engine 110 is that of water jacket 116 which is a conventional heat exchanger water jacket or radiator to remove heat generated by engine portion 114. Coolant water that enters water jacket 116 through cold water inlet 112 is allowed to flow through 7° hot water exhaust 118 in a known manner. Because engine 110 is an open system with water jacket 116 open to the environment and specifically open to the zebra mussel infested water in which the boat operates, zebra mussels may be able to travel through cold water inlet 112 and reproduce within water jacket 116 during lengthy periods of engine inactivity.
The invention, in one form, causes magnetically treated water, in the sense of a batch or feedback system, to treat the water within water jacket 116 under all engine operating conditions. A water line 120 is connected through outlet 124 to water jacket 116 to make a feedback loop such that inlet 122 allows water from water jacket 116 to enter water line 120 while water exits water line 120 through outlet 124 back into water jacket 116. Disposed within water line 120 is magnetic water treatment unit 40 constructed to ensure that the water flowing through water line 120 is sufficiently treated so that zebra mussel growth within water jacket 116 is eliminated. A pump 126 is disposed within water line 120 to maintain a constant flow of water through water line 120. For operation of the present invention when engine 110 is not running, pump 126 may be attached to an energy source such as a solar cell or panel 128 that generates electricity on exposure to light. In this way, solar cell or panel 128 may maintain pump 126 in operation at all times, independent of the operation of marine engine 110. Solar cell or panel 128 may be sized, as known in the art, for the desired current needed by pump 126. Alternatively, unit 40 may simply be disposed in line with water inlet 112.
Yet another embodiment of the invention within a boat 130 as shown in FIG. 6. Boat 130 includes a deck 132 under which a volume of bilge water 134 is located. It has been found that this bilge water 134 is a location in which zebra mussel infestations are quite common. This embodiment uses the same apparatus as that of FIG. 5 and operates in a similar fashion. Instead of a solar panel 128 for power, a conventional battery 136 may be utilized.
The invention possibly operates by changing the structure of the water on the macro scale, thereby changing its physical, chemical and biological properties, so that the growth of organisms in contact with this treated water may be altered.
It is know that zebra mussels are filter feeding mollusks as opposed to bottom scrapers and grazers. Their feeding mechanism is fairly complicated. Basically, water is siphoned into the body cavity of the mussel where it is circulated over its ctenidia. The ctenidial filaments, by way of synchronized ciliary beating, create water currents for respiration and feeding. The ctenidia is a surface in which particles, suspended in the water, including fluid and other nutrients are sorted. Frontal cilia, at the ridges of the ctenidium, help sort the particles along the surface. Separation is done by size alone, sorting valuable food from inedible particles. It has been known that ciliary activity can disclose information of the water quality in which they live. Feeding is a necessary requirement for growth and eventual reproduction of the mussels. Without the optimal nutrient conditions even other determining factors in the growth equation cannot overcome a nutrient poor diet. The inability to consume and assimilate proper nutrient demands (bioenergetics) can be externally observed through reduced growth rates.
Further, it is known that the growth of all organisms depends upon the essential presence of the proper chemical materials within the growth medium. Thus, eliminating the presence of an essential growth factor will result in the cessation of growth, which, if sustained over a prolonged period of time, usually will result in organism death. This is one possible explanation for the effect of magnetized water on zebra mussels.
The magnetic treatment of water alters the chemical macro-structure of water. This altered water structure, which is in effect a new solvent, causes chemical equilibria to shift, changing the concentration of existing chemical species and creating a new equilibrium system. It is theorized that chemical species essential for zebra mussel growth are reduced while other chemical species, some of them toxic to zebra mussels, are increased. Test results indicate that zebra mussel growth is retarded and processes essential for zebra mussel reproduction, veliger settlement and subsequent growth, and continued zebra mussel viability are interdicted by operation of the present invention. Thus, damage to water systems due to zebra mussel growth maybe reduced or eliminated.
Although the direct reason why zebra mussel growth is inhibited is unknown, test results have indicated that some activity is taking place to kill and retard the growth of zebra mussels exposed to the magnetically treated water of the present invention.
It is known that zebra mussels have a prodigious requirement for the element calcium and a substantial requirement for the element magnesium. They also have a high phosphorus requirement, a portion of which is found in an unusual group of biochemicals called phosphonolipids, which are polar fats containing the rare carbon-phosphorus chemical bond particular to pelagic organisms. It is believed, that, consistent with what is known about other biological systems, the proper chemical form of these elements is required in the growth medium for proper zebra mussel growth. It is believed further, that zebra mussels can only utilize certain specific complexes of these elements for growth. The presence of the wrong complex in the medium will not permit growth, even though, in a gross chemical quantitation that depends only upon the presence of a particular atom, such as would be obtained through inductively-coupled plasma spectrometry, the concentration of the element may appear to be adequate.
Use of the invention on zebra mussels has been determined to slow their growth with an increase in mortality. Additionally, the present invention appears to also effect the shells of the zebra mussel making them more fragile than normal.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. | A method and apparatus in which water is magnetically treated to retard the growth of zebra mussels in water systems, thereby reducing the requirements and cost of water-system maintenance and the quantity of toxic chemical treatments released to the environment. The method includes removing a volume of water from a zebra mussel infested environment, magnetically treating the water, then returning the treated water back to the environment. The apparatus includes a permanent magnet of alternating polarity to form a magnetic field through which the water is treated. |
BACKGROUND OF THE INVENTION
This invention relates to methods and apparatus for producing armatures for dynamo-electric machines such as electric motors and generators, and more particularly to improving the balance of such armatures.
The principal components of a dynamo-electric machine armature are typically a shaft, an axially slotted lamination stack or core mounted concentrically on the shaft, a commutator also mounted concentrically on the shaft, insulating end fibers at respective opposite axial ends of the lamination stack, insulating papers in the slots in the lamination stack, coils of wire wound on the lamination stack chiefly by passing through the slots in the stack with coil lead wires extending to the commutator, and a resin coating applied to at least the axial ends of the coils to help stabilize the coils.
It is becoming increasingly important for such armatures to be well balanced about the central longitudinal axis of the armature shaft. This increased importance is due, for example, to a growing interest (on the part of motor manufacturers and users) in motors that operate more smoothly, more reliably, with longer lives, and at higher speeds. The traditional techniques for balancing armatures include subjecting the annular outer surface of the lamination stack to a turning operation to ensure concentricity of that surface with the shaft, milling one or more axial grooves in the outer surface of the lamination stack to remove material from the side of the armature found to be heavier, and/or adding extra resin to the coil ends on the side of the armature found to be lighter. It would be desirable, however, to assemble the armature in such a way that unbalance is eliminated or at least substantially reduced so that the required extent of the above-mentioned traditional balancing operations can be at least substantially reduced. For example, removal of large amounts of material from the outer surface of the lamination stack by annular turning or axial milling may reduce the efficiency of the resulting motor. Also, to the extent that different amounts of material must be removed from different armatures, these techniques are not consistent with producing motors having uniform operating characteristics.
In view of the foregoing, it is an object of this invention to provide dynamo-electric machine armatures with improved balance.
It is a more particular object of this invention to provide methods for assembling dynamo-electric machine armatures in such a way that their balance is improved prior to the manufacturing stage in which final balancing operations are traditionally performed so that the extent to which such traditional final balancing operations must be carried out is at least substantially reduced.
SUMMARY OF THE INVENTION
These and other objects of the invention are accomplished in accordance with the principles of the invention by measuring the unbalance of the armature prior to the coil winding operation, and then winding the coils of the armature so that the coils are unbalanced in a way that compensates for the previously measured unbalance. For example, the direction and magnitude of unbalance prior to coil winding may be measured. Then the coils wound around a diameter of the lamination stack which is aligned with the unbalance direction may be wound so that the coil on the side of the armature opposite the unbalance direction has more turns of wire than the parallel coil on the other side of the armature. The difference in the number of turns of wire between these two coils may be such that the wire mass difference times the radial distance from the center of the armature through which that mass difference acts is equal to the magnitude of the unbalance of the armature measured prior to coil winding. Because the direction of coil unbalance is opposite the direction of unbalance prior to coil winding, the deliberately unbalanced winding substantially cancels out the unbalance prior to winding, thereby producing a fully assembled armature which requires little or no final balancing such as by axial milling of the outer surface of the lamination stack.
In addition to ensuring static balance of the armature as described above, dynamic balance may be achieved by adding masses to the armature in such a way as to cancel out any dynamic unbalance. For example, masses of a dense resinous gel may be added to the axial ends of the coils to eliminate or at least substantially reduce any dynamic unbalance. The magnitudes of these masses and their radial and axial locations on the armature are preferably chosen so that they do not affect the static balance of the armature but so that they are effective to counteract the dynamic unbalance of the armature.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of an early stage in the assembly of a typical armature for a dynamo-electric machine.
FIG. 2 is a view similar to FIG. 1 showing a subsequent stage in the assembly of a typical dynamo-electric machine armature.
FIG. 3 is another view similar to FIG. 1 showing a further subsequent stage in the assembly of a typical dynamo-electric machine armature.
FIG. 4 is still another view similar to FIG. 1 showing a still further subsequent stage in the assembly of a typical dynamo-electric machine armature.
FIG. 5 is a simplified cross sectional view of the armature assembly shown in FIG. 4. FIG. 5 includes a vector diagram useful in explaining the principles of this invention.
FIG. 6 is a simplified elevational view, partly in section, of illustrative armature unbalance measuring apparatus which can be employed in the practice of this invention.
FIG. 7 is another simplified elevational view of the apparatus shown in FIG. 6. FIG. 7 is taken from the left in FIG. 6, and shows some elements schematically.
FIG. 8 is a partly schematic, simplified, elevational view of illustrative armature winding apparatus which can be employed in the practice of this invention.
FIG. 9 is a view similar to FIG. 5, but shows the armature partly wound in accordance with this invention.
FIG. 10 is a fragmentary isometric view of an armature wound in accordance with this invention, together with apparatus for ensuring that the armature is dynamically balanced.
FIG. 11 is a simplified flow chart of illustrative steps for making an armature in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Assembly of a typical armature prior to winding is shown in FIGS. 1-4. In FIG. 1 a stack 14 of laminations of ferromagnetic material is pressed onto armature shaft 12. In FIG. 2 insulating end fibers 16a and 16b are pressed onto shaft 12 against respective opposite axial ends of lamination stack 14. Insulating papers (not shown) may also be inserted into the axial slots 18 in lamination stack 14. In FIG. 3 commutator 20 is pressed onto one axial end of shaft 12. The armature assembly 10 ready for winding is shown in FIG. 4.
The armature structure shown in FIG. 4 may be unbalanced about the central longitudinal axis 22 of shaft 12 as a result of any of several factors. The production of shaft 12 requires lathing and grinding a steel bar with extremely precise tolerances. Once the shaft has been produced, it is subjected to a straightening operation and is then placed within lamination stack 14 as shown in FIG. 1. By itself shaft 12 typically has relatively little unbalance about axis 22, although some unbalance of the shaft is always possible.
Lamination stack 14 is produced by punching individual laminations from steel sheets, and then assembling a stack of such individual laminations. The individual laminations may not be perfectly balanced due to variations in the thickness of the sheet from which a given lamination is cut, imprecision in the shape of the lamination, etc. The unbalance vectors of the individual laminations in stack 14 sum together to produce the net unbalance vector of stack 14. This may be the single largest source of unbalance in armature assembly 10, especially because stack 14 is typically the component of assembly 10 with the largest diameter and the greatest mass. The substantially cylindrical external surface of lamination stack 14 may be subjected to a lathe turning operation to ensure concentricity of that surface with axis 22. But stack 14 may still be significantly unbalanced about axis 22 due to such factors as nonuniform sheet thickness, imprecise lamination shape, etc.
In end fibers 16 imperfect mass distribution, imprecise geometry, and lack of concentricity with axis 22 may be another source of unbalance in assembly 10.
Still another source of unbalance in assembly 10 may be commutator 20, which may have less than perfect concentricity with shaft 12 or less than perfect mass distribution about axis 22. Commutator 20 may be subjected to a lathe turning operation to ensure concentricity of its substantially cylindrical external surface with axis 22, but imperfect mass distribution in the commutator may not be completely eliminated by this operation.
FIG. 5 shows a typical net unbalance vector R which may result from several individual unbalance sources such as are described above. In particular, vector R (having angle theta from radial reference axis 24) is the vector sum of individual unbalance components R 1 , R 2 , and R 3 (having angles theta 1 , theta 2 , and theta 3 , respectively, from reference axis 24). Unbalance component R 1 may be due, for example, to lamination stack 14, unbalance component R 2 may be due to commutator 20, and unbalance component R 3 may be due to end fibers 16. As shown in FIG. 5 static balance can be restored to assembly 10 by adding another unbalance component F to the assembly, component F being equal and opposite to vector R.
In accordance with the present invention, the magnitude and direction of net unbalance vector R are determined. This can be accomplished, for example, by placing assembly 10 in unbalance measuring apparatus 100 of the type shown in FIGS. 6 and 7. This apparatus, which may be conventional and commercially available, includes floating supports 102a and 102b for supporting the respective opposite axial ends of shaft 12 via idle wheels 104. Assembly 10 is then rotated about axis 22 by a motor-driven belt 106 which is pressed against the outer cylindrical surface of lamination stack 14. Any unbalance of assembly 10 causes supports 102 to reciprocate (as indicated by the double-headed arrow 108 in FIG. 7) as assembly 10 is thus rotated. Sensor 110 detects this reciprocation and applies a corresponding signal to the controls 120 of the machine. At the same time sensor 112 periodically reads a reference mark which has been placed at a particular angular location on the cylindrical surface of commutator 20. (Alternatively, sensor 112 may keep track of the angular location of the armature by detecting features of the commutator such as its bars 21a or tangs 2lb.) The output signal of sensor 112 is also applied to machine controls 120. Controls 120 can therefore determine the magnitude and direction (theta) of unbalance vector R. Vector magnitude is determined from the amplitude of the reciprocation detected by sensor 110. Vector direction is determined from the phase relationship between the reciprocation detected by sensor 110 and the reference mark (or other angular orientation) readings produced by sensor 112.
If desired, the values of vector R magnitude and direction determined as described above can be marked (in encoded form) on assembly 10 by a marking tool 130 driven by controls 120. Alternatively, any other suitable technique can be used for associating with assembly 10 the values of vector R magnitude and direction determined by apparatus 100 so that those values are available for future reference during the subsequent processing of that particular assembly. In the depicted embodiment, however, it will be assumed that marking tool 130 is used to record the vector magnitude and direction on the outer cylindrical surface of lamination stack 14 at a particular angular location (e.g., at a predetermined angular location relative to the reference mark read by sensor 112 or, alternatively, at a predetermined location relative to the direction of vector R).
After the magnitude and direction of net unbalance vector R have been determined as described above, assembly 10 may be placed in a coil winding machine 200 such as is shown in FIG. 8. In the particular embodiment shown in the drawings, coil winding machine 200 is a conventional dual-flyer type winding machine. It will be understood, however, that any other type of coil winding machine (e.g., machines of the type shown in commonly assigned, co-pending application Ser. No. 07/738,199) can be used instead if desired. In accordance with this invention, coil winding machine 200 is augmented by sensor 220 for reading from the cylindrical outer surface of lamination stack 14 the unbalance vector data previously inscribed there by marking tool 130 in FIGS. 6 and 7. The controls 202 of winding machine 200 use the machine's conventional armature rotating components 204 to rotate assembly 10 until sensor 220 can read the unbalance vector data from assembly 10.
Winding machine controls 202 use the unbalance vector data read by sensor 220 to modify the coil winding process to compensate for the unbalance of assembly 10. As shown in FIG. 9, for example, winding machine may compensate for unbalance vector R by winding coil 30b with sufficiently more mass than coil 30a so that the unbalance vector F which results from this coil unbalance is equal and opposite to vector R. As is conventional, coils 30a and 30b are diametrically opposite to one another in diametrically opposite pairs of slots 18 in lamination stack 14. Coils 30a and 30b are wound at substantially the same time by flyers 210a and 210b, respectively. Flyers 210a and 210b are respectively rotated about axis 206 by conventional flyer rotating components 208a and 208b controlled by controls 202.
Normally coils 30a and 30b would have the same number of turns and would be of the same size. Coils 30a and 30b would therefore normally be balanced about armature axis 22. However, in accordance with this invention, winding machine controls 202 cause flyer 210b to apply more turns of wire to coil 30b than flyer 210a applies to coil 30a. Controls 202 calculate the number of turns of wire by which coil 30b must differ from coil 30a in order to substantially compensate for vector R. For example if the parallel planes in which coils 30 lie are spaced apart by a perpendicular distance 2d, and if the mass of a turn of wire in each coil is m, then the difference n in number of wire turns between coils 30b and 30a required to offset unbalance vector R is given by the equation:
n=R/md (1),
where R in this equation is the magnitude of unbalance vector R. If winding machine 200 winds coil 30b with n more turns than coil 30a, then coils 30 will have an unbalance vector whose magnitude is given the equation:
F=nmd (2).
Because coils 30 are wound in planes that are perpendicular to vector R with the larger coil 30b in the direction away from vector R, vector F is directed away from vector R. Equal and opposite vectors F and R cancel one another and restore static balance to armature 10.
It will be appreciated that winding machine controls 202 determine not only the number of turns by which coils 30a and 30b must differ from one another, but also the angular position at which coils must be wound on lamination stack 14 so that coil unbalance vector F is directed oppositely from vector R. This can be done in any of several ways. For example, the apparatus of FIGS. 6 and 7 can rotate assembly 10 so that marking tool 130 always marks the outer surface of lamination stack 14 at a location which is 90° counterclockwise from vector R as viewed from commutator 20. Assuming that the end of assembly 10 visible in FIG. 8 is the commutator end, winding machine controls 202 will know that when sensor 220 can read the unbalance markings from tool 130, the coils it is about to wind on assembly will be in planes perpendicular to vector R, and that these are therefore the coils to be modified to compensate for R. Moreover, controls 202 will know that (like coil 30b in FIG. 9) the coil on the left is to be made larger than the coil on the right. The only parameter controls 202 must then compute is n as in equation (1) above. Of course many other techniques can be used to enable controls 202 to determine which coils to modify to produce an appropriate coil unbalance vector F.
In the example shown in FIG. 9 only one pair of coils must be modified to produce a vector F of appropriate magnitude and direction. In this example all other coil pairs (either wound before or after coils 30) can be wound in the conventionally balanced manner. If lamination stack 14 were configured differently, or if vector R were directed differently (e.g., along one of the arms of stack 14 in FIG. 9), it might be necessary to modify two pairs of coils in the manner described above in order to produce a net coil unbalance vector F directed oppositely to vector R. It will be readily apparent to those skilled in the art how this capability can be included.
It may also be desirable to have winding machine 200 base the angular orientation of all the coils to be wound on assembly 10 on the direction of unbalance vector R. For example, the coil winding pattern may be such that the last coils to be wound on the armature tend to be the largest and most massive (e.g., because they at least partly overlie previously wound coils). These last coils may also tend to have the largest moment arms d in equations (1) and (2). Thus both variable m and variable d may be greatest for these coils. A given magnitude of vector R may therefore be offset with a smaller difference in number of wire turns in these coils than in any previously wound pair of coils. In addition, because these coils are wound last, they can be of different sizes without having any secondary effects on the sizes, shapes, or balance of any other coils.
If it is desired to base the angular orientation of all coils on the direction of vector R as described above, assembly 10 can be rotated in apparatus 100 so that marking tool 130 marks the vector R data on lamination stack 14 at the angular location where that data can be read by sensor 220 when apparatus 200 has rotated assembly 10 to the position at which winding must begin in order for the last-wound coils to be in planes perpendicular to vector R. Again, this is only one example of how the data regarding the direction of vector R can be communicated to winding machine controls 202 so that winding machine 200 can rotate assembly to the angular position at which coil winding should start so that the last coils wound are those that are to be used to produce coil unbalance vector F. It will also be appreciated that in other coil winding patterns it may be desired that particular coils other than the last-wound coils are to be used to produce vector F. It will be apparent from the foregoing how the systems of this invention can use the direction of vector R to cause winding machine 200 to rotate assembly 10 to a coil winding start position such that, when the desired coils are being wound, vector R has a desired orientation relative to those coils (e.g., vector R is substantially perpendicular to the planes in which those coils are being wound).
FIG. 10 shows armature 10' after it has been completely wound. It will be apparent from this FIG. that the armature is statically balanced because the magnitudes of vectors R and F are equal and their directions are opposite to one another. However, as FIG. 10 also shows, vectors R and F may not be in the same plane perpendicular to axis 22. The axial location of vector F tends to be always at the axial center of lamination stack 14 because the coils are axially centered on that stack. Vector R, however, has components that may not be axially centered on lamination stack 14. For example, any contribution to R from commutator 20 will axially displace R toward the commutator. Thus although wound armature 10' is statically balanced by R and F, it may not be dynamically balanced. In particular, when armature 10' is rotated at high speed, as when it is used in a motor, the axial offset between R and F produces a couple in the plane defined by vectors R and F. This couple can eliminated by a dynamic balancing operation of this invention as will now be described.
The dynamic unbalance characteristics of wound armature 10' can be determined by placing armature 10' in unbalance measuring apparatus similar to that shown in FIGS. 6 and 7. In this case, however, the dynamic unbalance characteristics are determined from differences in the motions of floating supports 102a and 102b as armature 10' is rotated in the unbalance measuring apparatus. Once the characteristics of the dynamic unbalance have been determined, the armature is placed in another machine (indicated by resin dispensers 300a and 300b in FIG. 10). (Any of the techniques discussed above for transfer of unbalance information from machine 100 to machine 200 can be used for transferring dynamic unbalance information from the apparatus which measures dynamic unbalance to the apparatus which includes resin dispensers 300.) Each of dispensers 300 can add mass (e.g., a quantity of a dense resinous gel) to a respective opposite axial end of the coils wound on lamination stack 14. In particular, dispenser 300a adds gel mass 302a to armature 10' in plane 40a, while dispenser 300b adds gel mass 302b to armature 10' in plane 40b. The apparatus which includes dispensers 300 rotates armature 10' about axis 22 so that gel masses 302 are deposited on diametrically opposite sides of the armature, preferably in the plane defined by vectors R and F. The positions of gel masses 302 relative to axis 22 are such that when armature 10' is rotated about axis 22, the couple produced by masses 302 is opposite to the couple associated with vectors R and F. In addition, the magnitudes and radial locations of masses 302 are such that the magnitude of the couple produced by masses 302 is equal to the magnitude of the couple associated with vectors R and F. The couple of masses 302 therefore cancels the couple of vectors R and F, and armature 10' is dynamically balanced.
Masses 302 are preferably equal to one another and equally spaced from axis 22 so that they do not disturb the static balance of the armature. If R is the magnitude of vector R (or the magnitude of equal and oppositely directed vector F) and s is the axial spacing between vectors R and F, then to achieve dynamic balance the mass M of each mass 302 should be determined by the equation:
M=Rs/rS (3),
where r is the radial distance from axis 22 to either of masses 302, and S is the axial distance between those masses (i.e., between planes 40). Each of dispensers 300 is accordingly controlled to dispense a mass M.
Assuming that masses 302 are a resin material generally like the material that is typically used to impregnate at least the axial ends of the coils, masses 302 may be applied during the usual resin impregnation operation or immediately after that operation. Preferably, masses 302 are applied prior to the operation by which the impregnation resin is cured. In this way both the impregnation resin and masses 302 are cured together in one curing operation which ensures firm anchoring of masses 302.
It will be noted from equation (3) that if the apparatus of FIGS. 6 and 7 determines the axial location of vector R, everything necessary to compute M is known even prior to the coil winding operation. This is so because the vector F always has the same axial location (i.e., at the axial center of lamination stack 14). This makes it possible to omit subjecting the armature to a second unbalance measuring operation after winding.
FIG. 11 is a summary of the steps which can be carried out in accordance with this invention to produce armatures that are both statically and dynamically balanced. In step 400 lamination stack 14 is formed. In step 402 shaft 12 is pressed into stack 14 as shown in FIG. 1o In step 404 end fibers 16 are placed on the assembly as shown in FIG. 2. In step 406 commutator 20 is placed on the assembly as shown in FIG. 3. In step 408 assembly 10 is tested as shown, for example, in FIGS. 6 and 7 to determine the magnitude, direction, and axial location of unbalance vector R. In step 410 assembly 10 is wound with coils as shown, for example, in FIGS. 8 and 9. This winding operation includes adjusting the number of wire turns in certain coils to compensate (in a static balance sense) for vector R. Unbalance information from step 408 is accordingly employed in step 410. In step 412 the coils are impregnated with resin in the conventional manner. In step 414 gel masses 302 are added to the wound armature as shown, for example, in FIG. 10 to substantially eliminate any dynamic unbalance of the armature. Again, unbalance information from step 408 is used in step 414. (This unbalance information may be transferred from step 408 to step 414 by any of the techniques discussed above for transfer of such information from step 408 to step 410.) Finally, in step 416 the resin material applied in steps 412 and 414 is all subjected to a curing operation.
It will be understood that the foregoing is only illustrative of the principles of this invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. For example, masses 302 can alternatively be applied in a manufacturing stage other than that described above (e.g., after the impregnation resin has been cured). Whenever masses 302 are applied, however, there should thereafter be a curing operation which causes those masses to harden and permanently adhere to the armature. | Armatures for dynamo-electric machines are balanced during manufacture by measuring the unbalance of the armature assembly prior to winding the coils on the armature. The numbers of turns of wire in at least some of the coils subsequently wound on the armature are then adjusted so that the unbalance of the resulting coils compensates for the unbalance of the armature prior to coil winding. In addition, masses may be added to the armature to ensure that it is balanced dynamically as well as statically. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of the filing date of U.S. Provisional Patent Application No. 60/941,460, filed on Jun. 1, 2007, the contents of which are herein incorporated by reference.
FIELD OF THE INVENTION
This invention pertains to the storage of flexible hoses, and more particularly, to a water powered hose reel having a hydraulic motor operated by municipally supplied water pressure for purposes of winding a hose reel by use of pressurized water.
BACKGROUND OF THE INVENTION
Water hoses are used to transfer water from one location to another, a necessity for homeowners attempting to efficiently water lawns and gardens as well as for general all-around home care. Before the use of hose reels storage systems, water hoses were typically left on the ground in coiled or uncoiled position, either such position exposed the hose to the collection of dirt. If the hose was lifted from the ground the hose may still be stored in an arrangement that would lead to early degradation. The advent of hose reels gained wide public acceptance as a convenient device for properly storing of the water hoses. These devices include portable hose reel carts, stationary hose reel carts, and stationary hose reel hangers that can be mounted to a surface of a building all of which store the water hoses in a location in a convenient area for reuse. The hose reel provided proper coiling of the hose, positioning off of the ground, and in many instance portability in a storage condition.
A typical portable hose reel cart includes an open, rotatable reel or spool positioned between a pair of side frames. These carts include wheels to permit ready transport of the hose from one location to another. The hose is merely wound upon the reel for storage and pulled or dispensed from the reel for use.
The construction of a hose reel is primarily of molded plastic components having a rotatable spool for wheeling of the flexible hose, a frame for supporting of the spool, and a means for rotating of the spool, most commonly performed by a manually operated hand crank. Illustrative of the structure and operation of hose reels and hose reel carts can be viewed and referenced to various patents issued to the Suncast® Corporation such as U.S. Pat. Nos. Reissue 32,510; 4,512,361; 4,777,976; 5,046,520; 5,901,730; 5,998,552; 6,050,291; 6,834,670; 6,877,687; and 7,017,603 the disclosures of which are hereby incorporated by reference.
Common to such hose reels is the use of a crank handle secured to a hub for rotation of the spool. The spools are typically arranged with the crank handle located at the center of the hub to wind the flexible hose. Variations to the use of the hand crank include a battery powered hose reel wherein a small direct current motor obtaining power from a rechargeable battery supply can be coupled to the spool providing rotation. In many instances manual rotation of the spool is not convenient to the consumer. For instance, the consumer may require automatic hose take-up due to a physical aliment or the consumer may simply choose to have the convenience of automatic hose take-up. U.S. Pat. No. 6,877,687 is directed to a battery powered hose reel to provide an alternative to manual cranking of a hose reel. The battery powers a low draw motor allowing hundreds of hose retrievals before recharging, recharging may be performed by coupling to an electrical source such as an AC source or DC solar panel supplied current.
A water powered motor is yet another alternative means that can be used for automatic hose take-up. Various attempts at making water powered motors for use with hose reels can be found in U.S. Pat. No. 5,741,188 directed to a water driven motor having an external gear motor, a linearly translating actuator, and a rotatable actuator; U.S. Pat. No. 6,752,342 discloses the use of a water operated motor for conversion of linear motion to a rotational motion using pistons linked to a spool for rotation in a manner similar to a steam engine; and U.S. Publication No. 2006/0045733 discloses the use of a water turbine for use in rotation of a hose reel.
What is not disclosed in the prior art is a simplified hydraulic motor for use in a water powered hose reel.
SUMMARY OF THE INVENTION
Disclosed is a water powered hose reel driven by a traversing cylinder with a gear rack for use in retrieving a flexible hose. The hose reel includes a spool having a hub and a pair of flanges at opposing ends of the hub configured for storage, take-up and pay-out of the flexible hose. In the preferred embodiment, the hose reel is supported in an enclosure having front and rear wall panels, side wall panels extending between the front and rear wall panels, and a cover. The enclosure is configured for receiving the spool so as to rotate within the enclosure and for storing a length of flexible hose on the spool. The traversing cylinder is operatively associated with the spool by use of a reciprocating rack for driving a series of gears attached to the spool. Disengagement of the traversing cylinder allows for ease of manual pay-out of the hose. Operation of the spool is by of household water pressure. The hydraulic motor provides a reciprocating movement that is converted to rotational movement of the spool via the series of gears for retrieval of an elongated member such as a hose.
Thus, an objective of the invention is to disclose the use of a water powered traversing cylinder with a gear rack to provide rotational movement of a spool.
Another objective of the invention is to disclose the use of a water switching valve assembly allowing reciprocal movement of a traversing cylinder by placement of pressurized water to each side of a piston to cause and maintain a traversing motion.
Still another objective of the invention is to disclose the use of a spring loaded clutch paw to provide unidirectional winding.
Still another objective of the invention is to teach the use of a level winder driven by a powered motor wherein the level winder.
Other objectives, features, and advantages of the invention should be apparent from the following description of the preferred embodiment thereof as illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right front perspective view of the water powered hose reel enclosure;
FIG. 2 is a left front perspective view of the water powered hose reel enclosure;
FIG. 3 is a top view of the water powered hose reel enclosure illustrating the spool and motor;
FIG. 4 is a right perspective view of the hose reel enclosure illustrating the spool and motor;
FIG. 5 is a perspective view of the spool, level wind, and motor;
FIG. 6 is a rear perspective view of the spool and motor;
FIG. 7 is a left rear perspective view of the spool and motor assembly hosing;
FIG. 8 is a perspective view of the drive mechanism for the water powered motor;
FIG. 9 is a plane view of the motor and drive mechanism;
FIG. 10 is a cross sectional view of the motor and spool;
FIG. 11 is a cross sectional front view of the spool and motor assembly;
FIG. 12 is an enlarged view of the toggling switch in operation with the traversing cylinder;
FIG. 13 is a rear perspective view illustrating a water inlet connection and an exhaust port;
FIG. 14 is an exploded view of the switching assembly;
FIG. 15 is an exploded view of the traversing cylinder; and
FIG. 16 is an exploded view of the switching assembly and traversing cylinder forming the motor assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, set forth is a hose reel enclosure 100 having a front wall panel 10 , side wall panel 12 , and a hinged lid 14 . The enclosure 100 is generally constructed and arranged to enclose a spool 20 onto which a flexible elongated member, namely a garden hose, is rotatably wound or taken up, and from which the flexible hose is fed out or paid out. The front wall 10 includes a lower opening 16 to permit the taking up or paying out the garden hose, not shown. A right side wall 18 includes an aperture 21 that allows operation of a handle 60 used for diverting of inlet water and to disengage a gear train to allow a free wheeling of the spool allowing ease of hose removal. The handle 60 further allowing engagement of a hydraulic motor for use in rotating of the spool causing a garden hose to be drawn in as directed by an operator. FIGS. 3-4 set forth a top view and front right perspective view, respectively, showing the enclosure 100 with the spool 20 and motor housing 62 positioned within the enclosure 100 .
Now referring to FIGS. 5-16 , depicted is a water motor housing 62 having a water inlet 70 which is coupled to a pressurized water spigot, not shown, to obtain pressurized water from a municipal supply or pressured well water supply. An exhaust water outlet 71 is used to expel water used to power the water motor ( FIG. 13 ). The diverter handle 60 for use in directing water from the inlet to either the garden hose wherein the spool 20 may be free wheeled when the diverter handle is in a first raised position or to the motor when the diverter handle is in a second lowered position. An inlet diverted valve 116 directs the pressured inlet water to the out-tube 79 which passes into the center of the spool 20 for coupling to an end of the garden hose. The out-tube having a sealing o-ring to allow rotation of the spool without leakage of the water. When the diverter handle 60 is placed in the first lower position, the water flowing through the inlet 70 is directed through a fluid coupling line 72 to a switching valve 74 . The switching valve is preferably a spool valve ( FIG. 15 ) and preferably includes a valve body 118 having a plurality of suitably placed and sized apertures 120 for transferring water. Slidably located with the body 118 is at least one spool 122 operably connected to the toggle actuator 102 to cause the spool to translate within the body 118 for directing the fluid through the appropriate aperture 120 to cause motion of the cylinder 76 . The switching valve may also contain a pilot valve portion 126 to balance the load on the spool 122 and allow easier translation of the spool. The switching valve is preferably mounted within a lower frame 130 that is constructed and arranged to cooperate with an upper frame 132 that contains the cylinder 76 . The upper frame preferably includes a pair of end members 132 separated by a pair of guide rails 136 . The guide rails are constructed and arranged to prevent rotation of the cylinder 76 during traversal thereof.
Still referring to FIGS. 5-16 , the switching valve 74 is fluidly coupled to a first end 73 and a second end 75 of cylinder 76 . The pressurized water is directed through the one of the end members 134 through hollow cylinder rod 140 to force the traversing cylinder 76 to move across a stationary piston 82 . Linear motion of the traversing cylinder 76 is converted to rotational motion by use of a gear rack 90 which operates in conjunction with a first drive gear train 91 and a second drive gear train 93 ( FIG. 12 ). As the traversing cylinder is moved in a first direction the gear rack 90 is moved along with the cylinder 76 along guide rails 136 causing gear 92 to engage and rotate gear 96 which drives spool gear 94 . As the gear rack 90 traverses gear 92 traverses to engage the first gear 97 of the second drive gear train 93 . Gear 92 includes a central axel 113 which fits into elongated slot 115 to control the movement path of gear 92 . This construction allows gear 92 to traverse with the gear rack 90 until the gear 92 intermeshes with gear 96 or gear 97 . Gear 97 is intermeshed with idler gear 99 that is intermeshed with spool gear 94 . The idler gear 99 is provided to cause the spool gear to rotate in the same direction regardless of the movement direction of the cylinder. Once the gear rack 90 has then moved across to the opposite end of the cylinder housing, cylinder guide 124 again engages the toggle actuator 102 causing the switching valve to again move the spool 122 to divert the pressurized water to the now non-pressurized end of cylinder 76 resulting in a continuous traversing of the gear rack, and continuous rotation of the drive gear trains 91 , 93 for rotation of the spool 22 . A spring loaded clutch paw 111 prevents the spool from reversing direction during hose take-up and allows the spool to freewheel when the diverter handle is in the first raised position. In the preferred embodiment, the diverter handle includes a pin 110 that is constructed and arranged to cooperate with an aperture 112 in the clutch paw 111 to cause movement thereof when the diverter handle is moved. As shown in FIG. 8 , when the diverter handle 60 is in a the lowered position gear 92 engages the gear rack 90 on top of the cylinder 76 further causing coupling to the idler gear 96 for operation of the spool gear 94 . Gear 92 transverses between gears 96 and 97 which drives through gear 99 so as to cause spool gear 94 to rotate in one direction when the gear rack 90 moves back and forth along a horizontal plane. As mentioned previously, rotation of the spool results in operation of the level wind by rotation of the level wind gear train 38 , 36 , 34 and double helix screw 30 from attachment gear 32 . It should be noted that while spur gears are illustrated other types of motion transfer assemblies may be utilized without departing from the scope of the invention, such motion transfer assemblies may include, but should not be limited to, belts and pulleys, friction wheels, bevel gears and shafting, cables and the like. It should also be noted that while a spool valve is illustrated other types of valves well known in the art may be utilized without departing from the scope of the invention.
FIG. 5 depicts the spool 20 having a central hub 22 and a pair of radial extending flanges 24 and 26 that are configured to accommodate a length of flexible garden hose wrapped around the hub 22 . The flexible hose, not shown, may be properly placed upon the central hub by use of a level wind gear train 150 which utilizes rotation of the spool 20 to cause rotation of a double helix lead screw 30 . The lead screw gear 32 is suitably secured to the lead screw 30 to cause rotation therewith. Idler gears 34 and 36 are positioned with the spool gear 38 and directly meshed thereto to provide the spacing necessary to allow accumulation of hose on the spool and desired positioning of the level wind assembly. Rotational movement of the spool gear 38 will cause similar rotational movement of the lead screw gear 32 and reciprocation of the hose guide 40 . Preferably the spool gear 38 is larger than the lead screw gear 32 thereby achieving the desired amount of hose guide travel per spool revolution thereby providing compact hose storage configuration. Hose guide 40 includes a double helix lead screw release 42 that allows for consumer positioning of the hose guide 40 along the length of the double helix lead screw 30 by lifting of the release 42 , which is spring loaded, and positioning the hose guide 40 in a desired location so as to cause proper placement of the hose in relation to the spool. The hose guide 40 has a lower U shaped channel 44 for positioning over an alignment support 46 so as to maintain the aperture 48 of the hose guide in a position relatively perpendicular to the entry of the garden hose. Operation of the spool 20 allows manual rotation of the spool by pulling of the garden hose through the hose guide when the diverter handle 60 is positioned so as to disengage the hydraulic motor that is preferably positioned within motor housing 62 .
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings. | A water powered hose reel operated by household water pressure. The hose reel has a traversing hydraulic motor for use in retrieval of a flexible hose. The hose reel includes a spool carried by and enclosed within an enclosure, the spool having a hub with a pair of flanges at opposing ends configured for proper alignment of the hose during storage, take-up and pay-out of the hose. The enclosure is configured for receiving the spool so as to rotate within the enclosure. A hydraulic motor allows take-up of the hose by use of a reciprocating traversing motor driving a rack attached to the spool by a series of gears. Disengagement of the motor allows for manual pay-out of the hose. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a sealing device for sealing externally debouching, natural or artificial body canals of animals or human beings, the device enabling liquid tight sealing against the inner wall of the bowel system of the animal or human being, especially when performing irrigation through a natural or artificial body opening of the animal or human being. The invention further relates to the use of such a device.
[0003] The device is especially suitable as a sealing member incorporated with a disposable trans-anal or trans-stomal irrigation probe.
[0004] Faecal continence can be defined as the ability to control defecation, to be able to distinguish flatus from loose respectively formed faeces or to be able to maintain faecal continence even during sleep without use of external aids. In the bowel system the nerves and muscles of the colon, rectum and anus function together in a closely co-ordinated manner in order to maintain continence. In case of any malfunction e.g. if a person is suffering from some kind of defect in the control of the bowel, this person will very likely be incontinent. The defects may e.g. occur as result of a spinal cord injury, multiple sclerosis (MS), tumours or metastases, diabetes, spina bifida or ideopatic constipation.
[0005] In addition to surgical treatment of faecal incontinence, medication and regulating nutrition, meal times and defecation habits, enemas or irrigation are some of the treatments that have been practised for long time. Enemas or irrigation may also be used by completely healthy people if they for some reason want a colonic lavage.
[0006] 2. Description of the Related Art
[0007] For these purposes several devices have been proposed in the past. In addition to devices especially for use of performing irrigation for treatment of incontinence, other similar devices have been proposed for irrigation, e.g. products developed for administration of barium sulphate enema or the like as part of a radiological examination.
[0008] One example of a prior art device is disclosed in U.S. Pat. No. 3,459,175. The device includes an inflatable balloon for giving enemata. The balloon is located on the probe for introduction of irrigation liquid, and the balloon is to be inflated when positioned in the rectum of the patient close to the anal opening. The ballooned annular element thereby blocks for undesired flow from the bowel through anus.
[0009] However, existing enemata probe sealings of the type provided with inflatable balloons inherently possess a number of disadvantages.
[0010] To ensure a sufficiently tight sealing to be obtained when placed in the bowel system, the balloon is often inflated to a greater size than necessary thereby exerting an excessive pressure on the bowel wall and even on a larger surface than intended or necessary. Furthermore, all known products on the market have relatively hard and incompressible balloons. This is likely to induce refectory contraction of the muscles in the bowel and the lower part of colon, resulting in the enemata probe being forced out through the anal opening. Further to the unpleasant leakage, as a result of such premature displacement of the probe with the balloon still being inflated may cause serious injury to the fragile wall of rectum. Also, when expanding in axial direction the balloon may be brought to cover the openings of the probe, thus stopping the intended flow of liquid into the bowel system. Furthermore, there is a risk that a balloon may be overfilled and may result in a rupture of the balloon. Such a situation may likewise cause damage of the fragile wall of the rectum, leakage of the liquid filled content of the colon sigmoideum and rectum and stress of the patient. Also, the balloon may leak which will let the air of the balloon leak out. As a result of this, the device suddenly may fall out of the rectum followed by an unintended leakage of faecal matter. As the users of enemata probes may have no sensory function in the rectum they may not themselves immediately register if the device is falling out. Finally, balloons used in these devices are often made from latex. This may cause problems for patients and others suffering from latex allergy.
[0011] When having to perform irrigation on small children another problem may arise as the devices commercially available today are rather large, they therefore seem relatively scaring both for the small children and for their parents.
[0012] Another disadvantage in connection with the mentioned products are that they are too expensive to be used as disposable products. According to specialists these products are used several times for the same patient, while being cleaned in-between uses. Apart from being time consuming due to necessary cleaning steps it will be understood that the risk of contaminating the environment during storage of the product in between each use and the risk of infecting the user is much bigger than compared to the risk when using disposable products.
[0013] A disposable kit for trans-anal irrigation is described in WO 98/23312. The kit comprises a container for irrigation media and is connected to a catheter or probe through which the enemata liquid is administered into the bowel system. The probe is provided with a fixation member intended to ensure fixation of the probe inside the bowel system during inlet of the enemata liquid. The fixation member is made from a compressible material such as a foam or a moulded elastic material. The fixation member is provided in a compressed state and surrounded by a PVA film which will dissolve when getting into contact with humidity. The fixation member is as an example made of a polyurethane and has an open structure to allow for air passing through during irrigation. Using a foam material secures a lenient contact between the bowel wall and fixation member of the probe, and the open structure favourably enhances compressibility of the fixation member but has proved to imply the disadvantage of permeability for fluids during irrigation leading to undesired leakage of irrigation media and liquid bowel contents.
[0014] It is an object of the invention to provide a soft and compressible sealing device for providing liquid tight sealing properties in order to overcome the above mentioned disadvantages of sealing devices and avoiding leakage, especially avoiding triggering of the analreflex thus expulsing the device.
SUMMARY OF THE INVENTION
[0015] The present invention reveals a device for providing liquid tight sealing while avoiding the above mentioned disadvantages.
[0016] According to the invention a sealing device is provided, especially a device for sealing externally debouching, natural or artificial body canals of animals or human beings. The device is made from a resilient material e.g. a compressible foam, e.g. closed or open celled, or may be in the form of a soft and resilient balloon and can optionally be integrated with or include a sealing element. The device may have a maximum compression force of less than 4 N, more preferred between 3.5-0.2 N, more preferred between 3.0-0.25 N and most preferred between 2.0-0.25 rendering the device resilient enough for not triggering the anal-reflex or to cause damage to the colon, such as pressure ulcers.
[0017] The invention further relates to the use of a sealing device as a sealing plug providing faecal continence of a body opening. When further incorporated with a probe for administering liquids into the bowel system, use of the device provides security against leakage when performing irrigation through natural or artificial body canals of animals or human beings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention is disclosed in further detail with reference to the drawings in which FIG. 1 illustrates a sealing device according to the invention incorporated with a probe for administration of enemata liquid and placed in the bowel system close to the anal opening of a human being,
[0019] [0019]FIG. 2 a - 2 e illustrates the principle of alternative combinations of sealing device materials and sealing elements each constituting a sealing device according to the invention, and
[0020] [0020]FIG. 3 illustrates a sealing device according to the invention.
[0021] [0021]FIG. 4 illustrates a configuration of a dome-shaped sealing device during insertion into the anal canal of a person.
[0022] [0022]FIG. 5 illustrates alternative profiles of the dome-shaped sealing device.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0023] The device can have the form and purpose of a plug, or it can be an integrated part of an instrument for use in the bowel system e.g. an instrument such as a probe for administering liquid into the bowel system. In order to ease insertion of the probe a small diameter thereof is preferred as is a small total diameter of the probe surrounded with a compressed sealing element. This will provide a probe, which is easily insertable and simple to use. In use, the cells of the sealing device made from open celled foam will tend to take up liquid from the bowel content or from the administered liquid and thereby expand. In case of using a soft and resilient balloon it is inflated after insertion. In both cases use of the device minimises the risk of inducing plug- or probe-ejecting contractions in the bowel system as the pressure exerted by the device, being a swelled type or not, against the wall of the bowel is low because the body of the sealing element is far more compliant as compared to known sealing devices.
[0024] The present invention relates to a sealing device for sealing externally debouching, natural or artificial body canals of animals or human beings, the device enabling liquid tight sealing against the inner wall of the bowel system of the animal or human being, the device further being made from a resilient material, wherein said device has a maximum compression force of less than 4 Newton.
[0025] The softness of the device of the invention is obtained by the choice of material or the physical conformation of the device or a combination of these features.
[0026] The device may comprise a sealing element.
[0027] In a preferred embodiment of the invention the sealing element comprises a foam.
[0028] A substantially dome-shaped curvature of the device may even enhance its compliability with the wall of the bowel. It is understood that a more or less pronounced inclination of the device can be chosen to optimise the sealing effect, as can the radial size of the device. Furthermore, a number of alternative shapes of sealing devices are suggested in WO 98/23312. In order to obtain a sealing device which in compressed state has as small a radial extension as possible, a thin walled device is preferred, but also more voluminous shapes of the sealing device may be relevant, especially when the sealing element is made from very compressible materials. Finally, a collar shaped termination providing a curvature somewhat deviating from the curvature of the body part of the device may be desirable and can even bring about a better sealing effect against the bowel wall.
[0029] Further, the soft and compliant feature of the sealing element is mainly provided by the nature and shape of the material it is made from. A sealing device made from open celled foam provides the device with a desired softness and conformability. At the same time the foam is sufficiently compressible to enable the device to be provided for use in a—in order to ease insertion—desirable small and pleasant compressed shape. Examples of materials for such open celled foams are PU, silicone, PVC and PE. In a preferred embodiment of the invention the foam is polyurethane (PU). However, the probe can be made from a range of materials and matching production methods. Examples of materials can be a TPE, SEB, SEBS, such as Kraton™, various PE, PU foams based on PU or PE or other materials as Silicone, Latex or synthetic rubber. Accordingly production methods can be e.g. die casting or mould casting or punching.
[0030] The device can be provided for use in a compressed state as described above being wrapped in a thin film which dissolves when brought into contact with e.g. bodily humidity i.e. when being placed inside the bowel system whereby expansion of the device is enabled. An example of material for such a thin and dissolvable film is PVA.
[0031] Alternatively the device is provided in a non-compressed state. Due to the soft and compliant structure of the sealing element the dome-like shape of the sealing element can easily be inserted. Especially when the sealing device forms part of a probe for insertion through anus, capability of the device to invert during insertion eases the insertion process and can render the thin dissolvable film for wrapping a the sealing element in compressed form superfluous. The device can be provided for insertion in a configuration ready for insertion or in opposite configuration, in which case the sealing device is suitably inverted prior to insertion.
[0032] By choosing a more or less curved profile of the outer surface of the device, i.e. the surface facing in use a natural or artificial opening to the bowel system, the person skilled in the art can optimise the capability of the device to be inverted back and forth at desired phases during use of the device. Alternative curvatures of the radial curve close to the centreline of the sealing element can provide for different capabilities to inversion of the sealing element. Adjusting the thickness of material may further optimise the desired qualities of the device.
[0033] Providing the sealing element with a liquid tight feature may be obtained by incorporating into the sealing device a liquid tight foil or layer which prevents passage of bowel or irrigation liquids through the sealing device. This foil or layer may form the surface on one or both sides of the device, e.g. on the inner surface of the device, facing in use the content of the bowel system, or e.g. the outer surface of the device, facing in use a natural or artificial opening to the bowel system.
[0034] When the foil or layer form the inner surface of the sealing device, sealing properties of smooth character provided by the compressible material of the device can become fully exploited. On the other hand, when provided as the outer surface of the sealing device facing the bodily opening of the user, removal of the sealing device may become easier due to relatively smooth surface properties provided by the foil or layer.
[0035] In one embodiment of the invention the foil or layer may be embedded between two layers of compressible material inside the device, whereby an increased anchoring of the compressible material is obtained. This may be desirable when the compressible material chosen is of relative incoherent nature. Examples of materials for such foils or layers are e.g. plastics or hydrophobic non-wovens made from materials such as PU, silicone, TPE, latex or polyolefins.
[0036] Providing the sealing element with the liquid tight feature can also be obtained by making use of a foam possessing hydrophobic features. Hydrophobicity is obtainable as an inherent feature of the foam itself. Examples of such hydrophobic foams are foams based on PU, Silicone or PVC. A foam being sufficiently hydrophobic is alternatively obtainable by incorporating a hydrophobic agent into the foam during production or by treating the foam with a hydrophobic agent. Applicable hydrophobicity is obtainable by combining strength of hydrophobicity of material or agent with a sufficiently small cell size of the foam. In order to describe a foam material capable of substantially withstanding liquid pressure exerted thereon by liquid or solid contents in the bowel system, combinations of such foam and hydrophobic agent combinations are many. They may e.g. be combinations of foams chosen from the above mentioned foams and hydrophobic agents like silicone surfactants, various soaps or other surface reactants which increase the surface tension of the foam.
[0037] It is to be understood that the device can be made from several adjacent layers of e.g. foam or other suitable material of which at least one layer needs to provide the liquid tight properties to the device. Providing the sealing element with a liquid tight feature can further be obtained by incorporating super-absorbent particles in the foam. One preferred liquid absorbent material is sodium polyacrylate. Alternative absorbents can be chosen from a group comprising inorganic materials, such as gels, or organic compounds, such as a cross linked polymer, or alginates, reticular carboxymethylcelluloses, grafted starches, natural or modified polysaccharides or synthetic derivatives of acrylamides, acrylonitriles or polyacrylates. When being brought into contact with liquids from the bowel system or from administered irrigation or enemata fluids, the super-absorbent particles will swell and expand, thereby closing the cells of the foam to provide a liquid tight barrier. This phenomenon is known to be an undesirable consequence in relation to the use of super-absorbents in the technical field of absorbing articles, where problems arise when so-called gel-blocking occurs in upper layers of absorbing articles (pads, nappies etc.) as the intended distribution of liquid throughout the product is thereby inhibited.
[0038] A device according to the invention can be made from several layers of which at least one need to provide the device with the liquid tight quality arising from one or more of the above mentioned ways of providing a such quality.
[0039] To ease removal of the device after use it can preferably be provided with an anchored string or similar separate withdrawal means of types known in the art. This especially counts for plug type devices and a number ways of how to anchor such string or similar withdrawal means is described in European patent number EP 0759734 B1. When forming part of a probe the means for withdrawal of the device is advantageously provided by the probe itself.
[0040] In one embodiment of the invention the device comprises a balloon, preferably an inflatable balloon. The device may further comprise means for inflating the balloon.
[0041] The balloon may be substantially in the form of a standard Foley catheters, but a more resilient material is used for the balloon. In case silicone is used as material for the balloon, the silicone may preferably be of a type softer than a shore(A) hardness of 35. Natural rubber, Latex, neoprene or thermoplastic elastomers (as Styrene-Etylene-Butadiene-Coblockpolymers such as Kraton K™) may also be used.
[0042] The diameter of the device, when expanded, may preferably be in the range of 30-90 mm, more preferred 50-70 mm and even more preferred 65-55 mm. The design may most preferred enable a size of the expanded balloon to be approx. 60 mm in diameter to ensure a good seal between balloon and bowel wall and the expanded balloon shall not cover the passageway for the enemata fluid, even with an asymmetric deformation of the balloon due to pressure from stool or the bowel wall.
[0043] To avoid the mentioned risk of balloon rupture, the balloon material used should preferably be able to withstand an expansion of at least 3 times the prescribed.
[0044] Such material can be found among the many polysiloxanes supplied from eg. Dow Corning, NuSil or Rhodia. A preferred embodiment can be made of Silastic® Q7-4720 from Dow Corning.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] The invention is now explained more in detail with reference to the drawings showing preferred embodiments of the invention.
[0046] A first embodiment of the invention is illustrated in FIG. 1. A catheter-like probe 1 is shown inserted into the bowel system 6 of a user 4 and positioned close to the anal opening 3 . A sealing element 2 sealing against the wall 5 of the bowel system 6 is incorporated with the probe 1 and provides for a liquid tight sealing during introduction of irrigation liquid through the cavity 7 and the openings 8 of the probe 1 out into the cavity of the bowel system 6 of the user 4 .
[0047] [0047]FIG. 2 a - 2 e illustrates sealing devices in a number of preferred alternative shapes as well as it illustrates a number of combinations of sealing device materials and sealing elements.
[0048] The outer surface 14 of device 2 a illustrated in FIG. 2 a is provided by a liquid tight foil layer 11 , whereas the device 2 b illustrated in FIG. 2 b is provided with a liquid tight layer on the inner surface 15 . As illustrated in FIG. 2 c a liquid tight layer 11 is incorporated between two layers of same or different material 16 and 17 facing the outer surface 14 or the inner surface 15 respectively of device 2 c.
[0049] [0049]FIG. 2 d illustrates a device 2 d made throughout of a hydrophobic material, while FIG. 2 e illustrates a device 2 e wherein the sealing element is formed by super-absorbent particles 18 being incorporated in the foam.
[0050] Many further combinations of the compressible materials and the liquid tight sealing elements are practicable and may provide for different preferred embodiments for specific uses.
[0051] As further illustrated by FIGS. 2 a to 2 e shape and radial size in relact state, curvature, inclination and thickness of the sealing element as such can vary. Especially a device as illustrated by FIGS. 2 a , 2 b or 2 c provides a collar shaped termination 12 of the device providing a curvature somewhat deviating from the curvature of the body part 13 of the sealing device.
[0052] [0052]FIG. 3 illustrates a sealing device according to the invention positioned close to the anal opening of a user. The sealing device 2 is provided with withdrawal means 9 through an anchor part 10 .
[0053] [0053]FIG. 4 illustrates the inverted configuration of a dome-shaped sealing device 2 during insertion through the anal opening into the bowel system 6 of a user 4 . The sealing device surrounds a catheter like probe 1 .
[0054] [0054]FIG. 5 a - 5 c illustrates different forms of the outer profile of the sealing element. The radial curve 20 is situated close to the centreline 21 of the device thereby facilitating reversion between two configurations of a dome shaped sealing device.
[0055] Methods
[0056] In the following and by example a method for use is described in further detail.
EXAMPLE 1
[0057] Use of the Device According to the Invention for Anal Irrigation
[0058] Preferably anus and at least a first part of the product to be inserted and optionally the anal canal were lubricated with a lubricant such as Vaseline/petrolatum to ease insertion of the probe. The probe was inserted through the anal canal and placed in “ampulla recti”, the lower part of the bowel system. A mark or a stop on the probe may be provided to indicates how far the probe it is to be inserted. When inserted the elevated temperature and moisture in the “ampulla recti” will dissolve the PVAH layer surrounding the compressed sealing device and the probe will expand. Now the irrigation media, preferably tab water, was pumped from the reservoir to the bowel (in a typical amount of 0.5-2.5 l, preferably 0.75-1 l). When all the desired water had been pumped into the bowel system the probe was removed immediately or optionally after an additional 1-5 minutes. Evacuation of the bowel will take place over the next maybe 15-45 minutes by reflex action of the bowel system.
[0059] An alternative embodiment of a probe including a sealing device according to the invention which is not compressed and wrapped with a PVAH layer as described in the above example was used as follows. Instead of the dome shaped being compressed prior to insertion, it was inserted into the anal canal in inverted configuration. When inserted to a desired depth a slight pull in outward direction was carefully applied to the probe, thereby causing the sealing element to revert to the dome-shaped configuration. The change in configuration was brought about by the pulling force in combination with the resistance applied by the wall of the bowel system to the rim of the sealing device. After use, the probe was carefully removed as described above.
EXAMPLE 2
[0060] Determining the Resilience of the Device
[0061] An important feature of the device of the present invention is the resilience or softness of the sealing element. The relative resilience of different types of rectal probes was determined in the following way:
[0062] A standard tensile strengths apparatus was mounted with two flat plates. The probe was inflated (balloons) or expanded with water (foams) according to manufacturers instructions and inserted between the plates. If the manufacturer did not provide instructions of the size of the probe in the inflated state, inflation to diameter 60 mm was used in the test. The tensile strengths apparatus is activated to compress the balloon/foam 10 mm. The force/mm diagram is recorded and maximum force (N) was achieved. The test was repeated three times for each probe.
[0063] Table 1 shows the maximum compression force determined for two embodiments of the invention, a balloon and a foam device, and for different well-known probes in the market.
TABLE 1 Aver- Product Material Compr. 1 Compr. 2 Compr. 3 age Balloon device Neopren 3.32 3.26 3.24 3.27 according to the present invention Foam device Polyurethane 0.47 0.43 0.40 0.43 according to the present invention Radiologic Latex 5.54 5.50 5.46 5.50 probe (Astra Tec) CardioMed PE 21.3 20.0 19.6 20.3 Enema Curity urinary Silicone 9.06 8.60 8.31 8.65 catheter OEM Foley Silicone 6.50 6.36 6.29 6.38 catheter Sisco Foley Latex 14.45 14.22 14.16 14.28 catheter Maersk Siliconized 14.43 14.27 14.24 14.32 Medical, soft latex Foley Maersk Siliconized 14.06 13.86 13.84 13.92 Medical, hard latex Foley
[0064] As can be seen from the table, the devices according to the invention requires a substantially lower compression force than the probes known in the art, and is thus more resilient.
EXAMPLE 3
[0065] Preparation of a Sealing Device
[0066] In the following and by example only a method for making a sealing device is described in further detail.
[0067] A to-part mould was preheated and parted. The lower part was covered by a 15 μ PU-foil and kept in place e.g. by a rubber band. It is important that the foil is without wrinkles. The upper part of the form was carefully pressed unto the lower part, and a rounded mandrel was entered through the filling opening of the upper part to press and deform the foil. After removal of the mandrel the PU-based foam was formed by introducing the raw materials into the form and blocking the filling opening to stop the formed foam from escaping. The temperature was kept around 50° C. for about 8 minutes, hereafter the form was opened and the device removed for further drying at around 55° C. for approximately 1½ hour. | Sealing device for sealing externally debouching, natural or artificial body canals of animals or human beings, the device enabling liquid tight sealing against the inner wall of the bowel system of the animal or human being, the device further being made from a resilient material. The device is soft and resilient and may thus not trigger the analreflex, but is still able to provide a fluid-tight seal. |
DESCRIPTION
The invention pertains to a method for influencing the transmission ratio in a continuously variable transmission, whereby the choice of a desired value N p (DV) of the rate of revolution of the primary axle (2) of the system occurs on the basis of the current positional values (α) of an accelerator pedal and a current rate of revolution value N s of the secondary axle (8) of the system.
Moreover, the invention pertains to a continuously variable transmission system, provided with a transmission with a primary pulley and a secondary pulley, whereby each pulley includes two discs, between which discs a driving belt is fitted, which belt's working radii can be varied by means of control means fitted to an adjustable portion of one or both pulleys, and provided with selection means with an input for the application of an accelerator pedal signal (α) and an input for the application of a signal N s , which signal is a measure of the value of the rate of revolution N s of the secondary axle, and an output N p (DV) for the selected desired value of the rate of revolution N p (DV) of the primary axle, which output is connected to said selection means.
Such a method and such a continuously variable transmission system are known from EP-A-0451887.
A particular selection circuit is known from the above, wherein the accelerator pedal signal (α), together with a signal N s , which signal is a measure of the current value of the rate of revolution of the secondary axle, is used to select a desired value N p (DV) of the rate of revolution of the primary axle, with which selection circuit control means coupled to the adjustable portion of the primary pulley are driven, in order to thereby influence the transmission ratio.
As such, the known method and the known system function satisfactorily; however, it appears in practice that there is an increasing demand for a more flexible and universally applicable system.
The goal of the invention in question is to increase the degree of acceptability of the continuously variable transmission to the public at large, and to further improve the comfort and control thereof, and to endow it with a greater flexibility and applicability by creating the possibility of equipping the system to allow it to meet the individual requirements of any driver.
To this end, the method according to the invention is characterised in that one or more sub ranges from the range of possible desired rate of revolution values N p of the primary axle are composed, and that the possible positional values (α) of the accelerator pedal can be combined with one of the said sub ranges, to choice.
Of advantage in the application of the method according to the invention is that the flexibility in controlling the continuously variable transmission system is increased, due to the fact that said method provides the possibility of selecting a preferred range in the form of a certain sub range, whereby the domain of the accelerator pedal position signal (α) can be mapped to a selectable sub range of desired values N p (DV) of the rate of revolution of the primary axle.
In an embodiment of the method according to the invention, each sub range is composed in such a way that the content serves as a model for a desired driving programme.
Of advantage thereby is that in principle the desired driving programme can be established and modified by the driver himself to suit his individual related needs at the time.
In a further embodiment of the method according to the invention, the boundary values of the sub range are continuously adjustable, whereby at any moment a target driving performance can be optimally matched to the individual needs of the driver.
Characteristic of the continuously variable transmission system according to the invention, is that the selection means are arranged in such a way that one or more sub ranges are composed from a range of possible desired rate of revolution values N p of the primary axle, which sub ranges are stored in a memory of the selection means, whereby boundary values of a sub range correspond to accelerator pedal positions of 0% and 100%, respectively.
The invention shall be, together with its further advantages, elucidated on the basis of the attached drawings. The figure thereby depicts a schematic rendition of a continuously variable transmission system in accordance with the invention, which figure will also be used to elucidate the method according to the invention.
The figure shows a continuously variable transmission 1, containing a primary axle 2, upon which primary axle a primary pulley in the form of primary conical pulley discs 3 and 4 is fitted. The pulley disc 3 hereof is fixed rigidly to the primary axle 2 and the primary pulley disc 4 is movable over the axle 2 by means of the exertion of a hydraulic pressure in a primary pressure chamber 5. The control of the pressure in the primary pressure chamber 5 occurs through the use of primary control means 6 connected to the pressure chamber 5. The working radii of a driving belt 7 fitted between pulley discs 3 and 4 can be thereby adjusted.
Moreover, the transmission 1 contains a secondary axle 8, to which axle a pulley with secondary conical pulley discs 9 and 10 is fitted. Pulley disc 9 is fixed rigidly to the axle 8 and pulley disc 10 is fitted to the axle 8 in such a way that it can be slid. The pulley disc 10, which can be axially slid on the axle 8, is displaced by the exertion of a hydraulic pressure in a secondary pressure chamber 11, which pressure chamber is connected to secondary control means 12, to which secondary control means signals outside the scope of this description are supplied.
The primary and secondary control means 6 and 12, respectively, are connected to the pressure chambers 5 and 11, respectively, by means of pipes 13 and 14, respectively. Moreover, the driving belt 7 is laid between the secondary pulley discs 9 and 10. The tension in the driving belt 7 is maintained through the exertion of a hydraulic pressure in a secondary pressure chamber 11 by the secondary control means 12.
Signals which are used to determine the values of the pressures P prim and P sec , respectively, in the pressure chambers 5 and 11, respectively, are supplied to the control means 6 and 12 by means of input terminals. Further details are explained in the patent application EP-A-0451887.
In addition to the transmission 1, the continuously variable transmission system contains an engine 15 coupled to the primary axle 2, which engine is controlled with the aid of a fuel supply device 16. The device 16 contains a steering input 17 to which a fuel supply rate control signal B provided by selection means 18 is delivered. Moreover, the selection means 18 contain an input 19, to which by non-depicted means an input signal α, which signal contains a measure of the position of the accelerator pedal in a vehicle, is delivered. The signal β at control input 17, which signal is based on signal α, is generated in the control device 18. Preferably, an adjustable relationship exists between the signals α and β, whereby the flexibility and the variability of the continuously variable transmission system are increased and a wide application range for a large group of users is created.
Four driving characteristics indicated by E, C, S, and V, respectively, are included within the scope of the selection means 18, within which driving characteristics the rate of revolution N s of the secondary axle 8 is reproduced, which rate of revolution is a measure for the speed of the vehicle as a function of the rate of revolution N p of the primary axle 2, which rate is representative of the rate of revolution of the engine 15. The symbols represent, successively, economic, comfortable, sporty and variably-selectable driving programmes.
Lines are drawn through the origin, whereby the line marked i L indicates the lowest possible transmission ratio (highest gear), while the line marked i H indicates the highest possible transmission ratio (lowest gear). The transmission ratio i hereby, is defined as the quotient of the rate of revolution N p of the primary axle and the rate of revolution N s of the secondary axle.
The symbols A and B, which stand for the lower and upper limits of N p , respectively, are placed beside vertical lines in the various characteristics, which vertical lines indicate the boundaries of subsets of the desired choices for the rate of revolution N p of the primary axle. In the case of the characteristic V, the limits A and B are variable and the placement thereof can be influenced by means of one or more non-depicted potentiometers, the positions of which potentiometers can be adjusted by the driver of the vehicle to choice. Once, for example, a choice is made by means of a switch for a characteristic stored in a non-depicted memory of the selection means 18, the result hereof is that for α=100% (fully depressed accelerator pedal), the corresponding upper limit B is chosen and for intermediary values, the value of N p , which value is selected on the basis of N s , is chosen and delivered to the output N p (DV). In general, α=0% shall correspond to the lower limit A of N p .
The functioning of the system is such that after choosing a certain driving characteristic on the basis of signals α and N s , a certain value of N p (DV) is selected, which value is compared in control means 6 with a current, measured value N p (MV) of the rate of revolution of the primary axle 2. The pressure P prim is influenced on the basis of the difference between N p (DV) and N p (MV), whereby the current rate of revolution of the primary axle 2 changes. Given a certain value of the accelerator pedal signal α and of the signal β, the engine 15 shall start to operate at the modified current value of the primary axle 2 and shall deliver a torque to the axle 2, which torque is in harmony with the position of the fuel supply device 16, which position is determined by the value of the signal b.
The choice between the different driving characteristics and/or the adjustable limits A and B can be made, if desired, with the assistance of fuzzy logic. Every desired relation of N p can be placed between the limits A and B. The relation may be, but does not necessarily have to be, linear. | To obtain a flexible transmission system which can be adjusted to the meet the individual desires of a driver, the choice of the desired value of the rate of revolution of the primary axle in the system, based on the current position of an accelerator pedal, and based on the current rate of revolution of the secondary axle of the system, is influenced, whereby several sub ranges are composed from the range of possible desired rate of revolution values of the primary axle, so that the possible positional values of the accelerator pedal can be combined with one of the sub ranges, to choice. A sub range preferably serves as a model for a desired type of driving program. If desired, the boundary values of the sub range can be continuously adjusted through the use of potentiometers which are operated by the driver. To assist in the realization of a simple-to-implement digital construction, the sub range values are stored in a memory. |
DESCRIPTION
1. Technical Field
The field of art to which this invention pertains is coatings, and particularly lubricious, polymerized unsaturated compound containing coating compositions, additionally containing a thermosetting component such as an epoxy.
2. Background Art
While lubricious fluorocarbon polymers such as polytetrafluoroethylene have many properties which make them exceptional material where antistick and slip properties are desired, these same properties make such material difficult to use. For example, because of these superior antistick properties, it is difficult to adhere the material to any other material to which it is desired to impart such properties. U.S. Pat. No. 3,144,118 while extolling the virtues of Teflon® (Dupont de Nemours & Co., Inc.) as an antistick material, demonstrates the difficulty in the use of such material, for example, unmodified requiring heating to 700° F. Furthermore, Teflon coatings generally suffer in their abrasion resistance. This is underscored for example by U.S. Pat. No. 3,850,867 which speaks of such difficulties. Among the attempts which have been made to overcome the problems associated with the use of Teflon in compositions are such things as the inclusion of thermosetting material with the Teflon (note U.S. Pat. Nos. 3,144,118 and 3,853,690) and the inclusion of such things as fillers and wetting agents (U.S. Pat. No. 3,850,867). But, there is still a need for a composition with a combination of high lubricity, especially high lubricity toward rubber-type materials coming in contact with such compositions coated on a substrate, good adherence to a variety of substrates, abrasion resistance and high fluorocarbon polymer content without its attendant disadvantages.
DISCLOSURE OF INVENTION
The present invention is directed to a coating composition which is high in lubricity, high in abrasion resistance, has good adherence and yet has ease of application to a variety of substrates. The composition comprises essentially three parts: (1) a lubricious fluorocarbon polymer such as polytetrafluoroethylene, (2) a thermosetting resin such as an epoxy resin, and (3) a wetting agent such as a silane.
Another aspect of the invention includes relatively simple methods of application of the composition to substrates including roller, brush or spray application with room temperature or external heat drying.
Another aspect of the invention includes articles with improved lubricious properties coated with the composition of the present invention, such as glass and metal.
BEST MODE FOR CARRYING OUT THE INVENTION
The material of the present invention has utility in any area where a high abrasion resistant, highly lubricious material is desirable. And while the material has particular utility in a coating application because of its exceptional adhesion to various substrates such as metal and glass, it can also be used as a molded material where abrasion resistance and high slip properties in a molded form are desired, for example, in sheet or strip form, in laminate form, or laminated to a surface.
If the material is to be used in a coating process, the material is very adaptable to being applied by any method such as roller, brush or spraying, but is particularly adapted to application by spray to give an attractive smooth-looking coating. It also has particular utility in such uses as on skirt panels of moving stairways because of its high adhesion, high slip, and high abrasion resistance properties. For example, note U.S. Pat. No. 3,144,118.
The composition of the present invention comprises essentially three components. The first component which is most important for imparting the lubricative properties to the coating is a fluorocarbon polymer or copolymer. While polytetrafluoroethylene is the most preferred fluorinated polymer because of its well known highly lubricious properties, other lubricious fluorocarbon polymers or copolymers may be used, for example, chloro-fluoro-type polymers or fluorocarbon copolymers such as ethylene propylene-fluoroethylenes. The fluorocarbon polymer selected is a solid, desirably in finely powdered form. The second essential component is a settable resin which may be a thermosetting resin or a curable resin. For preference the resin is selected having regard to properties such as ease of application to a substrate, ease of setting or cure, and the desired abrasion resistance and adhesion characteristics of the cured composition. Selection of an epoxy resin is preferred, for example, Epotuff 54-105 available from A. C. Hatrick Chemicals Pty., Ltd. as a 74 to 76% solids by weight epoxy composition in a xylol solvent, having a viscosity of Z 3 to Z 6 and an epoxide equivalent of from 600 to 700.
When an epoxy resin is used then a cross-linking agent, preferably an amine cross-linking agent such as a fatty polyamide amine cross-linking agent, is desirably employed in conjunction with the resin for curing, e.g. in a ratio of from 1.5:1 to 2.0:1 by weight of epoxy resin and preferably in a ratio of 1.7:1 to 1.8:1. An example of a suitable fatty polyamide amine cross-linking agent is Versamid 54-405 available from A. C. Hatrick Chemicals Pty., Ltd. Versamid 54-405 is a fatty polyamide amine present as a 69 to 71% by weight solids composition in a xylol carrier. It has a viscosity of V-Z and an amine value of 161 to 173. When this cross-linking agent is used with Epotuff 54-105 in a composition according to the invention, high abrasion resistance and good adherence to glass and to metal substrates is obtained. However, other settable epoxy resins may be used in combination with other cross-linking agents or in their absence depending on the resin selected.
The third component of the composition which is considered essential for obtaining the improved results of the present invention is a silane wetting agent which contributes to wetting of the fluorocarbon polymer by the resin. For this purpose, it has been found that amino silanes, and more preferably di-amino-silanes, are particularly suitable. Silane 6020 available from Dow Corning and comprising an N-beta-amino-ethyl-gamma-amino-propyl-trimethoxy silane is especially preferred as the wetting agent and enables the fluorocarbons to be wetted by the resin and in some cases, bonded to the resin, contributing to both the superior adhesion and superior abrasion resistant properties of the present composition.
The silane is employed in an amount sufficient to achieve wetting of the fluorocarbon polymer by the resin and therefore, the amount used varies with the relative quantity of the polymer and resin component. Typically however, the quantity of silane is up to about 1.5% and generally varies from 0.1% to 1% by weight of total weight of solids in the composition and more typically from 0.3 to 0.7%.
The proportion of fluorocarbon polymer to resin in the composition may be as high as 4:1, but is preferably kept below 1.2:1 by weight. At higher ratios of fluorocarbon polymer to resin, it is more difficult to achieve satisfactory wetting between the polymer and the resin component. Much lower ratios of fluorocarbon polymer to resin may be employed if desired, but the lubricity of the composition decreases as the ratio of fluorocarbon polymer to resin is lowered. For example, ratios of 1.8:1 to 2.2:1 are quite satisfactory.
The composition may optionally include one or more solvents such as methyl isobutyl ketone, methyl ethyl ketone, Freon® (Dupont de Nemours & Co., Inc.) and xylene to facilitate the dispersion of the essential components one in another or for the purpose of facilitating application to a substrate. Such solvents can comprise up to 60% by weight of the composition, for example, and preferably comprise 40% to 60% by weight. Furthermore, when a resin is employed in conjunction with a curing agent then the fluorocarbon polymer may advantageously be mixed with the curable resin component in one solvent or mixture of solvents, and the curing agent in a second solvent or mixture of solvents, the two parts being combined immediately prior to application of the composition to a substrate on which the composition is to be coated. In this case, the silane can conveniently be predissolved in a third solvent or mixture of solvents and can be combined with the other two parts also immediately prior to coating of the substrate.
Other ingredients may also optionally be added to the composition of the invention. For example, coloring agents such as carbon black or other pigments or dyes, dispersing agent, and depending on the resin employed, accelerators for speeding cure and the like.
EXAMPLE 1
A coating composition was prepared in three parts according to the following formulation.
______________________________________ Parts by weight______________________________________PART ACarbon Black 3.5PolytetrafluoroethylenePowder (Fluon L169A) 40.0Versamid 54-405 36.2Methyl Isobutyl Ketone 8.0Methyl Ethyl Ketone 10.3Freon 13 4.0PART BEpotuff 54-105 Epoxy Resin 42.0Methyl Isobutyl Ketone 5.0Methyl Ethyl Ketone 4.0PART CSilane 6020 5.0Xylol 5.2______________________________________
Fluon L169A is available from ICI and is a 5 micron polytetrafluoroethylene powder.
Part A was manufactured in the manner of a paint and filtered through a 125 micron filter bag.
Part B was prepared as a simple mixture.
Part C was mixed under a gas blanket to exclude moisture and the silane preferably taken from fresh, dry stock.
In all cases moisture free grades were employed.
The parts were mixed thoroughly in the ratio of A:B:C of 2:1:0.2 by weight.
The order of mixing and the ratio of mixing is not critical but preferably mixing is continued for a period such as 5 minutes to ensure dispersion.
A substantial drop in viscosity occurs on addition of part C to part A indicative of wetting of the polytetrafluoroethylene by the silane.
The composition may be diluted for example with methyl isobutyl ketone to adjust viscosity to facilitate application to substrates by spraying.
EXAMPLE 2
A second embodiment according to the invention was prepared according to the following formulation.
______________________________________ Parts by weight______________________________________PART AEpotuff 54-105 Epoxy Resin 6.930Methyl Isobutyl Ketone 2.145Methyl Ethyl Ketone 2.950Butanol 0.250Nousperse 0.050Carbon Black 0.275PolytetrafluoroethylenePowder (Fluon L169A) 5.500PART BVersamid 54-405 4.0Methyl Ethyl Ketone 1.0PART CSilane 6020 0.165Accelerator HY960 0.480Xylene 0.175______________________________________
The parts were combined in the ratio A:B:C 23.437:5:0.82 by weight. Nousperse is an alkyd and lecithin based wetting agent obtainable from A. C. Hatrick Chemicals Pty., Ltd. Accelerator HY960 is a tri-dimethyl amino methyl phenyl catalyst hardener for epoxy resins obtainable from CIBA-GEIGY.
EXAMPLE 3
Panels of stainless steel were coated with the composition of Example 1 to a dry film thickness of 0.002 inch. The panels were prepared according to ASTM-D 609-52 (otherwise than in respect of the substrate since SAE 1010 specifies steel panels). The following test results were obtained
1. ELONGATION OF COATING WITH CONICAL MANDREL TESTER
ASTM D522-41
The coating passed on 3/8" mandrel (Elongation 6%)
2. EFFECT OF COMMON CHEMICALS ON THE COATING
ASTM D1308-57
Testing was done over two hours using both the covered and uncovered methods.
______________________________________(a) 50% ethyl alcohol NO MARKING(b) Vinegar (3% acetic Acid) NO MARKING(c) Detergent (20% Nonionic) NO MARKING(d) Lighter Fluid NO MARKING(e) Piece of cut fruit (orange) NO MARKING(f) Oils and Fats (Safflower, Butter) NO MARKING(g) Condiments (Mustard, Tomato Sauce) NO MARKING(h) Beverages (Tea, Coffee, Coca Cola) NO MARKING(j) Lubricating Grease NO MARKING______________________________________
3. WATER IMMERSION TEST
ASTM D870-54
Total testing time was 168 hours with regular visual checks. The coating passed with no visible blistering, wrinkling or film disintegration. It was noted that no loss of adhesion or color change occurred. The coefficient of friction was retested after immersion, and no change was noted.
4. KNOOP INDENTATION HARDNESS
ASTM D 1474-57T
Knoop hardness -28
5. TABOR ABRASOR ABRASION TEST
Less than 1% loss per 1000 cycles at 500 gm
Less than 5% variation on results when the test was repeated wet.
6. SNATCH TEST--PEEL ADHESION TEST
DEF 1044 -B
Pass
7. ADHESION GRID TEST
Pass--Class 1.
8. IMPACT RESISTANCE (DROPS G.E.) FALLING BALL METHOD
Mean result 560
9. COEFFICIENT OF FRICTION--INSTRON TESTER
Test at 25 psi at 5" per min.
(a) Against Steel--0.106
(b) Against Aluminum--0.150
(c) Against Hardwood--0.098
At higher speeds the coefficient of friction decreases marginally.
EXAMPLE 4
The compositions of Example 1 and Example 2 were applied to the metal skirt panels of a moving stairway after such panels were thoroughly cleaned with a toluol solvent. In this particular example, the compositions were applied as produced by spraying to a dry film thickness of about 0.002 inch. The coated skirts dried to a slippery, tough, adherent film in about six hours at normal room temperature. The drying time could be accelerated through the use of an external heater such as a blow drier. Attempts to force a rubber-shoe material, such as a sneaker, between the moving steps and the coated skirt panel were unsuccessful due to the highly lubricious character of the coating.
It can be seen that the composition of the present invention has utility in many situations where a dry lubricious coating having high abrasion resistance is desired. Preferred embodiments have exceptional adhesion to various substrates such as metal and glass and can also be used as a molding material when abrasion resistance and high slip properties in a molded form are desired for example, in sheet or strip form, in laminate form or as a surface lamination.
If the material is to be used in a coating process, the material is easily adapted for application by any method such as roller, brush or spraying, but is particularly adapted to application by spray to give an attractive smooth looking coating. Compositions according to the invention have particular utility in uses such as on skirt panels of moving stairways because of their high adhesions, high slip and abrasion resistant properties.
Although this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention. | A coating composition displaying an extremely low coefficient of friction particularly with respect to rubber-type materials and with high abrasion resistance and excellent adhesion to a wide variety of substrates, including metal and glass is provided. The composition contains a high fluorocarbon polymer content, (e.g., polytetrafluoroethylene), a silane wetting agent, a thermosetting resin (e.g. Epoxy), and optionally a crosslinking agent and is easy to apply. |
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to methods and devices for obtaining variable optical attenuation of a waive guide, and in particular to such methods and apparatus which cause radiation losses by selected curving of the waveguide.
Optical attenuation means making use of so-called fiber offset losses are known wherein two glass fibers are arranged with their respective end faces offset relative to one another. Adjustment of attenuation means of this type requires considerable technical outlay.
Other types of optical attenuation means are known which operate on the principal of absorption attenuation in imaging optical systems. Such attenuation means also typically require considerable technical outlay.
Attenuation means of the type described above all require as a condition for operation an enlargement of the fiber distance or line, which involves unavoidable additional signal losses.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for variable optical attenuation of a flexible waveguide which achieve such attenuation without difficult adjustment and without the need for imaging optical systems.
It is a further object of the present invention to provide such a method and apparatus which achieves exact and reproducable optical attenuation.
Another object of the present invention is to achieve such a method and apparatus which permits continuous adjustment from zero upwards.
Another object of the present invention is to provide such a method and apparatus which operates on a closed monomode optical waveguide.
The above objects are inventively achieved in a method and apparatus wherein a flexible monomode optical waveguide of specified length is guided in a defined manner around a means for imparting a variable curvature to the waveguide such that selected curvature-conditioned radiation losses result. An increasing curvature or curvature length of the waveguide increases such curvature-conditioned losses. Guidance of the monomode fiber which may, for example, be a glass fiber with cladding, may be varied constantly or in stages or steps. When the monomode fiber is guided in a mechanically curved fashion, defined attenuation values can be continuously adjusted.
The method and apparatus thus achieve a desired variable optical attenuation of a waveguide which requires only a means for variably spatially guiding the monomode fiber. Virtually no additional noise is introduced, therefore no noise-conditioned sensitive loss of the waveguide occurs.
The general theory of radiation losses caused by curving monomode fibers is described, for example, in "Curvature Loss Formula For Optical Fibers", Marcuse, J. Opt. Soc. Am., Vol. 66, No. 3, March 1976; "Bends in Optical Dielectric Guides", Marcatili, Bell System Technical Journal, September 1969; and "Analysis Of Curved Optical Waveguides By Conformal Transformation", Heiblum et al., IEEE Journal of Quantum Electronics, Vol QE-11, No. 2, February 1975.
The above articles consider this physical effect from the point of view that a attenuation and losses connected therewith are disadvantageous and should be avoided if possible. In contrast, the method and apparatus disclosed in claim herein advantageously exploit such radiation losses for achieving selected attenuation. Investigation has shown that conventional monomode fibers can withstand the mechanical demands associated with such curvature-induced attenuation in the context of the present method and apparatus. In accordance therewith, the curvature of the glass fiber may be varied along its entire length, or along only a portion of its length.
In one simplified embodiment of the method and apparatus a portion of the optical waveguide is subjected to a uniform curvature, with variable attenuation being achieved by causing an increased portion of the optical waveguide to conform to this uniform curvature.
In a further embodiment of the method and apparatus, a least a portion of the optical waveguide is subjected to a curvature or a radias of curvature which is variable.
In all embodiments, in order to achieve as precise an attenuation as possible, an optical waveguide should be employed which can assume substantially the same curvature as the mechanical guidance means. A fixed mechanical connection to the entire optical waveguide, in particular to the waveguide cross-section serves this purpose. Waveguides which are blank or solidly extrusion-coated fibers, preferably solidly extrusion-coated monomode fiber pigtails, are preferably employed.
Attenuators practicing the method and apparatus disclosed herein may be utilized in measuring arrangements for examining optical monomode light waveguide transmission systems, or as artificial extension lines.
The length of the optical waveguide is preferably selected such that the waveguide functions as a connection line, for example, between the transmitter or receiver and a first system-conditioned detachable interface.
In one embodiment of the apparatus, at least a portion of the optical waveguide is wound on a winding member. By winding an increased portion of the waveguide around the winding member, attenuation results to a selected degree. The winding element may have spindles rotatable in opposite directions and disposed on both sides of a supporting structure for reporting a loop of the optical waveguide.
The radius of curvature, in the axial direction of the spindles, may have various values corresponding to the desired characteristics of the optical attenuator. The spindle may thus be symmetrical or asymmetrical in relation to the central support of the optical waveguide. Upon winding of the optical waveguide on the spindle, the overall attenuation can be adjusted by adjusting the rotation angle of the spindle.
In another embodiment of the invention, the winding member is a double-threaded spindle with a constant radius of curvature. In this embodiment, the overall attenuation increases in a linear manner as the spindle is rotated and is thus directly adjustable by adjusting the rotational angle. The linear attenuation as a function of the rotational angle has an increasing gradient which is slightly dependent upon the wave length of the transmitted light, as well as upon the fiber properties, but is largely independent of temperature. Of particular advantage in this embodiment is the high stability of the adjusted attenuation over long term operation.
The two ends of the optical waveguide are preferably guided in a guide means also operably consistently with the winding member. The free ends of the optical waveguide may be supplied to the winding member tangentially and in parallel.
The guide device preferably includes a guide assembly, in the form of a double-spindle, a guide roller. By mounting the guide roller such that its distance relative to the guide assembly can be altered or adjusted, the tension of the optical wave guide during winding on the winding member can be adjusted. Additionally, by rotating the guide roller, the optical wave guide can be unwound from the winding member. A certain tension of the optical waveguide guarantees particularly low tolerances of the attenuation through the rotational angle.
In another embodiment of the invention, the waveguide is guided by means of at least one guide member having a semicircular shape such that a portion of the waveguide is pushed against the circumference of the guide member and conforms to the shape thereof.
Another embodiment of the apparatus includes a return device such that a portion of the waveguide entering the return device can be attenuated by causing that portion of the waveguide to conform to a serpentine surface of a guide element by means of a generally circular moveable slide which forces the waveguide into engagement with the surface, and the portion of the waveguide exiting from the return device can also be displaced in the opposite direction by a substantially mirror-image unit. The radius of the adjustment disk slideable transversely with respect to the waveguide specifies the maximum adjustable curvature radius. This embodiment is particularly useful as an extension line.
The optical waveguide may be tensioned by means of the return device.
In another embodiment of the invention the serpentine surface of the guide element may be formed by one or more rotatable disks disposed in sequence with the transversely slideable disks movable therebetween. The embodiment has the advantage that the attenuation, proceeding from a small minimum value, can be altered within a relatively large range in an approximately linear fashion by displacement of one guide roller.
In another embodiment suitable for use as an optical extension line, a support means including an arrangement of several guide members, in the form of cylindrical journals, and further including locking devices for supporting the waveguide is provided. The cylindrical journals are disposed on a rectangularly shaped support in rows and columns, and the locking means are disposed on the exterior of the support substantially centrally between two adjacent rows or columns.
For monomode optical waveguides transmitting light having a wave length in a range of approximately 1275 nm through approximately 1310 nm, suitable attenuation can be achieved by varying the diameter of curvature in the range of approximately 18 to 23 mm.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a prospective view of an optical wave guide attenuator constructed in accordance with the principals of the present invention.
FIG. 2 is a prospective view of a double-threaded spindle for use in the apparatus shown in FIG. 1.
FIG. 3 is a sectional view of the spindle shown in FIG. 2 taken along line III--III.
FIG. 4 is a prospective view of a further embodiment of a double-threaded spindle for use in the apparatus shown in FIG. 1.
FIG. 5 is an alternative embodiment for a support mount for the feed roller for the apparatus shown in FIG. 1.
FIG. 6 is a side view of another embodiment of an optical attenuator constructed in accordance with the principals of the present invention having laterally adjustable disk-shaped slides.
FIG. 7 is a top plan view of the embodiment shown in FIG. 6.
FIG. 8 is an end view of the apparatus shown in FIG. 6.
FIG. 9 is a side view of another embodiment of an optical attenuator constructed in accordance with the principals of the present invention having laterally adjustable disk shaped slides and a supporting frame having disk shaped rollers.
FIG. 10 is a top plan view of the apparatus shown in FIG. 9.
FIG. 11 is an end view of the apparatus shown in FIG. 9.
FIG. 12 is a plan view of a portion of an optical attenuator constructed in accordance with the principals of the present invention having adjustable guide rollers.
FIG. 13 is a top plan view of a further embodiment of the apparatus shown in FIG. 12.
FIG. 14 is a sectional view of the embodiment shown in FIG. 13 taken along line XIV--XIV.
FIG. 15 is an enlarged side view of the guide rollers for use in the apparatus shown in FIGS. 12-14.
FIG. 16 is a plan view of a futher embodiment of an optical attenuator constructed in accordance with the principals of the present invention for use as an extension line with selectable attenuation.
FIG. 17 is a sectional view of the embodiment shown in FIG. 16 taken along line XVII--XVII.
FIG. 18 is an attenuation diagram for selecting the diameter of the attenuation curvature.
FIG. 19 is an attenuation diagram for the optical attenuator shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of an optical attenuator constructed in accordance with the principals of the present invention is shown in FIG. 1 for imparting selected attenuation to a flexible optical waveguide 1.
The optical attenuator has a supporting frame 2 having a base 22 and two vertical walls 21 and 23. The frame 2 supports an attenuation spindle 3 having a shaft 37 received in bearing brackets 34 and 36 connected to the walls 21 and 23. The shaft 37 has an operating knob 33 at one end thereof in the form of a circular disk.
The attenuation spindle 3 has a central portion with a clamp 35 attached thereto for clamping a loop 10 of the optical waveguide 1. The outer portions of the attenuation spindle 3 are provided with spiral grooves running in the manner of a right-hand thread 31 and a left-hand thread 32.
The free ends of the optical waveguide 1, disposed on both sides of the loop 10, are respectively guided by means of a guide or feed spindle 4 and a guide roller 5. The guide spindle 4 has a shaft 47 rotatably received in the walls 21 and 23, and the guide roller 5 has a shaft 57 received in bearing brackets 54 and 56 connected to the walls 21 and 23. The guide roller 5 has a circular operating knob 53 connected to one end of the shaft 57.
The free ends of the optical waveguide 1, disposed on both sides of the looped end, are respectively received in guide grooves 41 and 42 disposed at outer portions of the guide spindle 4 so as to cause the free ends of the waveguide 1 to tangentially approach the attenuation spindle 3 in parallel. Rotation of the attenuation spindle 3 in the direction of the arrow causes the two ends of the optical waveguide to be wound on the spindle 3.
In order to increase attenuation, the operating knob 33 is rotated further in the direction of the arrow. Tension which stretchs or strains the optical waveguide 1 results from the contact pressure provided by the guide roller 5.
In order to reduce attenuation, the operating knob 53 is rotated in the direction of the arrow. The guide roller 4 entrains the optical waveguide 1, projecting slightly from the guide grooves 41 and 42, and slightly unwinds it from the attenuation spindle 3. In order to maintain the optical waveguide 1 stretched under such conditions, the bearing for the shaft 37 of the attenuation spindle 3 may be mounted with a certain friction or may have a breaking device associated therewith. The guide spindle 4 consists, at least on its surface, of a material which is suitable for entraining the optical waveguide, such as an elastic material, preferably rubber. In addition, it is preferable that the cladding of the optical waveguide 1 have a surface which ensures a certain adhesion to the guide spindle 4.
In some applications, which require attenuation of less precision, such as in the case of an extension line, the guide assembly consisting of the guide spindle 4 and the guide roller 5 may be omitted.
It is also within the scope of the subject matter disclosed and claimed herein to mechanically couple the shafts 37, 47, and 57 by suitable gearing or by toothed reeled rims so as to be able to simultaneously drive those shafts by means of a drive unit. If a motor-controlled regulated drive is employed, the tension can be controlled by means of slip disks attached to the shafts 37 and 47.
In order to achieve exact reproducability of the attenuation, the attenuator shown in FIG. 1 can readily be calibrated such that the progression of the attenuation is measured by the rotational angle of the attenuation spindle 3. If the attenuator shown in FIG. 1 is to be utilized with an automatic control means, this attenuation progression may be entered into a memory, the memory being utilized for controlling subsequent operation of the attenuator, such that small attenuation values can be adjusted in a specified manner.
Another embodiment of a guide spindle for use in the attenuator shown in FIG. 1 is shown in FIG. 2, which does not require the clamp 35. The spindle 3' shown in FIG. 2 has a curved guide groove 38 connecting the outer spiral guide grooves. A loop of the waveguide 1 can be inserted in the groove 38 and secured therein, such as by cementing with a suitable adhesive. In order to achieve a basic beginning attenuation which is as low possible, the guide groove 38 (as well as the loop 10 in the embodiment shown in FIG. 1), should have a radius of curvature which is as large as possible.
The attenuation spindle 3' is shown in sectional view in FIG. 3 showing how the guide groove 38, containing the waveguide 1, merges into a first flight 39 of one of the spiral threads.
A further embodiment 3" of the attenuators spindle is shown in FIG. 4, this embodiment having a cam 3a disposed in a center thereof, about which the loop 10 of the waveguide 1 is formed.
A modified bearing bracket 56' is shown in FIG. 5 which permits vertical movement of the guide roller 5 with respect to the guide spindle 4 so as to permit adjustment of the contact pressure in the nip formed between those rolls. The modified bearing bracket 56', when viewed from above, has an H-profile and is received in a recess 23' in the wall 23 so as to be vertically slideable therein. Once adjusted, the position of the bracket 56' can be fixed by tightening a clamp 58.
Another embodiment of an attenuator construction in accordance with the principles of the present invention is shown in side, top and end views in FIGS. 6 through 8. In this embodiment, the waive guide is subjected to a curvature along several portions of its lenght. By the use of two curvature slides as shown in this embodiment, an attenuation of two times 10 dB can be obtained.
The embodiment of FIGS. 6 though 8 has a generally rectangular supporting base 6 which has two pairs of communicating recesses 80 and 80a extending transversely therethrough. The term transversely as used herein means substantially perpendicular to the longest dimension of the support base 6. The waveguide, although not shown in FIGS. 6 through 8, extends through the attenuator along this longest dimension.
The support base 6 is provided with two side covers 61 each of which have smaller diameter recesses for receiving a threaded axle 81, which extends through the recess 80 in the support base 6. The threaded axle 81 is held at one end by a snap washer 82 and has a knob 84 at its opposite end.
A slide 83a having an interior threaded bore through which the threaded axle 81 extends has a disk 83 attached thereto. Rotation of the knob 84 causes rotation of the axle 81, in turn displacing the slide 83a such that the disk 83 moves transversely within the recess 83a. The axle 81, the slide 83a and the disk 83 comprise an adjustment assembly 8. The attenuator is provided with another adjustment assembly 8' consisting of identical elements.
The upper surface of the support base 6 has a serpentine recess therein into which the disks 83 are movable. The recesses have a curved segment therebetween providing a continuous curved path.
A return device is provided at one end of the attenuator connected to the support base 6. The return device includes a channel 7 having a coil spring 76 received therein having a free end connected to a slide 72. The coil spring 76 normally urges the slide 72 away from the support base 6, movement of the slide 76 being limited by a pin 71. The slide 72 has a cross-section in the form of a double-U for receiving a waveguide loop. The waveguide is held within the slide 72 by a clamp 73 attached thereto by a screws 74 and 75.
The opposite end of the support base 6 has another clamping device 62, of similar cross-section, with a clamp 63 held thereon by screws 64 and 65.
The support base 6 is covered by a cover plate 68 comprised of transparent material. The cover plate 68 is held to the support base 6 by screws 66 received in slots which permit adjustment of the cover plate 68 to accommodate different thicknesses of waveguide. Locating pins 67 also assist in positioning the cover 68 with respect to the support base 6.
The waveguide enters the attenuator through the clamping assembly 62 and is guided along the serpentine recess in the support base 6. The waveguide is deflected by a selected amount by rotation of the knobs 84 for the attenuation assemblies 8 and 8', causing one or both of the disks 83 to engage the wageguide and impart a greater or less curvature to the waveguide in the form of an S-curve. The waveguide is to be exposed to as low a tentile stress as possible, therefor the attenuation 8 and 8' are preferably actuated in a specified sequence with decreasing distance from the return device. In the embodiment shown in FIGS. 6 through 8, the right assembly 8' is the first to be deflected and the last to be reset.
The disks 83 are of a material such as plastic which permits the optical waveguide to slide along the circumference thereof. In order to reduce the friction of the waveguide, the disks 83 may be rotatably mounted on the slides 83a.
An embodiment showing such pivotally mounted disks 83' is shown in FIGS. 9 through 11. This embodiment also employs rotatable disks 69 mounted on the upper surface of the support base 6' and against which the waveguide slides as it longitudinally moves through the attenuator. In this embodiment, the lower portion of the support base 6' is provided with adjustable screws 66. Components corresponding to those already identified in connection with FIGS. 6 through 8 have been provided with the same reference numerals.
A further embodiment of an attenuator constructed in accordance with the principals of the present invention is partially shown in FIG. 12. In this embodiment the optical waveguide 1 is deflected by a guide roller 96 from a normal straight line a, the waveguide 1 being normally urged along this straight line by a coil spring 100 between clamping devices 91 and 101. The waveguide 1 is guided in a loop by three displaceably mounted guide rollers, 95, 96 and 97.
The guide roller 96 is mounted so as to be movable along a straight line b. The shafts of the guide rollers 95 and 97 are mounted so as to be displaceable relative to each other along a straight line c, which is perpendicular to the line b.
The guide rollers 95 and 97 are normally urged toward each other by respective springs 94 and 94' which are part of support elements 92 and 92' disposed on opposite sides of the rollers 95 and 97. The guide roller 96 may be displaced by means of a threaded rod similar to that described in the earlier embodiments (not shown in FIG. 12) along the straight line b. The guide roller 96 is thus movable between the rollers 95 and 97 and forces those rollers apart against the action of the springs 94 and 94'. When forced apart, the respective circumferences of the rollers 95 and 97 move along the straight line a
The optical waveguide 1 extends between the support mountings 92 and 92' and guide elements 93 and 93' on both sides of the guide roller pair 95 and 97 along the straight line a. The waveguide 1 is also guided around the circumference of the roller 96. If the roller 96 is in the position indicated by the solid line in FIG. 12, the waveguide is reflected out of the straight line a in the manner of a wavecrest such that the crest is determined by the guide roller 96 and the wavetroughs are determined by the guide rollers 95 and 97. At the other extreme position 96', indicated by dashed lines in FIG. 12, the guide roller 96' is disposed centrally with respect to the guide rollers 95 and 97. The optical waveguide 1 winds around approximately 5/6 of the circumference of the guide roller 96' and engages approximately 5/12 of the circumferences of the guide rollers 95 and 97.
Attenuation occurs according to an archtangent dependency and is approximately proportional to the path ΔS along which the guide roller 96 moves, and is therefor also approximately proportional to the number of revolutions of the threaded rod which moves the guide roller 96. The portion of the optical waveguide 1 subjected to a curvature corresponding to the radius r of the guide rollers 95, 96 and 97 may be altered between a minimum value corresponding to the length 2πr/3 and a maximum value corresponding to the length 10πr/3.
Further details of an attenuator constructed along the lines of FIG. 12 are shown in FIGS. 13 and 14. In FIGS. 13 and 14, the reference symbol 96 refers to the centrally disposed guide roller, as in FIG. 12, and the remaining two guide rollers, corresponding to guide rollers 95 and 97 in FIG. 12, are referenced 98 and 99 in FIG. 13. The guide rollers 96, 98 and 99 are disposed so as to be in circumferential contact. The relative movement of the guide rollers is as described in connection with FIG. 12.
The guide roller 96 is supported on a slide 102 which is moveable in a guide groove along a straight line in a upper frame comprised of elements 117 and 118 (shown in FIG. 14). The slide 102 (and the roller 96) are caused to move within the guide slot by rotation of a threaded axle 114 by means of a knob 115. The opposite end of the axle 114 is affixed by a snap ring 116. The rollers 98 and 99 are mounted on respective vertical shafts 106. The shaft 106 has a roller 105 thereon movable within a slot 103 in the frame elements 117 and 118, and the shaft 109 has a similar roller 108 moveable with a slot 110. Additionally, the roller 106 terminates in an abutment 104 engaging a spreading rod 111 mounted on a carrier 113 below the slide 102. Similarly, the shaft 109 terminates in an abutment 107 engaging another spreader rod 112 connected to the carrier 113. The abutments 104 and 107 and the carrier 113 are disposed in a recess formed by a bottom frame member 119.
As shown in FIG. 13, the attenuator has a clamping means 91 disposed at one side thereof and a turning device, only a portion of which can be seen in FIG. 13, which is the same as shown in the embodiments of FIGS. 6 through 11. The waveguide enters the attenuator through the clamping device 91 and curves around the surface of the roller 96 and is returned by means of the return device. As the knob 115 is rotated, the slide 102 and the roller 96 are caused to move between the rollers 98 and 99, the spreader rods 111 and 112 causing those rollers to move apart. An extreme position 102' for the slide and 96' for the roller is shown in FIG. 13, at which position the waveguide forms a complete loop around the roller.
The attenuator of FIG. 13 is covered with a cover plate 120.
The guide rollers 95 and 97 in the embodiment of FIG. 12 (and 98 and 99 in the embodiment of FIG. 13) have a groove as shown in FIG. 15 (only roller 97 being shown therein). The inner diameter of the roller 97 is equal to the diameter (2r) of the roller 96. The depth d of the groove is at least equal to the maximum diameter of the optical waveguide, for example, approximately 2 mm.
The embodiment shown in FIGS. 16 and 17 is particularly suitable for use as an extension line. In this embodiment, a 1-piece molded element 130 has a plurality of molded disks 132, 133, 134, 135, 136 and 137 thereon arranged in two columns and three rows. At the edge of the element 130 are recesses at which clamping devices 138, 139, 140, 141, 142 and 143 are located. The optical waveguide is mounted at one of these clamping devices at the respective entry and exit points of the element 130.
The clamping devices 138 and 143 are centrally disposed along the narrower edges of the element 130, with a recess extending therebetween esentially dividing the element 130 in half. The clamping devices 139 and 141 are disposed on opposite sides of the element 130, as are the clamping devices 140 and 142, with recesses extending between those respective pairs of clamping devices bounded on each side by one of the disks.
Between any two oppositely disposed clamping means, therefore, a path for the waveguide exists, and between any two adjacent disks there exists a region at which the guide grooves intersect. After the waveguide has been inserted in the guide grooves and wound around as many of the disks as needed, the unit may be covered by a cover plate 131.
It is also possible to manufacture the embodiment shown in FIG. 16 with the disks 132 through 137 simply projecting upwardly from a base plate, in which case guide grooves are not necessary.
By guiding the optical waveguide around as many of the disks as needed, attenuation can be adjusted in increments corresponding to multiples of πr/2, where r is the radius of the disks 132 through 137. In the embodiment shown in FIG. 16, wherein the waveguide is indicted by the broken line, attenuation amounts correspond to a curvature length of 5πr/2.
In order to achieve different attenuation values, the radius r may be varied within a permissable range r min ≦r≦r max . The number of disks may be reduced or expanded depending upon the amount of attenuation needed for particular applications.
The characteristic attenuation for a specific monomode optical waveguide at a specific wavelength (1275 nm) is designated by curve A in FIG. 18. As used herein the term "characteristic attenuation" means the attenuation per curvature loop with a respective curvature radius.
Curves B and C shown in FIG. 18 indicate the dependency of the waveguide curve guidance length upon the curvature diameter φ for specific attenuations (curve B: 40 dB; curve C: 10 dB).
From the corelation shown in FIG. 18, dimensioning of the radius of curvature can be selected. If, for example, a maximum curved waveguide length of one meter is selected as an upper practical boundary, a curvature diameter of approximately 23 mm results for the upper boundary of the curvature diameter.
In order to achieve as compact an apparatus as possible, small curvature diameters causing large characteristic attenuation values are of advantage. Investigations have shown, however, that wherein good reproducability of the attenuation adjustment is necessary, a lower boundary, below which the curvature cannot fall, exists. In the illustrated example, this boundary is a curvature diameter of 18 mm. This boundary generally lies at higher curvature diameters than the boundary values for mechanical loading capacity, which must also be taken into consideration.
The monomode optical fiber for which such investigations were undertaken has the following specifications:
Core diameter: 10 micrometers
Cladding diameter: 120 micrometers
Refractive index difference/core/cladding: 0.003
Cut-off wavelength: 1.225 micrometers
The cut-off wavelength is the wavelength at which the transition to the dual mode fiber occurs.
In the use of other monomode optical waveguides and/or other light wavelengths, the same criteria must be taken into account in measurement of the curvature diameter as long as the optical waveguide is to be operated in a monomode range.
The scatter or dispersion of the characteristic attenuation for various pigtails of the same fiber type is shown in FIG. 19 for the attenuator of the type depicted in FIG. 1 having a curvature diameter of 23.5 mm for various operating wavelengths. The linear corelation between the angle of rotation on the horizontal axis and the attenuation on the verticle axis is apparent.
Although modifications and changes may be suggested by those skilled in the art it is the intention of the inventors to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of their contribution to the art. | A method and apparatus for variable attenuation of a flexible optical waveguide empart a variable curvature to the waveguide such that selected, conditioned radition losses result. In one embodiment the curvature is emparted by winding a portion of the waveguide around a grooved roller, in other embodiments the curvature is emparted by slides which are laterally moveable within curved recesses of a supporting frame, the slides engaging the waveguide and causing the waveguide to conform to varying portions of the curved recesses. |
BACKGROUND OF THE INVENTION
The invention relates to a heat-sealable barrier laminate structure which produces an oxygen impermeable, leak free container. More particularly, this invention relates to barrier laminate structures which are comprised of specific high strength polymer resin layers which effectively prevent heat activation pinholes, cuts or cracking of oxygen barrier layers caused during scoring and especially during folding and heat sealing of the laminate in package formation.
The invention as disclosed and claimed herein is related to pending application Ser. Nos. 191,987; 191,988 now U.S. Pat. No. 4,888,822; 191,989 now U.S. Pat. No. 4,880,701; and 191,337 now U.S. Pat. No. 4,859,513, all owned by the Assignee and filed concurrently herewith. In addition, structures for paperboard containers using heat-sealable polymer resins and containing various oxygen barrier materials are disclosed in U.S. Pat. Nos. 3,972,467; 4,698,246; 4,701,360; 4,789,575; and 4,806,399, all owned by the Assignee.
Heat-sealable low density polyethylenes are well known to be components of current paperboard food and/or non-food packages which provide little barrier to the transmission of oxygen. Pinholes, cuts, score lines or channels, existent in conventional packaging and cartons, create additional leakage sites. It is well known that impermeable materials such as aluminum foil, polar brittle materials such as: polyacrylonitriles, polyvinylidene chlorides, polyvinyl chlorides, etc., provide varying degrees of barrier to the transfer of oxygen. However, all these materials lack the requisite strength at high rates of deformation, namely stress cracking resistance during scoring, package formation and distribution abuse to provide a resultant oxygen impermeable and airtight structure. In addition, leakage through the uncaulked channels of the carton in the top, bottom and side seam have likewise resulted in poor whole carton oxygen barrier properties.
The existing commercial structures for a paperboard carton for liquid and solid, food and non-food, products have utilized an easily heat-sealable barrier laminate composed of a paperboard substrate and a foil oxygen barrier layer, both being sandwiched between two thick layers of low density polyethylene (LDPE). The LDPE is a relatively inexpensive heat-sealable moisture barrier material. The conventional structure falters in that the foil layer which acts as the barrier to the transmission of oxygen in and out of the carton cracks during blank conversion, carton formation, and package distribution stages.
Bending and folding occurring during the formation of a gable "type" top, flat "type" top, or other folded, heat-sealed top closure, and a fin-sealed, or other conventional folded bottom puts excessive amounts of local stress on the thin foil and/or other oxygen barrier layer and, as typically results, cracks and pinholes appear.
To date, there have been no economically attractive commercially available paperboard packages which consistently approach the oxygen impermeability of glass or metal containers. The object of the present invention is to produce an oxygen impermeable, leak free container and/or laminate structure such as a paperboard based package or carton that prevents the transmission of gases therethrough, and in addition, prevents the escape of flavor components or the ingress of contaminates. A further object of the present invention is to produce such a package that is economical on a per-package cost basis, is fundamentally compatible with existing converting machinery and can be formed, filled and sealed at economically high speeds using conventional packaging machine temperatures, pressures and dwell times.
Another object of the present invention is to provide this oxygen impermeable package in a variety of applications including four-ounce to 128-ounce containers, or larger, as required by the packager.
A further object of this invention is to incorporate a functional polymer layer which exhibits high strength, abuse resistance and toughness during converting and carton forming in combination with aluminum foil or other oxygen barrier layers and paper, paperboard or other mechanically stable structural material such that the high-strength layer reduces the stresses incurred by the barrier layers during blank conversion, package formation, and distribution. Additionally, should a penetration of the barrier layer or layers occur, the high-strength layer serves to maintain package integrity at the failure site. The high-strength, heat-resistant layer effectively prevents heat activation pinholes through the product contact layer, even when non-foil barrier layers are used.
SUMMARY OF THE INVENTION
A preferred embodiment of the invention reveals an oxygen impermeable leak free barrier laminate, side-seamed blank and/or container providing a total barrier to the loss of essential food flavor oils or non-food components over an extended product shelf-life as well as an absolute barrier to the transmission of oxygen during the same extended shelf-life period. A preferred embodiment of the laminate structure comprises, from the outer surface to the inner surface, contacting the essential oils, flavors and/or components of food or non-food products: an exterior layer of a low density polyethylene, a mechanically stable structural substrate, such as a paper or paperboard material, a corrugated board, or a stiff polymer resin material such as high density polyethylene, polypropylene or the like, a co-extruded interior layer of an abuse resistant polymer such as a polyamide type polymer (nylon 6) and a caulking polymer resin such as an ionomer type resin (Surlyn® 1652), an oxygen barrier layer such as an aluminum foil layer, a second layer of a caulking polymer resin such as an ionomer type polymer (Surlyn® 1652), and a layer of low density polyethylene in contact with the food o non-food product rendering the laminate structure heat-sealable.
The cartons, side-seamed blanks, or containers constructed of the laminate of the present invention enable significant containment of gases in the container as well as preventing any migration of oxygen or contaminants into the structure. The present invention has produced a suitable container which has the ultimate barrier properties. It utilizes a laminate which can be heat-sealed easily with its exterior and interior layers being like, non-polar constituents. During the heat-seal processes, the scoring processes, the side-seaming processes, and the folding, forming and filling steps, the particular caulking polymer resins, namely ionomer type resins, ethylene acrylic acid copolymers, ethylene methacrylic acid copolymers, ethylene vinyl acetate copolymers, ethylene methylacrylate copolymers and the like have melt indexes which allow them to flow during the heat-sealing processes (temperatures ranging from 250° F.-500° F.).The particular selected resins act as a caulking agent to fill the channels produced during formation of the gable, or other type flat top, the fin-sealed, or other conventional type bottom and the skived side seam. Consequently, each of those gap areas is caulked to prevent the transmission of oxygen therethrough. In addition, the selection of the particular abuse resistant polymer, namely polyamide type polymers, polyester type polymers and ethylene vinyl alcohol copolymers or the like acts to prevent any type of significant deformation damage to the foil or other oxygen barrier layer which would result in a crack or pinhole allowing for the seepage of oxygen therethrough.
The preferred package structures formed from the preferred novel laminates of the present invention not only exhibit these novel oxygen impermeable and/or other high barrier properties, but the novel laminate structures are produced using conventional coextrusion coating equipment.
The novel laminate structure and materials selected therefor, namely the particular caulking polymer resins and abuse resistant polymer resins contemplated by the present invention, coupled with oxygen impermeable or high oxygen barrier materials, in various combinations, can be utilized in a variety of food or non-food packaging applications.
In one application, the preferred laminate structure is produced using conventional coextrusion coating equipment.
Secondly, this laminate is printed and forwarded through scoring dies and cutting dies to create flat blanks which are placed on conventional machinery for further preparation.
Thirdly, these flat blanks are skived and folded and side-seamed to create the side-seamed blanks. During the heat-sealing step of the side-seam operation, the resins which have been selected for their particular melt flow characteristics, caulk and seal along the seam. Resins which have melt flow indexes ranging from 4.5-14.0 are preferred. These side-seamed blanks are then forwarded to the particular customer for further assemblage.
Fourth, these side-seamed blanks are magazine fed into a machine wherein they are opened and placed on a mandrel, wherein sealing of the bottom takes place.
Typically, the bottom folding and sealing is where most of the damage to the interior thin barrier foil layer occurs in conventional cartons. Utilization of a particular strong polymer resin, comprising an abuse resistant polymer, such as a polyamide type polymer, prevents cracking of the foil layer during the bottom sealing process. The bottom is fully heat-sealed into a flat configuration at which time caulking polymer resins, such as ionomer resins, flow in a caulking manner to seal the bottom. The container or package is then forwarded to the filling step. Next, the top is "prebroken" and filled with the particular product and then top-sealed. Again, much damage is done to the foil or other barrier layer during this top-sealing process of conventional cartons. The utilization of the novel abuse resistant and caulking polymer resin constituents in the barrier laminate acts to prevent any damage to the foil or non-foil barrier layer and produce a top closure which has been caulked to doubly prevent any transport of oxygen.
The novel barrier laminate produced by the present invention not only exhibits excellent oxygen barrier properties and can be easily constructed, but also meets FDA approval for use in food packaging. The resins heat seal at low temperatures (250° F. to 500° F.) and the structures can be converted and cut on conventional machinery.
Thus, until the advent of the present invention, no suitable oxygen impermeable, leak free containers or packages have been developed which retain the advantages of using mechanically stable structural substrates such as paperboard or the like as the base material and FDA approved heat-sealable barrier layers which are economical and can be produced using conventional coextrusion coating equipment.
The present invention described herein is particularly useful as a coated paperboard structure employed in the packaging of food and non-food products. These types of containers make use of a heat-seal for seaming and closing, and are utilized in the formation of folding boxes, square rectangular cartons or containers, or even cylindrical tubes.
In addition, the novel combinations of caulking polymer resins, abuse resistant polymers and oxygen impermeable and/or high oxygen barrier materials have other applications as well.
Namely, the combination of high oxygen barrier materials such as ethylene vinyl alcohol copolymers o other brittle oxygen barrier materials coupled with abuse resistant type polymer resins such as polyamide type polymers or the like, have applications in combination with almost any mechanically stable structural substrate. Particularly, multilayer blow-molded containers incorporating abuse resistant polymer resins in combination with high oxygen barrier materials is one of the novel applications of this invention.
One specific example of such an application is the utilization of ethylene vinyl alcohol copolymer in combination with a polyamide type polymer mounted on a high density polyethylene structural substrate. The polyamide type polymer acts to protect the brittle ethylene vinyl alcohol copolymer oxygen barrier layer from abuse during shipping and transport of the overall container structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional elevation of the preferred embodiment of the laminate of the present invention;
FIG. 2 is a cross-sectional elevation of an alternate embodiment of the laminate of the present invention;
FIG. 3 is a cross-sectional elevation of an alternate embodiment of the laminate;
FIG. 4 is a cross-sectional elevation of an alternate embodiment of the laminate; and
FIG. 5 is a cross-sectional elevation of an alternate embodiment of the laminate.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the invention is for an hermetic, oxygen impermeable leak free and/or high oxygen barrier leak free package incorporating a laminate structure as disclosed in FIG. 1. All weights given for particular laminate layers are expressed in pounds per 3,000 square feet. Disclosed is a mechanically stable structural substrate 12 which is most suitably high grade paperboard stock, for example, 200-300 lbs. or higher sized carton board, to which is applied on one side a coating of a low density polyethylene polymer 10 in a coating weight of about 20 lbs. Layer 10 is the "gloss" layer which contacts the outer atmosphere. An extrusion coating grade LDPE having a melt flow index ranging from 4.0 to 7.0 is suitable for use herein. On the underside or interior portion of the paperboard substrate 12 is coextruded thereon a combined layer of an abuse resistant polymer resin such as a polyamide type polymer (nylon 6), 14, in a coating weight of about 7.5 lbs., with a caulking polymer resin such as an ionomer type resin (Surlyn® 1652), 16, in a coating weight of about 5.5 lbs. Laminated thereon is an absolute oxygen impermeable material or a high oxygen barrier material, such as a 0.000285-0.0005 inch layer of aluminum foil 18. Coated on the outer layer of the foil is a second layer of a caulking polymer resin such as an ionomer type resin (Surlyn® 1652), 20, in a coating weight of about 5 lbs., and lastly coated thereon is a second layer of a low density polyethylene polymer 22, in a coating weight of about 20 lbs. rendering the entire laminate structure heat sealable on conventional heat-seal equipment at conventional heat seal temperatures (250° F.-500° F.).
Referring to FIG. 2, an alternate preferred embodiment of the laminate of the present invention is shown. The embodiment adds additional layers of low density polyethylene (LDPE) as well as a layer of ethylene vinyl alcohol copolymer (EVOH) which provides additional barrier protection to the overall container structure. In this alternate preferred embodiment, the mechanically stable structural substrate 26, such as a paperboard substrate, having a weight of 200-300 lbs. or higher for a quart, half-gallon, gallon or larger structures, has extrusion coated on its external surface a 24 lb. layer of a low density polyethylene polymer 24. On the internal surface of the mechanically stable structural substrate 26, is applied a 12 lb. coating of a caulking polymer resin such as an ionomer type resin (Surlyn® 1652), 28. Laminated thereon is a 0.000285-0.0005 inch layer of an oxygen barrier material (aluminum foil) 30. Coextruded onto the exposed surface of the foil 30 is a sandwich 33 comprising a 9 lb. layer of a caulking polymer resin such as an ionomer type resin (Surlyn® 1652), 32, and a 3 lb. layer of a low density polyethylene polymer 34. Coated onto the first coextruded sandwich layer 33 is a second coextruded layer 39 comprising from interior contacting layer 33 to exterior, a 10 lb. layer of a low density polyethylene polymer 36, a 2 lb. adhesive tie layer, such as a Plexar 177®, 38, a 12 lb. layer of an ethylene vinyl alcohol copolymer, such as EVAL SCLE 105B, 40, a second 2 lb. adhesive tie layer, such as a Plexar 177®, 42, and an exterior 10 lb. layer of a low density polyethylene polymer 44. Finally, coated thereon, is a 22 lb. layer of a low density polyethylene polymer 46 which in combination with layer 24 renders the entire laminate structure heat sealable.
FIG. 3 is a modified version of the alternate preferred embodiment outlined in FIG. 2 dropping various interior layers of low density polyethylene. The structure is described as follows: a mechanically stable structural substrate such as a paperboard layer having a weight of 200-300 lbs., or higher, 50 is coated on its exterior with a layer of 20 lbs. of a low density polyethylene polymer 48. On the interior side of the mechanically stable structural substrate 50 is a coextruded sandwich 53 comprised of a 7 lb. layer of an abuse resistant polymer such as a polyamide type polymer (nylon 6), 52, and a 4 lb. layer of a caulking polymer resin such as an ionomer resin (Surlyn® 1652), 54. An adhesive tie layer, such as Plexar 177®, 56, having a weight of 3.5 lbs., an oxygen barrier layer, such as an aluminum foil having a thickness of 0.000285-0.0005 inches, 58, which acts as an absolute barrier to the transmission of oxygen and a second adhesive tie layer, such as a Plexar 177®, 60, in a weight of 3.5 lbs. are all coextruded onto said coextruded sandwich 53. Finally, a 25 lb. layer of a caulking polymer resin such as an ionomer resin (Surlyn® 1652), 62, is coated onto the second coextruded sandwich 57 and an interior food contact layer of low density polyethylene 64 having a weight of 2 lbs. is placed thereon. The addition of layer 64 in combination with layer 48 allows for a better heat seal between the outer and inner layers.
Referring to FIG. 4, another preferred embodiment of the invention is disclosed. A mechanically stable structural substrate such as a paperboard substrate having a weight of 200-300 lbs., or higher, 68 is coated with a 24 lb. layer of a low density polyethylene polymer on its exterior 66. On the interior layer of the substrate 68 is coextruded the following laminate structure 75: a 10 lb. layer of low density polyethylene 70, a 12 lb. layer of an abuse resistant polymer resin such as a polyamide type polymer (nylon 6), 71, a 2 lb. adhesive tie layer, such as a Plexar 177®, 72, an oxygen impermeable layer such as an aluminum foil layer having a thickness of 0.000285-0.005 inches, 74, a second 2 lb. adhesive tie layer such as Plexar 177®, 76 and a 10 lb. layer of a caulking polymer resin, such as (Surlyn® 1652), 78. Finally coated onto the coextruded layer is a 22 lb layer of low density polyethylene 80 which in combination with layer 66 allows for the final heat-sealable uniform homogeneous laminate structure.
Referring to FIG. 5, an alternate preferred embodiment of the invention is depicted as follows: a mechanically stable structural substrate such as a paperboard substrate having a weight of 200-300 lbs., or higher, 84 has coated on its exterior a 24 lb. layer of a low density polyethylene polymer 82. On its interior, a 12 lb. layer of a caulking polymer such as an ionomer type resin (Surlyn® 1652), 86, is coated thereon. Laminated onto said caulking polymer layer, 86, is a 0.000285-0.0005 inch oxygen barrier layer (aluminum foil) 88. Coextruded on the interior portion of the aluminum foil layer 88 is a sandwich 93 of 4 lbs., an adhesive tie layer, such as Plexar® 177, 90, 7 lbs. of an abuse resistant polymer such as a polyamide type resin (nylon 6), 92, and 4 lbs. of a second adhesive tie layer such as Plexar® 177, 94. Lastly, coated on the interior portion of the laminate sandwich 93 is a 25 lb. layer of a low density polyethylene polymer 96, to render the laminate structure heat sealable.
Although specific coating techniques have been described, any appropriate technique for applying the layers onto the mechanically stable structural substrate can be suitably employed, such as extrusion, coextrusion or adhesive lamination of single layer and/or multilayer films t the mechanically stable structural substrate to achieve the stated inventions of this patent. The unique effect provided by the oxygen impermeable, leak free packages made from the laminate of the present invention is clearly demonstrated by the following Examples outlined in Table I. The preferred embodiment of the present invention is listed as the "International Paper oxygen impermeable half-gallon" and it utilizes as its mechanically stable structural substrate a 282 lb. layer of paperboard. The preferred structure is compared in Table I to a variety of commercial paperboard based and non-paperboard based containers currently available in the market place and recommended for extended shelf-life applications.
TABLE I__________________________________________________________________________Average Whole Container Oxygen Transmission Rates (OTR) OTR (CC/M.sup.2 /Day) Avg., CC O.sub.2 /Pkg./Day To Fill -Container (75° F., 50% RH, in Air) Volume (ml) Ratio*__________________________________________________________________________INTERNATIONAL PAPER 0.000 0.000(OXYGEN IMPERMEABLEHALF-GALLON)TOPPAN, EP-PAK (1500 ml) 0.005 0.004WITH PLASTIC FITMENTINTERNATIONAL PAPER 0.016 0.2ASEPTIC (250 ml.)TETRA BRIK-PAK (250 ml.) 0.013 0.2CAPRI-SUN POUCH 0.01 0.3(200 ml.)TREESWEET COMPOSITE 0.29 0.4FIBER CAN (1360 ml.)CONOFFAST CUP 0.022 0.4(250 ml.)INTERNATIONAL PAPER 1.11 0.5HOT FILL (2000 ml.)GALLON HDPE 2.75 0.5(BLOW MOLDED BOTTLE)HALF-GALLON HDPE 1.98 1.1(BLOW MOLDED BOTTLE)HYPAPAK (700 ml.) 0.52 1.7HAWAIAN PUNCH COMPOSITE 0.09 2.0CAN (236 ml.)COMBIBLOCK (250 ml.) 0.21 3.2JUICE BOWL COMPOSITE 0.34 4.1CAN (355 ml.)__________________________________________________________________________ *All numbers should be multiplied by 10.sup.-2
It can be seen that the container prepared from a laminate of the present invention provides a complete hermetic barrier to the transport of oxygen.
The specially selected abuse resistant polymer constituents such as the polyamide type polymers which make up the container are resilient enough to prevent any type of cutting, pinholing, or other damage caused during the converting, carton formation and distribution steps. In addition, the container utilizes ionomer type resins as caulking material for the channels and seams.
The mechanically stable structural substrate may consist of a paper or paperboard material, a corrugated type board material or a stiff polymer resin material such as high density polyethylene, polypropylene or the like.
The barrier layer may consist of an aluminum foil, an ethylene vinyl alcohol copolymer, a polyvinyl alcohol polymer, a polyethylene terephthalate, a polybutylene terephthalate, a glycol-modified polyethylene terephthalate, an acid-modified polyethylene terephthalate, a vinylidene chloride copolymer, a polyvinyl chloride polymer, a vinyl chloride copolymer, a polyamide polymer or a polyamide copolymer, or combinations of these materials.
The preferred embodiments of the present invention utilize an aluminum foil layer as the primary absolute oxygen and flavor oil barrier material. All of the above-identified materials could be utilized in all alternate embodiments in place of the foil layer as well as in the preferred embodiment of the invention. The barrier and high strength layers may be applied as film laminations and/or as extrusion coatings.
The invention may be used in materials for all types of blank fed or web fed package forming equipment. The effectiveness of the laminate of the present invention as an oxygen impermeable package structure permits significant extension of shelf-life of the products packaged in the containers.
The tough, high strength, abuse resistant type materials can be selected from the following group of polymers: polyamide type polymers such as the preferred Nylon 6, or Nylon 6/66, Nylon 6/12, Nylon 6/9, Nylon 6/10, Nylon 11, Nylon 12; polyethylene terephthalate; polybutylene terephthalate; and ethylene vinyl alcohol copolymers; or other similar tough, high strength polymeric materials which have tensile strengths of 10,000 psi or greater at conventional heat-seal temperatures (250° F.-500° F.).
In addition, the high strength, low viscosity caulking resins preferred are selected from the following group of polymers: ionomer type resins, such as the preferred zinc or sodium salts of ethylene methacrylic acid (Surlyn® 1652 or the like); ethylene acrylic acid copolymers; ethylene methacrylic acid copolymers; ethylene vinyl acetate copolymers; ethylene methylacrylate copolymers; and the like, all exhibiting melt flow indexes ranging from 4.5-14.0.
Adhesive tie layers preferred are selected from the following: Plexars® from Quantum Chemical Co.; CXA's® from Dupont; Admer's® from Mitsui, and similar performing tie resins.
The common generic name for the preferred adhesives are: Plexars® are ethylene based copolymers with grafted functional groups; CXA's® are modified polyethylene resin containing vinyl acetate acrylate; and Admers® are polyethylene copolymer based materials with grafted functional groups.
Additional abuse resistant polymers, caulking polymer resins, mechanically stable structural substrates, oxygen barrier materials, and adhesive tie layers which meet the specifications and requirements outlined above could also be utilized to practice the present invention.
This invention provides a means of transforming the economical, high volume, gable top or flat top paperboard or non-paperboard food/non-food carton into an oxygen impermeable, leak free package that can be produced, sold, and filled economically at high production speeds, offering a low-cost hermetic packaging alternative to glass and metal, with the bulk of one embodiment of the package being biodegradable paperboard from a renewable resource. | The present invention relates to an improved container for food and non-food products. The container utilizes a novel paperboard barrier laminate structure which maintains an isolated gas environment in the container. The laminate makes use of high strength, heat-resistant and caulking polymer layers which prevent pinholes, cuts, or cracking of the barrier layers during blank conversion, package formation, and package distribution. In addition, the novel polymer resin layers act to caulk the seams and channels present in the carton providing a sealed leak free container. |
FIELD OF THE INVENTION
This invention relates generally to electronic control systems for automotive engines and more particularly, although in its broader aspects not exclusively, to an arrangement to compensate for errors associated with a functioning or failed fuel type sensor.
BACKGROUND OF THE INVENTION
Modern automotive engines contain electronic engine control systems which vary operating parameters of the engine such as air-fuel ratios and ignition timing to achieve optimum performance. Such control systems are capable of changing engine operating parameters in response to a variety of external conditions.
A primary function of electronic engine control systems is to maintain the ratio of air and fuel at or near stoichiometry. Electronic engine control systems operate in a variety of modes depending on engine conditions, such as starting, rapid acceleration, sudden deceleration, and idle. One mode of operation is known as closed-loop control. Under closed-loop control, the amount of fuel delivered is determined primarily by the concentration of oxygen in the exhaust gas. The concentration of oxygen in the exhaust gas being indicative of the ratio of air and fuel that has been ignited.
The oxygen in the exhaust gas is sensed by a Heated Exhaust Gas Oxygen (HEGO) sensor. The electronic fuel control system adjusts the amount of fuel being delivered in response to the output of the HEGO sensor. A sensor output indicating a rich air/fuel mixture (an air/fuel mixture above stoichiometry) will result in a decrease in the amount of fuel being delivered. A sensor output indicating a lean air/fuel mixture (an air/fuel mixture below stoichiometry) will result in an increase in the amount of fuel being delivered.
Engines which are capable of operating on different fuels, such as gasoline, methanol, a mixture of the two, or natural gas, utilize electronic engine control systems to change the engine operating parameters in response to the type of fuel being delivered to the engine. Such systems utilize a sensor to detect the type of fuel being delivered to the engine and an electronic engine control to vary the operating parameters accordingly. An instance of such a system is disclosed in U.S. Pat. No. 4,706,629 issued to Wineland et al.
Unfortunately, it is possible for the sensor to indicate erroneous mixture values under certain operating conditions. For example, in the instance of liquid fuels, if the fuel is 100% gasoline, but of a different composition than that used to "calibrate" the sensor, the sensor might indicate that the fuel is a mixture of gasoline and methanol rather than 100% gasoline. Since different mixtures of gasoline and methanol all have different burn rates and stoichiometric air/fuel values, errors in sensing the mixture can produce poor driveability, bad air/fuel control, and excessive exhaust emissions.
A similar problem occurs with engines that use natural gas as a fuel. Natural gas is an unregulated fuel which consists mostly of methane with varying amounts of ethane, propane, butane, and other inert gases. Each of these gases are characterized by different combustion properties, and consequently, the air/fuel ratio and ignition timing requirements differ with the gas composition. As with liquid fuels, errors in sensing the mixture can produce poor driveability, bad air/fuel control, and excessive exhaust emissions.
In the event that the flexible fuel sensor fails, the operating parameters which are dependent on the output of the fuel type sensor will be erroneous. Unlike systems which operate with a single type of fuel, an engine capable of, and actually operating on different fuels cannot revert to a preset value if the fuel sensor fails. As a result, the electronic fuel control system will continually vary the operating parameters to adjust for a detected fuel which is erroneous. Such a condition will at best lead to poor driveability, bad air/fuel control, and excessive exhaust emissions, and at worst can lead to complete failure of the engine.
SUMMARY OF THE INVENTION
The preferred embodiment of the invention compensates for inaccuracies in a fuel-type sensor, thereby improving the dynamic response and static performance of an internal combustion engine and obtaining higher catalyst conversion efficiencies, lower tail pipe emissions, and increased engine efficiency.
The arrangement contemplated by the present invention operates in conjunction with a closed-loop air/fuel mixture control system in which the oxygen level in the combustion products exhausted by the engine is monitored to vary the air/fuel mixture supplied to the engine, thereby maintaining the mixture near stoichiometry. In order to adapt to varying operating conditions, the closed-loop air/fuel mixture control system stores an array of control values which are adaptively varied whenever the closed-loop system fails to maintain the exhaust oxygen level within prescribed limits. These control values are advantageously stored in a lookup table which is indexed by values indicating engine speed and load (air charge). If the closed-loop system is unable to control the air/fuel ratio at or near stoichiometry for a given engine speed and load, a control value indexed by that given speed and load is incremented or decremented until stoichiometry is achieved, and the new "learned" control value is then retained in the lookup table (implemented with a non-volatile memory so that the stored table values are not lost when the vehicle's ignition key is turned off).
At least one of these stored control values is monitored to insure that it stays within a predetermined range of acceptable values. If the monitored value departs from that range, it is assumed that the departure is due to a faulty fuel-type sensor. In that event, further efforts to vary the control value in the table are temporarily discontinued. Instead, as contemplated by the present invention, a pair of adaptively varied control values are maintained to selectively modify the fuel-type signal from the sensor to drive the air/fuel mixture toward stoichiometry. In this way, the system according to the invention compensates for fuel-type sensor errors by two independent adaptive mechanisms which allow the normal fuel control adaptive variables in the lookup table to remain at more nearly normal levels.
In accordance with an important aspect of the present invention, the first adaptive control value that is monitored is indexed by a selected high rpm, high load engine operating condition. In this way, other engine malfunctions, which might be erroneously interpreted as a fuel-type sensor error, produce effects having relatively low magnitudes compared to the effects of a fuel-type sensor failure. In this way, the adaptive fuel control lookup table mechanism is made to perform the function of a selective filter which isolates fuel-type sensor errors from other errors which might otherwise lead to counterproductive adaptive corrections.
The second adaptive control value becomes operational when total sensor failure is detected, and responds much more rapidly in an effort to correct the malfunction by executing a combination of strategies to insure that the engine returns to normal operation: first, the normal limits on the exhaust oxygen level signal are relaxed, permitting that signal level to reach greater magnitudes in an effort to achieve stoichiometry; second, the second control variable is altered whenever an out-of-range value is detected, regardless of whether the engine is operating at the designated high-speed, high-load point; third, un-needed processing, such as the adaptive fuel canister purge routine, is discontinued as long as the system is operating in failure mode; and fourth, the system is forced into closed loop control to adaptively alter the second control variable, even when the exhaust gas sensor does not indicate an oxygen level transition, whenever a predetermined time interval has elapsed.
These and other features and advantages of the present invention will become more apparent through a consideration of the following detailed description of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic block diagram of an automotive fuel delivery system and electronic engine control system which embodies the invention;
FIG. 2 depicts the output of a proportional + integral controller for determining an output for a set of injectors based on a heated exhaust gas oxygen sensor;
FIG. 3 is a flowchart depicting the operation of a preferred embodiment of the invention;
FIG. 4 is a flowchart illustrating the manner in which closed loop operation is forced in the failure mode;
FIGS. 5 and 6 are flowcharts illustrating the process by which the two adaptive fuel type control variables are selectively altered depending upon whether or not the system is operating in failure mode;
FIG. 7 is a flowchart illustrating the manner in which the fuel canister purge mode is disabled during failure mode;
FIG. 8 is a flowchart which depicts the initialization of the two fuel type control variables at system startup; and
FIG. 9 is a flowchart which shows the manner is which the limits on the oxygen level signal are selectively relaxed during failure mode to increase the systems ability to achieve stoichiometry.
DETAILED DESCRIPTION
FIG. 1 of the drawings shows a system which embodies the principles of the invention. A fuel pump 12 pumps fuel from a fuel tank 10 through a fuel line 13 to a set of fuel injectors 14 which inject fuel into an internal combustion engine 11. The fuel injectors 14 are of conventional design and are positioned to inject fuel into their associated cylinder in precise quantities. The fuel tank 10 advantageously contains liquid fuels such as, gasoline, methanol, or a combination of fuel types.
A fuel-type sensor 24, positioned along the fuel line 13, optically detects the type of fuel being pumped to the fuel injectors 14 by measuring the refractive index of the fuel and transmits the resulting fuel-type signal 9 to an electronic engine controller (EEC) which implements the functions shown, in block diagram form, within the dashed line 100 in FIG. 1.
The EEC functions 100 are preferably implemented by one or more microcontrollers, each is comprised of one or more integrated circuits providing a processor, a read-only memory (ROM) which stores the programs executed by the processor and configuration data, peripheral data handling circuits, and a random access read/write scratchpad memory for storing dynamically changing data. These microcontrollers typically include built-in analog-to-digital conversion capabilities useful for translating analog signals from sensors and the like into digitally expressed values, as well as timer/counters for generating timed interrupts. Such microcontrollers are available from a variety of sources and include the Motorola 6800 family of devices which are described in detail in Motorola's Microprocessor and Microcontroller Families, Volume 1 (1988), published by Motorola, Inc., Microcontroller Division, Oak Hill, Tex.
The analog-to-digital converters (not shown) convert sensor signals, such as the fuel-type signal 9, into digital form for storage in the RAM memory. A mass air flow detector 15 positioned at the air intake of engine 11 detect the amount of air being supplied to cylinders for combustion. A heated exhaust gas oxygen (HEGO) sensor 30, positioned on the exhaust system 31 of the engine 11, detects the oxygen content of the exhaust gas generated by the engine 11, and transmits a representative signal 8 to the EEC 100. Still other sensors, indicated generally at 101, provide additional information about engine performance to the EEC 100, such as crankshaft position and speed, throttle position, etc., from which provide information on engine operating conditions which is used by the EEC 100 to control engine operation. As indicated at 20, The fuel-type signal 9 is used in this way to produce a desired air/fuel ratio (AFR) value 21 which corresponds to the type of fuel detected by the fuel-type sensor 24.
The memory within the EEC stores the fuel-type values which are supplied by the fuel-type sensor 24. Power to the writable memory which stores these fuel-type values is maintained even when the engine is turned off so as to maintain the information stored in the memory. Termed a "Keep Alive Memory" (KAM), this section of the memory is continuously powered by the vehicle battery, even when the ignition key is turned off, and advantageously allows values which describe past engine performance to be "learned" and then used later to better control the subsequent operation of the engine. The air/fuel ratio module 20 delivers the AFR signal 21 to the fuel-type sensor correction module 19 which corrects the air/fuel ratio for sensor error in the manner to be described.
A microcontroller within the EEC 100 further implements a Proportional + Integral (PI) controller seen at 36 which responds to the HEGO signal 8 to control the amount of fuel delivered by the injectors 14 by supplying a fuel rate control signal called LAMBSE to a further control module 16 which, in turn, supplies the fuel delivery rate control signal 17 to the injectors 14.
The input of to the PI controller 36 is supplied via a HEGO signal filter 32 which filters the HEGO signal value 8 to eliminate high frequency noise. Concurrently, the output of the PI controller 36 is applied to an adaptive logic module 41 which also receives data concerning engine speed and load (aircharge normalized to sea level) from a module 50 which processes sensor signals 51 and 52 from the engine sensors 101. The speed/load module 50 processes the signals on sensor lines 51 and 52 and transmits speed and load indicating values to the adaptive logic block 41.
The PI controller 36 determines, according to the filtered HEGO signal 5, whether the fuel delivery rate at the injectors 14 is to be increased or decreased, depending upon whether the HEGO sensor 30 indicates an oxygen level above or below stoichiometry, respectively. The PI controller 36 may take the form described by Zechnall, et al. in SAE Paper No. 730566, or by D. R. Hamburg and M. A. Schulman in SAE Paper 800826.
The graph in FIG. 2 shows the operation of a typical PI controller 36. The solid waveshape illustrates the fuel-rate signal applied to the fuel injectors in response the oxygen level in the combustion products as detected and measured by an exhaust sensor. The dashed line in FIG. 2 illustrates the variation in exhaust gas oxygen level at the sensor. Increasingly lean air/fuel ratios are represented by positive-going increases of the dotted line, while increasingly rich air/fuel ratios are represented by negative going increases of the dotted line. The lean and rich indications along the vertical axis in FIG. 2 indicate the direction of the solid line. Positive-going increases on the graph thus indicate instances where the PI controller 36 is commanding a leaner air/fuel ratio, while negative-going increases indicate instances where the PI controller 36 is commanding a richer air/fuel ratio.
As illustrated in FIG. 2, the fuel rate control system increases the amount of fuel injected whenever the exhaust oxygen sensor detects an oxygen level greater than stoichiometry, and decreases the amount of fuel injected whenever the exhaust gas sensor indicates that fuel in excess of stoichiometry has been injected. The PI controller 36 implements the control function by responding to the HEGO exhaust gas sensor 30 which operates as a simple switch, delivering either a positive or negative input signal to a simple integrator, depending on whether the exhaust gases are rich or lean. The integrator in turn generates a sawtooth ramp-waveshape which is combined with a component proportional to the square-wave HEGO signal, to produce the composite control signal, called "LAMBSE", indicated in FIG. 1. The LAMBSE signal is then used by the injection control signal generator module 16 to calculate the fuel delivery rate control signal based on the relation: ##EQU1## where MAF is the mass airflow rate per cylinder, AFR is the air/fuel ratio from module 44 (corrected for sensor error in the manner to be described), LAMBSE is the control signal developed from the HEGO sensor by the PI controller 36, and σO i is an error signal developed by the adaptive controller unit 40 to be described. The dashed horizontal lines in FIG. 2 represent allowable maximum (LAMMAX) and minimum (LAMMIN) limits for PI controller output signal LAMBSE.
The air/fuel ratio correction module 44 seen in FIG. 1 operates in conjunction with the adaptive learning module 40 to correct for errors in the fuel-type signal 9. As seen at the block 20 in FIG. 1, the air/fuel ratio correction module 44 first obtains an uncorrected the air/fuel ratio from a lookup table stored in read-only memory based on the value of fuel-type signal 9, whose magnitude indicates the refractive index of the fuel. The conversion of the fuel-type signal 9 to the uncorrected air/fuel ratio value limits that value, for example, to a minimum of 6 and a maximum of 15. The uncorrected AFR value 21 from the lookup table is then corrected at block 19 to create the value AFR in accordance with the relationship:
AFR=AFR.sub.uncorrected ×(1+AFRMOD)
where AFR -- MOD is a correction value stored in a register 43.
The corrected air/fuel ratio value AFR generated by the air/fuel ratio correction module 46 is supplied to the ignition timing block 53 to vary the time position of the ignition timing signal 54 supplied to the engine 11, and is also supplied to the injector control signal generator 16 which varies the magnitude of the injector control signal 17 supplied to the injectors 14 to control the rate at which fuel is delivered to the engine.
The adaptive learning module, shown generally within the dashed rectangle 40 as shown in FIG. 1, comprises an adaptive logic unit 41 and an adaptive fuel table 42. The adaptive fuel table 42 is a lookup table in memory comprising a two-dimensional array of learned fuel system correction values, each cell being addressed by a first and second values indicating engine speed and load respectively as supplied by the speed/load unit 50 seen in FIG. 1. The table 42 advantageously contains eight rows (indexed by normalized load value) by ten columns (indexed by normalized engine speed values), or 80 cells, plus either four or six special idle adaptive cells, resulting in 86 total cells. The value in each cell may range from 0 to 1. Ideally, if LAMBSE=1.0 and data from a mature adaptive fuel table 42 is used, a stoichiometric air/fuel ratio will result at any speed-load point where adaptive learning has taken place.
The adaptive logic unit 41 controls the functions of the adaptive learning module 40. The cell value that is read from table 42 varies between 0.0 and 1.0 and is increased, by the adaptive logic unit 41, by the offset value 0.5 to generate the fuel correction factor σO i supplied to the fuel injector control signal generator 16. Thus the fuel correction factor σO i will range advantageously from 0.5 to 1.5.
The adaptive learning module 40 operates under the control of the adaptive logic unit 41 to implement an adaptive learning strategy which enhances the performance of the engine. Fuel injected systems may exhibit vehicle to vehicle steady state air/fuel ratio errors due to normal variability in fuel system components. The adaptive learning module alleviates this problem by memorizing the characteristics of the individual fuel system being used. This memorized information is used to predict what the system will do based on past experience. The ability to predict fuel system behavior improves both open loop and closed loop fuel control. As an example, the memorized information can be used on cold starts to achieve better open loop fuel control before the HEGO sensor reaches operating temperature. The chief benefit of the adaptive fuel strategy however, is to reduce the effects of product variability in the field.
The adaptive learning module 40 operates as follows: The output of the PI controller 36 (LAMBSE) is checked against the upper and lower calibratable limits. The adaptive learning module 40 will determine LAMBSE to be outside of the calibratable range if LAMBSE is greater than the upper calibratable limit or less than the lower calibratable limit. This limit is specific to each type of engine in which the control system is installed and is typically about 1%. Thus, if LAMBSE exceeds the limit by more than 1%, the cell in the adaptive table 42 corresponding to the speed and load at which the engine is currently operating is decremented. If LAMBSE is below the limit by more than 1%, the cell in the adaptive table 42 corresponding to the speed and load at which the engine is currently operating is incremented to increase fuel delivery at that load and speed. Thus, each cell value is able to reflect an ongoing learned value representing the particularities of the specific engine in which the table 42 is installed.
Under high speed and high load conditions, the errors from the other sensors 101 may be expected to be small in comparison to errors caused by a faulty fuel-type sensor 24. Thus, at high speed and load, it may be safely assumed that any significant difference between the air/fuel ratio generated at 21 based on the detected fuel-type indicated by sensor 24, and the amount of fuel actually required to effect a switch in the HEGO sensor 30, is attributable largely to errors originating in the fuel-type sensor 24, which can be as high as 25%.
In accordance with the invention, a high speed/load region of operation of the engine 11 may be advantageously selected as being a "high confidence region" and, the engine is operating in this high confidence region, the value AFR -- MOD held in register 43 is varied as a function of LAMBSE to "learn" the errors in the fuel-type signal 9. This novel feature enhances combustion efficiency by more accurately compensating for inaccuracies in the output of the fuel-type sensor. When the engine 11 is operating at high speed and load the error from the other sensors 101 is minimal and any variation of HEGO from normal limits may be more confidently attributed to errors in the fuel-type sensor. Under these conditions, the register AFR -- MOD 43 is altered as a function of LAMBSE, which is generated as a function of the output of the HEGO sensor 30. The output of the HEGO sensor 30 will be representative of the accuracy of the air/fuel ratio 21. The invention thus contemplates learning the inaccuracies in the fuel-type sensor at high speed and loads to more accurately compensate for the inaccuracies in the fuel-type sensor.
The flowchart shown in FIG. 3 depicts the operation of the control system under conditions when the fuel-type sensor 24 is operating. First, as shown at 71 in FIG. 3, certain conditions are checked to determine if the adaptive fuel table is to be updated. The adaptive fuel table 42 will be updated if the engine has reached a certain steady state operating temperature, is not operating under highly transient throttle positions, and is under closed loop control.
If conditions to update the adaptive fuel table have been met, then, as shown at 72, a check is made to determine if the cell to be updated is the designated flexible fuel sensor (FFS) cell. This is done by checking to see if the engine is operating under the defined high speed/load conditions. If the engine is not operating at the defined high speed/load condition, then normal adaptive learning, as described above, is performed as indicated at 73.
If the cell to be updated is the high speed/load cell then, as shown at 74, a check is performed to determine whether the current fuel mixture is rich or lean. Step is performed by checking whether LAMBSE is being ramped in either the rich or lean direction. LAMBSE being ramped rich indicates that an lean condition has been detected by the HEGO sensor 30, and thus the high speed/load cell is designated to be decremented. LAMBSE being ramped lean indicates that a rich condition has been detected by the HEGO sensor 30, and thus the high speed/load cell is designated to be incremented.
If the high speed/load cell is to be incremented, then, as shown at 76, the cell is compared to determine if the value contained within it is greater than a predetermined maximum value FFS -- ADP -- HI for the cell. If the designated cell value is greater than or equal to FFS -- ADP -- HI, then, as shown at 79, AFR -- MOD is decremented and the value in the designated cell in table 42 is maintained. If the value is less than FFS -- ADP -- HI then, as shown at 80, AFR -- MOD is left unchanged and the value in the designated cell of table 42 is incremented.
If the air/fuel mixture detected by the HEGO sensor is lean as determined at 74, the designated cell value is compared against the lowest value allowed FFS -- ADP -- LO. If the cell is less than or equal to FFS -- ADP -- LO, then AFR -- MOD is incremented and the high speed/load cell is maintained as seen at 77. Otherwise, as shown at 78, the designated high speed/load cell is decremented and AFR -- MOD is maintained.
After AFR -- MOD or the adaptive table 42 have been updated, the air/fuel ratio is adjusted by the computation at 16, which processes the AFR value corrected at 19 using the current AFR -- MOD value which compensates for errors in the fuel-type sensor 24.
The corrected AFR value is also supplied to the ignition timing unit. In this way, the system better adapts to the varying ignition timing characteristics needed to advance or retard ignition to provide anti-knock control responsive to varying fuel octane characteristics.
In accordance with another feature of the invention, the adaptive AFR -- MOD value advantageously adjusts the long-term values contained throughout the adaptive table 42. For instance, as the fuel-type sensor 24 ages and the inaccuracies in the type of fuel detected become centered around a certain new point, the adaptive AFR -- MOD value effects the actual air/fuel mixture such that adaptive table 42 modifies its contents to accommodate for the long term change in the corrected fuel-type value AFR.
In accordance with the invention, when a failure in the fuel type sensor 24 is detected, a value AFR -- MOD -- FM contained in a register 47 is loaded and utilized in place of the value AFR -- MOD in register 43, and that failure mode value is thereafter used to learn the composition of the fuel type being injected into the engine. The flowcharts in FIGS. 4-9 depict the operation of these features. Before discussing the operations depicted in these flowcharts, it is necessary to note a number of initialization and control functions which are performed at the onset of the failure mode.
Failure Mode Initialization
In the event of a failure in the fuel type sensor 24, a failure mode flag (located at a predetermined memory address) named FFS -- FMFLG is set to 1, whereas FFS -- FMFLG equals zero if no failure has been identified. When FFS -- FMFLG is first set to 1, the value AFR -- MOD is loaded into register 47 from register 43 to initialize AFR -- MOD -- FM with whatever learned value exists for AFR -- MOD at the time.
AT this time also, the limits on the range within which LAMBSE is allowed to vary are widened by setting the lower LAMMIN boundary from its normal value of 0.75 to 0, and raising LAMMAX from its normal value of 1.25 to 1.99. When the fuel type sensor 24 has failed, the control system loses the ability to calculate an air/fuel ratio starting from a base value generated by the fuel type sensor. With a new fuel composition, with the fuel type sensor functioning, a dramatic change in the fuel type will result in dramatic difference in the base air/fuel ratio AFR being calculated. This base air/fuel ratio will then be modified slightly to generate a corrected, more accurate air/fuel ratio. When the fuel type sensor fails however, the ability of the control system to account for dramatic changes in fuel type must be maintained. Accordingly, the range of learning by widening the limits on LAMBSE to account for possible large variations in fuel type. As illustrated in FIG. 9 of the drawings, the allowable range limits for the LAMBSE variable are reset when the failure mode flag FFSFM -- FLG is set to 1.
In failure mode, not only must the range of learning be increased but also the rate at which learning occurs must be increased so as to increase the responsiveness of the control system to changes in fuel type. Consequently, the maximum limit FFS -- ADP -- HI and the minimum limit FFS -- ADP -- LO, which are the values against which AFR -- MOD or AFR -- MOD -- FM are compared to determine whether or not they should be changed, are brought closer together. Decrementing FFS -- ADP -- HI and incrementing FFS -- ADP -- LO increases the possibility that AFR -- MOD -- FM will be outside of the range set by these limits (when it is checked as discussed below), and thus increases the rate at which the composition of the fuel being ignited by the engine 11 is learned.
Finally, when the failed sensor is first detected, the "purge mode" of the engine control is disabled and the adaptive mode is enabled. Thus, the normal periodic disabling of the adaptive mode in order to purge the fuel lines vapor canister 93 of its contents no longer occurs. In failure mode, the control must remain in the adaptive mode because changes in fuel type, in the absence of a fuel type sensor, can only be accounted for in the adaptive mode. The failure mode flag FFSFM -- FLG which set and cleared by the system to indicate whether or not system is to operate in failure mode is interrogated, as depicted in the flowchart of FIG. 7, to control the enablement and disablement of the fuel canister purge routine.
FIG. 4 depicts the steps taken to force closed loop operation when the fuel type sensor 24 fails. Under normal conditions, closed loop control will be entered when the HEGO sensor 30 indicates a switch from rich to lean, or vice-versa. When the fuel type sensor 24 fails, all learning must take place as a function of the HEGO sensor output. Thus closed loop control must be maintained at all times when operating in the failure mode.
If during processing, the system would normally call for closed loop, rather than open loop, control, as indicated by a YES choice at decision block 130 in FIG. 4, control is passed to decision block 131. Closed loop control may be entered under one of two ways. If the HEGO sensor 30 is indicating a switch from rich to lean or vice-versa, then closed loop control will be entered at 134. The second way in which closed loop control will be entered is if, as shown at 132, a failure in the fuel type sensor 24 has been detected. If so, then, as shown at 133, closed loop control will be entered if the engine has been operating in the underspeed/run mode for at least 30 seconds. Thus, while the control system would normally wait for the HEGO sensor 30 to switch to enter closed loop control, the onset of failure mode operation forces the routine into closed loop control as a function of time since last entering the underspeed mode. This insures that adaptively determined fuel control values will be trained more rapidly than might otherwise be the case.
Having entered closed loop control, the system either alters the value of AFR -- MOD -- FM stored in register 47, or the currently indexed value in the adaptive table 42, in accordance with the procedure shown in FIGS. 5 and 6. The procedure for managing both AFR -- MOD and AFR -- MOD -- FM requires that the adaptive procedure shown in FIG. 3, which operated under the control of AFR -- MOD alone, be modified as shown in FIGS. 5 and 6.
In FIG. 5, as shown at 150, LAMBSE is checked against the range established by LAMMAX and LAMMIN (which, as noted earlier, are expanded when in failure mode), to determine if the mixture has become overly rich. If overly rich and the failure mode flag is set, as determined at 151, control is passed to the decision block 153 and AFR -- MOD -- FM instead of AFR -- MOD is varied.
Similarly, as shown in FIG. 6, when an overly lean mixture is detected at 160, and the failure mode flag is set as determined at 161, control is passed to routine beginning at decision block 163 to modify AFR -- MOD -- FM, rather than to decision block 162 which modifies AFR -- MOD. Note in both FIGS. 5 and 6 that the value AFR -- MOD -- FM is modified regardless of whether or not the engine is operating at the designated speed and load point, whereas AFR -- MOD is only modified when the engine is operating at the designated point. This too insures that the learning will progress rapidly when a sensor failure has been detected.
FIG. 8 depicts another feature of the failure mode strategy. As part of the failure mode strategy, the registers 43 and 47 storing AFR -- MOD and AFR -- MOD -- FM respectively are part of the "keep alive memory" which insures that, if the fuel type sensor 24 has failed and the engine is subsequently turned off, the values in AFR -- MOD and AFR -- MOD -- FM will keep the engine operating in the same manner as it was prior to failure of the fuel type sensor 24. It is only when a new type of fuel is pumped to the engine, that the learning procedure described in FIGS. 5 and 6 is critical. When the engine is restarted, it will take approximately two minutes for the new type of fuel to reach the injectors. During this time, the value contained in AFR -- MOD -- FM will provide a sufficiently accurate air/fuel ratio to start the engine 11 and keep it running until the EEC 1 is forced into closed loop control and quickly learns the composition of fuel being delivered to the injectors 14. Accordingly, as seen in FIG. 8, when the system begins operation, a check is made at 141 to determine if the keep alive memory is retaining prior values or has been re-initialized. If it has been re-initialized, both AFR -- MOD and AFR -- MOD -- FM are set to zero as seen at 142. Otherwise, AFR -- MOD and AFR -- MOD -- FM use the current values stored in the KAM memory as indicated at 143.
FIG. 3 depicts the operation of the EEC 1 under conditions when the fuel type sensor 24 is operating. First, as shown at 71 in FIG. 7, certain conditions are checked to determine if the adaptive fuel table is to be updated. The adaptive fuel table 42 will be updated if the engine has reached a certain steady state operating temperature, is not operating under highly transient throttle positions, and is under closed loop control.
If conditions to update the adaptive fuel table have been met, then, as shown at 72, a check is made to determine if the cell to be updated is the designated flexible fuel sensor (FFS) cell. This is done by checking to see if the engine is operating under high speed/load conditions. If the engine is not under high speed/load conditions then normal adaptive learning, as described above, is performed 73.
If the cell to be updated is the high speed/load cell then, as shown at 74, it is checked to determine if it is to be incremented. This step is performed by checking whether LAMBSE is being ramped in either the rich or lean direction. LAMBSE being ramped rich indicates that an overly lean condition has been detected by the HEGO sensor 30, and thus the high speed/load cell is designated to be decremented. LAMBSE being ramped lean indicates that an overly rich condition has been detected by the HEGO sensor 30, and thus the high speed/load cell is designated to be incremented.
If the high speed/load cell is to be incremented, then, as shown at 76, the cell is compared to determine if the value contained within it is greater than a predetermined maximum value for the cell. If the value is greater than or equal to the predetermined maximum value, then, as shown at 79, AFR -- MOD 43 is decremented and the value in the designated cell is maintained. If the value is less than the predetermined maximum value then, as shown at 80, AFR -- MOD 43 is maintained at its existing value and the value in the designated cell is incremented.
If the high speed/load cell is not to be incremented then, as shown at 75, it is compared against the lowest value allowed in the high speed/load cell. If the high speed/load cell is less than or equal to this value, then AFR -- MOD 43 is incremented and the high speed/load cell is maintained 77. Otherwise, as shown at 78, the high speed/load cell is decremented and AFR -- MOD 43 is maintained.
After AFR -- MOD 43 or the adaptive table 42 has been updated, the air/fuel ratio is corrected using AFR -- MOD 43 to compensate for errors in the fuel type sensor 24. The result of this computation is then used to generate the signal for the injectors 14 and the ignition timing unit 53 according to the equation shown at 16 in FIG. 1.
In accordance with another feature of the invention, the corrected air/fuel ratio is used to control the ignition timing of the engine. The output of the air/fuel ratio correction module 44 is used by the ignition timing module 53 to generate ignition timing signals for the engine 11. In this way the varying ignition requirements for different types of fuel, along with sensor errors in detecting the type of fuel are accounted for in generating the spark to ignite the air/fuel mixture.
In accordance with another feature of the invention, AFR -- MOD 43 is used to periodically alter the contents of the adaptive table 42. This functionality alters the adaptive table 42 to long term changes in the fuel type sensor 24. For instance, as the fuel type sensor 24 ages and the inaccuracies in the type of fuel detected become centered around a certain new point, AFR -- MOD 43 will learn of this new point and update the adaptive table 42 to modify its contents to accommodate for the long term change in the output of the fuel type sensor 24.
It is to be understood that the specific embodiment which has been described is illustrative of only one application of the principles of the invention. Numerous modifications may be made to the specific methods and apparatus disclosed without departing from the true spirit and scope of the invention. | An air/fuel control system for use with an internal combustion engine which is adapted to burn fuels having different combustion characteristics. The control system compensates for errors in the fuel-type signal produced by a sensor and provides a failure mode of operation when the sensor fails. A closed-loop air/fuel mixture controller responds to sensed exhaust oxygen levels to maintain combustion near stoichiometry. When the errors from the fuel type sensor predominate, at high engine speed and load, a selected one of two fuel-type variables, is adaptively modified. The first variable is modified in response to the control system's inability to achieve stoichiometry during high speed/high load operation, a condition which causes the first variable to correct the fuel type signal from the sensor. The second variable assumes control when the first variable is unable to achieve stoichiometry, indicating sensor failure, and is updated in accordance with a more vigorous strategy. The second variable is modified regardless of engine speed and load, and closed-loop adaptive processing is forced even when the exhaust level signal no longer switches. The limits on the exhaust level signal are relaxed to allow it to grow to larger magnitudes, and processing which is not needed during failure mode is discontinued to allow adaptive processing to proceed more rapidly. |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefits of and priority to U.S. Provisional Patent Application Ser. No. 60/722,073 entitled “MODIFIED ACME SCREW/NUT SET” which was filed on Sep. 29, 2005, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND
1. Field of the Disclosure
The present disclosure relates to an Acme screw/nut set, and more particularly to an Acme screw/nut set having a modified thread design.
2. Background of the Art
Drive mechanisms for different applications utilizing a lead screw as a driver usually use a standard Acme screw class G or C. A standard centralizing Acme screw/nut set class C has defined tolerances per ANSI B1.8 specification. Those tolerances provide very low clearances between the thread of the nut and the thread of the screw. For example: a 1-½-5 ACME thread class 2C has the following clearances:
for a major diameter a radial clearance is R min =0.0012″ to 0.0098″ and
for a pitch diameter an axial clearance is A min =0.0025″ to 0.14″.
The clearances are extremely low for the lower tolerance range. Therefore, a problem arises when using dissimilar materials with significantly different thermal expansion coefficients (e.g. steel and nylon). That is, the clearances will close quickly when the temperature of the joint increases due to the heat generated by friction between the components in the drive mechanism. The problem is especially prevalent in a design where the nut is confined in a rigid housing, thereby restricting radial expansion and allowing expansion of the nut material mainly in the inward direction. The lack of clearance between the screw and the nut may initially result in a grinding noise and finally in seizing the motion of the joint.
The following example is illustrative:
Assume the following materials and dimensions:
Acme screw D=1-½″ major diameter and P=0.200″ made of carbon steel Acme Nut (modified) of same basic thread with O.D.=1.125″ and 2.5″ long made of nylon 6 with a thread engagement L=2.312″ Nut housing made of aluminum with bore B=2.125″ dia. Carbon steel has a coefficient of thermal expansion
CTE s 8.1*10 E−6 in./in. ° F.
Nylon 6 has a coefficient of thermal expansion
CTE n 0.45*10 E−4 in./in. ° F.
Aluminum housing has a coefficient of thermal expansion
CTE h 13.1*10 E−6 in./in. ° F.
For the screw/nut pair in this example, it would take a temperature increase (ΔT) of 17° F. from the ambient temperature to close the gap of 0.0012″.
The relevant calculations for determining the effect of a temperature rise on the gap are as follows:
The nut material would expand radially inward (Rn) (assuming zero outward expansion allowed by the housing)
Rn=Δt*CTE n *D =17*0.45*10 *E −4*1.5=0.0011475″
The screw material would expand radially outward (Rs)
Rs=ΔT*CTE s *D =17*8.1*10* E −6*1.5=0.00020655″
The housing material would expand radially outward (Rh) (allowing the nut to expand outward the same amount). However, the expansion of the housing material is to a lesser degree than the expansion of the screw and the nut, due at least in part to the fact that the temperature of the housing material rises only approximately 30% of the temperature rise of the two other components (based on taken measurements).
Rh= 0.3 *ΔT*CTEh (aluminum)* B =0.3*17*13.1*10 *E− 6*2.125=0.00014187″
The total expansion (R) of the joint in a radial direction may be calculated as follows:
R=Rn+Rs−Rh =0.0011475+0.00020655=0.00014197=0.001212″
The temperature of the Acme screw/nut surface may be subjected to temperatures up to 200° F. based on the material specification of nylon 6, for example, for a high load condition. Accordingly, undue friction and potential binding of machine parts may occur. The screw/nut design of the present disclosure may ameliorate such occurrences.
SUMMARY
The present disclosure relates to a nut and screw set which reduce the amount of hindered motion therebetween caused by thermal expansion of the screw and the nut. The nut and screw set includes a screw (e.g., made of steel) and a nut (e.g., made of plastic). The screw (e.g., a 1½-5 Acme screw) includes a plurality of screw threads and the nut includes a plurality of nut threads, such that the screw and the nut and threadably engagable with each other. The nut threads are sized to reduce hindered motion between the screw and the nut as a result of thermal expansion of the screw and the nut. The temperature change which causes the thermal expansion is disclosed to be between about 100° F. to about 160° F.
In a disclosed embodiment, the screw has a first coefficient of thermal expansion and the nut has a second coefficient of thermal expansion. The two coefficients of thermal expansion are not equal in an embodiment.
In an embodiment, the nut and screw set also includes a housing which is dimensioned to at least partially cover the nut. Additionally, a disclosed nut includes a nut groove which is defined between two adjacent nut threads. The width of the nut groove is disclosed to be in the range of about 0.079 inches to about 0.082 inches.
The present disclosure also relates to a method of modifying a nut in a nut and screw set to reduce hindered motion between the screw and the nut as a result of thermal expansion of the screw and the nut. A disclosed method includes providing a nut and a screw, calculating the amount of thermal expansion for the nut and the screw for a predetermined change in temperature, and increasing the width of the nut groove if the calculated amount of thermal expansion is greater than the existing width of the nut groove.
The present disclosure also relates to a method of determining the width of grooves of a nut in a nut and screw set to optimize operation therebetween and while considering thermal expansion of the nut and the screw.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.
FIG. 1 is a side view in partial cross-section of a screw/nut set in accordance with an embodiment of the present disclosure;
FIG. 2 is an enlarged side view in cross-section of a modified Acme thread configuration on major diameter in accordance with an embodiment the present disclosure;
FIG. 3 is a side view in cross-section of a modified Acme thread configuration on a major diameter in accordance with an embodiment of the present disclosure with the details showing the relation between radial and axial clearances in the thread; and
FIG. 4 is an enlarged side view in cross-section of a modified Acme thread configuration on a major diameter in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
Various embodiments of the presently disclosed Acme screw/nut set are described in detail with reference to the figures, in which like reference numerals identify corresponding elements throughout the several views. The abbreviation “e.g.” in the figures stands for “for example” indicating that the dimensions and angles shown in the figures are exemplary dimensions and angles.
In the context of drive mechanisms and other mechanical devices, a high load application commonly creates a high amount of friction and, consequently, a high temperature condition. The modification of an Acme nut in accordance with the present disclosure minimizes noise generation, excessive friction and motion seizure in a high load condition for Acme screws. A method of calculating the radial clearance required on the major thread diameter, in an effort to minimize loss of performance and motion is also disclosed.
Referring now to FIG. 1 , a screw/nut set 10 in accordance with the present disclosure is shown. Screw/nut set 10 includes an Acme screw 15 and a nut 20 . Nut 20 is illustrated mounted within nut housing 25 . Screw 15 may be an Acme Screw class C, and Acme nut 20 shown in FIG. 1 may include a modified internal thread in accordance with the present disclosure. Screw/nut set 10 illustrated in FIG. 1 is representative of a 1½-5 screw having a diameter (x) equal to 1.50 inches. The diameter (y) of nut 20 is equal to 2.125 inches. These dimensions are provided as examples only and not provided to, nor intended to, limit the scope of this disclosure. It is contemplated that this disclosure is not directed to any one particular size screw and/or nut. Rather, the present disclosure may be applied to a plurality of screws and nuts having a plurality of different dimensions.
The following formula is applied to determine the minimum required clearance as a function of a predetermined temperature rise (ΔT) above the ambient temperature. The minimum required clearance is defined as the clearance necessary to essentially prevent seizure of the motion of the mechanical components at the elevated temperatures encountered during normal working conditions.
Since nut 20 is restrained on its outer periphery by housing 25 , as the temperature of nut 20 increases, nut 20 will expand radially inward. An assumption is being made that there will be no outward expansion of nut 20 due to the restraining force exerted by nut housing 25 . The amount of thermal expansion of nut 20 is calculated by the following equation where Rn is representative of the amount of thermal expansion. CTEn represents the coefficient of thermal expansion of the nut material, ΔT represents the raise in temperature from the ambient temperature, and D represents the major diameter of nut 20 .
Rn=ΔT*CTEn*D
Similarly, screw 15 is a solid mass and, therefore, will expand radially outward as its temperature increases. The amount of thermal expansion of screw 15 is calculated by the following equation where Rs is representative of the amount of thermal expansion of screw 15 . CTEs represents the coefficient of thermal expansion of the screw material, ΔT represents the raise in temperature from the ambient temperature, and D represents the major diameter of Acme screw 15 .
Rs=ΔT*CTEs*D
The material of nut housing 25 will also expand radially outward as its temperature increases. The amount of thermal expansion of the housing 25 is calculated by the following equation where Rh is representative of the amount of thermal expansion of nut housing 25 . Nut 20 is able to expand radially outward in an amount which is proportional to the amount of expansion of nut housing 25 . CTEh represents the coefficient of thermal expansion of the housing material, ΔT represents the raise in temperature from the ambient temperature, and the variable B represents the diameter of the bore of nut housing 25 .
Rh= 0.3 *ΔT*CTEh*B
The required clearance on the major diameter due to the thermal expansion may be calculated by the following equation:
R=Rn+Rs−Rh=ΔT*CTEn*D+=ΔT*CTEs*D −0.3 *ΔT*CTEh*B
R=ΔT{D ( CTEn+CTEs )−0.3 *CTEh*B}
Utilizing the values in the example described above, the following results are obtained:
R =17{1.5(0.45*10 *E −4+8.1*10 *E− 6)−0.3*13.1*10 *E− 6*2.125}=0.001212″
Thus, the total radial clearance required on the major diameter of the thread including a factor of safety (g) is calculated as follows:
Rt=Rn+Rs−Rh+g=ΔT*CTEn*D+=ΔT*CTEs*D −0.3*Δ T*CTEh*B+g
Rt=ΔT{D ( CTEn+CTEs )−0.3 *CTEh*B}+g
The factor of safety contemplates, for example, extra radial clearance on the major diameter of the thread for grease retention and a misalignment accommodation.
Applying the values of the example given above with a temperature rising from 70° F. to 200° F. (ΔT=130° F.) and factor of safety of g=0.004″ the total clearance will be as follows:
Rt= 130{1.5(0.45*10 *E −4+8.1*10 *E −6)−0.3*13.1*10 *E −6*2.125 +0.004=0.0133″
The clearance value may be rounded up to 0.014″+0.003″.
Since there will be an axial backlash increase due to the radial clearance increase, the width of the internal thread of nut 20 is adjusted to achieve a minimum axial clearance, in the design of the modified centralized AcmesScrew/nut set 10 in accordance with the present disclosure.
Referring now to FIG. 2 , a modified Acme thread configuration on major diameter in accordance with the present disclosure is illustrated. Width X 1 of screw thread 30 on major diameter and width X 2 of thread groove 35 of nut 20 also on the major diameter are shown as per ANSI B1.8 standard without any modification. Thread 30 of screw 15 remains unchanged. Screw 15 is shown crowded to the one side of the thread 35 of nut 20 .
The axial clearance expanded from Amin.=0.0025″ to 0.0058″ based on the relationship between radial and axial clearances shown in FIG. 3 . Referring to FIG. 3 , an Acme thread modified on major diameter in accordance with the above-described example is illustrated. The detail views in FIG. 3 illustrate the relationship between radial and axial clearances in the thread.
The increase in axial clearance (backlash) is governed by the following equations:
Δ A/ΔR=tg 14.5° where Δ R=Rt−Rmin . (from previous calculations)
Δ A =( Rt=Rmin )* tg 14.5°
Therefore, the total backlash ΔAr due to an increase in radial clearance and an initial minimum axial backlash is a sum of ΔA and Amin.
Δ Ar−ΔA+Amin .=( Rt−Rmin .)* tg 14.5 °+Admin.
In the example described herein:
Δ Ar =.(0.14−0.0012)* tg 14.5°+0025=0.0128*0.2586+0025=0.0058″
In accordance with an embodiment of the present disclosure, groove 35 of nut 20 is widened to accommodate an axial thermal expansion difference between the material of screw 15 and the material of nut 20 . The expansion of nut 20 in the axial direction is calculated in accordance with the following equation:
Δ An=ΔT*CTEn*L L—length of the nut
Next, the expansion of screw 15 in the axial direction for the length of nut 20 is calculated in accordance with the following equation:
ΔAs=ΔT*CTEs*L
Thus, the total required axial backlash due to the thermal expansion may be calculated in accordance with the following equation:
At=ΔAn−ΔAs=ΔT*CTEn*L−ΔT*CTEs*L=ΔT*L *( CTEn−CTEs ) where ΔAn>ΔAs
The value derived from this calculation represents the minimum backlash at the pitch diameter. Groove 35 of nut 20 may be physically enlarged to provide this backlash. As determined above, the backlash is equal to ΔAr and is due to the increase of clearance in the radial direction. Consequently, groove 35 of nut 20 may be widened based on the difference between total thermal expansion requirement At and an existing backlash ΔAr as shown in the following equation to determine Afin:
Afin=At−ΔAr=ΔT*L *( CTEn−CTEs )−( Rt−Rmin )* tg 14.5 °−Amin
Afin=ΔT*L *( CTEn−CTEs )−[(Δ T{D ( CTEn+CTEs )−0.3 *CTEh*B}+g −Rmin]*tg 14.5 °−Amin
After applying the values from the example described above, the following value Afin can be derived from the above formula:
Afin =130*2.312*(0.45*10 *E −4−8.1*10 *E 6)−[130{1.5(0.45*10 *E −4+8.1*10 *E −6) −0.3*13.1*10 *E −6*2.125}+0.004−0.0012 ]*tg 14.5°−0.0025.
Afin=0.00546″
This Afin value is the dimension value which has to be added to the existing width of groove 35 of nut 20 . In the example described herein, the minimum width for the top of groove 35 is 0.0738″ based on ANSI B 1.8 (see FIG. 2 ). After adding 0.00546 (Afin) to that dimension the final groove width Wg is:
Wg=0.079″
The additional axial clearance may be added to the Wg dimension if necessary. In this case, due to the flexibility of the plastic nut material with an unobstructed expansion flow in the axial direction, no additional clearance was implemented other than the positive tolerance.
As illustrated in FIG. 4 , nut 20 of the drawing calls for 0.079″+0.003/−0.000. FIG. 4 shows the Acme nut drawing in cross-section detail with the circled dimension 0.079+0.003/−0.000.
While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the present disclosure, but merely as illustrations of various embodiments thereof. For example, although the above embodiments are described with reference to one particular configuration of a screw/nut set, the present disclosure may find application in conjunction with screw/nut sets having many different configurations and dimensions. Accordingly, it is contemplated that the disclosure is not limited to such an application and may be applied to various screw/nut sets. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the present disclosure. | A nut and screw set for reducing the amount of hindered motion therebetween is disclosed. The nut and screw set includes a screw and a nut. The screw includes a plurality of screw threads. The nut includes a plurality of nut threads. The nut threads are threadably engagable with the screw threads. The nut threads are sized reduce hindered motion between the screw and the nut as a result of thermal expansion of the screw and the nut. |
This application is a continuation of application Ser. No. 07/012,550, filed Feb. 9, 1987 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic card having a plurality of stacked magnetic layers on which information is recorded in distribution, and a magnetic shielding layer which is located uppermost and used for shielding information.
In the prior art, a magnetic card of the multi-layer structure type is well known, as disclosed in Japanese Patent Disclosure (Kokai) No. 51-129209. FIG. 1 shows a magnetic card of this type. As shown, substrate 1 is overlaid with first magnetic layer 2, which is in turn overlaid with non-magnetic intermediate layer 30. Second magnetic layer 4 is laid over non-magnetic intermediate layer 30, and protection layer 50 is provided as an uppermost layer such that it covers the upper side of second magnetic layer 4. This laminated structure is employed so as to prevent the magnetic card from being forged or to prevent the information recorded on the card from being altered. Authentic data is recorded on first magnetic layer 2, while counterfeit data is recorded on second magnetic layer 4. Non-magnetic intermediate layer 30 is formed of α-Fe 2 O 3 , for example. Uppermost protection layer 50 is formed of a synthetic resin, for example.
It is recently found, however, that the counterfeit data recorded in second magnetic layer 4 can be easily erased by means of a so-called "paper clip magnet" or the like. If the counterfeit data is erased, the authentic data recorded on first magnetic layer 2 can be easily reproduced for decoding, by use of an ordinary technique. Therefore, it has become difficult to prevent the magnetic card from being fraudulently used by an unauthorized person or to prevent the information on the card from being forged or altered.
Furthermore, the thickness of non-magnetic intermediate layer 30 causes a spacing loss at the time of reproducing data from first magnetic layer 2. Therefore, the data is not always read out accurately from first magnetic layer 2.
SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a magnetic card which cannot be fraudulently used by an unauthorized person and the information on which is difficult to forge or alter.
To achieve this object, there is provided a magnetic card comprising a substrate; a plurality of magnetic recording layers which are provided on the substrate and each of which has a coercive force that enables magnetic recording of data, and a magnetic shielding layer stacked at least on the uppermost one of the magnetic recording layers and having such a small coercive force as is unsuitable for magnetic recording.
With the magnetic card of the present invention, it is possible both to distributively record valuable information on different recording layers and to magnetically shield the information, thus reliably preventing fraudulent reproduction or decoding of the information by a third party. Therefore, the magnetic card can be effectively prevented from being forged and the information on the card can be effectively prevented from being altered.
Furthermore, with the magnetic card of the present invention, information is reproduced from a magnetic recording layer by magnetically saturating the magnetic shielding layer, and if necessary, another magnetic recording layer. Therefore, reliable reproduction of information can be carried out without a spacing loss.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view illustrating the construction of a conventional magnetic card;
FIG. 2 is a partially-cutaway perspective view illustrating the construction of a magnetic card according to one embodiment of the present invention;
FIG. 3 is a view schematically showing the information recorded on the magnetic card shown in FIG. 2;
FIG. 4 is a view explaining how information is read out from the magnetic card shown in FIG. 3;
FIG. 5 is a view illustrating the construction of a magnetic card according to another embodiment of the present invention;
FIG. 6 is a view explaining how information is read out from the magnetic card shown in FIG. 5;
FIG. 7 is a perspective view illustrating the construction of a magnetic card according to still another embodiment of the present invention; and
FIG. 8 is a perspective view illustrating the construction of still another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description may now be given of the embodiments of the present invention, with reference to FIGS. 2 through 8.
FIG. 2 shows the magnetic card of the first embodiment of the present invention. As shown, the magnetic card comprises: substrate 1; first magnetic recording layer 2 having a coercive force that enables magnetic recording of data; first magnetic shielding layer 3, formed of a soft magnetic material with such a small coercive force as is unsuitable for magnetic recording (e.g., not more than 30 Oersted); second magnetic recording layer 4 having a coercive force that enables magnetic recording of data; and second magnetic shielding layer 5, formed of a soft magnetic material with such a small coercive force as is unsuitable for magnetic recording. The layers are stacked on substrate 1 in the order mentioned, The coercive force of second recording layer 4 is smaller than that of first recording layer 2.
First recording layer 2 is a magnetic layer of cobalt absorbed γ-Fe 2 O 3 or Ba ferrite. Second recording layer 4 is a magnetic layer formed of γ-Fe 2 O 3 , for example. First and second shielding layers 3 and 5 are magnetic layers formed of either a magnetic alloy including Al, Si and Fe, or MnZn.ferrite. Each of these magnetic layers is formed by coating a base layer or substrate 1 with a solution of material magnetic powder. When forming second recording layer 4, cobalt absorbed γ-Fe 2 O 3 or Ba ferrite may be used as long as these materials have the coercive force noted above. The shielding layers may be formed of an Fe-Ni alloy.
When using the magnetic card shown in FIG. 2, it is desirable that authentic information is distributively recorded on first and second recording layers 2 and 4 such that the information recorded on first layer 2 and that on second layer 4 will become "authentic" only when they are combined with each other.
A description may now be given of how information is recorded or decoded in actual use of the magnetic card.
Information is recorded as follows. Among pieces of information A which are authentic as a whole, information A1 is recorded on first recording layer 2 by use of a magnetic head which is generating a magnetic field stronger than the coercive force of layer 2. Next, the magnetic field from the magnetic head is controlled such that it is weaker than the coercive force of first recording layer 2 but is stronger than the coercive force of second recording layer 4. In this condition, information A2 (A2=A-A1) is recorded on second recording layer 4.
With the magnetic card of the present invention, information is read out as follows: FIG. 3 illustrates the magnetic condition in which information A1 and information A2 are recorded on first and second recording layers 2 and 4, respectively. Solid arrows 6 and 7 indicate the direction of magnetization, and the broken lines indicate the flow of magnetic fluxes. The magnetic fluxes are generated by recording information A1 and A2 on the magnetic recording layers and are shut inside the card by magnetic shielding layers 3 and 5 which have such a small coercive force as is unsuitable for magnetic recording. Information A1 and A2, thus, cannot be read out by a commonly used magnetic head. Information A2, recorded in second recording layer 4, is read out by use of dual-structure magnetic head 10 shown in FIG. 4. As shown, head 10 is comprised of inner yoke 12 provided with coil 11, and outer yoke 14 provided with coil 13. The magnetic card is moved relative to head 10, e.g., in the X direction. At this time, the magnetic field generated from outer yoke 14 is kept stronger than the coercive force of second shielding layer 5 and is weaker than that of second recording layer 4, thus permitting the magnetic characteristics of second shielding layer 5 to be regarded as being identical with those of the air. In other words, second shielding layer 5 is kept in the magnetically saturated condition. Under this condition, information A2 is read out from second recording layer 4 by inner yoke 12.
Thereafter, the magnetic card is moved again relative to head 10, and information A1 is read out from first recording layer 2 by a technique similar to that in which information A2 was read out. The manner in which information A1 is read out will be explained in more detail with reference to FIG. 4. First, the magnetic card is moved in the X direction. At this time, the magnetic field generated by outer yoke 14 is controlled such that it is stronger than the coercive force of second recording layer 4 and is weaker than the coercive force of first recording layer 2. As a result, first and second shielding layers 3 and 5 are magnetized in the directions indicated by arrows 15 and 16, respectively, thereby permitting magnetic fluxes to flow through outer yoke 14. Second recording layer 4 is brought into the condition indicated by arrow 18 after head 10 passes it, so that other magnetic fluxes flow through outer yoke 14. Information A1 is read out from first recording layer 2 by use of inner yoke 12, with first and second shielding layers 3 and 5 and second recording layer 4 magnetically saturated in the manner mentioned above.
In the magnetic card shown in FIG. 2, the upper sides of first and second recording layers 2 and 4 are covered with first and second shielding layers 3 and 5, respectively, thus magnetically shielding first and second recording layers 2 and 4. Therefore, the information recorded on the magnetic card is difficult to reproduce by an ordinary technique (e.g., by use of an ordinary recorder). In the magnetic card, furthermore, the number of recording layers provided is at least two and the coercive force of one recording layer differs from that of another, and information can be distributively recorded on different recording layers. Therefore, the information is considerably difficult to decode or alter, as compared with the information recorded on a conventional magnetic card.
In the foregoing description, the information to be recorded on the magnetic card was described as consisting of information A1 to be recorded on first recording layer 2 and information A2 to be recorded on second recording layer 4. However, the information to be recorded on the magnetic card may be distributed in various manners, e.g., in the following manner:
Information A0 is recorded on first recording layer 2, and two kinds of information, namely information B0 and identification information C0, are recorded on second recording layer 4. Identification information C0 may be function F(A0,B0), which depends on information A0 and information B0. If recorded in this manner, the information can be distributed very effectively. In addition, the function representing identification information C0 is very difficult to decode, so that it is possible both to effectively prevent the card from being forged and to prevent the data on the card from being altered.
FIG. 5 shows a magnetic card according to another embodiment of the present invention. The construction of this magnetic card is substantially the same as that shown FIG. 2, except in that first shielding layer 3 is not provided. In FIG. 5, the same reference numerals as those in FIG. 2 are used to indicate the corresponding structural elements. With the magnetic card of FIG. 5, information is recorded or read out in a manner similar to that described with reference to FIG. 2. When information A2 is read out from second recording layer 4 in the embodiment of FIG. 5, however, it may happen that magnetic fluxes 20 will leak from first recording layer 2 and flow into inner yoke 12 , resulting in the occurrence of noise. It is, therefore, desirable that a noise-removing filter is provided in a reproduction circuit. In addition, in order to prevent the noise, the location at which information A2 is recorded on second recording layer 4 may be determined such that information A2 is not influenced by magnetic fluxes which may be generated by information A1 recorded on first recording layer 2.
In this second embodiment, the recorded information is very difficult to decode or alter, as in the first embodiment shown in FIG. 2.
FIG. 7 shows the third embodiment of the present invention. In this embodiment, second recording layer 4 shown in FIG. 2 is not formed on the entire area of first shielding layer 3. It is formed on a selected part of first shielding layer 3 in a stripe pattern. Information is written or read out in a manner similar to that of FIG. 2. Part of information A2 to be recorded on second recording layer 4 can be distributively recorded on that part of first recording layer 2 which is not covered by the second recording layer 4.
Like the embodiment of FIG. 5, first shielding layer 3 may be omitted from the embodiment of FIG. 7, as shown in FIG. 8. In FIG. 8, the same reference numerals as those in FIG. 5 are used, and explanation of FIG. 8 will be omitted.
The above description was given of the case where the number of recording layers is two. However, this number does not limit the invention. Any number of recording layers can be provided as long as the number is not one. With an increase in the number of recording layers, it will become more and more difficult to decode the information recorded on the magnetic card.
The above description was given of the case where authentic information was distributively recorded on different recording layers. However, the authentic information may be recorded in one of the recording layers.
Furthermore, the magnetic material for forming the recording layers is not limited to the ones referred to above. For example, Sr-ferrite may be used, if desired. Still further, a protection layer may be formed on the second shielding layer in each embodiment. | In the subject magnetic card, first magnetic recording layer 2 is laid over substrate 1. First magnetic recording layer 2 has a coercive force that enables magnetic recording of data. Second magnetic recording layer 4, having a coercive force smaller than that of first magnetic recording layer 2, is laid over first magnetic recording layer 2, with shielding intermediate layer 3 interposed therebetween. Magnetic shielding layer 5 is provided as an uppermost magnetic layer. |
BACKGROUND OF THE INVENTION
The present invention relates to a device having a tool holder, which can be displaced in an x direction and a z direction which is perpendicular to the x direction, and a first tool in the form of a metering head, which can be removably secured to the tool holder.
Devices of this type are used, inter alia, for automatically metering substances into a plurality of reaction vessels or test tubes which are arranged, for example, next to one another.
In a device which is known as Caco-2 Assay produced by Mettler Toledo Bohdan, Greifensee, Switzerland, there are two tool holders with different tools. The tool holders can be displaced in a horizontal x direction, a horizontal y direction which is perpendicular to the x direction, and a vertical z direction which is perpendicular to the x and y directions, and in this way can serve reaction vessels arranged next to one another under the control of software. One of the tools is designed for metering liquid as a metering head in the form of a four-needle head with four parallel hollow needles which can be spread apart. The other tool is a gripper for handling substance plates which have a multiplicity of recesses for holding substance. To weigh matter which can be handled by the device, there is a balance, on which, by way of example, a corresponding substance plate or a test tube is placed.
Although the two fixedly installed tools do make it possible to handle liquids and solids, they do not, for example, allow a solid to be metered directly into a reaction vessel. Moreover, there are two tool holders which have to be able to move independently of one another, in which context it must be ensured that they do not collide with one another. Finally, accurate weighing out of a defined quantity of substance is relatively complex.
In view of the drawbacks of the devices of the prior art which has been described above, the invention is based on the object of providing a device which allows a very wide range of forms of substances to be handled as simply as possible.
SUMMARY OF THE INVENTION
The essence of the invention consists in the following: a device comprises a tool holder, which can be displaced in an x direction and a z direction which is perpendicular to the x direction, and a first tool in the form of a metering head, which can be removably secured to the tool holder. It comprises at least one further, other tool, which can be removably secured to the tool holder as an alternative to the first tool and which has at least one part which can move actively and independently of the movement of the tool holder, it being possible for the securing and removal of in each case one of the tools to be carried out automatically.
In the present context, the terms automatic securing and removal of a tool is understood as meaning that the securing and removal are carried out not by hand but rather by the device itself, at most under the control of an operator.
The fact that the device comprises various tools with different functions which can automatically be secured to and removed from the tool holder as alternatives means that a very wide range of substances, solids, etc. can be handled without problems. Since there is in each case only one tool attached to the tool holder, there is no risk of different tool holders and tools getting in one another's way.
The fact that the further tool has at least one part which can move actively and independently of the movement of the tool holder results in better and additional use options compared to a mechanically passive tool or a tool whose movement is dependent on the tool holder.
In an advantageous exemplary embodiment, the metering head carries with it a storage container which contains all the substance which is to be metered. This eliminates the need for substance-feed hoses, etc. leading to the metering head or to the tool holder. This has the additional advantage that the metering head can move more freely, without being impeded by hoses, etc.
In a preferred exemplary embodiment, the tool holder can rotate about the z direction. This in particular allows the tool to rotate through, for example, 90°, i.e. allows, by way of example, a multi-needle head having a plurality of hollow needles arranged next to one another to be used to meter substances, which may differ according to the hollow needle used, to vessels belonging to a matrix in rows, then allows the multi-needle head to be rotated through 90° and substances, which once again may differ according to the hollow needle used, to be metered to the vessels of the matrix in columns. It is thus possible for a different combination of substances to be metered to each vessel of the matrix in a simple way.
Moreover, the rotation allows reaction vessels, starting-material bottles, etc. to be arranged over an area and not just on a straight line.
Preferably, the tool holder can additionally be displaced in a y direction, which is perpendicular to the x direction and the z direction. This enables reaction vessels, starting-material bottles, etc. to be arranged over a larger area.
In an advantageous variant embodiment, the tool is secured to the tool holder by means of magnets, in which case it is preferable, where there are two permanent magnets which attract one another, for one of the two permanent magnets to be arranged on the tool holder and the other of the two permanent magnets to be arranged on the tool, and for it to be possible for the action of the attraction between the two permanent magnets to be cancelled out by means of at least one electromagnet. Connecting tool and tool holder by means of magnets allows automatic securing of the tool to the tool holder, for example by the tool holder being guided over the tool and then lowered onto it or the tool holder being moved laterally onto the tool. Detaching the tool from the tool holder by activating the at least one electromagnet by means of current pulses also contributes to enabling the tool change to take place automatically.
In alternative advantageous variant embodiments, the tool is secured to the tool holder by screw connection, by means of a bayonet catch or by means of a clamping connection, etc. Although these methods of securing are normally more complex to implement, they are relatively simple to automate, in particular if the tool holder can be rotated about the z direction.
Preferably, one of the tools is a screw metering head, which comprises a screw which can rotate forward and backward about the z direction in a tube which is at least partially open at its lower end and which can be used to take up and dispense substance. A screw metering head of this type can be used for targeted removal of pulverulent or liquid substance from a storage vessel and also for targeted dispensing of this substance.
Advantageously, the lower open end of the tube can be closed off by a diaphragm provided with holes, and there is preferably a ram, which runs on the screw and presses substance through the diaphragm as the screw rotates when substance is being dispensed, arranged in the tube. The use of a diaphragm leads to more uniform dispensing of substance, since the substance is forced uniformly through the holes in the diaphragm. This in turn has the advantage that metering can be carried out more accurately.
Advantageously, one of the tools is a capsule-transporting head, by means of which a capsule can be picked up and released, preferably by suction. A tool of this type makes it possible to transport substances in capsules or similar containers.
Preferably, one of the tools is a matrix-capsule-transporting head, by means of which capsules which are arranged in the manner of a matrix can be picked up, preferably by suction, and the capsules can be released individually, together or in groups. The matrix-capsule-transporting head also makes it possible to transport substances in capsules, it being possible for a large number of capsules which are arranged in matrix form to be handled at the same time.
Advantageously, one of the tools is a capsule-handling head, by means of which at least one capsule can be picked up, which capsule can be opened in the tool, preferably by means of a hollow needle, and in which tool the contents of the capsule can preferably be mixed with another substance, in particular a solvent. The mixing can be effected, for example, by adding solvent to the capsule, sucking up substance and solvent from the capsule and returning the material which has been sucked up into the capsule. Alternatively, the hollow needle can also be used to suck substance out of the capsule and dispense it again at another location. The capsule-handling head according to the invention makes it possible to prepare even more successfully for chemical reactions outside a reaction vessel.
In a preferred variant embodiment, one of the tools is a matrix-capsule-handling head, by means of which a plurality of capsules which are arranged in the form of a matrix can be picked up, which capsules can be opened in the tool, preferably using hollow needles, and in which tool the contents of one capsule can preferably in each case be mixed with another substance, in particular a solvent. The mixing can be effected, for example, by adding solvent to the capsule, sucking up substance and solvent from the capsule and returning the material which has been sucked up into the capsule. Alternatively, the hollow needle can also be used to suck substance out of the capsule and dispense it again at another location. The matrix-capsule-handling head also makes it possible to handle substances in capsules and to prepare for chemical reactions, it being possible for a multiplicity of capsules which are arranged in the form of a matrix to be picked up and processed simultaneously.
In another preferred variant embodiment, one of the tools is a capsule-dispensing head, in which a multiplicity of capsules are stored and can be dispensed individually, together or in groups, it preferably being possible for the capsules to be opened in the capsule-dispensing head, and it even more preferably being possible for the contents of the capsules to be mixed with another substance, in particular a solvent, in the capsule-dispensing head. The capsule-dispensing head according to the invention makes it possible to prepare for chemical reactions largely outside a reaction vessel and means that the appropriate capsules or the contents thereof simply have to be added to the reaction vessel in order to carry out these chemical reactions.
Advantageously, one of the tools is a needle head with a hollow needle, a multi-needle head with a plurality of hollow needles, which can preferably be displaced individually in the z direction and/or the distance between which can preferably be adjusted, a gripper, a lid opener, or a solids-metering head. Tools of this type are each known per se on their own and additionally increase the possible uses of the device according to the invention.
Advantageously, one of the tools is a combination head having at least two identical or different tool parts, one of the tool parts preferably being a needle head, multi-needle head, gripper, lid opener, capsule-transporting head, matrix-capsule-transporting head, capsule-handling head, matrix-capsule-handling head, capsule-dispensing head, screw metering head or solids-metering head. This allows a plurality of method steps to be carried out in succession or simultaneously using a single tool.
In a preferred exemplary embodiment, a balance, which can be used to weigh substance or capsules which has/have been taken up or dispensed by the tool, is arranged on the tool or on the tool holder.
The fact that a balance is arranged directly on the tool or on the tool holder makes it possible to weigh a substance, a substance capsule or another object which has been taken up or dispensed without the substance, the substance capsule or the other object or the tool for this purpose having to be placed onto a separate balance. Weighing in situ means that the material to be weighed does not have to be displaced, yet it is not necessary for a balance to be arranged at each working position, e.g. under each reaction vessel. This significantly simplifies the weighing operation.
A method for weighing out a desired quantity of substance using a device having a tool holder, which can be displaced in an x direction and a z direction which is perpendicular to the x direction, and a tool in the form of a metering head, which is secured to the tool holder, and a balance arranged on the tool or on the tool holder, by means of which substance which has been taken up by the tool can be weighed, is characterized by the steps that
a) substance is taken up by the tool; b) the substance is weighed; c) the difference between the weighed value obtained and the desired set value is calculated; and d) if the difference lies outside the range of a desired level of accuracy, the tool is used to discharge substance or take up additional substance depending on this difference;
steps b) to d) being repeated until the difference is equal to zero within the range of a desired level of accuracy.
A similar method for selecting a capsule with a desired quantity of substance using a device having a tool holder, which can be displaced in an x direction and a z direction which is perpendicular to the x direction, and a tool in the form of a metering head, which is secured to the tool holder, and a balance which is arranged on the tool or on the tool holder and can be used to weigh capsules which have been picked up by the tool, is characterized by the steps that
a) the tool is used to pick up a capsule containing substance; b) the capsule with substance is weighed; c) the difference between the weighed value obtained and the desired set value is calculated; and d) if the difference lies outside the range of a desired level of accuracy, the capsule is released again from the tool and a new capsule containing substance is picked up;
steps b) to d) being repeated until the difference is equal to zero within the range of a desired level of accuracy.
These two weighing methods which operate in accordance with the test principle make it easy to weigh out a desired quantity of substance or a desired object with the desired level of accuracy.
Advantageously, the device according to the invention has a camera, which is preferably arranged on the tool holder and which can be used to film an area below the tool holder, as well as a control computer having an image-processing unit, which evaluates images which have been filmed by the camera, it preferably being possible for the displacement of the tool holder and, the selection, securing or release of one of the tools to be controlled on the basis of the evaluation result.
In an advantageous alternative variant, the device according to the invention has an infrared analysis unit, which is preferably arranged on the tool holder and has an infrared transmitter, by means of which infrared waves can be radiated into an area below the tool holder, and an infrared sensor, which can be used to measure reflected infrared waves, as well as a control computer having a measured-value-processing unit, which evaluates the reflected infrared waves measured by the infrared sensor, it preferably being possible for the displacement of the tool holder and, the selection, securing or release of one of the tools to be controlled on the basis of the evaluation result. The precise way in which an infrared analysis unit of this type functions is described, for example, in U.S. Pat. No. 6,031,233, which is hereby specifically incorporated by reference in the present description.
The camera or the infrared analysis unit, together with the control computer, allows the device to operate completely automatically without an operator having to evaluate the substance or capsule to be handled and then actively control the displacement of the tool holder and/or the selection, securing or release of one of the tools.
Further advantageous tools comprise, for example, a sensor, e.g. a pH sensor, a bar code reader, etc.
In an advantageous variant embodiment, the device according to the invention comprises a further tool holder for attachment of a further tool which can be displaced in an x direction and in a z direction which is perpendicular to the x direction, it preferably additionally being able to rotate about the z direction and/or to be displaced in a y direction which is perpendicular to the x direction and to the z direction. The second tool holder may be designed and controlled in the same way as the first. With two or even more tool holders with tools attached to them, it is possible to multiply the speed of the device; at the control, it must be ensured that the various tool holders and tools do not impede one another.
BRIEF DESCRIPTION OF THE DRAWINGS
The devices according to the invention are described in more detail below with reference to the appended drawings and on the basis of exemplary embodiments.
In the drawings:
FIG. 1 shows a tool holder which can be displaced in all three spatial directions x, y and z on a linear axis system and can rotate about the z direction;
FIG. 2 shows the tool holder from FIG. 1 , having a needle head with a hollow needle as tool;
FIG. 3 shows the tool holder from FIG. 1 , having a needle head with four hollow needles which can be displaced with respect to one another as tool, the four hollow needles being at a minimum distance from one another;
FIG. 4 shows the tool holder with needle head from FIG. 3 , with the four hollow needles at a maximum distance from one another;
FIG. 5 shows the tool holder from FIG. 1 with a capsule-transporting head as tool;
FIG. 6 shows the capsule-transporting head from FIG. 5 when it is holding a capsule;
FIG. 7 shows the capsule-transporting head from FIG. 5 when a capsule is being placed in a reaction vessel arranged in a matrix;
FIG. 8 shows the tool holder from FIG. 1 with a matrix-capsule-transporting head as tool;
FIG. 9 shows the tool holder from FIG. 1 , with a gripper as tool;
FIG. 10 shows the tool holder from FIG. 1 with a lid opener as tool;
FIG. 11 shows a section view of a tool in the form of a capsule-handling head with hollow needle;
FIG. 12 shows the capsule-handling head from FIG. 11 on the tool holder from FIG. 1 with a closed capsule which has been picked up;
FIG. 13 shows the capsule-handling head with a capsule which has been picked up as shown in FIG. 12 during the addition of solvent after the capsule has been punctured by the hollow needle;
FIG. 14 shows the capsule-handling head with punctured capsule as shown in FIG. 13 when the capsule, which now contains dissolved substance, is being dispensed;
FIG. 15 shows the tool holder from FIG. 1 with a diagrammatically depicted matrix-capsule-handling head as tool and capsules arranged in a matrix;
FIG. 16 shows a sectional view of a tool in the form of a first exemplary embodiment of a capsule-dispensing head having a multiplicity of stored capsules at the tool holder shown in FIG. 1 ;
FIG. 17 shows a sectional view of a tool in the form of a second exemplary embodiment of a capsule-dispensing head having a multiplicity of stored capsules which can be opened in the capsule-dispensing head, at the tool holder shown in FIG. 1 ;
FIG. 18 shows the tool holder shown in FIG. 1 with a screw metering head as tool, with a diaphragm which has been pivoted away, in a partially sectional illustration;
FIG. 19 shows the tool holder with screw metering head from FIG. 18 with a diaphragm which has been pivoted under the screw, in a partially sectional view; and
FIG. 20 shows the tool holder from FIG. 1 with a solids-metering head as tool.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1
A linear axis system for holding and displacing a tool holder 1 comprises two guide rails 6 , 61 , which run parallel to one another in the y direction and are anchored in a fixed position in a manner which is not illustrated. The first ends of the two guide rails 6 , 61 are connected by a rotary rod 7 , which can be rotated by means of a stepper motor 71 . An upper running rail 5 is secured to the two guide rails 6 , 61 in such a manner that it can be displaced in the y direction. The upper running rail 5 is fixedly connected to a lower running rail 51 by means of two end plates 52 , 53 . As a result of the rotary rod 7 being rotated by means of the stepper motor 71 , in each case one toothed belt in the interior of the guide rails 6 , 61 is driven, causing the running rails 5 , 51 to be displaced in the y direction. In the present context, the term displacement in the y direction is to be understood as meaning both a displacement in the +y direction and in the −y direction (the opposite direction).
A carriage 4 is secured to the two running rails 5 , 51 in such a manner that it can be moved in the x direction. In the present context, the term movement in the x direction is once again to be understood as meaning both a movement in the +x direction and in the −x direction (the opposite direction). The carriage 4 is driven by a stepper motor 54 via a toothed belt arranged in the hollow upper guide rail 5 .
A tool rod 3 is secured to the carriage 4 in such a manner that it can move in the z direction. In the present context, the term movement in the z direction is once again to be understood as meaning both a movement in the +z direction and in the −z direction (the opposite direction). In order for the tool rod 3 to be displaced, a stepper motor 31 is attached to it via a hollow plate 32 , and a toothed belt is arranged in the hollow plate 32 and the tool rod 3 .
At the lower end of the tool rod 3 there is a rotary drive 2 , to which the tool holder 1 is secured. The tool holder 1 can be rotated both ways about the z direction, as indicated by the arrow c, with the aid of a rotary motor 21 . In order to secure and release a tool, the tool holder 1 substantially consists of a permanent magnet, in which an electromagnet is arranged.
A camera 10 , which is directed downward in the z direction and can be used to film an area below the tool holder 1 , is attached to the tool holder 1 . The images which are filmed by the camera 10 are transmitted via a data line to an image-processing unit of a control computer 11 , which evaluates these images. The control computer 11 can then control the displacement of the tool holder 1 in the x, y, z and c directions by means of the motors 54 , 71 , 31 and 21 and the selection, securing or release of a tool on the basis of the evaluation results.
The following consideration applies to the whole of the remainder of the description. If a figure includes reference symbols which are provided for the purpose of clarity of the drawing but these reference symbols are not mentioned in the immediately associated text of the description, or vice versa, reference is made to the corresponding explanations given in preceding descriptions of figures.
FIG. 2
In this case, a needle head 100 is removably secured as the tool to the tool holder 1 by means of a permanent magnet 101 . The permanent magnet 101 of the needle head 100 and the permanent magnet of the tool holder 1 attract one another, so that when the needle head 100 is removed it can be secured to the tool holder 1 by placing the tool holder 1 on it, an operation which can be performed automatically, i.e. the needle head 100 does not have to be attached to the tool holder 1 manually. The needle head 100 is detached from the tool holder 1 by means of the electromagnet which is arranged in the tool holder 1 , cannot be seen and, when it receives a current pulse, cancels out the action of the attraction between the permanent magnet 101 of the needle head 100 and the permanent magnet of the tool holder 1 .
A linear drive 103 is attached to the permanent magnet 101 via a plate 102 . A hollow needle 105 is secured to the outer cylinder of the linear drive 103 by means of two holding parts 104 , which are provided with continuous receiving holes for the hollow needle 105 . With the aid of the linear drive 103 , the hollow needle 105 can be displaced in the z direction.
A hollow needle 105 of this type can be used, for example, to meter or remove liquid substances into or from reaction vessels. In particular, for this purpose a suction and/or blowing means can be connected to the top end of the hollow needle 105 .
FIGS. 3 and 4
The tool is in this case formed by a needle head 120 with four hollow needles 125 , which can be individually displaced in the z direction and the distance between which can be adjusted from a minimum distance a min to a maximum distance a max , the distance between each pair of adjacent hollow needles 125 always being identical. To this end, the hollow needles 125 are each secured to the outer cylinder of a linear drive 123 by means of two holding parts 124 which are provided with continuous hollow-needle-receiving holes. The linear drives 123 which can be used to displace the hollow needles 125 individually in the z direction are for their part in each case attached to an associated plate 122 . The four plates 122 are arranged movably in two grooves in a permanent magnet 121 , the drive for this purpose being effected by means of two spindles which are driven by a motor and are located inside the permanent magnet 121 . The needle head 120 , as described in connection with FIG. 2 , is connected to the tool holder 1 via the permanent magnet 121 . Once again, the needle head 120 is detached from the tool holder 1 by means of the electromagnet (not visible) arranged in the tool holder 1 .
A needle head 120 of this type can be used, for example, to successively meter different liquids to a reaction vessel or to meter liquid to or remove liquid from a plurality of reaction vessels simultaneously. In particular suction and/or blowing devices can be connected to the top end of the hollow needles 125 for this purpose.
FIGS. 5 to 7
The tool is in this case formed by a capsule-transporting head 140 , by means of which a tightly closed capsule 150 , which is in the form of a small tube and contains a pulverulent substance 151 , can be picked up by suction. The capsule-transporting head 140 comprises a permanent magnet 141 , by means of which, as described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . It can be released by means of the electromagnet arranged in the tool holder 1 . A suction tube 143 having a capsule-holding end piece 144 is attached to the permanent magnet 141 via an intermediate part 142 . A reduced pressure can be generated in the suction tube 143 by means of a conventional suction means (not shown).
To pick up a capsule 150 , the capsule-transporting head 140 is moved such that the capsule-holding end piece 144 is above the top end of the capsule 150 , and then the capsule 150 is picked up as a result of a reduced pressure being generated in the suction tube 143 , as illustrated in FIG. 6 . Then, the capsule 150 is transported by the linear axis system to the intended location, in FIG. 7 a reaction vessel 171 arranged in a matrix 170 , where it is released into the reaction vessel 171 as a result of the reduced pressure in the suction tube 143 being eliminated.
FIG. 8
The tool is in this case formed by a matrix-capsule-transporting head 160 which comprises a permanent magnet 161 , by means of which, as has been described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . It is released by means of the electromagnet arranged in the tool holder 1 . Sixteen suction tubes 163 , which are arranged in the form of a matrix and each have a capsule-holding end piece 164 , are attached to the permanent magnet 161 via a suction-tube plate 162 . A reduced pressure can be generated in the suction tubes 163 via the suction-tube plate 162 by means of a conventional suction means (not shown).
To pick up capsules 150 , the matrix-capsule-transporting head 160 is moved such that the capsule-holding end pieces 164 are above the top ends of the capsules 150 , and then the capsules 150 are picked up as a result of a reduced pressure being generated in the suction tubes 163 . Then, the capsules 150 are transported by the linear axis system to the intended location, in this case reaction vessels 171 arranged in a matrix 170 , where the capsules 150 are dispensed into the reaction vessels 171 as a result of the reduced pressure in the suction tubes 163 being eliminated.
FIG. 9
In this case, a gripper 180 is secured as tool to the tool holder 1 by means of a permanent magnet 181 . Once again, the gripper 180 is released from the tool holder 1 by means of the electromagnet arranged in the tool holder 1 . The gripper 180 comprises three gripper arms 182 which can be pivoted away from the permanent magnet 181 in the direction of the arrows illustrated. The pivoting drive is arranged inside the permanent magnet 181 .
Similar grippers 180 of this type which, however, are fixedly connected to the tool holder 1 are already known from the prior art. They can be used, for example, to grip and transport solids.
FIG. 10
In this case, the tool is formed by a lid opener 200 , which comprises a permanent magnet 201 , by means of which, as has been described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . The lid opener 200 is released from the tool holder 1 by means of the electromagnet arranged in the tool holder 1 .
On the one side, a motor 202 , which opens and closes, under computer control, a clamp 203 having two clamping arms 204 and 205 in the directions indicated by arrows A and B, is secured to the permanent magnet 201 . The clamp 203 engages around and holds a starting-material vessel 210 which is closed off by a lid 211 .
On the other side, a strap 206 , to the free end of which a cap-like lid-gripping element 207 is rotatedly attached, and which can be folded up as indicated by arrow C, is articulatedly mounted on the permanent magnet 201 . The lid-gripping element 207 surrounds the lid 211 of the starting-material vessel 210 and is frictionally connected thereto. As an alternative, a positively locking connection would also be conceivable. To rotate the lid-gripping element 207 in the direction indicated by arrow D, a rotary motor 208 is attached to the strap 206 . Actuation of the rotary motor 208 causes the lid-gripping element 207 to be rotated, rotating the lid 211 with it via the frictional connection, with the result that the lid is detached from the starting-material vessel 210 . The strap 206 can then be folded up in the direction indicated by arrow C together with the lid-gripping element 207 and the lid 211 .
FIGS. 11 to 14
In this case, the tool is formed by a capsule-handling head 220 , which comprises a cylindrical housing 221 which is divided into two compartments 223 and 224 by a partition 222 and is closed off at the top by an end wall 227 . At the open end of the bottom compartment 223 , in the cylindrical housing 221 , there is an air-filled sleeve 225 , for example made from rubber, which in the unladen state as shown in FIG. 11 has an internal diameter d min . In the upper compartment 224 there is a plunger 226 , to which a plunger rod 228 , which projects out through the end wall 227 and is provided at its top end with an outer push-button 229 , is attached. Between the plunger 226 and the cylindrical housing 221 and between the plunger rod 228 and the end wall 227 there is in each case an annular seal 230 , 231 . Between the plunger 226 and the partition 222 there is a coil spring 232 , which in the unladen state holds the plunger 226 in the position shown in FIG. 11 . Between the plunger 226 and the end wall 227 there is an air-filled space 233 , which is in communication with the interior of the sleeve 225 via an air line 234 .
In addition, the capsule-handling head 220 comprises a hollow needle 235 , to which an inner push-button 236 is attached. The inner push-button 236 is mounted movably in a recess 237 in the outer push-button 229 , a coil spring 238 being arranged in the recess 237 below the inner push-button 236 , which coil spring 238 , in the unladen state, holds the inner push-button 236 and the hollow needle 235 in the position shown in FIG. 11 . The hollow needle 235 passes through the plunger rod 228 , the plunger 226 and the partition 222 . It is in communication with the internally hollow inner push-button 236 , which can be fed, for example, with a solvent or another liquid via a feed line 239 .
FIG. 12 shows the capsule-handling head 220 after it has picked up a capsule 150 , an operation which can be effected by placing the capsule-handling head 220 onto the capsule 150 . The capsule 150 is held by the sleeve 225 , which now has an internal diameter d which corresponds to the external diameter of the capsule 150 and is greater than the internal diameter d min in the stress-free state.
FIG. 12 also illustrates that the capsule-handling head 220 comprises a permanent magnet 240 , via which, as described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . The capsule-handling head 220 is detached from the tool holder 1 by means of the electromagnet arranged in the tool holder 1 . Moreover, the figure diagrammatically indicates that the inner push-button 236 can be actuated by a rotary lever 242 and the outer push-button 229 can be actuated by a rotary lever 244 , the two rotary levers 242 , 244 being articulatedly mounted on a rod 243 , which is secured to the permanent magnet 240 , in such a manner that they can rotate in the direction indicated by the arrows. The drives for the two rotary levers 242 , 244 , which are controlled by the control computer, are not shown. FIGS. 11 , 13 and 14 do not show the permanent magnet 240 , the two rotary levers 242 , 244 , the rod 243 , and the tool holder 1 , for reasons of clarity.
The coil spring 238 is compressed as a result of the inner push-button 236 being pushed downward, and as a result the hollow needle 235 is forced into the capsule 150 , as illustrated in FIG. 13 . As a result, the capsule 150 is opened and it can be supplied, via the hollow needle 235 , with a substance from the inner push-button 236 , which is fed via the feed line 239 . Alternatively, the feed line 239 could also be connected directly to the hollow needle 235 . The substance supplied, in this case a solvent, can be mixed with the substance which is already present in the capsule 150 , for example by the capsule-handling head 220 being shaken. If a sufficiently long hollow needle is used, the mixing could also be effected by the substances which are present in the capsule 150 being sucked up and discharged again a number of times.
If pressure is no longer being exerted on the inner push-button 236 , the coil spring 238 forces it back upward into the starting position.
In order for the capsule 150 to be released, the outer push-button 229 is pressed downward, as illustrated in FIG. 14 . In the process, the plunger rod 228 and the plunger 226 are moved downward so as to compress the coil spring 232 , with the result that the size of the space 233 between the plunger 226 and the end wall 227 is increased greatly and a reduced pressure is generated therein. This reduced pressure causes air to be extracted from the interior of the sleeve 225 via the air line 234 , with the result that the internal diameter of the sleeve 225 is increased to a maximum value d max , which is greater than the external diameter of the capsule 150 , so that the capsule 150 is no longer held by the sleeve 225 and drops downward under the force of gravity.
If pressure is no longer being exerted on the outer push-button 239 , the coil spring 232 forces it back upward into the starting position shown in FIG. 11 .
FIG. 15
The tool is in this case formed by a matrix-capsule-handling head 250 , which comprises a holding plate 255 which is removably connected to the tool holder 1 by means of a permanent magnet, in a manner which is not illustrated. The matrix-capsule-handling head 250 is detached from the tool holder 1 by means of the electromagnet which is arranged in the tool holder 1 and the power supply line 8 of which can be seen. Two rods 252 , 253 , which are fixedly connected to the holding plate 255 , extend upward in the z direction, i.e. vertically, from two diagonally opposite corner regions of the holding plate 255 . A release plate 254 , which can be displaced in the z direction and is guided by the rods 252 , 253 in two diagonally opposite corner regions, is arranged above the holding plate 255 . A trigger plate 251 located above the release plate 254 can likewise be displaced in the z direction and is guided by the two rods 252 , 253 . The vertical displacement of the release plate 254 and of the trigger plate 251 is effected by two motors (not shown), although in principle it could also be brought about manually.
Sixteen capsule-handling elements 256 are secured in the holding plate 255 . The capsule-handling elements 256 , which are only diagrammatically depicted in this figure, apart from the connecting part 241 and the permanent magnet 240 , are constructed in substantially the same way as the capsule-handling heads 220 shown in FIGS. 11 to 14 and each comprise, in addition to a cylindrical housing 221 , an outer push-button 229 and an inner push-button 236 . The inner push-buttons 236 with the hollow needles attached to them can be actuated jointly as a result of the trigger plate 251 being lowered. The joint actuation of the outer push-buttons 229 is effected as a result of the release plate 254 being lowered. The matrix-capsule-handling head 250 can be used to take hold of sixteen capsules 150 arranged in a matrix 149 together, to open each of them by means of a hollow needle 235 and if appropriate to mix the substances contained therein with other substances and release them again.
FIG. 16
The tool is in this case a first exemplary embodiment of a capsule-dispensing head 280 , which comprises a permanent magnet 295 , by means of which, as has been described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . The removal of the capsule-dispensing head 280 from the tool holder 1 is effected by means of the electromagnet arranged in the tool holder 1 .
The capsule-dispensing head 280 comprises a substantially cylindrical housing 281 , the lower part of which narrows to form a neck 282 and in which a large number of capsules 150 , which each contain a substance 151 , are stored. One of the capsules 150 is held by an air-filled sleeve 283 , which is arranged in the neck 282 and is made, for example, from rubber. In a separate cylinder 284 there is a plunger 285 , to which a plunger rod 286 , which projects out through an end wall 287 of the cylinder 284 and is provided at its top end with a push-button 288 , is attached. Between the plunger 285 and the cylinder 284 and between the plunger rod 286 and the end wall 287 there is in each case an annular seal 289 , 290 . Between the plunger 285 and the base 291 of the cylinder 284 there is a coil spring 292 , which in the stress-free state holds the plunger 285 in the position illustrated. Between the plunger 285 and the end wall 287 there is an air-filled space 293 , which is in communication with the interior of the sleeve 283 via an air line 294 .
In order for the capsule 150 which is being held by the sleeve 283 to be released, the push-button 288 is pressed downward. In the process, the plunger rod 286 and the plunger 285 are moved downward so as to compress the coil spring 292 , with the result that the size of the space 293 between the plunger 285 and the end wall 287 is increased greatly and a reduced pressure is generated therein. This reduced pressure causes air to be extracted from the interior of the sleeve 283 via the air line 294 , with the result that the internal diameter of the sleeve 283 is increased to a value which is greater than the external diameter of the capsule 150 , so that the capsule 150 is no longer held by the sleeve 283 and drops downward under the force of gravity. At the same time, a second capsule 150 moves up to take the place of the first capsule 150 , it being important for the pressure on the push-button 288 to be released again sufficiently quickly, so that the coil spring 292 moves the plunger 285 back upward into the starting position, the size of the space 293 is reduced again and air is fed back to the sleeve 283 via the air line 294 sufficiently quickly for the capsule 150 to be gripped by the sleeve 283 .
Moreover, the figure diagrammatically indicates that the push-button 288 can be actuated by a rotary lever 297 , the rotary lever 297 being articulatedly mounted on a rod 296 in such a manner that it can rotate in the direction of the arrow, this rod being secured to the permanent magnet 295 . The drive of the rotary lever 297 , which is controlled by the control computer, is not illustrated.
FIG. 17
The tool is in this case a second exemplary embodiment of a capsule-dispensing head 300 , which comprises a permanent magnet 317 , by means of which, as has been described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . The removal of the capsule-dispensing head 300 from the tool holder 1 is effected by means of the electromagnet arranged in the tool holder 1 .
The capsule-dispensing head 300 comprises a substantially cylindrical housing 301 , which in its lower part narrows to form a neck 302 and in which a multiplicity of capsules 150 , which each contain a substance 151 , are stored. One of the capsules 150 is held by an air-filled sleeve 303 , which is arranged in the neck 302 and is made, for example, from rubber, while the other capsules 150 are arranged in the cylindrical housing 301 in a chamber part 315 which can rotate in the manner of a revolver as indicated by arrow E. In a separate cylinder 304 there is a plunger 305 , to which a plunger rod 306 , which projects out through an end wall 307 of the cylinder 304 and is provided at its top end with a push-button 308 , is attached. Between the plunger 305 and the cylinder 304 and between the plunger rod 306 and the end wall 307 there is in each case an annular seal 309 , 310 . Between the plunger 305 and the base 311 of the cylinder 304 there is a coil spring 312 , which in the stress-free state holds the plunger 305 in the position illustrated. Between the plunger 305 and the end wall 307 there is an air-filled space 313 , which is in communication with the interior of the sleeve 303 via an air line 314 .
In addition, the capsule-dispensing head 300 comprises a hollow needle 316 , which passes through the push-button 308 , the plunger rod 306 , the plunger 305 and the base 311 . As a result of the hollow needle 316 being forced downward, the capsule 150 which is located above the capsule which is held by the sleeve 303 can be punctured. If necessary, another substance, in particular a solvent, can be fed to the open capsule 150 via the hollow needle 316 .
In order for the capsule 150 which is being held by the sleeve 303 to be released, the push-button 308 is pushed downward. In the process, the plunger rod 306 and the plunger 305 are moved downward so as to compress the coil spring 312 , with the result that the size of the space 313 between the plunger 305 and the end wall 307 is increased greatly and a reduced pressure is generated therein. This reduced pressure causes air to be extracted from the interior of the sleeve 303 via the air line 314 , with the result that the internal diameter of the sleeve 303 is increased to a value which is greater than the external diameter of the capsule 150 , so that the capsule 150 is no longer held by the sleeve 303 and drops downward under the force of gravity. At the same time, the capsule located above this capsule 150 drops into the position which was occupied by the capsule 150 which has been released, it being important for the pressure on the push-button 308 to be released again sufficiently quickly, so that the coil spring 312 moves the plunger 305 back upward into the starting position, the size of the space 313 is reduced again and air is fed back to the sleeve 303 via the air line 314 sufficiently quickly for the next capsule 150 to be gripped by the sleeve 303 . Then, the chamber part 315 is rotated one step onward, so that a new capsule 150 moves into the position directly above the neck 302 . The rotation of the chamber part 315 may be effected externally, for example by hand, or may be triggered by the actuation of the push-button 308 . For this purpose, if necessary, the cylindrical housing 301 has access openings.
Moreover, the figure diagrammatically indicates that the hollow needle 316 can be actuated by a rotary lever 319 and the push-button 308 can be actuated by a rotary lever 318 , the two rotary levers 319 , 318 being articulatedly mounted on a rod 321 , which is secured to the permanent magnet 317 , in such a manner that they can rotate in the direction indicated by the arrows. The drives of the two rotary levers 319 , 318 , which are controlled by the control computer, are not shown.
A cuboidal housing, in which the capsules 150 are arranged in a plate which can be moved in the x direction and in the y direction, may also be provided instead of the cylindrical housing 301 and the chamber part 315 which can rotate in the manner of a revolver.
FIGS. 18 and 19
The tool is in this case formed by a screw metering head 320 , which comprises a permanent magnet 321 , by means of which, as has been described in a corresponding way in connection with FIG. 2 , it is connected to the tool holder 1 . The removal of the screw metering head 320 from the tool holder 1 is effected by means of the electromagnet arranged in the tool holder 1 .
A motor part 326 is attached to the permanent magnet 321 by means of a connecting part 322 , and an open tube 323 , in which a screw 324 , which can rotate forward and backward about the z direction as indicated by arrow F, with screw shaft 325 is mounted, is secured to its bottom end. The screw 324 can be rotated via the screw shaft 325 by a motor arranged in the motor part 326 and is stably anchored in the z direction. Rotation of the screw 324 results in a ram 327 which runs on the screw moving up or down. The lower, open end of the tube 323 can be closed off by means of a diaphragm 328 which is provided with holes 329 and is secured to two pivot arms 330 , 331 which are mounted pivotably in a suspension 332 on the motor part 326 . In FIG. 18 , the diaphragm 328 has been removed from the open end of the tube 323 and can be moved into the closed position illustrated in FIG. 19 by being pivoted in the direction of the arrow.
To take up substance, the open end of the tube 323 is moved onto the substance with the diaphragm 328 in its pivoted-away position. Rotation of the screw 324 in the direction which moves the ram 327 upward causes substance to be carried upward directly by the screw 324 .
To dispense substance, the diaphragm 328 is pivoted under the screw 324 to cover the open end of the tube 323 . Then, the screw 324 is rotated in the direction which moves the ram 327 downward, with the result that substance is forced out downward through the holes 329 in the diaphragm 328 on the one hand directly by the screw 324 and on the other hand by means of the ram 327 .
The diaphragm 328 is responsible for continuous delivery of substance, but in principle metering is also possible without a diaphragm 328 .
FIG. 20
The tool is in this case formed by a solids-metering head 350 , which comprises a permanent magnet 351 , by means of which, as has been described correspondingly in connection with FIG. 2 , it is connected to the tool holder 1 . The removal of the solids-metering head 350 from the tool holder 1 is effected by means of the electromagnet arranged in the tool holder 1 .
On the permanent magnet 351 there is a bearing part 352 , on which a carriage 353 is mounted in such a manner that it can move in the z direction. A holding plate 354 has been pushed laterally into the carriage 353 and has attached to it a metering housing 355 , the internal diameter of which decreases in steps toward the bottom and which has an intermediate base 371 with a conical metering opening which tapers upward. The holding plate 354 with the metering housing 355 can be detached from the carriage 353 by means of a horizontal movement involving little force.
A rotating metering shaft 357 , which drives a stripper 356 and can be displaced in the z direction, runs in the z direction centrally through the metering housing 355 and the conical metering opening in the intermediate base 371 . At the lower end of the metering shaft 357 there is a closure cone 372 which tapers upward and partially or completely closes off the conical metering opening in the intermediate base 371 depending on the z position, substance which flows downward when the metering opening is partially open being fed to the stripper 356 .
The rotating metering shaft 357 is fixedly connected to a co-rotating bearing part 368 , projects from below into a shaft 359 driven by a motor 360 and is rotated with the shaft 359 . A rotating stripper 358 which is arranged in the upper part of the metering housing 355 runs through the bearing part 368 and likewise projects into the shaft 359 from below. The stripper 358 can move in the z direction in the bearing part 368 and is driven, together with the metering shaft 357 , by the shaft 359 .
The displacement of the metering shaft 357 in the z direction is brought about by two electromagnets 362 and 363 , which are mounted on the holding plate 354 and bear a cover plate 366 via two support parts 364 , 365 . The cover plate 366 is connected to the bearing part 368 fixedly in the z direction, a ball bearing 361 enabling the bearing part 368 to rotate on the rotationally fixed cover plate 366 . On activation, the electromagnets 362 , 363 generate a force in the z direction and raise or lower the cover plate 366 and as a result the bearing part 368 and the metering shaft 357 .
The motor 360 and the electromagnets 362 , 363 are controlled by a control part 367 , which is arranged laterally on the bearing part 352 and to which the motor 360 is secured.
Moreover, a balance 369 with a minimum weighing range from 0 to 2 kg and an accuracy of 0.1 g, which is in contact with the carriage 353 via a pin 370 , is attached to the bearing part 352 . Balances of this type are commercially available, for example from Sartorius AG, 37070 Gottingen, Germany.
If substance which is stored in the metering housing 355 is dispensed via the conical metering opening in the intermediate base 371 , the weight load applied to the carriage 353 is reduced and the carriage 353 is pulled downward less strongly, a fact which is measured by the balance 369 via the pin 370 .
A solids-metering head of this type, but without magnet coupling to the tool holder 1 and without balance 369 arranged directly on the solids-metering head, is marketed by Auto Dose SA, CH-1228 Plan-les-Ouates.
It is possible to execute further design variations on the devices according to the invention which have been described above. Express mention should also be made of the following at this point:
The other tools, like the solids-metering head 350 , may also be provided with a balance 369 . As an alternative, it is also conceivable for the balance to be attached to the tool holder 1 . The connection between tool holder 1 and tool may also be formed in a different way than with magnets. By way of example, screw connections, bayonet catch connections or clamping connections are conceivable. However, it should be possible for the connection to be produced and released again automatically, i.e. not by hand. In addition to the tools described, it is also possible to use further tools which are equipped with a connection point to the tool holder. By way of example, the camera 10 or the infrared-analysis unit could also be designed as independent tools. | The inventive device comprises a tool holder, which can be displaced in an x-direction, in a y-direction that is perpendicular thereto, and in a z-direction that is perpendicular to both the x-direction and the y-direction, and which can rotate about the z-direction A solid matter dosing head, provided as a tool, is automatically attached in a removable manner to the tool holder by means of a permanent magnet. The tool can be easily exchanged for another tool due to this automatic removable attachment of said tool to the tool holder involving the use of a permanent magnet. |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. Non-Provisional patent application Ser. No. 12/064,276, which is the national entry of PCT/US08/54085, which claims the benefit of U.S. Provisional Patent Application No. 60/890,831 entitled, “Directional Bone Drilling and Methods of Treatment” filed on Feb. 20, 2007 in the United States Patent and Trademark Office and U.S. Provisional Patent Application No. 60/891,183 entitled, “Directional Bone Drilling and Methods of Treatment” filed on Feb. 22, 2007 in the United States Patent and Trademark Office.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of Invention
[0004] The present invention relates to an apparatus to provide delivery of medical treatment to and within tissue or bone. In particular the present invention related to a minimally invasive and particularly small treatment delivery system including a drill and treatment delivery passage. Additionally, the present invention relates to a minimally invasive and particularly small apparatus for drilling of passages in bone for other purposes, such as the imposition of screws or other devices to fix a bone or bone portion in position.
[0005] 2. Description of the Related Art
[0006] Delivery of medical treatments to tissue, particularly hard tissue and notably the tissue within bone, is particularly difficult. Historically treatment has been delivered through the entire body in sufficient application amounts to ensure the necessary treatment amount reaches the desired tissue. As can be expected, this requires application amounts far in excess of the treatment amount necessary and can result in damage to other parts of the body as well as increased costs. Various solutions have been developed to attempt to reduce the application amount, typically by attempting to isolate the affected area from the body, including shunting of blood flow in the affected limb through a heart/lung machine to allow continued circulation within the limb while isolating the blood flow from the rest of the body. Similarly accessing bone to directly apply any treatment amount or to drill into the bone, such as drilling a passage for screws to fix a bone or bone particle in position, has historically been quite difficult and invasive. Moreover, such passages have generally been no smaller than 0.15875 cm (0.0625 inches). Likewise, drilling such passages has resulted in significant fracturing of the bone itself.
[0007] The need therefore exists for apparatus to provide delivery of medical treatment to and within tissue, and notably to tissue within the bone, which permits direct application of only the necessary treatment amount and for a system to access tissue, and particularly tissue within a bone, to directly apply any treatment amount or to drill into the bone such as drilling a passage for screws to fix a bone or bone particle in position, with minimal invasion. A need further exists for an apparatus which may be used with tissue or with bone.
[0008] Such a need may be particularly important in the treatment of osteosarcoma and similar cancers of bone.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention overcomes the foregoing drawbacks of previous systems.
[0010] The present invention provides an improved system to provide delivery of medical treatment to tissue, which may be within a bone, by providing an improved drill, hypodermic guide tube, a cortex adapter and a stylet. The drilling apparatus includes a miniature shaft, a bit, a hypodermic guide tube and a drive unit. The guide tube may comprise, in part, a hypodermic needle, thus providing a hypodermic guide tube. As a result, precise, straight holes may be drilled, targeted towards a cancerous lesion within the tissue. Once the bit reaches the desired depth, the hypodermic guide tube is retained in place, the bit withdrawn, and a capillary, referred to as a cortex adapter, is inserted through the hypodermic guide tube, through the hole in the bone and into the lesion. A stylet may be inserted in the capillary tube to prevent any movement of bodily fluids up the cortex adapter and to prevent coagulation about the opening of the cortex adapter. When needed, the stylet may be removed and the treatment directed to the tissue though the cortex adapter.
[0011] Due to the small diameter of the drill, the hole drilled is particularly small. As can be anticipated a plurality of holes can be drilled, spaced apart to deliver specific quantities of treatment across the lesion.
[0012] In another aspect of the present invention, the present invention provides an improved method of delivering medical treatment to and into bone.
[0013] The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS
[0014] So that the manner in which the described features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical preferred embodiments of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
[0015] In the drawings:
[0016] FIG. 1 illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone.
[0017] FIG. 2 illustrates a cross sectional view of the drilling and hypodermic guide tube portions of the present invention showing the relation of the shaft and hypodermic guide tube.
[0018] FIG. 3 illustrates a cross-sectional view of the drilling and hypodermic guide tube portions of the present invention, providing a better image of the bit and hypodermic guide tube.
[0019] FIG. 4 illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone in relation to a drive tube connected to the drill shaft.
[0020] FIG. 5 illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone after penetration through the bone and into a cancerous lesion.
[0021] FIG. 6 illustrates a side view of the hypodermic guide tube portion of the preferred embodiment of the present invention in relation to the bone after removal of the drill portion after penetration through the bone and into a cancerous lesion, leaving a usable passage to the cancerous lesion.
[0022] FIG. 7 illustrates a side view of the hypodermic guide tube, cortex adapter and stylet portions of the preferred embodiment of the present invention when nested together.
[0023] FIG. 8 illustrates a side view of the hypodermic guide tube, cortex adapter and stylet portions of the preferred embodiment of the present invention separated for clarity.
[0024] FIG. 9 illustrates a side view of the hypodermic guide tube portion and cortex adapter portions of the preferred embodiment of the present invention in relation to the bone after penetration through the bone and into a cancerous lesion during delivery of a treatment.
[0025] FIG. 10 illustrates one embodiment of the drive unit used with the drilling system.
DETAILED DESCRIPTION OF THE INVENTION
[0026] The invention may be further understood by the following non-limiting examples. Although the description herein contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of the invention. For example, thus the scope of the invention should be determined by the appended claims and their equivalents, rather than by the examples given. In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The following definitions are provided to clarify their specific use in the context of the invention. All references cited herein are hereby incorporated by reference to the extent not inconsistent with the disclosure herewith.
[0027] Referring to the FIG. 1 , a portion of a drilling system 10 , for drilling into a living bone 100 is shown. The drive unit 1000 , depicted in FIG. 10 , required for at least partial rotation of the bit 102 , the cortex adapter 702 and the stylet 710 , depicted in FIG. 7 , are not shown. While drilling system 10 is described for use in drilling into bone, it may be used to drill into other body tissues. The drilling apparatus includes a bit 102 , a shaft 104 , and a hypodermic guide tube 106 .
[0028] Referring to FIG. 1 , the hypodermic guide tube 106 may comprise a hypodermic needle section 108 , a hypodermic adapter fitting 110 at the receiving end 112 of the hypodermic guide tube 106 , and a sharp non-coring tip 114 at the penetrating end 116 of the hypodermic guide tube 106 . The hypodermic guide tube 106 therefore has a passage through its body along its length.
[0029] Referring to FIG. 2 , in the preferred embodiment the hypodermic guide tube 106 is particularly small compared to the bone to be drilled or the body to be entered. The inner diameter 202 of the hypodermic guide tube 106 may quite small.
[0030] Referring to FIGS. 2 and 3 , the shaft 104 and the bit 102 of the drilling system 10 are depicted. A portion of the shaft 104 proximate the first end 306 may be flattened and shaped to produce a bit 102 , which may be a spade drill bit. Different bits, such as spherical, helical twist, or burr cutting tips, may alternatively be used. Unlike standard drill bits, which have high strength and brittleness, the bit 102 is quite ductile. As can be appreciated, the loss of such a drill bit in the body, made more likely with a brittle drill bit, is to be avoided. The bit 102 has a width 302 smaller than the inner diameter 202 of the hypodermic guide tube 106 , such that the hypodermic guide tube 106 limits the flexing of the shaft 104 but permits withdrawal of the shaft 104 with the bit 102 after use. The bit 102 also has a drill point or cutting edge 304 . The shaft 104 therefore has a quite small outer diameter. The hypodermic guide tube 106 is therefore sized to surround the shaft 104 .
[0031] Referring to FIG. 4 , a drive tube 402 , having a larger diameter than the shaft 104 , may enclose the shaft 104 at its shaft second end 404 so the shaft 104 may be connected to a motor or other radial driver to at least partially rotate the shaft 104 and to a linear driver to drive the bit 102 into the bone 100 in operation. The drive tube 402 , affixed or connected to the shaft 104 , provide for better application of rotational and linear force due to its larger size.
[0032] Referring again to FIG. 1 and to FIG. 5 , the shaft 104 has a length sufficient to fully pass through the hypodermic guide tube 106 and to drill through the wall 118 of the bone 100 .
[0033] In operation, the hypodermic guide tube 106 is placed in abutment or proximate to the tissue, here bone 100 , at its penetrating end 116 . The drilling system 10 may be delivered directly to the bone or tissue to be drilled by driving the hypodermic guide tube 106 through tissue. Alternatively, the drilling system 10 may be placed adjacent or proximate the bone 100 after site preparation, which may include surgical relocation of intermediate parts of the body 120 , such as muscle and blood vessels.
[0034] Referring to FIGS. 1 , 3 , and 5 , the hypodermic guide tube 106 may include a sharp non-coring tip 114 extending from the hypodermic guide tube penetrating end 116 . The length of the sharp non-coring tip 114 is sufficient to maintain a desired angle of drilling while the penetrating end 116 contacts the bone 100 and prevents the cutting tip 304 from contacting the bone 100 prior to advancing the cutting bit 102 . The sharp non-coring tip 114 is sized to ensure contact between the hypodermic guide tube 106 and the bone 100 before the cutting bit 102 begins cutting into the bone 100 at the desired angle of attack. Referring to FIG. 1 , by virtue of the sharp non-coring tip 114 , the hypodermic guide tube 106 contacts the bone 100 , or tissue on the surface of the bone 100 , and becomes stationary, thereby preventing the cutting bit 102 from walking away from the point of its initial contact with the bone 100 or tissue on the surface of the bone 100 . Moreover, as the sharp non-coring tip 114 provides a limited point of contact between the bone 100 and the hypodermic guide tube 106 , any chips of bone 100 created by the cutting bit 102 are not trapped adjacent to the cutting bit 102 but rather may escape the passage 502 , depicted in FIG. 5 , created by the cutting bit 102 .
[0035] Referring to FIG. 5 , the shaft 104 is then driven so that the bit 102 is rotated against the bone 100 , while the shaft 104 is advanced, cutting through the bone wall 118 , until reaching the marrow 122 and creating a passage 502 .
[0036] Referring to FIG. 6 , the bit 102 , and the shaft 104 are then withdrawn from the hypodermic guide tube 106 , leaving only the hypodermic guide tube 106 in contact with the bone 100 and in communication with the passage 502 . The sharp non-coring tip 114 is therefore of critical importance in maintaining the position of the hypodermic guide tube 106 relative to the passage 502 and to providing the means to identify the location of the passage 502 .
[0037] Referring to FIGS. 7 and 8 , a cortex adapter 702 having a capillary 704 with an interior passage is provided for insertion into the passage of guide tube 106 and ultimately into the tissue passage 502 , which may be into the marrow 122 , permitting delivery of the treatment 900 as shown in FIG. 9 . The hypodermic adapter fitting 110 of the hypodermic guide tube 106 may include a tapered conic cavity 706 adapted to direct the bit 102 and the drill shaft 104 into the hypodermic needle section 108 via hypodermic adapter fitting 110 of the hypodermic guide tube 106 . The cortex adapter 702 may be constructed to include a nose 708 to fit into the tapered conic cavity 706 of the hypodermic guide tube 106 and may similarly include a tapered conic cavity 714 adapted to direct the stylet 710 into the hypodermic needle section 108 of the hypodermic guide tube 106 . Referring to FIG. 9 , the capillary 704 of the cortex adapter 702 is sized and capable of passing through the passage of the hypodermic guide tube 106 and extends the length of the hypodermic guide tube 106 , through the passage 502 and through the bone 100 and the marrow 122 to provide a controlled passage of any treatment 900 . Referring now to FIGS. 8 and 9 , as previously mentioned, the drilling system 10 also includes a stylet 710 , which is utilized to plug the cortex adapter 702 when the cortex adapter 702 is not in use, to prevent outflow through the cortex adapter 702 , and to prevent coagulation of blood in or at the end of passage 502 . To accomplish these goals, the wire section 718 of stylet 710 is capable of fitting within and through the cortex adapter 702 and may preferably extend the entire length of the capillary 704 and into the marrow 122 , as depicted in FIG. 7 . The stylet 710 may be constructed to include a nose 716 to fit into the tapered conic cavity 714 of the cortex adapter 702 . The wire section 718 of the stylet 710 is sized to fit within the cortex adapter 702 sufficiently close to preclude outflow of bodily fluids through the cortex adapter 702 , but not so close as to be irremovable from the cortex adapter 702 . Ideally both the cortex adapter 702 and the wire section 718 of the stylet 710 have cylindrical cross-sections to encourage this close fit.
[0038] Referring to FIG. 8 , an exploded view of the constituent parts, including the hypodermic guide tube 106 , the cortex adapter 702 , and the stylet 710 are depicted.
[0039] Referring to FIG. 9 , when sufficient numbers of cortex adapters 708 have been inserted into the tissue, the treatment 900 may be introduced into the cancerous lesion 124 through the cortex adapter 702 .
[0040] The bone 100 is relatively soft when drilled in this manner, thus the drilling system 10 is capable of drilling through the bone 100 without deleterious effects on the surrounding bone. Moreover, the drilling system 10 produces a uniform, clean and particularly small diameter passage 502 through the bone 100 . As a result of the small passage 502 directed toward the cancerous lesion 124 , any of the various treatments known in the art, such as chemotherapy, radiochemical therapy, directed energy, may be provided without damage of adjacent tissue.
[0041] Referring to FIG. 10 , the drilling system 10 may be driven by a drill unit 1000 . The drive unit 1000 may include a rotating motor 1002 capable of operable connection to the shaft 104 and capable of at least partially rotating the shaft 104 . In the preferred embodiment, the rotating motor 1002 is a rotating motor. The rotating motor 1002 may operate at a fixed speed and is ideally activated when the control arm 1006 is engaged, although a variable speed rotating motor 1002 may be used and as the rotating motor 1002 may be activated by other switches, such as a simple switch or a foot pedal. Regardless of the type of activation used or the fixed or variable speed, the operating speed of the rotating motor 1002 is sufficiently high to efficiently cut the bone 100 without generating thermal necrosis. A control arm 1006 associated with the drive unit 1000 may be moved through a range of positions, causing a linear drive 1004 to advance. The advance of the linear drive 1004 may be proportional to the movement of control arm 1006 , particularly if the control arm 1006 is moved radially, thus providing a moment about a pivot to provide a linear drive 1004 . The proportion of movement may be set to provide a leverage advantage in linearly driving the shaft 104 . The control arm 1006 may also be spring-loaded to cause the linear drive 1004 to retreat as the control arm 1006 is released. Alternatively, the control arm 1006 may be connected to a processor or other system to proportionally multiply the movement of the control arm 1006 to the input of a linear drive 1004 . The linear drive 1004 may be coupled or otherwise related to the shaft 104 , which may be via a connection of the linear drive 1004 to the rotating motor 1002 . Thus as the linear drive 1004 advances and retreats by operation of the control arm 1006 , the shaft 104 likewise advances or retreats.
[0042] In either embodiment, the bit 102 drills through the bone 100 to provide for application of the medical treatment 900 , as illustrated in FIG. 9 . Once a passage 502 has been drilled through the bone 100 , the medical treatment 900 may be introduced toward the cancerous lesion 124 . The treatment 900 may be chemotherapy, radiotherapy, heat therapy or any other therapy known in the art. The amount of treatment 900 necessary for effective treatment may be far less than typically applied when given orally or introduced into the blood stream since the treatment 900 is introduced proximate the cancerous lesion 124 . Likewise, the treatment 900 may be more effective as a result of directed application. As can be appreciated, the flow of the treatment 900 through the cortex adapter 702 toward the cancerous lesion 124 is limited by the uptake by the cancerous lesion 124 of the treatment 900 .
[0043] Alternatively, the treatment 900 may be directed toward the cancerous lesion 124 by a charge-driven application (not shown). Thus it may be possible to enhance the flow of the treatment 900 by applying a direct current potential between the cortex adapter 702 and an electrode in conductive contact with the exterior of the limb placed as closely as possible to the region of the cortex adapter 702 . In one embodiment, a very fine liquid aerosol is generated and applied through electrostatic charging. In one embodiment, a liquid is passed through a nozzle, wherein a plume of droplets is generated by electrically charging the liquid to a very high voltage. The charged liquid in the nozzle becomes unstable as it is forced to hold more and more charge. Soon the liquid reaches a critical point, at which it can hold no more electrical charge and at the tip of the nozzle it blows apart into a cloud of tiny, highly charged droplets. These tiny droplets are particularly small, and fly about searching for a potential surface to land on that is opposite in charge to their own. Such droplets would be attracted to the cancerous lesion due to electrical differential. The system may employ a sharply pointed hollow metal tube, such as a syringe needle, with liquid pumped through the tube. A high-voltage power supply may then be connected to the outlet of the tube and the tube positioned proximate a cancerous lesion 124 . When the power supply is turned on and adjusted for the proper voltage, the liquid being pumped through the tube transforms into a fine continuous mist of droplets that fly rapidly toward the cancerous lesion 124 .
[0044] Alternatively, if the treatment 900 consists of direct energy to be applied to the cancerous lesion 124 , an optical tube sheathed in a metal, such as nickel, may be used to direct the treatment 900 .
[0045] Additionally, via the passage 502 , it is possible to visually observe the cancerous lesion 124 , such as with appropriately-sized fiber-optic or laparoscopic devices.
[0046] Thus in operation, the drilling system 10 is applied to or in close proximity to the bone 100 at the penetrating end 112 of the hypodermic guide tube 106 . The shaft 104 and the bit 102 are rotated sufficient to cut the bone 100 . Force is linearly applied to the shaft 104 , which drives the bit 102 into the bone 100 and through the bone wall 118 to create a passage 502 . Additionally, it is possible to direct the hypodermic guide tube 106 against the bone 100 towards the cancerous lesion 124 from the opposite side of the cancerous lesion 124 . The shaft 104 and bit 102 are removed from the hypodermic adapter fitting 110 of the hypodermic guide tube 106 and the cortex adapter 702 and its capillary 704 , together with a stylet 710 therein, are inserted into the hypodermic adapter fitting 110 of the hypodermic guide tube 106 . While the cortex adapter 702 may alternatively be first inserted into the hypodermic guide tube 106 and the stylet 710 inserted thereafter, this is not the most desired operation as it permits backflow of bodily fluids into the cortex adapter 702 . When the treatement 900 , which may be radioactive, is ready to introduction, the stylet 710 is removed and the treatment introduced. Thereafter the hypodermic guide tube 106 and the cortex adapter 702 are removed, thus leaving treatment 900 at the desired location.
[0047] The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof. | A minimally invasive and particularly small system for drilling into bone) and for providing for delivery of medical treatment is provided. The drilling system includes a miniature shaft, a bit, a guide tube encapsulating the shaft during drilling and a capillary tube thereafter, a capillary tube, and a stylet. As a result, a hole, targeted towards a cancerous lesion within the bone, is possible. After removal of the shaft, the treatment may be introduced via the capillary tube after removal of the stylet. |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application No. 60/562,853 filed Apr. 15, 2004.
TECHNICAL FIELD
This invention relates to hemming the edges of inner and outer body panels to form a hemmed assembly having closed edges and to flanging of outer panels prior to hemming. More particularly, the invention relates to electromagnetic (EMF) flanging and hemming apparatus and methods.
BACKGROUND OF THE INVENTION
Electromagnetic (EMF) forming uses very high-current pulses in a specially designed electrical coil to generate magnetic fields, which impart opposing magnetic fields in a highly electrically conductive metal workpiece, such as an aluminum alloy or steel. With the coil held in a fixed position, the repulsive magnetic forces act upon the workpiece causing it to deform at very high strain rates. Metals deformed at these very high strain rates can exhibit “hyperplasticity,” a level of plastic ductility well beyond what the material is capable of during conventional forming, e.g. flanging and hemming, operations.
Roller hemming uses a solid wheel, driven and controlled by a robot (or other device) to gradually bend a 90° flange to a closed hem position as it traverses the perimeter of a panel. The roller hem usually requires two to three passes around the panel to completely bend the flange to the closed, flat hem position.
An advantage of the roller hem method compared to conventional hemming is the alternate strain path through which the flange is bent. Conventional hemmers deform the flange through a “plane strain bending” path, which is very severe and can cause cracking failure when hemming aluminum panels, especially panels stamped from AA6111. The roller hem method imparts a component of strain in the direction of the hem line, different from “plane strain bending,” that allows AA6111 to be flat hemmed without cracking.
SUMMARY OF THE INVENTION
This invention combines concepts from the technologies of electromagnetic force (EMF) forming and roller hemming to provide a method for flanging and hemming sheet metal panels.
In this invention, the solid roller of the roller hemming concept is replaced with an electromagnetic coil designed to force the sheet metal flange to bend around the hemline to the closed hem position. A robot, or other device, can drive the electromagnetic coil with translation and rotation around the part contour as required. The combined advantages of non-plane strain bending and hyperplasticity may be realized to avoid cracking failure in aluminum panels.
In an alternative embodiment, electromagnetic forces may be used to flange and/or hem a curved or otherwise shaped “difficult to hem” portion of a longer hem wherein the other portions of the hem could be flanged or hemmed by conventional hemming apparatus and methods. The electromagnetic forces could be applied by a stationary coil fitted in a conventional hemming machine and performing plane strain bending assisted by hyperplasticity of the formed material, or the forces could be applied by a traveling coil as previously mentioned to include the advantages of non-plain strain bending.
In another alternative embodiment, the very large electromagnetic forces would be managed by employing a rigid stationary electromagnetic hemming anvil, in which the forming coils would remain stationary, and the sheet metal components would be moved progressively through them, with rapidly repeating electromagnetic pulses forming the complete hem.
Benefits to be realized from the invention include:
Flexible Manufacturing—non-product specific tooling can be created to flat hem many different products.
Preservation of class—A surface quality—the electromagnetic forming process requires no direct contact with the workpiece.
Non-plane strain bending—the alternate strain path enables greater bending plasticity to avoid cracking in AA6111 aluminum panels.
Improved hem quality—electromagnetic (EMF) forming enhances the ductility of metals, which can enable greater bending strains and sharper hems to attain the “jewel” effect at the hemline.
Elimination of the conventional flanging process—EMF may be used to flange and hem panels from 180° open to the closed, flat hem condition. The hold-down fixture of the inner panel could be used to provide the support needed to establish the break line of the hem. Alternatively, the outer edge of the inner panel could also be used to wrap the outer flange around the inner panel, creating a tight, flat, crisp hem appearance.
The robotic end effector or stationary anvil-type flanging/hemming base could include two or more EMF coils in series to flange and hem the outer panel in a single pass. Multiple coils would each bend the flange a controlled amount.
These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 are simplified isometric cross-sectional views of an electromagnetic force (EMF) flanging apparatus illustrating steps in the EMF flanging of a panel sheet in preparation for hemming;
FIGS. 6-9 are simplified isometric cross-sectional views of an EMF hemming apparatus illustrating steps in the EMF hemming of a panel; and
FIGS. 10-13 are simplified isometric cross-sectional views of the fixtures and workpieces for EMF hemming of a panel with complex curvature and illustrating steps in the EMF hemming method.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
Manufacture of hemmed panel assemblies commonly involves a series of manufacturing steps, including forming, flanging and hemming. The hemming process begins with individual metal sheets that are cut, surface treated as desired and formed by known processes, such as by drawing or stamping, into three dimensional panels ready to be assembled into a panel assembly. These steps do not form part of the apparatus and method of the present invention, although they may be combined with this invention to form a hemmed panel manufacturing process.
This invention is directed to apparatus and methods used in flanging and/or hemming steps involving electromagnetic forming of hemmed panel assemblies. The following exemplary embodiments and steps incorporate various related concepts of flexible EMF flanging and hemming, as shown in the drawings.
Outer Panel Flanging
An initial step directed to electromagnetic (EMF) flanging of an outer panel for hemming is illustrated in FIG. 1 . The figure shows the initial setup wherein an electromagnetic coil 10 is positioned close to a sheet metal flange 12 extending from an outer panel 14 made from steel or aluminum alloy, as an example. The flange 12 is to be bent from a 180° open position to a flanged position of 90° open.
The outer panel 14 is supported by suitable tooling, such as anvil 16 , and is retained by hold-down tooling 18 , which provides a rigid support against which the flange will be bent and which establishes the flange radius. The EMF coil 10 is part of end-of-arm-tooling supported and driven by a robot or other device (not shown).
Electromagnetic forces are used in this invention to deform the sheet to produce a flange along the periphery of a formed outer closure panel, and, in a subsequent step, to further deform the flange to join inner and outer panels with a hem. A very high current pulse from a capacitor bank, not shown, is passed through the coil 10 held in proximity to the workpiece. The current pulse results in a high magnetic field around the coil.
The magnetic field induces eddy currents 20 in the workpiece as shown in FIG. 2 and an associated secondary magnetic field. The magnetic fields of the coil and of the workpiece are opposite in sign so that an electromagnetic repulsive force 22 causes the deformation of the workpiece as shown in FIGS. 3-5 . In this example, the electromagnetic force 22 bends the sheet metal flange to the 90° open position as shown in FIG. 5 . The exact design, shape and electrical characteristics of the coil depend on the specific flange material and geometry.
Electromagnetic deformation takes place at very high strain rates, on the order of 10 3 (in/in)/s, or greater. Metals, such as aluminum alloys, characterized by relatively poor formability in conventional forming processes, e.g. stamping, exhibit enhanced ductility when electromagnetically formed at very high rates. This “hyperplasticity” is usually accompanied by reduced springback and a decreased tendency for wrinkling.
As the flanging operation proceeds, the EMF coil is moved by the robot or other device in the direction of arrow 24 along the perimeter of the panel, as shown in FIGS. 3-4 , to bend the flange to the 90° open position as shown in FIG. 5 . As the coil moves along the panel, the 180° open flange 12 is progressively bent to the finished 90° open position of FIG. 5 .
Finish Hemming
Referring now to FIGS. 6-9 , there is shown a second apparatus and method for applying the EMF concept to the steps of flanging and hemming together of metal panels into a panel assembly. These figures illustrate a simplified apparatus and method for the hemming step.
After a panel is flanged, either by EMF flanging or by conventional flanging methods, the EMF hemming method can be used to hem the panel assembly. FIG. 6 shows the apparatus including a support or anvil 16 supporting the outer panel 14 with its upstanding flange 12 . An inner panel 25 is positioned against the main portion of the outer panel 14 with an outer edge 26 engaging the open flange 12 . Hold-down tooling members 28 clamp the panels against the anvil 16 to hold the panels in assembly. An EMF coil 10 , supported by a robot or other device, not shown, is positioned initially opposite one end of the flange 12
As described with respect to the flanging step, when current is pulsed through the EMF coil 10 , eddy currents 20 , shown in FIG. 6 , result in electromagnetic forces 22 acting on the flange as shown in FIGS. 7-9 . These forces act as the coil is traversed from one end of the flange to the other to bend the sheet metal in a non-plain strain manner.
As the hemming operation proceeds, the EMF coil 10 is moved in the direction of arrow 24 by the robot or other device along the perimeter or edge of the panel to bend the 90° open flange 12 to the flat hem position as shown in FIGS. 7 and 8 . As the coil moves along, the 90° open flange 12 is progressively bent to a finished, flat hem 30 . FIG. 9 shows the final position of the EMF coil as the hemming operation is finished.
In this embodiment, the EMF flanging and hemming procedures are distinct and can be applied together or independently to flange and/or hem sheet metal panel subassemblies. This EMF sheet bending procedure is “similar” to roller hemming concepts in the way that the sheet metal flange is progressively bent. By bending the flange in this way, the material deformed at the hemline goes through a “non-plane strain” bending path, avoiding plane strain bending (which is the worst case for extreme deformation—leading to failure by cracking in some aluminum alloys). The non-plane strain bending path provides more bending strain and enables flatter hemming with tighter radii in aluminum sheet metal panels without cracking along the hem line.
Alternative Embodiment
In another exemplary embodiment of the EMF hemming concept, an EMF coil could be incorporated within a traditional hemming device and specifically used to flatten hem areas or features that are very difficult to hem conventionally. One such difficult-to-hem area is shown schematically in FIG. 10 .
In this embodiment, the outer panel 32 has complex curvature in the flange area to accommodate a design feature. The inner panel 34 is shown slightly away from the married position wherein the outer edge 36 of the inner panel would engage the inside of curved flange 38 as well as of adjacent straight flanges 40 . The length (height) of the flange 38 in the difficult-to-hem area is usually cut much shorter than the flanges 40 immediately adjacent opposite ends of the difficult-to-hem area. The flange 38 length must be short in order to avoid splitting (of a stretch flange) or wrinkling (of a compression flange) during the conventional hemming procedure.
Whether a flange is a compression flange or a stretch flange depends on the complex curvatures of the outer panel 32 in the difficult-to-hem areas. When these areas have tight radii of curvature, the flanges must be very short (or narrow) and occasionally do not completely cover the edge 36 of the inner panel 34 after hemming. This situation does not provide a desirable appearance and may allow for water leakage if the hem adhesive does not provide a tight seal.
In accordance with the invention, a conventional hemming device (not shown) could be used for hemming the “simple” flange areas 40 , while an EMF coil, not shown, would be used to hem the difficult-to-hem flange 38 . The EMF coil could be mounted on the conventional hemmer and driven by a slide or other mechanism (not shown) to move into close proximity to the flange 38 for hemming.
Because EMF makes use of “hyperplasticity” to deform the sheet metal, it can be used to successfully hem flanges that would be considered too long (or wide) for conventional hemming. The hyperplastic deformation can resist splitting of stretch flanges and can inhibit wrinkling of compression flanges. As a result, the flange length in difficult-to-hem areas can be made longer, as shown by the curved flange 42 of FIG. 11 , in order to assure adequate sealing of the hem.
During hemming, the outer panel 44 is supported by an anvil 46 and the inner panel 34 is in the married position for hemming and has the longer curved flange 42 .
FIG. 12 illustrates one possible hemming sequence for this application with the hold down fixtures represented by numeral 28 . In this case, a conventional hemmer, not shown, could hem the “simple” flanges 40 , leaving the difficult-to-hem flange section 42 in the open position as shown by the cross-sectional views 12 A, 12 B, 12 C taken in planes 48 , 50 , 52 of each flange area. FIGS. 12A and 12C show their flanges 40 folded over to the finished flat hem position, while FIG. 12B shows the central difficult-to-hem flange 42 still in the 90° open position.
Finally, the EMF coil, not shown, would be moved into position to flat hem the difficult-to-hem flange 42 , with the longer flange length, without wrinkling or splitting as shown in FIG. 13 and cross section 13 A. The operation of the EMF coil, not shown in this embodiment, may be like that of coil 10 previously described. The coil may be designed to travel along the length of the flange where non-plane strain bending of the flange is desired or necessary, or the coil could be configured to the shape of the flange section 42 , to bend this section in a single fold.
While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims. | Apparatus and methods are disclosed for applying electromagnetic force (EMF) to flanging and hemming metal panels to form a hemmed panel assembly. First and second apparatus and method steps use a translating EMF coil to flange a sheet and to finish a hem by progressive non-planar bending. An alternate embodiment uses EMF hemming for difficult-to-hem portions of a flange and optionally precedes this with conventional hemming of straight hem portions. |
This application is related to application Ser. No. 371,160, application Ser. No. 371,376, and application Ser. No. 371,377, all filed of even date.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns the field of reaction injection molded elastomers containing internal mold release agents.
2. Description of the Prior Art
Reaction injection molded elastomers such as polyurethanes are becoming quite popular as automobile body pats and other applications. These materials must be molded into the desired shape and demolded quickly to be economical. Heretofore, external mold release agents were applied to the inside of the mold before the injection of the reactive streams which would form the RIM part. A new product called Dow Corning® Q2-7119 Fluid, which is a dimethyl siloxane with organic acid groups, has been developed for use in polyurethane RIM elastomers to avoid the necessity of an external application of mold release agent. However, since in polyurethane systems a tin catalyst is required for proper reactivity of the system and since the Dow Corning product mentioned above is reactive with and not compatible with tin catalysts or isocyanates, a third stream was necessary for the use of the internal mold release agent or the tin catalyst concentration was required to be adjusted. Product bulletins concerning the Dow Corning internal mold release agent advise that premixing the internal mold release agent with the polyol wouuld result in some gellation of the premix.
Most commercial RIM machines are of the two stream variety, thus limiting the application of the Dow Corning product.
We have discovered a method whereby the internal mold release agent described above may be used in a two stream system to make a RIM elastomer of superior properties.
SUMMARY OF THE INVENTION
The invention is a method of making a RIM elastomer which will release from its mold without the presence of an externally applied mold release agent comprising injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream primary or secondary amine terminated polyethers of greater than 1,500 molecular weight, an amine terminated chain extender and an internal mold release agent, and in the second stream an aromatic polyisocyanate. The invention is also the resulting RIM elastomer made from the method above.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The RIM elastomers of this invention may be prepared by reacting as few as three ingredients: a high molecular weight amine terminated polyether, an aromatic diamine chain extender and an aromatic polyisocyanate. An internal mold release agent is also required. The RIM elastomers of this invention do not require an added tin catalyst as it will interact with the mold release agent and harm the process and product.
The amine terminated polyethers useful in this invention include primary and secondary amine terminated polyether polyols of greater than 1,500 average molecular weight having from 2 to 6 functionality, preferably from 2 to 3, and an amine equivalent weight from about 750 to about 4,000. Mixtures of amine terminated polyethers may be used. In a preferred embodiment the amine terminated polyethers have an average molecular weight of at least 2,500.
The amine terminated polyether resins useful in this invention are polyether resins made from an appropriate initiator to which lower alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide or mixtures thereof are added with the resulting hydroxyl terminated polyol then being aminated. When two or more oxides are used, they may be present as random mixtures or as blocks of one or the other polyether. In the amination step it is highly desirable that the terminal hydroxyl groups in the polyol be essentially all secondary hydroxyl groups for ease of amination. Normally, the amination step does not completely replace all of the hydroxyl groups. However, the majority of hydroxyl groups are replaced by amine groups. Therefore, the amine terminated polyether resins useful in this invention have greater than 50 percent of their active hydrogens in the form of amine hydrogens. If ethylene oxide is used it is desirable to cap the hydroxyl terminated polyol with a small amount of higher alkylene oxide to ensure that the terminal hydroxyl groups are essentially all secondary hydroxyl groups. The polyols so prepared are then reductively aminated as outlined in U.S. Pat. No. 3,654,370, incorporated herein by reference.
In the practice of this invention, a single high molecular weight amine terminated polyether resin may be used. Also, mixtures of high molecular weight amine terminated polyols such as mixtures of di- and trifunctional materials and/or different molecular weight or different chemical composition materials may be used.
The aromatic diamine chain extenders useful in this invention include, for example, 1-methyl-3,5-diethyl-2,4 diaminobenzene, 1-methyl-3,5 diethyl-2,6 diaminobenzene (both of these materials are also called diethyltoluene diamine or DETDA), 1,3,5-triethyl-2,6 diaminobenzene, 3,5,3',5'-tetraethyl-4,4" diaminodiphenylmethane and the like. Particularly preferred aromatic diamine chain extenders are 1-methyl-3,5-diethyl-2,4 diaminobenzene or a mixture of this compound with 1-methyl-3,5-diethyl-2,6 diaminobenzene. It is within the scope of this invention to include some aliphatic chain extender materials as described in U.S. Pat. Nos. 4,246,363 and 4,269,945.
A wide variety of aromatic polyisocyanates may be used here. Typical aromatic polyisocyanates include p-phenylene diisocyanate, polymethylene polyphenylisocyanate, 2,6-toluene diisocyanate, dianisidine diisocyanate, bitolylene diisocyanate, naphthalene-1,4-diisocyanate, bis(4-isocyanatophenyl)methane, bis(3-methyl-3-isocyantophenyl)methane, bis(3-methyl-4-isocyantophenyl)methane, and 4,4'-diphenylpropane diisocyanate.
Other aromatic polyisocyanates used in the practice of the invention are methylene-bridged polyphenyl polyisocyanate mixtures which have a functionality of from about 2 to about 4. These latter isocyanate compounds are generally produced by the phosgenation of corresponding methylene bridged polyphenyl polyamines, which are conventionally produced by the reaction of formaldehyde and primary aromatic amines, such as aniline, in the presence of hydrochloric acid and/or other acidic catalysts. Known processes for preparing polyamines and corresponding methylene-bridged polyphenyl polyisocyanates therefrom are described in the literature and in many patents, for example, U.S. Pat. Nos. 2,683,730; 2,950,263; 3,012,008; 3,344,162 and 3,362,979.
Usually methylene-bridged polyphenyl polyisocyanate mixtures contain about 20 to about 100 weight percent methylene diphenyldiisocyanate isomers, with the remainder being polymethylene polyphenyl diisocyanates having higher functionalities and higher molecular weights. Typical of these are polyphenyl polyisocyanate mixtures containing about 20 to 100 weight percent methylene diphenyldiisocyanate isomers, of which 20 to about 95 weight percent thereof is the 4,4'-isomer with the remainder being polymethylene polyphenyl polyisocyanates of higher molecular weight and functionality that have an average functionality of from about 2.1 to about 3.5. These isocyanate mixtures are known, commercially available materials and can be prepared by the process described in U.S. Pat. No. 3,362,979, issued January 9, 1968 to Floyd E. Bentley.
By far the most preferred aromatic polyisocyanate is methylene bis(4-phenylisocyanate) or MDI. Pure MDI, quasi- prepolymers of MDI, modified pure MDI, etc. Materials of this type may be used to prepare suitable RIM elastomers. Since pure MDI is a solid and, thus, often inconvenient to use, liquid products based on MDI are often used and are included in the scope of the terms MDI or methylene bis(4-phenylisocyanate) used herein. U.S. Pat. No. 3,394,164 is an example of a liquid MDI product. More generally uretonimine modified pure MDI is included also. This product is made by heating pure distilled MDI in the presence of a catalyst. The liquid product is a mixture of pure MDI and modified MDI: ##STR1## Examples of commercial materials of this type are Upjohn's ISONATE® 125M (pure MDI) and ISONATE 143L ("liquid" MDI). Preferably the amount of isocyanates used is the stoichiometric amount based on all the ingredients in the formulation or greater than the stoichiometric amount.
Of course, the term polyisocyanate also includes quasi-prepolymers of polyisocyanates with active hydrogen containing materials.
Additional catalysts are not desired in the practice of this invention. In a preferred embodiment of our invention no added catalysts are employed.
Other conventional formulation ingredients may be employed as needed such as; for example, foam stabilizers, also known as silicone oils or emulsifiers. The foam stabilizers may be an organic silane or siloxane. For example, compounds may be used having the formula:
RSi[O-(R.sub.2 SiO).sub.n -(oxyalkylene).sub.m R].sub.3
wherein R is an alkyl group containing from 1 to 4 carbon atoms; n is an integer of from 4 to 8; m is an integer of from 20 to 40; and the oxyalkylene groups are derived from propylene oxide and ethylene oxide. See, for example, U.S. Pat. No. 3,194,773.
Reinforcing materials, if desired, useful in the practice of our invention are known to those skilled in the art. For example, chopped or milled glass fibers, chopped or milled carbon fibers and/or other material fibers are useful.
Post curing of the elastomer of the invention is optional. Post curing will improve some properties such as heat sag. Employment of post curing depends on the desired properties of the end product.
The mold release agents useful for the method of this invention are internal mold release agents. The preferred mold release agent is Dow Corning Q2-7119. This mold release agent is a dimethyl siloxane with organic acid groups manufactured by Dow Corning Corporation.
The examples which follow exemplify this invention. However, these examples are not intended to limit the scope of the invention.
EXAMPLE 1
Seventy-five parts of an amine terminated polyether resin, JEFFAMINE® D-2000, 25 parts of another amine terminated polyether resin, JEFFAMINE T-3000, 18.9 parts of diethyltoluene diamine chain extender and two parts of Dow Corning internal mold release for RIM Q2-7119 were premixed and charged into the B-component working tank of an Accuratio VR-100 RIM machine. ISONATE® 143L (46.7 parts) was charged into the A-component working tank. The A-component temperature was adjusted to 80° F. and pressured to 1840 psi. The B-component temperature was adjusted to 120° F. and pressured to 2,000 psi. The mold temperature was adjusted to 155° F. The weight ratio A/B indicated by the preceding formulation was adjusted to 0.3866 to yield an elastomer with an isocyanate index of 1.05. The components were impingement mixed at the aforementioned pressured and caused to flow into the 18"×18"×1/8" mold. After one minute holding time the parts were removed from the mold. Green strength was excellent and the parts were considerably less difficult to remove from the mold than if the Dow Corning internal mold release was not present. Parts were poured on the day that the material was charged, the day after and four days after charging. No appreciable difference in "release ability" or properties (Table I) were observed. Thus, the reactivity of the system most probably remained constant.
TABLE I______________________________________Properties of Example 1 Elastomer As A FunctionOf The Time The Components Were In The WorkingTanks; P/C 1 Hour at 250° F. Same Day as Day After 4 Days AfterTime Charged Charging Charging______________________________________Tensile, psi 3720 3600 3550Ult. Elongation, % 280 270 260Tear, pli 360 380 380Flexural Modulus,psi Measured atRoom temperature 21,600 23,500 21,900158° F. 16,900 17,100 17,000-20° F. 78,600 84,900 77,700Heat Sag, mm1 hr at 250° F.,4" overhang 3.4 3.8 4.0______________________________________
EXAMPLE 2
A similar experiment to Example 1 was tried, the only difference being that the 25 parts of JEFFAMINE T-3000 polyether resin was substituted by a higher molecular weight aminated polyether resin (about 5,000 molecular weight) at the same level as in Example 1 (25 parts). This experiment was designed to extend the scope of this invention to higher molecular weight aminated polyether resins. Similar results on the "release ability" of this material were obtained as compared to Example 1. The release characteristics of an elastomer are rather qualitative and subjective, but it appeared that this elastomer (Example 2) was slightly better than the elastomer of Example 1, especially when the mold temperature was set at higher temperatures, about 170° F.
COMPARISON EXAMPLE 3
The same formulation of Example 1 was run except that the Dow Corning internal mold release for RIM Q-7119 was left out. Sticking to various applied surfaces on the mold and to bare metal was considerably worse than in Examples 1 and 2.
COMPARISON EXAMPLE 4
One hundred parts of MULTRANOL® 3901, 18.9 parts of diethyltoluene diamine, 2 parts of Dow Corning Q2-7119 and 0.5 parts of FOMREZ® UL-28 tin catalyst were premixed and charged into the B-component working tank. This comparison example represents a conventional B-component with the internal mold release since a hydroxyl terminated polyether resin is used, therefore requiring the presence of a tin catalyst. ISONATE 143L was charged into the A-component working tank. When molded on the same day as charged, this elastomer exhibited porosity which did not improve even with higher mold temperature (˜170° F.). This porosity is best characterized as consisting of small liquid filled craters on the molded surface. The next day the problem got worse. This problem has been reported by the supplier of the Q2-7119 RIM internal mold release and was attributed to interference of the Q2-7119 with the tin catalyst. Because of this problem the part was unacceptable.
EXAMPLE 5
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 65 parts aminated 5,000 molecular weight polyoxypropyl- ene triamine (no ethylene oxide) 18.9 parts of DETDAA 44.4 parts of experimental isocyanate comprising (˜98%) 4,4' MDI THANOL® SF-5505 polyol quasi pre- polymer - 22% by weight polyol Equivalent weight = 167______________________________________
The parts had excellent properties, especially heat sag. They released from the mold well without mold release agents. On addition of internal mold release Q2-7119 at 0.25% by weight and 1.0% by weight of the total formulation, the plaques released much easier than without the Q2-7119 internal release agent. There was no need to wax the mold with external mold release agent. This example shows the use of this invention with an MDI/high molecular weight quasi-prepolymer and higher molecular weight amine terminated polyether resins.
EXAMPLE 6
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 71 parts aminated 5,000 molecular weight triamine (no ethylene oxide) 18.9 parts of DETDA A ##STR2##______________________________________
The formulation processed well and had excellent properties and had heat sag better than conventional system but not as good as Example 5. This example shows the use of this invention with an ISONATE 143L/high molecular weight quasi-prepolymer of the same composition (22% polyol) as in Example 5. On addition of internal mold release Q2-7119 at 0.25% by weight and 1.0% by weight of the formulation, the parts release much better than without the internal mold release. There was no need to wax the mold since the materials released well.
EXAMPLE 7
Accuratio Machine
The same formulation of Example 6 was evaluated except that an aminated 5,000 molecular weight triamine with 5 wt.% internal mixed ethylene oxide was used. Although this material could be processed without internal mold release and with internal mold release at 1.0 by weight of the total formulation (Dow Corning Q2-7119), the release characteristics were acceptable but not as good as for Examples 5 and 6.
EXAMPLE 8
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 62.33 parts aminated 5,000 molecular weight triamine (no ethylene oxide) 18.9 parts of DETDA A ##STR3##______________________________________
This example shows the use of this invention with a quasi-prepolymer with relatively high (33 wt.%) polyol content. This material processed very well and has excellent properties. It releases even without internal mold release; however, only from flat surfaces. With Dow Corning Q2-7119 internal mold release at 0.25 wt.% and 1.0 wt.% of the total formulation, the parts literally fell out of the mold. The release characteristics of this material with Q2-7119 are superior to the release characteristics of conventional systems employing wax external mold release agents.
EXAMPLE 9
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 42.6 parts aminated 5,000 molecular weight triamine (no ethylene oxide) 18.9 parts of DETDAA L-55-0 73.7______________________________________
This example shows the use of this invention with extremely high (50 wt.%) polyol containing quasi-prepolymers. The release characteristics of this formulation were acceptable but inferior to those of Examples 5, 6 and 8.
EXAMPLE 10
Accuratio Machine
The same formulation of Example 8 was run except that the L-55-0 quasi-prepolymer was replaced with L-6505-0 quasi-prepolymer. This example shows the use of this invention with quasi-prepolymers made from different polyols. The formulation was tried with Q2-7119 internal mold release at 0.25 wt.% and 1.0 wt.% of the total formulation. The parts with internal mold release had excellent release properties.
EXAMPLE 11
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 80 parts aminated 5,000 molecular weight triamine (no ethylene oxide) 17.7 parts of DETDAA MONDUR® PF 47.5 parts______________________________________
This material shows the utility of this invention with quasi-prepolymers which use low molecular weight polyols; e.g., dipropylene and tripropylene glycol. The green strength of the material was poor. However, when Q2-7119 internal mold release was added at 0.25 wt.% and 1.0 wt.% of the total formulation, the parts demolded easily.
EXAMPLE 12
Accuratio Machine
______________________________________Accuratio MachineFormulation (Streams A and B)______________________________________B 80 parts aminated 5,000 molecular weight triamine (no ethylene oxide) 18.9 parts DETDAA ISONATE 143L 36.8 parts______________________________________
This example shows the application of this invention to one-shot formulations using ISONATE 143L. With internal mold release Q2-7119 (Dow Corning) at 0.25 wt.% and 1.0 wt.% of the total formulation, the material had excellent release properties. The green strength of the material, however, was less than desirable.
EXAMPLE 13
Accuratio Machine
The same formulation as in Example 12 was evaluated except that an aminated 5,000 molecular weight triamine with 5 wt.% internal mixed ethylene oxide was used. The material was tough on demold; however, it did not release as well as Example 12.
______________________________________GLOSSARY OF TERMS AND MATERIALS______________________________________JEFFAMINE® D-2000 A polyoxypropylene diamine of about 2,000 molecular weight.JEFFAMINE T-3000 A polyoxypropylene triamine of about 3,000 molecular weight.ISONATE® 143L Carbodiimide modified liquid MDI, a product of the Upjohn Co.MULTRANOL® 3901 A conventional polyol of about 6,500 molecular weight prepared from propylene oxide and ethylene oxide containing mostly primary hydroxyl groups. A product of Mobay Chemical Co.FOMREZ® UL-28 A tin catalyst which is similar in structure to dibutyltin dilaurate, a product of Witco Corp.MONDUR® PF MDI quasi-prepolymer of about 180 E.W., a product of Mobay Chemical Co.Quasi-Prepolymer L-55-0 A quasi-prepolymer formed by react- ing equal weight of ISONATE 143L and THANOL SF-5505______________________________________ | The invention is a method of making a molded reaction injection molded elastomer which will release from its mold without the presence of externally applied mold release agents. The reaction injection molded (RIM) elastomer is made by injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream amine terminated polyethers of greater than 1,500 molecular weight, an amine terminated chain extender and an internal mold release agent, and in the second stream an aromatic polyisocyanate. The resulting RIM elastomer may be removed from the mold easily. RIM elastomers are useful, for example, for automobile body parts. |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional application No. 60/749,066 filed on Dec. 12, 2005 which is incorporated by reference, herein, in its entirety.
TECHNICAL FIELD
The present invention relates generally to application level security systems, and more particularity to a method for the correlation between Hypertext Transfer Protocol (HTTP) and structured query language (SQL) queries.
BACKGROUND OF THE INVENTION
The accessibility and convenience of the Internet rapidly changed the way people access information. The World Wide Web (“WWW”), usually referred to as “the web”, is the most popular means for retrieving information on the Internet. The web gives users access to practically an infinite number of resources, such as interlinked hypertext documents accessed by, for example, a hyper text transfer protocol (HTTP) from servers located around the world.
Enterprises and organizations expose their business information and functionality on the web through software applications, usually referred to as “web applications”. The web applications use the Internet technologies and infrastructures. A typical web application uses a backend database to store application data. The backend database is accessed through some proprietary network protocol carrying Structured Query Language commands.
The web applications provide great opportunities for an organization. However, at the same time these applications are vulnerable to attack from malicious, irresponsible, or criminally minded individuals. In the related art, an effective protection of web applications is achieved by means of application level security systems. Such systems prevent attacks by restricting the network level access to the web applications, based on the applications' attributes. Specifically, the security systems constantly monitor requests received at interfaces and application components, gather application requests from these interfaces, correlate the application requests, and match them against predetermined application profiles. These profiles include attributes that determine the normal behavior of the protected application. If one or more application requests do not match the application profile, an irregular event is generated, and then an alert indicating a potential attack is produced.
Typically, web applications use a backend database and a single application account to access the database. Consequently, any web oriented or database oriented security mechanism is not able to correctly establish the web application context (e.g., a URL, a sessionID, or a UserID) in which a request to the database is made. There are numerous consequences to this inability. First, regulatory requirements demand that any access to sensitive information in the database must be attributed to a single actual user. Complying with these regulations is impossible given separate web and database security mechanisms. This should not be viewed as merely a regulatory burden. The ability to correlate any database access with a specific user is crucial for pinpointing an attacker either in real-time or during forensic analysis. Moreover, the number of false alarms issued on SQL injection attacks by such systems is relatively high. As for another example, the security systems cannot provide information about users who made changes to the database.
SUMMARY OF THE INVENTION
Among others, therefore, it is one object of the invention to provide a solution that allows application level security systems to correlate HTTP requests to SQL queries.
The invention is taught below by way of various specific exemplary embodiments explained in detail, and illustrated in the enclosed drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawing figures depict, in highly simplified schematic form, embodiments reflecting the principles of the invention. Many items and details that will be readily understood by one familiar with this field have been omitted so as to avoid obscuring the invention.
FIG. 1 is a diagram of an application level security system that discloses one embodiment of the present invention.
FIG. 2 is a flowchart describing the method for identifying correlations of HTTP and SQL requests that discloses one embodiment of the present invention.
FIG. 3 is a flowchart describing the process for correlating URLs and SQL templates that discloses one embodiment of the present invention.
FIG. 4 is an exemplary URL-Template matrix.
FIG. 5 is a flowchart describing the process applied during the protect mode that discloses one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention will now be taught using various exemplary embodiments. The intended audience for the following discussion is the person already familiar with this field. Although the embodiments are described in detail, it will be appreciated that the invention is not limited to just these embodiments, but has a scope that is significantly broader. The appended claims should be consulted to determine the true scope of the invention.
FIG. 1 shows an exemplary diagram of an application level security system 100 that discloses one embodiment of the present invention. Security system 100 correlates HTTP requests to SQL queries for the purpose of providing enhanced protection features. These features may include, but are not limited to, the generating of databases' audit reports, creating access profile of tables in databases, improving the detection of SQL injection attacks, and so on. Security system 100 includes a HTTP sensor 130 and a SQL sensor 135 connected to a secure server 110 . Sensors 130 and 135 may be connected to server 110 through out-of-band network (not shown) for transferring traffic over a dedicated and secure network that is completely separated from the production traffic.
HTTP sensor 130 is placed on a network segment between a client 190 and a web server 160 to be protected. Sensor 130 collects and analyzes HTTP requests sent from a client 190 to web server 160 . SQL sensor 135 is placed on a network segment between web server 160 and a database (DB) server 170 and designed to collect and analyze SQL queries sent from web server 160 to DB server 170 . The sensors 130 and 135 communicate with each other using a dedicated link 180 for transferring data that is used for the correlation. For example, the two sensors can share URLs, pending SQL queries, pending HTTP requests, correlation parameters, and so on. Security system 100 is a non-intrusive system, and thus each of sensors 130 and 135 allows traffic passing directly through the HTTP sensor 130 to the protected web server 160 and through SQL sensor 135 to DB server 170 . It should be noted that security system 100 may include a plurality of HTTP and SQL sensors connected to a plurality of web and DB servers to be protected. It should be further noted that in some embodiments the HTTP and SQL sensors may be integrated in a single device.
Security system 100 operates in two modes: learn mode and protect mode. In learn mode, security system 100 monitors and learns the normal behavior of users and applications over time, and builds normal behavior profiles (NBPs) for each protected application. Specifically, during the learning period, security system 100 finds relations between URLs and SQL templates. In addition, system 100 discovers, for each URL, a set of parameters (hereinafter “correlation parameters”) that may impact the SQL queries. In accordance with the present invention, a SQL template is a SQL query statement where at least literals are replaced with, for example, question marks ‘?’ and comments and white-space characters are replaced by, for example, a single space character. As an example, for the SQL query statement:
“select a /* just a comment */ from table_1 where a>6”
the SQL template is:
“select a from table — 1 where a>?”.
The process for correlating HTTP and SQL requests during a learning period is performed by secure server 110 and will be described in detail below. Once, secure server 110 acquires sufficient information to start protecting the application, the information is added to NBPs and uploaded to sensors 130 and 135 . There are two types of NBPs: the HTTP NBP that is kept in HTTP sensor 130 and its characteristics include, but are not limited to, URLs, a hostname or a group hostnames to which a designated URL belongs, a HTTP method by which a designated URL is called, occurrence, cookies sent to the client, URL patterns, URL parameters and the constraints of each parameter, HTTP response code, and others; and, the SQL NBP that is maintained by SQL sensor 135 and its characteristics include, but are not limited to, SQL query statements used by a Web application to access the database, a list of IP addresses that are allowed to generate each specific query, database usernames used to invoke each query, and others. In accordance with an embodiment of the invention, both HTTP and SQL NBPs include pairs of correlated URLs and SQL templates, and for each such URL, a list of correlation parameters.
In protect mode, to each SQL query submitted by the user, security system 100 binds a session identifier (sessionID) of the respective HTTP request. Alternatively or collectively, system 100 may bind the user identity (UserID) of the actual user who submitted the query. Using this information, security system 100 may generate a plurality of reports. For example, one report may include information on tables in DB server 170 that require authentication, another report may include records on changes made to DB server 170 and by whom, and others. The operation of security system 100 during the protect mode will be described in greater detail below.
It should be appreciated by a person skilled in the art that the correlation is performed on-line, i.e., as traffic is sent from client 190 . It should be further appreciated that the correlation is performed without installing agents in neither web server 160 nor DB server 170 . Specifically, the ability to correctly establish a web application context in which a request to the database is performed without modifying DB server 170 or the protected web application. This is opposed to prior art solutions which demand to re-program the web application in order to associate submitted query with, for example, a UserID.
FIG. 2 shows an exemplary and non-limiting flowchart 200 describing method for learning the correlativity of HTTP requests and SQL queries in accordance with one embodiment of the present invention. At S 210 , a process for correlating between URLs and SQL templates is applied.
FIG. 3 shows the operation of S 210 in greater detail. At S 310 , a matrix (hereinafter “URL-Template matrix”) having M columns and N rows is created. Each row and column in the URL-Template matrix respectively represents a URL of a HTTP request and a SQL template extracted from a SQL query statement. The size of the URL-Template matrix dynamically changes according to the number of observed URLs and SQL templates. Each entry in the URL-Template matrix holds a counter that can be incremented by a fixed value. The counters are initialized with a zero value. At S 320 , a HTTP request is captured by the HTTP sensor and the URL is extracted from this request. Then, at S 330 , the URL is inserted to the URL-Template matrix to an entry in the first available row and first column. At S 340 , the captured HTTP request is added to a list of pending requests for this URL. That is, for each URL in the URL-Template matrix, system 100 maintains a list of pending requests. At S 350 , a SQL query statement is captured by the SQL sensor and, at S 360 , the statement is converted to a SQL template. Namely, each literal in the SQL query statement is replaced with a place holder (e.g., a question mark) and comments and white-space characters are removed. At S 370 , the SQL template is inserted to the URL-Template matrix to an entry in the first available column and the first row. At S 380 , the method searches for URLs in the URL-Template matrix that have at least one pending HTTP request, and at S 385 for each such URL the counter in the respective entry is incremented. FIG. 4 shows a non-limiting example of a URL-Template matrix that includes four URLs 410 and three SQL templates 420 . SQL template 420 - 2 currently being processed and URLs 410 - 1 and 420 - 3 having pending HTTP requests. Hence, the counters of entries 430 - 1 and 430 - 3 are incremented and the counters of entries 430 - 2 and 430 - 4 are decremented.
Referring back to FIG. 2 , where at S 220 a process for finding correlation parameters may be applied. A correlation parameter is a parameter that is part of a HTTP request and may imply on a literal in a SQL query. For example, the URL for a search operation in an application is “search.asp”. It accepts “query” as a parameter, thus a HTTP request to search for pages with the word “computers” would be:
http://www.mysite.com/search.asp?query=computers.
The actual query statement produced for this request is:
select page_id from page_keywords where
keyword like ‘%computers%’.
Identified correlation parameters may be added to the HTTP and SQL NBPs.
At S 230 entries in the URL-Template matrix having values that are above a predefined threshold are marked. The threshold is set to a number of observations that is considerably higher than the expected number of random observations. The expected number of random observations is determined based on the total number of occurrences for each query template and the total system time that each URL is observed. At S 240 , all marked pairs of URLs and SQL templates are added to the HTTP and SQL NBPs. At S 250 , upon decision of secure server 110 the HTTP NBP and SQL NBP are respectively uploaded to the HTTP sensor 130 and SQL sensor 135 .
FIG. 5 shows an exemplary and non-limiting flowchart 500 describing the operation during the protect mode that discloses one embodiment of the present invention. In this mode, security system 100 associates each SQL query with the sessionID and preferably with the user identity of the actual user. At S 510 , a SQL query is received at the SQL sensor and, at S 520 , this query is converted to a SQL template. At S 530 , the SQL sensor searches in its NBP for URLs that relate to the template. At S 540 , for each HTTP request with a URL that is correlated to the SQL template a parameters to literals matching is performed. For example, for the HTTP request shown above the value of the “query” parameter, i.e., “computers” is matched to the actual query. The outcome of the matching operation is a score given to each HTTP request based on the number of matches between parameters' values in the request and literals in the SQL query. At S 550 , the HTTP request with the highest score is selected and at S 560 , the method binds the sessionID of the request and UserID of the actual user that submitted the request to the incoming SQL query.
Many variations to the above-identified embodiments are possible without departing from the scope and spirit of the invention. Possible variations have been presented throughout the foregoing discussion. Moreover, it will be appreciated that, in an embodiment of the invention, the UserID may be detected using one or more of the techniques disclosed in U.S. application Ser. No. 11/563,589 entitled “Techniques for Tracking Actual Users in Web Application Security Systems” and filed on Nov. 27, 2006 assigned to the common assignee and hereby incorporated by reference in its entirety, especially so much of the disclosure that describes detecting the UserID or equivalent.
Combinations, subcombinations, and variations of the various embodiments described above will occur to those familiar with this field, and may safely be made without departing from the scope and spirit of the invention. | The system and method correlate between hypertext transfer protocol (HTTP) requests and structured query language (SQL) queries. The system operates in two modes: learn mode and protect mode. In the learn mode, the system identifies pairs of uniform resource locators (URLs) and SQL templates, in addition to, pairs of correlation parameters and SQL queries. In the protect mode, for each incoming SQL query, the system binds to each submitted SQL query a session identifier (sessionID) of a corresponding HTTP request and the user identity of the user that submitted the query. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a punch apparatus and more particularly to an apparatus for preparing elongated multiflanged extrusions for use in conjunction with fiberboard air handling ducts.
2. Description of the Prior Art
Air handling ducts of the type employed in heating and refrigeration systems have traditionally been formed of sheet metal, with a recently developed alternative being to form the ducts of insulative fiberboard. In many instances, the fiberboard ducts have an advantage over metal ducts due to such factors as weight, insulative properties, cost, and the labor involved.
However, fiberboard ducts have not achieved the acceptance they deserve due to the problems of assembling individual lengths of ducting and of interconnecting adjacent lengths thereof.
The fiberboard material employed in the air handling ducts is supplied in sheets, with the individual lengths of ducting being formed by longitudinally folding the sheet so that its opposite side edges are in contiguous abutting contact with each other and the resulting duct is either of square or rectangular cross sectional configuration. The abutting side edges of the fiberboard material are sealingly interconnected with tape, and the assembly of individual lengths of ducting into a complete duct system is accomplished in a similar manner by interconnecting adjacent lengths of the ducting with tape.
The use of tape as an assembly and closure material has, in many instances, been found to be unsatisfactory due to temperature, pressure and other factors causing the tape to lost its adhesive grip on the fiberboard material which, of course, will cause leakage of the duct system and in some cases can allow complete collapsing of the system.
Elongated multiflanged extrusions are now being employed in place of the above described tape for assembly and closure of the fiberboard ducts. Extrusions for this purpose are disclosed in U.S. Pat. No. 3,677,579, issued on July 18, 1972 to W. N. LaVanchy.
Briefly, a first type of extrusion, sometimes referred to as a longitudinal extrusion, is being employed for sealingly interconnecting the side edges of the fiberboard sheet to form the individual lengths of ducting.
Other configurations of extrusions, as determined by the type of interconnection desired, are being employed on the open ends of the individual ducts to facilitate interconnection of adjacent lengths of ducting. These latter extrusions may be referred to as joint extrusions.
Due to the great variations in lengths and cross sectional sizes of ducts, the above described extrusions are supplied in straight pieces which are individually prepared for installation and assembly when the specific sizes and configuration of the ducting are known.
Therefore, the longitudinal extrusions must be cut to the proper length and also must be provided with a recessed notch at each of their opposite ends to allow assembly of the joint extrusions to the fiberboard ducting.
The joint extrusions, which are also supplied in straight pieces, must be notched in specific locations along the length thereof to allow these extrusions to be bent into either the square or rectangular configuration suitable for mounting on the ends of the ducting. Also, the joint extrusions have a hanger flange which allows the assembled duct system to be suspendingly mounted therefrom. The hanger flange must be punched or otherwise provided with hanger holes at the proper locations.
Notching, cutting, and otherwise preparing the multiflanged extrusions for use with the fiberboard ducts is, in some instances, being accomplished with hand tools. Obviously, this is a very tedius, time consuming, and costly method, so a prior art apparatus for accomplishing these tasks was developed.
This prior art apparatus is a complex, slow operating and inadequately designed machine which has achieved only limited acceptance for those reasons as well as the cost which has placed this apparatus beyond the economic justification of many companies doing this sort of work.
Therefore, a need exists for a new and improved extrusion preparation apparatus which overcomes some of the problems of the prior art.
SUMMARY OF THE INVENTION
The multiflanged extrusion preparation apparatus of the present invention includes an input channel and an output channel aligningly positioned on opposite sides of the workpiece supporting plate of a suitable punch press. These channels serve as a feeding means by which the extrusion workpieces are fed through and punched by one of two interchangeable die sets, with the particular die set being determined by the type of extrusion being processed.
Each of the die sets are demountably attachable to the work piece supporting plate of the punch press, and each includes a fixed bottom pedestal and a movable top plate. The fixed pedestal of each of the die sets includes a fixture die means especially designed to slidingly receive the extrusion and to supportingly position the extrusion for the punching operation. The top plate of each of the die sections is reciprocally movable toward the pedestal by means of the punch press and includes the cutting die means which is especially designed to punch the extrusion as required.
Accordingly, it is an object of the present invention to provide a new and improved extrusion preparation apparatus.
Another object of the present invention is to provide a new and improved extrusion preparation apparatus which is economical to manufacture and efficient to operate.
Another object of the present invention is to provide a new and improved extrusion preparation apparatus which prepares elongated multiflanged extrusions for use in assembling and installing air handling ducts of the type fabricated of insulative fiberboard.
Another object of the present invention is to provide a new and improved extrusion preparation apparatus which employs exchangeable die sets for preparing various types of elongated multiflanged extrusions for use in assembling and installing fiberboard air handling ducts.
The foregoing and other objects of the present invention, as well as the invention itself, will be more fully understood from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the multiflanged extrusion preparation apparatus of the present invention which illustrates the various features thereof.
FIG. 2 is a fragmentary perspective view of one type of multiflanged extrusion after having been processed by the apparatus of the present invention.
FIG. 3 is a fragmentary perspective view of another type of multiflanged extrusion after having been processed by the apparatus of the present invention.
FIG. 4 is a fragmentary perspective view of still another type of multiflanged extrusion after having been processed by the apparatus of the present invention.
FIG. 5 is a front elevational view of one of the die sets employed in the apparatus of the present invention.
FIG. 6 is a side elevational view of the die set shown in FIG. 5.
FIG. 7 is a sectional view taken on the line 7--7 of FIG. 5.
FIG. 8 is a sectional view taken on the line 8--8 of FIG. 6.
FIG. 9 is a front elevational view of another one of the die sets employed in the apparatus of the present invention.
FIG. 10 is a side elevational view of the die set shown in FIG. 9.
FIG. 11 is a sectional view taken on the line 11--11 of FIG. 9.
FIG. 12 is a sectional view taken on the line 12--12 of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to the drawings, FIG. 1 illustrates the multiflanged extrusion preparation apparatus of the present invention which is indicated generally by the reference numeral 10. The apparatus 10 is shown to include an input channel 11 and an output channel 12 which are aligningly positioned on opposite side edges of a support plate 13. The support plate 13 may be a free standing structure as shown, or may be formed integral with a suitable punch press 14. In either instance, the support plate 13 serves as a carrying means for a die set 15. The die set 15 is one of an interchangeable pair of die sets 15 and 16, with the die set 15 being shown in FIGS. 1, and 5 through 8, and the die set 16 being shown in FIGS. 9 through 12. The die sets 15 and 16 are demountably attachable to the support plate 13 and are suitably coupled to the punch press 14 for reciprocal operation thereby as will hereinafter be described in detail.
It is believed that a more thorough understanding of the objects and operation of the apparatus 10 of the present invention will be achieved if the design and purposes of the various types of multiflanged extrusions or workpieces, are known. Therefore, FIGS. 2 and 3 show extrusions 17 and 18, respectively, which are of the type referred to as joint extrusions, and FIG. 4 shows a longitudinal extrusion 19.
The multiflanged extrusion 17, shown in FIG. 2, is a U-shaped in cross section elongated member having an inner flange 20, an outer flange 21 and an interconnecting surface 22 which extends beyond the outer flange 21 to form a hanger flange 23. The inner flange 20, outer flange 21 and interconnecting surface 22 define an open channel 24 for receiving the edge of fiberboard ducting material (not shown). This edge of the ducting material (not shown) is formed either into a square or rectangular end configuration of the duct and thus, the extrusion 17 must be bent at various points along its length to conform to this end configuration. Bending of the extrusion 17 requires that a portion, between points A and B of the inner flange 20, be removed, a V-shaped notch 25 be formed in the interconnecting surface 22, and that a V-shaped notch 26 be formed in the hanger flange 23. It will be noted that the outer flange 21 is left intact so that complete severing of the extrusion will not occur. After removal of the portion between points A and B and forming of the notches 25 and 26, the extrusion 17 can be bent into the dashed line position shown in FIG. 2 to form a square corner.
The extrusion 18 shown in FIG. 3 is H-shaped in cross section and has an inner flange 27, an outer flange 28 and a midpoint interconnecting surface 29 which is coplanar with a hanger flange 30 extending from the midpoint of the outer flange 28. The H-shaped configuration of the extrusion 18 defines back to back open channels 31 for receiving the open end edges (not shown) of two adjacent fiberboard ducting members (not shown). Thus, as was required with the extrusion 17, the extrusion 18 must be bent to conform to the end configuration of the lengths of ducting (not shown). To accomplish this bending of the extrusion 18, the portion between points C and D of the inner flange 27 must be removed, and V-shaped notches 33 and 34 must be formed in the interconnecting surface 29 and the hanger flange 30, respectively. As was the case with regard to extrusion 17, the outer flange 28 of the extrusion 18 is left intact, and the extrusion 18 is bent into the dashed line position to form a square corner.
It will be seen that both of the extrusions 17 and 18 are provided with oval shaped apertures 32 formed through their respective hanger flanges 23 and 30. These apertures 32 are employed for installation purposes of the assembled ducting system (not shown) and may be formed simultaneously with the above described extrusion preparation.
The longitudinal extrusion 19, as shown in FIG. 4, has a main angle member 35 with a secondary angle member 36 extending from one of the legs of the member 35. These angle members 35 and 36 are configured to define a pair of channels 37 and 38 which are adapted to receive the opposite side edges of a sheet of insulative fiberboard material (not shown) when that material is shaped to form a length of air handling duct (not shown). The extrusion 19 is supplied in elongated straight pieces and must be cut to the proper length and also must be notched at its opposite ends to allow mounting of the joint extrusions 17 or 18 on the ends of the duct (not shown). Thus, preparation of the extrusion 19 requires severing of the extrusion into predetermined lengths and requires that the secondary angle member 36 be formed with a notch 39 by removing the amount thereof which is shown in dashed lines in FIG. 4.
Referring now to FIGS. 5 through 8 wherein the die set 15 is shown as being mounted on the support plate 13, and as shown in FIG. 5 is aligningly disposed between the discharge end 40 of the input channel 11, and the receiving end 41 of the output channel 12.
The die set 15 includes a fixed pedestal 44 having a pair of vertical rods 45 extending therefrom. The rods 45 serve as supporting guideways for a movable top plate 46 which is slidably journaled on the rods for reciprocal movement toward and away from the pedestal 44, as will hereinafter be described. The pedestal 44 also has a matrix or fixture die means 48 mounted thereon which guides movement of the workpieces into a predetermined path through the die set 15 and supports these workpieces for the punching operation as will hereinafter be described.
The fixture die means 48, as seen best in FIG. 8, includes a pair of support dies 49 and 50 and a backup die 51. The support dies 49 and 50 are mounted adjacent to the front edge 52 of the pedestal 44 and are spaced apart with respect to each other to provide a gap 53 therebetween. Each of the supporting dies 49 and 50 are provided with a rearwardly disposed portion 54 of their upper surface and a forwardly disposed portion 55 thereof which are separated by a horizontally extending vertical channel 56 formed in the dies 49 and 50. The forward portion 55 of each of the dies 49 and 50 is also formed with a vertically extending oval shaped aperture 57 therein. The backup die 51 is mounted on the pedestal 44 so as to be rearwardly disposed from the support dies 49 and 50 to provide a horizontally extending vertical passage 58 therebetween. The backup die 51 is also provided with a vertically extending channel 59 intermediate its ends which is aligned with the gap 53 between the support dies 49 and 50.
To facilitate understanding of the movement guiding and supporting functions of the fixture die means 48, the positioning of the extrusion 18 therein will now be described. The horizontally extending vertical passage 58, between the support dies 49 and 50 and the backup die 51, is adapted to receive the inner flange 27 of the extrusion 18 which is oriented so that the midpoint interconnecting surface 29 rests on the rearwardly disposed portions 54 of the support dies 49 and 50. The hanger flange 30 of the extrusion 18 will rest on the forwardly disposed portions 55 of the dies 49 and 50, and the outer flange 28 of the extrusion 18 is received in the horizontally extending vertical channels 56 formed in the dies 49 and 50. It should be understood that the above described positioning of the extrusion 18 within the fixture die means 48 also applies to the extrusion 17, as either of these extrusions can be prepared for assembly and installation within the die set 15. Thus, it may now be seen that the fixture die means 48 provides a horizontally extending workpiece supporting and movement path which is transverse to the gap 53 and channel 59 thereof.
A spring loaded roller mechanism 60 is provided at the workpiece input end of the fixture die means 48 and another spring loaded roller mechanism 61 is located at the workpiece output end of the fixture die means. The roller mechanisms 60 and 61 are mounted on the pedestal 44 and are disposed so that the rollers 62 thereof are biased, by suitable springs 63 (one shown in FIG. 6), toward the backup die 51. These mechanisms 60 and 61 are employed to load the workpiece into sliding engagement with the backup die 51 which is accomplished by the rollers 62 bearing on the lower edge of the inner flange 27 of the extrusion 18 or the lower edge of the inner flange 20 of the extrusion 17.
As seen best in FIG. 8 a U-shaped stripper 64 is provided on the backup die 51, and that stripper is disposed so as to conform to and overlay the vertically extending channel 59 formed in the backup die. The stripper 64 is provided with extending ends 65 which protrude laterally from the backup die 51 over the passage 58 between the backup die 51 and the support dies 49 and 50. The extending ends 65 of the stripper 64 prevent upward movement of the workpiece as will become apparent as the desription progresses.
Each of the support dies 49 and 50 have a stripper 67 mounted thereon, and these strippers 67 each have a cantilevered bar 68 which extends proximate the apertures 57 formed in the support dies 49 and 50 and also extend toward the gap 53 between these dies. The strippers 67 also serve to prevent upward movement of the workpiece as will become apparent as the description progresses.
As hereinbefore mentioned, the top plate 46 of the die set 15 is reciprocally movable on the vertical guide rods 45, and this movement is provided by a punch press mechanism 14. It should be apparent that various types of punch presses could be employed; however, it is preferred that an electric clutch operated flywheel type of press be employed.
The top plate 46 is provided with a boss 70 extending upwardly therefrom to which the punch press 14 is suitably coupled, and the plate 46 has cutting die means 72 depending from the downwardly facing surface thereof, so that the cutting die means 72 will be reciprocally movable in a path which transversely intersects the workpiece supporting and movement path formed in the fixture die means 48.
As best seen in FIGS. 6 and 7, the cutting die means 72 includes a first cutting die 73 which is mounted adjacent the front edge 74 of the plate 46, and a second cutting die 75 that is spaced rearwardly from the first cutting die 73 to provide a recess 76 therebetween. The die means 72 also includes a pair of oval shaped punches 77, each positioned adjacent an opposite side of the first cutting die 73.
The first cutting die 73 has a pair of vertically extending angularly disposed surfaces 78 in a V-shaped configuration. This first cutting die 73 is positioned in vertical alignment with the forward position of the gap 53 provided between the support dies 49 and 50 of the fixture die means 48. Thus, downward movement of the plate 46 will move the first cutting die 73 into the forward portion of the gap 53, and this movement will punch out the V-shaped notch 26 in the hanger flange 23 of the extrusion 17, or the V-shaped notch 34 of the hanger flange 30 of extrusion 18 depending on which of these extrusions is positioned within the die set 15.
The second cutting die 75 is also provided with a pair of vertically extending surfaces 80 which are angularly disposed to form a V-shaped configuration. This second cutting die 75 is positioned in vertical alignment with the rearwardly disposed portion of the gap 53 between the support dies 49 and 50 and also aligns with the vertically extending channel 59 formed in the backup die 51. Thus, upon downward movement of the plate 46, the second cutting die 75 will move into the rear portion of the gap 53 and the channel 59 of the backup die 51. It will be noted that when the second cutting die 75 moves downwardly as described above, it will also move into the passage 58 between the support dies 49 and 50 and the backup die 51. Therefore, when the extrusion 17 is positioned within the die set 15, the second cutting die 75 will punch the V-shaped notch 25 in the interconnecting surface 22 of the extrusion 17, and also will remove the portion of material between the points A and B of the inner flange 20. Likewise, when the extrusion 18 is positioned within the die set 15, downward movement of the second cutting die 75 will punch the V-shaped notch 33 in the midpoint interconnecting surface 29, and will remove the material between the points C and D of the inner flange 27.
As hereinbefore described, the first and second cutting dies 73 and 75, respectively, are spaced apart with respect to each other to provide the recess 76 therebetween. This recess 76 is in alignment with the channel 56 formed in the supporting dies 49 and 50 so that when extrusion 17 is positioned in the die set 15, its outer flange 21 which is positioned in the channel 56 will not be touched by either of the cutting dies 73 or 75. Also, the extrusion 18 is positioned in the die set 15, the outer flange 28 thereof will be left intact. The recess 76 is somewhat larger than the thickness of the outer flanges 21 and 28, respectively, of the extrusions 17 and 18, thus a protruding lip (not shown) portion of the interconnecting surfaces 22 and 29, respectively, will remain. The second cutting die 75 is provided with a protrusion 82 which notches the protruding lip (not shown) so that uniform bending of the extrusions 17 and 18 will be possible.
The oval shaped punches 77 of the cutting die means 72 are in vertical alignment with the vertically extending aperture 57 formed in the front portions 55 of the supporting dies 49 and 50. These punches 77 will move into and out of the apertures 57 upon reciprocal movement of the top plate 46, and thus may be seen to be employed to punch the oval mounting apertures 32 in the hanger flanges 23 and 30 of the extrusions 17 and 18, respectively, as determined by which of these extrusions is positioned in the die set 15.
Referring now to FIGS. 9 through 12 wherein the die set 16 is shown as being mounted on the support plate 13, and as shown in FIG. 9 is aligningly disposed between the discharge end 40 of the input channel 11, and the receiving end 41 of the output channel 12.
The die set 16 includes a fixed pedestal 84 having a pair of vertical rods 85 extending therefrom. The rods 85 act as supporting guideways for a movable top plate 86 which is slidably journaled on the rods for reciprocal movement toward and away from the pedestal 84. The pedestal 84 also has a matrix or fixture die means 88 mounted thereon which guides lateral movement of the workpieces into a predetermined path through the die set 16, and supports the workpieces for the punching operation as will hereinafter be described.
The fixture die means 88, as seen best in FIG. 12 includes a pair of supporting dies 89 and 90, and a backup die 91. The support dies 89 and 90 are mounted adjacent to the front edge 92 of the pedestal 84 and the backup die 91 is disposed rearwardly therefrom. The support dies 89 and 90 are spaced apart with respect to each other at their upper ends to provide a gap 93 therebetween. Each of the supporting dies 89 and 90 are formed with a base plate 94 which is directly mounted on the pedestal 84, an intermediate block 95 having a rearwardly extending cantilevered end 96, with the intermediate block 95 being mounted on the base plate 94, and an upper block 97 mounted atop the intermediate block 95. As seen best in FIGS. 10 and 12, the base plate 94 of each of the support dies 89 and 90 extends rearwardly from the front edge 92 of the pedestal 84 into engagement with the backup die 91. The intermediate blocks 95 extend rearwardly in the same manner but terminate just short of coming into contact with the backup die 91 to pro ide a horizontally extending vertical passage 98 between the cantilevered end 96 of the intermediate block 95 and the backup die 91. The intermediate block 95 is also recessed on its bottom surface to form a horizontally extending horizontal passage 99 between the cantilevered end 96 of the intermediate block 95 and the upper surface of the base plate 94. The vertical passage 98 and the horizontal passage 99 intersect and are normal to each other. The upper block 97 extends rearwardly from the front edge 92 of the pedestal 84 and terminates just short of the cantilevered end 96 of the intermediate block 95, thus providing horizontally extending enlarged passage 100 between the upper block 97 and the backup die 91. The base plates 94 of the supporting dies 89 and 90 are separated from each other by a slot 101 which extends from the front edge 92 of the pedestal 84, and a slot 103 in the backup die 91 is in alignment therewith. An elongated aperture 102 is formed in the pedestal 84, and this aperture 102 is vertically aligned with the slots 101 and 103. The aperture 102 is provided so that metal cut from the workpiece can drop through this aperture 102.
To facilitate understanding of the movement guiding and supporting functions of the fixture die means 88, positioning of the extrusion 19 therein will now be described. The vertical passage 98, between the cantilevered end 96 of the intermediate block 95 and the backup die 91, and the horizontal passage 99, between the cantilevered end 96 of the intermediate block 95 and the upper surface of the base plate 94, are adapted to slidingly receive the main angle member 35 of the extrusion 19. The main angle member 35 will extend upwardly through the vertical passage 98 into the enlarged passage 100 so that the secondary angle member 36 of the extrusion is disposed within the enlarged passage 100 with one leg of the secondary angle member 36 resting on the upper surface of the intermediate block 95 and the other leg bearing on the rearwardly disposed end of the upper block 97. Thus, the movement of the workpiece is transverse with respect to the gap 93 and slot 101 of the support dies 89 and 90 and is transverse to the slot 103 of the backup die 91.
The top plate 86 is provided with a boss 104 extending upwardly therefrom to which the punch press 14 is suitably coupled for providing the reciprocal movement of the top plate. The top plate 86 is provided with a cutting die means 106 depending from the downwardly facing surface thereof.
The cutting die means 106 is formed with a blade die 107 which is in vertical alignment with the slots 101 and 103 formed between the supporting dies 89 and 90 and between the backup die 91. Thus, downward movement of the top plate 86 will move the blade die 107 downwardly through the enlarged passage 100, through the vertical passage 98, and through the horizontal passage 99 into the slots 101 and 103, and will therefore sever the main angle member 36 of the extrusion 19 when that extrusion is positioned in the fixture die means 88.
The cutting die means 106 also includes a pair of wedge shaped dies 108 and 109 which are preferrably integral with the blade die 107 and are positioned on opposite sides thereof. Each of the wedge dies 108 and 109 are formed with a leading cutting edge 110 which is upwardly and laterally offset from the leading cutting edge 111 of the blade die 107.
The wedge dies 108 and 109 are in vertical alignment with the gap 93 provided between the support dies 89 and 90 of the fixture die means 88 so that downward movement of the top plate 86 will move the wedge dies 108 and 109 downwardly into the gap 93. The above described offset relationship of the wedge dies 108 and 109 with respect to the blade die 107 is critical so that downward movement of the cutting die means 106 will not bring the wedge dies into an intersecting relationship with the laterally extending paths of the vertical passage 98, the horizontal passage 99 or the rearwardly disposed portion of the enlarged passage 100. Therefore, when the extrusion 19 is positioned within the fixture die means 88, the main angle member 35 thereof will not be touched by the wedge dies 108 and 109 upon downward movement thereof, and these wedge dies will come into cutting contact only with that portion of the secondary angle member which is disposed within the gap 93.
Thus, the operation of the die set 16 can now easily be seen to sever the extrusion 19, into what may be defined as an outgoing length (not shown) and an incoming length (not shown), and simultaneously form a notch 39 in the secondary angle member 36 of the adjacent ends of the outgoing length and the incoming length.
While the principles of the invention have now been made clear in an illustrated embodiment, there will be immediately obvious to those skilled in the art, many modifications of structure, arrangements, proportions, the elements, materials, and components used in the practice of the invention, and otherwise, which are particularly adapted for specific environments and operation requirements without departing from those principles. The appended claims are therefore intended to cover and embrace any such modifications within the limits only of the true spirit and scope of the invention. | Multiflanged extrusion preparation apparatus including means by which multiflanged elongated extrusions are aligningly fed to punch press operated dies which notch, trim, and otherwise prepare the extrusions for use in assembling and installing of fiberboard air handling ducts. |
This is a division of application Ser. No. 372,945, filed June 25, 1973, now U.S. Pat. No. 3,880,578, which is a division of application Ser. No. 69,593, filed Sept. 4, 1970, now U.S. Pat. No. 3,769,675.
BACKGROUND OF THE INVENTION
This invention relates to a novel process for the brazing of radiator cores all the parts thereof are made of aluminium or aluminium alloys and a part at least thereof are plated with a brazing alloy.
The invention relates to a non-stop brazing process, which means that the cores to be brazed are moved according to a strictly continuous motion or according to an intermittent but regular motion, and this with the use of hot gas instead of dipping the radiator cores into a melting salt bath.
Brazing by means of hot gas entails however some inconveniences which are well known. As a matter of fact, hot gas used must never be at a temperature above melting temperature of aluminium. Now, melting temperature of brazing alloys, particularly that of silicon-aluminium, is about the same as that of aluminium melting temperature (difference of about 30° to 40°C). On account of this small difference between the respective melting temperatures of aluminium and of brazing alloys thereof, the heating of parts, about the end of the heating, tends to an asymptote so that the end of the heating stage has to be long in order to reach regularly the brazing temperature.
It has been verified that the keeping of thin aluminium parts at a temperature close to brazing temperature is prejudicial to the making of good brazings, due to the flux covering inevitably the parts to be brazed is quickly damaged at high temperatures and there is a great risk that aluminium will reoxidate as a result of high temperature and the presence of oxygen in the hot gas.
Because of the large number of soldering joints involved in the manufacture of a radiator -- a few hundreds or even a few thousands -- it is also essential that all the joints be perfectly made, which requires that all the radiator parts in process of brazing be heated, at the same time, at the same temperature.
Another serious inconvenience lies in the fact the brazing being carried out at a temperature close to the melting temperature of aluminium, it follows that the metal when at a temperature close to said soldering temperature shows only extremely low strength characteristics, while, besides, all the radiator parts must remain pressed one against each other. Thereby, radiator manufacturers were heretofore fixed on the horns of the following dilemna: either tighten the parts and run the risk of the strain thereof when the metal softens, or to leave the parts loose which will not still prevent the straining thereof, and, consequently, to be no longer in contact one against the other which, as a result, making impossible the working out of brazing joints.
This problem becomes more complicated also with the expansion the core parts are subjected to, when heated at brazing temperature. Said expansion is, in fact, important and tends to create a play between the parts.
Another difficulty lies in the fact that the core, which must be tightened in a fitting, is necessarily in contact with said fitting. The holding fitting having to be rigid at brazing temperature is thus necessarily thick and the heating thereof, apart from the fact of its cost, is slow as compared with that of the core which results in the cooling of the core areas in contact with said fitting and a risk of faulty soldering close to said areas notwithstanding a tendency for the flux covering them to flow out towards the warmer parts of the core, where it may overflow and thereby pour too much soldering alloy into the aluminium which may perforate certain parts of the pieces. Moreover, the amount of flux may then be insufficient on certain areas of the parts.
The invention has been conceived and developed to provide means for brazing radiator cores with high efficiency and to ensure an improved brazing of all the joints.
According to the invention, the radiator cores, after being covered with flux, are moved into the successive areas of an enclosure, contiguous streams of hot gas directed at right angles to the front surface of said radiators are blown into each of said areas so as to create by themselves aerodynamic deflectors for the travelling of said streams in all the parts thereof, the velocity of a hot gas stream in one of the areas forming a pre-heating area is adjusted so as said velocity is just under the velocity limit at which the flux would be blown and carried away, the velocity of the hot gas stream in the next area wherein the cores are heated at soldering temperature is adjusted at a higher velocity than that prevailing in the pre-heating area, and one other area at least is arranged wherein the cores are cooled down at a temperature ranging about 300°C before they are withdrawn from the enclosure.
The practical implementing of the invention has disclosed that additional inconveniences had to be overcomed. In particular, the moving of the radiator cores requires a travelling device capable of supporting the heat of the successive gas streams, as well as the corrosion resulting from flux vapours or being at least partly protected from said vapours. Moreover, the operation of said travelling device must obviously not disturb the travelling of said gas streams and the leakages of the latter must also be as low as possible.
This invention also answers this problem and provides an equipment for the implementing of this process.
According to this second provision of the invention, the equipment includes a number of cells externally similar as concerns the width and the height thereof, said cells including, in the aperture of the frame they delimit, two sole-plates or pillar-plates substantially parallel, one of which is fixed and the other is movable so as it may travel cross-wise to the lengthwise direction thereof, the front parts opposite said sole-plates or pillar-plates being fitted with thin edge projections between which the radiator core is gripped, so that said cores are only connected to said cell pillar-plates at a certain distance from said pillar-plates and so that by means of spot junctions leaving clear the whole of the front surface thereof, said cells being suspensed and moved in an air furnace including at least at the inlet and the outlet thereof a chamber locked by the cells upon the passage thereof, said furnace being connected with separated blowing and exhausting means for at least three air streams having different velocities and delimiting pre-heating, brazing and precooling areas which are connected between them without break of continuity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic sectional elevational view of a furnace designed for implementing the invention;
FIGS. 2 and 2a are cross sectional views taken substantially as indicated by line II--II of FIG. 1;
FIG. 3 is a diagrammatic elevational view, fragmentary sectional, of an embodiment of one of the brazing cells travelling in the furnace shown on the above FIGS.;
FIG. 4 is a perspective view, at a larger scale, showing a specific feature of brazing cells;
FIGS. 5 and 6 are perspective views showing particular embodiment details;
FIG. 7 shows another embodiment of the feature which appears on FIG. 4;
FIG. 8 shows a different form of the cell shown on FIG. 3, and
FIGS. 9 and 10 are diagrammatic perspective views showing additional features of the invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown by FIGS. 1 and 2, the furnace is made of a long shaped structure 1 provided with heat insulated material 2. An enclosure 3 is delimited in the structure 1 by partitions 4 which may be partly or entirely made of ceramic or stainless metal, for example stainless steel, so as to resist corrosive effects of vapour and/or projection of highly active flux products which are generally used for brazing of aluminium. As shown on FIG. 2, partitions 4 hold an insulated duct 5 which shuts the top part of the enclosure 3 and forms a conveyor or transporter 6 which may be made of a single rail or of an axially mobile unit of the type currently used in handling technics. Duct 5, and particularly the bottom part 7 thereof forming the top part of enclosure 3, is heat insulated and said bottom part 7 bears a narrow lengthwise groove 8.
Partitions 4 form with structure 1 ducts 9, 9a connected by a duct section 9b. Partitions 4 are, besides, punched with port-holes 4a which are spaced so as to provide an even travelling of hot gas streams transversally to the axis of the enclosure 3, said travelling being created by turbines or fans 10 set, for instance, in duct 9. The heating of the air contained in the structure may be ensured by various means, by electric resistances 11, for instance, set into duct 9a, by town gas burners or fuel burners, said heating means being in any case properly controlled so as to obtain the temperatures hereinafter specified.
The setting of turbines 10 and port-holes 4a and, in case of need, of means for the distribution of the gas flux blown by the turbines, is so fixed as to create in enclosure 3 successive areas wherein hot gas travel at different temperatures and velocities along gaseous streams not separated between each other by partitions projecting in said enclosure. In other words, it has been found desirable that the successive hot gas streams be delimited by aerodynamic means exclusively in enclosure 3, properly so called.
Chambers 11 and 11a are however set at the inlet and outlet of enclosure 3 in order to cut down hot gas losses.
The furnace is intended to house cells 12, 12a . . . 12n which are all identical externally at least as concerns the height and the thickness thereof. In the case conveyor 6 is a mere fixed rail, then, as shown on FIG. 1, cells 12, 12a and so on are in mutual contact and push themselves one and another whether or not they are loaded with a core or a radiator to be brazed. On the contrary, in the case transporter 6 is mobile itself, this arrangement, though advantageous, is no longer necessary.
In the embodiment shown on FIG. 2, conveyor 6 is set in duct 5, and cells 12 are carried by suspension parts 13 having a small section which run through groove 8 of bottom part 7. Suspension parts 13 may be fitted with deflector units 14, 14a respectively set on either parts of bottom 7 so as to limit the amount of gas outflowing from duct 5 and entering into enclosure 3. It has, in fact, been found advantageous to maintain the inside of duct 5 under a slight over-pressure as compared with enclosure 3 by blowing, into said duct, air from a feeding device 15 fitted, if necessary, with a filtering, dehydrating and pre-heating device 16. Thereby, the inside of duct 5 which is thermally insulated from enclosure 3 and ducts 9, 9a, 9b, is at a temperature definitely lower than that of the latter hollows and the air it contains is free of flux vapour, which makes it possible to use a simple conveyor that cannot be damaged by corrosive products or by heat. It appears, moreover, that the air entering into enclosure 3 is lead in the direction of arrow f 1 by shutters and deflectors 14 and 14a so that the air vein travelling through cell 12 is not cooled neither disturbed.
A similar result is obtained by the embodiment shown on FIG. 2a according which duct 5a is built on the top part of the furnace and houses both the conveyor 6 and the air supply device 15. In this case, parts 13 which hold the cells are longer and run both through the top part of enclosure 3 and the furnace wall respectively through slots 8a and 8b. Shutters and deflectors 14, 14a of FIG. 2 may then be suppressed.
FIG. 3 shows an embodiment of cells 12 which each include a rectangular frame 17 made for instance of stainless square tubes 18, preferably of stainless steel, for instance of Ugine NS 24 steel, and the parts of said frame are joined together by boxing preferably, or also by welding provided that the welds be so made that they will not corrode more than the constituent metal of the frame. Such welding may be carried out in some instances by resistance, but, most often it has to be made under a neutral or reducing atmosphere, or also, under vacuum, preferably by means of electron beams.
The thickness of the frame and the height thereof correspond to the gaps worked out into chambers 11 and 11a, thereby when the frames are reciprocally pushed one by the other, there will always be one frame in each chamber, which ensures the relative tightness of the latter. When the frames are not in contact one with another, the position of chambers 15 is so determined that there will always be a cell at right angles with each chamber presented by the furnace.
Should this arrangement be not feasible, temporary shutting means for port-holes worked out into chambers 11, 11a will be fitted, said temporary shutting means being cleared upon the incoming and the outgoing of any cell.
By referring again to FIG. 3, it appears that the lower longitudinal girder 19 of frame 17 holds, by means of keys 20, preferable flexible, and made for instance of expanded metal or folded corrugated iron sheets, a support sole plate 21 which bears on its side opposite to that resting on keys 20 projections 22 having a small section, at least at the tips thereof. Said projections may, for instance, be made of pins relatively close one another, the spacing between two projections ranging about 15 to 20 mm.
Projections 22 are so arranged that they bear at precisely settled points, one of the flanges 23 of a radiator core 24 for instance, whereof 25 represents the pipes, 26 the dissipator parts and 27 the collectors.
As shown on FIGS. 2 and 2a, when the frame 17 forming the setting of a cell is carried by conveyor 6, the core thereof is at right angle with the travelling direction of the hot gas, i.e. exactly in the same way a complete radiator will be used on an automobile, which means according to the best aerodynamic conditions. Thereby, the hot gas travel through all the parts of the core, evenly, the core acting as air travelling regulator by itself.
In order to maintain the various parts of the core properly pressed against each other, a pillar-plate 30 is fitted which is similar to sole-plate 21 and bears, like the latter, projections 22 set in the direction of the core so as to rest, for instance on the second flange 23a, and occasionally, on other parts of the core, for instance, on fixing clips which are brazed onto the flanges and, also, to tighten, if necessary, the flange tips on collector supports.
Pillar-plate 30 is vertically movable and is guided, for instance, by means of rods 31 running through holes worked out in girder 18, or by means of clamps added to said girder, and rods 31 are advantageously fitted with a head 32 in order to limit the travel of pillar-plate 30.
In principle, the weight of pillar-plate 30 is sufficient for maintaining properly in contact between them the various parts of the radiator, namely the flanges, the pipes and the dissipators in order that the "squeeze" of said parts, i.e. the respective position thereof and the pressure they exert one against the other, be satisfactory at the time the brazing is made. In addition, if so desired, calibrated springs 33 may, also, be set between the pillar-plate and the girder 18, for instance, in the case it is assumed that the weight of pillar-plate 30 is not sufficient for maintaining the required pressure between the various parts of the radiator to be brazed, which is particularly the case for large size radiators, since it is an important feature of the embodiment of the cells of invention that steps be taken with a view that sole-plate 21, as well as pillar-plate 30 and projections 22 carried by the latter be light in order to show a low thermal inertia, so as to reduce as much as possible heat conductivity between core 24 and the parts on which it rests for which, besides, it is advantageous that the said parts be not heated up to temperature prevailing in the various partitions of the furnace, at least in those the temperature thereof is the highest.
Owing to the fact pillar-plate 30 is pressed either merely by the weight thereof onto the core to be brazed, or by means of calibrated springs and that, besides, keys 20 which hold sole-plate 21 show, preferably, a certain elasticity, the differential expansions between aluminium, basic constituent metal of the radiator, and stainless steel, basic constituent metal of the various parts of the cell, are compensated by this method, the lengthwise differential expansion being, if necessary, compensated by a slight sliding of the cell parts and the core one with respect to the others.
Since it often happens that different types of radiator core have to be brazed in a same furnace and without modifying the cells, projections 22 are arranged so as not to be necessarily all used for holding purpose during the brazing of a given type of core.
Since sole-plate 21 is normally fixed and that pillar-plate 30, as well as, in case of need, pressing parts 33 are guided into the cell, spacing means for said pillar-plate and parts 33 may easily be designed so as to make self-acting the loading of the cells by using mechanical means for the setting and the extrusion of the cores.
Projections 22 are not necessarily formed of pin shaped parts, and FIG. 4 shows that said projections, which are shown on sole-plate 21, may be formed of cross-bars 37 the part 37a thereof, coming into contact with the core to be soldered, is thinned down and bears advantageously notches 38 intended to lessen the contact surface. The projections may also be formed of U shaped parts 39 with triangular apices 40 or even flat edges 41, the shape of the cross-bars or U shaped parts depending chiefly of the core parts which have to be held, for instance in the case said parts are fragile or when accessories have to be held against core flanges 23 or on other parts thereof.
Sole-plates 21 as well as pillar-plate 30 may also be formed of T shapes as shown on FIGS. 5 and 6 and, in this case, the web 42 of the shapes is cut out so as to show resting parts 43 and 44 having different forms, depending on the core parts over which said parts exert a pressure. FIG. 6 shows that, in this case also, web 42 may be thinned down at the tip thereof, as shown at 45, in order to lessen the contact surface.
FIG. 7 shows another process for the making of sole-plate 21 and pillar-plate 30. In this case, a U shape is used and projections 22 are worked out by cutting and cambering, which provides small contact surfaces with the radiator core though said contact surfaces may be close to each other.
This arrangement has another advantage. As a matter of fact, by cutting out and cambering appropriately projections 22 from a U shape, it becomes possible to give them a certain set and, thereby, to pipe hot gas so they selectively are directed on certain parts to be brazed or to eliminate disturbances in the travelling of said hot gas.
In the case T or U shapes are used for the making of sole-plate 21 and pillar-plate 30, the cell may itself be simplified because these shapes have a great rigidity owing to the form thereof. In this case, as shown on FIG. 8, the sole-plate 21 constitutes the lower girder of the cell and is connected by struts 46 to another T or U shape 47 which constitutes the upper girder of the cell whereon is suspended pillar-plate 30, said suspension being made as described with reference to FIG. 3.
It has been found highly desirable not only to limit the heat conductivity between the core to be brazed and the cell holding it, but also to take such steps as the risks of adherence between the core, once brazed, and the projections of the cell be reduced as far as possible, or even entirely eliminated. This result may be obtained by following the process shown on FIGS. 9 and 10, i.e. that projections 22, 37, 39, when they are made of pins, are fitted, at the tips thereof, with bosses 48 or sleeves 49 made of a non-corrosive refractory material which does not draw the soldering; suitable materials are, for instance, ceramic or steatite.
As it appears from the foregoing, the supporting cells of the cores or radiators to be brazed on the one hand, show a low thermal inertia in the parts thereof which are close to the core and, on the other hand, include means which prevent almost entirely any heat transmission between them and the core and, further, allow hot gas to travel under the best aerodynamic conditions into all the core parts, thereby making it possible that all the core parts be heated at a fully homogeneous temperature.
The making of cells with a metal resisting to the corrosive action of soldering flux results in said cells may be used for the holding in position the constituent parts of the core during the course of the fluxing work itself, whether said work is made by means of bath or by gun spraying.
In the case the fluxing of the cores to be brazed is made by bath, the furnace, as shown on FIG. 1, delimits four areas or compartments A to D. On the contrary, in the case the core is fluxed by spraying, area A may be suppressed, since said area, which may be separated from the next area by a chamber contrarily to areas B to D, is chiefly used as a drying-oven and the temperature thereof ranges about 150°C. It, however, is possible, even in fluxing by spraying, to maintain area or compartment A in the furnace but in this case the furnace must be arranged in such way that said spraying fluxing be carried out in said compartment A, i.e. on the pre-heated core, the temperature then prevailing in said compartment A being close to the flux fluidifyzation temperature.
The length over which extend respectively the various areas of the furnace is settled in ratio to the moving speed of the cells and to the time during which the cores contained in the cells have to remain in each area for being heated at the desired temperature.
Compartment A, if any, serves, as indicated above, either as a drying-oven, or as a fluxing by spraying compartment and, in the case said compartment serves as a drying-oven, it has been found advantageous that the cores stay in said compartment during 10 to 60 minutes at a temperature ranging about 150°C in order that they become entirely dehydrated.
Area B is a pre-heating area and the cores to be brazed remain there during 10 to 20 minutes. The temperature at which are heated the core in this area depends directly on the nature of the brazing alloy. In the case said brazing alloy is a silicon-aluminium alloy having a 7.5 % silicon the temperature in area B is 570° ± 5°C; in the case the aluminium-silicon brazing alloy has a 12 % in silicon, the temperature may be only 550° ± 5°C.
Area C is the brazing area, properly so called, and, as an example, in said area the temperature is 615° ± 2°C in the case of the brazing alloy at 7.5 % in silicon but only 600° ± 2°C in the case of the alloy at 12 % in silicon.
Area D is used for pre-cooling and the temperature of the cores is lowered therein down to 300°C approximately so as to prevent the cores from being subjected to heat strokes which are prejudicial to good brazing.
As already indicated above, it is also of importance, according to the invention, that the travelling speeds of the hot gas in the various areas be properly regulated. As a matter of fact, it has been remarked that the flux deposited on the parts to be brazed has a tendency to be blown and carried away when the travelling velocity of the hot gas is too high. Generally, a velocity ranging about 4 m/s is suitable for most of the areas, however, it has been noted it is of importance that the brazing temperature, i.e. temperature in area C, be quickly reached. It has been established, surprisingly, that after the pre-heating in area B wherein the melting temperature of the brazing alloy is not reached, but wherein, however, the flux itself is molten, has flowed away and has been kept back by capillarity in the joints, i.e. just where the brazing can be made the best way, it becomes possible to increase fairly the travelling velocity of the hot gas.
To this end, is has been noted that, in area B, the travelling velocity of the hot gas should be limited at approximately 4 m/s, but however could advantageously reach 6 m/s in area C, enables reducing the time of the core in said areas, respectively at a duration ranging between 10 and 20 minutes for area B, and 3 to 5 minutes for area C, so that, during this short space of time, the risk of aluminium reoxidation is eliminated, and this all the more as a thin film of molten flux remains on all the surface of parts to be brazed thus preventing any oxidation.
The invention is not restricted to the embodiment examples shown and described in details, since various changes may be made which are contemplated as may come within the scope of the claims. In particular, the connection between ducts 9 and 9a may be executed in a different way, for instance, by setting duct 9b or pipes, either under the furnace, or laterally. | The process is characterized in that hot gas are blown at right angle with the front face of the parts to be brazed into the contiguous areas of an enclosure. The speed of the hot gas in a first area is regulated in order to ensure pre-heating, the speed in a second area is regulated in order to increase the temperature to the brazing temperature and the speed in a third area is regulated in order to ensure at least a partial cooling of the parts before they are withdrawn from the enclosure. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to ski equipment and, more particularly, to a device for widening the opening of a ski strap.
2. Summary of the Prior Art
As is well known, ski poles are fitted with ski straps which hang downward in a looped configuration. The wrist strap on ski poles are commonly fabricated from flexible materials which tend to narrow the opening as the strap hangs downward from the pole. A skier ordinarily will insert his hands in and out of a ski strap on numerous occasions during the course of a ski session. The flattened opening of the ski strap can interfere with the convenient and safe insertion and withdrawal of the bulky gloved hand of the skier during the course of skiing. The difficulty involved in using known straps can diminish the enjoyment of the sport and is a particularly a problem for inexperienced and young skiers. Accordingly, it is desirable in skiing to provide a device by which the permanent size and width of the opening of the ski strap is optimized during skiing.
SUMMARY OF THE INVENTION
It is therefore an objective of the invention to provide a ski strap device for maintaining the loop of a ski strap in a more opened configuration for allowing a skier to easily insert and withdraw his gloved hand in and out of the strap. The invention herein employs a ski strap device which is capable of being permanently affixed in a convenient manner to any conventional ski strap. The material forming the device of the invention is bendable, but is more rigid than known ski straps formed from leather, nylon, and the like. The rigidity of the device herein disclosed insures that the strap is maintained in an opened configuration for the convenience of the skier when inserting or withdrawing his hands. The ski strap device of the application includes retention means which facilitates rapid attachment of the device to the ski strap with permanence and without interfering with the function of the ski strap itself during skiing. The device is inexpensive to manufacture and demonstrates an extended lifetime of use after being attached.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective view of a ski strap mounted on a ski pole and having the strap device of the invention;
FIG. 2 is a top plan view of the ski strap device of the invention;
FIG. 3 is an end elevational sectional view taken along lines 3 — 3 of FIG. 2;
FIG. 4 is an enlarged partial view of the hinge portion ski strap device shown in FIG. 3; and
FIG. 5 is an end elevational view, with parts in section, of the ski strap device in a closed position when attached to a ski strap.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 to 5 , there is illustrated the ski strap device of the invention, generally designated by reference numeral 2 . As seen in FIG. 1, the ski strap device 2 is intended to be attached to the loop of a ski strap 4 hanging from a grip 6 of a conventional ski pole 8 . As is well known, ski straps are conventionally fabricated from a flexible material, such as, for example, leather, nylon, and the like. As will be apparent from the following description, the ski strap device 2 when attached to the ski strap 4 in accordance with the invention will establish an area of the increased rigidity for maintaining the opening 4 ′ of the ski strap 4 in a wider opened configuration for ease of insertion and withdrawal of the gloved hand of a skier.
In FIGS. 2-5, the ski strap device 2 has a one-piece construction made from a molded plastic as illustrated or some other suitable material, such as a rubber or metal (not shown). The material of ski strap device is selected to have the flexibility to bend in conformance to the contour of the ski strap 6 , but possess a greater rigidity than the material of strap 6 to cause the opening 4 ′ to widen and maintain a permanent enlarged opening for insertion and withdrawal of the gloved hand of the skier. In its unattached shape shown in FIGS. 2-4, the ski strap device 2 includes a flexible base 10 having a generally flat configuration when unattached to ski strap 4 . A plurality of outwardly extending, retention strips 12 are connected in spaced parallel relationship along one edge of flat base 10 . Although four retention strips are shown in FIG. 2, it is within the scope of the invention to employ other numbers of retention strips 12 , if desired.
The retention strips 12 have a generally elongated, rectangular shape as seen in FIG. 2 with flat bottom faces 14 and generally flat upper faces 16 having partially domes areas 18 . The outer ends 20 of the retention strips 12 are provided with openings 22 . Male projections 24 having a hooked, offset end 26 are respectively formed on upper face 16 and are disposed adjacent openings 22 . The inner end 28 of each retention strip 12 includes an upright wall 30 disposed adjacent a hinge 32 of the ski strap device 2 . As seen in FIGS. 2 and 3, the hinge 32 is formed by a thin strip 34 connecting the inner end 28 of the retention strip 12 to the edge portion 36 of the base 10 . A best seen in FIG. 3, the upper surface 38 of the thin strips 34 are provided with cut-out areas 40 to permit the retention strips 12 to be pivoted with ease into overlapping relationship with base 10 as shown in FIGS. 1 and 5.
A plurality of upright walls 41 are formed on base 10 immediately adjacent hinges 32 . The opposite edge portion 42 to edge portion 36 of base 10 is formed as raised edge areas having an inner vertical wall 42 ′ and four spaced locking pads 44 . Each locking pad 44 has a longitudinal axis aligned with the longitudinal axis of a respective retention strip 12 . The locking pads 42 have openings 46 to receive the male projection 24 of a respective retention strip 12 when inserted (FIG. 5 ). As seen in FIG. 3 and 5, the lower portion of opening 46 includes a notched area 48 which engages the hook end 26 of projection 24 and attaches the retention strip 12 to the locking pad 44 to permanently to secure device 2 to the ski strap 6 . In its locked configuration in FIG. 5, the walls 30 of the retention strips 12 engage the inner surface of the upright walls 41 of the bases 10 for better strength and securement. As seen in FIG. 5, the secured retention strips 12 form an opening 54 with base 10 to permit the adjacent portion 56 (FIG. 1) of the ski strap 6 to be sandwiched between base 10 and a respective retention strip 12 .
As further seen in FIG. 1, the device is attached by placing the base 10 on an inner surface of the ski strap 6 . The base 10 assumes a curved shape in contact with the strap 6 , but possesses rigidity to widen the opening 4 ′ normally occurring in a conventional strap. Although the device 2 may be placed at other locations on the strap 6 , the positioning of the base 10 adjacent the bottom of the strap loop as shown in FIG. 1 produces particular satisfactory results. The retention strips 12 are simply pivoted in the direction indicated by arrows in FIG. 1 to be locked as previously described. The convex portions of the retention strip aid in capture of the strap portion 56 between the retention strips 12 and base 10 . The inner surface of base 10 is smooth and provides no obstruction or discomfort to the skier in use. | A device for enlarging the opening of the loop of a ski strap including a base being in bended contact with the ski strap while possessing rigidity for enlarging the opening. A plurality or retention strips are pivotally mounted on the base. The base includes openings for receiving male projections affixed to the retention strips such that the retention strips overlap the base in a locked relationship on the ski strap. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally involves chemical lasers. More particularly, the present invention involves an improved chemical laser configuration for space and ground applications.
[0003] 2. Description of the Related Art
[0004] Conventional linear lasers provide a single chemical laser gain region from a combustion chamber as shown in FIG. 1 . With this configuration, mass efficiency is limited by heat loss to the large surface area i.e., three sides of the combustion chamber. The high weight of the conventional laser is driven by the structural requirement to contain combustion gases at high pressure and high temperature. Finally, the medium quality of the conventional laser is degraded with increasing device length and power due to systematic optical path disturbances in gain medium that cannot be compensated.
[0005] The use of a chemical reaction to produce a continuous wave chemically pumped lasing action is well known. The basic concept of such a chemical laser is described, for example, in U.S. Pat. No. 3,688,215, the subject matter of which is incorporated herein by reference. As therein described, the continuous wave chemical laser includes a plenum in which gases are heated by combustion or other means to produce a primary reactant gas containing dissociated atoms of a reactant element such as fluorine mixed with diluting gases, such as helium or nitrogen. The resulting reaction between the hydrogen (or deuterium) and fluorine produces vibrationally excited HF or DF molecules. These molecules are unstable at the low temperature and pressure condition in the cavity and return to a lower vibrational state by releasing photons. Mirrors spaced in the cavity along an axis transverse to the flow field amplify the lasing action from the released photons within the optical cavity formed by the mirrors. The lasing action is of the continuous wave type, which is pumped by the high-energy vibrationally excited molecules formed in the optical cavity. The lasing action depends on producing vibrationally excited states in the HF or DF molecules. This in turn requires that the molecules be formed under conditions of low temperature and pressure. As the pressure and temperature increase, the number of vibrationally excited molecules decreases and more energy goes into translational movement of the molecules, defeating the lasing action.
[0006] Cylindrical lasers as illustrated in FIG. 2 provide compact packaging of the gain generator, but require large volumes for handling the radial outflow of laser exhaust gas. End domes are required to contain the combustion products with atomic fluorine in the chamber. The domes are large surface area, heavy structural members that reduce mass efficiency from heat loss effects. Gain medium optical path disturbances increase with cylinder length and cannot be compensated, thereby limiting length and power scaling. Cylindrical combustion devices and optics for power extraction require stringent tolerances during fabrication and alignment, resulting in very high costs for a fragile beam generator. Conventional linear and cylindrical lasers experience large temperature gradients in the structure resulting in time-varying medium quality and laser performance. The radial flow of laser gas lowers the mass flux at the entrance to the diffuser, resulting in lower pressure recovery than linear flow devices.
[0007] A low-pressure hydrogen fluoride (HF) laser is a chemical laser, which combines heated atomic fluorine (produced in a combustion chamber similar to the one in a rocket engine) with hydrogen gas to produce excited hydrogen fluoride molecules. The light beam that results radiates on multiple lines between 2.7 μm and 2.9 μm. These wavelengths transmit poorly through the atmosphere. Conventional HF lasers utilize primary nozzles, referred to as hypersonic low temperature or HYLTE nozzles, the surfaces of which are smooth, curved planes that result in nearly parallel flow of gases at the exit of the nozzle. Helium and hydrogen cavity fuel are injected at oblique angles from the nozzle sidewalls. Mixing, reaction and laser gain are produced internal to the primary nozzles and in the downstream optical cavity region. A large base region is formed between adjacent primary nozzles. In a process referred to as helium base purge, helium or other gas must be introduced into these base regions to prevent recirculation of laser gas with ground-state HF that would reduce laser gain and mass efficiency. Conventional HYLTE nozzle configurations wherein hydrogen is injected with wall-jets produces gain internal to the primary nozzle and the large base region between the adjacent primary nozzles is subsonic helium flow that produces no gain. Further, there are flow regions at the laser cavity exit with unmixed atomic fluorine, hydrogen rich regions, and a large subsonic base flow region. These attributes of the conventional HYLTE nozzle result in inefficiencies within the HF laser and a significant loss of power.
[0008] There is a need in the art for a laser and nozzle configuration that reduces the inefficiencies currently found in the conventional configurations.
SUMMARY OF THE INVENTION
[heading-0009] Summary of the Problem
[0010] Available chemical lasers, including linear and cylindrical lasers, have limited mass efficiency due to heat loss and are structurally burdensome and heavy. Power is limited due to optical path disturbances resulting from the need for longer combustion chambers. Further, conventional chemical lasers experience large temperature gradients, which result in time-varying medium quality and reduced laser performance. Finally, available nozzle configurations are in efficient due to a number of non-gain regions resulting therefrom.
[heading-0011] Summary of the Solution
[0012] An embodiment of the present invention includes a chemical combustion laser component comprising: a first and a second gain region, a combustion region, and a first and a second nozzle blade, wherein the first and second nozzle blades separate the combustion region from the first and second gain regions.
[0013] In a further embodiment, each of the first and second nozzle blades is comprised of a primary structure and a secondary structure, wherein the primary structure is formed from a first material and the secondary structure is formed of a second material.
[0014] In a yet a further embodiment of the present invention, the second material is able to withstand higher temperatures than the first material.
[0015] In yet a further embodiment of the present invention, the first material is aluminum and the second material is nickel.
[0016] In yet a further embodiment of the present invention, the first and second nozzle blades are self-cooling.
[0017] In still a further embodiment of the present invention a component for a combustion laser comprises: at least one inlet manifold for receiving and distributing combustion fuel; at least one upper manifold sheet having holes therein for receiving combustion fuel from the at least one inlet manifold and further distributing the combustion fuel; at least one pair of nozzle blade structures for receiving the combustion fuel from the at least one upper manifold sheet; and at least one lower manifold sheet, wherein the at least one inlet manifold, the at least one upper manifold sheet, the at least one pair of nozzle blade structures, and the at least one manifold sheet are stacked one on the other and affixed one to the other in a stacked relationship.
[0018] In still a further embodiment of the present invention, each of the nozzle blade structures includes a primary nozzle having a serrated tip.
[0019] These embodiments result in a combustion laser having lighter weight (e.g., per unit flow area), a more compact, flexible configuration for packaging in spacecraft, aircraft, or ground mobile vehicles, higher mass efficiency from lower heat loss and proven power extraction efficiency of linear lasers, superior output beam quality by incremental compensation of gain medium optical path disturbances and by reduction in time-dependent variations in structural and gain medium characteristics, lower cost and shorter fabrication time for modular dual flow laser and linear optics, more efficient pressure recovery with side-wall isolation nozzles and compact diffuser configurations, and increased small signal gains for more efficient extraction of overtone power.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the Figures:
[0021] FIG. 1 depicts a conventional linear combustion laser;
[0022] FIG. 2 depicts a conventional cylindrical combustion laser;
[0023] FIG. 3 depicts a dual-chamber combustion laser component according to an embodiment of the present invention;
[0024] FIG. 4 depicts a dual-chamber combustion laser component according to an embodiment of the present invention;
[0025] FIG. 5 depicts a dual-chamber combustion laser component according to an embodiment of the present invention;
[0026] FIG. 6 depicts a nozzle blade structure according to an embodiment of the present invention;
[0027] FIGS. 7 ( a ) and ( b ) depict a manifold assembly according to an embodiment of the present invention;
[0028] FIG. 8 depicts a nozzle blade according to an embodiment of the present invention; and
[0029] FIG. 9 depicts a combustion laser assembly according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] According to an embodiment of the present invention, a chemical combustion laser is provided having a modular, aluminum design that produces two linear, supersonic gain regions from a single combustion chamber as shown in FIG. 3 . This structure results in a minimum surface area combustion chamber and a balanced thermal design. The laser module is referred to herein as a boxer laser module 1 . FIG. 3 is an end view of the boxer laser module that includes a combustion chamber 22 and on the left and the right sides, gain regions 28 . Gain is produced in the gain regions 28 by the out-flow of combustion products such as, deuterium fluoride, nitrogen, atomic fluorine, and heated helium and by the helium and hydrogen gases injected into the cavity which produce a chemical reaction.
[0031] As shown in FIGS. 4 and 5 , each boxer laser module consists of two nozzle blade structures 10 with combustor injectors 12 , cavity injectors 14 , combustor sidewalls 16 and cavity shrouds 18 with integral cavity isolation nozzles 20 . A combustion chamber 22 is formed between two nozzle blade structures 10 connected by combustor sidewalls 16 . The nozzle blade structures 10 are self-cooled by gaseous combustor reactants such as, nitrogen trifluoride, deuterium, and helium, which are injected and burned in the combustion chamber 22 to produce, for example, atomic fluorine, deuterium fluoride, nitrogen, and heated helium and by cavity injectant gases, hydrogen and helium. Boxer laser modules 1 are placed side-by-side to increase the length of the combustion chamber 22 and to form converging-diverging primary nozzles 26 between adjacent nozzle blade structures 10 . Combustion product gases, e.g., atomic fluorine, deuterium fluoride, nitrogen and helium, are expanded through these primary nozzles 26 from a high-pressure of approximately 0.5 atmospheres, a high-temperature of, e.g., approximately 1500K to 1700K condition to a low pressure of approximately 0.005 atmospheres, supersonic, e.g., Mach number of 3 to 5 condition, where cavity fuel, e.g., hydrogen and helium gas mixtures, is injected to produce laser gain. The heat is transferred to the combustor sidewalls 16 and by making the chamber length short, all of the heat that is transferred to the combustor sidewalls 16 , even in the case of a small quantity, can be conducted to the nozzle blade structures 10 and cooled. The nozzle blade structures 10 , combustor sidewalls 16 , and cavity shrouds 18 are designed to achieve dynamic and static thermal balance conditions. This thermal balance condition results in equal heating rates and nearly equal steady-state temperatures for nozzle blade structures 10 , combustor sidewalls 16 , and cavity shrouds 18 . Uniform heating and isothermal steady-state temperatures of the boxer modules 24 results in nearly time-constant combustor pressure and laser cavity flow conditions to maintain desired conditions for laser power and medium quality. According to this embodiment, all parts of the boxer laser module 1 can be heated at a nearly equal rate and operate at nearly equal steady state temperature, such that the throat gap of the primary nozzle 26 which is formed between side-by-side boxer laser modules 1 remains constant. If the throat gap remains constant, all of the properties in the laser gain region 28 remain time-independent and increase the efficiency of the gain regions 28 . This is important to efficient gain production, efficient power extraction, and the medium quality that is required for a high-power laser.
[0032] FIG. 5 is a side view of a boxer laser module 1 . The boxer laser module 1 incorporates isolation nozzles 20 in the cavity shrouds 18 downstream of the laser gain regions 28 . In an exemplary embodiment, helium is injected through the nozzles to energize flow along the cavity shrouds 18 to allow formation of strong shock waves just downstream of the laser gain regions 28 for efficient pressure recovery with compact diffuser configurations. Diffuser lengths can be factors of three to five times shorter than for conventional linear lasers when using the boxer laser modules 1 described above. The placement of the isolation nozzles 20 , ensures that the gain regions 28 are independent of their environment. Utilizing a boxer laser comprised of the boxer laser modules 1 having a single minimum surface area combustor region 22 which produces laser gain regions 28 described above, the structural weight to support the combustor is minimized, the heated surface area is minimized, and thereby heat loss to the combustor which drives mass efficiency is minimized. The boxer laser configuration described herein minimizes non-functional structure and facilitates incremental production of very long gain paths, such as those required for an overtone laser.
[0033] According to an embodiment of the present invention, FIG. 6 illustrates a nozzle blade structure 10 configuration for reducing heat loss. Combustor injector triplets 32 are incorporated into secondary structure 30 made of high temperature fluorine-compatible material such as nickel, stainless steel, or ceramics like lanthanum hexaboride or alumina. Referring to FIG. 6 , the secondary structure 30 fits into the primary structure 34 which is formed of a lightweight material such as aluminum. By making the secondary structure 30 out of high temperature fluorine-compatible material as opposed to aluminum, the secondary structure 30 can operate at significantly higher temperatures of e.g., 900K to 1300K, as compared to the safe operating temperature of 600K for aluminum. The secondary structure 30 is inserted into the primary structure 34 of the nozzle blade structure 10 in order to reduce heat transfer that would otherwise occur when operating with wall temperatures higher than allowed for an all aluminum nozzle blade structure. The secondary structure 30 is cooled by injected combustor reactants such as, nitrogen trifluoride, deuterium and helium and by conduction to the primary structure 34 that is cooled by the cavity injected hydrogen and helium. In a further embodiment of the present invention, the above-identified combustor reactants as well as cavity injectants hydrogen and helium are transferred from at least one boxer laser module 1 to at least one adjacent boxer laser module 1 for cooling and for injection into the combustor 22 and cavity flow.
[0034] In an embodiment of the present invention, the nozzle blade structures 10 and consequently, the boxer laser modules 1 , are connected by a thin, laminated manifold assembly 60 as shown in FIGS. 7 ( a ) and 7 ( b ). The thin manifold sheets 62 have flow channels 64 machined into their surfaces to provide gas flow passages from oxidizer inlet manifolds 66 to coolant and distribution passes (not shown) internal to the nozzle blade structures 10 . The manifold sheets 62 also contain and connect combustor fuel inlet manifolds 67 for facilitating the efficient conduction of fuel to the nozzle blade structures 10 . The manifold sheets 62 are joined together by brazing, diffusion bonding, or the like in order to form upper and lower manifold assemblies 60 and 68 on the top and bottom surfaces of the nozzle blades 10 . This configuration places parent material, e.g., aluminum, with no bond joints, between the oxidizer and the combustion fuels to eliminate the possibility of interpropellant leakage that could cause failure. This configuration also reduces the number of external connections that have to be made to the hardware.
[0035] In a further embodiment of the present invention, nozzle blade structures 10 as described in relation to FIG. 6 , increase laser chemical efficiency when used in, for example, HF (Helium Fluoride), HF-overtone, DF (Deuterium Fluoride), and gaseous iodine combustion driven lasers and increase the small signal gain for more efficient extraction of power. Referring to FIG. 8 , a nozzle blade 70 according to an embodiment of the present invention has serrated primary nozzle surfaces 72 to direct primary nozzle flow into the region 74 between primary nozzles. Cavity fuel, e.g., helium gas 76 and hydrogen gas 78 , is injected from the base region through pairs of nozzles that enhance molecular mixing and prevent recirculation of laser gas. Further, a secondary flow of atomic fluorine, is injected into the laser cavity between adjacent pairs of nozzles by means of the serrated primary nozzle surfaces in order to control the flow trajectory of the cavity fuel. This nozzle configuration eliminates the gas flow normally required for base purge, simplifies the design and fabrication of the nozzles, and increases overall mass efficiency of the laser by utilizing all of the cavity area 28 to produce gain. In this embodiment of the present invention, the placement of nozzle blades at the base, allows the laser to fully utilize a conventionally inactive zone that occupies approximately 40 percent of the length of gain region. By injecting the fuel internal to the nozzle, the expansion that the fuel will undergo in the cavity is limited. Referring to helium and hydrogen flow jet patterns 76 and 78 , respectively, complete use of the laser gain region 28 is illustrated.
[0036] In a further embodiment of the present invention, the components described above are assembled into a boxer laser 100 as shown in FIG. 9 . At least one boxer laser module is contained in a housing comprised of upper and lower manifold assemblies 160 and 168 surrounded by enclosed gain regions 128 . The at least one boxer laser module comprises the boxer laser 100 along with a surrounding optical train comprised of various optical elements (e.g., mirrors, reflectors, beamsplitters, lenses, switches, and the like) 180 . One skilled in the recognizes the necessity for optical elements and the many configurations of optical elements available for use within a combustion laser.
[0037] The embodiments described herein are intended to be exemplary, and while including and describing the best mode of practicing, are not intended to limit the invention. Those skilled in the art appreciate the multiple variations to the embodiments described herein, which fall within the scope of the invention. | The invention herein is directed to a dual-chamber combustion laser assembly having lighter weight (per unit flow area), a more compact, flexible configuration for packaging in spacecraft, aircraft, or ground mobile vehicles, higher mass efficiency from lower heat loss and proven power extraction efficiency of linear lasers, superior output beam quality by incremental compensation of gain medium optical path disturbances and by reduction in time-dependent variations in structural and gain medium characteristics, lower cost and shorter fabrication time for modular dual flow laser and linear optics, more efficient pressure recovery with side-wall isolation nozzles and compact diffuser configurations, and increased small signal gains for more efficient extraction of overtone power. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a hot water supply system and more particularly, to a hot water supply and fire hydrant system, which fuilly utilizes the roof space of a building to support a solar collector unit and, which can be used as a fire hydrant as well as a hot water supplier.
[0003] 2. Description of the Related Art
[0004] In tropical or subtropical countries, people may install a solar-collector system in the roof of the house to absorb the radiating energy of the sun for heating water for industrial or home use. A conventional solar-collector system is made of special materials system and has a complicated structure, resulting in a high cost. Because the high cost, conventional solar-collector systems are not popularly accepted.
[0005] Further, many private houses, public buildings or factory buildings use corrugated metal (galvanized) sheet members to construct the roof. Because metal sheet members provide a high heat absorbing effect, using metal sheet members to make the roof of a building cannot isolate the inside space of the building from the radiating heat of the sun. People working in this building during a hot day are very uncomfortable. It is practical to utilize the corrugated metal roof sheets of a building to absorb the radiating energy of the sun for heating water, saving much solar collector installation cost and preventing radiation of thermal energy into the inside space of the building.
SUMMARY OF THE INVENTION
[0006] The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a hot water supply and fire hydrant system, which fully utilizes the roof space of a building to support a solar collector unit for heating cold water to a hot status for service.
[0007] It is another object of the present invention to provide a hot water supply and fire hydrant system, which has a simple structure and a low manufacturing cost.
[0008] It is still another object of the present invention to provide a hot water supply and fire hydrant system, which can be used as a fire hydrant as well as a hot water supplier.
[0009] To achieve these objects of the present invention, the hot water supply and fire hydrant system comprises a plurality of heat-absorber plates arranged on the roof of a building in a sloping position, a plurality of collector tubes formed of metal tubes having a high heat transfer efficient and respectively mounted on the heat-absorber plates, each collector tube having a top end and a bottom end disposed at different elevations, and a plurality of pipe connectors respectively connected to the top and bottom ends of the collector tubes for guiding water in and out of the collector tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic perspective view of a hot water supply and fire hydrant system according to the present invention.
[0011] FIG. 2 is a side plain view of the hot water supply and fire hydrant system according to the present invention.
[0012] FIG. 3 is a sectional view taken in an enlarged scale along line 3 - 3 of FIG. 1 .
[0013] FIG. 4 is similar to FIG. 3 but showing foam material stuffed in the solar collector unit.
[0014] FIG. 5 is a schematic drawing showing an alternate form of the present invention.
[0015] FIG. 6 is a schematic drawing showing another alternate form of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIGS. 1-3 , a hot water supply and fire hydrant system in accordance with the present invention is shown comprising a solar collector unit 10 fixedly mounted on a light steel framework 20 on the roof of a building. The solar collector unit 10 fits the double-bevel configuration of the light steel framework 20 . A water reservoir pipe 50 is mounted in the peak of the light steel framework 20 . Two accumulation pipes 40 are mounted in the peak of the light steel framework 20 at two sides of the water reservoir pipe 50 . Two water delivery pipes 30 arranged in parallel at the two lowest opposite sides of the double-bevel configuration of the light steel framework 20 .
[0017] The solar collector unit 10 is comprised of a plurality of flat heat-absorber plates 11 and a plurality of collector tubes 12 . As shown in FIG. 3 , the heat-absorber plates 11 are laid to overlap one another and fixedly fastened to the light steel framework 20 with screws 13 . The heat-absorber plates 11 are metal plates, for example, painted iron sheet members. The collector tubes 12 are metal tubes, having a high heat transfer coefficient. Preferably, the collector tubes 12 are copper tubes or aluminum tubes. Connectors 15 are used to connect the top and bottom ends of the collector tubes 12 to the accumulation pipes 40 and the water delivery pipes 30 respectively.
[0018] The water delivery pipes 30 each have one end respectively connected to a water intake pipe 31 , which has a one-way control valve 32 installed therein. Guide tubes 41 are respectively connected between the accumulation pipes 40 and the water reservoir pipe 50 . The water reservoir pipe 50 has one end connected to a water tank 60 through a water outlet pipe 51 . The water tank 60 is provided with a relief valve 61 . A first float bowl switch 62 and a second float bowl switch 63 are provided inside the water tank 60 at different elevations. The water tank 60 has a main supply pipe 64 and a connecting pipe 66 connected to the bottom side thereof. The main supply pipe 64 is connected to water taps (not shown) at different locations inside the house. The connecting pipe 66 is connected to the water intake pipe 31 behind the one-way control valve 32 . An electric heater 65 is connected to the main supply pipe 66 .
[0019] When in use, cold water is delivered from the water intake pipe 31 to the water delivery pipes 30 and then the collector tubes 12 of the solar-collector unit 10 . The heat-absorber plates 11 of the solar-collector unit 10 absorb the radiating energy of the sun to heat water in the collector tubes 12 , allowing heated water to flow from the collector tubes 12 to the accumulation pipes 40 through connectors 15 . When the temperature of water in the accumulation pipes 40 reached a predetermined level, a respective temperature-controlled valve 42 is opened for letting hot water to flow out of the accumulation pipes 40 into the water reservoir pipe 50 , and then to flow from the water reservoir pipe 50 through the water outlet pipe 51 to the water tank 60 . At this time, the user can obtain hot water from each terminal water tap that is connected to the main supply pipe 64 . If the temperature of the supplied water is low due to bad weather, the user can operate the electric heater 65 to heat water to the desired temperature level.
[0020] Further, when the water level in the water tank 60 surpassed the elevation of the first float bowl valve 62 , the first float bowl valve 62 is driven to switch off the one-way control valve 32 , stopping cold water from passing into water intake pipe 31 . At this time, water passes out of the water tank 60 through the connecting pipe 66 into the water intake pipe 31 for circulation through the solar collector unit 10 . When the water level in the water tank 60 dropped below the elevation of the second float bowl valve 63 , the second float bowl valve 63 is driven to switch on the on-way control valve 32 for enabling cold water to enter the water intake pipe 31 for circulation through the solar collector unit 10 to keep the water in the water tank at a certain level.
[0021] Further, a cover plate 52 may be covered over the accumulation pipes 40 and the water reservoir pipe 50 . Further, foam material 80 may be used to surround the connector tubes 12 , keeping the connector tubes 12 warm.
[0022] Further, water sprayers 70 may be mounted in the house and connected to the connector tubes 12 at different locations and electrically coupled to the temperature sensors or smoke sensors of the fire system of the house so that the hot water supply and fire hydrant system can be used as a fire hydrant as well as a hot water supplier.
[0023] FIG. 5 shows an alternate form of the present invention. According to this embodiment, the solar collector unit 10 uses roof tile-shaped heat-absorber plates 72 to substitute for the aforesaid flat heat-absorber plates 11 .
[0024] FIG. 6 shows another alternate form of the present invention. According to this embodiment, the heat-absorber plates 11 are covered over the rood of the house as well as the vertical peripheral walls 74 and 76 of the house.
[0025] As described above, the invention provides a hot water supply and fire hydrant system, which has the following advantages:
[0026] 1. High economic effect: The invention uses the roof structure of the house to support the hot water supply and fire hydrant system, saving much installation cost and obtaining a great solar energy collecting area. Comparing to conventional solar-collector systems, the hot water supply and fire hydrant system of the present invention is less expensive and can collect the radiating energy of the sun more efficiently. The invention is practical for use in the roof of any of a variety of buildings, providing a high economic effect.
[0027] 2. High effect of hot water supply: The invention uses the radiating energy of the sun to heat water, keeping reserved water above a certain temperature level and providing hot water to satisfy daily requirement.
[0028] 3. High effect of heat isolation: Because the solar collector unit absorbs the radiating energy of the sun and converts the radiating energy into thermal energy in water in the collector tubes and because obtained hot water is stored in the water tank inside the house, the temperature inside the house is maintained in a comfortable level.
[0029] 4. Fire hydrant Function: The invention has water sprayers directly connected to the collector tubes and electrically coupled to the fire sensors or smoke sensors of the fire hydrant system of the house, the user needs not to arrange additional water pipes in the house for the fire hydrant system.
[0030] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A hot water supply and fire hydrant system includes a plurality of heat-absorber plates ( 11) arranged on the whole area of the roof of a building in a sloping position for absorbing the radiating energy of the sun, a plurality of collector tubes ( 12) formed of metal tubes having a high heat transfer efficient and respectively mounted on the heat-absorber plates ( 11) for transferring heat energy from the heat-absorber plates to water flowing through the collector tubes, and a plurality of pipe connectors ( 15) respectively connected to the top and bottom ends of the collector tubes ( 12) for guiding water in and out of the collector tubes. |
CLAIM FOR PRIORITY
This non-provisional patent application is based on U.S. Provisional Patent Application Ser. No. 61/182,004, filed May 28, 2009 entitled, “Method of Producing Non-Pyrophoric Metallic Iron”. The priority of U.S. Provisional Patent Application Ser. No. 61/182,004 is hereby claimed and its disclosure incorporated herein in its entirety.
TECHNICAL FIELD
The present invention relates very generally to methods for converting iron oxide containing materials into commercially viable metal, and more particularly relates to a method for cold bonding iron oxide agglomerates with internal carbon and subsequently reducing the iron oxides to produce non-pyrophoric metallic iron.
BACKGROUND OF THE INVENTION
Many processes, such as pig iron and steel production, generate byproducts that are rich in iron oxide, but are in the form of fine particles or sludge. Many approaches have been proposed for converting the iron oxide byproduct into commercially viable metallic iron which can be subsequently melted and refined into a metal product. Typically, the iron oxide containing material is combined with a binding agent, and the components are pelletized or otherwise agglomerated and subjected to high temperatures in the presence of a reducing agent. In the final step the iron oxide agglomerate is reduced to metallic iron. Agglomeration of the particles is necessary prior to the reduction step because the reduction gas velocities would blow finely divided material out of the reaction device.
U.S. Pat. No. 4,063,930 to Kusner et al. discloses a process in which particulate iron oxide dust is ground with lime and compacted at temperatures of about 1800° F. The compacted pellets are then subjected to heating in a reducing environment to convert the iron oxide to a ferrous state.
U.S. Pat. No. 3,895,088 to Goksel describes a method for producing iron oxide agglomerations for recovery of iron-rich byproducts of steel factories. The Goskel method entails blending together steel dust, calcium/magnesium oxide, a siliceous material, and optionally a carbonaceous material. The mixture is then moistened with water and pelletized. The pellets are then subjected to hydro-thermal conditions in a steam autoclave to provide integral, high strength agglomerates. A similar process is disclosed in U.S. Pat. No. 4,528,029 to Goksel which is directed to the formation of iron-oxide agglomerates with pyrolyzed carbonaceous materials.
U.S. Pat. No. 5,554,207 to Bogdan et al. teaches a method for recycling waste particulate iron oxide, where the iron oxide particles are agglomerated using water-insoluble thermoplastic resins as binding agents.
U.S. Pat. Nos. 5,865,875 and 6,270,551 both to Rinker et al. describe a process where an iron oxide material and carbonaceous material are agglomerated under high temperatures, without the presence of a binding agent to form “green compacts.” The green compacts are then added to a rotary hearth furnace to reduce the iron oxide.
U.S. Pat. No. 6,579,505 and U.S. Pat. No. 6,811,759, both to Tsuchiya et al., relate to a method of producing iron oxide pellets with improved strength by combining the iron oxide component with a carbonaceous material, an inorganic coagulant such as bentonite, and an organic binder such as starch. The materials are combined with water and pelletized into green compacts and subsequently dried prior to the reduction step.
A rotating hearth furnace is used to reduce iron oxide in numerous processes described in patents assigned to Kobe Steel. For example, U.S. Pat. No. 6,254,665 to Matsushita et al. relates to a method of producing reduced iron agglomerates by heating a composition of iron oxide and a carbonaceous substance in a moving hearth furnace. U.S. Pat. No. 6,152,983 to Kamijo et al. describes the reduction of iron oxide containing pellets in a rotary hearth furnace, where the pellets further include zinc oxide and a carbonaceous material. According to Kamijo et al., the pellets are heated to reduce the zinc oxide to zinc, to evaporate the zinc off of the pellets, and to reduce the iron oxide to iron.
Additional references of interest include U.S. Pat. No. 6,258,149 to Sugiyama et al.; U.S. Pat. No. 6,592,647 to Hino et al.; U.S. Pat. No. 6,605,130 to Takenaka et al.; and U.S. Pat. No. 6,918,947 to Maki et al.
Despite the advancements in iron waste reclamation, many conventional processes do not produce iron agglomerates with sufficient strength. For example, many of the above processes use expensive rotary hearth furnaces because the agglomerates lack the strength to withstand the agitation associated with more economical alternatives such as rotary kilns. Indeed, the prior art teaches that the pellets need to be subjected to complicated autoclaving processes in order to achieve suitable strength. Furthermore, the agglomeration and reduction processes in much of the prior art relates to the production of pyrophoric metallic iron, which must be further processed (e.g., by briquetting) to render safe for shipping and handling.
It has been surprisingly discovered according to the present invention that iron containing product may be conveniently and economically produced in a non-pyrophoric form, without the need of additional briquetting or processing steps. According to one aspect of the invention, iron oxide is agglomerated with a carbon source, zinc oxide and calcium or magnesium oxides. In addition to being non-pyrophoric when processed properly, the inventive combination enables the formation of the agglomerates (prior to reduction) at low temperatures and low pressures, yet which still exhibit high strength. Other desirable features of the invention include (1) the production of non-pyrophoric metallic iron; (2) low equipment costs; (3) low operating costs; (4) fewer and simpler process steps; (5) safe handling; (6) shipping convenience and (7) high energy efficiency.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a method for producing non-pyrophoric iron product comprising the steps of (a) agglomerating slag components: iron oxide, zinc oxide, calcium or magnesium oxide and, a particulate carbon source to form a bonded agglomerate by curing and drying at relatively low temperature; (b) heating the bonded agglomerate to temperatures of at least 900° C.; (c) reducing the iron oxide to metallic iron, to render the product substantially non-pyrophoric.
More particularly, the invention provides a method of producing a substantially non-pyrophoric metallic iron-containing product from virgin and waste iron oxide sources, said method comprising the steps of:
(a) agglomerating slag components:
(i) iron oxide, (ii) zinc oxide, (iii) calcium and/or magnesium oxide, and, (iv) a finely divided low volatile carbon source, Adjusting or blending the slag components to form a slag with a melting point exceeding a kiln treatment temperature by at least 100° C. to avoid a kiln ring formation, and, forming a bonded agglomerate thereof by curing and drying the agglomerates to form a calcium and/or magnesium-zincate bond; (b) heating the bonded agglomerate of step (a) to temperatures above 900° C. for a time and rate sufficient to reduce and evaporate the zinc oxide; (c) further increasing the temperature to reduce the iron oxide to metallic iron, wherein about 50 to 100 percent of the iron in the bonded agglomerate is metallized such that a metallic iron containing consolidated product is formed; and (d) controlling the heating time, heating rate, and temperatures of step (b) such that the consolidated product of step (c) is formed with low specific surface to render the product substantially non-pyrophoric.
Still further features and advantages of the invention are apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in detail below with reference to the following drawings:
FIG. 1 is a process flow chart which diagrams the steps of producing reduced metallic iron from an iron oxide source;
FIG. 2 is a graph illustrating the temperature of a rotating kiln versus time in the batch reduction process of Test A;
FIG. 3 is a graph illustrating the temperature of a rotating kiln versus time in the batch reduction process of Test B; and
FIG. 4 is a graph illustrating the temperature of a rotating kiln versus time in the batch reduction process of Test C.
DETAILED DESCRIPTION OF THE INVENTION
The invention is described in detail below with reference to numerous embodiments for purposes of exemplification and illustration only. Modifications to particular embodiments within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to those of skill in the art.
Unless more specifically defined below, terminology as used herein is given its ordinary meaning.
“Non-pyrophoric,” as used herein, refers to the combustibility of an iron-containing product in air. An iron-containing product is considered substantially non-pyrophoric if it will not spontaneously ignite in air at 130° F.
The process of the invention enables the production of non-pyrophoric metallic iron from iron oxide sources such as waste iron streams, iron ore, or the like. Very generally, iron oxide is agglomerated with zinc oxide, calcium or magnesium oxide, and a carbon source, and is subsequently heated to reduce the iron oxide to metallic iron. The agglomerate may also include a silica source. During heating, the specific surface of the iron particles is greatly reduced such that the metallic iron does not react with air at ambient temperatures and becomes a non-pyrophoric product for shipping and handling purposes.
The source of iron oxide used in the invention is not particularly limited and may be provided from steel plant or iron production waste dust such as dust collected from basic oxygen furnaces, blast furnaces, open hearth, electric furnace processes, mill scale fines, grit chamber dust, and the like, and in particular United Stated Environmental Protection Agency listed hazardous waste K061 EAF dust. Additionally, the iron oxide may be provided from virgin iron ore and concentrates.
The agglomerates produced in the invention also include calcium and/or magnesium oxide. The calcium oxide source can be burnt lime or hydrated lime. Burnt lime may also include some magnesium oxide. Various waste materials contain small amounts of calcium or magnesium oxides and zinc oxide which participate in the bonding process. An example of this is EAF dust which can contain sufficient active calcium oxide that minimizes the need for burned lime addition.
The iron oxide is also agglomerated with a zinc oxide. Conveniently, the zinc oxide source may be provided from electric arc furnace (EAF) dust, in particular K061 EAF dust. Indeed, this dust is preferred as it is believed that K061 EAF dust reacts more strongly with burned lime to form calcium zincate (Ca Zn O 3 ) than commercially available zinc oxide. The increased reactivity may reduce the curing time needed to produce the bonding strength required for the subsequent reduction step.
The above components shall be blended with a finely divided particulate carbon source prior to agglomeration. The inclusion of finely divided internal carbon makes the agglomerates self reducing. Additionally, the finely divided internal carbon in the agglomerate increases the reduction kinetics, and accordingly speeds up the reaction. Typically, the finely divided carbon source has particles small enough such that 90 percent passes through a 200 mesh sieve. The carbon source is not particularly limited and may come from low volatile coal char (which is produced in the reduction step), blast furnace dust, or the like. The use of coal in this inventive process results in a reducing agent, as well as an energy or fuel source. Iron oxide is accordingly mixed with the zinc oxide, calcium or magnesium oxides, and low volatile, finely divided carbon.
Generally, water is also blended with the above-mentioned components in amounts of about 5 to 30 percent, preferably from 5 to 20 or 10 to 20 weight percent. The components are then agglomerated by standard methods such as pellet disc, drum, or extrusion. Screening devices may also be used to produce agglomerates of the desired size. The agglomerates may then be cured by drying at ambient pressure in an atmosphere having a high water vapor content, or by contacting the agglomerates with low pressure steam. Preferably, the agglomerates is cured and dried on a traveling grate that would use a combination of hot air and water vapor to cure, dry and preheat the pellets prior to introduction into a kiln. The inventive process may also utilize the waste energy from the kiln to dry and preheat the agglomerated product. The heating and moisture removal during the curing/drying step may be controlled so that the agglomerates are not destroyed, e.g., by the popcorn effect. Typically, the heating in this step is controlled so the agglomerates are heated at a rate of less than 5° C./min.
Not wishing to be bound by theory, the curing process is thought to be as follows: (1) the calcium oxide reacts with water in the mix to form calcium hydroxide (Ca(OH) 2 ); (2) the zinc oxide reacts in the same way to form acidic zinc oxide; (3) under very mild hydrothermal conditions, the calcium hydroxide and acidic zinc oxide (H 2 Zn O 3 ) react together to form calcium zincate (Ca Zn O 3 .XH 2 O) which is a hydrated gelatinous material that assists in the agglomeration; (4) on further heating, the calcium zincate dehydrates, cementing the agglomerate together, with sufficient strength for subsequent process steps.
Advantageously, the agglomerates of the invention may be produced without the need for a complicated autoclaving step which uses steam pressures on the order of 300 psig. Indeed, the inventive agglomerates may be readily cured at temperatures of less than 300° C., less than 200° C., and even at ambient room temperature. Additionally, the agglomerates may be cured at pressures of less than 10 psi, and preferably at substantially atmospheric pressure. Conveniently, atmospheric steam may be used to cure the agglomerates.
The bonded agglomerates produced according to the invention exhibit strength values needed for chemical reduction in equipment, such as rotary kilns. If the bond in the agglomerate is too weak, the motion in the kiln will destroy the agglomerate and make the reduction process unfeasible. Typically, the agglomerates exhibit dry crush strength values of at least 1 pound, preferably at least 2 pounds (measured on an approximately ⅜″ by ½″ agglomerate).
The iron oxide agglomerates with internal carbon are then heated to reduce the iron oxide to metallic iron. The use of a reducing atmosphere will generally speed up the metallization process, and the reducing atmosphere may be provided by adding coal to the kiln. Desirably, rotary kilns are used to heat the agglomerates. Rotary batch kilns are well known and are typically used to simulate conditions in a continuous kiln. The batch kiln may be refractory lined and natural gas fired. Preferred is a ported rotary kiln which provides the versatility and temperature control that is desired for post reduction consolidation. Ported rotary kilns have ports flush with the interlining of the kiln. The ports are spaced down the length of the cylinder and may be present in any number depending on process demands; eight ports is typical. The ports may be activated to bring fuel and air to the kiln, either over the kiln bed or under the kiln bed.
The temperature, heating rate, and heating time in the kiln may be adjusted depending on the desired characteristics of the consolidated metallic iron product. In particular, the heating variables should be controlled to provide the consolidated product with a non-pyrophoric characteristic. Without intending to be bound by theory, it is believed that the consolidated product may be rendered non-pyrophoric by forming larger iron particles in the metallized product. This greatly reduces the specific surface of the iron, making re-oxidation more difficult. In addition, the prefluxed slag components in the agglomerate tend to seal and prevent air from entering.
Other properties of the metallic product can be adjusted as well. For example, higher levels of metallization generally require the agglomerate to be heated for longer periods of time. Generally, the agglomerate is heated for about one to 4 hours, more suitable from about 1 to 2.5 hours. Typically, the kiln is heated to temperatures of from about 900° C. to 1400° C., and more specifically from about 1000° C. to 1300° C. The kiln is also preferably heated quickly, and rates of about 5° C./min to about 10° C./min may be used.
The kiln is generally heated to temperatures of at least 900° C. (referring to the bed temperature of the kiln), so that zinc, if present, will begin to melt and boil off. The off gas from the kiln contains zinc metal and carbon monoxide that needs to be combusted prior to collection of the zinc fume. The zinc gas can enter a combustion chamber where air would be introduced to burn the zinc gas and carbon monoxide. Alternately, combustion can be conducted near the feed end of the kiln. The combusted gas then enters an energy recovery system. The zinc oxide is removed to form a clean gas stream. The cleaned gas may be used to cure, dry and preheat the pellets on the traveling grate. The collected zinc oxide can be sold to zinc reclaimers or recycled back to the pellet process.
The metallized product discharging from the kiln may enter a water-cooled rotary cooler to reduce the temperature below the re-oxidation point. The cooled product may then be stored in conventional storage bins prior to shipment to the final customer. The metallized product may be used as an iron feed for electric arc furnaces, blast furnaces, basic oxygen furnaces, and cupolas.
After cooling, the coal char from the reducing kiln may be separated from the consolidated metallic product with a dry magnetic separator or any other suitable means. The char may be ground and recycled to the pellet mix. Accordingly, the waste from the process is minimized.
Following is a specific process description outlining one embodiment of the present invention, which is discussed in reference to the process flow diagram of FIG. 1 .
1. A source of iron oxide 10 is intensively mixed with additives 20 in mixer 30 , with sufficient water for pellet making from stream 40 . The additives include a carbon source for reduction, a zinc oxide source, and a calcium oxide source for bonding. The amount of carbon depends on the degree of metallization that is desired. The amount of zinc oxide and burned lime depends on the strength requirements for subsequent curing, drying and reduction but are generally in the range of two to four percent for each of the two bonding components (dry basis). The water is added in amounts of from about 5-20 percent. 2. This mixture is then agglomerated in either a drum or disc pelletizer 50 in closed circuit with a sizing device to produce the pellet size desired. 3. Should the pellet mixture contain a large percentage of EAF dust it may not be necessary to add calcium oxide. Generally EAF dust contains considerable calcium oxide that can provide sufficient bonding materials for the bonding reaction. 4. The agglomerates are then cured and dried in a manner that is designed to bond the materials in the agglomerates to the necessary strength for subsequent handling and reduction. Steam from stream 60 may be contacted with the agglomerates on a traveling grate 70 , where the steam is at atmospheric pressure. 5. The cured and dried pellet is then charged into a rotary kiln 80 and the pellet temperature is increased. Coal can also be charged with the agglomerates to act as fuel from coal feed 82 , to provide a reducing atmosphere and also to produce coal char as an internal carbon source for pellet making. Air flow is also provided to the rotary kiln at stream 84 . As the temperature increases, the internal carbon in the agglomerate reacts with the metal oxides to produce carbon monoxide and carbon dioxide. At about 930° C. the reduced zinc begins to evolve as a gas that can easily be re-oxidized to zinc oxide and collected as a fume in the energy recovery system 90 , to produce zinc product 92 . In the case of iron bearing pellets, the rate of metallization is extremely fast once the pellet temperature reaches about 1100° C. A bed temperature of 1200° C. is suggested, however, to produce a consolidated metallized pellet of good internal strength. This consolidation also produces a non-pyrophoric product that allows for safe and simple down-stream handling. 6. The metallized pellet is then discharged from the heating device and cooled in an indirect rotary cooler 100 under a reducing atmosphere. 7. The metallized pellet is then separated from the coal char in magnetic separator 110 , to produce the iron-containing product 112 . The final product is hard, strong and nearly dust-free. The char composition 114 that is removed in the magnetic separator may be recycled back to feed additives as a particulate carbons source.
Alternately, the cured, unfired pellets can be charged directly to a hot empty, basic oxygen furnace (BOF) or uncharged electric arc furnace (EAF) where the sensible heat of the refractories from the hot turn around can be used to heat the pellets and start reduction of the iron. The subsequent charge of hot metal to the BOF or start of melting the initial scrap charge in the EAF can be used to finish the metalization of the pellets and subsequent recovery of the metal.
Pellets for the BOF will be specially formulated for this application. Best results will be obtained with higher than normal carbon contents due to the presence of an oxidizing atmosphere in the bottom of the vessel. This is also true of the pellets made for charging to an EAF. These are engineered materials and the formulation can be adjusted for the most economic result.
The iron source for these materials can be obtained from waste oxides generated during the steel making operation. The zinc oxide for bonding can be recycled and therefore does not represent a cost to the operation. In most situations, the burned lime becomes part of the slag cover of the BOF and EAF for energy conservation.
EXAMPLES
Example 1
A pellet mix was formulated using 45% iron oxide sludge, 32% blast furnace dust as a carbon source, 19% EAF K061 dust (which contains zinc oxide) and 4% burned lime. Water was added to the mix and it was pelletized. The pellets were dried overnight and then heated in a reducing atmosphere kiln. The metallic iron content peaked at 75 minutes of retention time with just over 72% of the iron metallized. The survival rate of the pellets when charged into a hot kiln and raised in temperature to 1100° C. at 12° C. per minute was excellent. The pellets also were observed to have very little dusting. The process produced a consolidated metallized pellet that was resistant to reoxidation.
Example 2
A pellet mix was formulated using 63.36% of iron oxide sludge, 24.96% blast furnace dust, 7.68% EAF K061 dust and 4.00% burned lime. This simulates a process where the coal char and zinc fumes are recycled. The process also produces a higher-grade product of enhanced value. The blended material was pelletized in a small rotary pan in batches. Water was sprayed into the pan to achieve the desired ball quality. The balls made in the pan were screened at 3/8 inch and 1/2 inch to provide the batch kiln feed. The agglomerates were prepared at around 16% moisture. The agglomerates were dried over night and tested for strength, prior to being fed into the batch rotary kiln. The compressive strength is tested according to ASTM E382-97.
TABLE 1
Agglomerate Strength
Compressive Strength, lbs
Number 18″
Run
Wet
Dry
Drops Wet
1
1.6
5
1
2
2.5
5.5
2
3
2.7
5.8
2
4
2.2
6
0.5
5
3
6.8
6
6
1.8
5.8
6
7
2.3
5
7
8
3.6
5
8
9
2.2
5.5
6
10
1.6
4.3
6
11
2.7
2.5
7
12
1.5
6.8
8
13
2.6
4.4
3
14
2.2
5.5
3
15
2.6
4.8
2
16
2.8
4.2
8
17
3.2
5.2
2
18
2
2.1
3
19
1.8
3.4
5
20
2.2
2.5
8
AVERAGE
2.4
4.8
5.4
The agglomerates were then heated with coal additions in a 24-inch diameter by 40-inch long batch kiln with a charge weight of 70 pounds in test A, 130 pounds in test B, and 108 pounds in test C. The three sets of data also differ somewhat in their temperature profiles, and heating times.
In test set A, below, 70 lbs of agglomerates were charged to the kiln with 10 lbs of coal to create a reducing environment. Coal was added periodically as needed to maintain the char in the bed. The kiln holding temp was set to 1150° C. and the kiln speed was 1.75 RPM. The temperature profile of the kiln bed and the off-gas temperature is shown below in Table 2, and illustrated graphically in FIG. 2 .
The pellets were fed to the preheated kiln. No evidence of pellet degradation was observed.
TABLE 2
Test A
Time
Bed Temp.
Off-Gas Temp.
(min)
(° C.)
(° C.)
0
157
264
5
224
302
10
297
402
15
378
425
20
466
458
25
524
481
30
553
497
35
583
512
40
591
663
45
677
779
50
712
893
55
786
952
60
837
992
65
875
1023
70
929
1044
75
946
1067
80
967
1087
85
980
1158
95
1032
1190
100
1111
1232
105
1168
1220
110
1177
1222
115
1204
1236
120
1206
1223
125
1211
1227
130
1142
1234
135
1217
1259
Samples were removed every 10 minutes after the kiln reached 800° C. When the bed temperature reached about 930° C., a white fume indicating zinc evolution was observed. Shortly afterwards, the temperature slope dramatically decreased as most of the energy was required for the iron reduction.
In the test B data, 130 lbs of pellets were charged to the kiln with 20 lbs of coal to create a reducing environment. The kiln holding temp was set to 1200° C. and the kiln speed was 1.75 RPM. The temperature was increased somewhat faster than in the first batch; otherwise conditions were similar. The temperature profile of the kiln bed and the off-gas temperature is shown below in Table 3, and illustrated graphically in FIG. 3 .
TABLE 3
Test B
Time
Bed Temp.
Off-Gas Temp.
(min)
(° C.)
(° C.)
0
109
377
5
153
525
10
234
577
15
376
642
20
487
685
25
574
738
30
643
812
35
729
872
40
759
923
45
804
988
50
846
1079
55
896
1123
60
937
1110
65
952
1154
70
961
1140
75
963
1140
80
970
1154
85
980
1160
90
1002
1184
95
1020
1201
100
1069
1241
105
1142
1277
110
1191
1249
115
1191
1201
120
1175
1227
125
1209
1247
130
1220
1242
135
1186
1232
140
1204
1243
Samples were removed every 10 minutes after the kiln reached 800° C. The test continued until the samples had a metallic appearance. Analysis of the last four samples showed that the metallization decreased somewhat at the end. It appears that the reaction was reversed.
For test C, 108.5 lbs of pellets were charged to the kiln with 20 lbs of coal to create a reducing environment. Conditions were similar to the previous batch. The temperature profile of the kiln bed and the off-gas temperature is shown below in Table 4, and illustrated graphically in FIG. 4 .
TABLE 4
Test C
Time
Bed Temp.
Off-Gas Temp.
(min)
(° C.)
(° C.)
0
101
311
5
130
485
10
192
536
15
333
608
20
453
670
25
551
723
30
654
816
35
726
870
40
895
919
45
817
987
50
865
1014
55
929
1054
60
946
1102
65
971
1138
70
974
1168
75
983
1159
80
994
1163
85
998
1175
90
1030
1200
95
1047
1206
100
1113
1244
105
1072
1183
110
1134
1218
115
1140
1240
120
1194
1241
125
1212
1251
130
1224
1256
132
1227
1264
135
1237
1271
140
1207
1263
All three tests (A-C) performed extremely well and produced a consolidated product that was hard and strong. Here again, an absence of fines was observed. In this regard, it is believed that the low fines are due to the superior bond produced by the calcium zincates that form from the reaction of the EAF dust and burned lime. Additionally, when molten zinc is present on the surface of the reducing pellets, it may pick up the fines in the charge and adhere them to the surface of the pellets. Typically, the metallized agglomerates (e.g. pellets) of the invention are generally characterized by a substantial absence of fines, i.e., less than 0.5 wt. percent.
The product of the batch kiln from Test B was measured for the tumble test according to ASTM E382-97. Briefly, the test entails screening approximately 25 lbs of pellets on ⅝, ½, ⅜, and 1/4 inch, Gilson screens. The weight of the test charge pellets that are retained on each screen are recorded. 25 pounds of plus ¼″ pellets are added to an abrasion drum and rotated for 200 revolutions. The pellets are then screened on a series of Gilson screens, and the weights retained on each screen and in the last pan are recorded. The results are shown in Table 5, below.
TABLE 5
Tumbler test
Test charge
Tumbled Product
Weight
Weight
Screen Size
(lbs)
(lbs)
⅝″
—
—
½″
0.01
—
⅜″
0.90
0.9
¼″
24.09
23.3
4M
—
0.52
10M
—
0.03
30M
—
Trace
Pan
—
0.25
As can be seen from the data in Table 5, the material originally charged was 100%+¼″. After tumbling, the material was 96.8%+¼″.
A summary of the metallized product in Tests A-C is outlined in Table 6, below.
TABLE 6
Summary
Re-
Product
Prod-
Sam-
cov-
Product
Test
Max
Bulk
Charge
uct
ples
ery
Strength
time
Temp
Density
Ex.
(lbs)
(lbs)
(lbs)
(%)
(psi)
(min)
(° C.)
(lb/ft 3 )
Test A
70
41.72
3.01
63.9
105
135
1217
102.5
Test B
130
77.94
3.00
62.3
172
140
1220
114.3
Test C
108.5
55.65
2.10
53.2
73
140
1237
83.6
While the invention has been illustrated in connection with several examples, modifications to these examples within the spirit and scope of the invention will be readily apparent to those of skill in the art. In view of the foregoing discussion, relevant knowledge in the art and references discussed above in connection with the Background and Detailed Description, the disclosures of which are all incorporated herein by reference, further description is deemed unnecessary. | A method for producing a substantially metallic iron-containing product from iron oxide. The metallic iron produced according to the invention is non-pyrophoric and may be safely shipped and handled without additional process steps. The method of the invention is simple, economical, and produces high quality metallic product which may be used as a feed for Electric Arc Furnace (EAF), Blast Furnaces and Cupolas among other applications. |
CROSS REFERENCE TO RELATED APPLICATION
This application is a Continuation-In-Part of application Ser. No. 10/963,469, filed Oct. 12, 2004 now abandoned.
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
The present invention relates to compositions of matter for thermoplastic nanocomposites containing nanoscale carbon fibers and tubes.
One-dimensional, carbon-based, nano-structured materials are generally divided into three categories based on their diameter dimensions: (i) single-wall carbon nanotubes (SWNT, 0.7-3 nm); (ii) multi-wall carbon nanotubes (MWNT, 2-20 nm); (iii) carbon nanofibers (CNF, 40-100 nm). While the length of carbon nanofiber) ranges 30-100 μm, it is difficult to determine the lengths of SWNT and MWNT because of their strong proclivity to aggregate (to form “ropes”), but they are generally considered to be two-orders of magnitude shorter than CNF. In comparison to single-walled or multi-walled carbon nanotubes, vapor-grown carbon nanofibers are more attractive from the standpoint of practicality in terms of their relatively low cost and availability in larger quantities as the result of their more advanced stage in commercial production. These nanofibers are typically produced by a vapor-phase catalytic process in which a carbon-containing feedstock (e.g. CH 4 , C 2 H 4 etc.) is pyrolyzed in the presence of small metal catalyst (e.g. ferrocene, Fe(CO) 5 etc.) and have an outer diameter of 60-200 nm, a hollow core of 30-90 nm, and length on the order of 50-100 microns. It follows that having aspect ratios (length/diameter) of greater than 800 should make them useful as nano-level reinforcement for polymeric matrices. Furthermore, since their inherent electrical and thermal transport properties are also excellent, there are many possibilities imaginable for tailoring their polymer matrix composites into affordable, light-weight, multifunctional materials. Conceptually, there are three general techniques for dispersing chemically unmodified VGCNF in the polymer matrices: (1) melt blending (2) solution blending, and (3) reaction blending. For the reaction blending route, there are two scenarios: (a) in-situ polymerization of monomers (AB) or co-monomers (AA+BB) in the presence of dispersed VGCNF that occurs without forming any covalent bonding between the VGCNF and the matrix polymer, or (b) in-situ grafting of AB monomers that occurs with direct covalent bonds formed between the VGCNF and the matrix polymer. While melt-blending is perhaps the most cost effective approach to VGCNF-based nanocomposites, and has been applied to thermoplastic, thermosetting and elastomeric matrices, the resulting nano-composite materials are by and large less than optimal, especially in the cases where polymer-VGCNF incompatibility adversely impact the desired level of dispersion and the breakage of the carbon nanofibers by high shear forces reduce the reinforcing aspect ratios. The solution blending appears to have circumvented these problems, for example, the nanocomposite materials produced by this route have shown 2-3 orders of magnitude higher in electrical conductivity and much lower percolation threshold (<1 vol %) than similar materials prepared by the melt-blending route. To our knowledge, we are not aware of any report in the literature that describes successful preparation of VGCNF-based nanocomposite materials via reaction blending. However, similar non-grafting, reaction blending processes have been reported for unmodified SWNT and MWNT g In addition, there are reports on the grafting of a polymer either to or from a SWNT or MWNT that typically involved prior oxidation or functionalization of the CNT with a reactive group (e.g. surface-bound acid chloride or initiator for atom-transfer radical polymerization).
Using Friedel-Crafts acylation, Applicants were able to chemically attach meta-poly(etherketone) onto the surfaces of VGCNF, viz. forming direct bonds between the polymer grafts and VGCNF, via in-situ polymerization of m-phenoxybenzoic acid in the presence of VGCNF in poly(phosphoric acid).
Accordingly, it is an object of the present invention to provide new in-situ nanocomposites derived from carbon nanofibers and carbon multiwalled nanotubes.
It is another object of the present invention to provide a process for attaching a poly(ether-ketone) onto the surfaces of nanoscale carbon fibers and tubes.
Other objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a poly(ether-ketone) composite of the formula:
Ar-carbon nanofibers or multi-walled carbon nanotubes
wherein Ar represents ether-ketone repeating groups of the formula
wherein Q is —O— or —O—(CH 2 ) n —O—, wherein n has a value of 2-12; wherein R is —H, —CH 3 , or —C 2 H 5 , m has a value of 1 or 2; wherein R′ is —H or —CH 3 ; and wherein — denotes a direct C—C bond between Ar and carbon nanofibers or multi-walled carbon nanotubes.
Also provided is a process for preparing the above composite.
DETAILED DESCRIPTION OF THE INVENTION
The composite of this invention is prepared by reacting an aromatic acid of the formula
wherein R, R′, m and Q are as described above, with a nanoscale carbon fiber or tube in polyphosphoric acid (PPA), as described below.
Suitable aromatic acids useful in this reaction include 3-phenoxybenzoic acid, 4-phenoxybenzoic acid, 3-(2,6-dimethylphenoxy)benzoic acid, 3-phenoxy-2-methylbenzoic acid, and the like.
Attachment of the poly(ether-ketone) onto the surfaces of nanoscale carbon fibers and tubes is conducted in polyphosphoric acid (PPA). Preliminarily it is helpful to describe the chemistry of phosphoric acids and strong phosphoric acids or polyphosphoric acids as follows: As used herein the term “phosphoric acid(s)” means commercial phosphoric acid(s) containing 85-86% H 3 PO 4 . The strong phosphoric acids, or polyphosphoric acids referred to as PPA (polyphosphoric acid) are members of a continuous series of amorphous condensed phosphoric acid mixtures given by the formula
H n+2 P n O 3n+1
or
HO—PO 3 H n H
where the value of n depends on the molar ratio of water to phosphorus pentoxide present.
In its most general definition, polyphosphoric acid composition can range from distributions where the average value of n is less than unity, giving rise to a mobile liquid, to high values of n, where the polyphosphoric acid is a glass at normal temperatures. Because the species of polyphosphoric acid are in a mobile equilibrium, a given equilibrium composition can be prepared in many ways. For instance, the same distribution or polyphosphoric acid composition could be prepared by either starting with concentrated orthophosphoric acid (H 3 PO 4 , n=1) and driving off water or by starting with phosphorus pentoxide (P 2 O 5 ) and adding an appropriate amount of water.
All polyphosphoric acid compositions can be described as a ratio of P 2 O 5 and water by reducing the various species present (on paper) to P 2 O 5 and water. We will then use the convention that polyphosphoric acid composition will be expressed in terms of a P 2 O 5 content (as a percentage) defined as P 2 O 5 content
=(weight of P 2 O 5 )/(weight of P 2 O 5 +weight of water)×100.
Thus, the P 2 O 5 content of pure orthophosphoric acid could be derived by reducing one mole of H 3 PO 4 to 0.5 moles P 2 O 5 +1.5 moles H 2 O. Converting to weights gives the P 2 O 5 content as
(0.5*142)/((0.5*142)+(1.5*18.01))*100%=72.4%.
Similarly, the P 2 O 5 content of commercial polyphosphoric acid can be derived in the following way. Polyphosphoric acid is available commercially in two grades, 105% and 115%. These percentages refer to H 3 PO 4 content, which means that 100 g of the two grades contain 105 and 115 grams of H 3 PO 4 . The P 2 O 5 content of 115% polyphosphoric acid can then be calculated knowing the P 2 O 5 content of 100% H 3 PO 4 .
(115 g/100 g)*72.4%=83.3%
The polymerization is conducted in polyphosphoric acid (PPA) at a polymer concentration of about 5 weight percent at a temperature of about 130° C. The acid, nanoscale carbon fibers or tubes, and PPA (83% assay) are combined and stirred with dried nitrogen purging at about 130° C. for about 3 hours. Additional P 2 O 5 is then added in one portion; and heating is continued, with stirring for about 24-60 hours. The reaction product is then precipitated from the PPA reaction solution with water or other polymer nonsolvent. The amount of P 2 O 5 added is optimized at 25 wt % of the PPA used at the beginning of the reaction, leading to a total P 2 O 5 content of about 86.7%.
The following examples illustrate the invention:
Example 1
Into a 250 mL resin flask equipped with a high torque mechanical stirrer, and nitrogen inlet and outlet, 3-phenoxybenzoic acid (2.7 g, 12.6 mmol), and VGCNF (Applied Science Inc., Cedarville, Ohio; 0.3 g), and PPA (83% assay, 60 g) was placed and stirred with dried nitrogen purging at 130° C. for 3 h. P 2 O 5 (15.0 g) was then added in one portion. The initially dark mixture became lighter and viscous after 1 h at 130° C. and started to stick to the stirring rod. The temperature was maintained at 130° C. for 48 h. At the end of the reaction, water was added into the flask. The resulting purple polymer product was poured into a Warring blender and the polymer bundles were chopped, collected by suction filtration, washed with diluted ammonium hydroxide, then Soxhlet-extracted first with water for three days and then with methanol for another three days, and finally dried over phosphorous pentoxide under reduced pressure (0.05 mmHg) at 140° C. for 72 h to give the polymeric product in quantitative yield. Anal. Calcd. for C 14.76 H 8 O 2 ; C, 81.56%; H, 3.71%; O, 14.73%. Found: C, 81.40%; H, 3.61%; O, 13.16%.
Example 2
Various polymerizations were carried out with different ratios of the AB-monomer, 3-phenoxybenzoic acid (PBA) and VGCNF using the procedure given in Example 1. The results of these polymerizations are given in Table 1:
TABLE 1
Feed
Calculated a
Found b
Elemental Analysis
VGCNF
PBA
VGCNF
mPEK
VGCNF
[η] c
C
H
O
(wt %)
(wt %)
(wt %)
(wt %)
(wt %)
(dL/g)
(%)
(%)
(%)
30
70
31.9
68.1
31.7
—
Calcd d
86.08
2.81
11.11
Found
84.14
3.21
9.79
20
80
21.4
78.6
20.5
—
Calcd d
83.95
3.23
12.81
Found
83.64
3.19
11.88
10
90
10.8
89.2
11.4
—
Calcd d
81.78
3.67
14.54
Found
81.40
3.61
13.16
5
95
5.4
94.6
5.6
1.73
Calcd d
80.68
3.89
15.42
Found
80.21
4.19
14.48
2
98
2.2
97.8
2.0
1.00
Calcd d
80.02
4.03
15.95
Found
80.06
4.17
15.07
1
99
1.1
98.9
1.2
1.42
Calcd d
79.80
4.07
16.13
Found
79.91
4.25
15.11
a Calculation based on the assumption that VGCNF is 100% C and the molar mass of the repeat unit of mPEK (C 13 H 8 O 2 ) is 196.20.
b Residual weight percent at 650° C. from TGA thermograms in helium.
c Intrinsic viscosity measured in MSA at 30.0 ± 0.1° C.
d Empirical formulas derived from the molar ratios of VGCNF:mPEK, i.e. C: C 13 H 8 O 2 are as follows: (30/70) C 20.64 H 8 O 2 ; (20/80) C 17.46 H 8 O 2 ; (10/90) C 14.98 H 8 O 2 ; (5/95) C 13.94 H 8 O 2 ; (2/98) C 13.96 H 8 O 2 ; (1/99) C 13.18 H 8 O 2 .
Example 3
The glass transition temperatures (T g 's) of PEK's containing VGCNF were determined by DSC. The DSC scans were run on the powder samples after they had been heated to 200° C. in the DSC chamber and allowed to cool to ambient temperature under nitrogen purge. The T g was taken as the mid-point of the maximum baseline shift from the second run. PEK without VGCNF displayed a T g at 136.6° C. As the VGCNF content increased, polymer T g 's gradually increased to 138.2° C. with VGCNF 10 wt % and to 144.0° C. with VGCNF 20%. The TGA experiments on the powder sample of pure VGCNF indicated that the temperatures at which a 5% weight loss (T d5% ) occurred at 682.7° C. in air and 696.8° C. in helium. All other PEK's with and without VGCNF displayed higher T d5% in the range of 408-448° C. in air and 365-409° C. in helium. Char percents at 650° C. in air are in excellent agreement with the amounts of VGCNF present during PEK polymerization. Thermal properties of PEK's and VGCNF are shown in Table 2:
TABLE 2
TGA
In Air
In Helium
Product
Tg
Char
Char
VGCNF
mPEK
DSC
TMA
T d5%
At 650° C.
T d5%
At 650° C.
(wt %)
(wt %)
(° C.)
(° C.)
(° C.)
(%)
(° C.)
(%)
100.0
0.0
ND
ND
682.7
98.2
696.8
96.7
31.9
68.1
157.6
164.2
448.2
31.7
409.0
68.6
21.5
78.5
151.8
153.9
408.6
20.5
388.6
63.1
10.8
89.2
143.7
145.4
430.5
11.4
406.8
55.3
5.4
94.6
143.7
141.2
492.4
5.6
479.9
61.9
2.2
97.8
141.0
138.5
485.7
2.0
478.0
53.7
1.1
98.9
142.5
141.5
477.5
1.2
463.1
54.6
0.0
100.0
136.6
137.1
414.2
0.8
365.6
48.3
Degree of Polymerization (DP) for the mPEK grafts. Based on the assumptions that the functionalization of VGCNF via Friedel-Crafts acylation reaction in PPA:P 2 O 5 (w/w 4:1) medium could result in arylcarbonylation of three carbon in every hundred carbon sites and the arylcarbonylation reaction is most likely to occur at the sp 2 C—H defect sites, the upper-limit values for the DP were determined and molecular weight of each VGCNF-bound mPEK, ranging from DP of 4 with the corresponding MW of 862 Da. to DP of 168 and MW of 32,935 Da. The computation algorithm (footnote) and results are shown in Table 3.
TABLE 3
wt %
Mol.
Sam-
(CNF/
Mol.
Mol.
Grafting
mPEK
mPEK
ple
mPEK) a
CNF b
mPEK b
Sites c
DP/chain d
MW/chain e
30/70
31.7/68.3
2.642
0.348
0.0793
4
862
20/80
20.5/79.5
1.708
0.405
0.0513
8
1,551
10/90
11.4/88.6
0.950
0.452
0.0285
16
3,109
5/95
5.6/94.4
0.467
0.481
0.0140
34
6,743
2/98
2.0/98.0
0.167
0.499
0.0050
100
19,601
1/99
1.1/98.8
0.100
0.504
0.0030
168
32,935
a TGA (air) data
b For a 100-g sample, mol (CNF) = wt (CNF)/12.00 and mol (mPEK) = wt (mPEK)/196.20 (FW C 13 H 8 O 2 ).
c Total number of grafting sites (mol.): mol. (CNF) × 0.03 based on the assumption that there are 3 arylcarbonylation sites for every 100 carbons of the VGCNF.
d Degree of polymerization (DP)/chain = mol (grafting sites)/mol (CNF)
e MW (mPEK) = DP × 196.20 (FW C 13 H 8 O 2 ).
Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the disclosures herein are exemplary only and that alternatives, adaptations and modifications may be made within the scope of the present invention. | A poly(ether-ketone) composite of the formula: wherein CNF is carbon nanofibers and MWNT is multi-walled carbon nanotubes; wherein Ar represents ether-ketone repeating groups of the formula wherein Q is --O-- or --O--(CH 2) n --O--, wherein n has a value of 2-12; wherein R is --H, --CH 3, or --C 2 H 5, m has a value of 1 or 2; wherein R' is --H or --CH 3 ; and wherein -- denoted the presence of a direct C--C bond between Ar and CNF or MWNT g Also provided is a process for preparing the composite. |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part application of U.S. patent application Ser. No. 115,484, filed Nov. 2, 1987.
BACKGROUND OF THE INVENTION
The present invention relates to a device for winding reels of material onto a core. More particularly, the present invention relates to an core holder assembly for tightly gripping and holding a resilient core on a mandrel for the winding of defined lengths of webs onto such core. The invention is particularly useful in the manufacture of labels in the printing industry, and is readily adaptable to the textile and other industries which wind sheets of material onto a core while the core is situated on a mandrel, then remove the filled core and replace it with an empty core.
In the manufacturing of labels, after printing, it is necessary to rewind reels of label-carrying webs bearing large quantities of labels onto smaller rolls of accurate and defined quantities of labels. In actual manufacture, it requires about twice as much time and accompanying manpower to rewind the labels as to accomplish the original manufacture or printing of the labels.
The present invention provides means for holding cores onto a mandrel or spindle when transferring large reels of labels onto small rolls or cores with excellent holding power, yet having ready removability and with a reduction in the manpower required for the current core installation and removal process.
Although applicable to many industries, the present invention will be described in relation to the manufacture of labels. A label auto-transfer turret rewind apparatus is basically a rotatable base plate having a plurality of protruding mandrels or spindles, each spindle adapted to receive and rotate a take-up spool, which spindles are journaled for rotation in the base. Each spindle is powered by a drive mechanism, which may be individual or common to all spindles. A counter controls a cut-off mechanism for accurately placing the correct number of labels on each spool or core, upon which the spindle rotates to a specified indexed position, and the spool is removed.
BRIEF DESCRIPTION OF THE PRIOR ART
Although a search was made, no segmented core holder similar to the invented core holder was located.
The following patents are believed to be exemplary of the prior art with regard to the subject invention:
Kupper U.S. Pat. No. 4,651,865, entitled Device for Unloading a Coil, shows mandrels and coils for textile threads, the coils being rotated by end contact to drive means.
Rohde U.S. Pat. No. 4,390,138, entitled Reeling Apparatus for a Web, shows presently used core tubes on a modern winding shaft, which has no provision for tightly holding the core tube to the shaft.
Most patents covering winders and rewwinders fail to show details of core holders. Such patents are exemplified by:
Marshal U.S. Pat. No. 4,518,126, entitled Take-Up Mechanism, which shows a winding takeup mechanism for controlling webs on tubes;
Cooper U.S. Pat. No. 4,416,426, entitled Web Treatment Apparatus, which shows four mandrels which index to various positions;
Clements U.S. Pat. No. 4,526,638, entitled Apparatus and Method for Joining Webs, which shows an expandable drivable support for reel core ends, which are only laterally expandable for reels of different widths;
Taitel U.S. Pat. No. 3,930,620, entitled Turret Rewinder, which teaches a core C on an apparently round spindle, and fails to suggest any means for causing both the spindle and the core to rotate at the same angular velocity;
Nichols U.S. Pat. No. 1,484,842, entitled Slitting and Rewinding Machine; and
Mulfarth U.S. Pat. No. 4,630,783, entitled Machine for Winding a Web of Paper on a Roll.
SUMMARY OF THE INVENTION
The invention is a core holder for a winding apparatus, including a core-receiving mandrel of specified geometric cross-section, journaled for rotation, a segmented friction core holder, expandable outwardly at selected points, by which the core is gripped when the mandrel is turning, and which readily releases its grip on the mandrel upon a simple manual maneuver by the operator. The mandrel is preferably connectable to drive means, but must also be capable of "idling", that is, being undriven at a specified instant.
OBJECTS OF THE INVENTION
It is the primary object of this invention to provide means of holding a core tightly on a mandrel for winding of a web onto the core.
It is also an object of this invention to provide a means of easy removal of a core from a mandrel.
It is also an object of this invention to provide apparatus for winding webs of material which is equally adaptable to the paper, printing, and textile industries.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects will become more readily apparent from the following detailed description and the appended drawings, in which:
FIG. 1 is a front view of a label auto-transfer turret rewind assembly on which the invented core holder is advantageously used.
FIG. 2 is a rear view of the label turret rewind assembly of FIG. 1.
FIG. 3 is an isometric view of one embodiment of the invented friction core holder in the deactivated position.
FIG. 4 is an end view of the friction core holder of FIG. 3 in the activated position, showing two alternative embodiments of core holder segment connectors.
FIG. 5 is an isometric view of a mandrel in accordance with the invented core holder embodiments of FIGS. 3 and 4.
FIG. 6 is an isometric view of an alternative friction core holder in the deactivated position.
FIG. 7 is an end view of the friction core holder of FIG. 6 in the activated position.
FIG. 8 is an end view of another alternative friction core holder in the activated position.
FIG. 9 is an end view of the friction core holder of FIG. 8 in the activated position.
FIG. 10 is a side view of a single segment of a 4-segment core holder.
FIG. 11 is an end view of the segment of FIG. 10.
FIG. 12 is a side view of an assembled 4-segment core holder using the segments of FIG. 10.
FIG. 13 is an end view of the assembled core holder of FIG. 12.
FIG. 14 is an end view of a 4-segment friction core holder showing an alternative segment connecting means.
FIG. 15 is a partially cutaway side view of the friction core holder of FIG. 14.
FIG. 16 is an end view of another 4-segment friction core holder showing several alternative connector devices.
FIG. 17 is an end view of a 2-segment friction core holder showing both alternative mandrel configurations and alternative segment connecting means.
DETAILED DESCRIPTION
Referring now to FIG. 1, which depicts the invention in use in the lable printing industry, a large disc 10 is mounted for rotation on a base 12, about axis 13. The disc 10 is provided with 8 label friction mandrels or spindles 14, all of which protrude from one side of disc 10 and are driven from the other side.
Each mandrel 14, which has a longitudinal flat or planar face 16, holds a core 18, which is generally made of cardboard, fiberboard, vinyl, plastic, or other resilient material. The core is held onto the mandrel 14 by a pair of semi-circular disc-like segments 20, 22, which have slightly offset respective centers 24, 26. Each segment 20 is identical to segment 22, but is reversed when mated. Mandrel 14 has a pair of opposed longitudinal planar faces 28, which accomodate the off-set centers in the non-round orientation, as shown in FIG. 3. The segments preferably have an annular outer groove 30 for receiving a resilient band or O-ring 32 to hold the mated segments together. Mandrels 14 are preferably made from steel, however, they can be made of any metal or alloy, wood, hard rubber, hard plastic, or the like.
The reverse side of the turret rewind base 12 carries drive means, including a motor driven sheave 36, and a drive sheave arrangement in which drive belt 38 engages only two or three of the mandrel drive sheaves 40 at any one time (See FIG. 2). Idler pulleys 42 are provided to create proper tension in belt 38 and the proper drive angle of belt 38 with regard to each sheave 40 in a driven position.
A glue unit 44 includes a glue-containing receptacle or trough 46, a roller-applicator 48 mounted at the trough so that a portion of the roller extends into the glue contained in the trough, and means for moving the glue unit laterally into and out of engagement with a core on a spindle. The glue unit is mounted on a track 50 which is connected to the frame 12, and is preferably reciprocally powered along the track by a pneumatic cylinder, not shown. The glue unit may advantageously carry a lower glue carrier roll 52 which is partially submerged in the glue pool and contacts the roller-applicator 48 by which the carrier roll applies glue to the applicator roll 48, which allows the applicator roll to be of a smaller diameter than otherwise would be required to extend into the glue pool in the trough. In addition, the use of a carrier roll will prevent excessive glue from being applied to the carrier roll and thus to the core.
A web cutting assembly 56, including a cutting blade 58, is mounted for horizontal movement on a track 60, which is fixed to frame 12. A solenoid-actuated pneumatic cylinder 62 is connected to the blade assembly for horizontal movement along the track 60. Another solenoid-actuated pneumatic cylinder controls vertical movement of the blade. The cutting assembly includes a web guide roll 66, which is an idler roll that controls the angle and path of the web as it is being cut, as well as preventing the moving web from contacting the knife blade 58 and causing a "cobble", or mishap. If desired, the blade 58 can be set to cut at an angle of up to 45 degrees from the vertical. Contact roller 68 pushes the web against the glued core momentarily, simultaneously with retraction of the knife blade 58.
The indexing of each core-containing mandrel to the next position is automatically controlled. A counter may be provided to accurately count the number of labels on the core, whereupon when a predetermined number is reached it would generate a signal to activate movement of the cutting assembly and blade, then to index the mandrel to the next position by rotation of the disc plate to its new orientation, and activate the glue unit to apply adhesive to a newly positioned core in the standby position.
A detector, comprising a photoelectric cell 70, is focused at a location indicated by reflector 72, and is so adjusted that its beam is aimed to just miss a mandrel if it carries no core thereon, but the beam will be interrupted by a filled core or roll. The detector is provided with an audible alarm which also controls an emergency stop for preventing further indexing of the turret apparatus until the label or web-containing roll can be removed from the mandrel at the focused position indicated at 75.
A safety guard 86 may be provided to prevent contact of any person with the cutting blade.
The preferred core holder embodiment is shown in FIGS. 10 through 13. The center C 1 of the outer arc having radius R 1 is not coincident with center C 2 of the bore having radius R 2 . The center C 2 of the bore is offset from center C 1 from 0.015 to 0.35 inches (about 0.4 to about 9 mm), as shown in FIG. 11, but preferably from 0.025 to 0.055 inches (about 0.63 to about 1.4 mm).
Four identical segments 102, as shown in FIGS. 10 and 11 are assembled with connectors, preferably resilient connectors such as O-Rings 104 in grooves 106 as shown in FIGS. 12 and 13 to form a core holder. When the segments are assembled, they provide a nonround hole for accomodating the mandrel, with stops preventing more than a quarter turn of the core holder about the mandrel.
In operation, a core 18 is placed on a mandrel 14, prior to the mandrel being indexed to the location for web accumulation. As it approaches location 18A, the mandrel begins turning, as its associated drive sheave 40 is engaged by drive belt 38. Upon reaching the core location indicated at 18A, the glue unit is activated to move horizontally until the applicator roll 48 touches a core for one core revolution, the applicator applying glue for one revolution, the exact time of the glue application being computer controlled. The glue unit retracts. When the active core is filled, the cutting unit moves forward to slice the label-containing web, the turret indexes, and the glue unit applies adhesive to the next core.
The action of the blade dropping and slicing the web actually forces the web down against the adhesive-bearing core, and immediately upon blade retraction, the core is already accumulating labels. Then the turret 10 indexes to the next station, meaning that the plate disc has revolved 1/8 of a revolution. The label-filled core 18 is removed after the turret has indexed twice, so that the associated drive sheave for the mandrel which that core is gripping is no longer engaged by drive belt 38, and the mandrel is no longer turning. The empty core is turning prior to the glue being applied, and the core is also turning while it is filling. Then when it indexes to the next station, it can be removed.
The elongated flat sides of each mandrel accomodate the core support segments when offset to the non-circular central orifice orientation. When the spindle 14 turns in an operative direction, it forces the split center of the core-gripping segments to assume a round configuration, rather than that of two slightly off-set half-moons. Reverse pressure on the core will release the outward force from the mandrel and allow the core to be readily removed therefrom.
A rewind machine is used to rewind the large rolls into small, easily handled rolls for a label applicator, such as a portable label applicator. Use of the subject invention allows the quicker installation of cores and removal of filled rolls, with an attendant reduction of required personnel time for these operations.
ALTERNATIVE EMBODIMENTS
Alternatively, the semi-circular core support segments may be wider than shown, thus requiring only one pair of segments to support a core. When two pairs of segments are used, each opposed pair may be connected by a spacer 80, as shown in FIG. 3, or by a pair of spacers 82, such as dowel rods.
In the embodiment of FIGS. 6 and 7, each mandrel 84, which has longitudinal flat faces, has a square cross-section. A core is held onto the mandrel 84 by four quad-circular disc-like segments 86, which have slightly offset respective center openings 88 to accomodate the mandrel. Each segment 86 is identical. As shown, four such segments form a completed core holder, when assembled. When the core holder is turned about the mandrel 84, one edge of each segment 86 is forced outwardly, as shown in FIGS. 7 and 8, tightening against the inner surface of the core 18. Upon a reverse twist, the segments of the core holder return to the positions shown in FIGS. 6 and 9, releasing their grip on the core.
The 2-segment embodiment depicted in FIGS. 5 and 17 utilizes a mandrel 14 or spindle, which has a pair of wide longitudinal flat faces 16, and a pair of short faces, which may be arcuate, either concave which accomodate the off-set centers in the non-round or convex, or flat, or may have any desired configuration that will not extend beyond the arc of the core segments, as shown in FIG. 3. The segments preferably have an annular outer groove for receiving a resilient band or O-ring to hold the mated segments together. The band may be seated low enough in the groove that it does not contact the core, or it may contact the core. In another alternative embodiment, there may no groove at all, and the bands will be prssed into contact with the core in the gripping position of the core holder.
The mandrel is constructed of harder material than the segments. Wear of the mandrel or spindle is minimal when the spindle is hard or hardened material such as steel, and the segments are readily replaceable softer materials such as wood, plastic, fibrous material, or other similar materials. When the segments are themselves a resilient material capable of holding by friction, such as rubber or polyvinyl chloride, the core material may be a hard wear resistant material, such as wood, hard plastic, metal, metal alloy, even stainless steel, and the invention is still readily operable.
The segments may be held together as shown in FIG. 6 by O-rings 90 in annular grooves 92. Alternatively, they may be connected loosely by any convenient connecting means that avoids interference with the operation of the segments, such as O-Rings 96 on pins 98 extending from the end faces of each segment 86, as shown in Fugres 14 and 15; wire connectors such as wire 110 having end loops for attaching to pins 112 on adjacent segments; rubber or resilient connectors 116 between fasteners 118 on adjacent segments, or other suitable connecting devices which will loosely maintain the segments in the proper juxtaposition.
Also shown in FIG. 16 is an alternative connecting means which comprises a slot 120 in each end face of each segment mating with an adjacent slot in the opposed segment and having an expanded recess 122 therein, and a double headed connector 124 with a shank between the heads engaged within said expanded recess to hold the segments loosely together.
The mandrel preferably has a regular polygonal cross section, such as an equilateral triangle, square, hexagon, etc. When the mandrel is a regular polygon, the core holder assembly has the same number of segments as the polygon has sides, and the centers of the outer and inner arcs of each segment are offset the same amounts as stated previously.
FIG. 17 shows an alternative embodiment of a 2-segment core-holder which is held by a pair of resilient connectors 126 in the same manner as the four-segment core holder connector 116, 118 of FIG. 16. In a 2-segment core holder, the mandrel 125 can have any rectangular cross-section configuration, and can have one or more recessed faces 130.
An alternative glue applicator unit includes a pressure spray dispenser directed to the core position at the glue applicator station, with associated glue supply. The spray dispensing heads can be mounted for horizontal movement toward and away from the active position, and each head is capable of being shut off without clogging by rotation to a standby position opening upwardly.
SUMMARY OF THE ACHIEVEMENTS OF THE OBJECTS OF THE INVENTION
From the foregoing description, it is readily apparent that I have invented apparatus for holding a tubular core tightly on a mandrel or spindle, yet which is readily removable with ease, and which is equally adaptable to the paper, printing, and textile industries, including the carpet industry.
While I have shown and described present preferred embodiments of the invention, it is to be understood that the invention is not limited thereto or thereby, but any changes or modifications within the scope of the following claims are included within the invention. | A core holder for a winding apparatus for winding webs of material in the paper, printing, and textile industries, including a rotatable core-receiving spindle or mandrel, and a segmented friction core holder, expandable outwardly at selected points, by which the core is tightly gripped when the mandrel is turning, and which readily releases its grip on the mandrel upon a simple manual maneuver by the operator, and is readily removable with little force. The core holder assembly is round, but the mandrel-receiving hole has segmented arcs which are not concentric with the outer surface of the core holder, creating stops which limit the movement of the segments about the mandrel. |
[0001] This application is a continuation-in-part of pending U.S. application Ser. No. 09/305,782 filed Apr. 30, 1999, which is a continuation of PCT/AU99/00260 filed Apr. 8, 1999.
FIELD OF THE INVENTION
[0002] This invention relates to an aluminium processing apparatus for separating aluminium from a mixture of aluminium and aluminium dross, and to a related process for separating aluminium from a mixture of aluminium and aluminium dross. In particular, the invention relates to a process for recycling aluminium from dross produced during an aluminium melting processes, and to an aluminium processing apparatus for carrying out that recycling process.
BACKGROUND OF THE INVENTION
[0003] When aluminium is melted eg. for manufacture of extrusions, ingots and billets, because of the influence of oxygen from environmental air on the aluminium and the existence of impurities, particularly oxides, nitrides and carbides, in the molten aluminium, a layer of sludge, also known as dross rises to the surface of the molten aluminium. This layer of dross has to be removed from the molten aluminium before the molten aluminium can be cast. This is done by the use of a ladle in a rather crude process, known as skimming, in which the ladle is dragged across the top of the molten aluminium and the dross is scraped into a suitable receptacle. During the skimming process, as well as removing sludge including oxides and other impurities, pure aluminium is also removed. The quantity of pure aluminium removed depends on the depth to which the ladle is inserted in the aluminium to ensure removal of all the dross and to a large extent depends on the skill of the furnace worker handling the ladle. However, typically 30 to 60% of the mixture/dross, by weight is aluminium.
[0004] The term dross, as used herein, refers to the impurities such as oxides which float to the surface of the molten aluminium, but the term is also used in the art to refer to the mixture of aluminium and the impurities.
[0005] Because of the amount of aluminium in the mixture, it is obviously desirable to remove as much aluminium from the dross/aluminium mixture as possible. Almost all recycling is currently carried out using a process known as rotary salt furnace processing. In that process, the dross containing pure aluminium is first allowed to cool. The longer the aluminium spends hot, the more oxidation occurs and less aluminium is recovered in the recycling process, so often cooling is encouraged and accelerated. In some cases some initial separation of aluminium from the mixture is first carried out by one of two rather inefficient devices know as drain pans and dross presses, respectively. In the former the mixture is allowed to sit while molten and some of the aluminium will sink to, and agglomerate in, the bottom of the pan. In the latter, the mixture is compressed and the aluminium droplets tend to stick together. U.S. Pat. No. 5,788,918 to Bramely discloses one example of a dross press. These processes are inefficient and have to be followed by rotary salt processing or other methods of external dross processing. Because the mixture is kept hot longer for the drain pan or dross press process, the recovery rate in the subsequent rotary salt process is reduced, so drain pans and dross presses are generally not commercially viable, and are not often used.
[0006] Recycling is not generally done at the furnace, but is usually is done by specialist metal-recycling companies. In the rotary salt recycling process, the dross is heated and remelted and various salts and fluxes are added in order to separate the aluminium from the oxides and other impurities. While the process is highly efficient in terms of the quantity of aluminium removed from the dross, removing approximately 85% of the available aluminium, the waste products from the recycling process, ie the mixture of salts and the oxides, is unpleasant, very environmentally unfriendly, and difficult to dispose of safely. Further, the process requires the transporting of the dross to the recycler in trucks or the like which is also undesirable from an environmental point of view, and inefficient in terms of fuel. Also, the dross has to be remelted in order to extract the aluminium in the recycling process which requires a substantial amount of energy. There are some smelting plants which have their own rotary salt recycling furnace, however, the process of cooling and transporting the cooled mixture to the furnace remains the same, although savings are made in total transport costs.
[0007] Proposals have been made for separating aluminium from dross in the past. GB 1533696 and U.S. Pat. No. 3,689,049 disclose two different devices for separating aluminium from dross. Neither device has had any commercial success, perhaps because they are over-complicated and too unreliable for the extreme environment in which they have to operate.
[0008] The present inventor has also invented an apparatus and process, disclosed in AU 56260/98, and Greek patent No 97-0100106 that provides a simpler and more cost effective method of recycling aluminium from dross. The present invention is directed to improvements to the apparatus earlier developed by the inventor.
SUMMARY OF THE INVENTION
[0009] In a first aspect of the present invention there is provided an aluminium processing apparatus for separating molten aluminium from a mixture of molten aluminium and aluminium dross comprising:
[0010] a table for supporting an insulated crucible, the crucible having an open top for containing the mixture of molten aluminium and aluminium dross;
[0011] vibration means for vibrating the crucible when supported on the table;
[0012] a frame adapted to support a paddle means, means for rotating the paddle means and means for relatively lowering the paddle means into the mixture in the crucible for stirring the mixture with the paddle means, the paddle means comprising a plurality of tines having a generally triangular cross section with a ridge of the triangular cross section being uppermost in use when lowered into the crucible;
[0013] a shroud adapted to cover the top of the crucible and maintain an oxygen reduced atmosphere in the crucible; and
[0014] a screening means comprising walls mounted to the frame which substantially surround the crucible when it is supported by the table, the screening means having at least a portion thereof movable between at least a first retracted position to allow access to the crucible and at least a second position where it prevents access to the crucible; wherein simultaneous vibration of the crucible by the vibration means and stirring of the mixture by the tines is enabled with the tines moving through the dross in a shearing action mixing and tumbling the mixture and causing the droplets of aluminium to coalesce.
[0015] The tines are removably attached to the rotatable plate for cleaning or repair.
[0016] The shroud may be formed from a heat insulating material and may be located adjacent the rotatable means to be lowered with the paddle means to cover the crucible in use.
[0017] The screening means can be removably mounted to the frame. In this embodiment, the movable portion may comprise a door that is retractable to allow access to the table of the apparatus. The door can be adapted to move upwardly, sidewards or downwardly to provide a portal for access to the table. The door can be slidably movable relative to the remainder of the screening means. In another embodiment, the door can be pivotally mounted to the wall. When the door is fully retracted, the portal must be of sufficient size to allow the crucible to pass through the portal.
[0018] In another embodiment, the entire screening means can be movable between the first retracted position and the second position. In this embodiment, the screening means can extend downwardly from the lowering means for the paddle means and is so movable relative to the table and crucible in concert with the operation of the lowering means.
[0019] The screening means is preferably adapted to prevent or at least ameliorate the escape of heat from the vicinity of the crucible. By preventing the escape of heat, the screening means serves to protect workers working near the apparatus. It also serves to slow the rate of cooling of the crucible and its contents which is desirable. The screening means can also preferably be adapted to prevent or at least substantially prevent the escape of dust and flame from the vicinity of the crucible. The screening means can also be adapted to safeguard workers working in the vicinity of the apparatus from explosions of aluminium and dross from the crucible.
[0020] The screening means is preferably formed from a multi-layer structure, comprising at least an inner layer and an outer layer. The inner and outer layer can be fabricated from a suitable metal or other material, including refractory or cementitious materials.
[0021] The crucible may be made of a refractory material having a metallic outer skin spaced from the refractory material by a layer of insulation. The crucible can be provided with a covering means that at least partially covers the upper opening of the crucible. The cover can be retractable or otherwise removable from the crucible when the paddle or stirring means is relatively lowered into the crucible. If desired, the cover can be adapted to surround the shaft of the paddle or stirring means while the paddle or stirring means is stirring the crucible's contents.
[0022] The table may be mounted on springs to assist in vibrating the crucible. Vibration of the table and crucible may be achieved by the mounting of at least one ultrasonic transducer, electric vibrator, mechanical vibrator or a combination of one or more of these transducers to the crucible and/or table. The table can be vibrated such that it oscillates in a horizontal axis, a vertical axis or in both axes.
[0023] The frame may consist of two or more upright pillars. A cross-beam may be supported by the frame and that cross-beam may carry the rotating means. The shaft for the blades may depend down from the cross-beam with the blades mounted on the lower end of that shaft.
[0024] The apparatus can include one or more exhaust pipes that allow gaseous product from the process performed by the apparatus to be vented to atmosphere outside the screening means. The exhaust pipes can incorporate bagging systems that collect the exhaust gaseous product for later disposal. The bagging systems can be adapted to also or instead extract dust from the gaseous product. The exhaust systems can also include filtering or scrubbing means that clean or substantially clean the gaseous product from the process of harmful or potentially harmful constituents.
[0025] The apparatus can include a weighing means, such as an electronic or mechanical scale, that allows measurement of the weight of the crucible and its contents while the crucible is sitting on the table. The apparatus can also include a control means. The control means is preferably adapted to allow an operator to operate all features of the apparatus from a central location. In a further preferred embodiment, the control means can be automated such that the apparatus runs normally without operator input.
[0026] The control means may also control the sequence and rate of the vibrations.
[0027] While the size of the crucible containing the dross is not important, typically the crucible should be large enough to carry between 800 kilograms to 1.5 tonne of dross. The process takes approximately 10 minutes and removes up to 95% of the aluminium in the dross, hence the present invention can separate approximately 1000 kilograms of aluminium from dross every 4-10 minutes.
[0028] Typically, the crucible will include plugholes which are plugged prior to carrying out the separation process with for example a cone or a sand and clay solution, and are unplugged to drain the crucible into a draining pan.
[0029] In yet a further aspect, the invention involves a method for separating molten aluminium from a mixture of aluminium and aluminium dross comprising the steps of:
[0030] removing the mixture from a furnace containing molten aluminium;
[0031] transferring the hot dross to an insulated crucible;
[0032] transferring the crucible to a table means;
[0033] inserting a paddle means into the mixture in the crucible;
[0034] relatively lowering a screening means such that it substantially surrounds the crucible;
[0035] stirring the mixture with the paddle means and simultaneously vibrating the table and crucible to cause the oxide skin on aluminium droplets in the dross to break, and to cause the aluminium droplets to coalesce, such that the droplets enlarge in volume and in weight and tend to sink to the lower part of the crucible; and
[0036] removing aluminium from the lower part of the crucible.
[0037] In still yet a further aspect, the invention involves a method of separating molten aluminium from a mixture of aluminium and aluminium dross comprising the steps of:
[0038] removing the mixture from a furnace containing molten aluminium;
[0039] transferring the hot dross to an insulated crucible;
[0040] transferring the crucible to a table means;
[0041] inserting a paddle means into the mixture in the crucible, the paddle means comprising a rotatable means and a plurality of tines depending from the rotatable means said tines having a generally triangular cross section, with a tip or ridge of the triangular cross section being uppermost in use when the tines are lowered into the crucible;
[0042] relatively lowering a screening means such that it substantially surrounds the crucible;
[0043] stirring the mixture with the tines and simultaneously vibrating the table and crucible with the tines moving through the dross in a shearing action mixing and tumbling the mixture to cause the oxide skin on aluminium droplets in the dross to break, and to cause the aluminium droplets to coalesce such that the droplets enlarge in volume and in weight and tend to sink to the lower part of the crucible; and
[0044] removing aluminium from the lower part of the crucible.
[0045] The pure aluminium can then be either cast as an ingot or recycled straight back into the furnace containing molten aluminium or drained into a crucible.
[0046] The process is carried out without substantially cooling the dross, preferably at a temperature of about 750° C.
[0047] In a yet further aspect the invention provides an apparatus for separating molten aluminium from a mixture of molten aluminium and aluminium dross including:
[0048] a table for supporting an insulated crucible containing the mixture of molten aluminium and aluminium dross;
[0049] at least one heating means such as a gas burner of the like adapted to either preheat the paddles or heat the contents of the crucible or heat both.
[0050] a frame adapted to support a paddle means or stirring means, means for rotating the paddle means and means for relatively lowering the same into the mixture in the crucible for stirring the mixture with the paddle means enabling simultaneous vibration of the crucible and stirring of the mixture.
[0051] The gas burners of the like can be used to maintain the heat in the contents of the crucible during the stirring process. In contrast with prior art devices such as dross presses maintaining heat during the separation process has been found to be desirable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0052] By way of example only, preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which:
[0053] [0053]FIG. 1 is a schematic and simplified illustration showing steps in the process of the present invention;
[0054] [0054]FIG. 2 is a detailed drawing of apparatus embodying the present invention but with an enclosure omitted;
[0055] [0055]FIG. 3 is a detailed drawing of the apparatus depicted in FIG. 2 illustrating an enclosure, in particular;
[0056] [0056]FIG. 4 shows a side view of a first tine for use in the apparatus;
[0057] [0057]FIG. 5 is a view of on arrow V of FIG. 4;
[0058] [0058]FIG. 6 shows a side view of a second tine; and
[0059] [0059]FIG. 7 is a side view of a variation on the apparatus shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0060] Referring the to the drawings, FIG. 1 which is a simplified and schematic illustration of a process embodying the invention shows a fork-lift truck 10 transporting a crucible 12 containing dross at a temperature of about 750° C. to an apparatus, generally indicated at 14 , for removing aluminium from the dross. The crucible is placed on a table 16 of the apparatus. Blades in the form of tines 18 described in more detail below are lowered into the molten dross. The table 16 is vibrated in a vertical direction, as illustrated by the arrows AA, the tines 18 rotate in the molten dross, and by virtue of the stirring and vibration, the aluminium droplets and particles in the dross coalesce to form larger droplets and gradually sink to the base of the crucible. The aluminium can then be drained out into a bucket 20 and either transferred directly back to the furnace or is allowed to cool to produce an aluminium ingot 22 .
[0061] [0061]FIG. 2 shows a more detailed drawing of the apparatus of the present invention with a protective enclosure which ordinarily encloses the apparatus, omitted for clarity. The device includes a frame comprised of a number of upright pillars or rails 50 , a base 52 and cross beam 54 . In plan view the frame includes four pillars located on the corners of a square. A table 54 is mounted on squat pillars 56 which rise up from the base 52 . A number of springs 58 also extend between the base 52 and the table 54 . On top of the table a crucible 59 is located. The crucible can be generally square or circular in plan view and has sides which taper outwardly. The inside of the base of the crucible is smooth without sharp corners, so that the dross can be stirred properly and so that the crucible can be cleaned easily. A pipe or channel 60 is formed in the base of the crucible which, when unblocked, allows molten metal to flow out from the crucible.
[0062] The crucible is made of a refractory material 61 , having an outer skin 62 of metal and an insulating layer 63 disposed between the skin and the refractory material. Although refractory material has insulating properties, the insulating layer 63 further helps to prevent the dross cooling as it is transported to the table. A shaft 64 defining a longitudinal axis 64 a depends from the cross-beam 54 and on the lower end of the shaft there are a series of tines or paddles 65 for stirring the contents of the crucible mounted on a rotatable plate 67 . The shaft is movable relative to the cross-beam in the vertical direction to raise and lower the tines 65 . A motor 66 is also provided to rotate the shaft in the direction B to stir the contents of the crucible by means of the tines 65 . Also raised and lowered with the tines is a shroud or “hungry board” 68 which covers the top of the crucible when lowered. The shroud which is most preferably formed from a heat insulating material, assists in creating an oxygen reduced environment in the crucible during processing, compared with normal oxygen levels in atmospheric air. It also assists in maintaining the temperature of the contents of the crucible.
[0063] The tines 65 are shown in more detail in FIGS. 4 to 6 . There are two designs 65 a and 65 b respectively, one 65 a for tines which are rotated in a circular near the walls of the crucible and the other 65 b for tines which rotate in a tighter circular path nearer the centre of the crucible to ensure mixing of the entire contents of the crucible. At the top of each tine there is a horizontal plate 100 defining a hole 102 through which a bolt 104 extends. A wing nut 106 is threaded on the bolt by means of which the tine is removably clamped to the rotatable plate 67 . Depending from the plate 100 is a flat bar 110 having a rectangular cross-section which depends down at an angle of about 70°-80° to the vertical and then bends through 100°-120° to define a relatively shorter tip portion 112 oriented at about 20°-30° to the horizontal. As is best shown in FIG. 5, an upper part 114 of the tine is fixed to the bar by welding. The upper part 114 is triangular in cross-section with the centre of the tine being hollow. The uppermost part of the tines define a pointed ridge 116 . The tines are made of cast iron or cast steel.
[0064] The shape of the blades is beneficial in the stirring process since the dross is stirred without undue agitation. The shape of the blades cuts through the dross in a shearing action gently rolling the dross, mixing and tumbling it and causing the droplets of aluminium to coalesce. The shape of the tines has been found to greatly enhance the efficacy of the process.
[0065] [0065]FIG. 3 illustrates walls 71 mounted to the frame 50 of the apparatus 14 . The walls are a multi-layer structure comprising a metallic inner layer 71 a and a metallic outer layer 71 b, illustrated in section in FIG. 3 a. The walls 71 serve to prevent heat, dust, flame and explosion from escaping the vicinity of the crucible and endangering any workers working nearby. The walls 71 also serve to lessen the rate of temperature drop of the crucible and its contents during operation of the apparatus. Disposed on one face of the apparatus is an opening 72 provided by a sliding door 73 that can be raised or lowered as desired on rails. In the depicted embodiment, the door is shown in dashed outline since it has been retracted upwards behind the upper wall 71 . The opening is of sufficient size to allow the fork-lift to insert the crucible into the apparatus. In FIG. 3, the device is depicted just after the crucible has been placed on the table 54 and with the blades 64 lowered into the crucible ready to stir the contents of the crucible. In normal operation, it would be anticipated that the door would be left open for a short as time as possible. Accordingly, in normal operation, it would be expected that the opening 72 would be closed by the door immediately after the crucible is placed on the table or as the blades 64 are lowered into the crucible.
[0066] In use, dross is taken from the furnace and placed straight into the crucible 59 . The crucible is then moved by a fork-lift or the like and placed directly onto the table 54 . Once the crucible is in place on the table, the blades/tines are lowered into the dross and the top of the crucible is covered by the shroud. The table on which the crucible sits is then vibrated in the vertical direction, at a rate of between 500 to 5,000 or more vibrations per minute. In the embodiment depicted in FIG. 2, the vibration of the table is achieved through use of electrical vibrators 70 mounted under the table 54 . In other embodiments, the vibration may be achieved through use of one or more ultrasonic transducers, mechanical vibrators, or a combination of such vibrators mounted to the table 54 . It is also possible to mount the electrical vibrators on the sides of the crucible or frame to provide horizontal vibration in addition to, or instead of, the vertical vibrations.
[0067] In normal operation, the blades 64 turn at a rate of between 3 to 40 rpm. The vibrations break the oxide layer surrounding the droplets of aluminium in the dross and allow the metal droplets to coalesce with the result that the droplets then become larger in volume and tend to sink to the bottom of the crucible where they can flow through the hole 60 into another bucket or drain pan. The tines cut through the dross in a shearing action gently rolling the dross, mixing and tumbling it and causing the droplets of aluminium to coalesce. The rate of vibration can change during the process and tends to start more slowly and then increase later for best results.
[0068] High vibrational rates are used to bond very small drops of liquid metal together and by utilising higher vibrational speeds a larger percentage of pure metal can be recovered. As discussed above, generally, the content of pure metal in dross from aluminium furnaces is usually between 30 to 60%, and once the process described above has been carried out on the dross the content of the remaining aluminium in the dross tends to be in the range of 3 to 5%. Both stirring and vibrating is needed.
[0069] The specific embodiment described above refers to vibrating the crucible in a generally vertical axis, and generally horizontal stirring, stirring and vibration could take place in other axes and by other methods. An important feature of the invention is that sufficient agitation, vibration, or stirring occurs at rates which cause the aluminium droplets to coalesce.
[0070] [0070]FIG. 7 shows a variant of the apparatus shown in FIGS. 2 and 3 having a number of additional features. First a hood 83 is provided and exhaust pipe 84 are also provided to allow safe extraction of dust and/or gaseous product from the process. A bagging system 86 for the capture of dust passing through the exhaust pipe is also provided so that gases leaving the exit 88 of the pipe are clean.
[0071] [0071]FIG. 7 also illustrates the provision of two gas burners 88 and 90 . The gas burner 88 is used to preheat the paddles/tines and burner 90 can be used to heat the surface of the contents of the crucible to assist in preventing solidification of the aluminium.
[0072] A further additional feature is the provision of a weighing means such as electronic scales adapted to weigh the crucible and contents and transmit that information to a computer control unit 94 . The control unit also receives inputs from sensors 96 associated with the paddle drive means which measure the force required to turn the paddles. From this information the control means can determine the optimal stirring time and feed control signals to a control box 94 which controls the rate and duration of stirring. The control means can also be used to control the sequence and rate of vibrations.
[0073] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. | An apparatus for separating molten aluminium from a mixture of molten aluminium and aluminium dross includes a table for supporting an insulated crucible containing the mixture of molten aluminium and aluminium dross. A rotatable frame supports a plurality of tines which can be lowered into the mixture in the crucible for stirring the mixture. Vibration means are provided enabling simultaneous vibration of the crucible and stirring of the mixture. The tines cuts through the dross in a shearing action gently rolling the dross, mixing and tumbling it and causing the droplets of aluminium to coalesce. The aluminium droplets and particles in the dross coalesce to form larger droplets and gradually sink to the base of the crucible. A screening means is disposed to substantially surround the crucible when it is supported by the table, which includes a door to both allow and prevent access to the crucible. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a non-provisional of U.S. Patent Application No. 60/948,384, filed on Jul. 6, 2007, entitled “Proppants for Gel Clean-Up,” which is incorporated by reference herein in its entirety.
BACKGROUND
[0002] Oil and natural gas are produced from wells having porous and permeable subterranean formations. The porosity of the formation permits the formation to store oil and gas, and the permeability of the formation permits the oil or gas fluid to move through the formation. Permeability of the formation is essential to permit oil and gas to flow to a location where it can be pumped or flowed from the well. In many cases the permeability of the formation holding the gas or oil is insufficient for economic recovery of oil and gas. In other cases, during operation of the well, the productivity of the formation drops to the extent that further recovery becomes uneconomical. In such cases, it is necessary to hydraulically fracture the formation and prop the fracture in an open condition by means of a proppant material or propping agent. Such fracturing is usually accomplished by hydraulic pressure, and the proppant material or propping agent is a particulate material, such as sand, resin coated sand or ceramic particles (all of which can be referred to as “proppant”), which are carried into the fracture by means of a fracturing fluid, typically containing high molecular weight polymers, such as guar gum, guar gum derivatives such as hydroxypropyl guar (HPG), carboxymethyl HPG (CMHPG), cellulose, cellulose derivatives such as hydroxyethyl cellulose (HEC), biopolymers, such as xanthan gum and polyvinyl alcohol, which increase the viscosity of the fracturing fluid.
[0003] Crosslinking agents can also be added to the fracturing fluid to generate cross-linked gelled fluids so as provide even higher viscosities, better proppant transport properties and to create fracture geometries not possible with other types of fluids. These cross-linked gelled fluids are highly viscous but non-Newtonian and shear thinning permitting them to be easy placed. While the viscous nature of the fluids is important for proppant transport, once the proppant is placed in the fracture it is not desirable for such fluids to remain in the proppant pack as the fluids can significantly hinder the flow of oil or gas in the propped fracture. In recognition of this, the fracturing fluids include “breakers” of various types that are designed to break the cross-linking bonds and reduce the molecular weight of the polymeric materials in such fracturing fluids after the proppant is placed thus dramatically reducing the viscosity of the fracturing fluid and allowing it to be easily flowed back to the surface from the proppant pack. Such chemical breakers are typically added directly to the fluid. While the breakers are designed to break the cross-linking bonds and reduce the molecular weight of the polymeric materials in such fluids and significantly lower the viscosity of the fluids, it is important the breakers not reduce the fluid viscosity and transport capability prematurely while the fluid is being pumped. If a premature “break” of the fluid occurs during the fracturing operation, the loss of viscosity will dramatically limit the transport characteristics of the fracturing fluid. If this occurs while pumping, proppant can accumulate near the well bore rather than being carried into the created fracture. Such near well bore accumulation of proppant can lead to an early termination of a fracturing job due to excessive pumping pressure. This early termination is often referred to as a “screen out”. Conventional techniques for attempting to avoid an early breaking of the fluid viscosity have included limiting the amount of breaker added to the fracturing fluid and/or encapsulating the breaker with a material that will limit the contact of the breaker with the high molecular weight and/or cross-linked polymers in the fracturing fluid during pumping.
[0004] Encapsulated breakers are simple pellets consisting entirely of breaker with a permeable coating. Such pellets are incorporated in a fracturing fluid along with the proppant in the anticipation that the breaker will be released and effectively break the surrounding gel. However, laboratory and field testing suggests that the “encapsulated breaker” pellets incorporated into a fracturing fluid are ineffective at contacting all the fracturing fluid, either due to physical separation/segregation of the proppant and encapsulated breaker pellets, or due to inadequate concentrations.
[0005] Other laboratory testing of conventional breaker systems demonstrates that such systems are often ineffective at removing the gel. The breakers are particularly poor at breaking and cleaning up the gel filter cake. A gel filter cake is often formed on the created fracture face during the hydraulic fracturing operation. The filter cake forms as hydraulic pressure in the fracture causes the liquid phase of the fracturing fluid to “leak off” into the permeable formation. The high molecular weight and/or cross linked gel particles are too large to enter the pores of the formation and consequently are filtered out at the fracture face creating a thin layer of highly concentrated gel referred to as a filter cake. This layer of filter cake is very resilient and can sometimes completely occlude the entire width of the created fracture upon closure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a graph of the release profile in terms of sodium persulfate released as a function of time for proppant coated with sodium persulfate and then coated again with polyvinylidene chloride; and
[0007] FIG. 2 is a graph of the release profile in terms of sodium persulfate released as a function of time for porous proppant impregnated with sodium persulfate and then coated with polyvinylidene chloride.
DETAILED DESCRIPTION
[0008] Methods and compositions for breaking and removing residual gel and gel filter cake that results from the use of viscous gelled fracturing fluids are described. According to embodiments of the present invention, a gel breaking composition is coated on proppant grains, impregnated in the pore spaces of a porous ceramic proppant grain or both. Proppants for use in the methods and compositions of the present invention include lightweight ceramic proppants, intermediate strength ceramic proppants, high strength ceramic proppants, natural frac sands, glass beads, other ceramic bodies and resin coated proppants used in the hydraulic fracturing of oil and gas wells. Suitable proppants are disclosed for example in U.S. Pat. Nos. 4,068,718, 4,427,068, 4,440,866 and 5,188,175, the entire disclosures of which are incorporated herein by reference. According to such methods and compositions, the chemical reactivity of the gel breaking composition and the gel occurs in the immediate vicinity of the proppant grains.
[0009] According to certain embodiments of the present invention, gel breaking compositions come into intimate contact with a residual gel and a gel filter cake formed on the created fracture face during an hydraulic fracturing operation by placing the gel breaking composition on the surface of a proppant or in the pore spaces of a proppant grain and then controlling the release of the gel breaking composition into the fracturing fluid by further coating the solid or porous proppant grain with a secondary coating. According to such embodiments, the gel breaking compositions act to at least partially reduce the viscosity of the fracturing fluid and include, but are not limited to, one or more of enzymes, oxidizing agents, peroxides, persulfates, perborates, silver, iron, or copper catalysts, sodium bromate, acids, oxyacids and oxyanions of halogens, derivatives thereof, and combinations thereof or any other material well known to those of ordinary skill in the art that is effective to at least partially reduce the viscosity of the fracturing fluid. Examples of persulfates include sodium persulfate, ammonium persulfate and potassium persulfate. Examples of acids include fumaric acid, nitric acid, acetic acid, formic acid, hydrochloric acid, hydrofluoric acid and fluroboric acid. Examples of oxyacids and oxyanions of halogens include hypochlorous acid and hypochlorites, chlorous acid and chlorites, chloric acid and chlorates, and perchloric acid and perchlorate.
[0010] According to certain embodiments of the present invention, the gel breaking composition coating is applied to the surface of the proppant or impregnated in the pore spaces of a porous ceramic proppant grain by one or more of a variety of techniques well known to those of ordinary skill in the art including spraying, dipping or soaking the proppant in a liquid solution of the gel breaking composition. Those of ordinary skill in the art will recognize that other techniques may also be used to suitably apply a substantially uniform consistent coating to the proppant or to impregnate a porous proppant.
[0011] Also according to certain embodiments of the present invention, the secondary coating comprises any coating material that is well known to those of ordinary skill in the art that is permeable, is dissolved by water or hydrocarbons, melts or degrades at reservoir temperature, or fails upon application of mechanical stress. The secondary coating is generally a polymer, wax, monomer, oligomer or a mixture thereof. In certain embodiments, the secondary coating comprises polyvinylidene chloride. Generally, the secondary coating may be applied to the surface of the proppant coated or impregnated with the gel breaking composition by one or more of a variety of techniques well known to those of ordinary skill in the art including spraying, dipping or soaking in a liquid solution of the secondary coating. In addition, the secondary coating may be applied by a droplet spraying technique in which discrete droplets of the secondary coating are sprayed onto the proppant grains to create a permeable matrix of the secondary coating. The secondary coating may also be applied by other methods well known to those of ordinary skill in the art such as microencapsulation techniques including fluidized bed processes, top spray methods, as well as other methods of coating such as disclosed in U.S. Pat. No. 6,123,965, the entire disclosure of which is incorporated herein by reference.
[0012] According to certain embodiments of the present invention, the surface of a proppant grain is coated with a sodium persulfate breaker wherein the breaker coating constitutes 10% by weight of the coated proppant. The amount or thickness of the breaker coating can be tailored to provide the optimal breaking action for the specific well conditions. The proppant grain is then coated with a polyvinylidene chloride by a droplet spraying technique wherein the polyvinylidene chloride coating constitutes 6-18% by weight of the proppant when coated with polyvinylidene chloride and sodium persulfate breaker. The polyvinylidene chloride coating is permeable such that when the coated proppant is placed in an aqueous solution at 160° F., significant release of the breaker to the solution is delayed by up to 4 hours or more.
[0013] FIG. 1 shows the release profile for the release of sodium persulfate as a function of time at 160° F. for varying amounts of a permeable coating of polyvinylidene chloride on a lightweight ceramic proppant which is commercially available under the tradename ECONOPROP® from CARBO Ceramics Inc. The lightweight proppant was first coated with a sodium persulfate breaker composition such that the breaker composition accounted for 10% of the weight of the coated proppant. Then the sodium persulfate coated proppant was coated with polyvinylidene chloride such that the polyvinylidene chloride constituted from 6% to 18% of the weight of final proppant product.
[0014] According to certain embodiments of the present invention, 10% by weight of a sodium persulfate breaker is placed or impregnated in the pore spaces of a porous ceramic proppant grain. The porous proppant grain is then coated with a polyvinylidene chloride by a droplet spraying technique wherein the polyvinylidene chloride coating constitutes 6-18% by weight of the proppant when coated with polyvinylidene chloride and sodium persulfate breaker. The polyvinylidene chloride coating is permeable such that when the coated proppant is placed in an aqueous solution at 160° F., significant release of the breaker to the solution is delayed by up to 4 hours or more.
[0015] FIG. 2 shows the release profile for the release of sodium persulfate as a function of time at 160° F. for varying amounts of a permeable coating of polyvinylidene chloride on a porous ceramic proppant which is commercially available under the tradename ULTRALITE® from CARBO Ceramics Inc. The porous ceramic proppant was first impregnated with a sodium persulfate breaker composition such that the breaker composition accounted for 10% of the weight of the impregnated proppant. Then the sodium persulfate impregnated proppant was coated with polyvinylidene chloride such that the polyvinylidene chloride constituted from 6% to 18% of the weight of final proppant product.
[0016] Certain embodiments of the present invention in which the proppant grain is coated with a breaker or a breaker is impregnated in the pore spaces of a porous proppant and the release of the breaker is delayed by coating it with a secondary coating, enable the incorporation of a high level of the breaker into the site of a fracture during a hydraulic fracturing process and improve the contact of the breaker with the gel or filter cake that remains in the proppant pack.
[0017] Breakers such as sodium persulfate are typically added to the viscous fracturing fluid at a concentration of about 0.1-4 pounds per 1000 gallons of fluid. By incorporating the breaker on or into the proppant and then delaying the release of the breaker by means of a permeable outer layer, it is possible to significantly increase the effective concentration of the breaker in the fluid and at the same time avoid a premature break of the fluid.
[0018] The foregoing description and embodiments are intended to illustrate the invention without limiting it thereby. It will be obvious to those skilled in the art that the invention described herein can be essentially duplicated by making minor changes in the material content or the method of manufacture. To the extent that such material or methods are substantially equivalent, it is intended that they be encompassed by the following claims. | Methods of incorporating a chemical breaker onto a proppant that will permit release of the breaker after the proppant has been placed in a hydraulic fracture are provided. The methods utilize a chemical breaker coated on the surface of a non-porous proppant grain or placed in the pore space of a porous proppant grain and secondarily coated with an outer layer which can be tailored to delay the release of the breaker. |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase Application of PCT International Application No. PCT/EP2013/075188, filed Nov. 29, 2013, which claims priority to German Patent Application No. 10 2012 224 102.7, filed Dec. 20, 2012 and German Patent Application No. 10 2013 217 892.1, filed Sep. 6, 2013, the contents of such applications being incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The invention relates to an electronic device and a method for producing the electronic device.
BACKGROUND OF THE INVENTION
[0003] WO 2010/037 810 A1 incorporated by reference herein discloses an electronic device in the form of a sensor for outputting an electrical signal based upon a determined physical variable. The electronic device comprises an electronic circuit that is enclosed in a circuit housing.
SUMMARY OF THE INVENTION
[0004] An aspect of the invention is to improve the known electronic device.
[0005] In accordance with one aspect of the invention, an electronic device comprises an electronic circuit that is enclosed in a circuit housing having a first coefficient of thermal expansion and preferably can be contacted by way of an electrical signal connection by an external circuit, said electronic device also comprises a molded body that surrounds the circuit housing, said molded body having a second coefficient of thermal expansion that is different to the first coefficient of thermal expansion, wherein the molding compound is fixed to the circuit housing at at least two different fixing points on the circuit housing that are spaced apart with respect to one another.
[0006] The coefficient of thermal expansion within the scope of the disclosed electronic device describes the heat-dependent expansion and shrinkage of the circuit housing or the molding compound respectively.
[0007] The basic principle of the disclosed electronic device is that on the one hand the electronic circuit that is used must be protected against mechanical and electrical damage, on the other hand however said electronic circuit must be tailored suit to its end application. While the mechanical and electrical protection can be produced in the form of the circuit housing together with the electronic circuit itself in mass production, the shape of the molding compound depends on the end application and must be individually produced for this application.
[0008] It has shown itself to be favorable with regard to manufacturing technology for the circuit housing that provides protection against mechanical and electrical damage to use a different material to that used for the shape-providing molding compound. In general, the two materials also comprise different coefficients of thermal expansion that can lead to different thermal movements between the circuit housing and the molding compound. For this reason, the molding compound could after a time detach from the circuit housing so that the circuit housing could in the worst case fall out of the molding compound and therefore out of the end application.
[0009] In order to avoid this, the molding compound could be fixed to the circuit housing. This could be achieved by way of example as a result of selecting a corresponding adhesive substance that produces a fixed connection to the circuit housing. In the case of an entirely two-dimensional fixing arrangement between the circuit housing and the molding compound, the problem however arises that as a result of the different coefficients of expansion between molding compound and the circuit housing, the two become mechanically stressed with respect to one another. These mechanical stressing arrangements then also act upon the electrical circuit and load said circuit accordingly.
[0010] The disclosed electronic device proposes only fixing the molding compound to the circuit housing by way of fixing points that are spaced apart with respect to one another. These fixing points can also be parts of fixing surfaces, wherein however the fixing surfaces are then spaced apart with respect to one another. The molding compound that in general is softer than the circuit housing can then be placed like a cloth around the circuit housing and can be fixed to said circuit housing at the mentioned fixing points. In a known manner, a cloth that is fastened at various points to an expanding body forms folds such as can be observed by way of example whilst putting on a jacket that is too tight. The mechanical stresses act as directionally dependent ripples that can be used within the scope of the disclosed electronic housing in order to mechanically protect the electronic circuit.
[0011] In a further development of the disclosed electronic device, the two fixing points are selected in such a manner that a thermal deformation of the molding compound on the electronic circuit, said deformation being caused as a result of the second coefficient of thermal expansion, counteracts a thermal deformation of the circuit housing that is caused as a result of the first coefficient of thermal expansion. For the selection, it is possible by way of example to simulate by way of example the electronic device, wherein the at least two fixing points are then displaced within the scope of the simulation until the counteraction of the deformation of the molding compound and the deformation of the circuit housing at the site of the electronic circuit fulfills a specific criterion. For the simulation, a suitable mathematical model can be produced by the electronic device in a known manner and the stresses that are to be expected can be investigated.
[0012] It is particularly preferred that the above mentioned criterion is selected in such a manner that in the case of a corresponding selection of the fixing points, the deformation of the molding compound and the deformation of circuit housing cancel each other out so that mechanical loads on the electronic circuit as a result of the different thermal expansion between the molding compound and the circuit housing are minimized.
[0013] In another further development of the disclosed electronic device, at least one of the fixing points is selected in such a manner that a gap between the circuit housing and the molding compound is sealed to prevent the penetration of moisture. The basic principle of the further development is that the molding compound could detach from the circuit housing as a result of the above previously described effects of thermal expansion and a gap could thus form between the molding compound and the circuit housing. Moisture and other reagents could penetrate into this gap and after a prolonged period of operation of the electronic device could lead to a corrosion or a migration of the electronic device by way of example in the region of a signal connection and thus could accordingly interrupt or short circuit the signal connection. In order to avoid short circuits of this type or other damage that is caused as a result of moisture, at least one of the fixing points should be positioned in such a manner that the above mentioned gap is sealed with respect to an outer side.
[0014] In another further development of the disclosed electronic device, the molding compound can be injection molded or poured around the circuit housing, wherein its shrinkage during the thermosetting process after the injection molding or pouring process is selected so as to be less than shrinkage that occurs during a process of cooling from a working temperature of the electronic device to a solidification temperature of the molding compound. In this manner, it is ensured that the molding compound also lies on the circuit housing during the solidification process and thus reliably closes the gap in the manner described above.
[0015] In yet another further development of the disclosed electronic device, the surface of the circuit housing activates at the fixing points. The term an “activation of the surface of the circuit housing” is to be understood to mean hereinunder an in part break down of the molecular structure of the surface of the circuit housing so that free radicals occur at the surface of the circuit housing. These free radicals are in the position to form chemical and/or physical connections to the molding compound so that said molding compound can no longer detach from the surface of the circuit housing. In this manner, the molding compound is fixed securely to the circuit housing.
[0016] The molding compound can comprise a polar material such as polyamide. The polar polyamide can physically connect to the activated surface of the circuit housing in a manner known to the person skilled in the art and can thus be securely fixed to the circuit housing. Further connections are possible that comprise a polar surface in the melted state of the molding compound and as a consequence, form a connection to the activated surface of the circuit housing. This connection that is produced is preserved after the solidification process of the melted molding compound.
[0017] In an additional further development of the disclosed device, at least one part of the surface of the circuit housing is roughened in the contact region that is fixed to the molding compound so that the effectively activated surface enlarges and the bonding effect between circuit housing and molding compound is increased.
[0018] In a particular further development of the disclosed electronic device, the roughened part of the surface of the circuit housing is roughened using a laser. Using the laser, it is possible to not only activate the surface but by means of the laser, mold-separating means that are possibly present are also removed from the surface of the circuit housing, said mold-separating means could inhibit a bonding arrangement between the circuit housing and the molding compound.
[0019] Alternatively, the laser can also be used to roughen the surface. The activation can then be performed by way of example using a plasma.
[0020] In a particularly preferred further development of the electronic device, the roughened part of the surface of the circuit housing is roughened into the form of an identifiable feature. In this manner, the roughening can additionally be used to identify the electronic device. The feature can be selected in any arbitrary manner. The feature can thus by way of example be a machine-readable code or a numerical code that can be recognized by a user.
[0021] In an alternative further development, the disclosed electronic device is embodied as a sensor so as, using the circuit, to output an electrical signal based upon a determined physical variable. The electronic circuit can comprise a measuring sensor so as to determine the physical variable. The physical variable can be by way of example the position in space of an object that the sensor is fastened to, a mechanical stress, a magnetic field or any other physical variable. In sensors of this type, the above mentioned mechanical stresses that are caused on the measuring sensor by the circuit housing and the molding compound lead to so-called mechanical interference errors that distort the actual electrical signal that is carrying the relevant information regarding the physical variables. This is where the disclosed electronic device particularly has an effect because as a result of minimizing the mechanical stresses at the electronic circuit, the mechanical interference errors of the measuring sensor are also minimized while generating the electrical signal that is dependent upon the physical variable.
[0022] In accordance with a further aspect of the invention, a method for producing an electronic device comprises the steps of:
enclosing an electronic circuit in a circuit housing, activating the circuit housing at at least two fixing points that are spaced apart with respect to one another, and enclosing the activated circuit housing with a molding compound in such a manner that the enclosed region of the circuit housing comprises at least the fixing points.
[0026] The disclosed method can be expanded with features that correspond to the above mentioned device in an expedient manner.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above described characteristics, features and advantages of this invention and also the manner in which they are achieved become more clearly understandable in connection with the description hereinunder of the exemplary embodiments that are further described in connection with the drawings, wherein:
[0028] FIG. 1 illustrates a schematic view of a vehicle having a dynamic driving control system,
[0029] FIG. 2 illustrates a schematic view of an inertial sensor from FIG. 1 , and
[0030] FIG. 3 illustrates a further schematic view of the inertial sensor from FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Identical technical elements in the figures are provided with identical reference numerals and are only described once.
[0032] Reference is made to FIG. 1 that illustrates a schematic view of a vehicle 2 having a known dynamic driving control system. Details regarding this dynamic driving control system can be found in by way of example DE 10 2011 080 789 A1 incorporated by reference herein.
[0033] The vehicle 2 comprises a chassis 4 and four wheels 6 . Each wheel 6 can be decelerated with respect to the chassis 4 by way of a brake 8 that is fixed to the chassis 4 in a positionally fixed manner in order to decelerate a movement of the vehicle 2 on a road that is not further illustrated.
[0034] It can happen in a manner that is known to the person skilled in the art that the wheels 6 of the vehicle 2 lose their road grip and the vehicle 2 can be moved from a trajectory as a result of under-steer or over-steer, said trajectory being determined by way of example by way of a steering wheel that is not further illustrated. This is avoided by means of known control circuits such as ABS (antilock braking system) and ESP (electronic stability program).
[0035] In the present embodiment, the vehicle 2 comprises for this reason rotational speed sensors 10 on the wheels 6 and said rotational speed sensors determine a rotational speed 12 of the wheels 6 . In addition, the vehicle 2 comprises an inertial sensor 14 that determines dynamic driving data 16 of the vehicle 2 and from said dynamic driving data it is possible to output by way of example a pitch rate, a roll rate, a yaw rate, a lateral acceleration, a longitudinal acceleration and/or a vertical acceleration in a manner that is known to the person skilled in the art.
[0036] Based upon the determined rotational speeds 12 and driving dynamic data 16 , a controller 18 can determine in a manner known to the person skilled in the art whether the vehicle 2 is slipping on the road surface or is even deviating from the above mentioned predetermined trajectory and can react to said deviation according to a controlling signal 20 that is known per se. The controller output signal 20 can then be used by a positioning device 22 in order by means of signals 24 to control control elements such as the brakes 8 that react to the slipping action and to the deviation from the predetermined trajectory in a manner known per se.
[0037] The controller 18 can be integrated by way of example into a motor control of the vehicle 2 , said motor control being known per se. The controller 18 and the positioning device 22 can also be embodied as a common control device and can be optionally integrated into the motor control in the above mentioned manner.
[0038] FIG. 1 illustrates the inertial sensor 14 as an external device outside the controller 18 . In a case of this type, said inertial sensor is known as an inertial sensor 14 embodied as satellites. However, the inertial sensor 14 could also be constructed as an SMD component so that said inertial sensor can be integrated by way of example in a housing of the controller 18 .
[0039] Reference is made to FIG. 2 that illustrates the inertial sensor 14 in a schematic illustration.
[0040] The inertial sensor 14 comprises an electronic circuit having at least one microelectromechanical system 26 , called MEMS 26 , as a measuring sensor that in a known manner outputs a signal that is not further illustrated and is dependent upon the driving dynamic data 16 by way of an amplifying circuit 28 to two signal evaluating circuits 30 in the form of application-specific integrated circuit 30 , ASIC 30 . The ASIC 30 can then generate the driving dynamic data 16 based upon the received signal that is dependent upon the driving dynamic data 16 .
[0041] The MEMS 26 , the amplifying circuit 28 and the ASIC 30 are carried on a circuit board 32 and are contacted in an electrical manner by different electrical lines 34 , which are formed on the circuit board 32 , and bond wires 35 . Alternatively, the circuit board 32 could also be embodied as a lead frame. An interface 36 could be present so as to output the driving dynamic data 16 that is generated.
[0042] In addition, the MEMS 26 and the ASIC 30 can be molded into a circuit housing 38 that can be produced by way of example from thermosetting material. The circuit housing 38 could therefore already be used alone as the housing of the inertial sensor 14 and could protect the circuit components that are received within said housing.
[0043] However, the inertial sensor 14 is not limited to the application in the driving dynamic control system that is described in the introduction and is therefore produced for a plurality of different end applications. In order to integrate the inertial sensor 14 into the driving dynamic control system, said inertial sensor is also injection molded using a molding compound 40 , also known as an overmold 40 . An overmold opening 41 can be left in the molding compound 40 in order by way of example to expose a serial number sign that is not further illustrated.
[0044] This molding compound 40 can be by way of example a thermoplastic and comprises a coefficient of thermal expansion that is different to the coefficient of thermal expansion of the circuit housing 38 .
[0045] As a result of these different coefficients of thermal expansion, the circuit housing 38 and the molding compound 40 expand in a different manner under the influence of temperature and, as is illustrated in FIG. 2 , detach from one another after a specific expansion so that between the circuit housing 38 and the molding compound 40 a gap 42 is formed by way of which inter alia moisture 44 can penetrate and can damage the circuit board 32 having the conductor paths 34 .
[0046] In order to avoid these gaps forming, the circuit housing 38 in the present embodiment, as is illustrated in FIG. 3 , is activated on the surface in specific surface zones 46 . Within the scope of the activation, the molecular structure of the surface of the circuit housing 38 is in part broken down in the region of the surface zones 46 so that free radicals occur on the surface of the circuit housing 38 . These free radicals are in the position to form chemical and/or physical connections with the molding compound 40 so that said molding compound can no longer detach from the surface of the circuit housing 38 in the region of the surface zones 46 . In this manner, the molding compound 40 is fixedly fastened to the circuit housing 38 .
[0047] In the present embodiment, the surface zones 46 are embodied in addition in predetermined spacings 48 with respect to one another and in FIG. 3 only one of said spacings is illustrated with a spacing arrow for reasons of clarity. The surface of the circuit housing 38 is not activated within these spacings 48 so that the molding compound 40 remains movable with respect to the circuit housing 38 . The molding compound 40 can therefore contort in the case of a thermal movement of the circuit housing 38 , fixed at the activated surface zones 46 of the circuit housing 38 like a cloth and a mechanical stress that is applied as a result of the thermal movement of the circuit housing 38 to the molding compound 40 counteracts a particular mechanical stress. If the spacings 48 of the surface zones 46 are suitably selected, the mechanical stresses of the circuit housing 38 and the molding compound 40 on the site of the MEMS 26 can cancel each other out and therefore reduce mechanical interference errors of the MEMS 26 that would otherwise occur under the influence of these mechanical stresses.
[0048] In order to suitably place the activated surface zones 46 in such a manner that the mechanical stresses cancel each other out at the site of the MEMS 26 , by way of example the inertial sensor 14 can be mechanically simulated in advance. Alternatively, the position of the activated surface zones 46 could also naturally be tested on prototypes.
[0049] In order to avoid the penetration of the above mentioned moisture 44 , as a further basic condition at least one of the activated surface zones 46 could extend around an edge of the overmold opening 41 .
[0050] The activation can be performed using a laser, wherein some activated surface zones 46 could be embodied so as to carry information. These surface zones 46 could thus be embodied by way of example as strings of characters that subsequently render it possible to read data regarding the inertial sensor such as by way of example production date and/or location. | An electronic device including: an electronic circuit accommodated in a circuit housing having a first thermal expansion coefficient, and a moulded body which surrounds the circuit housing, the body having a second thermal expansion coefficient that differs from the first thermal expansion coefficient. The moulded body is fixed to the circuit housing at least at two different mutually spaced fixing points on the circuit housing. |
RELATED APPLICATIONS
This application is a divisional of prior U.S. patent application Ser. No. 11/131,847 filed May 18, 2005, and claims the benefit of and priority to U.S. patent application Ser. No. 11/131,847 which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to vehicle recovery systems and, in particular, a vehicle locating unit of such a system with improved power management techniques.
BACKGROUND OF THE INVENTION
The applicant's successful and popular vehicle recovery system sold under the trademark LoJack® includes a small electronic vehicle locating unit (VLU) with a transponder hidden within a vehicle, a private network of communication towers each with a remote transmitting unit (RTU), one or more law enforcement vehicles equipped with a vehicle tracking unit (VTU), and a network center with a database of customers who have purchased a VLU. The network center interfaces with the National Criminal Information Center. The entries of that database comprise the VIN number of the customer's vehicle and an identification code assigned to the customer's VLU.
When a LoJack® product customer reports that her vehicle has been stolen, the VIN number of the vehicle is reported to a law enforcement center for entry into a database of stolen vehicles. The network center includes software that interfaces with the database of the law enforcement center to compare the VIN number of the stolen vehicle with the database of the network center which includes VIN numbers corresponding to VLU identification codes. When there is a match between a VIN number of a stolen vehicle and a VLU identification code, as would be the case when the stolen vehicle is equipped with a VLU, and when the center has acknowledged the vehicle has been stolen, the network center communicates with the RTUs of the various communication towers (currently there are 130 nationwide) and each tower transmits a message to activate the transponder of the particular VLU bearing the identification code.
The transponder of the VLU in the stolen vehicle is thus activated and begins transmitting the unique VLU identification code. The VTU of any law enforcement vehicles proximate the stolen vehicle receive this VLU transponder code and, based on signal strength and directional information, the appropriate law enforcement vehicle can take active steps to recover the stolen vehicle. See, for example, U.S. Pat. Nos. 4,177,466; 4,818,988; 4,908,609; 5,704,008; 5,917,423; 6,229,988; 6,522,698; and 6,665,613 all incorporated herein by this reference.
Since the VLU unit is powered by the vehicle's battery, power management techniques must be employed in the VLU to ensure the VLU does not drain the vehicle's battery. One prior technique employed by the applicant includes programming the VLU to “wake up” and check for messages from the communication towers only periodically, e.g., every 8 seconds for 0.2 seconds. The timing of the sleep and wake-up modes was synchronized to the transmission schedule of one communication tower. See U.S. Pat. No. 6,229,988.
But, if the vehicle equipped with the VLU so programmed moves out of the transmission range of that tower, when the VLU wakes up, no signal will be received from that tower. According to prior methods, the VLU must wake up for a longer time in order to be sure to receive a tower transmission since the VLU has no memory of which time slot the tower is likely to transmit. This results in increased power consumption.
BRIEF SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a vehicle locating unit with improved power management technique.
It is a further object of this invention to provide such a vehicle locating unit whose wake-up and sleep modes are synchronized to the communication source transmitting the strongest signal.
It is a further object of this invention to provide such a vehicle locating unit which continuously updates its memory to store the identity of one or more communication towers with the strongest signals.
The subject invention results from the realization that a more effective power management subsystem for a VLU is configured to alternately enter sleep and wake-up modes, to synchronize the wake-up mode to the communication source (e.g., tower) transmitting the strongest signal, and to test the signal strength of at least one additional communication source in sequence.
The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives.
The subject invention features a vehicle locating unit with improved power management. A receiver receives a signal from a network of communication sources and a signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. The power management subsystem is responsive to the signal strength monitoring subsystem and is configured to: alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source according to a predefined sequence.
Typically, the power management subsystem is configured to test and store the identity of two communication sources with the two strongest signals, switch to synchronization with any communication source having a signal stronger than the strongest signal of the two stored communication sources, and store the identity of any communication source with a signal stronger than the signal of any previously stored communication source.
In one embodiment, there are n (e.g., eight) communication sources each transmitting a signal at a different time every n seconds. Preferably, the power management system is configured to include a start-up mode wherein all communication sources are tested. In one preferred embodiment, the power management subsystem is implemented in a microcontroller which is configured to power down the receiver during the sleep mode and to power up the receiver during the wake-up mode. One example of a signal strength monitoring subsystem includes a demodulation circuit embodied in a transceiver.
A method of checking messages from a network of communication sources in accordance with this invention includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal, testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of the stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication source tested in sequence presents a signal stronger than the signal of said stored communication source.
For VLUs and other electronic receivers which receive a signal from a network of communication sources, a signal strength monitoring subsystem determines which of the communication sources are transmitting the strongest signals. A power management subsystem is responsive to the signal strength monitoring subsystem and is configured to: alternatively enter sleep and wake-up modes, synchronize the wake-up mode to the communication source transmitting the strongest signal, and test the signal strength of at least one additional communication source to ensure the wake-up mode is synchronized to the communication source transmitting the strongest signal.
One embodiment features a vehicle locating unit power management system comprising a memory, and a controller configured to alternatively output sleep and wake-up mode signals, store in said memory the identity of at least a first communication source presenting the strongest signal, test the signal strength of at least one different communication source during the wake-up mode, synchronize the wake-up mode to the communication source identified in said memory, and update the memory to store the identity of a different communication source presenting a signal stronger than the first communication source.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
FIG. 1 is a schematic block diagram showing the primary components associated with a vehicle recovery system in accordance with the subject invention;
FIG. 2 is a block diagram showing the primary components associated with a vehicle locating unit in accordance with the subject invention;
FIG. 3 is a flow chart depicting the primary steps associated with one example of the programming of the microcontroller of the vehicle locating unit shown in FIG. 2 as it relates to power management; and
FIG. 4 is a schematic timing diagram showing a time slot synchronization pattern for an example of a communication network including eight communication towers.
DETAILED DESCRIPTION OF THE INVENTION
Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
As discussed in the background section above, the applicant's successful and popular vehicle recovery system sold under the trademark LoJack® includes a small electronic vehicle locating unit (VLU) 10 , FIG. 1 , with a transponder 12 hidden within a vehicle 14 , a private network of communication towers 16 each with a remote transmitting unit (RTU) 18 , one or more law enforcement vehicles 20 equipped with a vehicle tracking unit (VTU) 22 , and network center 24 .
When a LoJack® product customer reports that her vehicle has been stolen, the VIN number of the vehicle is reported to law enforcement center 26 for entry into database 28 of stolen vehicles. Network center 24 includes software that interfaces with database 28 of law enforcement center 26 to compare the VIN number of the stolen vehicle with database 30 of network center 24 which includes VIN numbers corresponding to VLU identification codes. When there is a match between a VIN number of a stolen vehicle and a VLU identification code, as would be the case when stolen vehicle 14 is equipped with VLU 10 , network center 24 communicates with the RTUs 18 of the various communication towers 16 and each tower transmits a message to activate transponder 12 of VLU 10 bearing the particular identification code.
Transponder 12 of VLU 10 in stolen vehicle 14 , once activated, begins transmitting a unique VLU identification code. VTU 22 of law enforcement vehicle 20 proximate stolen vehicle 14 receives this VLU transponder code and, based on signal strength and directional information, the appropriate law enforcement vehicle can take active steps to recover stolen vehicle 14 .
VLU 10 ′, FIG. 2 , in accordance with the subject invention includes transceiver 40 or, in another example, a receiver without transmission capabilities. Signal strength monitoring subsystem 42 , in one embodiment, is a demodulator circuit on a chip within transceiver 40 and outputs a signal identifying and characterizing the signal strength of all signals received by transceiver 40 via antenna 44 from the communication network and one or more communication towers 16 , FIG. 1 .
Microcontroller 46 , FIG. 2 , (e.g., a Texas Instrument microcontroller model No. MSP430) receives the output of subsystem 42 , is programmed to evaluate the signal strength of all signals received by transceiver 40 , and is also programmed to alternatively cause transceiver 40 to enter sleep and wake-up modes to save battery power by outputting a signal to power supply unit circuitry 48 in accordance with the flow-chart of FIG. 3 . Memory 47 , FIG. 2 , is shown separate from controller 47 but many microcontrollers, as is known by those skilled in the art, have internal memories including the controller example above.
In the following example, there are eight communication sources or LoJack® towers A-H, FIG. 4 , transmitting signals to VLU 10 ′, FIG. 2 . Each transmits a synchronization signal at a different time t 0 -t 7 each eight seconds and possibly a message (in the case of a reportedly stolen vehicle) in which instance microcontroller 46 , FIG. 2 would activate transponder 12 .
But, transceiver 40 , if continuously left on to check for such a message, would more quickly drain the battery of the vehicle. According to the subject invention, microcontroller 46 at start-up, step 60 , FIG. 3 , tests the signal strength of towers A-H by analyzing the output of signal strength monitoring subsystem 42 . In this test mode, the signal strength of each tower is noted and if any signal carries a message, the message is acted upon.
The identity of the two strongest tower signals is stored in memory 47 , FIG. 2 , step 62 , FIG. 3 , and the wake-up mode is then synchronized, step 64 , to the strongest of these two signals. Next, the sleep mode is entered and when the wake-up mode is activated in synchronization with the communication tower presenting the strongest signal, the signal strength of the two previously stored towers is tested as is the signal strength of one additional communication tower, in sequence.
As an example, suppose towers A and B, FIG. 4 , are transmitting the strongest signals by virtue of their proximity to VLU 10 , FIG. 2 . If tower A's signal is assumed to be stronger than tower B's signal, the wake-up mode synchronization is in accordance with tower A's signal. Thus, in each cycle, (typical wake up times are 8 sec. apart), controller 46 would power up transceiver 40 by signaling power supply unit circuit 48 at time t 0 , FIG. 4 , and sleep between times t 1 -t 7 , steps 66 - 68 . At the next wake-up time, the signal strength of the two previously stored towers (A and B) is tested for strength as is the signal strength of the next tower according to a predefined sequence which, in this example, is tower C, step 70 . In this way, if at any time due to movement of the vehicle a different tower in the sequence A-H presents a stronger signal than a) the tower upon which controller 46 synchronizes the wake-up mode or b) the stored identity of the tower with the second strongest signal, the identity of the new tower is stored in memory 47 , FIG. 2 , steps 72 - 74 , FIG. 3 , and synchronization to the tower with the strongest signal is ensured at step 64 .
Suppose, however, that tower C does not present a stronger signal than either towers A or B and that the wake up and sleep modes are still synchronized to tower A in step 66 . At steps 68 and 70 towers A, B, and now D are tested and if tower D's signal strength is not stronger than either tower A or B and once again the sleep mode is entered, step 66 . Upon entering the wake-up mode at step 68 , still synchronized to tower A, the signal strength of towers A, B, and now E is checked, step 70 .
Now, if the signal strength of tower E is stronger than the signal strength of tower B, but not tower A, the identity of tower E is stored in memory 47 , FIG. 2 at step 74 , FIG. 3 , replacing tower B. But at step 64 the wake-up mode is still synchronized to the strongest tower, namely tower A at steps 64 - 68 .
So, next, the signal strengths of towers A, E, and F are tested, step 70 ; and suppose at step 72 the signal strength of tower F is stronger than tower A and E but tower A is still stronger than tower E. Now, synchronization will be according to tower F at step 64 and at step 70 , towers F, A, and G are tested, and so on.
In another example, imagine towers C and D initially present the strongest first and second signals to the VLU. The wake up mode is initially synchronized to tower C and the identity of towers C and D are stored in memory. After the first sleep mode, the signal strength of towers C, D, and E are tested, and next towers C, D, and F, and then towers C, D, and G, and then towers C, D, and H, and so on—one additional tower during each subsequent wake-up mode. If during this wake-up/sleep mode cycle, towers C and D remain the strongest two towers, synchronization remains with tower C and the memory continues to store the identity of towers C and D. If during the next cycle, when tower A is tested and is found to present a signal stronger than tower D but not C, the memory is updated to store the identity of towers C and A, synchronization continues according to tower C's transmission schedule, and during each subsequent wake-up mode the signal strength of towers C, A, and B; C, A, and D; C, A, and E; C, A, and F . . . and so on is tested.
In this way, the identity of the towers which transmit the two strongest signals is always stored and controller 46 , FIG. 2 in sequence checks another tower in the wake-up mode to maintain in storage 47 , FIG. 2 , the identity of the two towers emitting the strongest signals. Also, controller 46 ensures the wake-up mode is synchronized to only the tower emitting the strongest signal. Power is conserved but now in a way which ensures no communication message from any tower in the network is missed. To enter the sleep mode, microcontroller 46 sends a signal to power supply unit 48 which then powers down transceiver 40 . To enter the wake-up mode, microcontroller 46 sends a signal to power supply unit 48 which then again provides power to transceiver 40 so that it can receive signals via antenna 44 .
The example presented above in reference to FIGS. 3-4 assumes eight towers in a given region, continuous storage of the two strongest tower signals, and testing of an additional tower in a specific sequence, but this is an example only and not a limitation of the subject invention: any number and combination of towers and storage of tower combinations can be used. The example above also assumes that the power management method of the subject invention applies to a VLU of a vehicle recovery system but the invention hereof may find applicability to battery powered electronic devices other than VLUs.
Thus, although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. Moreover, the words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Also, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. Other embodiments will occur to those skilled in the art and are within the following claims.
In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended. | A method of checking messages from a network of communication sources includes initially testing the signal strength of a plurality of communication sources, storing the identity of the communication sources with the two strongest signals, and alternatively entering a sleep mode and a wake-up mode, the wake-up mode synchronized to the communication source with the strongest signal. The method further includes testing the signal strength of one additional communication source, switching synchronization to the additional communication source if said source presents a signal stronger than the signal of a stored communication source with the strongest signal, and replacing the identity of any stored communication source if an additional communication sources tested in sequence presents a signal stronger than the signal of said stored communication source. |
BACKGROUND OF INVENTION
This invention relates generally to asset funding, and more particularly, to automated identification of assets subject to transactions and automated offerings of financing in connection with such transactions.
Assets such as aircraft, locomotives, rail cars, and barges often are sold, leased or financed many times over the course of their useful lives. When such assets are sold, the purchaser often secures financing. More specifically, the purchaser typically identifies a number of financing sources and then selects one financing source for the transaction. The seller also may work with financing sources and explain to prospective purchasers that financing from a particular source is available for the transaction.
Financing sources typically market their services through various media. The marketing efforts also may be directed to both regular sellers and purchasers of specific types of assets. In addition, these financing entities also may search publications for information relating to assets being offered for sale. The known techniques for identifying sellers of assets as well as identifying assets being offered for sale are manually intensive and requires resources and time.
In addition, once a prospective customer for a financing product has been identified, i.e., a seller of an asset, an individual from the financing entity marketing operation may contact the prospective seller, explain the various financing products available, and work with the prospective seller towards closing the deal with the purchaser. Of course, numerous attempts may be required in order to make such contact, and once contact is made, it may require several conversations before an applicable financing product is identified and offered to the prospective purchaser.
SUMMARY OF THE INVENTION
In one aspect, a method for operating a computer to execute a search to identify potential transactions that meet pre-defined criteria, generate an offering for at least one of the identified potential transactions, and transmit the offering to a party for the potential transaction is described. In an exemplary embodiment, the search is automated and performed on-line via a wide area network such as the Internet. The search is automated in that once a user enters search criteria, the search is performed in accordance with a defined frequency and without requiring user intervention. Once search results are found, then an offering is generated and transmitted to a potential customer. Depending on the type of the transaction, a customer may be identified either as a buyer or a seller.
In another aspect, a database comprising data corresponding searches to be performed, and data corresponding to offerings generated utilizing search results from the performed searches, is described. The search criteria and search results are stored in the database. Once search results are found, then the data stored in the database is utilized to generate an offering that is then transmitted to a potential customer. Data related to the offering also is stored in the database.
In yet another aspect, a system for searching and generating offerings is described. In an exemplary embodiment, the system includes a database and a server coupled to the database. The database includes data corresponding searches to be performed and data corresponding to offerings generated utilizing search results from the performed searches. The server is configured to execute a search to identify potential transactions that meet pre-defined criteria, generate an offering for at least one of the identified potential transactions, and transmit the offering to a party to the potential transaction.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 a flow chart illustrating process steps for automated searching and product offering.
FIG. 2 is a block diagram of a network based system.
FIG. 3 is an exemplary screen shot of a log-on screen.
FIGS. 4 and 5 illustrate an exemplary screen shot of a register screen.
FIG. 6 is an exemplary screen shot of a screen for defining asset types.
FIG. 7 illustrates an exemplary screen shot of a screen for refining asset types.
FIG. 8 illustrates an exemplary screen shot of a screen for defining price ranges.
FIG. 9 illustrates an exemplary screen shot of a screen for defining search targets.
FIG. 10 illustrates an exemplary screen shot for defining search parameters.
FIG. 11 illustrates an exemplary screen shot for notification setup.
FIG. 12 illustrates an exemplary screen shot for a search setup confirmation.
FIG. 13 illustrates an exemplary screen shot for a screen for locating searches.
FIG. 14 illustrates an exemplary screen shot for a screen for viewing search results.
FIG. 15 illustrates an exemplary screen shot for a screen for customizing product offerings.
FIG. 16 illustrates an exemplary screen shot for a screen for customizing product text offerings.
FIG. 17 illustrates an exemplary screen shot for a screen for confirming that an offer had been sent.
FIG. 18 illustrates an exemplary screen shot for a screen for viewing offerings.
FIG. 19 illustrates an exemplary screen shot for a screen for locating offerings.
FIGS. 20-23 illustrate an exemplary screen shot for a screen for defining standards.
FIGS. 24-25 illustrate an exemplary screen shot for managing user administration.
DETAILED DESCRIPTION
Set forth below is a description of methods and systems for an automated deal lead generator which searches for and locates assets for sale, and offers financing products to potential customers of those assets. Depending on the type of the transaction, customers may be identified either as buyers or sellers. While the methods and systems are sometimes described in the context of aircraft, the methods and systems are not limited to practice in connection with only aircraft. The methods and systems can be used, for example, in connection with automobiles, rail cars, barges, and many other different types of assets.
In an exemplary system, a web server coupled to an application server performs the search and offer utilizing the internet. The application server includes a search engine for performing searches, via the web server, on the internet as described below in more detail. In the exemplary system, a database server is coupled to the application server.
Generally, a user defines asset types to search for as well as select sites to be searched. The user also defines the search parameters and sets-up, and designates, notification types and methods. The user defined assets and searches are stored in the database server and used by the application server in performing the search.
Specifically, the system searches for the user defined asset types on the user selected sites. Such a search is performed in accordance with the search parameters (e.g., at pre-designated intervals), and the search results are stored in the database. The user is notified that a search result or results have been found via the notification method selected by the user. A user can then review the search results.
In addition to the automated searching as described above, the system generates offerings that are sent to potential customers. Specifically, the user specifies pre-defined text and product types to be transmitted to a potential customer via e-mail, fax, or otherwise, upon identification of such potential customer by the user from the search results. Each offer also is stored in the database so that the user can review each offer.
The search and offer systems and methods facilitate effective searching and identification of deals. In addition, such methods and systems also facilitate effective sourcing of deals.
FIG. 1 a flow chart illustrating steps of an exemplary process for automated searching and product offering. As shown in FIG. 1, a user initially defines assets to be identified and searches to be performed. The assets can be a wide variety of types, and the method is not limited to practice in connection with any one particular asset type. For example, if the asset is an aircraft, then the asset can be defined by aircraft type, aircraft model, engine type, and aircraft age.
In addition, a search to be performed is identified. For example, the user selects web sites and web publications to be searched. The user also defines the search parameters. For example, the user specifies a search pattern (e.g., define whether the search is conducted daily, weekly, monthly, or yearly) and a search timing (e.g., define the day, month, and year the search is to be initiated).
Once the assets and search are defined, then a search is executed by the system. For example, a defined web publication is searched with the defined frequency, and the results of the search are returned if such results are within the defined parameters for the asset. The search results are stored in the database server. The system also alerts the user that a search has been completed and that assets have been identified. Specifically, the system generates a search notification that is communicated to the user, e.g., via e-mail, a fax, a page. The user can define the notification method based on various options available.
The system also generates a product offering. In an exemplary embodiment, the user identifies search results and selects pre-defined text and product types which are then transmitted to the customer via user requested notification method. In an exemplary embodiment, notification method is a notification via an electronic mail. In yet another embodiment, notification may be via a fax. The user can also define that if the same text result is found in subsequent searches, same offer will go automatically to the seller. For example, if an aircraft is identified that is the subject of a negotiation, the system generates an offering identifying financing that the seller of the aircraft could offer a prospective buyer in connection with the purchase or lease of the aircraft.
Set forth below are descriptions of specific exemplary embodiments of systems and methods for identifying assets being sold or financed and offering financing products that the sellers or lessors of those assets can utilize in connection with negotiating transactions with potential buyers. The systems and methods are not, of course, limited to the exemplary embodiments described below.
FIG. 2 is a block diagram of a network based system 22 . System 22 includes server sub-system 12 and end user devices 14 . Server sub-system 12 includes database server 16 , an application server 24 , a web server 26 , a fax server 28 , a directory server 30 , and a mail server 32 . A disk storage unit 34 is coupled to database server 16 and directory server 30 . Servers 16 , 24 , 26 , 28 , 30 , and 32 are coupled in a local area network (LAN) 36 . In addition, a system administrator work station 38 , a work station 40 , and a supervisor work station 42 are coupled to LAN 36 . Alternatively, work stations 38 , 40 , and 42 are coupled to LAN 36 via an Internet link or are connected through an intranet.
Each work station 38 , 40 , and 42 is a personal computer including a web browser. Although the functions performed at the work stations typically are illustrated as being performed at respective work stations 38 , 40 , and 42 , such functions can be performed at one of many personal computers coupled to LAN 36 . Work stations 38 , 40 , and 42 are illustrated as being associated with separate functions only to facilitate an understanding of the different types of functions that can be performed by individuals having access to LAN 36 .
Server sub-system 12 is configured to be communicatively coupled to various individuals or sites 44 via an ISP Internet connection 48 . The communication in the exemplary embodiment is illustrated as being performed via the Internet, however, any other wide area network (WAN) type communication can be utilized in other embodiments, i.e., the systems and processes are not limited to being practiced via the Internet. In addition, and rather than a WAN 50 , local area network 36 could be used in place of WAN 50 .
In the exemplary embodiment, an individual (e.g., an employee) 44 having a work station 52 can access server sub-system 12 . Work station 52 is a personal computers including a web browser. Also, work station 52 is configured to communicate with server sub-system 12 . Furthermore, fax server 28 communicates with individuals 44 and other work stations 38 , 40 , and 42 as well.
In one specific exemplary embodiment, the following commercially available hardware and software are utilized: Web Server platform Windows NT 4.0 SP 5; Database Server platform Windows NT 4.0; Internet Information Server (IIS) 4.0; Microsoft Transaction Server (MTS); COM objects using VB 6.0 dlls; Active Server Pages 3.0; JScript 5.0; VBScript 5.0; and Database Oracle 8.1.6 and 8.0.5. The extranet site operates under IE 4.0 and Netscape 4.0.
Set forth below are details regarding exemplary screen shots displayed by system. Generally, the following screen shots illustrate exemplary screens for log on and registration (FIGS. 3 - 5 ), search set-up (FIGS. 6 - 12 ), results review (FIGS. 13 - 17 ), offering review (FIGS. 18 19 ), standards definition (FIGS. 20 - 23 ), and administration (FIGS. 24 - 25 ).
FIG. 3 is an exemplary screen shot of a log-on screen. Users are required to enter a User Name and Password. The log-on screen can be accessed via an intranet or the internet. Generally, via the log-on screen, users can access the search set up, search results, offerings, user administration, and registration Specifically, after logging on, the user can select Search Setup (FIG. 6 ), Locate Searches (FIG. 13 ), Locate Offerings (FIG. 19 ), View/Amend Standards (FIG. 20 ), User Profile (FIG. 24 ), and Exit.
Users will can select Register (FIG. 4) to register for the site or select “forgotten password” to generate an email. The email is automatically addressed to the webmaster for the site with the subject “Forgotten Password” and in the message area the text “Please send me my password”. The user can enter additional information in the message area.
FIGS. 4 and 5 illustrate an exemplary screen shot of a register screen. The user can enter details about himself and submit the information to the webmaster via the register screen to be set-up as an authorized user. More specifically, the user is prompted to enter first name, last name, company, telephone, fax, e-mail, User Name, and a password. The user can also define how notifications are to be sent, e.g., e-mail, wireless devices, instant messengers. Once the fields are populated and the notification selections are made, and after the user selects Send, processing returns to the page illustrated in FIG. 3 . In addition, the user entered data is saved in the database and an e-mail is sent to the web master informing the web master that a new user has requested registration. The web master can then authorize a new user as described below in connection with FIG. 24 .
FIG. 6 is an exemplary screen shot for defining asset types. Using this screen, users select the aircraft types to be searched. At the top of this screen, a graphic is displayed illustrating the step being executed by the user. The graphic communicates to the user how many steps are involved in the process and where they are in the process.
Two “check” box options are above the tables, i.e., view standard aircraft type list and use custom aircraft type list. By selecting view standard aircraft type list, the user indicates that standard asset types listed in the standards table are to be searched. The standard tables are discussed below in more detail in connection with FIG. 20 . By selecting use custom aircraft type list, the user indicates that a customized list of aircraft types is to be searched. The tables are displayed, and each table is imbedded within the main screen with associated vertical scroll bars.
Regarding the customized aircraft type list, the user can use this list to view all asset types (in the database) and select individual aircraft types to be searched. Next to each aircraft type is a “check” box. By checking a box, the user indicates the asset type to be searched.
Below the tables, a “check” box provides the user with an option to further customize the search criteria (e.g., aircraft model, engine, age and price). If the User selects this option, when the user selects “Proceed”, processing proceeds the screen shot illustrated in FIG. 7 . If the User does not select this option, processing proceeds to the screen shot illustrated in FIG. 9 .
FIG. 7 illustrates an exemplary screen shot for refining asset types. Using this screen, users can refine the search criteria for each aircraft type that was selected on the screen illustrated in FIG. 6 . Columns of data are displayed based on the options selected by the User. Specifically, if the user selected the standard list option, all aircraft types in the standard list are displayed. If the user customized the list of aircraft to be searched, all aircraft types that were “checked” in the table are displayed.
For each aircraft model, each drop down list displays the model types that are applicable for the aircraft type in the corresponding row. Similarly, for engine type, each drop down list displays the engine types that are applicable for the aircraft type in the corresponding row. For aircraft age from and to, each drop down list has a series of options the user can select from.
Above Aircraft Model, engine Type, Aircraft Age From, and Aircraft Age To, the user has the option to select “Use Standards”. The standards are defined in the standards table as described below in connection with FIG. 20 . In addition, below each Use Standards selection is a View Standards selection. By selecting View Standards, processing proceeds to the screen shown in FIG. 20 .
Below the columns there is a “check box” that if selected by the user, causes processing to proceed to FIG. 8 upon selecting Proceed. This screen allows the user to select whether to further refine the search by “Price To” and “Price from”. If the user does not select to define from and to price ranges, then processing proceeds to the screen shown in FIG. 9 . The user can also select “Go Back” to return processing to the screen shown in FIG. 7 or EXIT to return processing to the screen shown in FIG. 3 FIG. 8 illustrates an exemplary screen shot for defining price ranges. Using this screen, users can refine the search criteria by “Aircraft Price From” and “Aircraft Price To” for the selections chosen on the screen illustrated in FIG. 7 .
The following columns of data will appear. The number of rows is dictated by the number of unique variations in “Aircraft Type”, “Aircraft Model”, “Engine Type”, “Aircraft Age From” and “Aircraft Age To” that the user selected, e.g., if the user selects 1 “Aircraft Type”, 4 “Aircraft Model”, 6 “Engine Type”, 2 “Aircraft Age From” and 2 “Aircraft Age To”, 96 rows of data will be shown.
For aircraft price from and to, each drop down list has a series of options that can be selected by the user. The user also has the option to select “Use Standards”. The standards are defined in the standards table as described below in connection with FIG. 20 .
In addition, below each Use Standards selection is a View Standards selection. By selecting View Standards, processing proceeds to the screen shown in FIG. 20 .
Upon selecting Proceed, processing proceeds to the screen shown in FIG. 9 . The user can also select “Go Back” to return processing to the screen shown in FIG. 7 or EXIT to return processing to the screen shown in FIG. 3 .
FIG. 9 illustrates an exemplary screen shot for defining search targets. Using this screen, users select the web sites and web publications to be searched. More specifically, the screen includes a web site selection section and a web publication section. A user can select to have all web sites and web publications searched, and if the user so selects, then other options on the screen are not selectable. In addition, if “Search Standard List” is selected, then “Search The Following Web Sites Only” cannot be selected and visa versa. The same applies for web publications.
In the web site selection section, users can select Search Standard List. If selected, then web sites that have been selected as described below in connection with FIG. 20 are searched. Next to the “Search Standard List” “check” box is a command button that will take the user to the screen illustrated in FIG. 20, which displays the standards so that an informed decision can be made whether to select “Use Standards”.
If search the following web sites only is checked, then only the web sites that have been checked in the table will be searched. The table has a list of the standard web sites. Next to each web site name is a “check” box. The User selects the web sites to be searched. If the user selects any web sites, then the search the following web sites only check box is automatically selected.
The user can also select the check box associated with the text In addition, search the following websites which I will add the URL for. If the user selects this option, the user then enters the URL for each additional web site to be searched.
For the web publication section, users can select Search Standard List. If selected, then web publications that have been selected as described below in connection with FIG. 20 are searched. Next to the “Search Standard List” “check” box is a command button that will take the user to the screen illustrated in FIG. 20, which displays the standards so that an informed decision can be made whether to select “Use Standards”.
If search the following web publications only is checked, then only the web publications that have been checked in the table will be searched. The table has a list of the standard web publications. Next to each web publication name is a “check” box. The user selects the web publications to be searched. If the user selects any web publication, then the search the following web publications only check box is automatically selected.
The user can also select the check box associated with the text In addition, search the following web publications which I will add the URL for. If the user selects this option, the user then enters the URL for each additional web site to be searched.
Upon selecting Proceed, processing proceeds to the screen shown in FIG. 10 . The user can also select “Go Back” to return processing to the screen shown in FIG. 8 or EXIT to return processing to the screen shown in FIG. 3 .
FIG. 10 illustrates an exemplary screen shot for defining search parameters. Using this screen, users define the search parameters to be utilized in performing the search. By selecting Use standard search parameters, the standard search parameters defined as described below in connection with the screen shown in FIG. 20 will be used. Next to the “Use standard search parameters” “check” box is a command button that results in processing proceeding to the screen shown in FIG. 20 so that the user can make an informed decision whether to select the “Use Standard Search Parameters”.
If the standard search parameters are not used, then the user selects a search pattern, a search timing, and defines the search data returned. For search pattern the user selects a period, e.g., daily, weekly, monthly or yearly, a recurrence, e.g., if the user selects a weekly search pattern, the user defines the number of weeks between occurrences. Similarly, if the user selects weekly, the user also can define the day on which the search is performed.
The user also selects a search timing. Specifically, the user defines a day, month and year (via drop down boxes) the search is to be initiated. If the user selects No end date, the search will repeat continuously. If the user selects End after x occurrences, then after entering a value for x, the search is conducted x times before ending. If the user select End by and specifies a Day, Month, and Year (drop down boxes), then the search will end on the entered date.
Regarding the search data returned, the user specifies the data to be displayed in the search results. For aircraft, for the example, the data includes Aircraft Type, Contact Name, Contact Telephone Number, and Contact Email.
The user also selects how the search results are to be sorted. Three layers for sorting are providing, and the user can select whether the data is to be sorted in ascending or descending order.
Upon selecting Proceed, processing proceeds to the screen shown in FIG. 11 . The user can also select “Go Back” to return processing to the screen shown in FIG. 9 or EXIT to return processing to the screen shown in FIG. 3 .
FIG. 11 illustrates an exemplary screen shot for notification setup. Using this screen, users define the notifications to be received and how the notifications are to be sent. For example, a user can select Use standard notification setup, and if this is selected, then the standard notification setup as explained below in connection with FIG. 20 is used. Next to the “Use standard notification setup” is a command button for View Standards which, if selected, causes processing to proceed to the screen illustrated in FIG. 20 so that the user can view the standards and make an informed decision whether to select the standard notification setup.
The User can be sent various notifications via the notification methods selected. The notification message includes, for example, an ID# and a link which links the user to the appropriate screen for that notification. For example, if Search ID# is selected, the user is provided with a search identifier number when completing the search setup as described in connection with FIG. 12 . An e-mail also is sent to the user with the number.
If Offer ID# is selected, then the user is provided with an offer identification number when completing the offering setup as described in connection with FIG. 17 . An e-mail also is sent to the user with the number.
If the user selects New Search Criteria Found, then the user will receive an e-mail when an automated (timed repeated) search finds a new match. If the user selects Old Search Criteria Re-Found, then the user receives an e-mail when an automated (timed repeated) search finds a old match again. If the user selects Offer Due, then the user receives an e-mail when an offering is due to go out. As explained in connection with FIG. 16, the user can specify whether an offering is automatically sent if the search finds a match. If Offer Sent is selected, then the user receives an e-mail when an offering is sent out. The URL attached to the message takes the user to the screen illustrated in FIG. 18 .
Regarding general notifications, if the user has set preferences in the profile, then these preferences will appear. If the preferences have not been set, then the e-mail “check” box will be checked and their e-mail address entered. The user can select more than one option for notification. For example, if the user is accessible via an intranet, then notification messages can be sent to a designated address on the intranet. Links can be associated with the notification to bring the user to the appropriate location. In addition, an e-mail notification can be received at the desktop (i.e., the user enters the desired e-mail address to be used). If the user selects to view/amend profile, then processing proceeds to the screen illustrated in FIG. 24 .
For wireless devices, a user enters a cell phone plan and phone number for a web phone and/or e-mail pager. If the message is to go to a PDA, the user enters the PDA type and PDA address. For instant messengers, a user enters the instant messenger addresses to which the notifications are to be sent.
Upon selecting Proceed, processing proceeds to the screen shown in FIG. 12 . The user can also select “Go Back” to return processing to the screen shown in FIG. 10 or EXIT to return processing to the screen shown in FIG. 3 .
FIG. 12 illustrates an exemplary screen shot for a search setup confirmation. Using this screen, users are provided with a confirmation number if the user has requested one (see FIG. 11 ). In addition, an e-mail is generated and sent to the user in accordance with the user selections. On this screen, the user can also select Go to Search Setup, Go to All Search Results, and Go to All Offerings. If the user selects Go to Search Setup, processing proceeds to the screen illustrated in FIG. 6 . If the user select Go to All Search Results, then processing proceeds to the screen illustrated in FIG. 8 . If the user selects Go to All Offerings, then processing proceeds to the screen illustrated in FIG. 19 . If the user selects Exit, then processing proceeds to the screen illustrated in FIG. 3 .
FIG. 13 illustrates an exemplary screen shot for a screen for locating searches. At the top of this screen, a graphic is displayed illustrating the step being executed by the user. The graphic communicates to the user how many steps are involved in the process and where they are in the process. Generally, via the screen illustrated in FIG. 13, a user can locate searches that were done in the past to view, amend or stop the search. If the user knows the search identification number, that number can be entered to locate the corresponding search results. In addition, and to locate a search identification number a user can use a drop down to locate search numbers. Searches applicable to the specific user are listed in the drop down.
A user also can search by date. Specifically, a user can enter a date from, a date to, or both. The user can select from drop downs to enter a day, month and year for both dates from and to.
Further, a user can select Find All Searches. When a user makes this selection, the data shown in the Searches Found section is shown. All search identification numbers applicable for the parameters that the user entered are shown. In addition, the search date for each search identification number is displayed.
If the user selects Stop/Unstop Search, the user can either stop a search or restart it. The search results for a stopped search are saved in the database. If a search has already finished based on the search parameters, then the “check” box is automatically “checked”. In this instance, the user can “Amend” to change the search parameters to restart the search. If the user selects view, then processing proceeds to the screen illustrated in FIG. 14 . If the user selects amend, then processing proceeds to the screen illustrated in FIG. 6 . The amended search is assigned a new Search ID#. If the user selects Exit, then processing proceeds to the screen illustrated in FIG. 3 .
FIG. 14 illustrates an exemplary screen shot for a screen for viewing search results. Generally, all the search results that match the user search setup are displayed. Users can then select various options to customize the search results to send out offerings. All search returns are displayed in accordance with the preferences as specified in connection with the screen illustrate din FIG. 10 .
The search identification number and search date fields are provided to identify the search to the user. The sort data by function is the same as described above in connection with FIG. 10 .
If the user selects Interested in all in the “select all” box, then the offers will be made against all results to the customer. If the user selects “Standard Product Offering”, the standard list of products as specified in connection with the screen illustrated in FIG. 20 are included in the offering for all search results. If the user selects “Custom product offering”, the user has the option to customize the products offered for all search returns.
If the User selects “Standard offering text” in the “select all” box, the standard list of products as specified in connection with the screen illustrated in FIG. 20 is included in the offering for all search results. If the user selects “Custom offering text” in the “select all” box, the user has the option to customize the products offered for all search returns.
The user can select View Standards in order to view the standards displayed on the screen as illustrated in FIG. 20 so that the user can make an informed decision whether to select the standard options. Selecting Go Back results in taking the user back to the screen illustrated in FIG. 13 . If the user selected Standard product offering and “Standard offering text Offering and then selects Proceed, processing continues with the screen illustrated in FIG. 17 . If the user selected Custom product offering and then selects proceed, processing continues with the screen illustrated in FIG. 16 . If the user selects Customise by result, then the user can customize each search result individually.
For the search results, and for a particular search identification number, a text box is displayed with the format Result X of X. All data that was found by the search engine is displayed in the format illustrated in FIG. 14 . The aircraft type, contact name, telephone and e-mail are displayed, if found. Other fields are displayed if the user selected such fields on the screen illustrated in FIG. 10 .
If a web location is found, the URL where the data was found is displayed. If the user selects View Website, processing proceeds to the URL at which the data was found. If the user selects Interested, the search result can then be customized for product and offering text or simply sent as a standard offering.
If the User selects “Standard product offering for an individual search result, the standard list of products as displayed on the screen shown in FIG. 20 is included in the offering for that individual search result. If the user selects Custom product offering, the user has the option to customize the products offered for that individual search return.
If the User selects “Standard offering text”, the standard list of products as specified in connection with the screen illustrated in FIG. 20 is included in the offering for that individual search result. If the user selects “Custom offering text”, the user has the option to customize the products offered for that individual search return.
The user can select View Standards in order to view the standards displayed on the screen as illustrated in FIG. 20 so that the user can make an informed decision whether to select the standard options.
Selecting Proceed results in processing proceeding to the screen illustrated in FIG. 15 . Selecting Go Back results in taking the user back to the screen illustrated in FIG. 13 . Selecting EXIT results in processing returning to the screen illustrated in FIG. 3 .
FIG. 15 illustrates an exemplary screen shot for a screen for customising product offerings. Generally, via the screen illustrated in FIG. 15, a user customizes the product offerings by search result that was selected on the screen illustrated in FIG. 14 . Regarding the screen illustrated in FIG. 15, the search identification number and search date identify the search to the user. The data found by the search engine is displayed in the format illustrated in FIG. 15 . Specifically, the aircraft type, contact name, telephone and e-mail are displayed, if found. Other fields are displayed if the user selects those fields on the screen illustrated in FIG. 10 .
All product offerings (as specified in the screen illustrated in FIG. 24) are displayed in the table next to each search result. Next to each product is a “check” box, and if the User selects the “check” box, the corresponding product will be offered. The user can select multiple products for each search result.
Selecting Proceed results in processing proceeding to the screen illustrated in FIG. 16 . Selecting Go Back results in taking the user back to the screen illustrated in FIG. 14 . Selecting EXIT results in processing returning to the screen illustrated in FIG. 3 .
FIG. 16 illustrates an exemplary screen shot for a screen for customising product text offerings. Generally, via the screen illustrated in FIG. 16, a user customizes the text offerings by search result that was selected on the screen illustrated in FIG. 14 . The search identification number and search date fields identify the search to the user. All data found by the search engine is displayed in the format illustrated in FIG. 19 . The aircraft type, contact name, telephone and e-mail are displayed, if found. Other fields are displayed if the fields are selected by the user on the screen illustrated in FIG. 10 . The standard text offering (as set forth in the screen illustrated in FIG. 24 is displayed next to each result. The text is editable, and dispersed within the text are fields (indicated by [abc]) that are fed data from the database. The user does not edit these text fields.
Selecting Proceed results in processing proceeding to the screen illustrated in FIG. 17 . Selecting Go Back results in taking the user back to the screen illustrated in FIG. 15 . Selecting EXIT results in processing returning to the screen illustrated in FIG. 3 .
FIG. 17 illustrates an exemplary screen shot for a screen for confirming that an offer had been sent. Generally, via the screen illustrated in FIG. 17, a user is provided with an Offer Sent Confirmation Number. If the user has requested, an email will also be generated and sent to the address specified by the user. If the user select I want my offering to go automatically each time unless the search result changes, then repeat offerings will be automatically sent.
The user also can select Go to This Offering Result, Go to Search Setup, Go to All Search Results, and Go to All Offerings. If the user selects Go to This Offering Results, then processing proceeds to the screen illustrated in FIG. 18 and the offering results for the offering just set up will be displayed. If the user selects Go to Search Setup, the processing proceeds to FIG. 6 . If the user selects Go to All Search Results then processing proceeds to the screen illustrated in FIG. 13 . If the user selects Go to All Offerings, then processing proceeds to the screen illustrated in FIG. 19 . If the user selects EXIT, then processing proceeds tot the screen illustrated in FIG. 3 .
FIG. 18 illustrates an exemplary screen shot for a screen for viewing offerings. Generally, via the screen illustrated in FIG. 18, a user can view each offering that was sent out or is due to be sent out. The search identification number and search date identify the search to the user. The sort data by function operates as described above. The search data returned is all data found by the search engine, and such data is displayed as illustrated in FIG. 18 . The aircraft type, contact name, telephone and e-mail are displayed, if found. Other fields are displayed if the user has selected such fields for display.
Regarding the Select Product Offerings, all product offerings selected on the screen illustrated in FIG. 15 are displayed in the table next to each search result. The check box indicates that this product was offered. All text offerings selected on the screen illustrated in FIG. 16 are displayed in the table next to each search result.
If the user selects Amend Offering, then processing proceeds to the screen illustrated in FIG. 14 and the search results for the offering are displayed. If the user selects Cancel Offering, then processing proceeds to the screen illustrated in FIG. 19 . If the user selects Go to Search Setup, then processing proceeds to the screen illustrated in FIG. 6 . If the user selects Go to All Search Results, then processing proceeds to the screen illustrated in FIG. 13 . If the user selects Go to All Offerings, then processing proceeds to the screen illustrated in FIG. 19 . If the user selects EXIT, then processing proceeds to the screen illustrated in FIG. 3 .
FIG. 19 illustrates an exemplary screen shot for a screen for locating offerings. Generally, via the screen illustrated in FIG. 19, a user can locate offerings that were done in the past or are due, and amend or stop the offering. To locate an offer, the user enters the offer identification number or locates an offer identification number via a drop down. The user also can locate an offer by entering a date from, a date to, or both. Once the user selects Find All Offerings, then the offer identification numbers applicable for the parameters that the user entered are displayed. If the user selects EXIT, then processing returns to the screen illustrated in FIG. 3 .
For the offerings found, the offer identification number, date due, and date sent for each found offer are displayed. If an offer has been sent, then the check box for Sent? is checked. If the user wants to send an offer, then the user selects the check box for Send? If the user selects View, then processing proceeds to the screen illustrated in FIG. 18 . Also, if the user selects Amend, the processing proceeds to the screen illustrated in FIG. 14 .
Once the user selects Send Offerings, then all offers that have been checked for Send? are sent. If the user selects EXIT, then processing proceeds to the screen illustrated in FIG. 3 .
FIGS. 20-23 illustrate an exemplary screen shot for a screen for defining standards. Generally, via the screen illustrated in FIGS. 20-23, a user defines the standards used in other portions of the system. Specifically, the standards are used to speed up data entry. The standards can be amended Users who have been granted the appropriate rights can amend these standards via the screen illustrated in FIG. 24 .
Referring to FIG. 20, the functionality accessible via the standards screen includes Asset Standards, which is a table that display variations of aircraft type, model, engine, age to, age from, price to and price from, that the user has entered. A check box next to each variation can be selected to indicate if that variable is still a standard for the corresponding row of data. A user can “switch” on and off standards using such check box. Filter selections above each column in the asset standards table are provided so that a user can set up the table quickly and can view a subset of data quickly.
The Standard Websites Searched table lists all the standard web sites that the users have entered. A check box next to each web site is provided so that a user can indicate if the corresponding web site is still standard, and also allows a user to switch on and off the standards.
The Standard Web Publications Searched table lists all the standard web publications that the Users have entered. A check box next to each web publication is provided so that a user can indicate if the corresponding web publication is still standard, and also allows a user to switch on and off the standards.
Using the Standard Search Parameters, which includes search pattern, search timing, and search data returned, the user can select standards that are then applied to all searches performed. Similarly and using the Standard Notification Setup, which includes notification type, general, wireless devices, and instant messengers, the user can select standards that are then applied when sending notifications.
The Standard Products Offered?” table lists all the standard product names that the users have entered. A check box next to each product name is provided so that a user can indicate if that product name is still standard, and also provides that a user can switch on and off standards. The Standard Offering Text is editable and dispersed within the text are fields (indicated by [abc]) that are fed data from the database. The user does not edit the data from the database that populates the fields. The Amend Standard command button is provided so that a user can amend the corresponding standard.
If the user selects SAVE And EXIT, the selections are saved in the database and processing returns to the screen from which the user entered this screen. If the user selects Go to Search Setup, then processing proceeds to the screen illustrated in FIG. 6 . If the user selects Go to Search Results then processing proceeds to the screen illustrated in FIG. 13 . If the user select Go to Offerings, then processing proceeds to the screen illustrated in FIG. 19 .
FIGS. 24-25 illustrate an exemplary screen shot for a screen for user administration. Generally, via the screen illustrated in FIGS. 24-25, a users who have administration rights can set up other Users. Generally, to Find Email Address, a drop down is provided that lists all e-mail addresses of persons who have attempted to register. The user can select an e-mail address and then select “Set Up User”. Upon making such selection a User Profile table to displayed all fields for which data is available are automatically populated. The data is captured when the person registered and is associated with the e-mail address in the registration database table. If no email address, then a blank form is displayed. The Find User Profile is a drop down and has the last name, followed by the first name for every active user profile. The user can select a profile and then select Amend User to open the appropriate user profile.
The User Profile Table includes the following fields, namely, First Name, Last Name, Company, Telephone, Fax, Email, User Name, Password, and Retype Password. In addition, User Rights are specified. Such rights include Administration Access, Amend Other Users (i.e., the user can access and amend other user profiles), Amend Personal Profile (i.e, the user can access their profile), Delete Users (i.e., the user can delete other users), Create Searches (i.e., the users can create searches), Make Offerings (i.e., the users can make offerings) and Amend Standards (i.e., the users can amend standards).
For e-mail notifications, the user can define how e-mail notifications are to be received. If the User selects “Save User Profile”, then the user file is saved in the database. If any mandatory fields are not complete, then a pop up box is displayed identifying the fields to be completed. Similarly, if the password field is less then 6 characters, then a pop up box is displayed to inform the user to enter at least 6 characters. Also, if the “Password” and “Retype Password” fields are different, then a pop up box is displayed informing the user to reenter the “Retype Password” field.
When the user selects Save User Profile, all the data the user entered is saved in the database. If the user is authorized, the user can select Delete User to remove the entire profile. The data associated with the removed user will still be saved in the database in case it has to be retrieved at a later date. If the user selects EXIT, processing proceeds to the screen illustrated in FIG. 3 .
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | Methods and systems for operating a computer to execute a search to identify potential transactions that meet pre-defined criteria, generate an offering for at least one of the identified potential transactions, and transmit the offering to a party to the potential transaction is described. In an exemplary embodiment, the offering generated is generated for a secondary product or products which are associated or bundled with the primary transaction. In another exemplary embodiment, the search is automated and performed on-line via a wide area network such as the Internet. The search is automated in that once a user enters search criteria, the search is performed in accordance with a defined frequency and without requiring user intervention. Once search results are found, then an offering is generated and transmitted to a potential customer. |
This is a continuation of application Ser. No. 07/368,080, filed Jun. 2, 1989 now abandoned which is a continuation of Ser. No. 07/057,849, filed Jun. 2, 1987 now abandoned.
CROSS-REFERENCE TO RELATED APPLICATIONS
"Method and Apparatus for Demodulating Color Television Chrominance Signals", filed simultaneously herewith, and assigned to the same assignee.
FIELD OF THE INVENTION
The present invention relates to television transmission and reception and, in particular, high definition television wherein a wide-aspect ratio television signal is generated at the transmitting end and this signal is decomposed into a main panel component adapted to be received on a standard NTSC receiver, and one or more augmentation panel components. For reception as a high definition television signal with a wide-aspect ratio, the two or more panels must be recombined at the receiver.
BACKGROUND OF THE INVENTION
A number of U.S. patents have issued describing compatible high definition television systems. However, none of these patents teaches a method or apparatus for generating the main and augmentation panels at the transmitter and recombining this information at the receiver.
Also known is a paper called "Edge Stitching of a Wide-Aspect Ratio HDTV Image" by J. L. Lo Cicero, M. Pazarci and T. S. Rzeszewski. While this gives mathematical analyses of the problem, no practical implementation is taught.
SUMMARY OF THE INVENTION
The way in which a wide aspect ratio display is divided into several panels at the transmitter and the way in which the recombination of these panels takes place at the receiver is crucial in determining the quality of the display. Even when the luminance and chrominance signals generating the main panel and augmentation panel displays are properly aligned in gain, time and phase at the receiver, a clearly visible vertical line with dot crawl would be created at each panel-to-panel junction. Such an artifact would render the display unacceptable to a viewer.
It is an object of the present invention to furnish a method and system of decomposing a wide-aspect ratio image into a main panel and at least one augmentation panel for transmission or recording, and recombining the panels at a receiving so that a viewer cannot see any indication of the "stitching" between the panels.
In accordance with the present invention, the plurality of horizontal line signals which together constitute a wide aspect ratio television display are each considered to have a main panel component having a first main panel end and a second main panel end, and at least one augmentation panel component having a first augmentation panel end adjacent the second main panel end, and a second augmentation panel end. At the transmitter, there is extracted from each horizontal line signal a first extracted signal which includes the main panel component, a plurality of main panel redundant samples (pixel values) extending from the second main panel end into the augmentation panel component, and a multiplicity of main panel transition samples which are weighted samples extending from the redundant main panel sample towards the second augmentation panel end and; forming a transition from full main panel component value to a second value such as, e.g., zero.
Similarly, a second signal includes the augmentation panel component, redundant augmentation panel samples some of which are weight and transition samples. At the receiver, the augmentation and main panel components are recombined by deleting the transition samples and weighting the redundant samples of the two panels to effect a smooth transition.
Further, the position in the horizontal line at which a stitch point occurs may be varied, thereby decreasing the visibility of the stitch in the final display.
The objects and features of the present invention will be clearly understood upon consideration of the following detailed description, when read in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a wide-aspect ratio image at the source, with extracted 4:3 main panel and two augmentation panels;
FIG. 2 illustrates a staircase luminance variation at the source and the resulting main and augmentation panels;
FIG. 3 is a block diagram of apparatus for main panel/augmentation panel separation and recombination in accordance with the present invention;
FIG. 4a illustrates gating signals for decomposing a wide aspect ratio picture into a 4:3 panel and two side panels without overlap;
FIG. 4b illustrates gating signals as in FIG. 4a, but with X-1 overlapping redundant samples at each stitch point;
FIG. 5 is a block diagram for the enabling signals required in the signal extracting apparatus of FIG. 6;
FIG. 6 is a schematic diagram illustrating the panel extraction apparatus according to the present invention;
FIG. 7 illustrates the transmitted and received video envelopes and the gating signals according to the present invention;
FIG. 8 illustrates graphically the main panel-augmentation panel stitch with a five sample overlap for linear recombination decoder gating; and
FIG. 9 is a block diagram of the receiver apparatus according to the present invention;
FIG. 10 is a block diagram illustrating apparatus for varying the switch point location on a line-by-line basis;
FIG. 11a illustrates the line format on an augmentation channel of a two channel system before fading; and
FIG. 11b is a block diagram for time multiplexed transmission of two augmentation panel components on one channel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described with respect to the embodiment shown basically in FIG. 1. Here, the output of a television camera or a telecine source has an aspect ratio of 5-1/3:3. For purposes of this example, the main panel is a center panel compatible with, and suitable for, reception on NTSC television receivers currently in service. This main center panel is flanked on each side by an augmentation panel, denoted by panel left and panel right, respectively. It should be noted that the present invention is entirely applicable to any situation wherein a given signal is divided into two or more panels, the panels then having to be recombined to yield a desired output display. The embodiment discussed here, wherein a center panel video signal is flanked by two side panels of equal width, is therefore to be considered illustrative only.
For further purposes of illustration, FIG. 2 shows a luma staircase example for one line of the television signal. FIG. 2a illustrates the 5-1/3:3 source which is divided into a center panel including most, but not all, of steps 2 and 7 at its respective extremities, and two side panels including, for the left panel, step 1 and part of step 2 and, for the right hand panel, part of step 7 and step 8.
As illustrated in the block diagram of FIG. 3, in the present preferred embodiment the wide aspect ratio source is subjected to luma/chroma separation, the luminance signal Y and the chrominance signals I, Q being applied to a center/panel separator stage 10. At the output of separator stage 10 there are thus two sets of luminance/chrominance signals, namely the luminance signal (Y) and chrominance signals (I, Q) associated with the center panel, and the luminance and chrominance signals associated with the side panels. The six signal packets are then passed through an edge shaper 12 and processed for transmission in a modulation stage 14 as is well known for NTSC transmission, or transmission in another standard as appropriate.
In a receiver stage 16, the individually received center and side panel signals are subjected to NTSC demodulation. The luminance signal is then applied to a luminance center/panel stitch stage 18, while the chrominance signals are applied to a similar stage 20. The resulting combined luminance and combined chrominance signals are then ready for display on a wide aspect ratio receiver.
Two ways of timing gating signals for use in separator stage 10, i.e. for decomposing a wide aspect ratio picture into a 4:3 aspect ratio picture and two side panels are illustrated in FIG. 4. In both FIG. 4a and FIG. 4b, the wide aspect ratio width is assumed to include M sampling points (pixels). In FIG. 4a these M pixels are divided into N center panel pixels and, on each side 1/2×x (M-N) side panel pixels. This type of gating results in separation of the panels without overlap. A simple implementation of a suitable gating circuit is illustrated in FIG. 5a and will be discussed in connection therewith below. On the other hand, in FIG. 4b, the timing of gating signals for accomplishing separation with overlap are illustrated. Here, the M pixels of a line are divided into center panel pixels which include the actual center panel pixels N and X/2 pixels on each side of the N pixels, i.e. a total of X redundant pixel samples. Similarly, the panel gating signal extends each panel by X/2 redundant panel pixels into the area of the N center panel pixels. Thus, in each line the separation of the center panel from the two side panels creates X-1 overlapping redundant samples at each of the two separation or "stitch" points.
FIG. 5 shows simple implementations of circuits for generating the gating signals illustrated in FIGS. 4a and 4b. A counter 50 counts clock pulses from the system clock and is reset by the horizontal synchronization signals of the video signal. The output signals from counter 50 are applied to a decoder 52. Decoder 52 furnishes the outputs P L , C, and P R , respectively. The first output is P L , that is the left panel enable signal, active from pixel number 1 to pixel number 128. Next, center panel enable signal C for separating the center panel is activated. Finally, after the pixel equal to N+1/2 (M-N), namely pixel 800, the signal P R is activated and remains active until the end of the line.
The circuit of FIG. 5 can also represent the circuit necessary to implement the signal output illustrated in FIG. 4b. The only difference is that the signal P L , which still starts at pixel 1, continues not to pixel 128, but to pixel 133. At the same time, signal C starts not at pixel 128 as above, but instead, at pixel 123, so that signals P L and C are active simultaneously over a range of 11 pixels. One of these pixels must be carried by one signal anyway, and is not considered redundant. The same is true at the right-hand side. The signal P R starts prior to cessation of the signal C, while the signal C continues past the former cut-off, for an additional period of 5 pixels. There is thus, both at the right-hand and at the left-hand side, an overlap of X-1=10 pixels.
Due to bandwidth limitations, a roll-off, that is a more gradual rise and fall for the center panel and for the side panels is required. A cosine curve implemented as illustrated in FIG. 6 may be utilized for this purpose. It should be noted that the roll-offs take place outside of the above-described overlap range, i.e. beyond pixel 133, e.g. for pixels 134-138 for the left panel; 118-122 for the left side of the center panel, etc.
Referring now to FIG. 6, the signals P L and P R are applied to the enable input of a programmable read-only memory 60 which is the memory for the panels. This PROM is thus enabled for either P L or P R . During the time that the PROM 60 is enabled, the addresses read-out from counter 50 cause the proper multiplication factors for generating the left panel component including overlap and cosine roll-off to appear on output lines 62 of PROM 60. This multiplication factor is then applied to the incoming luminance signal by a multiplier 64. Similarly, the signal C at the output of decoder 52 is applied to enable a PROM 66 which is the PROM storing the relevant addresses for the center panel. Again, the output of counter 50 addresses PROM 66 and the values read out from the addresses appear on output lines 68. These multiply the sampled value of the luminance signal in a multiplier 70, the resultant signals constituting the center panel signals with appropriate overlap and roll-off (herein also referred to as first extracted signals). While FIG. 6 illustrates the shaping of the cosine curve for the luminance signal, the process for the chrominance signals is identical and will therefore not be described herein. It is also possible to use the same method and apparatus for generating center and augmentation panel signals for baseband video, rather than for luminance and chrominance separately.
The signals at the outputs of multipliers 64 and 70 are thus the signals denoted as the center and side panel signals for the luminance signal Y at the output of edge shaper 12 in FIG. 3. These signals, along with the corresponding chrominance signals at corresponding outputs of corresponding stages for the I and Q components, are then transmitted, after suitable modulation in modulator stage 14.
The transmitted signals are received at a demodulator 16. With the exception of the "panel fade" input discussed below, the actual modulation and demodulation are not part of the present invention, are well known, and will therefore not be discussed in detail. It is sufficient to say that the output of demodulator stage 16 consists of three sets of signals, namely the Y signals for the center and side panels and the I, Q center and side panel signals. The waveshape for, for example, the Y signal is illustrated in FIG. 7c for the center panel and FIG. 7d for the side panels. It will be noted that due to transmission and reception, some ringing in the form of oscillations is created at each inflection point, in spite of the cosine roll-off. However, in accordance with the present invention, these oscillations do not form part of the display; i.e. they are gated out at the receiver.
A preferred linear combination gating scheme at the receiver is illustrated in FIG. 8.
Specifically, FIG. 8 illustrates an example of linear weighting for a left panel-center panel stitch with five sample overlap. The top line shows the luminance variation in the left panel, while the bottom line indicates the luminance variation for the center panel. Pixel samples 1, 2, 3, 4 and 5 in the left panel are adjacent to the stitch proper which includes pixel 6, 7, 8, 9 and 10. It will be noted that the transition from left to center panel commences with pixel 6. Therefore the initial ringing of the center signal transition does not affect the final display at all. The linear transition commences at pixels 6, but is still 100% weighted for the left panel. Pixels 7 are weighted 75% left panel, 25% center panel; pixels 8 at 50-50, pixels 9, 25% left panel 75% center panel, while at pixel 10 the transition is complete, i.e. the panel coefficient weight becomes 0 while the center coefficient weight is 100%.
A circuit similar to the circuit of FIG. 5 in combination with the circuit of FIG. 9 is used to implement the above described weighting. P L , P R , C will be generated as illustrated in FIG. 5 and described with reference to the transmitter. Signals P L and P R are applied to the enable input of a PROM 90 which has a plurality of address lines connected to the output of a counter 91 reset, as was counter 50, by the received horizontal sync signals. (If the right and left panel signals are transmitted on a separate channel from the center panel signals, the video from both channels is applied to a time base corrector. The H sync signal is then available at the time base corrector output.) Similarly, signal C is applied to the enable input of a PROM 92, also having address lines connected to the output of counter 91. PROMS 90 and 92 hold the weighting factors associated with the side panels and the center panel, respectively, including the weighting factors associated with the redundant pixels as described above. The outputs of PROMS 90 and 92 are applied, respectively, to multipliers 94 and 96 whose second inputs receive the signals received on the second and first channel, respectively. The outputs of multipliers 94 and 96 constitute, respectively, the left and right panel signals with redundant samples suitably weighted for transition with the center panel signal at each of its ends, and the, center signal with suitably weighted redundant samples at each end. The two signals are applied to respective inputs of an adder 98 at whose output appear signals suitable for display on a wide aspect ratio monitor.
The above description illustrates the decomposition and recombination of the wide aspect ratio signal on a single line, it being assumed that the stitching locations will be the same on all lines. The visual effect of the stitch can be decreased even further if the stitch location is varied somewhat from line to line, from frame to frame, or in accordance with any other convenient plan. For a line by line variation, the circuit of FIG. 10 may be used. There the address signals generated at the receiver are applied to one input of an adder 101. The second input of adder 101 is connected to the output of a random number generator 104 which is activated by the horizontal synchronization pulses. The outputs of the adder 101, when used to address PROMS 90 and 92 of FIG. 9, cause a variation in the start and end of the stitch intervals in a line, within the limits of the numbers within random number generator 104. The range of numbers in random number generator 104 may, for example, be ±2.
Alternatively, random number generator 104 can be reactivated twice per line, resulting in a slight shift of the left stitch point relative to the right stitch point.
The enabling signals P L , P R and C must either be delayed under control of the random number generator (delay units 106 and 108) or the range of pixels covered by each expanded to include all possible addresses given the range of random numbers.
It is also possible to omit the enabling signals entirely, if PROMS 90 and 92 store zero as a multiplication factor for all respective inapplicable addresses.
Finally, there is a preferred method for transmitting the left panel signals and the right panel signals on the second channel, if a two channel transmission system with multiplexed analog transmission is used. The most obvious way of arranging the sequence of signals in each line of the second channel would be as scanned, namely, the horizontal synchronizing signal, followed by the color burst, which is followed by the NTSC modulated left panel signal. The left panel signal is followed by, for example, audio signals, line differential signals for reconstructing the lines not transmitted in the first channel, and, finally, the right panel signal. This arrangement has the disadvantage that, for a pan and scan system, the respective widths of the left panel and of the right panel may change although the total side panel width will remain constant. Such changes would be difficult to carry out with this arrangement and are much simplified by transmitting the left panel signals immediately followed by the right panel signals, followed by the audio and line differential signals. Since changes in the width of the individual panels then do not affect the total panel width, both the audio and line difference signals would be in the same position in each line for any position of the center panel relative to the left and right panels.
Additional advantages are to be gained by the positioning of the right panel signals next to the left panel signals. As explained with reference to FIG. 8, the redundancy technique used at the receiver causes the right transition of the left panel and the left transition of the right panel to be discarded (e.g. pixels 11-15 of the left panel, and pixels 1-5 of the main panel are discarded). Instead of rolling off the right part of the left panel signal and the left part of the right panel signal to zero at the transmitter, a linear fade (interpolation) from the last utilized sample of the left panel to the first utilized sample of the right panel may be used. This fade will also decrease the chance of ringing noted in FIG. 7d. Additionally, the fade may be accomplished in a shorter time than the roll-off in the two directions. The time saved can be utilized for carrying additional signals.
The circuits illustrated in FIG. 11 can be used to accomplish this linear fade. The same circuit can be utilized whether the incoming signal is the luminance signal, one of the chrominance signals, or the composite television signal. In FIG. 11a it is assumed that the incoming signal is the second channel (side panel) luminance signal. The components of this signal, as scanned, are applied to a memory 120, for repositioning on the line. Insofar as the present invention is concerned, the output of memory. 120 consists of, in each horizontal line, the transition samples at the rising edge of the left hand panel, the left hand panel itself, the redundant samples associated with the left hand panel, a transition gap of, for example, three samples, the redundant samples associated with the right hand panel, the right hand panel as such, and the transition samples at the trailing edge of the right hand panel. The additional signals, which will be positioned at predetermined time slots on the remainder of the lines, are not illustrated since they are not relevant to the present invention.
The repositioned signal is applied to the circuit illustrated in FIG. 11b. This has an input terminal 121. A latch 124, timed by the trailing edge of P L , extracts the last valid sample (redundant sample) l o from the incoming signal. A latch 126 set by the same edge after a delay corresponding to the number of pixels between l o and r o extracts the first valid (redundant) sample r o from the right panel (see also FIG. 11a). A PROM fader, 128, operating in the same manner as the PROM 66 in FIG. 6, furnishes multiplying factors. These are applied to the sample at the output of latch 124 by a multiplier 132. Similarly, a PROM fader 130, operating as does PROM 66 in FIG. 6, supplies multiplication factors for the left panel sample extracted by latch 126. These multiplication factors are applied to one input of a multiplying unit 134 whose other input is the above-mentioned sample. The weighted signals from multiplier 132 are applied to one input of an adder 136 whose second, input receives the weighted samples from multiplier 134. The transition signals from adder 136, representing the fade from l o to r o , are applied to a multiplexer 138. Multiplexer 138 also receives the remainder of the second channel signals following a delay 140. Delay 140 is a delay corresponding to delay 129, plus any additional delay required to equalize processing time. Multiplexer 138 provides the appropriate gating between the two signals at its inputs. The output of the multiplexer 138 is thus the second channel signal ready for transmission.
At the receiver, the signal received on the second channel is applied to a memory (not shown). Readout from the memory takes place so that the augmentation and main channels are restored to their original relationship, i.e. the second augmentation panel component is followed by the main panel component which in turn is followed by the first augmentation panel component. Any additional signals such as audio signals and line difference signals follow in whatever empty slots may be on the line.
Although the system has been described in reference to a preferred embodiment, it should be noted that, throughout, chrominance signals could be substituted for the luminance signal, and even composite television signals can be used. Further, this system has been shown as embodied in certain hardware. Many variations of such hardware will be evident to one skilled in the art. Further, in many cases software can be substituted for the hardware in an obvious manner. Finally, although the system is discussed with reference to a two channel transmission, the invention is clearly applicable when transmission of the center panel and the side panels is accomplished in one channel.
All of the above embodiments are therefore to be encompassed in the following claims. | Each line of a wide aspect ratio television signal is divided into a main panel component and an autmentation panel component joined to the main panel component at a stitch point for transmission or storage. At the transmitter, a first signal is extracted from the horizontal line signal, the first signal including the main panel component, a plurality of main panel redundant pixels extending from the main panel into the augmentation panel component, and a multiplicity of weighted main panel transition samples extending further into said augmentation panel component from the redundant samples. Similiarly, a second signal includes the augmentation panel component, a plurality of augmentation panel redundant samples extending into the main panel and a plurality of transition augmentation samples extending from the redundant augmentation samples further into the main panel and weighted to create a predetermined transition curve. At the receiving end, both signals are gated to delete the transition curves, and the redundant samples are linearly weighted to effect the transition from the main panel component to the augmentation panel component. When two augmentation panels are transmitted in a multiplex analog format on the same channel, they are transmitted adjacent to one another and the weighted transition augmentation samples effect a transition from the last redundant pixel of one augmentation panel component to the first redundant pixel of the second augmentation panel component. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 10/515,214, filed May 20, 2005, now U.S. Pat. No. 7,156,918, which is hereby incorporated by reference.
FIELD OF THE INVENTION
This invention relates to weighing devices and in particular relates to devices that provide a ready indication of the weight of a piece of luggage.
BACKGROUND OF THE INVENTION
Commercial aircraft have to place strict controls on the amount and weight of luggage that passengers carry on the aircraft. Tourists and international travelers often experience difficulties in ascertaining the weight of their luggage and this can result in fines and surcharges for being overweight. Whilst the check-in counters have scales that accurately weigh luggage it is often then too late for a passenger to re-organize his or her luggage. What is needed and what is apparently absent from the marketplace today is a simple means of providing an indication of the weight of a piece of luggage so that passengers can determine the weight of the luggage before they reach the airport.
The issue of overweight luggage also has serious ramifications with regard to health and safety considerations. Heavy suitcases, rucksacks or satchels can cause serious spinal injuries. Research has indicated that children, and/or adults, should not over lengthy periods transport more than 10% of their weight.
It is these needs that have brought about the present invention.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a weighing device for providing a ready indication of the weight of a piece of luggage comprising load bearing means adapted to be placed through a carry handle of the piece of luggage and indicator means associated with the load bearing means whereby when the luggage is lifted via the load bearing means or carry handle the load bearing means is subjected to the mass of the piece of luggage and the indicator means provides an indication if a predetermined threshold mass has been exceeded.
According to a further aspect of the present invention there is provided a piece of luggage having a carry handle assembly comprising a handle connected to the piece of luggage, a pressure plate under the handle, a load cell between the pressure plate and the handle and means to provide an indication of weight coupled to the load cell wherein when the piece of luggage is lifted by the handle, the weight of the piece of luggage is transmitted to the load cell by contact with the pressure plate.
DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which:
FIG. 1 illustrates a first embodiment of a weighing device which is inserted under a handle of a suitcase;
FIG. 2 shows the device when placed under load;
FIGS. 3 a , 3 b and 3 c are side view of the device under varying loads;
FIG. 4 illustrates a second embodiment of a weighing device supported by a hand;
FIG. 5 shows the device of FIG. 4 when held under the handle of a suitcase to weigh the suitcase;
FIG. 6 illustrates a third embodiment in which a weighing device is also supported by a user's hand;
FIG. 7 shows the device of FIG. 6 when inserted under the handle of a suitcase to weigh the suitcase;
FIG. 8 illustrates a fourth embodiment in which a weighing device is incorporated into the handle of suitcase;
FIG. 9 is an exploded view of the handle assembly of FIG. 8 ;
FIGS. 10 a and 10 b are schematic side elevational views of the handle of FIG. 8 when free standing and under load;
FIG. 11 is an illustration of a variation of the fourth embodiment; and
FIG. 12 is an exploded view of the handle assembly in accordance with a fifth embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The first embodiment of the weighing device 10 shown in FIGS. 1 to 3 comprises an elongate flat strip 11 of sturdy yet flexible material usually plastics or metal having a central waisted portion 12 with enlarged end portions 13 and 14 each containing apertures 16 and 17 . An upstanding flange 18 is attached to the underside of the central portion of the waisted portion. The flange has an upward projection 20 having a calibrated forward face 19 .
To use the device to weigh suitcase S the elongate strip 11 is placed under the handle H of the suitcase S as shown in FIGS. 1 and 3 a.
By gripping the strip 11 by pressing fingers through the apertures 16 and 17 the suitcase S can be lifted via the strip 11 . As shown in FIGS. 2 , 3 b and 3 c , the mass of the suitcase causes the ends 13 , 14 to bend upwards against the calibrated scale 19 which then provides a ready indication of the weight of the suitcase S. It is envisaged that the calibrated scale 19 would include prominent marks that show the weight levels as determined by airlines for both economy and business class travel. Once the adjacent edge of the elongate strip has moved past one of these lines the user will be aware that the suitcase is above the prescribed limit.
FIG. 3 a shows the strip 11 carrying no load, FIG. 3 b shows a ready indication of a light load whilst FIG. 3 c illustrates the effect of a heavy load. The thickness and flexibility of the strip is selected to ensure the regular degree of movement against the calibrated scale.
The device 10 is about the size of an airline ticket and thus takes up very little room so that it can be simply carried in hand luggage.
Instead of the mechanical device described with reference to FIGS. 1 and 3 , it is understood that the strip 11 could carry suitably positioned strain gauges which would provide an electrical signal that could be correlated to the weight to which the strip is subjected. The strip 11 could also include a pressure sensitive chamber positioned directly under the handle to absorb the mass of the suitcase. The chamber could include a chemical substance that changes color under load so that a change to a selected color would indicate that the weight of the piece of luggage has exceeded a particular threshold.
It is understood that the chemical make-up of pressure sensitive pads or chemical substances that change color under load would be known to those skilled in the art.
In the second and third embodiments shown in FIGS. 4 to 7 , the weighing device 30 is handheld and is in the form of a substantially flat credit card shaped unit. The unit incorporates a sensor panel 31 on its upper surface that senses downward pressure on the panel. The panel incorporates a load cell that is coupled to a liquid-crystal display (LCD) 32 and a suitable battery power source. The load cell senses the pressure on the sensor panel and converts the pressure to an indication of weight.
In the embodiment shown in FIGS. 6 and 7 , the device is placed on the palm of a hand as shown in FIG. 6 . The hand is then placed under the handle 4 of the suitcase S as shown in FIG. 7 and the suitcase is lifted so that the weight of the suitcase presses down on the sensor panel 31 on the upper surface of the device. This pressure is then transmitted as a weight on the liquid crystal display 32 . In the embodiment shown in FIGS. 4 and 5 , instead of a liquid crystal display a series of lights 33 , 34 , 35 , 36 representing recommended weights such as 20 kg, 30 kg, 40 kg or 50 kg are provided. The lights are preferably light emitting diodes. When the device is slid under the handle as shown in FIG. 5 , the appropriate light 34 is illuminated showing that the suitcase is at least as shown in FIG. 5 30 kg. Alternatively, the 20 kg, 40 kg or 50 kg lights 33 , 35 or 36 can illuminate. The device 30 thus provides a ready and simple means of showing that a predetermined weight has been exceeded. The device of both of these embodiments is very small, runs on a small watch battery and takes up very little space. It is understood that the pressure sensitive panel would be one of a number of proprietary items that provide an electrical signal that is proportional to pressure.
In the fourth and fifth embodiments shown in FIGS. 8 to 12 , a weighing device 40 is incorporated into the handle 4 of the suitcases.
In the exploded view of FIG. 9 , the handle assembly 40 comprises an upper housing 41 with an aperture 42 . The housing is of an arcuate shape and supports end portions 43 , 44 . The housing 41 is arranged to contain a circuit board assembly 45 that includes a pressure sensitive mechanism 46 and a liquid crystal readout 47 . The assembly would also incorporate a battery to power the weighing device. The assembly terminates on the underside with an arcuate displaceable pressure plate 48 that has a central spigot 49 that rides on the pressure sensitive mechanism 46 of the circuit board 45 . As shown in FIGS. 10 a and 10 b , the pressure plate 48 is pulled up into the assembly 40 against the pressure sensitive plate 46 as the handle H is gripped and the suitcase S lifted off the ground. In this way, the weight of the suitcase S is transferred through the pressure sensitive plate to be recorded and indicated at the LCD readout 47 . The final assembly of the handle is shown in FIG. 8 from which it can be seen that the weighing device 40 is elegantly integrated into the design of a suitcase S so that travelers can buy a range of luggage each of which has its own built-in weighing device.
The assembly is molded in plastics and is light and substantially the same size as a conventional handle. In order to prolong the life of the batteries that power the unit, it is understood that an on/off switch may be provided somewhere on the handle to prevent use of the assembly whenever the suitcase is carried.
In the embodiment shown in FIG. 11 , a very similar device 40 is incorporated except in this case instead of a single LCD readout 47 , four space lights 50 , 51 , 52 , 53 are provided across the top of the handle H, each light representing a threshold weight such as 10 kg, 20 kg, 30 kg or 40 kg.
The load cell between the pressure plate 48 and the top of the handle 41 would send electrical signal to each light in dependence on the weight of the suitcase.
In the embodiment shown in FIG. 12 , the load cell is replaced by a colored indicator 60 which locates in an aperture 61 in the external cover 62 of the handle. The colored indicator 60 is mounted on a support plate 63 and a pressure plate 64 has a single upstanding spigot 65 that acts against the underside of the colored indicator 60 in the same manner as the spigot acts on the load cell in the embodiment of FIGS. 9 to 11 . However, in this embodiment the colored indicator is in the form of a disc that changes color under pressure and thus changes color proportional to the weight of the suitcase. As the pressure increases the color of the disc can be calibrated so that a change to a particular color indicates that the luggage weighs more than a particular threshold.
Other embodiments not illustrated also incorporate the use of pressure sensitive chemicals that change color in dependence on pressure. A card or plastics sheet could be provided with bands of such chemicals. The card or sheet could be placed under the handle of the suitcase and the suitcase lifted via the card or sheet. In this way, the weight of the suitcase would place pressure on the chemical laminate causing a change of color and the color would be calibrated to indicate whether airline thresholds have been exceeded.
The invention is also applicable to rucksacks or satchels especially those used by school children to carry their text books and laptops. The common practice of school children transporting excessively heavy loads in satchels and/or rucksacks is well known. | A piece of luggage, rucksack or satchel is provided having a pair of spaced shoulder straps. At least one strap has a stress/strain unit to monitor the stress/strain in the strap as the piece is worn on the shoulder of a user. The at least one strap also has an indicator that provides a visual indication when the stress/strain of the strap has exceeded a predetermined threshold. |
BACKGROUND OF INVENTION
[0001] The continuous development of magnetic recording disk drives results in ever increasing data storage densities in the storing layers. To read and write the magnetic signals, the read and write heads have to be kept in ever-closer distance to the rotating disc surface where the storing layers are deposited.
[0002] The read and write heads are typically integrated in the so-called sliders, which provide specifically designed three-dimensional features on their bottom side that is next to the disk surface. These three-dimensional features utilize the viscosity and kinetic energy of a rotating air stream induced by the spinning disk to lift the sliders on a predetermined fly height during the hard disk operation.
[0003] The viscosity of the air stream depends mainly on the air temperature and the air pressure.
[0004] The kinetic energy of the rotating air stream depends on its velocity relative to the slider and subsequently on the rotational speed of the hard disk.
[0005] The bottom side performs the function of an air bearing in closest proximity to the disk surface. As a result fly heights in the nanometer range can be implemented.
[0006] Such small fly heights require high precision of the disk surface since even the smallest surface inconsistencies result in a contacting of the slider with the fast moving disk surface. Even though the utilized fabrication processes provide for sufficient surface evenness of the hard disk, special wear-in procedures are commonly performed to eliminate eventual and/or recognized surface unevenness. These wear-in procedures are typically performed by reducing the fly height below the operational level and moving the slider over the surface until no contacting is recognized anymore. The slider, which is made of a relatively hard material is thereby utilized as an abrasive tool to remove any interfering surface inconsistencies from the relatively soft top layers of the hard disk.
[0007] The fly height is typically reduced by changing the rotational speed of the hard disk and/or by changing the air pressure.
[0008] A number of U.S. patents discloses variations of the hard disk wear-in procedure, which is commonly referred to as burnishing.
[0009] U.S. Pat. No. 5,696,643 and U.S. Pat. No. 5,863,237, for instance, describe methods to burnish away topographic irregularities from the disk surface. After recognizing an surface irregularity via a thermal contacting signal, the rotational speed of the hard disk is reduced and the fly height of the read/write head is lowered. The burnishing is performed over a certain time period, during which the height of the surface irregularities is continuously reduced. After finishing the disk burnishing the interference signals no longer occur during operational rotation of the hard disk.
[0010] Japanese Patent JP 06309636 describes a similar burnishing method, except that the read/write head is lowered by reducing the air pressure under which the hard disk drive operates.
[0011] The thermal contacting signal results from a dynamic resistance change in the read head, which is thermally induced by the frictional energy created during the contacting of the head.
[0012] The dynamic resistance change itself may be recognized with various methods. In one method, it is recognized during the regular read operation of the hard disk. This requires a fully functioning hard disk drive, including a partitioned hard disk. U.S. Pat. No. 5,751,510 describes such a method.
[0013] In another method, the dynamic resistance change is obtained by the read/write head without reading any data from the hard disk. In such a case, an electrical stimulus voltage is applied to the read head. This method can be performed at an earlier hard disk fabrication stage since it does not require operational data read from the hard disk surface. A calibration signal and/or a calibration value has to be obtained for a known non-interference condition. U.S. Pat. No. 5,806,978, for instance, describes such a method.
[0014] With continuously decreasing fly heights a contacting and non-contacting operational conditions in the head/disk interface become less and distinctly able. Read/write heads operate typically with their air bearing surface in an angulated orientation relative to the disk surface.
[0015] The microscopic air bearing features are typically fabricated with a common protrusion direction normal to the substrate plane, which results in essentially coplanar surfaces and linear edges. The design of the air bearing surface defines the primary contacting edge, which initially contacts the moving disk surface. In the case where the front portion of the air bearing surface is raised sufficiently, the primary contacting edge becomes the front edge with the read and write elements. In such a case, the contacting of the slider during the regular hard disk operation occurs mainly with the slider front edge.
[0016] The linear contacting of the slider with the primary contacting edge results in relatively high surface pressures, which result in wear of the disk surface and/or the slider. As a result of disk wear, debris may adhesively build up on the primary contacting edge. Since it is desirable to have the read/write heads in closest proximity to the disk surface, they are preferably in an area adjacent to the primary contacting edge. Debris built-up alters the read and write characteristic of the heads and needs to be prevented. U.S. Pat. No. 6,088,199, for instance, discloses an abrasive section placed on the hard disk to remove eventual debris built-up on the slider. The patent does not prevent debris from building up, however. It provides only a cleaning method.
[0017] Wear in the head/disk interface related to operational slider contact is explored in a number of scientific disclosures.
[0018] In IEEE Trans. Magn. (USA) vol 34, no.4, pt.1, p. 1714-16, a conference/journal paper is disclosed, which describes the abrasive wear and adhesion of the slider surface.
[0019] In the 1996 AME/STLE Tribology Conference (TRIB-Vol.6) p.17-23, a conference paper is disclosed, which describes new techniques for evaluating slider wear and burnishing of the head/disk interface.
[0020] Further, in the Proceedings of the SPIE—The International Society of Optical Engineering (USA) vol.2604 p.236-43, contact force measurements at the head/disk interface for contact recording heads in magnetic recording are disclosed and correlated to the burnishing in the head/disk interface.
[0021] Finally, in the Journal of Materials Research vol.8, no.7 p. 1611-28, friction and wear studies of silicon in sliding contact with thin-film magnetic rigid disks are disclosed.
[0022] The ever decreasing fly heights make the limitations described in the above scientific paper increasingly stringent.
[0023] The present invention addresses these limitations and provides a solution for them.
OBJECTS AND ADVANTAGES
[0024] It is a primary object of the present invention to provide a slider head in a wear reducing configuration and a method for creating the same.
[0025] It is another object of the present invention to provide a method for creating the wear-reducing configuration with feasible fabrication effort.
SUMMARY
[0026] A slider burnishing method is introduced, in which a primary contacting area of the slider is flattened in an abrasive way.
[0027] The primary contacting area is defined by the operational orientation of the slider relative to the hard disk surface. In the case of a planar slider, the contacting area is essentially a contacting edge at the front end of the slider where the read and write heads are located.
[0028] There are techniques known to those skilled in the art that apply a bending in the form of a crown and/or camber to the air bearing surface. The bending of the air bearing surface results in a smoother contacting of the air bearing surface with the hard disk surface. In such a case the contacting area may be at a more central location of the slider adjacent to the location of the read and write heads.
[0029] The abrasive flattening of the contacting area is accomplished by applying a slider burnishing method during which the slider is kept in contact with the rotating hard disk. The slider burnishing method is designed for:
[0030] preventing damage of the relatively soft surface layers of the hard disk;
[0031] preventing debris accumulation in the contacting area during the slider burnishing;
[0032] keeping the thermal rise in the slider below a critical maximum; and
[0033] creating a predetermined flattened area.
[0034] The slider burnishing creates a flattened area that is planar and essentially parallel to the hard disk surface. An eventual contacting of the slider with the hard disk surface results in reduced surface pressure in the contacting area, which is commonly referred to as the head/disk interface. The slider contacting may either be intermediate or permanent.
[0035] Under operational conditions where a fly height needs to be maintained, the flattened area defines, together with the hard disk surface, an even air bearing gap. This air bearing gap enhances the aerodynamic properties of the air bearing surface, such that smaller fly heights can be utilized in a stable fashion.
[0036] The slider burnishing method consists of a number of individual steps with various contacting forces and rotational disk speeds. The main steps perform the following tasks:
[0037] preparing the hard disk surface by removing eventual topographic inconsistencies;
[0038] burnishing the slider; and
[0039] checking the burnishing result.
[0040] In an alternate embodiment the slider burnishing process is mainly performed by the following steps:
[0041] deriving a resistive reference signal during a non-contacting condition of the slider.
[0042] preparing the hard disk surface by removing eventual topographic inconsistencies;
[0043] burnishing the slider;
[0044] checking the burnishing result; and
[0045] sweeping the disk surface to remove debris.
[0046] The calibration signal is derived prior to the slider burnishing, to have a reference value so as to determine the contacting signal. Calibration signal and contacting signal are a function of the read head resistance, which influences a bias voltage applied to the read head during the slider burnishing. The read head resistance is dependent on the read head temperature and changes during frictional contact with the disk surface, as is known to those skilled in the art.
[0047] The contacting signal is utilized to observe the contacting characteristic during the following steps of the slider burnishing method.
[0048] During the disk surface preparation the fly height is consecutively lowered in correspondence with a reduction of the rotational disk speed. Topographic inconsistencies are thereby removed without creating abrasive deposits on the contacting area.
[0049] The slider burnishing is the most time consuming step of the slider burnishing method and is performed with a predetermined contacting force at a relatively low rotational speed. Since the disk surface has been smoothened sufficiently a permanent slider contact can be maintained without the risk of vibrations and/or excessive abrasion induced by eventual topographic inconsistencies. During the slider burnishing, the slider is continuously moved over the rotating disk surface to prevent local thermal rise in the disk surface. Rotational speed and contacting force are also selected to keep thermal rise of the slider below a critical level at which the heat sensitive components of the slider may be damaged and/or debris may weld on the contacting area.
[0050] During the clearance check the fly height is raised to a level at which no contacting signal is recognized anymore.
[0051] The final sweeping step removes any debris accumulated on the disk surface during the prior burnishing operation.
[0052] The slider burnishing method is performed with various rotational speeds and independently defined fly heights and/or contact forces between the slider and the hard disk surface. To adjust the fly heights and/or the contact forces in an independent fashion to the rotational speeds, the air pressure under which the slider burnishing is performed is correspondingly adjusted.
BRIEF DESCRIPTION OF THE FIGURES
[0053] [0053]FIG. 1 shows a three-dimensional view of a simplified hard disk drive with a removed housing portion such that a hard disk and a slider attached on a slider arm are visible.
[0054] [0054]FIG. 2 shows an enlarged detailed view of the interface between the slider and the hard disk of FIG. 1 in a direction perpendicular to a reference plane also shown in FIG. 1.
[0055] [0055]FIG. 3 shows a simplified slider with an essentially planar adaptation surface.
[0056] [0056]FIG. 4 shows a simplified slider with a first curved adaptation surface having a curvature axis that is collinear with a symmetric plane of the slider.
[0057] [0057]FIG. 5 shows a simplified slider with a second curved adaptation surface having a curvature axis that is perpendicular to a symmetric plane of the slider.
[0058] [0058]FIG. 6 shows a simplified slider with a third curved adaptation surface having the first and second curvature axes.
[0059] [0059]FIG. 7 shows a simplified graph of a control signal change during the slider burnishing process for an exemplary case where the control signal sensor is within the burnishing area.
[0060] [0060]FIG. 8 shows a simplified graph of a control signal change during the slider burnishing process for an exemplary case where the control signal sensor is outside the burnishing area.
[0061] [0061]FIG. 9 shows a block diagram of a preferred embodiment of a burnishing method.
[0062] [0062]FIG. 10 shows a block diagram of an alternate embodiment of the burnishing method.
[0063] [0063]FIG. 11 shows a graph of four exemplary control signal voltages of four different sliders during their burnishing process.
[0064] [0064]FIG. 12 shows a graph of four relative resistance changes of read heads operating as contacting sensors during the burnishing process of the four sliders referred to in FIG. 11.
DETAILED DESCRIPTION
[0065] Although the following detailed description contains many specifics for the purposes of illustration, anyone of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following preferred embodiment of the invention is set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
[0066] [0066]FIG. 1 shows the a simplified hard disk drive HDD with the main operational components involved in the slider burnishing being visible through a removed housing portion of the hard disk drive HDD. A slider 1 is attached to a slider arm iC, which pivots around a slider arm axis iD. The slider has a front face 1 B and a symmetric plane IF. FIG. 1 also shows a hard disk 2 having a hard disk surface 2 A and a spinning axis 2 B.
[0067] During the slider burnishing, the slider arm IC pivots around the slider arm axis iD such that the slider 1 performs centripetal and centrifugal movements along the hard disk surface 2 A of the spinning hard disk 2 .
[0068] Dependent on the velocity of the centripetal and centrifugal slider movements relative to the rotational speed of the hard disk surface, the symmetric plane IF defines a movement angle together with the resulting movement vector in the interface between the slider 1 and the hard disk surface 2 A. In the case where the slider arm iC does not move, the movement angle is approximately zero. It is clear to one skilled in the art how the geometric and dynamic conditions of the hard disk 2 and the slider arm 1 C precisely define the movement angle.
[0069] [0069]FIG. 2 shows an enlarged view of the interface between the slider 1 and the hard disk 2 in a direction perpendicular to the reference plane iF. The main physical characterizing elements of the present invention in the slider/disk interface are:
[0070] the hard disk surface 2 A;
[0071] adaptation surfaces 1 E, 11 E, 12 E, 13 A (see FIGS. 3 - 6 );
[0072] front faces 1 B, 11 B, 12 B, 13 B (see FIGS. 3 - 6 );
[0073] burnishing areas 1 A, 11 A, 12 A, 13 A (see FIGS. 3 - 6 ); and
[0074] burnishing sensors 1 R, 11 R, 12 R, 13 R (see FIGS. 3 - 6 ).
[0075] The front faces 1 B, 11 - 13 B are shown in planar configuration for the purposes of general understanding. It is noted that front faces of sliders may have any shape without affecting the core of the invention.
[0076] For general understanding, the introductory example described in FIG. 2 refers to the slider 1 having a planar adaptation surface 1 E perpendicular to the symmetric plane 1 F. The adaptation surface 1 E is oriented with an adaptation angle 3 A relative to the hard disk surface. In the preferred embodiment of the invention, the adaptation angle 3 A is essentially identical with an operational angle (not shown) under which the adaptation surface 1 E will be kept in position during the operational use of the hard disk drive.
[0077] The core of the invention also applies to a case where the adaptation angle 3 A is different from the operational angle.
[0078] During the slider burnishing a contacting condition is provided between the adaptation surface 1 E and the hard disk surface 2 A, which results in a burnishing area 1 A abrasively formed by the hard disk surface 2 A. In the preferred embodiment the contacting condition is provided by altering dynamic and/or static fluid properties that influence a fly height of the slider 1 above the hard disk surface 2 A, as is known to those skilled in the art. The dynamic fluid properties are, for instance, altered by changing the rotational speed of the hard disk 2 , such that the velocity of a concentrically circulating fluid stream is reduced.
[0079] The static fluid properties are, for instance, altered by changing the fluid viscosity, for instance, by reducing the static pressure of a compressible fluid.
[0080] The fluid utilized for the slider burnishing may be identical to/or different from the operational fluid under which the hard disk drive is operated. In the preferred embodiment the burnishing fluid is air.
[0081] It is noted that the burnishing fluid may be any gaseous or liquid material that is suitable for providing the contacting characteristic. The preferred gaseous burnishing fluid is air. Alternate gaseous burnishing fluids may be, for instance He, or Ne, which may introduce a reduced fly height due to their low viscosity relative to the viscosity of the operational fluid in the preferred form of air. In general, the fly height may be adjusted during the burnishing process by altering the composition of the burnishing fluid and consequently the viscosity relative to the composition of the operating fluid. The operating fluid is the fluid, which fills the space between the slider and the disk surface during the operational use of the hard disk. In addition, the inert nature of He and Ne protect the slider and disk surface against oxidation, which may result from the elevated temperatures in the burnishing interface between slider and disk surface. In addition, any burnishing enhancing material may be applied to the hard disk surface 2 A and/or the adaptation surface 1 E, 11 - 13 E to enhance the slider burnishing process. In particular, slider burnishing enhancing materials that overcome the limitations imposed by the operational softness of the hard disk surface 2 A relative to the operational hardness of the adaptation surface 1 E may be applied to the hard disk surface 2 A prior to the slider burnishing process. This burnishing enhancing material may be applied in a fashion that corresponds to the burnishing process such that at the end of the burnishing process the burnishing enhancing material itself is abraded and no longer present on the hard disk surface 2 A.
[0082] During the slider burnishing process, material is removed from the slider 1 . The removed material 1 G leaves a burnished area 1 A behind. The removal material height 3 B defines, together with slider shape, the removed material volume. The removed material volume influences the slider burnishing time. To keep the slider burnishing time to a minimum the contacting characteristic has preferably a contact force gradient that corresponds to the increase of burnishing area during the slider burnishing. As a result, the contact pressure in the slider/disk interface remains constant and below a critical level. The critical pressure level is defined by the abrasion resistance of the hard disk surface 2 A and the thermal drain capacity of the slider.
[0083] The adaptation angle 3 A influences a fly characteristic of the slider 1 above the hard disk surface 2 A. The fly characteristic keeps the slider 1 in a predetermined fly height range under operational conditions as is known to those skilled in the art. The burnished areas 1 A, 11 - 13 A define, together with the hard disk surface 2 A, an operational gap that has stabilizing influence on the fly characteristic. In the preferred embodiment where the adaptation angle 3 A is essentially equal to the operational angle the operational gap has a consistent width. As a result, the fluid stream in the gap has a constant velocity resulting in a balanced fluid pressure in the gap. In case of a contacting of the slider 1 with the hard disk surface 2 A, the burnished areas 1 A, 11 - 13 A contact snuggly with the hard disk surface 2 A, which avoids unfavorable abrasion of the hard disk surface 2 A.
[0084] In FIGS. 3 - 6 a number of configurations of the sliders 1 , 11 - 13 is shown. The configurations of the sliders 1 , 11 - 13 are shown with the adaptation surfaces 1 E, 11 - 13 E, the contacting sensors in the preferred form of data read heads 1 R, 11 - 13 R, write heads 1 W, 11 - 13 W, the burnished areas 1 A, 11 - 13 A and the front faces 1 B, 11 - 13 B.
[0085] The sliders 1 , 11 of FIGS. 3 and 4 have their data read heads 1 R and 11 R within the burnished area 1 A, 11 A.
[0086] The sliders 12 , 13 of FIGS. 5 and 6 have their data read heads 12 R and 13 R outside the burnished area 12 A, 13 A.
[0087] In FIG. 4, the adaptation surface 11 E has a curvature with a curvature axis 11 F. The curvature of the adaptation surface 11 E is known to those skilled in the art as camber.
[0088] In FIG. 5, the adaptation surface 12 E has a curvature with curvature axis 12 F. The curvature of the adaptation surface 12 E is known to those skilled in the art as crown.
[0089] In FIG. 6, the adaptation surface 13 E has a curvature with a curvature axes 13 F and 13 G. The curvature of the adaptation surface 13 E is a combination of crown and camber.
[0090] For the exemplary sliders 1 , 11 the adaptation angle 3 A remains constant during the slider burnishing process. For the exemplary sliders 12 , 13 the adaptation angle 3 A increases during the slider burnishing process.
[0091] At the start of the slider burnishing the sliders 1 , 11 - 13 have initial burnishing contacts with the hard disk surface 2 A. At the initial burnishing contacts the burnishing areas 1 A, 11 - 13 A start to form and to expand.
[0092] For the slider 1 , the initial burnishing contact is an edge of the front face 1 B and the adaptation surface 1 E.
[0093] For the slider 11 , the initial burnishing contact is a point on the edge of the front face 2 B and the adaptation surface 2 E.
[0094] For the slider 12 , the initial burnishing contact is a initial contacting line parallel to the curvature axis 12 F.
[0095] The distance of the initial contacting line to the data read head 12 R depends on the overall orientation of the slider 12 to the hard disk surface 2 A.
[0096] For the slider 13 , the initial burnishing contact is an initial contacting point. The distance of the initial contacting point to the data read head 13 R depends on the overall orientation of the slider 13 to the hard disk surface 2 A.
[0097] The burnishing areas 1 A, 12 A have a first extension direction essentially perpendicular to the front faces 1 B and 11 B.
[0098] Since the sliders 1 , 11 - 13 are shown with final fabricated burnishing areas 1 A, 11 - 13 A, the initial burnishing contacts are no longer present and therefore not shown.
[0099] During the slider burnishing of the slider 1 , the burnishing area 1 A expands away form the edge between the front face 1 and the adaptation surface 1 E. As shown for the slider 1 , the burnishing area 1 A expands beyond the data read head 1 R and the write head 1 W.
[0100] During the slider burnishing of the slider 11 , the burnishing area 11 A expands away form the initial contacting point on the edge between the front face 2 B and the adaptation surface 2 E. As shown for the slider 11 , the burnishing area 11 A expands beyond the data read head 11 R and the write head 11 W.
[0101] During the slider burnishing of the slider 12 , the burnishing area 12 A expands away form the initial contacting line. As shown for the slider 12 , the initial contacting line is at a distance to the data read head 12 R, such that the final expanded burnishing area 12 A does not overlap with the data read head 12 R and the write head 12 W.
[0102] During the slider burnishing of the slider 13 , the burnishing area 13 A expands away form the initial contacting point. As shown for the slider 13 , the initial contacting point is in a distance to the data read head 13 R such that the final expanded burnishing area 13 A does not overlap with the data read head 13 R and the write head 13 W. It is clear to one skilled in the art that the configurations of the sliders 1 , 11 - 13 may be defined such that the burnishing areas 1 A, 11 - 13 A may or may not overlap with the data read heads 1 R, 11 - 13 R.
[0103] It is clear to one skilled in the art that the adaptation surfaces 1 E, 11 - 13 E may have any shape or configuration. Furthermore, the adaptation surfaces 1 E, 11 - 13 E may form an air bearing surface at is known to those skilled in the art, and/or may be a component of an air bearing surface.
[0104] The slider burnishing process is monitored by use of a contacting sensor. In the preferred embodiment the contacting sensors are the data read heads 1 , 11 - 13 R as they are known to those skilled in the art for the recognition of disk surface contact recognition.
[0105] In the preferred embodiment the natural resistance of the data read heads 1 R, 11 - 13 R is recognized prior to the slider burnishing process and utilized as a reference value. During the slider burnishing a dynamic and static resistance changes may occur in the data read heads 1 R, 11 - 13 R.
[0106] A dynamic resistance change is mainly induced by a thermal friction energy resulting from a disk surface contacting of the contacting sensors and/or surrounding areas of the sliders 1 , 11 - 13 .
[0107] A static resistance change is mainly induced in a case where the contacting sensors are or become part of the burnishing area during the slider burnishing as it is shown with the sliders 1 , 11 . The removing of material 1 G includes a removing of the contacting sensor material, which results in a static resistance change of the contacting sensor.
[0108] In FIG. 7 a simplified graph shows a curve 22 A representing the static resistance change and a curve 22 D representing the dynamic resistance change for a case where the data read heads 1 R, 11 - 13 R are overlapped by the burnishing areas 1 A, 11 - 13 A.
[0109] The vertical axis 20 (see also FIG. 8) represents the resistance change relative to the total read head resistance. The horizontal axis 21 , 31 , 41 (see FIGS. 8, 11, 12 ) represent a number of burnishing cycles during which the sliders 1 , 11 - 13 are moved back and forth on the disk surface 2 A.
[0110] Prior to the slider burnishing, a reference value 22 R, 23 R, 32 R and 42 R (see also FIGS. 8, 11, 12 ) is recognized preferably on a slider position for which a non-contacting condition is secured. Such a slider referencing position is preferably on a parking ramp where the slider arm 1 C is parked during non-operation of the hard disk drive.
[0111] The curve 22 A has an initial incline angle and becomes flatter during the slider burnishing. The curve 22 A approaches asymptotically to a theoretical maximum line 22 E. The incline angle of the curve 22 A over its length corresponds to the increasing removed material height 3 B. The burnishing areas 1 A, 11 - 13 A start to form from a contacting line or a contacting point, such that a relatively low amount of initially removed material 1 G results in a relatively high gain of removed material height 3 B.
[0112] With continuing material removal the burnishing areas 1 A, 11 - 13 A extend. As a result, for a given amount of removed material the gain of removed material height 3 B becomes ever smaller. The increase of the burnishing areas 1 A, 11 - 13 A also results in a reduced contacting pressure for a given contacting force. Since the contacting force is limited to prevent thermally induced damages to the disk surface 2 A and/or the sliders 1 , 11 - 13 , the contacting pressure reaches a level at which abrasion of the slider material no longer occurs. The material properties of the sliders 1 , 11 - 13 , the abrasive properties of the hard disk surface 2 A and the maximum contacting force define a theoretical maximal burnishing area extension, which is recognized by the theoretical maximum line 22 E.
[0113] In FIG. 8 the curve 23 A corresponds to the curve 22 A, except for the case where the contacting sensors do not become overlapped by the burnishing areas 1 A, 11 - 13 A. Hence, the contacting sensors, e.g. the data read heads 1 R, 11 - 13 R, are not exposed to the material removal process. Consequently, the data read heads 1 R, 11 - 13 R do not change their static resistance, and the curve 23 A is horizontal.
[0114] The curves 22 D, 23 D (see FIG. 8) provide examples for the dynamic resistance change during the slider burnishing. After recognizing the reference resistance 22 R, 23 R, 32 R, 42 R the slider burnishing process is initiated by bringing the sliders 1 , 11 - 13 into contact with the rotating disk surface 2 A. Initially, the dynamic resistance change has a relatively volatile nature. The reason for this is topographic inconsistencies in the hard disk surface that impose varying contacting conditions. During the slider burnishing these topographic inconsistencies are removed and the dynamic resistance change becomes smaller and smaller. This is shown in FIGS. 7 and 8 by the upper boundary curves 22 C, 23 C and the lower boundary curves 22 B and 23 B.
[0115] It is noted that the contacting sensor may be any device known to those skilled in the art to recognize the contacting characteristic. The contacting sensor may or may not utilize a reference signal.
[0116] It is further noted that the reference signal may be a predetermined signal derived independently from the hard disk drive subject to the slider burnishing. The reference signal may be statistically, empirically, or theoretically predetermined.
[0117] The slider burnishing is performed by a burnishing method in which the burnishing parameters are variously specified such that distinctive slider burnishing steps are created.
[0118] [0118]FIG. 9 shows a block diagram of the steps of a burnishing method of the preferred embodiment. The burnishing method begins with preparing the hard disk surface, followed by burnishing the slider and finally checking the burnishing result.
[0119] During the preparation of the hard disk surface 2 A, the sliders 1 , 11 - 13 are continuously lowered, preferably by changing the rotational speed of the hard disk 2 and/or by reducing the environment pressure. The lowering may be performed either in a predetermined fashion, or in correspondence with recognized dynamic resistance fluctuations. Dynamic resistance fluctuations indicate the contacting dynamic. In other words, it is important to prevent the sliders 1 , 11 - 13 from vibrating and from shifting their pitch angles to a negative value when hitting topographic inconsistencies. Topographic inconsistencies may be bumps, waves or the like on the hard disk surface 2 A as known to those skilled in the art. The pitch angle corresponds to the adaptation angle 3 A. A negative pitch angle would cause the slider to plow into the hard disk surface 2 A. This needs to be prevented at any cost.
[0120] Once the dynamic resistance fluctuations have reached a minimal level indicating a required planarity and/or smoothness of the hard disk surface 2 A, the burnishing parameters are adjusted to levels that create a contacting characteristic primary defined to perform the slider burnishing. The slider burnishing step may be initiated by recognizing the dynamic resistance fluctuations and/or after a predetermined surface preparation period.
[0121] Following the slider burnishing step, the hard disk drive is brought into operational mode, which includes, for instance, the adjustment of the environment pressure and/or the adjustment of the hard disk speed to operational levels. The contacting sensor recognizes then the actual fly height achieved by fabricating the predetermined burnishing areas 1 A, 11 - 13 A.
[0122] [0122]FIG. 10 shows a block diagram of the preferred embodiment with the additional steps of deriving a resistive reference signal during a non-contacting condition of the slider and sweeping the disk surface to remove debris.
[0123] The resistive reference signal may be the natural resistance of a resistive contacting sensor like, in the preferred embodiment, a magnetic read head as is known to those skilled in the art.
[0124] The sweeping of the disk surface 2 A may be performed with a sequence of centrifugal slider movements in disk contact alternating with centripetal slider movements without disk contact. Disk contacting and non-contacting may be provided, for instance, by changing the rotational speed of the hard disk 2 or the environment pressure.
[0125] In the case where the resistive reference signal is utilized, the checking of the burnishing result is performed by comparing an operational resistive signal of the contacting sensor derived under operational conditions of the hard disk drive. A non-contacting operation of the sliders 1 , 11 - 13 at a fly height that is accomplished by the defined burnishing areas 1 A, 11 - 13 A is established when the operational resistive signal is within a specified range of the resistive reference signal.
[0126] [0126]FIG. 11 shows four curves 34 A-D, each having one of the line styles 33 . The vertical axis 30 represents a voltage level of the contacting signal in the approximate occurring range during the burnishing method. The four curves 34 A-D are derived from experimental slider burnishing performed on sliders that are different from those described in the above. The four curves 34 A-D are shown for the sole purpose of general understanding without any claim of accuracy. The four curves 34 A-D are integrated from a filtered measured signal and correspond to the simplified curve 22 D. The filtered measured signal is cleared of electronic noise and other high and low frequencies, which do not relate to the burnishing process.
[0127] The burnishing method is applied during the period 31 A (see also FIG. 12). The preparation of the slider surface is performed during the period 31 B (see also FIG. 12). The slider burnishing is performed during the period 31 C (see also FIG. 12).
[0128] During the period 31 B the voltage level has strong fluctuations as explained above. Towards the end of the period 31 B the voltage level change becomes more steady, which indicates the successful preparation of the hard disk surface 2 . When the burnishing parameters are changed according to the requirements for the slider burnishing, the voltage level has again strong fluctuations for a short period 31 E. This indicates that hit clearance is not obtained yet, which means that the slider is still hitting the disk surface.
[0129] During the period 31 D at the end of the slider burnishing process, the rotational speed of burnished hard disk is gradually increased again and the regular operational conditions are established. An operational voltage signal 32 I is derived. The operational voltage signal 321 has a level discrepancy 31 F to a reference voltage signal 32 R that indicates a predetermined clearance increase and the successful slider burnishing as described above.
[0130] [0130]FIG. 12 shows four curves 44 A-D, each having one of the line styles 44 . The vertical axis 40 represents the static resistance change relative to the total resistance in magnetic read heads that are utilized as contacting sensors.
[0131] The four curves 44 A-D are derived during the same experimental slider burnishing as described in FIG. 11. The four curves 44 A-D are shown for the sole purpose of general understanding without any claim of accuracy.
[0132] The fluctuating static resistance change at the begin of the period 31 B results from the disk surface preparation, during which also the slider is exposed to a certain abrasion.
[0133] Once the topographic inconsistencies are removed, the relative static resistance change goes into a steady incline. During the change from the disk preparation step to the slider burnishing step the curves 44 A-D have a short inconsistency as described in FIG. 11. During the period 31 C the tangential angle of the four curves 44 A-D goes towards zero, which indicates that the maximum burnishing areas are reached. The curves 44 A-D are practically obtained curves that correspond to the simplified curve 22 A.
[0134] It is noted that the disk surface preparation may be optionally and eventually initiated after performing a disk surface verification process in which the evenness of the hard disk surface is recognized. The verification process may be performed by lowering the sliders 1 , 11 - 13 and recognizing the magnitude of the contacting signal fluctuations to derive information about the topographic inconsistencies. The verification process may be performed only for a relatively short period compared to the surface preparation process, since it does not perform a fabrication but only a measurement.
[0135] Accordingly, the scope of the invention described in the specification above is set forth by the following claims and their legal equivalent. | A slider burnishing method is introduced, in which the slider is brought into a predetermined surface contact with the rotating disk for a specified period. The predetermined surface contact and the specified time period are selected together with the surface condition of the rotating hard disk, such that smoothened slider surface is abrasively formed. The smoothened slider surface is substantially parallel to the disk surface and thus provides reduced contact pressure during eventual operational contacting. In addition, the smoothened slider surface creates a constant gap together with the disk surface, which enhances the aerodynamic properties of the air bearing surface and stabilizes a small fly height. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of building elements, and more particularly to a novel assemblage of constructional elements in which various structures may be assembled together to produce a variety of building structures.
2. Brief Description of the Prior Art
In the past, it has been the conventional practice in the field of constructional elements to provide structural or decorative forms that may be erected by employing a variety of components which are joined together in an assembly to provide architectural structures, amusement structures, toys or the like. However, attempts have been made to expand the range of forms that may be erected by providing many different kinds and shapes of construction elements or parts. Usually, such an expansion results in increasing the cost of the construction and tends to restrict the imaginative use of the structure. Also, many structural elements or assemblies have been devised and marketed which usually consist of elongated elements connected by tubes or spheres to form an architectural structure or a replica of a machine or vehicle. Such prior elements are of great variety and many of such elements are fairly complex. Particularly, when considering connecting elements, manufacturing expense must be taken into account. Difficulties and problems have been encountered which stem largely from the fact that rapid wear of the elements is experienced so that after short term use, the parts are no longer frictionally tight and can no longer be reused.
Therefore, a long-standing need has existed to provide a novel structural or decorative form that may be assembled from a plurality of polygonal tiles that may be joined at respective adjacent edges by means of notches which permit connecting elements to be insertably snapped into the notches or receptacles so that a temporary but firm joint is provided between the tiles. The flexible joint connections are made easy to form and to separate repeatedly whereby an infinite number of structural combinations may be assembled.
SUMMARY OF THE INVENTION
Accordingly, the above problems and difficulties are overcome by the present invention which provides a novel flexible joint connector system whereby a plurality of tiles of varying geometrical shape can be joined together to form a structural form or decorative item. Each of the tiles includes an edge marginal region having a plurality of receptacles formed therein and wherein each receptacle includes an entrance of reduced diameter so as to accept a snap-lock relationship with a retaining element used in common with other tiles so as to provide a composite object. A feature of the invention resides in providing the connecting element from a variety of geometrical configurations and which when snap-lock connected with a receptacle provides a flexible joint which is firm but permits the joined tiles to be rotated about the axis of the joint.
Therefore, a primary object of the present invention is to provide a novel flexible joint construction for a plurality of tiles where any tile may be attached to any other tile because the tiles are not intrinsically male or female whereby the tiles may be of many shapes and can be attached to each other so that the geometry is not limited to only right angles.
Another object of the present invention is to provide a novel flexible joint system for an assembly of structures allowing endless geometric ideas to be rendered in physical form wherein it is possible to construct all five of the regular polyhedron and where they can be employed to build globes and geodesic domes.
Yet another object of the present invention is to provide a novel assembly of polygonal tiles that can be joined at their adjacent edges by snap-lock elements so as to provide a variety of polygonal shapes.
Still another object of the present invention is to provide a novel structure having flexible joint connections whereby the joints are convenient to form and to break apart repeatedly so as to make an infinite number of structural combinations.
Yet another object of the present invention is to provide a novel flexible joint connection system having the flexibility of existing building block products without the limitation of strictly rectangular geometry.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood with reference to the following description, taken in connection with the accompanying drawings in which:
FIG. 1 is a front perspective view of a composite assembly of tiles using the novel flexible joint construction of the present invention;
FIG. 2 is a plan view of the plurality of tiles used in the composite assembly of FIG. 1 preparatory to final assembly;
FIG. 3 is a plan view of another assembled construction employing the flexible joint system of the present invention;
FIG. 4 is an enlarged side elevational view of a connecting element used in joining adjacent edges of tiles shown in FIGS. 1 and 3 respectively;
FIG. 5 is a side elevational view of another embodiment of a connecting element useful in joining tiles together;
FIG. 6 is an end elevational view of a connector alternative illustrating the flatness of its sides;
FIG. 7 is a cross-sectional view of the connector shown in FIG. 6;
FIG. 8 is a transverse cross-sectional view of the connector shown in FIG. 4 in the direction of arrows 8--8 and represents a similar transverse cross-sectional view of the alternate connector shown in FIG. 5 in the direction of arrows 8'--8';
FIG. 9 is an enlarged sectional view showing adjacent edge marginal regions of tiles joined by a retainer or connecting element;
FIG. 10 is an enlarged front fragmentary view of a notched receptacle having a reduced entrance leading into a retaining opening;
FIG. 11 is a diagrammatic view showing at least four tiles joined together by a single connecting element so as to be in a non-rotating position;
FIG. 12 is a view similar to the view of FIG. 11 illustrating three tiles connected by a connector element permitting rotation about a connecting point forming the axis of rotation;
FIG. 13 is a perspective view showing that the connecting elements may be carried on a rod preparatory for joining with the edge marginal regions of tiles;
FIG. 14 is a view similar to the view of FIG. 11 showing a tile snap-locked with the connectors carried by the rod; and
FIG. 15 illustrates flexibility of the tiles connected by the connecting element about respective axes at the edge of the respective tiles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, an assembled structure is illustrated in the general direction of arrow 10 which incorporates the flexible Joint construction of the present invention. In the embodiment shown, a cube is illustrated comprising a plurality of tiles, such as tile 11, which are arranged so that their adjacent edges are substantially parallel with respect to one another and wherein each of the tiles includes an edge marginal region having a pair of receptacles, such as receptacle 12 on tile 11, through which a retaining element, such as element 13, is snap-locked. It is noted that the retaining elements couple adjacent edge marginal regions of tiles together so that the resultant composite assembly is produced. The embodiment shown in FIG. 1 further illustrates that each of the tiles may include a central opening, such as opening 14, through which a rod may be inserted. The rod is indicated by numeral 15 and is illustrated assembled with tiles connected to the opposite edge marginal regions of tile 11 and the rod forms a part of the assembled construction. Furthermore, it is also to be noted that the corners of each of the respective tiles are provided with a semicircular cut, as indicated by numeral 16, so that when the adjacent tiles are coupled together by the retaining elements 13, the corners of three adjacent tiles provide an opening through which the rod 15 may be inserted and passed through the interior of the composite assembly to project through a similar hole on the other side or end of the composite structure 10. For purposes of illustration, the bottom of the composite structure 10 does not include a tile and therefore, no retainers are shown through the lower or bottom receptacles.
Referring now in detail to FIG. 2, the composite structure 10 is illustrated in a position preparatory for joining additional sides of the respective tiles together to form the cube shown in FIG. 1. In this connection, the tiles are shown in a laid-out pattern and the respective edge marginal regions are joined together by retaining elements preparatory for moving the respective tiles into the cube configuration so that additional retaining elements can be included to maintain the cube shape.
It is to be particularly noted that the edge marginal region of each tile, such as tile 11, includes a pair of receptacles, such as receptacle 12, wherein the receptacle takes the form of an opening having a reduced entrance, such as the tapered entrance 16 leading into opening 17 adjacent to the receptacle 12. Therefore, it can be seen that the retaining element 13 is introduced through the reduced opening 16 into the receptacle opening 17. This is a snap-lock relationship whereby the retaining elements may easily be forcibly urged through the reduced entrance into the enlarged opening 17 in a snap-lock manner. Conversely, the retaining element 13 can be withdrawn from the receptacle by exerting a force which would urge the retaining element out of the opening 17 through the reduced entrance 16. FIG. 2 also illustrates the provision for a central opening 14 in each of the respective tiles and that the corners include a semicircular cut so as to accommodate rod 15, if desired.
FIG. 3 is a front plan view of tiles having a different geometric configuration, notably that of a triangle, laid out in a pattern preparatory for being folded into a triangular structure. When the tiles indicated in the general direction of arrow 18 are folded over upon themselves, the triangular structure is produced and additional retaining elements can be introduced into corresponding receptacles. Numeral 20 indicates one of the tiles of triangular configuration and numeral 21 illustrates a typical receptacle which is carried along the edge marginal regions of each tile. Numeral 22 illustrates the joining retaining element, and numeral 23 illustrates a central hole for receiving a rod 15, if desired. As previously described, the respective corners or terminal points of the triangular tiles 20 are provided with semicircular cuts, as indicated by numeral 24, so that a circular opening is provided for receiving the rod 15, if desired.
Referring now to FIG. 4, a typical retaining element 13 is illustrated in which the overall configuration is that of a toroid having a central opening 25. The thickness of the retaining element is sufficient to require forcible urging through the receptacles 12 or 21 into the inner receptacle opening. The reduced opening will partially occupy the central opening 25 of each retaining element once installed. FIG. 8 illustrates a transverse cross-sectional view of the toroid retaining element 13. However, FIGS. 6 and 7 illustrate another form of retaining element which is not round but is flat so that when engaged in the tile, it is flush with the face of the tile. FIG. 5 is still another retaining element and has a similar cross-sectional view as that of the toroid shown in FIG. 4, and the cross-section is shown in FIG. 8 as taken in the direction of arrows 8'--8' in FIG. 5.
Referring now in detail to FIG. 11, it can be seen that the retaining element 13 connects the edge marginal regions of tiles 30, 31, 32 and 33 which may be identical to the tiles shown in FIG. 1. However, the adjacent terminating ends of the respective tiles form converging edges so that when the four tiles are placed together, no substantial movement is permitted within the respective tiles since the conformal surfaces of the wedged ends fits together into a solid assembly.
With respect to FIG. 12, it can be seen that tiles 30, 31 and 32 are held together by the retaining element 13 but in a loose manner since the wedge-shaped edge marginal regions of the respective tiles do not form a solid connection whereby the tiles may rotate about a common axis running through the opening 25 of the retaining element 13.
Referring now in detail to FIGS. 13, 14 and 15, another connecting arrangement is illustrated whereby the respective retaining elements 13 may be carried on the rod 15 and the body of each of the retaining elements may be pressed into receptacles of a respective tile. The tile is indicated by numeral 33 and a typical receptacle is indicated by numeral 34.
In view of the foregoing, it can be seen that many tiles can be assembled in the manner described above to make complex three-dimensional assemblies. Holes in the center of each face of a tile allows rods to be passed through. Rounded corners of each tile allow for connecting assemblies corner-to-corner. Thus, assemblies can be attached to each other at the corner, edge or face. Any tile may be attached to any other tile because the tiles are not intrinsically male or female. The tiles may be of any desired geometrical shape and can be attached to each other so the geometry is not limited to only right angles. The versatility of the tile with its joining system allows endless geometric ideas to be rendered in physical form. For example, it is possible to construct all five of the regular polyhedron. Also, the tile and joining system can be used to build globes and geodesic domes.
The tiles are polygons which can be joined at their adjacent edge marginal regions via the retaining elements and the receptacles in a snap-lock manner. The joint achieved is firm but flexible and the joined tiles can be rotated at the axis of the joint. The retaining elements snap into holes or receptacles along the edge of the tiles and the retaining elements project from the edge of the tile so other tiles can be attached. The tiles are held together firmly and can be rotated about the axis of the joint.
Therefore, the joints once formed allow free rotation of the tiles about the axis formed by the joint and polygons of various numbers of edges can be joined to each other. Several tiles can be combined to form three-dimensional objects and multiple tiles can share an edge with as many retaining elements as desired. The joints are easy to form and break away repeatedly to make an indefinite number of combinations.
The system of the present invention is intended to join the adjacent edges of two flat objects, such as the tiles illustrated. The system allows for easy joining and unjoining of the tiles in a repeated manner with little wear or resistance. It also allows rotation of the joint through a large angle about the axis of the joint edges. The system consists of a series of holes or slots along each edge marginal region of a tile to be joined with another tile. The slotted holes allow a flexible retaining element or ring to snap through the reduced entrance of the slot into a receptacle hole. Each hole is at a distance away from the edge that leaves enough of the retaining element or ring exposed to fit into a hole in another tile. The edge of each object is beveled to allow the joint to be made at any angle.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention. | An interlockable connection system is disclosed herein for releasably joining a selected number of tiles together wherein each tile includes a plurality of receptacles adapted to snap-lock with a retaining element used in common with other tiles so as to provide a composite object composed of multiple tiles of various polygonal shapes. The retaining elements may be of many shapes and tiles may be of a variety of geometric configurations. The connection system provides convenient repeatable joining and unjoining of the retaining elements with the tiles and permits rotation of the joint through a large angle about the axis of the joined tile edges. |
This is a division of application Ser. No. 07/602,626 filed Oct. 24, 1990, now U.S. Pat. No. 5,389,723.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to transparent materials that are capable of absorbing liquids, and, more particularly, to materials that can be used as ink-receptive layers for transparent imageable materials.
2. Discussion of the Art
Transparent materials that are capable of absorbing significant quantities of liquid, while maintaining some degree of durability and transparency, are useful in contact lenses, priming layers for coatings coated out of aqueous solutions, fog-resistant coatings, and transparent imageable materials for use with mechanized ink depositing devices, such as pen plotters and ink-jet printers. Transparent imageable materials are used as overlays in technical drawings and as transparencies for overhead projection. It is desirable that the surface of liquid absorbent materials for use in transparent graphical applications be tack free to the touch even after absorption of significant quantities of ink.
During normal use of pen plotters and ink-jet printers, the inks used in such machines are exposed to open air for long periods of time prior to imaging. After such exposure to air, the ink must still function in an acceptable manner, without loss of solvent. To meet this requirement, ink formulations typically utilize solvents of very low volatility, such as water, ethylene glycol, propylene glycol, and so on. Inks that contain water or water-miscible solvents are commonly referred to as aqueous inks, and the solvents for these inks commonly are referred to as aqueous liquids. Materials that are receptive to such aqueous liquids will hereinafter be referred to as hydrophilic compositions.
Because of the low volatility of aqueous liquids, drying of an image by means of evaporation is very limited. In the case of imaging onto a paper sheet which has a fibrous nature, a significant amount of the liquid diffuses into the sheet, and the surface appears dry to the touch within a very short time. In the case of imaging onto polymeric film, some means of absorbing aqueous liquids is needed if satisfactory drying of image is to occur.
Compositions useful as transparent liquid absorbent materials have been formed by blending a liquid-insoluble polymeric material with a liquid-soluble polymeric material. The liquid-insoluble material is presumed to form a matrix, within which the liquid soluble material resides. Examples of such blends are the transparent water-absorbent polymeric materials disclosed in U.S. Pat. Nos. 4,300,820, 4,369,229, and in European Patent Application No. 0 233 703.
A problem that frequently arises in the formulation of polymer blends is the incompatibility of the polymers being blended. When attempts are made to blend polymers that are incompatible, phase separation occurs, resulting in haze, lack of transparency, and other forms of inhomogeneity.
Compatibility between two or more polymers in a blend can often be improved by incorporating into the liquid-insoluble matrix-forming polymer chains monomeric units that exhibit some affinity for the liquid-soluble polymer. Polymeric materials having even a small amount of acid functionality are more likely to exhibit compatibility with polyvinyl lactams. Generally, the compatibility of polymers being blended is improved if the polymers are capable of hydrogen bonding to one another.
A second form of incompatibility noted in using blends of liquid-absorbent polymers is the incompatibility of the matrix forming insoluble polymer with the liquid being absorbed. For example, if the liquid being absorbed is water, and if the water-insoluble polymers are hydrophobic, some inhibition of water absorption ability can be expected. One method of overcoming this difficulty is to utilize hydrophilic matrix polymers that are water-insoluble at the temperatures at which they are to be used, though they may be water-soluble at a different temperature. In U.S. Pat. No. 4,503,111, ink-receptive coatings comprising either polyvinyl alcohol or gelatin blended with polyvinyl pyrrolidone are disclosed. Both polyvinyl alcohol and gelatin, being water-insoluble at room temperature, are able to act as matrix-forming polymers for these coatings, and the coatings are quite receptive to aqueous inks. However, the coatings do exhibit a tendency to become tacky, either because of imaging, or because of high humidity.
It therefore becomes clear that while blends of soluble and insoluble polymers may be useful as liquid absorbent compositions, they suffer major limitations in liquid absorption ability and in durability.
SUMMARY OF THE INVENTION
This invention provides a composition comprising a blend of (a) at least one polymeric matrix component comprising crosslinkable polymers comprising α,β-ethylenically unsaturated monomers, (b) at least one liquid-absorbent component comprising a water-absorbent polymer, preferably a water-soluble polymer, and (c) polyfunctional aziridines as a crosslinking agent. This composition is capable of forming liquid-absorbent, semi-interpenetrating networks, hereinafter referred to as SIPNs. The SIPNs disclosed herein are polymeric blends wherein at least one of the polymeric components is crosslinked after blending to form a continuous network throughout the bulk of the material, and through which the uncrosslinked polymeric component or components are intertwined in such a way as to form a macroscopically homogeneous composition.
SIPNs of this invention are capable of absorbing significant quantities of those liquids that are solvents of the uncrosslinked portion of the SIPN without loss of physical integrity and without leaching or other forms of phase separation. In cases where the SIPNs are initially transparent, they also remain transparent after absorption of significant quantities of liquids.
The nature of the crosslinking used in the formation of the matrix component of the SIPN is such that it combines durability in the presence of the liquids encountered during use with compatibility toward the liquid-absorbent component. The crosslinked matrix component and the liquid-absorbent component are miscible, exhibit little or no phase separation, and generate little or no haze upon coating. The nature of the crosslinking should also be such that it does not interfere with pot-life and curing properties that are associated with commonly available methods of processing. More particularly, crosslinking should be limited to the matrix component of the SIPN, and should not cause phase separation or other inhomogeneity in the SIPN.
This invention provides polymeric matrices which, when coated on a transparent backing, result in transparent coatings capable of providing improved combinations of ink absorption and durability, while at the same time retaining transparency and being amenable to the types of processing commonly used in producing transparent graphical materials.
DETAILED DESCRIPTION
The crosslinkable portion of the SIPN will hereinafter be called the matrix component, and the liquid-absorbent portion will hereinafter be called the absorbent or liquid-absorbent component.
The matrix component of the SIPN of the present invention comprises crosslinkable polymers that are either hydrophobic or hydrophilic in nature, and are derived from the copolymerization of acrylic or other hydrophobic or hydrophilic ethylenically unsaturated monomers with monomers having acidic groups, or by hydrolysis, if pendant ester groups are already present in these ethylenically unsaturated monomers.
Hydrophobic monomers suitable for preparing crosslinkable matrix components generally have the following properties:
(1) They form water-insoluble homopolymers if polymerized with themselves.
(2) Polymers formed from them contain no pendant groups having more than 18 carbon atoms, preferably no more than 4 carbon atoms, and more preferably, 1 to 2 carbon atoms.
(3) They have hydrogen bonding capabilities so that the backbones of polymers formed therefrom or in substituents of the backbones of polymers formed therefrom exhibit enhanced absorption of water or other hydrogen-bonding liquids.
These monomers are preferably selected from:
(1) acrylates and methacrylates having the structure: ##STR1## wherein R 1 represents hydrogen or --CH 3 , and R 2 represents a member selected from the group consisting of alkyl groups having up to 18 carbon atoms, preferably up to 4 carbon atoms, and more preferably 1 to 2 carbon atoms, cycloaliphatic groups having up to 9 carbon atoms, aryl groups having up to 14 carbon atoms, and oxygen containing heterocyclic groups having up to 10 carbon atoms;
(2) acrylonitrile or methacrylonitile;
(3) styrene or methylstyrene having the structure: ##STR2## where X and Y independently represent hydrogen, alkyl groups having up to 4 carbon atoms, preferably 1 or 2 carbon atoms, a halogen atom, alkyl halide groups, or OR m , where R m represent hydrogen or an alkyl group having up to 4 carbon atoms, preferably 1 or 2 carbon atoms, and Z represents hydrogen or methyl; and
(4) vinyl acetate.
Hydrophilic monomers suitable for preparing crosslinkable matrix components typically have the characteristic that they form water-soluble homopolymers when polymerized with themselves. They are preferably selected from:
(1) Vinyl lactams having the repeating structure: ##STR3## where n represents the integer 2 or 3. (2) Acrylamide or methacrylamide having the structure: ##STR4## where R 1 is as described previously, R 5 represents hydrogen or an alkyl group having up to 10 carbon atoms, preferably having from 1 to 4 carbon atoms, and R 6 represents a member selected from the group consisting of hydrogen, alkyl groups having up to 10 carbon atoms, preferably having from 1 to 4 carbon atoms, and hydroxy-substituted alkyl groups or alkoxy-substituted alkyl groups having the structure of --(CH 2 ) p --OR 7 where p represents an integer from 1 to 3, inclusive, and R 7 represents hydrogen or an alkyl group having up to 10 carbon atoms, preferably having from 1 to 4 carbon atoms.
(3) Tertiary amino alkylacrylates or tertiary amino alkylmethacrylates having the structure: ##STR5## where q represents the integer 1 or 2, and R 1 and R 5 are as described previously, and each R 5 can be the same or different.
(4) Alkoxy alkylacrylates, hydroxy alkylacrylates, alkoxy alkylmethacrylates, or hydroxy alkylmethacrylates having the structure: ##STR6## where r represents an integer from 1 to 4, inclusive, preferably 2 or 3, R 1 is as described previously, and R 8 represents hydrogen or an alkyl group having 1 to 4 carbon atoms.
(5) Alkoxy acrylates or alkoxy methacrylates having the structure: ##STR7## where s represents an integer from 5 to 25, inclusive, and R 1 is as described previously.
Some of the structures of both the above-mentioned hydrophobic and hydrophilic monomeric units contain pendant ester groups, and these can be rendered crosslinkable by hydrolysis. For the others, monomers containing acidic-groups can be copolymerized with non-functionalized monomers by free-radical solution, emulsion, or suspension polymerization techniques to produce crosslinkable polymers. Suitable monomers containing acidic-groups include acrylic acid or methacrylic acid, other copolymerizable carboxyclic acids, and ammonium salts. Monomers containing acidic-groups can also be grafted onto polymers.
When acrylic or methacrylic acid is used, the acidic group is present at a level of from about 1.0% to about 20% by weight of the crosslinkable polymer, and preferably from about 2.5% to 9% by weight. When ammonium salts are used, the amine structure can be as follows: ##STR8## where R 9 independently represents hydrogen or an alkyl group having up to 5 carbon atoms, preferably 1 or 2 carbon atoms, with the preferred amine being NH 3 or another volatile amine.
While it is the primary function of the matrix component of the SIPN to impart physical integrity and durability to the SIPN without adversely affecting the liquid-absorbency of the SIPN, it is the primary function of the liquid-absorbent component to promote liquid-absorbency. When aqueous liquids are to be absorbed, as is in the case of most inks, the liquid-absorbent component can be water-absorbent, preferably water-soluble, and can be selected from polymers formed from the following monomers:
(1) Vinyl lactams having the repeating structure: ##STR9## where n is as described previously. (2) Tertiary amino alkylacrylates or tertiary amino alkylmethacrylates having the structure: ##STR10## where p, R 1 and R 5 are as described previously, and each R 5 can be the same or different.
(3) Alkyl quaternary amino alkylacrylates or alkyl quaternary amino alkylmethacrylates.
Polymerization of these monomers can be carried out by typical free radical polymerization techniques as described previously.
Alternately, the liquid-absorbent component can also be selected from commercially available water-absorbent polymers such as polyvinyl alcohol, copolymers of vinyl alcohol and vinyl acetate, polyvinyl formal, polyvinyl butyral, gelatin, carboxymethylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl starch, polyethyl oxazoline, polyethylene oxide, polyethylene glycol, polypropylene oxide. The preferred polymers are polyvinyl lactams, and, in particular, polyvinyl pyrrolidone, polyvinyl alcohol, and polyethylene oxide.
Crosslinking can be performed by means of polyfunctional aziridines, such as trimethylol propane-tris-(β-(N-aziridinyl)propionate) ##STR11## pentaerythritol-tris-(β-(N-aziridinyl)propionate) ##STR12## trimethylol propane-tris-[β-(N-methylaziridinyl propionate) ##STR13## These polyfunctional aziridines must possess at least two crosslinking sites in one molecule.
A preferred use of the SIPNs of this invention is for forming ink receptive layers for graphical materials. Typically, these SIPNs comprise from about 0.5 to 6.0% by weight of crosslinking agent, more preferably from about 1.0 to 4.5% by weight based, on the total weight of the SIPN. The matrix component can be present at a level of from about 23.5 to about 98.5% by weight of the total SIPN, more preferably from about 30 to about 57.5% by weight. The absorbent component can be present at a level of from about 1 to about 70.5% by weight, and more preferably from about 38.0 to about 69% by weight. When polyvinyl pyrrolidone is used as the absorbent component of the SIPN and acrylates are used as the matrix component, good absorption of aqueous inks can be obtained at room temperature if the polyvinyl pyrrolidone comprises at least about 30% by weight, more preferably at least about 50% by weight of the SIPN. Higher absorption can be obtained at the expense of durability if the polyvinyl pyrrolidone is present in greater amounts. When polyvinyl pyrrolidone is present at a level of about 80% by weight of the SIPN, the matrix component is not able to form a complete network, and the entire composition loses its physical integrity when washed with water.
In cases where the SIPNs of the invention are to be used as liquid-receptive layers borne by solid substitutes, as in transparent graphical materials, it is convenient to apply such layers to the substrates in the form of a coatable liquid composition, which is subsequently dried to form a solid layer. A coatable liquid composition can be prepared by dissolving the matrix component and the absorbent component in appropriate proportions in a common solvent, preferably water or a water miscible solvent, depending on the solubility of the polymers. The solvents can be selected on the basis of Hansen solubility parameters. The crosslinking agent is then added to the solution, and the solution is mixed until it becomes uniform. This solution can then be applied to a transparent substrate, e.g., a polymeric film, by coating, and allowed to dry. The amount of heat required to accomplish the drying in a reasonable time is usually sufficient for causing crosslinking of crosslinkable polymer of the the matrix component to occur. The pot life of the solution after the addition of the crosslinking agent is between 18 to 24 hours, but it is preferred that the blend be used within three to four hours.
SIPN solutions of the present invention may contain additional modifying ingredients such as adhesion promoters, particles, surfactants, viscosity modifiers, and like materials, provided that such additives do not adversely affect the liquid-absorbing capability of the invention.
Coating can be carried out by any suitable means, such as by a knife coater, a rotogravure coater, a reverse roll coater, or other conventional means, as would be known to one of ordinary skill in the art. Drying can be accomplished by means of heated air. If preferred, an adhesion promoting priming layer can be interposed between the applied coating and the substrate. Such priming layers can include prime coatings. Alternatively, surface treatments, such as corona treatment, or other appropriate treatment can be used to promote adhesion. Such treatments would be known to one of ordinary skill in the art. Adhesion of the SIPN layer can also be promoted by interposing a gelatin sublayer of the type used in photographic film backings between the priming layer and the SIPN layer. Film backings having both a priming layer and a gelatin sublayer are commercially available, and are frequently designated as primed and subbed film backings.
When the SIPNs of the present invention are to be used to form the ink-absorbing layers of films for use with ink-jet printers, it is preferred that the backing of the film have a caliper in the range of about 50 to about 125 micrometers. Films having calipers below about 50 micrometers tend to be too fragile for graphic arts films, while films having calipers over about 125 micrometers tend to be too stiff for easy feeding through many of the imaging devices currently in use. Backing materials suitable for graphic arts films include polymeric materials, such as, for example, polyesters, e.g., polyethylene terephthalate, cellulose acetates, polycarbonates, polyvinyl chloride, polystyrene, and polysulfones.
When the SIPNs of the present invention are to be used to form ink absorbing layers for films for ink-jet printing, the SIPN layer may further be overcoated with an ink-permeable anti-tack protective layer, such as, for example, a layer comprising polyvinyl alcohol in which starch particles have been dispersed, or a semi-interpenetrating polymer network in which polyvinyl alcohol is the absorbent component. A further function of such overcoat layers is to provide surface properties which help to properly control the spread of ink droplets so as to optimize image quality.
In order to more fully illustrate the various embodiments of the present invention, the following non-limiting examples are provided. All parts are parts by weight unless indicated otherwise.
EXAMPLE 1
The polymeric material for the matrix component of this example was prepared by combining N-vinyl-2-pyrrolidone (75 parts by weight), N,N-dimethyl acrylamide (2 parts by weight), the ammonium salt of acrylic acid (5 parts by weight), azo-bis-isobutyronitrile (0.14 part by weight, "Vazo", available from E. I. du Pont de Nemours and Company), and deionized water (566 parts by weight) in a one-liter brown bottle. After the mixture was purged with dry nitrogen gas for five minutes, polymerization was effected by immersing the bottle in a constant temperature bath maintained at a temperature of 60° C. for between 18 to 24 hours. The resulting polymerized mixture was then diluted with deionized water to give a 10% solution in water (hereinafter Solution A).
Solution A (8 g of a 10% aqueous solution) was mixed with surfactant (0.2 g of a 2% aqueous solution, "Triton X100", Rohm and Haas Co.), polyvinyl alcohol (8 g of a 5% aqueous solution, "Vinol 540", Air Products and Chemicals, Inc.), and polyfunctional aziridine crosslinking agent (0.5 g of a 10% aqueous solution, XAMA-7, Sanncor Ind., Inc.) in a separate vessel.
The resultant solution was coated onto a backing of polyethylene terephthalate film having a caliper of 100 micrometers, which had been primed with polyvinylidene chloride, over which had been coated a gelatin sublayer of the type used in photographic films for improving gelatin adhesion ("Scotchpar" Type PH primed and subbed film, available from Minnesota Mining and Manufacturing Company). Coating was carried out by means of a knife coater at a wet thickness of 200 micrometers. The coating was then dried by exposure to circulating heated air at a temperature of 90° C. for five minutes to form a clear SIPN layer.
Printing was performed with an ink-jet printer and pen using ink containing Direct Blue 99 dye (3% solution in water). After six minutes, the imaged film was immersed in water and no dye was removed from the image. The SIPN layer remained intact.
COMPARATIVE EXAMPLE A
Example 1 was repeated with the exception that the crosslinking agent was omitted. When the imaged film was immersed in water, dye was removed from the imaged area within 15 minutes.
Example 1 and Comparative Example A demonstrate that a blend can absorb ink, but not retain it, while an SIPN can do both.
EXAMPLE 2
The polymeric material for the matrix component of this example was prepared by combining N-vinyl-2-pyrrolidone (72 parts by weight), N,N-dimethyl acrylamide (20 parts by weight), the ammonium salt of acrylic acid (5 parts by weight), the ammonium salt of 2-acrylamido-2-methyl propane sulfonic acid (3 parts by weight), azo-bis-isobutyronitrile (0.14 part by weight, "Vazo"), and deionized water (566 parts by weight) in a one-liter brown bottle. After the mixture was purged with dry nitrogen gas for five minutes, polymerization was effected by immersing the bottle in a constant temperature bath maintained at a temperature of 60° C. for 18 to 24 hours. The resulting polymerized mixture was diluted with deionized water to give 12% solids solution (hereinafter Solution B).
Solution B (4 g) was mixed with surfactant (0.2 g of a 2% aqueous solution, "Triton X100"), polyethylene oxide (molecular weight=4,000,000, 18 g of a 2% aqueous solution), and crosslinking agent (0.46 g of a 10% aqueous solution, XAMA-7) to form a coatable solution.
The resultant solution was coated onto a backing of polyethylene terephthalate film having a caliper of 100 micrometers, which had been primed with polyvinylidene chloride, over which had been coated a gelatin sublayer of the type used in photographic films for improving gelatin adhesion ("Scotchpar" Type PH primed and subbed film, available from Minnesota Mining and Manufacturing Company). The coating was then dried by exposure to circulating heated air at a temperature of 90° C. for five minutes to form a clear SIPN layer.
Printing was performed with an ink-jet printer and pen using ink containing Direct Blue 99 dye (3% solution in water). After six minutes, the imaged film was immersed in water, and no dye was removed from the image. The SIPN layer remained intact.
COMPARATIVE EXAMPLE B
Example 2 was repeated with the exception that the crosslinking agent was omitted. After the coated film was imaged by means of an ink-jet printer using water-based ink, the coating was completely dissolved by the ink.
EXAMPLE 3
The polymeric material for the matrix component of an ink-receptive layer was prepared by combining in a one-liter bottle N-vinyl-2-pyrrolidone (65 parts by weight), 2-hydroxyethyl methacrylate (15 parts by weight), methoxyethyl acrylate (15 parts by weight), the ammonium salt of acrylic acid (5 parts by weight), azo-bis-isobutyronitrile (0.14 part by weight, "Vazo"), deionized water (300 parts by weight), and ethyl alcohol (100 parts by weight). After the mixture was purged with dry nitrogen gas for five minutes, the mixture was polymerized at a temperature of 60° C. for 16 to 20 hours. The resulting polymerized mixture was diluted with 100 parts of a 1:1 mixture of deionized water and ethyl alcohol to give a solution containing 16.37% by weight of solids (98.25% conversion). This polymer was further diluted with water to give a solution containing 10% solids (hereinafter Solution C).
Solution C (10 g of a 10% aqueous solution) was mixed with polyvinyl alcohol (15 g of a 10% aqueous solution), and polyfunctional aziridine (1.1 g of a 10% solution in ethyl alcohol), prior to coating. The solution was coated onto a primed and subbed polyethylene terephthalate film having a thickness of 100 micrometers (such as that described in Example 1), at a coating weight of 1.0 g/sq ft., and dried in an oven at a temperature of 90° C. for five minutes.
The coated film was imaged on both a Hewlett-Packard Pen Plotter and a Hewlett-Packard Desk Jet ink-jet printer. The ink was absorbed quickly, giving a dry, tack-free image having good image quality.
EXAMPLE 4
A mixture containing methyl methacrylate (85 parts by weight), 2-hydroxy ethyl methacrylate (10 parts by weight), acrylic acid (5 parts by weight), azo-bis-isobutyronitrite (0.14 part by weight, "Vazo"), ethyl acetate (150 parts by weight), and ethyl alcohol (50 parts by weight) was combined in a 500 ml brown bottle. After the mixture was purged with dry nitrogen gas for five minutes, it was polymerized at a temperature of 60° C. for 24 to 36 hours. The polymerized material was diluted with 100 g of ethyl acetate to give a solution containing 20.13% by weight solids (hereinafter Solution D).
Solution D (5.72 g) was mixed with polyvinyl pyrrolidone (10.60 g of a 10% solution in ethanol, PVP-K90, GAF Corporation), crosslinking agent (1.5 g of a 10% solution in ethyl acetate, XAMA-7), and ethyl acetate (2.1 g) to form a coatable solution.
The resultant solution was coated onto a backing of polyethylene terephthalate film having a caliper of 100 micrometers, which had been primed with polyvinylidene chloride, over which had been coated a gelatin sublayer of the type used in photographic films for improving gelatin adhesion ("Scotchpar" Type PH primed and subbed film, available from Minnesota Mining and Manufacturing Company). The coating was then dried by exposure to circulating heated air at a temperature of 90° C. for five minutes to form a clear SIPN layer.
Printing was performed with an ink-jet printer and pen using ink containing Direct Blue 99 dye (3% aqueous solution). After six minutes, the imaged film was immersed in water and no dye was removed from the image. The SIPN layer remained intact. The coated film was also imaged by means of an Hewlett-Packard 7550A Graphic Printer Pen Plotter. Drying time for the ink was less than 60 seconds.
COMPARATIVE EXAMPLE C
Example 4 was repeated with the exception that the crosslinking agent was omitted from the formulation. The resulting coated film did not absorb the ink. Furthermore, the ink clogged in the pen of the Hewlett-Packard 7550A Graphic Printer Pen Plotter.
EXAMPLE 5-8
A mixture containing methyl methacrylate (70 parts by weight), 2-hydroxyethyl methacrylate (25 parts by weight), acrylic acid (5 parts by weight), azo-bis-isobutyronitrile (0.11 part by weight, "Vazo"), ethyl acetate (150 parts by weight), and ethyl alcohol (50 parts by weight) was combined in a 500 ml bottle. After the mixture was purged with dry nitrogen gas for five minutes, it was polymerized for 18 to 24 hours at a temperature of 60° C. The polymerized composition was diluted with 50 g of ethyl acetate to give a solution containing 25.04% by weight solids (87.65% conversion) (hereinafter Solution E).
The following formulations were prepared:
TABLE I______________________________________ Amount (g) Water-Example soluble Crosslinking Ethylno. Solution E polymer agent.sup.e acetate______________________________________5 4.17 10.42.sup.a 1.44 4.06 4.90 12.25.sup.b 1.80 2.37 5.40 13.50.sup.c 1.80 3.58 4.21 8.80.sup.d 1.22 2.5______________________________________ .sup.a 5% polyethylene oxide in CHCl.sub.3 (Polyox100,000, Union Carbide) .sup.b 10% quaternized copolymer of vinyl pyrrolidone and dimethyl amino ethyl methacrylate in ethanol (Gafquate 734, GAF Corp.) .sup.c 10% polyvinyl pyrrolidone dimethyl amino ethyl methacrylate in ethanol (Copolymer 965, GAF Corp.) .sup.d 10% poly4-vinyl pyridine in ethanol .sup.e 10% crosslinking agent in ethyl acetate (XAMA7)
The compositions of Example nos. 5, 6, 7, and 8 were coated onto separate backings of polyethylene terephthalate film having a caliper of 100 micrometers that had been primed with polyvinylidene chloride. The coatings were then dried by being exposed to circulating heated air at a temperature of 90° C. for five minutes to form a clean SIPN layer in each case.
Printing was performed with ink-jet printer and pen using ink containing Direct Blue 99 dye (3% solution in water). When the coated films were imaged by a Hewlett-Packard 7550A Graphic Printer Pen Plotter, images of all colors were bright, with no pick, no pen clogging, and no dye diffusion.
EXAMPLE 9
A mixture containing methyl methacrylate (160 parts by weight), 2-hydroxyethyl methacrylate (30 parts by weight), acrylic acid (10 parts by weight), azo-bis-isobutyronitrile (0.28 part by weight, "Vazo"), and ethyl acetate (466.6 parts by weight) was combined in a one-liter bottle. After the mixture was purged with dry nitrogen gas for five minutes, it was polymerized for 24 to 36 hours at a temperature of 60° C. The polymer was diluted with 75 parts by weight of ethanol to give a solution containing 26.62% by weight solids (98.7% conversion). To this solution was sparged anhydrous ammonia gas with mechanical stirring until the pH of the solution reached 7.0 to 7.5. The solution (hereinafter Solution F) was hazy.
The following ingredients in the amounts indicated were thoroughly mixed to obtain a coating solution:
______________________________________Ingredient Amount (g)______________________________________Solution F (26.62% solids) 5.0Polyvinyl pyrrolidone (PVP-K90) 1.99Polyvinyl butyral ("Butvar-B76", 0.175Monsanto Co.)Ethyl acetate 14.0Ethyl alcohol 11.0Crosslinking agent (XAMA-7, 10% in 1.2ethyl acetate)______________________________________
The resultant solution was coated onto a backing of polyethylene terephthalate film having a caliper of 100 micrometers, which had been primed with polyvinylidene chloride, over which had been coated a gelatin sublayer of the type used in photographic films for improving gelatin adhesion ("Scotchpar" Type PH primed and subbed film, available from Minnesota Mining and Manufacturing Company). The coating was then dried by exposure to circulating heated air at a temperature 90° C. for five minutes to form a clear SIPN layer.
Printing was performed with an ink-jet printer and pen using ink containing Direct Blue 99 dye (3% solution in water). After six minutes, the imaged film was immersed in water and no dye was removed from image. The SIPN layer remained intact. When the coated film was imaged by a Hewlett-Packard 7550 Graphic Printer pen plotter, the images of all colors were bright, with no pick, with no pen clogging, and with no dye diffusion.
EXAMPLE 10
A mixture of methyl methacrylate (83 parts by weight), ethoxylated methacrylate monomer having 5 moles of ethylene oxide (10 parts by weight, HEM-5, available from Alcolac Inc.), acrylic acid (5 parts by weight), dodecyl thiol (0.075 part by weight), azo-bis-isobutyronitrile (0.14 part by weight, "Vazo"), and ethyl acetate (200 parts by weight), was combined in a 500 ml bottle. After the mixture was purged with dry nitrogen gas for five minutes, it was purged for 24 hours. The polymer was diluted with 50 g of a mixture of ethyl acetate and ethyl alcohol (1:1 ratio) to give a solution containing 20.79% by weight solids (83.16% conversion)(hereinafter Solution G).
The following ingredients were thoroughly mixed in the amounts indicated to form a coatable solution:
______________________________________Ingredient Amount (g)______________________________________Solution G (20.79% solids) 5.5Polyvinyl pyrrolidone (PVP-K90) 1.93Polyvinyl butyral (Butvar-B76, 0.196Monsanto Co.)Ethyl acetate 12.5Ethyl alcohol 10.0Crosslinking agent (XAMA-7, 10% in 1.35ethyl acetate)______________________________________
The resultant solution was coated onto a backing of polyethylene terephthalate film having a caliper of 100 micrometers, which had been primed with polyvinylidene chloride, over which had been coated a gelatin sublayer of the type used in photographic films for improving gelatin adhesion ("Scotchpar" Type PH primed and subbed film, available from Minnesota Mining and Manufacturing Company). The coating was then dried by exposure to circulating heated air at a temperature of 90° C. for five minutes to form a clear SIPN layer.
Printing was performed with an Hewlett-Packard Desk Jet ink-jet printer and Hewlett-Packard 7550 Graphic Printer pen plotter using ink containing Direct Blue 99 dye (3% solution in water). After six minutes, the imaged film was immersed in water and no dye was removed from image. The SIPN layer remained intact. The images were satisfactory and tack-free. This film also exhibited a better tendency to lay flat as compared with other coated films under ambient conditions.
EXAMPLE 11 AND COMPARATIVE EXAMPLE D
Example 11 illustrates a composition comprising a blend of two absorbent polymers, where the presence of the second absorbent polymer results in improved compatibility and liquid absorption as compared to the composition of Comparative Example D, where the second polymer is absent. The compositions set forth in Table II were coated onto polyester film at a wet thickness of 200 micrometers and were allowed to dry for five minutes at a temperature of 85° C.
TABLE II______________________________________ Amount (g) Cross- Absorbent Ab- linkable polymer 1 Cross- sorbentExample polymer (Polyethylene Surfact- linking Poly-no. (A) oxide) ant.sup.a agent.sup.b mer 2.sup.c______________________________________11 4 2 0.2 0.35 8Compar- 4 2 0.2 0.35 0ative D______________________________________ .sup.a "Triton X100" (2% in water) .sup.b XAMA7 (10% in water) .sup.c "Natrosol" 250L (5% water, available from Hercules, Inc.)
The composition of Comparative Example D provided a relatively hazy film because of crystallization of the polyethylene oxide on the surface of the film after the film was imaged. The composition of Example 11 provided a very clear transparent coating with no crystallization after the film was imaged.
EXAMPLE 12
The following example illustrates a SIPN employing gelatin as one of the components of the blend. The following composition was coated onto polyester film at a wet thickness of 200 micrometers and was allowed to dry for five minutes at a temperature of 85° C.
______________________________________Ingredient Amount (g)______________________________________Solution B 4.0(as in Example 2)Gelatin (669-10, 10% aqueous solution) 4.0Surfactant ("Triton X100", 0.22% aqueous solution)Water 3.0Crosslinking agent (XAMA-7, 0.3510% aqueous solution)______________________________________
The composition of Example 12 provided a clear film upon which ink dried very fast when applied by an ink-jet printer.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein. | Semi-interpenetrating polymeric networks comprising a blend of hydrophilic and hydrophobic polymers wherein at least one of the polymeric components is crosslinked after blending to form a continuous network throughout the bulk of the material, and through which the uncrosslinked polymeric components are intertwined in such a way as to form a macroscopically homogeneous composition. The integrity of such networks persists even after absorption of solvent. These materials can be used to form durable, non-tacky, ink-absorbent, transparent coatings for graphical materials. |
RELATED APPLICATION
[0001] The present application claims priority of U.S. Provisional Application Serial No. 60/210,922, filed Jun. 12, 2000, entitled “SYSTEM AND METHOD FOR HOST AND NETWORK BASED INTRUSION DETECTION AND RESPONSE”, the disclosure of which is incorporated by reference herein in its entirety.
[0002] The present application is related to patent application entitled “SYSTEM AND METHOD FOR HOST AND NETWORK BASED INTRUSION DETECTION AND RESPONSE” (HP Docket No. 10004512-1) and assigned to the instant assignee and filed on even date herewith and is hereby incorporated by reference into this specification in its entirety.
FIELD OF THE INVENTION
[0003] The present invention relates generally to intrusion detection, and more particularly, to a host-based Intrusion Detection System (IDS). Intrusion detection is a process of monitoring events occurring in a computer system or network and analyzing the events for signs of security violations.
BACKGROUND OF THE INVENTION
[0004] Intrusion detection systems can be applied at many levels in an enterprise environment: to protect host systems from exploits of known vulnerabilities, to protect from attacks coming in from the network (from outside the firewall or from within), to protect against security policy violations within a system or enterprise, and even to protect some applications. Currently, IDS comes in two types:
[0005] 1) “Network-based” IDS, and
[0006] 2) “Host-based” IDS.
[0007] Network-based IDS's function inside a monitored network and monitor network packets searching for patterns of activity indicative of an attack on the network or probing/attacking of systems from outside the firewall. Examples of such attacks include: “Ping of Death”, SYN flooding, “winnuke”—an attack on Windows NT systems and various denial-of-service attacks. This type of IDS can run on local host systems that have (a lot of) bandwidth to spare, or (conveniently for the IDS vendors) they can be packaged and sold as a dedicated systems that monitor network activity “in the background” without adding overhead to the production system.
[0008] Properties of network-based intrusion detection are:
[0009] Observes network packets in a dedicated IDS system attached to LAN
[0010] Collect router and gateway data
[0011] Protects against a variety of network attacks
[0012] Lacks host contextual information.
[0013] Is easier to implement than host-based IDS
[0014] Plays to over-hyped “outsider” attacks.
[0015] Host-based IDS on the other hand reside and execute on the system being protected. Although host-based IDS incurs some overhead penalty on protection systems, the host-based IDS can provide significantly better protection because the host-based IDS can monitor low level system activity and thereby detect misuse/intrusions activities that are impossible to detect from the network. Host-based IDS is also capable of detecting misuse/intrusions by users directly logged on to the system who are not even using the network. In addition, all network-based misuse/attacks can also be detected by a host-based IDS.
[0016] System misuse (attacks) that can be detected by the host-based IDS but which are impossible to detect from the network are those that exploit system vulnerabilities to obtain elevated privilege: buffer overflow attacks, symlink exploits, setgid root, modifying or moving system binary files, etc.
[0017] By monitoring low-level system activity, less knowledge is required about the wide variety of attack scenarios employed by hackers. This is because many attack scenarios exploit the same basic system vulnerabilities. Low-level activity monitoring requires only that activity patterns exploiting these few vulnerabilities be detected, instead of requiring activity checks against a vast library of “attack pattern scenarios” that must be updated whenever a new scenario discovered.
[0018] A number of technologies have emerged as potential solutions to the various security problems faced by companies. Firewalls, encryption, and security auditing tools are useful in the world of security. A firewall is a system that is placed between two networks that controls what traffic is allowed between those networks. A firewall is usually placed between the Internet and the internal intranet. It can be viewed as a useful point of policy enforcement through which you can decide what network traffic is and is not permitted to and from the organization. When deployed correctly (itself a difficult task in a complex business environment), a firewall is an efficient tool to prevent attacks on the critical systems and data. However, a firewall connected to the Internet cannot protect the user against an attack against the systems launched from inside the organization. Often the firewall cannot stop an attacker inside the organization from attacking systems on the Internet.
[0019] A further complication in deploying a firewall is that it is difficult to establish clearly where the boundary exists between inside and outside. At one time it was obvious that the Internet was outside and the intranet was inside. However, more and more corporations are joining their intranets in multiple-partner arrangements, often termed extranets. A firewall becomes difficult to deploy in an extranet environment; if inside and outside have been joined together, where can you draw the line and place the firewall? In such an environment, some form of continuous security monitoring tool is needed to ensure that critical systems are not being abused and valuable data is not being pilfered by the so-called partners.
[0020] Encryption is a mathematical technique that prevents the unauthorized reading and modification of data. It does this in such a way that the intended recipients of the data can read it but no intermediate recipient can read or alter the data. It also allows authentication of the sender of a message—is the claimed sender really the person who sent the message? In any well-designed cryptographic system, the heart of the security is the key which is used to encrypt the message. Knowing the key allows you to decrypt any message, alter it, and retransmit it to the sender. Even if the inner workings of the encryption software are known completely, without knowing the key you cannot read or alter messages.
[0021] The problem with relying on encryption lies in the old adage a chain is only as strong as its weakest link. In this case, the weakest link is not the encryption technology but the systems on which the key is stored. After all, how can you be sure the program you are using to encrypt the data has not saved the key to a temporary file on the disk, from which an attacker can later retrieve it? If attackers gain access to the key, not only can they decrypt the data, they can impersonate you and send messages claiming to be signed only by you.
[0022] Encryption does not protect the data while it is in the clear (not encrypted) as you process it (for example, preparing a document for printing). Moreover, encryption cannot protect the systems against denial of service attacks. So despite the advantages in the space of privacy and authentication that encryption brings, it is still only part of an overall security solution. A security auditing tool probes the systems and networks for potential vulnerabilities that an attacker could exploit, and generates a report identifying holes and recommending fixes. Of course, the assumption is that once you find the holes, you will quickly patch them before they are exploited. If used in this fashion, and run regularly, a security auditing tool can be a very valuable weapon against attackers.
[0023] But how regularly should you run the tool? Attacks can occur at any point in the day; an attacker can penetrate the systems, cover up his or her tracks, and install a variety of backdoors all within a matter of minutes. Running the tools every hour gives attackers a very large window of opportunity to exploit the systems, steal the data, and cover their tracks before you ever detect them. It is obvious that if some form of continuously running security audit tool were available, life would be much simpler and the systems more secure. This brings us to the need for an Intrusion Detection System.
[0024] The amount of information that flows through a typical corporate intranet and the level of activity on most corporate servers make it impossible for any one person to continually monitor them by hand. Traditional network management and system monitoring tools do not address the issue of helping to ensure that systems are not misused and abused. Nor can they help detect theft of a company's critical data from important servers. The potential impact of computer-based crime is significant to most corporations: their entire intellectual property often resides on server machines. A tool that could detect security-related threats and attacks as they occur would significantly ease the burden that most network administrators face.
[0025] The current market perception is that network-based intrusion detection systems are the more important, probably because of the current media and market focus on hackers breaking into systems from the Internet (from outside the firewall). More importantly, this perception is being sustained by current IDS vendors because Network-based IDS is easier to do and easier to package.
[0026] However, statistics provided by the FBI have shown that the major portion of computer security break-ins are done by insiders and from inside the Intranet firewalls: the greater threat is the insider attack. In short, most threats come from within the enterprise and firewalls cannot prevent attacks from within. Some statistics are worth noting:
[0027] 30% of all Internet break-ins occurred despite the presence of a firewall. Source: Fortune Magazine, February 1997.
[0028] 32% of the losses were due to internal hackers. Source: 1996 Information Week/Ernst & Young Information Security Survey.
[0029] Total 1996 estimated damage in dollars from security break-ins: $10 billion. Source: FBI.
[0030] 78% of the companies surveyed reported losing money through security breaches. Source: FBI and the Computer Security Institute
[0031] Reasons given for not reporting a known break-in:
[0032] 75% wanted to avoid negative publicity.
[0033] 72% felt that a competitor would use this info against them.
[0034] 53% were unaware that they could report such a crime.
[0035] 60% decided that a civil remedy was better.
[0036] Source: 1996 Computer Security Institute/FBI Computer Crime and Security Survey.
[0037] Firewalls cannot detect or prevent attacks on enterprise systems from within the Intranet. The challenge is to know when systems have been compromised from within. Many inside attacks can not be prevented, but can be detected as abnormal system activity by host-based intrusion detection.
[0038] When a security system has failed, it is important to be notified of that fact as soon as possible. A crude form of intrusion detection could be the daily or weekly audit-log review, searching for inappropriate system activity. The difficulties with this approach are:
[0039] 1) Even with an effective, disciplined daily review the successful hacker could have up to 24 hours of free reign inside the systems before being detected, and any damage that might have been done might not be discovered for a long time thereafter.
[0040] 2) No human review process can be as effective and disciplined as necessary in order to provide even this poor level of protection.
[0041] 3) Audit logs are very large and a person may not detect patterns of misuse spanning many entries.
[0042] 4) Reviewing audit logs is the kind of work a machine should do.
[0043] Misuse of a system is a difficult term to define, but may be loosely described as any action that attempts to undermine the data protection, access control or user authentication mechanisms on a system. An attacker may be an outsider attempting to gain access to certain systems, but more often than not is an insider using specialized knowledge to subvert security controls on a system.
[0044] Financial institutions are very sensitive to the damage a single rogue individual in a point of trust can do. A similar threat exists in the electronic sphere. Every day billions of dollars are transferred around the world over computer networks. Increased connectivity and the use of the Internet have increased the exposure to subversion faced by financial institutions. As more and more banks offer bank-at-home facilities via the Web, the risk of a customer's financial information being intercepted grows dramatically.
[0045] When most people think of theft, they initially think of financial theft. However, a far more damaging form is theft of intellectual property. Intellectual property refers to what it is that only you know that allows you to outsmart the competitors. The intellectual property could be the design of a new engine, the code to the latest product, or even the customer contact list. If this information got into the hands of the competitors, it would seriously damage the business. The threat to intellectual property is keenly felt by companies worldwide and any technology that can reduce the risk of information falling into the wrong hands is very valuable.
[0046] Information is of no use if it cannot be acted upon, and not having the computing resources available to process information renders it useless. Any company that offers its customers an online service is acutely aware of the potential losses that can result from even a minute of downtime. This is especially true in the case of web pages. Lack of availability of critical computing resources because of malicious actions is a serious threat faced by any company doing business on the Internet today: the loss of business (measured in dollars) can be significant. Harder to quantify, but more damaging in the long term, is the loss of consumer confidence in a business that suffered an online attack.
[0047] Another example of a loss of a critical computing resource is a corporate e-mail system crash. When the outage is caused intentionally by an attacker who is continually disrupting business, the financial cost to a company can be very high—lost sales or miscommunication with customers, for example.
[0048] There are real concerns about privacy, for example, in the medical, insurance and banking fields. If a computer system is broken into by an outside attacker, personally sensitive data may be obtained that could leave you liable to legal action because of a lack of due diligence on the part to protect sensitive data.
[0049] Most perpetrators often are not nefarious hackers who roam the Internet, but the very own employees, whom you trust with the critical data and systems. Disgruntled employees who have an intimate knowledge of the systems and network are far more likely to abuse their positions of trust. However, most effort has been expended in defending against the perceived threat from outside. As a result, most security solutions have focused on firewalls and web servers, completely ignoring the serious problem that comes from within. Industrial corporate espionage is also a significant threat to companies, especially in foreign countries.
[0050] The following show the circumstances that leas to the vast bulk of security problems.
[0051] Misplaced Trust
[0052] When you access a company's web page, you are trusting that it really is the company's web page you are viewing and not some interloper pretending to be that company. When you download product data from it, you are trusting that it is accurate and correct. When you order their product, you are trusting that the order information is being kept confidential. When you receive e-mail, you trust that the person identified as the sender really did send you the e-mail. When you type the password into a program, you are entrusting that its designers did not include code to save the passwords so they can break into the system at a later date. In each of these examples, the trust can be misplaced.
[0053] Computer viruses are the single biggest cause of lost productivity in a business environment. The real cost of viruses is not the damage they cause, but the total cost of cleanup to ensure that the infection has not spread to other computers. Moreover, Java and ActiveX permit the downloading of executable code from the Internet without any assurances as to its real purpose. There are many examples of Web pages that contain ActiveX or Java applets that will steal a file from the hard drive.
[0054] As the saying goes, “A chain is only as strong as its weakest link.” There is no point in investing in a complex security solution if there is a simple backdoor around it. For example, one router vendor recently had a problem whereby all of their boxes shipped with a default password that was easy to guess. Most administrators forgot to change the password. Despite investing many hours in correctly configuring the routers for secure operation, their security could be defeated in seconds by an attacker who knew the password.
[0055] As more business is done over the Internet, more trust is placed in critical infrastructure elements: the routers, hubs, and Web servers that move data around the net. They also include DNS name servers that allow users to access www.mycompany.com from their browsers. A DNS server is a computer that maps names such as www.company.com to an Internet address such as 10.2.3.4. By attacking these important infrastructure services, a hacker can bring the whole organization to its knees. Sometimes an attacker does not have to steal information. By simply making the systems unavailable for use the attacker can cause you losses in both financial terms and in credibility in the industry.
[0056] It may seem obvious, but if you misconfigure a critical piece of software or hardware, you can open your self up to many security problems. This is a particular problem in the area of firewalls, where configuration rules are complex—one missed rule can leave the whole internal network open to attack. Another example is a network where the system administrator has not taken the time to put some simple security measures in place.
[0057] Code that runs with privilege (as root on UNIX systems, or as Administrator on Windows NT systems) is particularly vulnerable because a simple bug can have major impact. Most security problems are found in code that runs with privilege that is poorly designed. Moreover, most code runs with more privilege than it needs to accomplish its task. Often a site will install its Web server to run as root, granting it far greater privilege than it needs to simply serve up Web pages and CGI scripts. A Web server running as root is a prime target for an attacker-exploiting CGI script vulnerability can gain the attacker full root privileges on the systems.
[0058] In summary, although host-based systems have numerous advantages as compared to network based systems, the difficulty is that prior art host-based systems require traditional signature matching against hundreds of templates. Up until now there have not been any effective host-based IDS systems. Thus, a need exists for an efficient host-based intrusion detection system.
SUMMARY OF THE INVENTION
[0059] It is therefore an object of the present invention to provide a host-based intrusion detection system that observes kernel audit data, network packets and system log files on target host.
[0060] Another object of the present invention is to provide a host-based intrusion detection system that provides more accurate determinations (fewer false positives, fewer missed attacks).
[0061] Yet another object of the present invention is to provide a host-based intrusion detection system that detects building blocks of attacks, not a variety of attack scenarios that may require frequent update.
[0062] Still another object of the present invention is to provide a host-based intrusion detection system that detects insider attacks that do not use the network. Network traffic encryption has no impact.
[0063] In a first aspect of the present invention a computer architecture is provided for an intrusion detection system. The computer architecture includes a control agent to interface with a management system and to monitor system activity. At least one data gathering component gathers kernel audit data and syslog data. At least one correlator interprets and analyzes the kernel audit data and the syslog data using at least one detection template.
[0064] In another aspect of the present invention a computer architecture is provided for detecting intrusions. Reading means read kernel records. Reformatting means reformat each of the read kernel records into a different format. Parsing means parse the records and compare the parsed records against one or more templates.
[0065] In still another aspect of the present invention a computer system includes a processor and a memory coupled to the processor. The memory has stored therein sequences of instructions, which, when executed by the processor, causes the processor to perform the steps of reading kernel records, reformatting each of the read kernel records into a different format, parsing the records and comparing the parsed records against one or more templates.
[0066] The inventive host-based intrusion detection system operates by monitoring low level system activity for possible security breach. Unlike other IDS products, the host-based intrusion detection requires only a small handful of detection templates from which to capture hundreds of attack attempts. The host-based IDS monitors for fundamental system vulnerabilities instead of the traditional signature matching against the hundreds of known attacks. In addition, the host-based IDS operates in near real-time. All processing takes place on the system being protected so there is no need to send data to a central point for post-processing.
[0067] The present application is directed to a host-based IDS on an HP-UX intrusion detection system that enhances local host-level security within the network. It should be understood that the present invention is also usable on, for example, Eglinux, solaris, aix windows 2000 operating systems. It does this by automatically monitoring each configured host system within the network for possible signs of unwanted and potentially damaging intrusions. If successful, such intrusions could lead to the loss of availability of key systems or could compromise system integrity.
[0068] As a host-based IDS continuously examines ongoing activity on a system, it seeks out patterns of activities that might suggest security breaches or misuses. These might include, for example, a hacker attempting to break into or disrupt the system, subversive “insider” activities, or someone trying to spread a virus. Once a host-based IDS has been activated for a given host system, if it detects an intrusion attempt, an alert is issued to the administrative interface where you can immediately investigate the situation, and when necessary, take action against the intrusion. In addition, a local response to an alert can be undertaken.
[0069] The host-based IDS can even provide notification in the event of suspicious activity that might precede an attack. It is important to note that, in contrast, other intrusion detection systems which rely entirely on an operator-instigated analysis of system log files, typically performed at the end of a day, often allow a potential intruder considerable time to damage the system before being detected.
[0070] The host-based IDS is particularly useful for enterprise environments where centralized management tools control networks of heterogeneous systems. These environments include, for example, web servers, transaction processors, application servers, and database systems.
[0071] The host-based IDS uses knowledge about how host systems, the network, or the entire enterprise might be exploited and applies that expertise to the flow of system events. Many intrusions, while differing in their scenarios, re-use the same “building blocks” to exploit a wide variety of system vulnerabilities. As a result, the host-based IDS can use known building blocks to provide protection against both existing attack scenarios and even against some as of yet unknown scenarios.
[0072] The host-based IDS provides for simplified administration through a secure, management graphical user interface (GUI).
[0073] A host-based IDS provides an intrusion response capability by means of an automated response script that can be customized for the host that is being monitored.
[0074] Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] The present invention is illustrated by way of example, and not by limitation, in the figures of the accompanying drawings, wherein elements having the same reference numeral designations represent like elements throughout and wherein:
[0076] [0076]FIG. 1 is a high level illustration of the logical architecture according to the present invention;
[0077] [0077]FIG. 2 is a more detailed illustration of the logical architecture according to the present invention;
[0078] [0078]FIG. 3 is a flow diagram according to the present invention;
[0079] [0079]FIG. 4 is a logical architecture illustrating in greater detail the different correlators usable in the present invention; and
[0080] [0080]FIG. 5 is a logical architecture illustrating in greater detail the administrative component used to administrate one or more agent nodes according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0081] The following definitions are provided:
[0082] Agent: The host-based IDS component that gathers system data, monitors system activity, and issues notifications upon detection of an intrusion.
[0083] Alert: Also referred to as a notification. A message sent by host-based IDS warning of a suspected or actual intrusion and usually calling for some sort of action in response. Typically, the alert is sent to a display window on the management component and logged as an entry to a log file.
[0084] Audit Data: Also referred to as a kernel audit data. The most detailed level of system data utilized by host-based IDS. As each system call is executed, its parameters and outcome are recorded in a log file. These records of system activity are used by host-based IDS for intrusion detection.
[0085] Console: Also referred to as the GUI. The administrative or management component of host-based IDS.
[0086] Correlator: This is the core component of host-based IDS. The correlator interprets and categorizes the data sources, correlates the information to known detection templates, and sends notification of any suspected intrusions to the administration or management console, or GUI.
[0087] Data Source: The host-based IDS requires data generated by the system to detect intrusions. A data source is such a generator of data. For example, the system log file (syslog) is a potential data source, as is kernel audit data.
[0088] Detection Template: Basic “building block” or pattern known to be used in security attacks on systems. It is knowledge of these characteristic types of unauthorized system activity that is used by host-based IDS when detecting security attacks.
[0089] GUI: A Graphical User Interface (GUI) through which the user controls the operations of host-based IDS and where notification of alerts occurs.
[0090] Host System: Also referred to as a node. This is one of the systems in the network that the user chose to monitor using host-based IDS.
[0091] Intrusion: Also referred to as an attack. A violation of system security policy by an unauthorized outsider or by an otherwise authorized user. A violation could include improperly accessing the network, accessing certain systems within the network, accessing certain files, or running certain programs.
[0092] Intrusion Detection System (IDS): An automated system that can detect a security violation on a system or a network.
[0093] Kernel: The core of the operating system. The kernel is the compiled code responsible for managing the computer's resources, such as memory, file system, and input/output.
[0094] Memory Mapped File: Interprocess communication mechanism used to send data between processes on the IDS such that it places very little overhead on the system.
[0095] Response Script: Once the host-based IDS detects an intrusive activity, the response script is executed on the machine which was attacked and then the IDS agent sends an alert to the management GUI. This script is passed the details of the alert, and can take whatever actions the system administrator requires.
[0096] SSL: Secure Sockets Layer (SSL) is a protocol for sending data across a network that prevents an eavesdropper from observing and/or modifying any data transmitted. SSL is used for all communication between agent nodes and the management GUI in the host-based IDS.
[0097] Surveillance Group: A way of grouping related detection templates. For example, all detection templates related to checking for file system intrusions might be grouped into a “File System” surveillance group.
[0098] Surveillance Schedule: A set of configurable surveillance groups to be deployed to one or more systems on a scheduled basis. A particular surveillance group is assigned to run on a given system at one or more particular times of day on one or more given days of the week.
[0099] Virus: A piece of code that when run attaches itself to (“infects”) other programs, running again when those programs are run.
[0100] Vulnerability: A point at which a system can be subverted by an attacker. Vulnerabilities result from flaws in coding or design.
[0101] Referring now to FIG. 1, the host-based IDS 50 includes the following components.
[0102] A graphical user interface 55 , or GUI, for administering the host-based IDS. The GUI allows the administrator to configure, control and monitor the host-based IDS system 50 . Any intrusions actually detected are reported here as alerts.
[0103] A host-based agent 60 . This is the component that gathers system data, monitors system activity, and issues notifications upon detection of an intrusion.
[0104] Detection templates 65 . Most attacks exhibit a limited number of common patterns and similar steps. Therefore, once these patterns of activity are recognized as matching one of host-based IDS detection templates, host-based IDS's can detect the intrusion.
[0105] A set of data gathering components which use kernel audit data 70 and system log data 72 provides a way of observing what activity is occurring on the systems and networks. This is accomplished through a set of data gathering modules that gather and format information from data sources at various points within the system.
[0106] A correlation engine 78 . This processes the data from the data sources described below and determines whether an intrusion has occurred.
[0107] A secure communications link 78 . The host-based IDS needs a means of stopping an attacker from observing the traffic between its components and possibly sending false data to disrupt its operations. An encrypted link can prevent this from happening.
[0108] A brief overview of FIG. 1 operation is now provided. The host-based IDS 50 examines information about system activity from a variety of data sources. These include kernel audit data 70 and system log files 72 .
[0109] The host-based IDS 50 analyzes this information against stored configured attack scenarios. The host-based IDS 50 then identifies possible intrusions and misuse immediately following any suspected activity and simultaneously communicate an alert and detailed information on the potential attack to the host-based IDS GUI.
[0110] The host-based IDS 50 includes a set of pre-configured “patterns” or detection templates 65 . These patterns are the building blocks used to identify the basic types of unauthorized system activity or security attacks frequently found on enterprise networks. Within the host-based IDS 50 , these patterns 65 are referred to as detection templates. As a result of the inclusion of these detection templates 65 , the user will be able to start detecting potential intrusions right away, rather than having to first create and/or configure a set of detection templates.
[0111] The user can construct different combinations of detection templates into what are referred to as surveillance groups. A surveillance group often includes related detection templates, such as, for example, those related to file system intrusions or web server attacks. Each surveillance group provides protection against one or more particular kinds of intrusion.
[0112] Using host-based IDS, a surveillance group is then scheduled to be run regularly on one or more of the host systems it is protecting, on one or more chosen days of the week, and at one or more chosen times. This process of configuring surveillance groups to protect hosts on the basis of a regular weekly schedule is referred to as creating a surveillance schedule. A single surveillance schedule can be deployed on one or more host systems; the user has the option of creating different surveillance schedules for use on one or more of the different systems within the network.
[0113] As mentioned above, the host-based IDS 50 provides intrusion detection by monitoring the following two data sources:
[0114] Kernel audit data. This includes kernel audit logs which are generated by a trusted component of the operating system. The kernel audit logs generally include all the information about every system call executed on the host, including parameters and outcomes, and are the lowest level of data utilized by the host-based IDS system 50 . (System calls are services requested to the underlying operating system by an application or user level program.) This data may also include information about starting and stopping sessions for users.
[0115] System log files. System log files include data on system activity at the user level recorded via the syslog facility. This includes successful logins and logouts, reports from network service daemons, and httpd. Such data provide a high level view of the status and health of the various services in the system.
[0116] Within the host-based IDS system 50 , there must be secure messaging and protocols for all communications between its components. Host-based IDS's secure communication is built upon the Secure Socket Layer (SSL) protocol for client/server interaction.
[0117] Secure Sockets Layer (SSL) is a widely used standard for securing communications over untrusted networks. SSL prevents unauthorized modification or deletion of data as it flows across the network. In addition, it can detect when an interloper sends messages which purport to be from another machine. It is a general communications protocol and can use a variety of encryption techniques.
[0118] IDS uses SSL to encrypt all traffic between the management station (i.e., the host running the GUI) and the agent systems (systems performing intrusion detection).
[0119] [0119]FIG. 2 is a diagram illustrating logical architecture of an intrusion detection system according to the principles of the present invention. FIG. 2 provides greater detail than FIG. 1 regarding agent 60 .
[0120] Data input: a data input channel.
[0121] Data output: the channel that the process sends its output on.
[0122] Command input: command from the idsagent are sent to each process on this channel.
[0123] Status output: status data is provided by the process on this channel in response to a status command on the command channel.
[0124] The IDS agent 210 provides an interface between the IDS system 50 and the network. The IDS agent 210 encrypts all traffic to a GUI and decrypts traffic from an idsSSLadmin process which runs on the computer which runs the GUI.
[0125] Idsagent 210
[0126] An idsagent 210 is the main control process of the intrusion detection system. The idsagent 210 is responsible for starting and stopping all other processes. When started, it will fork off a copy of the idsSSLagent 200 to communicate with the GUI.
[0127] The idsagent 210 will perform initialization steps and then await commands from the GUI. If a schedule is downloaded and started, the idsagent 210 will start an idscor process 220 , and whichever of the idssysdsp 230 and idskerndsp 240 processes are required.
[0128] The idsagent 210 creates the low and high bandwidth connections between itself and the agent processes. The low bandwidth connections are built using POSIX message queues. The high bandwidth connection is built using a memory-mapped file. The advantage of the memory mapped file is that it does not require a system call to read or write data from/to it. Processes access the map file via a pointer in their address region.
[0129] The idsagent 210 will monitor each of the agent processes. If a process dies unexpectedly it will reap the return value. In addition, it will attempt to handle failures gracefully either by restarting the failed process or by shutting down and sending an error message to the administrative GUI. If this occurs the administrator can examine the error and attempt to restart. The restart process will be attempted a fixed number of times, as defined in a header file. If after the maximum number of restart attempts the idsSSLagent 200 cannot be started, the idsagent 210 , and all other processes, continue to run as usual. However, no alerts can be sent to the GUI and no commands can be received.
[0130] If one of the agent processes dies (idscor 220 , idssysdsp 230 or idskerndsp 240 ) then the idsagent 210 will halt the currently executing schedule and send an error message to the GUI.
[0131] If the idscor 220 process reports an intrusion then the idsagent 210 will perform three steps:
[0132] 1. It will log the intrusion alert record to the local alert log file.
[0133] 2. It will execute the alert response scripts and pass then the alert details as command line arguments. The alert response script are located in /opt/ids/lbin/ids_alertResponse
[0134] 3. It will package the alert text encrypt it and write it to the GUI for display.
[0135] When a schedule is downloaded to the idsagent 210 , it will first consult its configuration file to verify that the detection templates specified in the schedule are installed on this agent system. This step merely verifies that the templates in the schedule are supported by the idsagent 210 , it does not perform any checking on the parameters specified for each template. If a template is found in the schedule which does not exist in the configuration file, an error message is sent to the GUI. If all templates are supported, the idsagent 210 will parse the groups in the schedule and determine which groups are scheduled at which time. It will then write a crontab file for the “IDS”user. This crontab file will be used at a later point to execute a program that instructs the idsagent 210 to start a particular group.
[0136] The role of the correlator 220 is to determine if an intrusion has occurred. All the other processes in the IDS architecture support the correlator 220 in this role—the data source processes provide it with raw data, and the idsagent 210 waits for output from the correlator 220 .
[0137] Event Correlation Services (ECS) allows for the correlation of discrete events over time. It operates similarly to a virtual machine into which bytecode is loaded. The bytecode corresponds to correlation “circuits”. Each circuit is written by a user to analyze the flow of events through the ECS engine in real-time.
[0138] The ECS engine in the ids is embedded within the IDS correlator process 230 to improve performance. The rate of data generated from the kernel is very high; the path from the kernel to the correlator must be as short as possible. The ECS engine in host-based IDS 50 has been built to parse and understand kernel audit records, system log files and other data sources. It uses a meta-description language (MDL) to define what a record in a data stream looks like. The MDL specifications allow for fast parsing of the event streams.
[0139] The idscor process 220 is a virtual machine which interprets the bytecodes stored in the detection templates. The templates (alternatively described as circuits) encode the logic required to determine if an intrusive activity is present in the input data stream.
[0140] The correlator 220 is said to be event driven: as each event arrives it is sent to the templates. Templates may be configured to receive events of specific types, so a template which processes kernel audit data will not receive system log data, for example. Because the correlator 220 is event driven, it will not poll the system for data: if no data is arriving then the correlator process 220 is idle.
[0141] The correlator runs as the idscor process 220 in the host-based IDS architecture. At its heart lies a technology developed by HP named ECS: Event Correlation Services. ECS was originally developed in the telecommunications division to monitor SNMP and CMIP traps from network elements. It was used by a network administrator to suppress alarm storms and perform root-cause analysis on network failures. We have adapted its core event-flow functionality for use in intrusion detection, and layered our code around the core ECS library.
[0142] ECS Terminology
[0143] ECS: Event Correlation Services—an event driven correlation product from HP.
[0144] circuit or template: A bytecode specification for correlation, created by the ECS Designer GUI. The bytecode is loaded by the engine core and executed as events are received by the engine.
[0145] engine core or core library or ECS library: The core correlation executes the circuit bytecode.
[0146] Designer GUI: A graphical component used to build circuits for ECS.
[0147] idscor: The correlation process that is executed as part of the host-based IDS infrastructure. It encapsulates the ECS engine core with functionality that interfaces with the other host-based IDS processes.
[0148] MDL: Meta-Data Language is a specification of the layout of events as an ECS circuit will view them. For example, the MDL file for kernel audit will specify how the fields are laid out in the audit records.
[0149] endecoder: A translator module that interprets an MDL specification and converts audit records and other events into internal ECS event format structures.
[0150] template group: The GUI groups templates together into template groups which are scheduled to execute at certain times of the week. These template groups are literally a list of circuit names to load.
[0151] data store: Circuits are fixed bytecode streams, but the circuits need information about the outside world passed to them. A data store parameterizes a circuit and allows passing of external values that can be queried by the circuit at run time. Values are encoded as (name, value) pairs; the circuit performs a lookup based on the name part, and receives a value back.
[0152] fact store: Almost the same as a data store, except that the values stored in a fact store are encoded as (leftval, relation, rightval) and queries can be performed on both leftval and rightval.
[0153] enable/disable of circuits: After being loaded a circuit is in an idle state and will not receive events from the engine until it has been enabled. Once enabled it will process events and carry out any internal functions until it is later disabled.
[0154] event flow or event driven: Programs are usually thought of as being driven by a flow of control: if the code requires data it will obtain it. However, the ECS engine core operates using an event driven model: events arriving at the engine core trigger processing.
[0155] event or message: Any piece of information which is being correlated by the circuits in the engine. For example, kernel audit data, syslog records or login records are all delivered to the engine as events.
[0156] cron 250
[0157] The cron daemon 250 reads the crontabl for user “ids” and executes the idssc program at the specified intervals. This is used to start and stop surveillance groups.
[0158] Once an intrusion is detected, the idsagent 200 will execute the binary located at the path/opt/ids/Response. Each command line argument to this binary will be a field of the alert.
[0159] The order of the arguments passed are:
Argument Type Description argv[0] string Name of the executable argv[1] integer Unique code for alert message argv[2] integer Version number on alert (identifies product version) argv[3] integer Severity level of alert (1 is most severe) argv[4] string Timestamp on alert YYYYMMDDHHMMSS argv[5] string Source of attack if known argv[6] string Target of attack if known argv[7] string Alert description argv[8] string Full alert text
[0160] idscor 220
[0161] The idscor 220 process contains the correlator which processes the raw events and determines if an intrusion has occurred. It obtains the data from the memory mapped file created by the idsagent 200 . The idscor 220 is linked via this mmap file to the idssysdsp 230 and the idskerndsp 240 . The idscor 220 will poll each file in turn looking for data.
[0162] The idscor 220 is essentially a virtual machine which runs the bytecode defined for each detection template. Each template contains code that will determine if a particular type of intrusion has occurred. The idscor 220 can run many templates simultaneously.
[0163] The idscor 220 is forked by the idsagent 200 when a surveillance group is being started. It is passed on the command line the id's of the low-bandwidth status and command channels, and the high-bandwidth memory-mapped file channel. The idscor 220 then receives commands over the command channel from the idsagent 200 .
[0164] idssysdsp 230
[0165] The idssysdsp 230 , also termed the Syslog DSP, is responsible for gathering data from ASCII line oriented files. It can also read from btmp/wtmp/utmp formatted files. The acronym DSP stands for Data Source Process.
[0166] The idssysdsp 230 will read data from a file and then forward it to the idscor 220 for processing. The idssysdsp process 230 does no processing on the data read, other than to format it as ASCII. Thus, any binary data read from btmp/utmp/wtmp is printed as ASCII and sent to the correlator idscor 220 .
[0167] The idssysdsp 230 is started by the idsagent 200 when a surveillance group is started. It is passed on the command line the name of the memory-mapped file to communicate with the idscor 220 .
[0168] idskerndsp 240
[0169] The idskerndsp 240 , also termed the kernel DSP, is responsible for opening and reading data from the kernel audit device driver, /dev/idds. The idskerndsp 240 will read blocks of audit records from the driver and reformat them as ASCII data to send to the correlator idscor 220 .
[0170] The idskerndsp 240 is started by the idsagent 200 when a surveillance group is started. The idskerndsp 240 is passed on the command line the name of the memory-mapped file to communicate with the idscor 220 .
[0171] The idskerndsp 240 is also responsible for enabling audit of selected audit records according to which templates are being used as described in greater detail below. When the idsagent 200 is starting the surveillance group, it will send data to the idskerndsp 240 indicating which audit records the detection templates require. The idskerndsp 240 will then do a ioctl call to the idds driver to enable those system calls for audit.
[0172] IDDS Kernel Driver 270
[0173] The IDDS (Intrusion Detection Data Source) driver 270 is a kernel pseudo-driver which provides an interface to the new kernel audit system. The audit system was designed to specifically support the intrusion detection system 50 .
[0174] The idskerndsp 240 will open the driver device and send configuration data to the kernel. The idskerndsp 240 will read audit records in blocks from this device.
[0175] The IDDS kernel 270 component has a fixed size buffer in which to store audit information before it is passed to a user space application. If that storage buffer becomes too full, the IDDS system has two choices on how to handle a new audit record: discard it, or wait until space is available for it in the kernel buffer.
[0176] In blocking mode the IDDS subsystem 270 will wait until there is space in the buffer for the new audit record. The calling process is blocked until space becomes available for the audit record. Once space is made available the audit record is stored in the buffer and the process continues. Blocking mode sacrifices some system performance for security.
[0177] Reading from the audit buffer is done on a separate context from writing to the buffer, so there is no danger of the system deadlocking.
[0178] In non-blocking mode the host-based IDS will discard the audit record information if no space is available in the buffer. Non-blocking mode sacrifices security for system performance.
[0179] The IDDS provides the IDS agents with a system call level trace of activity on a system.
[0180] The developers of the host-based IDS have identified a subset of system calls on HP-UX which have security relevance, and occur frequency in exploits. The IDDS subsystem 270 in the kernel will record these system calls as they occur. The system call trace is made available to the host-based IDS agents via a device driver in the kernel: /dev/idds. The host-based IDS agent opens this device and reads system call information as it occurs.
[0181] Some key features:
[0182] Designed for minimal overhead impact on the system
[0183] Gathers path and file data
[0184] The data is designed to support intrusion detection and not to be logged and forgotten about.
[0185] Allows per-user and per-system call filtering of events
[0186] Can operating in “blocking” mode: system calls are halted until the host-based IDS agent can catch up reading the data stream.
[0187] Can also operate in “non-blocking” mode: if system calls occur faster than the host-based IDS agent can read them, the audit record is discarded.
[0188] In order to obtain the best possible degree of host-based activity monitoring (and to protect against viruses and the attacks described above) the IDS must have secure access to a robust, low-level system audit stream. Some effective host-based intrusion detection can be achieved by monitoring the syslog file and other various log files. These logs provide valuable information about system activity that can be used to detect a wide range of attacks, but because the log-files only contain high-level information the attacks described earlier could not be detected using only log-file data. Furthermore, log-files themselves are subject to attack and could be altered to either confuse, over-activate, or bypass the intrusion detection system. Nevertheless, some common attacks that can be detected using log-file data include: SATAN scans, NIS spoofing, attempts to discover passwords, failed accesses, etc.
[0189] The host-based IDS 50 may accept data streams from a number of log files, from the network, from ServiceGuard™ “monitors”, and/or from special versions of the HP-UX audit system. This special audit system called “IDDS” is developed for the host-based IDS and may:
[0190] a) Operate in both standard mode and trusted mode (vs. trusted mode only)
[0191] b) Provide enhanced audit content to maximize misuse detection capability.
[0192] c) Feed the audit stream directly to the host-based IDS 50 for maximum security—there may be no intervening audit file subject to attack and modification—and minimum response time.
[0193] d) Enable selective audit and filtering to reduce the amount of data that must be processed by the host-based IDS 50 thereby reducing system overhead and improving overall IDS performance.
[0194] Detection Templates
[0195] A detection template is a representation of an algorithm to detect a vulnerability exploitation. For example, a detection template may be written to generate an alert when the setuid bit is enabled on root owned executables. The template contains logic which will process the kernel event stream and determine if a file has had the setuid bit enabled. A detection template contains filtering code to discard events not relevant to the activity it is looking for. It also contains state nodes to record previous event activity for comparison with future activity.
[0196] The host-based IDS provides a hierarchy of groupings to simplify configuration of an agent system:
[0197] Surveillance Schedule: A grouping of surveillance groups set to execute at particular times of the week.
[0198] Surveillance Group: A grouping of detection templates to be used in building a surveillance schedule.
[0199] Detection Template: The lowest level of the hierarchy: a bytecode representation of an algorithm to detect intrusions.
[0200] Detection Templates are grouped into Surveillance Groups which are in turn scheduled to execute in a Surveillance Schedule. The Surveillance Schedule is the item downloaded to a host-based IDS agent system.
[0201] The following processes are present on a host-based IDS system: these two processes are always running on an agent. idsagent master control process 210 for the IDS agent; idsagent 210 provides SSL connection to GUI.
[0202] These processes may be running if a Surveillance Schedule is active on the agent system: idscor 220 which is the correlator process which analyzes events; idskerndsp 240 which gathers the kernel audit records for idscor 220 ; and idssysdsp 230 which gathers system log data for idscor 220 .
[0203] A host-based IDS management station which is running the GUI will have the following processes: idsgui The GUI process, running under a Java VM; the IDS GUI provides SSL connections to all the agents.
[0204] The host-based IDS does not provide an alert that exploit XYZ has been launched against the host. Rather the host-based IDS lets the user know of suspicious activity on the system that is taking place. The user will need to customize the detection templates to meet the needs of the environment. If the user has a particular application that generates a heavy volume of alerts due to its normal mode of operation, the user can enter additional filtering into the necessary detection templates to reduce the number of alerts generated by this application. Most notably is the creation of world writable files and modifying non-owned files. Most templates offer mechanisms by which these spurious alerts can be suppressed. This type of filtering should be part of the product configuration so that the user does not get overwhelmed with unnecessary alert generation.
[0205] Refer now to FIG. 3, where a flow diagram illustrating an example of how intrusions are detected. At step 305 , a user process makes a libc library call: the open() or unlink() calls for example. At step 310 , the libc library translates the call into a system call and calls the system call dispatch entry point. At step 315 , the initial component of the syscall handler checks to see if this system call is being audited by the host-based IDS. If the system call is being audited, the initial component of the syscall handler gathers some header related information: user id, group id, timestamps, process id, etc. At step 315 as the system call is processed, information is stored in temporary buffers. This information corresponds to the arguments of the system call and any further data that is reported. Once the system call completes, the return value and errno value are recorded. At that point the entire record is placed in a circular buffer in the kernel audit driver. At step 325 , the system call returns to the user process context. At step 330 , a read() of /dev/idds has forced the IDDS kernel driver 370 to read the next audit record block from the circular buffer. At step 335 , the system call block is passed up to the user context of the idskerndsp 240 in response to the read () call. At step 340 , the idskerndsp 240 reformats the raw binary audit record as ASCII data in a format that the correlator idscor 220 will understand. At step 345 , the correlator idscor receives the data and parses it using MDL into an internal vent format. At step 350 , the detection templates take this internal event format and process it. The ECS using a detection template may decide that an intrusion has occurred. At step 355 , the detection template generates an alert message in the internal event format. The idscor 220 takes this alert message and reformats it as an ASCII message. This message text is sent on the status output channel to the idsagent 210 . At step 360 , the idsagent 210 is polling the status connection from the idscor 220 periodically. The IDS agent 200 receives the alert message and reads it from the status connection. At step 365 , idsagent 210 then executes any local alert response script and passes them the alert details. At step 370 , the alert is logged to the local alert log file. At step 375 , the idsagent 210 reformats the alert for the GUI. At step 380 , the alert message is sent to the idsSSLagent 200 .
[0206] [0206]FIG. 4 is an illustration of a logical architecture, similar to FIG. 2, but showing in greater detail the idscor 220 which is shown in FIG. 4 as corrrelator 1 , correlator 2 . . . correlator n. Information flows upward from data source process 1 , data source process 2 , data source process 3 . . . data source process n to any or all of the correlators 1 -n. It should be noted that data process source 1 corresponds to idssysdsp 230 in FIG. 2 and data source process 2 corresponds to the idskerndsp 240 . Further it should be appreciated that the host-based IDS 50 may not necessarily have all these processes that the overall architecture of the host-based IDS 50 supports. In fact, the host-based IDS 50 can support multiple correlators and multiple data sources. However, there does not need to be a corresponding number of data source processes and correlators. In other words, there can be one or more correlators with many data source process or one or more data source processes with only a single correlator. Each data source process and correlator should add some measure of intrusion detection capability or the expense of processing speed and additional processing resources required. The IDS monitor process 410 is the main control process and corresponds to a combination of the functionality of the idSSLAgent 200 and the idsagent 210 described with respect to FIG. 2. The IDS monitor 410 is responsible for connecting with all the functional components depicted in FIG. 4 and it is responsible for taking commands issued by the user and translating them into commands to send on to the processes that are running below it. In addition, the IDS monitor 410 is responsible for monitoring the status of the processes running on the system and it is responsible for gathering alert information generated by the correlators 1 -n and forwarding that to the GUI 55 . The other task the IDS monitor process 410 must perform is if the user has scheduled to run surveillance schedules at a future time, the IDS monitor 410 is responsible for initiating the processing. The IDS monitor 410 is responsible for executing with the response scripts 260 (shown in FIG. 4 as C-Magent 260 ). When an alert is detected, the alert will be written in a notification log (shown as local alert file in FIG. 2). A configuration file 440 details how the host-based IDS 50 is put together, what circuits are installed, etc. The IDS monitor 410 interacts with cron job 250 as described with respect to FIG. 2 to launch surveillance schedules at a specific time.
[0207] The correlator 1 , correlator 2 , . . . correlator is a layer which processes the data coming off the system in conjunction with the templates to determine if there has been an intrusion. As depicted in FIGS. 1 and 2 there is only one correlator present, but the architecture supports multiple correlators.
[0208] Correlator 1 uses the previously described ECS technology. Correlator 2 -n can use other correlation technologies. Communication occurs between the correlators 1 -n and data source using memory mapped files 1 -n and processes 1 -n. The memory mapped files are low overhead, high bandwidth connection between processes running on a system. Specifically by generating data and pulling data into a memory mapped file by reading the data, the host-based IDS 50 does not generate system calls. These memory mapped files 1 -n are created by the IDS monitor 50 when the correlators 1 -n are being started. When the IDS monitor 50 starts the correlator it also creates a connection to send commands from the IDS monitor 410 to the correlators (see arrows 445 ) and creates other connections ( 446 , 448 , 450 ) from the correlators to the IDS monitor 410 .
[0209] The IDS monitor 410 also interacts with a management system 460 . The management system 460 includes an IDS security administration component 465 and an enterprise management component 470 . The IDS monitor 410 sends notifications to the enterprise management component 470 . The IDS monitor 410 interacts bi-directionally with the IDS security administration component 465 including configuration, notification, control and status. The IDS security administration component 465 has a GUI 455 for displaying alert notifications. The enterprise management component 470 provides the application launch and node list to the IDS security administration component 465 . The IDS security administration component 465 also sends an alert configuration to the enterprise management component 470 .
[0210] Referring now to FIG. 5, FIG. 5 illustrates a more detailed view of the IDS security administration component 465 . It should be noted that one administration component 465 can control many IDS agent nodes.
[0211] The IDS security administration component 465 is responsible for creating surveillance schedules and groups and communicating these with the respective IDS host-based agent nodes. A software install/update module 505 which is located in the IDS GUI 55 can be used to install or update software on IDS agent nodes as updates become available. A security configuration preferences module 510 allows the administrator to save various security configuration preferences for the particular GUI. Also the security schedule groups and configurations can be saved using module 510 . Operation module 515 is used for query, shutdowns and various other operations of the GUI and IDS agent nodes. The IDS browser 520 is used to sort, query and search alerts. An IDS enterprise interface module 550 allows the IDS GUI 55 to be plugged into various other enterprise architectures such as HP OpenView VP/0 architecture. Thus, the IDS GUI 55 can be managed from HP OpenView VP/0 management software. When a surveillance schedule is generated the program object 565 is generated. When the preferences are saved, then the preference object 570 is generated. The program object and preference object send information to the IDS administrative core which in turn communicates control configuration and notification status along secure connections to the respective IDS agent nodes. A node list is generated by the operation module 515 . The object node list is generated when the processes are stopped, started and queried the status of the agent nodes which in turn is packaged as an object file and sent to the IDS administrative core 580 and then is forwarded on to the respective IDS agent node. The IDS administrative core 580 is responsible for secure communications with the multiple IDS agent nodes.
[0212] The Surveillance Group and Surveillance Schedule Screens
[0213] Configuration Screens enable the user to create and configure host-based IDS detection templates, surveillance groups, and surveillance schedules. These Screens are accessed from the System Management or Host Management Screens by selecting either Surveillance Group or Surveillance Schedule from the Edit pull-down menu.
[0214] The host-based IDS product includes a number of detection templates which have been created and pre-configured. When the user initially select the Surveillance Group menu item, the Select a Surveillance Group box will open. The predefined detection templates will become visible when the user either presses the Edit button in this box to modify an existing surveillance group or the New button to create a new surveillance group.
[0215] The host-based IDS does not come with any pre-existing surveillance schedules. The user can create and subsequently view the host-based IDS surveillance schedules when you select the Edit→Surveillance Schedule menu item. This will open the Select a Surveillance Schedule box. Which surveillance groups have been combined into a given surveillance schedule can be viewed by pressing the Edit button in this box.
[0216] Changing the Pre-Configured Detection Templates
[0217] Each detection template is designed to identify a specific type of unauthorized system activity and may have configurable parameters. The detection template directs the agent to monitor a security related activity on a host system.
[0218] For example, a Failed Login detection template checks the number of failed logins within a given time interval on a host system. Both the number of failed attempts and the time interval are configurable. If a user fails to correctly login and meets the triggering criteria, an alert is issued.
[0219] If a detection template has configurable parameters, the parameters may be configured once the detection template has been incorporated into a surveillance group.
[0220] One or more detection templates can be configured into a surveillance group. After a surveillance group has been created, it can later be modified or deleted.
[0221] The Modification of Files/Directories Template
[0222] The template:
[0223] Monitors a user specified set of files for successful change attempts.
[0224] Monitors user specified directories (with exclusion rules) for successful attempts to change the content or the addition/deletion of files in the directory and all subdirectories below it.
[0225] Monitors for changes of owners or file permissions of the specified files, and logs an alert only if an actual change to the permissions/owner occurs.
[0226] This template does not determine that a file's contents were changed—only that a change might have been made (i.e. it does not watch the content of the files).
[0227] The modification of files/directory template uses kernel audit data generated by the IDS set of kernel patches.
[0228] The modification of files/directory template is useful because many of the files on a HP-UX system should not be modified during normal operation. This includes the various configuration options, system supplied binaries and libraries, and the kernel. Additionally, software packages are generally not installed or modified during a system run. However, when an attacker breaks into a system, the attacker frequently will create backdoors to let themselves in later. Also, the attacker might use a “rootkit” to modify the system binaries such that they do not report the changes that were made.
[0229] There are four configurable properties that are used in the filtering system:
[0230] Watch these files for modification/creation
[0231] Ignore these files
[0232] Watch these directories for modification
[0233] Ignore these directories
[0234] If a file is explicitly included, then any change will be logged. This template ignores the exclusion clauses for explicit listings of files only.
[0235] If a file is not explicitly included, but its directory is, then any change will be logged only if
[0236] 1) The directory is not explicitly excluded, and
[0237] 2) The file is not explicitly excluded by name.
[0238] For example, if the following values are set
[0239] Watch these files for modification/creation=[/etc/passwd, /etc/foo/conf/nochange]
[0240] Ignore these files=[/etc/ptmp]
[0241] Watch these directories for modification=[/etc, /bin]
[0242] Ignore these directories=[/etc/foo/conf]
[0243] then if a change was made to /etc/foo/conf/changeable, no alert would be generated because the directory /etc/foo/conf is explicitly excluded.
[0244] If /etc/foo/conf/nochange was modified, an alert would be generated because that file is explicitly listed, even though the directory is excluded.
[0245] If /etc/ptmp is modified, no alert is generated because it is specifically excluded.
[0246] If /etc/rc.config.d/lp is modified an alert is generated.
[0247] The default files for modification/creation include
[0248] /stand/vmunix
[0249] /stand/kernrel
[0250] /stand/bootconf
[0251] These are the system kernel and its configuration files. Changes made to these files will affect the system at the next kernel configuration or system reboot.
[0252] /etc/passwd
[0253] /etc/group
[0254] These files define the users on a system. Changes to /etc/passwd can create accounts, including accounts with superuser access.
[0255] /etc/inetd.conf
[0256] This file controls what network services are running, and what programs are used to fulfill the service requests. An attacker might change this file to open up a backdoor that they can access over the network.
[0257] /.rhosts
[0258] /.shosts
[0259] These files are used to control the remote access of the user ‘root’ without requiring a password. One technique used to create a backdoor is to modify these files to permit root access without a password from anywhere.
[0260] Ignore these files
[0261] /etc/ptmp
[0262] /etc/.pwd.lock
[0263] These are temporary files created by the program vipw and are not used for any system configuration.
[0264] Watch these directories for modification
[0265] /bin
[0266] /sbin
[0267] /usr/bin
[0268] These directories hold the system supplied binaries.
[0269] /lib
[0270] These are the system libraries that control the way that most user and system programs behave.
[0271] /opt
[0272] This is where software packages are installed.
[0273] /etc
[0274] This is where most of the system configuration files are stored.
[0275] /stand
[0276] This is where most of the kernel configuration data is stored.
[0277] Ignore these directories
[0278] There are none set by default.
[0279] Changes to Log Files Template
[0280] The changes to log files template monitors a user defined list of files for attempts to modify them in any way other than appending.
[0281] The log files template does not:
[0282] It does not examine the actual disk I/O that takes place. It will generate alerts if someone is capable of modifying the data.
[0283] It does not monitor the owners or permissions of files. This template will not detect if they are changed.
[0284] This template uses kernel audit data generated by the IDS set of kernel patches.
[0285] The changes to log files template is useful because there are certain files that are used to store logs of system activities. This includes login attempts, commands executed, and miscellaneous system log messages.
[0286] The files that store this information should only be appended to, not overwritten. An attacker will often either modify or delete these files to remove information about their intrusion.
[0287] The default file list includes:
[0288] /var/adm/utmp
[0289] /var/adm/btmp
[0290] /var/adm/wtmp
[0291] /etc/utmp
[0292] /etc/btmp
[0293] /etc/wtmp
[0294] These are the log files that store information on logins and login attempts.
[0295] /var/adm/messages
[0296] /var/adm/syslog/mail.log
[0297] /var/adm/syslog/syslog.log
[0298] These are frequently used to store syslog messages (messages generated by various programs).
[0299] /var/adm/pacct
[0300] This file keeps a log of what user executed what command and a timestamp of the occurrence.
[0301] Creation of SetUID Files Template
[0302] The creation SetUID files template looks for the creation of a SetUID file by users from a list of UIDs. A SetUID file is one that will run with the access level of the owner instead of the access level of the user executing it.
[0303] The SetUID template monitors for the following actions:
[0304] Modification of the permissions on a file to enable the SUID bit.
[0305] Changing the owner of an SUID file to one of the UIDs on the user specified list.
[0306] Creation of a file that has the SUID bit set.
[0307] The SETUID template uses kernel audit data generated by the IDS set of kernel patches.
[0308] The SETUID template is useful because a SUID file is one that, if executed, will operate with the permissions of the owner of the file, not of the person executing the file. One of the frequent backdoors that a intruder will install on a system is the creation of a copy of the /bin/sh program that is the setuid root. Such a file allows any command to be executed as the superuser.
[0309] The default list of users being monitored is:
[0310] 0—root
[0311] 1—daemon
[0312] 2—bin
[0313] 3—sys
[0314] 4—adm
[0315] 5—uucp
[0316] 9—lp
[0317] 11—nuucp
[0318] Creation of World-Writable Files Template
[0319] The creation of world-writable files template looks for the creation of world-writable files owned by users from a list UIDs. A world-writable file allows any user to modify the contents of the file.
[0320] This template monitors for the following actions:
[0321] Modification of the permissions on a file to enable the world-writable bit.
[0322] Changing the owner of a world-writable file to one of the UIDs on the user specified list.
[0323] Creation of a file that has the world-writable bit set, owned by one of the listed UIDs.
[0324] This template uses kernel audit data generated by the IDS set of kernel patches.
[0325] The creation of world-writable files template is useful because a world writable file is one that any user of the system can modify. In many cases, the files owned by the system users (see the default list) are used to control the configuration and operation of the system. Allowing regular users to modify these files exposes the system to attacks by regular users.
[0326] The default list of users being monitored are:
[0327] 0—root
[0328] 1—daemon
[0329] 2—bin
[0330] 3—sys
[0331] 4—adm
[0332] 5—uucp
[0333] 9—lp
[0334] 11—nuucp
[0335] Repeated Failed Logins Template
[0336] The repeated failed logins template monitors the records of failed attempts to login to the system, and generates an alert if a user defined threshold is exceeded.
[0337] This template collects information from /var/adm/btmp. This log is used to detect failed login attempts.
[0338] The repeated failed logins template is useful because any way an attacker might gain access to a system is by repeatedly attempting to guess the password for an account. Most standard login programs are able to record these failures, and if an unusual number of them occur, an administrator should be notified.
[0339] The defaults are:
[0340] Time span to detect failures over (seconds)=10 seconds
[0341] Number of failures to trigger on=2
[0342] Suppression period for reporting=30 seconds
[0343] 22. The settings mean that any 2 failures by a user within 10 seconds will cause an alert to be generated, and duplicate alerts that occur within 30 seconds will not be reported.
[0344] 22. It is not an uncommon occurrence for a user to mistype a password when attempting to login. By modifying the values, this template can be customized to local user behavior.
[0345] Repeated Failed Su Commands Template
[0346] The repeated failed su template monitors failed attempts to change UIDs. After a threshold of failures occur, it generates an alert.
[0347] This template collects information from /var/adm/sulog. This log is used to detect failed su attempts.
[0348] The repeated failed su template is useful because the system binary su (which stands for Set User) allows one user to assume the permissions/identity of another user by giving the correct password. One way to try and gain privileges on a system is by making guesses as to what the root password is. This template will detect such attacks.
[0349] The defaults are:
[0350] Time span to detect failures over=24 hours
[0351] Number of failures to trigger on=2
[0352] 22. The settings mean that any 2 failures by a user within a day will cause an alert to be generated.
[0353] 22. In many environments, users do not run the su program frequently, hence the long interval.
[0354] Race Condition Attacks Template
[0355] The race condition template monitors the file accesses that a privileged program makes and generates an alert if a file reference appears to have unexpectedly changed.
[0356] The race condition template is useful because there is a class of attacks that utilize the time between a program's check of a file to the time that program utilizes that file. For instance, a mail delivery program might check to see if a file exists before it changes ownership of the file to the intended recipient. If an attacker is able to change the file reference between these two steps, he/she can cause the program to change the ownership of an arbitrary file.
[0357] Most of these attacks require the attacker to have a local account on the machine being monitored.
[0358] The default list of users being monitored are:
[0359] 0—root
[0360] 1—daemon
[0361] 2—bin
[0362] 3—sys
[0363] 4—adm
[0364] 5—uucp
[0365] 9—lp
[0366] 11—nuucp
[0367] This represents the default set of “privileged” user accounts on a particular system. Removing any of these (especially UID 0) means that an attack against one of those users will not be detected by this template.
[0368] It would be wise to add in the UID for ids based on the local numbering convention.
[0369] The default value for the property “How many paths to keep track of per process” is 20. This is the number of file accesses to store per process. A larger number gives the template a larger view of user actions. However, a larger number will slow down the response speed of the template as well as increase the memory requirements.
[0370] If the user needs the special instance where memory needed may grow unbounded, set this value to 0. In this case, potentially all accesses will be stored. In extreme cases, this may cause this template to exhaust all available memory when all accesses are stored.
[0371] Buffer Overflow Attacks Template
[0372] The buffer overflow attack template watches the execution of SUID binaries. An SUID binary is an executable that runs with the access permissions of the file's owner instead of those of the user invoking the program.
[0373] The template monitors for the following actions:
[0374] SUID programs executing programs other than themselves (commonly seen in local root exploits).
[0375] A program “unexpectedly” gaining UID=0 privileges.
[0376] This template uses kernel audit data generated by the IDS set of kernel patches.
[0377] The SUID template is useful because an SUID file is one that if executed will operate with the permissions of the owner of the file, not of the person executing the file. One of the methods used to gain privileges on a machine is to gain access to a normal user account, and then exploit a buffer overflow condition to gain higher access.
[0378] The default list of users being monitored are:
[0379] 0—root
[0380] 1—daemon
[0381] 2—bin
[0382] 3—sys
[0383] 4—adm
[0384] 5—uucp
[0385] 9—lp
[0386] 11—nuucp
[0387] This list should contain those users that you consider to have elevated access to the system. Only programs that set the user ID to one of the listed numbers will be monitored by this template.
[0388] In general, the user should add the UIDs of other privileged accounts to the list (e.g., Webmaster, News Administrator, etc.) and not remove any of the defaults.
[0389] Modification of Another User's Files Template
[0390] The modification of another user's files monitors users access of files and generates an alert when a user modifies a file owned by someone else.
[0391] The modification of another user's files template does not examine the actual disk I/O that takes place. It will generate alerts if someone is capable of modifying the data.
[0392] This template uses kernel audit data generated by the IDS set of kernel patches.
[0393] The modification of another user's files template is useful because in many environments, users are expected to only be working with their own files. Someone attempting to compromise the security of the machine might cause a system program to modify various files on the system. Since many daemons run as a particular user, this template may generate a notice when such an attack occurs.
[0394] The defaults are:
[0395] All of the fields are empty initially. These will need to be configured based on the individual machine configuration and usage.
[0396] Ignore changes to these files: Adding files to this list allows specific files to be modified without generating alerts. These need to have exact, full pathnames.
[0397] Ignore changes to these directories: Adding directories to this permits anything in or below that directory to be modified without generating an alert. These should be full pathnames, but need not be exact. For instance “/tmp/a” will match “/tmp/apple”. If you want to specify a specific directory, be sure to append a trailing “/”.
[0398] List of user Ids to ignore: Adding user ID numbers to this list will cause those users to be ignored by this template. It is recommended that this be left blank unless specifically needed.
[0399] Monitor for the Start of Interactive Sessions Template
[0400] The monitor for the start of interactive sessions template monitors for the start of interactive user sessions. This includes ftp sessions, remote logins, and using the su command to switch to another user ID.
[0401] This template collects information from /var/adm/sulog, and /var/adm/wtmp. Note that wtmp will not be created by the login programs, so be sure that it exists if you wish this template to function properly.
[0402] The monitor for the start of interactive sessions template is useful because there are certain user accounts that are intended to be used by system programs or only for maintenance purposes. Therefore, it is useful to be notified if anyone begins an interactive session using one of those user names.
[0403] There is a default list of users supplied. These should be changed if you use a different naming convention, and any additional non-user accounts should also be added in. The following shows what the default accounts are normally used for:
root Superuser - system maintenance ids Praesidium IDS/9000 maintenance www Web Server maintenance news News maintenance
[0404] The rest are usually never logged into directly, and are used for the execution of some services:
[0405] daemon
[0406] bin
[0407] sys
[0408] adm
[0409] uucp
[0410] nuucp
[0411] hpdp
[0412] Monitor Logins/Logouts Template
[0413] The monitor logins/logouts template monitors for users logging in or logging out of the system.
[0414] This template collects information from /var/adm/wtmp. Note that wtmp will not be created by the login programs, so be sure that it exists if you wish this template to function properly.
[0415] The monitor logins/logouts template is useful because in certain environments, and at certain times, no (or only selected) users are expected to be accessing the system remotely. This template will alert you at the start and end of connections by all users except for ones you specifically indicate to ignore.
[0416] The default list of users to ignore is empty. The user configuration will change depending on how this template is deployed. By adding a user name to the list, no alert will be generated when that user logs in or out.
[0417] For example, on a database server, the user might only have user “dbmaint” logging in during a specified range of hours. No other users are expected to be using the system. You could build a surveillance schedule that ignored user “dbmaint” during the expected hours, and would watch everyone otherwise.
[0418] Other machines might only be used during business hours, so this template can be deployed during non-business hours to report on any connections.
[0419] The following list maps the Code values to the name of the detection template that generates them.
Code Detection Template 5 Buffer overflow attacks 6 Race condition attacks 9 Creation of SetUID files 13 Creation of world-writable files 15 Repeated failed su commands 16 Repeated failed logins 27 Modification of files/directories 28 Changes to log files 29 Modification of another user's files 30 Monitor start of interactive sessions 31 Monitor logins/logouts
[0420] The following list maps the Message values to the name of the detection template that generates them.
[0421] Message Detection Template
[0422] Append-only file being modified
[0423] Changes to log files
[0424] Failed login attempts
[0425] Repeated failed logins
[0426] Filename mapping change
[0427] Race condition attacks
[0428] Filesystem change detected
[0429] Modification of files/directories
[0430] Login: “USERNAME”
[0431] Monitor logins/logouts
[0432] Logout: “USERNAME”
[0433] Monitor logins/logouts
[0434] Multiple failed su attempts by FROM_USER
[0435] Repeated failed su commands
[0436] Non-owned file being modified
[0437] Modification of another user's files
[0438] Potential buffer overflow
[0439] Buffer overflow attacks
[0440] Setuid file created
[0441] Creation of SetUID files
[0442] Successful su detected
[0443] Monitor start of interactive sessions
[0444] Unexpected change in privilege
[0445] Buffer overflow attacks
[0446] User login detected
[0447] Monitor start of interactive sessions
[0448] World-writable file created
[0449] Creation of world-writable files
[0450] Detailed Detection Templates
[0451] This section gives details for the detection templates that are summarized above.
[0452] 5: Buffer Overflow Attacks
[0453] Unexpected Change in Privilege
[0454] Code: 5
[0455] Version: 1
[0456] Severity: 1—Critical
[0457] Source: User ID: UID
[0458] Target Subsystem: 14:PROCESSES
[0459] Time: YYYYMMDDhhmmss
[0460] Message: Unexpected change in privilege
[0461] Details: Unexpected change in privilege detected with UID: UID(GID: GID) EUID: EUID(EGID: EGID) executing BINARY1 with arguments ARGLIST1 and
[0462] system call SYSCALL
[0463] where: UID Current User ID of the attacked process
[0464] GID Current Effective User ID of the attacked process
[0465] EUID Current Group ID of the attacked process
[0466] EGID Current Effective Group ID of the attacked process
[0467] PID Process ID of the attacked process
[0468] BINARY1 Name of program being attacked
[0469] SYSCALL System call involved in the attack
[0470] ARGLIST1 Arguments passed to BINARY1
[0471] Potential Buffer Overflow
[0472] Code: 5
[0473] Version: 1
[0474] Severity: 1—Critical
[0475] Source: User ID: UID
[0476] Target Subsystem: 14:PROCESSES
[0477] Time: YYYYMMDDhhmmss
[0478] Message: Potential buffer overflow
[0479] Details: Potential buffer overflow detected with UID: UID(GID: GID) EUID: EUID(EGID: EGID) executing BINARY1 with arguments ARGLIST1 now executing: BINARY2 with arguments ARGLIST2 as PID: PID
[0480] where: UID Current User ID of the attacked process
[0481] GID Current Effective User ID of the attacked process
[0482] EUID Current Group ID of the attacked process
[0483] EGID Current Effective Group ID of the attacked process
[0484] PID Process ID of the attacked process
[0485] BINARY1 Name of program being attacked
[0486] SYSCALL System call involved in the attack
[0487] ARGLIST1 Arguments passed to BINARY1
[0488] BINARY2 Name of new program being invoked
[0489] ARGLIST2 Arguments passed to BINARY2
[0490] 6: Race Condition Attacks
[0491] Filename Mapping Change
[0492] Code: 6
[0493] Appendix D 163
[0494] Version: 1
[0495] Severity: 1—Critical
[0496] Source: User ID: UID
[0497] Target Subsystem: 02:FILESYSTEM
[0498] Time: YYYYMMDDhhmmss
[0499] Message: Filename mapping change
[0500] Details: UID: UID (EUID: EUID)
[0501] Reference: PATHARG
[0502] currently kern_SYSCALL1:PATH1(FILEINFO1)
[0503] was kern_SYSCALL2:PATH2(FILEINFO2)
[0504] program running is PATH3(FILEINFO3) with arguments [ARGLIST3]
[0505] ATTACKER was UID: A_UID running
[0506] PATH4(FILEINFO4) with arguments [ARGLIST4]
[0507] where: UID Target's User ID
[0508] EUID Target's Effective User ID
[0509] PATHARG Symbolic pathname supplied by program
[0510] SYSCALL1 Name of system call currently being executed
[0511] PATH1 Absolute path of PATHARG as seen by SYSCALL1
[0512] FILEINFO1 Type, Inode, and Device number of PATH1
[0513] SYSCALL2 Name of previous system call using PATHARG
[0514] PATH2 Absolute path of PATHARG as seen by SYSCALL2
[0515] FILEINFO2 Type, Inode, and Device number of PATH2
[0516] PATH3 Absolute path of target program FILEINFO3 Type, Inode, and Device number of PATH3
[0517] Appendix D 164
[0518] ARGLIST3 Comma separated list of arguments used when PATH3 was invoked
[0519] A_UID The User ID of the Attacker
[0520] PATH4 Absolute path of the attacking program
[0521] FILEINFO4 Type, Inode, and Device number of PATH4
[0522] ARGLIST4 Comma separated list of arguments used when PATH4 was invoked
[0523] 9: Creation of SetUID Files
[0524] Setuid File Created
[0525] Code: 9
[0526] Version: 1
[0527] Severity: 1—Critical
[0528] Source: User ID: UID
[0529] Target Subsystem: 02:FILESYSTEM
[0530] Time: YYYYMMDDhhmmss
[0531] Message: Setuid file created
[0532] Details: User UID enabled the setuid bit on file PATH1 executing PATH2(FILEINFO2) with arguments ARGLIST2 as PID: PID
[0533] where: UID Attacker's User ID number
[0534] PATH1 Absolute path to the file being attacked
[0535] PATH2 Absolute path of attacking executable
[0536] FILEINFO2 Type, inode, and device number of PATH2
[0537] ARGLIST2 Comma-separated list of arguments used when PATH2 was invoked
[0538] PID Process ID of program PATH1
[0539] Example: User 0 enabled the setuid bit on file “/etc/xxx” executing /usr/bin/chmod(1,2093,“40000005”) with arguments [“chmod”, “u+xs”, “/etc/xxx”] as PID:2216
[0540] 13: Creation of World-writable Files
[0541] World-Writable File Created
[0542] Code: 13
[0543] Version: 1
[0544] Severity: 3—Alert
[0545] Source: User ID: UID
[0546] Target Subsystem: 02:FILESYSTEM
[0547] Time: YYYYMMDDhhmmss
[0548] Message: World-writable file created
[0549] Details: User UID ACTION FILENAME DESCRIPTION executing PATH1(FILEINFO1) with arguments ARGLIST1 as PID: PID
[0550] where: UID User ID number of the attacker
[0551] ACTION One of the following strings:
[0552] created
[0553] made file
[0554] FILENAME Absolute path to file affected
[0555] DESCRIPTION One of the following messages:
[0556] owned by UID: FILE_UID world writable with world writable permissions
[0557] FILE_UID User ID number of the owner of FILENAME
[0558] PATH1 Absolute path of attacking executable
[0559] FILEINFO1 Type, Inode, and Device number of PATH 1
[0560] Appendix D 166
[0561] ARGLIST1 Comma separated list of arguments used when PATH1 was invoked
[0562] PID Process ID of program PATH1
[0563] Example: User 0 created “/etc/xxx” with world-writable permissions executing /usr/bin/touch(1,27,“40000005”) with arguments [“touch”, “/etc/xxx”] as PID:2213
[0564] 15: Repeated Failed Su Commands
[0565] Multiple Failed Su Attempts by FROMUSER
[0566] Code: 15
[0567] Version: 1
[0568] Severity:
[0569] 3—Alert
[0570] 2—Severe, for ids or root
[0571] Source: User: FROMUSER
[0572] Target Subsystem: 05:LOGIN
[0573] Time: YYYYMMDDhhmmss
[0574] Message: Multiple failed Su attempts by FROMUSER
[0575] Details: User “FROMUSER” had at least MAXCOUNT failed su attempts in the past TIME. Targets included USERLIST
[0576] where: FROMUSER The user issuing the su command. Note that this is the original login account, and might not reflect a past successful su attempt.
[0577] TOUSER The account that FROMUSER is attempting to access
[0578] MAXCOUNT The configurable number of attempts permitted before alarm
[0579] TIME The configurable time window in which attempts are observed
[0580] USERLIST A list of all accounts to which they attempted to switch to in the interval
[0581] Example: User “ids” had at least 2 failed su attempts in the past 24 h. Targets included [“root”]
[0582] 16: Repeated Failed Logins
[0583] Failed Login Attempts
[0584] Code: 16
[0585] Version: 1
[0586] Severity:
[0587] 3—Alert
[0588] 2—Severe, for ids or root
[0589] Source: IP: IP
[0590] Target Subsystem: 05:LOGIN
[0591] Time: YYYYMMDDhhmmss
[0592] Message: Failed login attempts
[0593] Details: More than LIMIT failed logins by user USER (REMOTE: HOST IP)
[0594] where: LIMIT Maximum number of failures to permit before alert
[0595] USER User name attempting to login
[0596] HOST Remote host initiating the connection
[0597] IP IP address for HOST
[0598] Example: More than 2 failed logins by user root (REMOTE: machine.hp.com 127.0.0.1)
[0599] 27: Modification of Files or Directories
[0600] Filesystem Change Detected
[0601] Code: 27
[0602] Version: 1
[0603] Severity:
[0604] 3—Alert
[0605] 2—Severe, if file is truncated, deleted, modified, renamed
[0606] Source: User ID: UID
[0607] Target Subsystem: 02:FILESYSTEM
[0608] Time: YYYYMMDDhhmmss
[0609] Message: Filesystem change detected
[0610] Details: User UID ACTION FILENAME executing PATH1(FILEINFO1) with arguments ARGLIST1 as PID: PID
[0611] where: UID User ID number of attacker
[0612] ACTION Describes the action the attacker performed:
[0613] 22. changed the owner of
[0614] 22. changed the permissions of
[0615] 22. created a symbolic link
[0616] 22. created as a hard link
[0617] 22. created the directory
[0618] 22. created the file (and overwrote any existing file) named
[0619] 22. deleted the directory
[0620] 22. deleted the file
[0621] 22. opened for modification/truncation
[0622] 22. performed kern_SYSCALL on the file
[0623] 22. renamed a file to
[0624] 22. renamed the file
[0625] 22. truncated the file
[0626] FILENAME Name of the file being modified
[0627] PATH1 Absolute path of attacking executable
[0628] FILEINFO1 Type, inode, and device number of PATH1
[0629] ARGLIST1 Comma separated list of arguments used when PATH1 was invoked
[0630] PID Process ID of program PATH1
[0631] Example: User 0 created the file (and overwrote any existing file) named “/etc/passwd” executing /usr/bin/vi(1,14665,“40000005”) with arguments [“vi”, “/etc/passwd”] as PID:2220
[0632] 28: Changes to Log Files
[0633] Append-Only File Being Modified
[0634] Code: 28
[0635] Version: 1
[0636] Severity: 2—Severe
[0637] Source: User ID: UID
[0638] Target Subsystem: 02:FILESYSTEM
[0639] Time: YYYYMMDDhhmmss
[0640] Details: User UID ACTION FILENAME executing PATH1(FILEINFO1) with arguments ARGLIST1 as PID: PID
[0641] where: UID Attacker's UID
[0642] ACTION One of the following actions:
[0643] 22. created a symbolic link
[0644] 22. created as a hard link
[0645] 22. created the directory
[0646] 22. created the file (and overwrote any existing file named)
[0647] 22. deleted the file
[0648] 22. opened for modification/truncation
[0649] 22. renamed a file to
[0650] 22. renamed the file
[0651] 22. truncated the file
[0652] FILENAME File that was modified
[0653] PATH1 Absolute path of attacking executable
[0654] FILEINFO1 Type, inode, and device number of PATH1
[0655] ARGLIST1 Comma-separated list of arguments used when PATH1 was invoked
[0656] PID Process ID of program PATH1
[0657] Examples:
[0658] User 0 created the file (and overwrote any existing file) named “/var/adm/sulog” executing /usr/bin/vi(1,14665,“40000005”) with arguments [“vi”, “/var/adm/sulog”] as PID:2232
[0659] User 0 renamed the file “/var/adm/wtmp” executing /usr/bin/mv(1,2117,“40000005”) with arguments [“mv”, “wtmp”, “wtmp2”] as PID:2209
[0660] User 0 renamed a file to “/var/adm/wtmp” executing /usr/bin/mv(1,2117,“40000005”) with arguments [“mv”, “wtmp2”, “wtmp”] as PID:2211
[0661] 29: Modification of Another User's Files
[0662] Non-Owned File Being Modified
[0663] Code: 29
[0664] Version: 1
[0665] Severity:
[0666] 3—Alert
[0667] 2—Severe, if file is truncated, deleted, modified, renamed
[0668] Source: User ID: UID
[0669] Target Subsystem: 02:FILESYSTEM
[0670] Time: YYYYMMDDhhmmss
[0671] Message: Non-owned file being modified
[0672] Details: User UID ACTION FILENAME owned by UID: UID2 executing PATH1(FILEINFO1) with arguments ARGLIST1 as PID: PID
[0673] where: UID User ID number of attacker
[0674] ACTION Describes the action the attacker performed:
[0675] 22. changed the owner of
[0676] 22. changed the permissions of
[0677] 22. created a symbolic link
[0678] 22. created as a hard link
[0679] 22. created the directory
[0680] 22. created the file (and overwrote any existing file) named
[0681] 22. deleted the directory
[0682] 22. deleted the file
[0683] 22. opened for modification/truncation
[0684] 22. performed kern_SYSCALL on the file
[0685] 22. renamed a file to
[0686] 22. renamed the file
[0687] 22. truncated the file
[0688] FILENAME Name of the file being modified
[0689] UID2 User ID number of owner of file being modified
[0690] PATH1 Absolute path of attacking executable
[0691] FILEINFO1 Type, Inode, and Device number of PATH1
[0692] ARGLIST1 Comma separated list of arguments used when PATH1 was invoked
[0693] PID Process ID of program PATH1
[0694] 30: Monitor Start of Interactive Sessions
[0695] User Login Detected
[0696] Code: 30
[0697] Version: 1
[0698] Severity:
[0699] 3—Alert
[0700] 2—Severe, for ids or root
[0701] Source: IP: NETADDR
[0702] Target Subsystem: 05:LOGIN
[0703] Time: YYYYMMDDhhmmss
[0704] Message: User login detected
[0705] Details: User “USERNAME” logged in on DEVICE (Remote: NETADDR HOSTNAME)
[0706] where: USERNAME Name of the user logging in
[0707] DEVICE Device (tty or service) for the connection
[0708] NETADDR Network address of remote connection (dotted decimal)
[0709] HOSTNAME Truncated hostname of NETADDR
[0710] Example: User “root” logged in on pts/3 (Remote:127.0.0.1 machine.hp.com)
[0711] Successful Su Detected
[0712] Code: 30
[0713] Version: 1
[0714] Severity:
[0715] 3—Alert
[0716] 2—Severe, for ids or root
[0717] Source: User: FROMUSER
[0718] Target Subsystem: 05:LOGIN
[0719] Time: YYYYMMDDhhmmss
[0720] Message: Successful su detected
[0721] Details: User “FROMUSER” switched to user “TOUSER” on DEVICE
[0722] where: FROMUSER Name of the user changing login
[0723] TOUSER Name of the user FROMUSER is becoming
[0724] DEVICE Device associated with this connection
[0725] USERNAME Name of the user logging in
[0726] DEVICE Device (tty or service) for the connection
[0727] NETADDR Network address of remote connection (dotted decimal)
[0728] HOSTNAME Truncated hostname of NETADDR
[0729] Examples:
[0730] User “root” switched to user “ids” on 2
[0731] User “root” switched to user “root” on 2
[0732] 31: Monitor Logins and Logouts
[0733] Login: “USERNAME”, Logout: “USERNAME”
[0734] Code: 31
[0735] Version: 1
[0736] Severity:
[0737] 3—Alert
[0738] 2—Severe, for ids or root
[0739] Source: IP: NETADDR
[0740] Target Subsystem: 05:LOGIN
[0741] Time: YYYYMMDDhhmmss
[0742] Message: Login: “USERNAME”
[0743] Logout: “USERNAME”
[0744] Details: User “USERNAME” ACTION on DEVICE (Remote: NETADDR HOSTNAME)
[0745] where: USERNAME Name of the user logging in
[0746] ACTION Logged in/out
[0747] DEVICE Device (tty or service) for the connection
[0748] NETADDR Network address of remote connection (dotted decimal)
[0749] HOSTNAME Truncated hostname of NETADDR
[0750] Example: User “root” logged in on pts/3 (Remote: 127.0.0.1 machine.hp.com)
[0751] Virus Protection
[0752] Virus exhibits many of the same characteristics of a host-based attack and so the IDSSO according to the present invention provides a second tier virus protection. Virus protection software operates by searching (in one form or another) for known virus codes within system, application, or data files, or in data coming in via the network. Sometimes the viral code sequences can be removed (the file is “repaired”), other times an alert is provided and activity related to that file is blocked. Such virus protection schemes are completely ineffective against new and unknown virus codes, or against viruses whose codes have not been added to the published list of known viruses.
[0753] A host-based IDS can also provide second-tier virus protection: All current virus protection software operates by searching in one form or another for known virus codes within system, application, or data files or in data coming in via the network. Sometimes the viral code sequences can be removed (the file is “repaired”), other times an alert is provided and activity related to that file is blocked. Such virus protection schemes are completely ineffective against new and unknown virus codes, against viruses whose codes have not been added to the published library of known viruses and against “polymorphic” viruses that alter their own codes as they propagate.
[0754] However, in order for a virus to propagate it almost always has to replicate itself into data or program files for which it does not usually have legitimate access. This sort of activity is exactly what is flagged by a host-based intrusion detection system monitoring for system misuse. Thus, the host-based IDS 50 may alert system administrators against certain viral propagation activities from heretofore unknown viruses that easily traverse the filters of the virus protection system(s).
[0755] Furthermore, the host-based IDS 50 may provide an alert even if a successfully propagated virus code attempts to do damage to local system or data files. However, if a virus has gotten this far, it has usually infected a process that has legitimate access to the data being damaged and would not generally be detected as system misuse.
[0756] Alert Message Output
[0757] The templates (circuits) in the correlator will generate an ASCII text message if an intrusion is detected. The event must be sent from the correlator 220 to the outside world, which is the idsagent 200 . Remember, the correlator process idscor 230 is executing as a single thread, so the only way to asynchronously read an output event from the engine core is to define a callback function. The callback function is called by the engine core whenever it wishes to send an event to the outside world.
[0758] Interfacing to the ECS Engine Core
[0759] At the heart of the correlator lies the ECS correlator core which controls the engine.
[0760] Engine Initialization—CORE_engineInitialize
[0761] The engine needs some basic initialization steps performed before it can start. One of the first steps is to initialize a trace and logging buffer. These buffers are used to generate log or trace messages by the engine core. The trace mask based is set on the value of the -t command line argument. A value of −1 will turn on full tracing, which generates a huge amount of trace data in the log file. The user can select what elements of the ECS engine core operation to trace using the tracing value as a bit mask.
[0762] The engine core needs to load an MDL file which specifies the format and layout of all events that the engine must deal with. The mdlFile global is set from the environment variables created when the idscor process 130 is started. It specifies the location of the mdl file, which should be in /opt/ids/lib/mdl.md by default. The ECS_MDL_MD environment variable is created for further use by the engine. However, the ECS engine does not load the MDL file directly. Instead it loads a file which contains a line that specifies the full path to the shared libraries for all the endecoders it must load.
[0763] Some scratchpad space is created for the engine to work with, and the engine's internal time is set. We set the internal engine instance variable to 1 to indicate that this is the first (and only) engine instance in this process. Up to 8 engine instances can be supported simultaneously, but we only run one instance in the idscor process.
[0764] The circuits are loaded by command calls into the ECS engine. The commands are ASCII strings with certain fields parameterized. For example, the load datastore function needs two parameters: the data store name and the path to the data store file. Passing these two parameters into a macro will result in a correctly formed command string for the engine core. These commands are passed into strings of a command tuple opaque data type for the ECS engine core. Finally, the ECS API function will execute the command.
[0765] Loading and Unload Circuits
[0766] The correlator loads and unloads templates (circuits) in response to commands from the idsagent process 110 .
[0767] A group of templates is loaded which form a surveillance group defined in the GUI. The command from the idsagent 110 is in the form of an ASCII string, with the parameters to the command separated by spaces. The comment block on this function is detailed enough to explain what it does. If one of the templates fails to load, then all of the templates are unloaded. Each circuit to be loaded is specified as a name in the parameter list. The idscor 130 will load the circuit using the circuit name. For simplicity the idscor 130 assumes that each circuit to be loaded has an associated data and fact store. So the sequence of steps to load a template group are (for each circuit specified in the group):
[0768] 1. Create the data store name based on the circuit name.
[0769] 2. Load the data store into the engine.
[0770] 3. Create the fact store name based on the circuit name.
[0771] 4. Load the fact store into the engine.
[0772] 5. Create the full path to the circuit to load.
[0773] 6. Load the circuit, and associate it with the data and fact stores which were just loaded. Any data/fact store references from the circuit will be directed to these data/fact stores.
[0774] 7. Enable the circuit—it will now accept input events from the engine.
[0775] It will be readily seen by one of ordinary skill in the art that the present invention fulfills all of the objects set forth above. After reading the foregoing specification, one of ordinary skill will be able to affect various changes, substitutions of equivalents and various other aspects of the invention as broadly disclosed herein. It is therefore intended that the protection granted hereon be limited only by the definition contained in the appended claims and equivalents thereof. | The present application is directed to a host-based IDS on an HP-UX intrusion detection system that enhances local host-level security within the network. It should be understood that the present invention is also usable on, for example, Eglinux, solaris, aix windows 2000 operating systems. It does this by automatically monitoring each configured host system within the network for possible signs of unwanted and potentially damaging intrusions. If successful, such intrusions could lead to the loss of availability of key systems or could compromise system integrity. |
FIELD OF THE INVENTION
This invention relates to an electromechanical actuator and, in particular, to an electromechanical actuator that is ideally suited for use in controlling the positioning of a valve.
BACKGROUND OF THE INVENTION
More specifically, this invention involves an extremely compact electromechanical actuator. Actuators are well known in the art and are used in many applications where a reciprocating linear motion is needed for some intended purpose. These hydraulic or pneumatic devices, as well as electrically powered devices, and to some extent pneumatic actuators, are capable of being contained in compact packages, while at the same time being capable of delivering relatively high forces. These devices, however, develop leaks which render them unreliable or inoperative over a period of time.
Electrically powered devices are generally referred to as electromechanical actuators and have proven to be more reliable than the hydraulic and pneumatic devices and exhibit a relatively longer life. In addition, the electrical power devices afford greater control over the positioning of the device. The electrically powered devices, however, consume more space than their hydraulic and pneumatic counterparts. Heat disruption is sometimes a problem with the electrical devices, particularly when attempting to compact the actuator in a small package.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to improve linear actuators and, in particular, to improve electromechanical linear actuators.
A further object of the present invention is to provide a compact electromechanical linear actuator that is capable of delivering a relatively high linear force at high speed.
A still further object of the present invention is to provide an electromechanical linear actuator having improved control capabilities and a high force vs. stroke characteristic.
Another object of the present invention is to provide a compact electromechanical linear actuator that efficiently conducts motor generated heat to the surrounding ambient.
These and other objects of the present invention are attained by an electromechanical linear actuator that includes a hollow shaft and a brushless servo motor that is contained within a compact housing. The motor includes a stator containing the motor windings that is secured to an inner wall of the housing by a tapered wedge fabricated of a material having a high coefficient of thermal conductivity. The housing is provided with fins that surround the motor for dissipating heat efficiently into the immediate ambient. Springs are employed to hold the wedge supporting the motor stator in place to prevent displacement of the stator over a broad change in temperature. A rotor assembly is contained within the housing and includes an extended ball screw shaft that is aligned along the axis of the motor and coacts with a ball screw nut to position a push rod. The push rod and ball screw nut are linked to a linear guideway for directing the push rod along a linear path of travel.
BRIEF DESCRIPTION OF THE DRAWING
For a further understanding of these and other objects of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, wherein:
FIG. 1 is a sectional view of a linear actuator embodying the teachings of the present invention; and
FIG. 2 is an enlarged section taken along lines 2 — 2 in FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, there is illustrated a compact electromechanical linear actuator, generally referenced 10 , that embodies the teachings of the present invention. Although the present invention is ideally suited for controlling the positioning of a valve, the actuator can be employed equally as well in many other similar applications such as controlling the inlet vanes to a rotating machine or the like. The actuator includes a cylindrical housing 12 that includes a center section 13 and two end sections 14 and 15 . The sections are brought togther in a telescoping relationship as shown in FIG. 1 with the sections being secured together by any suitable means such as press fitting, threaded connections or screws such as screw 17 . End section 14 is closed in assembly by an end cap 18 . End section 15 is similarly closed by means of a second end cap 20 . A brushless permanent magnet servo motor, generally designated 22 , is contained within the center section 13 of the housing. The stator assembly 24 of the motor is secured to the inside wall of the housing in a stationary condition by means of an annular wedge 25 . The wedge includes tapered outer surface 26 that is fitted into a tapered opening in the housing that complements the wedge taper. In assembly, the wedge is inserted tightly between the body of the stator assembly and the tapered wall of the housing to securely hold the motor stator in a stationary condition. In this arrangement the stator contains the windings of the motor.
The motor rotor assembly generally designated 30 is rotatably contained within the housing so that the motor rotor 31 , which contains a series of magnetic elements, turns about the central axis 32 of the housing. As will be explained in greater detail below, the servo motor is designed to yield a high energy density due to low rotating inertia and has greatly improved thermal performance. This type of motor is generally referred to as a brushless dc motor that behaves similarly to a brush type dc motor except for the method of commutation. The brushless motor is commutated by an electronic controller 35 rather than by brushes and commutator bars. Because there are no brushes to wear out, little or no motor maintenance is required over the life of the motor.
The motor rotor is supported upon a hub generally referenced 40 that is rotatably supported in the center section of the housing in ball bearing 41 . The hub further contains a radially extended shoulder 42 that forms a space between an adjacent shoulder 43 on the central section 13 of the housing. A thrust bearing 45 is mounted in the space between the two shoulders to take up any axial loading exerted upon the rotor assembly. An end closure 47 is mounted on the bearing end of the rotor assembly which contains a flange 48 that is arranged to contact the ball bearing 41 . A gap 49 is maintained between the end closure and the hub and a series of spaced apart screws 50 are passed through the end closure and are threaded into the hub. Tightening the screws draws shoulders 42 and 43 together thereby securing the thrust bearing in a preloaded condition in the rotor assembly. By the same token, the enclosure is drawn between shoulder 43 and flange 48 that is located upon the end closure. One or more Belville washers are mounted between the wedge 25 and end section 15 of the housing to provide a holding force against the wedge in assembly.
The end closure contains an extended nose section 55 that is rotatably mounted in the left hand end section 14 , as viewed in FIG. 1 . The nose section, in turn, is used to support a part of the electronic resolver 90 that is used to provide both position sensing data to the controller 35 along with motor control data.
A ball screw assembly generally referenced 63 is mounted in the rotor hub. The ball screw assembly includes a shaft 65 that is coaxially aligned along the center line 32 of the housing. A ball screw nut 66 is mounted upon the ball screw shaft 65 which is adapted to move linearly along the axis of the ball screw shaft as the shaft turns with the rotor. The ball screw assembly of the type shown is commercially available from Hewin Corporation and Jena Tech, Inc., or others.
The left hand end of the ball screw shaft contains a tapered section 68 that is contained within a complementary opening formed in wall 69 of the hub rotor 40 . The end of the shaft further includes a threaded spline 70 that passes through the wall 69 and is engaged by a nut 71 . Tightening the nut down pulls the tapered section of the shaft tightly into the complementary opening in the hub wall thereby locking the shaft tightly in the hub.
The opposite end of the ball screw shaft is adapted to ride freely within a blind clearance hole 73 formed in push bar assembly 75 . The push bar assembly includes an elongated rod 76 having a pusher disc 77 located at the distal end of the rod. An end flange 78 is located at the proximal end of the rod. The end flange 78 of the push bar assembly is located adjacent to a second flange 79 located upon the ball screw nut 66 and the two are connected in assembly by a series of screws 80 (FIG. 2 ). As best illustrated in FIG. 2, each flange is provided with a pair of ball bearings 83 that are arranged to ride in longitudinal guideways 84 that are formed in the housing end section 15 and which are aligned parallel to the axis 32 of the housing. The bearings are captured within the guideway and prevent rotation of the ball screw nut while at the same time insuring that the nut and the push bar assembly both move along a linear path of travel.
An electronic resolver unit 90 is mounted upon an internal shoulder 91 formed in end section 14 of the housing. The resolver is a combination of a stator and a rotor. The resolver stator is mounted upon the housing 14 and the rotor is mounted upon the shaft 55 . The resolver is mounted concentrically to the motor rotor to provide exact motor position data to the controller 35 via line 94 . The motor controller uses the position data to adjust the motor phase current for optimum motor torque output which is also referred to as the commutation process. Resolvers of this type are available from Admotec, Inc. and have windings and iron case materials similar to those of the motor.
The motor controller is externally mounted within an EM1 enclosure which also contains necessary capacitors and filters to accommodate for lengthy cables of up to at least 150 meters in length. The controller is microprocessor based and operates the actuator positioning loop. The controller monitors the rotor position via the resolver and provides a sinusodial current to the motor windings via line 97 to control motor torque. The controller employs pulse width modulation for high efficiency regulators of the motor phase current.
The stator wedge 25 and the center section 13 of the actuator housing are each fabricated of a material having a high coefficient of thermal conductivity. In addition, the center section of the housing is provided with a plurality of heat exchanger fins 99 that encircle the center section of the housing. Accordingly, any excessive heat that is generated by the motor windings is quickly and efficiently rejected into the surrounding ambient thereby keeping the temperature within the housing at a low level, that is, at a level at which the mechanical and electrical component located within the housing will not become thermally damaged. As noted above, the stator wedge is secured in place by a prestressed Belville washer so that the wedge will not be displaced from its holding position due to the thermal stress.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims. | An electromechanical linear actuator that contains an electric servo motor mounted within a compact housing. A thermally conductive path of travel is provided to efficiently transfer heat out of the housing into the surrounding ambient. A further mechanism is provided for holding the stator windings of the motor in undisturbed contact with the inner wall of the housing when the motor is subjected to thermal stress. The motor is arranged to linearly position a push rod through means of a ball screw unit. The ball screw nut and the push rod ride on bearings within guideways to insure that the push rod tracks along a linear path of travel. |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims the benefit of European Patent Application No. 10197416.0, filed Dec. 30, 2010, the entire teachings and disclosure of which are incorporated herein by reference thereto.
FIELD OF THE INVENTION
[0002] The present invention relates to a composite vane used in any field (aeronautics, energy, etc.) where the energy of a flow is exploited. More particularly, the present invention relates to a composite vane used in a turbomachine.
[0003] The present invention also relates to a fixed stage or a rotor stage of a turbomachine comprising said composite vanes.
[0004] The present invention also relates to a method for manufacturing a composite-material vane.
STATE OF THE ART
[0005] Axial compressors are well known per se and are used inter alia in turbomachines.
[0006] These low or high pressure compressors comprise several rotary-vane stages, also called mobile vanes, which are separated by rectifier stages, the purpose of which is to reposition the speed vector of the fluid leaving the preceding stage before sending it to the following stage.
[0007] Rectifier stages are essentially made up of fixed vanes, also called rectifier vanes, connecting an outer shroud to an inner shroud, both concentric and delimiting the airflow zone or aerodynamics stream.
[0008] Today, turbomachine rectifier vanes are made of metal materials such as titanium alloys (TA6V), steel or aluminum.
[0009] There are vanes with a simple shape made of composite material such as outlet guide vanes (OGV) located in the secondary stream of a turbojet engine and manufactured using a method for manually depositing pre-impregnated tissues or using the RTM (Resin Transfer Molding) method from braided or woven dry pre-forms.
[0010] Also known from U.S. Pat. No. 2,859,936 A is a method for manufacturing a straight vane where the vane comprises at its foot a metal insert used to position resin-impregnated fibers and where a mixture of resin and short fibers is then added into the mold and covers and surrounds the pre-impregnated fibers.
[0011] Also known from patent application US 2010/0080710 A1 is a method for manufacturing OGV blades where two metal sheets are welded to form the skin of the vane and a space within which a plastic material is injected. The cohesion between the different components of the vane is solely ensured by the mechanical connection between the skin and the core.
[0012] Also known from patent application US 2010/0129651 A1 succeeding the aforementioned application, is a method for manufacturing fan or stator vane blades where a layer of polyurethane is inserted between the metal skin and the composite material of the core in order to ensure better connection between the core and the skin, and thereby reduce the risk of delamination, and also in order to absorb the expansion differences between the composite material of the core and the metal skin.
[0013] Also known from application US 2010/0150707 A1 is a method for manufacturing composite-material vane blades, such as OGVs, where the blade comprises a hollow enclosure formed from distinct layers of composite material and also comprises a core with a corrugated shape and positioned in the enclosure and ensuring the spacing of the enclosure walls. Platforms are fastened to the ends of the blade by welding or gluing.
[0014] The methods for manufacturing composite vanes of the state of the art each have one or several of the following drawbacks:
they do not allow to produce complex shapes; they allow to produce vanes with a relatively significant thickness (15-20 mm) such as OGV vanes, and do not allow to produce compressor vanes with smaller thicknesses (less than 10 mm); the platform(s) of the vane are not integrated with the blade of the vane and must therefore be attached later; the cohesion between the component parts of the vane is ensured by a mechanical connection.
AIMS OF THE INVENTION
[0019] The present invention aims to provide a solution that allows to overcome the drawbacks of the state of the art.
[0020] The present invention thus aims to produce vanes with complex shapes, while limiting subsequent machining or finishing operations.
[0021] The present invention also aims to produce vanes with a wide range of possible thicknesses.
[0022] The present invention also aims to produce vanes with a blade and a platform in a single piece.
[0023] The present invention also aims to produce vanes where the cohesion between the different component parts is ensured using a chemical bond.
MAIN CHARACTERISTIC ELEMENTS OF THE INVENTION
[0024] The present invention relates to a composite-material turbomachine vane comprising a blade, wherein said vane comprises a first resin reinforced by long fibers and a second resin reinforced by short fibers, said first and second resins being chemically compatible or identical, said long fibers serving to stiffen the vane and said short fibers dispersed in the second resin serving to fill in the parts of the vane that are not reinforced by the long fibers and giving the vane its substantially final shape.
[0025] According to specific embodiments of the invention, the vane comprises one or a suitable combination of the following features:
it comprises, at one end of the blade, a means for fastening said vane to an external element and said fastening means is integrated into the blade of the vane; the long fibers are positioned at the skin end of the vane or in an intermediate position between the skin end and the core of the vane; the long fibers are positioned so that a same long fiber can be positioned both at the skin end of the vane and at the same time in an intermediate position between the skin end and the core end of the vane; the long fibers are continuous between the blade and the fastening means; the fastening means is a platform or bulb in the shape of a dovetail; the blade and the platform form an L-shape or a T-shape; the short fibers and the long fibers are selected from the group consisting of glass fibers of and carbon fibers; the long fibers are unidirectional or woven and the short fibers have a length that is shorter than a few millimeters; the first and second resins are thermoplastic resins; the first and second resins are thermosetting resins; the skin of the vane is also comprises erosion-protected; the first resin and/or the second resin comprise(s) fillers ensuring protection of the vane against erosion.
[0038] The present invention also relates to a method for manufacturing a composite-material turbomachine vane comprising a blade and a fastening means to an outside element, said fastening means forming a single piece with said blade, said vane comprising long fibers positioned over at least a portion of the skin of the vane and also comprising short fibers filling in the parts of the vane that are not filled by the long fibers, said method successively comprising at least the steps of:
a) manufacturing pre-consolidated plates comprising the long fibers pre-impregnated with the first thermoplastic resin; b) cutting the plates to the required dimensions; c) shaping the plates; d) injection-molding the core of the blade and the core of the fastening means with a second thermoplastic resin loaded with short fibers, said second resin being identical to the first resin or chemically compatible with the first resin, said preformed plates acting as composite inserts in the injection mold.
[0043] The present invention also relates to a rectifier stage or to a rotor stage of a turbomachine comprising composite vanes as described above.
BRIEF DESCRIPTION OF THE FIGURES
[0044] FIG. 1 shows a diagrammatic transverse cross-sectional view of the blade of a vane as in the invention.
[0045] FIG. 2 shows a diagrammatic longitudinal cross-sectional view of the blade of the vane incorporating a platform as in the invention.
[0046] FIG. 3 shows a diagrammatic front view of a vane as in the invention.
KEY
[0000]
( 1 ) Vane
( 2 ) Blade
( 3 ) Platform or bulb of the vane or, more generally, means for fastening the vane to an outside element
( 4 ) Long fibers
( 5 ) Short fibers
GENERAL DESCRIPTION THE INVENTION
[0052] The vane as in the present invention can be used in any field where vanes, whether mobile or static, are necessary. In aeronautics, it may for example be used as a compressor vane or as an outlet guide vane (OGV).
[0053] According to the present invention, the vane is made of a composite material and comprises continuous-fiber reinforcements, which will also be called long fibers, and short-fiber reinforcements. An organic matrix is associated with each reinforcement in such a way that all matrices are identical or chemically compatible in order to ensure a chemical bond between the different components. The organic matrices can be thermoplastic resins or thermosetting resins.
[0054] The continuous-fiber reinforcement is used to ensure the structural stiffness of the vanes, while the short-fiber reinforcement associated with its resin is used to fill in the volume and give the vane its final or almost final shape. The assembly of these two materials thereby allows to produce the complex shapes that the vane may assume and to directly obtain the final shape of the vane, i.e. integrating the blade and its fastening means, upon exiting the mold after manufacture.
[0055] Preferably, the continuous fibers are unidirectional or woven and the short fibers have a length of a few millimeters or less. Typically, the short fibers have a diameter comprised between 1 and 15 μm for a maximum length of 1 mm. According to the invention, the short and continuous fibers may be of the same nature or of different natures. For example, the long and short fibers may be carbon fibers or glass fibers, respectively. The fibers within the short fibers or within the long fibers may also be of different natures; for example, the long fibers can comprise glass fibers and carbon fibers.
[0056] Preferably, the short fibers are positioned at the core of the vane and the continuous fibers at the skin end, in which case the continuous fibers fit the external surface of the vane, or in an intermediate position between the skin end and the core. In the latter case, the short fibers mixed with the resin also fill in the space between the intermediate position and the skin end. The present invention also extends to embodiments where, over the length of the fibers, a same long fiber is successively positioned at the skin end of the vane and at the intermediate position.
[0057] Optionally, the surface of the composite vane as in the invention may be erosion-protected.
DETAILED DESCRIPTION OF THE INVENTION
[0058] The present invention is detailed below, as a non-limiting example, for a vane used in a turbomachine, and more specifically for a vane used in the first portion of a turbomachine, in the so-called low pressure part.
[0059] According to the present invention and as illustrated in FIG. 2 , the vane 1 comprises a blade 2 and at the foot of the plate a platform 3 or, generally, a means for fastening the vane to an external element. In the particular case of a compressor rectifier vane, the blade comprises a foot in its first end that is intended to be fastened to an external shroud of the compressor while the other end, the head of the blade, is intended to be assembled to an internal shroud of the compressor. If the foot is of the platform type, it can form a T-shape as shown in FIG. 2 , an L-shape or any other adapted shape. In the example illustrated in FIG. 3 , the foot of the blade comprises, instead of a platform, a dovetail-shaped bulb 3 . This bulb thus has two inclined surfaces flaring from the blade foot toward a third surface that is perpendicular to the plane of the blade. The present invention also extends to the production of a composite vane with only one blade.
[0060] FIGS. 1 to 3 diagrammatically illustrate the arrangement of the long fibers 4 and of the short fibers 5 within a transverse section of the blade, within a longitudinal cross-section of the foot of the blade with integrated platform, and within the vane as a whole. The long-fiber reinforcement 4 is positioned in or near the skin of the vane and the rest of the vane is filled in with short-fiber reinforcement 5 . As illustrated in FIGS. 1 to 3 , only a portion of the skin can be made of the long-fiber reinforcement, the skin of the vane that is not made of the long-fiber reinforcement then being filled in with short-fiber reinforcement. In this way, the skin of the blade at the level of the leading and trailing edges can be deprived of long fibers and only comprise short fibers. Likewise, the long-fiber reinforcement can extend in the skin in the longitudinal direction of the vane from the platform of the vane as far as a distance that is substantially equal to the mid-height of the blade, this distance of course being adjustable.
[0061] As illustrated in FIG. 2 , the long fibers are preferably continuous between the blade and the platform or, generally, between the blade and the means for fastening the vane to an external element.
[0062] The vane as in the invention can be made using a method described below as a non-limiting example in order to manufacture a thermoplastic vane with an integrated fastening means such as, for example, a platform. The method successively comprises at least the following steps:
a) manufacturing preconsolidated plates, i.e. having undergone at least partial densification, comprising long fibers 4 and a first thermoplastic resin; b) cutting the plates to the required dimensions; c) shaping the plates; d) injection-molding the core of the blade 2 and the core of the fastening means 3 with a second thermoplastic resin loaded with short fibers, the second resin being identical to the first resin or chemically compatible with the first resin, said preformed plates acting as composite inserts in the injection mold.
[0067] According to the invention, the final shape of the vane can be directly obtained upon exiting the mold. After step d) for injection molding, the part may also undergo other operations such as machining operations or any operation required to implement protection against erosion. Protection against erosion can also be directly integrated into the part by adding filler into the first and/or second resin during manufacture.
[0068] As already mentioned, through the use of a same resin or of chemically compatible resins in step a) and d), the different component parts of the vane are bound by a chemical bond.
[0069] The method extends to the production of thermoplastic or thermosetting vanes with a skin at least partially made of long fibers and the core at least partially made of short fibers, the steps of the method being possibly adapted accordingly.
[0070] It will also be specified that, preferably, the continuous-fiber reinforcement is preimpregnated if a composite vane with thermoplastic matrix is being produced, or it involves dry reinforcement or pre-impregnated reinforcement if a composite vane with a thermosetting matrix, for example of the epoxy type, is being produced.
ADVANTAGES OF THE INVENTION
[0071] The vanes thus produced will benefit from savings in terms of mass relative to the existing vanes owing to the use of composite materials.
[0072] They will also benefit from a limited manufacturing cost owing to the reduced number of steps in the manufacturing method, the final shape being possibly directly obtained upon leaving the mold.
[0073] Using a same resin or compatible resins for the continuous fibers and the short fibers allows to obtain a chemical bond between the different components (within the blade and between the blade and the fastening means) and to ultimately obtain a composite vane with a continuous matrix.
[0074] The vane as in the invention thus allows to manufacture fixed vanes or mobile vanes with low mass and at low cost.
[0075] The method as in the invention allows to produce complex shapes within a wide range of thicknesses. | The present invention relates to a composite-material turbomachine vane ( 1) comprising a blade ( 2), wherein said vane ( 1) comprises a first resin ( 4) reinforced with long fiber and a second resin ( 5) reinforced with short fibers, said first and second resins being chemically compatible or identical, said long fibers ( 4) serving to stiffen the vane ( 1) and said short fibers ( 5) dispersed in the second resin serving to fill in the parts of the vane that are not reinforced by the long fibers ( 4) and giving the vane ( 1) its substantially final shape. |
FIELD OF TECHNOLOGY
The present disclosure belongs to the field of hermetically sealed reciprocating refrigeration compressors, in particular, relating to a discrete refrigeration compressor exhaust muffler device and a refrigeration compressor using the same.
BACKGROUND
Technological advancements in refrigeration appliances such as refrigerators have led to rapid progress in the field of refrigeration compressors. With increasing demands for environmental protection and energy conservation, refrigerator manufacturers have increased their efforts in developing energy efficient chlorofluorocarbon (CFC) free refrigerators. Therefore it is necessary for the refrigerator compressor industry to explore new products in order to keep pace with the progress in the refrigerator industry.
Existing refrigerator compressors have a reciprocating piston construction. FIG. 1 shows the structure of a typical refrigeration compressor of a refrigerator. The compressor mainly includes a compressor housing 1 , a compressor cylinder block 2 , a piston rod 3 , a crankshaft 4 , an exhaust muffler chamber 5 , a compressor cylinder cover 6 , a valve plate 7 , an intake muffler chamber, an electric motor, and other components. The exhaust muffler chamber 5 is casted onto the compressor cylinder block 2 . Compressed gas from the compressor passes through a gas flow passage in the valve plate 7 , through the compressor cylinder cover 6 , into an exhaust gas flow passage in the compressor cylinder block 2 , then is expended and enters the exhaust muffler chamber 5 to reduce the pressure of exhaust gas, and to moderate the high pressure flow of the compressed gas to reduce a noise level from the compressor.
However when the above compressor operates, the temperature and pressure of the compressed gas increases as a result of being compressed (temperature reaching 160° C.±, pressure reaching 32 kg). When the high-temperature-high-pressure gas flows through the exhaust muffler chamber 5 , it transfers heat to the exhaust muffler chamber 5 . Since the traditional exhaust muffler chamber 5 is casted onto the compressor cylinder block 2 , heat is retained at the compressor cylinder block 2 , cannot be dissipated outside of the compressor. Due to the heat retained inside the compressor, the compressor cylinder block 2 becomes a heating source. In addition to the heat produced by gas compression, heat is also produced by the electric motor during operation. As a result the temperature inside the compressor can be extremely high, and incoming gas is heated by heating sources inside the compressor. The extremely high temperature of incoming gas lowers the gas density, and thereby reduces the mass of incoming gas and the amount of compressed gas produced by the compressor. This leads to a reduction in the mass of output refrigerant. Thus, the compressor may consume a large amount of energy but deliver poor cooling performance.
FIG. 2 illustrates another exhaust muffler device for an existing refrigeration compressor. The exhaust muffler device includes an ellipsoidal exhaust buffer chamber 11 . The exhaust buffer chamber 11 is located outside the compressor cylinder block and is connected to the compressor cylinder block via a pipe. The exhaust buffer chamber 11 is formed by rotating and extruding a copper pipe and the manufacturing process is complicated. The resulting exhaust buffer chamber is heavy and expensive to produce. In addition, copper conducts heat rapidly, and further reduces compressor cooling efficiency when coupled with the high temperature inside the compressor.
SUMMARY
An object of the present disclosure is to overcome aforementioned shortcomings of traditional compressors by providing a discrete heat-insulated exhaust muffler device and a refrigeration compressor using the exhaust muffler device. The exhaust muffler device is capable of effectively reducing compressor noise levels and reducing negative effects of hot gas inside the compressor. The exhaust muffler device can significantly improve compressor cooling performance and is suitable for use in a hermetically sealed refrigeration compressor, particularly a small-sized hermetically sealed refrigeration compressor.
A further object of the present disclosure is to provide a discrete exhaust muffler device that is low cost, light weight, structurally simple, and easily manufactured, and a refrigeration compressor using the exhaust muffler device, particularly a small-sized hermetically sealed refrigeration compressor.
According to one embodiment of this disclosure, a discrete, heat-insulating exhaust muffler device for a refrigeration compressor includes a metal cavity body defining a cavity, installation holes on the metal cavity body configured to respectively connect a gas intake pipe and an exhaust pipe to the cavity. A non-metallic shell is disposed on an outside of the metal cavity body. The non-metallic shell has installation holes associated with the respective installation holes on the metal cavity body for connecting the gas intake pipe and the exhaust pipe.
According to the above embodiment, the non-metallic shell can be separately formed and subsequently mounted outside the metal cavity. The non-metallic shell can be casted with the metal cavity body to form a single body. The non-metallic shell can be chemically deposited on the outer surface of the metal cavity by electroplating, electrophoresis, or other methods.
According to the above embodiment, the non-metallic shell includes raised projections disposed on an interior wall of the non-metallic shell.
According to the above embodiment, the non-metallic shell is made of a non-metallic heat-insulating material that is intermiscible with refrigerant or engine oil for the refrigeration compressor. The non-metallic heat-insulating material includes a plastic or a rubber.
According to the above embodiment, the non-metallic shell includes first and second shell bodies that are configured to be joined together. Each of the shell bodies is separately formed and subsequently joined together to form the non-metallic shell that is to be mounted on the outside of the metal cavity body.
According to the above embodiment, the first and second shell bodies of the non-metallic shell are joined together by snap-fitting, adhesive bonding, or heat bonding when mounted on the outside of the metal cavity body.
According to the above embodiment, the raised projections are provided on an interior wall of a major surface of each of the first and second shell bodies.
According to the above embodiment, the first shell body of the non-metallic shell has a level bottom and vertical side walls extending perpendicularly from a periphery of the level bottom. The side walls have an equal height. The second shell body has a slanted bottom and side walls extending from a periphery of the slanted bottom, the side walls extend in parallel to each other toward ends in flush with each other that mate with the sidewalls of the first shell body.
According to the above embodiment, the first shell body has protrusions on the vertical side walls along two long sides thereof, and the second shell body has snap-fitting rings on the side walls along two long sides thereof. Alternatively, the first shell body has the snap-fitting rings and the second shell body has the protrusions. The snap-fitting rings and the protrusions are configured to snap-fitted with each other.
According to the above embodiment, the case is made from a PBT engineering plastic.
According to the above embodiment, the non-metallic shell has a thickness of 0.5 mm-2.5 mm. Raised projections are provided on an interior wall of the non-metallic shell. The raised projections are projected from the interior wall to a distance of 0.2 mm to 1 mm.
According to the above embodiment, the metal cavity body is formed by welding together first and second cavity bodies to define the cavity.
According to the above embodiment, each of the two cavity bodies is formed by stamping a steel plate or a metal alloy plate.
According to the above embodiment, a baffle is mounted inside the metal cavity body between the first and second cavity bodies. The baffle has a gas flow buffer hole and an exhaust pipe installation hole. The gas flow buffer hole has a diameter smaller than that of the exhaust pipe installation hole.
According to the above embodiment, the baffle is mounted vertically or horizontally inside the metal cavity body between the first and second cavity bodies.
According to the above embodiment, the metal cavity body has a rectangular shape, and the non-metallic shell has a shape matching that of the metal cavity body.
According to the above embodiment, the exhaust muffler device is located outside of a compressor cylinder block of the refrigeration compressor, and is separated from the compressor cylinder block.
The present disclosure provides a hermetically sealed refrigeration compressor using the exhaust muffler device described above, major components inside the sealed compressor housing include a compressor cylinder block, a crankshaft piston connecting rod assembly, a valve assembly, an intake muffler chamber assembly, an electric motor, and an exhaust muffler device. The electric motor is located on a bottom inside the compressor housing. The compressor cylinder block is located above the electric motor. The crankshaft piston connecting rod assembly connects to the valve assembly through the compressor cylinder block. The compressor cylinder cover is located at an end of the valve assembly. The intake muffler chamber assembly and the valve assembly are disposed adjacent with each other inside the compressor housing. The exhaust muffler device is located outside the compressor cylinder block and is separated from the compressor cylinder block. The non-metallic shell is mounted at an outside of the metal cavity body of the exhaust muffler device.
According to the above embodiment, a gas intake pipe extends through a gas intake pipe installation hole on the exhaust muffler device. The gas intake pipe connects to the compressor cylinder cover via a gas intake connection pipe, an exhaust pipe extends through an exhaust pipe installation hole on the exhaust muffler device, and the exhaust pipe is in fluid communication with the outside of the compressor housing via an internal high pressure exhaust pipe.
According to the above embodiment, the exhaust muffler device is mounted vertically or horizontally inside the compressor housing.
According to the above embodiment, inside the compressor housing, the gas intake connection pipe between the gas intake pipe of the exhaust muffler device and the compressor cylinder cover is horizontally disposed. A first end of the gas intake connection pipe connects to the gas intake pipe of the exhaust muffler chamber. A second end of the gas intake connection pipe is welded to an annular exhaust connection ring on the compressor cylinder cover. A circular gas flow passage in the center of the annular exhaust connection ring is in fluid communication with a gas flow passage of the gas intake connection pipe. The circular gas flow passage allows gas to flow therethrough after installation of a compressor cylinder cover screw thereon. The circular gas flow passage in the annular exhaust connection ring is in fluid communication with a gas flow passage of the compressor cylinder cover.
Compared to existing technologies, the embodiments described herein have the following advantages:
1. A non-metallic shell is mounted on the outside of a metal cavity body of an exhaust muffler device. The non-metallic shell is made of a non-metallic material that possesses superior heat insulating properties and can reduce thermal contact between exhaust gas inside the exhaust muffler device and gas inside the compressor. The non-metallic material can also reduce outward heat transfer from the metal cavity body of the exhaust muffler device. As a result, the temperature inside the compressor can be reduced and the efficiency of the compressor can be improved.
2. Raised projections are provided on an interior wall of the non-metallic shell that can prevent thermal contact between the metal cavity body and the non-metallic shell and reduce heat transfer from the metal cavity body to the non-metallic shell. As a result, heat transfer from hot compressed gas produced by the compressor cylinder to refrigerant inside the compressor housing is reduced. Therefore the temperature inside the compressor can be reduced and the efficiency of the compressor can be improved.
3. Placing the exhaust muffler device outside the compressor cylinder block can greatly reduce heat transfer therebetween during operation of the compressor and can dramatically improve the efficiency of the compressor.
4. The metal cavity body of the exhaust muffler device can be formed by stamping and subsequent welding of a thin metal sheet. The non-metallic material of the shell can have a light weight. Therefore the cost and weight of the device can be significantly reduced. The manufacturing process can be simplified, and more space can be made available around the compressor cylinder block.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a traditional exhaust muffler device of a compressor.
FIG. 2 is an illustration of a traditional discrete exhaust muffler device.
FIG. 3 is an illustration of a metal cavity body of an exhaust muffler device, according to one embodiment.
FIG. 4 is a left side perspective view of the exhaust muffler device of FIG. 3 .
FIG. 5 is an illustration of a non-metallic shell, according to one embodiment.
FIG. 6 is a left side perspective view of the non-metallic shell of FIG. 5 .
FIG. 7 is a top perspective view of the non-metallic shell of FIG. 5 .
FIG. 8 is a three-dimensional view of a shell body of a non-metallic shell with raised projections, according to one embodiment.
FIG. 9 is cross-sectional view along the A-A axis of FIG. 8 .
FIG. 10 is a front perspective view of a shell body of a non-metallic shell with snap-fitting rings that is a variant of the embodiment of FIG. 8 , according to another embodiment.
FIG. 11 is a cross-sectional view along the D-D axis of FIG. 10 .
FIG. 12 is a three-dimensional view of a shell body of a non-metallic shell with snap-fitting rings to be joined with the shell body of the non-metallic shell shown in FIG. 8 .
FIG. 13 is a three-dimensional view of the internal structures of an exhaust muffler device according to one embodiment.
FIG. 14 is an illustration of an exhaust muffler device placed inside a compressor housing according to one embodiment.
FIG. 15 is a front view of a connection between a gas intake hole of an exhaust muffler device and a compressor cylinder block, according to one embodiment.
FIG. 16 is a left side perspective view of the connection in FIG. 15 .
FIG. 17 is a right side perspective view of the connection in FIG. 15 .
DETAILED DESCRIPTION
The following, in conjunction with the examples in FIGS. 1-17 , provides a detailed description of the embodiments which are to be considered in all respects as illustrative and not limiting.
As shown in FIGS. 3-4 and 5 - 14 , an exhaust muffler device 8 is disposed on an outside of a compressor cylinder block 14 . The exhaust muffler device 8 includes an upper cavity body 9 and a lower cavity body 10 each defining a cavity thereof. Each of the cavity bodies 9 and 10 can be formed by stamping a piece of metal. Then the cavity bodies 8 and 9 are mated and joined together. The upper cavity body 9 and the lower cavity body 10 can be welded together to form a metal cavity body. The shape of the metal cavity body can be rectangular or other regular shapes such as, for example, ellipsoidal, spherical, cubical, etc. A shell 12 made of a non-metallic material is mounted on the outside of the metal cavity body. In one embodiment, the shell 12 can be separately formed by, for example, injection molding. In another embodiment, the shell 12 can be formed by injection-molding together with the metal cavity body. In another embodiment, the shell 12 can be formed by depositing a non-metallic material onto the outer surface of the metal cavity body through a chemical process such as, for example, electroplating. The non-metallic material can be a non-metallic heat-insulating material that is intermiscible with refrigerant or engine oil for a refrigeration compressor. The non-metallic heat-insulating material can include, for example, a plastic, or a rubber. A preferred non-metallic material is polybutylene terephthalate (PBT) engineering plastic or other non-metallic material(s) suitable for use with a refrigeration compressor.
Preferably, raised projections 25 are provided on an interior wall of the non-metallic shell 12 to prevent the shell 12 from contacting the metal cavity body. The surface area covered by the raised projections 25 can vary as long as the contact between the shell 12 and the metal cavity body is prevented. Further, the non-metallic shell 12 of the exhaust muffler device 8 has a wall thickness of 0.5 mm to 2.5 mm, and the raised projections 25 are projected from a surface of the interior wall of the shell 12 to a distance of 0.2 mm to 1 mm.
As shown in FIGS. 5-12 , the non-metallic shell 12 is mounted on the outside of the metal cavity body of the exhaust muffler device 8 . The non-metallic shell 12 can be formed by injection molding. The shell 12 includes shell bodies 17 and 18 . The shell bodies 17 and 18 can be joined together by, for example, snap-fitting, adhesive bonding, or heating bonding, and be mounted on the outside of the metal cavity body. FIGS. 5-12 illustrate an example of a non-metallic shell formed by snap-fitting. The shell bodies 17 and 18 are joined together by engaging a snap-fitting ring on a side wall of one shell with a corresponding protrusion on a side wall of the other shell. FIGS. 8-9 and 10 - 11 respectively illustrate two embodiments of the shell body 17 that respectively have a protrusion and a snap-fitting ring. The shell body 17 of FIG. 9 can be mated with the shell body 18 of FIG. 12 .
In the above embodiments, the raised projections 25 are located on the interior walls of the shell bodies 17 and 18 of the non-metallic shell 12 to prevent a thermal contact between the shell 12 and the metal cavity body. The amount of surface area covered by the raised projections 25 can vary as long as the thermal contact between the shell 12 and the metal cavity body can be prevented. In one embodiment, the raised projections 25 extend along a long edge of a rectangle and form spaced rows on an interior wall of a major cover surface of the shell bodies 17 and 18 . The raised projections 25 may also be located on a side wall of the major cover surface of the shell bodies 17 and 18 .
As shown in FIGS. 3-5 and 13 , the metal cavity body of the exhaust muffler device 8 is formed by stamping and subsequent welding of a metal material. A preferred metal material is 08AL or other relatively thin metal sheets or metal alloys suitable for deep-stamping. A baffle 13 is mounted transversely inside the metal cavity body between the upper cavity 9 and the lower cavity 10 ( FIGS. 6 and 13 ). In another embodiment, the baffle 13 can be mounted vertically inside the metal cavity body between the upper cavity body 9 and the lower cavity body 10 (not shown), as long as the baffle 13 can partition the cavity defined by the metal cavity body. It is to be understood that the baffle 13 may not be required in situations where the compressor as a whole is relatively quiet during operation. The baffle 13 may have two small holes 33 and 34 as shown in FIG. 13 . One is a gas flow buffer hole 33 , and the other is an exhaust pipe installation hole 34 . The diameter of the gas flow buffer hole 33 is smaller than the diameter of the exhaust pipe installation hole 34 . High-temperature-high-pressure gas from a compressor cylinder enters the inside of the upper cavity body 9 of the metal cavity body via a gas intake pipe (not shown). The gas intake pipe is connected to the upper cavity body 9 through a gas intake pipe installation hole thereof. The intake gas is decompressed and enters the inside of the lower cavity body 10 through the gas flow buffer hole 33 on the baffle 13 . The gas is further decompressed inside the lower cavity body 10 , flows upward through an exhaust pipe 15 mounted in the exhaust pipe installation hole 34 of the baffle 13 , through other pipes inside a compressor housing 26 to be discussed further below, and flows out of the compressor.
The gas flow buffer hole 33 of the baffle 13 has a diameter of 2.0 mm to 4.0 mm. The exhaust pipe installation hole 34 of the baffle 13 has a diameter of 3.0 mm to 7.0 mm.
As shown in FIGS. 13 and 14 , the compressor housing 26 is a hermetically sealed refrigeration compressor using the exhaust muffler device 8 . The compressor housing 26 includes a compressor cylinder block 14 , a crankshaft piston connecting rod assembly 21 , a valve assembly 22 , an intake muffler chamber assembly 23 , an electric motor 24 , and the exhaust muffler device 8 . The electric motor 24 is located on the bottom inside the compressor housing 26 . The compressor cylinder block 14 is located above the electric motor 24 . The crankshaft piston connecting rod assembly 21 connects to the valve assembly 22 via the compressor cylinder block 14 . The compressor cylinder cover 20 is disposed on an end of the valve assembly 22 . The intake muffler chamber assembly 23 and the valve assembly 22 are disposed adjacent with each other and are inside the compressor housing 26 . The exhaust muffler device 8 is located outside the compressor cylinder block 14 and is separated from the compressor cylinder block 14 . A non-metallic shell such as, for example, the shell 12 in FIG. 6 , is mounted at the outside of the metal cavity body of the exhaust muffler device 8 .
A gas intake pipe extends through the gas intake pipe installation hole on the exhaust muffler device 8 . The gas intake pipe connects to the compressor cylinder cover 20 via a gas intake connection pipe 19 . The exhaust pipe 15 extends through an exhaust pipe installation hole on the exhaust muffler device 8 and connects to an internal high-pressure exhaust pipe 16 inside the compressor housing 26 .
The exhaust muffler device 8 is mounted vertically inside the compressor housing 26 .
As shown in FIG. 14 , the exhaust muffler device 8 is vertically disposed, and the gas flow into and out of the exhaust muffler device 8 is also in the same vertical direction. In the embodiment shown in FIGS. 6 and 13 , the baffle 13 is mounted horizontally inside the metal cavity body between the upper cavity body 9 and the lower cavity body 10 . It is to be understood that the exhaust muffler device 8 may be mounted horizontally or vertically, and the exhaust gas may flow horizontally. It is also to be understood that various connection methods can be envisioned and will not be described in detail.
Further, inside the compressor housing 26 , a gas intake pipe and an exhaust pipe can be connected to the exhaust muffler device 8 using conventional butt joints or using the connection configuration shown in FIGS. 15-17 . As shown in FIGS. 15-17 , a gas intake connection pipe 29 is oriented horizontally. One end of the gas intake connection pipe 29 is connected to a gas intake pipe on the exhaust muffler device 8 , and the other end is welded to an annular exhaust connection ring 31 on the compressor cylinder cover 20 . A circular gas flow passage 27 is defined in the center of the annular exhaust connection ring 31 and is in fluid communication with a gas flow passage 28 of the gas intake connection pipe 29 . Gas can flow through the circular gas flow passage 27 smoothly after installation of a compressor cylinder cover screw 30 thereon. The circular gas flow passage 27 of the annular exhaust connection ring 31 is in fluid communication with a gas flow passage 32 on the compressor cylinder cover 20 .
In the embodiments described herein, the non-metallic shell 12 made of a non-metallic material is mounted on the outside of the metal cavity body of the exhaust muffler device 8 . The non-metallic material possesses superior heat insulating properties, thereby can significantly reduce heat transfer from the exhaust gas to the inside of the compressor. The raised projections 25 located on the interior walls of non-metallic shell 12 can prevent the contact between the metal cavity body and the non-metallic shell 12 and reduce heat transfer from the metal cavity body to the non-metallic shell 12 . As a result, heat transfer from high-temperature-high-pressure gas produced by the compressor cylinder to the refrigerant inside the compressor housing can be reduced. The exhaust muffler device 8 is disposed outside of the compressor cylinder block 14 . This can greatly reduce heat transfer during operation of the compressor since heat transfer between the compressor cylinder block 14 and the exhaust muffler device 8 is reduced. Hot compressed gas exiting the compressor cylinder flows through the exhaust pipe 15 and the internal high pressure exhaust pipe 16 and is effectively expelled to the outside of the compressor. Negative impact of hot gas on the compressor can be reduced and cooling performance of the compressor can be significantly improved. The exhaust muffler device of the present disclosure is suitable for use with a hermetically sealed refrigeration compressor, particularly a small-sized hermetically sealed refrigeration compressor.
The above disclosure is only intended to illustrate the preferred embodiments of the present invention and is not intended to limit the scope of the present invention. Therefore any equivalent changes made based on the disclosure of the present invention, such as improvements on the process parameters or the apparatus, are still within the protective scope of the present invention. | A discrete, heat-insulating exhaust muffler device ( 8) and a refrigeration compressor using the exhaust muffler device are provided. The exhaust muffler device ( 8) includes a metal cavity body defining cavities ( 9, 10), and intake pipe and exhaust pipe installation holes respectively arranged on the cavities ( 9, 10). Non-metallic shell bodies ( 17, 18) are further arranged outside the cavities ( 9, 10), and the exhaust muffler device ( 8) is disposed outside cylinder blocks ( 14) and is separated from the cylinder blocks ( 14). By disposing a layer of the non-metal shell bodies ( 17, 18) outside the metal cavity body ( 9, 10), thermal contact between exhaust gas and gas inside a compressor can be reduced owing to a better heat-insulating effect of the non-metallic material, thereby reducing heat transfer from the metal cavity body ( 9, 10) to the outside. The gas inside the compressor can have a relatively lower temperature, and the efficiency of the compressor is improved. The metal cavity body ( 9, 10) are formed by stamping, thereby reducing material cost and the weight of the device, simplifying the manufacturing process, and leaving more room at the periphery of the cylinder blocks ( 14). |
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/383,192, filed May 12, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to manufacture of heat dissipation devices, and more specifically, to manufacture of embedding a heat pipe into a seat.
BACKGROUND OF THE INVENTION
[0003] FIG. 1 shows a U-shaped heat pipe pressed. The heat pipe 1 a has an evaporation section 10 a . The bottom of the evaporation section 10 a must be pressed to form a flat heated surface 100 a for directly and planarly touching a heat source. During the pressing process, the stamping die must have a flat plane. When a plane of the stamping die initially meets a curved surface of the heat pipe 1 a , the touch portion will be linear and then become planar. However, the initially linear touch tends to invite a problem of stress concentration. Therefore, a recess 101 a often forms on the heated surface 100 a of the heat pipe 1 a . When once the recess 101 a appears, an additional grinding procedure after pressing will be necessary for effacing the recess 101 a.
[0004] This problem can be solved by adopting a multi-stroke progressive pressing procedure. This procedure can progressively press the pipe to be flat, but it must use various stamping dies with different recessing depth or shapes. Meanwhile, only one stamping die can be used to press the pipe at some time. Thus, during the pressing process those stamping dies must be changed one by one in order to ensure the flatness of the pipe being pressed. It is very inconvenient and uneconomical for the manufactures.
SUMMARY OF THE INVENTION
[0005] An object of the present invention is to provide a new and improved method, which can embed a heat pipe into a slot of a seat and form a flat plane on the heat pipe at the same time without changing stamping dies.
[0006] To accomplish the object abovementioned, one preferred embodiment of the invention includes the steps of:
[0007] a) preparing a heat pipe and a heat-conducting seat having a slot;
[0008] b) disposing the heat pipe in the slot;
[0009] c) arranging the heat pipe with the heat-conducting seat on a power press machine, wherein the power press machine has:
[0010] a bolster bed for being placed by the heat pipe with the heat-conducting seat; and
[0011] a ram over the bolster bed, having a plurality of stamping dies, each of the stamping dies having a pressing surface, wherein one of the pressing surfaces is a flat plane, and each of the others has a recess sequentially with different depth; and
[0012] d) pressing the heat pipe deposed in the slot sequentially with each of the stamping dies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The object, features and advantages of the invention will become readily apparent to those skilled in the art upon reading the description of the exemplary embodiment, in conjunction with the attached drawings, in which:
[0014] FIG. 1 shows a heat pipe with a plane pressed by conventional method;
[0015] FIG. 2 is a flowchart of the method according to the present invention;
[0016] FIG. 3 is an exploded view of the heat pipes, heat-conducting seat and holder;
[0017] FIGS. 4 and 5 illustrate how the heat pipe passes through the heat-conducting seat and the holder;
[0018] FIG. 6 is a partially sectional view showing the heat pipe in the slot;
[0019] FIG. 7 illustrates a perspective view of the power press machine;
[0020] FIG. 8 shows how the holder is mounted on the working area of the bolster bed;
[0021] FIG. 9 shows the holder with the heat pipe and heat-conducting seat, which is mounted on the power press machine;
[0022] FIGS. 10A-D sequentially illustrate the progressive status for the heat pipe pressed by different stamping dies; and
[0023] FIG. 11 shows a heat pipe pressed by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] Referring to FIG. 2 , which shows a flowchart of the invention, the present invention provides a method for embedding a heat pipe into a heat-conducting seat.
[0025] Referring to FIGS. 2 and 3 , step S 1 of the method provides at least one heat pipe 1 and a heat-conducting seat 2 for coupling with the heat pipe 1 . FIG. 2 shows an embodiment in which there are 3 heat pipes 1 , but those skilled in the art must know the number of the heat pipes 1 can vary for practical requirements. The bottom 20 of the heat-conducting seat 2 has slots 21 for accommodating an evaporation section 10 of the heat pipes 1 .
[0026] Step S 2 of the method disposes the evaporation section 10 of the heat pipes 1 in the slots 21 of the heat-conducting seat 2 . Both the heat pipes 1 and the heat-conducting seat 2 are fixed on a holder 3 . As shown in FIGS. 4 and 5 , the holder 3 may have a through hole 30 for accommodating the condensation section 11 of the heat pipes 1 . Further referring to FIG. 6 , the slot 21 is of a C shape. A part of the heat pipe 1 is higher than the bottom 20 of the heat-conducting seat 2 and protrudes from the slot 21 when the heat pipe 1 is accommodated in the slot 21 . The protrusive portion of the heat pipe 1 is just the portion which will be pressed in later steps. Additionally, as shown in FIG. 3 , the holder 3 may preferably has one or more handles 32 for conveniently being held by a user.
[0027] Referring to FIGS. 2 and 7 , step S 3 of the invention arranges the holder 3 on a power press machine 4 . The holder 3 includes a bolster bed 40 and a ram 41 over it. There are a plurality of working areas for positioning the holder 3 on the bolster bed 40 . In a preferred embodiment as shown in FIG. 7 , there are a first working area 400 , a second working area 401 , a third working area 402 and a fourth working area 403 . These working areas 400 - 403 are arranged in a row. Each of the working areas 400 - 403 has two positioning bars 400 a - 403 a responding to grooves 31 on the holder 3 as shown in FIG. 8 , so that the holder 3 can be precisely mounted on each working area 400 - 403 of the bolster bed 40 . Moreover, one or more receiving holes 400 b , 401 b , 402 b and 403 b , which can accommodate excessive portion of the heat pipe 1 , are disposed on each working area 400 - 403 . The holder 3 is not a necessary element. The heat pipe 1 and heat-conducting seat 2 may also be directly mounted on the bolster bed 40 if there is a particular arrangement between them.
[0028] The ram 41 of the power press machine 4 is used for downward pressing a material on the bolster bed 40 . There are a plurality of stamping dies 410 - 413 under the ram 41 . In a preferred embodiment as shown in FIG. 9 , the number of the stamping dies 410 - 413 is four, i.e. first, second, third and fourth stamping die. Those stamping dies 410 - 413 are corresponding to the working areas 400 - 403 , respectively.
[0029] FIGS. 10A-10D shows the differences among the stamping dies 410 - 413 . Each of the stamping dies 410 - 413 has a pressing surface 410 a - 413 a , wherein the fourth pressing surface 413 a is a flat plane as shown in FIG. 10D , and the first, second and third pressing surfaces 410 - 412 separately have a recess 410 b - 412 b with different depth from deep to flat. Additionally, a plurality of guiding rods 414 downward extend from the ram 41 . The guiding rods 414 are corresponding to guiding holes 404 on the bolster bed 40 for providing necessary pressing depth of the guiding rods 414 .
[0030] Step S 4 of the invention sequentially presses the heat pipe 1 with different stamping dies 410 - 413 by means of moving the heat pipe 1 onto different working areas 400 - 403 . In other words, the holder 3 holding both the heat pipe 1 and the heat-conducting seat 2 is moved sequentially from the first working area 400 to the fourth working area 403 after one of the stamping dies 410 - 413 corresponding to heat pipe 1 on the holder 3 has pressed the heat pipe 1 once. For example, the first stamping die 410 presses the heat pipe 1 on the holder 3 mounted on the first working area 400 . Then, the holder 3 is moved to the second working area 401 for being pressed by the second stamping die 411 . Therefore, the heat pipe 1 being pressed by the stamping dies 410 - 413 can be progressively transformed to form a flat plane 100 as shown in FIG. 11 .
[0031] While exemplary embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention. | A method for embedding a heat pipe into a slot of heat-conducting seat is disclosed. The method has the exposed portion of the heat pipe be flat and coplanar with the surface of the heat-conducting seat after the heat pipe is embedded into the slot of the seat. The method utilizes a power press machine with multiple stamping dies to progressively press the heat pipe. |
FIELD
[0001] The present disclosure relates to high pressure pump control.
BACKGROUND
[0002] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
[0003] Referring now to FIG. 1 , a functional block diagram of an engine system 100 is shown. Air is drawn into an engine 102 through an intake manifold 104 . A throttle valve 106 is actuated by an electronic throttle control (ETC) motor 108 to vary the volume of air drawn into the engine 102 . The air mixes with fuel from one or more fuel injectors 110 to form an air-fuel mixture. The air-fuel mixture is combusted within one or more cylinders 112 of the engine 102 . Resulting exhaust gas is expelled from the cylinders to an exhaust system 113 .
[0004] Fuel is supplied to the engine 102 by a fuel system. For example only, the fuel system may include the fuel injectors 110 , a fuel tank 114 , a low pressure pump 115 , a high pressure pump 116 , and a fuel rail 118 . Fuel is stored within the fuel tank 114 . The low pressure pump 115 draws fuel from the fuel tank 114 and provides fuel to the high pressure pump 116 . The high pressure pump 116 provides pressurized fuel to the fuel injectors 110 via the fuel rail 118 .
[0005] An engine control module (ECM) 120 receives a rail pressure signal from a rail pressure sensor 122 . The rail pressure signal indicates the pressure of the fuel within the fuel rail 118 . The ECM 120 controls the amount and the timing of the fuel injected by the fuel injectors 110 . The rail pressure decreases each time fuel is injected by one or more of the fuel injectors 110 . The ECM 120 maintains the rail pressure via the high pressure pump 116 .
[0006] The speed of the engine 102 is measured by a revolutions per minute (RPM) sensor 124 . The RPM sensor 124 provides the ECM 120 with the measured RPM.
SUMMARY
[0007] An engine control system comprises an engine speed monitoring module and a pump control module. The engine speed monitoring module compares an engine speed and a predetermined threshold. The pump control module deactivates a pressure pump based on the comparison. In further features, the engine speed monitoring module determines whether the engine speed is less than or equal to the predetermined threshold, and the pressure pump is deactivated based on the determination. In other features, the engine control system further comprises a fuel injector control module that adjusts a timing of actuation of a fuel injector based on the comparison.
[0008] In other features, the engine control system further comprises a fuel injector control module that adjusts a length of time of actuating a fuel injector based on the comparison. In still other features, the pump control module deactivates the pressure pump by adjusting a valve. In still other features, the engine speed monitoring module compares the engine speed to a second predetermined threshold, and the pump control module suspends deactivating the pressure pump when the engine speed is greater than or equal to the second predetermined threshold.
[0009] In other features, the engine speed monitoring module additionally compares an engine speed idle time and a predetermined period of time, and the pump control module deactivates the pressure pump based on the additional comparison. In other features, the engine speed monitoring module determines whether the engine speed idle time is greater than or equal to the predetermined period of time, and the pressure pump is deactivated based on the determination.
[0010] An engine control method comprises comparing an engine speed and a predetermined threshold, and deactivating a pressure pump based on the comparison. In further features, the engine control method further comprises determining whether the engine speed is less than or equal to the predetermined threshold, and deactivating the pressure pump based on the determination. In further features, the engine control method further comprises adjusting a timing of actuation of a fuel injector based on the comparison.
[0011] In other features, the engine control method further comprises adjusting a length of time of actuating a fuel injector based on the comparison. In other features, the engine control method further comprises deactivating the pressure pump by adjusting a valve In other features, the engine control method further comprises comparing the engine speed to a second predetermined threshold, and suspending deactivation of the pressure pump when the engine speed is greater than or equal to the second predetermined threshold.
[0012] In other features, the engine control method further comprises additionally comparing an engine speed idle time and a predetermined period of time, and deactivating the pressure pump based on the additional comparison. In other features, the engine control method further comprises determining whether the engine speed idle time is greater than or equal to the predetermined period of time, and deactivating the pressure pump based on the determination.
[0013] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0015] FIG. 1 is a functional block diagram of an engine system;
[0016] FIG. 2 is a functional block diagram of an exemplary engine system according to the principles of the present disclosure;
[0017] FIG. 3 is an exemplary implementation of the engine control module 208 of FIG. 2 according to the principles of the present disclosure; and
[0018] FIG. 4 is a flowchart that depicts exemplary steps performed in deactivating the high pressure pump 202 of FIG. 2 according to the principles of the present disclosure.
DETAILED DESCRIPTION
[0019] The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.
[0020] As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
[0021] A high pressure pump supplies pressurized fuel to a fuel rail. Fuel injectors are connected to the fuel rail and inject the pressurized fuel into a cylinder. The pressure within the fuel rail decreases as the fuel injectors inject more fuel. The rail pressure is monitored to determine whether the high pressure pump may supply more pressurized fuel.
[0022] The high pressure pump of the present disclosure is deactivated based on speed of an engine. When the high pressure pump is deactivated, the pressure within the fuel rail is not maintained. Fuel is supplied to the fuel rail by a low pressure pump and the pressure within the fuel rail decreases. The amount and timing of the fuel injected by the fuel injectors are modified to accommodate for the change in pressure.
[0023] Referring now to FIG. 2 , a functional block diagram of an engine system 200 according to the principles of the present disclosure is shown. A high pressure pump 202 provides pressurized fuel to fuel injectors 204 via the fuel rail 118 . The high pressure pump 202 is controlled by a pump control module 206 that may be located within an ECM 208 .
[0024] The pump control module 206 receives a rail pressure signal from a rail pressure sensor 210 . The rail pressure signal indicates the pressure of the fuel within the fuel rail 118 . A fuel injector control module 212 controls the amount and the timing of the fuel injected by the fuel injectors 204 . The rail pressure decreases each time fuel is injected by one or more of the fuel injectors 204 . The pump control module 206 maintains the rail pressure via the high pressure pump 202 . The pressure of the fuel exiting the high pressure pump 202 may be greater than the pressure of the fuel exiting the low pressure pump 115 . For example only, the pressure of the fuel exiting the high pressure pump 202 may be between 2-26 Mpa, while the pressure of the fuel exiting the low pressure pump 115 may be between 0.3-0.6 Mpa.
[0025] The high pressure pump 202 includes a valve (not shown) that controls the pressure of fuel exiting the high pressure pump 202 . When the valve is fully open, the pressure of the fuel exiting the high pressure pump 202 is the same as the pressure of the fuel entering the high pressure pump 202 . By adjusting the valve to a position that is less than fully open, the pressure of the fuel exiting the high pressure pump 202 increases. The pump control module 206 may deactivate the high pressure pump 202 . For example only, the high pressure pump 202 may be deactivated by adjusting the valve to the fully open position.
[0026] When the high pressure pump 202 is deactivated, the fuel injector control module 212 adjusts the amount and the timing of the fuel injected by the fuel injectors 204 . For example, the pump control module 206 may generate a deactivation signal when the high pressure pump 202 is deactivated. The fuel injector control module 212 may adjust the amount and the timing of the fuel injected by the fuel injectors based on the deactivation signal.
[0027] The speed of the engine 102 is measured by a revolutions per minute (RPM) sensor 214 . The RPM sensor 214 provides the ECM 208 with the measured RPM. For example, the RPM sensor 214 may generate a RPM signal. The pump control module 206 receives the RPM signal from the RPM sensor 214 . Based on the RPM signal, the pump control module 206 may deactivate the high pressure pump 202 . For example only, the high pressure pump 202 may be deactivated when the RPM signal indicates that the RPM is less than or equal to a predetermined threshold. For example, if the high pressure pump 202 is deactivated, then the pump control module 206 generates a deactivation signal.
[0028] The fuel injector control module 212 modifies the timing and amount of fuel injected by the fuel injectors 204 when the deactivation signal is generated. The pump control module 206 resumes controlling the high pressure pump 202 and suspends generating the deactivation signal when the RPM is greater than the predetermined threshold.
[0029] Referring now to FIG. 3 , an exemplary implementation of the engine control module of FIG. 2 according to the principles of the present disclosure is shown. The pump control module 206 includes a pump actuation module 300 and an engine speed monitoring module 302 . The pump actuation module 300 controls actuation of the high pressure pump 202 based on rail pressure. The engine speed monitoring module 302 monitors the RPM signal.
[0030] The engine speed monitoring module 302 determines whether the RPM signal indicates that the RPM is less than or equal to a predetermined threshold. If the RPM is less than or equal to the predetermined threshold, then the engine speed monitoring module 302 generates a deactivation signal. In various implementations, the engine speed monitoring module 302 may generate the deactivation signal when the RPM is idle for at least a predetermined amount of time.
[0031] The engine speed monitoring module 302 may generate the deactivation signal until the RPM is greater than a second predetermined threshold. In various implementations, the second predetermined threshold may be equal to the predetermined threshold. The pump actuation module 300 and a fuel injector timing module 304 receive the deactivation signal.
[0032] The pump actuation module 300 suspends actuation of the high pressure pump 202 when the deactivation signal is generated. The pump actuation module 300 may suspend actuation of the high pressure pump 202 based on the deactivation signal. When actuation of the high pressure pump 202 is suspended, the pressure within the fuel rail 118 decreases.
[0033] The fuel injector timing module 304 may be located within the fuel injector control module 212 . The fuel injector timing module 304 controls the amount and the timing of the fuel injected by the fuel injectors 204 . For example only, the fuel injector timing module 304 may generate a fuel signal to control the opening of the fuel injectors 204 . By changing the timing of generating the fuel signal and the pulse width of the fuel signal, then the amount and timing of fuel injection changes. When the deactivation signal is generated, the fuel injector timing module 304 modifies the amount and the timing of the fuel injected by the fuel injectors 204 .
[0034] The fuel injector timing module 304 may continue modifying the generation of the fuel signal until the engine speed monitoring module 302 suspends generating the deactivation signal. When the deactivation signal is suspended, then the fuel injector timing module 304 may resume controlling the fuel injectors 204 as before the modifications to the fuel signal.
[0035] Referring now to FIG. 4 , a flowchart that depicts exemplary steps performed in deactivating the high pressure pump 202 of FIG. 3 according to the principles of the present disclosure. Control begins in step 400 where an engine is started. In step 402 , control activates a high pressure pump. In step 403 , control activates a fuel injector. In step 404 , control monitors engine speed.
[0036] In step 406 , control determines whether the engine speed is less than a predetermined threshold. If control determines that the engine speed is less than the predetermined threshold, then control transfers to step 408 ; otherwise, control transfers to step 410 . In step 408 , control deactivates the high pressure pump. In step 412 , control changes fuel injector timing. In step 414 , control changes fuel injector pulse width.
[0037] In step 410 , control monitors fuel rail pressure. In step 416 , control determines whether the fuel rail pressure is less than a predetermined threshold. If control determines that the fuel rail pressure is less than the predetermined threshold, then control transfers to step 418 ; otherwise, control returns to step 410 .
[0038] In step 418 , control actuates the high pressure pump. In step 420 , control determines whether the engine is off. If control determines that the engine is off, then control ends; otherwise, control returns to step 404 .
[0039] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims. | An engine control system comprises an engine speed monitoring module and a pump control module. The engine speed monitoring module compares an engine speed and a predetermined threshold. The pump control module deactivates a pressure pump based on said comparison. |
BACKGROUND OF THE INVENTION
The present invention relates to method for machining or turning surfaces of revolution at workpieces preferably at crankshafts, whereby the workpiece is rotated during machining, and wherein a disk-shaped tool that is provided with cutting elements at its circumferential edge for roughing of the workpiece and subsequent finishing of the workpiece is used. The tool for performing the method is provided with cutting elements for the roughing process and with cutting elements for the finishing process.
In the machining of crankshafts it is known from European Patent 0 211 216 and German Offenlegungschrift 35 23 274 to perform a roughing process of the crankshaft by radially plunge-cutting by turning with a formed cutter. Subsequent to this roughing process, the finishing process of the crankshaft is performed by turning broaching in which the crankshaft is rotated at a relatively high speed while the disk-shaped tool is rotated at a relatively low speed. For each individual width of a crankshaft pin, special cutters for the turning broaching of the finishing process must be employed since the cutting edges extend at an angle relative to the axis of rotation of the tool and furthermore must be embodied in a dished fashion. The cutting elements which must be special ordered are manufactured only in small quantities and are provided with only two cutting edges. Correspondingly, the cutting element costs for the broaching turning step of the finishing process are high. In order to produce cylindrical pins, the tool must further be provided with complicated plate seats for the cutting elements used for the broaching turning process. During broaching turning the cutting edges penetrate at a very great negative angle into the crankshaft resulting in very high normal forces. This results in an increased wear at the cutting edges of the cutting elements and in an increased bending of the crankshaft during the turning broaching process. As a consequence, during broaching turning processes a rattling tendency is observed which leads to a reduced accuracy of the cutting process. Furthermore, during the machining of steel in a turning broaching process long, curled cuttings are produced which inhibit a reliable flow of cuttings within the tool and the machine. Especially with automated machines the removal of these long, curled cuttings is difficult and expensive. These long, curled cuttings furthermore differ considerably with variations of the excess material to be removed.
It is therefore an object of the present invention to provide a method and a disk-shaped turning tool of the aforementioned kind in which as the cutting elements commercially available cutting plates that are made of various cutting materials may be employed and with which the workpiece may be machined during the finishing operation such that at low cutting material costs and with a reliable removal of cuttings a high precision cutting of the workpiece may be accomplished, while low cutting pressures will be generated.
BRIEF DESCRIPTION OF THE DRAWINGS
This object, and other objects and advantages of the present invention, will appear more clearly from the following specification in conjunction with the accompanying drawings, in which:
FIG. 1 is a side view of a portion of the inventive disk-shaped turning tool;
FIG. 2 is a developed projection of the cutting element arrangement of the turning tool according to FIG. 1;
FIG. 3 is a schematic representation of the machining of a crankshaft pin by various cutting elements of the turning tool according to FIG. 1;
FIG. 4 is a side view of a crankshaft pin which is finished with the inventive turning tool;
FIG. 5 is a schematic representation of the cutting elements of the inventive turning tool used for the of the crankshaft pin;
FIG. 6 is a developed projection of the turning tool with the cutting elements used for the finishing operation;
FIG. 7 demonstrates the engagement between tool and workpiece according to the inventive method for finishing the crankshaft pins; and
FIG. 8 is a representation corresponding to FIG. 7 showing the engagement between tool and a crankshaft pin during finishing according to the prior art.
SUMMARY OF THE INVENTION
The method for machining surfaces of revolution at workpieces according to the present invention is primarily characterized by the steps of:
Rotating the workpiece during machining;
roughing the workpiece with a disk-shaped tool having at is circumferential edge cutting elements with cutting edges; and,
for finishing the workpiece, plunge-cutting by turning the workpiece with the disk-shaped tool wherein the step of plunge-cutting by turning is divided into a sequence of individual plunge-cutting by turning steps so that material of overlapping portions of the workpiece is removed sequentially.
In the inventive method the finishing process is not carried out by a turning broaching step, but by a plunge-cutting by turning step in which the disk-shaped tool during the finishing operation is not rotated about its axis. For plunge-cutting by turning process commercially available, constructively simple turnplates may be employed which have a triangular or tetragonal shape with three or four cutting edges. Accordingly, when the inventive method is employed and the inventive tool is used for the inventive method the cutting material costs are very low. The constructively simple turn plates for the use as cutting elements require only simple plate seats at the tools so that the manufacture of the tool is simple and inexpensive. Due to the division of the plunge-cutting by turning step into individual plunge-cutting by turning steps an identical cutting width and thus also an identical width of the resulting cuttings for different end of the formation of the cuttings, does not occur, so that the plunge-cutting edges are not excessively worn. With the inventive method and the inventive tool crankshafts, drive shafts, and other workpiece surfaces that are rotational symmetrical may be machined.
In a preferred embodiment of the present invention, the sequence of the individual plunge-cutting by turning steps further comprises the steps of positioning the cutting element for the individual plunge-cutting by turning step with its cutting edge on an imaginary connecting line between the axis of rotation of the workpiece and the axis of rotation of the disk-shaped tool; and moving the cutting element into engagement with the workpiece. Preferably, the sequence further comprises the steps of: after completion of each individual plunge-cutting by turning step, radially removing the disk-shaped tool from engagement with the workpiece; and subsequently, rotating the disk-shaped tool about its axis of rotation until a further one of the cutting elements reaches the connecting line, followed by the step of moving the cutting element into engagement. It is also possible to simultaneously end of the formation of the cuttings, does not occur, so that the plunge-cutting edges are not excessively worn. With the inventive method and the inventive tool crankshafts, drive shafts, and other workpiece surfaces that are rotational symmetrical may be machined.
In a preferred embodiment of the present invention, the sequence of the individual plunge-cutting by turning steps further comprises the steps of positioning the cutting element for the individual plunge-cutting by turning step with its cutting edge on an imaginary connecting line between the axis of rotation of the workpiece and the axis of rotation of the disk-shaped tool; and moving the cutting element into engagement with the workpiece. Preferably, the sequence further comprises the steps of: after completion of each individual plunge-cutting by turning step, radially removing the disk-shaped tool from engagement with the workpiece; and subsequently, rotating the disk-shaped tool about its axis of rotation until a further one of the cutting elements reaches the connecting line, followed by the step of moving the cutting element into engagement. It is also possible to simultaneously radially remove and rotate the disk-shaped tool about its axis of rotation until a further one of the cutting elements reaches the connecting line.
The disk-shaped tool for performing the inventive method is comprised of a disk-shaped base body with a circumferential edge; and a first set and a second set of cutting elements, connected to and distributed over the circumferential edge, the first set for a roughing process and the second set for a finishing process by plunge-cutting by turning, with the cutting elements of the second set being spaced at a distance from one another in the circumferential direction of the tool and axially staggered such that, when viewed in the circumferential direction of the tool, the working areas of the cutting elements overlap. Preferably the cutting elements have cutting edges that extend parallel to the axis of rotation of the tool. Advantageously the cutting elements are turn plates. In a preferred embodiment, each cutting element has at least two cutting edges. Preferably, the tool comprises flat contact surfaces (plate seats) at the circumferential edge for receiving the cutting elements.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described in detail with the aid of several specific embodiments utilizing FIGS. 1 through 8.
During the machining of crankshafts it is known to machine the cylindrical surfaces (lift bearing and main bearing) during the roughing step by a turning process and during the finishing step by a turning broaching process. For this purpose, the crankshaft 1 is rotated at a high speed about the axis of the lift bearing or main bearing while the turning broaching tool 2 (FIG. 8) is rotated at a low speed in a counter clockwise or clockwise direction. The dash-dotted line in FIG. 8 represents the initial diameter of the crankshaft pin, which after completion of the turning broaching process, corresponds to the diameter indicated by a solid line. During the first engagement of the cutting edge 3 of the turning broaching tool with the crankshaft 1 the cutting angle γ r corresponds approximately to 5°, while the effective cutting angle γ re corresponds to approximately 30°. During the removal of excess material at the crankshaft 1 the effective cutting angle changes constantly until at the end of the turning broaching process it is identical to the cutting angle γ r . At this point, the cutting edge 4 of the cutting element 3 is positioned on the connecting line 5 between the axis of rotation 6 of the crankshaft 1 and the non-represented axis of rotation of the tool 2. Since the effective cutting angle γ re constantly changes during the turning broaching process, optimal cutting conditions may not be achieved. At the beginning of the turning broaching process the cutting element 3 penetrates the crankshaft 1 at a negative angle, as represented in FIG. 8. Accordingly, a high nominal force is generated resulting in a very strong cutting edge wear at the cutting element 3. This wear in combination with the high normal force results in an increased bending of the crankshaft 1 during the turning broaching process. As a consequence a rattling tendency is observed during the turning broaching process which also leads to a loss in precision during machining.
These disadvantages may be prevented by performing the finishing operation of the crankshaft exclusively by a plunge-cutting by turning process. FIG. 7 shows schematically how the cutting element 13 of the turning tool with its cutting edge 14 penetrates the crankshaft 11 at the connecting line 15 between the axis of rotation 16 of the crankshaft 11 and the non-represented axis of rotation of the turning tool. Independent of the amount of excess material that already has been removed, the position of the cutting element 13 relative to the crankshaft 11 remains unchanged, i.e., the cutting angle γ r always corresponds to the effective cutting angle γ re . Accordingly, during the entire finishing process, the same engagement between the cutting elements and the workpiece is present so that during the entire machining process the optimal cutting conditions are maintained. The front clearance angle 17 of the cutting element 13 may be very small so that the wedge angle 18 enclosing the cutting edge 14 may be correspondingly great. The cutting element 13 may thus be provided with an optimal cutting geometry. The front clearance angle 17 of the cutting element 3 of the turning broaching tool 2 is substantially greater so that the wedge angle of the cutting element in the area of the cutting edge is substantially smaller and the cutting element thus has a reduced stability.
FIGS. 1 and 2 show in an exemplary manner a portion of the turning tool 12. At the circumferential edge cutting elements 19 to 26 are provided one after another in the circumferential direction via which different machining steps may be performed at the crankshaft 11. The cutting elements 24 to 26 perform the finishing operation of the crankshaft pin 27. The cutting elements 19 to 26 form a cutting element array. At the circumferential edge of the turning tool 12 a plurality of such cutting element array are provided so that the turning tool 12 has a long service life.
FIG. 3 shows in an exemplary manner how in a turning process the crankshaft 11 may be machined with the individual cutting elements 19 to 26. Only the circumferential surface of the pin 27 of a crankshaft 11 is schematically represented as are the adjacent collars 28 and 29. In the upper left representation of FIG. 3 the blank of a crankshaft pin 27 is represented in a dash-dotted line. The pin 27 is machined further with the plunge-cutting by turning process until the shape represented by a solid line in FIG. 3 has been reached. In a first step the collars 28, 29 of the crankshaft pin 27 are machined with the cutting elements 19 located at the sides of the disk-shaped turning tool 12 (FIG. 1). After completion of this first turning operation, the turning tool 12 is radially removed, rotated in the direction of the arrow 30 (FIG. 1), and is then radially displaced to engage the crankshaft 11. In the following step, the cutting element 20 roughs the center section of the crankshaft pin 27 with the turning tool 12 remaining stationary and the crankshaft 11 being rotated.
After the completion of this second turning operation the turning tool 12 is again radially removed from the crankshaft 11, rotated in the direction of the arrow 30, and moved back into engagement with the crankshaft 11. In this manner, the cutting elements 21 to 23 are subsequently brought into engagement with the crankshaft 11 (FIG. 3). With the cutting elements 21 and 22 the crankshaft pin 27 is roughed over its entire length until the final diameter has approximately been reached.
In a subsequent turning operation the cutting elements 23 are brought into engagement with the crankshaft 11. The cutting elements 23 are arranged opposite one another on either side of the disk-shaped turning tool 12 (FIG. 2). With the cutting elements 23 the collars 28 and 29 at the transition of the crankshaft pin 27 to the lateral webs are machined and, if necessary, the recesses 31 and 32 are also machined.
After completion of the different turning steps with the cutting elements 19 to 23 the crankshaft pin 27 is approximately formed according to the desired final shape. The crankshaft pin 27 is subsequently finished with the cutting elements 24 to 26 in a finishing operation carried out by plunge-cutting by turning. The plunge-cutting elements 24 to 26 are brought into engagement with the crankshaft 11 one after another as represented in FIG. 3. The cutting elements 24 to 26 have cutting edges 33 to 35 (FIGS. 5 and 6) that extend parallel to the plane 15 defined between the axis of rotation 16 of the crankshaft 11 and the non-represented axis of rotation of the turning tool 12. The cutting edges 33 to 35 are one after another aligned in this plane 15. In a first step, the turning tool 12 with its cutting edges 24 to 26 is not engaged with the crankshaft 11. The turning tool 12 is then rotated in the aforedescribed manner in the direction of the arrow 30 until the first cutting element 24 with its cutting edge 33, viewed in the direction of rotation of the crankshaft 11, respectively, of the turning tool 12, is aligned with the plane 15 (FIG. 5). Then, the turning tool 12 is brought into engagement with the crankshaft 11 in the direction of the arrow 36 (FIG. 5). The crankshaft 11 is rotated in the direction of rotation 37 during the finishing operation, while the turning tool 12 remains stationary during the finishing operation. The cutting element 24 is maintained in engagement with the crankshaft 11 parallel to the plane 15 until the desired amount of excess material has been removed from the crankshaft pin 27 and the pin 27 has been provided with the desired radius, respectively, circumference that is indicated as a solid line in FIG. 5.
The width of the cutting element 24 corresponds only to a portion of the length of the crankshaft pin 27. In the represented embodiment, the cutting element 24 is arranged at the circumferential edge of the turning tool 12 such that it extends from one of the sides 38 of the turning tool 12 toward the center plane (FIG. 6).
The subsequently arranged cutting element 25 is spaced at a distance from the cutting element 24, when viewed in the circumferential direction of the turning tool, and is preferably identical to the cutting element 24. Viewed in the circumferential direction of the turning tool the cutting element 25 overlaps the cutting element 24. In the same manner the cutting element 26 is arranged at a distance from the cutting element 25 in the circumferential direction and also overlaps the cutting element 25.
As soon as the desired radius of the crankshaft pin 27 has been machined with the cutting element 24, the turning tool 12 is removed in the radial direction, indicated by arrow 39 in FIG. 5, until the cutting element is disengaged from the crankshaft 11. Subsequently, or simultaneously during removal, the turning tool 12 is rotated in the direction of arrow 30 to such an extent that the following cutting tool 25 with its cutting edge 34 is positioned in the plane 15. The turning tool 12 is then brought into engagement with the crankshaft 11 by being moved in the direction of arrow 36 whereby the cutting edge 34 remains in the plane 15 (FIG. 5). The cutting element 25 is maintained in engagement with the crankshaft pin 27 until the desired radius has been produced. With the cutting element 25 a center section of the mantle surface of the crankshaft pin 27 is machined.
As soon as the finishing operation with the cutting element 25 is complete, the turning tool 12 is rotated in the aforementioned manner so that now the cutting element 26 can machine the remaining portion of the mantle surface of the crankshaft pin 27 in the finishing operation.
Depending on the thickness of the turning tool 12, various numbers of cutting elements may be arranged in the circumferential direction, spaced at a distance and staggered relative to one another. The individual cutting elements may be arranged at a very short distance in the circumferential direction of the turning tool so that very short switching times are required in order to bring these cutting elements into sequential engagement with the crankshaft 11. Accordingly, the crankshaft may be machined by roughing as well as finishing in a very short period of time. Since the turning tool 12 during the entire machining of the crankshaft 11, especially during the finishing operation, is not rotated about its axis, and since the cutting elements 24 to 26 with their cutting edges 33 to 35 are parallel to the axis of rotation of the turning tool 12, and the cutting edges 33 to 35 are positioned in the plane 15 during the finishing operation, viewed in the rotational direction of the crankshaft 11, the cutting geometry remains the same during the entire machining process. Accordingly, a constant precision cutting with high accuracy of the crankshaft 11 is possible. Due to the stepwise finishing operation a small cutting pressure results which can be compensated by the crankshaft 11 to be finished without undue bending. Consequently, the commonly occurring after grinding of the cutting element at the workpiece, observed during turning broaching operations subsequent to the removal of the excess material, is not observed. This after grinding is a direct consequence of the increased normal force generated during turning broaching at the end of the removal process. This high normal force also accounts for a great elastic system loading which must be compensated before the workpiece and the tool may be disengaged. These problems do not occur during the divided plunge-cutting by turning process so that very high rotational speeds of the crankshaft may be achieved. Even for different amounts of excess material to be removed a constant cutting pressure is maintained. Due to the aforedescribed stepped arrangement of the cutting elements 24 to 26, an identical cutting width and thus an identical width of the resulting cuttings is achieved even for different amounts of excess material to removed. Due to the plunge-cutting by turning process only short curled cuttings are produced. Accordingly, the removal of the curled cuttings does not present any difficulties, and the turning tool 12 and the inventive method may also be employed with automated machines.
Since the cutting edges 33 to 35 are parallel to the axis of rotation of the tool 12 a simple adjustment of the cutting edges is possible. As can be taken from FIGS. 5 and 6 the turning tool 12 is provided with flat contact surfaces 40 to 42 for attaching thereto the cutting elements 24 to 26. The contact surfaces 40 to 42 are spaced at a distance one after the other in the circumferential direction of the turning tool 12 and are axially staggered relative to one another. The cutting elements 24 to 26 are connected to these contact surfaces. The contact surfaces 40 to 42 are connected to one another by slanted surfaces 43 and 44 (FIGS. 5 and 6) which in the direction of the axis of rotation of the turning tool 12 extend past the cutting elements 24 to 26 (FIG. 5). Conventional ISO turnplates may be used as cutting elements which are commercially available made from various materials. The cutting elements may be made of hard metals, ceramic materials, Cermet or similar material. The turnplates have a triangular or tetragonal configuration and thus three or four cutting edges which may all be used. Accordingly, very low cutting material costs arise. Due to the simple embodiment of the cutting elements 24 to 26, the respective contact surfaces 40 to 42 at the turning tool 12 are also of a simple embodiment. Since the cutting elements 24 to 26 are arranged at the turning tool 12 such that the cutting edges 33 to 35 are parallel to the axis of rotation of the turning tool, they do not require any special design and may be provided as straight edges.
The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. | A method for machining surfaces of revolution at workpieces comprises the eps of: rotating the workpiece during machining; roughing the workpiece with a disk-shaped tool having at its circumferential edge cutting elements with cutting edges; and, for finishing the workpiece, plunge-cutting by turning the workpiece with the disk-shaped tool, wherein the step of plunge-cutting by turning is divided into a sequence of individual plunge-cutting by turning steps so that material of overlapping portions of the workpiece is removed sequentially. The tool comprises a disk-shaped base body with a circumferential edge and a first set and a second set of cutting elements that are connected to and distributed over the circumferential edge of the disk-shaped base body. The first set is used in the roughing process, and the second set is used in the finishing process by plunge-cutting by turning. The cutting elements of the second set are spaced at a distance from one another in the circumferential direction of the tool and axially staggered such that, when viewed in the circumferential direction, the working areas of the cutting elements overlap. |
TECHNICAL FIELD
This invention relates to computer data entry, and more particularly, to an improved technique which ensures that data entered at a computer which is utilized to generate transaction records is correct and consistent.
BACKGROUND OF THE INVENTION
Computers are often used in today's society to generate a variety of business forms, many of which relate to or reflect business transactions. For example, computers may be used to generate receipts, purchase orders, or other transaction records. Typically, a user is required to enter one or more items of data into different fields, and the information is then utilized by the computer to generate one or more different business forms or transaction records. It is understood that for purposes of explanation herein, the terms "data" and "text" are both meant to be any type of information entered into the computer, including numerics, dates, character data, text, logical values (e.g.; true or false) etc.
In order to ensure that the correct data is entered into the appropriate fields, many computer programs include restricted fields. For example, if a particular field to be filled in by an operator is titled "location code", the field may be restricted to one of two values, each of which represents one of the two company locations. Other fields may be "masked", meaning that the data entry clerk either cannot alter the field, or cannot see it because it will not even be displayed.
While prior art systems provide some level of assurance that inappropriate data is not entered into particular fields, prior systems are not foolproof because they leave open the possibility of inconsistent and incorrect values being entered into various fields. Additionally, sometimes entry of specific data in a particular field requires a particular value or set of values to be entered in a second field. In other instances, entry of data into a particular field requires that a different field not have particular data, or not have any data at all. Another alternative might be that the absence of data in a particular field requires that a particular other field have certain data. All of this checking is left to the data entry clerk.
The above described problems are particularly troublesome in the financial community, where large sums of money are involved and complex legal documents must be generated. There exists no way of assuring that the above requirements are met. The best technique presently known is to simply invest in training the appropriate personnel to carefully check for errors. Not only does this require a relatively highly skilled, and therefore somewhat costly data entry clerk, but it is also subject to human errors.
For example, consider a letter of credit, issued by a bank and often used to effectuate payment to a seller in international transactions. The letter of credit may include, among other items, shipment terms. For any particular shipment terms, a set of further information may be required to be entered. If an insurance term is required, there may be specific types of insurance which either (i) must be present or (ii) must not be present. Moreover, the particular terms which either must be present or may not be present may depend upon other data entered into other fields, such as the particular customer, the particular shipment destination, etc.
Correct generation of a letter of credit and supporting conditions and documents is critical because the banking institution, which ultimately pays the seller, does so upon presentation of the proper documentation. The bank has no interest in, and little knowledge of, the actual commercial transaction taking place. Moreover, the bank will normally not be legally liable for any damages provided that it pays upon properly presented letter of credit documents. Thus, documents incorrectly generated can, and sometimes do, result in errors causing millions of dollars in losses.
There is no known technique to ensure that the proper information is entered on the letter of credit. Since most international transactions utilize letters of credit and often involve many millions of dollars, mistakes can be extremely costly. It is therefore desirable to provide a technique to improve the integrity of the data being entered to generate a letter of credit as well as to provide a system of ensuring that data entry is restricted to correct values, is consistent, etc.
SUMMARY OF THE INVENTION
The above and other problems of the prior art are overcome in accordance with the present invention which relates to the use of a hierarchical technique for linking text, data, etc. at different levels of a hierarchy to permissible values of data, text, etc. at other levels of the hierarchy. The data is entered into various "fields" of a database as these fields are presented to a user on the screen of a personal computer (PC). The data which can be entered into each field is predefined into different classifications (i.e; lists or groups). Depending upon which data is entered, a particular group of data is selected for entry into a different field. Once a group is selected, only an entry from that group can be entered into the corresponding fields.
The particular rules for selecting data from ech group are defined by the user using a menu. This allows the user to choose which phrases should and should not be entered into each field as a result of data entered in other fields. Thus, the set of rules is user definable, rather than being programmed in by the system designer. This greatly enhances flexibility and the user's ability to customize the system.
For example, field 1 can comprise any data from an exemplary group A (A1-A5). The entry of A1 into field 1 may require that field 2 include data from an exemplary group B, including entries B1-B5. Alternatively, entry into field 1 of the value A2 may trigger a requirement that field 2 be restricted to entries from group C, which includes elements C1-C8.
The technique takes advantage of the fact that most possible values to be entered into a field can be classified. The technique uses the entry of data into each field to select a group of values, one or more of which must be entered into other fields. Thus, the groups of elements form a system of linked lists, whereby entry into a field of a particular element from a particular list triggers a requirement that a different field must be filled in with data from a particular list, which list is determined by the entry into the first field.
The required element or entry may be the absence of any entry at all, the absence of a particular entry, or the presence of a particular one or more entries. Thus, entry of data into a particular field may require that a particular second field be blank.
In general, the system uses a hierarchy to classify text and data at each level of the hierarchy, and then uses the classification to ensure that there are no inconsistencies, duplicates, etc. The hierarchical classification is also used to tie together text with data, create audit trails, classify documents as well as a variety of other functions.
The system includes other enhancements to make it more user friendly which include maintenance of audit trails, creation of an "amalgamated" document incorporating the latest filled-in data, allowing for editing, deletion or addition of permissible phrases, and other analyses of the data.
The system's advanced functionality may provide one or more of the following capabilities: (i) classify text and data\or data (e.g.; numeric, date, character, etc.); (ii) tie text to data using a hierarchy structure; (iii) check for duplicates and\or mutual exclusivity; (iv) define specific questions, explanations, etc. to assist the user in filling in data into one or more fields; (v) display questions and answers to elicit the proper data to be filled in by the user (vi) save data filled into one screen for use in other screens and (vii) maintaining audit trails for system security.
A better understanding of the features and benefits of the present invention can be obtained by referring to the following detailed description and the drawings included herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a table showing different lists of data suitable for entry into one of four different fields from a database;
FIG. 2 is a logic diagram indicating how a set of linked lists may be used to ensure data accuracy; and
FIG. 3 shows a computer display after a transaction has been processed in accordance with the novel technique.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a system of four different tables, each of which represents data to be filled into fields 1-4, respectively, of a hypothetical data entry screen on a computer. Beneath each of fields 1-4 is a listing of possible data entries which are denoted A(n)-H(n), where n is a number ranging from 1-5. Each field represents an element of information to be entered into, for example, a database or other type of data structure.
The potential elements in the list A could be any type of information such as type of shipment, type of insurance, payment terms or any other information utilized in the generation of the business transaction form. Importantly, it is possible to define the list A1-A5 because in most data entry screens, the permissible choices for each field are both finite and ascertainable in advance.
As an example, we consider a situation where field 1 may comprise different types of letters of credit which are known to those in the financial industry. For each type of letter of credit, certain types of information may be required. Thus, if the letter of credit is a type 1 letter of credit, then it may require an insurance policy. The insurance policy may be selected from a group of five possible insurance policies.
If, on the other hand, the letter of credit is of type 2, then it does not require an insurance policy, but rather, requires transportation documents which indicate that the transportation fees must be collected. If the insurance documents are to be provided, then there may be a choice among the plurality of different insurance documents. These documents comprise a group from which the user must select a particular entry.
The system can be thought of as a hierarchy. At each "level" of the hierarchy text is classified into groups which are permitted to be entered into particular fields. At each level of the hierarchy, the data entered defines the next level of the hierarchy. The system then checks each level of the hierarchy for various items such as inconsistencies, mutual exclusivity (if required), duplicates, and other items to be more fully described hereafter.
By providing that each entry into any field requires that data entered into a different field be chosen from a particular group, the system minimizes errors. Reliance on human checking is minimized.
As an enhancement, the system can also deal with the requirement that information not be contained in particular fields. Specifically, if a particular type of insurance is selected, then the system will ensure that a particular field which relates to that insurance does not contain certain entries so that there are no inconsistencies in the document. By way of example, and referring to the chart of FIG. 1, the element F1 could be the null set. The system ensures that when a particular entry is placed into field 2, F1 is required to be in field 3. Since F1 is the null set, field 3 will be empty when F1 is required.
The technique can also ensure that there are no inconsistent terms. For example, consider first that the user enters Free on Board (FOB) as the shipment terms on the letter of credit and is then requested to fill in a shipment method. The method is selected from a group of several (ship, train, etc.). At this point, the program would allow the user to enter two different shipment methods because it is possible that the goods may be shipped by sea to a first location and then by train to their final destination. On the other hand, if one of the fields is date of delivery, the system may be configured to not allow two entries, but only one.
The hierarchy can be used to check for mutually exclusive text as well. For example, if text entered at a first level of the hierarchy is intended to be mutually exclusive with particular text entered into a lower level of the hierarchy, then entry of such text by the operator will result in an error indication at the time of processing, as more fully set forth below. A similar technique can be used to check for duplicate text at different levels of the hierarchy.
In general terms, the system can be thought of as an arrangement of a plurality of lists or levels, (i.e.; the hierarchy) where each list comprises one or more elements. Referring to FIG. 1, field 1 comprises a list of A1-A5 which is one list of five elements. Field 2 may be filled in with entries from any of the three lists B1-B2, C1-C3, and D1-D2. Similarly, Field 3 may be filled in with entries from either of the two lists E1-E3 or F1, and field four may be filled in with entries from either the list G1-G3, or the second list H1-H4. The entry of data from a list into a field dictates which list is required to be used for entry of data into a different field. The user may then choose the value from that list based upon the particulars of the transaction.
FIG. 2 shows, in conceptual form, the operation of the technique in conjunction with the information in fields 1-4 in FIG. 1. The actual input screens, as displayed on the personal computer, are described later herein. FIG. 2 is only meant to be a conceptual diagram which is useful for explanation.
In accordance with the inventive technique, the user enters in field 1 any of the list of values A1-A5. The user then fills into field 2 any of the values in groups 204-206, in field 3 any of the values in groups 207-208, and in field 4, any of the values contained within groups 211 through 213. As explained, the entry of particular data into a field defines from which group data entered into a different field must be chosen.
It is important to note that the term "data" includes, text data, numerals, amounts, etc. Moreover, in a conventional manner, different fields can be defined to accept only dates, only numerals, or other specified data. For example, the shipment term can be restricted to the items FOB, FAS, or other such industry accepted terms related to shipment. Moreover, such data can be entered in response to user defined instructions, questions, explanations, etc.
Returning to FIG. 2., when the entered data is to be saved and processed, the technique then executes the algorithm indicated by the interconnection between groups 201-213 and the arrows interconnecting them. It can be appreciated that the diagram of FIG. 2 is a hierarchy which ties the data (e.g.; text) at each level of the hierarchy to data or text at other levels of the hierarchy.
Specifically, if field 1 includes either A1 or A2, both from group 201, then the technique ensures that field 2 contains only one of two values, B1 or B2. This check is indicated by arrow 214 of FIG. 2. If the user, on the other hand, enters A3 into field 1, then the system ensures, via arrow 215, that one of C1-C3 of group 205 has been entered in field 2. Finally, with respect to field 1, if either A4 or A5 from group 203 are entered, then the system ensures that field 2 includes either D1 or D2 from group 206 as indicated by arrow 216.
This system of checking each level also ensures that the text entered at each level is in fact so entered. If, for example, an FOB term is entered, then the next level requires an insurance term to be entered. Moreover, other shipment terms are such that they do not allow an insurance term. In that case, the system will check among the various levels for "not allowed" terms to ensure that there are no insurance terms when such terms are not supposed to be present.
Proceeding to the next "level", if B1 is entered into field 2, then the system checks to ensure that one of the values from group 207, namely E1-E3 is entered into field 3 via arrow 217. If B2 is entered into field 2, then the system ensures that F1 from group 208 is entered into field 3 via arrow 218. Without going through every possible combination, it can be seen that each time an entry from the particular group of entries is entered into a particular field, the system triggers a check which ensures that one or more other fields include information from a particular other group. To return to the letter of credit example, A1-A5 may represent shipment terms, and B1-B2 may represent different types of insurance. As FIG. 2 shows, if either of shipment terms A1 or A2 are chosen by the user, then an insurance term must be chosen, where B1 and B2 represent the insurance terms. Of course, the invention is not limited to letters of credit and may be used in conjunction with any type of system for generating documents automatically.
Additionally, as with group 208, the system may also check to ensure that if an entry is present in a first field, a different field does not include any entry (see arrow 219). It is also noted that the elements A1-A5, B1-B2, etc. may actually include negatives. Specifically, if a particular entry is entered into field 1, the system may, for example, check to ensure that a particular different entry is not entered into field 2. For example, if the shipment term FOB is entered into field 1, the system would ensure that field 2 does not contain the terms of an insurance policy, because no insurance should be purchased for FOB shipments. The user would then be permitted to alter information previously entered.
FIG. 3 shows a typical screen which may be presented on the user's personal computer after the data is entered and the transaction is processed. In the example of FIG. 3, personal computer screen 301 shows a first window 302 and the second window 303. Window 302 is a type of window which would be generated after data entry and processing of an exemplary transaction.
In the example of FIG. 3, the algorithm displayed in FIG. 2 has shown that there were two errors/inconsistencies in the data that was entered. Window 302 shows that field 2 is missing an ID number and that there is no payment term in field 3. The ID number and payment terms are examples of the types of terms which are contained in financial documents. The arrangement has checked all of the fields and based upon the algorithms described with respect to FIG. 2, has determined that both field 2 and field 3 have incorrect or inconsistent data contained therein. For example, field 1 may include an entry which requires field 2 to include an ID number. Since the user has not entered an ID number into field 2, the system flags the inconsistency and displays it to the user as shown in window 302. Additionally, window 302 shows that field 3 is missing a required term of payment.
The user may then "click" upon the first or second line of window 302. After the first or second line is selected, appropriate values appear in window 303. In the example shown at FIG. 3, the user has selected the second line. Since no payment term exists in field 3, four possible payment terms appear in window 303, any of which may be selected and "dragged" into field 3 using a mouse on a personal computer.
It is also noted that an override function may be built into the software. Specifically, when the user clicks upon the second line, four possible payment terms are presented to the user as shown in FIG. 303. The user may have the capability to override the software and permit a different payment term to be entered into field 3, or, may enter a command so that even though the absence of a payment term from field 3 would normally result in an error, this particular transaction is permitted to be processed without such payment term. Thus, the system may be used as a way of warning the user to check for possible inconsistencies, than allowing the user to process the transaction with the data entered by the user whether or not it is part of the group of permissible values.
Once all required information is entered by the user, and verified the technique may provide for printing and/or display of current or other versions of the completed document.
While the above describes the preferred embodiment of the invention, it will be apparent to those of ordinary skill of the art that other variation and modifications are apparent. For example, groups may overlap in that a first group may contain entries K1,K2,K3, and a second group may contain entries K3, K4, K5. Also, the checking can be done at the time the data is entered, rather than when the document is processed and saved. Audit trails of data entered/updated maintained for use by the system administrator. The important point is that through utilizing groups of linked lists and classifying the possible entries into groups, the system ensures that there are no inconsistencies in the document. | A technique for insuring the integrity of documents such as, for example, letters of credit, contracts, etc., wherein groups of possible entries are linked to one another. When an entry from a particular group is placed in a first field, it requires entry of an element from a particular other group in one or more other fields. By checking the entries in each field against entries in other fields, inconsistences are eliminated. |
BACKGROUND OF INVENTION
[0001] 1. Field of Invention
[0002] This invention relates generally to chair pads and, more particularly, to wood chair pads.
[0003] 2. Background Art
[0004] Chair pads are used as a protective covering for a floor area on which a chair rests or some other furniture item. The chair pad is utilized to protect the underlying floor from damage due to wear and tear caused by the chair and/or the occupant of the chair moving about within the floor area on which the chair rests. A typical chair pad is made of plastic or other appropriate material that is semi flexible, but resilient enough such that when the chair pad is placed on the floor area a semi rigid surface is provided by the chair pad. The semi rigid surface makes it easier to move about in the floor area with a chair with wheels.
[0005] Most chair pads are a unitary one piece flattened body. Some chair pads as indicated are made of plastic. However others are made of a hardwood material to provide a better aesthetic appeal. Hardwood chair pads, however, are not flexible. These chair pads, particularly larger ones, are difficult to move about and very difficult to ship because of the special packaging required. Also, one alternative to hardwood is bamboo, which can also be utilized for a chair pad if processed like a hardwood.
[0006] Bamboo is a grass, that belongs to the sub-family Bambusoidae of the family Poaceae (Graminae). Bamboo occurs naturally on every industrialized and populated continent with the exception of Europe. There are over 1000 known species of bamboo plants. It is a durable and versatile material, that has been utilized by various cultures and civilizations for various applications. Bamboo has been an integral part of the cultural, social and economic traditions of many societies. There is a vast pool of knowledge and skills related to the processing and usage of bamboo, which has encouraged the use of bamboo for various applications
[0007] Clumping bamboo can be widely grown in tropical climates. The trunk of the plant is called the “culm”. The culm is wider at the trunk or bottom and narrows toward the top. In some varieties of bamboo the culm may grow 40 to 60 feet tall. Once established, bamboo plants can replenish themselves in two or three years. Each year a bamboo will put out several full length culms, that are generally hollow, in the form of a tube having “nodes”. There are other parts of the bamboo plant that can be utilized other than the culm, including commonly used parts of a bamboo such as branches and leaves, culm sheaths, buds and rhizomes. Some species are very fast growing at the rate of one metre per day, in the growing season.
[0008] As mention above, bamboo occurs naturally on most continents, mainly in the tropical areas of a given continent. Its natural habitat ranges in latitude from Korea and Japan to South Argentina. It has been reported that millions tons of bamboo are harvested each year, almost three-fifths of it in India and China. On known source of quality bamboo is found in the Anji Mountains of China.
[0009] Bamboo has many uses such as substituting commercially for wood, plastics, and composite materials in structural and product applications. There is a large diversity of species, many of which are available in India, which is the second largest source of bamboo in the world ranking only behind China. These grow naturally at heights ranging from sea level to over 3500. Most Indian bamboo is sympodial (clump forming); the singular exception is Phylostacchus bambuisodes, cultivated by the Apa Tani tribe on the Ziro plateau in Arunachal Pradesh.
[0010] Bamboo has to undergo certain processing stages to convert them into boards/laminates. The green bamboo culms are converted into slivers/planks and then to boards. The boards are finally finished by surface coating. The common primary processing steps for making sliver/planks from green bamboo culms are 1. Cross Cutting; 2. Radial Splitting; 3. Internal Knot Removing & Two-side Planing; 4. Four-side Planing; and 5. forming slivers/planks. The common secondary processing steps for making board/laminate from slivers/planks are 1. Starch Removal & Anti-fungal Treatment; 2. Drying; 3. Resin Application; 4. Laying of Slivers/Planks; 5. Hot Pressing & Curing; and 6. form Laminates/Boards. The common surface coating and finishing stages are 1. Surface Sanding & Finishing; 2. Surface Coating with melamine/polyurethane; 3. Curing of Laminate; 4. Fine Sanding; 5. Evaluation of Surface Properties.
[0011] There are various types of bamboo flooring including tongue and groove and the type that needs to be butted together. The lacquered flooring tiles are finished using wear resistant UV lacquer and the unlacquered flooring tiles need to be coated/waxed and polished after installation. The strength of Bamboo Boards can be better than common wood board for its special Hi-steam pressure process. The board has good water resistance for its shrinking and expanding rate. Its water-absorbing rate is better than wood and is further humidity resistant and smooth. It has been reported that the strength of 12 mm bamboo ply-board is equivalent to that of a 25 mm plywood board. There are also removable bamboo floor covering having bamboo on one side and carpeting on the other side. Although this type of flooring may be removable, the carpet backing construction makes the overall flooring have limited flexibility.
[0012] There are also various types of bamboo chair pads made of flat elongated planks or strips arranged side by side length wise and attached along abutting adjacent edges binding them together in a side by side arrangement. There is also usually a cloth or felt backing or some other fibrous material bonded to the underside. The bamboo chair pad as with any other wood chair pad is rigid.
[0013] The bamboo material is very durable for chair pad application, however, the construction of many bamboo pads are rigid lacking the capability to flex or bend. A novel bamboo chair pad construction is needed.
BRIEF SUMMARY OF INVENTION
[0014] The invention is a hard wood chair pad formed from multiple elongated bamboo planks that have been processed like hardwood flooring. The chair pad provides a substantially hardwood rigid surface but the pad can be rolled up like a chair pad for ease of transport and shipping. The hardwood planks have sufficient thickness such that when they are bonded to a backing in an adjacent side by side manner a substantially rigid surface is provided. The planks are not adjacently connected along their side edges, therefore the pad can be rolled up for ease of transport.
[0015] The bamboo chair pad can be manufactured from 100% Anji Mountain bamboo from China. The bamboo is all treated with various protective coatings to add resistance to natural factors including water, sun and dirt. All bamboo chair pads are made from the harder portions of the bamboo trunk. (Some bamboo used for indoor purposes are manufactured from the softer fibers of the inside of the bamboo trunk). This portion of the bamboo trunk is not utilized for this invention. The bamboo utilized in the present invention is taken from the harder part of the bamboo trunk to assure maximum endurance and longevity. The lower trunk portion of the bamboo plant is harder and less porous.
[0016] The bamboo for the present invention is kiln dried to prevent warping and remove moisture that can cause future warping. Certain styles of bamboo are oxidized in a boiling vat of liquid to bring out different variations of color vs. the common method of spray staining the bamboo planks to a particular color. The oxidation process also makes the bamboo less porous to moisture. A UV coating can also be applied to the bamboo planks. One embodiment of the invention can have 7 coats of UV protection. The bamboo can be arranged with a series of planks lying next to one another and then assembled into a chair pad utilizing the same manufacturing processes and machinery utilized for bamboo rugs. The chair pad can then be rolled or pressed thereby compressing all of the layers of the chair pad.
[0017] During the assembly process a mesh sheet is placed on the bottom side of the chair pad. The mesh sheet can be made of nylon fibers. A mastic layer is then placed over the nylon mesh sheet before a final layer of high density felt or sisal is applied, which can be preferably about approximately 2 mm in thickness. Then the chair pads are cut to the desired dimensions.
[0018] Certain bamboo that can be used in the manufacture of the present Bamboo Chairpad is oxidized and gives it an extra step in making the bamboo more impermeable to water, sunlight and dirt. Once the elongated bamboo planks have been processed, they are adjacently aligned lengthwise, and side by side. A fibrous strip, or multiple threads and/or a fibrous tape material can be applied to the underside to connect the bamboo planks. A fiber mesh sheet can then be applied and bonded to the underside to hold the strips together. Then the porous mating is bonded to the underside. The present inventions construction provides a product that is easily packaged, transported, shipped and moved about to the flexibility of the chair pad and ability to roll up.
[0019] These and other advantageous features of the present invention will be in part apparent and in part pointed out herein below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
[0021] FIG. 1 is a perspective view of the chair pad;
[0022] FIG. 2 is a perspective partial cut away view of the bamboo chair pad;
[0023] FIG. 3 is a perspective partial cut away exploded view of the chair pad layers;
[0024] FIG. 4 is a perspective partial cut away view of the chair pad illustrating its flexibility; and
[0025] FIG. 5 is a partial end view of the chair pad.
DETAILED DESCRIPTION OF INVENTION
[0026] According to the embodiment(s) of the present invention, various views are illustrated in FIG. 1-5 and like reference numerals are being used consistently throughout to refer to like and corresponding parts of the invention for all of the various views and figures of the drawing. Also, please note that the first digit(s) of the reference number for a given item or part of the invention should correspond to the Fig. number in which the item or part is first identified.
[0027] One embodiment of the present invention comprising bamboo planks and a felt or sisal backing teaches a novel apparatus and method for a bamboo chair pad that is highly flexible along the plank seams for ease of rolling up.
[0028] The details of the invention and various embodiments can be better understood by referring to the figures of the drawing. Referring to FIG. 1 , a perspective view of the present chair pad invention is shown. The chair pad construction includes a plurality of elongated bamboo planks 102 arranged lengthwise in a side by side manner where the long side edge of each plank can abut against the adjacent long side edge of the adjacent plank. The abutting relationship between the planks can form a seam 114 . The adjacent long side edges of adjacent planks can be unattached. The bamboo chair pad as shown is cut into a typical chair pad pattern outline that is a substantially rectangular outline with adjacent corner sections cut away. See the notched or cutaway areas 104 and 106 .
[0029] Referring to FIG. 2 , the layers are shown assembled together forming the bamboo chair pad with a cut away revealing the inner layers. At least one loom fibrous tape strip extending orthogonally with respect to the lengthwise extension of the planks, see item 210 of FIG. 2 , can be utilized to connect the plank together in an abutting relationship with each other adjacent plank in a loom system forming a chair pad. The loom fibrous tape strip can have some adhesive or adhesion properties on at least one facing surface of the tape strip such that it bonds to the underside of the planks to connect the adjacent planks together from the underside of the plank. The strip can extend orthogonally with respect to the lengthwise extension of the planks and can extend edge to edge of the bamboo layer portion 304 , see FIG. 3 .
[0030] Also, in lieu of the tape embodiment, the planks can be connected by a series of substantially parallel fibers having adhesive properties extending orthogonally with respect to the lengthwise extension of the planks. The connecting tape strips or fibers 210 can also extend in a crossing angular fashion with respect to the lengthwise extension of the seams 114 . A fiber mesh sheet 206 can then be applied on the underside 308 of the bamboo layer portion 304 , see FIG. 3 . The mesh sheet further bonds the bamboo planks together. The chair pad as described herein can be such that the bamboo planks are kiln dried to prevent warping. The chair pad as described can also be such that the bamboo planks are oxidized in a boiling vat of liquid for coloring the bamboo rather than performing a staining process. The planks can vary in size, however one embodiment can have planks that are about approximately 5 mm thick and about approximately 5 cm wide. However, these dimensions can vary based on intended usage and preference. One embodiment of the chair pad can have planks with 7 layers of UV protection applied for mar and scuff resistance.
[0031] The chair pad, as described, can have a resin layer that is a mastic resin layer for sealing and moisture resistance. The chair pad invention as described herein can be such that the bamboo planks are made of the harder lower trunk portions of the bamboo plant. The loom fiber such as the fibrous tape strip, can be a poly resin fiber. The fiber mesh sheet can also be a poly fiber mesh sheet.
[0032] All of these features provide significant flexibility. The construction of the layers bonded under the bamboo planks provide strength and durability as well as portability. The construction and the material contained in the construction described herein also provide substantial flexibility such that he chair pad can be easily rolled up.
[0033] Referring to FIG. 3 , an exploded partial cut away view of the present invention's bamboo chair pad layers is shown. The chair pad 100 is shown and with the layers revealed in an exploded view. The chair pad 100 comprises a plurality of elongated flat bamboo planks 102 arranged lengthwise and side by side and each plank connected in a substantially abutting relationship with respect to an adjacent plank forming seams 114 between adjacent planks. The connected planks form the bamboo chair pad layer portion 304 (bamboo layer). The abutting long edges of adjacent planks can be unattached along the seams 114 .
[0034] The adjacent planks can be connected to each other on the chair pad's bamboo layer underside 308 (the underside of the planks) by at least one loom fibrous tape strip extending orthogonally with respect to the lengthwise extension of the planks, see item 210 of FIG. 2 , using a loom system forming a chair pad. The loom fibrous tape strip can have some adhesive or adhesion properties on at least one facing surface of the tape strip such that it bonds to the underside of the planks to connect the adjacent planks together from the underside of the plank. The strip can extend orthogonally with respect to the lengthwise extension of the planks and can extend edge to edge of the bamboo layer portion 304 .
[0035] Also, the planks can be connected by a series of substantially parallel fibers having adhesive properties extending orthogonally with respect to the lengthwise extension of the planks. The connecting tape strips or fibers 210 can also extend in a crossing angular fashion with respect to the lengthwise extension of the seams 114 . A fiber mesh sheet 206 can then be applied on the underside 308 the bamboo layer portion 304 . The mesh sheet further bonds the bamboo planks together. One embodiment of the mesh sheet can be a nylon mesh sheet.
[0036] A resin material layer applied to the fiber mesh sheet underside 310 bonding the mesh sheet to the underside 308 of the chair pad's bamboo layer 304 . The resin material can be for example a mastic resin layer. The mastic resin layer will assist in providing a moisture seal for the underside of the chair pad for durability as well as bond the mesh sheet to the bamboo planks' underside 308 . Then a high density layer 312 of matted natural or man made fiber is applied to the mesh sheet underside 310 . The resin layer assists in bonding the high density fiber layer to the mesh underside. The high density fiber layer can be moisture, mildew and skid resistant. The high density fiber layer can be made of matted sisal or felt bonded under and to the resin material layer or the high density fiber layer can be made of another appropriate fiber. One embodiment of the high density fiber layer can be about approximately 2 mm in thickness. However, the thickness of the high density fiber layer can vary significantly depending on the application and the environment for which the chair pad is to be used. Once the layers have been bonded, they can be pressed or rolled further compressing and bonding the layers together.
[0037] Referring to FIGS. 4 and 5 , a perspective partial cut away view of the chair pad illustrating its flexibility, and a partial end view of the chair pad is shown. The high density layer 312 , the mesh layer 206 , the tape 210 , and the bamboo plank layer 102 are all shown in these views. The adjacent long side edges 502 and 504 of the planks 102 are shown unattached along the seams 114 .
[0038] The various bamboo chair pad examples shown above illustrate a novel outdoor/indoor bamboo chair pad construction. A user of the present invention may choose any of the above bamboo chair pad construction embodiments, or an equivalent thereof, depending upon the desired application. In this regard, it is recognized that various forms of the subject outdoor/indoor bamboo chair pad could be utilized without departing from the spirit and scope of the present invention.
[0039] As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the sprit and scope of the present invention.
[0040] Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims. | A bamboo Chair pad that can be manufactured from 100% Anji Mountain bamboo from China. The bamboo is all treated with various protective coatings to add resistance to natural factors including water, sun and dirt. All bamboo chair pads can be manufactured from the harder portions of the bamboo trunk. (Some bamboo are manufactured from the softer fibers of the inside of the bamboo trunk). This portion of the bamboo trunk is not utilized for this invention. The bamboo utilized in the present invention is taken from the harder part of the bamboo trunk to assure maximum endurance and longevity. The lower trunk portion of the bamboo plant is harder and less porous. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application Ser. No. 12/699,474 filed Feb. 3, 2010 entitled “Method to Strip a Portion of an Insulated Wire,” which claimed the benefit of Swiss Patent Application No. CH 0178/09 filed Feb. 6, 2009 under 35 U.S.C. §119, the disclosures of both applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method to strip a portion of an insulated wire and a machine carrying out this method. This method is advantageously used for the manufacturing of electronic components like transponders, whose antenna is commonly made of very thin insulated wires, more particularly in the case of embedded wire antennas for HF transponders.
STATE OF THE ART
[0003] Wire stripping per se is as old as the use of insulated wire. Electric and electronic engines and devices are commonly using insulated wires the ends of which have to be stripped in order to realize an appropriate electrical connection. In case of electrical installations, this is commonly achieved by hand tools comprising a pair of stripping jaws manually activated. In case of industrial production, automatic machines have been developed to cut, strip and handle continuous insulated wires on a very high frequency base.
[0004] In the last decades, numerous machine to strip a portion of a continuous insulated wire have been proposed using laser, electrical arc or flames as stripping means. Example of these are given in U.S. Pat. Nos. 4,761,535, 4,970,367 and 7,317,171, respectively.
[0005] In the manufacturing of small electronic components, a difficulty resides in the extremely small diameter of the wires used, in the high numbers of connections to be made in a very short time and in the very reduced space available. Additionally, security (for the handling of laser, flames or gases) or quality (strict handling of the stripped insulation particles in order to keep clean rooms) requirements make that available solutions are not always scalable (in terms of yield, costs and ease to use) for high production volume. Stripping solutions as proposed in U.S. Pat. Nos. 4,693,778 or 4,031,612, for example, and which are integrated in the manufacturing device, are not working at full satisfaction.
[0006] A domain which is of most interest for the present applicant and where the above-mentioned issues are critical is the manufacture of RFID transponders, in particular where the antenna to be connected to the RFID chip is formed by an insulated wire.
[0007] The examples and preferred embodiments of the invention described and claimed further in present application refer specifically to this field. However this should not be understood as a general limitation of the scope of the invention which can as well be applied to numerous other technical domains.
[0008] A prior art in this field is illustrated in EP0756736 (corresponding to WO 93/18493), where the problem of connecting an insulated copper wire directly to an IC is solved through the prior removal of the insulation of the wire by means of a hot gas jet (from 500 to 850 degrees C.). An inert gas is preferably used to prevent oxidation of the copper. Then the bare local portion of the wire can then be connected to the IC pads by means of one of the following joining techniques: ultrasonic welding, thermo-compression welding, soldering or gluing for example. Alternatively, in this prior art, it is mentioned that the insulation material of the wire can be removed simultaneously with the actual jointing process by using the increased temperature of the jointing process itself.
[0009] In U.S. Pat. No. 6,088,230 and German Patent DE102006060385, the antenna is formed by embedding an insulated wire on a support previous to the connection to the chip or the chip module. It is proposed in particular to integrate a laser stripping chamber in the embedding head in order to be able to strip the wire on demand before that the wire is embedded in the support, the bonding laser doubling as a wire stripper (in U.S. Pat. No. 6,088,230).
[0010] Finally, the used wire stripping techniques have not be proven to be effective enough for high production volume and for the most currently used bonding technique, that is the direct thermo-compression of an insulated portion of wire as described in U.S. Pat. No. 6,233,818. The insulated portion of the wire is pressed directly against the contact pad of the chip or the chip module by a thermode which is shortly heated over 1,000 degrees C. This results first in the disruption/consumption of the insulation layer (usually a lacquer) in the heated zone, and then in the creation of a soldering connection and/or a diffusion welding between the materials forming the contact pad and the wire. The drawback of this method is that the extremely intense heat impulse creates a thermo shock which geometrically, mechanically and/or chemically modifies the structure of the thermode, of the module and/or of the substrate around. This induces additional production costs and creates residual stresses in the products that affect the final product (surface of a card for example).
[0011] An alternative is proposed in WO2007134590, where a soldering head is applied in such a manner on the insulated wire that the insulation layer is also disrupted/consumed/molten. This solution has essentially the same drawbacks as the previous one, but due in this case to a too long exposure of the different elements at high temperatures.
[0012] Accordingly, if in theory the stripping of portion of wire is a desired feature in the process of manufacturing transponders with a wire antenna, this principle has not been applied in practice since no known solution has been working at satisfaction for high volume production level.
SUMMARY OF THE INVENTION
[0013] It is therefore an aim of the present invention to propose a method to strip a portion of an insulated wire which can be acceptable for high volume production level.
[0014] A further aim of the invention is to provide a wire stripping machine which can be integrated in a mass-production line, in particular for the production of RFID transponders, for example in combination with a wire embedding station.
[0015] A further objective of the invention is to provide an insulated wire with bare portions which are so formed that this wire can be advantageously used for the manufacture of RFID transponders, in particular high frequency (HF: 3-30 MHz) tags with wire embedded antennas.
[0016] An idea of the invention is to deform (for example flatten or squeeze) the said portion of the insulated wire and also the core of the wire before stripping away the insulation. As the insulation layer(s) doesn't (don't) have the same mechanical/elastic/plastic characteristics as the core of the wire, the mechanical deformation (flattening/squeezing) has the double advantage to create cracks in the insulation layer(s) and dissociate it partially from the core of the wire. This greatly eases the stripping action, which is advantageously applied on a flat surface (better achievement as on a round surface).
[0017] Another advantage of the method according of the invention is to provide flattened portions of bare wire, i.e. of the core of the wire. This increases the available surface for the electrical contact, which is finally the main purpose of stripping a wire. So the method of the invention allows in addition to create real connection pads along an otherwise insulated wire. The flattened geometry improves the mechanical stability of the connection. It also eases the correct positioning of the bare portion, in particular in regards of stripping only defined surface(s) of this portion (and then orienting the wire accordingly to the bare surface(s)). Additionally, the mechanical deformation of the core also improve the mechanical/structural strength of this portion of the wire, improving his ability to be applied on a substrate and/or to be submitted to a bonding process.
[0018] To carry out this method, the insulation should be less deformable(elastically and plastically) than the core of the wire. Preferably, this method concerns also wires with a metallic core (for ex. copper or silver) and at least an insulation layer made of lacquer or enamel. This kind of insulation is preferably applied on very thin wire, typically of less than 250 micrometers, or even about 100 micrometers for the particular application of wire antenna for HF tags.
[0019] The first objective of the flattening (creating cracks and dissociating the insulation layer(s)) is typically reached when the width of the wire and of the wire core is increased by about 20% (resp. the thickness decreases by about 20%) at least. Preferably, a flattening grade of about 50% (resp. about 50% width increase) has proven to be a good choice in term of efficiency of the process and stability of the bare portion. Of course, other values are possible within the frame of the present invention.
[0020] In a preferred embodiment of the invention, the portion of the insulated wire is flattened by means of a pair of rotating barrels, wherein the distance between the barrels (as the applied pressure on the wire) can be regulated and controlled. This mean is advantageously integrated in manufacture processes working with continuous insulated wires, where such pair of rotating barrels are commonly used as a handling/transport means.
[0021] In another preferred embodiment of the invention, the portion of the insulated wire is flattened by means of a press or a hammer, which is activated such as to squeeze the wire on the chosen portion. Such means are advantageously used to disrupt and/or dissociate strong insulation layers (strong lacquers/enamels), in particular by combining a plurality of wire deformations in series. Typically, a first hammer/press deforms and flatten lightly the portion according one direction, and a second hammer/press then flattens the same portion in a direction roughly perpendicular to the first one. This sequence of orthogonal squeezes can be repeated three, four times or more if needed. A challenge for this embodiment is to regulate the press/hammering parameters to the treatment of a continuous wire, in particular to reduce as much as possible the variation of the scrolling speed of the wire.
[0022] According a particular embodiment of the invention, the flattening means described above can be equipped with means to crack the insulation. To this effect, the pressure surface of the barrels, presses or hammers used can show special layout profiles to be imprinted in the insulation layer, creating disruptions and weaknesses finally resulting in cracks in these layers.
[0023] In a preferred embodiment of the invention, the insulation material is stripped away by mechanical means. Such mechanical stripping means are well know as scrapers and can be generally defined as a pair of jaws. These jaws show scraping edges which can be applied in a controlled manner on the flattened surface surfaces of the said portion of the wire. The mechanical scraping is eased as the insulation material/layer(s) has (have) been already partially disrupted, cracked and/or dissociated during the flattening step and by the flattened geometry of the surface. Special edges made of ceramic material for example can be used. Advantageously, the metallic core of the wire shows no thermal or chemical changes, and even oxidation layers can be scraped away. To improve the cleaning effect of the scraping, a small vibrating movement (longitudinal to the wire axe) can also be given to the scraping edges. This mean is advantageously integrated in manufacture processes working with continuously scrolling wire, as the normal movement of the wire itself is used to create the scraping effect.
[0024] In another preferred embodiment of the invention, the insulation material is stripped away by means of laser radiation. This technique is well described in the publications cited above. The geometry of the flattened wire portion can be used advantageously if the laser radiation is oriented approximately perpendicular to the flattened surface to be stripped/cleaned. This allows to have an uniform impact of the laser on a large part of the surface and improves the quality and homogeneity of the stripping result. Advantageously, if the core of the wire is made of copper, the laser ablation process will not modify the chemical structure or any other characteristics of the metal.
[0025] Any other flattening means and stripping means known in the art, and their different combinations can be used in the framework of this invention (like for example hot gases, flames or electric arc as stripping means).
[0026] It has also to be understood and comprised in the scope of the invention, that only one small part of one of the flattened surfaces of the wire may be stripped/cleaned. This can be desired to simplify the tool, improve the speed of the process or if it is desired to use the insulation on the opposite surface further in the manufacturing process (like in the case of a baked enamel which is used to improve the adhesion of a wire on a substrate).
[0027] According a particular embodiment of the invention, a partial stripping means can also be applied on the insulated portion of the wire before the flattening step. This can be for example achieved by means of a usual scraper. This step creates a first breaking zone in the insulation which in turn improves the cracking and dissociation effect of the flattening step. According to different embodiments described previously, one can also imagine a method of the invention with a plurality of successive flattening and stripping steps in any order, the preferred measure being that at least one flattening step is applied before a stripping step.
[0028] The invention also concerns a wire stripping machine to strip a portion of a continuous insulated wire according the method describes above. Essentially, this machine comprises at least wire flattening means and wire stripping means, the wire flattening means being placed preferably before the wire stripping means on the treatment line. A unique tool can also be designed to achieve both flattening and stripping actions (for example with a flattening edge followed by a scraping edge). Naturally, such machine should comprises or may be combined with a length measuring means for determining the correct length on which the wire has to be flattened/stripped and this in regards/coordination with further manufacturing steps (as wire embedding for example).
[0029] A preferred application of the method of the invention concerns the manufacture of transponder antennas and wire antennas manufactured by such method, in particular for high frequency (HF: 3-30 MHz) tags based on wire embedded antennas. Such flattened and stripped portion on an insulated antenna wire can have a many uses which are detailed further in the present application. They are forming contact pads to connect electronic elements like chips, chip modules, switches, or even other wires. They can also be used to form wire crossing and watermarks for example.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The invention will be better understood by the following detailed description taken together with the following drawings:
[0031] FIG. 1 shows a cross section of an insulated wire.
[0032] FIG. 2 shows a wire being stripped by a mechanical stripper.
[0033] FIG. 3 shows a cross section of a wire stripped without preliminary flattening.
[0034] FIG. 4 shows a cross section of a wire after a flattening step of the method of the invention.
[0035] FIG. 5 shows a cross section of a wire after the stripping method of the invention.
[0036] FIG. 6 shows a top view of a stripped portion of a wire according to the invention.
[0037] FIG. 7 shows a top view of a wire with two stripped portions according to the invention.
[0038] FIG. 8 shows a wire stripping machine according to the invention.
[0039] FIG. 9 shows a top view of a crossover bridge.
[0040] FIG. 10 shows a top view of an antenna circuit according to the invention.
[0041] FIG. 11 shows a wire being stripped by laser radiation according to the invention.
[0042] FIG. 1 shows an insulated wire before being submitted to a stripping step. The wire has a metallic core 2 , typically made of copper, surrounded by two successive insulation layers 3 , 3 ′. The first insulation layer 3 is made of a strong lacquer or enamel and forms the base insulation (mechanical and electrical). The second external insulation layer 3 ′ is made of a said baked-enamel which has improved adhesion characteristic. Such a layer is advantageously used to improve the attachment of the layer on a substrate, as for example in case of a wire embedding process. One can also imagine to use thermosetting plastic, adhesive, enamel, etc., as insulation. Any possible combination is to be considered in the scope of the invention. Preferably, at least the insulation layer 3 which is directly in contact with the wire core shows smaller elastic and/or plastic characteristics than the material of the wire core 2 .
[0043] FIG. 2 illustrates the stripping of an insulated wire by a mechanical stripper according to the known state of the art. The insulated wire 1 is pulled through a pair of jaws 8 having scraping edges 9 which can be applied in a controlled manner against the insulated wire. When applied simultaneously on both sides of the wire, the edges 9 penetrate through the insulation layers 3 and 3 ′ and get in contact with the wire core 2 . By virtue of the scrolling movement of the wire, and as long as the edges are applied against the wire, particles 10 of the insulation material are being scratched off the wire core surface by the edges 9 . The length of the bare portion of wire can be easily calculated by multiplying the wire scrolling speed by the time of application of the edges 9 on the wire.
[0044] FIG. 3 shows the said portion of bare wire with the wire scraper of FIG. 2 according the known state of the art. The wire core 2 has been stripped bare only along a very thin surface 11 of its perimeter, leaving the insulated layers 3 and 3 ′ intact on a large part of the wire surface. As illustrated in FIG. 3 , the scraped profile is flat as the profile of the scraping edges. Naturally, the bare surface could be increased by choosing a curved profile for the edges 9 for example. But then, the work pressure applied by the scraping edges 9 will no more be homogeneous with respect to the radial direction of the surface of the malleable metallic core 2 . This would result in uneven scraping and non reproducible results (in term of cleaning/stripping of the wire surface).
[0045] It should also be said that the mechanical stripping as shown in FIG. 2 will results mostly in a slight squeezing/flattening of the wire core 2 , due to the pressure applied by the scraping edges 9 . But contrarily to the invention, both flattening and scraping take place here simultaneously. It will be extremely difficult to produce bare portions of wire with a flattening grade of more 20% with such a simple tool. It is not impossible as the pressure applied and the spacing between the both edges 9 could be regulated adequately. But this will have numerous drawbacks: slowing down of the manufacturing speed, less reproducible results.
[0046] In this sense, the method of the invention differs from this state of the art in that at least a flattening step is carried out previously and separately to a stripping step. This allows to control the forming of the wire during the first step, disrupting in the same time the insulation layer in order to facilitate the stripping process which can be applied with less efforts and more precision. However, one can imagine a unique tool achieving both flattening and stripping actions, for example with at least a flattening edge followed by a scraping edge. Such a tool falls under the scope of the present invention, as long as both means/actions are clearly separated. A better result is obtained if the flattening mean and the stripping mean can be controlled separately (force, precision, timing, . . . ).
[0047] The following figures illustrates the method of the invention in more detail.
[0048] FIG. 4 illustrates the state of a portion of the wire after a flattening step but before a stripping step. The wire core 2 has been plastically deformed and does not show any essential structural changes (except for its shape). In contrary, the insulation (layers 3 and 3 ′ of FIG. 1 ) has been disrupted by the flattening action and forms now a cracked/disrupted layer 4 . Of course, the flattening process chosen should be adapted to the materials involved (insulation, core) and to the requirements of the next stripping step. One can use flattening means with imprinting profiles, in order to multiply the cracking/weakness points in the insulation. One can also regulate the speed or the number of the flattening steps in order to reinforce the dissociation of the insulation from the core.
[0049] FIG. 5 shows the cross section of the same portion of the wire as in FIGS. 1 and 2 , but after the stripping step. In this case, the stripping has been applied exclusively on the flat section of wire, stripping the flattened surfaces 5 of the wire core 2 . So residual cracked insulation 4 is showed on the side portions. This is only an example, and any variations between the full cleaning of the wire core surface and the scraping of a very limited single surface is possible within the framework of the invention. A preferred embodiment, in particular when a baked-enamel insulation layer 3 ′ is used, is to strip only one of the two flattened wire core surfaces 5 .
[0050] FIG. 6 illustrate schematically the result of the stripping method of the invention, with a top view of a flattened and stripped portion 7 of the wire between two insulated portions 6 of the same wire. In this case, the portions 7 are shown as being totally cleaned of any residual insulation. But as said above (or illustrated in FIG. 3 ) the invention provides that at least a part of the portion 7 is bare. It could be for example also only a very small area in the center of the portion 7 . Optionally, a hole 21 can be formed through the flattened portion 7 . This hole 21 can facilitate contacting as is show further in the present description.
[0051] FIG. 7 show an enlarged view of a insulated wire 6 comprising near of each of its extremities a stripped (and flattened) portion 7 according the invention. These portions 7 are typically going to be used as contact pads/surfaces for connecting other electronic elements to the wire 6 . In the preferred application described in the present specification, this would be a RFID chip (or chip module) and the wire 6 would be the antenna of the resulting RFID transponder/tag.
[0052] FIG. 8 shows a preferred embodiment of a wire stripping machine 12 according the present invention. As said previously, such a machine should preferably be able to strip out small portions of a continuous wire, which is scrolled through the machine before being delivered to other manufacturing stations (for example such as wire embedding, etc.).
[0053] When in the machine 12 , the wire 1 is pulled at least by driving barrels (or rollers) 19 at a predetermined linear speed. Typically, as a non-limiting example, this speed is about 6,000±2,000 mm/min.
[0054] Preferably, a pre-scraper 13 is applied on the insulation of the wire (on a portion of the wire where the insulation is to be removed later in the process) and a pre-scraping operation is carried out. Typically, the pre-scraper 13 is similar to the stripping device illustrated in FIG. 2 with a set aperture between the jaws that is not sufficient to strip the wire but still enough to scrape a small part of the insulation (see FIG. 3 ). In order to recover the particles freed by this pre-scraping operation, a first particle filter guide 14 is used just after the pre-scraper 13 . Once the pre-scraping operation is finished, the pre-scraper jaws are opened.
[0055] The pre-scraped portion of the wire then arrives at the flattening barrels (rollers) 15 and the barrels are closed. The flattening barrels are used to flatten the portion of wire that is to be stripped bare according to the principle of the invention. Once the chosen portion of the wire has been flattened the flattening barrels 15 are open.
[0056] The flattened portion of the wire then reaches the scraper 16 (similar to the scraper described above in relation to FIG. 2 ) and the isolation of the flattened portion is removed in accordance with the principles of the present invention. Next to the scraper 16 , there preferably is a second particle filter guide 17 which is used to recover the particles created by the scraping operation. Once the scraping operation is finished the scraper 16 jaws are opened and the wire is further pulled by the driving barrels 19 .
[0057] In addition, there are sensors barrels 18 provided in the machine. These sensors are used to control the portion of the wire that has been stripped, i.e. the fact that it has been properly (and sufficiently) stripped. The sensors used can be electrical sensors, but also optical sensors (for example detecting the difference of reflection between the insulation of the wire and the flattened and bare wire portion). Other detecting means are of course possible as well in the frame of the present invention.
[0058] FIGS. 9 and 10 illustrate different embodiments of wire arrangements that can be realized with the principles of the invention.
[0059] In FIG. 9 , the example illustrated is an antenna with a cross-over bridge 20 having two flattened zones made of flattened portions of wire 7 . Preferably, the zones 7 are firstly used for their flattened properties, meaning that they allow a crossing of the wires without increasing substantially the thickness of the crossing. Indeed, as the crossing is made in a zone where the wires have been flattened, the thickness of the zone is less than the addition of the thickness of each wire.
[0060] This zone can also be used to yield capacitances at the cross-over zone, in accordance with the teaching of U.S. Pat. No. 5,541,399 which is incorporated by reference in the present application to this effect.
[0061] FIG. 10 illustrates another embodiment of wires with flattened and bare portions 7 , this figure showing several examples of possible use of the flattened portions created according to the present invention.
[0062] For example, on the left side of FIG. 10 , the two flattened and bare facing portions of wire 7 can be used as a switch zone to enable the functioning of the wire 6 as an antenna. An example of such a switch is given in EP 1 868 140 A1 incorporated by reference to this effect in the present application. In this prior art application, use is made of a contacting material that becomes conductive under pressure, said material being disposed between two contact zones of the antenna. Accordingly, the antenna is functional only when the contact material is put under pressure.
[0063] These two flattened and bare facing portions of wire 7 can also be used as contacts for a RFID chip for example, according to principle known in the art.
[0064] Similarly, the three contacts 7 shown in the middle of FIG. 10 can be used as switches or contacts for RFID chips, as mentioned above.
[0065] The contacting hole 21 (represented in the middle and at the top of FIG. 10 ) illustrates another use of the flattened and bare portions according to the invention. In this case, they are used to contact two wires together in a simple and efficient way. To improve the contacting, a contacting hole 21 can be used, but this is an option. This is mainly to illustrate how wires could be connected together in a simple way using the principle of the invention.
[0066] On the right side of FIG. 10 , another use of the stripped and flattened portions of the invention is illustrated. In this case, there is a succession of flattened portions 22 along the wire 6 . This succession of flattened and bare portions can be used as a watermark, i.e. as a security element. Typically, such a watermark can be purely optical (where such portions can be readily seen or detected optically) or also they can induce magnetic/electric effects for their detection. Of course, any number and/or configuration and/or shape of such portions may be envisaged in the frame of the present invention and is not limited to the example illustrated in FIG. 10 .
[0067] On the right side of FIG. 10 , a bridge similar to the one described with reference to FIG. 9 is illustrated once again.
[0068] As one will readily understand, different uses of the bare and flattened portions of a wire are possible and these different uses may also be combined together, as illustrated in FIG. 10 .
[0069] FIG. 11 illustrates schematically an embodiment in which a laser (or other equivalent means) is used to remove the insulation layer of the wire core 2 . This example illustrates an optical fiber 23 which projects a laser radiation 24 onto the insulation of the flattened wire, typically replacing the scraper 16 of FIG. 8 . Of course it is possible to combine the technologies and to use a laser in combination with a scraper, according to the principles of the present invention.
[0070] An advantage of using a laser is the fact that it can be used to remove a selected part of the insulation of the flattened portion, for example one side of the flattened portion only. Such a result is difficult to obtain with a mechanical system, for example using scrapers as described above.
[0071] List of Numerical References:
[0072] 1 insulated wire
[0073] 2 wire core
[0074] 3 insulation layer (as 3 ′)
[0075] 4 cracked insulation layer
[0076] 5 stripped flat surface of wire
[0077] 6 insulated portion of wire
[0078] 7 bare/stripped and flattened portion of wire
[0079] 8 jaw of a scraper
[0080] 9 scraping edge
[0081] 10 scraped insulation particles
[0082] 11 stripped surface of non flattened wire
[0083] 12 wire stripping machine
[0084] 13 pre scraper
[0085] 14 first particle filter guide
[0086] 15 flattening barrels
[0087] 16 scraper
[0088] 17 second particle filter guide
[0089] 18 sensor barrels
[0090] 19 driving barrels
[0091] 20 crossover bridge
[0092] 21 contacting hole
[0093] 22 flattened bare wire surfaces used as watermarks
[0094] 23 end of fiber optic cable
[0095] 24 laser radiation | According to the method of stripping a portion of a wire of the invention, the insulated wire including the wire core are first flattened before the insulation is stripped away. The flattening eases the stripping as the insulation is partially cracked and dissociated of the wire core, and the stripping is more efficiently applied on a flat surface. A wire stripping machine and a transponder antenna with stripped portions are also claim as being part of the invention. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 778,885 filed Mar. 18, 1977, now U.S. Pat. No. 4,074,840 issued Feb. 21, 1978.
BACKGROUND OF THE INVENTION
This invention relates to tools and, more particularly, to a hand-held tool for preparing the ends of optical fiber waveguides.
A major impediment to the development of optical communications is the implementation of low-loss splicing and coupling techniques. These techniques require properly prepared fiber ends, meaning that the ends must be smooth, flat, and perpendicular to the fiber axis if high coupling efficiencies are to be obtained. An effective technique for fiber end preparation has been the score-and-break technique, originally designed for use in the laboratory. This technique involves the stretching of the fiber over a curved surface and a light scoring by a hard, sharp edge such as a diamond to produce a microcrack which is diametrically propagated through the fiber to produce a clean break. The curved surface insures a proper break for fibers having a diameter greater than a critical diameter, which for fused quartz is 110 μm, by providing a stress gradient in the stretched fiber. It is not necessary to provide a curved surface, however, if the fiber waveguide has a diameter which is less than this critical value.
It may be appreciated that fiber end preparation is likely to occur under field conditions, and it is therefore desirable to provide a fiber preparation tool which is highly portable and simple to operate. Preferably the tool should be similar to one familiar to service personnel.
One tool which has been developed for carrying out the score-and-break technique in the field is described in an article entitled "Splicing of Optical Fiber Cable on Site" by H. Murata et al. (Procedures of the Fiber Communication Conference; London; September 1975; p. 93.) By means of the tool the fiber is bent at a given radius and held in a tension-applied condition while it is scored and broken. The tool includes a curved fiber-supporting surface, a pair of clamps which secure the fiber to the surface, means for including tension in the fiber, and a wedge-like diamond blade that scores the fiber. The clamps and blade are actuated by a plurality of manually adjustable rod-shaped members which are coupled to an A-shaped mechanism, the legs of which are a pair of manually actuated arms and the lateral element of which is a centrally hinged linkage member. As the arms are squeezed together, the rods are pulled downward by the folding linkage, clamping the fiber to the curved surface and lowering the blade for scoring action on the fiber. The tool construction is complicated. The rod activators must be manually adjusted to achieve both the proper clamping force and blade penetration for various fiber diameters. The difficult construction of this complicated tool is reflected in its high cost.
Another fiber preparation tool for use under controlled conditions is disclosed in an article entitled "Simplified Optical Fibre Breaking Machine" by P. Hensel (Electronics Letters, Vol. 11, No. 24, p. 581 [27 Nov. 1975]). With this tool, a fiber having one end secured to a fixture is secured at its other end to the periphery of a rotatable segmented drum and is tensioned by the rotation of the drum. A cutting blade, working against a dashpot, scores and breaks the tensioned fiber. As stated in the article, the tool is for use under controlled conditions. The tool is larger than a hand tool and comparatively unwieldy.
SUMMARY OF THE INVENTION
It is an object, therefore, of the present invention to provide a hand-held fiber end preparation tool which is relatively simple in construction.
It is another object of the present invention to provide a fiber end preparation tool which is similar in operation to other tools heretofore used by service personnel on, for example, electrical wire telecommunication systems.
A hand-held tool for the preparation of optical fiber waveguide ends in accordance with the present invention comprises a pair of jaw members coupled for separating rotational movement about a pivot axis and means of biasing the jaw members in a comparatively unseparated position. First and second fiber supporting surfaces, respectively, are located on different ones of the jaw members for receiving and supporting an optical fiber waveguide generally circumferentially about the pivot axis. A third fiber supporting surface is positioned between the first and second fiber supporting surfaces and is generally aligned therewith. The tool includes a pair of spaced-apart handle members which are adapted for movement by a squeezing human hand. Fiber clamping means are responsive to movement of the handle members to exert a waveguide securing force against the first and second fiber supporting surfaces and to exert a jaw member separating force in response to further movement of the handle members, thereby inducing a tensile stress along the waveguide. A descendable cutting blade is releasable from a position above the third fiber supporting surface to contact the portion of the fiber waveguide thereon and produce a microcrack in the waveguide periphery whereby the induced tensile stress in the waveguide coupled with the circumferential support thereof causes a diametric propagation of the crack across the waveguide to produce an appropriately prepared cleaved fiber end.
The tool in accordance with the present invention may incorporate various modifications and refinements. For example, a stop means may be provided for limiting the movement of the cutting blade so as to prevent the cutting blade from contacting the third fiber supporting surface. The tool may incorporate a force adjusting means for adjusting the waveguide securing force exerted on the fiber waveguide. Jaw restraining means may be employed in order to maintain the jaw members in the separated position, and means may be incorporated for causing the cutting blade to be released automatically when the jaw members have been separated by a predetermined amount, and also for restoring the cutting blade to its initial position.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 illustrates a hand-held fiber end preparation tool in accordance with the present invention;
FIG. 2 shows the tool of FIG. 1 in its fiber clamping position;
FIG. 3 illustrates the tool of FIGS. 1 and 2 in its fiber tensioning position with the blade alighting on the fiber waveguide;
FIG. 4 is a side view of the tool as shown in FIG. 1 partially in section taken along the line 4--4 of FIG. 1;
FIG. 5 is a rear view of the tool as shown in FIG. 1 prior to the lowering of the cutting blade onto the fiber waveguide;
FIG. 6 is a rear view of the tool as shown in FIG. 3 subsequent to the lowering of the cutting blade onto the fiber waveguide;
FIG. 7 illustrates a modification of the hand-held fiber end preparation tool in accordance with the present invention;
FIG. 8 illustrates the tool of FIG. 7 in its fiber tensioning position with the blades alighting on the fiber waveguide;
FIG. 9 is a fragmentary side view of the tool of FIG. 7;
FIG. 10 is a fragmentary side view in perspective illustrating a detail of the tool of FIG. 7;
FIG. 11 is a fragmentary view illustrating another modification of the tool in accordance with the present invention;
FIG. 12 is a view with portions broken away illustrating a further modification of a tool in accordance with the present invention;
FIG. 13 is a side view of the tool as shown in FIG. 12 partially in section taken along line 13--13 of FIG. 12;
FIG. 14 is a rear view of the tool as shown in FIG. 12; and
FIG. 15 is a fragmentary view illustrating a still further modification of the tool in accordance with the present invention.
For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIGS. 1, 4, and 5, the front, side, and rear views, respectively, of a fiber end preparation tool in accordance with the invention are shown. As shown in FIG. 1, the tool comprises a pair of jaw members 12 and 14 coupled for separating rotation about a pivot axis 16 which is normal to the plane of the drawing. In the embodiment illustrated the jaw member 12 is affixed to a backplate 11 while the jaw member 14 is coupled for rotation with respect thereto by a bolt at the pivot axis.
The jaw members 12 and 14 are biased toward each other in a comparatively unseparated position primarily by a tension spring 18 coupled therebetween. Other springs also urge the jaw member toward each other as will be described hereinbelow. The term "comparatively unseparated" is employed to connote that the jaw members need not necessarily be contiguous in their unseparated position but may simply be spaced from each other by a lesser distance than that subsequent to the separating rotational movement of jaw member 14 as will be described hereinbelow.
Respectively associated with the jaw members 12 and 14 are a pair of members providing fiber supporting surfaces 20 and 22 which receive and support an optical fiber waveguide 25 in a generally circumferential manner about the pivot axis 16. An anvil or platform provides a third fiber supporting surface 24 which is circumferentially disposed about the axis 16 and lies between the first and second surfaces 20 and 22 with its ends tangentially aligned therewith. The anvil providing the fiber supporting surface 24 is fixed with respect to the backplate 11 and the stationary jaw member 12. The surfaces 20, 22, and 24 have machined finishes which are essentially free of nicks which might damage a fiber. Surface 24 has a low coefficient of friction and may conveniently comprise a metal which is spray-coated with teflon to provide the low friction coefficient.
The tool is held by a pair of spaced-apart handle members 34 and 36 which are adapted for rotational movement about the pivot axis 16 in response to a squeezing force exerted by the operator's hand. The handle members are biased apart by a compression spring 38. The handle members 34 and 36 are coupled to a respective one of a pair of fiber clamping members 26 and 28 by way of a pair of linkage members. As shown in FIGS. 1 and 4, handle member 36 is coupled to one end of the linkage member 40 by a pin 43 and the other end of the linkage member is coupled to the fiber clamping member 28 by a pin 42. The clamping member 28 is mounted for confined movement in a track 41 so that the squeezing of the arm 36 is translated into a movement by the fiber clamping member 28 towards the fiber supporting surface 22. The handle member 34 is similarly coupled to the fiber clamping member 26 which is mounted for movement in a similar track. Accordingly, it may be appreciated that compression of the handle members 34 and 36 by a squeezing human hand, as shown in FIG. 2, causes the optical fiber waveguide 25 to be securely held against the fiber supporting surfaces. The teflon coating on the fiber supporting surface 24 also serves to cushion the fiber as it is bent.
As shown in an exaggerated manner, for clarity, in FIG. 3, further squeezing of the handle members 34 and 36 causes separating rotation of the jaw members 12 and 14 inducing tensile stress in the waveguide 25. The jaw separation is caused by a clockwise torque on the jaw member 14 about the axis 16 which is, in turn, produced by the lateral force of the pin 42 against the track 41. Analytically, the additional squeezing force may be conveniently resolved, with respect to the axis 16, into a generally radial component exerting the fiber securing force and a circumferential component exerting the clockwise torque. The counter-torque produced by the tensioned spring 18, which initially maintains the jaw members in their comparatively unseparated relationship, is overcome by the circumferential component when the fiber clamping members 26 and 28 securely clamp the waveguide 25 and additional manual squeezing force is applied to the handle members 34 and 36.
The counter-torque required to be overcome by the circumferential component may be made adjustable in order to adjust the amount of fiber clamping force exerted on the fiber waveguide by the fiber clamping members 26 and 28. A compression spring 70 may be mounted within a yoke 72 which is fixed to the backplate 11. The spring is compressed between the yoke 72 and the jaw member 14. The amount of force in the compression spring may be adjusted by means of an adjusting screw 73. With this arrangement the tension spring 18 and the compression spring 70 operate together to determine the amount of clamping force which must be applied by the squeezing of the handle members 34 and 36 before the jaw members 12 and 14 begin to separate.
The fiber clamping members 26 and 28 each include a member 30 and 32, respectively, providing fiber contacting surfaces which preferably are of rubber. The clamping force and the resulting net tension induced on the fiber are related in a complex way to the friction coefficients of the fiber, the rubber, and the fiber supporting surfaces. Continuous squeezing of the handle members 34 and 36 increases the tension on the fiber between the two gripped regions. Since the fiber is not elastic, the friction coefficients are selected to allow a degree of slippage and consequently limit the induced stress level in the fiber. It has been found that carbon filled butyl rubber provides a satisfactory friction coefficient.
Once the fiber waveguide 25 has been stressed, a descendable cutting blade 46 is released from an initial suspended position above the fiber supporting surface 24, as shown in FIG. 2, to a fiber contacting position as shown in FIG. 3. The blade contacts the periphery of the optical fiber waveguide 25 to produce a microcrack therein. The induced tensile stress in the waveguide 25 coupled with the circumferential curve thereof causes a diametric propagation of the crack across the waveguide to cleave the waveguide and produce an appropriately prepared fiber end. The blade 46 is preferably a diamond honed to a sharp 60° edge, and mounted in a supporting block 47. Other blade materials such as sapphire or tungsten carbide may also be used. As will be discussed in more detail hereinbelow, the supporting block 47 is mounted in a slide which allows motion along an axis perpendicular to the plane that is tangent to the fiber at the point of contact of the diamond edge thereon. As will also be further discussed hereinbelow, in the embodiment under discussion the supporting blade 47 with the blade 46 is held in its suspended position by a thumb release latch 48 which is positioned on the tool in alignment with the natural position of an operator's thumb when the handles are being squeezed. Rotation of the thumb latch 48 from its position in FIG. 2 to its position in FIG. 3 permits the blade to fall under the influence of gravity. Preferably, however, the blade speed is slowed by means such as an air-pot (air-filled dashpot) to an adjusted constant velocity so that the blade just alights on the optical fiber waveguide.
The manner in which the blade 46 is controlled may be more readily appreciated by reference to FIGS. 4 and 6. As shown in FIG. 4 which is a side view of the tool taken in partial section along the line 4--4 of FIG. 1, the blade 46 is suspended from a supporting member 47 which is mounted for vertical sliding motion in a vertical slot formed in the backplate 11. The rear portion 47A of the supporting member 47 is coupled to an arm 54 of a dashpot 56. The thumb latch 48 is connected by means of a pin 50 to a cam 60, shown in FIGS. 5 and 6, on the rear of the tool.
FIGS. 5 and 6 show the rear of the tool when the blade 46 and blade supporting member 47 are in the suspended and in the fiber contacting positions, respectively. As may be appreciated by a comparison of these two figures, the counterclockwise rotation of the thumb latch 48 as viewed in FIG. 1 causes a corresponding clockwise rotation of the cam 60 as viewed in FIGS. 5 and 6. One tip 60A of the cam 60 contacts an outwardly extending contact member 74 associated with a linkage member 62. The linkage member 62 includes an annular sleeve 62A at its other end through which the dashpot arm 54 passes. The upper surface of the sleeve 62A supports the blade supporting member 47 in its suspended position. It may be fully appreciated that the clockwise rotation of the cam 60 causes its edge 60A to depress the contact member 74 of the linkage member 62. The unsupported blade supporting member 47 is thereby permitted to fall, as shown in FIG. 6, at a velocity which is limited by the dashpot 56. The velocity may be controlled by adjusting the dashpot by means of a manually rotatable thumb wheel 58 in a manner known in the art.
In the embodiment illustrated the cam 60 is additionally provided with a hook-shaped extension 64 which engages an outwardly extending pin 66 on the sleeve 62A when the blade is in its fiber contacting position. The engagement of the pin 66 by the cam 60 provides a locked position which may be utilized during transportation and storage of the tool in order to protect the blade.
When the thumb latch 48 is reset to its initial position, the counterclockwise rotation of the cam 60, as viewed in FIGS. 5 and 6, removes the cam surface 60A from the contact member 74. A resilient member such as a leaf spring 68 is coupled to the blade supporting member 47 in a manner which exerts an upwardly directed force so that the blade returns to its initial suspended position.
Although a scoring action by the blade of the present tool has been found unnecessary for most fiber waveguides, there may be instances where service personnel would find such a capability helpful. The presently described embodiment may be easily modified to provide scoring when necessary. Accordingly, a small clearance, such as 0.005 inch, may be provided between the rear portion 47A of the blade supporting member and the backplate 11 so that a slight lateral movement thereof through the backplate slot is permitted. A resilient member such as a small weak leaf spring may be located in the newly defined gap to prevent lateral blade movement unless the rear blade support member portion 47A is pressed forward.
FIGS. 7 and 8 illustrate a modification of the hand-held fiber end preparation tool shown in FIGS. 1 through 6. The tool is basically similar, employing two jaw members 80 and 81 mounted for pivotal movement with respect to each other on a backplate 82. The squeezing of handle members 83 and 84 causes fiber clamping members 85 and 86 which are slidably mounted on jaw members 80 and 81, respectively, to clamp an optical fiber waveguide 90 against fiber supporting members 91 and 92.
As in the previously described embodiment further squeezing of the handle members 83 and 84 causes jaw member 81 to rotate about the pivot point 88 and place the optical fiber waveguide 90 under tensile stress while bending it across a fiber supporting surface provided by an anvil 93. A cutting blade 95 is fixed in a supporting member 96 which is mounted for vertical sliding motion on the backplate 82 as in the previously described embodiment. The supporting member 96 is released by actuation of a thumb latch 97 causing the cutting blade to descend and cleave the fiber optic waveguide 90, thereby providing a proper break as explained hereinabove.
As illustrated in FIGS. 7 and 8, but shown more clearly in the fragmentary side view of FIG. 9, in the embodiment presently under discussion a stop member 100 is mounted in the blade supporting member 96 so as to limit the descent of the cutting blade 95. The principal purpose of the stop is to insure that the cutting blade descends onto the periphery of the optical fiber waveguide so as to produce a microcrack therein but does not strike the surface of the anvil 93. Thus the surface of the anvil is protected from nicks and scratches which might be caused by the cutting blade, and in addition the cutting blade is protected. As illustrated most clearly in FIG. 9 the stop 100 includes a screw which is threaded into the blade supporting member 96 and retained in place by a lock nut 101 permitting adjustment of the minimum distance between the cutting blade and the anvil surface.
The hand-held fiber end preparation tool as illustrated in FIGS. 7 and 8 also includes a circular locking cam 105 having an extension 106 permitting actuation by thumb. The cam 105 is mounted eccentrically on jaw member 81 to permit pivotal movement with respect thereto. As illustrated in FIG. 7 with the jaw members 80 and 81 in their comparatively unseparated position the cam is in a rotational position so as not to interfere with the separating or closing together of the jaw members. While the jaw members are separated by squeezing of the handle members 83 and 84, the blade is lowered to cleave the waveguide and then the blade is raised. The cam 105 is then rotated to the position shown in FIG. 8. In this position the cam bears against the lower portion 93A of the anvil 93 which protrudes forward of the jaw members 80 and 81. Jaw member 81 is thus locked in the separated position as shown in FIG. 8 even after release of the handle members 83 and 84.
After the fiber waveguide has been cleaved and the cutting blade returned to its initial position, the handle members 83 and 84 are released while the cam 105 is holding the jaw members in the separated position. Compression spring 87 urges the handle members apart, and the linkage coupling the handle members to the clamping members 85 and 86 causes the clamping members to move upward releasing the two portions of the cleaved fiber waveguide 90. Unclamping of the waveguide portion prior to movement of the jaw members toward each other insures that the newly severed fiber ends will not be pushed against each other possibly breaking the waveguide or otherwise disrupting the properly prepared end surface. After the fiber waveguide portions have been removed from the tool, the handle members 83 and 84 may be squeezed together sufficiently to permit the cam 105 to be rotated to its original position as shown in FIG. 7 and the handle members released, thereby readying the tool for the next cleaving operation.
The fragmentary view of FIG. 10 illustrates a detail of the tool shown in FIGS. 7, 8, and 9. A fiber locating or positioning plate 110 is mounted on the side of the fiber support member 91. The plate has two upstanding portions forming an intermediate valley which receives and properly positions the fiber waveguide 90. A similar plate is mounted on the side of the other fiber support member 92. The two plates insure that the waveguide 90 is properly located on the fiber supporting members 91 and 92 and properly positioned on the anvil 93 with respect to the cutting blade 95.
FIG. 11 is a fragmentary view illustrating another modification of the hand-held fiber end preparation tool in accordance with the present invention. FIG. 11 shows the tool with the jaw members 115 and 116 in the separated position subsequent to cleaving of the fiber waveguide 117 by the cutting blade 125. The two portions 117A and 117B of the cleaved waveguide are shown clamped against the fiber supported members 118 and 119 by clamping members 120 and 121, respectively. In this embodiment the cutting blade 125 is positioned above the anvil 126 at a point which is nearer to one clamping member 120 than to the other 121. That is, the arrangement is asymmetric and the two portions 117A and 117B of the cleaved waveguide are of different lengths. As illustrated in FIG. 11 the two portions extend tangentially from the curved surfaces of fiber supporting members 118 and 119 to which they are clamped, and by virtue of the difference in their lengths their ends are staggered. Thus, the newly prepared ends do not interfere with each other even if the jaw members return to their comparatively unseparated position prior to release of the waveguide portions by the clamping members.
FIGS. 12, 13, and 14 are front, partial side, and rear views, respectively, of another modification of the hand-held fiber end preparation tool in accordance with the invention. The tool operates generally in the manner of previously described embodiments to cleave the waveguide by placing it under tensile stress across the curved surface of the anvil and initiating a microcrack therein by lowering the cutting blade into contact with its periphery. In addition, the embodiment under discussion includes additional features for automatically lowering the cutting blade when the jaw members are separated to a predetermined position, for latching the jaw members in the separated position, and for automatically restoring the cutting blade to its initial position after cleaving.
A pair of jaw members 130 and 131 are mounted for relative pivotal movement on a backplate 132. Jaw member 130 which is fixed to the backplate 132 has a fiber supporting member 133 mounted thereon. A similar fiber supporting member 134 is mounted on the movable jaw member 131. Fiber clamping members 136 and 137 are movably mounted on jaw members 130 and 131, respectively. An anvil 138 is mounted on the backplate 132 between the two fiber supporting members 133 and 134, and a cutting blade 139 in a supporting block 140 is mounted for vertical movement above the surface of the anvil 138. An optical fiber waveguide 141 is supported on the surfaces of the fiber supporting members and may be properly positioned as by plates such as shown in FIG. 10. The handle members 145 and 146 are squeezed together in opposition to the compression spring 147 causing the fiber clamping members 136 and 137 to clamp the waveguide 141 against the surfaces of the fiber supporting members 133 and 134. Further squeezing of the handle members 145 and 146 causes the jaw member 131 to pivot with respect to the jaw member 130 placing the waveguide 141 under tensile stress as explained hereinabove.
The tool of FIGS. 12, 13, and 14 employs a latching member 150 which is mounted by means of a pivot 151 on the backplate 132. The latch member is biased in a clockwise direction as shown in FIG. 12 by a spring 152. When the handle members 145 and 146 are squeezed together moving the jaw members 130 and 131 apart by a predetermined distance, a notch 153 in the latch member 150 is engaged by a pin 154 fixed to the jaw member 131. The amount of relative movement of the jaw member is thus limited to a predetermined amount selected to provide the desired tensile stress in the fiber waveguide 141.
The blade supporting block 140 has an arm 160 which extends over a protrusion or shoulder 161 at the upper portion of the jaw member 131 when the jaw members are in the unseparated position as shown in FIG. 12. The length of the arm 160 is set so as to become disengaged from the protrusion 161 on the jaw member 131 as the pin 154 engages the notch 153 of the latch member 150 or just before the pin 154 engages the notch 153. As the protrusion 161 clears the arm 160, the supporting block 140 containing the blade 139 is released from the initial position. The blade descends to contact the periphery of the waveguide 141 cleaving it in accordance with the previously described explanation.
Although an arrangement in which the blade mounting element 140 descends under the influence of gravity as in the previously described embodiments may be employed, the present embodiment as shown in FIGS. 13 and 14 employs a tension spring 165 to lower the cutting blade. the spring 165 is fixed to the rearwardly extending portion of the blade supporting block 140 and to an extension 166 of the backplate 132. The rate of movement of the cutting blade is controlled by an air dashpot 170 as explained hereinabove. Lowering of the cutting blade by a tension spring rather than by gravity permits operation of the tool in any attitude.
After the cleaving of the waveguide 141, the handle members 145 and 146 are released. Since the pin 154 engages the notch 153, the latch member 150 prevents the jaw members 130 and 131 from moving toward each other. Thus, the first movement of the handle members 145 and 146 raises the clamping members 136 and 137 releasing the two portions of the cleaved fiber waveguide 141. Since the two portions of the waveguide are released while the jaws are separated, their ends do not interfere with each other. As the fiber clamping members 136 and 137 are returning to their initial positions, either one or both of pins 174 and 175 which are mounted on the clamping members 136 and 137, respectively, engage the bottom surface of the blade supporting block 140. The blade supporting block 140 and blade 139 are thus raised along with the clamping members restoring them to the initial position. The two portions of the cleaved waveguide 141 may then be removed from the tool.
After the handle member 146 has moved a predetermined amount, the surface of its upper portion 172 strikes a tab 155 on the latch member 150. Further movement of the handle member rotates the latch members releasing the latch member from the pin 154. Then, tension springs, as discussed previously, rotate the jaw member 131 and restore it to its initial position. Return of the jaw members to the comparatively unseparated position thus takes place after the clamping members have released the fiber waveguide and the cutting blade has been restored to its initial position leaving the tool in readiness for the next cleaving operation.
FIG. 15 illustrates a fragment of a still further modification of the hand-held tool of the invention. The feature illustrated may be employed with any of the embodiments discussed hereinabove in place of the disclosed means for holding the jaw members separated or together with the latching arrangement shown in FIGS. 12 and 13. In the embodiment illustrated in the fragmentary view of FIG. 15, jaw members 190 and 191 are held in a separated position by means of a ratchet 192. The ratchet 192 is mounted for pivotal movement on the jaw member 190 and is biased in a clockwise direction, as shown, by a spring 193. The ratchet teeth 194 bear against a stop member 195 mounted on the movable jaw member 191. The ratchet teeth 194 engage the stop member 195 permitting opening of the jaw members but preventing closing of the jaw members. After the tool has been operated to cleave the fiber waveguide 200 as explained hereinabove, the handle members are released, the waveguide is unclamped and the cutting blade is returned to its initial position. The ratchet 192 may then be released as by pushing upward on a release pin 196 protruding from the ratchet 192 thereby disengaging the ratchet teeth 194 from the stop 195 and causing the jaw members to be restored to the comparatively unseparated position.
While there has been shown and described what are considered preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims. | A tool for preparing the ends of optical fiber waveguides prior to such operations as coupling and splicing. The tool is adapted for single-handed operation and comprises a pair of manually actuated handles, first and second fiber supporting surfaces, and a third fiber supporting surface between the first and second surfaces. The optical fiber waveguide is secured to the first and second surfaces by a pair of clamping members which are responsive to the squeezing of the handles. Once the fiber waveguide is secured to the surfaces, further squeezing of the handles produces separating rotation of a pair of jaw members to put the fiber under tensile stress. A cutting blade suspended above the third surface is released to produce a peripheral microcrack on a portion of the optical fiber waveguide lying on the third fiber supporting surface. The induced stress and curved support of the fiber waveguide act in combination to propagate the microcrack diametrically through the fiber so that an appropriate fiber end is obtained. Various modifications and refinements of the tool provide for greater control and semi-automatic operation in preparing fiber ends. |
BACKGROUND OF THE INVENTION
The present invention relates to recent improvements in the handling and utilization of potentially harmful substances, such as organic solvents, to improve environmental safety associated with their use. More particularly, it relates to a new and improved apparatus and method for removing residues and impurities from a circulating solvent flow circuit including a self-scrubbing thermosyphon distillation subassembly for separating purified solvent for return to the flow circuit and a controlled waste collector subassembly for overflowing concentrated residues and impurities into an easy-to-service container.
Recently, the number of kinds of organic solvents commercially employed in a variety of end use applications has increased. Hydrocarbons, halohydrocarbons, fluorocarbons and aromatic solvents are now employed in a number of cleaning applications. Dry cleaning operations for clothing, sometimes referred to as chemical cleaning in Europe, may be the most widespread use for organic solvents of this type. Other uses include cleaning operations for electronic equipment, e.g., refluxing of printed circuit boards. Moreover, various metal cleaning and parts washing apparatus employ special solvents. Some metal cleaning operations prepare surfaces to receive paint or other coatings. Alternatively, solvents may be used to soften and remove unwanted paint and coatings from various substrates such as, for example, in spray guns or other automatic painting equipment.
Concurrently, an awareness of the possibility of environmental damage caused by careless handling and disposal of these organic solvent materials has also increased. Concerns over contamination of ground water supplies caused by the leaking and spilling of used or contaminated solvent onto the ground has long been a concern. More recently, it has been suggested that uncontrolled release of some or all of these organic solvent vapors into the atmosphere may be harmful. Release of some materials may cause a health hazard by increasing the ozone content of the lower atmosphere. Other materials are believed to cause an increased degradation of the ozone layer in the upper atmosphere. Various chlorinated fluorocarbons have been seriously implicated in this regard and a reduction and eventual ban of their use has been recommended by international agreements, such as the Montreal Protocol. Additional health concerns have been noted with respect to the possible carcinogenicity of low molecular weight hydrocarbon and halo-hydrocarbon materials.
The environmental, health and safety concerns surrounding a common end use application for controlled organic solvents is well illustrated by the case of a small to moderately-sized commercial dry cleaning operation. In a commercial dry cleaning operation, customers clothes are collected at a storefront location. The clothes are washed in cleaning machines located on the premises or at a separate location. The clothes are tumbled in an amount of a cleaning solvent which is periodically circulated in batches into the cleaning machines from a reservoir. After agitation of the clothes in the presence of the fluid takes place, the cleaning fluid, usually 1,1,1-trichloroethane (prohibited as of 1995), tetrachloroethylene, or 1,1,2-trichloro-1,2,2-trifluoroethane (known as CFC-113 or Freon®113 (DuPont)) is drained into a collecting basin associated with the clothes washing units. Additional fluid remaining on the clothes is extracted by spin cycling and this additional solvent is added to the collecting basin.
The used, collected cleaning solvent is then returned to the reservoir and is recycled and continuously used from the reservoir until it is time to replenish the solvent supply, in whole or in part. Frequently, during a portion of the dry cleaning solvent circulation cycle, the solvent may be subject to treatment for removal of solids or particulate matter, namely, lint, grit and the like by means of filters and for removal of water or the like by liquid separators.
In the course of repeatedly re-using the dry cleaning solvent, the solvent per se is not degraded or damaged but becomes contaminated with non-volatile residues and impurities of varying kinds. Normally, the kinds of impurities miscible with a cleaning solvents are oily residues from a number of sources, such as body fluids, air pollution and various foods and beverages. As the concentration of these non-volatile residues builds up in the solvent, the solvent becomes increasingly less effective at cleaning. Eventually, the entire batch of solvent must be removed containerized and transported to a recycling or disposal center.
At this point a number of disadvantages and environmental concerns may be identified. It is now well known that every effort should be made to reduce, reuse and recycle potentially harmful materials. Reuse of the solvents is currently practiced, but after a given level of contamination is reached, re-conditioning or replacement of the solvent is required. Recycling of the dry cleaning fluids however also presents special additional risk factors to be considered. During recycling care should be taken to reduce or eliminate the risk of spillage and/or of exposing volatile organic solvents to humans and the atmosphere. Removing the solvent from the dry cleaning circuit and placing it into containers for shipment to a treatment center introduces the added possibility for spillage and exposure to vapors. Furthermore, transporting the containers to a remote solvent reconditioning center increases the risk of spillage and exposure because of the risk of highway or rail accidents. For these reasons providing a controlled, on-site solvent regeneration system is clearly more desirable than shipping new solvent to a location and shipping used solvent away from the same location on a frequent basis.
Prior art equipment for separating re-usable solvent fractions from non-volatile residues and impurities introduced into the solvent during use have generally been based on distillation equipment and has not been altogether satisfactory. Prior art distillation equipment is generally involves heating with high pressure steam by means of a jacket located in a wall of the distillation vessel. Sometimes a tube bundle is used as a heat source. Frequently, a motor-driven agitator designed to scrape the walls is provided. The prior art scraper systems are generally ineffective to prevent deposition of resinous coatings on the heat transfer surfaces. Once deposition occurs, heat transfer is impeded or halted completely. At this point, it becomes necessary to dismantle the distillation equipment to permit the interior of the vessel to be scraped and cleaned exposing workers and the environment to chemical vapors.
Prior art batch stills usually comprise manually operated apparatus requiring undesirably high amounts of solvent handling. In the case of stills used for dry-cleaning solvents, direct heating without agitation is typical. In the hands of an unskilled operator with little or no distillation background, these stills are frequently operated at overheating temperatures. Overheating causes residue decomposition which may also produce and introduce secondary contaminants into the air or solvent which are possibly toxic. Moreover, overheating causes excess carry-over of residues resulting in unsatisfactory separations.
In one prior art still equipped with a wall scraping stirrer/agitator and adapted for solvent flow rates of as high as 500 gallons per hour, the heating surfaces become coated and ineffective after only about one hour.
In view of the failure of the prior art to provide effective devices and methods for providing environmentally-safe cleaning and regeneration/separation of re-usable solvent from non-volatile residues (NVRs) on the premises, it is an object of this invention to provide improved apparatus and methods for accomplishing on the premises cleaning and regeneration/separation of re-usable solvent from non-volatile residues (NVRs).
It is another object of this invention to provide a new and improved still apparatus for concentrating NVRs and other impurities for batch collection and removal in easy-to-service containers.
It is a further object of the present invention to provide a new and improved apparatus for regenerating clean solvent including a self-scrubbing thermosyphoning heat transfer assembly which does not become dirty and retains its heat transfer efficiency, even after prolonged periods of continuous operation and even when exposed to NVR concentrations in excess of 40%.
It is still another object of the present invention to provide a new and improved solvent distillation apparatus adapted to be placed in a parallel in-line relationship with a circulating solvent stream to extend the useful life of a given quantity of solvent cycling through the solvent stream on the premises of use.
It is a further object of the present invention to provide an on-the-premises solvent recovery distillation plant employing a new and improved self-cleaning heating system which may be maintained without disturbing the remaining portions of the distillation apparatus to reduce or eliminate exposure of personnel to chemicals.
It is still another object of the present invention to provide an apparatus and method for conducting solvent distillation under conditions mild enough to avoid decomposition of solvent and solvent contents, so that non-volatile residues and impurities stripped from the solvent may be recovered intact, should. The NVRs be known or discovered to be separately useful or reusable.
SUMMARY OF THE INVENTION
In accordance with these and other objects, the present invention provides a new and improved apparatus for controlled, on-site concentration and removal of non-volatile residues and other impurities from a circulating solvent stream in an end use flow circuit for said solvent. The new and improved apparatus of the invention comprises a generally hollow vessel defining a fluid-receiving chamber. The fluid receiving chamber within the still vessel includes an upper vapor-receiving portion and a lower liquid-receiving sump portion. The lower sump portion has an associated maximum liquid level fill height generally defined by an overflow exit port and optionally but preferably, also has a minimum liquid fill height determined generally by the placement and position of a liquid level sensor. A dirty or contaminated solvent entry port is provided in said vessel disposed below the minimum liquid fill height.
The apparatus additionally comprises a condenser subassembly mounted to said vessel adjacent an upper end thereof having an inner cooling channel disposed in fluid flow communication with the upper vapor-receiving portion. The condenser subassembly includes means for collecting an evaporated, decontaminated solvent fraction in liquid form as it is condensed along the cooling channel surfaces and for returning the collected liquid, i.e., reclaimed, solvent fraction to the circulating solvent stream.
In accordance with the invention, the new and improved apparatus further comprises a thermosyphon heat transfer subassembly. The heat transfer subassembly includes an elongate, vertically oriented heating tube having an upper end with a discharge opening, and an opposed lower end with a heater rod-receiving opening. A solvent entry aperture is also defined in the heating tube adjacent the lower end.
The thermosyphon heat transfer subassembly further includes an elongate heater rod having a lower end with a base mounting portion and an opposed upper free end. The heater rod is mounted to the heating tube so that the free end of the rod is telescopically and coaxially received in said tube with the base mounting portion sealably, mountedly engaged in the rod-receiving opening. The heater rod has an outer diametrical dimension which is less than the inner diameter of the heater tube to thereby define a generally narrow annular heat transfer region therebetween.
The thermosyphoning heat transfer subassembly is mounted to a lower end of the vessel so that the lower end of heating tube extends below the vessel and the upper end of heating tube extends through the bottom of the vessel in sealed relation therewith. The upper end of the heating tube is positioned so that its discharge opening is disposed in the fluid receiving chamber at a point above the maximum liquid fill height.
The apparatus additionally includes means for providing fluid flow connection between the lower sump portion of the vessel and the solvent entry aperture communicating with the annular heat transfer region. Pump means are also provided for introducing contaminated solvent from the circulating solvent stream in said end use solvent circuit to the contaminated solvent entry port defined in the lower portion of the vessel.
Finally, the new and improved apparatus includes means for interactively automatically controlling operation of the distillation operation, including means for sensing overflow volume, an on/off heater power switch, means for sensing temperature, means for sensing a lower liquid level and means for supplying cold water to said condenser.
Generally, after an initial start up sequence, the heater switch in its on position or condition causes rapid reboiling and thermosyphoning liquid flow of the dirty solvent from the sump portion, through the heating region and out the upper discharge end of the tube. Movement of the contaminated solvent along the annular heat transfer space causes vaporization of the exiting solvent. Heated solvent vapor travels upwardly into the condenser cooling chamber where it condenses to form droplets of purified liquid solvent along the chilled surfaces of the cooling channel. An undercut collection trough receives the dripping condensate and routes it for return to the circulating solvent stream.
Gradually the liquid level of contaminated solvent in the sump portion falls due to the evaporation and removal of pure solvent condensate. Concurrently, the temperature of the re-boiling sump liquid gradually increases with each pass through the heat transfer zone. If either of two conditions are satisfied, namely that the liquid level drops to the minimum fill height or that the sump liquid temperature reaches a predetermined upper temperature value, the interactive controller turns on the pump to introduce a new amount of relatively colder dirty solvent into the sump portion. Fresh dirty solvent is added to the bottom of the sump portion until the temperature of the body of liquid has been reduced a predetermined number of degrees. Normally, in the course of this process there will be overflow from the top of the sump portion.
If the controller senses that the condenser cool water flow is impeded, the heater rod power switch is turned off.
The present invention is directed to a method and apparatus which extends the use life of a given quantity of dry cleaning or other solvent. The invention is concerned with a novel still apparatus which may be placed in parallel with the portions of the solvent cycle circulation loop. The apparatus periodically withdraws a portion of the being-used solvent, subjects it to a still separation or evaporative cleaning operation and returns the clean portion of the solvent to the solvent supply as a whole. As this process continues, the concentration of the contaminated solvent in the liquid section of the still continues to increase in the contaminated or nonvolatile residue (NVR) portion. After a significant amount of clean solvent is created through the evaporative and cleaning recollection, the collected concentrated non-volatile residues may be drained or overflowed to a controlled waste container as the still vessel is refilled and the sequence of operation continues. The solvent regeneration may be performed as continuous batch sequence operation wherein successive quantities of solvent are introduced and separated into a clean solvent fraction and a concentrated NVR contaminant fraction.
According to the present invention, vertical flow tubes providing in effect a cylindrical column of liquid surrounding upwardly extending heater rod electrodes provides a circulation pattern which ensures rapid turbulent travel of the solvent past the surfaces of the heating element or elements. This action has been found effective to reduce or eliminate deposition of solid materials on heater surfaces. This reduction in residue build up on the heater surfaces in turn promotes better and extended heat transfer, improved recirculation and more orderly boiling action. By concentrating the non-volatile residues in the still, and continually supplying a clean solvent to the solvent supply, the supply is kept clean for an extended time.
Other objects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1. is a schematic plan view of a dry cleaning circuit of operation incorporating the new and improved parallel in line controlled waste concentrator and solvent regenerator apparatus of this invention;
FIG. 2 is a perspective view of the new and improved apparatus of this invention;
FIG. 3 is an elevated vertical cross-sectional view of the new and improved apparatus of the invention taken along view lines 3--3 in FIG. 2; and
FIG. 4 is an enlarged, elevated cross-sectional view of the new and improved thermosyphon heating subassembly of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a schematic diagram depicting the use of the new and improved waste concentrator/solvent regenerator apparatus 10 of this invention shown in use installed in a parallel in-line relationship to a looped, cyclic dry cleaning solvent circuit 12. Dry cleaning solvent circuit or loop 12 includes a reservoir, R, for holding an excess supply of dry cleaning fluid which may contain an organic solvent such as 1,1,1-trichloroethane, or tetrachloroethylene, as well as, non-volatile residues (NVRs) and other impurities such as detergents and previously removed soils, spots and/or stains. Typically, the circulating dry cleaning solvent travelling around dry cleaning solvent circuit loop 12 a water emulsion containing about 11/2% by weight NVRs. This circulating solvent fluid, frequently referred to as perk, has a boiling temperature range which varies depending on the concentration of NVRs present. Substantially purified solvent may vaporize or boil at a temperature of about 247° F., whereas contaminated solvent has a boiling range above that temperature, e.g., at about 40% by weight NVRs the contaminated solvent generally boils at a temperature of about 270° F.
As shown in FIG. 1, dry cleaning solvent circuit loop 12 includes a first pump, P-1, for causing solvent to flow from a lower portion of reservoir R into washing machine, W, wherein dirty clothes are tumbled in dry cleaning solvent to clean the garments. After a washing cycle has been completed, the used solvent exits from the machine drains and passes through a lint trap and/or fiber filter, F-1. After filtering, the used and filtered solvent is returned to reservoir, R, for recycling and re-use.
The new and improved apparatus 10 of this invention comprises a part of a parallel, in-line solvent flow circuit or loop 14. As depicted in FIG. 1, parallel loop 14 includes a flow circuit wherein solvent from reservoir, R, is pumped by a pump, P-1, through an in-line filter, F-1, such as a gasoline type fuel filter. Filter F-1 may be a 10 inch long, 30 micron cotton wound filter which may be used alone but preferably is used in combination with a lint screen filter, F-2, disposed upstream of filter F-1. The lint screen, F-2, and filter, F-1, should be generally effective to substantially remove all clothing fibers from the being-pumped dirty solvent stream prior to its introduction into the thermosyphon evaporation purification unit or still, S.
In accordance with this invention, the dirty solvent enters still S and is treated by a thermosyphoning distillation method which separates purified evaporated solvent from a more concentrated NVR solution fraction. Evaporated solvent is condensed and collected in a first cooling condenser, C 1 , before being pumped by a pump, P-2, through a second cooling heat exchanger unit, C 2 , for return to reservoir, R. Concentrated NVRs are overflowed from still, S, in accordance with this invention, through another cooling heat exchanger, C 3 , and into an exit line having a sealed and engaged NVR concentrate removal jug, J, mounted thereon. The parallel, in-line solvent flow circuits 12 and 14 provide a controlled, on-site apparatus and method for reducing, reusing and recycling potentially harmful solvent chemicals. The NVRs are concentrated from about 11/2% by weight to about 20%-40% by weight and the NVR rich small volume is stored in an easy to service container for disposal or further processing.
In accordance with the arrangement illustrated in FIG. 1, the volumes of newly regenerated solvent being transported to the dry cleaning location and the volumes of regulated used organic solvent materials transported away from the location may be dramatically reduced. Although, the new and improved self-cleaning single stage distillation apparatus and loop 14 are described in use with a dry cleaning solvent circuit loop 12, the apparatus may also be used with other primary solvent flow circuits, such as a printed circuit board reflux/washing apparatus or a parts washer/cleaner apparatus.
Referring now to FIGS. 2-4, the new and improved distillation and waste concentrator apparatus 10 (indicated as distillation apparatus S in FIG. 1) is shown in greater detail. The new and improved apparatus 10 of the invention comprises a modified distillation apparatus including a small closed vessel 16 typically with a diameter to height ratio of 1:2 having a total volume of perhaps twice the hourly feed rate. In the case of the dry cleaning solvent recovery application depicted therein, the dry cleaning solvent used is normally tetrachloroethylene and the volume of vessel 16 may be from about five to six gallons.
A vertical reflux condenser subassembly 18 attached to the upper end of vessel 16 and is designed so that condensed vapors are caught in a gutter 20 and exit the vessel through a u-tube vapor seal 22. Dirty solvent feed enters the vessel 16 through a tube 24 extending down through the top of vessel 16 into the interior chamber 28 and sump portion 26 of vessel 16 to assist in rapid mixing and to prevent accidental draining of the vessel. The interior fluid receiving chamber 28 of the vessel 16 contains a standard mechanical level control 30 designed to sense and maintain the solvent at a predetermined minimal fill height. A thermocouple 32 for sensing and monitoring the liquid temperature is also provided. Vapor relief 34 is provided at the top of the condenser subassembly 18 and connected to the vapor space 36 of a product storage tank 38. All equipment is preferably constructed of stainless steel to assure cleanliness.
In accordance with the present invention, the new and improved apparatus 10 includes a new and improved self-scrubbing heater subassembly 40. Heater subassembly 40 is designed so that solvent liquid, P, is confined in a tube 42 or part thereof, while being heated. The annular confinement and heating space of the heater design causes a rapid circulation of a mixture of boiling liquid and vapor. It has now been discovered that this circulation can be made rapid enough to preclude formation of coatings on the surface of heater rods 44 even when the boiling liquid is very dirty.
In accordance with this aspect of the invention, self-scrubbing heating subassembly 40 includes a concentric tube design, having a central heater rod 44 containing the heater element 46 and a thermocouple 48 insulated from each other within an outer tube 44. In the preferred embodiment depicted in FIGS. 3-4, the heater rod 44 is about one inch in diameter and the outer tube 42 is about two inches resulting in an annular heating space 50 of about one-half inch. Two heating subassembly units 40 may be mounted vertically and arranged symmetrically in the distillation vessel extending through the bottom of the vessel. Each of the annular heating spaces 50 was connected to the sump portion 26 of the vessel 16 by solvent feed tubes so that smooth flow of liquid could take place. The heater rod 44 was welded to the male half 52 of an O-ring union with the female half 54 welded to the wall of the heating tube 42. In use the heater O-ring union may be operated hand tight.
For maintenance purposes, with the still vessel 16 in an empty condition, the entire heater assembly 40 may be easily removed to present the entire heat-transfer surface. We have discovered that with a power density of about 2000 to 5000 watts per heating rod 44, for example, a high speed flow of boiling liquid and vapor of tetrachloroethylene can be achieved. The annular heating space 50 should be long enough to provide a mixture of liquid and gaseous solvent at the boiling point of the solvent at the exit or discharge end 56. An apparatus in accordance with this invention may be used for example under these conditions for a period of about eight hours per day for several years without formation of a coating on the exchange surfaces of heater rods 44. This is true even though concentrated dry cleaning NVRs and impurities, when isolated from still-bottoms, are rubbery, sticky materials that are expected to readily form coatings.
The top or upper ends 56 of the heating tubes 42 are disposed at about the mid-point of the height of the still vessel 16. The mechanical level control 30 is set for a liquid level about one-half inch below the top opening of the thermal syphon tubes 42. The concentrated still bottoms or NVRs are discharged by gravity flow through an adjustable overflow port 58. The overflow level is set for about one inch above the top of the heater rods 44 in their fully installed positions.
The NVRs must be and are completely soluble in the dry cleaning solvent. Large particulates have been previously separated by the filter F before dirty feed enters the still vessel 16. The boiling temperature of the solution is a function of NVR content. NVR content control is accomplished by means of the thermocouple temperature sensor 48 that is used to maintain the discharge control temperature. Pure tetrachloroethylene has a boiling point of about 247° F., whereas the same solvent containing about 40% NVRs, has a boiling point of about 265°-272° F. Information provided by the thermocouple temperature sensor is employed in a controller operation to turn the dirty solvent pump on and off. Incoming dirty solvent lowers the temperature of the still bottoms and incoming replacement volume causes the concentrated NVR solution to overflow out of overflow port 58 into the NVR storage container 60. Dirty-feed normally has an NVR content of 1 to 1.5 percent. The heaters, set for a specific rate of distillation, are turned on at start-up and left on for the duration of the processing. At solvent temperatures below the discharge control temperature (DCT), the mechanical level control 30 keeps the liquid level below the overflow level within a 1.5 inch span by turning the feed pump off at the upper level and turning it on at the lower level. When the discharge control temperature is reached, a system control 62 turns on the dirty solvent pump and overrides the mechanical level control 30 allowing the dirty solvent feed to be fed into the bottom of the sump until the boiling temperature is depressed usually 7° to 10° F. below the discharge temperature. If the added volume is sufficient to cause overflow, then that overflow is directed to the still bottoms container 60. If not, the level control circuit takes over until the discharge control temperature is again reached and the cycle is repeated.
As distillation proceeds, a steady state is reached with distillation, addition of feed, and discharge of the still bottoms at the pre-determined final NVR content occurring at a substantially uniform or constant rate, dependent upon the heater setting.
Thermal efficiency and reduced energy consumption are achieved by using heat exchangers 70 and 72 to exchange the heat from the distillate and still bottoms to pre-heat the incoming dirty solvent.
The apparatus of this invention is preferably a closed system with all the containers vented to each other. As shown in FIG. 2, the distillate storage tank is vented to the still vessel 16 and the waste NVR concentrate vessel 60 is vented to the atmosphere through a carbon filter 68.
Although the present invention has been described with reference to certain preferred embodiments, modifications or changes may be made therein by those skilled in this art without departing from the scope and spirit of the present invention as defined in the appended claims. | An apparatus for removing non-volatile residues and impurities from a used solvent includes a self-scrubbing heating distillation subassembly for separating purified solvent for reuse and a controlled waste collector subassembly for overflowing concentrated residues and impurities stripped from the used solvent into an easy-to-service container. The apparatus may be disposed in a parallel in-line relationship with a circulating solvent flow circuit, such as in a dry cleaning operation, to continuously withdraw and purify aliquot portions of the circulating solvent stream, returning good solvent back to the flow circuit and concentrating non-volatile residues and impurities to a removable, environmentally sound serviceable container. The new and improved self-scrubbing heater assembly causes a rapid turbulent reboiling flow of solvent within a confined column and substantially avoids build up of residues on heat exchange surfaces for prolonged heater life and longer uninterrupted service life before service is needed. |
This application is the national phase of international application PCT/US99/11109 filed May 20, 1999 which designated the U.S.
This application also claims the benefit of U.S. Provisional Application No. 60/ 086,596, filed May 22, 1998.
FIELD OF THE INVENTION
This invention relates to an interior trim component for a motor vehicle.
BACKGROUND OF THE INVENTION
Hard interior automotive trim such as door panels, instrument panels, steering column covers, glove box doors, knee bolsters, consoles, pillar post covers,'seat backs, speaker grilles, vent grilles, mirror housings, and HVAC housings are often produced by injection molding the more expensive resins, such as ABS or PC/ABS. Hard appearance surface parts are used in many small cars, trucks and sport utility vehicles.
It is desirable to use lower cost polyolefins in these applications. Unfortunately, these materials have relatively soft surfaces, which are prone to scuff, mar and scratch damage. Thus, to maintain the aesthetic appearance of these visible internal components when polyolefin materials are used, the polyolefins must be painted to provide a more durable surface. This adds significant cost and requires surface treatment with an adhesion promoter in order to provide good adhesion between the paint and the polymer. Even then, inconsistent paint adhesion remains a problem.
Summary of the Invention
The disadvantages of the prior art may be overcome by providing an interior trim component for an automobile comprising a structure formed from at least one polyolefin material and reinforcement particles dispersed within the at least one polyolefin material. The reinforcement particles comprise less than or equal to 10% of a total volume of the rigid structure. At least 40% of the reinforcement particles have a thickness less than about 50 nanometers. The interior trim component is constructed and arranged to be devoid of any decorative coating layer disposed thereon in its final finished form for installation into a vehicle so that the trim component is provided with an unpainted visible surface finish.
More preferably, at least 50% of the reinforcement particles have a thickness less that 20 nanometers. In addition it is preferable for at least 99% of the particles to have a thickness of less than 30 nanometers.
Also in accordance with the invention, an interior trim component is preferably loaded with nanoparticles in amounts of 3-5% of the total volume of a polyolefin interior trim part, wherein over 40% of the particles are less than about 50 nanometers in thickness, and thereby enable the part to withstand marring and scuffing (known as the “mar threshold”). It is even more preferred that the interior trim component be loaded with nanoparticles in amounts of 3-7% of the total volume of a polyolefin interior trim part, wherein over 50% of the particles are less than about 20 nanometers in thickness, Thus, the mar threshold of a polyolefin interior trim part can be more than doubled by adding nanoparticles in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of an interior trim component in accordance with the present invention, shown installed in a motor vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, nanoparticle fillers are added in levels of only a few percent by volume. As a result, the resistance of polyolefins to the standard mar and scuff tests can be doubled or even quadrupled. This allows these lower cost materials to be used for the interior trim component, without needing paint to be adequately resistant to scuffing and marring.
The automotive parts manufactured in accordance with the present invention comprises a composite material of a polymer having dispersed therein reinforcement fillers in the form of very small mineral reinforcement particles. The reinforcement filler particles, also referred to as “nanoparticles” due to the magnitude of their dimensions, each comprise one or more generally flat platelets. Generally, each platelet has a thickness of between about 0.7-1.2 nanometers. The average platelet thickness is approximately 1 nanometer thick.
The preferred aspect ratio (which is the largest dimension divided by the thickness) for each particle is about 50 to about 300. At least 80% of the particles should be within this range. If too many particles have an aspect ratio above 300, the material becomes too viscous for forming parts in an effective and efficient manner. If too many particles have an aspect ratio of smaller than 50, the particle reinforcements will not provide the desired reinforcement characteristics. More preferably, the aspect ratio for each particle is between 100-200. Most preferably at least 90% of the particles have an aspect ratio within the 100-200 range.
The platelet particles or nanoparticles are derivable from larger layered mineral particles. Any layered mineral capable of being intercalated may be employed in the present invention. Layered silicate minerals are preferred. The layered silicate minerals that may be employed include natural and artificial minerals. Non-limiting examples of more preferred minerals include montmorillonite. vermiculite, hectorite, saponite, hydrotalcites, kanemite, sodium octosilicate, magadiute, and kenyaite. Mixed Mg and Al hydroxides may also be used. Various other clays can be used, such as claytone H.Y. Among the most preferred minerals is montmorillonite.
To exfoliate the larger mineral particles into their constituent layers, different methods may be employed. For example, swellable layered minerals, such as montmorillonite and saponite are known to intercalate water to expand the inter layer distance of the layered mineral, thereby facilitating exfoliation and dispersion of the layers uniformly in water. Dispersion of layers in water is aided by mixing with high shear. The mineral particles may also be exfoliated by a shearing process in which the mineral particles are impregnated with water, then frozen, and then dried. The freeze dried particles are then mixed into molten polymeric material and subjected to a high sheer mixing operation so as to peel individual platelets from multi-platelet particles and thereby reduce the particle sizes to the desired range.
The composites of the present invention are prepared by combining the platelet mineral with the desired polymer in the desired ratios. The components can be blended by general techniques known to those skilled in the art. For example, the components can be blended and then melted in mixers or extruders.
Additional specific preferred methods, for the purposes of the present invention, for forming a polymer composite having dispersed therein exfoliated layered particles are disclosed in U.S. Pat. Nos. 5,717,000, 5,747,560, 5,698,624, and WO 93/11190. Additional background is included in the following references: U.S. Pat. Nos. 4,739,007 and 5,652,284.
Preferably, the polymer used for the purposes of the present invention is a polyolefin or a blend of polyolefins. The preferred polyolefin is at least one member selected from the group consisting of polypropylene, ethylene-propylene copolymers, thermoplastic olefins (TPOs), and thermoplastic polyolefin elastomers (TPEs).
The exfoliation of layered mineral particles into constituent layers need not be complete in order to achieve the objects of the present invention. The present invention contemplates that at least 40% of the particles should be less than about 50 nanometers in thickness and, thus, at least 40% of the particles should be less than about 50 platelets stacked upon one another in the thickness direction. More preferably, at least 50% of the particles should be less than about 20 nanometers in thickness and, thus, at least 50% of the particles should be less than about 20 platelets stacked upon one another in the thickness direction. It is also preferable for at least 90% of the particles to have a thickness of less than about 5 nanometers. Finally, it is preferable for at least 99% of the particles to have a thickness of less than about 30 nanometers. It is most preferable to have as many particles as possible to be as small as possible, ideally including only a single platelet.
Generally, in accordance with the present invention, each of the interior parts to be manufactured should contain nanoparticle filler in amounts less than 15% by volume of the total volume of the part. The balance of the part is to comprise an appropriate polyolefin material and suitable additives. If greater than 15% by volume of reinforcement filler is used, the viscosity of the composition becomes too high and thus difficult to mold. It more is preferable for the rigid structure forming the interior panel to have reinforcement particles of the type described herein comprise less than 10% of the total volume of the part. It is even more preferable for these relatively rigid parts to have reinforcement particles of the type described herein comprising about 2-10% of the total volume of the part, with the balance comprising the polyolefin substrate. It is most preferable for these exterior panels to have reinforcement particles of the type contemplated herein comprising about 3%-7% of the total volume of the part, wherein over 50% of the particles are less than about 20 nanometers in thickness.
A non-limiting example of an interior trim component in accordance with the present invention can b e a front dash, as generally indicated at 10 in FIG. 1 . This trim component is clearly visible to a vehicle occupant and need not be painted in order to retain an aesthetically pleasing appearance over a long period of time.
In accordance with the amount of reinforcement loadings and thicknesses discussed above, it has been found that the flex modulus for the interior trim component can be increased by a factor of about 1.5 to about 4.0 times that of a part produced from the same unreinforced polymer (or thermoplastic). In addition, the coefficient of linear thermal expansion (CLTE) is decreased by a factor of about 1.5 to about 4.0. Improved stiffness and reduced CLTE can be accomplished without loss of impact resistance.
In a test conducted in the automotive industry in order to determine a particular part's resistance to scuffing and marring, it was found that the surface toughness or resistance to marring could be more than doubled by using various nanoparticles in an amount of about 3-5% by volume of the total volume of a polyolefin interior trim part. In one specific example, the test used about 5% by volume claytone H.Y. nanoparticles, wherein over 40% of the particles were less than about 50 nanometers in thickness. The balance of the trim part volume comprised polypropylene plastic and suitable conventional additives.
It should be appreciated that the foregoing description is illustrative in nature and that the present invention includes modifications, changes, and equivalents thereof, without departure from the scope of the invention. Thus, the present invention covers all embodiments and equivalents in accordance with the spirit and scope of the following claims. | An interior trim component ( 100) for an automobile comprising a structure formed from at least one polyolefin material and reinforcement particles dispersed within the at least one thermoplastic olefin. The reinforcement particles comprise less than or equal to 10% of a total volume of the rigid structure. At least 40% of the reinforcement particles have a thickness less than about 50 nanometers. The interior trim component ( 100) is constructed and arranged to be devoid of any decorative coating layer disposed thereon in its final finished form for installation into a vehicle so that the trim component ( 100) is provided with an unpainted visible surface finish. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The Direct Synchronization of Synthesized Clock (DSSC) contributes a method, system and apparatus enabling reliable and inexpensive synthesis of inherently stable local clock synchronized accurately to a referencing signal received from an external source.
Such local clock can be synchronized to a referencing frame or a data signal received from wireless or wired communication link and can be utilized for synchronizing local data transmitter or data receiver.
Such DSSC can be particularly useful in OFDM systems such as LTE/WiMAX/WiFI and Powerline/ADSL/VDSL, since it can secure lower power consumption, better noise immunity and much more reliable and faster receiver tuning than those enabled by conventional solutions.
This invention is also directed to providing low cost high accuracy phase and frequency recovery techniques (PFRT) offering significantly better stability and accuracy in synchronizing systems and circuits in multiple fields including communication systems, distributed control, test and measurement equipment, and automatic test equipment.
Such PFRT comprises software controlled clock synchronizer (SCCS) which can be used in multiple fields exemplified above wherein said communication systems include communication networks for wireless or wireline or optical transmissions with very wide ranges of data rates.
The SCCS comprises further novel components such as; programmable phase synthesizers (PS), precision frame phase detectors (FPD) of an incoming wave-form, and noise filtering edge detectors (NFED) for precise recovering of wave-form edges from noisy signals.
Furthermore: since said FPD and NFED define circuits and methods enabling ˜10 times faster and more accurate location systems than conventional solutions, they allow reliable location services for mobile and traffic control applications including fast movements at close ranges in noisy environments unacceptable for solutions.
Still furthermore this invention comprises receiver synchronization techniques (RST), utilizing a referencing frame, recovered from an OFDM composite signal, for synchronizing an OFDM receiver clock to a composite signal transmitter clock.
2. Background Art of Software Controlled Clock Synchronizer
Conventional solutions for software controlled synchronization systems use software controlled digital phase locked loops (DPLLs) for implementing software algorithm minimizing phase errors and providing programmed transfer function between a DPLL output clock and a timing reference.
In conventional solutions said timing reference can be provided:
as a conventional external clock connected to a digital phase detector, which compares it with the local clock in order to produce the digital phase error;
or with time stamp messages sent by an external source, initiating a capture of local clock time and communicating external clock timing corresponding to the captured local timing, wherein software is used for producing said digital phase errors by comparing the captured local timing with the communicated external timing.
However the conventional DPLL configurations have four major limitations listed below:
1. DPLLs are inherently unstable if said timing reference comprises components having frequencies higher than ⅕ of the DPLL bandwidth. Since time stamp messages are sent over regular communication links they are subjected to highly unpredictable time delay variations (TDVs) resulting from collisions between different packet streams sharing a common communication line. Such unpredictable TDVs are bound to introduce timing reference components having unknown frequency spectrums, when said timing reference is provided by exchanging time stamp packages sent over shared communication link. Resulting stability problems cause such conventional DPPL configurations to be highly unreliable in many applications. 2. Conventional digital phase detectors and said software algorithms minimizing phase errors, involve accumulation of phase digitization errors. Such accumulation causes an uncontrolled phase drift of the output clock, when a software error minimization procedure is unable to recognize and eliminate persistent existence of an digitization error corresponding to a lasting unknown frequency error of the output clock. 3. Conventional digital phase detectors; offer resolutions worse than that of phase steps limited by maximum clock frequency of IC technology, and they require complex processing for calculating precise phase skews when highly irregular edges of a reference timing are defined in newly emerging timing protocols such as IEEE 1588. Similarly clock synthesizers have phase steps resolutions bounded by maximum clock frequency of IC technology and furthermore they use frequency synthesis method unable to provide high precision control of phase transients of synthesized clock. 4. Conventional clock synchronization systems require expensive local oscillators, expensive external off-chip analog components, and expensive IC technologies suitable for mixed mode operations; in order to provide highly stable and low jitter synchronization clocks required in industrial control systems and in communication networks. Temperature stable crystal oscillators are major cost contributors exceeding ⅔ of total costs of synchronization systems. However in conventional solutions; low cost highly stable crystal cuts can not be used, since their oscillation frequencies are to low to be transformed into a stable low jitter clock.
Conventional synchronization systems use digital phase detectors which are >5 times less accurate than this inventions FPD, and frequency synthesizers producing uncontrolled phase transients during any frequency switching and introducing 10 times less accurate phase steps than this inventions phase synthesizer PS.
Such frequency synthesizers are based on direct digital frequency synthesis (DDFS) method modifying average frequency of an output clock by periodical removal of a clock pulse from a continues stream of pulses. Since said frequency synthesizers use over 10 times slower phase processing and introduce unknown numbers of 10 times less accurate phase steps than the PS, they are unable to perform any phase synthesis and produce uncontrolled phase transients during frequency switching and introduce much more jitter than the PS.
Consequently; in order to limit phase transients to acceptable levels, said conventional synchronization systems are bound to work in closed loop configurations wherein output clock phase is subtracted from reference clock phase and resulting phase error is minimized by a programmable control unit driving frequency synthesizer producing said output clock
3. Background art of Receiver Synchronization Techniques
Insufficient accuracy of conventional synchronization for OFDM receivers impose major limitations on OFDM communication quality (see Cit. [ 1 ] and [ 2 ] listed below) and such limitations are compounded by rapidly growing data rates.
Some conventional solutions add specific preambles inserted into composite signal (Cit. [3], [4], [5], and [6]). Such preamble comprises similar parts having known phase (displacement in time) within the preamble.
Such preambles enable detection of symbol boundary time offset, by steps of:
evaluating correlation functions between OFDM signal portions shifted properly in time until such similar preamble parts are detected;
using a phase of local clock frame marked by the similar parts detection and said known phase of such similar parts detected, for estimating time offset of the local frame;
estimating frequency offset of the local clock versus transmitter clock by analyzing said correlation functions between such preamble parts shifted properly in time.
Other synchronization solutions analyze correlation estimates of received pilot preambles or pilot tones with predefined pilot preambles or pilot tones (Cit.[7]), in order to estimate time offset and frequency offset of the local clock frame.
However such use of preambles or pilots; reduces system efficiency by using signal power that could otherwise have been used for transmitting data, and allows limited accuracy only due to such detection and estimates sensitivity to channel interference and insufficient data supplied in the preamble.
There are also pilot-less synchronization techniques. One such pilot-less technique, named maximum likelihood (ML) method (Cit.[8]), utilizes inherent redundancy in OFDM signal, by correlating parts of the signal with other parts having known positioning within frame (cyclic prefix). However; as such pilot-less technique uses statistical methods and depend on transmitted data patterns, they are even less accurate than those using preambles or pilots.
Another pilot-less technique calculates timing offset and frequency offset from displacements of tone phases caused by said timing and frequency offsets (Cit.[9]).
Fundamental deficiency of conventional solutions characterized above is their inability to perform any accurate measurement of frequency offset; due to their reliance on using phase offset observed over single preamble/pilot period only for the frequency offset estimation. Such estimates degraded by unpredictable OFDM channel interference, can not be helped enough by averaging them for as long as each estimate is calculated over single preamble/pilot.
Still other significant deficiency of conventional synchronization is instability of their phase locked loops (used for phase and frequency tracking), caused by changing data patterns and/or unpredictable phase error components introduced into OFDM channel by generally unknown interference.
Such conventional synchronization solutions for OFDM receivers did not succeed in providing reliable and accurate recovery of a referencing frame providing time domain definition of phase and frequency of received OFDM composite frame. However such referencing frame defined in time domain, is essential for achieving accurate control of local oscillator frequency offset and receiver time offset (receiver phase error).
OFDM composite signal has not been originally designed to carry distinctive edges enabling detection of composite frame boundaries, and conventional DFT/IDFT frequency domain processing is not well suited for any accurate detection of such boundaries occurring in time domain either.
Conventional DSP techniques and processors used are not equipped to perform real-time processing of OFDM signal needed to produce such referencing frame maintaining predictable accurate timing relation to the OFDM signal received.
Such major deficiencies of conventional solutions are eliminated by the RST as it is explained in Subsection 2 of BRIEF SUMMARY OF THE INVENTION.
CITATIONS
[1] “Equalization for DMT-Based Broadband Modems” by Thierry Pollet at al., IEEE Communications Magazine, Volume 38, Issue 5, May 2000.
[2] “Retraining WLAN Receivers for OFDM Operation” by Ivan Greenberg, CommsDesign, January 2002.
[3] “A Symbol Synchronization Algorithm for OFDM Systems” by T. Salim at al., Communication Systems and Networks ˜AsiaCSN 2007˜April 2007.
[4] “Synchronization Approach for OFDM based Fixed Broadband Wireless Access Systems” by M. Gertou, G. Karachalios, D. Triantis, K. Papantoni and P. I. Dallas, INTRACOM S.A., July 2005.
[5] “A Novel Scheme for Symbol Timing in OFDM WLAN Systems” by Yong Wang at al., ECTI Transactions on Electrical Eng. Electronics and Communications, August 2005.
[6] “Performance of a novel carrier frequency offset estimation algorithm for OFDM-based WLANs” by ZHAO Zhong-wei, Journal of Zhejiang University SCIENCE A, 2006 7(3).
[7] “Synchronization Schemes for Packet OFDM System” by Haiyun Tang, Kam Y. Lau and Robert W. Brodersen, IEEE International Conference on Communications, May 2003.
[8] “ML Estimation of Timing and Frequency Offset in Multicarrier Systems” by Jan-Jaap van de Beek, Magnus Sandell, Per Ola Borjesson, Lulea University of Technology, April 1996.
[9} “A Robust Timing and Frequency Offset Estimation Scheme for Orthogonal Frequency Division Multiplexing (OFDM) Systems” by Bruce McNair, Leonard J. Cimini, Nelson Sollenberger, VTC99 May 1999.
BRIEF SUMMARY OF THE INVENTION
1. Brief Summary of SCCS
Since the SCCS system is using said very accurate FPD and said very accurate PS free of any uncontrolled phase transients, it can implement an inherently stable open loop configuration wherein a programmable control unit (PCU) provides signals producing totally predictable output clock phase implementing precisely defined phase transfer function between an external timing reference and the output clock. In addition to elimination of said feedback related instability problems, such SCCS system allows ˜10 times better control of output clock phase transients and much lower phase jitter by synthesizing output phase with ˜10 times smaller and more accurate phase steps than conventional solutions.
The SCCS eliminates all four limitations mentioned in the “Background art” section, by contributing improvements listed below:
1. Since the SCCS uses an open-ended phase control system without any closed loop feedback, the SCCS enables inherently stable synthesis of the output clock, independently of reference frequency spectrum. 2. The SCCS defines digital frame phase detector (FPD), which eliminates said accumulation of digitization errors during phase tracking of highly irregular waveforms communicated with stamp messages of IEEE 1588 protocol. 3. The FPD part of the SCCS offers >5 times more accurate measurements of time errors, between the local clock and an external clock, occurring during variable lengths time intervals communicated by the external source. The SCCS defines digital phase synthesizer (PS) enabling direct precise control of phase transfer function between PSs input and output clocks, and the PS allows ˜10 times lower jitter of output clock phase. 4. The SCCS significantly reduces system manufacturing costs, by enabling use of inexpensive lower frequency oscillators including all oscillators already used by potential customers, and by enabling use of inexpensive standard CMOS technologies for synthesizing high precision synchronization clocks. The SCCS includes a Hybrid PLL (HPLL) which can multiply crystal frequencies as low as 30 kHz into a stable low jitter clock in GHz frequency range. The HPLL comprises a DPLL driving an analog PLL (APLL) using an analog phase detector (APD) with return input connected to an APLL output clock and with reference input connected to said PS receiving the APLL output clock. The DPLL minimizes digital phase error between said crystal oscillator clock and the APLL output clock, by introducing phase steps into a transfer function of said PS which produce appropriate phase errors on an output of said APD. Since the DPLL is programmable; it can convert any oscillator frequency into any local clock frequency, and consequently it allows use of local oscillator of any frequency including low frequency crystals and oscillators proven already in customers products.
Such HPLL solution is unique, as it allows: multiplication of said very low frequency clocks by factors which can be made as high as 50 000 without increasing jitter or causing stability problems, combined with indefinite flexibility and precision in setting frequency of generated high frequency clocks.
This major contributions over conventional solutions make the HPLL conclusively superior alternative to conventional PLLs in many major areas including analog, mixed mode SOC, signal processing, and all frequency control products where low jitter high multiplication is the major bottleneck.
In addition to the above mentioned advantages over conventional solutions; the SCCS offers unique ability of precise recovering of every single edge of incoming noisy wave-form, with adaptive time-domain noise filtering edge detector (NFED). The NFED densely over-samples incoming wave-form, and filters out phase noise from wave-form edges and eliminates amplitude glitches from wave-form pulses.
Still other advantage of SCCS is its ability to provide a single SOC design accepting all practically possible frequencies of timing references, as it is presented by a Heterodyne Timing Configuration of SCCS shown in FIG. 3 described in the next section.
In contrary to conventional solutions, the SCCS is not limited to discrete sets of input/output frequencies or local oscillator frequencies, but accepts a local oscillator (LocOsc) of any frequency and accepts an external reference clock (Ext_RefClk) of any frequency or an external reference waveform (Ext_RefWfm) carrying any reference frequency, while providing any required frequency of an SCCS output clock (OutClk).
Such very wide universality will allow synchronization products suppliers to replace wide variety of their SOC products with a single chip solution. Consequently, their own costs will be significantly reduced and such single chip solution will make their product much more competitive as being easier to use across diversified product lines produced by major equipment manufacturers who are their major clients.
The next section SUMMARY OF THE INVENTION; explains major configurations of the SCCS (see also FIG. 1 , FIG. 2 and FIG. 3 ), and justifying said configurations novel components such as the phase synthesizer, the frame phase detector and the noise filtering edge detector.
2. Brief Summary of Receiver Synchronization Techniques
The RST alleviates said deficiencies of conventional solutions, since the RST comprises:
supplementing or replacement of said conventional DSP techniques and processors unequipped to perform real-time processing of OFDM signal, with real-time synchronous processing techniques enabling very accurate detection of composite frame boundaries enabling time domain definition of said referencing frame maintaining predictable accurate timing relation to the OFDM signal received;
recovery of timing of composite frames boundaries, and using such timing to define said referencing frame;
using such referencing frame interval corresponding to any required plurality of OFDM symbols for estimating frequency offset, wherein estimation accuracy by one order higher than that of conventional solutions can be achieved (such accuracy improves proportionally to a length of referencing frame interval);
inherently stable frequency locked phase synthesis method (FLPS) for receiver frequency and phase control, wherein such highly accurate frequency offset estimates are used by a frequency locked loop for controlling frequency of its oscillator clock while time offset (phase error) estimates are applied only to a phase synthesizer utilizing such oscillator clock for synthesizing local symbol frame phase minimizing such time offset estimates (i. e. phase aligned with the composite signal frame).
The RST comprises methods and systems for accurate and reliable recovery of said referencing frame from preambles or pilots commonly used already in OFDM systems, thus enabling substantially better receiver synchronization to OFDM composite signal frame.
Furthermore the RST comprises solutions enabling very accurate recovery of the referencing frame from data carrying tones only, and thus RST contributions over conventional solutions include; 10× lower frequency and time offset combined with improvement of system efficiency by eliminating preambles and pilots needed previously.
3. Brief Summary of Direct Synchronization of Synthesized Clock
An open-ended software controlled synchronizer (OE-SCS) has been described in the subsection 1 of SUMMARY OF THE INVENTION and shown in FIG. 1 .
Such OE-SCS enables stable generation of a local clock implementing a programmable phase frequency transfer function versus a referencing signal.
A frequency locked phase synthesizer (FLPS), contributing superior accuracy and reliability of local clock phase synchronization, has been presented in the subsection 10 of SUMMARY OF THE INVENTION and shown in FIG. 15 .
Such FLPS utilizes a Frequency Locked Loop (FLL) circuit for generating an intermediate clock having frequency aligned to the referencing signal and applies a feed-forward phase synthesis (FPS) to such intermediate clock for achieving phase alignment of the local clock to the referencing signal.
The DSSC presented herein lowers the cost and complexity of the clock synchronizers cited above by eliminating such FLL circuit and its intermediate clock.
Consequently such DSSC contributes much simpler direct synchronization solutions, which enable:
resulting direct implementation of FLPS functionality (securing all FLPS performance advantages despite such elimination of FLL circuit);
or other direct synchronization methods utilizing feed-forward phase synthesis for securing even further size and power reductions while enabling sufficient accuracy.
Resulting cost, power and size reductions secured by DSSC shall be of particular importance for all System On Chip (SOC) based devices for mobile communication, home networking and other major markets for consumer electronics.
SUMMARY OF THE INVENTION
1. Open Ended Configuration of Software Controlled Clock Synthesizer
The open ended configuration of SCCS (OEC) is presented in FIG. 1 . Such configuration comprises two major parts described below.
The first part is said Hybrid PLL (HPLL) for multiplying said local oscillator frequency provided by a crystal producing frequencies as low 30 kHz, by a programmed by PCU factor which can exceed 50 000 without any increase of jitter levels and without any stability problems.
The HPLL provides practically indefinite flexibility and precision in setting frequency of generated high frequency clocks. Resulting frequency can rise as far as is it supported by a voltage controlled crystal oscillator (VCXO), as long as it remains lower than maximum clock frequency which exceeds GHz ranges in present IC technologies.
The HPLL comprises a DPLL (DPLL) driving an analog PLL (APLL) using an analog phase detector (APD) with return input connected to an APLL output clock (LocClk) and with reference input connected to a local phase synthesizer (LOC_PS) receiving the APLL output clock. The DPLL minimizes digital phase error 2 (PhaErr2) between said local oscillator (LocOsc) and the LocClk, by introducing phase steps into an output phase of said LOC_PS which are converted by the APD into analog phase errors controlling phase locking between the LocClk and the OscClk. The DPLL uses a frame phase detector 2 (FPD2) for measuring said PhaErr2 which is read by a programmable control unit (PCU) using it for producing said phase steps introduced into said LOC_PS output phase, wherein amount of introduced phase steps is controlled using an MC=1_INT signal received by the PCU from the LOC_PS. The MC=1_INT signals a request from the LOC_PS demanding the PCU to send the next series of said phase steps when the last series is applied already. The FPD2 receives PCU control signals programming expected relation between phase of the OutClk and phase of a sampling clock (SampClk) derived from the LocClk through a simple multiplication by a factor <8.
The second part is an open ended software controlled synthesizer (OE_SCS) using PCU software sub-routines for providing a programmable phase transfer function (PTF) between the Ext_RefWfm and the OutClk.
The OE_SCS offers; unique ability to program very precisely synchronized phase free of any uncontrolled transients. Therefore, the OE_SCS provides ˜10 times better precision in frequency and phase control than conventional solutions. Furthermore, the OE_SCS offers inherently stable configuration independently of said highly unpredictable frequency spectrum of the time delay variations occurring in the Ext_RefWfm. Consequently, the OE_SCS eliminates serious stability problems of conventional clock synchronizers bound to use closed loop configurations for implementing message-based protocols.
Said PCU controls operations of the OUT_PS by defining series of phase steps inserted by the OUT_PS into a phase of the OUTCLK.
The PCU calculates said phase steps by processing:
a phase error 1 (PhaErr1) received form a frame phase detector 1 (FPD1) measuring phase error between the sampling clock and a filtered reference wave-form (Filt_RefWfm);
time stamp messages received from a Time Stamp Decoder (TSD) recovering such messages from the FILT_RefWfm produced by a noise filtering edge detector (NFED).
The PCU supplies the next series of said phase steps in response to the interrupt MC=1_INT from the OUT_PS which signals that insertions of the last series has been completed.
Furthermore the PCU controls operations of the NFED providing adaptive time domain filtering of the Ext_RefWfm carrying synchronization signals which can be encoded into time stamp messages or can be conventional BITS references.
The PCU receives unfiltered wave-form samples from the NFED and calculates most suitable noise filtering masks and algorithms which the PCU communicates back to the NFED (see Subsection 8. Noise Filtering Edge Detector).
Compared to a moment when a sync message requesting capturing of a time stamp is received by the PCU; an exact sync edge of the FILT_RefWfm destined to capture said time stamp can be displaced in time by a known number of message symbols (edge displacement). Such edge displacement is determined by a messaging protocol used.
Since FPD1 keeps capturing time stamps of all received edges of the FILT_RefWfm, the FPD1 or the PCU shall be equipped with an edge selection circuit (ESC). The ESC provides selection of time stamps captured by said sync edge and is synchronized by the time stamp messages produced by the Time Stamp Decoder.
Further definitions of a synchronization means provided by the OEC, such as Free-Run and Hold-Over modes, are provided in the Subsection 4.
2. Open Ended Configuration of SCCS with External Synchronization Mode
The open-ended configuration of SCCS with external synchronization mode (OEC_ESM) is presented in FIG. 2 and is described below.
The OEC_ESM comprises the previously explained OEC and is further extended by adding an output clock analog PLL (OutClk_APLL). The OutClk_APLL filters out jitter from a synthesized clock from the OUT_PS (SynOutClk) and produces SCCS output clocks (OutClk(T:1)) which are phase aligned with a reference clock selected by the PCU from a set of timing references including the SynOutClk, external reference clocks (Ext_RefClk) and a clock signal form a mate SCCS unit (f_mate).
Said external reference clocks are used in the external synchronization mode, wherein they are produced by a master synchronization unit and are used to synchronize multiple other units located in a back-plane of a network element. However said other units can alternatively use other synchronization references available in other synchronization modes and may be synchronized by the Ext_RefWfm carrying a message based protocol or BITS clocks.
Such plurality of synchronization references and modes allows switching to one of alternative references when an active reference fails.
The f-mate clock from a mate unit allows Master/Slave protection switching which is described in the Subsection 4.
The output clock analog PLL comprises:
a reference selector (RFS) connected to the SynOutClk from the OUT_PS and to the external reference clocks and to the f_mate clock and to the PCU, wherein the PCU controls selections of made by the RFS producing a reference clock (RefClk) for the OutClk_APLL;
a return clock divider (RCD) connected to a filtered output clock (Fil_OutClk) of the OutClk_APLL and to the PCU, wherein the PCU defines a division coefficient matching frequency of a return clock (RetClk) for the OutClk_APLL with a frequency of the RefClk; an analog phase detector OutClk APD connected to the reference clock and to the return clock, and producing an analog phase error (PhaDet_UP/DN) driving an output clock loop filter (OutLoopFil) which drives a VCXO producing the filtered output clock;
an output PLL (OUT_PLL) for multiplying one selected OutClk(T:1) clock and for providing phase alignment between all the OutClk_APLL and the Fil_OutClk, wherein the OUT_PLL is connected to the selected OutClk(T:1) clock and to the Fil_OutClk;
an output clocks generator (OCG) connected to the output of the OUT_PLL and to the PCU, wherein the OCG produces the OutClk(T:1) which are phase aligned but have different frequencies wherein the PCU controls OCG operations by programming said frequencies of the SCCS output clocks.
Further definitions of synchronization means provided by the OEC_ESM, are provided in the Subsections 3 and 4.
3. Heterodyne Timing Configuration of SCCS
The heterodyne timing configuration (HTC) simplifies SCCS by integrating:
both the APLL and the OC APLL from the OEC_ESM, into a single APPL;
and both the REF_PS and OUT_PS from the OEC_ESM, into a single RET_PS.
The two previous configurations of SCCS offer said practically unlimited universality in accepting said local oscillator (LocOsc) of any frequency and accepting said external reference waveform (Ext_RefWfm) carrying any reference frequency, while providing all practically needed frequencies of said SCCS output clocks (OutClk(T:1)).
The HTC extends this universality even further by enabling acceptance of practically unlimited ranges of said external reference clocks (Ext_RefClk) as well.
Therefore despite implementing a close loop system, the HTC may still be used as a less costly alternative; if timing reference is not provided by a message based protocol, or if a message-based protocol is used in simple networks with stable TDVs.
Said integration is achieved by placing a return phase synthesizer (RET_PS) into a return path of the integrated APLL. Consequently said phase steps supplied by the PCU need to be reversed as they are subtracted from a phase of a reference clock of the APLL instead of being added to it. Indefinite RET_PS flexibility in phase and frequency generation makes it much better frequency divider than the previous configuration Return Clock Divider and allows said unlimited flexibility in accepting all frequencies of the Ext_RefClk.
Resulting HTC comprises:
a programmable control unit (PCU) for implementing a programmable phase transfer function (PTF) between the OutClk and the Ext_RefClk or the Ext_RefWfm, wherein the PCU controls operations of the return phase synthesizer (RET_PS), the PCU has a terminals for an interrupt MC=1_INT and for a first phase error (PhaErr1) and for a second phase error (PhaErr1) and for a time stamp message and for a waveform sample;
the reference selector (RFS) connected to a filtered local clock (Fil_OutClk) and to the external reference clocks (Ext_RefClk) and to the f_mate clock and to the PCU, wherein the PCU defines selections made by the RFS producing a reference clock (RefClk) for the analog phase detector (APD);
the RET_PS connected to a filtered output clock (Fil_OutClk) and connected to the PCU wherein the RET_PS requests PCU to supply the next series of phase steps by activating the MC=1 INT, wherein the RET_PS introduces such phase steps into the Fil_OutClk thus synthesizing a return clock (RetClk) for the APD;
the APD connected to the RefClk and to the RetClk, the APD producing an analog phase error (PhaDet_UP/DN) driving an output clock loop filter (OutLoopFil) which drives a VCXO producing the filtered output clock;
the output PLL (OUT_PLL) for multiplying one selected OutClk(T:1) clock and for providing phase alignment between all the OutClk_APLL and the Fil_OutClk wherein the OUT_PLL is connected to the selected OutClk(T:1) clock and to the Fil_OutClk, wherein the OUT_PLL produces an output reference clock (OutRef) connected to the OCG and to the FPD2;
the output clocks generator (OCG) connected to the output of the OUT_PLL and to the PCU, wherein the OCG produces the OutClk(T:1) which are phase aligned but have different frequencies wherein the PCU controls OCG operations by programming said frequencies of the SCCS output clocks;
the NFED and the TSD and the FPD1 and the FPD2 having the same connectivity and performing the same operations as defined in the Subsection 1, with the exception of the FPD2 which is connected to the OutRef and to the LocOsc and to the PCU;
wherein the PCU uses its internal micro-operations for implementing filter functions of an on chip digital PLL (DPLL) by processing the PhaErr1 and the PhaErr2 and the time stamp messages into the PCU output driving the RET_PS into producing the synthesized return clock providing compliance of the SCCS output clocks with the phase transfer function defined by the PTF, wherein the PCU controls NFED operations as it is described in the Subsection 1.
4. SCCS Configurations
In contrary to conventional frequency synthesizers, SCCS phase synthesizer produces totally predictable phase and frequency responses to received from the PCU control signals.
Therefore it enables said open ended configurations which can work with only one frame phase detector (FPD) for measuring phase errors between a timing reference and a local clock, in order to implement an actual synchronization system. The second FPD in the open ended configuration explained in the Subsection 1, is used for the frequency multiplication of said local oscillator only. If a local clock had sufficiently high frequency, the FPD would not be needed at all.
As said conventional frequency synthesizers produce unpredictable transient during frequency switching, they require second digital phase detector for providing feedback about a phase of synthesizers output clock in order to reduce said phase transients with a DPLL.
An open ended configuration without said multiplication of LocOsc frequency is defined below. A Software Controlled Clock Synthesizer (SCCS) for implementing a programmable phase transfer function (PTF) between an SCCS output clock (OutClk) and external reference clocks (Ext_RefClk) or an external reference carrying wave-form (Ext_RefWfm) such as BITS references or line references or time stamp messages; the SCCS comprises:
a programmable control unit (PCU) using software subroutines for controlling SCCS status and for said implementation of the PTF, wherein the PCU controls operations of a return clock phase synthesizer (RET_PS), the PCU has terminals for interrupts from other SCCS circuits and for a first phase error (PhaErr1) and for a second phase error (PhaErr2) and for a time stamp message and a for a waveform sample;
the RET_PS for synthesizing a return clock (RetClk), the RET_PS connected to the PCU and to the SCCS output clock (OutClk);
the APLL for producing the OutClk, wherein a reference input of the APLL is connected to the OutClk or to the Ext_RefClk while the return input of the APLL is connected to the synthesized RetClk;
a first frame phase detector (FPD1) receiving a local reference clock (LocClk) and the Ext_RefWfm or receiving the LocClk and the OutClk or receiving the Ext_RefClk and the OutClk, wherein the FPD1 produces the PhaErr1 connected back to the PCU;
wherein said PCU uses said software subroutines for implementing a digital PLL (DPLL) by processing said first phase error and the second phase error into the PCU output driving the RET_PS into synthesizing the RetClk providing compliance of the APLL output clock with the phase transfer function defined by the PTF.
The SCCS includes reference selection means for alternative use of one of multiple connected external timing references, such as reference clocks or external waveforms, for producing the SCCS output clock, the SCCS further comprises:
a reference selector connected to multiple external timing references and controlled by the PCU, wherein the PCU selects one of the multiple timing references for being connected to the FPD1 which is read by the PCU and used by PCU subroutines for controlling the SCCS output clock;
activity monitors for the external timing references for producing status signals indicating active/non-active conditions, wherein said status signals are connected to the PCU;
wherein the output signals of the activity monitors are read and processed by the microprocessor which is producing reference selection signals connected to the reference selectors.
The SCCS further comprises:
an output phase locked loop (OUT-PLL) referenced by the APLL output clock and producing a fundamental output clock, wherein the OUT-PLL has a return input connected to one SCCS output clock;
an output clock generator (OCG) connected to the fundamental output clock, the OCG produces a plurality of the SCCS output clocks (OutClk).
The SCCS further comprises:
interface circuits, for communication with an external control processor, connected to the external control processor and to the PCU (see the Parallel Interface and the Serial Interface in the FIG. 1 and FIG. 2 and FIG. 3 );
wherein the interface circuits and the PCU enable the external control processor to read information about statuses of the activity monitors and to select an external reference clock or the local reference clock for referencing the SCCS output clock.
Furthermore in the interface circuits and the PCU enable the external control processor to perform switching of mode of operation of the SCCS between the APLL mode and the DPLL mode.
The SCCS PCU is provisioned to perform operations listed below:
reading information about statuses of the activity monitors and selecting an external timing reference or the local reference clock for referencing the SCCS output clock;
switching mode of operation of the SCCS between the APLL mode and the DPLL mode.
Furthermore the SCCS is provisioned to perform a master/slave mode switching for maintaining phase alignment between an active SCCS unit and a backup SCCS unit installed in a back-plane for protection switching, the SCCS comprises:
a master/slave subroutine reading activity monitor of a reference clock provided by a mate SCCS unit and reading internal status of the own SCCS unit;
wherein the master/slave subroutine performs switching to the master mode by selecting other reference clock than the mate's reference clock when the mate's reference clock becomes inactive or performs switching to the slave mode by selecting the mate's reference clock when the mate's reference clock is detected active during a power-up initialization of the own SCCS unit.
The SCCS comprises using a programmable phase synthesizer to produce an Analog PLL return clock, which can be reprogrammed to match a frequency of a reference clock of said Analog PLL.
Furthermore the SCCS comprises:
applying an output clock of the APLL to a reference input of the APLL;
using the return clock synthesizer for inserting phase deviations between the APLL return clock and the output clock applied to the APLL reference input;
using the inserted phase deviations for implementing required phase and frequency transfer functions between the APLL output clock and other SCCS reference clocks;
implementing digital PLL (DPLL) algorithms for providing the required phase and frequency transfer functions.
Still furthermore the SCCS comprises:
using frame phase detectors (FPDs) for measuring phase errors between the APLL output clock and said other SCCS reference clocks;
using the PCU for processing the measured phase errors and producing control codes for the return clock synthesizer, which implement pre-programmed phase and frequency transfer functions between the APLL output clock and said other SCCS reference clocks.
The SCCS comprises:
Said analog phase locked loop (APLL) for producing the output clock (OutClk) which can be locked to the external reference clock (Ext_RefClk), unless the APLL is driven by the digital phase locked loop (DPLL);
Said DPLL can provide locking to the Ext_RefWfm (which can be a GPS clock), or to a local oscillator.
The SCCS further comprises:
programmable frequency dividers for a reference signal and for return signal of said APLL, for providing programmable bandwidth adjustments of the APLL;
programmable frequency dividers in the output clock generator (OCG) which can be reprogrammed by the PCU, in order to allow utilizing a single pin of the OutClk(T:1) for providing multiple different output clock frequencies;
activity monitoring circuits for synchronizer input clocks and output clocks;
frequency monitoring circuits for synchronizer reference clocks;
status control circuits for switching synchronizer modes of operation and active reference clocks, based on an analysis of said activity and frequency monitoring circuits;
phase transfer control circuits for providing a required phase transfer function between an active reference clock and synchronizer output clocks;
a serial interface which allows the status control circuits and the phase transfer control circuits to be monitored and reprogrammed by an external controller (see the Serial Interface in the FIG. 1 , FIG. 2 and FIG. 3 );
a parallel interface which allows the status control circuits and the phase transfer control circuits to be monitored and reprogrammed by an external controller controller (see the Prallel Interface in the FIG. 1 , FIG. 2 and FIG. 3 );
automatic reference switching functions including hold-over and free-run switching, which are performed by the status control circuits and are based on monitoring a status of the activity and frequency monitoring circuits;
a master/slave switching circuit which allows a pair of integrated synchronizers to work in a master/slave configuration having a slave synchronizer being phase locked to a mate clock which is generated by a mate master synchronizer;
The above listed status control circuits and phase transfer control circuits can be implemented as separate on-chip control units or with a single on-chip PCU.
APLL mode of operation in the Heterodyne Timing Configuration is described below.
One of the external reference clocks (Ext_RefClk) is selected to be applied to the APLL reference input and the return phase synthesizer (RET_PS) is switched by the PCU into producing the APLL return clock which is matching said selected external reference clock.
The implementation of a DPLL mode is explained below.
The APLL output clock Fil_OutClk is applied to the APLL reference input and the return phase synthesizer (RET_PS) is switched by the PCU into producing the APLL return clock which is matching said output clock Fil_OutClk.
The FPD1 measures a phase error between the output clock multiplication SampClk and the Ext_RefWfm, and the FPD2 measures a phase error between the SampClk and the local oscillator LocOsc.
The PCU reads the above phase errors and uses them to calculate new contents of the RET_PS's periodical adjustment buffers and the fractional adjustment buffers needed for inserting phase deviations required for providing a phase transfer function (PTF), between the output clock Fil_OutClk and the Ext_RefWfm, which is already preprogrammed in the PCU.
The invention includes providing slave mode implementation which replaces the external reference clock with the mate SCCS output clock f_mate, in order to drive the above described APLL configuration. The slave mode allows maintaining phase alignment between active and reserve SCCS units, for the purpose of avoiding phase hits when protection switching reverts to using clocks from the reserve SCCS unit.
The invention includes using the above mentioned method of slave SCCS phase alignment for all 3 configurations shown in the FIG. 1 , FIG. 2 and FIG. 3 ).
5. Digital Wave Synthesis from Multi Sub-Clocks
The invention comprises the digital wave synthesis from multi-sub-clocks (DWS MSC) as a new timing method and circuit for programming and selecting a phase and a frequency of a synthesized clock.
The DWS MSC comprises programmable phase modifications which are defined below:
Phase increases of the synthesized clock are provided; by adding whole clock periods and/or fractional sub-clock delays, obtained from serially connected delay elements which the reference clock is propagated through, to a present phase obtained from a counter of reference clock periods and/or a present fractional sub-clock delay.
Phase decreases of the synthesized clock are provided; by subtracting whole clock periods and/or fractional sub-clock delays, obtained from serially connected delay elements which the reference clock is propagated through, from a present phase obtained from a counter of clock periods and/or a present fractional sub-clock delay.
The DWS MSC provides ˜10 times better phase adjustment resolution than the commonly used DDFS method; because the DWS MSC can modify phase with time intervals specified in fractions of clock cycle, instead of inserting or eliminating whole clock cycles from a synthesized clock. Therefore, the phase hits and resulting jitter are reduced by around 10 times compared to the DDFS method.
The DWS MSC provides an implementation of programmable algorithms for synthesizing a very wide range of low and high frequency wave-forms.
The DWS MSC comprises; a 1-P phase generator, a synchronous sequential phase processor (SSPP) for real time processing and selection of a phase of out-coming wave-form, and a programmable computing unit (PCU) for controlling SSPP operations and supporting signal synthesis algorithms.
Said 1-P phase generator is an extension of a 1 bit odd/even phase generator to p bits enabling 2 p =P phases to be generated from every reference sub-clock, as it is defined below.
The odd/even phase generator provides splitting of reference sub-clocks, generated by outputs of a reference propagation circuit built with serially connected gates which a reference clock is propagated through, into odd phase sub-clocks which begin during odd cycles of the reference clock and even phase sub-clocks which begin during odd cycles of the reference clock, wherein the odd/even phase selector comprises:
said reference propagation circuit connected to the reference clock;
serially connected flip-flops, wherein a clock input of a first flip-flop is connected to the reference clock and a data input of a first flip-flop is connected to an inverted output of the first flip-flop while a clock input of any other Nth flip-flop is connected to an (N−1) output of the reference propagation circuit and a data input of the N flip-flop is connected to an output of the (N−1) flip-flop;
connected to the serially connected flip-flops an odd/even selector generating the odd sub-clocks which begin during every odd reference clock cycle and the even sub-clocks which begin during every even reference clock cycle, wherein the output of the 1 st flip-flop is used to select odd and even reference clocks while the output of the Nth flip-flop is used to select odd and even reference sub-clocks from the (N−1) output of the reference propagation circuit.
The odd/even phase generator is extended into the 1-P phase generator splitting the reference sub-clocks into 1-P phase sub-clocks which begin during the corresponding 1-P cycles of the reference clock, wherein the 1-P phase selector further comprises:
a parallel 1-P sub-clock counter built as an extension to the first flip-flop working as 1-2 counter wherein the whole 1-P sub-clock counter is clocked by the first reference sub-clock, wherein an output of the 1-P sub-clock counter represents a 1-P phase number of the first sub-clock;
2-N parallel multi-bit buffers built as extensions to the original 2-N flip-flops working as 1 bit buffers wherein the whole 1-P sub-clock counter is clocked by the 2 nd reference sub-clock into the first multi-bit buffer which is clocked by the 3 rd reference sub-clock into the 2 nd multi-bit buffer and the content of the 1-P counter is similarly propagated into all next buffers until the Nth sub-clock loads the N−2 buffer into the N−1 buffer, wherein the 1 st buffer defines a phase number minus 1 for the 2 nd reference sub-clock and next buffers define similarly phase numbers for their corresponding reference sub-clocks until the N−1 buffer defines a phase number minus (N−1) for the Nth reference sub-clock.
1-P phase selectors built as extensions to the corresponding odd/even selectors wherein a first 1-P selector is connected to the 1-P sub-clock counter and selects a phase, of the first reference sub-clock, defined by the 1-P sub-clock counter while every next N−K+1 phase selector is connected to its N−K buffer and to its N−K+1 reference sub-clock (O<K<N), wherein every next N−K+1 phase selector generates phases, of its N−K+1 sub-clock, defined by its buffer content plus (N−K).
The 1-P phase generator can use both solutions defined below:
using rising edges of the reference sub-clocks for clocking the 1-P sub-clock counter and the 2-P buffers while negative pulses of the reference sub-clocks are used for activating outputs of the 1-P selectors generating the 1-P phase sub-clocks;
or using rising edges of the reference sub-clocks for clocking the 1-P sub-clock counter and the 2-P buffers while negative pulses of the reference sub-clocks are used for activating outputs of the 1-P selectors generating the 1-P phase sub-clocks.
Furthermore the 1-P phase generator can use the serially connected gates of the reference propagation circuit, which are connected into a ring oscillator controlled by a PLL circuit or are connected into a delay line control by a delay locked loop (DLL) circuit or are connected into an open ended delay line.
Furthermore this 1-P phase generator includes extending the remaining 2-N flip-flops with parallel sub-clock counters, the same as the parallel sub-clock counter extending the Pt flip-flop, instead of using the defined above 2-P multi-bit buffers. The use of the 2-P parallel counters requires adding preset means for all the 1-P counters, in order to maintain the same or predictably shifted content in all the 1-N parallel counters. Continues maintaining of said predictability of all the parallel counters content is necessary for generating predictable sequences of multiphase sub-clocks.
Said SSPP comprises a selection of one of multi sub-clocks for providing an edge of out-coming synthesized signal, where said sub-clocks are generated by the outputs of serially connected gates which an SSPP reference clock is propagated through.
The SSPP comprises calculating a binary positioning of a next edge of the out-coming wave-form versus a previous wave edge, which represents a number of reference clock cycles combined with a number of reference clock fractional delays which correspond to a particular sub-clock phase delay versus the reference clock.
Furthermore the SSPP comprises selective enabling of a particular sub-clock, which provides the calculated phase step between the previous and the current wave-form edges.
The SSPP further comprises a synchronous sequential processing (SSP) of incoming signal by using multiple serially connected processing stages with every stage being fed by data from the previous stage which are clocked-in by a clock which is synchronous with the reference clock. Since every consecutive stage is driven by a clock which is synchronous to the same reference clock, all the stages are driven by clocks which are mutually synchronous but may have some constant phase displacements versus each other.
The synchronous sequential processor (SSP) multiplies processing speed by splitting complex signal processing operation into a sequence of singular micro-cycles, wherein:
every consecutive micro-cycle of the complex operation is performed by a separate logical or arithmetical processing stage during a corresponding consecutive time slot synchronous with a reference clock providing a fundamental timing for a synthesized wave-form;
serially connected sequential stages are connected to a programmable control unit (PCU), wherein the sequential stages are clocked by reference sub-clocks generated by a reference propagation circuit built with serially connected gates which the reference clock is propagated through;
whereby inputs from the PCU are processed into a phase delay between a next edge of the synthesized wave-form versus a previous edge and a position of the next edge is calculated by adding the phase delay to a position of the previous edge, wherein the positions of wave-form edges are provided by a last of the sequential stages and said positions are expressed as numbers identifying reference sub-clocks needed for generating said wave-form edges.
The above defined SSP can be implemented by processing said inputs from the PCU into a phase modification step which is added to a period of the reference clock in order to calculate the phase delay.
Furthermore this invention includes the SSP circuit upgraded into a parallel multiphase processor (PMP) by extending the time slot allowed for the micro-cycles of the synchronous sequential processor by a factor of P, wherein:
2-P stages are added to the original sequential stage and every one of the resulting 1-P parallel multiphase stages is clocked with a corresponding 1-P phase sub-clock, wherein such 1-P phase sub-clock begins during the corresponding to that phase 1-P cycle of the reference clock and has a cycle which is P times longer than the reference clock cycle;
whereby consecutive 1-P parallel multiphase stages have processing cycles overlapping by 1 cycle of the reference clock wherein every 1-P parallel processing stage has P times longer cycle time equal to the cycle time of the corresponding 1-P phase sub-clock used for timing that stage.
The parallel multiphase processor further comprises:
a parallel processing phase 2-P built with plurality of 2-P parallel multiphase stages which are connected serially and are driven by the phase sub-clocks belonging to the same 2-P phase.
The SSPP invention comprises the use of the parallel multiphase processing for synthesizing a target wave-form by assigning consecutive parallel phases for the processing of a synthesized signal phase using signal modulation data provided by a programmable control unit (PCU) or by any other source.
Consequently the SSPP comprises using 1 to N parallel phases which are assigned for processing incoming signal data with clocks corresponding to-reference clock periods number 1 to N, as it is further described below:
circuits of phase1 process edge skews or phase skews or other incoming signal data with a clock which corresponds to the reference clock period number 1; circuits of phase2 process edge skews or phase skews or other incoming signal data with a clock which corresponds to the reference clock period number 2; finally circuits of phaseN process edge skews or phase skews or other incoming signal data with a clock which corresponds to the reference clock period number N.
Said parallel multiphase processing allows N times longer processing and/or sub-clocks selection times for said multiphase stages, compared with a single phase solution.
The above mentioned sub-clock selecting methods further include:
using falling edges of said sub-clocks for driving clock selectors which select parallel processing phases during which positive sub-clocks are enabled to perform said synthesized wave-form timing, or using rising edges of said sub-clocks for driving selectors which select parallel processing phases during which negative sub-clocks are enabled to perform said synthesized wave-form timing; using serially connected clock selectors for enabling consecutive sub-clocks during said processing phases, in order to assure that the enabled sub-clocks will occur within a selected processing phase and to enable selection of a sub-clock specified by a number contained in a fraction selection register of a particular processing phase.
The SSPP includes using said serially connected gates:
as being an open ended delay line; or being connected into a ring oscillator which can be controlled in a PLL configuration; or being connected into a delay line which can be controlled in a delay locked loop (DLL) configuration.
Every said sub-clock phase delay versus the reference clock phase amounts to a fraction of a reference clock period which is defined by a content of a fraction selection register which is assigned for a particular processing phase and is driven by the SSPP.
The SSPP includes a parallel stage processing of an incoming signal by providing multiple processing stages which are driven by the same clock which is applied simultaneously to inputs of output registers of all the parallel stages.
The SSPP further comprises:
a merging of processing phases which occurs if multiple parallel processing phases are merged into a smaller number of parallel phases or into a single processing phase, when passing from a one processing stage to a next processing stage; a splitting of processing phases which occurs if one processing phase is split into multiple processing phases or multiple processing stages are split into even more processing stages, when passing from a one processing stage to a next processing stage.
The SSPP includes using the 1-P phase generator defined above to generate SSPP clocks which drive said parallel phases and said sequential stages, and to generate selector switching signals for said merging and splitting of processing phases.
The SSPP includes time sharing of said parallel phases: which is based on assigning a task of processing of a next wave-form edge timing to a next available parallel processing phase.
The SSPP comprises a timing control (TC) circuit, which uses decoding of reference clock counters and/or other wave edge decoding and said SSPP clocks, for performing said time sharing phase assignments and for further control of operations of an already assigned phase.
The SSPP comprises passing outputs of a one parallel phase to a next parallel phase, in order to use said passed outputs for processing conducted by a following stage of the next parallel phase.
The outputs passing is performed: by re-timing output register bits of the one phase by clocking them into an output register of the next parallel phase simultaneously with processing results of the next parallel phase.
The SSPP further comprises all the possible combinations of the above defined: parallel multiphase processing, parallel stage processing, synchronous sequential processing, merging of processing phases, splitting of processing phases, and outputs passing.
The SSPP includes processing stage configurations using selectors, arithmometers, and output registers, which are arranged as it is defined below:
input selectors select constant values or outputs of previous stages or outputs of parallel stages or an output of the same stage to provide arithmometer inputs, and arithmometer output is clocked-in to an output register by a clock which is synchronous to the reference clock; multiple arithmometers are fed with constant values or outputs of previous stages or outputs of parallel stages or an output of the same stage, and an output selector selects an arithmometer output to be clocked-in to an output register by a clock synchronous to the reference clock; the above defined configuration as being supplemented by using an output of an output selector of a parallel processing stage for controlling functions of other output selector.
The SSPP comprises:
using switching signals of said input selectors for producing pulses which clock data into output registers of previous stages;
using switching signals of said output selectors for producing pulses which clock data into output registers of previous stages;
The SSPP also comprises:
using results obtained in earlier stages for controlling later stages operations, and using results obtained in the later stages for controlling the earlier stages operations.
Proper arrangements of said parallel and sequential combinations and said stages configurations provide real time processing capabilities for very wide ranges of signal frequencies and enable a wide coverage of very diversified application areas.
The DWS MSC comprises two different methods for accommodating a phase skew between the reference clock and a required carrier clock frequency of the transmitted signal, and both methods allow elimination of ambiguities and errors in encoding of output signal data patterns. Said two methods are further defined below:
a source of the reference clock provides frequency or phase alignment with the timing of the data which are being encoded and sent out in the synthesized output wave-form; phase skews between the reference clock and the timing of the destined for transmission data are digitally measured and translated into implemented by the SSPP phase adjustments of the synthesized signal which provide required carrier frequency of the transmitted output signal; both above mentioned methods include measurements of phase or frequency deviations of the destined for transmission data versus the reference clock, and using said measurements results to assure required carrier frequency of the synthesized signal.
Furthermore the DWS MSC method comprises phase modulations of the synthesized wave-form by adding or subtracting a number of reference clock periods and/or a number of fractional delays to a phase of any edge of the synthesized wave-form.
Said adding or subtracting of a number of reference clock periods is further referred to as a periodical adjustment, and said adding or subtracting of fractional delays is further called a fractional adjustment.
The DWS MSC method allows synthesizing of any waveform by modulating a phase of the reference clock with periodical and/or fractional adjustments of any size.
6. Phase Synthesizer
The invention also includes the Phase Synthesizer (PS) for carrying out the DWS MSC method; as it is further explained below and is shown in FIG. 4 , FIG. 4A , FIG. 5 , and FIG. 6 . The Timing Diagram of the PS is shown in the FIG. 7 .
Said phase synthesizer provides programmable modifications of a phase of a synthesized clock by unlimited number of gate delays per a modification step with step resolution matching single gate delay at steps frequencies ranging from 0 to ½ of maximum clock frequency, wherein:
a delay control circuit is connected to a programmable control unit (PCU) wherein the delay control circuit defines size and frequency of phase delay modifications of the synthesized clock versus a reference clock, the delay control circuit also having a terminal connected to reference sub-clocks generated by a reference propagation circuit or connected to odd/even sub-clocks generated by an odd/even phase selector;
the reference clock is connected to the reference propagation circuit consisting of serially connected gates wherein outputs of the gates generate the reference sub-clocks providing variety of phase delays versus the reference clock;
the reference sub-clocks are connected to an odd/even phase selector which splits the reference sub-clocks by generating separate odd sub-clocks and even sub-clocks, wherein the odd sub-clocks begin during odd cycles of the reference clock and the even sub-clocks begin during even cycles of the reference clock;
a clock selection register is loaded by the odd sub-clocks and by the even sub-clocks with the outputs of the delay control circuit, wherein the odd sub-clocks or the even sub-clocks beginning during an earlier cycle of the reference clock download outputs of the delay control circuit which select the even sub-clocks or the odd sub-clocks beginning during a later cycle of the reference clock for providing the synthesized clock;
an output selector is connected to the output of the clock selection register and to the outputs of the odd/even phase selector, wherein the output selector uses inputs from the clock selection register for selecting output of the odd/even phase selector which is passed through the output selector for providing the synthesized clock.
The above defined PS can use the odd/even phase generator or the 1-P phase generator, which have been already defined above.
The PS can use the delay control circuit implemented with the parallel multiphase processor (PMP) which has been already defined above.
The PS comprises 2 different implementation methods, which are explained below.
The first PS implementation method is based on moving a synthesized clock selection point from a delay line which propagates a reference clock (see the FIG. 4 ); wherein:
said phase increases are provided by moving said selection point of the synthesized clock from the reference clock propagation circuit, in a way which adds gate delays to a present delay obtained from the propagation circuit;
said phase decreases are provided by moving said selection point of the synthesized clock from the reference clock propagation circuit, in a way which subtracts gate delays from a present delay obtained from the propagation circuit;
The first PS implementation method is conceptually presented in FIG. 4 & FIG. 6 , and its principles of operations are explained below.
The PLL×L Freq. Multiplier produces the series of sub-clocks Clk0, Clk-Clk1.
The sub-clock Clk0 keeps clocking in a reversed output of its own selector PR0.
The sub-clocks CLkR-Clk1 keep clocking in outputs of the previous selectors PR0, PRR-PR2 into their own selectors PRR-PR1.
Since the selector PR0 is being reversed by every Clk0, every selector in the PR0, PRR-PR1 chain is being reversed as well by a falling edge of its own sub-clock Clk0, ClkR-Clk1, and every selector in the chain represents reversal of its predecessor which is delayed by a single sub-clock fractional delay.
Consequently the PR0, PR1N-PRR select sub-clocks Clk0, Clk1-ClkR during any odd processing phase, and their reversals PR0N, PR1-PRRN select sub-clocks Clk0, Clk1-ClkR during any even processing phase.
The odd/even processing phase has been named phase1/phase2, and their sub-clocks are named 1Clk0,1Clk1-1ClkR/2Clk0,2Clk1-2ClkR accordingly.
Since said phase1/phase2 sub-clocks are used to run a phase synthesis processing in separate designated for phase1/phase2 phase processing stages which work in parallel, a time available for performing single stage operations is doubled (see also the FIG. 6 for more comprehensive presentation of said parallel processing).
Furthermore, the Clock Selection Register 1 (CSR1) can be reloaded at the beginning of the phase2 by the 2Clk0 and its decoders shall be ready to select a glitch free phase1 sub-clock which is defined by any binary content of the CSR1.
Similarly the CSR2 is reloaded by the 1Clk0, in order to select a single glitch free sub-clock belonging to the phase2.
The second PS implementation method is based on adjusting alignment between an exit point of the synthesized clock from the reference propagation circuit versus an input reference clock; in a way which adds gate delays for phase increases, and subtracts gate delays for phase decreases. The second method is presented in FIG. 4A , and its differences versus the FIG. 4 are explained below.
The moving exit point from the driven by Fsync/2Dsel phase locked delay line is used as a return clock for the PLL×2Dsel multiplier, instead of using a fixed output of the INV0 to be the PLL return clock.
The fixed output of the INV0 is divided by the programmable frequency divider (PFD) in order to provide the synthesized clock Fsynt, instead of the moving synthesized clock selection point.
The first method exit point alignments, introduce phase jumps which cause synthesized clock jitter. The second method configuration shown in FIG. 4A , filters out Fsynt jitter frequencies which are higher than a bandwidth of the multiplier's PLL.
While any of the two PS implementation methods is shown above using a particular type of a reference clock propagation circuit, the PS comprises using all the listed below reference clock propagation circuits by any of the two methods:
an open ended delay line built with serially connected logical gates or other delay elements; a ring oscillator built with serially connected logical gates or other delay elements, which have propagation delays controlled in a PLL configuration;
a delay line built with serially connected logical gates or other delay elements, which have propagation delays controlled in a Delay Locked Loop (DLL) configuration.
It shall be noticed that further splitting to more than 2 parallel phases is actually easier than the splitting to the original 2 processing phases; because while one of the phases is active, its earlier sub-clocks can be used to trigger flip-flops which can segregate sub-clocks which belong to multiple other phases and can be used to drive the other parallel phases.
Consequently using this approach; allows increasing parallel stages processing times to multiples of reference clock periods, and provides implementation of said DWS MSC multiple phase processing which has been introduced in the previous section.
Said selection of a sub-clock for synthesized clock timing, can be physically implemented in two different ways:
by using phase producing gates from 1inv0 to 1invR and from 1inv0 to 1invR, as having 3 state outputs with enable inputs EN, one of which is enabled by one of the outputs of the sub-clock selection gates from 1sel0 to 1selR and from 2sel0 to 2selR;
or by using the sub-clock selection gates which have all their outputs connected into a common collector configuration (instead of having them followed by the 3state gates), in order to allow a currently active output of one of the sub-clock selection gates to produce a phase of the synthesized clock FselN.
The PS comprises fractional adjustments of synthesized clock phase for providing high resolution phase modifications by fractional parts of a reference clock period.
The PS comprises combined periodical and fractional adjustments of synthesized clock phase, which use counters of reference clock periods for generating counter end (CE) signals when a periodical part of a phase adjustment is expired.
The PS further comprises using said counter end signals for generation of control signals which assign and/or synchronize consecutive parallel processing phases for processing consecutive combined or fractional phase adjustments of the synthesized clock.
The PS comprises:
Using a basic periodical adjustment and a basic fractional adjustment for providing a basic phase step, which can remain the same for multiple edges of the synthesized clock. Using a modulating periodical adjustment and a modulating fractional adjustment, which can be different for every specific edge of the synthesized clock. Using said DWS MSC and SSPP methods for processing of said basic periodical adjustments, basic fractional adjustments, modulating periodical adjustments and modulating fractional adjustments for calculating periodical and fractional parts of combined adjustments.
Processing of said calculated combined adjustment with a positioning of a synthesized clock previous edge for calculating a periodical and a fractional part of the next edge position of the synthesized clock.
7. Frame Phase Detector
The Frame Phase Detector (FPD) operates as follows:
local clock phase is measured continuously by counting time units signaled by the local clock;
abstract frame, consisting of time intervals defined by software, is used for high resolution measurements of local clock phase error versus an external clock phase defined by it's frame signaled by external events, wherein such time intervals expected by software and expressed in local time units are subtracted from time intervals, occurring between said external events, measured in local clock units;
resulting phase error is read back by software subroutines.
Using such software defined frame instead of using an equivalent frame produced by hardware is advantageous, as it eliminates circuits and errors associated with using such electrical local frame and allows instant phase adjustments to be applied after the arrival of the external frame thus resulting in more stable DPLL operations.
Furthermore such software frame is more suitable for time messaging protocols such as IEEE 1588.
Subtracting a nominal number of local clock cycles corresponding to an imaginary frame has been anticipated by Bogdan in U.S. Pat. No. 6,864,672 wherein basic circuits and timing diagrams are shown, however this invention comprises further contributions, such as:
more comprehensive programming of said software frame, in order to allow timing adjustments in more complex systems with rapidly changing references frequencies and references phase hits;
programmable presetting of numerical first edge allows elimination of an initial phase error when phase error measurements begun, in order to enable the use of the FPD for very precise delay measurements in critical traffic control applications;
elimination of any accumulation of digitization errors with an alternative solution simpler than presently existing arrangement.
The FPD comprises solutions described below.
1. A frame phase detector (FPD) for measuring a frame phase skew between a first frame consisting of a programmable sequence of expected numbers of sampling local clocks, and a second frame defined with a series of time intervals located between second frame edges defined by changes of an external frame signal or by changes of a frame status signal driven with external messages such as time stamps, wherein a frame measurement circuit captures a number of said sampling clocks occurring during an interval of the second frame and a phase processing unit subtracts the captured number from the expected number representing expected duration of the corresponding interval of the first frame; wherein-the frame phase detector comprises:
a means for a detection of said second frame edges, by detecting said changes of the external frame signal, or by detecting said changes of the frame status driven by the external messages;
the frame measurement circuit using the sampling local clock, which is a higher frequency signal, to measure said time intervals of the second frame having lower frequency, wherein the frame measurement circuit counts said sampling clocks occurring during every interval of the second frame and captures and buffers the counted value until it is read by a phase processing unit;
the phase processing unit for subtracting the expected number of the sampling clocks from the counted number of the sampling clocks, in order to calculate an interval phase skew between the expected interval of the first frame and the corresponding interval of the second frame.
a means for combining said interval phase skews of particular frame intervals into said frame phase skew.
2. A frame phase detector as described in statement 1, wherein said second frame begins with a numerical first edge, representing initial phase of the second frame, defined as a number of sampling delays between an expected location of such numerical first edge and the first counted sampling clock, wherein the frame measurement circuit is preset to the numerical first edge before any said counting of the sampling clocks takes place; the frame phase detector comprising:
a means for presetting the frame measurement circuit to said numerical first edge before said counting of the sampling periods of the first interval of the second frame takes place;
a means for supplementing said preset numerical first edge by adding following sampling periods counted until the second edge of the second frame is encountered, and a means for for capturing and buffering a resulting total number of sampling periods until it is read by a phase processing unit;
wherein the resulting total number of the sampling periods represents duration of such first interval of the second frame and is made available for further processing.
3. A frame phase detector as described in statement 1 receiving an incoming wave-form carrying the external frame signal or carrying the external message; the frame phase detector wherein:
said detection of the second frame edges from the incoming wave-form, is performed by a circuit synchronized with the local sampling clock and producing a known propagation delay.
4. An FPD as described in statement 1, wherein the frame phase skew is calculated without any accumulation of digitization errors of said intervals phase skews while the single intervals phase skews are still available for intermediate signal processing; the FPD comprising:
a means for rounding said counted number of the sampling periods by adding 1 such sampling period to the counted number defining length of said frame interval, wherein ½ of the added sampling period approximates a fraction of the sampling period occurring before said counting of the interval sampling periods and another ½ of the added sampling period approximates a fraction of the sampling period occurring after said counting;
whereby such addition of 1 sampling period to every interval measurement, provides all sampling periods occurring between said counted numbers of sampling periods relating to consecutive intervals of the second frame, and reduces a digitization error of any long frame to a time sampling error of a single interval.
5. A frame phase detector as described in statement 1 including a high resolution circuit for extending resolution of phase measurements below a period of the local clock, wherein the high resolution circuit propagates the local clock through a delay line built with serially connected gates producing different phases of the local clock; the frame phase detector comprising:
the high resolution circuit using a phase capture register for capturing a state of outputs of the serially connected gates, which the local clock is propagated through, at an edge of the interval of the second frame;
or the high resolution circuit using a phase capture register for capturing an edge of the interval of the second frame by using the outputs of the serially connected gates as sampling sub-clocks applied to clocking-in inputs of the phase capture register while said second frame, defined with the frame signal or the frame status, is applied to data inputs of the phase capture register.
6. A frame phase detector as described in statement 1 including a high resolution circuit for extending resolution of phase measurements below the period of the local clock, wherein the high resolution circuit propagates the second frame, defined with the frame signal or the frame status, through a delay line built with serially connected gates producing different phases of the second frame; the frame phase detector comprising:
the high resolution circuit using a phase capture register for capturing a phase of an edge of the interval of the second frame by applying the outputs of the serially connected gates which the second frame is propagated through to data inputs of the phase capture register while the local clock is used for clocking the data inputs in;
or the high resolution circuit using a phase capture register for capturing a phase of an edge of the interval of the second frame by using the outputs of the serially connected gates—which the second signal frame is propagated through—as clocking in signals while the local clock is applied to data inputs of the phase capture register.
7. A frame phase detector as described in statement 1 including a noise filtering edge detector (NFED) improving reliability and precision of said detection of the second frame edges by removing phase noise from wave-form edges and amplitude glitches from wave-form levels through continues over-sampling and digital filtering of an entire incoming wave-form carrying said external frame signal or said external messages, wherein the incoming wave-form is over-sampled with sampling sub-clocks generated by a delay line built with serially connected gates which the sampling local clock is propagated through, and wave-forms variable length pulses are processed by comparing an edge mask, which provides an expected pattern of wave-form samples corresponding to an edge of the wave-form, with a sequence of wave-form samples surrounding a consecutive analyzed sample; the FPD wherein the NFED further comprises:
a wave capturing circuit for capturing results of sampling the incoming wave-form in time instances produced by the outputs of the delay line which the sampling local clock is propagated through;
means for performing logical or arithmetic operations on particular samples of the edge mask and their counterparts from the wave-form samples surrounding the consecutive analyzed sample of the captured wave-form;
means for using the results of said operations for deciding if said operations can determine a filtered location of an edge of a filtered wave-form, wherein such filtered location is further used for said detection of boundaries of the second frame.
8. Noise Filtering Edge Detector
The NFED is directed to signal and data recovery in wireless, optical, or wireline transmission systems and measurement systems.
The noise filtering edge detector (NFED) provides digital filtering of waveform pulses transmitting serial streams of data symbols with data rates reaching ½ of maximum clock frequency of IC technology.
The NFED enables:
continues waveform over-sampling with sampling frequencies 5 times higher than the maximum clock frequency;
elimination of phase jitter from edges of the pulses and elimination of amplitude glitches from insides of the pulses as well;
and a system for adaptive noise filtering based on analysis of captured unfiltered portions of the over-sampled waveform.
The noise filtering edge detectors (NFED) shall be particularly advantageous in system on chip (SOC) implementations of signal processing systems.
The NFED provides an implementation of programmable algorithms for noise filtering for a very wide range of low and high frequency wave-forms.
The NFED is based on a synchronous sequential processor (SSP) which allows >10 times faster processing than conventional digital signal processors.
The NFED comprises:
the SSP used for capturing and real time processing of an incoming waveform (see the end of this Subsection);
a wave-from screening & capturing circuit (WFSC) (see the end of this Subsection);
a programmable control unit (PCU) for supporting adaptive noise filtering and edge detection algorithms;
The NFED compares: a captured set of binary values surrounding a particular bit of a captured waveform, with an edge mask comprising a programmed set of binary values.
Such comparison produces an indicator of proximity between the surrounded bit and an expected edge of the waveform. The indicator is named edge proximity figure (EPF).
Said comparison comprises:
performing logical and/or arithmetic operation on any bit of the captured set and its counterpart from the edge mask; integrating results of said operations performed on all the bits of the captured set, in order to estimate the EPF for the surrounded bit; defining a waveform transition area by comparing the EPF with an edge threshold, wherein a set of bits having EPFs exceeding the threshold defines the waveform transition area where an edge is expected. Finding the most extreme EPF by comparing all the EPFs belonging to the same waveform transition area, wherein such EPF identifies a bit position localizing a filtered edge.
The NFED further comprises:
modulating locations of detected rising and/or falling waveform edges by an edge modulating factor (EMF) used to modify edge thresholds which are subtracted from the EPFs, wherein such reduced EPFs are used for finding edge location;
using an edge modulation control register (EMCR) programmed by the PCU, for defining function transforming said EMFs into said modifications of edge thresholds.
The NFED still further comprises displacing detected edges by a preset number of bits, in order to compensate for inter-symbol interference ISI or other duty cycle distortions.
The NFED further includes:
using the WFSC for programmable screening of the over-sampled unfiltered wave-form, and for capturing screened out wave-form intervals, and for communicating said captured intervals and other results to the PCU; programmable waveform analysis and adaptive noise filtering algorithms; edge mask registers for providing said edge masks used for detecting rising and/or falling waveform edges; edge threshold registers for providing said edge thresholds used for detecting rising and/or falling waveform edges; edge displacement registers for providing said edge displacement numbers used for shifting detected rising and/or falling edges by a programmable number of bits of waveform processing registers; filter control registers which control; said logical and/or arithmetic operations conducting the comparison of captured waveform bits with the edge mask, and said edge displacements in the processed waveforms; using the PCU for calculating and loading said edge mask registers and/or said edge threshold registers and/or said edge displacement registers and/or said filter control registers; using the PCU for controlling said calculations of the EMF by presetting the EMCR in accordance with adaptive noise filtering algorithms. using the PCU for controlling and using the WFSC operations for implementing adaptive filters by controlling noise filtering edge detection stages of the SSP.
Further description of the NFED is provided below.
The NFED comprises:
a wave capturing circuit for capturing an incoming wave-form sampled by sub-clocks produced by the outputs of the delay line which the sampling clock is propagated through;
a circuit performing logical or arithmetic operations on particular samples of the edge mask and their counterparts from the wave-form samples surrounding the consecutive analyzed sample of the captured wave-form;
using the results of said operations for defining a filtered location of an edge of the waveform.
Such NFED further comprises:
a filter arithmometer for comparing the edge mask with the captured wave-form in order to introduce noise filtering corrections of the edges of the filtered wave-form;
a filter mask register providing the edge mask which is compared with the captured wave-form of an input signal and/or filter control register which provides code for controlling operations of said filter arithmometer in order to provide said corrections of the filtered wave-form.
The NFED compares said edge mask samples of the expected edge pattern with samples from a consecutive processed region of the captured wave-form.
Consequently the NFED comprises:
accessing any said consecutive processed region of the captured wave-form and using such region as comprising samples corresponding to the edge mask samples;
selection of a consecutive sample from the edge mask and simultaneous selection of a corresponding consecutive sample from the processed region of the captured wave-form;
calculating a correlation component between such selected samples by performing an arithmetical or logical operation on said selected samples;
calculating a digital correlation integral by adding said correlation components calculated for single samples of the edge mask.
The NFED includes calculating correlation integrals for said consecutive processed regions uniformly spread over all the captured wave-form, wherein the calculated correlation integrals are further analyzed and locations of their maximums or minimums are used to produce said filtered locations of said edges of the filtered wave-form;
Such NFED operations comprise:
moving said processed region by a programmable number of samples positions of the captured wave-form;
storing and comparison of said correlation integrals calculated for different processed regions, in order to identify said maximums or minimums and their locations;
using said locations of said maximums or minimums for producing the filtered locations of the edges of the filtered wave-from.
The NFED includes compensation of inter-symbol interference (ISI) or other predictable noise by adding a programmable displacement to said filtered location of the edge of the wave-form.
Therefore the NFED comprises:
programmable amendment of the filtered location of the wave-form edge by presetting said programmable displacement with a new content;
using such newly preset displacement for shifting the filtered location of the next detected edge.
The NFED includes compensation of periodical predictable noise with programmable modulations of said filtered locations of the wave-form edges by using an edge modulating factor (EMF) for a periodical diversification of said edge thresholds corresponding to different said regions of the wave-form; wherein the NFED comprises:
modulation of the filtered locations of the wave-form edges by using the edge modulating factor (EMF) for modulating said edge thresholds;
subtracting such modulated thresholds from the correlation integrals calculated in said different wave-form regions;
using such reduced correlation integrals for locating said maximums defining locations of filtered edges.
whereby said EMF provides such modulation of the edge thresholds, that predictable noise introduced to consecutive wave-form samples by known external or internal sources, is compensated.
The NFED further includes:
using an edge modulation control register (EMCR) programmed by the PCU, for said modulation of the edge thresholds.
The NFED comprises:
sequential processing stages configured into a sequential synchronous processor driven synchronously with said sampling clock.
The NFED further comprises parallel processing phases implemented with said synchronous sequential processors; wherein:
said parallel processing phases are driven by clocks having two or more times lower frequencies than said sampling clock;
consecutive parallel phases are driven by clocks which are shifted in time by one or more periods of said sampling clock;
The NFED comprises using multiple noise filtering sequential stages in every parallel processing phase for extending said wave-form filtering beyond a boundary of a single phase.
Such NFED further includes an over-sampled capturing of consecutive wave-form phases in corresponding phases wave registers which are further rewritten to wave buffers with overlaps which are sufficient for providing all wave samples needed for a uniform filtering of any edge detection despite crossing boundaries of the wave buffers which are loaded and used during different said phases; wherein the NFED comprises:
rewriting the entire wave register belonging to one phase into the wave buffer of the same phase and rewriting an end part of said wave register into a front part of the next phase wave buffer, while the remaining part of the next wave buffer is loaded from the wave register belonging to the next phase;
whereby every wave buffer contains entire said wave-form regions needed for calculating said EPF's corresponding to the samples belonging to the phase covered by this buffer.
The NFED includes:
merging of said parallel processing phases, wherein multiple said parallel processing phases are merged into a smaller number of parallel phases or into a single processing phase, when passing from one said sequential processing stage to the next sequential stage.
splitting of said parallel processing phases, wherein one said processing phase is split into multiple parallel processing phases or multiple parallel processing phases are split into even more parallel phases, when passing from one said sequential processing stage to the next sequential stage.
The NFED includes said PCU for analyzing results of said real time signal processing form the SSP and for controlling operations of the SSP; wherein the PCU comprises:
means for reading results of captured signal processing from the SSP;
means for programming the filter mask register and/or the filter control register and/or said presetting of the programmable displacement and/or the edge modulating factor, which are applied for achieving said filtering of the captured wave-forms.
The NFED includes a wave-form screening and capturing circuit (WFSC) for capturing pre-selected intervals of unfiltered over-sampled wave-form; wherein the WFSC comprises:
using programmable screening masks and/or programmable control codes for verifying incoming wave-form captures for compliance with said programmable screening masks.
buffering captured wave-form for which the pre-programmed compliance or non-compliance has been detected, or for counting a number of said detections;
communicating said buffered wave-form and a detections counter to the PCU.
The PCU reads resulting captured signals from the WFSC and controls operations of the WFSC; wherein the PCU comprises:
programming the screening masks and/or the control codes for performing said verification of captured wave-forms compliance or non-compliance with said screening patterns;
reading verification results and/or reading captured wave-forms which correspond to the preprogrammed verification criteria.
The NFED includes using said PCU for adaptive noise filtering; wherein the PCU comprises:
means for programmable waveform analysis;
means for loading edge mask registers which provide said edge masks used for detecting rising and/or falling wave-form edges;
or means for loading edge threshold registers which provide said edge thresholds used for detecting rising and/or falling waveform edges;
or means for loading edge displacement registers which provide said edge displacements used for shifting detected rising and/or falling edges by a programmable number of samples positions of the captured wave-form;
or means for loading filter control registers which control said logical and/or arithmetic operations conducting the comparison of captured wave-form samples with the edge mask, and said edge displacements in the processed wave-forms;
or means for controlling said EMF by presetting the EMCR in accordance with adaptive noise filtering algorithms.
General definition of the SSP is provided below.
The SSP includes real time capturing and processing of in-coming wave-form and a programmable computing unit (PCU) for controlling SSP operations and supporting adaptive signal analysis algorithms.
Said SSP comprises an over-sampling of incoming wave-form level by using a locally generated sampling clock and its sub-clocks generated by the outputs of serially connected gates which the sampling clock is propagated through. If an active edge of the wave-form is detected by capturing a change in a wave-form level, the position of the captured signal change represents an edge skew between the wave-form edge and an edge of the sampling clock.
In addition to the above wave-form capturing method, the SSP includes 3 other methods of the edge skew capturing which are defined below:
the sampling clock captures the outputs of serially connected gates which the incoming wave-form is propagated through; the outputs of serially connected gates which the incoming wave-form is propagated through, provide wave-form sub-clocks which capture the sampling clock. the incoming wave-form captures the outputs of serially connected gates which the sampling clock is propagated through;
The above mentioned edge skew capturing methods further include:
using falling edges of said sub-clocks for driving clock selectors which select parallel processing phases during which positive sub-clocks are enabled to perform said edge skew capturing, or using rising edges of said sub-clocks for driving selectors which select parallel processing phases during which negative sub-clocks are enabled to perform said edge skew capturing; using serially connected clock selectors for enabling consecutive sub-clocks, in order to assure that consecutive sub-clocks will target appropriate consecutive bits of appropriate capture registers. The SSP invention includes using said serially connected gates: as being an open ended delay line; or being connected into a ring oscillator which can be controlled in a PLL configuration; or being connected into a delay line which can be controlled in a delay locked loop (DLL) configuration.
Every said edge skew amounts to a fraction of a sampling clock period.
The SSP comprises measuring time intervals between active wave form edges, as being composed of said edge skew of a front edge of the incoming waveform, an integer number of sampling clock periods between the front edge and an end edge, and said edge skew of the end edge of the wave-form.
The SSP further comprises a parallel multiphase processing of incoming signal by assigning consecutive parallel phases for the capturing of edge skews and/or processing of other incoming wave-form data with clocks which correspond to consecutive sampling clocks.
Consequently the SSP invention comprises using 1 to N parallel phases which are assigned for processing incoming signal data with clocks corresponding to sampling clock periods numbered from 1 to N, as it is further described below:
circuits of phase1 process edge skews or phase skews or other incoming signal data with a clock which corresponds to the sampling clock period number 1;
circuits of phase2 process edge skews or phase skews or other incoming signal data with a clock which corresponds to the sampling clock period number 2;
finally circuits of phase N process edge skews or phase skews or other incoming signal data with a clock which corresponds to the sampling clock period number N.
Said parallel multiphase processing allows N times longer capturing and/or processing times for said multiphase stages, compared with a single phase solution.
The SSP includes parallel stage processing of incoming signal by providing multiple processing stages which are driven by the same clock which is applied simultaneously to inputs of output registers of all the parallel stages.
The SSP further comprises a synchronous sequential processing of incoming signal by using multiple serially connected processing stages with every stage being fed by data from the previous stage which are clocked-in by a clock which is synchronous with the sampling clock.
Since every consecutive stage is driven by a clock which is synchronous to the same sampling clock, all the stages are driven by clocks which are mutually synchronous but may have some constant phase displacements versus each other.
The SSP further comprises:
merging of processing phases which occurs if multiple parallel processing phases are merged into a smaller number of parallel phases or into a single processing phase, when passing from a one processing stage to a next processing stage;
splitting of processing phases which occurs if one processing phase is split into multiple processing phases or multiple processing stages are split into even more processing stages, when passing from a one processing stage to a next processing stage.
The SSP includes a sequential clock generation (SCG) circuit which uses said clock selectors and said sub-clocks: to generate SSP clocks which drive said parallel phases and said sequential stages, and to generate selector switching signals for said merging and splitting of processing phases.
The SSP includes time sharing of said parallel phases: which is based on assigning a task of processing of a newly began wave-form pulse to a next available parallel processing phase.
The SSP comprises a sequential phase control (SPC) circuit, which uses results of a wave edge decoding and said SSP clocks, for performing said time sharing phase assignments and for further control of operations of an already assigned phase.
The SSP comprises passing outputs of a one parallel phase to a next parallel phase, in order to use said passed outputs for processing conducted by a following stage of the next parallel phase.
The outputs passing is performed: by re-timing output register bits of the one phase by clocking them into an output register of the next parallel phase simultaneously with processing results of the next parallel phase.
The SSP further comprises all the possible combinations of the above defined: parallel multiphase processing, parallel stage processing, synchronous sequential processing, merging of processing phases, splitting of processing phases, and outputs passing.
The SSP includes processing stage configurations using selectors, arithmometers, and output registers, which are arranged as it is defined below:
input selectors select constant values or outputs of previous stages or outputs of parallel stages or an output of the same stage to provide arithmometer inputs, and arithmometer output is clocked-in to an output register by a clock which is synchronous to the sampling clock; multiple arithmometers are fed with constant values or outputs of previous stages or outputs of parallel stages or an output of the same stage, and an output selector selects an arithmometer output to be clocked-in to an output register by a clock synchronous to the sampling clock; the above defined configuration as being supplemented by using an output of an output selector of a parallel processing stage for controlling output selector functions.
Proper arrangements of said parallel and sequential combinations and said stages configurations provide real time processing capabilities for very wide ranges of signal frequencies and enable a wide coverage of very diversified application areas.
Summary of the WFSC is provided below (see the Subsection 4 of the next section for preferred embodiment of WFSC).
The wave-form screening and capturing circuits (WFSC) comprises:
using programmable data masks and programmable control codes for verifying incoming wave-form captures for compliance or non-compliance with a pre-programmed screening patterns; buffering captured data for which the pre-programmed compliance or non-compliance have been detected; counting a number of the above mentioned detections; communicating both the buffered captured data and the number of detections, to an internal control unit and/or to an external unit; using programmable time slot selection circuits for selecting a time interval for which wave-form captures shall be buffered and communicated to the PCU.
Said PCU comprises implementation of the functions listed below:
programming of verification functions and patterns for checking captured wave-forms for compliance or non-compliance with the patterns; reading verification results and reading captured wave-forms which correspond to the preprogrammed verification criteria; reading captured wave-forms which can be pre-selected by the PCU arbitrarily or based on other inputs from the SSP; programming of noise filtering functions and noise filtering masks for filtering captured wave-forms; reading results of real-time wave-form processing from the SSP, processing the results and providing control codes and parameters for further real-time wave-form processing in the SSP, in accordance with adaptive signal processing algorithms; reading output data from the SSP, interpreting the data, and communicating the data to external units.
9. Summary of SCCS
SCCS introduced above comprises methods, systems and devices described below.
1. A phase synthesizer providing programmable modifications of a phase of a synthesized clock by unlimited number of gate delays per a modification step with step resolution matching single gate delay at steps frequencies ranging from 0 to ½ of maximum clock frequency; the phase synthesizer comprising:
a delay control circuit connected to a programmable control unit (PCU) wherein the delay control circuit defines size and frequency of phase delay modifications of the synthesized clock versus a reference clock, the delay control circuit also having a terminal connected to reference sub-clocks generated by a reference propagation circuit or connected to odd/even sub-clocks generated by an odd/even phase selector;
the reference propagation circuit, connected to the reference clock, consisting of serially connected gates wherein outputs of the gates generate the reference sub-clocks providing variety of phase delays versus the reference clock;
an odd/even phase selector, connected to the reference sub-clocks, for splitting the reference sub-clocks by generating separate odd sub-clocks and even sub-clocks, wherein the odd sub-clocks begin during odd cycles of the reference clock and the even sub-clocks begin during even cycles of the reference clock;
a clock selection register loaded by the odd sub-clocks and by the even sub-clocks with the outputs of the delay control circuit, wherein the odd sub-clocks or the even sub-clocks beginning during an earlier cycle of the reference clock download outputs of the delay control circuit which select the even sub-clocks or the odd sub-clocks beginning during a later cycle of the reference clock for providing the synthesized clock;
an output selector connected to the output of the clock selection register and to the outputs of the odd/even phase selector, wherein the output selector uses inputs from the clock selection register for selecting output of the odd/even phase selector which is passed through the output selector for providing the synthesized clock.
2. A phase synthesizer providing programmable modifications of a phase of a synthesized clock by a programmable number of gate delays per a modification step with step resolution matching single gate delay at steps frequencies ranging from 0 to ½ of maximum clock frequency, wherein uncontrolled phase transients inherent for frequency synthesizers are eliminated; the phase synthesizer comprising:
a reference propagation circuit, connected to a reference clock, consisting of serially connected gates wherein outputs of the gates generate reference sub-clocks providing variety of phase delays versus the reference clock;
a delay control circuit, connected to a programmable control unit (PCU) and to the reference propagation circuit, for applying phase delay modifications of the synthesized clock versus a reference clock by modifying selections of said reference sub-clocks chosen for sourcing the synthesized clock;
the PCU, connected to an interrupt signal generated by the delay control circuit, for supplying programmable sequences of said phase delay modifications in response to interrupt signals sent by the delay control circuit.
3. A noise filtering edge detector (NFED) for recovering digital signal transitions and their phases from noisy waveforms while assuming ideal signal shape between the transitions, in order to identify digitally transmitted data, by continues over-sampling and digital filtering of the incoming waveform based on comparing an edge mask, representing an expected pattern of wave-form samples corresponding to an edge of the original wave-form, with a sequence of wave-form samples surrounding a consecutive analyzed sample; the NFED comprising:
a wave capturing circuit for capturing results of sampling the incoming wave-form in time instances produced by the outputs of the delay line which the sampling clock is propagated through;
a correlation calculating circuit for performing logical or arithmetic operations on particular samples of the edge mask and their counterparts from a wave samples region surrounding the consecutively analyzed sample of the captured wave-form, in order to calculate a correlation integral between the wave samples region and the edge mask;
a proximity estimating circuit for deciding if there is an edge occurrence at the consecutively analyzed sampling instant based on processing of such correlation integrals calculated for samples belonging to a surrounding wave region.
4. A noise filtering edge detector (NFED) for recovering digital signal transitions and their phases from noisy waveforms while assuming ideal signal shape between the transitions, in order to identify digitally transmitted data, by continues over-sampling and digital filtering of the incoming waveform based on comparing an edge mask, representing an expected pattern of wave-form samples corresponding to an edge of the original wave-form, with a sequence of wave-form samples surrounding a consecutive analyzed sample; the NFED comprising:
a wave capturing circuit, connected to a sampling clock and to the incoming waveform, for continues over-sampling of the incoming wave-form;
a correlation calculating circuit for performing logical or arithmetic operations on particular samples of the edge mask and their counterparts from a wave samples region surrounding the consecutively analyzed sample of the captured wave-form, in order to calculate a correlation integral between the wave samples region and the edge mask;
a proximity estimating circuit for deciding if there is an edge occurrence at the consecutively analyzed sampling instant based on processing of such correlation integrals calculated for samples belonging to a surrounding wave region.
5. A hybrid phase locked loop (HPLL) producing a stable low jitter output clock while enabling very high frequency multiplication factor which can be programmed to any real number belonging to a continues range from 1 to tens of thousands, wherein a low frequency reference clock multiplied by such factor produces such HPLL output clock while a desirable preprogrammed phase and frequency transfer function (PFTF) is maintained by a micro-controller (MC); the HPLL comprising:
an analog phase locked loop (APLL) having one input of it's analog phase detector (APD) connected to the HPLL output clock while another APD input is connected to a local synthesized clock produced by a local phase synthesizer (LPS) connected to the HPLL output clock;
a frame phase detector (FPD) for measuring a digital phase error between the output clock and the reference clock, wherein such digital phase error is read by said micro-controller which controls operations of said local phase synthesizer;
a digital phase locked loop (DPLL) comprising the frame phase detector and the micro-controller and the local phase synthesizer, wherein the MC drives said local phase synthesizer into producing phase differences between the APD inputs needed for implementing said preprogrammed PFTF between the output clock and the reference clock.
6. An open-ended software controlled synchronizer (OE-SCS) using micro-controller (MC) subroutines for providing programmable phase frequency transfer function (PFTF) between a reference clock and an output clock generated by a phase synthesizer totally avoiding uncontrolled phase transients inherent for frequency synthesizers, wherein such phase synthesizer works in an open loop configuration enabling inherently stable generation of said output clock and maintains low phase jitter of the output clock independent of phase jitter levels in the reference clock; the OE-SCS comprising:
a frame phase detector (FPD) measuring digital phase error between a local clock and said reference clock;
the MC for reading said digital phase error and for processing it and for driving said phase synthesizer into generating the output clock implementing said PFTF between the output clock and the reference clock;
the phase synthesizer, connected to a local clock and controlled by the MC, for producing said output clock in the open loop configuration.
7. The OE-SCS configuration of claim 6 further including an external synchronization mode (ESM) enabling analog phase locking of the output clock to an external clock which can be provided by a local reference clock or an output clock from a backup synthesizer unit, wherein such OE-SCS with ESM comprises:
an analog PLL (APLL-ESM), connected alternatively to the phase synthesizer output clock or to such external clock, for producing such phase locked output clock.
8. The OE-SCS configuration of statement 7, wherein the APLL-ESM further comprises: a reference selector (RFS) for selecting the phase synthesizer output clock or said external clock as sourcing an APLL-ESM reference clock which the output clock has to be phase locked to. 9. A heterodyne timing configuration of a software controlled synchronizer (HTC-SCS) using a local oscillator which can have very low frequency and a micro-controller (MC) for securing programmable phase frequency transfer functions (PFTF) between a reference clock and an output clock while enabling very high frequency multiplication factor which can be programmed to any real number belonging to a continues range from 0 to tens of thousands, wherein very low phase jitter of the output clock is maintained independent of phase jitter levels in the reference clock; the HTC-SCS comprising:
a frame phase detector (FPD) for measuring a digital phase error between the reference clock and the output clock;
the MC for reading the digital phase error and for implementing the PFTF by controlling operations of a phase synthesizer defining analog phase errors produced by an analog phase detector (APD) of an analog phase locked loop (APLL), wherein such analog phase errors control phase and frequency of the output clock produced by the APLL;
the phase synthesizer, controlled by the MC while connected to the output clock and supplying an input of the APD, for introducing the analog phase errors programmed by the MC;
an analog phase locked loop (APLL), having one input connected to the output of the phase synthesizer while another input is connected to the output clock, for generating said output clock;
a digital phase locked loop (DPLL) using the FPD and the MC and the phase synthesizer for controlling operations of the APLL in order to implement the PFTF between the output clock and the reference clock.
10. The HTC-SCS of statement 9 further including the HPLL of statement 5 in order to multiply a very low frequency of an inexpensive local oscillator to much higher frequency range needed to synthesize the output clock required; such configuration comprising:
an additional frame phase detector (A-FPD) for measuring a digital phase error between the output clock and the local oscillator applied as an additional reference clock;
an additional DPLL subroutine in the MC for implementing another PFTF applicable to the relation between the output clock and the additional reference clock.
11. The HTC-SCS of statement 9 further including an external synchronization mode (ESM) enabling analog phase locking of the output clock to an external clock which can be provided by a local reference clock or an output clock from a backup synthesizer unit, wherein such HTC-SCS with ESM comprises:
an additional clock selector (CLK-SEL) inserted between the output clock and said another input of the APLL for providing alternative selection of the output clock or such external clock for being connected to said another input of the APLL.
12. The OE-SCS configuration of statement 6 or the HTS-SCS of statement 9 further including the NFED of claim 4 for time domain phase noise filtering from an external reference waveform in order to produce a filtered reference waveform used further on as the reference clock, wherein the NFED can enable by one order more accurate phase detection when the external reference waveform is coming from a noisy serial link such as those utilized by network time protocols; wherein such synchronizer configuration comprises:
the NFED circuit, controlled by the MC and connected to the MC and to the external reference waveform, for producing the filtered reference waveform which is further used as the reference clock by the synchronizer.
13. The OE-SCS configuration of statement 6 or the HTS-SCS of statement 9 further including a time stamp decoder (TSD) circuit for decoding time stamp messages received from a remote serial link in order improve accuracy of phase/frequency detection by eliminating timing uncertainties caused otherwise by interrupts decoding software sub-routines; wherein such synchronizer configuration comprises:
the time stamp decoder, connected to a serial link receiver recovering a message signal, for producing time stamp messages communicated to the MC and for signaling time stamp detections to the FPD;
network time protocol subroutines residing in the MC for reading the digital phase errors occurring between message signal transitions and for reading the time stamp messages and for controlling operations of the phase synthesizer;
wherein such MC subroutines implement said programmed PFTF between the output clock and the reference clock signal defined with pulses occurring between those message signal transitions which are specified by stamp messages as signaling arrivals of such stamp messages.
14. A frame phase detector (FPD) for measuring a frame phase skew between a first frame consisting of a programmable expected number of sampling local clocks, and a second frame defined with a series of time intervals located between second frame edges defined by changes of an external frame signal or by changes of a frame status driven with external messages such as time stamps, wherein a frame measurement circuit captures a number of said sampling periods occurring during an interval of the second frame and a phase processing unit subtracts the captured number from the expected number representing expected duration of the corresponding interval of the first frame; wherein-the frame phase detector comprises:
a circuit for a detection of said second frame edges, by detecting said changes of the external frame signal, or by detecting said changes of the frame status driven by the external messages;
the frame measurement circuit using the sampling local clock, which is a higher frequency signal, to measure said time intervals of the second frame having lower frequency, wherein the frame measurement circuit counts said sampling periods occurring during every interval of the second frame and captures and buffers the counted value until it is read by a phase processing unit;
the phase processing unit for subtracting the expected number of the sampling periods from the counted number of the sampling periods, in order to calculate an interval phase skew between the expected interval of the first frame and the corresponding interval of the second frame.
a circuit and/or a subroutine for combining said interval phase skews of particular frame intervals into said frame phase skew.
15. A frame phase detector as described in statement 14, wherein said second frame begins with a numerical first edge, representing initial phase of the second frame, defined as a number of sampling delays between an expected location of such numerical first edge and the first counted sampling clock, wherein the frame measurement circuit is preset to the numerical first edge before any said counting of the sampling clocks takes place; the frame phase detector comprising:
a circuit for presetting the frame measurement circuit to said numerical first edge before said counting of the sampling periods of the first interval of the second frame takes place;
a circuit and/or a subroutine for supplementing said preset numerical first edge by adding following sampling periods counted until the second edge of the second frame is encountered, and a means for capturing and buffering a resulting total number of sampling periods until it is read by a phase processing unit;
wherein the resulting total number of the sampling periods represents duration of such first interval of the second frame and is made available for further processing.
16. A frame phase detector as described in statement 14 receiving an incoming wave-form carrying the external frame signal or carrying the external message; the frame phase detector wherein:
said detection of the second frame edges from the incoming wave-form, is performed by a circuit synchronized with the local sampling clock and producing a known propagation delay.
17. An FPD as described in statement 14, wherein the frame phase skew is calculated without any accumulation of digitization errors of said intervals phase skews while the single intervals phase skews are still available for intermediate signal processing; the FPD comprising:
a circuit and/or a subroutine for rounding said counted number of the sampling periods by adding 1 such sampling period to the counted number defining length of said frame interval, wherein ½ of the added sampling period approximates a fraction of the sampling period occurring before said counting of the interval sampling periods and another ½ of the added sampling period approximates a fraction of the sampling period occurring after said counting;
whereby such addition of 1 sampling period to every interval measurement, provides all sampling periods occurring between said counted numbers of sampling periods relating to consecutive intervals of the second frame, and reduces a digitization error of any long frame to a time sampling error of a single interval.
10. Receiver Synchronization Techniques
RST comprises methods and systems utilizing said referencing frame for achieving substantially more accurate and more stable of synchronization OFDM receiver to composite signal frame.
Furthermore RST comprises methods and systems enabling more accurate recovery of said referencing frame from OFDM data tones only and thus RTS enables both; better accuracy and improved efficiency resulting from elimination of preambles or pilots needed previously.
RST includes a method, a system and an apparatus for recovering said referencing frame signal from received composite frames carrying transmitted data or control pilot information, and for using such recovered referencing frame for synchronizing timing and frequency of receiver's local oscillator and data recovering circuits.
The RST comprises a method for recovering a referencing frame signal from OFDM composite frames carrying transmitted data or control pilot information, and for using such recovered referencing frame for synchronizing timing and frequency of receiver's local oscillator and data sampling circuits wherein a recovered frame lengths of such referencing frame interval represents a combined length of single or multiple composite frame intervals originating this referencing frame interval; wherein such RST comprises:
detection of boundaries of the data carrying frames or pilot frames by processing received OFDM composite signal or a recovered sub-carrier signal;
using such boundaries detections for specifying said referencing frame signal, wherein such detections delimit said referencing frame interval;
calculating a lengths difference between the recovered frame length and a measured frame length wherein such measured frame length of an equivalent symbol frame is the combined length of symbol frame intervals corresponding to said composite frame intervals originating this referencing frame, wherein the symbol frame defines a set of composite signal samples belonging to the same OFDM composite frame;
calculating frequency offset between the referencing frame and such equivalent symbol frame by dividing such lengths difference by the recovered frame lengths or by the measured frame lengths;
using such frequency offset for adjusting frequency of said local oscillator in order to maintain frequency alignment between a local oscillator clock and an OFDM transmitter clock; using such length difference for measuring a time offset between the composite frame and the symbol frame;
using such time offset to synthesize phase of the symbol frame from the local oscillator clocks, in order to maintain correct time alignment between the symbol frame and the composite signal frame.
The RST further comprises:
application of time or frequency domain filters and/or statistical methods for evaluating reliability of such boundary detection, wherein:
if said boundary detection signal is evaluated as reliable,
it is used for delimiting said referencing frame interval corresponding to said single or multiple symbol frames;
if said boundary detection signal is dismissed as unreliable, said measured frame length of equivalent symbol frame is increased by the length of symbol frame interval corresponding the composite frame interval which the boundary detection has failed for.
The RST further includes a frequency locked phase synthesis (FLPS) method and system for producing said symbol frame maintaining frequency and phase alignment to said referencing frame providing frequency and phase transmittal from an external source, wherein a frequency locked loop utilizes said local oscillator clock for producing frequency aligned symbol frame and a programmable phase synthesizer utilizes such local oscillator clock for producing the frequency and phase aligned symbol frame; wherein such FLPS comprises:
measuring a frequency error between the referencing frame and the symbol frame;
using such frequency error for maintaining frequency alignment between the symbol frame and the referencing frame by controlling frequency of said local oscillator clock;
presetting said phase synthesizer to an initial phase displacement needed to maintain a phase alignment between the referencing frame and the symbol frame;
measuring a phase error between the referencing frame and the symbol frame;
using such phase error for maintaining said phase alignment between the symbol frame and the referencing frame by controlling phase synthesis functions of said phase synthesizer from the local oscillator clock.
Such RST methods systems and apparatus are described below.
The RST comprises:
detection of boundaries of the data carrying frames or pilot frames by processing received OFDM composite signal or recovered sub-carrier signal;
using such boundaries detections for specifying said referencing frame signal, wherein such detections delimit referencing frame interval and/or are utilized to define a nominal number of local oscillator output clocks expected to occur during such interval if frequency offset between the local oscillator clock and a transmitter clock equals zero;
The RTS further comprises using such referencing frame signal for measuring a normalized phase skew (equal to said frequency offset) and said time offset between the receiver and transmitter, wherein:
the local oscillator clock is counted during such referencing frame interval, and the counted value is buffered until it is used for calculating a phase skew between a local oscillator interval consisting of said nominal number of local oscillator clocks and the referencing frame interval;
said phase skew is calculated as equal to a difference between the counted number of said local oscillator clocks and the nominal number;
said normalized phase skew is calculated by dividing such phase skew by the nominal number;
such normalized phase skew is used for synchronizing local oscillator frequency to a transmitter oscillator frequency;
time offset is measured utilizing a phase difference between the referencing frame and a receiver symbol frame which defines a set of composite signal samples carrying an OFDM symbol, or between the referencing frame and an local oscillator frame consisting of the nominal number of said local oscillator clocks;
such time offset is used to synthesize phase of the receiver symbol frame from the local oscillator clocks, in order to maintain correct time displacement between the receiver symbol frame and the composite signal frame.
The RST includes using such boundary detections for defining referencing frame intervals corresponding to multiple composite frames detected and thus such inter-detection intervals can represent multiple OFDM symbol intervals.
Accuracy of time offset measurement (evaluating timing difference between such boundary detection and a corresponding boundary of local symbol frame) is determined by a pilot/preamble form and/or processing method used.
Said frequency offset (equal to the normalized phase skew) measured over referencing frame interval is derived by dividing said phase skew, detected within the interval, by the expected interval length specified by the nominal number.
Accuracy of such phase skew detection is similar to that of the time offsets, since all of them are defined using said boundary detections.
Consequently such use of said referencing frame consisting of such prolonged intervals, greatly improves accuracy of frequency offset measurements.
RST includes:
maintaining known or predictable processing delay between reception of composite frame samples supplying direct or embodied definition of composite frame boundary, and a detection signal of such frame boundary produced by said synchronous processor operating synchronously with the local oscillator while processing such composite signal samples;
The RST further comprises:
using the synchronous sequential processing method and circuit (such SSP is defined in Subsection 8 of SUMMARY OF THE INVENTION), for implementing such synchronous processor maintaining said known or predictable processing delay.
RST comprises application of time or frequency domain filters and/or statistical methods for evaluating reliability of such boundary detections, wherein:
if said boundary detection signal is evaluated as reliable, it is used for delimiting said referencing frame interval corresponding to a singular or multiple said received symbol frames;
if said boundary detection signal is dismissed as unreliable;
an expected filtered lengths of said symbol frame period specifies generation time of a signal delimiting said referencing frame interval,
or said nominal number of local oscillator clocks, corresponding to zero frequency offset within the last symbol frame, is added to said nominal number, corresponding to zero frequency offset within the current referencing frame interval, instead of generating such delimiting signal.
The RST covers both versions explained below:
utilizing said conventional DSP techniques and processors, implemented already by conventional solutions for the time offset measurement, for the detection of composite frame boundaries;
or using said real-time synchronous processing techniques for such detection of composite frame boundaries (by ˜10× more accurate than that of such conventional DSP techniques).
Even if such conventional less accurate boundary detection is implemented; said RTS frequency offset measurement (10 times more accurate) will similarly improve amount of time offset introduced between consecutive boundary detections. Therefore time offset tracking and protection from any inter-symbol interference will be greatly improved as well, despite implementing such less accurate boundary detection.
RST includes an inherently stable frequency locked phase synthesis (FLPS) method and system producing said symbol frame maintaining frequency and phase alignment to a referencing frame providing frequency and phase transmittal from an external source, wherein a frequency locked loop utilizes an oscillator for producing a frequency aligned oscillator clock and a programmable phase synthesizer utilizes such frequency aligned oscillator clock for producing the frequency and phase aligned symbol frame (see FIG. 13 and FIG. 15 ); wherein:
the oscillator clock is counted during an interval of the referencing frame, and the counted value is buffered until it is used for calculating a phase skew between an oscillator nominal frame, consisting of a nominal number of said oscillator clocks, and said referencing frame, wherein the nominal number is such number of oscillator clocks which is expected to occur during such referencing frame interval if the phase skew equals zero;
said phase skew is calculated as equal to a difference between the counted number of said oscillator clocks and the nominal number;
if said referencing frame intervals are expected to have varying lengths specified by their nominal numbers varying accordingly, a normalized phase skew is calculated by dividing such phase skew by the nominal number assigned to such interval;
said phase skew or normalized phase skew is applied back to the oscillator, in order to maintain said frequency alignment of the oscillator clock to the referencing frame;
the referencing frame is applied to the phase synthesizer which utilizes said such oscillator clock for synthesizing said symbol frame maintaining frequency and phase alignment to the referencing frame;
wherein such phase synthesizer (PS) (described in Subsections 5 and 6 of SUMMARY OF THE INVENTION) has its phase synchronization acquisition initialized by presetting initial phase of the synthesized frame (as it is exemplified in Subsection 5 of DESCRIPTION OF THE PREFERRED EMBODIMENT).
Furthermore RST comprises a second version of the FLPS offering better stability than that of conventional phase locked loops combined with highly accurate phase control (see FIG. 14 ); wherein the last step of the described above first version is replaced with the 2 steps listed below:
phase error (time offset) is measured as a phase difference between the referencing frame interval and a symbol frame interval produced by the phase synthesizer;
such phase error is applied back to the phase synthesizer which utilizes said oscillator clocks for synthesizing the symbol frame maintaining frequency and phase alignment to the referencing frame.
Such phase synthesizer can be implemented; by utilizing methods and circuits defined in said Subsections 5 and 6 of this section.
Such second version comprises using much simpler phase synthesizer (without phase jitter control & reduction), which can be implemented as modulo (nominal-number) counter of oscillator clocks wherein such phase error is applied as counter preset value.
In addition to the stability improvements, both FLPS versions explained above enable by one order (˜10×) faster acquisition of frequency/phase alignment than that of conventional configurations for phase/frequency synchronization or control.
Such much faster synchronization acquisition shall be advantageous; in reducing mobile phone hand-over losses, or improving reliability of Wi/Fi or WiMAX connection switching.
RST comprises methods and systems enabling recovery of referencing frame phase (i.e. time offset) from OFDM data sub-carriers (or tones) only, without any use of bandwidth consuming preambles or pilot tones needed in conventional solutions.
Such phase (time offset) recovery from data sub-carriers (PRDS) methods comprise using said real-time synchronous processing techniques for recovering amplitudes and phases of sinusoidal cycles or half-cycles of a sub-carrier (tone) selected as being most reliable based on previous training session and/or on-fly channel evaluation. Such synchronous processing techniques are shown in the U.S. 60/894,433 claimed as priority application.
Such synchronous processing performed in phase with OFDM waveform capturing circuit, uses frequency sampling filters for recovering time domain sinusoidal representations of two tones (sub-carriers) elected as being reliable enough and spaced sufficiently in frequency domain.
Every half-cycle of such recovered sinusoid identifies phase and amplitude of the tone (or sub-carrier) signal.
Such redundancy enables using statistical and deterministic filtering methods, much more efficient than DFT/FFT averaging effect, for selecting the half-cycle supplying most reliable and accurate tone parameters.
Such in phase synchronous processing implementing said SSP is used to provide said time domain recovery of only one or several such tones (sub-carriers), selected to facilitate said recovery of the referencing frame.
Such in phase processing assures maintaining said known or predictable processing delay between; said reception of composite frame, and said detection signal of referencing frame boundary.
By evaluating amplitudes and/or phases of such recovered sinusoidal cycles or half-cycles, said received symbol boundary is detected when correlation between consecutive amplitudes and/or phases recovered falls down after maintaining a middle-symbol plateau, thus indicating the end of the received symbol frame.
Such in phase synchronous processing enables recovery of single half-cycles of said selected sub-carrier. Therefore the phase of the end of last negative half-cycle recovered during such symbol frame, can be treated as the end boundary E B of this symbol frame.
Furthermore such ending phase enables detection of the received symbol boundary (time offset) with accuracy by ˜10× better than that of conventional solutions, when a data coding phase displacement C D of such selected tone is recovered and used to correct this ending phase, as it is explained below.
For a displacement code D C equal to 0, 1, 2 or 3, and for tone period T T , such coding displacement C D shall be calculated as:
C
D
=
D
C
T
T
4
Plurality of half-cycles detected over symbol interval supplies a lot of redundant timing information about in phase processed tones (sub-carriers). If another selected tone T2 is similarly in phase processed, than both tones coding displacements (C DT1 for T1, C DT2 for T2) can be calculated by analyzing time delay T KT1-KT2 measured between T1 cycle number K T1 and T2 cycle number K T2 .
Such displacement code can be calculated first as explained below:
T KT1-KT2 =K T1 ·T T1 +C DT1 −( K T2 ·T T2 +T DT2 ),
consequently:
D
CT
1
T
T
1
4
-
D
CT
2
T
T
2
4
=
T
KT
1
-
KT
2
-
(
K
T
1
·
T
T
1
+
K
T
2
·
T
T
2
)
=
Δ
,
D
CT
1
=
D
CT
2
T
T
2
T
T
1
+
Δ
4
T
T
1
wherein final D CT1 digit can be derived by substituting D CT2 =0, 1, 2, or 3 into the above equation and by choosing for D CT1 this one of integers 0, 1, 2, 3 which is the closest to the D CT1 value calculated with the above equation.
Knowing the D CT1 number said coding displacement of T1 can be calculated as:
C
DT
1
=
D
CT
1
T
T
1
4
It shall be noticed that if Tone 1 frequency is by 4 times greater than that of Tone 2; than the multiplier T T2 /T T1 =4 and consequently a time delay between a T1 cycle and closest to it T2 cycle supplies the value of the coding displacement C DT1 directly.
Furthermore in phase tones processing circuits implemented using said SSP techniques, define efficient and accurate registration of such time delays (between neighbor cycles of different tones), which can represent said direct C DT1 measurement.
RST comprises methods and systems enabling referencing frame phase recovery from OFDM data sub-carriers with ˜10× greater accuracy than that of conventional solutions without even requiring said preambles or pilot tones; wherein such high accuracy phase recovery (HAPR) method comprises steps listed below:
said in phase processing techniques are used for recovering amplitudes and phases of sinusoidal cycles or half-cycles of selected sub-carriers (tones), wherein such in phase processing assures maintaining said known or predictable processing delay between; said reception of composite frame, and said detection signal of referencing frame boundary;
delay time between sinusoidal cycles of different selected tones is registered and used to recover data coding displacements occurring in the selected tones of the received composite frame;
an approximate symbol frame boundary is detected by evaluating amplitudes and/or phases of such recovered sinusoidal cycles or half-cycles, when correlation between consecutive amplitudes and/or phases recovered falls down after maintaining a middle-symbol plateau, thus indicating the end of the received symbol frame;
a phase of last cycle of such recovered sinusoidal tone is derived by analyzing amplitudes and/or phases of said sinusoidal cycles or half-cycles recovered before the end of symbol frame;
an accurate symbol boundary is derived by correcting such phase of last cycle with the data coding displacement.
11. Summary of Direct Synchronizer of Synthesized Clock
The Direct Synchronizer of Synthesized Clock (DSSC) presented herein includes said direct implementation of FLPS, named as direct frequency locking phase synthesis (DFLPS).
The DFLPS replaces the FLL circuit with a predictive compensation of a systematic phase error between the referencing signal and the synthesized clock contributed by miss-alignment of their frequencies.
The DFLPS can be implemented with such direct synchronization method by comprising operations listed below:
an oscillator frame of the oscillator clock (see FIG. 19B ), is initialized numerically as comprising a known nominal number (N) of oscillator clocks;
a synthesized frame of the synthesized clock, is initialized numerically as having a preprogrammed phase offset to the referencing signal frame and comprising a known nominal number (Nsynth) of synthesized clocks;
frequency errors between the referencing signal frame and the oscillator frame, are measured without accumulation of digitization errors (with periodical phase errors equal to Nl-N for the last or Nn-N for the next referencing frame shown in FIG. 19B );
such frequency errors are used for estimating
a predictive component eliminating such systematic phase error from the next synthesized frame,
and a variable component reducing a total remaining phase error passed to the next synthesized frame from previous synthesized frames;
a phase of the synthesized clock produced from the oscillator clock is amended based on such estimates of predictive and variable components (and on Nsynth/N factor), in order to track phase and frequency of the referencing signal;
wherein such amendments of synthesized clock phase are made in said feed-forward phase control system without introducing uncontrolled phase transients.
Such DFLPS can be implemented with the phase synthesizer (PS) controlled by the PCU in the feed-forward configuration shown in FIG. 19A , as it is explained below:
a non-cumulative (i.e. free of uncontrolled phase transients) periodical measurement of phase error between a referencing signal phase and an oscillator clock phase, is conducted by a phase/frequency analysis (PFA) system implemented with the Frame Phase Detector (FPD) and a PCU subroutine calculating such measured phase error (by subtracting a nominal expected number of oscillator clocks from an actually counted number of such clocks);
such phase error measurements are used by PCU for estimating a frequency error between the external referencing signal and the oscillator clock;
a systematic phase amendment compensating such frequency error, is calculated by PCU based on the frequency error estimate;
a periodical phase error is calculated by PCU by adding the systematic phase amendment, to the measured phase error;
a variable phase amendment is calculated by PCU by processing an accumulated phase tracking error or both said accumulated tracking error and the systematic phase amendment, wherein such accumulated tracking error is calculated by adding a previous variable phase amendment to a sum of the periodical phase error and the previous accumulated tracking error;
PCU calculates a periodical phase amendment by adding the variable phase amendment to the systematic phase amendment, and calculates PS control signals distributing the addition of such periodical phase amendment evenly over the next measurement period;
wherein the accumulated tracking error calculated by and stored in PCU enables accurate control of phase alignment of the synthesized clock to the external referencing signal, since such accumulated tracking error shows an accurate amount of a phase difference, between the external referencing signal and the synthesized clock, expressed in oscillator clock sub-periods.
Said other direct synchronization method (DSM) of the synthesized clock frame, containing the nominal number (Nsynth) of synthesized clocks produced from local oscillator clocks, to the referencing signal frame; can be implemented as follows:
frequency errors between the referencing signal frame and an oscillator frame containing said nominal number (N) of oscillator clocks, are estimated based on measurements of phase errors between those frames made without accumulation of their digitization errors;
a phase of the synthesized clock is amended based on such frequency error measurements (and on Nsynth/N factor), in order to track phase of the referencing frame with the phase of the synthesized frame maintaining a predefined phase offset to the referencing frame;
wherein such amendments of synthesized clock phase are made in said feed-forward phase control system without introducing uncontrolled phase transients.
The direct synchronization methods covered by this application include also a predictive compensation of deterministic phase error. Such direct synchronization with predictive compensation (DSPC) can be implemented by comprising the steps listed below:
measuring frequency errors between the referencing signal frame and an oscillator frame containing a nominal number (N) of said oscillator clocks, wherein such frequency errors are measured without accumulation of their digitization errors;
tracking a phase of the referencing frame with the phase of the synthesized frame controlled with amendments based on such frequency error measurements, wherein such synthesized frame consists of local clocks synthesized from local oscillator clocks;
wherein such amendment comprises
a predictive component eliminating such deterministic phase synthesis error from the synthesized frame,
and a variable component reducing a total phase error remaining still in the synthesized frame;
wherein such amendments are applied in a feed-forward phase control system maintaining predefined phase offsets within such phase tracking.
Such direct synchronization with predictive compensation covered herein includes also synchronization of the local synthesized clock to the referencing signal implemented with the steps listed below:
measurements of frequency errors between a referencing signal frame and an oscillator frame consisting of a known number of oscillator clocks, free of accumulation of their digitization errors;
tracking phase of the referencing signal with phase of the synthesized clock modified with amendment based on such frequency error measurements;
wherein such amendment of synthesized clock phase comprises
a predictive component eliminating such deterministic phase synthesis error from the next synthesized frame consisting of a known number of synthesized clocks,
and a variable component reducing a total remaining phase error carried to the next synthesized frame from previous synthesized frames.
wherein such amendment is applied in a feed-forward phase control system maintaining predefined phase offsets within such phase tracking.
In addition to the implementations explained above, the DSSC contributed herein enables multiple other inherently stable synchronization systems which can be designed to implement wide variety of different frequency multiplication and/or phase tracking functions optimized for different applications.
However all such inherently stable synchronization systems have been enabled by the more basic designs of frame phase detector (FPD) and phase synthesizer (PS), since such FPD and PS secure phase-detection and phase-synthesis without uncontrolled phase transients.
The FPD and PS enable a totally predictable synthesis of phase with resolution matching single basic delay which can be as minimal as single gate delay.
Such elimination of uncontrolled transients in both FPD and PS used in the DSSC, is the pre-condition enabling replacement of inherently unstable feedback based clock synchronization systems with the inherently stable feed-forward based phase synthesis systems.
In addition to the inherent stability, such feed-forward DSSC configurations enable by two orders (˜100×) faster recovery of frequency/phase tuning than conventional feedback based PLL systems.
While synchronization losses are the most disruptive factors in mobile communication (causing call drop-outs etc.), stability problems of conventional receiver synchronizers will be very much worsen by additional noise contributed by further rapid expansion of wireless communication.
Therefore such inherent stability and much faster recovery of DSSC based synchronizer enable fundamental improvements in wireless and wired communication fields including OFDM based systems such as LTE/WiMAX/WiFI and Powerline/ADSL/VDSL.
BRIEF DESCRIPTION OF THE DRAWINGS
General conventions making drawings easier to follow are explained below.
Interconnect signals between interrelated drawings have unique names identifying their sources and destinations explained in the Description of the Preferred Embodiments utilizing the same names. Inputs supplied from different drawings are connected at the top or left side and outputs are generated on the bottom, due to the top-down or left-right data flow observed generally. Clocked circuits like registers or flip-flops are drawn with two times thicker lines than combinatorial circuits like arithmometers or selectors.
FIG. 1 Shows an Open Ended Configuration of Software Controlled Clock Synchronizer.
FIG. 2 Shows Open Ended Configuration of SCCS with External Synchronization Mode
FIG. 3 Shows Heterodyne Timing Configuration of SCCS enabling acceptance of a very wide range of referencing clock frequencies.
FIG. 4 Shows Sequential Clocks Generator (SCG) and Output Selection Circuits (OSC) enabling high resolution selections of mutually overlapping sub-clocks.
FIG. 4A Shows Sequential Clocks Generator (SCG) and Return Selection Circuits (RSC), lowering output clock jitter
FIG. 5 Shows Timing Control (TC) and Clocks Equalization (CE), which control timing of high frequency switching of synthesized clock
FIG. 6 Shows Synchronous Sequential Phase Processor (SSPP), which performs programmable high-speed phase synthesis.
FIG. 7 Shows Timing Diagram of Phase Synthesizer.
FIG. 8 Shows Wave Capturing including Edge Regions (WCER), which enable continues capturing of a an oversampled high frequency waveform.
FIG. 9 Shows Sequential Clocks Generation for the NFED(SCG NFED), which provides mutually overlapping sub-clocks enabling high accuracy detection of noisy signal edges.
FIG. 10 Shows Noise Filtering Edge Detectors (NFED)
FIG. 11 Shows Wave Form Screening & Capturing (WFSC), which enables analysis of incoming noisy waveform facilitating adaptive noise filtering
FIG. 12 Shows Timing Diagrams of the WFSC.
FIG. 13 Shows a block diagram of Inherently Stable Synchronization System.
Notes referring to FIG. 13 and its timing diagrams, are provided below:
Boundary detection delay (Tbd) determines predictable part of referencing frame delay to OFDM composite frame. Frequency offset (Fos) is not affected by the boundary detection delays Tbd for as long as Tbd remains constant. In order to make up for the boundary detection delay, Phase Synthesizer (PS) positions Local Symbol Frame forward in time compared to Referencing Frame. Frequency offset Fos derived using counted number of sampling clocks (Fcnt) and the nominal number (Fnom), can be measured with over 10× greater accuracy if it is measured over a reference frame interval over 10× longer.
FIG. 14 Shows a block diagram of Synchronization System with Improved Stability.
Notes referring to FIG. 14 and its timing diagrams, are provided below:
Boundary detection delay (Tbd) determines predictable part of referencing frame delay to OFDM composite frame. Frequency offset (Fos) is not affected by the boundary detection delays Tbd for as long as Tbd remains constant. Time error (Terr) between local symbol frame and composite frame, amounts to boundary detection delay added to the phase error between reference frame and local symbol frame i.e. Ter=Tbd+(Trf−Is).
FIG. 15 Shows an Inherently Stable Frequency Locked Phase Synthesis system.
FIG. 16 Shows a similar FLPS system with its Frequency Detector utilizing local XTAL clock.
FIG. 17 Shows a similar FLPS with Improved Stability.
FIG. 18 Shows a similar FLPS but enabling more accurate generation of a synchronized clock.
FIG. 19A shows the configuration of circuits implementing Direct Frequency Locked Phase Synthesis
FIG. 19B shows the timing for this configuration for Direct Frequency Locked Phase Synthesis.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
1. Phase Synthesizer
The above mentioned first PS implementation is selected for the preferred embodiment, and it is shown in the FIG. 4 , FIG. 5 , FIG. 6 and FIG. 7 .
The PS comprises wave timing definition, which includes two major components downloaded to the PS from the PCU:
basic less frequently changed phase adjustments, which can include both periodical adjustments and fractional adjustments, define more stable components of wave-form phase;
high frequency phase modulations, which can include both the periodical adjustments and the fractional adjustments, allow every leading edge phase and/or every falling edge phase to be modulated with a different modulation factor.
Said phase modulations are downloaded to the PS simultaneously in batches containing multiple different modulation factors, where every said batch refers to a series of consecutive wave edges. The PS has internal selection circuits, which select and use consecutive modulation factors for modulating phases of consecutive edges.
In order to allow higher wave generation frequencies, 2 parallel processing circuits are implemented which use consecutive phase1/phase2 circuits for synthesizing phases of consecutive odd/even edges.
As it is shown in the FIG. 6 , said basic phase adjustments are loaded to the Periodical Number Buffer (PNB) and to the Fractional Number Buffer (FNB); where they remain unchanged until PS internal Modulations Counter (MC) reaches MC=0 condition.
On the other hand, said modulation factors M1, M2-M6, M7 are shifted left, by one factor for every new edge, in the Phase Modulation Buffers (PMB1/PMB2) for providing consecutive modulation factor needed for a next edge in the left end of the PMB1/PMB2.
Such updated modulation factor is then added to the basic phase adjustments and resulting modulated phase adjustments are downloaded into the Periodical Number Registers (PNR1/PNR2) and into the Fractional Number Registers (FNR1/FNR2).
In order to synthesize an actual position of a new edge of the synthesized waveform; said downloaded modulated phase adjustments need to be added to a current edge position, and the results of said addition are downloaded into the Periods Counters (PC1 or PC2) and into the Fractional Selection Register (FSR)
The Sequential Clocks Generator (SCG) and Output Selection Circuits (OSC) are shown in the FIG. 4 and have been already explained in the Subsection “6. General Definition of Phase Synthesizer” of the previous section.
The Clock Selection Register 1/2 (CSR1/CSR2) specifies a sub-clock which will be selected in a forthcoming Phase2/Phase1 cycle of the reference clock fsync.
In order to remain settled during a whole next cycle of the fsync, the CSR1/CSR2 registers are loaded by the early sub-clocks of the present Phase2/Phase1 cycle of the fsync.
The CSR1/CSR2 are loaded:
with a current content of the Fractional Selection Register (FSR) (shown in FIG. 6 ), if the LD_C1 or LD_C2 (Load Counter 1 or Load Counter2) signal indicates that an end period of the present phase adjustment is indicated by the C2E or C1E (Counter 2 End or Counter 1 End) accordingly (see FIG. 2 and FIG. 3 );
with the binary value 2 S -1=R+1 which exceeds ranges of the 1 st Clock Selector (ICS) and the 2 nd Clock Selector (2CS) and results in none of selectors outputs being activated and none of sub-clocks being selected during a following phase cycle.
The Timing Control (TC) circuits are shown in FIG. 5 , the resulting Timing Diagram of Phase Synthesizer (TDPS) is shown in FIG. 7 , and TC operations are explained below.
The LD_C1 signal enables loading of the Period Counter 1 (PC1) with a number of periods which the previous stages of the Synchronous Sequential phase Processor (SSPP) have calculated for the current phase adjustment.
Said download deactivates/activates the C1E signal if a downloaded value is (bigger than 1)/(equal to 1) accordingly. When said downloaded value is bigger than 1, the C1EN=1 enables decreasing the PC1 content by 1 at every leading edge of the Clk1.1 until the PC1=1 condition is achieved and is detected by the PC1-OVF Detector which signals it with the C1E=1 signal.
It shall be noticed that: when a fractional part of a phase adjustment calculated in said FSR reaches or exceeds a whole period of the fsync, the overflow bit FSR(OVF)=1
is activated and switches the PC1=1-OVF DETECTOR from said 1 detection mode to a 0 detection mode which prolongs current phase adjustment by 1 fsync period.
The phase 2 control circuit is driven by the C1E and by the LD_C1, and controls phase 2 operations with signals LD_C2, LD_RE2, LD_BU2; as it is further explained below:
The first C1E activation period generates the LD_C2 signal, and is followed by setting the LDR2_FF which terminates the LD_C2. The LD_C2 signal; enables loading of PC2 with a periods number for the next phase adjustment, enables loading of the FSR with a fractional adjustment for the next phase adjustment, and enables a downloading of the FSR to the CSR1 or to the CSR2. The LDR2_FF=1 generates the leading edge of the LD_RE2 signal. The LD_RE2 signal clocks in; a new modified fractional adjustment to the Fractional Number Register 2 (FNR2), and a new modified periodical adjustment to the Periodical Number Register 2 (PNR2). When the period number loaded by the LD_C2 is counted down to its end by the PC2, the C2E signal activates the LD_C1 similarly as the C1E has activated the LD_C2. The LD_C1=1 resets both the C1E and the LDR2_FF in the next cycle; The LDR2_FF=0 generates the leading edge of the LD_BU2 signal. The LD_BU2 signal clocks in; a previous PMB2 content shifted left by S+1 bits, or a new PM[M6,M4,M2,M0] content from the PCU when the Modulations Counter (MC) is decoded as MC=0.
The phase 1 control circuit is similarly driven by the C2E and by the LD_C2; and similarly generates the LD_C1, LD_RE1, LD_BU1 signals for controlling phase1 operations.
The only differences in the phase 1 versus phase 2 operations, are specified below:
The LD_BU1 signal clocks in a decreased by 1 value to the MC which is the modulo 4 counter. The DECODER MC=0 generates the MC=0 signal which selects provided by the PCU; the Periodical Number (PN)/the Fractional Number (FN)/the Phase Modifications (PM) to be loaded into the Periodical Number Buffer (PNB/the Fractional Number Buffer/the Phase Modifications Buffer 1 (PMB1) by the leading edge of the LD_BU1. The DECODER MC=1 generates the MC=1_INT interrupt signal to the PCU, which informs the PCU that all the above mentioned phase adjustment parameters have been already stored in the PS buffers and can be replaced by new phase adjustment parameters.
2. Heterodyne Timing Configuration
FIG. 3 shows the heterodyne timing configuration (HTC) according to the preferred embodiment. The HTC integrates both Digital PLLs (DPLLs) and Analog PLLs (APLLs) into a single CMOS ASIC, with the exception of the external VCXO which provides a stable clock (Fil_LocClk) having very low phase jitter.
Said APLL mode of the HTC is described below.
The Reference Selector (RFS) is programmed by the PCU to select one of the external reference clocks (Ext_RefClk). Such selected external reference clock is applied to the reference input of the Analog Phase Detector (APD) which drives the Loop Filter of the VCXO which provides the stable low jitter output f_filter.
The Fil_OutClk; drives the Output PLL (OUT_PLL), and is connected to the fsync/L input of the Return Clock Synthesizer (RET_PS) which is implemented with the PS embodiment described in the previous section.
The RET_PS synthesizes the RetClk, which is connected to the APD return input.
It shall be noticed that very wide ranges of the RET_PS frequency adjustments, enable the PCU to tune the RET_PS to any frequency which the selected external reference may have.
Said OUT_PLL generates the output reference clock (OutRef) which drives the Output Clocks Generator (OCG) which provides all the major HTC output clocks OutClk(T:1).
Since the OCG consists of frequency dividers having very tightly controlled and well matched propagation delays, all the OutClk(T:1) are phase aligned with the Fil_OutClk and between themselves.
The DPLL mode of the HTC is described below.
The Fil_OutClk signal is programmed to be selected by the RFS for the APD reference signal, and the RET_PS provides the APD return signal which is synthesized from the same Fil_OutClk signal. One of the external reference waveforms (Ext_RefWfm) is selected by a selector controlled by the PCU for being processed by the NFED providing the filtered reference waveform (Fil_RefWfm), which is connected to the Time Stamp Decoder (TSD) and to the FPD1.
Local oscillator fixed output (LocOsc) is connected to the FPD2.
Both frame phase detectors FPD1/FPD2 shall use the high frequency sampling clock (SampClk) for accurate digital measurements of the PhaErr1 and the PhaErr2.
Said sampling clock is generated by the frequency multiplier OutRefxR from the OutRef generated by the OUT_PLL.
Since the OutClk(T:1) output clocks are phase aligned with the OUT_PLL output clock OutRef, and the sampling clock SampClk is phase aligned with the OutRef as well; the SampClk is phase aligned with the HTC output clocks OutClk(T:1).
The FPD1 measures a phase error between the sampling clock SampClk and the Ext_RefWfm, as Δφ1=φ_samp−φ_wfm.
The FPD2 measures a phase error between the sampling clock SampClk and the LocOsc, as Δφ2=φ_samp−φ_osc.
The PCU reads the measured phase errors and uses the RET_PS to introduce digital phase displacements between the APD reference input and the APD return input which will drive the VCXO based PLL for providing required phase transfer functions between the Fil_OutClk and the Ext_RefWfm.
Since the Fil_OutClk drives the OUT_PLL which has much higher BW than the VCXO PLL and the OUT_PLL determines phase of the OutClk, the OutClk implements the same phase transfer function as the Fil_OutClk.
Based on the measurements of Δφ1 and Δφ2, the PCU calculates said Periodical Numbers (PN), Fractional Numbers (FN) and Phase Modifications (PM) which need to be provided to the Return Phase Synthesizer (RET_PS); in order to achieve a preprogrammed transfer function between the HTC output clocks and the selected DPLL reference clock Ext_RefWfm.
HTC free-run and hold-over modes use the above described DPLL mode configuration, as it is described below.
In the free-run mode; the PCU uses the phase error measurements for calculating phase differences which need to be inserted via the RET_PS for providing said OutClk locking to the local oscillator LocOsc.
In the hold-over mode; the PCU inserts phase differences via the RET_PS which cause the OutClk to maintain its last frequency displacement versus the LocOsc.
3. Noise Filtering Edge Detectors
The preferred embodiment implements the above defined general components of the NFED and is shown in FIG. 8 , FIG. 9 and FIG. 10 .
The NFED comprises over-sampling and capturing of consecutive wave-form intervals in specifically dedicated consecutive wave registers, wherein odd intervals are written into the wave register 1WR and even intervals are written into the wave register 2WR. Therefore incoming stream of samples is split into the two parallel processing phases (sometimes named as parallel synchronous pipelines). The first processing phase begins in the wave register 1WR and the second begins in the register 2WR. Such splitting into 2 parallel phases obviously doubles cycle time available in the sequential stages following the register 1WR and in the stages following the 2WR as well.
A sequential clock generation circuit (SCG) shows a method for splitting a steady stream of mutually overlapping sub-clocks spaced by a gate delay only into sub-sets of sub-clocks active during their dedicated phases only and non-active during all other phases. Such subsets are obviously used for providing timing for their dedicated phases.
The wave register 1WR is further split into 2 parallel sub-phases and the 2WR is split into other 2 parallel sub-phases, for the purpose of quadrupling cycle time available in said sub-phases (see the FIG. 8 showing the wave registers 1WR, 2WR followed by the wave buffers 11WB, 12WB, 21WB, 22WB).
In order to provide all wave samples needed for the filtering edge detection along a whole wave buffer, the NFED includes rewriting:
the end part 2WR(R:(R−M+1) of the wave register 2WR, into the front parts 11WB(M:1), 12WB(M:1) of the wave buffers 11WB,12WB; the end part 1WR(R:(R−M+1) of the wave register 1WR, into the front parts 21WB(M:1), 22WB(M:1) of the wave buffers 21WB,22WB.
The preferred embodiment is based on the assumptions listed below:
the wave registers 1WR and the 2WR are 15 bit registers (i.e. R=14); the rising edge mask REM(M:0) and the falling edge mask FEM(M:0) are 8 bit registers (i.e. M=7) and the PCU loads the same masks equal to 00001111 to both mask registers; the rising edge threshold RET is loaded with 0110 (6 decimal), and the falling edge threshold FET is loaded with 0010 (2 decimal);
The digital filter arithmometers 21DFA1/22DFA1/11DFA1/12DFA1 perform all the comparison functions, between the edge mask registers REM/FEM and the waveform buffers 21WB/22WB/11WB/12WB involving the edge threshold registers RET/FET, with the 3 basic operations which are further explained below.
The first operation is performed on all the waveform bits and involves the edge mask bits as it is specified below:
For every waveform buffer consecutive bit WB k the surrounding bits WB k−4 , WB k−3 , WB k−2 , WB k−1 , WB k , WB k+1 , WB k+2 , WB k+3 are logically compared with the mask bits B 0 , B 1 , B 2 , B 3 , B 4 , B 5 , B 6 , B M and the resulting 8 bit binary expression BE k (7:0) is created as equal to; BE k (0)=(WB k−4 =B 0 ), BE k (1)=(WB k−3 =B 1 ), BE k (2)=(WB k−2 =B 2 ), BE k (3)=(WB k−1 =B 3 ), BE k (4)=(WB k =B 4 ), BE k (5)=(WB k+1 =B 5 ), BE k (6)=(WB k+2 =B 6 ), BE k (7)=(WB k+3 =B 7 ).
The second operation adds arithmetically all the bits of the binary expression BE k (7:0) and the resulting edge proximity figure EPF k is calculated as equal to EPF k =BE k (0)+BE k (1)+BE k (2)+BE k (3)+BE k (4)+BE k (5)+BE k (6)+BE k (7) which shall amount to a 0-8 decimal number. During the first and the second operations: all bits of any particular wave buffer have their specific edge proximity figures calculated at the same time during a cycle assigned for one of the arithmometers 21DFA1/22DFA1/11DFA1/12DFA1 attached to that buffer.
Since there are 15 bits in every wave buffer every such arithmometer consists of 15 parallel micro-arithmometers, wherein each such micro-arithmometer performs operation on an 8 bit edge mask and on 8 bit wave region.
Since this arithmometers perform the most intense processing, said quadrupling of cycle time by gradual splitting from the original 1 phase into the present 4 parallel phases was needed.
The third operation performs functions explained below:
In order to carry the same level from the last bit of the previous phase DFR1 into the following bits of the present phase digital filter register2 (DFR2), the last bit DFR1(R) of the previous DFR1 is always rewritten into the carry bit DFR1(C) of the present DFR1 and is used by the digital filter arithmometer2 (DFRA2) to fill front bits of the DFR2 with the same level as the last bit of the previous phase DFR1. The verification is made if the EPF k indicates a rising edge condition by exceeding the content of the rising edge threshold RET(T:0). Consequent detection of the EPF k >RET=6 condition, sets to level=1 the corresponding DFR1 k bit of the DFR1 and all the remaining bits of the present DFR1 until a falling edge is detected as it is explained below. The verification is made if the EPF k indicates a falling edge condition by being smaller than the content of the falling edge threshold FET(T:0). Consequent detection of the EPF k <RET=2 condition, sets to level=0 the corresponding DFR1 k bit of the DFR1 and all the remaining bits of the present DFR1 unless a rising edge is detected as it explained above.
The digital filter arithmometers 21DFA2/22DFA2/11DFA2/12DFA2 perform; the inter-phase continuation of filling front bits of the present phase register in accordance with the level set in the last bit of the previous phase, followed by said edge displacement which compensates for duty cycle distortions due to inter-symbol interference (ISI), etc.
The edge displacement comprises the 3 basic operations described below.
Any DFR1 rising edge, indicated by a level 0 to 1 transition, is shifted left by a number of bits specified by a content of the rising edge displacement register (RED(D:0)) loaded by the PCU in accordance with its filtering algorithms. Any DFR1 falling edge, indicated by a level 1 to 0 transition, is shifted left by a number of bits specified by a content of the falling edge displacement register (FED(D:0)) loaded by the PCU in accordance with its filtering algorithms. In order to propagate said displacement operations from the present phase to the previous phase; the propagated sign of the edge bit (DFR2(Sp)) and the propagated bits (DFR2(Dp:0)), are calculated by the DFR2 and are written down into the DFR2 extension DFR2(Sp,Dp:0).
In order to propagate said displacement operations from the next phase DFR2 into end bits of the present phase digital filter register3 (DFR3); the propagated sign of the edge bit and the propagated displaced bits DFR2(Sp,Dp:0) from the next phase, are used by the digital filter arithmometer3 (DFRA3) to fill end bits of the digital filter register3 (DFR3) with the correctly displaced bits propagated form the next phase to the present phase.
4. Wave-Form Screening and Capturing
The wave-form screening and capturing (WFSC) of screened out intervals is performed by the circuits which are shown in FIG. 11 and the timing diagrams of the WFSC are shown FIG. 12 .
The WFSC allows the PCU to perform screening and capturing of the incoming signal, for timing intervals which correspond roughly to a period of a single data bit, based on a content of the wave buffers 11WB, 12WB, 21WB and 22WB.
The WFSC allows the PCU to screen signal quality of incoming wave form, by applying programmable screening functions using programmable data masks, as it is listed below:
content of said wave buffers can be verified for compliance or non compliance with a mask provided by the PCU, based on verification functions and verification tolerances which are programmed by the PCU; if any wave buffer verification detects preset by PCU screening out criteria to be met, the corresponding content of a wave buffer is captured and made available for PCU for further analysis; in addition to the wave buffer capturing, a number of said screened out results will be counted and communicated to the PCU as well.
In addition to the above mentioned screening; the WFSC allows also the PCU to select arbitrarily a content of any of the wave buffers during any particular time slot; for being captured and made available for analysis by the PCU.
The above mentioned signal screening is implemented by the WFSC, as it is explained below. The Mask Detection Arithmometrs (11MDA and 12MDA) for the WFSC are positioned similarly as the DFAs of the NFED.
The second stage uses the mask detection arithmometers 11MDA/12MDA for identifying wave-forms which are beyond usually acceptable range defined by the PCU.
The programmable control unit (PCU) determines logical and/or arithmetical processing which the 11MDA/12MDA shall perform, by pre-loading the detection control register (DCR) with a control code applied as the DCR(P:0) to the 11MDA/12MDA.
Additionally the PCU determines the mask DMR(R:0) which the captured data 11WB(R:0)/12WB(R:0) shall be processed against, by pre-loading the detection mask register (DMR). The 11SEL signal equal to I/O selects; the 11WB(R:0)/12WB(R:0) to be downloaded to the phase one detected data buffer (1DDB) by the clock 1Clk2 (see FIG. 11 and FIG. 12 ), if the 11DET/12DET indicate detection of a pre-selected mask by the mask detection arithmometer 11DMA/12DMA.
At the beginning of the next time frame, which has 128 phase1 cycles, the last captured 1DDB content is further downloaded to the phase1 data register (1DDR) by the clock signal 1Clk3/128. Number of said mask detections is counted in the mask counter buffer (1MCB), as it is explained below:
at the beginning of every time frame which has 128 phase1 cycles, the 1MCB is reset/preset to 0/1 if there isn't/is a mask detection for the first cycle of the frame which is signaled by the 1PHA/128ena=1; the 1MCB is increased by 1/kept the same, if there is/isn't any mask detection during a particular phase1 cycle; at the beginning of the next time frame, the 1MCB is downloaded to the phase1 mask counter register (1MCR) and the output of the 1MCB>0 decoder (MCB>0 DEC) is downloaded to the 1MCR(P) bit, by the 1Clk3/128.
Said 1DDR and 1MCR are read by the PCU, when the beginning of the next frame is communicated to the PCU by the phase1 128 th clock enable signal (1PHA/128ena) and the above mentioned 1MCR(P)=1 indicates that at least 1 detection of a pre-selected mask occurred during the previous frame.
Said PCU controlled capturing of a wave buffer content is implemented, as it is explained further below.
The sample number register (SNR) is loaded by the PCU: with a phase number defined as phase1/phase2 if the SNR(0) is set 0/1, and with a particular phase cycle number in a time frame defined by SNR(7:1) bits.
Since there are 2 phases with 128 cycles per time frame, SNR(7:0) bits define 1 of 256 sampling cycles for having its wave buffer captured and made available for a further analysis by the PCU. Said SNR is downloaded into the phase1 sample number buffer (1SNB) at the beginning of a time frame by the first phase1 clock of the frame 1Clk2/128.
At the beginning of a time frame: the phase1 sample number counter (1SNC) is set to 0, since the 1PHA/128ena selects 0 to be loaded into the 1SNC by 1Clk2.
During every other cycle of the time frame: 1 is added to the SNC content, since the 1PHA/128ena is inactive during all the next cycles of the frame.
The 1SNC(7:1) and the 1SNB(7:1) are being compared by the logical comparator (Log.Comp.), which produces the Eq=1 signal when their identity is detected.
Said Eq=1 enables the 1SNB(1)=0/1 to select the 11WB(R:0)/12WB(R:0) in the 3:1 selector (3:1 SEL), for capturing in the phase1 sampled data buffer (1SDB).
At the beginning of the next time frame, the output of the 3:1 SEL is additionally captured in the phase1 sampled data register (1SDR) by the signal 1Clk3/128.
Said 1SDR is read by the PCU, which is notified about availability of the requested sample by the signal 1PHA/128ena.
5. Receiver Synchronization Techniques
Functional block diagram of inherently stable synchronization system is provided in FIG. 13 wherein recovery of OFDM receiver sampling clock Cs and local symbol frame Fls is shown. More detailed implementation and partitioning of such system is shown in FIG. 15 .
Samples from an OFDM composite signal interval, long enough to comprise entire OFDM symbol, are processed by the Synchronous Sequential Processor (defined in Subsection 8 of SUMMARY OF THE INVENTION) which uses Cs as its reference clock (see FIG. 13 and FIG. 14 ).
Sub-clocks of such reference clock, driving such SSP used for OFDM processing, may not need to facilitate phase resolution matching single gate delay. Therefore a conventional delay line, consisting of serially connected flip-flops driven by a frequency multiplier of the reference clock, can be sufficient to generate such lower resolution sub-clocks instead of using the delay line consisting of serially connected gates with all elaborate timing involved.
However independent of any delay line implementation, SSP architecture guaranties that all SSP micro-operations are performed in exactly predefined time windows within known time displacements to such reference clock. Therefore SSP processing delay measured from entering last sample of an interval processed to producing the final result of such interval processing is totally predictable.
As specified therein, SSP includes real-time processing stages of incoming wave-form and a programmable computing unit (PCU) for supporting any adaptive signal processing dependent of previous micro-operations results or wave-form content.
SSP uses interrupts to acquire results of such PCU adaptive processing, while PCU produces such results in advance before they are needed (see also Subsection 8 of SUMMARY OF THE INVENTION). Therefore SSP can use such results in predefined time windows synchronizing known sequence of said SSP micro-operations, while PCU accommodates all changes of processing time and/or algorithms.
Since such SSP is used to detect composite frame boundary, resulting boundary detection delay Tbd is known very accurately.
Despite such accurate Tbd, composite signal distortions due to channel interference and inherent problems of conventional methods for composite frame boundary detection, shall be expected to cause noticeable errors in boundary detection times which convey into receiver time offset errors.
However said predictable Tbd of the boundary detection signal Sbd (see FIG. 13 ) facilitates generation of the referencing frame Fr, re-timed by the sampling clock Cs.
Such Fr is applied to the digital frequency detector (DFD) which produces frequency offset estimate Fos by subtracting said expected nominal number of sampling clocks form the number of sampling clocks counted during said referencing frame interval.
As such DFD arrangement facilitates measuring frequency offset within referencing frame intervals corresponding to multiple periods of OFDM composite frame, such prolongation of frequency sensing intervals multiples accuracy of frequency offset measurements (see also time-diagrams and Note 4 in FIG. 13 ).
Such much more accurate frequency offset Fos applied to the frequency locked loop FLL, enables generation of said sampling clock with frequency by one order more accurate and thus prevents any inter-bin leaking endangering IDFT/IFFT processing of OFDM composite frame.
Such DFD/FLL configuration offers other significant advantages as well over phase locked loops PLL used conventionally in OFDM receivers. Such configuration assures much faster frequency acquisition when connecting to new composite signal source, and avoids PLL instability when exposed to an unknown spectrum of phase noise caused by unpredictable channel interference and inaccuracy of conventional phase measurements methods.
Inherent stability is achieved by combining such stable sampling clock generation by FLL with the phase synthesizer PS (defined in Subsections 5 and 6 of SUMMARY OF THE INVENTION) working in the open ended configuration (shown in FIG. 13 and FIG. 15 ).
Such open ended PS configuration applies modifications of referencing frame phase with programmable phase steps defined by sub-clocks of sampling clock, wherein such sub-clocks are generated internally in PS from flip-flop based delay line driven by FreqDetClk produced by the frequency multiplier Samp-Clk×R of sampling clock Cs.
Such PS method (defined in the Subsections 5 and 6 mentioned above) uses the same SSP architecture as that used for the boundary detection discussed above. Similarly sub-clocks driving such SSP do not need to facilitate phase resolution matching single gate delay. Coincidentally sub-clocks used by PS for defining programmable phase steps applied to the local symbol frame do not need to provide phase resolution matching single gate delay either. Therefore the same sub-clocks, generated by conventional flip-flop based delay line, can be used for both; for driving said SSP utilized by SP, and for defining said programmable phase steps.
Such conventional delay line is used as consisting of serially connected flip-flops driven by the frequency multiplier Samp-Clk×R of the sampling clock wherein the sampling clock represents frequency multiplication of the local symbol frame (utilized as the reference clock by the SF_PS) by said nominal number Nn. Consequently total frequency multiplication factor amounts to R×Nn.
PCU produces such steps number definition before it is requested by PS and places such steps number on its output PCU-OUT in response to PS interrupt MC_INT.
PCU shown in FIG. 15 receives; the referencing frame Fr, the sampling clock Cs, the boundary delay time Tbd and said frequency offset Fos.
When synchronization acquisition is initialized, Fr presets an PCU internal Fr phase register to Nn-Tbd, wherein Nn is said nominal number expected for reference frame interval covering single OFDM symbol.
As such presetting of PCU internal Fr register provides said programmable presetting of numerical first edge specific for the FPD (see Subsection 7 of SUMMARY OF THE INVENTION), it utilizes such PCU function for upgrading this DPD to provide such FPD functionality.
At the same time the referencing frame prompts the PCU_OUT register to provide definition of such Nn-Tbd phase step, and prompts the symbol frame phase synthesizer SF_PS to generate PCU interrupt MC=1 INT and to implement such Nn-Tbd phase step.
Consequently the first edge of the Local Symbol Frame Fls is generated with the Nn-Tbd phase displacement to the initializing edge of Fr.
Dependent of specifics of a particular PS design;
such generation of Fls first edge displaced by Nn-Tbd phase step to the referencing frame edge, can include resetting the phase of frame generated previously by PS before such phase step is applied.
As PCU receives consecutive Fos values defining displacements of next detected Fr boundaries to consecutive expected boundaries, it keeps updating track record of previous Fos and said Fr phase register with such Fos values in order to maintain continues record of Fr phase changes and present status.
In order to avoid uncontrolled phase transients resulting from an accumulation of DFD digitization errors, only DFD design eliminating such digitization errors accumulation can be used (such DFD is defined in U.S. Pat. No. 6,864,672 by Bogdan).
Similarly PCU keeps also track record of previous phase steps defined to SF_PS and keeps updating its internal Fls phase register defining present phase of the local symbol frame.
Based on such data about Fr phase and Fls phase, PCU calculates a number of said phase steps which the referencing frame phase needs to be modified by, in order to implement a preprogrammed phase/frequency transient function between the local symbol frame and the referencing frame.
Such configuration enables accurate phase frequency control reducing phase noise and jitter.
In addition to the SF_PS, configuration shown in FIG. 15 uses another phase synthesizer FLL_PS placed in the return path of the analog phase locked loop APLL used to modify sampling clock frequency in order to minimize said frequency offset between the sampling clock and said composite signal clock.
Additionally to the data mentioned above, PCU keeps track of phase steps introduced into the sampling clock Cs via the FLL_PS. Therefore PCU has all the data defining frequency and phase relations between the sampling clock Cs and the crystal oscillator clock LX_Clk, and between the LX_Clk and said composite frame clock outlined by the referencing frame clock.
Similar configuration shown in FIG. 16 utilizes LX_Clk, instead of the sampling clock, for producing said Freq.DetClk. Therefore PCU scales said nominal number Nn, proportionally to frequency offset between the LX_Clk and the composite clock outlined by the Fr, before utilizing such Nn for measuring Fos with the DFD referenced by the LX_Clk.
Synchronization System with improved stability shown in FIG. 14 and FIG. 17 , includes:
using the additional DPD for measuring time offset (phase error) Trf-ls between the referencing frame Fr and the symbol frame Fls, instead of relying entirely on PCU subroutines explained above;
such Trf-ls is supplied to PCU which uses it to maintain close control of such time offset (phase error) by defining appropriate phase steps to the symbol frame synthesizer SF_PS.
Such synchronization system can facilitate even closer control of such phase offset, while it implicates lesser stability improvements and simpler phase frequency control less efficient in reducing phase/frequency transients.
High Accuracy FLPS shown in FIG. 18 represents high performance synchronization system which will be needed in future high speed wireless/wireline OFDM and mobile receivers, including next generations of ADSL, WiFi or WiMAX.
Such system facilitates multiplying low frequency (down to 30 kHz) of XTAL oscillator (LX_Clk) by very high factor (up to 50 000), in order to utilize very inexpensive low frequency crystal cuts for producing highly stable local oscillator clock.
Such frequency multiplier utilizes DFD 1 for measuring frequency error XTALos between the XTAL oscillator clock (LX_Clk) and the sampling clock Cs represented by the FreqDetClk, wherein the frequency multiplication factor R shall be lower than 10 in order to avoid stability problems in SOC PLL implementations.
PCU reads the frequency error XTALos and produces sequence of PCU-OUT signals supplied to the frequency locked loop phase synthesizer (FLL_PS) located in the reference path of VCXO based analog PLL having very low bandwidth (for example 0.1-1 kHz).
Such PCU_OUT signals cause said FLL_PS to insert phase errors which drive said analog PLL into producing sampling clock Cs maintaining pre-programmed frequency relation to the LX_Clk.
Since such PCU-OUT signals represent sequence of small phase steps applied with frequency by several orders higher than that of analog PLL bandwidth, resulting Cs jitter shall be very low.
Consequently, such system multiplies low frequency of highly accurate inexpensive local XTAL oscillator (LX_Clk), in order to produce sampling clock frequency with accuracy much better than 1 ppm.
Such system utilizes SCCS concept of multiplying low frequency of highly accurate inexpensive local XTAL oscillator, in order to produce sampling clock frequency with accuracy much better than 1 ppm (see Subsections 1, 2 and 3 of SUMMARY OF THE INVENTION).
This system combines all the advanced features, explained above for the FLPS shown in FIG. 15 , combined with such highly efficient frequency multiplication method.
6. Direct Synchronization of Synthesized Clock
The direct FLPS (DFPLS) configuration and timing are shown in FIG. 19A and FIG. 19B and such DFLPS operations are described below.
Said phase error between the referencing signal frame and corresponding to it oscillator frame is sensed by the frame phase detector (FPD).
Such FPD is explained in greater detail in subsection “7. Frame Phase Detector” of “SUMMARY OF THE INVENTION”.
The FPD utilizes an oscillator clock counter (OscClk_Counter) for counting oscillator clocks (OscClk) occurring during a particular period of the referencing signal frame.
PCU performs operations listed below:
1. Reading such OscClk_Counter, in response to the read counter request (RdCounter_Req) sent by FPD. 2. Calculating the measured phase error (MeasPhaError) by subtracting a nominal number of oscillator clocks (N) expected during such referencing frame period, from the actually counted number of oscillator clocks represented by such OscClk_Counter. 3. Estimation of frequency error (FreqErr), between the oscillator clock and the referencing signal, based on such measured phase errors. Such FreqErr can be estimated as equal to an average sum of previous consecutive periodical frequency errors (PerFreqErr) added for grater accuracy without accumulation of their digitization errors, wherein:
PerFreqErr
=
MeasPhaErr
N
=
OscClkCounter
-
N
N
4. Calculation of the next systematic phase amendment (Next_SystPhaAmend), needed to compensate such frequency error, based on such frequency error estimate; wherein:
Next_SystPhaAmend=−Last_FreqErr
5. Calculation of the last periodical phase error (Last_PerPhaErr) based on adding the last systematic phase amendment to the last measured phase error; wherein:
Last_PerPhaErr=Last_MeasPhaErr+Last_SystPhaAmend
Last_PerPhaErr=Last_MeasPhaErr−Penult_FreqErr
6. Calculation of the next variable phase amendment (Next_VarPhaAmend) based on processing the last accumulated tracking error (Last_AccTraErr) wherein such last accumulated tracking error can be calculated by adding the last variable phase amendment (Last_VarPhaAmend) to a sum of a penultimate accumulated tracking error (Penult_AccTraErr) and the last periodical phase error; i.e.:
Next_VarPhaAmend= F (Last_AccTraErr);
Last_AccTraErr=Penult_AccTraErr+Last_PerPhaErr+Last_VarPhaAmend
7. Wherein the simplest implementation of the above equation can be accomplished by assuming that:
Next_VarPhaAmend=−(Last_AccTraErr);
therefore
Last_AccTraErr=Last_PerPhaErr
and
Next_VarPhaAmend=−(Last_PerPhaErr);
8. PCU calculates the next periodical phase amendment by adding the next variable phase amendment to the next systematic phase amendment, i.e.:
Next_PerPhaAmend=Next_SystPhaAmend+Next_VarPhaAmend
9. PCU calculates control signals distributing the addition of the next periodical phase amendment evenly over the next measurement period.
10. Wherein the accumulated tracking error calculated by and stored in PCU enables accurate control of phase alignment of the synthesized clock to the external referencing signal, since such accumulated tracking error shows an accurate amount of a phase difference between the referencing signal and the synthesized clock expressed in local oscillator sub-periods.
The phase synthesizer (PS) produces the synthesized clock based on PCU control signals (PCU_OUT) communicating such periodical phase amendments (PerPhaAmend) implementing phase synthesis functions specified above.
Such phase synthesizer and its internal operations and circuits are explained in greater detail in the subsection “6 Phase Synthesizer” of “SUMMARY OF THE INVENTION”, and in the subsection “1. Phase Synthesizer” of “DESCRIPTION OF THE PREFERRED EMBODIMENTS”.
DSSC initialization presetting or eliminating start-up phase offset of the synthesized clock versus the referencing signal, can be implemented with PCU operations listed below:
an initial validation of the referencing signal frame received by PCU;
resetting internal PCU register containing said accumulated phase tracking error,
sending PCU-OUT content presetting to correct initial values all LocClk_PS internal phase & frequency modification registers including PNB, FNB and PMB.
Other initialization methods, securing such offsets elimination, may include:
presetting said PCU register containing accumulated tracking error to a desirable initial offset value;
and sending specific initial reset request signal (InitResetReq) to the LocClk_PS which shall respond by resetting its all internal phase & frequency modification registers including PNB, FNB and PMB.
Such DSSC can be used in OFDM receivers, as it is explained below:
the oscillator clock mentioned above can be provided by the Local XTAL Clock shown in FIG. 16 (see also subsection “5. Receiver Synchronization Techniques” of “DESCRIPTION OF THE PREFERRED EMBODIMENTS”);
said referencing signal frame can be provided by the Referencing Frame shown in FIG. 13 and FIG. 14 as the OFDM frame recovered from the Composite Frame;
the Local Symbol Frame (shown in the FIG. 13 and FIG. 14 ) can be generated as containing N synthesized clocks, if an initial offset equal to the boundary detection delay Tbd is preset using one of the initialization methods exemplified above.
One of said other direct synchronization solutions utilizing feed-forward hardware configuration shown in FIG. 19A (for securing even further size and power reductions critical for mass consumer markets), is described below:
A non-cumulative (i.e. free of uncontrolled phase transients) periodical measurement of phase error between said referencing signal phase and said oscillator clock phase, is conducted by said phase/frequency analysis (PFA) system implemented with the Frame Phase Detector (FPD) and said PCU subroutine calculating such measured phase error (by subtracting said nominal expected number of oscillator clocks from an actually counted number of such clocks); PCU utilizes such phase error for calculating a control signal (PCU_OUT) which can distribute a phase amendment compensating such phase error evenly over a time period between consecutive phase error measurements; PCU applies such control signals (evenly distributing this phase amendment) to the phase synthesizer (PS), in order to produce said synthesized clock tracking phase of the reference signal with phase ramps approximating phase steps corresponding to such periodical phase amendments; wherein such replacement of phase steps with ramps, eliminates most of high frequency jitter from the synthesized clock.
Still other even simpler direct synchronization solution utilizing such feed-forward configuration, can be accomplished as it is explained below:
a non-cumulative (i.e. free of uncontrolled phase transients) periodical measurement of phase error between said referencing signal phase and said oscillator clock phase, is conducted by a phase/frequency analysis (PFA) system implemented with the Frame Phase Detector (FPD) and said PCU subroutine calculating such measured phase error (by subtracting said nominal expected number of oscillator clocks from an actually counted number of such clocks); PCU utilizes such phase error for producing a control signal driving the phase synthesizer (PS) into adding a phase amendment (compensating such phase error) to the synthesized clock phase in order to produce a synthesized clock phase tracking such reference signal phase; such very simple inherently stable configuration enabled by the PS can secure very flexible conversion of the local oscillator frequency into the frequency of synthesized clock free of uncontrolled phase transients, and tracking reference signal phase with the phase of synthesized clock free of waveform glitches; resulting phase steps (introduced to the synthesized clock for compensating phase errors measured with FPD), can be still acceptable in less demanding mass markets where cost and power reductions are the most critical.
CONCLUSION
In view of the above description of the invention and associated drawings, other modifications and variations will now become apparent to those skilled in the art based on the teachings contained herein. Such other modifications and variations fall within the scope and spirit of the present invention. | The Direct Synchronization of Synthesized Clock (DSSC) contributes a method, system and apparatus for reliable and inexpensive synthesis of inherently stable local clock synchronized to a referencing signal received from an external source. Such local clock can be synchronized to a referencing frame or a data signal received from wireless or wired communication link and can be utilized for synchronizing local data transmitter or data receiver. Such DSSC can be particularly useful in OFDM systems such as LTE/WiMAX/WiFI or Powerline/ADSL/VDSL, since it can secure lower power consumption, better noise immunity and much more reliable and faster receiver tuning than those enabled by conventional solutions. |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a Division of U.S. application Ser. No. 11/181,531, filed Jul. 14, 2005, which is a Division of U.S. application Ser. No. 10/225,084, filed Aug. 20, 2002, and incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to amine-reactive acridinium labeling reagents. In a particular aspect, the present invention relates to acridinium labeling reagents having one or more hydrophilic substituents thereon. In another aspect, the present invention relates to conjugates containing invention acridinium labeling reagents, kits containing same, and assays employing same.
BACKGROUND OF THE INVENTION
[0003] The following description of the background of the invention is provided simply as an aid in understanding the invention and is not admitted to describe or constitute prior art to the invention.
[0004] Chemiluminescence immunoassays which employ acridinium labels have advantages of high throughput and high analytical sensitivity for low-level analytes of clinical significance. Usually it is desirable to use labeled antibodies with a large number of chemiluminescent tags, which produce high luminescence counts, which, in turn, allows one to achieve lower detection limits. This holds true provided that non-specific binding can be minimized.
[0005] During conjugation of antibodies with presently available labeling reagents at relatively high reagent-to-protein ratios, low recoveries of the labeled proteins are often obtained. In most of these labeling reactions, protein precipitation and/or formation of protein aggregates have been observed. Presumably, the precipitates and aggregates are the result of protein molecules with higher degree of labeling than the immunologically active conjugates, which remain in solution. The tendency towards precipitation and aggregation can be attributed to the hydrophobic nature of the four-ring aromatic acridinium ester label.
[0006] Accordingly, there is a need in the art for acridinium labeling reagents which have a reduced propensity to cause protein precipitation and/or promote formation of protein aggregates.
BRIEF DESCRIPTION OF THE INVENTION
[0007] In accordance with the present invention, it has been discovered that introduction of hydrophilic sulfoalkyl substituents and/or hydrophilic linkers derived from homocysteic acid, cysteic acid, glycine peptides, tetraethylene oxide, and the like, offset the hydrophobicity of the acridinium ring system to produce a more soluble label which can be attached to an antibody at higher loading before precipitation and aggregation problems are encountered.
[0008] Additional compounds described herein contain linkers derived from short peptides and tetraethylene oxide which increase aqueous solubility due to hydrogen bonding with water molecules. The present invention also embraces reagents for multiple acridinium labeling for signal amplification composed of a peptide bearing several acridinium esters with sulfonate groups at regularly spaced intervals for increased solubility.
[0009] In accordance with another aspect of the present invention, there are provided assays for the presence of an analyte in a sample, said assay comprising:
[0010] contacting an analyte with an invention conjugate,
[0011] inducing chemiluminescence by decay of an intermediate formable in the presence of a peroxide or molecular oxygen, and
[0012] measuring chemiluminescence therefrom to assay the analyte.
[0013] In accordance with still another aspect of the present invention, there are provided improved diagnostic assays for the detection of an analyte using a chemiluminescent label conjugated to a specific binding material, the improvement comprising employing an invention compound as the chemiluminescent label compound.
[0014] The summary of the invention described above is not limiting and other features and advantages of the invention will be apparent from the following detailed description of the preferred embodiments, as well as from the claims.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 provides a reaction scheme for preparation of exemplary hydrophilic chemiluminescent compounds according to the invention, useful as labeling reagents.
[0016] FIG. 2 provides a reaction scheme for preparation of 2,6-(dimethyl)-3-chlorosulfonylphenyl-N-(3-sulfopropyl)-acridinium-9-carboxylate (“SPAE”).
[0017] FIG. 3 provides a reaction scheme for preparation of SPAE-(Lys-HCA) 5 -PFP.
[0018] FIG. 4 provides a reaction scheme for preparation of exemplary acridinium-protein conjugates according to the invention.
[0019] FIG. 5 provides reaction schemes describing the formation of exemplary acridinium-protein conjugates using NHS esters ( FIG. 5 a ) and pentafluorophenyl esters ( FIG. 5 b ) according to the invention.
[0020] FIG. 6 presents the chemical structures of several acridinium labeling reagents (e.g., MeAE and SPAE derivatives).
DETAILED DESCRIPTION OF THE INVENTION
[0021] In accordance with the present invention, there are provided chemiluminescent compounds having the structure:
[0000]
[0000] wherein:
[0022] X=O, S or NR′, wherein R′ is H or alkyl or substituted alkyl;
[0023] Y=O or S;
[0024] Z=alkyl, sulfoalkyl, alkenyl, or sulfoalkenyl;
[0025] Ar=aryl or heteroaryl bearing at least one —SO 2 L substitutent, wherein L is halogen or NHQ, wherein Q is a linker bearing an amine reactive group;
[0026] R=sulfoalkyl or sulfoalkenyl;
[0027] A − is an optional suitable counter-ion; and
[0028] n=0-3;
[0029] provided that if L is halogen, Z is sulfoalkyl or sulfoalkenyl.
[0030] Thus, in one aspect of the present invention, there are provided amine-reactive acridinium labeling reagents comprising: 1) a chemiluminescent acridinium ester, 2) a hydrophilic substituent such as a sulfoalkyl group and/or a hydrophilic linker such as those derived from a sulfonated amino acid such as cysteic acid or homocysteic acid or a short peptide such as diglycine, triglycine or tetraglycine or a peptide containing cysteic acid or homocysteic acid with multiple acridinium labels or a linker containing tetraethylene oxide and 3) a reactive group such as sulfonyl chloride, succinimidyl ester (NHS ester) or pentafluorophenyl ester. A variety of structures and commonly used designations therefor, together with the prior art chemiluminescent reagent, MeAE, are shown in FIG. 1 .
[0031] As employed herein, “alkyl” refers to saturated straight or branched chain hydrocarbon radical having in the range of 1 up to about 20 carbon atoms. “Lower alkyl” refers to alkyl groups having in the range of 1 up to about 5 carbon atoms. “Substituted alkyl” refers to alkyl groups further bearing one or more substituents selected from hydroxy, alkoxy (of a lower alkyl group), mercapto (of a lower alkyl group), cycloalkyl, substituted cycloalkyl, heterocyclic, substituted heterocyclic, aryl, substituted aryl, heteroaryl, substituted heteroaryl, aryloxy, substituted aryloxy, halogen, trifluoromethyl, cyano, nitro, nitrone, amino, amido, —C(O)H, acyl, oxyacyl, carboxyl, carbamate, dithiocarbamoyl, sulfonyl, sulfonamide, sulfuryl, and the like.
[0032] As used herein, “sulfoalkyl” refers to substituents having the structure:
[0000] —(CR″ 2 ) q —SO 3 − ,
[0000] wherein:
each R″ is independently H, lower alkyl, substituted lower alkyl; and
[0034] q=1-6.
[0035] Thus, the term sulfoalkyl embraces such groups as sulfomethyl, sulfoethyl, sulfopropyl, sulfobutyl, sulfopentyl, sulfohexyl, and the like. A presently preferred sulfoalkyl group according to the invention is sulfopropyl.
[0036] As used herein, “sulfoalkenyl” refers to substituents having the structure:
[0000] —(CR″ 2 ) r —C(R″)═C(R″)—(CR″ 2 ) r —SO 3 − ,
[0000] wherein:
each R″ is independently H, lower alkyl, substituted lower alkyl and each r is independently 0-4.
[0038] Thus, the term sulfoalkenyl embraces such groups as sulfoethenyl, sulfopropenyl, sulfobutenyl, sulfopentenyl, sulfohexenyl, and the like. A presently preferred sulfoalkenyl group according to the invention is sulfopropenyl.
[0039] As employed herein, “aryl” refers to aromatic groups having in the range of 6 up to 14 carbon atoms and “substituted aryl” refers to aryl groups further bearing one or more substituents as set forth above. In one aspect of the invention, aryl is a 2,6-dialkyl substituted phenyl, such as, for example, 2,6-dimethylphenyl, 2,6-diethylphenyl, and the like. A presently preferred aryl contemplated for use in the practice of the present invention is a group having the structure
[0000]
[0040] In accordance with another preferred aspect of the present invention, Ar has the structure:
[0000]
[0000] wherein Q is polyoxyalkylene, poly-L-lysine, poly-(lysine-homocysteic acid), poly-(lysine-cysteic acid), polyglycine, aminodextran, or the like.
[0041] As employed herein, “heteroaryl” refers to aromatic groups having in the range of 4 up to about 13 carbon atoms, and at least one heteroatom selected from O, N, S, or the like; and “substituted heteroaryl” refers to heteroaryl groups further bearing one or more substituents as set forth above. Exemplary heteroaryl compounds contemplated for use in the practice of the present invention include pyridyl, pyrimidyl, pyrazinyl, triazolyl, isooxazolyl, isothioazolyl, imidazolyl, and the like.
[0042] As employed herein, “halogen” refers to fluoride, chloride, bromide or iodide atoms.
[0043] As employed herein, “suitable counter-ion”, A − , refers to halogen ions, sulfate ions, nitrate ions, carboxylate ions, triflate ions, fluoroslufonate ions, difluorosulfonate ions, and the like. The use of a counter-ion is optional, in that certain molecules may use an internal “counter-ion”; for example, when Z is sulfoalkyl or sulfoalkenyl, the sulfo-moiety provides a suitable counter-ion.
[0044] Linkers bearing an amine reactive group, Q, contemplated for use in the practice of the present invention include succinimidyl esters (e.g., N-hydroxysuccinimide esters or NHS esters), N-hydroxyphthalimide esters, pentafluorophenyl esters, tetrafluorophenyl esters, 2-nitrophenyl esters, 4-nitrophenyl esters, dichlorotriazines, isothiocyanates, and the like.
[0045] In one aspect of the invention, compounds wherein X is O are presently preferred. In another aspect of the present invention, compounds wherein Y is O are also preferred. In a particularly preferred aspect of the invention, both X and Y are O.
[0046] Exemplary compounds contemplated by the present invention include compounds wherein:
[0047] X is O,
[0048] Y is O,
[0049] Z is sulfoalkyl,
[0050] Ar is 2,6-dimethyl-3- or 4-chlorosulfophenyl,
[0051] R is not present,
[0052] A − not present, and
[0053] n is O.
[0054] Especially preferred compounds are those having the above-described substitution pattern and wherein Z is sulfopropyl. Additional preferred compounds are those wherein Ar is 2,6-dimethyl-3-chlorosulfophenyl or 2,6-dimethyl-4-chlorosulfophenyl.
[0055] Additional exemplary compounds according to the present invention are set forth in FIG. 6 , e.g., 2,6-(dimethyl)-3-chlorosulfonylphenyl-N-(3-sulfopropyl)-acridinium-9-carboxylate (“SPAE”), SPAE-(polyethyleneoxide) 4 -pentafluorophenyl ester (“SPAE-PEO4-PFP”), 2,6-(dimethyl)-3-chlorosulfonylphenyl-N-methyl-acridinium-9-carboxylate triflate (“MeAE”), and MeAE-(polyethylene oxide) 4 -N-hydroxysuccinimide ester (“MeAE-PEO4-NHS”).
[0056] In accordance with another aspect of the present invention, there are provided chemiluminescent conjugates comprising a chemiluminescent compound as described herein, conjugated with a specific binding material.
[0057] “Specific binding material” means herein any material which will bind specifically by an immunoreaction, protein binding reaction, nucleic acid hybridization reaction, and any other reaction in which the material reacts specifically with a restricted class of biological, biochemical or chemical species. Specific binding materials contemplated for use in the practice of the present invention include antibodies, enzymes and substrates therefor, antibodies and antigens therefor, avidin-biotin, nucleic acids, and the like.
[0058] Invention chemiluminescent compounds are useful in a broad range of specific binding assays for the presence of analyte in a sample. “Presence” shall mean herein the qualitative and/or quantitative detection of an analyte. Such assays may be directed at any analyte which may be detected by use of the improved chemiluminescent compound in conjunction with specific binding reactions to form a moiety thereon. These assays include, without limitation, immunoassays, protein binding assays and nucleic acid hybridization assays.
[0059] In a typical immunoassay, the analyte is immunoreactive and its presence in a sample may be determined by virtue of its immunoreaction with an assay reagent. In a typical protein binding assay, the presence of analyte in a sample is determined by the specific binding reactivity of the analyte with an assay reagent where the reactivity is other than immunoreactivity. Examples of alternative specific binding reactions for use in assays include enzyme-substrate recognition and the binding affinity of avidin for biotin. In the typical nucleic acid hybridization assay, the presence of analyte in a sample is determined by a hybridization reaction of the analyte with an assay reagent. Analyte nucleic acid (usually present as double stranded DNA or RNA) is usually first converted to a single stranded form and immobilized onto a carrier (e.g., nitrocellulose paper). The analyte nucleic acid may alternatively be electrophoresed into a gel matrix. The immobilized analyte may then be hybridized (i.e., specifically bound) by a complementary sequence of nucleic acid.
[0060] The foregoing specific binding assays may be performed in a wide variety of assay formats. These assay formats fall within two broad categories. In the first category, the assay utilizes an invention chemiluminescent conjugate which comprises a chemiluminescent moiety of the invention attached to a specific binding material. In this category of assays, the invention chemiluminescent conjugate participates in a specific binding reaction and the presence of analyte in the sample is proportional to the formation of one or more specific binding reaction products containing the invention chemiluminescent conjugate. The assay is performed by allowing the requisite specific binding reactions to occur under suitable reaction conditions. The formation of specific binding reaction products containing the invention chemiluminescent conjugate is determined by measuring the chemiluminescence of such products containing the invention chemiluminescent conjugate or by measuring the chemiluminescence of unreacted or partially reacted invention chemiluminescent conjugate not contained in such products.
[0061] This first category of assay formats is illustrated by sandwich assays, competitive assays, surface antigen assays, sequential saturation assays, competitive displacement assays and quenching assays.
[0062] In a sandwich format, the specific binding material to which the chemiluminescent moiety is attached is capable of specifically binding with an analyte of interest. The assay further utilizes a reactant which is capable of specifically binding with the analyte to form a reactant-analyte-chemiluminescent conjugate complex. The reactant may be attached to a solid phase, including without limitation, dip sticks, beads, tubes, paper, polymer sheets, and the like. In such cases, the presence of analyte in a sample will be proportional to the chemiluminescence of the solid phase after the specific binding reactions are completed. Such assay formats are discussed further in U.S. Pat. Nos. 4,652,533, 4,383,031, 4,380,580 and 4,226,993, which are incorporated herein by reference in their entirety, including all figures, tables, and claims.
[0063] In a competitive format, the assay utilizes a reactant which is capable of specifically binding with the analyte to form an analyte-reactant complex and with the specific binding material, to which a chemiluminescent moiety of the invention is attached, to form a chemiluminescent conjugate-reactant complex. The reactant may be attached to a solid phase, or alternatively reaction products containing the reactant may be precipitated by use of a second antibody or by other known means. In this competitive format, the presence of analyte is “proportional,” i.e., inversely proportional, to the chemiluminescence of the solid phase or precipitate. A further discussion of this assay format may be found in the immediately above mentioned U.S. patents.
[0064] In another assay format, the analye may occur on or be bound to a larger biological, biochemical or chemical species. This type of format is illustrated by a surface antigen assay. In this format, the specific binding material is capable of specifically binding with the analyte and the presence of analyte is proportional to the analyte-chemiluminescent conjugate complex formed as a reaction product. This is illustrated by attaching a chemiluminescent moiety of the invention to an antibody which is specific to a surface antigen on a cell. The presence of the cell surface antigen will be indicated by the chemiluminescence of the cells after the completion of the reaction. The cells themselves may be used in conjunction with a filtration system to separate the analyte-chemiluminescent conjugate complex which is formed on the surface of the cell from unreacted chemiluminescent conjugate. This is discussed further in U.S. Pat. No. 4,652,533.
[0065] Chemiluminescent moieties of the invention may be used in additional assay formats known in the art including without limitation sequential saturation and competitive displacement, both of which utilize a chemiluminescent conjugate where both (1) the specific binding material, to which the moiety is attached, and (2) the analyte, specifically bind with a reactant. In the case of sequential saturation, the analyte is reacted with the reactant first, followed by reaction of the chemiluminescent conjugate with the remaining unreacted reactant. In the case of competitive displacement, the chemiluminescent conjugate competitively displaces analyte which has already bound to the reactant.
[0066] In a quenching format, the assay utilizes a reactant which is capable of specifically binding with (i) the analyte to form an analyte-reactant complex, and (ii) with the specific binding material to which the chemiluminescent moiety is attached to form a chemiluminescent conjugate-reactant complex. A quenching moiety is attached to the reactant. When brought into close proximity to the chemiluminescent moiety, the quenching moiety reduces or quenches the chemiluminescence of the chemiluminescent moiety. In this quenching format, the presence of analyte is proportional to the chemiluminescence of the chemiluminescent moiety. A further discussion of this format may be found in U.S. Pat. Nos. 4,220,450 and 4,277,437, which are incorporated herein by reference in their entirety, including all figures, tables, and claims.
[0067] In consideration of the above discussed assay formats, and in the formats to be discussed below, the order in which assay reagents are added and reacted may vary widely as is well known in the art. For example, in a sandwich assay, the reactant bound to a solid phase may be reacted with an analyte contained in a sample and after this reaction the solid phase containing complexed analyte may be separated from the remaining sample. After this separation step, the chemiluminescent conjugate may be reacted with the complex on the solid phase. Alternatively, the solid phase, sample and chemiluminescent conjugate may be added together simultaneously and reacted prior to separation. As a still further alternative, the analyte in the sample and the chemiluminescent conjugate may be reacted prior to addition of the reactant on the solid phase. Similar variations in the mixing and reaction steps are possible for competitive assay formats as well as other formats known in the art. “Allowing under suitable conditions substantial formation” of specific binding reaction products shall herein include the many different variations on the order of addition and reaction of assay reagents.
[0068] In the second category of assay formats, the assay utilizes an unconjugated chemiluminescent compound of the invention. The presence of analyte in the sample is proportional to the formation of one or more specific binding reaction products which do not themselves contain the chemiluminescent moiety. Instead, the chemiluminescent compound chemiluminesces in proportion to the formation of such reaction products.
[0069] In one example of this second category of assays, the assay utilizes a reactant capable of binding with the analyte to form an analyte-reactant complex which causes the chemiluminescent compound to chemiluminesce. This is illustrated by a simple enzyme-substrate assay in which the analyte is the substrate glucose and the reactant is the enzyme glucose oxidase. Formation of the enzyme-substrate complex triggers the chemiluminescent compound. Such enzyme-substrate assay for glucose is disclosed in U.S. Pat. Nos. 3,964,870 and 4,427,770, which are incorporated herein by reference in their entirety, including all figures, tables, and claims. This enzyme-substrate assay is a specific binding assay in the sense that the substrate specifically binds to the active site of the enzyme in much the same way that an antigen binds to an antibody. In this assay, the enzyme specifically binds with the substrate which results in the production of peroxide which, in turn, causes the chemiluminescent compound to chemiluminesce.
[0070] Also included in the second category of assays are those assays in which the formation of the reaction products promotes or inhibits chemiluminescence by the chemiluminescent compound in a less direct manner. In this assay, a first reactant, which is cross reactive with the analyte, is attached to an enzyme such as glucose oxidase close to its active site. A second reactant which is specific for both the analyte and the immunoreactive material is added to the sample and the altered enzyme in the presence of the substrate (i.e., glucose). When the second reactant binds to the first reactant located near the active site on the enzyme, the second reactant blocks the active site in a way that the substrate cannot bind to the enzyme at the active site, or the binding of the substrate at the active site is significantly decreased. The second reactant blocking the enzyme in this manner inhibits the enzyme from producing peroxide which, in turn, would have triggered the chemiluminescent moiety. Analyte in the sample, however, will tie up the second reactant, thus preventing the second reactant from inhibiting the production of peroxide. The presence of analyte will be proportional to the chemiluminescence of the compound.
[0071] The assays contained in the above two categories of assay formats may be heterogeneous or homogeneous. In heterogeneous assays, the reaction products, whose formation is proportional to the presence of analyte in the sample, are separated from other products of the reaction. Separation can be achieved by any means, including without limitation, separation of a liquid phase from a solid phase by filtration, microfiltration, double antibody precipitation, centrifugation, size exclusion chromatography, removal of a solid phase (e.g., a dip stick) from a sample solution or electrophoresis. For example, in a sandwich assay the reactant-analyte-chemiluminescent conjugate complex is separated from unreacted chemiluminescent conjugate. In a surface antigen assay, the analyte-chemiluminescent conjugate complex is separated from unreacted chemiluminescent conjugate. In a competitive assay, the reactant-chemiluminescent conjugate complex is separated from unreacted chemiluminescent conjugate. In a sequential saturation assay and in a competitive displacement assay, the reactant-chemiluminescent conjugate complex is separated from unreacted chemiluminescent conjugate. Alternatively, in homogeneous assays the reaction products are not separated. After the assay reagents have been allowed to react, the chemiluminescence may be measured from the whole assay mixture whether such mixture is in solution, on a solid phase or distributed between various membrane layers of a dip stick or other solid support. The glucose assay using glucose oxidase and a chemiluminescent moiety illustrates a simple homogeneous assay in which separation is unnecessary. The quenching assay illustrates a more complex homogeneous assay in which separation is unnecessary.
[0072] Finally, “measuring the chemiluminescence” shall include, where relevant, the act of separating those specific binding reaction products, the formation of which are proportional to the presence of analyte in the sample, from other reaction products. It shall also include, where relevant, the acts of (i) treating the chemiluminescent moiety with acid to cleave an acid labile group from the moiety, and/or (ii) triggering the chemiluminescent moiety to chemiluminesce in the case of those assay formats in which the formation of the reaction products does not itself trigger the chemiluminescent moiety.
[0073] In accordance with yet another aspect of the present invention, there are provided chemiluminescent assay kits comprising a conjugate as described herein. Such kits preferably comprise one or more assay components as described above, including at least one chemiluminescent assay component comprising chemiluminescent moiety of the invention, and may optionally include one or more of: instructions for performing the detection; reagents, such as buffers, for use in performing the detection; pipets for liquid transfers; etc.
[0074] The invention will now be described in greater detail by reference to the following non-limiting examples.
EXAMPLE 1
Preparation of Hydrophilic Chemiluminescent Acridinium Labeling Reagents
[0075] The relatively hydrophobic compound MeAE [2,6-(dimethyl)-3-chlorosulfonylphenyl-N-methyl-acridinium-9-carboxylate triflate] was prepared from 2,6-(dimethyl)phenylacridine-9-carboxylate by N-methylation with methyl triflate followed by reaction to form the sulfonyl chloride [U.S. Pat. No. 5,284,952]. This compound was converted to hydrophilic acridinium esters by reaction with a hydrophilic amino acid or peptide followed by formation of the N-hydroxysuccinimide (NHS) or pentafluorophenyl (PFP) ester according to the scheme in FIG. 1 . The synthesis of exemplary compounds is described in additional detail below.
EXAMPLE 2
MeAE-PEO4-NHS
[0076]
[0077] To a stirred solution of 130 mg (0.34 millimole) tetraethyleneglycol amino propionic acid, TFA and 190 mg (1.4 millimole) diisopropylethylamine in 4 ml dry acetonitrile was added three portions of MeAE in dry DMF [total amount =100 mg (0.17 millimole) in 1.5 ml]. The mixture was stirred in the dark under argon at room temperature for 2.5 hrs. The mixture was acidified by addition of 2 M aqueous trifluoroacetic acid to pH 3 on a wet pH strip. The volatiles were removed on a rotary evaporator and then the residue was redissolved in 10% acetonitrile-90% aqueous 50 mM acetic acid. The mixture was passed through a Sephadex G10 gel filtration column using 10% acetonitrile/90% aqueous 50 mM acetic acid as eluting solvent. The amount of product was 47.5 micromole (28% yield) as determined by UV-vis absorbance. The solution collected from the gel filtration was acidified to pH 2 by addition of 2 M aqueous methanesulfonic acid. The volatiles were removed by vacuum to produce the yellow solid MeAE-PEO4-COOH. ESI mass spec. Positive mode m/z=669 (acridinium ion carboxylic acid), m/z=691 (sodium salt). Negative mode m/z=781 (acridinium trifluoroacetate carboxylate).
[0078] The MeAE-PEO4-COOH was dried by azeotropic evaporation with 1 ml pyridine followed by vacuum dessication. To a solution of 48 micromole MeAE-PEO-COOH and 0.52 millimole pyridine in 0.5 ml dry DMF was added 61 mg (0.24 millimole) solid disuccinimidyl carbonate. The reaction was allowed to proceed for 6 hrs with stirring at room temperature under argon. Dry ether (5 ml) was added to precipitate the MeAE-PEO4-NHS product. The supernatant was removed by aspiration and then the solid was redissolved in DMF, reprecipitated by addition of ether, washed with ether and dried. ESI mass spec. Positive mode m/z=766 (acridinium ion NHS ester).
EXAMPLE 3
MeAE-HCA-NHS
[0079]
[0080] A mixture composed of 293 mg (1.6 mmole) homocysteic acid, 0.5 ml water, 2.8 ml of 1 M NaOH, 4 ml of 0.2 M carbonate buffer pH 9.3 and 1 ml DMF was cooled externally in an ice bath. A freshly prepared solution of 40 mg (0.2 mmole) MeAE in 0.5 ml DMF was added with stirring. More carbonate buffer pH 9.3 (3 ml of 0.2 M) was added. Another portion of freshly prepared MeAE (40 mg (0.2 mmole) in 0.5 ml DMF) was added to the stirred cooled mixture. Carbonate buffer pH 9.3 (0.5 ml of 0.2 M) and DMF were added to the stirred mixture. The mixture was stirred in the ice bath for 30 min and then at room temperature for 30 min. The mixture was acidified to pH 2 by addition of 1 M aqueous methanesulfonic acid. After removal of volatiles on a rotary evaporator, the product was extracted from the solid residue into three 20-ml portions of hot methanol. The methanol extract was filtered and then concentrated to dryness to produce a yellow solid. The solid was recrystallized twice by dissolving in hot methanol followed by addition of ethyl acetate to produce 92 mg (78% yield) of MeAE-HCA product. ESI negative mode using DMSO/MeCN as solvent: m/z=603 (pseudobase sulfonate anion). Negative mode using MeOH/H 2 O as solvent: m/z=617 (methoxy adduct sulfonate anion), m/z=308 (methoxy adduct sulfonate carboxylate dianion).
[0081] Trifluoroacetic acid in acetonitrile (2 ml of 2 M solution) was added to solid MeAE-HCA (25 mg, 43 micromole) to convert the pseudobase to acridinium. The volatiles were removed in vacuum and then the yellow solid was dried in vacuum for 2 hrs. A mixture of the dry MeAE-HCA, 41 μl pyridine 0.51 mmole) and 66 mg (0.26 mmole) disuccinimidyl carbonate was stirred under argon at room temperature for 5 hrs. Ether (10 ml) was added to precipitate the product and then the supernatant was removed by aspiration. The product was dried in vacuum, redissolved in 1.5 ml DMF, reprecipitated by addition of 6 ml ether, collected and dried in vacuum. The ether precipitation was repeated to produce 31.7 mg (100%) of MeAE-HCA-NHS product. ESI mass spec, positive mode: m/z=684 (acridinium NHS ester sulfonic acid), m/z=706 (acridinium NHS ester sodium sulfonate).
EXAMPLE 4
C. MeAE-Gly2-NHS
[0082]
[0083] A mixture of glycylglycine (264 mg, 2 mmole), water (1 ml), 1.8 ml of 1 M NaOH, 4 ml of 0.2 M carbonate buffer pH 9.3 and 1 ml DMF was cooled externally in an ice bath. Three aliquots of freshly prepared solution of MeAE (total amount=120 mg (0.20 millimole) in 3 ml DMF) were added with stirring. After stirring for 30 min in the ice bath, 1 M aqueous methanesulfonic acid was added to acidify the mixture to pH 2.5. The volatiles were removed in vacuum and then the product was extracted from the yellow solid by treatment with three 15-ml portions of hot 2-propanol. The solution was filtered and concentrated to dryness to produce 123 mg of yellow solid. The solid was recrystallized from hot 2-propanol-ethyl acetate to produce 32 mg (25% yield) of MeAE-Gly2 product. ESI mass spec, positive mode: m/z=536 (acidinium carboxylic acid), m/z=558 (acridinium sodium carboxylate), m/z=590 (acridinium potassium carboxylate).
[0084] A mixture of 20 mg (32 micromole) MeAE-Gly2, 30 μl (0.3 mmole) pyridine and 49 mg (0.19 mmole) disuccinimidyl carbonate in 0.8 ml dry DMF was stirred in the dark overnight at room temperature under argon. The volatiles were removed in vacuum and then the residue was redissolved in 0.5 ml dry DMF and then the product was precipitated by addition of 3 ml dry ether. After drying in vacuum, the steps of dissolving in DMF, precipitating with ether and drying in vacuum were repeated three times to produce 8.7 mg (37% yield) of MeAE-Gly2-NHS product. ESI mass spec, positive mode: m/z=633 (NHS acridinium ion).
EXAMPLE 5
MeAE-Gly3-NHS
[0085]
[0086] A mixture composed of 96 mg (0.51 mmole) triglycine, 4 ml 0.5 M carbonate buffer pH 9.5, and 1 ml DMF was cooled externally in an ice bath. Three aliquots of freshly prepared solution MeAE in DMF (total amount=100 mg (0.17 mmole) in 1.5 ml) were added with stirring five minutes apart. The mixture was stirred for 15 min in the cold and 30 min at room temperature. The mixture was acidified to pH 2.5 by addition of 2 M aqueous methanesulfonic acid and then concentrated to dryness to produce a yellow solid. The product was extracted with three 40-ml portions of 2-propanol, filtered and concentrated to dryness. The 2-propanol extraction was repeated to produce 96 mg (80% yield) of yellow solid MeAE-Gly3 product. ESI mass spec, positive mode: m/z=593 (acridinium carboxylic acid).
[0087] A mixture composed of 47 mg (67 micromole) MeAE-Gly3, 64 μl (0.79 mmole) of pyridine and 103 mg (0.40 mmole) disuccinimidyl carbonate in 2 ml dry DMF was stirred for 5 hr in the dark at room temperature under argon. The product was isolated by ether precipitation following the same procedure as in the MeAE-Gly2-NHS preparation to produce 23.9 mg (45% yield) of MeAE-Gly3-NHS product. ESI mass spec, positive mode: m/z=690 (acridinium NHS ester).
[0000]
EXAMPLE 6
SPAE
[0088] The compound SPAE [2,6-(dimethyl)-3-chlorosulfonylphenyl-N-(3-sulfopropyl)-acridinium-9-carboxylate] is a hydrophilic acridinium ester and has the following structure:
[0089] This compound was synthesized from 2,6-(dimethyl)phenylacridine-9-carboxylate according to the scheme in FIG. 2 . The synthesis of this compound is described in additional detail below.
[0090] 2,6-Dimethylphenyl 9-acridinecarboxylate (0.654 g, 2.0 mmole) and molten 99+% 1,3-propane sultone (2.4 g, 20 mmole) was placed in an oven-dried 20-ml glass vial. The mixture was microwaved at 70% power in a Sanyo Carousel Model R-230-BK microwave oven for two 15-second periods followed by one 10-second period with swirling between microwaving periods. Total microwaving time=40 seconds. To hydrolyze sulfonate ester groups, 5 ml of 50% methanol. 50% aqueous 0.2 M hydrochloric acid was added and then the black mixture was heated with magnetic stirring in a 80° C. oil bath for 5 hours. The product was purified by preparative HPLC through a 250 mm×21.2 mm Phenomenex Luna 5 micron C18(2) column using isocratic mobile phase with 60% A and 40% B at 8 ml/min flow rate. (Solvent A=0.1% aqueous trifluoroacetic acid, Solvent B=acetonitrile). For each of 30 chromatographic runs, 200 microliters of sample was injected. The product with a retention time between 14 to 15 min was collected when the absorbance at 430 nm was greater than 0.2. The combined collected 14-15 min fraction was concentrated to dryness on a rotary evaporator to produce 0.49 g of yellow solid. The 2,6-(Dimethyl)phenyl-N-(3-sulfopropyl)acridine-9-carboxylate product was recrystallized from hot 1:1 acetonitrile/methanol with addition of ethyl acetate to produce 401 mg of crystals. The mother liquor was concentrated to produce a second crop (76 mg). Yield 53%. ESI mass spec in methanol. Positive mode: m/z=450 (acridinium sulfonic acid) and 472 (acridinium sodium sulfonate). Negative mode: m/z=480 (methoxy adduct sulfonate anion) and 466 (pseudo base sulfonate anion). UV-visible spectrum in 100 mM phosphate pH 2.0: λ max =370 and 430 nm.
[0091] To a stirred suspension of 2,6-(dimethyl)phenyl-N-(3-sulfopropyl)acridine-9-carboxylate (180 mg, 0.40 mmole) in 12 ml dry dichloromethane in a 25-ml oven-dried flask under argon, was added 400 microliters of 99+% chlorosulfonic acid (0.70 g, 6.0 mmole). The chlorosulfonation was allowed to proceed overnight under argon at room temperature. The small amount of insoluble brown solid was allowed to settle and then the yellow supernatant was added dropwise from a Pasteur pipet to a flask containing stirred 100 ml of anhydrous ether under argon. The product was collected on a sintered glass funnel under a blanket of argon under a large inverted funnel and then washed with about 30 ml of dry ether. The yellow solid SPAE product (212 mg, 97% yield) was dried overnight in vacuum over phosphorus pentoxide. ESI mass spec in methanol. Positive mode: m/z=548 and 550 (acridinium sulfonyl chloride). Negative mode: m/z=578 and 580 (sulfonyl chloride methoxy adduct sulfonate anion ). UV-visible spectrum in 100 mM phosphate pH 2.0: λ max =371 and 431 nm (acridinium ion). UV-visible spectrum in 100 mM carbonate pH 9.6: λ max 287 and 320 nm (pseudo base). Specific chemiluminescence activity in 0.4% BSA in phosphate buffer pH 6.0 using the Berthold chemiluminometer=3.8×10 19 relative luminescence units per mole.
EXAMPLE 7
F. SPAE-PEO4-PFP
[0092] The hydrophilicity of SPAE can be further enhanced by attachment to a linker such as a hydrophilic amino acid or peptide followed by conversion to the NHS or PFP ester. For example, SPAE-PEO4-PFP was prepared which has the following structure:
[0000]
[0093] A freshly prepared solution of 5.8 mg (10.6 micromole) SPAE in 0.5 ml anhydrous methanol was added to a stirred solution of 32 mg (82 micromole) of tetraethylene glycol amino propionic acid and 32 μl (0.18 mmole) of diisopropylethylamine in 0.2 ml methanol. The reaction was allowed to proceed for 1 hr in the dark at room temperature under argon. The mixture was acidified by addition of 20 μl of glacial acetic acid and then concentrated to 0.2 ml. Water (0.4 ml) was added and then the product was purified by HPLC through a 10 mm×250 mm Phenomenex Luna C18(2) column using a linear gradient of acetonitrile with absorbance monitoring at 360 nm. Gradient program: 10% B for 2 min, 10% to 90% B in 16 min, 90% B for 3 min, 90% B to 10% B in 1 min, 10% B for 2 min. (Solvent A=0.1% trifluoroacetic acid, Solvent B=acetonitrile). The fraction with retention time of 16 min contained the SPAE-tetraethylene glycol propionic acid (3.2 micromole based on UV-vis spectrum (30% yield). ESI mass spec, positive mode: m/z=777 (acridinium sulfonic acid carboxylic acid), m/z=799 (acridinium carboxylic acid sodium sulfonate). Negative mode: m/z=807 (methoxy adduct sulfonate anion), m/z=403 (methoxy adduct sulfonate carboxylate dianion).
[0094] A mixture of SPAE-tetraethylene glycol propionic acid (0.77 micromole), 2.66 μl (15.5 micromole) of pentafluorophenyl trifluoroacetate and 1.3 μl (16 micromole) pyridine in 0.2 dry DMF was stirred in the dark at room temperature under argon for 1 hr. The reaction mixture was distributed into four vials and then the volatiles were removed in vacuum to produce SPAE-PEO4-PFP. ESI mass spec Positive mode: m/z=943 (acridinium PFP ester sulfonic acid), m/z=965 (acridinium PFP ester sodium sulfonate). Negative mode: m/z=973 (PFP ester methoxy adduct sulfonate anion).
EXAMPLE 8
SPAE-(Lys-HCA) 5 -PFP
[0095] Signal amplification can be achieved by the use of a hydrophilic peptide linker that can carry several acridinium labels attached to pendant groups on the peptide backbone. This peptide amplifier can also carry several sulfonate groups at regular intervals for improved aqueous solubility and an amine-reactive functional group for covalent attachment to proteins. One advantage of such labeling strategy is that high specific chemiluminescence activity can be achieved while keeping most of the lysines intact to preserve immunoaffinity. An example of such amplifier is SPAE-(Lys-HCA) 5 -PFP. A synthesis for this exemplary molecule is provided schematically in FIG. 3 , and in additional detail below.
[0096] The amplifier peptide SPAE-(Lys-HCA) 5 was prepared by the reaction between the synthetic peptide Lys-HCA-Lys-HCA-Lys-HCA-Lys-HCA-Lys-HCA (HCA=homocysteic acid) and excess SPAE (>10 moles SPAE per mole of peptide) in the presence of a base such as diisopropylethylamine. The resulting multi-acridinium peptide carboxylic acid was purified by gel filtration and then treated with excess pentafluorophenyl trifluoroacetate to produce the amine-reactive PFP ester.
EXAMPLE 9
Preparation of Acridinium-Protein Conjugates
[0097] The chemiluminescent compounds of the present invention can be reacted with specific binding partner such as an antibody, antibody fragment, avidin or streptavidin, protein A or protein G, oligonucleotide, ligand, or hapten. A sulfonyl chloride group reacts readily with lysine or the terminal amino group of proteins in aqueous or mixed aqueous/organic buffered solution, typically at pH>9 to produce stable sulfonamide linkages as shown in the scheme in FIG. 4 . The following exemplary procedure used to label anti-TSH with SPAE is generally applicable for preparing the acridinium-antibody conjugates using sulfonyl chloride reagents/
[0098] In preparation for conjugation using SPAE, 1 mg (6.7 nanomole) of goat anti-TSH tag antibody was buffer-exchanged in an Amicon Centricon concentrator cartridge (MW cut-off=30,000) to produce a solution of 1 mg antibody in 400 μl of 100 mM carbonate pH 9.6. In a typical conjugation, the labeling reagent (7 μl of freshly prepared 22.8 mM SPAE (MW=547) in dry DMF, as determined by UV-vis absorbance at 368 nm, was added and then the mixture was shaken. The conjugation reaction was allowed to proceed for 30 minutes at room temperature with occasional shaking. The conjugate was purified by gel filtration though a 27 cm×1 cm column containing 2:1 bed volume of Sephadex G-75 and Sepharose 6B. The column was eluted with 100 mM phosphate pH 6.0 containing 150 mM NaCl with monitoring of UV absorbance at 280 nm. The fractions with elution times of 12 min, 18 min and 32 min contained the antibody aggregate, the antibody-SPAE conjugate and the hydrolyzed excess labeling reagent, respectively. The protein recovery based on Coomasie Blue colorimetric protein assay was 73%. The UV-vis spectrum of an aliquot of the conjugate fraction acidified to pH 2 was recorded to determine the number of acridinium labels per IgG molecule. Based on the acridinium and protein absorbances at 368 nm (ε=15,700 M −1 cm −1 ) and 280 nm (extinction coefficient=1.35 O.D. for a 1 mg/ml solution), respectively, the conjugate was estimated to contain 2.6 labels per IgG molecule. The specific chemiluminescence activity for this conjugate measured using the Berthold Chemiluminometer was 743 RLU/pg.
[0099] The NHS ester activated acridinium compounds react with amino groups of proteins in aqueous solution in the pH range 7-9 to produce stable amide linkages as shown in the scheme in FIG. 5 a . In a similar manner, the pentafluorophenyl ester group reacts with amino groups of proteins in aquesous buffered solution typically at pH 7-8 to produce bioconjugates with the label attached via stable amide linkages as shown in the scheme in FIG. 5 b . The following procedure was used to prepare exemplary conjugates with the NHS or PFP activated acridinium derivatives:
EXAMPLE 10
Preparation of Conjugates Using Acridinium-NHS Reagents
[0100] In a typical conjugation reaction, 1.5 mg of goat polyclonal ant-TSH antibody was buffer-exchanged twice on a 30,000 MW cutoff Amicon Centricon concentrator with 20 mM phosphate buffer pH 7.8 to produce 600 uL of 2.5 mg/ml antibody solution. MeAGly2-NHS (66 uL of 2.27 mM soln based on UV-vis absorbance) was added to produce a 15× reagent/antibody molar ratio. The conjugation was allowed to proceed for 1 hr at room temperature with occasional mixing. The conjugate was purified by gel filtration through a mixed bed column in the same manner as the SPAE conjugates. The recovery based on UV absorbance was 87%. The conjugate was found to contain 1.4 acridinium labels per antibody based on UV-vis absorbance.
EXAMPLE 11
Preparation of Conjugates Using Acridinium-PFP Reagents
[0101] Goat polyclonal anti-TSH antibody (1.12 mg) was buffer-exchanged twice to produce 450 uL of 2.5 mg/mL antibody solution in 100 mM phosphate pH 7.4. Freshly prepared SPAE-PEO-PFP in dry acetonitrile (40 uL of 4.2 mM solution based on UV-vis absorbance) was added with mixing to produce a 22× reagent antibody molar ratio and then the conjugation was allowed to proceed for 1 hr at room temperature in the dark. The reaction was quenched by addition of 10 uL of 1 M glycine in water and then the mixture was chromatographed through the mixed bed gel filtration column in the same manner as the SPAE conjugates. The specific chemiluminescence activity was 332 RLU/pg.
EXAMPLE 12
Analysis of Conjugates
[0102] The anti-TSH and anti-ACTH were labeled with the hydrophilic acridinium compounds at various molar ratios. The protein recovery was determined by Coomasie Blue colorimetric protein assay. The results are summarized below. Compared to the relatively hydrophobic MeAE compound, the hydrophilic labels gave much higher protein recovery. Very high levels of acridinium labeling were achieved with the hydrophilic labels.
[0000]
TABLE 1
TSH Goat Polyclonal Ab Conjugates
Labeling Ratio
% Recovery
MeAE
26X
17
MeAE-Gly2-NHS
65X
41
MeAE-Gly3-NHS
46X
49
MeAE-Gly4-NHS
26X
72
MeAE-HCA-NHS
72X
108
SPAE
13X
104
SPAE
17X
91
SPAE
21X
82
SPAE
24X
73
SPAE
32X
53
SPAE
36X
55
SPAE
46X
34
[0000]
TABLE 2
ACTH Monoclonal Ab Conjugates
Labeling Ratio
% Recovery
MeAE
5X
58
SPAE
5X
72
SPAE
9X
78
SPAE
14X
86
Assay Results
[0103] The assays were run on a Nichols Advantage Specialty System with Nichols Advantage assay wash and triggers. The assay results were generated using the magnetic particles, biotinylated antibodies, buffers and standards from commercially available Nichols Advantage Immunoassay kits.
TSH Assay Protocol
[0000]
1. Pipette 25 uL of a solution containing biotinylated monoclonal anti-TSH and acridinium labeled polyclonal goat anti-TSH.
2. Pipette 200 uL of patient sample.
3. Incubate for 20 minutes at 37°
4. Pipette 50 uL of assay buffer and 13 uL of streptavidin coated magnetic particles.
5. Incubate for 10 minutes at 37°.
6. Wash 3× with assay wash.
7. Trigger and count (2 sec.).
ACTH Assay Protocol
[0000]
1. Pipette 70 uL of biotinylated monoclonal anti-TSH.
2. Pipette 20 uL of acridinium labeled monoclonal anti-TSH.
3. Pipette 150 uL of patient sample or standard/
4. Incubate for 20 minutes at 37°
5. Pipette 20 uL of streptavidin coated magnetic particles and 150 uL of buffer.
6. Incubate for 10 minutes at 37°.
7. Wash 3× with assay wash.
8. Trigger and count (2 sec.).
[0119] Because the high acridinium labeling was achieved with the hydrophilic acridinium esters, less antibody was required in the assay. The amount of tracer antibody used was decreased by a factor of 2 for the TSH assay and a factor of 3 for the ACTH assay. Even with significantly less antibody, the hydrophilic acridinium ester labeled antibodies gave improved standard curves with higher signal to noise observed at all standard levels.
[0120] The analytical sensitivity (limit of detection) was determined by reading the +2SD response from n=20 replicate measurements of the zero standard from the standard curve. The analytical sensitivity of the both the TSH and ACTH assays was significantly improved using the new hydrophilic acridinium labeled antibodies at a lower antibody concentration than the relatively hydrophobic acridinium (MeAE) labeled antibody.
[0000]
TABLE 3
TSH Assay Standard Curve and Analytical Sensitivity
0.4 ug/mL
0.8 ug/mL
TSH Conc.
24X SPAE
24X MeAE
STD
uIU/mL
RLU
RLU
0
0
385
343
1
0.014
669
520
2
0.021
906
651
3
0.048
1632
1045
4
0.49
13111
7541
5
2.6
54164
30449
6
4.6
96720
56068
7
9.5
164203
93869
8
19
282692
166464
9
51
487052
310816
Analytical Sensitivity
0.0018 uIU/mL
0.0031 uIU/mL
(uIU/mL)
[0000]
TABLE 4
ACTH Assay Standard Curve and Analytical Sensitivity
0.2 ug/mL
0.6 ug/mL
ACTH Conc.
5X SPAE
5X MeAE
STD
pg/mL
RLU
RLU
0
0
507
436
1
3.4
928
624
2
10.3
1943
1035
3
36
5512
2438
4
110
15590
6441
5
355
55645
22393
6
1160
172923
73275
Analytical Sensitivity
0.29 pg/mL
0.73 pg/mL
(uIU/mL)
[0121] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.
[0122] While the invention has been described in detail with reference to certain preferred embodiments thereof, it will be understood that modifications and variations are within the spirit and scope of that which is described and claimed. | In accordance with the present invention, it has been discovered that introduction of hydrophilic sulfoalkyl substituents and/or hydrophilic linkers derived from homocysteic acid, cysteic acid, glycine peptides, tetraethylene oxide, and the like, offset the hydrophobicity of the acridinium ring system to produce a more soluble label which can be attached to an antibody at higher loading before precipitation and aggregation problems are encountered. Additional compounds described herein contain linkers derived from short peptides and tetraethylene oxide which increase aqueous solubility due to hydrogen bonding with water molecules. The present invention also embraces reagents for multiple acridinium labeling for signal amplification composed of a peptide bearing several acridinium esters with sulfonate groups at regularly spaced intervals for increased solubility. The invention also embraces assays employing the above-described compounds. |
TECHNICAL FIELD
The present invention relates to a keyfact-based text retrieval method and a keyfact-based text index method. In particular, the methods describe the formalized concept of a document as a pair comprising an object that is the head and a property that is the modifier, and uses the information described by the pair as index information for efficient document retrieval.
BACKGROUND OF THE INVENTION
A keyfact means an important fact contained in sentences which constitute a document. The keyfact is represented by an object and property information through syntactic analysis of the sentence.
The keyword-based text retrieval method was the main stream in conventional text retrieval methods. However, the precision of the keyword-based text retrieval method was not good due to the following reasons. First, the meaning of the document is not precisely represented and the representativeness of document expression is low because the document is represented by keywords, which are nouns. This is a fundamental reason for poor retrieval precision. Second, when a query includes a natural language phrase or a natural language sentence or keywords, the intention of the user's query is not reflected precisely in a keyword-based text retrieval method because the query is expressed by keywords. Therefore, the keyword-based text retrieval method has a fundamental limitation in retrieval precision because it performs document retrieval by keywords. As a result, because the keyword-based text retrieval system provides such low level of retrieval precision, it causes a number of unnecessary retrievals and therefore precious resources, such as time and effort, are wasted.
Recently, a number of studies have been performed in the area of phrase-based text retrieval methods in order to compromise such defects of the keyword-based retrieval method. The phrase-based text retrieval methods extract a precise phrase pattern through a morphological-syntactic normalization process and perform indexing and retrieval by extracted phrase. Therefore, the phrase-based retrieval method performs more precise text retrieval than the keyword-based text retrieval method but performs less precise text retrieval than a concept-based text retrieval method, which expresses text by concept units.
A new approach to keyfact-based text retrieval methods has been proposed in order to overcome the shortcomings of the keyword-based text retrieval method and generalize phrase-based text retrieval method. In the keyfact-base text retrieval method, a part of text that represent the same meaning is described as a keyfact. Since the keyfact-based retrieval method is a sort of concept-based retrieval method, and therefore indexing and retrieval of the keyfact-based retrieval method are performed with the unit of the keyfact, precision of the retrieval is greatly improved.
In the keyfact-based retrieval method, it is desirable that phrases or words having the same meaning are indexed as the same indexing terms. For example, noun phrases including “the retrieval of information” as a subset of “the efficient retrieval of information”, “the retrieval of the distributed information”, and “the fast retrieval of the distributed information” must have common indices which can be possibly generated from “the retrieval of information” as subsets and recognize also them as different meaning with subtle conceptual different indexes at the same time.
Since the keyword-based retrieval method doesn't recognize the conceptual difference between “the retrieval of the information” and “the efficient retrieval of the information”, users are not able to retrieve the exact document that is desired.
SUMMARY OF THE INVENTION
A keyfact-based retrieval method, which extracts the precise keyfact pattern using the natural language processing techniques and indexes documents with the unit of the keyfact, is provided.
In addition, a keyfact-based retrieval method, which extracts precise keyfact patterns included in a natural query of a user using the natural language processing techniques and retrieves documents similar to the query in the keyfact-based index file, is provided.
In addition, a keyfact-based retrieval method, which retrieves and indexes documents with the unit of keyfact, is provided.
A keyfact-based text retrieval system of the present invention includes keyfact extracting means, keyfact indexing means, and keyfact retrieving means. The keyfact extracting means analyze a document collection and a user query, and extracting keywords not having part-of-speech ambiguity from the document collection and the user query, and respectively extracting keyfacts of the document collection and the user query from the keywords. The keyfact indexing means for calculating the frequency of the keyfacts of the document collection and generating a keyfact list of the document collection for a keyfact index structure. The keyfact retrieving means for receiving the keyfact of the user query and the keyfacts of the document collection and defining a keyfact retrieval model in consideration of weight factors according to a keyfact pattern and generating a retrieval result.
The keyfact extracting means includes morphology analyzing means, part-of-speech tagging means, keyfact pattern extracting means, and keyfact generating means. The morphology analyzing means analyze morphology of an input sentence and obtaining tag sequences of part-of-speech by attaching part-of-speech tags. The part-of-speech tagging means selects a tag sequence of part-of-speech out of the tag sequences of part-of-speech. The tag sequence of part-of-speech is precise. The keyfact pattern extracting means extracts a keyfact pattern by applying the tag sequences of part-of-speech to a keyfact pattern rule. The keyfact generating means applies the keyfact pattern to a keyfact pattern generation rule and generating a keyfact list, which is a set of keyfact terms.
The keyfact indexing means includes frequency calculating means, table generating means, and keyfact indexing means. The frequency calculating means calculates a frequency of various keyfacts and a document frequency of the keyfacts. The various keyfacts are included in the document collection, and the document frequency is the number of documents contained the various keyfacts. The table generating means generates a document index table, a document table, and a keyfact index table of the document collection. The keyfact indexing means forms a keyfact index structure. The keyfact index structure has information regarding document frequency, document identifier, and keyfact frequency in each corresponded documents.
The keyfact retrieving means includes following means. A means forms a document and a user query vector with an index file and the keyfact of the user query. The index file generated by the keyfact indexing means. The keyfact of the user query generated by the keyfact extracting means. A means determines keyfact weight constants in accordance with the keyfact pattern. A means calculates keyfact weights for the document and the user query by applying the keyfact weight constants to the document and the user query vector. The retrieval results displaying means displays the retrieval result by applying the keyfact weights to keyfact retrieval model. The retrieval result indicates documents with a keyfact similar to the keyfact of the user query.
A keyfact-based text retrieving method of the present invention includes keyfact extracting step, keyfact indexing step, and keyfact retrieving step. The keyfact extracting step is to analyze a document collection and a user query, and extracts keywords without part-of-speech ambiguity from the document collection and the user query, and respectively extracts keyfacts of the document collection and the user query from the keywords. The keyfact indexing step is to calculates the frequency of the keyfacts of the document collection and generates a keyfact list of the document collection for a keyfact index structure. The keyfact retrieving step is to receives the keyfact of the user query and the keyfacts of the document collection and defines a keyfact retrieval model in consideration of weigh factors according to the keyfact pattern and generates the retrieval result.
The step of keyfact extracting includes the following steps. The first step is to analyze morphology of an input sentence and obtaining tag sequences of part-of-speech by attaching part-of-speech tags. The second step is to select a tag sequence of part-of-speech out of the tag sequences of part-of-speech. The third step is to extract a keyfact pattern by applying the tag sequence of part-of-speech to a keyfact pattern rule. The fourth step is to apply the keyfact pattern to a keyfact pattern generation rule and generating a keyfact list.
The step of analyzing morphology includes the following steps. The first step is to divide the input sentence into words. The second step is to perform morphological analysis on the words using part-of-speech dictionaries. The third step is to perform morphological variation and recover prototypes. The fourth step is to obtain the tag sequence of part-of-speech by tagging part-of-speech tags in accordance with the result of the morphological analysis.
The part-of-speech dictionaries include a noun dictionary, a verb dictionary, an adjective dictionary, an adverb dictionary, a preposition dictionary, a conjunction dictionary and a stop-word lexicon.
The step of keyfact indexing includes the following steps. The first step is to calculate a frequency of various keyfacts and a document frequency of the keyfact. The second step is to generate a document index table, a document table and a keyfact index table of the document collection. The third step is to form a keyfact index structure including document frequency, document identifier and keyfact frequency.
The step of keyfact retrieving includes the following steps. The first step is to form a document and a user query vector with an index file and a keyfact of the user query. The second step is to determine keyfact weight constants in accordance with the keyfact pattern. The third step is to calculate keyfact weights for the document and the user query by applying the keyfact weight constants to the document and the user query vector. The fourth step is to display the retrieval result by applying the keyfact weights to the keyfact retrieval model. The retrieval result indicates documents with a keyfact similar to the keyfact of the user query.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a keyfact-based text retrieval system of the present invention;
FIG. 2 is a block diagram illustrating a hardware structure of a keyfact-based text retrieval system in accordance with an embodiment of the present invention;
FIG. 3 is a block diagram illustrating a keyfact extraction device of a keyfact-based text retrieval system in accordance with an embodiment of the present invention;
FIG. 4 is a block diagram illustrating a keyfact index device of a keyfact-based text retrieval system in accordance with an embodiment of the present invention;
FIG. 5 is a block diagram illustrating a keyfact retrieval device of a keyfact-based text retrieval system in accordance with an embodiment of the present invention; and
FIG. 6 is a screen image illustrating a document retrieval result in response to a query.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram illustrating a keyfact-based text retrieval system of the present invention. The keyfact-based text retrieval system comprises a keyfact extraction device 11 , a keyfact index device 12 , and a keyfact retrieval device 13 . FIG. 2 is a block diagram illustrating a hardware structure of a keyfact-based text retrieval system in accordance with an embodiment of the present invention.
As shown in FIG. 2, the main memory device 21 includes a keyfact extraction device, a keyfact index device 12 , a keyfact retrieval device 13 , and an index structure 16 . The central processing device 23 supervises the keyfact-based text retrieval. A hard disk 24 stores document collection 25 , dictionaries for keyfact retrieval 26 , and an index file that is the result of the keyfact index. The index file 27 is loaded onto the main memory as an index structure 16 and the keyfact retrieval device 13 uses the index file. The input and output device 22 receives a query from a user and generates retrieval results to the user.
Now, the keyfact-based text retrieval system in accordance with the present invention is explained with reference to FIG. 1 . Once a document collection 14 or a query 15 is given, the keyfact extraction device 11 extracts words without ambiguity by performing morphological analysis and tagging. The keyfact generation rule is applied to the words and then the keyfacts are extracted.
The keyfact index device 12 indexes the document collection 14 or the query with the unit of keyfact and calculates the frequencies of the keyfacts. The frequencies of the keyfacts are stored into the index structure 16 with the document ID information. The keyfact retrieval device 13 orders documents using the similarity calculation method and shows retrieval results. The similarity calculation method considers document collection and keyfact weights with the help of a keyfact-based text retrieval model. In a keyfact-based text retrieval, when a document collection 14 or a query is given, the keyfact extraction device 11 expresses it in the unit of keyfacts. All keyfacts express semantic relation between words in the form of [object, property]. Keyfacts can be categorized by configurations of an object and a property. Parts of text that express the same conceptual meaning in the document collection or the query are categorized into the same keyfact type. The keyfact extraction device will be reviewed in detail below with FIG. 3 .
The keyfact index device 12 indexes the extracted keyfacts with frequency information. In other words, the keyfact index device 12 calculates frequencies of the various forms of keyfacts included in the documents and generates a keyfact list of the document collection. Therefore, an index structure 16 that reflects keyfacts is created and the index file is stored. The keyfact index device 12 will be reviewed in detail below with FIG. 4 .
When the keyfact retrieval device 13 receives a query, it retrieves appropriate documents on the basis of the keyfact-based retrieval method. The keyfact retrieval model is defined by considering weights of keyfact patterns. The similarity between the query and the documents is calculated and appropriate documents for the query are shown as a result in the order of the similarity. The keyfact retrieval device 13 will be reviewed in detail below with FIG. 5 .
As shown in FIG. 3, the keyfact extraction device 11 analyzes a document and generates keyfacts through the processes of morphological analysis, part-of-speech tagging, keyfact pattern extraction, and keyfact generation.
A document is supplied at stage 31 and morphological analysis is performed at stage 32 . A sentence in the document is divided into words and the morphological analysis is performed with dictionaries 36 at stage 32 . The morphological variation is considered in order to recover prototypes. The dictionaries 36 include a noun dictionary, a verb dictionary, an adjective dictionary, an adverb dictionary, a preposition dictionary, a conjunction dictionary, and a stop-word lexicon. In some cases, a part-of-speech of a word is determined by rules without dictionaries.
The part-of-speech tag in dictionaries 36 includes noun (N), verb (V), adjective (A), preposition (P), and stop-word (S). The noun is further divided into proper noun (NQ), name noun (NN), vocative noun (NV), unit nouns (NJ), predicate noun (NU), non-predicate noun (NX), etc. The reason for such division is that the class of noun determines the object or the property of the keyfacts.
For example, in a sequence of words having two or three nouns in a row, it is likely that name noun (NN), proper noun (NQ), and non-predicate noun (NX) are objects and vocative noun (NV), unit noun Id), and predicate noun (NU) are properties. Additionally, in a phrase having proper noun (NQ), name noun (NN), and non-predicate noun (NX), the order of priority of nouns in the object is name noun (NN)>proper noun (NQ)>non-predicate noun (NX).
The preposition is divided into the possessive preposition (PO) which is used as “of” and the positional preposition (PP) and etc. The adjective or the variated verb which makes up the noun is tagged as a pronoun (MP), which is a separate keyfact tag. For example, in analyzing “the fast retrieval of the distributed information” with morphological analysis, a result of the sequence of the tag would be “S (stop-word) A (adjective) NV (vocative noun) PO (possessive preposition) S (stop-word) V-ed (verb) NV (vocative noun). The V-ed (verb) is a modified form of verb and makes up the noun. Like the A (adjective), the V-ed (verb) is converted into a keyfact tag MP and the sequence of nouns is converted into a keyfact tag KEY. The final result would become “NMP KEY PO MP KEY”.
Once the stage 32 of morphological analysis is performed, various results are obtained.
At stage of 33 in which part-of-speech tagging is performed, a precise sequence of tags is chosen among the various results of the morphological analysis. In other words, the part-of-speech tags obtained from the morphological analysis are used at the stage of part-of-speech tagging. The modified form of verb that makes up a noun or an adjective is converted into a modifier (MP) and the sequence of nouns is converted into KEY tag. The exemplary sentence “the fast retrieval of the distributed information” shows the final sequence of tags “MP KEY PO MP KEY”.
Once the final sequence of tags in response to the input sentence is obtained, the stage of keyfact pattern extraction 34 searches the keyfact pattern rule 37 and extracts meaningful keyfact patterns necessary for keyfact generation. The keyfact pattern rule 37 which is used for keyfact pattern extraction describes keyfact patterns as to the sequence of the input tags. A part of the keyfact pattern rule is illustrated at following table 1.
TABLE 1
Keyfact pattern
Keyfact term list
KEY1 PO KEY2
[KEY2, KEY1], [KEY1, NIL],
(the retrieval of information)
[KEY2, NIL],
[KEY2 KEY1, NIL]
[information, retrieval],
[information, NIL],
[retrieval, NIL],
[information retrieval, NIL]
KEY1 PO MP KEY2
[KEY2, KEY1], [KEY1, NIL],
(the retrieval of the
[KEY2, NIL],
distributed information)
[KEY2 KEY1, NIL], [KEY2, MP]
MP KEY1 PO KEY2
[KEY2, KEY1], [KEY1, NIL],
(the fast retrieval of
[KEY2, NIL],
information)
[KEY2 KEY1, NIL], [KEY1, MP]
MP1 KEY1 PO MP2 KEY2
[KEY2, KEY1], [KEY1, NIL],
(the fast retrieval of the
[KEY2, NIL],
distributed information)
[KEY2 KEY1, NIL], [KEY1, MP1],
[KEY2, MP2]
(Note:
The italic is the examples.)
The final sequence of tags “MP KEY PO MP KEY” obtained from “the fast retrieval of the distributed information” is applied to the keyfact pattern rule and the keyfact pattern “MP1 KEY 1 PO MP2 KEY2” is the result.
Keyfact terms that have forms of [object, property] are generated as to the input keyfact pattern at the stage of the keyfact generation 35 by searching the keyfact generation rule 38 . The object is a noun or a compound noun represented by a keyword and the property is a verbal word or a noun that makes up another noun, or a prototype of a verbal word.
The keyfact generation rule includes possible keyfact lists, each of which can be generated in each keyfact pattern. In the example stated above, if the keyfact pattern “MP1 KEY1 JY MP2 KEY2” is applied to the keyfact generation stage, “[KEY 2 , KEY 1 ], [KEY 1 , NIL], [KEY 2 , NIL], [KEY 2 KEY 1 , NIL], [KEY 1 , MP 1 ], [KEY 2 , MP 2 ]” is going to be the outcome. That is, a keyfact list 39 “[information, retrieval], [retrieval, NIL], [information, NIL], [information retrieval, NIL], [retrieval, fast], [information, distributed]” is obtained from the keyfact pattern “the fast retrieval of the distributed information”.
The keyfact index device is now reviewed in detail with FIG. 4 .
The keyfact index device calculates statistical frequencies of keyfacts in a document obtained from the keyfact extraction device 11 and forms the index structure. Therefore, index information is efficiently maintained and processed by the keyfact index device. Each index term of the keyfact index device is an extracted keyfact term representing each document.
For each document, the keyfact frequency (tf) and document frequency of the keyfact (df) are calculated in order to obtain the frequency information of the keyfacts.
Next, supplementary tables such as a document index table, a document table, and a keyfact index table are generated to form an efficient index structure 44 . The document index table contains keyfacts of the document, the frequency information. The document table includes a real document text. The keyfact index table is the main table that includes the document frequency (df) of each keyfact, and pair list of the document identifier of each keyfact and the frequency information within a document (tf).
Next, an index structure is formed in the unit of the keyfact and an index file is stored. Efficient storage structures like the B+ tree can be used for the index structure. The inverted file structure of the keyfact index table is used as posting information file structure.
A part of the result of the keyfact index is shown in the following table 2.
TABLE 2
Document id:
Keyfact index
Df
frequency
[thorn, sharp]
2
(162:1)(197:1)
[thorn, dull]
3
(102:2)(188:3)(193:1)
. . .
[reed, NIL]
2
(6:2)(29:1)
[reed field, NIL]
1
(6:1)
[branch, NIL]
4
(21:1)(33:2)(88:1)(90:3)
[Dahurian buckhorn
1
(102:1)
family, NIL]
At table 2, in case of [branch, NIL], “branch” appears at 4 documents and therefore the document frequency (df) for keyfact index [branch, NIL] is four. In addition, “branch” appears once in document 21 , twice in document 33 , once in document 88 , and three times in document 90 .
The keyfact retrieval device 13 is now reviewed in detail with FIG. 5 . The keyfact retrieval device forms the document vector and query vector with the keyfact, which is supplied from the keyfact extraction device 53 , and the index file 52 generated by the keyfact index device 51 .
The keyfact weight constants (C KfType# ), which are fit for the attribute of a document collection, are determined 55 before calculating the keyfact weights from document and query vector. Table 3 shows that keyfact weight constants are assigned to various patterns of keyfacts.
TABLE 3
Types
Keyfact pattern
Weight constants
Type 1
[KEY, NIL]
C KfTypeI
Type 2
[KEY, MP] or
C KfTypeII
[KEY, VH/VB]
Type 3
[KEY1, KEY2]
C KfTypeIII
Type 4
[KEY1 KEY2, NIL] or
C KfTypeIV
[KEY2 KEY 1, NIL]
Type 5
[KEY1 KEY2 KEY3]
C KfTypeV
. . .
. . .
. . .
The keyfact weight constants are assigned with the sequence like C KfTypeI <C KfTypeII <C KfTypeIII <C KfTypeIV <C KfTypeV < . . . and do important role for the precision of keyfact-based text retrieval. Therefore, weight constants are determined experimentally on the basis of distribution of keyfact pattern of document collection.
The keyfact weight constant is applied to the following equation 1 and the result of equation 1, a keyfact weight (W xk ), is used in the keyfact-based text retrieval model. w xk = tf xk · log ( N + 1 df k ) · C KfType # [ Equation 1 ]
W xk : a keyfact weight
tf xk : frequency of a keyfact
N: size of a document
df k : document frequency of a keyfact
C kfType# : a keyfact weight constant
Conventionally, only the frequency of keywords (tf keyword ), the document frequency of keywords (df keyword ), and the number of the documents in a document collection are considered in calculating the keyword weight in the keyword-based text retrieval system. However, the keyfact weight constant (C kfType# ) of the keyfact pattern is also reflected in calculating keyfact weights in the keyfact-based retrieval system, so as to make it possible to index and retrieve in the unit of a keyfact.
Next, the similarity of the document appropriate for the query is calculated by employing the keyfact retrieval model based upon the vector space model. The result of the similarity calculation determines the order of appropriate documents 57 .
FIG. 6 shows a screen image for illustrating a document retrieval result in response to a query. A user makes a query in query section 61 with natural language. The keyfact is extracted by the keyfact-based text retrieval system and the documents close to the query are found. The result of the retrieval of the query is displayed at the document retrieval result screen 62 in the order of similarity. Document title and weight are also displayed with the order of similarity. In addition, if the document displayed is selected, document text screen 63 shows the contents of text of the document.
According to the present invention, texts of document collection and user queries are expressed, indexed and retrieved by concept-based keyfacts. Therefore, more precise retrieval results are achievable. Additionally, since indexing and retrieval with high precision are possible, time and efforts can be minimized, the keyfact-based retrieval method in accordance with the present invention can be used in various applications. Especially, digital library, text and annotation based multimedia information retrieval of broadcasting station, internet application, information retrieval of electronics commercial trading, and education/medical/military application areas can take advantage of the present invention.
Although representative embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as recited in the accompanying claims. | A keyfact-based text retrieval method and a keyfact-based text index method that describes the formalized concept of a document by a pair comprising an object that is the head and a property that is the modifier and uses the information described by the pairs as index information for efficient document retrieval. A keyfact-based text retrieval system includes keyfact extracting, keyfact indexing, and keyfact retrieving. The keyfact extracting analyzes a document collection and a query and extracts keywords and keyfacts. The keywords do not have part-of-speech ambiguity and the keyfacts are extracted from the keywords. The keyfact indexing calculates the frequency of the keyfacts and generates a keyfact list of the document collection for a keyfact index structure. The keyfact retrieving receive a keyfact of the query and keyfacts of the document collection and defines a keyfact-based retrieval model in consideration of a weight factor of the keyfact pattern and generates a retrieval result. The retrieval result is a document similar to the query. |
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates in general to electron-beam lithography techniques for producing semiconductor devices and the like, and in particular to a new and useful method of forming a pattern in an insulator layer for a semiconductor structure utilizing an electron-beam (e-beam) sensitive polyimide which becomes soluble when exposed to the e-beam.
In the fabrication of multi-level metal-insulator integrated circuit structures, a polyimide as KAPTON (a trademark of DuPont) has proven to be a good insulator when applied between metalization layers in integrated circuit structures. This is because of the high thermal stability, chemical resistance and dielectric properties of KAPTON polyimide. KAPTON polyimide has the following formula: ##STR2##
An intermediate polyamic acid which is subjected to heat to form the KAPTON polyimide, is itself soluble and can be spun into films which can be cured into the insoluble polyimide structures. Once the material is cured, it is generally insoluble and infusible and is extremely thermally stable. The insolubility and the infusibility of the KAPTON polyimide requires that patterning of the polyimide layers be accomplished indirectly by photoresist technology. This process entails the spinning and curing of the polyimide layer, formation of a polysulfone lift-off layer and deposition of an SiO 2 masking layer followed by a top layer of resist coating.
The pattern is defined by either electron beam or optical lithography and the underlined layers are etched with reactive ion etching. Metal is deposited onto the pattern and the polysulfone and excess are lifted off with a solvent.
If the polyimide layer itself could be made intrinsically photosensitive, the formation of a pattern in the polyimide layer would be greatly simplified. Several photonegative polyimide systems have been developed which utilize photosensitive polyimides. These are generally made by the reaction of the corresponding polyamic acid with a photosensitive group. In the most common case, the intermediate polyamic acid is partially esterified with photo-crosslinkable acids. Irradiation of these esters causes them to become insoluble and enables them to be used to form negative images upon treatment with solvent. After imaging, the films are thermally converted to the polyimide which itself is not sensitive to light.
A positive working system would be more desirable because of the swelling attendant upon solvent development of negative images. A photopositive polyimide containing photosensitive sulfonium salt units has been described in a article by Crivello et al entitled "Synthesis and Characterization of Photosensitive Polyimides", Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 25, 3293-3309 (1987).
It would also be advantageous if a positive working system could be derived which, rather than being photosensitive, was sensitive to an electron-beam. Electron-beam lithography has certain advantages and differences from photolithography that makes it particularly useful for certain purposes.
A polyimide resin which has good transparency and is useful to produce molded products with substantially no coloring and good thermal resistance, is disclosed in European patent application 0 130 481 to Noriaki et al. This reference does not consider or discuss the possibility of photo or electron-sensitivity for the polyimide product.
SUMMARY OF THE INVENTION
The present invention involves a process for making and using an intrinsically electron-beam positive polyimide so that direct, positive e-beam lithography can be accomplished even after a complete thermal curing which forms the polyimide structure has taken place.
The process for preparing the e-beam positive polyimide comprises irradiating maleic anhydride (MA) solution with ultraviolet light. See "Photodimerization of Maleic Anhydride in Carbon Tetrachloride", Boule et al., Tetrahedron Letters, No. 11, pp. 865-868 (1976). This excites the anhydride molecule to dimerize and form a cyclobutane unit. Because the olefin is consumed in the dimerization process, ultraviolet absorption of the cyclobutane unit shifts to a shorter wavelength. Once the anhydride is formed, it can be used to form a polyimide which can be imaged by irradiation with an electron beam.
The cyclobutane unit is reacted with an aromatic diamine, such as oxydianiline (ODA) to form a polyamic acid which can thereafter be heat cured to produce the corresponding electron-beam positive polyimide which is insoluble.
The invention also includes a method of forming a patterned insulator layer useful for example in a semiconductor structure, which comprises forming a layer of the intrinsically e-beam positive insoluble polyimide, irradiating the layer with an electron-beam pattern to produce exposed and unexposed areas in the layer, the exposed areas becoming soluble, and applying a solvent to the layer to remove the soluble exposed areas to form the patterned insulator layer.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a differential scanning calorimogram of the polyamic acid and its conversion into the e-beam sensitive polyimide of the present invention;
FIG. 2 is a graph plotting weight loss against temperature of the polyamic acid to show its thermogravimetric behavior as it is converted by curing into the e-beam polyimide structure; and
FIG. 3 is a schematic view of an electron-beam lithography device for scanning and irradiating a layer of the polyimide; and
DESCRIPTION OF THE PREFERRED EMBODIMENT
The electron-beam positive-acting polyimide in accordance with the present invention is prepared by irradiating a solution of maleic anhydride (I) in carbon tetrachloride with light at a maximum wavelength of 280 nm from a high power mercury arc lamp for one hour. This forms 1, 2, 3, 4-cyclobutane tetracarboxylic 1,2:3,4-dianhydride (CBDA) shown at II in the Equation 1. ##STR3##
CBDA is precipitates from solution and is collected by filtration. CBDA (maximum wavelength of absorption 232 nm) is then purified by successive recrystaliztion from acetic anhydride (until the filtrate is colorless) to yield a white solid. ##STR4##
To form the polyamic acid shown at IV in Equation 2, 0.62714 g (3.1977 mmoles) of CBDA (II) is added to 60 ml of dry DMAC (dimethylacetamide) and 0.64031 g (3.1977 mmoles) of oxydianiline (Aldrich Gold Label, III) are mixed together and reacted in a 3-necked, 100 ml round-bottomed flask fitted with a mechanical stirrer, a nitrogen inlet and a condenser. The reaction was allowed to proceed at room temperature under dry nitrogen for 18.5 hours. The resulting polyamic acid (IV) was precipitated twice into methanol and dried in vacuo at room temperature for 24 hours.
The intrinsic viscosity of the resulting polyamic acid was 1.47 dl/g measured with an Ubbelohde viscometer at 25.00° C. in DMAC.
The polyamic acid is cured to the polyimide (V), as shown in Equation 2, by heating films or layers cast by solvent evaporation in a watch glass, in an oven for two hours at 100° C., two hours at 175° C. and two hours at 250° C.
The resulting uniform polyimide film (V) is colorless.
A thin 0.2 micron thick film of polyimide (V) was formed and exposed to an electron beam of 25 KeV electrons using an electron beam lithography tool. This results in the scission which breaks the polyimide chain as shown at VI in Equation 2. While the polyimide (V) is insoluble in polar, aprotic solvents, such as DMAC and DMF (dimethyl formamide) the exposed compound VI is readily soluble therein. Irradiation doses were from 200 to 500 micro-coulombs/cm 2 followed by development with DMAC to form a positive image.
The electron-beam positive polyimide of the present invention is, to the knowledge of the inventors, the first electron-beam positive polyimide. It has utility as a high temperature resist material (about 350° C.) for an electron-beam imagaeble dielectric material. Both applications are useful in the fabrication of electronic devices or packages.
FIG. 1 shows a differential scanning calorimogram, under nitrogen, of the polyamic acid. From this scan, it is apparent that conversion of polyamic acid to polyimide takes place in the range of 150° C. to 250° C. Subsequent rescanning of the sample showed no transitions in this range.
FIG. 2 shows the thermogravimetric behavior, under nitrogen, of the polyamic acid. The weight loss corresponding to the curing of the polyamic acid into the insoluble polyimide structure, can be seen. Once the polyimide is formed, 50% weight loss occurs at about 460° C. and after heating the sample to 1200° C. there is a residual weight of approximately 35%. Thus, despite the incorporation of an aliphatic repeat unit in the chain, the thermal stability of the polyimide is quite high.
According to the present invention thus a readily synthesized polyimide is provided which has utility for image generation or the like.
The polyimide V can also be produced by reacting ODA and CBDA in other solvents such as DMF, to yield polyamic acid that is cured to the polyimide.
FIG. 3 is a schematic representation of an electronic beam lithography tool which can be used in the method of the present invention.
The device of FIG. 3 can produce an integrated circuit pattern on a silicon chip with sub-micron edge definition (resolution). The pattern actually consists of sub-patterns "written" on top of each other with sub-micron overlay accuracy.
To accomplish this, the device comprises an electron source which produces an electron beam 10 which is focused onto small rectangular spots of specified features on a substrate 20 at the bottom of the column. These spots can be controlled in shape, position and intensity with high speed and accuracy. The beam then exposes the substrate which is coated with the polyimide of the present invention that has been shown to be electron beam sensitive.
The shape of the exposure spots is formed by passing the electron beam 10 through a first square aperture 12. The beam is then focused by condensor lens 14 into a spot shaping deflector 16 made of electrically chargeable panels. This produces a first image of the electron source which is shown onto a second square aperture member 18. This produces shaped beam 22 which exposes the surface of substrate 20. Square spots having two to four micro-meter maximum size can thus be generated on the surface of substrate 20. Some of the spots are blank, that is, blocked from any exposure to the electron beam to form unexposed areas.
The exposed areas of the polyimide layer on substrate 20 are rendered soluble so that they can be removed using a solvent to fabricate a pattern on the substrate 20.
While a specific embodiment of the invention has been showed and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | An insoluble electron beam positive polyimide having the formula ##STR1## can be exposed by an electron beam to render the exposed areas soluble. The exposed areas can then be dissolved using a solvent to leave the pattern which can be used directly as an insulator layer in a semiconductor device. |
BACKGROUND OF THE INVENTION
This invention relates generally to gas turbine engines, and more particularly, to methods and apparatus for assembling gas turbine engine compressors.
At least some known gas turbine engines include, in serial flow arrangement, a compressor, a combustor, a high pressure turbine, and a low pressure turbine. The compressor, combustor and high pressure turbine are sometimes collectively referred to as the core engine. Compressed air is channeled from the compressor to the combustor where it is mixed with fuel and ignited. The combustion gasses are channeled to the turbines which extract energy from the combustion gasses to power the compressors and to produce useful work to propel an aircraft in flight or to power a load, such as an electrical generator.
Known compressors include a rotor assembly and a stator assembly. Known rotor assemblies include a plurality of rows of circumferentially-spaced rotor blades that extend radially outward from a shaft or disk. Known stator assemblies may include a plurality of stator vanes which extend circumferentially between adjacent rows of rotor blades to form a nozzle for directing air passing therethrough towards downstream rotor blades. More specifically, known stator vanes extend radially inward from a compressor casing between adjacent rows of rotor blades.
In at least some compressors, each stator vane is unitarily formed with an airfoil and platform that are mounted through an integrally-formed dovetail to the compressor casing. To facilitate assembly of the stator vanes to the casing, a small amount of clearance is permitted between a casing dovetail or vane rail and the vane platform. However, the clearance enables a small degree of relative motion between the vane platform and the casing vane rail. Over time, continued movement between the stator vanes and the casing rail may cause vane platform and/or casing wear. Such relative movement of the stator vanes may be enhanced by vibrations generated during engine operation.
To facilitate reducing wear between the casing and vane platform, at least some stator assemblies are coated with wear coatings or lubricants. Other known compressors use casing rail liners, and/or vane springs to facilitate reducing such wear. However, known wear coatings may not be useful in some single vane applications, and known vane springs may not be suitable for use with vanes that include air bleed holes. Moreover, known rail liners are only useful in a limited number of engine designs.
BRIEF DESCRIPTION OF THE INVENTION
In one aspect, a method for assembling a gas turbine engine compressor is provided. The method includes providing a compressor casing including at least one stator vane casing rail extending from the casing, coupling a rail liner to the casing rail, and coupling a stator vane assembly including at least two stator vanes coupled together to the casing rail within the liner.
In another aspect, a stator vane assembly for a gas turbine engine is provided that includes a plurality of circumferentially-spaced stator vane doublets. Each doublet includes a pair of stator vanes coupled together at a respective outer stator vane platform of each vane. Each stator vane platform is configured to slidably couple each doublet to a vane rail extending from a compressor casing that extends at least partially circumferentially around the stator vane assembly.
In another aspect, a compressor for a gas turbine engine is provided. The compressor includes a casing including a plurality of stator vane rails. The casing defines an axial flow path for the compressor. A rotor is positioned within the flow path. The rotor includes a plurality of rows of circumferentially-spaced rotor blades. A stator vane assembly extends between adjacent rows of the plurality of rows of rotor blades. Each stator vane assembly includes a plurality of circumferentially-spaced stator vane doublets received within the vane rail. Each stator vane doublet includes a pair of stator vanes coupled together at a respective outer stator vane platform of each vane.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a gas turbine engine;
FIG. 2 is a cross sectional view of a compressor suitable for use with the engine shown in FIG. 1 ;
FIG. 3 is a perspective view of an exemplary stator vane doublet suitable for use in the compressor shown in FIG. 2 ; and
FIG. 4 is a cross sectional view of the stator vane doublet shown in FIG. 3 mounted in a compressor casing.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic illustration of a gas turbine engine 10 including a low pressure compressor 12 , a high pressure compressor 14 , and a combustor 16 that defines a combustion chamber (not shown). Engine 10 also includes a high pressure turbine 18 , and a low pressure turbine 20 . Compressor 12 and turbine 20 are coupled by a first rotor shaft 24 , and compressor 14 and turbine 18 are coupled by a second rotor shaft 26 . In one embodiment, engine 10 is a CF6 engine available from General Electric Aircraft Engines, Cincinnati, Ohio.
In operation, air flows through low pressure compressor 12 and compressed air is supplied from low pressure compressor 12 to high pressure compressor 14 . The highly compressed air is delivered to combustor 16 . Airflow from combustor 16 drives rotating turbines 18 and 20 .
FIG. 2 is a cross-sectional illustration of a portion of a compressor 30 that may be used with gas turbine engine 10 . FIG. 3 illustrates an exemplary stator vane doublet 80 . In an exemplary embodiment, compressor 30 is a high pressure compressor. Compressor 30 includes a rotor assembly 32 and a stator assembly 34 that are positioned within a casing 36 that defines a flowpath 38 . The rotor assembly 32 defines an inner flowpath boundary 40 of the flowpath 38 . Stator assembly 34 defines an outer flowpath boundary 42 of flowpath 38 . Compressor 30 includes a plurality of stages with each stage including a row of circumferentially-spaced rotor blades 50 and a row of stator vane assemblies 52 . In an exemplary embodiment, rotor blades 50 are coupled to a rotor disk 54 . Specifically, each rotor blade 50 extends radially outwardly from rotor disk 54 and includes an airfoil 56 that extends radially from an inner blade platform 58 to a blade tip 60 .
Stator assembly 34 includes a plurality of rows of stator vane assemblies 52 with each row of vane assemblies 52 positioned between adjacent rows of rotor blades 50 . The compressor stages are configured for cooperating with a motive or working fluid, such as air, such that the motive fluid is compressed in succeeding stages. Each row of vane assemblies 52 includes a plurality of circumferentially-spaced stator vanes 66 that each extends radially inward from casing 36 and includes an airfoil 68 that extends from an outer vane platform 70 to a vane tip 72 . Airfoil 68 includes a leading edge 73 and a trailing edge 74 . In an exemplary embodiment, stator vanes 66 have no inner platform. Compressor 30 includes one stator vane row per stage, some of which are bleed stages 76 .
At bleed stages 76 , vane assembly 52 includes a plurality of circumferentially-spaced stator vane doublets 80 . As shown in FIG. 3 , stator vane doublet 80 includes a pair of stator vanes 66 joined at abutting edges 82 of their respective outer stator vane platforms 70 to form a vane segment. The joined platforms 70 are configured to be received in a vane rail 88 formed in compressor casing 36 as will be described. The stator vane doublet 80 includes two airfoils 68 joined together through a brazing process and has a circumferential width W. In an exemplary embodiment, stator vanes 66 are joined by a gold-nickel braze material. Each stator vane platform 70 includes an inwardly facing surface 84 that defines a portion of outer flowpath boundary 42 in compressor 30 . At bleed stage 76 , stator vane doublet 80 includes a bleed hole 86 formed in the joined vane platforms 70 between airfoils 68 . Bleed holes 86 bleed off a portion of the motive fluid for use in cooling one or more stages of HP turbine 18 .
FIG. 4 illustrates a cross sectional view of stator vane doublet 80 mounted within casing 36 . Casing 36 includes casing vane rails 88 that each includes a vane platform engagement surface 90 . Stator vane platform 70 includes dovetails 92 that are received in casing vane rails 88 . In an exemplary embodiment, a vane rail liner 94 is mounted within casing vane rails 88 and stator vane doublets 80 are received within vane rail liner 94 . Vane rail liner 94 provides a sacrificial wear surface between casing vane rails 88 and stator vane platform dovetails 92 .
In operation, stator vane doublet 80 provides a vane segment that has a circumferential width W that is sufficiently large to substantially reduce a range of relative movement between stator vane platforms 70 of stator vanes 66 and casing vane rails 88 . The reduced allowable movement reduces an amount of wear experienced between casing vane rails 88 and stator vane platforms 70 . In an exemplary embodiment, vane rail liner 94 and stator vane doublet 80 cooperate to further reduce the range of relative movement between stator vane doublet 80 and casing vane rail 88 . Vibration from the coupled stator vane airfoils 68 partially cancel each other so that with stator vane doublet 80 , vibration transmitted to joined platforms 70 is reduced.
Stator vanes 66 are joined to form vane doublets 80 . In forming vane doublets 80 , at least a portion of abutting edges 82 of stator vane platforms 70 of stator vanes 66 is first nickel-plated. The stator vanes 66 are then mounted in a precision tack welding fixture (not shown) that has a curvature substantially corresponding to a curvature of casing vane rail 88 and tack welded. The tack welded stator vanes 66 are then placed in a carbon member (not shown) to hold the desired shape during the braze furnace cycle. The tack welded stator vanes 66 are then brazed along outer vane platforms 70 using a gold-nickel braze alloy to form stator vane doublet 80 . The gold-nickel braze provides ductility and temperature stability in the braze joint necessary for durability of the joint during engine operation. After brazing, the stator vane doublet 80 is re-aged in the carbon member to restore metallurgical properties.
Assembly of vane doublet 80 into compressor casing 36 is accomplished by mounting a casing vane rail liner 94 on casing vane rail 88 and mounting vane doublet 80 within vane rail liner 94 . The extended platform length of vane doublet 80 together with casing vane rail liner 88 take up excess clearance in casing vane rail 88 which facilitates reducing a vibration response of vane doublet 80 with respect to individual vanes 66 .
The above described compressor assembly provides a cost effective and reliable means for reducing stator vane platform to casing vane rail wear. More specifically, the compressor assembly employs stator vane doublets at the compressor bleed stages. The stator vane doublets provide vane segment that have a circumferential width that is sufficiently large to substantially reduce the amount of allowable movement between stator vane platforms and the casing vane rails. The reduced allowable movement reduces the amount of wear experienced between the casing vane rails and the stator vane platforms. A vane rail liner further reduces movement between the stator vane doublet and casing vane rail and provides a sacrificial surface which can be easily replaced. Vibration from the coupled stator vane airfoils also partially cancels each other so that with the stator vane doublet, vibration transmitted to the joined platforms is reduced.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims. | A gas turbine engine compressor including a stator assembly and a method of assembling the same are provided. The method includes providing a compressor casing including at least two stator vane casing rails extending from the casing, coupling a rail liner within each respective casing rail, and coupling a stator vane assembly including two dovetails, and at least two stator vanes coupled together within the casing rails within the liner such that a first dovetail is received within a first casing rail and a first rail liner, and a second dovetail is received within a second casing rail and a second rail liner. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a dense substrate for a solid oxide fuel cell (which will hereinafter be referred to as SOFC) in which an electrochemical reaction is carried out to take out electric energy, a solid oxide fuel cell using the same substrate, and a method of manufacturing the same solid oxide fuel cell.
2. Description of the Prior Art
There are known SOFC's which include a tubular SOFC (Japanese Patent Laid-Open No. 73246/1979) formed by providing a plurality of single cells, each of which consists of a fuel electrode, electrolyte and an air electrode, on the outer surface of an elongated cylindrical porous support tube, and connecting the single cells in series, and a monolithic SOFC (Japanese Patent Laid-Open No. 100376/1985) formed by sandwiching a flat cell section, which consists of three layers of a fuel electrode, an electrolyte and an air electrode, between corrugated mutual-connection walls each of which consists of three layers of an air electrode, an interconnection and a fuel electrode.
Regarding the practical use of SOFC's a tubular SOFC can be manufactured comparatively easily but a support tube cannot be made extremely thin in view of the structure thereof. Therefore, this type of SOFC does not have as high of an output performance per volume. A monolithic SOFC has a high output performance per volume but involves very difficult manufacturing problems in the production of a cell, a gas sealing, assembling, etc. The inventors of the present invention then filed a patent application, i.e. Japanese Patent Application No. 106610/1990, which has been laid-open to public inspection under Laid-Open No. 6752/1992, for the solid oxide fuel cell disclosed therein, so as to solve these problems. According to this invention, the portion of a dense substrate to which a cell section is to be fixed is subjected to a mechanical boring process. Carrying out this process is difficult, and presents a problem concerning the dimensional accuracy thereof.
Moreover, in a conventional method of this kind, a plurality of cell sections are manufactured simultaneously or assembled unitarily at a time. Consequently, when a failure occurs in one cell section, there is the possibility that the whole assembly cell stacks or cell sections become unusable.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a highly reliable SOFC which permits the formation of cell mount portions of a dense substrate without carrying out a boring process therein, and therefore is capable of being manufactured easily and at a reduced cost, a method of manufacturing the same SOFC, and a dense substrate for the same SOFC.
In order to solve the above problems, the inventors of the present invention have earnestly studied the construction of a dense substrate to obtain the knowledge that it is effective to provide grooves in a dense substrate and arrange cells, which have been produced in advance, in these grooves, and come to achieve the present invention.
The present invention is as follows:
(1) A dense substrate for a solid oxide fuel cell, comprising: a base portion, support portions and fixing portions, all of which project from the base portion so as to be arranged sequentially in one direction; grooves formed between the support portions and the fixing portions and between the support portions; and mount portions which are provided on the support portions between the fixing portions for mounting and affixing at least cell sections thereon.
(2) A solid oxide fuel cell having a plurality of cell sections and, if required, a plurality of plate sections, on the mount portions of the dense substrate defined in (1) above, the cell sections and the mount portions being joined together by an insulating bonding agent, adjacent cell sections being joined together by interconnections.
(3) A method of manufacturing a solid oxide fuel cell, comprising the steps of:
arranging a plurality of cell sections and, if required, plate sections, on the mount portions of the dense substrate defined in (1) above;
fixing the cell sections and, when used, plate sections, onto the mount portions with an insulating bonding agent; and
joining adjacent cell sections together with interconnections.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view showing the dense substrate according to the present invention and the relation of arrangement between cell sections and plate section mounted thereon.
FIG. 2 is a plan view showing the outline of Example 1 of the SOFC according to the present invention.
FIG. 3 is a cross-sectional view of the SOFC taken along the line Y--Y of FIG. 2.
FIG. 4 is a cross-sectional view of the SOFC taken along the line X--X of FIG. 2.
FIG. 5 is a plan view showing the outline of Example 2 of the SOFC.
FIG. 6 is a cross-sectional view of the SOFC taken along the line Y--Y of FIG. 5.
FIG. 7 is a cross-sectional view of the SOFC taken along the line X--X of FIG. 5.
FIG. 8 is a perspective view of a cell section using a porous air electrode base.
FIG. 9 is a perspective view of a cell section using a porous fuel electrode base.
FIG. 10 is a perspective view of a cell section formed by laminating an air electrode, an electrolyte and a fuel electrode in the mentioned order on a porous support base.
FIG. 11 is a perspective view of a cell section formed by laminating a fuel electrode, an electrolyte and an air electrode in the mentioned order on a porous support base.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An example of a dense substrate 1 for a solid oxide fuel cell according to the present invention is shown in FIG. 1. Referring to FIG. 1, a reference numeral 2 denotes a base portion, 3 fixing portions, 4 support portions, 5 grooves and 6 mount portions provided between the fixing portions and on the support portions. As is clearly noted from FIG. 1, in the solid oxide fuel cell according to the present invention, a plurality of cell sections 7 are mounted on and fixed to the mount portions 6 on the support portions 4 projecting from the base portion 2 of the dense substrate 1, and the fixing portions 3 also projecting from the base portion 2. A dense plate section 8 is provided as necessary on an end portion of the dense substrate 1 or between the cell sections 7. The cell sections and plate sections are affixed to the dense substrate 1 by an insulating bonding agent. Consequently, hollow portions 15 are formed, which are defined by the grooves 5, cell sections 7 and plate sections 8, in the dense substrate 1.
A first type of cell section produced in advance so as to be used in the present invention is formed, as shown in FIGS. 8 and 9, by laminating on a porous base of an electrode material, which consists of either a porous air electrode base 11 or a porous fuel electrode base 16, an electrolyte film 12 and then another electrode film, i.e. a fuel electrode film 13 or an air electrode film 17. A second type of cell section is formed, as shown in FIGS. 10 and 11, by laminating an air electrode film 17 (or a fuel electrode film 13), an electrolyte film 12 and a fuel electrode film 13 (or an air electrode film 17) in the mentioned order on a porous base 18 which constitutes a support body.
In the above example, the hollow dense substrate 1 consists preferably of a ceramic material, an electrically insulating material, and, for example, alumina, magnesia or a mixture thereof are suitably used.
The electrolyte film 12 consists suitably of yttria-stabilized zirconia (which will hereinafter be referred to as YSZ). The porous electrode base and electrode film consisting of an air electrode film are suitably composed of alkaline earth metal-added LaMnO 3 and LaCoO 3 , and the porous electrode base and electrode film consisting of a fuel electrode film Ni-zirconia cermet.
The porous base 18, which is to constitute a support body, consists preferably of a porous ceramic material. For example, alumina, magnesia, a mixture thereof and stabilized zirconia are suitably used, and it is more desirable that electronic conductivity be provided to the porous base if possible.
The cell sections 7 produced in advance are placed on the mount portions 6 between the fixing portions 3, 3 of the dense substrate 1 by preferably fitting the former on the latter, and then affixed, and the electrodes of adjacent cell sections are connected in series and in parallel by interconnections. When the dense substrate and cell sections and the adjacent cell sections are joined together with an insulating bonding agent to form interconnections, an SOFC having excellent gas sealability can be obtained.
When a gas sealing film 14 is formed in the fitted portion and an interconnection thereafter is formed, or, when a cell section is affixed to an insulating bonding agent and, then, a gas sealing film and an interconnection are formed in that order, an SOFC having a higher gas sealability can be obtained.
The interconnection referred to above consists suitably of a material having electronic conductivity and which is stable in an oxidation-reduction atmosphere, for example, a perovskite oxide obtained by adding an alkaline earth metal to LaCrO 3 .
The bonding agent consists preferably of a material which is stable in an oxidation-reduction atmosphere, has insulating characteristics and is capable of being densified, such as a ceramic material including alumina, silica and zirconia, and the gas sealing film an electrically insulating material, such as alumina.
Out of the structural elements of the SOFC, the hollow dense substrate is formed by extrusion, and the porous electrode base and porous support base by a doctor blade method and a powder pressing method.
The electrode film, electrolyte film, interconnection and gas sealing film are formed by film forming techniques including dry type methods, such as plasma spray, gas flame spray, CVD and PVD, and wet type methods, such as a screen printing method and a dipping method.
An SOFC according to the present invention in which the porous electrode base for cell sections consists of an air electrode will now be described. When oxygen is supplied to the hollow portions of the dense substrate while supplying hydrogen to the outer portion of the dense substrate, which is on the side of the fuel electrode, with the SOFC maintained at about 1000° C., an electrochemical reaction occurs to generate electric energy.
According to the present invention, the following effects can be obtained.
(1) Since the cell sections are produced in advance, an imperfect cell section can be rejected, and perfect cell sections only can be set on the dense substrate. Therefore, the yield and reliability of the SOFC are improved.
(2) Since cell sections produced in advance are set on a dense substrate, the dense substrate does not receive the influence of the processing heat used during the formation of electrode films and electrolyte films, unlike the case where cell sections are formed by a vapor deposition method or a spray method on a dense substrate, so the reliability of the SOFC is improved.
(3) Since the cell section has a simple construction and can be mass-produced simply and mounted on a dense substrate easily, the manufacturing cost decreases.
(4) The fixing portions, support portions, mount portions and grooves which are used to set and fix cell sections can be formed integrally when a dense substrate is extruded. Therefore, the manufacturing steps are simplified. Further, unlike a conventional SOFC, the SOFC according to the present invention does not require a process for boring a substrate. This also enables the manufacturing cost to decrease.
EXAMPLE 1
A first embodiment of the present invention will now be described with reference to the drawings.
FIG. 2 is a plan view showing the outline of an SOFC as a whole, and FIGS. 3 and 4 are sectional views taken along the lines Y--Y and X--X, respectively.
The dense substrate 1 was formed from a raw material, i.e. alumina, by extrusion, and then fired at 1400°-1700° C. A method of manufacturing the cell section 7 will now be described. First, a green film was formed from La 0 .8 Sr 0 .2 MnO 3 by a doctor blade method, and the film was then cut into pieces with a cutter. The cut pieces were fired at 1200°-1500° C. to obtain porous air electrode bases 11. The porous air electrode base 11 was then masked to form a current takeout portion, and yttria stabilized zirconia was then sprayed onto the base 11 by a plasma spray method to form an electrolyte film 12. Finally, the upper surface of the electrolyte film 12 was masked, and NiO-YSZ was then sprayed onto the electrolyte film 12 by a gas flame spray method to form a fuel electrode film 13 and complete the production of a cell section 7.
A plurality of cell sections 7 thus produced were affixed to the fixing portions 3 and mount portions 6 of the dense substrate 1 by an alumina bonding agent 9. If necessary, dense plate sections 8 were then affixed to the portions of the dense substrate 1, which were adjacent to the cell sections 7, by an insulating bonding agent. In this embodiment, 25 cell sections were affixed to one surface of the dense substrate 1, which were then masked, and LaMgCrO 3 was thereafter sprayed onto the dense substrate 1 by a plasma spray method or a gas flame spray method to form interconnections 10, the cell sections 7 being connected in series and in parallel. After the cell sections have been affixed to one surface of the dense substrate 1, the other surface was subjected to the same operations to produce an SOFC.
EXAMPLE 2
A second embodiment will now be described with reference to FIGS. 5, 6 and 7.
FIG. 5 is a plan view showing the outline of an SOFC as a whole, and FIGS. 6 and 7 are sectional views taken along the lines Y--Y and X--X, respectively. The gas sealing films 14 shown in the drawings were formed by spraying alumina by a plasma spray method after the cell sections 7 had been affixed to the dense substrate 1 and before the interconnections 10 had been formed. The other materials used and the manufacturing method employed were the same as those in Example 1.
An electric current can be generated by supplying oxygen to the hollow portions 15 defined by the dense substrate 1, cell sections 7 and dense plate section 8, and hydrogen to the fuel cell side portion of the completed SOFC, with the SOFC maintained at about 1000° C.
The shapes of the dense substrate 1, cell sections 7, dense plate section 8 and masking films are not limited to those of the parts in the above-described embodiments; they may be formed in other shapes. The effect of an SOFC which uses a porous support base for the cell sections 7, owing to the above-described manufacturing method, and that of an SOFC provided with fuel electrodes on the side of the hollow portions 15 thereof, owing to the same method, are identical to each other.
As described in detail above, the portions of a conventional dense substrate to which cell sections are to be affixed are subjected to a boring process (mechanical process), so that a conventional dense substrate has processing difficulty and problems concerning the dimensional accuracy thereof. On the other hand, the dense substrate according to the present invention can be manufactured easily and in a high yield by, for example, extrusion (molding), and enables the reduction of the manufacturing cost. Since this dense substrate consisting of a fragile material does not require a boring process, it has a high dimensional accuracy. In the solid oxide fuel cell, cell sections produced in advance are set on a dense substrate, and interconnections or gas sealing films and interconnections are then formed. Therefore, imperfect cell sections can be rejected before an SOFC has been assembled, and the dense substrate receives little influence of processing heat. This enables the yield and reliability of the SOFC to be improved. Moreover, according to the manufacturing method of the present invention, the production of solid oxide fuel cell can be carried out with a high efficiency, and this method is suitable for the mass production of the same products and enables the yield thereof to be improved. | A dense substrate for a solid oxide fuel cell, comprising: a base portion, support portions and fixing portions all of which project from the base portion so as to be arranged sequentially in one direction; grooves formed between the support portions and the fixing portions or between the support portions; and mount portions which are provided on the support portions between the fixing portions for mounting and fixing at least cell sections thereon. A solid oxide fuel cell is easily manufactured at a reduced cost by arranging a plurality of cell sections and, if required, plate sections, on the mount portions of the above dense substrate; fixing the cell sections and, when used, plate sections, onto the mount portions with an insulating bonding agent; and joining adjacent cell sections together with interconnections. |
FIELD OF THE INVENTION
The present invention relates to polymeric materials containing a decorative item, the polymeric material is also capable of releasing a fragrance. In a preferred embodiment of the invention the decorative item and the fragrance which is emitted from the polymeric material are related.
BACKGROUND OF THE INVENTION
The release of fragrance to mask malodor or to provide a pleasant surrounding is desirable in various applications. Room deodorizers can be applied by aerosol means, but suffer from the deficiency of needing repeated applications. Consequently, solid room deodorizers have been developed, but unfortunately the object have been relatively unsightly. Consequently, the room deodorizers have been relegated to areas such as under sinks, behind doors or inside of closets. It would be highly desirable to create attractive articles that would release fragrances to create pleasant environments.
The slow sustained release of a fragrant molecule is a desirable trait in various applications including personal care products, air fresheners and the like. Among the suitable techniques for providing long lasting scents are dissolving or suspending fragrance compounds in emulsions (see U.S. Pat. Nos. 5,525,588; 5,525,555; 5,490,982 and 5,372,806); encapsulation of a fragrance (U.S. Pat. Nos. 5,500,223; 5,324,444, 5,185,155, 5,176,903 and 5,130,171); dissolving a fragrance into a hydrophilic phase such as silicone U.S. Pat. No. 5,234,689) incorporation of a fragrance into a cross-liked polymer (U.S. Pat. Nos. 5,387,622 and 5,387,411) incorporation of a fragrance into permanent laminates (U.S. Pat. Nos. 5,071,704 and 5,008,115) incorporation of a fragrance that softens at body temperature (U.S. Pat. No. 4,908,208) incorporation of a fragrance into silanes with fragrant alcohol to form alkoxysilanes (U.S. Pat. Nos. 4,524,018 and 4,500,725 incorporation of fragrant moieties via hydrosilation of an olefinic silane molecule (U.S. Pat. No. 6,054,547). The disclosure of the above U.S. patents are hereby incorporated by reference as if set forth in their entirety.
While all of these approaches release fragrant molecules, there is a continuing need to provide attractive dispensing means from which the fragrant molecules can be delivered.
SUMMARY OF THE INVENTION
The present invention provides an attractive item which can be prominently displayed and which also releases fragrance into the surrounding environment. In a first embodiment of the present invention provides a decorative item, a polymer matrix and fragrance wherein the decorative item is encased in the polymer matrix and a fragrance is emitted from the polymer.
In a second embodiment of the invention comprises a method for making the a decorative item encased in a polymer matrix comprising:
providing a monomer; a fragrance; and a catalyst suitable for the monomer;
admixing the monomer, fragrance and a catalyst;
providing a mold, said mold containing a decorative item;
providing the fragrance, monomer and catalyst mixture to the mold;
allowing the catalyst to polymerize the monomer mixture in the mold;
removing the decorative item encased in a fragrant polymer.
The present invention is suitable for use as an air freshener, an environmental fragrancing device and other applications. These and other embodiments of the present invention will become apparent upon referring to the following figure and description of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a flower contained in a polymeric matrix in accordance with the present invention.
FIG. 2 is an exploded view of the present invention and an accompanying protective case.
DETAILED DESCRIPTION OF THE INVENTION
The polymer materials that are employed in the preset invention are selected from any material that will accept a fragrance material and which are transparent when used to encapsulate the decorative material. As used herein, essentially transparent is understood to mean the ability to transmit light without appreciable scattering so that bodies lying beyond the polymer material are visible. More preferably, the polymeric materials that are used are of sufficient clarity so that the decorative item is visible when it is encased in the polymeric material. Suitable polymers include, but are not limited to siloxanes, silicones, acrylics, polycarbonates, polyesters such as polyester terephthalate, copolymers and mixtures of these polymers and the like. The most preferred materials are siloxanes such as polydimethylsiloxanes, especially when catalyzed with an organotin compound and zinc silicate in the presence of a base. This polymethylsiloxane material was found to possess excellent optical properties, good structural properties as well as can be used to deliver fragrance over a period of time.
Structural properties are understood to mean the ability to remain rigid after being cast into a shape. Rigid is understood to mean that the polymer matrix will retain its shape after being removed from a mold and will not run, or sag. Some polymers are not very suitable in that they are too soft and will not retain the desired shape over time. Other polymers are undesirably soft in that the object feels mushy when handled. Other polymers are easily deformed when handled, acting similarly to putty materials. In a preferred embodiment, the polymer should appear like glass when initially viewed. In a highly preferred embodiment the polymer should also be capable of delivering a fragrance over an extended period of time.
The polymer is typically provided in an amount of greater than about 50 weight percent of the item, preferably greater than 70 weight percent and in a preferred embodiment greater than about 80 weight percent of the item.
The fragrance employed in the invention is not critical, so long as it is compatible with the polymer that is employed. As is appreciated in the art, some polymer and fragrances are not compatible with each other, that means that a particular fragrance can not be delivered with a specific polymer. The fragrance of the present invention can preferably be continually delivered over time such as more than a week, more than two weeks, preferably more than a month and most preferably over a period two or more months. Technologies for the control release of fragrances are well known in the art and include encapsulation, use of emulsions and surfactants and other techniques as set forth above.
Many types of fragrances can be employed in the present invention, the only limitation being the compatibility with the polymer matrix being employed. Suitable fragrances include but are not limited to fruits such as almond, apple, cherry, grape, pear, pineapple, orange, strawberry, raspberry; musk, flower scents such as lavender-like, rose-like, iris-like, carnation-like. Other pleasant scents include herbal scents such as and woodland scents derived from pine, spruce and other forest smells. Fragrances may also be derived from various oils, such as essential oils, or from plant materials such as peppermint, spearmint and the like. Other familiar and popular smells can also be employed such as baby powder, popcorn, pizza, cotton candy and the like can also be employed in the present invention.
A list of suitable fragrances is provided in U.S. Pat. No. 4,534,891, the contents of which are hereby incorporated by reference. Another source of suitable fragrances is found in Perfumes Cosmetics and Soaps, Second Edition, edited by W. A. Poucher, 1959. Among the fragrances provided in this treatise are acacia, cassie, chypre, cylamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth, jasmin, lilac, lily, magnolia, mimosa, narcissus, freshly-cut hay, orange blossum, orchids, reseda, sweet pea, trefle, tuberose, vanilla, violet, wallflower, and the like.
The level of fragrance varies from about 0.1 to about 10 weight percent, preferably from about 2 to about 8 and most preferably from about 3 to about 7 weight percent. In addition to the fragrance other agents can be used in conjunction with the fragrance. Well known materials such as surfactants, emulsifiers, polymers to encapsulate the fragrance can also be employed without departing from the scope of the present invention.
Also included in the present invention is a decorative item that is encased into the polymer matrix. Any decorative item can be included in the polymer, including but not limited to plant materials such as flowers, leaves, branches and twigs. Suitable materials include roses, lilac blooms, carnations and the like. Miniature items as models of cars, planes, and trains; miniature replicas of animals, including a stuffed animal such as a teddy bear, toys, cartoon figures, action figures, and the like can also be included in the polymeric matrix. The use of a child's favorite toy in the polymer matrix would be ideal for use in a child's room. Encased in the polymer matrix is understood that the decorative article is surrounded in three dimensions by the polymer. The present invention is not contemplated as including the placing of a decorative item on top of a polymer matrix.
In a highly preferred embodiment of the present invention, the item embedded in the polymer matrix and the fragrance incorporated into the polymer is the same. This provides a visual clue as to the scent when the person who may enter an area views it. Once a person notes the item, the person will associate the fragrance in the area with the item inside the polymer matrix.
The decorative items of the present invention are particularly well suited to be employed as room fresheners. Since the item has a pleasant appearance, it is not necessary to place the item out of sight. In fact, because the polymer matrix preserves the decorative item, the present invention makes it highly desirable to have the item in a visible place.
Now referring to the Figures, in FIG. 1 an embodiment of the invention is presented. The polymer matrix 10 is visible as well as the decorative item. In FIG. 1, a flower 10 , more specifically a daisy, is employed as the decorative item in the polymer 20 . A fragrance (not shown) is provided in the polymer matrix.
In FIG. 2 an explode view of the polymer matrix, decorative item and a container is visible. The polymer matrix 120 containing the decorative item 110 , the model car is visible, just above the container 100 . The container in a preferred embodiment also has a lid 140 which can be employed to retain the fragrance within the polymer matrix when it is not desired.
The use of a container is not required in the present invention but has several advantages. First the container provides protection to the polymer and decorative item during shipping and display prior to purchase. In addition, the container also acts to prevent diminution of the fragrance prior to purchase and use. The container can be made of various materials, including cardboard, papers and films and the like. It is preferred that the package retards the release of fragrance before use. Films, including shrink-wrap films, used in food packaging would be useful especially if the film limits or prevents air mobility across the film. Suitable films include polymers and copolymers containing polyethylene, polypropylene and vinylidene chloride, which are known in the art.
Preferably the container is also made of a transparent material such as glass, acrylics, polycarbonates and the like. If the container is transparent the article can remain in the container and the top removed only when fragrance is desired.
As polymers are employed in the present invention, it is possible to make many different shapes and sizes in which to encase the decorative item. Cubes are a preferred shape inasmuch as they are generally considered to be appealing to the eye. Cubes are understood to include cube-like shapes that generally have sides that are similar in dimension, however they are not all required to have the exact same dimension. However, one with skill in the art will be able to cast polymers in a wide number of three-dimensional shapes such as spheres, ellipses, pyramids, parrellelpipeds, and the like.
These and additional modifications and improvements of the present invention may also be apparent to those with ordinary skill in the art. The particular combinations of element described and illustrated herein are intended only to represent only a certain embodiment of the present inventions and is not intended to serve as limitations of alternative articles with the spirit and scope of the invention.
EXAMPLE
A decorative rose encased in a polysiloxane matrix was prepared using the following method. One hundred (100) parts by weight of a siloxane (TBT-4750 available from Path Silicones, Elmwood Park, N.J.) and 5 weight percent rose fragrance from International Flavor and Fragrance Inc. were mixed until a clear uniform solution is formed. To the clear mixture, 10 parts by weight of catalyst, an organotin compound and ethyl silicate (sold as Catalyst 25×, also from Path Silicones, Elmwood Park, N.J.) was added. The preferred ratio of siloxane to catalyst is 10 to 1. The mixture was poured into a mold containing a rose. The mixture was allowed to set for twenty-fours hours before being removed. The polysiloxane matrix was removed from the mold. The resulting polymer had excellent clarity, the rose was clearly visible inside the polymer, and had excellent structural stability. The polymer remained rigid and did not slump or slide when placed upon a table. | The present invention provides a fragrant article that delivers fragrance over a period of time by an article comprising a polymer matrix, a fragrance and a decorative object. The decorative object is contained within a polymer matrix and in a preferred embodiment is the similar to the fragrance that is being released. The article is particularly well suited to be used as a room freshener, which because of its attractive appearance does not need to be hidden. |
BACKGROUND OF THE INVENTION
This invention relates to cutters for rubber samples, and to cutting machines having toggle mechanisms for reciprocal motion of a cutting die.
In the operation of rheometers or curemeters for evaluating the physical behavior of rubber compounds during the process of vulcanization, it has been found helpful for obtaining repeatability to charge the rheometer or curemeter with samples which are of consistent volume. The sample volume should be just slightly more than that required to fill the cavity of the testing device. If the sample volume is insufficient to fill the cavity, cavity pressure is inadequate and erroneous values will result. If the sample volume is significantly too large, an excess of rubber will be squeezed out of the cavity during the initial stages of the test, retarding sample heating and causing erratic results and also necessitating excessive cleaning effort. Thus, a device which could produce an accurate, constant volume of sample would be of value in maintaining testing accuracy and speed, especially in a quality control application, where samples are continually tested to monitor production operations.
It is an object of the present invention to provide a reliable, quick and relatively simple mechanical cutter which will produce constant-volume samples of rubber compound. It is another object of this invention to provide a method for cutting samples of rubber compound by first sizing, then cutting a portion of rubber compound to a constant volume.
SUMMARY OF THE INVENTION
The objects of the invention are achieved in a device which, as described below comprises an anvil, a piston and a cutter which, when actuated, cooperate to cut quick and accurate samples; also, in a method wherein a portion of material is first pressed to accurate size between an anvil and a piston, then cut to produce a constant volume of material.
In a preferred embodiment, the device of the invention is more completely described as follows: on a frame, containing upper and lower frame members connected by support members, at least one guide rod is attached (to one of the support members). A crosshead, carrying a cutter, is journalled on the guide rod. A piston is positioned inside the cutter, so that it slides freely through the cutter, and coaxially with an anvil. Drive means are connected to the frame and arranged to move both the cutter and the piston towards and away from the anvil.
A preferred method of the invention is as follows: a portion of material to be cut is first placed, in a thickness greater than the thickness of a desired sample, upon an anvil. Then the sample is pressed to the desired thickness and cut while being held. Finally, the sample is expelled from contact with the cutter.
A better understanding of the invention may be obtained by reference to the accompanying drawings and descriptions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation showing a preferred embodiment of the device of the invention in its open position, with a portion of the cutter and piston in relief.
FIG. 2 is similar to FIG. 1, but shows the device in its closed position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, a preferred embodiment of the device is shown in FIG. 1 in its open position, and in FIG. 2 in its closed position.
Upper frame member 1 is supported on lower frame member 2 by left and right supports 3, 4. Guide rod 5 is attached to right support 4, and crosshead 6 is journalled on guide rod 5 and onto another guide rod (behind rod 5, and not shown) for sliding motion up and down. Cutter 7 is attached to crosshead 6 and moves with it. Piston 8 is mounted within cutter 7 and is free to move up and down independent of cutter 7 and crosshead 6. Anvil 9 is supported on lower frame member 2, and is located coaxially with cutter 7 and piston 8.
Bellcrank 10 is pivotally mounted on ram 11 by means of ram pivot pin 12, and pivotally mounted to bracket 21 by means of main pivot pin 13. The opposite end of ram 11 is secured to lower frame member 2 by lug 22. Bracket 21, in turn, is attached to upper frame member 1. Piston link 14 is pivotally attached at one end to bellcrank 10 by means of upper piston link pin 15 and at its other end to the piston 8 by means of lower piston link pin 16. Cutter link 17 is similarly pivotally attached at one end to bellcrank 10 by means of upper cutter link pin 18 and at its other end to the crosshead 6 by means of lower cutter link pin 19.
The preferred operation of the cutting device of the invention is shown by reference to FIG. 1 and FIG. 2, showing the device first in its fully open position, then in its fully closed position. With the device in the fully open position as shown in FIG. 1, a portion of the material to be cut is placed on anvil 9, sized so its thickness is slightly larger than the desired thickness of the finished sample. By actuating ram 11 downward, bellcrank 10 is pivoted about main pivot pin 13, which forces both the crosshead 6, carrying the cutter 7, and the piston 8 downwards by means of the action of the toggle links 14 and 17. Piston 8 precedes cutter 7, and forces the material against anvil 9, to its desired thickness. Cutter 7 then slides past the piston 8, cuts the material, and the lower-most edge of Cutter 7 finishes just below the upper edge of anvil 9. The device is then in the fully closed position as shown in FIG. 2, with the sample 20 fully enclosed between the upper surface of anvil 9 and the lower surface of piston 8, and surrounded at its edge by cutter 7. The ram 11 is then actuated upward, first raising cutter 7 out of sliding contact with anvil 9, then sample 20. The retraction of cutter 7 thus expells sample 20 from contact with cutter 7 as the piston 8 protrudes through cutter 7, facilitating removal of the sample 20.
Although the device as pictured and described shows a combination of a single anvil, cutter and piston it is within the scope of the invention to provide plural or multiple combinations of anvil, cutter and piston driven by a single drive means so as to enable production of plural or multiple samples at one time.
The preferred biasing means for moving the cutter and piston is an air cylinder. However, any convenient biasing means can be adapted for this purpose, such as, for example a one-revolution clutch mechanism.
The usual shape of the desired sample is that of a cylinder the diameter of which is significantly greater than its height. Other shapes can be produced, if desired, and this invention is not limited to methods and devices for producing the pictured cylindrical samples.
Although the invention has been illustrated by typical examples, it is not limited thereto. Changes and modifications of the examples of the invention herein chosen for purposes of disclosure can be made which do not constitute departure from the spirit and scope of the invention. | A cutting device for rubber samples produces constant-volume samples of rubber. The samples are suitable for testing, such as curemeter or rheometer testing, and their constant volume eliminates erratic test results caused by samples which are too large or too small. The device features a sizing mechanism which works in conjunction with a cutter, so as to ensure constant volume samples. |
FIELD OF THE INVENTION
The present invention relates to a light-sensitive silver halide photographic material, and more particularly relates to an image forming method for a light-sensitive silver halide photographic material, that can form an image by rapid processing in a high sensitivity and without causing any processing non-uniformity.
BACKGROUND OF THE INVENTION
A method is known in which a radiation image used for medical diagnosis is converted into digital data, the data are image-processed utilizing a computer so as to be more suitable for diagnosis, and the image is reproduced by exposure to laser beams.
For the laser beams, lasers such as semiconductor lasers or helium-cadmium layers are commonly used as light sources of such a scanner-type recording apparatus.
Of these, the semiconductor lasers have many advantages such that they are compact in size and inexpensive, and yet can be readily modulated and have a long lifetime.
On the other hand, it is necessary for light-sensitive silver halide photographic materials adapted thereto, used for laser scanners, (hereinafter "light-sensitive materials for laser scanners") to be spectrally sensitized to regions of from the red region to the infrared region, having wavelengths of 600 nm or more, and cyanine dyes are commonly used.
In recent years, achievement of rapid processing of light-sensitive materials has made great strides, and the light-sensitive materials for laser scanners are also no exception thereto. That is to say, there is a strong demanded for making the development processing time shorter for the reason that it is desired to catch image information more rapidly.
Achievement of rapid processing of such light-sensitive materials, however, is not necessarily so simple as in the case of other light-sensitive silver halide photographic materials, because such light-sensitive materials for laser scanners have difficulties peculiar to themselves. Namely, development non-uniformity tends to be caused in the resulting image after development. This is presumably because a latent image formed as a result of exposure to a high-intensity light for a short time using the laser beams tends to be influenced by the changes in development conditions such as processing time, processing temperature, and stirring. In particular, the development temperature dependence is remarkable.
In relation to methods of preventing such development non-uniformity, a method in which a specific surface active agent is used is known, which is an attempt as disclosed, for example, in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 29835/1989 or No. 148257/1988.
However, as the development processing is made more rapid, such conventional techniques can not be said to be satisfactory. For example, when the development time is within several ten seconds, a photosensitive layer in a developing solution may become very susceptible to the diffusion phenomenon that the concentration of a developing solution in a film shifts from a low-density image region to a high-density image region and finally becomes uniform over the whole region. In particular, the development temperature has a great influence in view of the fact that it governs the degree of swell of a film.
As another problem, from the view point of photographic performance, the above techniques have been involved in the problem that the maximum density can be obtained with difficulty, the resulting silver image has a yellowish tone as a result, and a tone of neutral gray, which is advantageous for the evaluation of an image, can not be obtained.
SUMMARY OF THE INVENTION
Accordingly, a first object of the present invention is to provide an image forming method for a light-sensitive silver halide photographic material, that can give a superior maximum photographic density and may cause no development non-uniformity or development staining.
A second object of the present invention is to provide an image forming method for a light-sensitive silver halide photographic material, that can obtain a silver image of neutral gray in the tone of an image after development.
A third object of the present invention is to provide an image forming method that can obtain the above performances by rapidly processing a light-sensitive silver halide photographic material spectrally sensitized to 600 nm or more.
Other and additional objects of the present invention will become apparent from the following descriptions.
As a result of intensive studies, the present inventors have found that these objects can be achieved by the following, and thus accomplished the present invention.
Namely, the above objects can be achieved by an image forming method comprising the steps of subjecting to imagewise exposure a light-sensitive silver halide photographic material which comprises a support and a silver halide emulsion layer provided on said support, wherein said silver halide emulsion layer contains a silver halide grain having an area ratio of (100) face to (111) face of not less than 5 and being spectrally sensitized with a sensitizing dye represented by the following Formula (I); and at least one layer included in said light-sensitive silver halide photographic material contains a fluorine-containing surface active agent; and
processing said exposed light-sensitive silver halide photographic material with processes comprising developing with a developing solution, for a period of time of from 20 seconds to 60 seconds in total. ##STR1## wherein Z 1 and Z 2 each represent a group of non-metallic atoms necessary to complete a benzothiazole nucleus, benzoselenazole nucleus, naphthothiazole nucleus or naphthoselenazole nucleus that may have a substituent; R 1 and R 2 each represent a lower alkyl group, or a substituted lower alkyl group; X.sup.⊖ represents an anion; and n represents an integer of 1 or 2, provided that n is 1 when an intramolecular salt is formed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below in detail.
The silver halide photographic emulsion grains of the present invention comprise a grain having a crystal surface with an area ratio of (100) face to (111) face of not less than 5. Various methods are known for preparing such grains. A commonly available method is a method in which an aqueous silver nitrate solution and an aqueous alkali halide solution are mixed by the controlled double-jet method while keeping the pAg value to a given value of not more than 8.10. A more preferred pAg value is not more than 7.80, and more preferably not more than 7.60.
There are not particular limitations on the pAg value at the time of the nucleation of silver halide grains. Mixing may also be carried out under conditions as in any methods well known by those skilled in the art.
The silver halide emulsion of the present invention may contain silver halide grains comprising a grain having an area ratio of (100) face to (111) face of not less than 5, and preferably not less than 10, preferably in an amount of not less than 50 wt. %, more preferably not less than 60 wt. %, and particularly not less than 80 wt. %.
The faces of a silver halide grain can be measured by Kubelka-Munk's dye adsorption method. In this method, used is a dye that is preferentially adsorbed on either the (100) face or the (111) face, and gives a different state of aggregation, depending on the face. The area ratio of (100) face to (111) face can be determined by spectrometry after the dye is adsorbed in varied amounts for its addition.
In regard to the face ratio of the surface of a silver halide grain, reference can be made on the method as disclosed in Journal of Chemical Society of Japan, 6, 942-946 (1984).
The sensitizing dye of the present invention, represented by Formula (I), will be described below. ##STR2##
In the formula, Z 1 and Z 2 each represent a group of non-metallic atoms necessary to complete a benzothiazole nucleus, benzoselenazole nucleus, naphthothiazole nucleus or naphthoselenazole nucleus that may have a substituent or no substituent. The benzothiazole nucleus includes, for example, benzothiazole, 5-chlorobenzothiazole, 5-methylbenzothiazole, 5-methoxybenzothiazole, 5-hydroxybenzothiazole, 5-hydroxy-6-methylbenzothiazole, 5,6dimethylbenzothiazole, 5-ethoxy-6-methylbenzothiazole, 5-phenylbenzothiazole, 5-carboxybenzothiazole, 5-ethoxycarbonylbenzothiazole, 5-dimethylaminobenzothiazole, and 5-acetylaminobenzothiazole. The benzoselenazole nucleus includes, for example, benzoselenazole, 5-chlorobenzoselenazole, 5-methylbenzoselenazole, 5-methoxybenzoselenazole, 5-hydroxybenzoselenazole, 5,6-dimethylbenzoselenazole, 5,6-dimethoxybenzoselenazole, 5-ethoxy-6-methylbenzoselenazole, 5-hydroxy-6-methylbenzoselenazole, and 5-phenylbenzoselenazole. The naphthothiazole nucleus includes, for example, β-naphthothiazole, and β,β-naphthothiazole. The naphthoselenazole nucleus includes, for example, β-naphthoselenazole. R 1 and R 2 each represent a lower alkyl group, or a substituted lower alkyl group, as exemplified by a methyl group, an ethyl group, a n-propyl group, a β-hydroxyethyl group, a β-carboxyethyl group, a γ-carboxypropyl group, a γ-sulfopropyl group, a γ-sulfobutyl group, a δ-sulfobutyl group, and a sulfoethoxyethyl group.
X.sup.⊖ represents an anion, as exemplified by a halide ion, a perchlorate ion, a thiocyanate ion, a benzenesulfonate ion, a p-toluenesulfonate ion, a methylsulfonate ion. The letter symbol n represents a positive integer of 1 or 2, provided that n is 1 when an intramolecular salt is formed.
The sensitizing dye of the present invention belongs to thia- or selenacarbocyanaines wherein an ethyl group is substituted on the meso position on a trimethine chain, and has a sensitizing ability advantageous to the spectral sensitization in a particular wavelength region.
For the purpose of exemplification, typical examples of the sensitizing dye of the present invention are shown below. The present invention, however, is by no means limited to these only. ##STR3##
These sensitizing dyes according to the present invention can be readily obtained by the synthesis methods as disclosed in British Patent No. 660,408, U.S. Pat. No. 3,149,105, etc.
The above dyes according to the present invention may be directly dispersed in an emulsion. Alternatively, these dyes may also be first dissolved in a suitable solvent as exemplified by methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine, or a mixed solvent of any of these to form a solution, which is then added in the emulsion.
The amount of the sensitizing dye according to the present invention, added in the silver halide emulsion, is not uniform and depends on the type of silver halide or the silver halide content. The dye, however, may preferably be added in an amount of from 0.005 to 1.0 g, and more preferably from 0.01 to 0.6 g, per mol of silver halide.
These sensitizing dyes are added alone or in combination in the silver halide emulsion according to the method of the present invention so that the desired spectral sensitivity can be obtained.
The above sensitizing dye according to the present invention may be added at any time of from before completion of a desalting step to immediately before completion of chemical ripening. It may preferably be added at the step of chemical ripening, and particularly preferably at the time the chemical ripening is started.
The desalting may be carried out by any methods employed in the present industrial field. For example, it may be carried out by the coagulation process or the noodle washing process, as disclosed in Research Disclosure No. 17643, page 23, 1978.
Next, the fluorine-containing surface active agent added and contained in at least one layer of the light-sensitive silver halide photographic material of the present invention includes nonionic, anionic or cationic surface active agents or those having a betaine structure. It may preferably have a fluoroalkyl group having 4 or more carbon atoms.
The anionic surface active agents include, for example, those having a group such as sulfonic acid or a salt thereof, carboxylic acid or a salt thereof, or phosphoric acid or a salt thereof; the cationic or betaine-type surface active agents, those having a group such as an amine salt, an ammonium salt, a sulfonium salt, a phosphonium salt, or an aromatic amine salt; and also the nonionic surface active agents, those having a polyalkylene oxide group, a polyglyceryl group, or the like.
These fluorine-containing surface active agents include the compounds as disclosed in U.S. Pat. No. 4,335,201 and No. 4,347,308, British Patents No. 1,417,915 and No. 1,439,402, Japanese Examined Patent Publications No. 26687/1977, No. 26719/1982 and No. 38573/1984, Japanese Patent O.P.I. Publications No. 149938/1980, No. 48520/1979, No. 14224/1979, No. 200235/1983, No. 146248/1982 and No. 196544/1983, etc.
Preferred examples of these compounds are shown below, to which, however, the present invention is by no means limited. ##STR4##
The above fluorine-containing surface active agents according to the present invention may be added in any of the component layers of the light-sensitive silver halide photographic material. For example, they are added in a non-light-sensitive layer such as a surface-protective layer, an intermediate layer, a subbing layer or a backing layer, or in a silver halide emulsion layer.
They may more preferably be added in an emulsion layer and its surface-protective layer, and a subbing layer and its surface-protective layer. They may be not only used in a layer on one side, but also simultaneously used in layers on both sides.
The fluorine-containing surface active agents according to the present invention may be used in combination of two or more kinds, or may be used in combination with other synthetic surface active agents.
The above compound may be added in an amount, though variable depending on the type of the compound, of from 0.0001 to 2 g, and preferably from 0.001 to 0.5, per 1 m 2 of the silver halide emulsion layer of the light-sensitive silver halide photographic material according to the present invention.
When the compound is added in a hydrophilic colloid layer other than the silver halide emulsion layer, it may be in an amount of from 0.0001 to 2 g, and preferably from 0.001 to 0.5 g, thereby satisfactorily bringing about the effect as aimed in the present invention.
The silver halide emulsion used in the present invention will be described below.
The silver halide grains contained in the light-sensitive silver halide photographic material of the present invention are comprised of a silver halide containing silver iodide, which may be any of silver iodochloride, silver iodobromide and silver chloroiodobromide. In particular, it may preferably be silver iodobromide in view of the advantage that grains with a high sensitivity can be obtained.
The silver iodide contained in such silver halide grains may be in an amount of from 0.05 to 10 mol %, and preferably from 0.5 to 8 mol %, on the average. In the inner part of the grain, a localized part is present in which the silver iodide has localized in a content of not less than 20 mol %.
In such an instance, the silver iodide-localized part of the grain may preferably be present at the part as inner as possible from the outer surface of the grain, and it is particularly preferable for the localized part to be present 0.01 μm or more distant from the outer surface.
In the inner part of the grain, the localized part may be present in the form of a layer. Alternatively, it may have so-called core/shell structure, in which the core may form the localized part. In this instance, part or the whole of a core of the grain, excluding a shell with a thickness of 0.01 μm or more from the outer surface, may preferably be the localized part in which the silver iodide has localized in a content of not less than 20 mol %.
The silver iodide in the localized part may preferably be in a content of from 30 to 40 mol %.
The outer side of such a localized part is covered with a silver halide containing no silver iodide. More specifically, in a preferred embodiment, a shell with a thickness of 0.01 μm or more, particularly from 0.01 to 1.5 μm, from the outer surface is formed of a silver halide containing no silver iodide (silver bromide, in usual instances).
In the present invention, a method by which the localized area in which the silver iodide has localized in a high content of not less than 20 mol % is formed in the inner part (preferably at an inner side of the grain, 0.01 μm or more distant from the outer wall of the grain) may be a method in which no seed crystal is used.
In the instance where no seed crystal is used, no silver halide grain that may serve as a growth nucleus before start of ripening is present in a reaction mixture phase containing a protective-colloidal gelatin (hereinafter referred to as "mother liquor"), and hence a silver salt solution and a halide solution containing an iodide in a high concentration of 20 mol % or more are first fed to form the nucleus. Then, the feeding thereof is continued to make the grain to grow. As a final step, a shell layer having a thickness of 0.01 μm or more is formed with a silver halide containing no silver iodide.
In the instance where a seed crystal is used, not less than 20 mol % of silver iodide may be contained in only the seed crystal, which may be thereafter covered with a shell layer. Alternatively, the seed crystal may be made to contain silver iodide in an amount of 0 (zero) or within the range of not more than 10 mol %, and then at least 20 mol % of silver iodide is contained in the inner part of the grain in the step of making the seed crystal to grow, which may be thereafter covered with a shell layer.
In the light-sensitive silver halide photographic material of the present invention, at least 50% of the silver halide grains present in its emulsion layer may preferably be composed of the grain in which the silver iodide has localized as described above.
In another preferred embodiment of the present invention, a monodisperse emulsion having the silver iodide-localized grains as described above is used.
Here, the monodisperse emulsion refers to an emulsion having a variation coefficient of σ/r≦0.20, where r is the average grain size of silver halide grains and σ, the standard deviation thereof.
In the present specification, the average grain size is expressed by the average based on the diameters of grains in the case of spherical silver halide grains, and, in the case of grains with shapes other than the spherical shape, the diameters obtained when a projected area of the grain is calculated into a circle having the same area.
Monodisperse emulsion grains are prepared by double-jet precipitation as in the case of the preparation of regular silver halide grains. Conditions for the double-jet precipitation are the same as those in the method of preparing the regular silver halide grains.
Preparation of a monodisperse emulsion is known in the art, and described, for example, in J. Phot. Sic., 12, 242-251 (1963), Japanese Patent O.P.I. Publications No. 36890/1973, No. 16364/1977, No. 142329/1980 and No. 49938/1983.
In order to obtain the above monodisperse emulsion, it is particularly preferred to use seed crystals and feed silver ions and halide ions to the seed crystals as growth nuclei, thereby making grains to grow.
The broader the grain size distribution of the seed crystals is, the broader the grain size distribution of the grown-up grains also is. Hence, in order to obtain the monodisperse emulsion, it is preferred to use seed crystals with a narrow grain size distribution at the initial stage.
The silver halide grains as described above, used in the light-sensitive silver halide photographic material of the present invention, can be prepared using methods such as the neutral method, the acidic method, the ammoniacal method, the normal precipitation, the reverse precipitation, the double-jet precipitation, the controlled double-jet precipitation, the conversion method and the core/shell method, as described, for example, in the literature such as T. H. James, The Theory of the Photographic Process, Fourth Edition, Macmillan Publishing Co., Inc., (1977), pp. 88-104.
A silver halide emulsion of a surface latent image-forming type can also be prepared by the so-called controlled double-jet precipitation, in which the pH and EAg in a reaction vessel are controlled by gradually increasing the amount of the silver ion solution and halide solution to be added.
A cadmium salt, a palladium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt or a complex salt thereof, a rhodium salt or a complex salt thereof, an iron salt or a complex salt thereof, etc. may also be made present together at the stage of the formation or physical ripening of silver halide grains. The silver halide emulsion of a surface latent image may also be the monodisperse emulsion.
Known photographic additives can be used in the silver halide emulsion of the present invention.
Known photographic additives include, for example, the compounds as described in Research Disclosures RD-17643 (December, 1978) and RD-18716 (Novemeber, 1979), which are as shown in the following table.
______________________________________ RD-17643 RD-18716Additives Page Paragraph Page Column______________________________________Chemical sensitizer: 23 III 648 Upper rightSensitizing dye: 23 IV 648 Right to 649 LeftDevelopment acceler- 29 XXI 648 Upper rightator:Antifoggant: 24 VI 649 Bottom rightStabilizer: 24 VI 649 Bottom rightUV absorbent: 25-26 VIII 649 Right to 650 LeftFilter dye: 25-26 VIII 649 Right to 650 LeftHardening agent: 26 X 651 LeftCoating aid: 26-27 XI 650 RightSurfactant: 26-27 XI 650 RightPlasticizer: 27 XII 650 RightLubricant: 27 XII 650 RightAntistatic agent: 27 XII 650 RightMatting agent: 28 XVI 650 RightBinder: 26 IX 651 Left______________________________________
In the hydrophilic colloid layer of the light-sensitive silver halide photographic material of the present invention, a vinylsulfone compound can preferably be used as a gelatin hardening agent.
The vinylsulfone compound preferably used in the present invention may be any compounds so long as they have at least two vinylsulfonyl groups in the molecule. In particular, the compound that can bring about a greater effect of the present invention includes a compound represented by Formula (H). ##STR5##
In the formula, R represents a hydrogen atom or a lower alkyl group, and preferably represents a hydrogen atom or a methyl group.
Z represents a linkage group with a valency of n, which may contain at least one of atoms of an oxygen atom, a nitrogen atom and a sulfur atom. The atom contained in Z may preferably be an oxygen atom or a nitrogen atom.
The letter symbol m is 0, 1 or 2, and n is 2 or 3.
Examples of the compound of Formula (H) are shown below. ##STR6##
Preferred vinylsulfone-type hardening agents used in the present invention include, for example, aromatic compounds as disclosed in West German Patent No. 1,100,942, alkyl compounds combined with hetero atoms as disclosed in Japanese Examined Patent Publications No. 29622/1969 and No. 25373/1972, sulfonamides or ester compounds as disclosed in Japanese Examined Patent Publication No. 8736/1972, 1,3,5-tris[β-(vinylsulfonyl)propionyl]-hexahydro-s-triazine as disclosed in Japanese Patent O.P.I. Publication No. 24435/1974, and alkyl compounds as disclosed in Japanese Patent O.P.I. Publicaton No. 44164/1976.
In addition to the above exemplary compounds, the vinylsulfone-type hardening agent that can be used in the present invention also includes a reaction product obtained by reacting a compound having at least three vinylsulfonyl groups, with a compound having a group capable of reacting with the vinylsulfonyl groups and a water-soluble group as exemplified by diethanolamine, thioglycolic acid, surcosine sodium salt, and taurine sodium salt.
In the light-sensitive silver halide photographic material according to the present invention, a dye can be used in a layer which is lower to the emulsion layer of the present invention and contiguous to the support, for the purpose of decreasing so-called cross-over effect, and a dye can also be added in a protective layer and/or the emulsion layer of the present invention for the purpose of improving the sharpness of an image or decreasing the fog caused by safelight. Then, all sorts of known dyes used for the above purposes can be used as the above dye.
The support used for the silver halide photographic emulsion of the present invention includes all of known supports, as exemplified by films of polyesters such as polyethylene terephthalate, polyamide films, polycarbonate films, styrene films, baryta paper, and papers coated with synthetic polymers. The emulsion of the present invention may be coated on one side or both sides of the support. In the instance where it is coated on both sides, it may be so coated that the constitution of emulsion layers is symmetric or asymmertric.
The light-sensitive silver halide photographic material according to the present invention can be subjected to development processing by known methods usually used. As developing solutions, the developing solutions usually used can be used, as exemplified by those containing hydroquinone, 1-phenyl-3-pyrazolidone, N-methyl-p-aminophenol or p-phenylenediamine, which can be used alone or in combination of two or more. As other additives for developing solution, those conventionally used can be used.
A developing solution containing an aldehyde hardening agent can also be used in the light-sensitive silver halide photographic material according to the present invention. For example, it is possible to use developing solutions containing dialdehydes such as maleic dialdehyde, or glutaraldehyde, and sodium bisulfite salts of these, which are known in the photographic field.
The total processing time according to the present invention refers to the time through which the light-sensitive material of the present invention is inserted to first rollers, which constitute the inlet of an automatic processor to which the light-sensitive material is inserted, and thereafter it passes through a developing tank, a fixing tank, and a washing tank until it reaches the last roller at a drying section outlet.
The total processing time is 60 seconds or less, and preferably from 20 to 60 seconds. A processing time of less than 20 seconds may give rise to insufficient sensitivity, or bring about a dye residue, or a non-uniform image.
The processing is carried out at a temperature of 60° C. or less, and preferably from 20° to 45° C.
An example of particulars of the total processing time is shown below.
______________________________________ Processing temperature Precessing timeProcessing steps (°C.) (sec.)______________________________________Inserting -- 1.2Developing + 35 14.6cross-overFixing + 33 8.2cross-overWashing + 25 7.2cross-overSqeegeeing 40 5.7Drying 45 8.1Total: -- 45.0______________________________________
EXAMPLES
The present invention will be described below in greater detail by giving Examples. The present invention, however, is by no means limited to these.
EXAMPLE 1
While conditions were controlled to be 60° C., pAg=8 and pH=2.0, a monodisperse emulsion (A) of cubic silver iodobromide, having an average grain size of 0.15 μm and containing 2.0 mol % of silver iodide, were obtained by the double-jet precipitation. Observation on an electron microscope photograph revealed that twinned grains were produced at a rate of not more than 1% in terms of number. Using this emulsion (A) as a seed emulsion, grains were made to grow in the following manner.
Namely, the seed crystals (A) were dispersed in 8.5 l of a solution kept at 40° C. and containing a protective-colloidal gelatin and optionally ammonia, and then the pH of the resulting dispersion was adjusted with acetic acid.
Using the resulting solution as a mother liquor, an aqueous ammoniacal silver ion solution and a aqueous mixed solution of potassium bromide and potassium iodide, of 3.2N each, were added by the double-jet method while the pAg and the pH were controlled to be 7.3 and 9.7, respectively. A layer of silver halide with a silver iodide content of 35 mol % was thus formed over the seed seed crystals.
Next, an aqueous silver nitrate solution and an aqueous potassium bromide solution were added while the pH and the pAg were controlled to be 6.3 and 7.7, respectively. Emulsion A was thus obtained.
The area ratio of (100) face to (111) face was measured by the Kubelka-Munk's method to reveal that it was 96/4.
Next, with a change of the pAg value to 7.85 in the reaction vessel, Emulsion B was prepared in the same manner as Emulsion A. As a result of measurement by the Kubelka-Munk's method, the area ratio of (100) face to (111) face was 92/8.
With a change of the pAg value to 8.0, Emulsion C was similarly prepared.
The face ratio of the resulting emulsion was 88/12.
Similarly, with a change of the pAg to 8.05, Emulsion D was prepared. The face ratio of the resulting emulsion was 84/16.
Similarly, with a change of the pAg to 8.3, Emulsion E was prepared. The face ratio of the resulting emulsion was 66/34. With a change of the pAg to 8.95 in the reaction vessel, Emulsion F was further prepared. The face ratio of the resulting emulsion was 15/85.
By a method similar to the above, a layer of silver halide with a silver iodide content of 35 mol % was formed, and thereafter a cyanorhodium salt was added in an amount of 16 μmol of rhodium per mol of silver. Then, an aqueous silver nitrate solution and an aqueous potassium bromide solution were added while the pH and the pAg were controlled to be 6.3 and 7.7, respectively. Emulsion G was thus obtained. The area ratio of (100) face to (111) face was measured by the Kubelka-Munk's method to reveal that it was 96/4.
Grain size of these emulsions was measured by centrifugal precipitation to reveal that it was 0.45 μm on the average.
To these seven kinds of emulsions, sodium thiosulfate, ammonium thiocyanate and chloroauric acid were added to effect chemical sensitization at 60° C. to an optimum.
Subsequently, the compounds represented by Formula (I) according to the present invention and comparative compounds were each added as shown in Table 1, and 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene was also added in an appropriate amount to effect stabilization of the emulsions.
Separately, supports were prepared in the following way: To provide a backing layer, a backing layer coating solution comprising 400 g of gelatin, 2 g of polymethyl methacrylate, 6 g of sodium dodecylbenzenesulfonate, 20 g of the following anti-halation dye, and glyoxal was prepared, and coated on one side of a polyethylene terephthalate base coated with a subbing solution comprising an aqueous copolymer dispersion obtained by diluting to a concentration of 10 wt. % a copolymer composed of three kinds of monomers of 50 wt. % of glycidyl methacrylate, 10 wt. % of methyl acrylate and 40 wt. % of butyl methacrylate, together with a protective layer solution comprising gelatin, a matting agent, glyoxal and sodium dodecylbenzenesulfonate. A back-coated support was thus obtained.
The coating weights in the backing layer and the protective layer are 2.5 g/m 2 and 2.0 g/m 2 , respectively, in terms of gelatin coating weight.
ANTI-HALATION DYE ##STR7##
PREPARATION OF COATED SAMPLES
As additives for the emulsion layer, following compounds were added in amounts per mol of silver halide.
______________________________________Diethylene glycol 10 gNitrophenyl-triphenylphosphonium chloride 50 mgAmmonium 1,3-dihydroxybenzene-4-sulfonate 1 gSodium 2-mercaptobenzimidazole-5-sulfonate 10 mgPolyacrylamide (average molecular weight: 40,000) 10 g ##STR8## 35 mg ##STR9## 1 g1,1-dimethylol-1-bromo-1-nitromethane 10 mg ##STR10## 100 mg______________________________________
As additives for the protective layer, the following compounds were added in amounts per gram of gelatin.
______________________________________ ##STR11## 20 mgMatting agent comprising silica with an average particle 7 mgdiameter of 7 μmColloidal silica with an average particle diameter 70 mgof 0.013 μm______________________________________
The exemplary compounds of the fluorine-containing surface active agent according to the present invention and comparative compounds were further added as shown in Table 1, and as a hardening agent
CH.sub.2 ═CHSO.sub.2 --CH.sub.2 OCH.sub.2 --SO.sub.2 CH═CH.sub.2
was added in an appropriate amount.
On the back-coated base as previously described, the respective layers were provided by slide hopper coating in the manner that the silver halide emulsion layer and the protective layer, in this order from the support, were both simultaneously formed in layers at a coating speed of 60 m/min. Samples were thus obtained. Coating weight of silver was 2.9 g/m 2 , and the coating weight of gelatin was 3 g/m 2 on the emulsion layer and 1.3 g/m 2 on the protective layer.
These samples were stored for 3 days under conditions of 23° C. and 55% RH, and thereafter exposed to light using an He-Ne laser beam, with variations in the amount of light at intervals of 1/100,000 second per one picture element (100 μm 2 ). Thereafter, the resulting samples were processed with a developing solution and a fixing solution (each having the composition shown below), using an automatic processor SRX-501 (manufactured by Konica Corporation), in two modes of time so as for the total processing time to be 90 seconds and 45 seconds, respectively.
To examine processing uniformity, 8×10 inch size samples were subjected to overall exposure in the same amount of light, followed by the same processing as the above.
Sensitivity, gradation (density: 1.0 to 2.0), tone of developed silver, maximum density, and processing uniformity were evaluated on each sample after processing. The sensitivity is indicated as a relative value, assuming as 100 the value of Sample 6 for the amount of exposure required for giving the density of fog +1.0.
Results obtained are shown in Table 1.
______________________________________Composition of developing solution and fixing solution:Developing Solution 1:______________________________________Potassium sulfite 55.0 gHydroquinone 25.0 g1-Phenyl-3-pyrazolidone 1.2 gBoric acid 10.0 gSodium hydroxide 21.0 gTriethylene glycol 17.5 g5-Nitrobenzimidazole 0.10 gGlutaldehyde metabisulfite 15.0 gGlacial acetic acid 16.0 gPotassium bromide 4.0 gTriethylenetetraminehexaacetic acid 2.5 gMade up to 1 liter by adding water.______________________________________
______________________________________Fixing Solution 1:______________________________________Ammonium thiosulfate 130.9 gAnhydrous sodium sulfite 7.3 gBoric acid 7.0 gAcetic acid (90 wt. % solution) 5.5 gDisodium ethylenediaminetetraacetic acid 3.0 gSodium acetate trihydrate 25.8 gAluminum sulfate octadecahydrate 14.6 gSulfuric acid (50 wt. % solution) 6.77 gMade up to 1 liter by adding water.______________________________________ ##STR12##
TABLE 1__________________________________________________________________________ Sensitizing dye 35° C., 90 sec Processing 35° C., 45 sec ProcessingFace Surfactant A- Max. Max. ratio A- mount Gra- den- Gra- den- (100)/ mount (mg/ (1) da- si- (1) da- si-No. Em (111) (mg/m.sup.2) AgX) S tion ty (2) (3) S tion ty (2) (3) (4)__________________________________________________________________________ 1 F 15/85 F-32 10 Ex (18) 80 101 1.7 2.9 3 4 100 2.3 2.6 2 1 X 2 F 15/85 F-32 10 Ex (15) 80 105 1.6 3.0 3 4 102 2.2 2.7 2 1 X 3 E 66/34 F-32 10 Ex (15) 80 105 1.6 3.0 3 4 103 2.3 2.7 2 2 X 4 D 84/16 F-32 10 Cp-1 80 20 1.5 2.9 3 4 18 1.9 2.9 2 2 X 5 D 84/16 F-32 10 Cp-2 80 35 1.4 2.9 3 4 32 1.9 2.9 2 2 X 6 D 84/16 Cp-A 10 Ex (15) 80 100 1.9 3.1 4 3 100 2.3 3.0 4 3 X 7 D 84/16 Cp-B 10 Ex (8) 80 100 1.7 3.2 4 3 98 2.4 3.1 4 3 X 8 D 84/16 F-29 10 Ex (8) 80 108 1.8 3.3 4 5 107 1.9 3.2 4 5 Y 9 D 84/16 F-3 10 Ex (9) 80 108 1.8 3.3 4 5 107 1.9 3.2 4 5 Y10 D 84/16 F-5 10 Ex (9) 80 108 1.8 3.3 4 5 107 1.9 3.2 4 5 Y11 D 84/16 F-11 10 Ex (19) 80 108 1.8 3.3 4 5 107 1.9 3.2 4 5 Y12 D 84/16 F-14 10 Ex (22) 80 108 1.8 3.3 4 5 107 1.9 3.2 4 5 Y13 D 84/16 F-17 10 Ex (6) 80 95 1.7 3.3 3 4 94 1.9 3.2 3 4 Y14 D 84/16 F-20 10 Ex (26) 80 95 1.7 3.3 3 4 94 1.9 3.2 3 4 Y15 D 84/16 F-20 10 Ex (7) 80 95 1.7 3.3 3 4 94 1.9 3.2 3 4 Y16 D 84/16 F-27 10 Ex (7) 80 96 1.7 3.2 3 4 95 1.8 3.1 3 4 Y17 D 84/16 F-27 10 Ex (8) 80 103 1.9 3.2 4 4 102 1.9 3.2 4 4 Y18 D 84/16 F-27 10 Ex (24) 80 103 1.6 3.1 4 4 103 1.6 3.1 4 4 Y19 C 88/12 F-36 5 Ex (24) 80 103 1.7 3.2 4 4 103 1.8 3.2 4 4 Y20 C 88/12 F-36 10 Ex (24) 80 105 1.9 3.0 5 4 105 2.0 3.0 5 4 Y21 C 88/12 F-28 10 Ex (18) 40 88 1.6 2.9 5 4 85 1.6 2.9 5 4 Y22 C 88/12 F-28 10 Ex (18) 80 102 1.9 3.0 5 4 101 1.9 3.1 5 4 Y23 C 88/12 F-28 10 Ex (18) 200 135 2.0 3.2 3 4 133 2.0 3.2 3 4 Y24 B 92/8 F-28 10 Ex (18) 80 101 1.8 3.2 5 5 101 1.9 3.2 5 5 Y25 B 92/8 Cp-B 10 Ex (8) 80 106 1.8 3.3 3 2 106 1.9 3.2 2 2 X26 B 92/8 Cp-C 10 Ex (8) 80 102 1.9 3.2 3 2 102 2.0 3.2 2 2 X27 A 96/4 F-32 10 Ex (21) 80 110 1.7 3.1 4 5 123 2.1 3.1 4 5 Y28 A 96/4 F-32 10 Ex (5) 80 125 2.0 3.2 5 5 110 1.7 3.2 5 5 Y29 A 96/4 F-29 10 Ex (5) 80 123 1.9 3.1 5 5 124 1.9 3.1 5 5 Y30 G 96/4 F-29 10 Ex (5) 80 128 1.9 3.2 5 5 128 1.9 3.1 5 5 Y__________________________________________________________________________ (1): Sensitivity (2): Tone; 5: Very good, 4: Good, 3: Ordinary, 2: Poor, 1: Very poor (3): Processing uniformity; 5: Very good, 4: Good, 3: Ordinary, 2: Poor, 1: Very poor (4): Remarks; X: Comparative Example, Y: Present Invention
As will be evident from Table 1, the samples according to the present invention each show a good tone and at the same time are superior in all the sensitivity, gradation, and maximum density. The use of the fluorine-containing surface active agent has brought about good processing uniformity and good photographic performance.
EXAMPLE 2
The same samples as those obtained in Example 1 were exposed to light in the same manner as in Example 1, and processed with the following processing solutions, using an automatic processor SRX-501 (manufactured by Konica Corporation) so as for the total processing time to be 45 seconds.
______________________________________(Composition of developing solution)______________________________________Potassium hydroxide 24 gSodium sulfite 40 gPotassium sulfite 50 gDiethylenetriaminepentaacetic acid 2.4 gBoric acid 10 gHydroquinone 35 gDiethylene glycol 11.2 g4-Hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone 1.0 g5-Methylbenzotriazole 0.06 gPotassium bromide 2 g1-Phenyl-3-pyrazolidone 0.5 gMade up to 1 liter using water, and adjusted to pH 10.5.______________________________________
______________________________________(Composition of fixing solution)______________________________________Ammonium thiosulfate 140 gSodium sulfite 15 gDisodium ethylenediaminetetraacetic acid dihydrate 0.025 gSodium hydroxide 6 gMade up to 1 liter using water, and adjusted to pH 5.10with acetic acid.______________________________________
Sensitivity, gradation (density: 1.0 to 2.0), tone of developed silver, maximum density, and processing uniformity were evaluated in the same manner as in Example 1 on each sample after processing.
Results obtained are shown in Table 2.
TABLE 2__________________________________________________________________________ Surfactant Sensitizing dye 35° C., 45 sec Processing Face ratio Amount Amount Sensitivity Maximum ProcessingNo. Em (100)/(111) (mg/m.sup.2) (mg/AgX) S Gradation density Tone uniformity Remarks__________________________________________________________________________ 1 F 15/85 F-32 10 Ex (15) 80 101 2.3 2.6 2 1 X 4 D 84/16 F-32 10 Cp-1 80 18 1.9 2.9 2 2 X 6 D 84/16 Cp-A 10 Ex (15) 80 110 2.3 3.0 4 3 X10 D 84/16 F-5 10 Ex (9) 80 118 1.9 3.2 4 5 Y16 D 84/16 F-27 10 Ex (7) 80 110 1.8 3.1 3 4 Y20 C 88/12 F-36 10 Ex (24) 80 116 2.0 3.0 5 4 Y22 C 88/12 F-28 10 Ex (18) 80 111 1.9 3.1 5 4 Y25 B 92/8 Cp-B 10 Ex (8) 80 112 1.9 3.2 4 4 X29 A 96/4 F-29 10 Ex (5) 80 133 1.9 3.1 5 5 Y30 G 96/4 F-29 10 Ex (5) 80 138 1.9 3.1 5 5 Y__________________________________________________________________________ X: Comparative Example, Y: Present Invention
As will be evident from Table 2, the samples according to the present invention are seen to show the same effect as in Example 1, in particular, a superior effect in respect of the sensitivity, as a result of the processing with the developing solution and fixing solution having the above composition.
As having been described in the above, the present invention has provided an image forming method for a light-sensitive silver halide photographic material, which can remarkably suppress the processing non-uniformity from occurring.
From the viewpoint of photographic performance, the present invention has also made it possible to obtain a silver image with superior maximum density and tone. | An image forming method for a light-sensitive silver halide photographic material that provides a superior silver image in a short time is disclosed. The image forming method comprises the steps of subjecting to imagewise exposure of said light-sensitive silver halide photographic material which comprises a support and a silver halide emulsion layer provided on said support, wherein said silver halide emulsion layer contains a silver halide grain having a crystal surface with an area ratio of (100) face to (111) face of not less than 5 and being spectrally sensitized in the wavelength range of 600 nm or more with a specific sensitizing dye; and at least one layer included in said light-sensitive silver halide photographic material contains a fluorine-containing surface active agents; and processing said exposed light-sensitive silver halide photographic material for a period of time of from 20 seconds to 60 seconds in total. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 11/514,064 filed on Aug. 31, 2006. The disclosure of the above application is incorporated herein by reference.
FIELD
[0002] The present teachings relate to a part time hybrid electric all wheel drive system and more particularly relate to a pair of compact electric wheel motor assemblies that can selectively drive a pair of wheels that are not otherwise driven by an engine.
BACKGROUND
[0003] Typically, a hybrid electric all wheel drive system includes an electric motor and an internal combustion engine. The internal combustion engine drives the front wheels and a centrally mounted electric motor couples to a rear axle to drive the rear wheels.
[0004] Space under a vehicle is relatively limited and the above example requires the rear axle in addition to a relatively large centrally mounted electric motor. While the above system works well in various applications, there remains room in the art for improvement.
SUMMARY
[0005] A drive axle assembly for driving a wheel of a vehicle includes a moveable suspension arm and a wheel spindle fixed to the suspension arm. A planetary gearset includes a sun gear, a ring gear and a carrier rotatably supporting a plurality of planet gears in meshed engagement with the sun gear and the ring gear. The carrier encompasses the wheel spindle and is drivingly connected to the wheel. An electric motor includes a rotor and a stator. The rotor drives the sun gear.
[0006] In another arrangement, a drive axle assembly for driving first and second rear wheels of a vehicle includes a rear suspension having first and second spaced apart wheel spindles respectively fixed to individually moveable first and second suspension arms. A first electric motor is fixed to the first suspension arm and is adapted to independently drive the first rear wheel. A second electric motor is fixed to the second suspension arm and is adapted to independently drive the second rear wheel.
[0007] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings.
DRAWINGS
[0008] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present teachings in any way.
[0009] FIG. 1 is a diagram showing a vehicle with a front wheel drive configuration that can accept an electric all wheel drive system.
[0010] FIG. 2 is similar to FIG. 1 and shows the rear wheels removed from the vehicle.
[0011] FIG. 3 is a diagram of a hybrid electric all wheel drive system constructed in accordance with the present teachings showing a pair of electric wheel motor assemblies coupled to the vehicle of FIG. 1 .
[0012] FIG. 4 is a perspective view of an electric wheel motor assembly constructed in accordance with the present teachings showing an outboard side thereof.
[0013] FIG. 5 is similar to FIG. 4 and shows an inboard side thereof.
[0014] FIG. 6 is a cross-sectional view of FIG. 4 showing a portion of a planetary gearset operable in the electric wheel motor assembly.
[0015] FIG. 7 is an exploded assembly view of the electric wheel motor assembly of FIG. 4 showing a planetary gearset, an electric motor and a brake rotor in accordance with the present teachings.
[0016] FIG. 8 is a partial exploded assembly of the electric wheel motor assembly of FIG. 4 showing the planetary gearset.
[0017] FIG. 9 is a perspective view of the electric wheel motor assembly of FIG. 4 showing active cooling of the electric motor with the brake rotor having vanes formed therethrough.
DETAILED DESCRIPTION
[0018] The following description is merely exemplary in nature and is not intended to limit the present teachings, their application, or uses. It should be understood that throughout the drawings, corresponding reference numerals can indicate like or corresponding parts and features.
[0019] With reference to FIGS. 3 and 4 , the present teachings generally include an electric wheel motor assembly 10 . A hybrid electric all wheel drive system 12 can be implemented on a vehicle 14 . The all wheel drive system 12 can include a driver side electric wheel motor assembly 10 a and a passenger side electric wheel motor assembly 10 b , which can be collectively referred to as the electric wheel motor assemblies 10 . Each of the electric wheel motor assemblies 10 can couple to a rear suspension 16 that can couple to a vehicle body 14 a and/or other suitable suspension components, such as springs or shocks. Each of the electric wheel motor assemblies 10 can be selectively engaged to provide all-wheel drive on a part time basis.
[0020] The vehicle 14 can include an engine 18 driving front wheels 20 . The electric motor assemblies 10 can replace a conventional wheel and a wheel mounting structure (not specifically shown) that would otherwise rotatably support the rear wheels 22 and couple the rear wheels 22 to the vehicle 14 . It will be appreciated that the vehicle 14 can be equipped with the conventional wheel and wheel mounting structure and can be subsequently retrofit with the electric motor assemblies 10 . Moreover, the electric motor assemblies 10 can be provided as original equipment in lieu of the conventional wheel and wheel mounting structure.
[0021] With reference to FIG. 1 , the vehicle 14 can have a front wheel drive configuration. The front wheel drive configuration includes the engine 18 that can drive the front wheels 20 . The rear wheels 22 can be coupled to the rear suspension 16 and can receive no power from the engine 18 . With reference to FIG. 2 , the rear wheels 22 ( FIG. 1 ) can be removed from the vehicle 14 leaving portions of the rear suspension 16 exposed. With reference to FIG. 3 , the vehicle 14 can include the retrofit or original equipment electric wheel motor assemblies 10 that can couple to the rear suspension 16 . The rear wheels 22 can couple to the electric motor assemblies 10 , respectively.
[0022] While the vehicle 14 is illustrated as having a front wheel drive powertrain that serves as the primary source of propulsive power and the hybrid electric all wheel drive system 12 that provides supplemental power to the rear wheels of the vehicle 14 , it will be appreciated that the all wheel drive system 12 can also be implemented so that the electric motor assemblies 10 can drive the front wheels 20 , while the rear wheels 22 can be driven by the engine 18 . The all wheel drive system 12 can also be independent of a certain type of engine in the vehicle 14 such that the engine 18 can be an internal combustion engine, a hybrid configuration, an electric motor, other suitable power sources and combinations thereof.
[0023] With reference to FIGS. 4 and 5 , one of the electric motor assemblies 10 is shown that can be retrofit or can be originally assembled to a suspension component 24 that can be part of the rear suspension 16 ( FIG. 3 ). With reference to FIG. 6 , the electric wheel motor assembly 10 can include an electric motor 26 , a planetary gearset 28 and a wheel spindle 30 . The planetary gearset 28 can include a sun gear 32 , a ring gear 34 and a plurality of planet gears 36 that can be rotatably supported on a planet carrier 38 . It will be appreciated that when a first component or an input of the planetary gearset 28 is driven and a second component of the planetary gearset 28 is held rotationless, a third component or an output of the planetary gearset 28 can spin at an output rotational velocity that is less than the input rotational velocity. The torque transmitted through the output, however, is greater than the torque received at the input.
[0024] In the example provided, the sun gear 32 is the input, the ring gear 34 is maintained in a stationary (non-rotating) condition, and the planet carrier 38 is the output; but it will be appreciated that other configurations are possible such that modifications are within the capabilities of one skilled in the art. The ring gear 34 can be formed onto a portion of the wheel spindle 30 , which can be fixedly coupled to the suspension component 24 . The sun gear 32 can be driven by the electric motor 26 . The planet carrier 38 can be driven by the sun gear 32 via the planet gears 36 . Upon activation of the electric motor 26 , the planetary gearset 28 can provide, for example, a gear reduction ratio of about 1:2.64.
[0025] With reference to FIGS. 4 and 5 , the electric wheel motor assembly 10 can also include a brake rotor 40 that can couple to a flange portion 42 ( FIG. 7 ) of the planet carrier 38 . With reference to FIG. 9 , a wheel rim 44 can additionally support a pneumatic rubber tire 46 . The wheel rim 44 can also couple to the flange portion 42 ( FIG. 7 ) with the brake rotor 40 disposed therebetween, as shown in FIG. 6 . Returning to FIGS. 4 and 5 , a caliper 48 having brake pads 50 can be mounted to the suspension component 24 and can clamp against the brake rotor 40 . The brake rotor 40 can spin relative to a housing 52 of the electric motor 26 that can also connect to the suspension component 24 .
[0026] The electric wheel motor assembly 10 can generally be an annular structure symmetrical about the wheel spindle 30 . For purposes of this disclosure and with reference to FIG. 6 , the following discussion generally begins with a spindle portion 54 of the wheel spindle 30 and proceeds radially outward (upward relative to FIG. 6 ) toward the electric motor 26 , the brake rotor 40 , etc.
[0027] With reference to FIGS. 6 , 7 and 8 , the wheel spindle 30 can include the spindle portion 54 , a spindle bridge portion 56 and a ring gear portion 58 . The spindle portion 54 can define a central axis 60 about which the brake rotor 40 and portions of the planetary gearset 28 can spin. The spindle bridge portion 56 can extend in a generally perpendicular direction between the spindle portion 54 and the ring gear portion 58 . The ring gear portion 58 can be concentric with the spindle portion 54 and can be generally parallel to the central axis 60 . The ring gear portion 58 can be associated with the planetary gearset 28 and can include a plurality of gear teeth 62 that can engage gear teeth 64 on the planet gears 36 . The wheel spindle 30 can be fixedly coupled to the suspension component 24 and, therefore, the ring gear portion 58 can remain rotation less.
[0028] A first wheel bearing B 1 and a second wheel bearing B 2 can be disposed between the spindle portion 54 and the planet carrier 38 to permit the planet carrier 38 to rotate about the wheel spindle 30 . The first wheel bearing B 1 can be disposed in a position that is outboard of the second wheel bearing B 2 . Outboard can refer to a direction away from the suspension component 24 to which the wheel spindle 30 is attached. Inboard can refer to a direction toward the suspension component 24 . The first wheel bearing B 1 can establish a first imaginary plane PL that can extend in a radial direction outwardly from the first wheel bearing B 1 (i.e., radially away from the spindle portion 54 ). The second wheel bearing B 2 can establish a second imaginary plane PR that can extend in a radial direction outwardly from the second wheel bearing B 2 . The first imaginary PL and the second imaginary plane PR can be generally perpendicular to the central axis 60 .
[0029] A sun gear bearing B 3 can be disposed between the planet carrier 38 and the sun gear 32 and can permit the sun gear 32 to rotate relative to the planet carrier 38 . The sun gear 32 of the planetary gearset 28 can also be disposed between the first imaginary plane PL and the second imaginary plane PR. Moreover, the sun gear bearing B 3 can be disposed between the first imaginary plane PL and the second imaginary plane PR of the first wheel bearing B 1 and the second wheel bearing B 2 , respectively.
[0030] Further, the first wheel bearing B 1 can have an outboard face B 10 (i.e., a face farthest from the suspension component 24 ), while the second wheel bearing B 2 can have an inboard face B 21 (i.e., a face closest to the suspension component 24 ). The outboard face B 10 of the first wheel bearing B 1 can be associated with a third imaginary plane PLO. The inboard face B 21 of the second wheel bearing B 2 can be associated with a fourth imaginary plane PRI. The sun gear 32 , the planet gears 36 and/or the sun gear bearing B 3 can be contained between the third imaginary plane PLO and the fourth imaginary plane PRI.
[0031] The planet carrier 38 can be formed from a first carrier member 100 and a second carrier member 102 . The first carrier member 100 can rotatably support the planet gears 36 . The second carrier member 102 can couple to the wheel rim 44 ( FIG. 9 ) and/or the brake rotor 40 . The first carrier member 100 can include a hub portion 104 and a flange portion 106 . The flange portion 106 can include three apertures 108 . Each of the apertures 108 can receive a pin 110 that can rotatably support one of the planet gears 36 .
[0032] Each planet gear 36 can have a plurality of gear teeth 64 on an outer periphery 112 . A needle bearing 114 can be disposed between each planet gear 36 and its respective pin 110 . A pair of thrust bearings 116 can be disposed on each side of each of the planet gears 36 . While three planet gears 36 are illustrated in FIG. 7 , additional planet gears can be rotatably coupled to the flange portion 106 of the first carrier member 100 . Moreover, while straight toothed gears (e.g., spur gears) are illustrated, it will be appreciated that gears with other tooth forms (e.g., helical) and/or other suitable types of gears can be used.
[0033] The second carrier member 102 can include a flange portion 118 and a hub portion 120 . The hub portion 120 of the second carrier member 102 can couple to the hub portion 104 of the first carrier member 100 and can form a fixed (i.e., rotationless) connection between the first carrier member 100 and the second carrier member 102 . The flange portion 118 of the second carrier member 102 can have a plurality of threaded holes formed thereon to receive respective threaded fasteners, such as threaded studs (F) that can extend outwardly from the flange portion 118 . Whether using threaded studs (F) or threaded bolts, the brake rotor 40 and the wheel rim 44 can couple to the flange portion 118 of the second carrier member 102 .
[0034] The electric motor 26 can include a rotor 122 and a stator 124 . The rotor 122 of the electric motor 26 can generally include a sun gear portion 126 , a bridge portion 128 , and a magnet portion 130 . The sun gear portion 126 can be concentric with the magnet portion 130 and can be generally perpendicular to the bridge portion 128 . The bridge portion 128 can extend between and connect the sun gear portion 126 and the magnet portion 130 . The bridge portion 128 can include an annular groove 129 that can receive portions of the pins 110 that rotatably support the planet gears 36 . The sun gear portion 126 can include a plurality of gear teeth 132 and can form the sun gear 32 of the planetary gearset 28 . To that end, the sun gear portion 126 can meshingly engage with the planet gears 36 . The magnet portion 130 can extend from the bridge portion 128 and can hold one or more magnets 134 that can form an additional annular structure around the rotor that can be electrically associated with the electric motor 26 .
[0035] A plurality of electric windings 136 can be connected to the housing 52 of the electric motor 26 and can at least partially form the stator 124 of the electric motor 26 . The housing 52 of the electric motor 26 can be fixedly coupled to the suspension component 24 along with the wheel spindle 30 having its ring gear portion 58 . As voltage is applied to the electric motor 26 , the input torque can be delivered to the planetary gearset 28 via the sun gear portion 126 of the rotor 122 . Because the stator 124 and the ring gear portion 58 of the wheel spindle 30 are maintained in a non-rotating condition (i.e., remain rotationless) in the example provided, the electric motor can drive the planet carrier 38 via the planet gears 36 .
[0036] The housing 52 of the electric motor 26 can contain the plurality of electric windings 136 that can form the stator 124 of the electric motor 26 . The windings 136 can include a suitable copper wire winding pattern. The windings can remain rotationless within the housing 52 but the magnets 134 can be coupled to the magnet portion 130 of the rotor 122 and can be generally opposite the windings 136 and form an air gap therebetween. The magnets 134 of the rotor 122 , therefore, can spin relative to the windings 136 , when voltage is applied to the electric motor 26 .
[0037] The housing 52 of the electric motor 26 can include a first seal S 1 and a second seal S 2 . The first seal S 1 can seal the rotor 122 to the housing 52 . The second seal S 2 can seal the rotor 122 to the wheel spindle 30 at a location that can be near the spindle bridge portion 56 and the ring gear portion 58 . As such, the first seal S 1 and the second seal S 2 can provide a seal (e.g., a lubrication seal) between the planetary gearset 28 and the plurality of windings 136 of the electric motor 26 . The windings 136 can be disposed a predetermined distance away from the plurality of the magnets 134 to insure the air gap therebetween.
[0038] A third seal S 3 can seal the sun gear bearing B 3 to maintain the lubrication for the sun gear bearing B 3 . A fourth seal S 4 can seal the first wheel bearing S 1 to the hub portion 120 of the second carrier member 102 and to the wheel spindle 30 and, therefore, seal lubrication in the planetary gearset 28 for, among other things, the first and second wheel bearings B 1 , B 2 .
[0039] A plurality of cooling fins 200 can extend radially outward from the housing 52 of the electric motor 26 . The cooling fins 200 can be exposed to the environment. In this regard, the cooling fins 200 can facilitate heat removal from the electric motor 26 , as heat is dispersed into the surrounding environment.
[0040] In one aspect of the present teachings and with respect to FIG. 9 , the brake rotor 40 can contain a plurality of vanes 202 that can be configured to forcefully direct air over the cooling fins 200 on the housing 52 , when the brake rotor 40 spins relative thereto. The electric motor 26 generates heat when it provides torque to drive the planetary gearset 28 and thus drive the wheel rim 44 and tire 46 . When the vehicle 14 is moving, whether there is power to the electric motor 26 or not, the rotation of the tire 46 , and thus the rotation of the brake rotor 40 , can provide forced air or active cooling to the electric motor 26 . In this regard, rotation of the brake rotor 40 can force cooling air from the vanes 202 of the brake rotor 40 over the cooling fins 200 to cool the electric motor 26 .
[0041] With reference to FIG. 5 , the brake caliper 48 can be coupled to (or packaged with) the electric wheel motor assembly 10 and can provide a braking mechanism that can slow the brake rotor 40 and thus slow the vehicle 14 . The brake caliper 48 can include a parking brake assembly 300 to further provide parking brake functionality, when the vehicle 14 is on a hill or otherwise. The parking brake assembly 300 can include an arm 302 and a lever 304 that can be biased in a first position by a spring 306 . The arm 302 can hold a brake cable 308 from which an actuator line 310 can extend. The actuator line 310 can pass through the arm 302 and can be held by the lever 304 . By pulling on the actuator line 310 , e.g., via a brake lever (not shown) in the vehicle, the lever 304 can be drawn toward the arm 302 and can extend a piston (not shown) in the brake caliper 48 toward the brake rotor 40 . As the force on the brake cable is released, the lever 304 can return to an initial position away from the arm 302 , urged by the spring 306 . The parking brake assembly 300 can then release the piston (not shown) to move away from the brake rotor 40 .
[0042] In one aspect, the suspension component 24 to which the electric wheel motor assembly 10 can couple can be a wheel bearing mount 400 that can be coupled to a spring pocket 402 . A brace 404 can further secure the electric wheel motor assembly 10 to the wheel bearing mount 400 . A spring seat 406 can be coupled to the spring pocket 402 and can receive, for example, a spring (not shown) that can suspend the electric wheel motor assembly 10 from the vehicle 14 . A control arm 408 can couple to the spring pocket 402 and can further couple to other portions of the vehicle body 14 a ( FIG. 3 ) via a bushing sleeve 410 . In addition, a twist beam mounting plate 412 can couple to the control arm 408 . The wheel bearing mount 400 can extend through a back cover 68 ( FIG. 7 ) of the housing 52 of the electric motor 26 and can couple to the wheel spindle 30 . It will be appreciated that the hybrid electric all wheel drive system 12 ( FIG. 3 ) need not rely on any specific vehicle suspension configuration and further need not rely on access to a transmission or exhaust tunnel. In this regard, the all wheel drive system 12 can be implemented on or with any type of suspension.
[0043] In accordance with one aspect of the present teachings and with reference to FIG. 3 , the hybrid electric all wheel drive system 12 can provide a part time drive to the rear wheels 22 of the vehicle 14 . Myriad situations can benefit from drive torque delivered to the rear wheels 22 , such as, but not limited to, a situation requiring sudden acceleration. In this regard, an engine computer 500 and/or an electric all-wheel drive module 502 can detect that a driver is requesting more power. The engine computer 500 and/or the electric all-wheel drive module 502 can then activate the all wheel drive system 12 to provide additional torque to the real wheels 22 , while the engine 18 of the vehicle 14 can provide torque to the front wheels 20 via a suitable drivetrain 504 . The electric all-wheel drive module 502 can regulate power directed from a battery 508 to the driver side electric motor assembly 10 a and/or to the passenger side electric motor assembly 10 b . In this situation, the torque from both the engine 18 and the all wheel drive system 12 can provide relatively faster acceleration time compared to torque only delivered to the front tires 20 .
[0044] In a stability control situation, the engine computer 500 and/or the electric all-wheel drive module 502 can detect slip from one of the vehicle wheels 20 , 22 and can, therefore, provide torque to one or both of the rear wheels 22 to aid in the stability situation. A conventional anti-lock brake system can be employed, for example, to detect slip at each of wheels 20 , 22 . The electric motor assemblies 10 can be controlled by a control module 512 that can be part of or included with the engine computer 500 and/or the electric all-wheel drive module 502 . The control module 512 can also be resident in other portions of the vehicle 14 .
[0045] A wheel spindle from a conventional rear wheel assembly can be removed from a wheel bearing mount 510 . When the conventional rear wheel assembly is removed, the brake rotor, wheel rim and brake caliper or brake drum can also be removed with the conventional assembly. The electric wheel motor assembly 10 a , 10 b can then be mounted to the wheel bearing mount 510 . Specifically and with reference to FIGS. 3 , 5 and 7 , the back cover 68 of the housing 52 can include an aperture 70 sized to receive the wheel bearing mount 400 such that the wheel bearing mount 400 can pass through the housing 52 of the electric motor 26 and couple to the wheel spindle 30 . Moreover, the brake caliper 48 can couple to a flange 72 coupled to the wheel bearing mount 400 and can clamp against the brake rotor 40 when the service brakes (not specifically shown) are engaged.
[0046] In accordance with one aspect of the present teachings, each of the electric wheel motor assemblies 10 can, after the gear reduction of the planetary gearset 28 , provide drive torque to each of the rear wheels 22 . In particular example provided, each electric wheel motor assemblies 10 can provide a maximum torque of about 250 foot pounds for about sixty seconds. When producing less torque, the electric wheel motor assemblies can be activated for longer periods. It will be appreciated that using the planetary gearset 28 in series with the electric motor 26 can provide the ability to reduce the size of the electric motor 26 because of the mechanical advantage of the planetary gearset 28 . Moreover, because the all wheel drive system 12 can be a part time system, and therefore not full time system, liquid cooling of the electric motor 26 may not be necessary. As such, the all wheel drive system 12 can be a completely air-cooled system.
[0047] While specific aspects have been described in this specification and illustrated in the drawings, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present teachings, as defined in the claims. Furthermore, the mixing and matching of features, elements and/or functions between various aspects of the present teachings may be expressly contemplated herein so that one skilled in the art will appreciate from the present teachings that features, elements and/or functions of one aspect of the present teachings may be incorporated into another aspect, as appropriate, unless described otherwise above. Moreover, many modifications may be made to adapt a particular situation, configuration or material to the present teachings without departing from the essential scope thereof. Therefore, it may be intended that the present teachings not be limited to the particular aspects illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out the present teachings but that the scope of the present teachings will include many aspects and examples following within the foregoing description and the appended claims. | A drive axle assembly for driving a wheel of a vehicle includes a moveable suspension arm and a wheel spindle fixed to the suspension arm. A planetary gearset includes a sun gear, a ring gear and a carrier rotatably supporting a plurality of planet gears in meshed engagement with the sun gear and the ring gear. The carrier encompasses the wheel spindle and is drivingly connected to the wheel. An electric motor includes a rotor and a stator. The rotor drives the sun gear. |
This is a continuation of application Ser. No. 07/661,133, filed Feb. 27, 1991, which is a continuation-in-part of application Ser. No. 07/337,760, filed Apr. 13, 1989, now abandoned.
FIELD OF THE INVENTION
The present invention relates to fills for pneumatic tire casings. A preferred embodiment of the present invention is directed to novel and unobvious method of manufacturing an elastomeric fill for a pneumatic tire casing and in a novel and unobvious method of fitting the fill into the casing to provide a soft-core flat-proof tire. More specifically, the preferred embodiment of the present invention contemplates extruding and molding strips of elastomer to predetermined dimensions to accommodate various sizes of tire casings. The strips of elastomer which can accommodate a variety of different tire casings are then subsequently shipped to remote locations, such as mines, to be installed into a predetermined size of tire casing as required. The elastomer can be extruded and molded into large flat sheets and shipped to the remote location where slitting machines can be employed to dimension the side edges to interfit the tire casing in increasing and decreasing widths as the tire casing dimension requires.
BACKGROUND OF THE INVENTION
It is known to provide a pneumatic tire casing with a fill to create a flat-proof assembly when fitted to a wheel of a vehicle. One common method is to assemble the tire and wheel and employ a valve to fill the cavity with a hardening material under pressure which when in place can be allowed to harden and create the fill. Once such material is urethane liquid accompanied by a hardening agent. Other polymers can be used and can be cured within the casing.
Urethane filled tires have a number of disadvantages associated therewith. Specifically, the known methods of filling urethane are performed while the tire casing is on the wheel and the curing and vulcanizing of the fill often requires a factory site. Further, urethane filled tires cannot be employed on vehicles which are to be driven at high speeds. This limitation is due to the fact that urethane tires when driven at high speeds experience heat build-up between the rubber tire casing and the urethane fill.
Furthermore, urethane is expensive and cannot be reused when the tire casing is worn out and subsequently discarded. Urethane filled tires provide a rough ride which is unacceptable to machine operators who must drive their vehicles during an entire working day. Further, filled tires have a high rolling resistance which contributes to the rough ride and results in high fuel consumption. Finally, filled tires are difficult to retread and due to the problem of casing stretching often become loose at the rim resulting in a loss of pressure.
Where solid vulcanized polymers other than urethane are used as tire fills, similar problems are encountered, especially reversion to liquid when used at high speeds resulting from the heat generated between the casing and the fill. The polymer in liquid form can leak from a loose rim or a cut or puncture in the tire casing. Low density foamed rubber is preferable, if it could maintain its strength at high speeds.
The best known of the presently used tire fill systems is the use of high density foam rubber as illustrated in U.K. Patent Application No. 2,164,903A. As is described in this patent, independent concentric rings of high density foam rubber are manufactured and installed in pneumatic tire casings. However, there are a number of disadvantages inherent in manufacturing and installing independent concentric rings in pneumatic tire casings. First, due to the vast number of different sizes and shapes of tires, it would be necessary for an installer to carry a huge inventory of rings. Further, the tooling required to produce the vast number of shapes and sizes of concentric rings is extremely expensive. Finally, forming the filler layers in concentric rings hinders their insertion into the pneumatic tire casing.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
An object of the present invention is provide a means of filling many different shapes of tires with a polymeric filler which can be easily made and inserted in large or small shops or in the field with minimal skill and equipment.
It is another object of the present invention to provide a polymeric fill for a tire casing which gives a ride comparable to a pneumatic tire but which is puncture resistant and flat-proof.
A further object of the present invention is to provide a method of manufacturing a variety of fill members that will fit different sizes of casings by extruding, molding and curing the polymer in strip form having the thickness and side edges of the fill members predetermined by the mold and then providing a cross-cutting step to create a layer suitable for insertion as one of a plurality of layers of the fill for a pneumatic tire.
Yet a further object of the present invention is to install the layers of fill such that the total volume of layers making up the fill is equal to or greater than the internal volume of the casing to allow the fill to be pressed into the casing when fitted to a wheel resulting in a tire and wheel combination having load bearing capabilities.
Still yet another object of the present invention is to provide a simple and inexpensive method of obtaining the profile of a tire casing in the relaxed and stretched states for use in forming the particular configurations of the fill layers therefor.
Still a further object of the present invention is to oversize the innermost layer, i.e. the layer adapted to be positioned adjacent the wheel-rim, by a percentage based on the percentage of air cells therein to securely fasten the tire casing to the wheel-rim.
These objects and advantages as well as others will be readily apparent from a review of the specification, the claims and the accompanying drawings.
In summary, the present invention herein disclosed contemplates the teaching of a process and method of making a reusable fill in the form of concentric layered strips of high density pressurized foam rubber for installation in a pneumatic tire casing. The preferred embodiment of the present invention includes the steps of: Extruding into a mold a sheet or strip of high density foam rubber where the mold sides are shaped to create on the molded cured strip a shape compatible with the taper of the inside of the casing wall of a tire to be filled; fitting the strips in layers into the tire casing, each of the layers being cut and dimensioned by width and length to fit in close snug abutment with its ends to itself and its sides to the casing walls and succeeding layers; spreading open the casing walls at the bead of the tire to receive the inner layers of the fill in an expanded or overfill mode; releasing the spread-open casing walls to thereby contain the concentric layers together tightly in the casing; and, forcing a wheel-rim onto the filled tire casing under pressure to create a tire-wheel combination for load-bearing road use.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a tire casing cut from tread to bead depicting section by section the layers of fill mating one with another and tapered during molding differently by degrees along their mating edges with the casing wall. The dotted lines show the position of the walls when the casing is spread open to receive the upper or last layers which are overly wide by the predetermined amounts to obtain the required fill pressure by compression when the wheel rim is pressed over the beads.
FIG. 2 is a cross-sectional view of the tire casing with the fill layers removed therefrom and a flexible material inserted therein to obtain a profile. The dotted lines depict the tire casing and flexible member in the spread state.
DETAILED DESCRIPTION OF THE INVENTION
Numeral 10 designates a pneumatic tire casing shown cut in profile to reveal the cross section of the casings walls 21 and 22, the tread area 23 and the bead portions 24 and 25. The dotted lines 26 and 27 designate the profile of the casing walls as spread open by a tire spreader to receive the layers of foam rubber. The layers are designated 11 through 20. Preferably, the thickness of the layers vary from one quarter inch to one inch. As is readily evident from FIG. 1, the width of the layers vary depending upon their particular position in the tire casing 10.
Each of the layers 11 through 20 has been designed and shaped by the flat cure mold to have a variable angle of contact 28 with the sidewalls of the casing. The manner in which the angle of contact is determined will be explained in detail below. The upper layers 14 through 20 are oversized by a predetermined amount to provide the desired pressurization of the tire casing 10 when mounted on the wheel-rim 30. With the aid of the tire press the casing 10 with its layers 11 through 20 inserted therein is pressed onto the wheel-rim 30. Subsequently, the lock ring 31 is forced over one side of the casing 10 to pack the fill layers 11 through 20 therein and to maintain the casing on the wheel-rim at the predetermined pressure.
METHOD OF MANUFACTURING AND INSTALLING THE FILL LAYERS
The preferred method of manufacturing and installing the fill layers 11 through 20 will be described hereinafter.
In order to appropriately engineer, design and manufacture the layers 11 through 20, it is necessary for the manufacturer to determine the intended uses of the soft-core, flat-proof pneumatic tire including the type of machine on which the wheels are to be mounted, the speeds at which the machine is driven, the environment in which the machine is used and other related background information.
Further, it is necessary for the manufacturer to obtain the dimensional data for the particular pneumatic tire casing. More specifically, it is beneficial for the manufacturer to obtain the profile of the interior of the casing, the inner diameter of the casing, the rim width of the wheel upon which tire casing is to be mounted, the width of the beads of the tire casing, the volume of fill material necessary to pressurize the pneumatic tire to a predetermined pressure and similar data.
The manufacturer, using the above information, can readily determine the particular type of rubber to use, the level to which the rubber is to be foamed, the specific dimensions for the layers and the number of layers to be used in a particular tire casing. The following examples will clearly illustrate the preferred method of manufacturing the layers 11 through 20.
If it is determined that the filled tire is to have an internal pressure of 100 psi, the volume of fill needed to obtain this pressure is preferably obtained as follows. The particular tire casing is pumped with water to pressurize the tire casing to 100 psi. Subsequently, the tire casing is weighed. From the weight of the tire casing and the specific gravity of the material of the fill, one can readily obtain the corresponding volume of fill which will pressurize the tire casing to 100 psi.
Subsequently, the inner diameter of the tire casing is measured in the relaxed and spread states. From the inner diameter of the tire casing, one can readily determine the length of the outermost layer 11, i.e. the layer positioned directly adjacent the tread of the tire casing. The length for the subsequent layers can be readily determined by using the value of the inner diameter and subtracting two times the total thickness of any intermediate layers. More specifically, if one is trying to determine the length of layer 13, he merely subtracts two times the combined thickness of layers 11 and 12 from the inner diameter of the tire casing 10. It is important to measure the inner diameter in both the relaxed and spread states for the following reasons. When the tire casing is spread by a spreader, the inner diameter shrinks a predetermined amount. Therefore, if the length of the layers 11 through 20 were determined in the relaxed state irrespective of the spread state, the installer may be prevented from or hampered in the installation of the layer because of the shrinkage in the inner diameter of the tire casing when spread by a tire spreader. Therefore, the length of the layer is sized to fall within a range of lengths corresponding to the spread inner diameter and the relaxed inner diameter. Accordingly, the step of measuring the inner diameter in both the relaxed and spread states facilitates the insertion of the layers therein.
The profile of the tire casing 10 is obtained in the following manner. Preferably, a flexible member 32, such as a copper wire, is inserted into the tire casing 10. Subsequently, the copper wire is deformed to conform with the interior of the tire casing 10, as seen in FIG. 2. This procedure is performed both when the tire casing is in the relaxed state (solid lines) and when the tire casing is in the spread state (dotted lines). The angle of contact 128 for each of the layers 11 through 20 is readily determined from the profile of the tire casing in the relaxed state. Thus, the precise manner in which to orient the side edges of the mold to form the desired angles in the side edge of the layers 11 through 20 can be readily determined.
The profile of the tire casing in the spread state provides the manufacturer with a maximum width for the layers 11 through 20. More specifically, it is desirable to make sure that the width for any particular layer does not exceed the width of the corresponding section of the profile taken in the spread state.
The manner for determining the specific width of layer 20 will be described hereinafter. The distance-between the sidewalls of the tire casing in the relaxed state can be readily determined by subtracting the width of beads 24 and 25 from the width of the wheel-rim 30. For example, if the width of the wheel rim is 6.5 inches and the combined thickness of beads 24 and 25 is one inch, the distance between the inner walls of the tire casing at the uppermost point thereof is approximately 5.5 inches. If the upper surface of layer 20 is provided with a width of 5.5 inches and sides edges are angled to conform to the profile of the tire in the relaxed state, the layer 20 would not experience any compression loads when the tire casing 10 is mounted on the wheel-rim 30. It is desirable to place the layer 20 under compression loads to provide a force fit between the beads 24 and 25 and the wheel-rim 30.
However, if the layer 20 is placed under excessive compression loads, the percentage of air cells therein will be negligible. This is undesirable because the advantages of a soft-core are lost. Moreover, excess compression will cause the layer 20 to buckle toward the tire tread 23 resulting in the side edges losing contact with the inner walls of the tire casing 10.
To avoid these undesirable results, the layer 20 is oversized such that when inserted into the tire casing 10 and mounted on the wheel-rim 30 it will not be compressed a percentage which exceeds the percentage of air cells therein. The percentage of air cells in the layers 11 through 20 varies depending upon the use of the pneumatic tire into which they are to be inserted. Specifically, if the tire is to be placed under heavy loads the percentage of air cells is kept to a minimum. However, if the tires are not placed under heavy loads, the percentage of air cells is increased. Preferably, the percentage of air cells in the layers 11-20 ranges from approximately 5% to approximately 40%.
If the tire casing 10 is to be placed under heavy loads, the layer 20 is preferably formed such that it contains approximately 15% air cells and approximately 85% rubber. Thus, the layer 20 is not to be oversized such that it will be compressed greater than approximately 15% of its volume. If such compression were to occur, the layer would no longer have any air cells therein and would be merely a solid fill rather than a soft fill. Preferably, the layer 20 is oversized such that the percentage of compression of the layer does not exceed 75% of the percentage of air cells therein. The layers 14 through 19 are oversized by an amount such that when the total volume of the layers 11 through 20 is compiled, it equals the volume required to pressurize the tire casing 10 to the desired amount. In a number of instances, the layers 14 through 19 are compressed by a percentage less than the percentage of the compression of layer 20. However, the layers 14 through 19 are not to be oversized by an amount which would cause the layers to be compressed by a percentage exceeding the percentage of air cells therein.
With the above information, one can readily determine the number of layers and the configuration of each layer to be inserted into a particular type of tire casing. Preferably, the manufacturer forms large sheets of foam rubber at a site remote from the installation site. The large sheets may be formed such that the width thereof corresponds to the width of a particular layer when installed. Moreover, the sides of the sheet may be oriented to correspond to the angle of contact 28 for a particular layer. The large sheet is provided with a length which will permit an individual to cut the same along its transverse axis to form a number of sections which have the desired dimensions for a concentric layer in a predetermined size tire casing.
Alternatively, the large sheet may be formed with a width sufficient to permit the sheet to be cut along its longitudinal axis to form a plurality of sections which have the desired dimensions for concentric layers. The large sheet is cut such that the desired angle is formed in the side edges of the sections. These are only two of the many ways in which the large sheet may be formed so that it has a sufficient size to form a plurality of fill layers.
The manufacturer supplies the installer with data sheets informing the installer of the number of layers and specific dimensions thereof to be inserted into a particular size tire casing. The data sheets are compiled from the information obtained above. Samples of the tire data sheets are listed below.
__________________________________________________________________________EXAMPLE ATIRE SIZE 825 × 15RIM = 6.5" BEAD = 1"P.S.I.: 100 WATER WEIGHT 147 5% COMPRESSIONMOLD ANGLE THICKNESS TOTAL WIDTH TOTAL LENGTH__________________________________________________________________________ 25 1 in. Thick × 6.5 in. Wide × 88.965 inches 55 1 in. Thick × 9.5 in. Wide × 82.074 inches 72 1 in. Thick × 10 in. Wide × 75.79 inches 90 1 in. Thick × 10 in. Wide × 69.115 inches104 1 in. Thick × 10 in. Wide × 62.439 inches132 1 in. Thick × 9 in. Wide × 55.763 inches112 1 in. Thick × 7 in. Wide × 49.48 inches__________________________________________________________________________EXAMPLE BTIRE SIZE 825 × 15RIM = 6.5" BEAD = 1"P.S.I.: 75 WATER WEIGHT 140 5% COMPRESSIONMOLD ANGLE THICKNESS TOTAL WIDTH TOTAL LENGTH__________________________________________________________________________ 25 1 in. Thick × 6.5 in. Wide × 88.965 inches 55 1 in. Thick × 9 in. Wide × 82.074 inches 72 1 in. Thick × 9.5 in. Wide × 75.79 inches 90 1 in. Thick × 9.5 in. Wide × 69.115 inches104 1 in. Thick × 9.5 in. Wide × 62.439 inches132 1 in. Thick × 8.5 in. Wide × 55.763 inches112 1 in. Thick × 6.5 in. Wide × 49.48 inches__________________________________________________________________________
Examples A and B illustrate the fill for the same size tire casing but under different internal pressures. Specifically, Example A refers to a tire casing placed under 100 psi while Example B refers to the same tire casing placed under 75 psi. The only difference in Examples A and B is that the width of some of the layers in Example B is less than that of Example A. Accordingly, the volume of the fill in Example B is less than that for Example A. With this information an installer, at a site remote from the manufacturing site, can readily form the fill layers for the above-identified tire size at 75 psi and 100 psi. It will be readily appreciated that the data sheets for differently sized and pressurized tires are formed in the same manner.
Once the installer has cut the large sheet to form the appropriate number of layers, the tire casing is spread by a tire spreader. Subsequently, each of the layers is inserted into the tire casing. A tire press is used to secure the tire casing to the wheel rim.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptions of the invention following in general the principle of the invention including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains, and as may be applied to the central features set forth and fall within the scope of the invention and the limits of the appended claims. | The preferred embodiment is directed to a pneumatic tire having a plurality of layers of high density foam rubber formed therein and methods of manufacturing and installing the layers therein. The preferred method of forming the layers of fill to be inserted in the pneumatic tire casing includes the following steps. Forming an elongated strip of elastomeric material of a size sufficient to form at least two concentric layers in a predetermined size casing of a pneumatic tire at a manufacturing site. At least one dimension of the elongated strip is the same as at least one dimension of the two concentric layers when inserted in the casing. Formulating data sheet having information from which the elongated strips can be cut to form the at least two layers for at least one predetermined condition. Transporting the elongated strip of the elastomeric material and the data sheet to an installation site remote from the manufacturing site. |
FIELD OF THE INVENTION
The invention relates generally to agricultural and construction vehicles, and more particularly to skid steer loaders. The invention, in combination with existing locking pins, prevents loader arms from moving in two directions.
BACKGROUND OF THE INVENTION
Skid steer loaders and other work vehicles with traversing booms typically require maintenance both in the field and in a dedicated repair shop. The repairman needs access to all parts of the vehicle. Lifting the booms to an intermediate position is required, allowing manual access to the otherwise blocked area of, for example, a skid steer loader. Skid steer loader arms, or booms, are hydraulically controlled. If there are small leaks in the hydraulic system, the booms will slowly lower over time. To avoid this, there are various common mechanisms for preventing booms from lowering inadvertently. These include locking the boom control levers in the operator cab, placing a block such as a drum under the implement at the end of the booms, and locking the boom(s) itself.
In the area of boom locking devices the prior art teaches various methods of locking a boom for transport. Typically the boom is lowered against the chassis such that the chassis blocks movement in one direction and the boom lock blocks movement in the opposite direction. One example of a transport boom lock uses an operator in-cab control with a linkage to a pin or hook assembly that locks a backhoe boom against the chassis in the boom's fully upright position. While this locks the backhoe boom against all movement, it requires the boom to be in a non-working position, i.e. fully upright, as for transport. This blocks access to part of the backhoe for repair.
The prior art also teaches locks that are carried on the boom itself, either on the housing, rod or cylinder, locking the boom in an intermediate position. One example teaches a lock that is placed on the end of the hydraulic cylinder, and acts against the rod and cylinder, preventing retraction of the rod into the cylinder and thereby preventing the loader arm from lowering. This method only prevents the boom movement in one direction relative to the boom itself, that of the rod retracting into the cylinder, i.e. boom contraction.
The prior art also teaches locking pins that extend through the cab wall and extend into the plane of the skid steer loader arms, locking the booms in an intermediate position. This method prevents the loader arms from lowering with respect to the cab, but not from raising.
However, in the case of a skid steer loader with a removable combined cab and boom assembly, the situation is different. The cab and boom are tilted away from the base of the vehicle during the repair. As a result, the boom overhangs the end of the vehicle considerably. While the skid steer loader may be equipped with locking pins or sliding bars that prevent the loading arms from lowering (see U.S. Pat. No. 3,730,362 for a complete description of the layout and function of such locking pins), the weight of the cab and boom assembly will tend to pull the boom arm upwards from the cab and away from the locking pins. During repair, the implement at the end of the boom arms (bucket, rake, blade, dozer blade, etc) will typically be supported on a stand. By the force of gravity, the tilted cab boom assembly will descend toward the ground if there is a hydraulic leak, causing the boom arms to pivot upward with respect to the cab. In other words, the existing locking device only prevents the boom from pivoting downward with respect to the cab, and what is needed is a second complimentary device, or boom clamp, to prevent boom movement in the other direction. What is further needed is a simple, low cost-to-manufacture boom clamp. What is also needed is a clamp that a repairman or operator can install and remove quickly without tools when needed. What is further needed is a boom clamp that will not pinch hydraulic cables.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a boom clamp for a work vehicle having a lock and a boom, said lock configured to prevent movement of the boom in a first direction is provided, the boom clamp comprising a restraint configured to engage the boom, and a sleeve fixed to the restraint, the sleeve configured to engage the lock, wherein the restraint prevents the boom from moving in a second direction.
The second direction may be opposite the first direction. The lock may be movable between a first position and a second position, wherein the lock does not prevent the boom from moving in the first direction when the lock is in the first position, wherein the lock prevents the boom from moving in the first direction when the lock is in the second position, and further wherein the restraint prevents the boom from moving in the second direction when the lock is in the second position. The clamp may be configured to be installed and removed by an operator without tools. The boom clamp may further comprise a handle configured to be grasped by an operator during installation and removal of the clamp. The sleeve may be configured to surround the lock. The lock may be a pin and the sleeve may be a cylinder. The restraint may comprise a first plate fixed to the sleeve and configured to face a lower surface of the boom, a second plate fixed to the first plate and configured to extend parallel to the boom, and a third plate fixed to the second plate configured to face an upper surface of the boom. The boom may further include hydraulic lines, and a shroud surrounding the hydraulic lines, wherein the restraint is configured to surround the shroud.
In accordance with a second aspect of the invention, a boom lock for a skid steer loader, said skid steer loader having a chassis, an operator cab removably attached to the chassis, and a boom pivotally coupled to the operator cab is provided, the boom lock comprising first means for preventing the boom from pivoting in a first direction with respect to the cab, and second means for holding the first means and the boom together.
The second means may prevent the boom from pivoting in a second direction with respect to the cab. The first means may comprise a locking pin movably attached to the cab. The second means may comprise a boom restraint and a pin sleeve. The second means may be removably attached to the first means and the boom.
In accordance with a third aspect of the invention, a method for locking a boom on a work vehicle is provided, comprising the steps of extending a locking pin to prevent motion of the boom in a first direction, and coupling a clamp to the locking pin after the step of extending, to prevent motion of the boom in a second direction.
The step of extending may include extending the locking pin from an operator cab. The step of extending may include moving the boom to a position adjacent the locking pin. The step of coupling may include sliding the locking pin into a hole in the clamp after the step of extending. The clamp may be c-shaped and the step of coupling may include sliding the clamp around the boom. The step of coupling may include sliding the clamp around a protective shroud.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a skid steer loader with the invention attached.
FIG. 2 is a partial perspective view of the skid steer loader from FIG. 1 showing a loader arm with locking pin extended and without the invention attached.
FIG. 3 is identical to FIG. 2 except the invention is attached.
FIG. 4 is a cross section view of the skid steer loader taken at line 4 — 4 of FIG. 3 showing the cab wall, boom and extended locking pin, with the invention attached.
FIG. 5 is a perspective view of the invention from the handle (back) side.
FIG. 6 is a perspective view of the invention from the front side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a skid steer loader 100 for material handling viewed from the left side, with the booms locked in an intermediate position according to the present invention. The “front” of the vehicle is defined as the direction of normal forward movement and the direction the operator will face when operator will face when operating the vehicle to handle materials, and is shown in FIG. 1 by the directional arrow F. The directions of boom movement of “up” and “down” are relative to the operator cab.
The loader includes wheels 102 , a main body frame 104 , and a cab boom assembly 106 . The wheels 102 (left front and rear wheels shown, right front and rear wheels not visible in this drawing) are rotatably coupled to and support the main body frame 104 . The main body frame 104 encloses the engine, drive mechanism, and hydraulics (not shown), and supports the cab boom assembly 106 .
The cab boom assembly 106 is removably attached to the main body frame and rests on top of the frame. The assembly 106 includes the operator cab 108 , the boom structure 110 , and the boom clamp 111 . The operator sits in the operator cab while operating the skid steer loader. Operator controls and seat (not shown) are enclosed by the cab. The cab is composed of left and right sidewalls 112 , a roof, and a (left, right) pair of boom locking pins 113 . The right sidewall and roof are not visible in FIG. 1 . The boom structure 110 is pivotally attached to the left and right side of the cab 108 .
The boom structure 110 uses hydraulics and a four-bar linkage to move materials with an implement according to operator commands issued via control levers in the cab 108 . The FIGS. 1–4 show only the left side portion of the boom structure 110 . An identical mirror-image right side boom structure (not shown) is coupled to the right side of the cab. The left side portion and the right side portion together comprise the boom structure 110 . In all ways other than as stated below, the function and interconnection of the right boom elements is identical to that of the left boom elements. The boom structure comprises left side and right side upper boom arms 114 , left and right side lower boom arms 116 , left and right side supporting links 118 , left and right side hydraulic cylinders 120 , left and right side linkage plates 122 and an implement mounting plate 124 . Further description relates to the left side interconnections of the boom structure, however the right side of the boom structure is interconnected identically.
The upper boom arm 114 , the supporting link 118 , the hydraulic cylinder 120 and the lower boom arm 116 are all coupled to the linkage plate 122 and, together with the cab, create a four-bar linkage. One end of the lower boom arm 116 is pivotally attached to a rearward section of the sidewall 112 of the cab 108 and extends generally rearwardly and upwardly. The other end of the lower boom arm is pivotally attached to a lower portion of the linkage plate 122 . The cylinder end of the hydraulic cylinder 120 is pivotally attached to a central section of the sidewall 112 and extends generally rearwardly and upwardly. The rod end of the hydraulic cylinder is pivotally attached to a central section of the linkage plate 122 . One end of the supporting link 118 is pivotally attached to an upper section of the sidewall 112 and extends generally rearwardly. The other end of the supporting link is pivotally attached to an upper section of the linkage plate 122 . One end of the upper boom arm 114 is pivotally attached to the implement holder 124 and extends generally rearwardly and upwardly, curving down. The other end of the upper boom arm is fixed to an upper section of the linkage plate 122 .
The boom structure 110 operates in a left vertical plane parallel to the left sidewall 112 and a right vertical plane parallel to the right sidewall 112 (not shown). By extending the hydraulic cylinder 120 , the four-bar linkage moves such that the implement holder 124 located at the front end of the upper boom arms 114 moves upward. Conversely, retracting the hydraulic cylinder moves the implement holder downward. Further details of the boom structure can be found in U.S. Pat. No. 3,215,292.
Locking pins 113 (only the left side shown, an identical pin exists on the right side) are slidably supported by the cab of the vehicle. They are configured so the operator can slide them laterally and horizontally from a first position in which they do not interfere with the movement of the boom to a second outward position where they interfere with the movement of the boom, preventing it from pivoting downward. (See FIGS. 2 & 3 and additional details in U.S. Pat. No. 3,730,362 which is incorporated herein by reference for all that it teaches.)
In FIG. 1 , the operator has extended the hydraulic cylinder 120 far enough such that the lower boom arm 116 is above locking pin 113 . The operator has then engaged the locking pin 113 by moving it from the first non-interfering position laterally outward from loader 100 to the second interfering position. The locking pin 113 extends through the sidewall 112 of the operator cab 108 and crosses the left vertical operation plane of the boom structure 110 . The operator has then retracted the hydraulic cylinder and lowered the lower boom arm 116 until it is close to or resting on the locking pin 113 . The operator has then installed the boom clamp 111 , by getting out of the vehicle, picking up the boom clamp, orienting it with the locking pin 113 , orienting it with the lower boom arm 116 , and simultaneously sliding it over the lower boom arm 116 and the locking pin 113 . The combination of the locking pin and the boom clamp prevent the lower boom arm, and thus the entire boom structure 110 , from pivoting either upward or downward with respect to the cab 108 . The hydraulic cylinder 120 is under compression from the weight of the boom structure 110 .
FIG. 1 also shows, in phantom, a tilted position 126 of the cab boom assembly 106 . This is a common position during repairs, allowing the repairman access to the components contained within the main body frame 104 . It can be seen that tilting the cab boom assembly 106 toward the front moves more of the boom structure 110 and cab 108 closer to or forward of a vertical centerline of the vehicle. This causes the weight of the cab, implement holders 124 and upper boom arms 114 to act upon the hydraulic cylinder 120 such that the cylinder is under extension rather than compression. When the cab 108 is tilted thusly, if there is a hydraulic leak the weight of the cab will tend to cause the cylinder to extend and the lower boom arm 116 to pivot upward with respect to the cab unless the lower boom arm is locked from upward movement (with respect to the cab) with the boom clamp 111 . Thus the boom clamp provides additional useful boom locking functionality as compared to the locking pin 113 which only prevents the lower boom arm 116 from moving downward (with respect to the cab).
FIGS. 2 & 3 show the left lower boom arm 116 in intermediate locked position and the locking pin 113 in its second interfering position. The FIGURES are identical except FIG. 3 shows the boom clamp 111 installed and does not show the hydraulic cables 206 . The locking pin 113 extends outward through the sidewall 112 and beneath the lower boom arm 116 . The lower boom arm includes a lower surface 200 , a wear plate 201 , an outer surface 202 , an upper surface 400 ( FIG. 4 ), an inner surface 402 ( FIG. 4 ), a protective shroud 204 and hydraulic cables 206 (shown in phantom). The lower surface, inner surface, outer surface and upper surface are fixed to each other such that they form a beam of rectangular cross section. The wear plate 201 is parallel to and fixed to the bottom of the lower surface 200 , and strengthens the area where the boom rests on the locking pin 113 . The wear plate only extends 4–6″, providing a stop for the locking pin to rest against. The shroud 204 is also generally rectangular in cross section, and is attached to the upper surface 400 of the lower boom arm 116 . In the present embodiment, the shroud does not extend the entire length of the lower boom arm, but only extends 6–8″, and is open at both ends. This is sufficient to restrain the hydraulic cables 206 inside the shroud. The cables run parallel to the lower boom arm 116 , entering the shroud 204 at one open shroud end and leaving at the other open shroud end.
The lower boom arm 116 pivots about a point 208 where it is connected to the sidewall 112 . The lower boom arm pivots in a first direction downward, shown by arrow A. The lower boom arm also pivots in a second direction upward, shown by arrow B. The locking pin 113 contacts the wear plate 201 of the lower boom arm 116 , preventing the lower boom arm from pivoting in the first direction A beyond it's current intermediate locked position. In FIG. 2 there is nothing preventing the lower boom arm from pivoting in the second direction B.
FIG. 3 shows the lower boom arm 116 in its intermediate locked position, the locking pin 113 extended to its second interfering position, and the boom clamp 111 installed onto the lower boom arm 116 and locking pin 113 . The lower boom arm is locked from pivoting upward or downward. The boom clamp comprises a pin sleeve 300 , a boom restraint 302 and a handle 304 . The pin sleeve 300 is configured to slide around the locking pin 113 . The sleeve is cylindrical with an inside diameter slightly larger than the outside diameter of the locking pin. The restraint 302 is c-shaped and fixed to the sleeve, and is configured to slide around the lower boom arm 116 . The handle 304 is a rod bent into a generally semicircular shape, fixed at one end to the restraint 302 and fixed at the other end to the sleeve 300 . The restraint is further made up of a first plate 306 , a second plate 308 and a third plate 310 . The first plate 306 is fixed to the top of the sleeve 300 and is disposed generally parallel to the lower surface 200 of the lower boom arm 116 . The second plate 308 is fixed to the first plate and is disposed generally vertically and parallel to the outside surface 202 . The third plate 310 is fixed to the second plate and is disposed generally parallel to the upper surface 400 . The second plate is long enough such that the first plate 306 and third plate 310 define an opening therebetween wide enough to surround the lower boom arm 116 .
In FIG. 3 the lower boom arm is prevented from pivoting in the second direction B by the third plate 310 of the restraint 302 . Thus the addition of the boom clamp locks the lower boom arm 116 (and thus the entire boom structure 110 via the four-bar linkage) in the intermediate position.
FIG. 4 shows a partial cross section of the lower boom arm and locking mechanism taken at line 4 — 4 of FIG. 3 . The rectangular cross section of the lower boom arm 116 beam is clearly evident, as a box formed by surfaces 400 , 402 , 200 & 202 . The protective shroud 204 is a similar cross section extending upward from the beam. The wear plate 201 is fixed to the bottom of the lower surface 200 of the lower boom arm 116 and touches the top of the locking pin 113 . The handle 304 is fixed to the third plate 310 and the bottom of the sleeve 300 . By grasping the handle and pulling, the boom clamp 111 may be quickly removed from the vehicle without the use of any tools.
FIGS. 5 and 6 show two perspective views of the boom clamp 111 removed from the vehicle. Typically, the boom clamp is installed after the lower boom arm 116 has been lowered all the way to the locking pin 113 . This means that there is no space between the locking pin 113 and the wear plate 201 of the boom. Thus the sleeve 300 has a gap 500 in the outside of the cylinder along the top edge of the cylinder, and the first plate 306 has a corresponding gap 502 in the central section. The sleeve 300 and restraint 302 are joined by a weldment along each side of the gaps 500 , 502 . If a different intermediate position of the lower boom arms is desired, the boom clamp could be configured with a continuous cylinder sleeve 300 and a spacer between the sleeve and the restraint 302 . This would lock the arms in a position higher than that of the locking pins alone, equal to the original height plus the width of the spacer. In this case, the locking pins would not directly contact the lower boom arm.
It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. For example, the boom clamp may be attached upside down, after the boom has been lowered below the locking pin, such that the pin prevents upward movement and the boom clamp prevents downward movement—allowing the pin/clamp combination to work with the boom at two different levels with only one pin predetermined height. There may be multiple locking pins at predetermined heights on each side of the skid steer loader, and the clamps may be attached at any pair of pins, thereby locking the arms at a plurality of predetermined heights. The coupling between the sleeve and the restraint need not be fixed, as in a weldment, but may be variable. The coupling may be fixed with a spacer such that there is a considerable separation between the locking pin and the boom. The locking pin may be a rectangular bar or other shape, and may project in a non-orthogonal manner across the plane of boom movement. The sleeve may be rectangular or some other shape, as long as it captures the locking pin. The restraint may be made of one continuous plate, and may be semicircular in shape. The protective shroud surrounding the cables may be inside the boom arm housing rather than outside. The handle may be a different shape, may be attached at only one end, and may be attached to either the restraint or the sleeve or both.
Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown. | A boom clamp for a work vehicle having a lock and a boom is provided, the lock being configured to prevent movement of the boom in a first direction, the clamp comprising a restraint configured to engage the boom; and a sleeve fixed to the restraint, the sleeve configured to engage the lock; wherein the restraint prevents the boom from moving in a second direction. |
BACKGROUND OF THE INVENTION
This invention relates to centrifugal pumps in which fluid is led to the "eye" or center of an impeller through an inlet, and the pressure is produced as the fluid is rotated by the impeller at high speed. Higher fluid pressure can be obtained when the high speed fluid is slowed to a lesser velocity.
The total pressure of a particle of fluid is made up of its static pressure, which is what is measured on a pressure gauge, and its dynamic pressure, which depends on the speed at which it is moving. The dynamic pressure is the pressure exerted on an object suddenly introduced in front of the moving particle. The dynamic pressure increases as the square of the velocity. It is not possible to convert all the dynamic pressure in a flowing fluid to static pressure, but it is possible to recover about 50 to 80 percent of the dynamic pressure. One method of recovering some of the dynamic pressure is to slowly increase the delivery channel area, as for example with a diverging taper of about 8°. This recovery can be accomplished in a diffuser, i.e., fluid passages which carry fluid from an impeller to the inlet of another impeller or to a pump discharge. Most pumps of any size have some type of diffuser. In many of the so-called centrifugal pumps, there are a plurality of pump stages, i.e., a plurality of impellers, each discharging into a diffuser, and to a final discharge.
The usual vertical diffuser pump assembly comprises a plurality of interconnected castings, for example, an intake casting, one or more bowl castings, and a discharge head. A centrifugal impeller is associated with each bowl casting and each impeller is driven by a common shaft connected to an electric motor or other prime mover. The bowl casting includes an acorn, i.e., the inner structural core of the pump in the form of a conical-shaped part which defines the inner profile of the diffuser passageways and which surrounds the shaft and retains a shaft sleeve bearing. An annular wall of the acorn defines a portion of an impeller chamber with another portion of the impeller chamber being defined by the next preceeding casting, whether it be a bowl casting or intake casting. In addition to the acorn portion, the bowl casting comprises an outer, generally circular by cylindrical wall joined to the conical wall of the acorn by a plurality of connecting and generally radially oriented walls or vanes, thus forming a plurality of fluid passageways for the flow of fluid from the impeller. The radially oriented walls or vanes terminate short of the ends of the bowl castings to thus define generally annular chambers for receiving and discharging fluid to and from the passageways, respectively. In the usual pump described, each of the fluid passageways has a cross-sectional area which increases from inlet to outlet, i.e., in the direction of the fluid flow.
SUMMARY OF THE INVENTION
In accordance with the invention herein to be described, a vertical radial diffuser pump comprises essentially the same general components and arrangement of prior art pumps of the same type, i.e., a pump assembly constructed of an intake casting, one or more bowl castings and a discharge casting. A centrifugal impeller is associated with each bowl casting. The impeller is driven by a shaft connected to an electric motor or other prime mover. A major difference between a pump constructed according to this invention and prior art pumps is a modified bowl casting. The modified bowl casting of this invention results in certain advantages which will be described hereinafter.
The modified bowl casting of this invention comprises an acorn portion, similar to configuration and function to the prior art acorn previously described. However, unlike the previously described bowl casting, each fluid passageway is individually defined by surrounding walls, some of which extend radially from the acorn portion, such that portions of the acorn actually define parts of the exterior walls of the bowl casting. In the prior art acorn configurations, the acorn is completely surrounded by the exterior wall of the bowl casting. The individual passageways or volutes of the bowl casting of this invention are generally spaced from each other and can be generally spirally configured. The individual passageways join spaced, annular regions, one communicating with the impeller chamber and the other communicating either with the discharge casting or a succeeding impeller chamber, as the case may be.
A higher ratio of radial to axial displacement of fluid in an impeller produces a greater pressure for a given capacity. A radial diffuser shape following the impeller allows the maximum amount of kinetic energy to be changed to static energy before it is lost in a bend or turn while being directed back to the next stage impeller or to discharge.
The invention herein described relates to a single suction vertical pump assembly that permits radial diffusers (fluid expansion and velocity-to-pressure conversion passageways extending in a fully tangential and radial direction, not axial, outward from the impeller) which is lighter in weight than conventional pumps. This is accomplished by individually enclosing each fluid passage in the crossover region with an individual covering or wall which is integrally cast on to the acorn.
The passages are not constrained to follow a hydraulic path dictated by an outer circular shaped boundary. By eliminating outer circular boundary design constraint, the fluid passages can be shaped to suit an optimum crossover to the next stage or discharge. Also, because the effective pressure boundary size is reduced, wall thicknesses, and thus weight, are reduced. Two or more diffuser-crossovers are used. Using this invention, the pump specific speed, i.e., a dimensionless ratio between the amount of energy imparted to a fluid and the amount of fluid being pumped, can be altered by simply changing the number of individual crossover passageways on the bowl casting. Considering the specific speed of a pump to achieve high pressures, the specific speed will be relatively low and to achieve high volumes of pumped fluid, the specific speed will be relatively high. Thus the flow characteristic of the bowl casting of this invention can be effectively changed by changing the number of crossover passageways while retaining the basic mechanical form and the basic passageways hydraulic shape.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a typical vertical pump;
FIG. 2 is an enlarged section view of a prior art diffuser pump taken on line 2--2 of FIG. 3 and is labeled "PRIOR ART";
FIG. 3 is a sectional view taken on line 3--3 of FIG. 2 and is also labeled "PRIOR ART";
FIG. 4 is an enlarged sectional view of a pump constructed according to ths invention taken on line 4--4 of FIG. 5; and
FIG. 5 is a sectional view taken on line 5--5 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 of the drawings illustrates schematically the general arrangement of vertical diffuser pumps which comprise, from bottom to top, an intake casting, one or more bowl castings, a discharge casting and a motor. Details of prior art pumps and the pump of this invention will be described with specific reference to FIGS. 2 and 3, and FIGS. 4 and 5, respectively, of the drawings.
FIGS. 2 and 3 illustrate a portion of a prior art pump 10 comprising, from top to bottom, an intake casting 12 having an intake port 14, one or more bowl castings 16 (only one being illustrated), a discharge casting 18, having a discharge port 20, and a motor 22. The castings are interconnected, generally by bolts and the like, to form the pump assembly 24. A shaft 26 connected to the motor 22 provides the power to rotate centrifugal impeller means 28, an impeller 30 being associated with each bowl casting 16. Fluid enters the center of the impeller 30 from the intake port 14 and is ultimately discharged from the discharge port 20. The impellar 30 is so constructed and arranged to throw the fluid outwardly into the bowl casting
The bowl casting 16 comprises an acorn 34 having a sleeve portion 36 surrounding the shaft 26 with a sleeve bearing 38 therebetween, a conical portion 40 connected to the sleeve portion 36, and an annular wall portion 42 connected to the conical portion 40. The wall portion 42 defines in part an impeller chamber 44 and also supports a wear ring 46 for the impeller 30. The remainder of the impeller chamber is defined by a portion of the intake casting 12 which also supports a wear ring 48 for the impeller. The conical portion 40 of the casting 16 is connected to the outer wall 50 of the casting 16 by a plurality of vanes 52 to thus define a plurality of fluid passageways 54. The passageways 54 intersect, at their ends, annular zones 56 and 58. The impeller 30 discharges fluid in the zone 56. The zone 58 is connected to the intake of the next succeeding impeller or to the discharge casting. The outer wall 50 defines in part the outer wall of the pump assembly 24. Ribs 60 are also provided to connect and reinforce portions 36, 40 and 42 of the acorn 34. Each of the castings 16 is provided with a flange having a plurality of bolt holes therethrough, so that the castings can be bolted together to form the composite structure. As will be noted in the prior art pump, the outer configuration of the pump is generally circular and the bowl casting adds considerable mass to the pump assembly.
The pump 70 of the present invention is illustrated in FIGS. 4 and 5, and like the prior art pump 10, comprises an intake casting 72 with an intake port 74, and one or more bowl castings 76, a discharge casting 78 having a discharge port 80, and an electric motor or other prime mover 82, interconnected as illustrated. A shaft 84 connected to the motor 82 drives impeller means 86 comprising a centrifugal impeller 88 in each bowl casting 76. The differences between the prior art pump 10 of FIGS. 2 and 3 and the pump 70 of this invention, as illustrated in FIGS. 4 and 5, is in the construction and configuration of the bowl castings 76.
The bowl casting 76 comprises an acorn 90 having a sleeve portion 92 surrounding the shaft 84 with a sleeve bearing 94 therebetween, a conical portion 96, and an annular wall portion 98, the wall portion defining in part an impeller chamber 100. Ribs 102 connect the portions 92, 96 and 98 of the casting 76. A plurality of individual fluid passages 104 are each defined by walls 106, 108 and 110 (see FIG. 5), the walls 106 and 110 extending radially outwardly from the conical portion 96 of the acorn 90. Passages 104 can be any generally square, rectangular, trapezoidal, oval or circular shape. Two or more passages 104 can be used without departing from the spirit of the invention. The outside of the pump assembly, generally identified as 112, is defined in part by the conical portion 96 of the acorn 90 and the passage walls 106, 108 and 110. The passages 104 are connected to annular chambers 114 and 116, defining, respectively, an intake to the passages 104 from the impeller 88 and a discharge from the passages 104. The discharge from the passages 104 serves as an inlet to the next succeeding impeller 88, or to the discharge port 80. As in the usual pumps, the various parts of the pump are bolted together.
The invention herein described relates to a single suction vertical pump assembly that permits radial diffusers (fluid expansion and velocity-to-pressure conversion passageways extending in a fully tangential and radial direction, not axial, outward from the impeller) which is lighter in weight than conventional pumps. This is accomplished by individually enclosing each fluid passage in the crossover region with an individual covering or wall which is integrally cast on to the acorn.
The passages are not constrained to follow a hydraulic path dictated by an outer circular shaped boundary. By eliminating outer circular boundary design constraint, the fluid passages can be shaped to suit an optimum crossover to the next stage or discharge. Also, because the effective pressure boundary size is reduced, wall thicknesses, and thus weight, are reduced. Two or more diffuser-crossovers are used. The pump specific speed can be altered by simply changing the number of individual passageways on the bowl casting. | A centrifugal pump assembly comprising one or more bowl castings each housing an impeller and also two or more individual fluid passageways for the flow of fluid discharged by an impeller to the next impeller, the passageways having some exterior walls defining the exterior of the assembly. By changing the number of the individual passageways, the specific speed of the pump, i.e., the ratio of the amount of energy imparted to the fluid and the amount of fluid being pumped, can be changed. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a solar module arrangement, in particular for solar-thermal and/or photovoltaic energy generation, and to a roof arrangement having a plurality of such solar module arrangements.
[0003] 2. Description of Related Art
[0004] Both photovoltaic and also solar-thermal energy generation plants are known from the prior art. Both use the incident solar radiation to generate either electrical or thermal energy and supply it to a further consumer. So-called combination modules also exist, which allow a combination of photovoltaic and solar-thermal energy generation. In all modules, an orientation toward the sun which is a function of the geographical usage region is absolutely necessary to optimize the efficiency.
[0005] Typically, such modules are mounted elevated on roofs, flat roofs, free surfaces, or also façades in such a way that they have this optimum orientation toward the sun. In order to further optimize the efficiency here, solar energy generation plants are also known, which are actively tracked to the course of the sun, in order to ensure an optimum orientation toward the sun at nearly every time of day.
[0006] However, it is problematic in the case of such solar energy generation modules which are mounted elevated, i.e., inclined to the horizontal on one side to the south or north depending on the use on the southern or northern hemisphere, that modules arranged in a composite lose efficiency due to mutual shadowing. Sufficient distances to keep this shadowing as slight as possible are absolutely necessary here.
[0007] In this regard, German Utility Model DE 90 10 696 U1 proposes, to achieve better utilization of the sunlight incident on the solar modules in the case of collector surfaces arranged adjacent to one another, using reflection surfaces which are capable of deflecting components of the incident light onto the solar modules. However, the component usable for solar energy generation per unit of area is also reduced here, so that the overall efficiency sinks.
[0008] German Utility Model DE 20 2006 020 180 U1 and corresponding U.S. Patent Application Publication No. 2010/0000165 A1 also propose such a solution, solar and reflection surfaces which are alternately inclined toward one another being used in the arrangement of solar modules as a solar roof. These reflection surfaces also reflect sunlight onto the solar modules here. The overall efficiency is correspondingly low, as above.
[0009] In addition, the attempt is made in all of the above-mentioned arrangements to optimize the output of the solar modules by optimum orientation toward the sun and an inclination by 25°. However, in addition to the shadowing problems, such a structure also has disadvantages with respect to its static resistance capability, in particular in the case of strong occurring wind loads, such structures requiring a very complex and costly static reinforcement.
SUMMARY OF THE INVENTION
[0010] The object of the present invention is therefore to offer a solar module arrangement or a roof arrangement making use of such solar module arrangements, which has an improved overall efficiency with respect to the self-cleaning, the efficiency, and in consideration of the installation costs in relation to the static resistance capability and in particular the static resistance capability against wind loads.
[0011] Overall efficiency is understood here, in particular, as the economic efficiency in consideration of all above-mentioned factors.
[0012] This object is achieved by a solar module arrangement as described herein.
[0013] In particular, this object is therefore achieved by a solar module arrangement for solar-thermal and/or photovoltaic energy generation, in particular, comprising a solar module arrangement for solar-thermal and/or photovoltaic energy generation, in particular, comprising at least three solar module elements, which are arranged in an essentially horizontal, planar composite and are each inclined relative to horizontal with respect to one another in such a manner that a peripheral lateral border of the solar module arrangement is lower or higher relative to horizontal than an essentially middle central area.
[0014] Furthermore, this object is achieved by a roof arrangement having a plurality of the above-mentioned solar module arrangements, the solar module arrangements being arranged to form a roof arrangement via parts of the lateral borders of adjacent solar module arrangements which run essentially parallel to one another.
[0015] The term solar module element is understood in the scope of this application as any element for solar-thermal and/or photovoltaic energy generation. Therefore, it also comprises the combination modules known from the prior art.
[0016] An essential point of the solar module arrangement according to the invention is that, through the arrangement of the individual solar module elements to form a composite having a peripheral lateral border area which is elevated or depressed in relation to the middle central area, arrangements result which have an optimum overall efficiency in consideration of all factors relevant for the implementation of the above solar module arrangements. In particular in tropical latitudes, this effect has proven to be particularly serious.
[0017] In the case of a solar module arrangement whose peripheral lateral border is higher than the essentially middle central area, a depression or shell essentially results geometrically, whose efficiency remains essentially constant with respect to its geographical orientation. Studies in this regard have shown that, in particular in tropical latitudes, essentially an efficiency deviation of 1% exists as a function of the orientation, i.e., for example, between a north-south and east-west orientation. This means that almost no restrictions are predefined with respect to the installation planning, so that even in the case of installation surfaces which offer bad conditions with respect to their location and local conditions upon the use of solar modules according to the prior art, the solar module arrangements or roof arrangement according to the invention are installable without problems. In comparison to solar modules oriented “optimally” to the north or south, the efficiency is only slightly reduced, these efficiency losses being well compensated for by the further accompanying advantages of the solar module arrangement or roof arrangement according to the invention.
[0018] The solar module arrangement or roof arrangement according to the invention thus allows nearly complete coverage of the space available for the installation. The ratio of energetically active surface to used installation surface of the solar module arrangement or roof arrangement according to the invention is practically one. While shadow-related minimum distances between the individual modules significantly reduce the degree of surface usage in the case of systems up to this point, the built-over surface is optimally utilized according to the invention here. The solar module arrangements according to the invention may thus be installed directly adjacent to one another arbitrarily, often, without shadowing the respective adjacent solar module arrangements, and therefore, impairing the energy generation thereof, reliable self-cleaning of the solar module elements nonetheless remaining ensured in particular. The energy generation, in contrast to typical systems having solar thermal or photovoltaic modules installed elevated on one side, is independent of the distance of the adjacent module, which also significantly increases the planning possibilities.
[0019] In addition, in the case of the roof arrangement mentioned at the beginning employing the solar module arrangements according to the invention, a very statically stable geometry results, whose production costs are significantly less than the production costs for the solar roofs known from the prior art. In particular in geographic areas in which high wind loads are to be expected, such an arrangement, which is characterized in particular by a reduced inclination of the solar module elements, represents an optimum structure, since the static reinforcing measures for dissipating the wind loads are significantly reduced and the costs may thus be decreased immensely. The tropics are also an optimum usage region here because of the cyclones, hurricanes, and typhoons which occur very frequently in these regions. However, this positive effect is also significant in other latitudes.
[0020] If multiple solar module arrangements according to the invention are connected to form a roof arrangement via connection of the parts of the lateral border areas of adjacent solar module arrangements, which run essentially parallel to one another, an economically optimized structure therefore also results for large surfaces, which offers decisive energetic and also static advantages in particular because of the discontinuous surface development.
[0021] Depending on whether the solar module arrangements have lower or higher lateral borders relative to the middle central area, a roof arrangement results in which the respective solar module arrangements, having their solar module elements arranged in a composite, form roof arrangement depressions or roof arrangement peaks. These differences will be discussed in greater detail hereafter.
[0022] The solar module elements are preferably implemented as essentially rectangular solar module elements and are also arranged in an essentially rectangular 2×2 matrix, and in particular, in the form of a helm roof or inverted roof.
[0023] A helm roof or helm roof arrangement is understood in the context of this application as the typical design from the prior art for a roof arrangement having a rectangular projection surface, having four gables, on which further essentially identical “four-gable roofs” adjoin in the case of a corresponding helm roof arrangement. The term rhomboid roof arrangement is also typical in the prior art for such a helm roof arrangement. Of course, such a helm roof arrangement only results when the solar module arrangements arranged according to the helm roof arrangement also have a rectangular projection surface. In the case of a projection surface differing therefrom, for example, a triangular projection surface, a sequence of pyramidal roof arrangements results, the definition roof arrangement also comprising all corresponding roof arrangements which are discontinuous with respect to their surface development here.
[0024] The term “rectangular 2×2 matrix” essentially relates here to the projection surface of the resulting solar module arrangement. Such a rectangular solar module arrangement allows the combination of multiple solar module arrangements to form a large-area roof arrangement or helm roof arrangement cost-effectively, a decisive cost factor here being the rectangular production of the individual solar module elements. Of course, it is instead also possible, as already noted at the beginning, to form solar module arrangements from solar module elements having different geometric shapes, for example, by a composite of three triangular solar module elements or by the combination of differently shaped solar module elements. Optimization can be performed as needed here as a function of the geographic usage region and the available installation surface. Of course, it is also possible, instead of implementing continuous solar module elements to form the solar module arrangements, to also implement the solar module elements from individual solar modules which are also arranged in a composite, and which are grouped as the solar module elements. This has advantages in particular with respect to the production, the transport, and the ventilation of the solar module arrangements.
[0025] In the case of rectangular solar module elements which are connected to form the solar module arrangement according to the invention, the rectangular solar module elements are inclined relative to one another around an axis which is nonparallel in each case to their lateral edge, and in particular, around a diagonal axis running essentially diagonally. Through this inclination, a solar module arrangement results in a very simple way having a peripheral lateral border area lying elevated or lowered in relation to the middle central area. The inclination of the rectangular solar module elements around an axis which does not run coaxially, but rather axially-parallel to the diagonal axis, i.e., is arranged somewhat offset thereto, allows the arrangement of the inclined solar module elements in the solar module arrangement, without the solar module elements touching at their lateral border, inter alia, an optimum surface utilization thus being achievable per unit of area.
[0026] The angle of inclination of each solar module element in the direction of the middle central area is preferably essentially between 5° and 25°, in particular 15°, or −5° and −25°, in particular −15°. Such an inclination of the individual solar module elements has an optimum overall efficiency in their composite as the solar module arrangement and in consideration of possible wind loads to be dissipated. In particular, such an inclination takes the self-cleaning of the solar module elements into consideration, which has a decisive influence on the efficiency of a corresponding energy generation plant, since the soiling of the solar module elements is known to cause significant efficiency losses over time. In geographic latitudes in which snow or ice covering is to be expected, a reduction of the efficiency can thus also be avoided. In general, it is possible in this context, of course, to assign a different inclination to each individual solar module element within the solar module arrangement and in particular as a function of the geographic location, and thus, to optimize the energy generation. In association with this varying inclination, it is possible to adapt the lengths or widths of each solar module element accordingly, in order to minimize shadowing in particular. The result would be a solar module arrangement whose middle central area is arranged “shifted”, similarly to an “offset” focal point of a parabola section. Of course, the entire solar module arrangement can also be inclined, if the boundary conditions at the installation location allow it.
[0027] The solar module arrangement preferably has at least one inclination control element to adjust the inclination angle of at least one solar module element. Such an inclination control element can be both a passive and also an active inclination control element, i.e., adjustable using a positioning motor. The change of the inclination offers, on the one hand, the possibility of optimizing the energy introduction and, on the other hand, taking occurring soiling or occurring wind loads into consideration. The inclination can thus be increased in the case of strong soiling and a strengthened cleaning effect can thus be achieved. For example, if it is established over a specific period of time that the solar module arrangement is soiled, this soiling can be counteracted via a changed inclination of the individual solar module elements.
[0028] The inclination control element preferably has a communication connection to at least one sensor element, in particular a precipitation sensor, an energy output sensor, a time encoder, or a light sensor, so that the adjustment of the inclination angle can be regulated as a function of at least one item of detected sensor information. The inclination control element is preferably implemented in such a way that the inclination angle of at least one solar module element is adjustable between a production or day position, having an optimum inclination angle for energy generation in particular, and a night and/or precipitation position, having a greater inclination angle, which is optimal for self-cleaning in particular.
[0029] Since solar modules are well known to only be energetically active during the daytime, it is possible to adjust the solar module arrangement between a day position and a night position, the inclination being increased in the night position, in order to improve the cleaning of the modules in the case of precipitation. In the day position, the inclination can be reduced to an optimum minimal inclination (in tropical latitudes approximately 0°) in order to optimize their energy output. In this context, timers or also light or output sensors may initiate the required regulation. Such a regulation is also possible, of course, as a function of occurring precipitation phases, during which the solar module arrangement or the individual solar module elements may be adjusted into a precipitation position having increased inclination. The use of corresponding precipitation sensors is conceivable here, for example, which allow automatic regulation of the inclination. Such a principle is fundamentally applicable to nearly all other types of solar module arrangements.
[0030] A ventilation free space, and in particular, a ventilation gap is preferably arranged between the solar module elements arranged in the composite. This ventilation gap takes air circulation between the bottom side and the top side of the solar module arrangement into consideration, and thus, results in cooling of the individual solar module elements. This cooling of the solar module elements has a significant effect on the efficiency, solar module elements having a lower temperature typically having better efficiency than heated solar module elements. Efficiency differences of up to 5% have been observed here in the case of a temperature difference of 10 K.
[0031] The ventilation free spaces, and in particular, ventilation gaps, which are provided between the individual solar module elements and naturally also between the adjacent solar module arrangements of the roof are arrangement according to the invention, additionally ensure that if wind loads occur, the pressure differences on the top side and a bottom side of the respective modules and elements are reduced, which in turn relieves the structure and thus results in significant cost savings.
[0032] The ventilation free space or ventilation gap can additionally be used simultaneously as a drain for occurring precipitation water, and thus, also for removing contaminants.
[0033] The ventilation free space preferably has a water drain element for this purpose, in particular on the solar module bottom side, which collects or drains water which has penetrated via the top side of the solar module arrangement and via the ventilation free space. It is preferably to be ensured here that the air circulation between bottom side and top side of the solar module arrangement is impaired only slightly or not at all by the arrangement of the water drain element. Of course, these water drain elements may additionally also adopt the function of supply units, i.e., for example, for guiding the feed and drain lines of the individual solar module elements.
[0034] In this context, it is additionally possible to situate corresponding evaporation devices on the solar module bottom side, and in particular, in the area of the ventilation free space, which are fed in particular by the water supply unit or directly by the individual solar module elements, and which cool the solar module arrangement by the evaporation of the water, which is collected in particular during a precipitation phase. Water-storing tiles, mats, etc. may be used here, for example, which are arranged on the bottom side of the solar module arrangement, in particular spaced apart therefrom. Air which passes over these mats is preferably guided via flow-guiding units along the bottom side of the solar module elements, so that the modules are effectively cooled. Of course, the evaporation device can also be actively supplied in this context, for example, via a water feed line. Such a device is also fundamentally applicable in any type of solar module.
[0035] Preferably, at least one solar module element, and in particular, the solar module element which is irradiated least by the sun as a function of the geographical orientation of the solar module arrangement, at least partially has a reflector surface, a transparent surface, or a similar surface which differs from the surfaces of the other solar module elements. The use of a reflector surface can increase the energy output in the other adjacent solar module elements depending on the geographic latitude, so that the overall efficiency of the solar module arrangement rises. In contrast, the use of a transparent surface allows the illumination of the space lying underneath.
[0036] The solar module elements are preferably implemented as static self-supporting elements and are connected to one another so they are statically stable by connection units and in particular are linked to one another so they are pivotable. In the case of such an embodiment, the solar module arrangement formed from the statically stable solar module elements can therefore be installed nearly without a substructure, for example, as a roof surface, the connection units on the solar module elements preferably being implemented as complementary here in such a way that the solar module elements can be arranged to form the solar module arrangements similarly to a building block principle. All connection units known from the prior art are applicable here. Such a design also applies for the arrangement of the solar module arrangements to form the roof arrangement according to the invention.
[0037] The solar module arrangement and/or each solar module element preferably has a peripheral support frame in particular, into which the solar module elements are insertable or inserted or via which the solar module elements are connectable to one another. Such a support frame allows the arrangement of multiple solar module arrangements to form large roof arrangements or surfaces and, in addition, the simple replacement of defective solar module elements.
[0038] Fundamentally, both an embodiment having statically stable solar module elements, which are connected to one another in a statically stable way via connection elements, and also the embodiment of the solar module arrangement via a particularly peripheral support frame can be industrially prefinished, so that the individual components are connectable to one another cost-effectively and rapidly at the construction site.
[0039] Of course, the solar module arrangement according to the invention can also be arranged on typical roof substructures, which then preferably already predefine the geometry of the solar module arrangements or the roof arrangement.
[0040] If a support frame is used, the solar module elements are preferably mounted so they are pivotable in support frames, so that an inclination adaptation is easily possible.
[0041] Fundamentally, the roof arrangement according to the invention, comprises a plurality of solar module arrangements, has a three-dimensional structure, which stabilizes it very much better than large-area, flat systems. Simultaneously, it has a relatively small front face, which makes it easier to use the roof arrangement for roofing in windy regions, while typical elevated systems are extraordinarily problematic in the case of high wind loads.
[0042] Studies have shown that the roof arrangement according to the invention has an extraordinarily high-performance in comparison to elevated systems known from the prior art. In the case of a simulated installation in tropical latitudes, and in particular, at a geographic location of 60° east/15° south, the solar module arrangement or roof arrangement according to the invention only displays losses in the yearly output in the magnitude of approximately 10% in the case of an inclination of the individual solar elements by 15°. In the case of 10° inclination of the modules, the relative yearly losses are decreased to approximately 8%. Through the optimum adaptation to the self-cleaning conditions, the significantly reduced static requirements, and in particular, in the case of usage as roofing, due to the extraordinarily advantageous cost structuring, these losses are not reflected negatively in the pure energy generation so that, in comparison to typical systems, a positive benefit balance and improved overall efficiency nonetheless result.
[0043] The invention is described hereafter on the basis of exemplary embodiments, which are explained in greater detail with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is an isometric view of a first embodiment of a solar module arrangement;
[0045] FIG. 2 is a top view of the solar module arrangement shown in FIG. 1 ;
[0046] FIG. 3 is a cross-sectional view through the solar module arrangement from FIG. 1 ;
[0047] FIG. 4 shows a longitudinal section through the solar module arrangement from FIG. 1 ;
[0048] FIG. 5 shows a second embodiment of the solar module arrangement;
[0049] FIG. 6 shows a first embodiment of a roof arrangement according to the invention;
[0050] FIG. 7 shows a second embodiment of the roof arrangement according to the invention;
[0051] FIG. 8 shows a third embodiment of the roof arrangement according to the invention;
[0052] FIG. 9 is a transverse cross-sectional view of a fourth embodiment of the roof arrangement according to the invention; and
[0053] FIG. 10 is a longitudinal sectional view of the roof arrangement from FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
[0054] The same reference numerals are used hereafter for identical and identically acting components, apostrophes and quote marks sometimes being used.
[0055] FIG. 1 perspective view of a first embodiment of the solar module arrangement 1 according to the invention. It comprises four solar module elements 2 , 2 ′, 2 ″, 2 ″′ which are arranged in an essentially horizontal, flat composite and are each inclined relative to a horizontal plane H and relative to one another by an inclination angle α in such a way that a peripheral lateral border 4 of the solar module arrangement 1 is higher relative to the horizontal plane H than an essentially middle central area 6 .
[0056] In the following explanations, reference is made to FIGS. 1 to 4 . The solar module arrangement 1 comprises, as noted, four solar module elements 2 in this embodiment, which are all implemented as rectangular solar module elements 2 . To form the solar module arrangement 1 , these solar module elements 2 are arranged via their lateral borders 3 in a 2×2 matrix. The resulting solar module arrangement 1 is thus also rectangular at least in its projection relative to the plane H.
[0057] Each individual solar module element 2 is inclined around an axis A in the direction of the middle central area 6 , so that the form of an inverted helm roof 10 results for the solar module arrangement 1 .
[0058] The respective axis A around which the solar module elements 2 are inclined runs nonparallel to the lateral borders 4 , and in this embodiment, axially-parallel to the respective diagonal axis A D and offset in the direction of the middle central area 6 .
[0059] The inclination angle α by which the respective solar module elements 2 are inclined in relation to the horizontal plane H in the direction of the middle central area 6 is essentially 15° in this embodiment. Such an inclination has had a very positive effect with respect to the overall efficiency, inter alia, because of the self-cleaning effect and the static resistance capability of the solar module arrangement 1 .
[0060] Because of the two-axis inclination, namely around an axis parallel to the transverse axis A Q and around an axis parallel to the longitudinal axis A L , the inclination angles α Q and α L shown in FIGS. 3 and 4 result for the total inclination angle α of each solar element 2 .
[0061] In order to achieve an optimization with respect to the efficiency, the self-cleaning, or also a reduction of the wind loads to be dissipated during operation of the solar module arrangement 1 , it is possible to adapt the individual solar module elements 2 in their inclinations α, α Q , and α L via the inclination control elements 8 shown in FIGS. 3 and 4 . For example, if it proves at a starting angle α of 10°, for example, that the solar module arrangement tends to be soiled quickly, the angle α can be increased by activation of the inclination control element 8 and the self-cleaning can thus be improved. The mentioned inclination control elements 8 may be both active inclination control elements, for example, activatable via a wired control unit, for example, or also elements which are manually lockable via screw connections.
[0062] Ventilation free spaces 12 are arranged between the individual solar module elements 2 arranged in the solar module arrangement 1 , as is clearly recognizable in FIG. 2 in particular, which are implemented as increasing from the lateral borders 4 toward the middle central area 6 because of geometric boundary conditions and resulting from the inclination of the respective solar module elements 2 . These ventilation free spaces 12 fulfill multiple functions. Thus, they allow air circulation between the bottom side 14 and the top side 15 of the solar module arrangement 1 , so that the individual solar module elements 2 are cooled. This contributes to improving the energetic efficiency.
[0063] In addition, of course, the free spaces or gaps 12 for ventilation reduce the wind pressure loads acting on the solar module arrangement 1 , so that smaller static demands may be placed on the design here.
[0064] Finally, the ventilation free spaces 12 also allow the drainage of precipitation water which hits the top side 15 of the solar module arrangement 1 or the solar module elements 2 . Because of the inclination of the solar module elements, this precipitation water runs into the ventilation free spaces or gap 12 , which advantageously increase in the direction of the central area 6 for this purpose, where it is then either drained via water guiding units 16 (see, FIG. 5 ) or simply drips off of the solar module arrangement 1 onto the floor lying underneath. Of course, it is also possible in this context to seal the transition areas between the individual solar module elements 2 fluid-tight and only situate a corresponding water drain unit in the middle central area 6 .
[0065] For static stabilization of the solar module arrangement 1 , a support frame 20 runs completely around the solar module arrangement 1 following the geometry of the lateral borders 4 . The solar module elements 2 are fitted in this support frame 20 and are particularly linked thereto so they are pivotable, so that their inclination is changeable via the inclination control elements 8 . Of course, it is also possible in this context to use substructures known from the prior art instead of a support frame 20 , on which the solar module elements 2 are mounted.
[0066] FIG. 5 shows a second embodiment of the solar module arrangement 1 , which differs from the above-described embodiment according to FIGS. 1 to 4 essentially through the static implementation of the solar module elements 2 . They are implemented here as static self-supporting elements 2 and are connected to the solar module arrangement 1 via connection units 18 , which are also statically stable. Such a structure can therefore be mounted with very little material outlay for the substructure on corresponding mounting surfaces, the installation being significantly simplified in particular by the self-supporting capability of the individual solar module elements 2 .
[0067] In addition, the water drain element 16 , which extends on the solar module bottom side 14 along the ventilation free spaces 12 between the individual solar module elements 2 , is arranged on the bottom side 14 of the solar module arrangement 1 shown here. The water drain element 16 is used, as noted, for draining precipitation water which is supplied from the top side 15 of the solar module elements 2 . So as not to obstruct the above-described air circulation between the bottom side 14 and the top side 15 , the water drain element 16 is spaced apart from the bottom side 14 of the solar module arrangement 1 .
[0068] FIG. 6 shows an embodiment of the roof arrangement 30 according to the invention, in which a total of five solar module arrangements 1 according to FIG. 5 are installed to form a helm roof arrangement. The solar module arrangements 1 are arranged on parts 22 of the lateral borders 4 of the adjacent solar module arrangements 1 running essentially parallel to one another, so that a discontinuous helm roof arrangement essentially running in a “zigzag” results in their surface development. This has an efficiency which is essentially independent of the geographical orientation because of the respective solar module elements 2 inclined toward the middle central area 6 . In addition, the installation of the solar module arrangements 1 according to the invention to form a helm roof arrangement 30 allows an optimum surface exploitation of the surface 40 to be overbuilt, as is recognizable in FIG. 6 .
[0069] FIGS. 7 and 8 schematically show two further embodiments of the roof arrangement 30 , which essentially differ through the implementation of the solar module arrangements 1 .
[0070] The roof arrangement 30 from FIG. 7 is thus formed by four solar module arrangements 1 , which are arranged on adjacent parts 22 of the border areas 4 . The solar module arrangements 1 used here are implemented in such a way that the peripheral lateral border 4 of the solar module arrangement 1 is higher in relation to the horizontal plane H (see, FIG. 1 ) than the essentially middle central area 6 . The respective inclination of the solar module elements 2 is shown in both FIGS. 7 and 8 by arrows, the arrow points each indicating the gradient direction.
[0071] In the embodiment shown in FIG. 8 , the roof arrangement 30 is formed by a solar module arrangement 1 whose lateral border 4 lies lower in relation to the horizontal plane H (see FIG. 1 ) than the essentially middle central area 6 . Further correspondingly implemented solar module arrangements 1 ′, 1 ″ (only partially shown here) each adjoin this solar module arrangement 1 , which is shown in the middle here. As a result, identity therefore results for the geometry of the helm roof arrangement in the embodiments from FIGS. 7 and 8 , the structure only making use in each case of differently implemented solar module arrangements 1 .
[0072] FIGS. 9 and 10 show a fourth embodiment of the roof arrangement 30 according to the invention in transverse and longitudinal cross-sectional views, respectively. A water drain element 16 is also arranged on the bottom side 14 of the solar module bottom 14 , here, into which precipitation water can run via the ventilation free space or gap 12 . An evaporation unit 24 , which is implemented here as a water-storing tile, is arranged inside the water drain element. The water stored in the tile evaporates successively after a precipitation phase, whereby energy is withdrawn from the air which flows from the bottom side 14 to the top side 15 , which results in cooling of the solar module arrangement 1 . In order to channel this cooled air stream, flow-guiding elements 25 are arranged above the evaporation unit 24 .
[0073] The inclination adjustment of the individual solar module elements 2 is also performed here via inclination control elements 8 , which are arranged in this embodiment on corresponding diagonal supports 44 attached to a middle support 42 in this embodiment, however. These supports 44 are simultaneously used as load-bearing supports for the protruding solar module elements 2 . | A solar module arrangement for, in particular, solar-thermal and/or photovoltaic energy production, comprising at least three solar module elements ( 2) which are arranged in a substantially horizontal, flat composite and are each inclined relative to one another with respect to the horizontal plane (H) in such a way that side edges ( 4) which frame the solar module arrangement ( 1) are lower or higher than a substantially middle central region ( 6) relative to the horizontal plane (H). Furthermore, a roof arrangement with a plurality of solar module arrangements of the above-mentioned type, wherein the solar module arrangements ( 1) are arranged on subsections ( 22), which run substantially parallel to one another, of the side borders ( 4) of adjacent solar module arrangements ( 1) to form an, in particular, diamond-shaped, roof arrangement ( 30). |
BACKGROUND OF THE INVENTION
The present invention is directed to the field of non-woven fabrics in general and is directed to a single layer non-woven recyclable polyester fabric suitable for use as bale covering having high strength and resistance to tears and abrasion and to which labels can stick. The fabric of the present invention can be recycled. The present invention is also directed to a process for producing such a non-woven fabric.
For many years fiber producers have sought a solution to the problem of wrapping bales of fibers to protect the fibrous material from contamination and damage during shipping. Some wraps commonly used are jute or burlap. Other wraps include polypropylene. Such wraps require disposal in landfills.
Other wraps include woven polypropylene, the predominant bale wrapping material. These wraps however, fibrillate in use, the polypropylene strands becoming closely entwined with the fibers, and thereby contaminating it. Such contamination cannot be separated and is extremely difficult to detect in raw fibers. Moreover, polypropylene wraps are not biodegradable or recyclable and have few end uses. An example of this type of woven wrap is disclosed in U.S. Pat. No. 4,557,958 (Barkis) wherein woven polypropylene or polyethylene fabric is infused with a series of stripes of thermoplastic resin to prevent fraying when the fabric is cut.
U.S. Pat. No. 5,104,703 (Rachman et al) discloses a single layer non-woven fabric suitable for use as a cotton bale covering that is a single layer batt formed of a blend of fibers including polyester and low melt thermoplastic fibers such as bicomponent fibers. As will be shown, the present invention exhibits superior products to the blend of the polyester fibers and the binder fibers.
It is a primary object of this invention to provide a recyclable polyester bale cover usable for fiber materials.
A further object of this invention is the provision of a new type of single layer non-woven recyclable fabric suitable for use as polyester bale covering, wherein a combination of needle punching and calendering lend high strength to the fabric.
It is a further object of this invention to provide a non-woven single layer recyclable polyester fabric that does not fibrillate in use as do woven polypropylene bale wrapping materials.
Still another object is to provide a non-woven single layer recyclable polyester fabric that provides greater resistance to tears, rips and holes over conventional woven polypropylene bale wrapping materials.
A further object is to provide a non-woven single layer recyclable polyester fabric that is comparable in cost to polypropylene wraps.
Still another object of the present invention is to provide a non-woven polyester fabric that is recyclable. The fabric can be used in polyester bale wrap. Recyclability of the wrap is further enhanced with the use of polyester labels.
SUMMARY OF THE INVENTION
These and other objects of the invention are achieved by provision of a non-woven polyester recyclable fabric comprising a batting of crosslapped recyclable polyester staple fiber that has been needle punched and calendered. The recyclable polyester bale covering is formed essentially of non-woven fabric that is crosslapped, needlepunched, calendered, and cut and sewed into the fabric suitable for the recyclable bale cover.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing the preferred embodiments of the subject invention illustrated herein, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected and resulting batt is stabilized for further processing by needling at a specific density of about 1,200 to about 3,000 penetrations per square inch to achieve a weight of preferably between 4 and 14 ounces per square yard. The resulting batt is then calendered by pressing the batt between two rolls at a temperature of between 300° and 500° F. and calendered to a thickness of between 0.01 and about 0.100 inch. The resulting fabric is then subject to conventional techniques of fabric rollup.
The fabric can be used on various types of automatic balers, i.e., Sunds, Lumus, etc. The fabric can also be made into sewn bags using conventional cut and sew techniques and equipment. Such fabric is suitable as a direct replacement for woven polypropylene material.
The all polyester bale wrap, including a polyester label may be recycled using conventional methods to recycle polyester. The all polyester fabric is ground into particles which are processed through glycolysis or methanolysis to recycle the material.
COMPARATIVE EXAMPLE
Various samples were prepared using a blend of 90% polyester fibers and 10% bicomponent fibers. The bicomponent fiber commercially available as Type 254 from Hoechst Celanese it is to be understood that each specific term includes all technical equivalents which operate in an equivalent manner to accomplish a similar purpose.
The fiber used is a recyclable polyester fiber. These fibers should be between about 2 inches and 4 inches in length and have a denier or denier equivalent between about 2.25 and 15 dpf. The fibers are individualized, that is separated into individual fibers using conventional textile fiber carding equipment, and are then formed into a web using fibrous web forming devices.
The fibers may also be treated with a fiber lubricant or finish before or during processing to permit subsequent needle operations to be performed. Such a fiber finish precludes excessive needle breakage, poor fiber penetration, inefficient stitching, and reduced stitching breaks. Finishes may include silicone lubricants, metallic soaps and low molecular weight polyethylene waxes to provide needle lubrication. Methods of application include padding, spraying or immersion and press rolling. The fibers may further be treated with a flame retardant.
The fibrous web is increased in thickness by crosslapping or layering through the use of conventionally known multiple forming devices such as disclosed in U.S. Pat. No. 4,183,985. The has a polyester core in an isophthalic polyester sheath material. The fibers were processed into a fibrous web needle punched according to standard procedures and calendered. It was found that the fabrics calendered at 400° F. yielded a stiffer fabric. Such fabrics are found to result in fabric tears as well as contamination of the fibrous materials in the bales due to the clinging of the bale cover material. In another case the fabrics were calendered at 300° F. to increase elongation. In such cases tearing was not a problem with these fabrics. However, fiber clinging was still a problem. It appeared from other comparative examples that the inclusion of the binder fibers such as a bicomponent fiber resulted in fiber cling of the cover to the fibers within the bale.
EXAMPLE
The present invention will be illustrated with the following example. A blend of 65% 3 dpf by 3 inch and 35% 6 dpf and 3 inch polyester was used. The blend was carded, cross-lapped, and needled at 1,200 psi.
It has been found that when all polyester fibers incorporated into the fabric are without a binder fiber are calendered from about 0.021 to about 0.018 inches using the calender roll at about 475° F. with the pressure of the calender set at 1,500 psi, a fabric was produced that resulted in improved tearing resistance and improved clinging resistance.
It will be apparent to those skilled in the art, that the present invention may be practiced in a wider variety of embodiments without materially departing from the spirit and scope of this invention. It is also to be understood that in the foregoing specification, specific embodiments and components thereof, have been illustrated and discussed by way of illustration only and not of limitation, and that the invention may be practiced by those skilled in the art utilizing a wide variety of materials and configurations without departing from the true spirit of the invention. | A non-woven recyclable polyester fabric suitable for use as a bale covering that is a single layer batt formed of crosslapped fiber having a structure compacted by needlepunching and calendering. A process for producing this non-woven recyclable polyester fabric that includes forming a web of fiber, crosslapping the web to form a batt, needlepunching the batt, and calendering the batt under suitable conditions. |
This is a continuation of copending application Ser. No. 07/537,583 filed on Jun. 14, 1990, now abandoned.
FIELD OF THE INVENTION
The present invention is directed toward an apparatus for monitoring the keyboard matrix of a personal computer, and, more particularly, to a hardware module for scanning the keyboard matrix.
BACKGROUND OF THE INVENTION
In a personal computer the keyboard associated with the computer is scanned periodically to ensure that the activation of the keys initiate some action. Typically, a microcontroller that is within the computer will, under program control, scan the keyboard matrix on a periodic basis to ensure that the computer acts properly when a key is struck.
The scanning function requires a significant amount of the microcontroller's processing bandwidth that could be used for other tasks. In addition, utilizing the microcontroller to perform this function will require that a certain amount of power be consumed by the personal computer. In certain instances this power consumption may significantly decrease the operating time of battery operated portable computers.
As personal computers become more and more compact, and particularly with the advent of portable computers, such as the laptop or notebook type computers, it is important to provide schemes that reduce the power consumed by the personal computer. In addition, as computers become smaller, it is more and more important that all the precious processing bandwidth of the microcontroller be utilized efficiently.
In the laptop or notebook computer environment, the same microcontroller which does the keyboard scanning might also perform other functions. If this microcontroller performs the scanning strictly under program control, without the benefit of a hardware keyboard scanner, there can be a significant performance penalty.
Another problem encountered in previously known keyboard scanning systems is what is known as "ghost" key closures of the keyboard. What is meant by ghost key closures is when several key switches on the keyboard are activated, there is another "closed circuit" on the matrix even though the associated key switch is not depressed. This problem is typically solved by providing additional circuitry within the keyboard. However, in the portable computer environment this additional circuitry can be expensive and can also unfavorably contribute power consumption.
What is needed to use with a personal computer is a system which will scan the keyboard and minimize the use of the microcontroller that is in a personal computer. What is further needed is a keyboard scanning technique that will minimize the power consumption in a personal computer. This system should not only satisfy the above requirements but should be simple and easy to use with a personal computer, a portable computer such as a laptop or notebook type.
SUMMARY OF THE INVENTION
A logic circuit is disclosed that assists the microcontroller in the keyboard scanning function. The logic circuit will use significantly less power than the microcontroller and in addition will allow the microcontroller to use its processing capability to perform other functions.
The present invention provides for, in combination with a personal computer, the personal computer including a microcontroller and a keyboard including a plurality of key switches, the keyboard further including a plurality of intersecting strobe lines and sense lines, a key closure being made when the appropriate strobe and sense lines are connected together by a particular key switch, a hardware assisted keyboard scanner.
The hardware assisted keyboard scanner comprises a random access memory (RAM), the RAM being organized as a plurality of bytes of data and plurality of addresses, each of the plurality of bytes of data corresponding to one of the plurality of sense lines and each of the plurality of addresses corresponding to one strobe line, a counter for providing an address to the RAM, the counter also for sequentially asserting each of the strobe lines; a comparator for comparing the data bytes from the RAM to the corresponding sense lines to determine if there has been a change in any of the key switches of the keyboard; and a flip flop for providing an interrupt signal to the microcontroller when there is a change in any of the key switches of the keyboard.
Through the use of the present invention the overall performance of the personal computer is improved. In addition, the power consumed in a personal computer can be significantly reduced. The present invention will find significant utility in the portable personal computer environment.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram of a prior art keyboard scanning system.
FIG. 2 is a block diagram of a typical keyboard matrix utilized with a personal computer.
FIG. 3 is a schematic representation of a portion of a first prior art keyboard matrix.
FIG. 4 is a schematic representation of a portion of a second prior art keyboard matrix.
FIG. 5 is a simplified block diagram of the hardware assisted keyboard scanning system of the present invention.
FIG. 6 is a block diagram of the logic circuit described and shown in FIG. 5.
FIG. 7 is a diagram of the preferred embodiment of the present invention.
DETAILED DESCRIPTION
The present invention relates to an improvement in the scanning of a keyboard matrix associated with a personal computer. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a particular application and its requirements.
Various modifications to the preferred embodiment will be readily apparent to those skilled in the art and the generic principles defined herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and novel feature disclosed herein.
Referring now to FIG. 1, what is shown is a microcontroller 10 coupled to the keyboard 12. In general, in previously known systems, the microcontroller 10 sequentially drives each strobe line active while monitoring the sense lines for data pattern changes. These data pattern changes would indicate keyboard activity. To more fully understand the operation of the microcontroller 10 when scanning the keyboard 12 refer now to FIG. 2.
FIG. 2 is a diagrammatic representation of the keyboard matrix of the keyboard 12. The keyboard matrix of this embodiment comprises a plurality of intersecting conducting wires arranged in columns (C1-C16) and rows (R1-R8). The columns wires are called the strobe lines in this specification. The row wires are called the sense lines in this specification. It should be recognized by one of ordinary skill in the art that there can be any number of sense lines and strobe lines and still be within the spirit and scope of the prevent invention.
In a typical keyboard, a key switch (not shown) is placed at each intersection of a row wire and column wire. The strobe (column) lines and sense (row) lines allow for the scanning of the keyboard matrix to determine when key switch make/break activity occurs. In one embodiment the strobe lines may be driven either individually or as a group, and the sense lines may be pulled high with resistors in this type of keyboard matrix. When no key switch make/break activity is present, the sense lines are all high, regardless of which strobe line is driven active. When key switch make/break activity exists, then at least one of the sense lines will be low, dependent upon the strobe line that is asserted.
Referring back to FIG. 1, the microcontroller 10 along with its other duties (which are not shown in this figure) has to monitor the keyboard 12 for key switch activation. Hence the microcontroller must sequentially drive each strobe line active while monitoring the sense lines for data pattern changes indicating keyboard activity.
One problem encountered in the previously known keyboard scanning system of FIG. 1 is the problem of "ghost" key switch closures. To more fully describe this problem, refer now to FIGS. 3 and 4.
FIG. 3 is a simplified diagram of a portion of a typical keyboard matrix. In this embodiment, there are four sense (R1-R4) signals and four strobe (C1-C4) signals. Key switches 30 connect respective rows of strobe (C1-C4) and sense (R1-R4) signals when closed. The boxes shown in the Figure indicate an activated key switch 30. In this embodiment, as is shown, there are key switch 30 closures between R1 and C3, between R1 and C1 and between R3 and C1.
Generally, "ghost" closures occur due to three or more key switch closures occurring simultaneously on the keyboard 12. The "ghost" closure indicated by the circle at R3 and C3 is caused by the key switch closures at R3 and C1, R1 and C1, and R1 and C3. The closure at R3 and C3 is detected even though the key switch 30 is not pressed. Hence, when strobe C3 is asserted, the row data pattern is 1010. This type of keyboard matrix does not have the ability to distinguish between the ghost closures and real key switch 30 closures.
There have been previously known systems for eliminating this problem. One method to eliminate the "ghosting" problem is shown in FIG. 4. FIG. 4 is identical to FIG. 3 except that each key switch 30 has a diode circuit 32 attached in series. These diode circuits prohibit continuity from one column to another column, thereby avoiding "ghost" key closures. Hence, when strobe C3 is asserted, C1 remains diode isolated and the row data pattern is 1110.
Although the use of a diode or the like in a keyboard matrix is effective in preventing ghost closures, in a portable computer environment it is more desirable to provide a keyboard matrix that does not include additional complexity and thereby additional cost. In addition, the use of diode circuits, or the like, adds to the overall complexity of keyboard matrix and hence personal computer.
There are at least two other problems with the microcontroller performing the keyboard scanning function without any assistance.
Firstly, the microcontroller 10 consumes a large amount of power. For example, the current drawn by a microcontroller 10 while performing this function can be as high as 30 mA. The overall power consumption in a personal computer becomes a significant factor when the computer is a laptop or notebook type personal computer because power conservation is critical to the total cost of the computer.
Secondly, when the microcontroller 10 is performing the keyboard scanning, as is well known, it cannot perform any other operation. The microcontroller 10 can require as much as 5 Ms to scan every key switch on the keyboard 12. As has been before mentioned, this function requires processing bandwidth of the microcontroller 10 that could be used for other tasks.
Hence, particularly in the portable computer environment, it becomes more important to be able to minimize the use of power when no tasks are being done by the microcontroller 10 and it is also important to free the microcontroller 10 to perform as many functions as possible. Accordingly, the present invention provides a solution to these problems through the use of a logic circuit to assist the microcontroller with the keyboard scanning function.
Referring now to FIG. 5, what is shown is a logic circuit 14 coupled between the microcontroller 10 and the keyboard 12. As is seen, the logic circuit 14 receives the sense signals via line 11 from the keyboard 12 and provides a strobe signal to the keyboard 12 via line 13 and outputs to the microcontroller 10 at appropriate times, an interrupt signal via line 15. Furthermore, the microcontroller 10 updates RAM 24 in logic circuit 14 via lines 17 and also provides an acknowledge signal to the logic circuit 14 via line 19 to allow the logic circuit 14 to continue to function.
The use of the logic circuit 14 addresses two major concerns with the previously known microcontroller keyboard scanning system shown in FIG. 1. Firstly, the logic circuit 14 can be constructed from CMOS technology which uses significantly less power than the CMOS microcontroller 10 which it replaces. For example, the logic circuit 14, when properly fabricated, can draw current in the 500 uA range.
Hence, logic circuit 14 will consume an order of magnitude less power than the typical microcontroller 10 which, as before mentioned, draws current in the mA range when performing the keyboard scanning function. During times when the keyboard scanning function is occurring, the microcontroller 10 can enter a power down mode of operation until interrupted by the logic circuit 14.
In addition, through the use of the logic circuit 14, the keyboard scanning function can be totally interrupt driven. That is, the microcontroller 10 can perform other functions while the logic circuit 14 is scanning the keyboard 12. When a key switch closure is detected on the keyboard 12 by the logic circuit 14 an interrupt signal is provided by logic circuit 14 which will cause the microcontroller 10 to respond to the keyboard activity.
To more fully describe the operation of the logic circuit 14, refer now to FIG. 6, which shows a more detailed embodiment. The logic circuit 14 comprises a comparator 22 which is coupled to a random access memory (RAM) 24 which is further coupled to a counter 26. Comparator 22 also provides signals to an interrupt circuit 20 which in this embodiment is preferably a flip-flop.
As is also seen, the interrupt circuit 20 sends an interrupt signal to the microcontroller 10 and receives an acknowledge signal via line 19 from the microcontroller 10. Furthermore, the microcontroller 10 is coupled to the RAM 24 via line 17 and updates data and address information within the RAM 24. Finally, as is seen, the comparator 22 receives sense signals from the keyboard 12 via line 11. The sense signals are also supplied to the microcontroller 10 at appropriate times. Finally, the counter 26 also provides a strobe signal to the keyboard 12 via line 13.
The logic circuit 14 operates in the following manner. Typically, there is initially a data pattern of key closures in the RAM 24. In this embodiment, the RAM 24 is organized as 16 bytes of data, with their corresponding addresses. Each data byte corresponds to a row of sense lines and each RAM address corresponds to one of the columns or strobe lines. The data pattern initially in the RAM 24 would be "FF" in hexadecimal code indicating that all the sense lines are pulled high and therefore none of the key switches are activated.
The scanning process is controlled by the counter 26, which in this embodiment is a four-bit counter. The counter 26 provides address signals to the RAM 24 and asserts a strobe line on the keyboard 12. Every time the counter 26 increments, a new strobe line is asserted and the next sequential data byte is referenced.
The data byte from the image RAM 24 is then compared with the corresponding sense line state of the keyboard 12 by the comparator 22 to determine whether there has been at least one key switch closure change on the keyboard 12 since the last scan cycle. An interrupt signal is provided to the microcontroller 10 by the interrupt circuit 20 for all data miscompares due to any key switch activity. The interrupt signal also stops the counter 26, thereby freezing the image RAM address and allowing the microcontroller 10 to read the sense line data and update the RAM 24 data. When the interrupt is acknowledged by the microcontroller 10, the counter 26 is released by the microcontroller 10 to continue the scan cycle.
This logic circuit 14 thereby provides for a hardware assist to the keyboard scanning that removes this function from the microcontroller control. In so doing, the valuable processing bandwidth of the microcontroller is not utilized for this function and, therefore, the microcontroller 10 is free to perform other tasks during the times that the keyboard 12 is not active.
Referring now to FIG. 7, FIG. 7 shows a block diagram of the preferred embodiment of a logic circuit 140 utilized for the keyboard scanning function. The logic circuit 140 comprises many of the same elements as described in logic circuit 14 of FIG. 3, that is, it includes the image RAM 24, the counter 26 and the comparator 22 and the interrupt circuit 20. These devices operate in basically the same way as above described in FIG. 4.
A first multiplexer 142 is coupled to the output of the counter 26 and provides signals to a decoder 144. The decoder 144 outputs one of sixteen strobe signals to the keyboard 12 dependent upon which number the counter 26 is on. Registers 150 and 152 allow for reading data bytes and address information from RAM 24.
Data bytes are read from the keyboard matrix 12 through register 148 by the microcontroller. A multiplexer 154 is provided between the comparator 22 and the RAM 24 to provide the data to the comparator 22 at the proper time. Multiplexer 154 is used to provide the "FF" pattern for the comparator when no keys are pressed.
There is a signal provided to the decoder 144 and the multiplexer 154 called ALLO. This signal is asserted once there are no key switch closures on the keyboard 12. The ALLO signal is initiated from the microcontroller 10 when the data in the RAM 24 is all "FF". When ALLO is asserted, all the strobe lines 13 go low and the counter 26 is stopped.
As long as there are no keyboard closures, the logic circuit 140 will be inactive. Once keyboard activity occurs, an interrupt from flip-flop 20 will cause the microcontroller to release the ALLO signal. Circuit 140 will operate in the manner as before described. Hence, this embodiment has all the above mentioned advantages of a logic circuit 14 of FIG. 4, namely, lower power consumption and allowing the microcontroller to perform other activities. In addition, logic circuit 140 includes this additional power down capability in which the circuit will dissipate no power during those times of no keyboard activity.
De-ghosting is the process of validating the row data to ensure that each detected key switch closure is caused by the corresponding key switch and not by a combination of unrelated key switch closures. De-ghosting in this embodiment involves comparing the key switch closure data pattern of the current row with the key switch closure data pattern of each and every row to determine if there are any key switch closures which occupy the same position within the row data (for example, two rows which have key closures in position R1). If common data patterns are present, ghost closures may exist and the corresponding row data must be discarded as invalid.
In this embodiment, a signal is provided to decoder 144 called COMP via line 180 which is used to accelerate the process of collecting the data from each and every row. When COMP is asserted, the decoder 144 outputs are complemented. This will assert all column strobes except the strobe associated with the current row.
When this-action occurs, the sense lines reflect the logical "or" of all the rows except the current row. The sense line data can be read by the microcontroller 10 via buffer 148 and compared to the current row data to determine if common key closures exist. Normally, this process is done under program control, one row at a time.
It is understood that the above described embodiments are illustrative of but a small number of the many possible specific embodiments which can represent application of the principles of the present invention. Numerous and various other arrangements can be readily devised in accordance with these principles by one of ordinary skill in the art without departing from the spirit and scope of the present invention. The scope of the present invention is limited only by the following claims. | A system for assisting the scanning of a keyboard associated with a personal computer. The system comprises a logic circuit which interacts with the microcontroller and the keyboard to reduce power consumption by the personal computer as well as freeing the microcontroller to do other tasks. The logic circuit "interrupts" the microcontroller whenever keyboard activity is detected. An image RAM stores a pattern of current key closures to be compared in subsequent keyboard scans. A subsequent miscompare between the keyboard and the Image RAM indicates that keyboard activity has occurred. When no keys are pressed, scanning may be stopped. Any key closure will then generate an interrupt, and the microcontroller will restart scanning. |
FIELD OF THE INVENTION
The invention refers to the treatment of dairy wastewater, i.e. animal industrial waste from dairies, which for example includes whey and sludge from separators. More specifically, the invention refers to a process for recycling dairy wastewater as well as a dairy wastewater treatment plant.
BACKGROUND OF THE INVENTION
Today, wastewater is disposed of by sewage treatment plants, in which it is mixed with all different kinds of more or less polluted wastewater. The result is that odors are spread and a questionable, and sometimes a hazardous sludge is obtained, which has to be disposed of.
The wastewater from a dairy can amount to 20–30 million liters, which requires large areas for sedimentation basins for settleable solids. Such amounts require the corresponding amounts of raw water. Since water becomes a more and more expensive raw material, its economic effects can not be underestimated. For example, in Saudi Arabia the water costs are SEK 25 per m 3 . Pure water requires substantial investments.
In modern plants for treating wastewater from dairies gravity thickening is used in order to improve the sedimentation rate, for example by releasing fine air bubbles as in a plant of the type dissolved air flotation (DAF). However, sufficiently pure water can not be obtained with an ordinary plant for wastewater treatment of the DAF type when wastewater from a dairy is treated. Furthermore, this type of water purification does not result in a sufficiently pure water to be reused as a technical water or as a raw water.
With the above-mentioned volumes of wastewater from a dairy an overflow may occur without control and the wastewater may reach small waters which can be very sensitive to this discharge. The average characteristics of the wastewater from a milk processing includes a biochemical oxygen demand (BOD) of about 1,000 mg/l, a chemical oxygen demand (COD) of about 1,900 mg/l, a total solids content of 1,600 mg/l, and a suspended solids content of 300 mg/l. These figures dramatically exceed those permitted by governments in different countries. In Australia for example, the maximum allowable amount of BOD to be discharged to a recipient, such as a river, is 180 ppm.
SUMMARY OF THE INVENTION
The purpose of the invention is to provide a process of dairy wastewater treatment for obtaining a more clean water than with existing processes. A further purpose of the invention is to provide a sludge from such a wastewater treatment, which could be used as an animal fodder.
In order to achieve this purpose the process according to the invention has the characterizing features of claim 1 .
In order to explain the invention in more detail an illustrative embodiment thereof will be described below reference being made to the accompanying drawing in which:
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a flow diagram of a preferred embodiment of a dairy wastewater treatment plant.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1 wastewater A from a dairy factory is supplied to an effluent pit 1 of about 1 million liters. Preferably, wastewater is first pumped through a filter which removes bigger lumps (not shown). The wastewater A supplied has a BOD level of less than 3 800 ppm and a COD level of less than 2 200 ppm and the wastewater treatment plant is adapted to feeds of 3 millions liters per 24 hours.
The wastewater is “standardized” (c.f. below) in the effluent pit 1 with reference to its dry matter (DM) content. A first effluent B of 0.5% DM and 4 bar is via a heat exchanger 2 conveyed to a first evaporator 4 and a second evaporator 5 . A first pump 3 supplies antiscale in order to provide a second effluent C which is prevented from forming deposits of overheated material on the evaporator heating surface.
These evaporators are adapted to high flow rates and have for example been used for the evaporating of sea-water. Preferably, the evaporators are so called Vacuum Vapor Compression units. In such a device the heat delivered by compressed vapor at sub-atmospheric pressure and corresponding low temperatures is used for evaporating the wastewater.
First and second sludges E, H from the first 4 and second 5 evaporators, respectively, are adapted to third and fourth sludges F, I of about 3.3% DM. These are mixed to a first mixed sludge J and conveyed to a first buffer tank 7 , from which a fifth sludge K may be further concentrated to a sixth sludge L before it is allowed to enter a third evaporator 6 of the same kind as those mentioned above. From this evaporator a seventh sludge P is removed which is further adapted to an eighth sludge Q of about 10% DM.
A first distillate M from the third evaporator 6 is mixed with second and third distillates D, G from the first and second evaporators, 4 , 5 , respectively, to a mixed distillate N. This distillate has a BOD level of less than 21 ppm and a COD level of less than 150 ppm. The average BOD level is about 14 ppm and the average COD level is about 57 ppm.
The eighth sludge Q is conveyed to a second buffer tank 8 . A second pump 9 supplies this tank with antiscale. A third pump 10 provides acid for the buffering of the tank 8 .
Sedimented sludge T of pH 7–8 is conveyed to a fourth evaporator 12 . This evaporator is preferably a so called Casette Evaporator, i.e. a closed unit which earlier has been used for concentrating juice or for removing residual moisture from for example whey to obtain solid or semi solid components as well as a condenser condensate. The sludge treatment according to the invention results in this evaporator in a first condensate V, and a concentrated product in the form of a ninth sludge e.
The ninth sludge e is conveyed to a fifth evaporator 13 which is of the same type as the fourth evaporator 12 . The evaporation process results in a tenth sludge d and a second condensate X. Here, the sludge is further concentrated to a final sludge d of about 30% DM.
A condensate a from the fifth evaporator 13 is mixed with the first condensate V to a first mixed condensate Z.
At last, the first mixed condensate Z is mixed with the mixed distillate N to recycled water O which is allowed to the heat exchanger 2 .
The water of the liquid wastewater material is according to the invention evaporated in two steps. Of course, the number of evaporators depends on the capacity of the system to be used. A plant with only one evaporator of each type in series is suitable for about 1 million liters of wastewater per 24 hours, which figure can be increased by adding two of the first and second type evaporators in series.
In the preferred embodiment of the invention the dairy wastewater treatment plant according to the invention is adapted to flow at 3 millions liters per 24 hours. In order to optimize the process technically as well as economically two types of evaporators are arranged in series.
The first type of evaporator, preferably a Vacuum Vapor Compression unit, is not suitable for evaporation to a dry matter content of more than 3–10%. If this limit is exceeded deposits of overheated material will occur on the heating surface of the evaporator in dependence of the equipment utilized.
The evaporation process in the first type of evaporator results in one stream of a distillate and one stream of a sludge which is concentrated to about 3.3% dry matter (DM). The wastewater condensate from the first evaporator type has a COD of less than 57 ppm and a BOD of less than 21 ppm.
The wastewater treated in the first type of evaporator is according to the invention fed to a second type of evaporator. The change of evaporator type should take, place when the feed reaches a dry matter content of 3–10%. The second type of evaporator is designed to successfully treat feeds of 10% dry matter, which is preferred. Deposits will not occur on the heating plates of this evaporator since it is adapted to aqueous liquids with high dry matter contents.
Thus, in the end of the first evaporator type clean water as well as a sludge is obtained, the sludge directly being transferred to the second evaporator type, preferably a Cassette Evaporator or Plate Evaporator, for further concentration. More water is obtained as well as a further concentrated sludge. The inflow to the second evaporator type is from 1 to 50 ton per hour, the sludge being concentrated to about 30% DM or higher.
The final sludge is transported to a buffer tank, in which the pH is automatically adjusted to a pH level between 7–8. Finally, the final sludge is pumped to a container for further transport. The sludge can then be used directly or further concentrated to a dry product.
The condensate obtained from the second type of evaporator has a BOD of about 36 ppm and a COD of about 99 ppm. The condensate is mixed with the condensate from the first type of evaporator, a completely recycled water being obtained.
An advantage of the inventive method is that the resulting recycled water without any further treatment can be returned to any of the water-supplies with a quality of technical water. The water can also be discharged into a suitable recipient, such as a river or the sea.
In principle, nothing of the wastewater is discarded. Everything is reused. The water can be reused in the dairy as a technical water or as a raw water. In this case the water has to be further purified from volatile odorous substances which accompany the water during the evaporation procedure. This can be accomplished by physically removing these substances, for example by passing the water through a filter of active carbon. In order to supply pure water to the food industry the water is subjected to radiation, e.g. UV-radiation. This procedure guarantees a microbiologically pure water.
The quality of the recycled water is in accordance with WHO guideline values as well as the technical requirements of most countries:
Taste
None
Smell
None
Turbidity
Max. 5 NTU
Colour
Max. 20 mg/l Pt
Oxygen demands
Max. 20 mg/l KMnO 4
total dissolved solids
Max. 500 mg/l
An example of the quality of the waste water feed according to the invention is shown in Table 1 below.
TABLE 1
Component
Conductivity
μS/cm
4,560
pH
6–11
Dissolved
ppm
>2,700
Solids
Suspended
ppm
>250
Solids
NH 4 (as N)
ppm
<2.3
Na
ppm
<1,000
Mg
ppm
<20
Ca
ppm
<55
Fe
ppm
<3.5
Fe filtered
ppm
PO 4 (as P)
ppm
<45
CO 3 (as
ppm
<210
CaCO 3 )
Total
ppm
<940
Alkalinity
as CaCO 3
Cl
ppm
<300
SO 4 (as S)
ppm
<20
SiO 2
ppm
<9.2
K
ppm
<30
Total Solids
%
<0.5%
Ash (dry
%
<47%
basis)
Total N
ppm
<22
Protein
%
<0.1
Fat/oil
ppm
<25
COD
ppm
<3,800
BOD
ppm
<2,200
Free chlorine
ppm
0.00
According to the invention a more environmentally acceptable process is obtained than with previous processes for treating wastewater from dairies because of the very low BOD and COD levels as well as the low turbidity of the recycled water. This should be compared with a traditional wastewater plant of the type DAF, in which a reduction of only about 60–70% can be obtained.
Both products of the wastewater process—water and sludge—have a potential economic value, since both are pure enough to be reused. In addition, neither the water nor the sludge has to be disposed of. This more than compensates for the higher investment costs than for traditional plants.
As much as 98% of the wastewater results in a distillate/condensate which can be reused in the dairy. This means that the dairy is more or less self sufficient with water and that a minimal usage of raw water is required.
The wastewater recycled according to the invention has a value in itself and can for example be further used in for example vegetable gardening.
The wastewater from a dairy is in principle very diluted milk in water. Thus, the sludge contains valuable nutritive matter, such as protein (7.4%), carbohydrates, fat and salts. The sludge can be used directly for the manufacturing of an animal fodder or further concentrated by evaporation to a dry product.
The process according to the invention is a very environmentally friendly process since no polluted water is discharged from the plant, less raw water is used, no hazardous sludge has to be disposed of, no odours are spread, and there is less risk of an accidental untreated overflow to the environment. Furthermore, the process efficiency independent of external parameters.
Another advantage of the invention is its low space requirements, the high reliability and availability of the evaporators used, and the low maintenance costs. | A process and apparatus for recycling dairy wastewater wherein the wastewater is supplied to at least one first evaporation apparatus to produce a water distillate and sludge. The sludge is then supplied to at least one second evaporation apparatus arranged in series with the first evaporation apparatus. The process results in recycled water and a final sludge. |
This application is a Continuation of application Ser. No. 08/024,050, filed Mar. 1, 1993 now abandoned.
This invention relates to the manufacture of thin-film field-effect transistors and, in particular, concerns a process for patterning the source-drain contacts in such transistors.
BACKGROUND OF THE INVENTION
In some types of imaging and display devices, a thin-film field-effect transistor (TFT) is associated with each pixel. The TFT must be small for several reasons. One, it consumes space within the pixel, which would otherwise be devoted to light collection or light control. Two, the TFT must be small because the pixels themselves are small; over one million pixels may be constructed on a plate measuring 8×8 inches. Three, the TFT must be small to minimize (a) the total gate capacitance, (b) the gate-to-source capacitance, and (c) the gate-to-drain capacitance.
The total gate capacitance should be small in order to reduce the total capacitance of the address line (i.e., scan line) which controls a row of TFTs in the imaging or display device. The charging time of this address line is controlled by the product of the line resistance and line capacitance. The total gate capacitance is added to the line capacitance in determining the address line charging time.
The drain-to-gate and source-to-gate capacitances should be small to minimize the coupling capacitance between the input address line, which is connected to the gate, and the imaging or display element connected to the source or drain.
PRIOR ART
In pursuit of reduced capacitances, the gate-to-drain and gate-to-source overlaps in the TFT should be kept minimal. However, it can be difficult to manufacture small TFTs in which the overlap is exactly a desired amount. One reason is that a photolithographic process is commonly used to form the source and drain. In such process, there is a typical positioning misalignment of about 2 microns or more which must be accounted for in the device layout. This amount of misalignment requires that the regions where the gate overlaps the source and drain be made larger than otherwise required, to allow for this misalignment. These enlarged sizes increase the capacitances discussed above, which is undesirable.
One approach to reducing this misalignment is found in commonly-assigned G. Possin et al. U.S. Pat. No. 5,010,027, issued Apr. 23, 1991. This patent, which discusses a self-alignment technique for constructing thin-film transistors, is hereby incorporated by reference.
OBJECTS OF THE INVENTION
One object of the invention is to provide improvements in alignment of the source and drain contacts in the manufacture of thin-film transistors.
Another object of the invention is to provide a thin-film transistor of reduced size.
SUMMARY OF THE INVENTION
Briefly, in accordance with a preferred embodiment of the invention, during construction of a thin-film field-effect transistor, a cap is positioned over the channel region, between the source and drain. A coating of source-drain material, which will form the source and drain contacts, is then applied over the source and drain regions, and the cap. One type of source-drain material is a layer of metal over a layer of semiconductor, such as N+ silicon. An etchant is thereafter applied, which etches away the cap, causing the source-drain materials coated on the cap to lift away, leaving the source and drain contacts in place.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing(s) in which:
FIG. 1 is a schematic illustration of a field-effect transistor;
FIGS. 2-5 illustrate a sequence of steps used in constructing one form of the invention;
FIGS. 6 and 7 schematically illustrate a lift-off procedure used in the invention;
FIGS. 8-14 illustrate in more detail the construction of one form of the invention;
FIG. 14A is an enlarged view of a portion of FIG. 14;
FIG. 15 illustrates an intermediate structure showing in detail a cap, a brim, and an island;
FIG. 16 illustrates an intermediate structure used in another form of the invention;
FIG. 17 illustrates processing steps used in another form of the invention;
FIG. 17A is an enlarged view of a portion of FIG. 17; and
FIG. 17B is a view similar to that of FIG. 17A, after further processing.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a TFT of a type known in the art, showing an overlap O between the gate electrode G and each of the source S and drain D electrodes or contacts. The metallic source and drain electrodes are attached to the transistor semiconductor substrate 10, typically of silicon, through a thin N+ silicon layer 11. The metallic gate electrode is spaced from substrate 10 by a layer of insulation 12. The channel region exists in substrate 10 above gate electrode G, primarily in the region not overlapped by drain and source electrodes D and S, respectively.
In pursuit of reduced capacitances, this overlap should be kept small. However, manufacture of small TFTs in which the overlap is exactly a desired amount is known to be difficult due, at least in part, to the typical positioning misalignment of about 2 microns or more resulting from the photolithographic process commonly used to form the source and drain contacts. This positioning misalignment requires that the regions where the gate electrode overlaps the source and drain contacts be made larger than otherwise necessary, to allow for the misalignment, resulting in the undesirable increases in the capacitances as discussed above.
Simplified Form of the Invention
FIG. 2 shows a starting structure, which can be constructed using known techniques. The substrate-carrier 20 may be comprised of glass; however, other materials may be substituted therefor, providing they are sufficiently transparent to ultraviolet light in the 400 nanometer (nm) range. The gate electrode G is deposited on substrate-carrier 20, as by sputtering, and gate electrode G and substrate-carrier 20 are overlaid, in sequence, by a layer of insulation 21, a layer of silicon 22, a second layer of insulation 23, and cap material 24, which may comprise, for example, molybdenum or indium tin oxide sufficiently thin to be transparent or semi-transparent to actinic light. Layers 21, 22, 23 and 24 may be deposited by any of several conventional techniques such as plasma-enhanced chemical vapor deposition, while the cap layer may be applied by sputtering for example.
An island 34 is constructed from cap material 24, as shown in FIG. 3. The island is centered on the gate between the source and drain regions by use of a self-alignment technique, such as described in the aforementioned U.S. Pat. No. 5,010,027, in its formation. A cap 32 having a brim 33 is then formed on the island. The brim prevents material, deposited in the next step, from accumulating in region 31 beneath the outer portion of the brim.
As the next step, the conductive source and drain contacts 41 and 42, respectively, are formed, as shown in FIG. 4. Although these contacts are shown as single layers, in practice they can be constructed of two layers 51 and 52 as shown in FIG. 5, wherein they comprise source-drain (SD) metal and n+ silicon, respectively. During this step, the material forming source and drain layers 41 and 42, respectively, also accumulates as unwanted material 43 upon cap 32 as shown in FIGS. 4 and 5. However, brim 33 reduces or eliminates accumulation of source and drain material in region 31.
The entire structure shown in FIG. 4 is next subjected to an etch, which attacks cap 32 at its exposed portion in region 31. However, the etch does not damage the other structures, such as source and drain contacts 41 and 42, respectively, or island 32. The cap etches away, as indicated by the sequence of FIG. 6, and eventually lifts off, as indicated by the arrows and phantom lines shown in FIG. 7, leaving an overlap O between the gate electrode and each of the source and drain contacts. No masking and patterning operation, as done in photolithography, is required to remove the unwanted material 43 which accumulated upon the cap.
More Detailed Explanation of the Invention
The starting structure is shown in FIG. 8 and is built up by conventional techniques as previously described. In FIG. 9, a layer 61 of material that may be either semi-transparent or transparent is deposited, followed by a layer 62 of photoresist. Lift-off layer 61 may comprise a thin metal, such as molybdenum, or indium tin oxide (ITO), and is transmissive in the near ultraviolet, i.e., in the 400 nanometer range.
The photoresist of layer 62 is exposed to near ultraviolet light 69, as indicated in FIG. 10, such that gate G casts a shadow 66 upon photoresist layer 62 within the region bounded by dashed lines. The photoresist of layer 62 is then developed so as to remove the exposed portion of photoresist layer 62, but not the portion of photoresist layer 62 shadowed by gate G, resulting in the structure of FIG. 11. The shadowed portion has at this juncture become a photoresist pattern.
Photoresist Shadowed by Gate Defines Shape of Thin Metal
An etchant is applied to the structure of FIG. 11, which etches away lift-off layer 61 except where it is covered by the now-patterned photoresist 62, resulting in the structure shown in FIG. 12.
Next, silicon nitride layer 23 is etched away, producing the structure shown in FIG. 13. This etching of layer 23 can be achieved by a wet etch of hydrofluoric acid or buffered hydrofluoric acid. Alternatively, a dry etch, e.g., reactive ion etching with CHF 3 and CO 2 gases, can be used to preferentially attack the silicon nitride but leave the amorphous silicon largely intact. (Photoresist 62, shown in phantom, can be removed either before or after this step.) The resulting structure is shown in FIG. 14, and FIG. 14A shows, in greater detail, the amount D by which lift-off layer (or cap) 61 overhangs silicon nitride island 23.
Deposition of SD Metal
At this juncture, an N+ amorphous silicon (N+ microcrystalline silicon) layer 64 is deposited, resulting in the structure shown in FIG. 15. Silicon layer 64 is about 10 to 100 nanometers (nm) thick and forms a contact region which borders silicon nitride island 23. A layer of SD metal 65, about 10 to 200 nm thick, is next applied, typically by sputtering or evaporation.
Because the brim of the lift-off layer or cap 61 acts as an overhang, region 27 is not significantly covered by layers 64 and 65; instead, the two layers deposit onto the top of cap 61 and onto amorphous silicon layer 22, but are interrupted by a discontinuity in the two layers.
It is not necessary that the brim completely inhibit all deposition of these last two layers in region 27. If the two layers are deposited very thinly in region 27, the etching step which lifts off the cap can still succeed.
Preferably, the discontinuity in layers 64 and 65 causes the portions of these two layers atop cap 61 to be electrically disconnected from the SD metal which is located on amorphous silicon layer 22. This discontinuity allows lift-off layer 61 to be attacked by etchant.
Lift-off layer 61 is next etched away, causing the two-layer film (layers 64 and 65) coating it to lift off, in the manner shown in FIGS. 6 and 7. The resulting structure, shown in FIG. 16, is a precursor to the final TFT, and can be processed in known fashion to produce the TFT. The aforementioned U.S. Pat. No. 5,010,027 provides details on one such type of further processing.
Embodiments
Indium tin oxide can be used as the lift-off layer 61, and molybdenum can be used as the source-drain (SD) metal 65. Candidates which are possible substitutes for indium tin oxide as the lift-off layer are tungsten, tantalum, aluminum, and zinc oxide. Etchants which will selectively etch the proper layers are known in the art. Alternatively, molybdenum can be used as the lift-off layer, and chromium can be used as the SD metal; or chromium can be used as the lift-off layer, with molybdenum as the SD metal.
Use of molybdenum as lift-off layer 61 and chromium as SD metal 65 is shown in FIG. 17. One advantage to this combination is that the chromium can be reacted with the underlying N+ silicon layer 64 to form a silicide layer 33 schematically shown in FIG. 17A, which is an enlarged view of the encircled region of FIG. 17. The unreacted chromium can be etched away, leaving silicide layer 33, as indicated in FIG. 17B, which is a view of the region shown after the chromium has been etched away. (Known etchants will selectively etch chromium layer 65 and leave the silicide.) As a result of using this combination, moreover, etching away of molybdenum lift-off layer 61 is simpler, because the amount of chromium on top of it has been reduced by the chromium etch.
As another alternative, SD metal 65 and N+ silicon layer 64 can be replaced by a single N+ microcrystalline silicon layer to form the source and drain contacts. Selectively etching away the lift-off layer while leaving the microcrystalline silicon is a known procedure. N+ microcrystalline silicon has the advantage of a much higher electrical conductivity than amorphous silicon, and thus a separate source-drain metal is not required.
Additional Considerations
Although molybdenum has been identified as a candidate material for the lift-off layer, other metals can alternatively be used. The metal used must be subject to etch but, at the same time, the etchant must not destroy the SD metal 65 shown in FIG. 15.
As stated above, an alternative combination is chromium for the lift-off layer and molybdenum for the SD metal. Hydrochloric acid can be used as the etchant and it will not significantly attack the molybdenum. Other SD metals which may be used are tungsten, tantalum, gold, nickel-chrome alloys, and aluminum.
In general, an etchant must be available which etches the lift-off layer, yet does not destroy the SD metal, nor the passivation dielectric (i.e., the silicon nitride island 23 in FIG. 15), nor the amorphous silicon (shown in FIG. 15).
Two important features of this process are the following. First, material forming the source and drain contacts does not envelop the cap, but leaves the underside of the brim exposed. (If the brim of the cap were nonexistent, or very small, envelopment would occur. ) Second, the material which accumulates in a layer upon the cap is delaminated from the silicon nitride island by applying the appropriate etchants. The etchants attack the cap as indicated by the schematic sequence of FIGS. 17, 17A and 17B.
As stated above, the semi-transparent material which acts as lift-off layer 61 in FIG. 9, for example, should be transmissive at 400 nanometers (nm). If the lift-off layer is a metal (such as molybdenum, for example), then it must be thin enough to transmit sufficient light to expose photoresist 62, shown in FIG. 9, in an acceptable length of time. Limitations on the thickness of the lift-off layer can be determined in the following manner, using molybdenum as an example.
Measurements of thin sputtered films of molybdenum indicate that the absorption coefficient is about 1.6×106 cm -1 , for light of 400 nanometers wavelength. From these measurements, a 25 nm film of molybdenum is estimated to have an attenuation factor of about 330; that is, if light passes through the film, light intensity at the exit point would be about 1/330 of the light intensity at the entry point.
A comparison with a self-alignment procedure used in the prior art is appropriate. In the prior art procedure, photoresist is exposed by light which passes through a layer of amorphous silicon (instead of a metal). For a layer of about 25 nm thickness, attenuation is approximately a factor of 10, meaning that the exiting light intensity is about 1/10 of the incoming light intensity.
Thus, by using such molybdenum lift-off layer, the required exposure time has been increased from about 30 seconds (for amorphous silicon) to about one hour. Although this is longer than for amorphous silicon, it is not unreasonable. If the lift-off layer is comprised of indium tin oxide, the exposure time remains about the same as for amorphous silicon.
The layers in the starting structure shown in FIG. 8 preferably have the following thicknesses:
lowermost silicon nitride layer 21 is about 50-500 nm thick;
amorphous silicon layer 22 is about 20-100 nm thick;
upper silicon nitride layer 23 is about 100-1000 nm thick.
Those skilled in the art will appreciate that the channel of the TFT need not be amorphous silicon, but that other semiconductor materials can be used.
While only certain preferred features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | A thin-film field-effect transistor is fabricated by forming an electrically insulative island between the source and the drain. A cap is formed on the island with a brim that overhangs the island. A layer of source-drain metal, which will subsequently constitute the source and drain contacts, is then deposited upon the source, the drain, and the cap, but the overhang creates an exposed region which can be attacked by an etchant. When the etchant is applied, it etches away the cap, thereby lifting off the source-drain metal which coated the cap, leaving the fully formed source and drain contacts separated by the island. |
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
The invention described herein was made in the performance of work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958, Public Law 85-568 (72 Stat. 435; 42 U.S.C. 2457).
CROSS-REFERENCE TO RELATED APPLICATION
The invention described herein was described in a Provisional Patent Application, application Ser. No.: 60/022,526; filed: Jul. 10, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Real time, on-line detection and quantitation of aqueous ammonia is a critical requirement for closed loop environmental life support systems. Dissolved ammonia and the ammonium cation are primarily of biogenic origin, resulting from the metabolic degradation of nitrogenous biomolecules such as amino acids, purines, and pyrimidines. The predominant hydrophilic metabolite, urea, is unstable with respect to hydrolysis and readily decomposes to ammonia and carbon dioxide. Hence, accurate and timely characterization of ammonia levels in closed loop reclamation streams is required to ensure proper water processor operation.
Conventional analytical techniques are generally unsuitable for continuous ammonia monitoring due to sample conditioning requirements, measurement instability, interferences, discontinuous aliquot sampling, and slow response times. For example, calorimetric determinations such as Nesslerization, or the phenate method require sample conditioning as well as reaction with chromogenic reagents. Ion chromatography requires the addition of a buffer and can only analyze selected aliquots whose interval depends on the time needed for separation and elution of ionic constituents. Ammonia ion selective electrodes require pH adjustment and the presence of ionic strength adjusting buffers, need frequent recalibration, suffer from slow response at low concentrations, and can become unstable due to contamination of the ammonia permeable membrane which then must be replaced. Although some of these techniques can be adapted to quasi-real time operation, the added cost and complexity makes them unattractive.
2. Description of Related Art Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98
The subject invention was made as a real time, online detection and quantitation system for aqueous ammonia for use in a closed loop environmental life support system. However, it may be used in any aqueous process stream for detection and quantitation of ammonia.
The following references relate to detection and measurement of ammonia in liquids.
U.S. Pat. No. 4,700,709 to Kraig discloses an apparatus for determining the concentration of ammonium ion in fluid or tissue without adjusting the pH thereof, the apparatus comprising (a) an ammonia concentration measuring electrode for contacting the fluid or tissue and producing a first output signal related to ammonia concentration therein, (b) a hydrogen ion concentration measuring electrode for contacting the fluid or tissue and producing a second output signal related to hydrogen ion concentration therein, (c) temperature measuring means for contacting the fluid or tissue and producing a third output signal related to temperature therein, and (d) means for calculating ammonium ion concentration based upon the first, second and third output signals utilizing a disclosed equation.
U.S. Pat. No. 4,314,824 to Hansen et al. discloses a method of preparing a sample for treatment in which a continuous flow of liquid carrier receives sample portions, the method comprising: passing the carrier through a conduit in a manner such that flow of the carrier is laminar, unsegmented and continuous; introducing sample portions into the carrier; controlling dispersion of the sample portion in the carrier by varying at least one of the volume of the sample portion, the flow velocity of the carrier, or the dimensions of the conduit conducting the sample and the carrier. Also disclosed is an apparatus for practicing the method.
U.S. Pat. No. 3,718,433 to Emmet discloses a process for determining in an aqueous sample the content of nitrogen containing compounds from the group consisting of urea and tyrosine, through chemical reaction and spectral absorbency determination. The process comprises: (1) mixing the aqueous sample at a pH between 4.0 and 8.0 with a solution containing free chlorine; (2) mixing the resultant solution between a pH of 8.0 and 11.0 with a phenol solution; (3) determining the absorbency of the resultant solution substantially in the 454 μ and in the 375 μ region of the spectrum; and (4) comparing the resultant absorbency of step 3 at 454 mu with a standard urea sample, and the resultant absorbency of step 3 at 375 mu with a standard tyrosine sample.
U.S. Pat. No. 4,209,299 to Carlson discloses a method for determining the amount of volatile electrolyte present in an aqueous liquid sample, comprising: transferring volatile electrolyte from the sample into a second liquid of known electrical conductivity through a gas-permeable hydrophobic membrane that does not pass the aqueous liquid, during a predetermined time interval, and then determining the change in electrical conductivity in the second liquid resulting from such transfer. The invention also discloses an apparatus for practicing the method.
U.S. Pat. No. 5,158,868 to Bergkuist et al. discloses a method for measuring a constituent of interest of a biological fluid or the like comprising the steps of: providing a reaction chamber that contains an immobilized enzyme capable of modifying a constituent of interest; providing a measuring system; placing a first portion of a biological fluid to be analyzed in the reaction chamber and concurrently exposing a second unmodified portion of the biological fluid to the measuring system to provide a first data output; oscillating the first biological fluid portion with bidirectional flow in the reaction chamber to facilitate modification by the immobilized enzyme of the constituent of interest in the biological fluid; then exposing the first portion of the biological fluid to be analyzed to the measuring system to provide a second data output; and modifying the second data output as a function of the first data output to provide an indication of the actual amount of the constituent of interest in the biological fluid. The invention also discloses a detecting means that comprises an ion selective electrode and a reference electrode.
U.S. Pat. No. 3,765,841 to Paulson et al. discloses a method for determining the concentration of a component in a sample, wherein the sample, upon being introduced into solution with a reagent, reacts therewith at a rate indicative of the concentration. The method comprises: monitoring a characteristic of the solution or a component or product of the reaction which is proportional to the concentration; generating an output signal proportional to the time rate of change of the characteristic; measuring the value of the output signal; and inhibiting the measurement of the value of the output signal for a predetermined, fixed time interval from introduction of the sample into the reagent, the time interval being sufficient to permit thorough mixing of the sample with the reagent. Also disclosed is an apparatus for practicing the method.
SUMMARY OF THE INVENTION
The invention is a real time, on-line system and method for the detection and quantitation of aqueous ammonia in a closed loop environmental life support system. More specifically, it is a system in which on-line pH conditioning takes place through the incorporation of solid phase acid (SPA) and/or solid phase base (SPB) beds into a process stream, the separation and detection takes place on a continuous, real time basis with an adjustable response time through use of a liquid--liquid exchange module(LLEM), and an ammonia monitor allows the on-line detection of NH3 and NH 4 + species in the concentration range of 10 ug/L to 20 mg/L in solutions whose pH ranges between 4.5 and 8.5, and which contain a volatile potential interference from CO 2 .
Broadly, in one aspect, the present invention provides a method for detecting ammonia in an aqueous process stream. The method includes:
(a) contacting the aqueous process stream with a solid phase base to obtain a conditioned stream with a substantially constant pH;
(b) selectively transporting any ammonia in the conditioned stream into an aqueous analytical stream;
(c) detecting the ammonia in the analytical stream.
The analytical stream and the conditioned stream in step (b) flow along opposite sides of a microporous, hydrophobic gas permeable membrane. The membrane in step (b) is preferably in the form of hollow tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of an integrated ammonia monitor according to the principles of the present invention.
FIG. 2 is a graph showing CO 2 speciation as a function of pH in terms of the percent carbon between CO 2 (∘--∘--∘), HCO 3 --(----) and CO 3 .sup.═(∇--∇--∇).
FIG. 3 is a graph of NH 3 speciation as a function of pH in terms of the ratio of NH 3 to NH 4 + on a logarithmic scale.
FIG. 4 is a schematic diagram which can be used in the ammonia monitor of FIG. 1.
FIG. 4a is a schematic diagram of the inlet of the liquid--liquid exchange module of FIG. 4.
FIG. 4b is a cross sectional view of the face of the epoxy plug used in the inlet of the liquid-liquid exchange module of FIG. 4a as seen along the lines 4b-4b.
FIG. 5 is a graph showing unbuffered NH 3 speciation as a function of the ratio of NH 3 to the sum of NH 3 and NH 4 + in terms of the total concentration of NH 3 and NH 4 + species on a logarithmic scale.
FIG. 6a is a graph showing system ammonia transfer performance of the ammonia monitor of FIG. 1 as a function of the process stream ammonia concentration in terms of the analyte ammonia concentration for process stream ammonia concentrations up to 20 mg/L NH 3 .
FIG. 6b is a graph of the system ammonia transfer performance of FIG. 6a for the ammonia concentrations over the range from 0 to 5.0 mg/L NH 3 .
FIG. 7 is a graph showing the resulting pH of non-buffered ammonia in water.
FIG. 8a is a graph showing the correlation of the influent ammonia level in the process stream being analyzed as a function of conductivity where the influent ammonia is in the form of NH 4 Cl (∘--∘--∘), (NH 4 ) 2 CO 3 (----) and (NH 4 ) 2 CO 3 without SPA bed or other degasification (--).
FIG. 8b is an enlarged graph of the influent ammonia concentration versus conductivity of FIG. 8a for conductivities from 0 to 15 micromho/cm.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention allows real time separation and detection of ammonia and eliminates many of the problems present in conventional forms of analysis. The technology disclosed herein involves, principally, the performance of three major sequential steps in which five sub-processes are accomplished. An overview of one particular embodiment of the technology is shown schematically in FIG. 1. Initially those volatile species such as carbon dioxide which may interfere with the later selective segregation of ammonia are eliminated. The second step uses a liquid--liquid exchange across a vapor channel in a microporous membrane to equilibrate the ammonia level of the process stream with that in the analytical stream. Significantly, these first two steps are moderated by pH conditioning which occurs via equilibrium dissolution of a solid phase acid or a solid phase base placed in-line with the process stream being measured. In both cases, membrane separation is used for segregation of chemical species. The final step is either a conductometric or electrochemical detection of ammonia in the analytical stream. This technique provides a reliable, interference free method of ammonia detection and quantitation.
With reference to FIG. 1, the process stream 10 is initially passed via pump 12 through the solid phase acid (SPA) bed 14. The purpose of the bed 14 is to enhance the volatility of purgable, acidic chemical species such as carbon dioxide, acetates, sulfur dioxide, nitrogen oxides and others which might later interfere with ammonia detection. The method used for this purpose is pH control. In the case of the SPA bed 14, an effluent pH of 3.25±0.25 is achieved for a variety of influents provided that sufficiently long contact times are allowed. At this pH nearly all carbonate and bicarbonate species will be converted to carbon dioxide as shown in FIG. 2. At a pH below 5, the solubility of carbon dioxide is given by Henry's Law, P i =k i X i , where P i is partial pressure of CO 2 , k i is the Henry's Law constant, and X i is the mole fraction of CO in solution. The Henry's Law constant as a function of temperature is given by:
k.sub.i,CO2 =(55.556)*exp(-6789.04T-11.4519*lnT-0.10454*T+94.4914)
where T is in degrees Kelvin. 2 With air containing 300 ppm of carbon dioxide the amount of CO 2 remaining in solution at equilibrium is 0.462 mg/L demonstrating that extremely low levels of carbon dioxide can be achieved under equilibrium conditions. These conditions are reached prior to the gas-liquid separator (GLS) 16 where the supersaturated carbon dioxide will be eliminated.
The GLS 16 removes the dissolved CO 2 by transferring it across a microporous, hydrophobic, polypropylene gas permeable membrane to CO 2 free purge gas stream 18. Since the pH is low, ammonia will remain in solution as NH 4 + as shown in FIG. 3. This membrane is in the form of small hollow tubes 20. Such a unit is very permeable to gases due to the high surface porosity, high surface to volume ratio, and short diffusion distances. Due to the small pore size (0.05 μm) and hydrophobicity, these tubes can support high internal pressures before water is forced through the pores. According to the equation of Young and Laplace, ΔP=2γcosθ/r where ΔP is differential pressure, γ is the surface free energy for a water-air interface, θ is the contact angle for a water droplet on polypropylene, and r is the equivalent pore radius, the membrane can support a differential pressure of 258 psi. The purge gas of choice is nitrogen due to its low CO 2 content although other gases with low CO 2 levels can also be used.
The second step is the transfer of ammonia in the conditioned acidified, degassed process stream 22 to the analytical stream 24. In order to initiate this step, the pH of the process stream 22 must first be raised so that NH 4 + is converted to its volatile form, NH 3 . The solid phase base (SPB) bed 26 accomplishes this task by raising the pH for a variety of challenge solutions to 10.00±0.25. Even though the transfer membrane is identical to that in the GLS 16, the nature of the transfer of NH 3 from the process stream 28 to the analytical stream 24 in the liquid--liquid exchange module (LLEM) 30 which is shown in FIGS. 4, 4a and 4b is markedly different than the CO 2 removal process. NH 3 is first transferred from the aqueous process stream 28 into the trapped gas phase within the process of the membrane, and then to the aqueous analytical stream 24 on the other side of the membrane 32. If an attempt was made to purge NH 3 from an aqueous stream into air, the process would be extremely slow due to the very low value of Henry's Law constant for ammonia which is given by k i ,NH3 =(55.556)*exp(-157.552/T+28.1001*lnT-0.049227*T-149.006)and is ˜1750 times lower than that for CO. This low value means that NH 3 is much more stable in the aqueous phase than in the gas phase, and consequently, only an extremely small quantity of gas phase NH 3 is present at equilibrium. As a result, the NH 3 transfer rate is controlled by the diffusional flux in the gas phase which is dominated by two terms, the NH 3 chemical potential gradient and the transport distance. Both of these terms are improved dramatically when transport occurs between two aqueous streams rather than from an aqueous stream to the gas phase. In the first place, the transport distance in the gaseous medium is narrowed to the length of the pore rather than from the surface of the liquid to some unspecified distance away from the surface of the membrane. Secondly, the analytical stream 24 initially acts as an NH 3 sink via NH 4 + which increases the chemical potential gradient and drives the transport. Consequently, the transfer process will be dominated by geometric considerations such as the high surface area to volume ratio within tubular membranes 32, the short gas phase diffusion distances, and the mass transfer zone length (i.e. LLEM 30 length). 4 ,5 With the properly designed LLEM 30, the NH 3 content in the analytical stream 34 will be identical to that in the process stream 28. Alternatively, by changing the geometry and flow conditions, the NH 3 concentration of the analytical stream 34 can be adjusted for maximum sensitivity or for minimum response time.
The final step in the analysis is the detection of the ammonia in the analytical stream 34. The speciation of ammonia as a function of concentration in unbuffered water as shown in FIG. 5 indicates that the relative -- concentration of NH 4 + available for conductivity detection should be more than adequate over the concentration range of 0.1 to 20 mg/L. Since non-volatile species are not transferred to the analytical stream 34, the detection of NH 3 is made much easier due to the absence of most interferences. Conductivity is a particularly attractive detection technique due to its simplicity and reliability. The most likely interfering chemical species which are transferable under basic conditions and which have ionic forms are organonitrogen compounds such as amines, amides, and imines. This should be a fairly limited list due to the aqueous solubilities, speciation, volatilities, and Henry's Law constant for these species.
Additional details regarding the LLEM 30 are illustrated in FIGS. 4, 4a and 4b. The LLEM 30 includes inlet tee 40 and outlet tee 42 which are connected by an outer tubing 44 which can be provided in the form of a coil as illustrated in FIG. 4. The inlet tee 40, which is similar in construction to the outlet tee 42, is illustrated in FIG. 4a to show that the process stream 28 is introduced via the side connection to the tee 40 and that the tubular membranes 32 pass through the straight continuous portion of the tee 40. On the downstream side of the tee 40, the tubular membranes 32 generally run colinearly with the outer tubing 44. On the connection at the other side of the tee 40, the tubular membranes 32 pass through a plug 46 in fluid communication upstream with the analytical stream 24 (see FIG. 4b).
This new approach to real time, on-line ammonia monitoring has a number of distinct advantages over conventional alternatives. Foremost among these is the separation and detection on a continuous, real time basis with an adjustable response time. Secondly, the complete separation of the analytical stream 24 from the process stream 28 reduces the complexity and improves the reliability of the detection scheme since virtually no secondary chemical species will be present to foul, alter, or in any way change the response of the detector 38. Another feature is the passive control of the pH of the process stream through the equilibrium dissolution in the SPA and SPB beds. Included in the attributes of these pH beds is the relatively low concentration of chemical additives required to adjust the pH. In fact, for those cases where the SPB bed is used alone, the amount of contamination added to the stream in the form of metal ions is well below the NASA potable water specifications.
There are three novel features of this technology. One is the incorporation of the SPA and/or SPB beds into the process stream for on-line pH conditioning. These beds allow good control of the pH even in the presence of other chemical species. The second is the design of the LLEM which provides greater efficiency and controllability for NH 3 transport. The third is the combination of these devices in the ammonia monitor which allows the on-line detection of NH 3 and NH 4 + species in the concentration range of 40 μg/L to 20 mg/L in solutions whose pH ranges between 4.5 and 8.5, and which contain a volatile potential interference from CO 2 .
Solid phase acids and bases are a reliable and effective means for pH control. The equilibrium dissolution from the SPA or SPB beds 14 and 26 can produce acidic pH's of 3.25±0.25 or basic pH's of 10.0±0.20. These values are only moderately influenced by the pH of the influent streams 10, 22. The primary factors which determine how closely the equilibrium pH value is approached are the contact time of the solution with the bed (i.e. kinetics), the temperature, and the composition of the challenge solution. The volatility of both CO 2 and NH 3 in the process streams 22 and 28, respectively is readily controlled at the pH of the SPA and SPB beds 14 and 26. In addition, the speciation of CO 2 and NH 3 as a function of pH allows the segregation of one from the other. This segregation can also occur with only the SPB bed 26 in place since CO 2 species remain in solution under basic conditions. Such an arrangement would minimize the amount of expendables required for system maintenance.
The equilibrium pH for the SPA bed 14, when challenged with distilled water, is 3.25. Table 1 shows the behavior of the bed 14 when challenged by 5.6 to 20.7 mg/L of NH 4 Cl, and 1.6 to 28.0 mg/L of (NH 4 ) 2 CO 3 . The data show that the inlet pH of 4.7 to 5.2 for NH 4 Cl is lowered to values between 3.1 and 3.2 after passage through the bed 14, while the inlet pH of 6.0 to 8.2 for (NH 4 )CO 3 's is lowered to values between 3.2 and 3.4. In both cases, at these effluent pH's, the equilibrium value of the dissolved carbonate species consists solely of dissolved CO 2 in accordance with Henry's Law, and consequently, the total inorganic carbon remaining in solution is extremely small.
TABLE 1______________________________________Solid Phase Acid Module Performance(NH.sub.4).sub.2 CO.sub.3 mg/L NH.sub.4 Cl mg/L Influent pH Effluent pH______________________________________1.57 -- 5.97 3.172.80 -- 6.20 3.1527.96 -- 8.26 3.48-- 5.63 5.17 3.09-- 20.73 4.74 3.15______________________________________
The SPB bed 26 was challenged with the acid solutions. This Bed 26 normally produces a pH of 10.0 when challenged with distilled water under equilibrium conditions. The results from the acidic challenge are shown in Table 2. The effluent pH was raised from the influent range of 3.0 to 3.5 to a consistent value between 9.8 and 10.2 with the lower pH's occurring at higher total NH 4 + concentrations. This makes sense if one considers that in order to purge one mole of NH 4 + from the process stream, one mole of OH - must react with NH 4 + to form H 2 O and NH 3 . The lower pH's are due to the elimination of OH - by this reaction. As previously shown in FIG. 3, NH 3 will predominate at this pH. Between 50 and 80% of all ammonia species will be in the purgable NH 3 form which over the length of the LLEM 30 will allow a full purging of NH 3 .
TABLE 2______________________________________Solid Phase Base Module Performance(NH.sub.4).sub.2 CO.sub.3 mg/L NH.sub.4 Cl mg/L Influent pH Effluent pH______________________________________0.50 -- 3.26 10.161.75 -- 3.18 10.162.80 -- 3.20 10.1027.96 -- 3.50 9.78-- 0.37 3.12 10.23-- 3.23 3.13 10.19-- 20.73 3.15 10.00______________________________________
The LLEM 30 was challenged with NH 3 concentrations ranging between 0.104 to 19.5 mg/L. The challenges consisted of both NH 4 Cl and (NH 4 ) 2 CO 3 solutions which were previously run through the SPA bed 14 and the degasser 16 combination, and then through the SPB bed 26. In addition to these acidified solutions which are devoid of CO 2 , an (NH 4 ) 2 CO 3 solution was run without acidification. The flow rate of the process stream was, 5 ml/minute and the flow rate of the analytical stream 24 was 0.22 ml/minute. The two streams flowed co-currently with equal velocities under these flow conditions. The levels of both the process influent stream 28 and analytical effluent stream 34 were analyzed using the Nesslerization technique. The results are shown in FIG. 6.
These, data demonstrate the effective exchange of NH 3 from process stream 28 to analytical stream 34 in the LLEM 30. In addition, this exchange does not require the prior removal of CO 2 , CO 3 .sup.═, or HCO 3 - species indicated by the fact that all data points track the same curve. At concentrations above 6 to 10 mg/L the exchange curve bends over indicating a sub-equilibration of the analytical stream 34 with the process stream 28. There are two likely reasons for this behavior. As the concentration of NH 3 increases, the net flux of NH 3 across the membrane 32 must also increase, and eventually the transport conditions such as exchange area, concentration gradient, and contact time will no longer support this high flux. A more important contribution to this behavior is the decreasing chemical potential gradient between the two streams at a high NH 3 concentration. The available NH 3 in the process stream 28 is fixed by the total concentration of all ammonia species, and the pH. This determines the chemical potential of NH 3 at the gas-liquid interface of the process stream 28. The pH of analytical stream 34 is not fixed and depends on the concentration of all ammonia species as shown in FIG. 7. As the pH increases with higher NH 3 levels, the chemical potential of NH 3 at the gas-liquid interface in the analytical stream 34 will be increased. These changes can be calculated from the equilibrium expression for the ammonia-water hydrolysis reaction. For example, regardless of the ammonia concentration in the process stream 28 the buffered pH of 10 requires that 84.9% of all ammonia species will consist of NH 3 , while in the unbuffered analytical stream 34 a 1 mg/L ammonia solution will contain 58.1% NH 3 and a 10 mg/L ammonia solution will contain 84.0% NH 3 . As can be seen from these values, the driving force for NH 3 transport decreases as the total equilibrium concentration increases, and at lower concentrations, the percentage of NH 3 available in the process stream 28 will always be higher than in the analytical stream 34. Under such conditions, ammonia can be pumped into the analytical stream 34 until their chemical potentials are equal. This behavior can be manipulated to increase the sensitivity of the technique or conversely to optimize the response time.
The complete ammonia monitoring system was challenged with both (NH 4 ) 2 CO 3 and NH 4 Cl solutions containing NH 3 levels between 0.042 and 19.8 mg/L. The results are shown in FIG. 8. The conductivity response curve displays excellent sensitivity over the entire concentration range and little selectivity between the carbonate and chloride ammonium salts. In addition, the same relative response decrease at higher concentrations that was present in the earlier exchange curve is evident. The curvature at low concentrations of NH 3 is especially pronounced and is much steeper than in the NH 3 exchange curve (see FIG. 7). This response is most probably due to the combined effects of the increasing ratio of NH 4 + /NH 3 with dilution and the capacity of the LLEM 30 to concentrate NH 3 in the analytical stream at low concentrations where relatively low pHs produce a higher driving force for NH 3 exchange. These data follow a smooth curve with little scatter which can be fitted to a quadratic equation given by NH 3 ! (mg/L)=0.0188*σ2 (μmho -1 /cm) 2 -0.0490*σ(μmho -1 /cm)+0.1938 with a correlation coefficient of r 2 =0.9936. These measurements were generally taken going from high concentrations to low, with a single NH 3 curve, although on occasion, the procedure was changed to fill in data gaps. This response is remarkable since data were generated for different challenge solutions at different times. | Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia. |
FIELD OF THE INVENTION
The present invention concerns a low density ablative material for heat protecting portions of space vehicles when they return into the earth's atmosphere.
BACKGROUND OF THE INVENTION
When returning into the atmosphere, a vehicle, such as a probe, capsule inhabited vehicle, etc., needs to confront the intense heat flows and consequently the most exposed portions need to be heat-protected.
To combat the heat flows, thermic insulating materials, known as ablative materials, are used to coat the structures to be protected and whose gradual destruction under the action of the heat flow impelled by a re-entry into the atmosphere protects the coated structure from the heat by means of various mechanisms summed up as follows:
storage of energy resulting in a rise of the internal temperature of the ablative material;
endothermic reaction, namely : depolymerization, fusion, sublimation, vaporization;
energy loss via radiation;
flow of gaseous substances opposing the heat flow.
This protection via the destruction of the thermic insulant is one of the most effective means available to combat the intense heat flows produced by an atmospheric return.
This type of material, known for a large number of years, is formed of an elastomer and/or a silicon resin. There is a RTV (Room Temperature Vulcanization) type elastomer loaded with organic components (carbonated compounds, cork) or inorganic (SiC, silica, aluminium).
This material is used as such and placed in the form of panels or mounted elements, especially glued elements, onto the surface to be protected.
So as to prevent a possible flowing of the ablative material under the heat flow, the constitutive matrix of the material, composed, for example, of a RTV elastomer, silica ecospheres and phenolic microballoons and/or other loads, is inserted in a honeycomb type structure.
Thus, it is possible to embody light, flat and mechanically resistant coating panels offering heat protection and good refractory properties.
Furthermore, by using honeycomb structures being flexible in various directions; it is possible to embody bent structures.
This technique consists of preparing the honeycomb structure, for example by indenting the walls of the cells so that the structure can be bent, followed by lining the cells of a siliconed matrix with a suitable formulation, of compacting the matrix and then shaping the entire unit in a press.
However, the flexibility of this honeycomb structure has limits concerning the degree of bending of the panels able to be made according to this technique which moreover poses the problem of filling which needs to be thorough without having any vacuum in the cells of the honeycomb structure.
Finally, the reinforcement constituted by this structure needs to be homogeneous concerning the entire weight of the final panel which does not make it possible to differentially reinforce the panel according to its various portions. For example, as it concerns a leading edge panel, it is not possible to significantly reinforce the most exposed portions of the panel, the reinforcement technique, as described earlier, proceeding by all or nothing.
SUMMARY OF THE INVENTION
The present invention offers a new technique for reinforcing low density ablative materials making it possible to obtain complex shapes and accentuated curves and the deliberate local modulation of the reinforcement on the shaped element.
To this effect, the invention concerns an element made of a reinforced low density ablative heat protective material including an elastomer and/or silicon resin matrix loaded with organic and/or inorganic components, wherein the reinforcement is formed of glass or ceramic thread sections or the like or of organic materials disposed in the mass of said matrix along directions approximately orthogonal to at least one of the faces of the element and being flush, at least at one of their extremities, with at least one of said faces, said fibers in one particular embodiment being impregnated with a polymerized phenolic resin.
The thread sections are preferably distributed regularly in zigzag fashion.
If appropriate, the element may comprise zones, such as those most stressed by the heat flow, and having a number of thread sections per surface unit exceeding the number of the other less stressed zones.
The invention also concerns a method for obtaining these elements, wherein, after molding to the general dimensions and shapes of said element with the aid of a loaded silicon matrix, said thread sections are placed by stitching.
So as to preserve the face of the element directly struck by the needle of the stitching machine, said face is preferably coated with a fabric or silica or glass felt or even organic materials.
According to one variant for implementing the method, threads are used pre-impregnated with a suitable phenolic resin, and after stitching, this resin is polymerized.
According to another variant, non-impregnated threads are used, and after stitching, the element is impregnated with a suitable phenolic resin and said resin is polymerized.
After polymerization of the phenolic resin, the faces of the element, possibly provided with said fabric or felt on one of its faces, are leveled so as to eliminate the projecting thread portions.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages shall appear more readily from the following description of embodiments of the material of the invention, said description being given solely by way of example and with reference to the accompanying drawings on which:
FIG. 1 is a perspective diagrammatic view of a sample element made of the material of the invention;
FIG. 2 is a diagram illustrating a mode for placing reinforcements in an element of the type of FIG. 1;
FIG. 3 is a perspective view of a panel shaped according to the invention and intended to be used for the heat protection of a leading edge of a space vehicle, for example, and
FIG. 4 is a section of the element of FIG. 3 illustrating a mode for installing the reinforcements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows at 1 a parallelpiped block formed of a reinforced low density ablative material in accordance with the invention and including a silicon elastomer matrix 2 and loads of various natures, especially silica ecospheres and phenolic resin microballoons whose role are to reduce the density of the material and, by virtue of their heat properties, reduce heat conductivity and thus block the radiative heat in the material, and finally contribute by the reactions established inside the material during ablation in enriching the carbonated residual layer on the surface of the ablative element, that is of providing this layer with good structural strength and good refractory properties.
A large number of formulations have been put forward for these matrix, possibly including additives for increasing the mechanical and refractory properties of the ablative material. The present invention does not target a particular type of formulation, but mainly concerns the reinforcement of these matrix, regardless to their composition.
As can be seen on FIG. 1, the element 1 includes rigid picots 3 distributed regularly in the mass of the matrix. The picots 3 are rectilinear sections of ceramic, glass or organic threads disposed orthogonal to the upper flat face of the element 1. They extend into the entire thickness of the element and are thus flush with the two opposing faces.
The grid for distributing the picots 3 is to the square pitch P of several millimeters, such as ten.
According to a preferred placing embodiment of the present invention of this reinforcement, the picots 3 are inserted in the matrix 2 by stitching with the aid of a suitable thread.
For example, it is possible to use ceramic/glass fibers known under the trade-mark 312 or 440 NEXTEL (sold by the 3M Company), KEVLAR thread type organic fibers (sold by the DUPONT DE NEMOURS Company).
The stiffening of the thread sections of picots 3 is after stitching ensured via the polymerization of a suitable impregnation resin.
As a suitable phenolic resin, it is possible to use resins from the family of resols or those from the family of novolaks, but also epoxy resins stitching is carried out with a suitable machine.
FIG. 2 shows a diagram of a mode for stitching an element 1 of the type of FIG. 1.
The needle (not shown on FIG. 2) appears on one of the faces of the element 1 (the upper face on FIG. 2) perpendicularly and traverses the element on both sides by moving the thread 4 which thus on each to-and-fro movement of the needle through the element 1 makes a to-and-fro movement 3' which shall subsequently constitute a picot 3.
Disposed on the upper face of the element 1 is a fabric or piece of felt formed of glass fibers so as to protect the matrix whose portions or particles could be pulled up by the needle coming out of the element. This fabric or felt moreover avoids incrusting in the material of the element 2 of the thread 4 portions 6 for linking between two consecutive stitchings following the traction exerted on the thread by the needle driven into the element.
The needle opens on the lower face of the element 1 and forms a loop on each stitching.
Once the stitching operations have ended, the element 1 is impregnated with the appropriate resin, is polymerized and finally is machined. To this effect, the lower face of the element 1 of FIG. 2 is made flush at 9 so as to remove the loops 7 and also at 10 so as to remove the thread sections 6 on the surface of the fabric or felt 5. This fabric or felt 5 is represented under the same numerical reference on FIG. 1 at the lower face of the element.
The method of the present invention has the advantage that the reinforcement of the matrix is carried out after molding of the matrix to the shapes and dimensions of the element to be obtained and that this reinforcement can be adapted, that is accentuated in the most stressed zones of the element.
By way of example, FIG. 3 illustrates a panel 11 intended to constitute a leading edge element and embodied via the molding of a matrix formed of a RTV 141 type silicon elastomer loaded with silica ecospheres and phenolic microballoons.
The method for producing this panel formed of this material is well known and is accordingly not described in detail.
FIG. 4 is a section of the panel of FIG. 3 illustrating a mode for implanting reinforcement elements constituted by picots similar to those of FIG. 1.
After the element 11 has been removed from the mold, said element is stitched normally on the surface with the aid of a suitable thread of the type mentioned above and a stitching machine whose needle shall be available to penetrate into the matrix of the element on either of its opposing faces, depending on the type of reinforcement to be inserted.
So as to embody the picots 12 or 13 being flush with the two opposing faces of the element 11, the needle shall attack the face affording the easiest access, the element to this effect being placed in a holding and positioning cradle.
If desired, the method of the invention makes it possible to densify a particular more exposed zone of the element, such as the portion 11a, by implanting picots 12 with a pitch smaller than that of the picots 13 of a portion 11b confronting the heat flows under the lowest incidences.
In the most curved portions 11c of the element, it is possible to insert picots 14 by means of stitching traversing the element on both sides and insert picots 15 in the gap between two adjacent picots, these latter picots being flush with the convex face of the element but not opening onto the concave face so as to keep an approximately constant gap between the threads in all directions. The penetration depth of these picots 15 can of course be adjusted.
The picots 12 to 15 can advantageously be distributed regularly in each zone and in zigzag fashion, the picots having a density per surface unit which varies from one zone to another.
The face attacked by the needle can firstly be coated with a fabric or felt 5.
The stiffening of the picots 12 to 15 can be obtained in two ways.
The thread used for stitching is pre-impregnated with a suitable resin, such as a phenolic resin. After the threads have been placed, the resin of the threads is polymerized and then the element is machined to the dimensions of the final element, as shown on FIG. 2 (making level of the faces of the element).
According to a second method, the thread used is not pre-impregnated and after stitching, the element undergoes an impregnation operation with the aid of a suitable resin and this operation is followed by a polymerization of the resin and this element is finally machined as indicated above.
Owing to the fact that the reinforcement is embodied after molding of the element, it is possible to give the latter a complex shape with large localized curves. It shall always be possible to gain access to one of the faces of the element so as to insert there threads perpendicularly or almost perpendicularly, possibly over the entire thickness of the element, and with any distribution pattern.
Finally, the invention is not merely limited to the embodiment examples described above, but on the contrary covers all possible variants as regard the nature of the loaded silicon matrix, the nature of the threads stitched or introduced in another way into the mass of the matrix, the thread distribution pattern, the nature of the thread impregnation resin, the ways and means for placing and polymerizing this resin, as well as the shapes, dimensions and intended location of the elements able to be made of this reinforced ablative material. | An element made of a reinforced low density heat protective material including an elastomer and/or a silicon resin matrix loaded with organic and/or inorganic components, wherein the reinforcement is formed of glass or ceramic thread sections or the like or organic materials fitted in the mass of the matrix along directions approximately orthogonal to at least one of the faces of the element and being flush, at least at one of their extremities, with at least one of the faces. The method for obtaining this element, includes, after molding to the general dimensions and shapes of the element with the aid of a loaded silicon matrix, placing the thread sections by stitching. |
BACKGROUND OF INVENTION
[0001] The present invention relates generally to manufacturing assembly systems and more particularly to assembly verification systems employed during manufacturing assembly.
[0002] Significant investment may be required to implement electronic verification of assembly for some types of assembly plants—for example, assembly of automotive vehicles. In the past, integrated solutions have been employed where a centralized controller with a plant floor field-bus that branches out to a node at every assembly process work station is employed. The nodes at the ends of the branches are not smart devices capable of execution on their own, requiring control from the centralized controller to operate. Due to the centralized controller architecture, these systems are not scalable on an individual work station basis.
[0003] For example, one can choose to have error proofing (also called assembly verification) within a geographic area of the assembly plant, but does not have the resolution to decide to have error proofing on a per operator station basis. The cost to install this type of assembly error proofing necessitates the installation of an infrastructure within every operator workstation in the particular geographic area of the assembly plant, regardless if it is used at each work station or not. Consequently, these systems rely on an infrastructure investment that at many manufacturing facilities far exceeds the desired investment cost on a per operator workstation basis. The investment concern is particularly acute in more-price sensitive low-labor cost regions, where the quantity of electronic stations at an assembly plant may be small, making the total investment on a per workstation basis cost prohibitive. In addition, such error proofing systems have limited ability to be expanded for growth in the facility without excessive additional cost being incurred. Accordingly, for many assembly plants in low-labor cost regions, electronic error proofing may not be implemented, with secondary manual inspection used instead of error proofing systems.
SUMMARY OF INVENTION
[0004] An embodiment contemplates a scalable manufacturing assembly verification system for use in a manufacturing facility to verify assembly of a product, the system comprising assembly process work stations and assembly verification system stations. The assembly process work stations are each configured to provide at least one device configured to aid in assembly of the product. The assembly verification system stations are each located within a different one of the assembly process work stations, with each of the assembly verification system stations including a computing device in communication with the device, and with each computing device including a respective set of business rules corresponding to the assembly process work station within which the computing device is located, wherein each set of the business rules provides assembly verification for the device to error check assembly of the product with the device. Each of the computing devices can execute its respective business rules independently of the other computing devices executing their business rules.
[0005] An advantage of an embodiment is that assembly verification systems within manufacturing facilities are created at a much lower cost, while maintaining or improving assembly build quality. In addition, the manufacturing assembly verification system allows for ease of scaling the system to build a smaller or a larger integrated system of distributed assembly verification system stations. The scaling also includes allowing one to choose the appropriate balance between cost and automation in determining whether and what size each of the levels of the system may be introduced into a manufacturing facility, with changes in scale achievable as the business at the manufacturing facility changes over time.
BRIEF DESCRIPTION OF DRAWINGS
[0006] FIG. 1 is a schematic drawing of a scalable manufacturing assembly verification system.
[0007] FIG. 2 is a schematic drawing of the scalable manufacturing assembly verification system with a different number of subcomponents installed in the system.
[0008] FIG. 3 is a schematic drawing of an assembly process work station that is employed in either of the verification systems of FIGS. 1 and 2 .
DETAILED DESCRIPTION
[0009] Referring to FIG. 1 , a scalable manufacturing assembly verification system, indicated generally at 10 , is shown. The system 10 includes a first level 12 of assembly verification architecture and may also include a second level 14 or a third level 16 or both additional levels of assembly verification architecture. The levels of verification architecture are different levels of communication and tracking of the assembly verification process within the manufacturing environment and are indicated by phantom lines in the figures.
[0010] The first level 12 includes multiple assembly verification system stations 18 , each located at a different assembly process work station 20 , indicated by dashed lines in the figures. The number of assembly verification system stations 18 are based on the number of work stations 20 where it is desired to have assembly verification and it is cost effective to do so. This may be only a few assembly verification system stations 18 or it may be in the hundreds at a larger manufacturing facility. Each assembly process work station 20 is a location at a manufacturing facility where some assembly of the product, which may be a vehicle, takes place. For work stations 20 in the assembly process where assembly verification is important (i.e., where it is important to assure the assembly occurred properly), an assembly verification system station 19 is preferably operating.
[0011] Each assembly verification system station 18 is configurable via a human-machine interface (HMI). The HMI may be a keyboard, mouse, touch screen, some other means of human input/output to the system station 18 or a combination of these. The system stations 18 at the first level may generally operate without systems connections to other levels since the information and instructions for verification to prevent/track errors (business rules) are contained in the system stations 18 themselves. The first level system stations 18 may operate based on reading a product ID, such as a vehicle ID obtained from a barcode on the product being assembled.
[0012] The second level 14 is located in the manufacturing facility and communicates with the first level system stations 18 through network communications (indicated by arrows in FIG. 1 ). These may be wired or wireless networks.
[0013] The second level 14 may include a global standard inspection process (GSIP) system 22 , which is a quality reporting system that is in communication with each of the system stations 18 . The GSIP system 22 may track potential vehicle defects for various assembly verification operations to better error proof the assembly operations. For example, the system stations 18 may report a current status of assembly verification actions, report faults to the GSIP system 22 for historical reporting, or submit vehicle records for storage in a database.
[0014] The second level 14 may also include a global enterprise production information control system (GEPICS) 24 , which is a vehicle order data system that is in communication with the system stations 18 . This system 24 may include manifest information, vehicle sequencing information and part scan traceability. The system stations 18 can obtain the build sequence and vehicle option data directly from GEPICS 24 , if so desired, with the system stations 18 confirming vehicle sequencing at the work stations 20 . Alternatively, the system stations 18 may provide offline sequencing, even with GEPICS 24 communication available, since each system station 18 contains the work rules for its own work station 20 .
[0015] The second level 14 may additionally include a global production monitoring and control (GPMC) system 26 , which is a real time plant monitoring system that is in communication with the system stations 18 . The second level systems may allow some of the processes (e.g., vehicle identification and quality reporting) to be further automated and may also allow for automated oversight of part kitting and part sequencing. In addition, the GPMC system 26 may receive reports of assembly verification faults from the system stations 18 , or reports from system stations 18 where a work station 20 is holding the assembly line in order to escalate any problems to assure prompt correction.
[0016] The third level 16 may include a centralized system 28 having functionality to provide a centralized location for vehicle configuration as well as add visualization capability to determine the status of the assembly verification system stations 18 throughout the manufacturing facility. Having this third level centralized system 28 may make disaster recovery and system configuration tracking more efficient as well.
[0017] FIG. 2 illustrates another configuration of the scalable manufacturing assembly verification system 10 . In this configuration, the assembly verification system stations 18 at the various assembly process work stations 20 communicate with the second level 14 , which has just one system 30 . That system may be any one of the GSIP, GEPICS or GMPC systems.
[0018] FIG. 3 illustrates an assembly process work station 20 that may be employed in the scalable manufacturing assembly verification systems 10 of FIGS. 1 and 2 . The work station 20 may be located along side a conveyor 40 that transports the products to be assembled. One of the assembly verification system stations 18 is located in the work station 20 .
[0019] This system station 18 may include a computing device 42 , such as, for example, a laptop or desktop general purpose computer or a tablet type of computer. The computing device 42 has the functionality to execute the business rules applied to the particular work station 20 independent from the other system stations 18 and independent from the second level systems 14 and the third level system 16 . The computing device 42 may operate employing an industrial Windows CE™ based computer running application specific programs that implement the assembly verification business rules.
[0020] The business rules are implemented by the computing device 42 and are the rules used to verify the assembly process at that particular work station 20 . The business rules may include, for example, verification of assembly of fasteners to the product, verification of proper part picks, verification of part bar code scans, verification of fluid fill volumes or air pressures, verification of dimensional tolerances, verification of station cycle times, verification of operator motion, or any combination of these assembly processes or other assembly processes that occur at the particular work station 20 . With the business rules for each system station 18 contained in its respective computing device 42 , scalability of the assembly verification is relatively easy and cost effective, with an ability for independent determination as to the desire for a system station 18 at any particular work station 20 being made on a per work station basis.
[0021] The computing device 42 may receive input from a manually operated handheld scanner 44 , and may communicate with other components via a computer interface 46 . The computer interface 46 may communicate with a visual alert device 48 that may employ red, green and yellow lights to indicate the status of the system station 18 , and may also include an audio output device that provides alerts to the person performing the assembly at the particular work station 20 . The computer interface 46 may also communicate with input/output interface devices 50 and an unmanaged switch 52 . The unmanaged switch 52 may, for example, communicate with a fixed scanner 54 that reads bar codes or other information affixed to the products as they travel on the conveyor 40 and with torque controllers 56 that read the torque applied by various tools used during the assembly process being completed at this particular work station 20 . All of these devices are operated based on the business rules contained in the computing device 42 at that particular work station 20 , with the computing device 42 also verifying the operation of these devices for purposes of error proofing the assembly operations that take place at this work station 20 .
[0022] The computing device 42 contains the device drivers needed to communicate with the particular components at this work station 20 . Again, this allows the assembly verification system stations 18 at each work station to operate independently, thus allowing for ease of scalability of the scalable manufacturing assembly verification system 10 .
[0023] An example of operation of an assembly process work station 20 includes the fixed scanner 54 reading a bar code on a partially assembled vehicle moving on the conveyor 40 . The scanned information is transmitted to the computing device 42 , which has the associated vehicle and build data stored therein. This activates the assembly verification. As assembly processes take place at that work station 20 , for example a fastener assembly, the applied torque (via a torque controller 56 ), operator cycle time and part number of the component (read by the hand scanner 44 ) may be stored in the computing device 42 . This information may be used later for reporting purposes to second or third level systems.
[0024] The computing device 42 may operate off-line without communication to other devices, on-line with real time network communication with other systems (indicated by the arrows in FIG. 3 ), and/or near-line with other than real time network communications. Also, this information may be used by the computing device 42 to signal an error should assembly verification (based on the business rules) detect an error. Thus, assembly verification is achieved in a system that is scalable to meet the needs and cost requirements at manufacturing facilities having significantly different requirements.
[0025] While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims. | A scalable manufacturing assembly verification system for use in a manufacturing facility to verify assembly of a product, the system comprising assembly process work stations and assembly verification system stations. The assembly process work stations are each configured to provide at least one device configured to aid in assembly of the product. The assembly verification system stations are each located within a different one of the assembly process work stations, with each of the assembly verification system stations including a computing device in communication with the device, and with each computing device including a respective set of business rules corresponding to the assembly process work station within which the computing device is located, wherein each set of the business rules provides assembly verification for the device to error check assembly of the product with the device. |
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
[0001] The present invention relates to a noise suppressing device suited for installation within a container, such as a fuel tank, to lessen and absorb the sloshing sound or the like of the liquid contained therein, i.e., to disperse or dampen the energy of the wave action.
[0002] Fuel tanks are provided with noise suppressing devices of various structures as shown in Japanese Utility Model Publication (KOKOKU) No. H06-6986, Japanese Patent No. 2719002, and Japanese Patent Publication (KOKAI) No. 2004-122902.
[0003] The structure disclosed in Japanese Utility Model Publication No. H06-6986 employs several sheets of mesh material that are stacked in layers at intervals by interposing raised ribs between the mesh material, and disposed and attached along the fuel tank's inner wall using brackets and the like. The operation is characterized such that when the fuel in the tank is sloshed around or moved by vibration or the like, the fuel within the tank passes through the mesh, and the wave action is dispersed, lessened or absorbed while the liquid passes through the intervals between the mesh materials.
[0004] The structure disclosed in Japanese Patent No. 2719002 has a spongy baffle part adhered to a section of the mounting bracket. In other words, the baffle part is a mass of entangled lint-like material of a predetermined size formed by extruding a molten resin as fine linear material through a number of nozzles onto a corresponding section of the bracket. The operation is characterized such that when the fuel in the tank is sloshed around or moved by vibration or the like, the liquid surge is dispersed, lessened or absorbed while the fuel passes through the baffle part having numerous small spaces and maze-like intervals.
[0005] The structure disclosed in Japanese Patent Publication No. 2004-122902 has a mesh material formed as a flat bag, numerous small pieces contained within the mesh bag, and a frame that holds the side edges of the bag. The operation is characterized by the synergy between the effect of lessening or absorbing the liquid surge of the fuel achieved by the two surfaces of the flat mesh bag and the effect of lessening or absorbing the liquid surge achieved through the spaces created by the small pieces in the bag as well as the numerous small pieces themselves.
[0006] The conventional devices described above have the following problems. The structure disclosed in Japanese Utility Model Publication No. H06-6986 is difficult to handle, as the mesh material is stacked in layers. The installation of the device in a fuel tank is time consuming, and the noise suppressing effect tends to vary depending on the installation conditions.
[0007] The structure disclosed in Japanese Patent No. 2719002 has low forming efficiency, as the spongy baffle part is created while a molten resin is extruded from nozzles. In addition, the noise suppressing effect tends to vary depending on the manner in which the resin is extruded through nozzles or the manner in which the resin hardens.
[0008] The structure disclosed in Japanese Patent Publication No. 2004-122902 can be more easily installed in a fuel tank than the device disclosed in Japanese Utility Model Publication No. H06-6986, and can more effectively stabilize the noise suppressing characteristics than the device disclosed in Japanese Patent No. 2719002. However, forming a mesh bag, storing small pieces in the bag, and disposing a frame makes it difficult to reduce manufacturing cost.
[0009] Accordingly, it is an object of the present invention to provide a noise suppressing device that solves all of the problems described above, and that has excellent installation and mass production qualities, and stable noise suppressing characteristics.
[0010] Further objects and advantages of the invention will be apparent from the following description of the invention.
SUMMARY OF THE INVENTION
[0011] In order to achieve the objectives described above, the present inventors devised the device structures explained below.
[0012] According to a first embodiment of the invention, a noise suppressing device is attachable within a liquid container for lessening and absorbing the noise generated by the liquid as it moves within said container (this refers to dispersing or dampening the energy of the liquid surge). The device has a main plate body provided with through holes extending through the upper and lower surfaces of the plate for permitting the flow of the liquid from one side to the other and projections formed on the plate, and a means for installing said main plate body to an installation wall within said container, and tapering said projections from the base to the tip thereof.
[0013] In one embodiment of the noise suppressing device attachable within a liquid container for lessening and absorbing the noise created by the liquid as it moves within said container, the device has a plurality of plates with through holes extending through the upper and lower surfaces of the plate for permitting the flow of the liquid from one side to the other, with the plates stacked at intervals.
[0014] It is preferable to embody the invention described above as specified by the following description.
[0015] The device comprises disposing the through holes between the projections.
[0016] The device comprises setting the through holes of each plate so that the substantial hole area for permitting the passage of the liquid varies from plate to plate.
[0017] The device comprises setting the through holes of each plate so that the substantial hole area increases as the distance from the first plate increases.
[0018] Moreover, the device comprises providing the first plate with the projections tapering from the base to the tip thereof, and varying the substantial hole area by inserting the projections into the plates other than the first plate.
[0019] The device comprises shifting the positions of the through holes of the first plate from those of the through holes of the plate most distant from the first plate.
[0020] Moreover, the device is provided with a tubular part disposed on the first plate, a frame part disposed on the plates other than the first plate for inserting the tubular part, and a substantially tubular connector to be inserted from the top of the tubular part and locked therein via the engagement between a flexible tab and a locking hole.
[0021] The installation structure for securely attaching the noise suppressing device to an installation wall of a container includes a stud, which has a stem and a plurality of flexible locking wings axially disposed along the stem at substantially regular intervals and is preinstalled to the installation wall. The device is pushed against the installation wall while inserting the stud through the tubular part of the first plate close to the installation wall and into the connector, and engaging one of the flexible locking wings located at a given height with the engaging piece projecting within the connector.
[0022] The installation structure for securely attaching the noise suppressing device to an installation wall of a container includes installing the first plate so that the projections protrude from the plate surface not opposing the installation wall (i.e., of the two surfaces of the first plate, the surface that is not facing the installation wall).
[0023] The noise suppressing device has a means for installing the device, and includes a main plate body that is provided with through holes and projections. Thus, it is simple and easy to handle. The device is capable of efficiently absorbing the wave action of a liquid, such as fuel, as designed in accordance with the shape and size of the container by eliminating variations in operational characteristics easily produced among products, and utilizing the number and size of the projections and through holes to lessen and absorb the liquid surge.
[0024] The noise suppressing device is capable of efficiently absorbing the wave action of a liquid, such as fuel, as designed in accordance with the shape and size of the container by utilizing the intervals set between plates and the number of such intervals provided in proportion to the number of plates to lessen and absorb the liquid surge, as well as utilizing the number and size of the projections and through holes to lessen and absorb the liquid surge. In other words, the present invention is excellent in terms of formability and handling qualities because through holes are created in each plate, for example. The device is particularly suited for achieving the optimal shape which corresponds to the shape of a container, and is capable of eliminating variations in operational characteristics that occur among products.
[0025] According to one aspect of the invention, the noise suppressing device sets the through holes of each plate so that the substantial hole area varies from plate to plate, and thus widely varies the channels for a liquid, such as fuel, to pass through in accordance with the hole area variations. The wave action, therefore, can be efficiently absorbed in accordance with the varying channels.
[0026] According to another aspect, the noise suppressing device enables a cost-effective implementation of the device by preparing, for example, two types of plates consisting of the first plate with projections, and plates other than that.
[0027] According to another aspect of the noise suppressing device, shifting the positions of the through holes of the first plate from those of the through holes of the plate most distant from said first plate, for example, can widely vary the channels for a liquid, such as fuel, to pass through in accordance with the displacement of the hole positions, and thus allow for more efficient absorption of the liquid surge.
[0028] According to another aspect of the invention, two types of plates consisting of the first plate with a tubular part, and other plates with frames, for example, are prepared to constitute a stack structure. The plates can be integrated easily with one-touch operation, with spacing maintained therebetween, through the insertion of a connector.
[0029] In the installation structure, the noise suppressing device can be installed by pushing the device against the stud that is preinstalled to the installation wall of a container. According to one aspect of the invention, the projections are formed to project from the installation wall side, and thus allow for efficient absorption of the wave action of a liquid, such as fuel.
[0030] When the operation involving the installation structure cannot be performed visually, it is preferable to provide guide ribs disposed on the outer surface of the first plate to guide the positioning of the stud to be inserted into the plate's tubular part and the connector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIGS. 1 ( a ) and 1 ( b ) are schematic illustrations of one embodiment of a noise suppressing device shown in use, and in general appearance, respectively.
[0032] FIG. 2 is an enlarged cross section of the noise suppressing device in FIG. 1 ( b ).
[0033] FIGS. 3 ( a )- 3 ( c ) are top, front, and bottom views, respectively, of the noise suppressing device.
[0034] FIG. 4 is a left side view of the noise suppressing device in FIGS. 3 ( a )- 3 ( c ).
[0035] FIGS. 5 ( a ) and 5 ( b ) are top and front views, respectively, of one plate constituting the above noise suppressing device.
[0036] FIGS. 6 ( a )- 6 ( c ) are top, front, and bottom views, respectively, of another plate constituting the above-described noise suppressing device.
[0037] FIG. 7 ( a ) is a right side view, and FIG. 7 ( b ) is an enlarged cross section of the right side section along line 7 ( b )- 7 ( b ) in FIG. 6 ( a ).
[0038] FIGS. 8 ( a )- 8 ( d ) are front view, right end view, and cross sections at lines 8 ( c ) - 8 ( c ) and 8 ( d )- 8 ( d ) in FIG. 8 ( b ), respectively, of a connector.
[0039] FIGS. 9 ( a ) and 9 ( b ) are schematic illustrations of a simplified, first variation of the above-described noise suppressing device shown in the condition of use, and in general appearance, respectively, in correspondence with FIGS. 1 ( a ) and 1 ( b ).
[0040] FIG. 10 is an enlarged cross section of the first variation of the noise suppressing device shown in correspondence with FIG. 2 .
[0041] FIGS. 11 ( a )- 11 ( c ) are top views of the individual plates constituting a second variation of the noise suppressing device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] Embodiments of the noise suppressing device of the present invention will be explained with reference to the drawings. FIG. 1 ( a ) is an illustration of a noise suppressing device while in use, and FIG. 1 ( b ) is an illustration of the appearance thereof. FIG. 2 is a schematic, enlarged cross section of the noise suppressing device. FIGS. 3 ( a )- 3 ( c ) and 4 show the noise suppressing device in the state prior to installation. FIGS. 5 ( a ) and 5 ( b ) illustrate a plate constituting the noise suppressing device, FIGS. 6 ( a )- 6 ( c ) and 7 ( a )- 7 ( b ) illustrate another plate, and FIGS. 8 ( a )- 8 ( d ) illustrate a connector. FIGS. 9 ( a ) and 9 ( b ) and 10 show, in correspondence with FIGS. 1 ( a ) and 1 ( b ) and 2 , the first variation, or simplified version, of the noise suppressing device of the invention. FIGS. 11 ( a )- 11 ( c ) show the second variation of the noise suppressing device, in which the shape thereof is modified. In the following, the device's structure, operation, the first variation, and the second variation will be explained in detail in the order stated. Device Structure The noise suppressing device 1 shown in FIGS. 1 ( a ) and l( b ) through 8 ( a ) - 8 ( d ) is constructed by integrally stacking a plurality of plates 2 - 5 at intervals using connectors 6 , and is to be attached by utilizing studs 7 disposed upright on the installation wall 13 within the fuel tank (container) 10 for containing fuel (liquid). Resin is used for both the plates 2 - 5 and connectors 6 , but other materials may do as well. Although all of the plates 2 - 5 are rigid and substantially rectangular in shape that are resistant to deformation, the shape of the innermost plate (first plate) 2 positioned closest to the installation wall 13 differs significantly from the other plates 3 - 5 . For convenience sake, in the explanation of these plates, the respective surfaces that oppose the installation wall 13 will be referred to as lower surfaces and the opposite surfaces will be referred to as upper surfaces. Since the plates 3 - 5 have the same or similar shape, plate 3 will be used as an example in the explanation.
[0043] As shown in FIG. 1 ( a ), the upper shell 11 and the lower shell 12 of the fuel tank 10 are integrated by means of a conventional method, such as welding the respective flange sections. On the inner side of the upper shell 11 , one wall section denoted by reference number wall 13 , for example, is set up as an installation wall. In the installation 13 , a pair of studs 7 for installing the noise suppressing device 1 is disposed upright. Each of the pair of studs 7 , as shown in FIG. 2 , integrally forms a head 15 , which is securely attached to the installation wall 13 by welding or the like, a stem 16 , which is disposed on the head 15 and inserted from a through hole 14 of the installation wall 13 , and a plurality of flexible locking wings 17 disposed axially along the stem 16 at substantially regular intervals.
[0044] The innermost plate 2 , as shown in FIGS. 6 ( a )- 6 ( c ) and 7 ( a ) and 7 ( b ), integrally forms a plurality of through holes 23 that extend through the upper and lower surfaces 21 and 22 of the plate 20 , numerous projections 24 and two tubular parts 25 disposed on the upper surface 21 of the plate 20 , guide ribs 26 disposed on the lower surface 22 of the plate 20 , and an upright wall 27 disposed so as to stand forward from the front or rear edge of the plate 20 .
[0045] The through holes 23 are disposed at substantially regular intervals from front to back and from side to side, and are substantially the same in shape. In other words, the through holes 23 are small circular holes, but the holes may take other shapes. The projections 24 are disposed at substantially regular intervals from front to back and from side to side so as to surround one through hole 23 with four projections 24 except for the areas where two tubular parts 25 are located. The projections 24 are conical in shape with the inside hollowed out; they may take another shape as long as the size tapers from the base to the tip. The height of the projections 24 is determined by the number of plates used, excluding the innermost plate 2 , and the spacing provided between the plates.
[0046] The tubular parts 25 are formed in the right and left sections of the upper surface 21 , penetrable at the upper and lower ends, and have cross sections that are substantially rectangular in shape. Each of the tubular parts 25 is formed higher than the projections 24 , and provided with locking holes 25 a , which extend through the front and rear walls of the rectangular tube so as to oppose one another near the base, and a pair of restraining ribs 28 , which project from the outer surface of the respective left and right side walls of the rectangular tube. The tubular part 25 on the right side is provided with a pair of restraining ribs 29 to project on the inner surface of the respective left and right side walls of the rectangular tube so as to oppose one another. The locking holes 25 a are formed as substantially rectangular holes to lock the later described flexible tabs 62 of the connector 6 . The restraining ribs 28 are projections provided for maintaining the spacing between the upper surface 21 and the plate 3 disposed thereon. The restraining ribs 29 are provided to guide the connector 6 . In the tubular part 25 on the left side, the retaining ribs 29 are omitted in order to allow for the positioning of the connector 6 to be inserted into the tubular part 25 against the stud 7 of the installation wall 13 .
[0047] As shown in FIG. 6 ( c ), the guide ribs 26 are formed to accommodate the inlet sections of the tubular parts 25 and are constructed in such a way that each of the inlets of the tubular parts 25 is provided with a pair of guide ribs 26 a and 26 b , which are disposed at both sides of the inlet and spread apart as they become further distant from the inlet (V-shaped), in combination with a locking rib 26 c , which is disposed on one outer side of the inlet to connect the ends of the guide ribs 26 a and 26 b where they approach one another. The upright wall 27 is abutted against the corresponding section of the tank's installation wall 13 when the noise suppressing device 1 is installed so as to prevent the device from rattling when subjected to a shock; the upright wall is omitted in some cases.
[0048] The plate 3 , as shown in FIGS. 2 and 5 ( a ) and 5 ( b ), is rectangular in shape and substantially the same in size as the innermost plate 2 , and the upper and lower surfaces 31 and 32 of the plate 30 are shaped in the same way. The plate 3 has a plurality of through holes 33 and 34 that extend through the upper and lower surfaces, frames 35 disposed on the left and right sides through which the tubular parts 25 are inserted, and restraining ribs 36 that border the upper and lower edges of the respective frames 35 .
[0049] The through holes 33 are circular holes having the same diameter as that of the through holes 23 of the innermost plate 2 that are similarly disposed at substantially regular intervals from side to side and from front to back. However, the through holes 33 are set so that the center is slightly shifted from the center of the through holes 23 when the plate 3 is stacked on the innermost plate 2 . The through holes 34 are circular holes large enough to allow for the projections 24 of the innermost plate 2 to be inserted therethrough with play, and are disposed at substantially regular intervals from side to side and from front to back as in the case of the projections 24 . In other words, the projections 24 plays in the corresponding through holes 34 when the plate 3 is stacked on the innermost plate 2 . The frames 35 are rectangular holes, which correspond to the tubular parts 25 , bordered with the restraining ribs 36 disposed so as to project from the upper and lower surfaces. The restraining ribs 36 maintain the spacing between plate 2 and plate 3 (and between plates 3 and 4 , and between plates 4 and 5 ) at a predetermined distance when the plate 3 ( 4 and 5 ) is stacked on the innermost plate 2 with the tubular parts 25 inserted through the corresponding frames 35 .
[0050] As shown in FIGS. 8 ( a )- 8 ( d ), the connector 6 is substantially tubular rectangular in shape, and has an insert portion 60 a , which can be inserted into the tubular part 25 , a handle portion 60 b , which is connected to the insert portion 60 a and will be disposed outside of the tubular part 25 , a rectangular flange 61 , which is projected from the outer periphery so as to partition the insert portion 60 a from the handle portion 60 b , flexible tabs 62 disposed on two opposing walls that define the insert portion 60 a , and engaging pieces 63 disposed on the inner surfaces of the other opposing walls, having no flexible tabs 62 , that define the insert portion 60 a.
[0051] As is inferred from FIG. 2 , the insert portion 60 a having a rectangular frame-shaped cross section is given the dimensions so that the sides having the flexible tabs 62 can be inserted into the tubular part 25 without any gap; the sides having the engaging pieces 63 can be inserted without any gap when the restraining ribs 29 are provided, and with a small gap when the restraining ribs 29 are not provided. The gap allows for the slight movement of the connector 6 thereby enabling the adjustment of its position relative to the corresponding stud 7 , while maintaining the engagements between the flexible tabs 62 and the locking holes 25 a , even if the spacing between the studs 7 is slightly off the design value.
[0052] The handle 60 b is the section where the connector 6 is held manually or by using a robotic hand, and, at the same time, is the tubular section that covers the tip of the stud 7 . The flange 61 abuts against the end surface of the tubular part 25 when the insert section 60 a is inserted into the tubular part 25 and the flexible tabs 62 engage with the locking holes 25 a , and, at the same time, functions as a retainer to prevent the plates 3 - 5 , which are stacked together via the tubular part 25 , from slipping off. Such a flange 61 may also be provided with a locking hole to engage with a projection formed on the restraining rib 36 or the like of the outermost positioned plate 5 so that the connector 6 is even more stably fastened via the engagement between the projection and the locking hole. Each flexible tab 62 is defined by a substantially U-shaped slit 62 a created in the lower section of the insert section 60 a ; it is resiliently displaced inwardly when inserted into the tubular part 25 , and, upon reaching the locking hole 25 a , regains its initial state to engage with the locking hole 25 a.
[0053] Each engaging piece 63 is formed to slant upwardly to allow, with resilient displacement, the passage of some of the flexible locking wings 17 of a stud stem 16 , which are located towards the tip thereof and beyond the engaging piece 63 , when inserted into a connector 6 , while engaging at the neck between two locking wings after the locking wing at a target height passes the engaging piece, as shown in FIG. 2 .
[0000] Operation
[0054] The plates 3 - 5 described above are assembled as the noise suppressing device 1 upon stacking them on the innermost plate (first plate) 2 via the fitting of the tubular parts 25 with the frames 35 , followed by the insertion of the connectors 6 into the tubular parts 25 and the engagement between the flexible tabs 62 and the locking holes 25 a . In the assembled state, as shown in FIG. 2 , the spacing between the plate 2 and the plate 3 is the distance set by the restraining ribs 28 and the restraining ribs 36 , while the spacing between the plates 3 and 4 and the spacing between plates 4 and 5 are the distances set in proportion to the ribs 36 and the ribs 36 , respectively.
[0055] The projections 24 on the plate 2 are inserted into the through holes 34 of the plate 3 and the through holes 34 of the plate 4 in that order. In this construction, therefore, each of the plates 3 - 5 is maintained at the predetermined intervals, and, at the same time, the substantial hole areas of the plates 3 - 5 are varied by sequentially inserting the substantially conical projections 24 into the through holes 34 of the plate 3 and the through holes 34 of the plate 4 . In this case, the further distanced the plate is from the tank's installation wall 13 , the larger the substantial areas of the through holes 34 become. Moreover, the positions of the through holes 23 of the innermost plate 2 are shifted from the through holes 33 of the outermost plate 5 . These have been employed upon testing and determined to be preferable in terms of efficiently dispersing or dampening the noise, i.e., the energy of the wave action, associated with the movement of fuel in the tank 10 .
[0056] The noise suppressing device 1 described above is securely attached to the studs 7 disposed on the tank's installation wall 13 by engaging the engaging pieces 63 of the connectors 6 with the studs' locking wings 17 located at a desired height. During the installation operation, the guide ribs 26 align the inlets of the tubular parts 25 with the studs 7 , and allow for one-touch positioning thereof when the noise suppressing device 1 is moved towards the studs 7 to insert the studs 7 into the tubular parts 25 (and the connectors 6 inserted within the tubular parts) from the lower surface side of the plate 2 in the case of attaching the noise suppressing device 1 to the studs 7 of the tank's installation wall 13 manually or automatically via a robotic hand.
[0000] First Variation
[0057] FIGS. 9 ( a ) and 9 ( b ) and 10 show, in correspondence with FIGS. 1 ( a ) and 1 ( b ) and 2 , a simplified version of the noise suppressing device described above. The fuel tank 10 in FIG. 9 ( a ) has a noise suppressing device 1 A of the first variation attached to the installation wall 13 of the inner surface of the tank. In the first variation, a pair of studs 7 is disposed on the installation wall 13 for attaching the noise suppressing device 1 A thereto. Each of the studs 7 integrally forms a head 15 securely attached to the installation wall 13 by welding or the like, a stem 16 projecting on the head 15 and inserted from the through hole 14 of the installation wall 13 , and a plurality of flexible locking wings 17 disposed axially along the stem 16 at substantially regular intervals.
[0058] FIG. 9 ( b ) is a front view of the noise suppressing device 1 A in FIG. 9 ( a ), and FIG. 10 is a cross section thereof. The noise suppressing device 1 A is constructed with a plate 2 , which constitutes the main plate body, and is the innermost plate (first plate) 2 described above, and a means for installing the plate 2 to the installation wall 13 of the fuel tank 10 , such as the connectors 6 . In other words, the plate 2 , or the main plate body, as previously described, integrally forms a plurality of through holes 23 that extend through the upper and lower surfaces 21 and 22 of the plate 20 , numerous projections 24 and two tubular parts 25 disposed on the upper surface 21 of the plate 20 , guide ribs 26 disposed so as to project from the lower surface 22 of the plate 20 , and an upright wall 27 disposed so as to stand forward from the front or rear edge of the plate 20 .
[0059] The plate 2 , or the main plate body, described above is assembled as the noise suppressing device 1 A by inserting the connectors 6 or the installing means into the tubular parts 25 and engaging the flexible tabs 62 with the locking holes 25 a . The noise suppressing device 1 A is securely attached to the studs 7 disposed on the tank's installation wall 13 by engaging the engaging pieces 63 of the connectors 6 with the studs' locking wings 17 located at a desired height. In this case, when attaching the noise suppressing device 1 A to the studs 7 of the tank's installation wall 13 manually or automatically via a robotic hand, the guide ribs 26 align the inlets of the tubular parts 25 with the studs 7 , allowing for a one-touch positioning upon moving the noise suppressing device 1 A towards the studs 7 for insertion into the tubular parts 25 (and the connectors 6 inserted within the tubular parts) from the lower surface side of the plate. These are exactly the same as those described in relation to the first embodiment of the noise suppressing device 1 described above.
[0060] Second Variation FIGS. 11 ( a )- 11 ( c ) show the second variation of the noise suppressing device shown in FIGS. 1-8 per plate. In the second variation, the plate construction comprises a total of three plates: the innermost plate 2 A shown in FIG. 11 ( a ), which corresponds to the innermost plate 2 of the aforementioned embodiment, and plates 3 A and 4 A shown in FIGS. 11 ( b ) and 11 ( c ), which correspond to plates 3 and 4 of the aforementioned embodiment. On the innermost plate 2 A, the projections 24 and the upright wall 27 of the previous embodiment are omitted. The innermost plate 2 A integrally forms a plurality of through holes 23 that extend through the upper and lower surfaces of the plate 20 , two tubular parts 25 disposed on the upper surface of the plate 20 , and guide ribs (not shown) disposed on the lower surface (the surface that opposes the installation wall 13 ) of the plate 20 . The plates 3 A and 4 A are the same in the following respects: they are rectangular in shape and substantially the same as the innermost plate 2 A in size; the upper and lower surfaces of the plate 30 are shaped the same; and have frames 35 , which are disposed on the left and right sides and insertable into the tubular parts 25 , and restraining ribs 36 that border the frames 35 .
[0061] They differ, however, as follows: the plate 3 A is to be disposed between the innermost plate 2 A and the plate 4 A, and provided only with a plurality of through holes 34 that are larger than the through holes 23 , whereas the plate 4 A is to be disposed at the furthest position from the tank's installation wall 13 and provided with a plurality of through holes 33 and through holes 34 .
[0062] Although drawings are omitted, the plates 3 A and 4 A described above are assembled as the noise suppressing device 1 in the same manner as in the previous embodiment; they are stacked together on the innermost plate 2 A via the fitting of the tubular parts 25 with the frames 35 , followed by the insertion of the connectors 6 into the tubular parts 25 and the engagement between the flexible tabs 62 and the locking holes 25 a.
[0063] Many modifications and variations of the present invention are possible, excluding those of the requirements as described above. Naturally, for the main plate body of the noise suppressing device 1 A of the first variation described above, the innermost plate 2 A of the second variation may do as well. Moreover, the fuel tank 10 may be provided with a bracket or the like disposed therein to serve as an installation wall in some cases, instead of setting up a given wall section of the tank as installation wall 13 .
[0064] In the above embodiments, a fuel tank has been used as a container. The present invention, however, is not limited to that, and may be applied to various types of liquid containers. In the above embodiments, the projections have been given a conical shape, but they may also have a conical shape without a tip, or a shape having a curved peripheral wall. The through holes described above have been formed in the flat areas of the plates, but may also be formed, for example, in the hollowed projections. In this case, forming these through holes or small holes at the tips of the hollow projections would prevent a liquid, such as fuel, from collecting therein even when the projections are disposed with their tips facing down.
[0065] The disclosures of Japanese Patent Application Nos. 2005-123441 filed on Apr. 21, 2005, and 2005-361315 filed on Dec. 15, 2005, are incorporated herein.
[0066] While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative, and the invention is limited only by the appended claims. | A noise suppressing device attachable to a wall within a liquid container can lessen and absorb noise generated by a liquid as it moves within the container. The device has a main plate body with an upper plate surface and a lower plate surface, through holes extending through the upper and lower plate surfaces for permitting flow of the liquid from one side of the main plate body to the other side of the main plate body, and projections formed on the main plate body. Each projection has a base and a tip, and is tapered from the base to the tip. The noise suppressing device also has an attachment device for attaching the main plate body to the container wall. The device is easy to manufacture and install, and effectively suppresses liquid noise. |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to U.S. Provisional Patent Application No. 60/773,010, filed Feb. 14, 2006, the disclosures of which are incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates to a method of preparing a molecular sieve, particularly but not exclusively to a method for synthesizing a crystalline molecular sieve composition and a catalyst.
BACKGROUND
Molecular sieve materials, both natural and synthetic, have catalytic properties for various types of hydrocarbon conversion. Certain molecular sieves (e.g., zeolites, AlPOs, and/or mesoporous materials) are ordered, porous crystalline materials having a definite crystalline structure. Within the crystalline molecular sieve material there are a large number of cavities which may be interconnected by a number of channels or pores. These cavities and pores are uniform in size within a specific molecular sieve material. Since the dimensions of these pores are such as to accept for adsorption molecules of certain dimensions while rejecting those of larger dimensions, these materials have come to be known as “molecular sieves” and are utilized in a variety of industrial processes.
Such molecular sieves, both natural and synthetic, include a wide variety of positive ion-containing crystalline silicates. These silicates can be described as a rigid three-dimensional framework of SiO 4 and Group IIIA element oxide (e.g., AlO 4 ) (as defined in the Periodic Table, IUPAC 1997). The tetrahedra are cross-linked by the sharing of oxygen atoms whereby the ratio of the total Group IIIA element (e.g., aluminum) and silicon atoms to oxygen atoms is 1:2. The electrovalence of the tetrahedra containing the Group IIIA element (e.g., aluminum) is balanced by the inclusion in the crystal of a cation, for example a proton, an alkali metal or an alkaline earth metal cation. This can be expressed as the ratio of the Group IIIA element (e.g., aluminum) to the number of various cations, such as H + , Ca 2+ /2, Sr 2+ /2, Na + , K + , or Li + , being equal to unity.
Molecular sieves that find application in catalysis include any of the naturally occurring or synthetic crystalline molecular sieves. Examples of these sieves include large pore zeolites, intermediate pore size zeolites, and small pore zeolites. These zeolites and their isotypes are described in “Atlas of Zeolite Framework Types”, eds. W. H. Meier, D. H. Olson and Ch. Baerlocher, Elsevier, Fifth Edition, 2001, which is herein incorporated by reference. A large pore zeolite generally has a pore size of at least about 7 Å and includes LTL, VFI, MAZ, FAU, OFF, *BEA, and MOR framework type zeolites (IUPAC Commission of Zeolite Nomenclature). Examples of large pore zeolites include mazzite, offretite, zeolite L, VPI-5, zeolite Y, zeolite X, omega, and Beta. An intermediate pore size zeolite generally has a pore size from about 5 Å to less than about 7 Å and includes, for example, MFI, MEL, EUO, MTT, MFS, AEL, AFO, HEU, FER, MWW, and TON framework type zeolites (IUPAC Commission of Zeolite Nomenclature). Examples of intermediate pore size zeolites include ZSM-5, ZSM-11, ZSM-22, “MCM-22 family material”, silicalite 1, and silicalite 2. A small pore size zeolite has a pore size from about 3 Å to less than about 5.0 Å and includes, for example, CHA, ERI, KFI, LEV, SOD, and LTA framework type zeolites (IUPAC Commission of Zeolite Nomenclature). Examples of small pore zeolites include ZK-4, ZSM-2, SAPO-34, SAPO-35, ZK-14, SAPO-42, ZK-21, ZK-22, ZK-5, ZK-20, zeolite A, chabazite, zeolite T, gmelinite, ALPO-17, and clinoptilolite.
The term “MCM-22 family material” (or “material of the MCM-22 family” or “molecular sieve of the MCM-22 family”), as used herein, includes one or more of:
(i) molecular sieves made from a common first degree crystalline building block unit cell, which unit cell has the MWW framework topology. (A unit cell is a spatial arrangement of atoms which if tiled in three-dimensional space describes the crystal structure. Such crystal structures are discussed in the “Atlas of Zeolite Framework Types”, Fifth edition, 2001, the entire content of which is incorporated as reference); (ii) molecular sieves made from a common second degree building block, being a 2-dimensional tiling of such MWW framework topology unit cells, forming a monolayer of one unit cell thickness, preferably one c-unit cell thickness; (iii) molecular sieves made from common second degree building blocks, being layers of one or more than one unit cell thickness, wherein the layer of more than one unit cell thickness is made from stacking, packing, or binding at least two monolayers of one unit cell thickness. The stacking of such second degree building blocks can be in a regular fashion, an irregular fashion, a random fashion, or any combination thereof; and (iv) molecular sieves made by any regular or random 2-dimensional or 3-dimensional combination of unit cells having the MWW framework topology.
The MCM-22 family materials are characterized by having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 3.57±0.07 and 3.42±0.07 Angstroms (either calcined or as-synthesized). The MCM-22 family materials may also be characterized by having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstroms (either calcined or as-synthesized). The X-ray diffraction data used to characterize said molecular sieve are obtained by standard techniques using the K-alpha doublet of copper as the incident radiation and a diffractometer equipped with a scintillation counter and associated computer as the collection system. Materials belonging to the MCM-22 family include MCM-22 (described in U.S. Pat. No. 4,954,325), PSH-3 (described in U.S. Pat. No. 4,439,409), SSZ-25 (described in U.S. Pat. No. 4,826,667), ERB-1 (described in European Patent No. 0293032), ITQ-1 (described in U.S. Pat. No. 6,077,498), ITQ-2 (described in International Patent Publication No. WO97/17290), ITQ-30 (described in International Patent Publication No. WO2005118476), MCM-36 (described in U.S. Pat. No. 5,250,277), MCM-49 (described in U.S. Pat. No. 5,236,575) and MCM-56 (described in U.S. Pat. No. 5,362,697). The entire contents of the aforesaid patents are incorporated herein by reference.
It is to be appreciated the MCM-22 family molecular sieves described above are distinguished from conventional large pore zeolite alkylation catalysts, such as mordenite, in that the MCM-22 materials have 12-ring surface pockets which do not communicate with the 10-ring internal pore system of the molecular sieve.
The zeolitic materials designated by the IZA-SC as being of the MWW topology are multi-layered materials which have two pore systems arising from the presence of both 10 and 12 membered rings. The Atlas of Zeolite Framework Types classes five differently named materials as having this same topology: MCM-22, ERB-1, ITQ-1, PSH-3, and SSZ-25.
The MCM-22 family molecular sieves have been found to be useful in a variety of hydrocarbon conversion processes. Examples of MCM-22 family molecular sieve are MCM-22, MCM-49, MCM-56, ITQ-1, PSH-3, SSZ-25, and ERB-1. Such molecular sieves are useful for alkylation of aromatic compounds. For example, U.S. Pat. No. 6,936,744 discloses a process for producing a monoalkylated aromatic compound, particularly cumene, comprising the step of contacting a polyalkylated aromatic compound with an alkylatable aromatic compound under at least partial liquid phase conditions and in the presence of a transalkylation catalyst to produce the monoalkylated aromatic compound, wherein the transalkylation catalyst comprises a mixture of at least two different crystalline molecular sieves, wherein each of said molecular sieves is selected from zeolite beta, zeolite Y, mordenite and a material having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom (Å).
The MCM-22 family molecular sieves including MCM-22, MCM-49, and MCM-56 have various applications in hydrocarbon conversion processes. Unfortunately, industrial applications of zeolite catalysts have been hindered due to some major disadvantages associated with the current synthesis techniques that make large scale production of these catalysts complicated and therefore expensive. At present, crystalline zeolite catalysts are synthesized mainly by conventional liquid-phase hydrothermal treatment, including in-situ crystallization and seeding method, and the vapor phase transport method.
In the hydrothermal method, a reaction mixture of silica, alumina, caustic agent, an organic template or structure directing agent, and water is heated at a high temperature in a liquid phase to produce crystalline zeolite crystals (see also U.S. Pat. No. 5,871,650, Lai et al.). The main drawbacks of this method are the difficulty in assuring the uniformity of the crystallization conditions and limited reproducibility of high quality membranes.
In the vapor phase transport method, an extrudate reaction mixture of silica, alumina, caustic agent, an organic template or structure directing agent and water is heated at autogenous pressure at 100° C. in a sealed reactor for a number of days. The extrudate is then dried in a vacuum oven overnight and calcined in air at a high temperature for a further eight hours to produce a crystalline zeolite (see also U.S. Pat. No. 5,558,851, Sep. 24, 1996, Miller). This method is unsuitable for producing crystalline zeolite on a large scale as the process is complicated and it takes a long time. In addition, the resulting crystalline zeolite has a low crush strength and lacks uniformity and consequently has poor quality.
The present invention aims to obviate or at least mitigate the above described problems and/or to provide improvements generally.
SUMMARY OF THE INVENTION
According to an embodiment of the invention, there is provided a method and a catalyst as defined in any of the accompanying claims.
In an embodiment of the invention there is provided a method of preparing a crystalline molecular sieve comprising:
(a) providing a reaction mixture comprising at least one source of ions of tetravalent element Y, at least one source of alkali metal hydroxide, water, optionally at least one seed crystal, and optionally at least one source of ions of trivalent element X, said reaction mixture having the following mole composition:
Y:X 2 = 10 to infinity OH − :Y = 0.001 to 2 M + :Y = 0.001 to 2
wherein Y is a tetravalent element, X is a trivalent element, M is an alkali metal and the amount of water is at least sufficient to permit extrusion of said reaction mixture;
(b) extruding said reaction mixture to form a pre-formed extrudate; and
(c) crystallizing said pre-formed extrudate under vapor phase conditions in a reactor to form said crystalline molecular sieve whereby excess alkali metal hydroxide is removed from the pre-formed extrudate during crystallization.
In this way, a more efficient and simpler vapor phase crystallization process is provided which no longer requires a binder for binding the crystallized zeolite prior to extrusion. The element Y ion source in the reaction mixture, eg silica where Y is silicon, acts as a binder to bind the reaction components after extrusion and prior to crystallization so that the pre-formed extrudate retains its structure during crystallization.
During the process, the level of alkali metal hydroxide required for the reaction is present at all times during crystallization as superfluous alkali metal hydroxide is removed. In this way the critical level of alkali metal hydroxide is maintained uniformly in the pre-formed extrudate mixture. The removal of excess alkali metal hydroxide results in the formation of a good quality sieve in-situ extrudate which has a uniform crystalline structure. In addition, the process allows more efficient utilization of the template or structure directing agent and element Y ion source eg silica. This makes it possible to eliminate the steps of decanting and filtration which are otherwise necessary in the production of molecular sieves on the basis of the afore described conventional methods.
Furthermore, since the reaction mixture is extruded prior to crystallization the crystalline sieve structure/morphology is not damaged in any way by a part-crystallization extrusion step which would otherwise affect its mechanical properties. This is a problem in sieves produced in conventional processes.
The sources of the various elements required in the final product may be any of those in commercial use or described in the literature, as may the method of preparation of the synthesis mixture.
In the present synthesis method, the source of ions of tetravalent element Y may be provided by a source of the oxide of the tetravalent element, YO 2 . The source of the oxide preferably comprises solid YO 2 , more preferably about 30 wt. % solid YO 2 in order to obtain the crystal product of this invention. When YO 2 is silica, the use of a silica source containing preferably about 30 wt. % solid silica, e.g., silica sold by Degussa under the trade names Aerosil or Ultrasil (a precipitated, spray dried silica containing about 90 wt. % silica), an aqueous colloidal suspension of silica, for example one sold by Grace Davison under the trade name Ludox, or HiSil (a precipitated hydrated SiO 2 containing about 87 wt. % silica, about 6 wt. % free H 2 O and about 4.5 wt. % bound H 2 O of hydration and having a particle size of about 0.02 micro) favors crystal formation from the above mixture. Preferably, therefore, the YO 2 , e.g., silica, source contains about 30 wt. % solid YO 2 , e.g., silica, and more preferably about 40 wt. % solid YO 2 , e.g., silica. The source of silicon may also be a silicate, e.g., an alkali metal silicate, or a tetraalkyl orthosilicate. Alternative tetravalent elements may be germanium, titanium and tin. The reaction mixture may contain a source of ions of a single tetravalent element such as silicon or of two or more tetravalent elements, eg silicon and germanium.
The source of the ions of the trivalent element X, when present, is preferably the oxide, X 2 O 3 . For example the trivalent element may be aluminum, and the ion (oxide) source is preferably aluminum sulphate or hydrated alumina. Other aluminum sources include, for example, other water-soluble aluminum salts, sodium aluminate, or an alkoxide, e.g., aluminum isopropoxide, or aluminum metal, e.g., in the form of chips.
The alkali metal of the hydroxide is advantageously potassium or sodium, the sodium source advantageously being sodium hydroxide or sodium aluminate. The alkali metal hydroxide may also comprise a caustic agent, preferably sodium hydroxide.
In a preferred embodiment of the method of the invention, the crystallization is carried out in the presence of a structure directing agent R. Thus in one embodiment, the reaction mixture additionally comprises R, such that the pre-formed extrudate comprises a structure directing agent R. In another embodiment, the structure directing agent R is made available to the crystallization reaction by being contained in the reactor but not in the pre-formed extrudate. In yet another embodiment the structure directing agent may form part of the reaction mixture used to form the pre-formed extrudate, and a further amount of structure directing agent R, may be provided in the reactor separate from the preformed extrudate.
Directing agent R is preferably selected from the group consisting of cycloalkylamine, azacycloalkane, diazacycloalkane, and mixtures thereof, with alkyl preferably comprising from 5 to 8 carbon atoms. Non-limiting examples of R include cyclopentylamine, cyclohexylamine, cycloheptylamine, hexamethyleneimine (HMI), heptamethyleneimine, homopiperazine, and combinations thereof.
The amount of the directing agent affects the cost and the product quality of the synthesis of a crystalline molecular sieve. The directing agent is generally the most expensive reactant(s) in the hydrothermal reaction mixture of many crystalline molecular sieves. The lower the amount of the directing agent in the hydrothermal reaction mixture, the cheaper the final molecular sieve produced. The term “low directing agent” as used herein means the molar ratio of the directing agent over the tetravalent element in the hydrothermal reaction mixture is less than 0.5, preferably less than 0.34, even more preferably less than 0.2, and most preferably less than 0.15.
In one embodiment of this invention R:SiO 2 molar ratio ranges from 0.001 to 0.34, preferably from 0.001 to 0.3, more preferably from 0.001 to 0.25, even more preferably from 0.001 to 0.2, and most preferably from 0.1 to 0.15.
The composition of the preformed extrudates and reaction parameters are critical for producing a high quality and a homogeneous phase product. In preferred embodiments, the Y:X 2 ratio may be 50 to 5000 and/or the H 2 O:Y ratio may be 0.5 to 5 and/or the OH − :Y ratio may be 0.1 to 1 and/or the M + :Y ratio may be 0.01 to 2 and/or the R:Y ratio may be 0.01 to 2.
The method of the invention requires the reaction mixture to contain sufficient water to permit extrusion of the reaction mixture. The reactor may contain a further amount of water such that under the applied vapor phase conditions that water is made available to the crystallizing extrudate.
Preferably the preformed extrudate includes seed crystals of the molecular sieve, to facilitate the crystallization reaction. The seeds may be present in a wide range of concentration eg from 0.1 to 40 wt % of the extrudate, such as from 0.2 to 5 wt %.
In one embodiment of the invention, the preformed extrudate mixture may be exposed to an autogenous pressure and temperature which allow crystallization of the mixture under vapor phase conditions. Suitable pressures may be in the range, for example, of from 345 kPag (50 psig) to 6.9 MPag (1000 psig), preferably from 550 kPag (80 psig) to 3.95 MPag (500 psig), and more preferably 690 kPag (100 psig) to 2.07 MPag (300 psig). Suitable temperatures may vary from 50° C. to 500° C., preferably from 80° C. to 250° C., more preferably from 100° C. to 250° C. The reactor may comprise an autoclave or any other suitable chamber in which controlled pressure and elevated temperature conditions for promoting crystallization can be provided.
In another preferred embodiment of the invention, the pre-extruded mixture is provided within the reactor on a support, the support being adapted to allow removal of the excess alkali metal hydroxide eg caustic solution during crystallization. The support spaces the extrudate from the reactor wall. The support may also promote heat circulation during crystallization of the synthesized mixture. As the support enables removal of the excess alkali metal hydroxide eg caustic during crystallization, a critical level of alkali metal hydroxide eg caustic in the extruded mixture is maintained uniformly which will result in the formation of good quality zeolite in-situ extrudate. The support may comprise one or more apertures to facilitate separation of leached alkali metal hydroxide eg caustic from the extrudate. The apertures also promote heat exchange between the extrudate and the reactor.
To date, it has been known that molecular sieves may be prepared by a method called the in-situ extrudate technique. This process involves formation of an extrudate followed by crystallization in an autoclave. We have discovered that in the prior art preparation technique, leached caustic solution from the pre-formed extrudate reacts with portions of the extrudate which are in contact with the caustic solution. This results in a poor, non-uniform product having poor mechanical properties and in particular having a low crush strength in comparison to zeolites which are synthesized via conventional hydrothermal treatments. In the present invention, the method provides for separation of the pre-formed extrudate from the excess alkali metal hydroxide solution or excess caustic, for example by bearing the pre-formed extrudate on a support in the reactor, which results in a higher quality crystalline extrudate product, thereby overcoming a longstanding problem in molecular sieve (zeolite) catalyst crystals which are produced by means of conventional vapor phase crystallization processes.
In addition, removal of the alkali metal hydroxide caustic material during crystallization in turn enhances the vaporized atmosphere which further promotes the vapor phase crystallization. The support thus improves the vapor phase conditions and prevents the crystalline structure from being compromised by the inadvertent presence of unnecessary caustic within the formed crystalline structure during crystallization.
In a preferred embodiment, the pre-extruded synthesis mixture is spaced from at least one inner perimeter of the reactor by any suitable means such as the support. The mixture may be spaced from one or more walls. The mixture may also be spaced from a floor of the reactor. Separation of the mixture from the reactor walls promotes removal of the caustic agent and enhances heat circulation and promotes exposure of the mixture to the vapor phase.
The support may be formed by a sieve or grid or mesh. In this way the support does not affect the heat circulation whilst allowing efficient removal of the alkali metal hydroxide caustic agent during crystallization.
In another embodiment of the invention, the method is suited to crystallize extrudates of molecular sieve materials such as ZSM-5, ZSM-11, ZSM-12, ZSM-35, ZSM-48, Y and in particular, MCM-22 family molecular sieves. The MCM-22 family sieves may comprise MCM-22, MCM-49 and MCM-56.
In a further embodiment, the pre-formed extrudate additionally comprises an already synthesized further molecular sieve to form a dual molecular sieve after crystallization. The synthesized further molecular sieve may comprise, for example, zeolite beta, zeolite Y, Mordenite, ZSM-5 or ZSM-12.
In a preferred embodiment of the invention, the tetravalent element is silicon and the source of ions thereof preferably comprises a source of silica. The trivalent element is preferably aluminum and the source of ions thereof preferably comprises a source of alumina. In a particular embodiment, there is thus provided a method of preparing a molecular sieve comprising:
In a further embodiment, combinations of extrudates of the MCM-22 family with an open network structure of interconnected crystals are prepared by crystallizing HMI-containing preformed extrudate reaction mixtures under vapor phase conditions. The mixtures may contain seed crystals for each of the MCM-22, MCM-49, and MCM-56.
In a preferred embodiment of the invention, the compositions of the pre-formed extrudate for making MCM-22 or MCM-49 or MCM-56 or mixtures thereof may comprise (molar ratios):
(v)
SiO 2 /Al 2 O 3 :
10-500;
(vi)
OH − /SiO 2 :
0.001-0.5;
(vii)
Na/SiO 2 :
0.001-0.5;
(viii)
HMI/SiO 2 :
0.05-0.5;
(ix)
H 2 O/SiO 2 :
1-20; and,
In the case where seed crystals are present, the seed concentration of the respective MCM-22, MCM-49 or MCM-56 seed crystals is preferably 0.1 to 40 weight % of the extrudate.
Dual zeolite crystals such as Beta/MCM-22 may be synthesized in a similar fashion. The reaction mixture may comprise silica, alumina, caustic, water, Beta and MCM-22 seed crystals and a structure directing agent. The resulting dual zeolite extrudates comprise a high surface area, high porosity, high crush strength, high activity and intergrown crystal morphology.
In another embodiment of the invention, the pre-extruded mixture comprises two or more phases of zeolite. In this way, dual zeolite or multiple zeolite catalyst systems can be produced.
In a further embodiment of the invention there is provided a method for preparing a catalyst comprising preparing a molecular sieve according to the method as hereinbefore described and activating the sieve to form the catalyst. The sieve may be activated for example by water post-treatment of the crystal and/or by surface modification. Suitable surface modification may comprise surface treatment to provide a metal oxide on the catalyst surface such as aluminum oxide.
In yet another embodiment of the invention, there is provided a catalyst which is formed from a zeolite crystal produced by means of the afore described method.
In a further embodiment of the invention, there is provided a catalyst formed from a pre-extruded mixture, said mixture being crystallized under vapor phase conditions whereby excess caustic agent is removed to form a catalyst with low density, high intrusion volume and high crush strength. The catalyst of the invention may also be suitable as a catalyst additive to enhance the performance of existing catalysts.
By virtue of the manufacturing method as herein described, the molecular sieves produced and the corresponding catalyst may for example comprise a surface area of at least 300 m 2 /g preferably at least 500 m 2 /g and more preferably at least 600 m 2 /g, as measured by BET surface area analysis using a Tristar 3000 instrument available from Micromeritics Corporation of Norcoss, Ga., USA.
The crush strength values as reported herein are measured according to the Mobil Test using an anvil/strike plate instrument by determining the resistance of formed molecular sieve extrudate to compressive force. The measurement is performed on cylindrical extrudate having a length to diameter ratio of at least 1:1 and a length greater than ⅛″ (0.32 cm). The determination is performed by placing the extrudate sample between the driven anvil and the fixed strike plate of an instrument comprising a Willrich Test Stand in combination with an Ametek Electronic Force Guage. The Test Stand comprises a movement that holds the Force Guage, and a strike plate. The strike plate is considerably larger than the anvil, and during testing carries the extrudate pellet under test. The anvil portion of the instrument comprises a rectangular ⅛″×½″ (0.32 cm×1.27 cm) anvil surface arranged to apply compressive force to the pellet carried on the strike plate during the testing procedure. Prior to performing the test the minimum gap between opposed surfaces of the anvil and strike plate is about half the diameter of the cylindrical extrudate pellet.
The sample is prepared by placing the extrudate pellet in a crucible and drying at 121° C. (250° F.) for at least 1 hour. This step may be eliminated if the sample has been previously dried or calcined. Thereafter, the crucible containing the sample is placed on a crucible tray which is transferred to a muffle furnace at 538° C. (1000° F.) for 1 hour. Drying temperature/time may be altered as appropriate for the material under evaluation. However, consistency in treatment and drying between samples is imperative. All samples being compared for a given project or family should be evaluated after pretreatment at the same temperature/time. After such heating the crucible is removed from the furnace and sealed in a desiccator until cool.
For crush strength determination of a particular molecular sieve product, a representative sample of typically 25 cylindrical extrudate pellets is tested. Such pellets, once cooled in the desiccator, are placed in a buchner funnel under nitrogen flow. For testing a pellet is removed from the funnel using tweezers and placed on the strike plate directly under the raised anvil in a configuration such that the longitudinal axis of the cylindrical pellet is at 90° to the longitudinal axis of the ⅛″×½″ (0.32 cm×1.27 cm) anvil shoe; with the pellet extending entirely across the ⅛″ (0.32 cm) width of the anvil shoe. In this configuration, when under test, the anvil subjects a ⅛″ (0.32 cm) longitudinal portion of the cylinder wall to the applied compression force. Once the pellet is in the required configuration, the instrument is activated such that the anvil is lowered in controlled fashion to apply gradually increasing force to a ⅛″ (0.32 cm) contact area along the “spine” of the pellet until the pellet is crushed. The force reading displayed on the instrument guage at the point of collapse of the pellet is recorded. This technique is repeated for the 25 pellets of the sample, and the average measured crush strength value for the molecular sieve over the 25 readings is calculated. This crush strength is reported in normalized fashion as the average applied force per unit length along the spine of the extrudate to which the anvil sole is applied. Since the anvil dimension is ⅛″ (0.32 cm) the crush strength is reported as force units (lb, kg) per length unit (inch, cm). Thus, if the measured force is, say, 2 lbs (0.91 kg) over the ⅛″ (0.32 cm) width of the anvil, the crush strength would be reported as 16 lb/inch (2.84 kg/cm). As mentioned, the important feature of this test method is the comparative crush strength values obtained for different molecular sieves.
Preferably the molecular sieve products of the method of the invention have crush strength measured by the above-described Mobil Test of at least 5.4 kg/cm (30 lb/inch), more preferably at least 7.2 kg/cm (40 lb/inch) and most preferably at least 9.8 kg/cm (55 lb/inch).
According to another embodiment of the invention there is provided an organic compound eg (hydrocarbon) conversion process comprising contacting an organic eg hydrocarbon feedstock with a catalyst or catalyst additive as hereinbefore described under conversion conditions to convert the feedstock to converted product.
The catalyst compositions of present invention are useful as catalyst in a wide range of processes, including separation processes and hydrocarbon conversion processes. In a preferred embodiment, the catalyst composition of the present invention may be used in processes that co-produce phenol and ketones that proceed through benzene alkylation, followed by formation of the alkylbenzene hydroperoxide and cleavage of the alkylbenzene hydroperoxide into phenol and ketone. In such processes, the catalyst of the present invention is used in the first step, that is, benzene alkylation. Examples of such processes includes processes in which benzene and propylene are converted to phenol and acetone, benzene and C4 olefins are converted to phenol and methyl ethyl ketone, such as those described for example in international application PCT/EP2005/008557, benzene, propylene and C4 olefins are converted to phenol, acetone and methyl ethyl ketone, which, in this case can be followed by conversion of phenol and acetone to bis-phenol-A as described in international application PCT/EP2005/008554, benzene is converted to phenol and cyclohexanone, or benzene and ethylene are converted to phenol and methyl ethyl ketone, as described for example in PCT/EP2005/008551.
The catalyst composition of the present invention is useful in benzene alkylation reactions where selectivity to the monoalkylbenzene is required. Furthermore, the catalyst of the present invention is particularly useful to produce selectively sec-butylbenzene from benzene and C4 olefin feeds that are rich in linear butenes, as described in international application PCT/EP2005/008557. Preferably, this conversion is carried out by co-feeding benzene and the C4 olefin feed with the catalyst of the present invention, at a temperature of about 60° C. to about 260° C., for example of about 100° C. to 200° C., a pressure of 7000 kPa or less, and a feed weight hourly space velocity (WHSV) based on C4 alkylating agent of from about 0.1 to 50 hour-1 and a molar ratio of benzene to C4 alkylating agent from about 1 to about 50. The catalyst composition of the present invention is also useful catalyst for transalkylations, such as, for example, polyalkylbenzene transalkylations.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings in which:
FIG. 1 presents a diagrammatic cross sectional view of a chamber for crystallizing a molecular sieve synthesis mixture under vapor phase conditions according to one embodiment of the invention, and
FIG. 2 presents a diagrammatic cross sectional view of a chamber for crystallizing a molecular sieve synthesis mixture under vapor phase conditions according to another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In an embodiment of the invention to prepare a zeolite catalyst, a pre-formed mixture is prepared from the following compounds: silica, alumina, a caustic agent, water, seed crystals and a structure directing agent. Typically, the silica and alumina ratios define the type of zeolite crystal that can be produced. Various examples are described herein below but generally, the silica/alumina ratio is between 10 and infinite. The caustic agent is preferably sodium hydroxide although potassium ions can also be used. The structure directing agent is typically HMI for making in-situ extrudate with a structure type of MWW although other structure directing agents or templates may be used.
Now turning to FIG. 1 , the mixture is extruded by means of a conventional extruder such as a 5.08 cm (2 inch) Bonnot extruder and the extruded mixture ( 10 ) is provided on a support ( 12 ) for location inside an autoclave chamber ( 14 ). The pre-formed extruded mixture ( 10 ) is subsequently crystallized under vapor phase conditions to form the zeolite crystal catalyst whereby the excess caustic agent is removed from the crystallized material during crystallization. As the support ( 12 ) separates the mixture from the floor of the chamber, this promotes removal of the excess caustic agent and enhances heat circulation and promotes exposure of the mixture to the vapor phase.
In FIG. 2 , the mixture ( 20 ) is located on a different support ( 22 ) which spaces the mixture from the perimeter or surrounding walls ( 26 ) of the autoclave chamber ( 24 ). This arrangement further enhances the removal of the caustic agent and enhances heat circulation and promotes exposure of the mixture to the vapor phase. This in turn increases the crush strength and the silica/alumina ratio as will be evident from the below Examples 1 and 2.
Embodiments of the invention will now be described in the following Examples to further illustrate the invention.
Preparation of MCM-22 Pre-formed Extrudate Mixture
Extrudates for MCM-22 vapor phase in-situ crystallization were prepared from a mixture of 908 g of Ultrasil Non-PM silica, 330 g of HMI, 180 g of sodium aluminate solution (45%), and 104 g of 50% sodium hydroxide solution, 950 g of de-ionised (DI) water, and 40 g of MCM-22 seed crystals. The mixture had the following molar composition:
(x)
SiO 2 /Al 2 O 3 =
29.4
(xi)
H 2 O/SiO 2 =
4.54
(xii)
OH − /SiO 2 =
0.17
(xiii)
Na + /SiO 2 =
0.17
(xiv)
HMI/SiO 2 =
0.23
The mixture was mulled and formed into a 0.16 cm ( 1/16″) diameter cylinder extrudate using a 5.08 cm (2″) Bonnot extruder. The extrudates were then stored in a sealed container before use in the below Examples 1 and 2.
Example 1
A 750 g sample of the above-formed wet pre-formed extrudate was placed in a 2-liter autoclave with wire mesh support as shown in FIG. 1 . The mesh size of the support was 2 mm. The distance between bottom of autoclave and wire mesh support is >1.25 cm (½″).
The extrudate was crystallized at 160° C. (320° F.) for 96 hrs. After the reaction the product was discharged, washed with water and dried at 120° C. (250° F.), the XRD pattern of the synthesized material showed the typical pure phase of MCM-22 topology. Scanning Electron Microscopy (SEM) analysis showed that the material is composed of agglomerates of platelet crystals (with a crystal size of about 1 microns). The synthesized extrudate was pre-calcined in nitrogen at 482° C. (900° F.) for 3 hrs and was then converted into the hydrogen form by three ion exchanges with ammonium nitrate solution at room temperature, followed by drying at 120° C. (250° F.) and calcination at 540° C. (1000° F.) for 6 hours. The resulting extrudate crystals have a SiO 2 /Al 2 O 3 molar ratio of 24.1, surface area of about 680 m2/g, crush strength of 11.3 kg/cm (63 lb/inch), particle density of 0.432 g/cc, bulk density of about 0.25 g/cc (ASTM D4284), intrusion volume of 1.72 ml/g (measured in accordance with ASTM D4284 Standard Test Method for Determining Pore Volume Distribution of Catalyst by Mercury Intrusion Porosimetry).
Example 2
A 500 g sample of the wet pre-formed extrudate produced as described in Example 1 was placed in a 2-liter autoclave with wire mesh holder as shown in FIG. 2 . The mesh holder separates the sample from the bottom of autoclave and side walls by a distance of greater than 1.25 cm (½″).
The extrudate was crystallized at 160° C. (320° F.) for 96 hrs. After the reaction the product was discharged, washed with water and dried at 120° C. (250° F.). The XRD pattern of the synthesized material again showed the typical pure phase of MCM-22 topology. The SEM showed that the material is composed of agglomerates of platelet crystals (with a crystal size of about 0.5 microns). The crush strength of the synthesized sample was measured at 12.35 kg/cm (69 lb/inch) which is higher than the crystal in Example 1. The extrudate was pre-calcined in nitrogen at 482° C. (900° F.) for 3 hrs and then was converted into the hydrogen form by three ion exchanges with ammonium nitrate solution at room temperature, followed by drying at 120° C. (250° F.) and calcination at 540° C. (1000° F.) for 6 hours. The resulting extrudate crystals have a SiO 2 /Al 2 O 3 molar ratio of 24.2.
Preparation of MCM-22 Pre-Formed HMI-Free Extrudate Mixture
Aluminosilicate pre-formed extrudates for MCM-22 vapor phase in-situ crystallization were prepared from a mixture of 908 g of Ultrasil Non-PM silica, 180 g of sodium aluminate solution (45%), and 104 g of 50% sodium hydroxide solution, 1080 g of DI water, and 40 g of MCM-22 seed crystals. The mixture had the following molar composition:
(xv)
SiO 2 /Al 2 O 3 =
29.4
(xvi)
H 2 O/SiO 2 =
4.54
(xvii)
OH − /SiO 2 =
0.17
(xviii)
Na + /SiO 2 =
0.17
No HMI was present in the mixture. The mixture was mulled and formed into a 0.16 cm ( 1/16″) diameter cylinder extrudate using a 5.08 cm (2″) Bonnot extruder. The extrudates were then stored in a sealed container before use. Dried extrudates were prepared separately by drying the wet extrudates in an oven at 120° C. (250° F.) for 2 hours. These extrudates were then used in below Examples 3 and 4
Example 3
The wet extrudates were placed in a 2-liter autoclave with wire mesh support as shown below. The distance between the bottom of the autoclave and the wire mesh support was greater than 1.25 cm (½″). A mixture of 300 g of DI water and 200 g of HMI was added to the bottom of the autoclave. The extrudates were crystallized at 160° C. (320° F.) for 120 hrs. After the reaction, the product was discharged, washed with water, and dried at 120° C. (250° F.). XRD patterns of the as-synthesized and calcined materials showed the typical pure phase of MCM-22 topology identical to the topology of the MCM-22 as prepared in the presence of HMI. SEMs of the as-synthesized material showed that the material was composed of agglomerates of platelet crystals with a crystal size of about 1-2 microns. The resulting dried extrudate had a SiO 2 /Al 2 O 3 molar ratio of 22.2 and crush strength of 3.6 kg/cm (20 lb/inch). Calcined extrudate had a surface area of 640 m 2 /g, bulk density of 0.41 g/ml, and a total intrusion volume of 1.75 ml/g (measured in accordance with ASTM D4284 Standard Test Method for Determining Pore Volume Distribution of Catalyst by Mercury Intrusion Porosimetry).
Example 4
The dried extrudates were placed in a 2-liter autoclave with wire mesh support located near the bottom of the autoclave so that the distance between bottom of autoclave and wire mesh support is >1.25 cm (½″). A mixture of 200 g DI water and 200 g of HMI was added to the bottom of the autoclave. The extrudates were crystallized at 160° C. (320 F) for 132 hrs. After the reaction, the product was discharged, washed with water, and dried at 120° C. (250° F.). The XRD pattern of the as-synthesized material showed the typical pure phase of MCM-22 topology. The SEM of the as-synthesized material showed that the material was composed of agglomerates of platelet crystals (with an crystal size of about 1-2 microns). The resulting dried extrudate had a SiO 2 /Al 2 O 3 molar ratio of 25.4 and crush strength of 7.5 kg/cm (42 lb/inch). Calcined extrudate had a surface area of 540 m2/g, a bulk density (measured in accordance with ASTM D4284) of 0.6 g/ml, and a total intrusion volume (measured in accordance with ASTM D4284) of 1.07 ml/g.
Preparation of MCM-49 Pre-Formed Extrudate Mixture
Extrudates for MCM-49 vapor phase in-situ crystallization were prepared from a mixture of 908 g of Ultrasil Non-PM silica, 348 g of HMI, 262 g of sodium aluminate solution (45%), and 36 g of 50% sodium hydroxide solution, 576 g of DI water, and 40 g of MCM-49 seed crystals. The mixture had the following molar composition:
(xix)
SiO 2 /Al 2 O 3 =
20.8
(xx)
H 2 O/SiO 2 =
3.11
(xxi)
OH − /SiO 2 =
0.15
(xxii)
Na + /SiO 2 =
0.15
(xxiii)
HMI/SiO 2 =
0.24
The mixture was mulled and formed into 0.16 cm ( 1/16″) cylinder extrudates using a 5.08 cm (2″) diameter Bonnot extruder. The extrudates were then stored in a sealed container before use in Examples 5 and 6.
Example 5
A 300 g sample of the above formed wet extrudate was loaded in a 600 ml autoclave without providing a support so that the mixture was in direct contact with the autoclave walls.
The extrudate was crystallized at 160° C. (320° F.) for 96 hrs. After the reaction the product was discharged, washed with water and dried at 120° C. (250° F.). A significant amount of clumps of extrudates or loose powder were found at the bottom of the autoclave. The XRD patterns of the synthesized MCM-49 material collected from the top showed a poor crystalline phase of MCM-49 topology, and clump materials collected from the bottom shows MCM-49 and impurity phase of ZSM-35. Continuing the crystallization for 24-48 hrs produced a product with more ZSM-35 impurity. The SEM of the “good quality” MCM-49 synthesized material showed that the material is composed of agglomerates of intergrown platelet crystals (with a crystal size of about 1 micron). The resulting extrudate crystals have a SiO2/Al2O3 molar ratio of 18.
Example 6
A 600 g sample of the pre-formed wet extrudate was placed in a 2-liter autoclave with wire mesh support as shown in FIG. 1 . The distance between bottom of autoclave and wire mesh support is >1.25 cm (½″). 100 g of DI water was added to the bottom of the autoclave.
The extrudate was crystallized at 160° C. (320° F.) for 120 hrs. After the reaction the product was discharged, washed with water and dried at 120° C. (250° F.). Only small amount of clumps of the extrudate or loose powder was found at the bottom of the autoclave. The XRD pattern of the as-synthesized material showed the highly crystalline of MCM-49 topology. The SEM of the as-synthesized material shows that the material is composed of agglomerates of platelet crystals (with a crystal size of about 1 microns). The supported method appears to be an effective procedure for producing more homogenous and better quality product as compared to above Example 3. Crush strength of the dried extrudate was measured at 8.4 kg/cm (47 lb/inch). The as-synthesized extrudates were pre-calcined in nitrogen at 482° C. (900° F.) for 3 hrs and then were converted into the hydrogen form by three ion exchanges with ammonium nitrate solution at room temperature, followed by drying at 120° C. (250° F.) and calcination at 540° C. (1000° F.) for 6 hours. The resulting extrudate crystals have a SiO2/Al2O3 molar ratio of 17.2, surface area of approximately 620 m 2 /g.
Preparation of Beta/MCM-22 Pre-Formed Extrudate Mixture
Beta containing pre-formed extrudates were prepared from a mixture of 908 g of Ultrasil Non-PM silica, 500 g of beta crystal, 330 g of HMI, 180 g of sodium aluminate solution (45%), and 104 g of 50% sodium hydroxide solution, 1200 g of distilled water and 40 g of MCM-22 seed crystals. The mixture had the following molar composition:
(xxiv)
SiO 2 /Al 2 O 3 =
30.1
(xxv)
H 2 O/SiO 2 =
5.7
(xxvi)
OH − /SiO 2 =
0.17
(xxvii)
Na + /SiO 2 =
0.17
(xxviii)
HMI/SiO 2 =
0.24
(xxix)
Beta crystal/Ultrasil =
35/65 (wt %)
The mixture was mulled and formed into 0.127 cm ( 1/20″) Quad extrudates using a 5.08 cm (2″) Bonnot extruder. The extrudates were then stored in a sealed container before use in Example 7.
Example 7
The pre-formed wet extrudates were placed in a 2-liter autoclave with wire mesh support as shown below. The distance between bottom of autoclave and wire mesh support is greater than 1.25 cm (½″).
The extrudates were crystallized at 150° C. (300° F.) for 96 hrs. After the reaction, the product was discharged, washed with water, and dried at 120° C. (250° F.). The XRD pattern of the as-synthesized material showed the typical mixed phases of MCM-22 and Beta. The scanning electro microscopy (SEM) of the as-synthesized material showed that the material was composed of agglomerates of MCM-22 platelet crystals (with a crystal size of 1-2 microns) and sphere-like Beta crystals. The SEM showed the cross-section of the resulting product. The as-synthesized extrudates were pre-calcined in nitrogen at 482° C. (900° F.) for 3 hrs and then were converted into the hydrogen form by three ion exchanges with ammonium nitrate solution at room temperature, followed by drying at 120° C. (250° F.) and calcination at 540° C. (1000° F.) for 6 hours.
The dried extrudate had a crush strength of approximately 14.3 kg/cm (80 lb/inch) and improved to 19.7 kg/cm (110 lb/inch) after calcination at 282° C. (540° F.). The calcined H-form extrudate crystals had a surface area of 715 m 2 /g, bulk density (measured in accordance with ASTM standard D4284) of 0.51 g/ml, and intrusion volume (measured in accordance with ASTM standard D4284) of 1.35 ml/g.
The above examples show that both the composition of the pre-formed extrudates and the reaction parameters, including the supporting method, are critical for producing a good quality and more homogeneous phase of products. The additions of HMI and seed crystals in the pre-formed extrudates accelerate the crystallization and promote the formation of the desired MCM-22/49 product, although these compounds can be omitted. The support grid functions to provide better heat circulation inside the reactor to allow separation of the excess caustic liquid from the mixture. This also prevents contamination of the mixture with accumulated caustic at the bottom of the autoclave. This in turn reduces clumps formation resulting from liquid phase reaction of the extrudates.
Evaluation in Cumene Test
Catalyst A: Water Wash Post-Treatment of MCM-22 of Example 1
A 5 g sample of MCM-22 of Example 1 was mixed with 13 ml of de-ionized water in a beaker. After soaking in water for about one hour, any excess water was drained and the catalyst was then air dried at room temperature until free flowing. It was further dried at 120° C. (250° F.) for about 16 hours. The modified sample was evaluated in an aromatics alkylation unit (Cumene unit) as will be discussed below.
Catalyst B: Surface Modification of Aluminum Oxide of MCM-22 of Example 1
A quantity of 0.695 g of aluminum nitrate nonahydrate was dissolved in about 14 ml of deionized water. This solution was dispersed evenly into 5 g of MCM-22 produced by conventional means without vapor phase crystallization. The wet mixture was then dried at 120° C. (250° F.) for about 16 hours and then calcined in air at 360° C. (680° F.) for 4 hours. Catalyst B has the same shape as catalyst A.
Catalyst C: Surface Modification of Aluminum Oxide of MCM-22 of Example 1
A quantity of 0.695 g of aluminum nitrate nonahydrate was dissolved in about 14 ml of deionized water. This solution was dispersed evenly into 5 g of MCM-22 produced conventionally without vapor phase crystallization. The wet extrudate was then dried at 120° C. (250° F.) for about 16 hours and then calcined in air at 360° C. (680° F.) for 4 hours.
Catalyst D: Activation of Beta/MCM-22 of Example 7
A 5 g sample of the catalyst of Example 7 was dried in an oven at 260° C. (500° F.) for 2 hours, prior to weighing into the catalyst basket.
Evaluation in Cumene Unit of Samples of Catalysts A, B, C and D.
Evaluation was carried out in a 300 ml autoclave reactor. 0.25 g of catalyst was transferred into the catalyst basket, and 6 gram of quartz chip was layer below and above the catalyst bed inside the basket. The catalyst and the basket were then dried in an oven at 260° C. (500° F.) for about 16 hours. This catalyst basket was then transferred into a 300 ml autoclave quickly with minimum exposure to ambient atmosphere. The catalyst was subsequently purged with dry nitrogen for 2 hours at 181° C. (358° F.) inside the reactor to remove air and moisture from the reactor. 156 g of benzene was transferred to the reactor under nitrogen and equilibrated with the catalyst for 1 hour at 130° C. (266° F.). 28 g of propylene was transferred into the reactor under 2.07 MPag (300 psig) of nitrogen pressure.
The reaction started as soon as propylene was added and a constant pressure of 2.07 MPag (300 psig) nitrogen blanketed the autoclave. The reaction was allowed to run for four hours and propylene was completely consumed during this period. Small samples of liquid were withdrawn from the autoclave at regular interval for analysis of propylene, benzene, cumene, diisopropylbenzene (DIPB), and triisopropylbenzene, using gas chromatography. Catalyst performance was assessed by a kinetic activity rate parameter which is based on the propylene and benzene conversion. For a discussion of the determination of the kinetic rate parameter, reference is directed to “Heterogeneous Reactions: Analysis, Examples, and Reactor Design, Vol. 2: Fluid-Fluid-Solid Reactions” by L K Doraiswamy and M M Sharma, John Wiley & Sons, N.Y. (1994) and to “Chemical Reaction Engineering” by O Levenspiel, Wiley Eastern Limited, New Delhi (1972). Cumene selectivity was calculated from the weight ratio of DIPB/cumene which was expressed as percentage.
The results of the evaluation of the catalysts of the invention A and D were compared with two different formulations of MCM-22 catalysts B, C as set out in the below table. The activity of the catalyst was normalized on the activity of Catalyst B.
TABLE 1
Cata-
Normalized
Selectivity
Normalized
lyst
Description
Activity %
% DIPB/IPB*
% DIPB/IPB**
A
Example 1, in-
166
20.3
120
situ MCM-22
extrudate,
0.16 cm cylinder
B
Conventional
100
16.9
100
MCM-22 bound
with alumina in
0.16 cm cylinder
extrudate
C
Conventional
171
20.8
123
MCM-22 bound
with alumina in
0.127 cm
quadrulobe
extrudate
C
(repeated run)
180
19.1
113
D
Example 3, in-
274
21.1
125
situ Beta/MCM-
22 extrudate,
0.127 cm
quadrulobe
extrudate
DIPB = diisopropylbenzene
IPB = isopropylbenzene
*Normalized to 1 gram cat load
**Normalized to Catalyst B performance
It is known that for propylene alkylation of benzene, the reaction is diffusion limited, and extrudate with a high surface to volume ratio should normally have a higher activity. From the results, catalyst A, despite having a lower surface to volume ratio in comparison to catalyst C, has similar activity and selectivity (% DIPB/IPB). Also, in comparison to the conventionally produced MCM-22 catalyst B of the same extruded shape, catalyst A has much higher activity, and slightly higher % DIPB/IPB. The catalyst comprising a molecular sieve as produced by the method of the present invention shows dramatically higher activity than an alumina bound conventionally produced MCM-22 extrudate.
The unique properties of the resulting extrudates found from this invention include high surface area, high porosity, high crush strength, high activity, and an intergrown-crystal morphology. The H-form extrudate was tested in an aromatics alkylation unit and showed very encouraging performances for both activity and selectivity. The performance of the catalyst crystals can also be further enhanced by post treatments such as with water, mild acid solution washing, or metal oxide surface modification which are well known performance enhancing methods. | A method of preparing a crystalline molecular sieve is provided, which method comprises (a) providing a reaction mixture comprising at least one source of ions of tetravalent element Y, at least one source of alkali metal hydroxide, water, optionally at least one seed crystal, and optionally at least one source of ions of trivalent element X, said reaction mixture having the following mole composition: Y:X 2 = 10 to infinity OH - :Y = 0.001 to 2 M + :Y = 0.001 to 2 wherein M is an alkali metal and the amount of water is at least sufficient to permit extrusion of said reaction mixture; (b) extruding said reaction mixture to form a pre-formed extrudate; and (c) crystallizing said pre-formed extrudate under vapor phase conditions in a reactor to form said crystalline molecular sieve whereby excess alkali metal hydroxide is removed from the pre-formed extrudate during crystallization. The crystalline molecular sieve product is useful as catalyst in hydrocarbon conversion processes. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an arrangement of at least three holding, centering or knife jaws, lying in a plane, in cutting and/or stripping apparatuses for rod-like or cable-like articles.
It also relates to an arrangement of at least three holding, centering or knife jaws, lying in a plane, in cutting and/or stripping apparatuses for rod-like or cable-like articles, which jaws are each displaceable or pivotable in the direction of a first straight line, and adjacent first straight lines make a first angle with one another. The position of the first straight line is defined by the direction of displacement or by the position of a tangent on the outermost swivel radius of each jaw. In the latter case, the outermost swivel radius is determined by the distance from a center of rotation to that point of each jaw which is farthest away from the said center of rotation.
For the purposes of the present invention, the term line also means a curved line. Such an arrangement is used, for example, for stripping wires.
2. Background Art
Corresponding arrangements are available in a very wide variety of embodiments: German Offenlegungsschrift 2122675 shows four knife jaws, two of which lie in a plane while the other two knife jaws lie in a parallel plane, in each case opposite one another. Hence, a rectangular area is formed between these four knife jaws, the said area being surrounded by blades. This rectangle is enlarged when the opposite knife jaws are pushed apart. By pushing the knives together, the rectangle is made smaller. Furthermore, a control is provided which synchronizes the movement of all four knives so that the rectangle always has sides of equal length. Such knife arrangements have a large variable diameter range and are of a simple design.
A similar arrangement is disclosed in Swiss Patent 651426 (British Patent 2063580). The embodiment is in principle very similar to the embodiment described in the German Offenlegungsschrift, but the cutting line or the contact line of the knife jaws is curved.
The entire content of these publications as well as the content of the publications cited below is to be regarded as part of the disclosure of the present invention.
The French Patent 2282179 describes a knife arrangement having radially guided knives whose cutting line is at an angle of about 45° to the direction of displacement.
As a result of the substantial automation of production lines, there is a constant requirement for increased stability of the knife jaws. It is necessary to take into account in particular the fact that the stripping processes often involve different diameters. The stability of the known knife jaws described above is limited because, even when the cables to be stripped are of different diameters, it is always one and the same part of the knives which bears the load or at least part of the load. For example, it is clear from FIG. 12 of the German Offenlegungsschrift and from FIG. 2 of the Swiss Patent that, even when the knives are pushed together or pulled apart, it is always the middle region of the knives which performs the cutting function. Hence, the middle region is subject to great wear while the edge regions may suffer scarcely any wear. In the case of the French Patent, the same applies to the frontmost tip of the jaws. In the case of holding or centering arrangements, "grinding" of the holding or centering surfaces occurred in a similar manner and after some time had an adverse effect on the precision. This also applies to the arrangement according to U.S. Pat. No. 1,597,460, which arrangement, however, only has two knife jaws and therefore does not permit centering of the cables.
Knife arrangements have also been disclosed, for example in U.S. Pat. No. 3,892,145, which have rotatable knives whose service lives are also longer than those of previously known static knives. A disadvantage, however, is that these knives have only a slightly variable diameter range and furthermore cannot be closed to extremely small diameters, as is the case with conventional arrangements. Furthermore, such knife arrangements require additional sliding bearings and may require expensive rotary drives and have therefore not become established in practice.
German Patent 28 48 445 (U.S. Pat. No. 4,327,609) and, for example, also European Offenlegungsschrift 146 397 disclose arrangements which employ different points but, like some of the constructions mentioned above, lie back to back or in two planes. Consequently, when cutting into a cable, the latter is perforated along its circumference, viewed in the axial direction, along different lines, which can lead to uneven tearing during subsequent stripping; this is particularly the case when the knife blades are provided with a chamfer, as is essential for increasing the stability.
SUMMARY OF THE INVENTION
The object of the invention is to increase several-fold the stability of the jaw arrangement and of the knife blades and that of the surface used.
This object is achieved to a surprisingly great extent by an arrangement wherein the jaws are displaceable or pivotable under positive control in such a way that a certain line of each holding or centering surface or a certain point of each knife blade is assigned to each diameter of an article or can be brought into tangential contact with the article. More particularly, the end points of a line which, when the jaw is viewed, define that surface of the said jaw which can be turned to face the article, define a second straight line, and each second straight line forms a second angle of less than 90 degrees with its associated first straight line, and wherein the line can be brought into tangential contact with the article. Depending on the frequency of diameter changes (different cable diameters) in a jaw arrangement during a working cycle, it is possible, with an arrangement according to the invention, to increase the life of the knives and prolong the unchanged holding properties of the holding or centering jaws by up to two powers of ten compared with the conventional arrangements mentioned. This in turn means less maintenance and hence less susceptibility to faults in combination with very precise cutting and holding or centering by the holding, centering and knife jaws. The greater the number of jaws provided in an arrangement, the greater is the second angle. 90 degrees therefore cannot be reached since in this case the area of engagement can no longer be changed. Zero degrees means that only two jaws are provided, whose second straight line is parallel to the first straight line. In this extreme position, only part of the effect according to the invention would still be achieved but at the same time the centering effect would be lost.
The arrangement of the jaws in a plane ensures, in an outstanding manner, that, for example during stripping of a cable, the latter is cut exactly along a single circumferential line, so that, when the tubular sleeve is stripped off from the cable, it is impossible for different stripping moments--and hence defective tearing--to occur. The blade can be provided with a chamfer on both sides, and fragmentation of the blade is thus prevented (for example in the case of hard metals).
In this disclosure, further advantageous embodiments and possible variations of the invention are described.
In one arrangement, the first angle is determined by the formula 360:n, where n denotes the number of jaws while the second angle is determined by the formula 90 minus one-half the first angle. In another arrangement, the second angle is 30 to 60 degrees, preferable 45 degrees. These arrangements are distinguished by geometric exactness and simple production, all jaws having the same construction.
An arrangement wherein each jaw has a recess for an adjacent jaw permits an extremely wide range from small to large diameters. The change in the cutting or holding diameter when the jaws are adjusted with respect to one another takes place linearly in the case of a linear embodiment and as a function of the curve function in the case of the embodiment having a curved cutting line or holding surface. The arrangement is controlled synchronously for all jaws.
Although U.S. Pat. No. 4,528,741 also describes a possible method for placing the cutting surfaces in a plane (FIG. 7), this is possible only for an arrangement of two knives in accordance with the arrangement shown there. Since in a four-fold arrangement, however, at least the adjacent knives must overlap, there is once again inevitably a slight difference between one side and the other in the embodiment according to the U.S. Patent, even if the distance between the knives is perhaps only a few hundredths of a millimeter. In the case of small cable diameters or firmly adhering or hard or tough insulations, this may be very troublesome and may lead to spoilage.
Advantageous guide mechanisms are disclosed which are of simple and compact design and ensure a play-free and long life of the arrangement, for example, wherein the jaws are controlled by a rotating control means having two-armed levers, via wedge surfaces, the control according to claim 6 corresponding to that according to EP-A 195932, which is herewith completely incorporated by reference. In another advantageous guide mechanism, each jaw is guided in a track and has at least one guide pin which interacts with a control means which may have a disk possessing a spiral control groove or the like for the guide pin.
Life-increasing measures which simultaneously permit rapid tool change and nevertheless permit very precise guidance are measures where the jaws consist of two parts and have a body which carries replaceable holding, centering or cutting plates--preferably of hard metal or sintered material--the jaws carrying retaining pins which interact with diametrically opposed plate holders.
By choosing the position of the knife jaws wherein each knife jaw has at least one ground phase, those phases of each knife jaw which point in the same direction being similar, and one out of two phases of each knife jaw preferably being in the form of a support phase, the positive effect of the invention in providing an exact tear line and clear cutting control along a single circumferential line is reinforced. Consequently, it is possible to cut into soft plastics as well as to cut through, for example, hard wire nettings (shielding) or wires (conductors). The durability of knife blades is increased.
The curvature of the contact line wherein the contact line of the knife jaws curves inward or outward, the radius of curvature (RK) preferably being determined by the formula RK=2.2×RS, in which RS represents the outermost swivel radius or the distance of the outermost point of the jaw from its pivot axle permits a larger outer diameter of the articles to be handled in the case of a concave shape and the simple use of pivotable jaws in the case of a convex shape, so that the said jaws close tightly against one another without overlapping one another.
A self-inhibiting action with spring force prevents independent uncontrolled shiftings of positions which have been selected. This gives a centering or holding arrangement whose tension permits small tolerances at the surface of the articles, the engagement pressure on the surface of the articles always being constant. In most embodiments, oblique abutting surfaces with suitable frictional contact provide the self-inhibiting effect.
An apparatus according to EP-A-195932, which likewise discloses a self-inhibiting effect, serves as an example of a possible application of the invention.
At least two groups of jaws may be provided, each of which lie in a plane and are parallel to the others and may be arranged so that they are displaceable in the axial direction of the articles. This permits multi-stage stripping in a single operation. This arrangement can also be used in fully automatic operation.
Although the invention is described in particular with reference to stripping apparatuses, it may also be used for many other holding or cutting tasks. Such applications are thus also embraced by the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in more detail with reference to the sketches, by way of example.
FIG. 1 shows a plan view of an arrangement having four holding jaws and a control means in the open state,
FIG. 2 shows the same arrangement in the closed state,
FIG. 3 shows an arrangement having three holding jaws in the open state,
FIG. 4 shows another arrangement having five holding jaws in the closed state,
FIG. 5 shows another arrangement having three holding jaws which do not make positive contact with one another,
FIG. 6 shows an arrangement of cutting jaws in the entirely open state,
FIG. 7 shows the same arrangement closed,
FIG. 8 shows an arrangement having pivotable cutting jaws in the closed state,
FIG. 9 shows the same arrangement open,
FIG. 10 shows another variant having a curved contact line, in the half-open state,
FIG. 11 shows knife and holding jaws mounted one behind the other, in the open state, partially cut away and concealed,
FIG. 12 shows a cross-section along the line XII--XII from FIG. 11,
FIG. 13 shows a cross-section along the line XIII--XIII from FIG. 11,
FIG. 14 shows a cross-section through a detail of FIG. 13 along the line XIV--XIV,
FIG. 15 and 16 show a knife jaw having replaceable cutting plates, as a side view and elevation, respectively,
FIG. 17 shows a combination of holding jaws and knife jaws forming a holding and cutting arrangement, in partially concealed and cut away form, and
FIG. 18 shows a corresponding part according to the prior art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The Figures are described in relation to one another. Identical reference symbols denote the same or similar parts. In the case of identical reference symbols, different indices indicate different embodiments or identical components in an assembly.
The embodiment according to FIG. 1 and 2 shows an open and closed arrangement of four holding jaws 18a-d, each of which can be displaced longitudinally along dash-dot straight lines 1a-d. The holding jaws 18a-d each have recesses 9a, so that they can engage one another. They each have a contact line 5a-d, on which a rod-shaped article 22 can be held when the holding jaws are in the open state. In FIG. 2, the holding jaws 18a-d are completely closed, i.e. they are lowered into associated recesses 9a, and the area circumscribed by the contact lines 5a-d is zero.
The contact line of the holding jaws 18a-d is a straight line and extends along a second straight line 2a-d shown as a dash-dot line in the drawing. Each second line 2a-d forms an angle 4a of 45 degrees with the associated first straight lines 1a-d. Adjacent first straight lines 1a-d form an angle 3a of 90 degrees with one another, and the first straight lines 1a-d of non-adjacent holding jaws form an angle of 180 degrees with one another.
Opening of the holding jaws 18a-d is shown stepwise in the sequence in FIG. 1-2. It occurs as a result of synchronous pulling apart of the holding jaws 18a-d, with the result that an area which can be increased continuously occurs between the contact lines 5a-d. Within this area, it is thus possible to hold an article 22a which, for example, may be elongated and may pass through the plane of the drawing.
To permit them to be pulled apart, the holding jaws slide in tracks 10 of a guide plate 23. Guide pins 11 indicated by a dashed line are rigidly connected to the holding jaws 18a-d. These guide pins 11 engage spiral control grooves 14 (likewise indicated by a dashed line), which are formed in a disk 13. The disk 13 having the control grooves 14 thus forms a control means 12a which pulls the holding jaws 18a-d apart when rotated about its own axis in one direction but pushes the holding jaws together when rotated in the other direction. As a result, the guide pins 11 slide on the inclined sliding surface of the control grooves 14 with a certain friction, so that a self-inhibiting effect against unintentional displacement occurs at a certain angle of inclination.
The disk 13 is rotatably mounted on the guide plate 23 in a manner not shown and is connected to the said plate via a tension spring 21. The tension spring 21 exerts a force on the control means 12a in that rotary direction of the disk 13 which causes the holding jaws 18a-d to close.
Thus, if the disk 13 is rotated randomly in the opening direction of the jaws 18a-d, as shown, for example, in FIG. 1, and an article 22a is then clamped between the contact lines 5a-d and the disk 13 is released again, the holding jaws 18a-d close under the pressure of the spring 21. Assuming uniformity of the spring force, a uniform contact pressure is thus exerted at the surface of the article 22, regardless of its diameter. A strong contact pressure which could damage the article 22 is thus avoided.
If the article 22a (as in many cases) has a circular periphery, the contact line 5a-d rests on the surface of the article 22 only in a very small, linear region 24a-d. As can be seen from the two FIGS. 1 and 2, this region 24a-d is always at a different point of the contact line 5a-d of the holding jaws 18. In FIG. 2, the region 24a-d is located theoretically entirely at the beginning of each contact line 5a-d. Because this region 24a-d moves outward, wear at the surface of the holding jaws 18a-d is also distributed over a wide region, so that it is scarcely possible for pronounced wear to occur at a single point--assuming an average change in the holding diameter.
FIG. 10 shows a similar arrangement but with a curved contact line 5m-p and with holding jaws 18m-p. The starting and end points of each contact line 5m-p can be connected by means of a straight line, which in turn lies along the second straight line 2a-d described above.
As a result of the curvature of the contact line, the displacement of a region 24m-p for contact with an article 22b is not optimal, but it is possible, with otherwise identical dimensions of the holding jaws 18m-p, to hold larger diameters of the articles 22b (cf. FIG. 1, 18a-d and 22a).
FIG. 6 and 7 show schematic knife jaws 7a-d which in principle are similar to the holding jaws 18a-d described above. It is of course also possible for the knife jaws 7a-d to have a curved contact line or cutting line. The contact lines or cutting lines are denoted by 5e-h. In the case of the contact lines 5e-h of the knife jaws 7a-d, a displacement of the region 24e-h of contact with an article 22c during cutting is readily recognizable. If the blades of the knife jaws 7a-d penetrate into the surface of the article 22c, the region 24f-24f' is automatically displaced toward the edge (dashed line in FIG. 6). In this case too, wear of the knife blade or contact line 5e-h is distributed uniformly over a certain length. By means of such knife jaws 7a-d, it is therefore possible to strip or cut, for example, very thin wires in an advantageous manner.
In order to meet very high requirements, it is also envisaged that knife jaws 7i (FIG. 15, 16) will be equipped with hard metal cutting plates 16f. The knife jaws 7i are in this case provided with a body 15b which has two retaining pins 19 which engage recesses 20 in the cutting plates 16f. The cutting plates 16f are screwed to the body 15b by means of a screw 25. The retaining pins 19 ensure play-free positioning of the cutting plates 16f. The cutting plates 16f are in the form of indexable inserts and therefore have two contact lines 5i and 5k, the contact line 5i or the knife blade of this side first coming into use. If the cutting plate 16f is worn along its contact line 5, it can very simply and rapidly be raised by loosening the screw 25, reversed and fastened again. As a result, the contact line 5k is then used for cutting.
For this purpose, it is necessary for the retaining pins 19 to be arranged as a mirror image about screw 25.
FIG. 3 to 5 likewise show two divided jaws (holding jaws 18e-g (FIG. 3) and 18h-l (FIG. 4), and cutting jaws 7e-g (FIG. 5)), each of which are also divided into two parts and have a body 15a (FIG. 3 and 5) and 15c (FIG. 4). The difference between the bodies 15a and 15c is that body 15c has a flat area 26 (FIG. 4). The flat area 26 allows the five jaws 18h-l of the embodiment according to FIG. 4 to come into contact with one another without overlapping one another.
All variants are in any case based on the same principle, which therefore need not be discussed in detail. It is merely necessary to mention that the replaceable holding jaws in FIG. 3 are denoted by 16a and those in FIG. 4 by 16b.
FIG. 5 shows replaceable cutting plates 16c which--as described further above--are fastened to the bodies 15a. In all variants shown, with the exception of FIG. 5, the holding jaws 18 or cutting jaws 7 always come into contact with one another. The example of FIG. 5, however, shows that this closed contact is not absolutely essential for the purposes of the invention in order to obtain acceptable cutting or holding properties. However, one of the advantages of this arrangement is that a relatively small number of components are provided, and the said components may therefore be of uncomplicated design. Moreover, the geometric dimensions of the indexable inserts 16c are such that they can also be intended for an arrangement having six cutting jaws 7.
An arrangement of this type is not shown but can easily be imagined by rotating the cutting jaws 7e-g shown through 60 degrees to the right and placing them over the drawing shown. As a result, the spaces between the cutting jaws 7e-g are filled with similar cutting jaws.
The innermost point is the cutting line 51-n, as shown for cutting jaw 7e, advantageously supported both to the left and to the right by the same amount of material of the indexable insert 16c. This is necessary for turning the indexable insert but is also expedient for transmission of force from the body 15a to the cutting line 51-n. A connecting line between the outermost point and the screw 25 makes a right angle with the first straight line 1e-g.
The Figures show three to five holding or knife jaws. Of course, there is in theory no limit to the number of these jaws but, for example, an arrangement having only two jaws is disadvantageous in that an article to be cut is not guided on a plurality of sides and can therefore leave the two jaws laterally. Arrangements having more than six jaws are in practice certainly somewhat more complicated to produce and can be produced, for example, only by a punching process. However, if it were impossible to guarantee extremely high precision, the entire arrangement might easily jam and no longer function.
The system of knife jaws 7m-p according to FIG. 8 and 9 differs in principle from the previously described embodiments. The guidance of the knife jaws 7m-p differs. The jaws 7m-p are each pivotable about an axis 29. The guide or cutting lines 5r-u have a convex curvature of radius RK, the radius of this curvature being obtained from 2.2 times the value of the outermost swivel radius RS of the individual knife jaws 7m-p, which in turn is defined by the distance between the individual axes 29 and that point of the associated contact or cutting line 5r-u which is furthest away from the relevant axis. The middle point of the radius of curvature RK is located on a dash-dot line 33, which is located at a distance of 1.55×RS from the associated axis 29. This type of cutting jaw 7m-p can be produced at less expense than the displaceable jaws (for example, track guides or the like are dispensed with); however, control, for example in the case of rotating jaws, entails somewhat greater expense.
FIG. 11 shows the assembly of an arrangement having knife jaws 7e-h and of holding jaws 18o-r. This Figure does not show the control in detail, but the guide pins are formed on two-armed levers 31, 32 and each engage between two extensions 34 of the knife or holding jaw (cf. FIG. 13).
The holding jaws 18a-d hold or center an article in the field of operation. The knife jaws 7e-h cut the article in the position according to FIG. 11 to a pronounced extent. FIG. 12 shows this situation in section, along the line XII--XII. The blades 5e-h of the knife jaws 7a-d are exactly opposite one another, so that, for example during stripping of the article, identical tensile forces occur (cf. FIG. 17). FIG. 18 shows, in comparison, a conventional knife jaw arrangement (70a, b) whose blades are opposite one another at a distance x apart.
In order to describe the support phase 8b according to FIG. 17, it should furthermore be mentioned that an embodiment of this type is advantageous in particular for cutting plates of sintered material, in order to avoid fragmentation of the latter. Thus, it is also very easy, for example, to shield the article 22e with sheet metal without greatly reducing the life of the cutting plates.
Furthermore, FIG. 12 shows the guide plate 23 and the body 15a for the holding jaws 18p and 18r and for the knife jaws 7a and 7c. The blades of the knife jaws 7a-d are provided with a phase 8a.
FIG. 13 shows the control means 12b for the arrangement of the jaws in section. The two-armed levers 31 and 32 are each mounted in a holder 36 by means of a pivot axle 35. The levers 31 engage the holding jaws 18u-r, while the levers 32 engage the cutting jaws 7a-d. Control is effected via wedge surfaces 27 and 28 for the levers 31 and 32, respectively, whose displacement is controlled by a slide rod 38. The levers 31 are subjected to the force of a spring 21b. Instead of using a spring 21b, control of the levers 31 could also be effected by means of constraining grooves or joints, so that the levers 31 are under spring-free positive control both in one direction and the other.
The wedge surface 27 together with the associated levers 31 form a self-inhibiting system, so that increased pressure exerted by the holding jaws 18o-r on the levers 31 cannot cause the wedge surfaces 27 to be pushed back against the spring 21b. Hence, an uncontrolled alteration of the predetermined and set distances of the holding jaws 18u-r from one another is not possible. The wedge surfaces 28 are in contact with a slide rod 38 which is guided with the spring 21b in a bush-like holding part 39. For a detailed description of the mechanics of this control means 12b, reference may be made to EP-A-195932.
Details of the wedge control through section XIV--XIV of FIG. 13 are more clearly evident from FIG. 14.
The invention is not restricted by the Figures shown and the description of these Figures. Instead, it would also be possible, for example, for the angles of inclination of the contact lines to vary and, if necessary, for toothed surfaces to be provided, in particular in the case of holding jaws or centering jaws. | The invention relates to an arrangement of a plurality of holding, centering or knife jaws (7, 18) for cutting and/or stripping apparatuses for rod-like or cable-like articles (22). The jaws (7, 18) are each displaceable or pivotable in a certain direction. The end points of a line (5) which, when the jaw (7, 18) is viewed, is turned to face the article (22) define a straight line (2). The angle between the particular direction of each jaw (7, 18) and this straight line (2) is less than 90 degrees. This results in constantly changing contact points for changing diameters of the articles (22), and distributed wear of the jaws (7, 18). |
FIELD OF THE INVENTION
The present invention relates to a heat dissipation device with two heat sinks for electronics particularly a heat dissipation device having a bracket to fix and interconnect the two heat sinks.
DESCRIPTION OF RELATED ART
With the continued development of computer technology, electronic packages such as computer central processing units (CPUs) are generating more and more heat that needs to be dissipated immediately to avoid damage to the circuitry. Conventional heat dissipating devices such as heat sinks mounted onto the CPU are not sufficiently effective at dissipating heat to cope with modern circuitry. New heat dissipation devices featuring twin heat sinks are increasingly being used to enhance efficiency of these electronic packages. US Publication No. 2003/0183373 A1 shows an example of this kind of heat dissipation device. The heat dissipation device includes a first heat sink, a second heat sink and a heat pipe conducting heat from the first heat sink to the second heat sink. However, this type of the heat dissipation device is not sturdy. The two heat sinks only interconnect via the heat pipe. When an external force acts on heat dissipation device, the heat pipe is likely to deform, thereby reducing the heat transfer performance of the heat pipe and thus also reducing the heat dissipating efficiency of the whole heat dissipation device.
SUMMARY OF INVENTION
According to a preferred embodiment of the present invention, a heat dissipation device comprises a first heat sink, a second heat sink and a heat pipe transferring heat from the first heat sink to the second heat sink. A bracket includes a first end attached to the first heat sink and a second end attached to the second heat sink, thus enhancing the strength and stability of the heat dissipation device.
Other advantages and novel features of the present invention will become more apparent from the following detailed description of the preferred embodiment when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an assembled view of a heat dissipation device according to a preferred embodiment of the present invention; and
FIG. 2 is an exploded, isometric view of FIG. 1 .
DETAILED DESCRIPTION
Referring to FIGS. 1-2 , a heat dissipation device 10 in accordance with a preferred embodiment of the present invention is illustrated. The heat dissipation device 10 mainly comprises a first heat sink 20 , a second heat sink 30 and a heat pipe 40 conducting heat from the first heat sink 20 to the second heat sink 30 . A bracket 50 connects the first heat sink 20 , the heat pipe 40 and the second heat sink 30 , so as to reinforce the whole structure of the heat dissipation device 10 .
The first heat sink 20 comprises a base 22 , two spaced groups of fins 24 extending upwardly from the base 22 and a separating member 28 mounted between the two groups of fins 24 . A connection area 26 of the base 22 is formed between the two groups of fins 24 . A groove 260 is defined in the connection area 26 of the base 22 for receiving an evaporating portion 42 of the heat pipe 40 . The separating member 28 is mounted on the connection area 26 of the first heat sink 20 . The separating member 28 comprises a base 282 parallel to the base 22 and a plurality of fins 284 extending upwardly from the base 282 thereof. Each of the fins 284 is parallel to each of the fins 24 of the first heat sink 20 . The base 282 of the separating member 28 has a same length as the base 22 of the first heat sink 20 along a lateral direction. A length of the fins 284 is shorter than that of the base 282 such that a mating area 281 is formed at a top edge of the base 282 . A pair of threaded holes 283 is defined in the mating area 281 of the base 282 . A groove 280 corresponding to the groove 260 is defined in a bottom of the base 282 . The groove 280 and the groove 260 cooperatively form a channel for receiving the evaporating portion 42 of the heat pipe 40 .
The second heat sink 30 comprises a plurality of fins 34 spaced from and snapped (i.e. connected) with each other. The fins 34 are perpendicular to the base 22 of the first heat sink 20 . A through hole 340 is defined in the fins 34 for receiving a condensing portion 44 of the heat pipe 40 .
The bracket 50 is made from any high strength material such as metal, metal alloy, plastic or any other suitable material. The bracket 50 comprises two free ends 51 , 52 and a connecting arm 53 . The free end 51 parallel to the base 22 of the first heat sink 20 is mounted on the mating area 281 of the separating member 28 of the first heat sink 20 and the free end 52 parallel to the fins 34 of the second heat sink 30 is mounted on the second heat sink 30 . The free end 51 defines a pair of mounting holes 513 corresponding to the threaded holes 283 of the mating area 281 of the first heat sink 20 . The free end 52 is substantially perpendicular to the free end 51 , and defines a through hole 520 therein. The through hole 520 has an annular sidewall 522 extending perpendicularly from an edge thereof. The connecting arm 53 has a bend 530 at a substantially central portion thereof.
In assembly, the grooves 280 , 260 , the connection area 26 , an inner surface of the through hole 340 and the sidewall 522 are coated with solder. The evaporating portion 42 of the heat pipe 40 is soldered into the channel of the first heat sink 20 formed by the grooves 260 , 280 . The free end 52 of the bracket 50 abuts against a lateral side of an outmost fin 34 of the second heat sink 30 near the first heat sink 20 and the through hole 520 of the bracket 50 is aligned with the through hole 340 of the second heat sink 30 . The condensing portion 44 of the heat pipe 40 is brought to extend in the through holes 340 , 520 and is soldered therein so that the second heat sink 30 and the bracket 50 are connected together via the condensing portion 44 of the heat pipe 40 soldered to the free end 52 of the bracket 50 and the fins 34 . The free end 51 of the bracket 50 is positioned on the mating area 281 of the separating member 28 of the first heat sink 20 . A pair of screws 54 extends through the mounting holes 513 of the bracket 50 and screw into the threaded holes 283 of the first heat sink 20 . Thus the first heat sink 20 and the second heat sink 30 are immovably connected together. In a further preferred embodiment, the free end 52 is also soldered to the lateral side of the outmost fin 34 of the second heat sink 30 .
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A heat dissipation device ( 10) includes a first heat sink ( 20), a second heat sink ( 30) and a heat pipe ( 40) transferring heat from the first heat sink to the second heat sink. A bracket ( 50) includes a first end ( 51) attached to the first heat sink and a second end ( 52) attached to the second heat sink. |
BACKGROUND
[0001] The present disclosure relates to rotary electric machines such as electric motors or generators, particularly of the polyphase type, and, more particularly, to apparatuses and methods for manufacturing multiple-pole stators used therein.
[0002] Rotary electric machines operate by exploiting the interaction of rotating magnetic fields with a rotor carrying magnets, the rotor disposed within and rotatable relative to a stator. The rotor is typically fixed to a shaft mounted for rotation centrally by means of bearings in a casing that surrounds the stator. These machines include armatures or a configuration of insulated wire coils in the stator, which are distributed about the stator central axis, the coils arranged in a progressive sequence to define the different phases. The stator coil windings are typically wound around ferromagnetic poles of the stator to enhance the strength of the generated magnetic field. The poles generally are tooth-like cross sections that are usually rectangular or trapezoidal, and typically defined by longitudinal slots in the stator core.
[0003] In a polyphase electric motor, flowing current of different phases through a progressive sequence of wire coils in the stator generates rotating magnetic fields in the stator, which impart electromechanical torque to the rotor and its shaft. Conversely, in a polyphase electric generator, externally forced rotation of the shaft and rotor imparts rotation to magnetic fields that induce current flows in the stator coils.
[0004] As is well-known in the relevant art, the stator may have a stator core defined by a stack of interlocked, ferrous laminae each having a hole, the holes being aligned in the lamina stack to form a stator core central bore. Thus, the stator core may be a unitary annular member, its central bore defining a stator core radially internal face that is typically cylindrical and centered about a stator central axis. The radially internal face is typically provided with a plurality of generally axially extending elongate slots formed by aligned, notched portions of the laminae holes. The stator slots pass axially through the lamina stack adjacent the central bore since they extend over the entire axial length of the lamina stack and are open radially on an internal side and the two opposite axial ends. The stator slots extend between the axially opposite ends of the stator core and define the stator poles. The slots formed by the lamina stack may lie in planes that intersect along and contain the stator central axis, but are sometimes inclined with respect to that axis. It may nevertheless be said that the stator core slots are generally parallel with the stator central axis. The plurality of stator slots is typically distributed at an even pitch about the stator central axis. Relative to the stator, radial and axial directions mentioned herein are respective to the stator central axis, and the stator slots generally extend radially outwardly from and axially along the stator central axis.
[0005] Disposed in and extending along these stator slots are elongate electrical conductors that define the stator coil windings. By virtue of the conductors being routed through the stator slots, they are wrapped about the stator poles. Typically, a stator slot insulator insert is interposed between the conductors and the edges of the stator slots to ensure electrical isolation of the stator coil from the stator core. The insulator insert is inserted into the slot before a conductor is installed therein.
[0006] In a polyphase rotary electric machine, the stator coil windings include a plurality of (typically three) different phase windings each consisting of a continuous, elongate electrical conductor, such as a wire or bar. The conductor may, for example, be made from copper covered with an insulator such as enamel. Alternatively, each phase winding may include an interconnected plurality of such conductors. Conventional wire sizes may be used for the conductors of the wire coils. Optionally, thick bar conductors can be used for making a wire coil with a designed current-carrying capacity requiring fewer turns than is possible with smaller size wire. The conductor cross-section is typically circular or rectangular (including square).
[0007] The stator slots may have a radial depth that is a multiple of the cross-sectional dimension of the conductor in the slot's radial direction. In an example three-phase stator, two electrical conductor lengths may be housed within each of the stator slots so as to line up in one row in a radial direction. The electrical conductors are arranged in a predetermined winding pattern to form the stator winding. The particular winding patterns of stator windings may vary considerably between different machine designs, and are generally beyond the scope of the present disclosure.
[0008] Thus, a stator assembly includes a stator core, a stator winding constituted by a number of electrical conductors disposed inside slots formed in the stator core, and inserted insulators providing electrical insulation between the stator core and the electrical conductors.
[0009] For example, in a three-phase machine having eighty-four stator slots, there are three slot groups, one for each phase, each having twenty-eight slots in which are disposed the conductors of a single current phase. The twenty-eight slots of each slot group or current phase, may be distributed about the stator central axis in, for example, seven equal sets of four circumferentially adjacent slots. Such is a typical example that would be well-understood by one of ordinary skill in the relevant art. Further, each of the three phase windings may consist of a single formed conductor, or an interconnected plurality of formed conductors.
[0010] Prior to their installation, the stator winding conductors are formed by bending lengths of the elongate conductors into shapes defining elongate straight portions, herein also referred to as conductor axial branches, that are installed into the stator slots. The axial branches of a conductor are serially connected by relatively shorter head branches, which are conductor portions that generally extend tangentially relative to the stator bore. Depending on its number of axial branches, a formed conductor's pair of connection segments may have more than one head branch disposed therebetween. The head branches typically lie outside of the stator slots, and outside of the stator bore, at one or both axial ends of the stator core. These undulating conductors are thus said to be of the “S-type” and “wave-wound” about the stator poles.
[0011] The longitudinal ends of each formed conductor are commonly referred to as its connection segments, and are each typically located at a longitudinal end of an axial branch opposite a connected head branch, at an axial end of the stator core, and preferably at a common stator core axial end. Locating the connection segments of a stator winding at a common axial end of the stator core facilitates their being quickly and easily interconnected. The connection segments of a plurality of conductors in the same phase winding may be interconnected prior, or subsequent, to the stator winding conductors being installed in the stator slots. The interconnection of the connection segments of a phase winding may be done directly, such as through a suitable joining process, for example by soldering or a crimped connector; or indirectly such as through a buss bar assembly. Interconnection of conductors via a buss bar assembly is done subsequent to the installation of the windings into the stator core.
[0012] The stator core slot openings may have a circumferential width corresponding to the circumferential width of the conductor wire; the opening may have a circumferential width substantially equal to the corresponding cross-sectional dimension of the conductor. Retention of the coil windings in the stator core may be done by deforming the axial branch occupying the radially innermost position to broaden it in a circumferential direction, relative to the stator central axis, at a plurality of discrete locations axially therealong. The deformation of the conductor compresses it against the opposite sides of its stator slot and holds it, and conductor axial branches occupying the other positions, inside the stator slot. Alternatively, once the coil windings have been inserted into the stator slots, insulating covers may be installed over the stator slots to mechanically retain the conductors in position. Alternatively, or additionally, an insulating resin is applied to the assembly of the stator core and the installed windings to connect the conductors together, and to fix the conductors to and insulate them from the stator core.
[0013] Insertion of the stator coil windings into the stator core slots may be from a cylindrical magazine, also referred to in the art as a slotted bobbin or dummy rotor, onto which the conductors have been loaded, and which is insertable into the bore of the stator core. Such a magazine, while outside of the stator bore, is loaded with the conductors of the stator windings in an arrangement corresponding to, e.g., generally radially reversed relative to, their desired configurations in the resulting stator. The conductors loaded onto the magazine may be partially or fully preformed as described above, or may be formed on the magazine, which serves as a mandrel as well as a carrier of the formed conductors and an aid to their insertion into the stator core slots. Such magazines are well known in the art; they typically include a cylindrical part having a radially external surface in which is provided a plurality of radial recesses extending in respective radial planes equiangularly distributed around the central axis of the magazine. The magazine recesses also extend between the axially opposite ends of the generally cylindrical magazine. The radial recesses in the magazine are equal in number to the number of slots in the stator.
[0014] The magazine, once loaded with formed conductors arranged in a desired winding pattern, has an insertion mode in which the magazine has been disposed within the cylindrical stator core bore, with the magazine recesses aligned with the stator slots in the surrounding, radially inner cylindrical surface of the stator core bore. The radial disposition of the conductor axial branches carried by the magazine recesses, correspond to their radial disposition in the resulting stator assembly. Thus, relative to the magazine, the magazine-to-stator core conductor transference may be described as being according to a last-in-first-out or LIFO system. The magazine has radial blade members moveably disposed in the magazine recesses. The blade members are used to push the arranged, preformed conductors carried by the magazine radially outwardly from the recesses, away from the magazine central axis and towards the stator core bore, and press the axial branches into the stator slots.
[0015] A known magazine, winding installation method, and apparatus suitable for insertion of windings into stator slots are described in U.S. Pat. No. 2,873,514, issued Feb. 17, 1959, the disclosure of which is incorporated herein by reference.
[0016] Methods and apparatuses that streamline prior stator assembly processes and facilitate greater speed and efficiency thereof would be desirable advancements in the relevant art.
SUMMARY
[0017] A method and apparatus according to the present disclosure provides such an advancement.
[0018] In accordance with the present disclosure, the stator coil conductors are placed into slots located on the outer perimeter of a circular rack. The placed conductors may first be preformed, or shaped on a mandrel, and subsequently transferred to the circular rack. Alternatively, unformed conductors may be placed into the slots of the circular rack, and formed thereon; that is, in some embodiments the rack may itself serve as a mandrel.
[0019] The shaped conductors, positioned relative to each other in the slots of the circular rack in a pattern that corresponds to their desired arrangement in a resultant stator assembly, are subsequently transferred from the rack to a generally cylindrical magazine of the type described above. Relative to the circular rack, the magazine has a load mode in which conductor transference therebetween occurs. The loaded magazine is receivable into the central bore of a stator core for transference of the formed conductors carried by the magazine to the stator core slots as described above, in a magazine installation mode.
[0020] The apparatus and method disclosed herein may be adapted to the manufacture of stator assemblies having any number of stator core slots, and to stator coils having any number of phases and winding patterns.
[0021] The present disclosure provides an apparatus for installing an elongate conductor having a plurality of axial branches into stator core slots that extend outwardly into the cylindrical surface of a stator core bore. The apparatus includes a magazine having a central axis and a radially outer cylindrical surface disposed thereabout, the magazine provided with a plurality of recesses that extend inwardly of the cylindrical surface towards the central axis. The apparatus also includes a circular rack having a radially outer periphery provided with a plurality of rack slots, the magazine and circular rack each capable of carrying at least one conductor intended for installation into a plurality of stator core slots. The magazine has an installation mode in which a stator core coaxially surrounds the magazine, there is concurrent radial alignment between each of a plurality of pairs of magazine recesses and stator core slots, and at least one conductor axial branch is receivable by a stator core slot from a respectively paired magazine recess. The magazine also has a load mode in which the circular rack and the magazine have synchronized rotative movements, corresponding pairs magazine recesses and rack slots are sequentially aligned, and at least one conductor axial branch is receivable by a magazine recess from its aligned rack slot.
[0022] A further aspect of this disclosure is that the magazine also includes at least one blade member defining within each respective recess a floor movable substantially radially relative to the cylindrical surface. A conductor axial branch receivable into a stator core slot in the magazine installation mode is urged radially away from the magazine central axis and into the stator slot by the blade member in the magazine installation mode.
[0023] A further aspect of this disclosure is that the magazine recesses and the rack slots have substantially identical circumferential widths.
[0024] A further aspect of this disclosure is that circumferentially adjacent magazine recesses and rack slots are respectively spaced circumferentially at substantially identical distances.
[0025] A further aspect of this disclosure is that the circular rack has an axis of rotation, the rack axis of rotation and magazine central axis substantially parallel in the magazine load mode.
[0026] A further aspect of this disclosure is that the circular rack has an axis of rotation, adjacent rack slots extend in substantially parallel slot directions relative to each other, and the rack axis of rotation and each slot direction are oriented in different directions.
[0027] A further aspect of this disclosure is that, in the magazine load mode, the circular rack perimeter and the magazine cylindrical surface interface through a transfer plane tangential to the circular rack perimeter and the magazine cylindrical surface, and each conductor axial branch receivable by a magazine recess from its aligned rack slot is transferrable from the circular rack to the magazine through the transfer plane.
[0028] A further aspect of this disclosure is that the circular rack perimeter is concentric with a rack axis of rotation, and the transfer plane is parallel with the rack axis of rotation and the magazine central axis.
[0029] A further aspect of this disclosure is that the apparatus also includes a ramp surface axially adjacent the circular rack perimeter and facing towards the magazine cylindrical surface in the magazine load mode. The ramp surface is capable of being slidably engaged by conductors carried by the circular rack. The axial branch of a conductor slidably engagable with the ramp surface is urged by the ramp surface from a rack slot into its aligned magazine recess in response to rotative movements of the circular rack in the magazine load mode.
[0030] A further aspect of this disclosure is that the number of rack slots is an integer-multiple of the number of magazine recesses.
[0031] A further aspect of this disclosure is that, in the magazine load mode, a full complement of conductors for a stator assembly is receivable from the circular rack by the recesses of a magazine through a 360° rotation of the magazine about its central axis.
[0032] A further aspect of this disclosure is that the apparatus includes a plurality of magazines circumferentially disposed about the circular rack perimeter in the magazine load mode.
[0033] A further aspect of this disclosure is that the plurality of magazines is simultaneously receivable of conductors from the circular rack in the magazine load mode.
[0034] A further aspect of this disclosure is that the plurality of magazines is simultaneously disposed in respective stator core bores in the magazine installation mode.
[0035] The present disclosure also provides a method for loading an elongate conductor onto a magazine for subsequent installation into stator core slots, including: carrying at least one elongate conductor in a plurality of rack slots provided on the radially outer periphery of a circular rack; rotating the circular rack and a cylindrical surface of a magazine positioned adjacent the circular rack periphery relative to each other in synchronicity; sequentially aligning the rack slots with the respectively paired ones of a plurality of magazine recesses provided in the cylindrical magazine surface during their synchronous relative rotation; and urging an axial branch of the elongate conductor radially outwardly from a rack slot and into the respectively paired magazine recess aligned therewith, whereby the conductor is transferred between the relatively rotating circular rack and the magazine portion-by-portion during sequential alignments of their respectively paired rack slots and magazine recesses.
[0036] A further aspect of this disclosure is that the cylindrical magazine surface is selectively positioned adjacent the circular rack periphery in a magazine load mode, and that the method further includes carrying the elongate conductor in the plurality of magazine recesses during transition from the magazine load mode to a magazine installation mode in which the elongate conductor is transferred from the magazine to slots of a stator core surroundingly disposed about the magazine.
[0037] A further aspect of this disclosure is that the method includes: slidably engaging the conductor carried by the circular rack against a ramped surface; and displacing from a rack slot and receiving into the magazine recess aligned with the rack slot, the conductor as the conductor slides against the ramped surface.
[0038] A further aspect of this disclosure is that the step of rotating includes rotating the circular rack and cylindrical magazine surface about parallel axes.
[0039] A further aspect of this disclosure is that the step of slidably engaging the conductor carried by the circular rack against a ramped surface includes slidably engaging a conductor axial branch against ramped surfaces disposed on opposite axial sides of the circular rack.
[0040] A further aspect of this disclosure is that the method includes tamping portions of the conductor transferred to the magazine recesses radially inwardly.
[0041] A further aspect of this disclosure is that the method includes forming the conductor carried by the circular rack prior to disposing the conductor into rack slots.
[0042] A further aspect of this disclosure is that the method includes forming the conductor carried by the circular rack subsequent to disposing the conductor into rack slots.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The above-mentioned aspects and other characteristics and advantages of an apparatus and/or method according to the present disclosure will become more apparent and will be better understood by reference to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, wherein:
[0044] FIG. 1 is a planar projection of portions of an S-style stator winding conductor disposable on a circular rack according to the present disclosure;
[0045] FIG. 2 is a fragmented, partial, perspective view of an apparatus according to one embodiment of the present disclosure;
[0046] FIG. 3 is another fragmented, partial, perspective view of the apparatus of FIG. 2 ;
[0047] FIG. 4 is a partial plan view of an alternative embodiment of the apparatus in the magazine load mode, the circular rack periphery portion shown as a planar projection;
[0048] FIG. 5 is an enlarged view of encircled portion 5 of FIG. 4 ; and
[0049] FIG. 6 is a further enlarged view of FIG. 5 , showing transference of conductor axial branches from the circular rack slots to the magazine recesses as the circular rack and magazine synchronously rotate.
[0050] Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the disclosed apparatus and method, the drawings are not necessarily to scale or to the same scale and certain features may be exaggerated or omitted in order to better illustrate and explain the present disclosure. Moreover, in accompanying drawings that show sectional views, cross-hatching of various sectional elements may have been omitted for clarity. It is to be understood that this omission of cross-hatching is for the purpose of clarity in illustration only.
DETAILED DESCRIPTION
[0051] The following description is set forth in the context of the manufacture of polyphase, multiple-pole stators for rotary electric machines. The embodiments described below are not intended to be exhaustive or to limit the present disclosure to the precise forms or steps disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.
[0052] An example stator assembly resulting from an assembly process facilitated by and according to the apparatus and method hereby disclosed is substantially as described above, and may be intended for use in a three phase rotary electric machine. It has a number of slots arranged about the stator central axis, with each of the stator slots associated with one of the three current phases. This association progressively repeats itself in sequence around the radially inner face of the cylindrical stator core bore. The stator core is formed of a cylindrical lamina stack having an axial axis of symmetry and axial slots formed in the radially internal face of the lamina stack. The slots are separated from one another by the stator poles. Thus, intercalated sequences of slots are associated with the first, second and third current phases.
[0053] The stator poles are suitably designed to accommodate insertion of thick bar conductors in the stator slots, the stator slot opening widths being about the same as the general widths of the stator slots over their entire radial depths. These enlarged slot opening widths allow unrestricted insertion of the conductors into the stator slots. The longitudinal slot passages in the stator core may be generally U-shaped with approximately parallel pole sides. Insulation inserts may line the walls of the stator slots to electrically isolate the conductors inserted therein. These inserts may be made, for example, from plastic sheeting.
[0054] The stator slots have a circumferential width that is substantially equivalent to the corresponding, circumferentially extending cross-sectional dimension of the conductor to be inserted therein, plus a clearance of, for example, from about 0.4 to 1.0 mm. The stator slots can have a radial depth into the cylindrical wall of the stator core bore that is a multiple of the corresponding, radially extending cross-sectional dimension of the insertable conductor. The dimensions chosen for the stator slots result in the axial branches of the conductors coming to be stored in several well-ordered radial alignments in the stator slots.
[0055] Long, insulated copper wire material having a rectangular cross section, for example, may be used for the stator coil windings, and there may be two conductor axial branches disposed in each stator slot. In other words, two lengths of wire are disposed to line up in one row in a radial direction within each stator core slot, with the rectangular conductor cross-sections aligned in a radial direction. The connection segments of different conductors of the same electrical phase are interconnected to form one of the phase windings, and the interconnections may be done prior to or subsequent to the insertion of the conductors into the stator slots. A conductor 20 intended for installation into a plurality of stator core slots may be formed into an S-style configuration having parallel axial branches 22 , each conductor corresponding to a current phase and wound or connected in series in a “wave configuration” with the elongate axial branch portions running in the stator slots of the sequence associated with a particular current phase. FIG. 1 shows a planar projection of a portion of such a conductor.
[0056] Conductor wire segment portions referred to herein as head branches 24 , extend tangentially relative to the stator bore axis and electrically connect in series the axial branches 22 that are placed in the stator slots. These head branches 24 are placed along at least one of the opposed axial faces of the cylindrical stator core. With the use of this wave winding configuration, each of the three current phases corresponds to a single group of conductors arranged about the stator central axis. Thus, in a three-phase stator, there are three conductor groups. Each conductor group may consist of a single, elongate conductor 20 appropriately formed into an undulating shape, or an interconnected plurality of formed conductors 20 having connection segments 26 that are interconnected, their interconnections preferably being at the same axial end of the resulting stator assembly. One of the two connection segments 26 of conductor 20 is shown in FIG. 1 .
[0057] The operation of inserting elongate conductors 20 into stator core slots, and the stator assembly described above which results from the apparatus and method herein described, may be substantially as disclosed in incorporated U.S. Pat. No. 2,873,514, and in U.S. Publication No. 2012/0112597 A1, the disclosure of which also is hereby incorporated by reference.
[0058] The magazine 30 included in apparatus 32 of the present disclosure is substantially similar to that described in incorporated U.S. Pat. No. 2,873,514, and the drawings thereof may be usefully referred to in the following description. Magazine 30 is provided with central shaft 34 and radially outer cylindrical surface 36 concentric about central axis 38 . A plurality of recesses 40 of uniform width extend radially inwardly from cylindrical surface 36 towards axis 38 . The conductors 20 are received in the recesses 40 in the magazine load mode, which is depicted in FIGS. 2-6 , for subsequent installation into the stator core slots in the magazine installation mode, which is known in the art and substantially as described above and in incorporated U.S. Pat. No. 2,873,514 and U.S. Publication No. 2012/0112597 A1. The magazine load and installation modes are mutually exclusive; i.e., relative to a particular magazine, only one mode may be selected at a time.
[0059] In the manufacturing process disclosed herein, the magazine load mode occurs prior to the magazine installation mode, but is discussed further below. The magazine installation mode is known, and is described immediately hereafter. The installation mode entails a magazine 30 , carrying formed conductors 20 previously received into magazine recesses 40 in the magazine load mode, being disposed in a surrounding stator core bore. Preferably, in the magazine installation mode, the magazine 30 carries a full complement of conductors 20 , i.e., the entire number of conductors 20 to be installed into a stator core, the carried conductors 20 arranged in a configuration corresponding to the desired stator coil winding pattern.
[0060] In the magazine installation mode, the conductors 20 to be installed into the annular stator core and carried in radial recesses 40 of magazine 30 are ejected from the magazine 30 and pressed into radially aligned slots of the stator core disposed about the magazine. The magazine 30 fits in the bore of stator core such that its radial recesses 40 are aligned with the stator core slots. The conductors 20 , located in the magazine recesses 40 , are simultaneously ejected therefrom and inserted into the stator core slots. The ejection of the conductors 20 from the magazine 30 , and the pressing of the conductor axial branches 22 into the stator slots, is done by a plurality of circumferentially spaced magazine end members 42 adapted to move blade members (not shown) disposed in the recesses 40 of the magazine beneath the conductor axial branches 22 . The blade members are moveable radially towards the outside of the magazine 30 to eject the axial branches 22 of the coil winding conductors from the radial recesses 40 of the magazine 30 , and press them into the aligned slots of the stator core in the magazine installation mode.
[0061] Once the loaded magazine is disposed within the stator core bore, the magazine 30 in its installation mode is secured between a pair of press unit heads (not shown). The conductor axial branches 42 disposed in the radial recesses 40 of the magazine 30 are forced from the magazine 30 into the stator slots by movement of the press heads axially towards each other, which forces the conductor axial branches 42 radially out of the magazine recesses 40 and into the stator slots from inside to outside.
[0062] The radial recesses 40 of the magazine 30 are equal in number to the number of stator slots. Each radial recess 40 of magazine 30 has a uniform circumferential width substantially equivalent to the uniform circumferential width of each stator slot. The width of the magazine recesses 40 correspond to the circumferentially extending cross-sectional dimension of the conductor 20 . Thus, the axial branches 42 of the conductors 20 , when loaded on magazine 30 are all aligned radially in the respective magazine recesses 40 , and in the resulting stator assembly will likewise be aligned radially relative to their respective stator slots.
[0063] The width of each magazine recess 40 also corresponds to the thickness of the blade members, and is uniform. The magazine walls 44 separating the magazine recesses 40 are, therefore, wedge-shaped, and are narrower near the magazine's central axis 38 and wider at the radially outer cylindrical surface 36 . The widths of the magazine walls 44 at their radially outer ends 46 , which define the cylindrical magazine surface 36 , are substantially equivalent to the circumferential widths of the stator poles. The stator poles and magazine recess wall radially outer ends 46 are thus of common pitch about their respective center axes.
[0064] After the conductors 20 have been inserted in the stator slots, the now-empty magazine 30 is removed from the stator bore, and suitable covers or shims may be placed over the stator slots to mechanically retain the wire coil conductors 20 in position, as disclosed in incorporated U.S. Publication No. 2012/0112597. The covers may include suitable ferromagnetic material sections that enhance passage of magnetic flux through the poles of the stator core. In some stator designs, installation of slot covers to restrain wire coil conductors 20 may not be suitable or required, or may be optional. In a case where the stator core slots have a circumferential width corresponding to the diameter or circumferential width of the conductor 20 , the conductor axial branch 22 occupying the radially innermost position, i.e., the position closest to the radially inner cylindrical surface of the stator core bore, is deformed by broadening the conductor 20 in a circumferential direction at discrete locations along the stator bore, thereby bringing the axial branch 22 into compressive abutment with the two opposite radial faces of the stator slot and locking the axial branch 22 in position in the stator slot. The axial branches 22 occupying the other positions are thus held inside the stator core slot. Alternatively, the stator windings inserted into the stator slots may be fixed in place by driving magnetic wedges into the slots. At discrete locations along the stator bore, a wedge or shim may be fixedly driven into the stator slot to prevent the conductors from moving out of their desired positions. Regardless of how this is done, the fixing of the conductors into the stator slots may be carried out after insertion of the conductors into the stator slots, along each stator slot.
[0065] The magazine load mode and antecedent process operations will now be described. Prior to the apparatus being in its magazine load mode, each conductor 20 is conformed into a desired shape, such as that of the undulating, S-type conductor having at least two substantially parallel axial branches 22 and a head branch 24 connecting the two axial branches 22 , such as shown in FIG. 1 . If each conductor 20 includes only two axial branches, the head branches 24 of the conductors may be all disposed on the same axial side of a circular rack 50 of the apparatus 32 . Alternatively, if each conductor 20 includes more than two axial branches 22 (as depicted in FIG. 1 ), the head branches 24 may alternate between opposite axial sides of the circular rack 50 and the opposite axial ends of the stator core when installed therein. The longitudinal ends of the conductor defining connection segments 26 are preferably located on a common axial side of the circular rack 50 and thus a common axial end of the stator core in which the conductors 20 are to be installed, which facilitates their interconnection to connection segments 26 of other conductors 20 of the same phase winding directly or through a buss bar assembly as mentioned above.
[0066] The shaping of the conductors 20 may involve the use of a coil-form or mandrel (not shown) prior to the formed conductors 20 being disposed in circular rack 50 . For example, the stator conductors may first be formed on a separate mandrel in a wave or S-shaped configuration, and then transferred to rack slots 52 provided in circular rack 50 . The rack slots 52 are open toward the outer circumferential surface 54 of the circular rack outer perimeter 56 , and regularly distributed circumferentially along the perimeter 56 at a constant separation distance or pitch between adjacent rack slots 52 , which matches the pitch of magazine recesses 40 . The rack slots 52 extend generally axially relative to the central axis of rotation (not shown) of circular rack 50 , and circumferentially adjacent rack slots 52 are parallel, though they may extend in directions inclined relative to the rack central axis.
[0067] Alternatively, circular rack 50 itself may serve as a mandrel, with unformed conductors 20 each disposed in a rack slot 52 and shaped into their desired configurations on the circular rack 50 . Assuming the circular rack 50 is to serve as a mandrel on which conductors 20 are shaped, unformed elongate conductors 20 are disposed parallel to each other in rack slots 52 , and then folded and bent into the desired stator winding configuration corresponding to the winding configuration desired for the resulting stator assembly. In other words, each conductor 20 , once placed in a rack slot 52 , is then formed into its desired shape and positioned in other, designated rack slots 52 so as to correspond to the desired winding pattern of the resulting stator. This shaping is repeated for all conductors 20 of a stator assembly. The circular rack 50 is thus filled with formed conductors 20 intended for installation into a stator core.
[0068] In the magazine load mode, the cylindrical outer surface 36 of the magazine 30 is positioned adjacent the perimeter 56 of the circular rack 50 with their respective central axes substantially parallel. In the magazine load mode, the circular rack 50 and magazine 30 are coupled together, and rotatably driven simultaneously about their respective central axes by any suitable drive means, such as a servo or stepper motor and/or a linking belt. The radially outer surfaces 54 , 36 of the circular rack 50 and the magazine 30 interface on opposite sides of a plane of mutual tangency, herein referred to as transfer plane 60 . Transfer plane 60 has at least one point of tangency 62 with both the circular rack perimeter 56 and the magazine outer radial surface 36 , and they have a common tangential speed and direction in transfer plane 60 . Circular rack 50 , loaded with formed conductors 20 intended for installation into a stator, and magazine 30 rotate in synchronicity such that in transfer plane 60 , slots 52 of circular rack 50 are sequentially aligned with radial recesses 40 of magazine 30 , with the axial branches 22 of conductors 20 carried by circular rack 50 coming to be transferred portion-by-portion, that is, axial branch-by-axial branch, from each rack slot 52 in turn to the respective magazine recess 40 aligned therewith at tangency point 62 , as best seen in FIG. 6 . The sequential transfers of the conductor axial branches 22 between aligned pairs of rack slots 52 and magazine recesses 40 are each through transfer plane 60 .
[0069] The central axes of the circular rack 50 and the cylindrical magazine 30 , about which they are respectively rotatable, are generally parallel but may be slightly inclined relative to each other. Though mutually inclined, these axes may, however, each be parallel with transfer plane 60 .
[0070] In the magazine load mode, the circular rack 50 and the magazine 30 are both rotatably mounted to base 70 of apparatus 32 . The transfer of conductors 20 from the rack slot 52 and into the aligned magazine recess 40 occurs during, and as consequence of, their movements relative to apparatus base 70 . Wedges 72 having ramp surfaces 74 are fixed to apparatus base 70 and disposed on opposite axial sides of the circular rack 50 . The ramp surfaces 74 are closely adjacent to the cylindrical surface 36 of magazine 30 . The ramp surfaces 74 are slidably engaged by conductor axial branches 22 , and sequentially urge the conductors 20 in a radial direction away from the circular rack axis of rotation, out of their respective rack slots 52 , and into the respective, aligned magazine recess 40 , as circular rack 50 rotates. Wedges 72 each have a leading edge 76 disposed slightly upstream of the point of tangency 62 of magazine 30 and rack 50 , relative to their common tangential direction of travel in transfer plane 60 . Downstream of their leading edges 76 , the ramped surfaces 74 of wedges 72 bear on the axial branches 22 of the conductors 20 and urge them away from the circular rack central axis and towards magazine central axis 38 . Ramped surfaces 74 may be substantially curved as shown, defining a concave profile that at least partially conforms to magazine cylindrical surface 36 .
[0071] Axial branches 22 of conductors 20 disposed in each rack slot 52 approaching point of tangency 62 slidably engage the ramped surfaces 74 and, near and after point of tangency 62 , are directed by ramped surfaces 74 into the magazine radial recess 40 aligned through the point of tangency 62 with the rack slot 52 . As shown in FIG. 6 , two axial branches 22 may be transferred between a rack slot 52 and a magazine recess 40 as the circular rack 50 and magazine 30 rotate in synchronicity.
[0072] In apparatus 32 , magazine 30 is fixtured while in the load mode such that it turns inside of a mount 80 secured to apparatus base 70 . Mount 80 rotatably supports magazine 30 by its central shaft 34 and has an encircling portion 82 that substantially surrounds the cylindrical surface 36 of magazine 30 . According to one embodiment of apparatus 32 , shown in FIGS. 2 and 3 , the encircling portion 82 of mount 80 includes a pair of separable halves 84 , 86 that together define an internal, cylindrical face 88 which closely encircles the magazine cylindrical surface 36 . Internal face 88 of the mount encircling portion 82 keeps the axial branches 22 engaged inside the radial recesses 40 of magazine 30 .
[0073] An alternative embodiment of apparatus 32 shown in FIG. 4 provides a mount 80 having an encircling portion 82 having a guide slot 90 through which a ram 92 is slidably positioned relative to magazine central axis 38 . Ram 92 is located axially adjacent the magazine cylindrical surface 36 , and is extendable radially inward of the outer radius of magazine cylindrical surface 36 . Ram 92 reciprocatively slides in directions substantially perpendicular to the magazine central axis 38 for tamping the transferred conductors 20 radially into magazine recesses 40 , thereby ensuring a compact, abutting, radially-stacked arrangement of conductor axial branches 22 within recesses 40 .
[0074] In the load mode, during the conductor transfer operation, magazine 30 may make a complete, 360° rotation about its central axis 38 while the circular rack 50 rotates only partially about its central axis. Thus, a magazine 30 may receive a full complement of formed conductors upon one complete rotation after first receiving a conductor axial branch 22 , and after only a partial rotation of circular rack 50 , which is of much greater diameter. The number of rack slots 52 may be an integer multiple of the number of magazine recesses 40 . Therefore, a plurality of magazines 30 may be fully loaded with formed conductors 20 from a single, fully loaded circular rack 50 .
[0075] Relative to the outer diameter and number of recesses 40 of the magazine 30 , which correspond to the inner diameter of and number of slots in a cylindrical stator core bore, the outer diameter and number of slots of the circular rack 50 is substantially greater. Consequently, the circular rack 50 may be provided with a number of conductors 20 sufficient to load multiple magazines 30 , either sequentially or simultaneously.
[0076] It is envisioned that multiple magazines 30 may be interchanged at a single conductor transfer station 94 of apparatus 32 that is passed by the circumference 54 of the circular rack 50 as it rotates about its central axis. At the transfer station 94 , each of a sequence of magazines 30 enters its load mode and is filled in turn with sufficient conductors to entirely form its stator winding during a partial rotation of the circular rack 50 . The magazines 30 of the sequence are interchanged for sequential loading from a common circular rack 50 . The loaded magazines 30 may be transitioned to an installation station (not shown) at which it enters a magazine installation mode, with a stator core disposed about the filled magazine 30 . In the installation mode, conductors 20 carried by the magazine 30 are inserted into the stator slots in a conductor installation operation as described above.
[0077] It is also envisioned that, in the alternative, multiple transfer stations 94 may be positioned about the perimeter 56 of the circular rack 50 , with multiple magazines 30 receiving conductors 20 transferred from the circular rack 50 simultaneously, as the rack 50 and the magazines 30 rotate about their respective central axes. In other words, a plurality of magazines 30 may be positioned about the perimeter 56 of a single circular rack 50 and simultaneously receive their respective conductors 20 therefrom in the magazine load mode.
[0078] Thus, in the magazine load mode, the conductors 20 from circular rack 50 are transferred in apparatus 32 to one or a plurality of cylindrical magazines 30 .
[0079] While exemplary embodiments have been disclosed hereinabove, the present disclosure is not limited to the disclosed embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the present disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this present disclosure pertains and which fall within the limits of the appended claims. | An apparatus for installing an elongate conductor into stator core slots, including a magazine having a radially outer cylindrical surface with recesses that extend inwardly of the cylindrical surface, and a circular rack having a radially outer periphery provided with rack slots. The magazine has an installation mode in which a stator core coaxially surrounds the magazine, there is concurrent radial alignment between pairs of magazine recesses and stator core slots, and a conductor axial branch is receivable by a stator slot from a respectively paired magazine recess; and a load mode in which the circular rack and the magazine have synchronized rotative movements, corresponding pairs of magazine recesses and rack slots are sequentially aligned, and a conductor axial branch is receivable by a magazine recess from its aligned rack slot. Also, a method for loading an elongate conductor onto a magazine for subsequent installation into stator core slots. |
BACKGROUND OF INVENTION
(1) Field of the invention
The present invention concerns a rechargeable lithium anode for polymer electrolyte batteries. More particularly, the invention is concerned with an electrochemical generator, for example a generator, which operates with an anode of lithium or other alkali metals, pure or alloyed, and a polymer electrolyte and whose characteristics are such that it is possible to substantially increase the number of cycles obtained during the normal life of the battery.
(b) Description of Prior art
The rechargeability of lithium in the presence of organic electrolytes generally leads to an important morphological evolution of the anode of an alkali metal, such as lithium resulting in a loss of utilization of the anode and/or the appearance of dendrites during recharge. This phenomenon is known to be very general with all generators in which metallic lithium is used. Reference is made to the following: Industrial Chemistry Library, Volume 5, LITHIUM BATTERIES, New Materials, Developments and Perspectives, Chapter 1, authored by J. R. Dahn et al. edited by G. Pistoia, Elsevier (1994). The generally acceptable explanation for this phenomenon is based on the following:
1--lithium is thermodynamically unstable in the presence of organic electrolytes (solvent+lithium salt) and produces an oxidation layer (which is more or less passivating and, under certain conditions, remains a conductor for lithium ions); in the latter case the passivating layer is designated SEI: Solid Electrolyte Interface;
2--during consecutive cycles of discharge and recharge, lithium is dissolved and is re-deposited unevenly and at the end, becomes electrically insulated and/or is chemically consumed, by reaction with the organic electrolyte (solvent and salt);
3--the result is a loss of activity for the anode and the formation of a porous and irregular anode consisting of dispersed lithium, which is more or less passivated.
In general, this phenomenon is compensated by increasing the capacity of the lithium anode with respect to the cathode so as to obtain a significant number of charges and discharges during cycling. The term capacity of the anode means the "coulomb" capacity, i.e., the quantity of electricity present in the anode, knowing that one mole of lithium contains the equivalent of 96,500 coulombs. Normally, this value is defined in cm 2 , for example, 10 coulombs/cm 2 . The capacity may also be defined in milliampere-h/cm 2 and the conversion is carried out as follows: 1 mAh/cm 2 =3.6 C/cm 2 .
The concept generally used to define the general behavior associated with the difficulty of redepositing lithium with a yield of 100% is called F.O.M. (Figure of Merit) Second International Symposium on Polymer Electrolytes, Siena, Italy, Jun. 14-16, 1989, Belanger et al.
For these reasons, lithium anodes whose capacity is 3 to 8 times the capacity of the corresponding cathode, are generally used in secondary generators. This procedure enables to obtain a significant number of discharge/charge cycles, however, it substantially reduces the density of energy of the generator because of the penalty associated with an excess volume of lithium. Moreover, an excess of lithium substantially increases the cost of the generator. On the other hand, the risks associated with handling rechargeable Li batteries are higher when the Li excess number is higher, more so if cycling is accompanied with an important morphological evaluation of lithium which makes it more reactive.
The term "morphology" applied to lithium anodes is a description of the roughness of the surface developed during cycling. This surface roughness in some cases extends within the body of the anode when the latter becomes porous during cycling. Therefore, when the morphology of a surface is developed this also means that it becomes coarser. Many apparatuses are known for scanning the surface of an electrode to determine its roughness to ±1 micron.
It has been observed that a development of morphology of lithium may also take place in the presence of a polymer electrolyte although at a lesser degree. This observation has confirmed the evolution of the morphology of an anode of lithium, when it is cycled under repetitive conditions. Applicants have illustrated this phenomenon in a previous work (Siena, Belanger et al., cf. supra). Relatively high F.O.M. values noted during tests made wherein F.O.M. >100, have, however, led to using an excess of lithium close to or higher than three times the capacity of the cathode.
As a consequence, relatively thick lithium sheets are generally used in metallic lithium rechargeable generators for reasons of commercial availability and ease of handling. It is also possible to use a rigid current collector which is applied against the film of lithium in order to facilitate its handling and to provide for an electrical contact.
In order to optimize the designs and performances of polymer electrolyte generators, and to provide a generator capable of storing enough energy for an electrical vehicle, the Applicant has designed a process of manufacturing lithium films which are increasingly thin. Reference is made to U.S. Pat. Nos. 4,517,265; 4,652,506; 4,794,060; and 4,897,917, as well as U.S. application Ser. Nos. 08/273,756 and 08/273,759. At the same time, Applicant has removed the rigid current collector so as to optimize the production cost and the energy density of the generators.
By way of example, Applicant has produced devices in the laboratory of a few mWh as well as other devices of more than 10 Wh utilizing lithium films without collectors in which the thickness varies between 20 and 40μ (J. Power Sources, 54 (1995) 163).
In all cases, good performances during cycling are obtained by providing an anode whose capacity is three times higher than that of the corresponding cathodes, and sometimes even more. Under similar conditions, when there are used films of lithium which are thinner and whose capacity is lower (capacity three times higher than that of the cathode), a rapid reduction of the number of cycles have been observed. After dismantling these generators, an important morphological evolution of the thin film of lithium has been noted, which is visible by a simple observation to the eye or by observation with a scanning electronic microscope. In the case of these very thin sheets, the morphological evaluation is visible throughout the entire sheet.
The morphological evolution of lithium is particularly fast under the following conditions:
1--when the excess of lithium is small;
2--when the film of lithium is thin <30μp, and 3--when lithium is free, i.e. non-supported by a rigid current collector.
These observations corroborate the tendency noted in the prior art and constitute a major limitation with respect to the optimization of the performances of generators having a metallic lithium anode, i.e., when it is intended to reduce the excess of the capacity of lithium with respect to that of the cathode, to remove the presence of a rigid collector, which is often thick and costly, or even when it is intended to reduce the thickness of the group of films constituting the generator: anode/polymer electrolyte/cathode/collector to optimize the power and the cyclability.
It is an object of the present invention to provide a rechargeable polymer electrolyte generator operating with an alkali metal anode, such as metallic lithium, and which is capable of undergoing repeated deep cycles of charge and discharge.
It is another object of the present invention to provide a generator in which the alkali metal anode has a low excess lithium capacity enabling it to preserve the reversible reaction of the anode and the electrical collection of the latter by maintaining the initial morphology without forming porous alkali metal or particles of electrically insulated metal. This characteristic of the invention is made possible by the absence of a substantial consumption of lithium by the polymer electrolyte during cycling under the conditions of the invention.
It is another object of the present invention to provide for the utilization of very thin lithium films, such as <50μ, while enabling to reduce and/or eliminate the excess of metal installed with respect to the cathode, and to maintain good cycling characteristics.
It is another object of the present invention to reduce and/or eliminate the excess of capacity of the lithium anode required with generators according to the invention as compared to the prior art, in terms of security, electrochemical performance, and cost associated with this excess of capacity of the anode.
SUMMARY OF INVENTION
In accordance with the present invention there is provided a rechargeable generator including an alkali metal anode, an electrolyte comprising a solid polymer and a salt of an alkali metal, and a cathode capable of reversibly cycling the ion of the alkali metal, the anode and the electrolyte defining a sub-assembly of the generator. The sub-assembly has the following characteristics:
a--the solid polymer electrolyte contains a maximum amount of accumulated and mobile impurities which can react with the anode and can consume at the most the equivalent of 1,000 Å of lithium in a way to keep substantially intact the electrochemical characteristics of the SEI film;
b--the polymer electrolyte is homogeneous, elastic and is capable of transmitting a mechanical pressure on the anode, and of being resistant against the dendritic stress of the metal of the anode by utilizing deformations of less than 35% of its thickness.
More particularly, the invention concerns a rechargeable generator consisting of an anode of a metal, or of a malleable free alkali alloy, at least one polymer electrolyte which is conductive with respect to alkali cations and act as a separator, as well as at least one cathode and a current collector, said cathode being reversible towards cations of alkali metal and its current collector, characterized in that:
the anode consists of a thin metallic sheet, less than 100 micrometers thick, which includes at its surface a passivation film SEI, which is conductive of alkali metal ions, and is capable of limiting the reaction between said metal and the polymer electrolyte and to exchange lithium ions during consecutive cycles of charge and discharge;
the polymer electrolyte is a homogeneous separator, which resists against mechanical deformations and is capable of transmitting mechanical pressure on the anode to resist against a dendritic stress on the metal of the anode by undergoing a rate of deformation which is lower than 35% of its thickness.
the polymer electrolyte of the separator, and possibly of the cathode, when a composite cathode is used, containing a maximum amount of movable species which are reactive towards lithium and accumulated to the surface of the anode, corresponds to a consumption equivalent to less than 3000 Å of the alkali metal, so as to preserve the quality of the ionic exchanges at the anode/polymer electrolyte interface;
the assembly, i.e., alkali metal anode, electrolyte separator, cathode and collector, is maintained under a sufficient mechanical constraint so that the separator can maintain in compact form the sheet of the anode to preserve the chemical and mechanical integrity of its SEI during consecutive cycles of dissolution/plating.
In accordance with a preferred embodiment of the invention, the anode is less than 100μ thick, such as less than 40μ. It is preferably made of lithium or an alloy thereof. A slight excess may also be provided to ensure electronic conductivity and lateral current collection. On the other hand, the anode may also be made of a non-supported sheet used as anode on the two faces thereof.
In accordance with another preferred embodiment of the invention, the polymer electrolyte is usually less than 50μ thick, such as less than 30μ. A preferred electrolyte includes hetero-atoms, such as oxygen or nitrogen, which are capable of solvating the cations of an alkali salt which is the same alkali metal as the anode.
In accordance with another preferred embodiment of the invention, the electrolyte is capable of resisting a stress of about 200 psi at about 60° C. without undergoing more than 35% deformation while still continuing to protect the battery against short-circuit.
A preferred polymer electrolyte according to the invention has a modulus of elasticity of about 50 psi at 60° C. Preferably, the polymer electrolyte according to the invention has a density of cross-linking nucleii or has sites of chain tangling which are sufficient to limit deformability to less than 35%, such as 25% of its original thickness, and making it resistant against lithium deformation during cycling.
The properties of deformability may be obtained according to the invention by adding an inert charge into the electrolyte which is used in an amount which is sufficient to limit the above mentioned deformability and which size is preferably lower than 1 micrometer. Preferred charges comprise alumina, silica or magnesia in sizes lower than 1 micron.
The impurities which are present in the polymer electrolyte and which should be in substantially limited quantity normally may, for example, be made of movable reactive functions which are located at the ends of the polymer chains. In accordance with the invention, the amounts used should be less than those required to consume the equivalent of 1000 Å of lithium. With this amount of impurities it is possible to preserve the integrity of the passivating film at the surface of Li (SEI). The impurities may also consist of water, solvents, small amounts of polymer capable of diffusing towards Li by consuming the latter. They may also comprise protic molecules having OH or NH terminal groups (see Table I below). Control of impurities to a minimum level is essential according to the present invention because the lithium surface is not rejuvenated by evolution of the surface morphology of lithium during cycling.
The mechanical stress necessary to provide one of the characteristics of the invention may be ensured by rolling films of the anode of the electrolyte and of the cathode as coils confined in a fixed external volume, or by keeping films of the anode of the electrolyte and of the cathode under compressive load, generally between 5 and 150 psi.
Another way to provide mechanical stress is to form the anode, the electrolyte and the cathode into a prism which is kept under constant pressure or at a constant volume. For example, the prism may be obtained by flat rolling an assembly consisting of the films of the anode, electrolyte and cathode or by piling the components of the generator. Another prismatic arrangement may also be obtained by a zig-zag piling of the components of the generator. Another way to achieve the invention consists in constraining by mechanical means, the electrochemical device as a fixed volume.
According to another embodiment, the anode is a hardened anode of lithium so as to maintain the integrity of the non-supported anode sheet and to ensure current collection during cycling. The anode may also be made of an alloy with a high content of lithium which is less malleable than pure lithium and in which the excess of lithium ensures the function of non-deformable current collector.
In accordance with another embodiment of the invention, the capacity of the anode is between about 1.5 to 3.5 that of the reversible capacity of the cathode.
According to another embodiment, the anode may comprise a sheet of an alkali metal, such as lithium, or an alloy thereof, supported on a collector which adheres to the sheet. The collector may be made of a conductive metallic sheet, such as copper, iron or nickel or another metal or alloy, which is stable towards lithium. It may also be made of a sheet of plastic material, such as polypropylene or polyethylene which is also stable with respect to Li.
In accordance with another embodiment, the anode may be mounted between two half-cells made of an electrolyte and a positive electrode. It may also comprise two films of alkali metal, such as lithium, or an alloy thereof, mounted on both sides of a thin and rigid central support.
According to another embodiment a second electrolyte which is thin and adhesive may be provided between the electrolyte and the anode, or between the electrolyte and the cathode, the latter ensuring the formation of stable interfaces between the various components of the generator.
BRIEF DESCRIPTION OF DRAWINGS
Characteristics and advantages of the invention will appear from the annexed drawings given by way of illustration and without limitation and in which:
FIG. 1 illustrates the constitution of a lithium rechargeable generator using a liquid electrolyte contained in a porous separator;
FIG. 2 shows a generator utilizing a polymer electrolyte according to the prior art (Siena, Belanger et al. supra) at a more or less advanced level of cycling with a collector on the metallic anode;
FIG. 3 shows a generator utilizing a polymer according to the prior art (Siena, Belanger et al, supra) at a more or less advanced level of cycling without collector with deformation of the reverse side;
FIG. 4 illustrates a polymer electrolyte rechargeable generator, after dismantling and before cycling according to the invention, showing the beneficial effect of the mechanical pressure on the polymer lithium interface and the preservation of the film SEI when the polymer electrolyte is slightly deformable;
FIG. 5 shows the micrography of a cryogenic cross-section illustrating the various interfaces of a battery according to the invention, showing the preservation of the thin sheet of dense lithium and the preservation of the interface Li o /SEI/SEPD (slightly deformable polymer electrolyte separator) after many hundreds of cycles, the micrography having been realized at an enlargement of 1000;
FIG. 6 is a schematic description of the cryogenic cross-section of a generator according to the invention which illustrates the preservation of the surface state of the electrolyte SEPD when dismantling after many hundreds of cycles.
DESCRIPTION OF PREFERRED EMBODIMENTS
First it will be noted that the thickness of the SEI was exaggerated to facilitate its viewing. With reference to the drawings, more particularly FIG. 1, it will be seen that the illustrated generator includes an anode of Li o a, having a thickness of about 100μ mounted on an anode collector g, here a sheet of copper. The generator additionally includes a composite e well known to one skilled in the art, mounted on a cathode collector f, here a sheet of nickel. Disposed between the cathode e and the Li o a, there is a liquid electrolyte d which is impregnated in a conventional porous separator. At b one sees the surface profile of the anode after cycling with its film SEI. Reference c represents particulate Li o embedded in electrically insulated electrolyte d resulting from the cycling.
Now considering FIG. 2 which illustrates a prior art generator utilizing a polymer electrolyte with a metallic collector according to the prior art (Siena, Belanger et al. supra) at a more or less advanced level of cycling, it will be seen that the latter includes, as in the generator illustrated in FIG. 1, an anode of Li o a', except that its thickness is about 20μ, mounted on an anode collector g, here a sheet of copper. This generator as well as the one illustrated in FIG. 1 comprises a composite cathode e, well known to one skilled in the art, mounted on a collector f, here a sheet of nickel. Disposed between the cathode e and the Li o a', there is a polymer electrolyte d' which has been deformed by cycling of the lithium anode with its SEI film. Reference h represents the mechanical deformation of the sheet of Li o a' induced by cycles of deposit/dissolution of lithium. At b' one sees the profile surface of the anode after cycling with its film SEI.
The generator illustrated in FIG. 3 is a modification of the one illustrated in FIG. 2 in which the generator has no collector for the anode. There are, therefore, included an Li o anode a' which, in this case, is not supported, a polymer electrolyte d similar to the one illustrated in FIG. 2, a composite cathode e and its collector f. In this case the surface profile b" of the anode surface after cycling with its film SEI is more severe than the one illustrated in FIG. 2. The reference i represents the mechanical deformation of the rear face of the sheet of Li o without collector induced by cycles of deposit/dissolution of lithium.
It should be noted that with respect to the two generators illustrated in FIGS. 2 and 3, we are dealing with rechargeable Li o generators with deformable polymer electrolyte and cycled without pressure control on the interface Li o /SEI/polymer electrolyte.
Referring now to FIG. 4, one observes that a generator according to the invention includes an anode a" of lithium as a thin film <30μ and of a capacity lower than three times that of the composite cathode e expressed in C/cm 2 . Between the cathode provided with a collector f, here nickel, composite e and anode a", there is a slightly deformable polymer electrolyte separator d (SEPD) with a low content of impurities which are reactive with Li o , having a thickness lower than 30μ. The solid electrolyte interface, SEI, which is conductive of Li + ions is represented by reference b". According to the invention a pressure j is applied on the interface Li o /SEI/SEPD by means of a volume stress of the generator or an external pressure on the electrochemical device.
In FIG. 5 there is the micrography of the cryogenic cross-section of cathode e mounted on its collector f, the electrolyte SPE d", a lithium anode a"' and its collector g.
The elements which constitute the generator illustrated in FIG. 6 are the same elements corresponding to the generator illustrated in FIG. 5, i.e., a lithium anode a", an interface Li o /SEI/SEPD after many hundreds of cycles b", a polymer electrolyte d" and a composite cathode e, as well as its collector f.
FIG. 1 illustrates that after many cycles of charge and discharge in a liquid medium, lithium develops a dendritic surface morphology and that particles may be detached from the surface causing lithium from becoming electrically insulated.
On the other hand, with reference to FIGS. 2 and 3 which illustrate the prior art in a polymer medium, it will be noted that after cycling, the morphology of lithium has developed, but much less than previously, since the anode is only 20μ thick. No pressure was then applied.
In the case of FIG. 4 the electrolyte SEPD transmits the pressure on the anode of the generator and prevents by the same fact the development of a morphology at the surface and in depth of the lithium.
It will be shown hereinafter in some examples of the invention that after many hundreds of cycles the surface of lithium is still quite smooth and that the asperities are <1-2μ.
These results confirm that the combination of pressure and a light deformability of the electrolyte-separator, SEPD, enables to maintain a thin film of lithium in a dense and uniform state.
Table 1 illustrates the effect of the concentration of terminal OH in the chains of a polymer, such as polyethylene oxide, on the average molecular weight of the latter. The reaction lithium-reactive species is calculated on the basis of a reaction of one equivalent with respect to another equivalent to evaluate the approximate thickness of the film of lithium which is chemically consumed.
TABLE 1
Quantity of reacted lithium in contact with electrolytes of various molecular weight, given a polymer density of 1.1 g/cc, an electrolyte thickness of 30μ, 2 OH terminal groups per chain and one Li atom reacting with each OH group.
______________________________________Molecular OH group Thickness of weight of concentration Moles of OH lithium polymer (moles of OH group per cm.sup.2 reacted with Mw group) of electrolyte OH groups______________________________________5,000,000 2.2 × 10.sup.4 6.6 × 1.sup.-10 1 × 10.sup.-5 μ or10 Å 1,000,000 1.1 × 10.sup.-3 3.3 × 10.sup.-9 5 × 10.sup.-5 μ or50 Å 100,000 1.1 × 10.sup.-2 3.3 × 10.sup.-8 5 × 10.sup.-4 μ or500 Å 50,000 2.2 × 10.sup.-2 6.6 × 10.sup.-8 1 × 10.sup.-3 μ or1000 Å 10,000 1.1 × 10.sup.-1 3.3 × 10.sup.-7 5 × 10.sup.-3 μ or5000 Å______________________________________
This Table considers only mobile species capable of reaching lithium.
This criteria has been found to be very important to preserve the nature and the electrochemical property of the SEI of solid present at the surface of the lithium film (300-500 Å). It is applicable to other sources of impurities capable of consuming Li, such as protic impurities, H 2 O, --OH, NH--, etc. A substantial consumption of the installed lithium (quantity of coulombs/cm 2 contained in the lithium electrode when mounting the generator) by impurities of mobile and reactive liquids may cause the formation of a film of oxidized lithium which is too thick, non passivating or very slightly conductive through the Li + ions.
In addition to the chemical purity which is required for the polymer electrolyte, in order to preserve the quality of the Li o /solid polymer electrolyte interface during cycling, the latter should also have its own mechanical properties which enable it to be active as a mechanical separator and to preserve the geometry of the interface Li o /solid polymer electrolyte during discharge/charge cycles. The macroscopic or microscopic mechanical resistance of the polymer electrolyte enables the latter to be resistant against mechanical deformations of lithium during discharge/charge cycles and against a possible appearance of dendrites. The use of a polymer electrolyte which is capable of undergoing local mechanical deformations therefore constitutes a completely different approach from the one which is used with liquid electrolytes, where generally mechanical separation is obtained by the use of a porous separator which is impregnated with a liquid electrolyte in which the pores are generally smaller than 1μ. In this case, it is the porous separator which is resistant against the formation of dendrites and the deformation of the lithium anode.
The minimum mechanical properties required from the polymer electrolyte separator are determined by means of a standard penetration test which is carried out on the face of the electrolyte which is exposed to the lithium anode.
A preferred method of preparing the generator according to the present invention consists in preserving the lithium surface as well as the geometry of the Li o /solid polymer electrolyte interface by an internal confinement of the generator (cylindrical shape) and/or by controlling the pressure of the generator on the assembly.
Preferably, the generators according to the invention have a thickness of less than 200μ and include a lithium anode of less than 50μ thick, in which the installed capacity is lower than four times the capacity of the corresponding cathode. These generators enable to obtain a large number of deep cycles without an extended morphological evolution of the lithium anode.
This dramatically reduces preoccupations concerning security, since having dispensed with the pulverization of lithium, the dangers associated with the reactivity of highly dispersed lithium are eliminated.
The invention is illustrated by means of the following non-limiting examples.
Three types of polymers have been used for examples:
ethylene oxide base copolymers having a statistic distribution with cross-linkable allyl functions. These polymers have high molecular weight (more than 200,000) in order to confer mechanical properties to the separator and to limit the number of reactive groups at the ends of the chain (as described in U.S. Pat. Nos. 4,578,326 and 4,758,483);
an ethylene oxide base copolymer with statistical distribution and easily cross-linkable methacrylate functions. These polymers have high molecular weights (200,000) for the same reasons as above (Canadian patent application 2,111,049);
low molecular weight polymers (in the order of 10,000) having at the end of the chain multi-functional acrylate groups so as to eliminate OH groups. These easily cross-linkable polymers give mechanical properties such as low deformability associated with the high density of cross-linking nucleii (application U.S. Ser. No. 08/371,437, Jan. 11, 1995).
The types of cross-linking of these different types of polymers are given by way of examples: free radical initiation, chemical activity, thermal activity or by irradiation with Irgacure 651.
Cells of 4 cm 2 mounted for characterizing different examples are as follows:
the anode consists of metallic Li about 10 to 35 microns with or without Ni support;
the electrolyte membrane made from the polymers described above with LiCF 3 SO 2 N in a concentration of 0/Li=30/1 and a thickness between 10 and 30 microns;
the cathode consists of a mixture of active materials, carbon black and electrolyte in volume ratios near 40:03:57, and resting on a metallic collector generally Ni or Al, having a capacity between 1 and mAh/cm 2 and a thickness between 40 and 80 microns. Assembling the generator was carried out in a glove box under argon.
EXAMPLE 1
Two identical generators were mounted both including a lithium/Ni anode and a vanadium oxide base cathode. In the first generator, the 50μ thick electrolyte membrane was dried under vacuum at 80° C. for 24 hours (H 2 O<50 ppm according to the technique of Karl Fischer). In the second generator the same membrane was exposed to ambient air for 30 minutes (water >2000 ppm) before being used in the generator. After having cycled the two generators at 60° C. for 20 cycles, the impedance of the generator measured at 25° C. has more than tripled (160 ohm-cm 2 vs. 50 ohm-cm 2 ) with respect to a generator in which the electrolyte was conveniently dried.
In a second test we have added 20% polyethylene oxide in which the molecular weight was Mw=2000 containing terminal hydroxyl groups to the electrolyte. As in the previous case, in less than 15 cycles, a lithium/vanadium oxide generator cycled at 60° C. has developed an impedance higher than 200 ohm-cm 2 while the first generator gave an impedance lower than 50 ohm-cm 2 .
Measure of impedance mainly attributed to the anode confirms the results contained in Table I on the effect of movable reactive impurities which can accumulate at the surface of lithium.
For the examples which follow, the water content, or the content of reactive impurities, will always be maintained below 200 ppm to preserve the electrochemical properties of SEI.
EXAMPLE 2
In this Example we have characterized four types of membranes belonging to the families of the polymers described above depending on their degree of deformability. To characterize the deformation we have used a device which measures the penetration of a tip of 7 mm under a weight of 240 g and a film thickness of the order of 40-60 microns. This test was carried out at 60° C., i.e., when the electrolyte is amorphous and corresponds to the temperature of operation of the generators.
The results are presented in Table II hereinafter. After having characterized their deformability these electrolytes were mounted as generators which are identical to those of the previous Example.
It is interesting to note that these measurements of the deformability of the separator such as presented in Table II are close to those measured under the same conditions for a sheet of metallic lithium (of the order of 20%). These values therefore illustrate the possibility of controlling the morphology of Li during cycling by means of the property of non-deformation of the separator electrolyte.
TABLE II______________________________________Type of polymer Crosslinking Penetration Hardness______________________________________Vandenberg none 66% soft Anioic slightly 58% soft irradiated Vandenberg 2% peroxide 35% semi-hard Anionic strongly 30% semi-hard irradiated VdB-Met-6 2% peroxide 20% hard ERM UV 22% hard Lithium 20% (150 microns)______________________________________
Penetration is expressed in percentage of the thickness of membrane which is normally between 40 and 60 microns. This penetration test will be used as a semi-quantitative measurement of the deformability of separators.
The substantially equal rates of penetration between the separators of the invention and lithium suggest that a beneficial effect may be obtained whenever the Young modulus of the separator is close to or exceeds that of Li or about 80 psi.
EXAMPLE 2a
A generator was mounted with electrolyte considered as "soft", typically a VdB electrolyte of molecular weight 200,000 dried without a cross-linking agent, which has a deformation of 66% of its thickness. This corresponds to the description of FIG. 2. It was noted that after dismantling (100 cycles) there was a highly notable interpenetration of the electrolyte and lithium in spite of the presence of Cu as collector. In addition, after 50 cycles problems of coulombic efficiency have been observed. The surface of Li also had important rugosities in the order of 15 microns.
EXAMPLE 3
Three identical cells were assembled in an argon-filled glove box using the same anionic electrolyte cross-linked at 2% benzoyl peroxide and having a hardness of 30% deformation under the same load conditions described in example 2. The electrolyte is thus a semi-hard electrolyte. Lithium was 35μ thick, backed with an 8μ thick Ni current collector and its capacity in coulombs was about four times that of the cathodic material used, i.e., 1 mAh/cm 2 of a vanadium oxide composite electrode. These three cells were cycled under strictly the same conditions of currents and voltages, except that each cell was put under different compressive loads (pressure): 0 psi, 50 psi and 100 psi. After 100 cycles, the three cells were dismantled and examined under a Scanning Electrode Microscope (SEM). It was noted that the morphology of lithium had developed significantly with 0 psi pressure while at 50 psi, the surface had roughened a little, and the one under 100 psi load showed a lithium that was almost identical to the one used during the original assembly. This was also confirmed through a surface profilometry examination with a DEKTAK apparatus. The deformability of the electrolyte in this case was of the order as that of Li. The influence of pressure is notable but cannot completely prevent the morphological development during an extended cycling.
EXAMPLE 4
Two identical cells were assembled in an argon-filled glove box. This time an unsupported (free) lithium was used in a bi-face configuration, i.e., sandwiched between two half cells consisting of vanadium oxide cathodes of 1 mAh/cm 2 in capacity and films of electrolytes 35 microns thick. The free lithium was 30μ thick; the hardness of the electrolyte was 35% so it is considered a semi-hard membrane. The configuration corresponds to: positive/electrolyte/lithium/electrolyte/positive.
The total cell thickness is in the range of 200μ. This configuration includes an excess of Li which is equivalent to twice the capacity of the cathode which ensures that it acts as collector. Both cells were put under identical cycling conditions: 1.5-3.3 volts as voltage limit with a 6 hour discharge regime and a 12 hour charge regime. One was cycled under a 50 psi load pressure and the other without pressure for 50 cycles. Both had excellent cycling properties: coulombic efficiencies near 100% and a high rate of utilization of the cathodic material. A post-mortem analysis has revealed that the cell that was cycled without pressure had a surface profile showing peaks and valleys of ±10μ while in the second cell, the lithium remained very uniform with a surface roughness that does not exceed ±1μ.
EXAMPLE 5
Two similar cells were assembled in a dry-room in which there is less than 1% relative humidity. In the two cells measuring 3.9 cm 2 the same positive electrode (vanadium oxide at 5 C/cm 2 ) and the same 30 microns thick electrolyte were used. In the first case a free lithium film 20μ thick was used as the anode whereas in the second case the anode consisted of lithium 20μ thick and was laminated on a 9μ nickel foil.
After 100 cycles (C/6 discharge and C/12 charge), both cells were dismantled for examination. In the first cell, the lithium that was unsupported had developed a measurable surface morphology of the order of ±5μ and showed the presence of some encapsulated (passivated) lithium on its surface which is the result of an interpenetration of lithium and SPE during consecutive cycles (illustrated in FIG. 3). During the same period the second cell had developed substantially less rugosity. Determination of the chemical activity of lithium when reacted with methanol (by measuring the hydrogen produced) showed that Li was still a completely active event if some portion was not in electrical contact with the bulk of the electrolyte.
This Example (cell #1) shows the morphological evolution of very thin and nonsupported Li (at the surface and within the body of Li), see FIG. 3, and the loss of electrical contact resulting from cycling, since lithium remains mostly in metallic state in the presence of a dry polymer electrolyte. Cell #2 (FIG. 2), however, shows that this morphological evolution may be controlled more or less by using a collector support which adheres to the thin sheet of Li.
EXAMPLE 6
A combination of favorable factors may be used to improve the behavior of the cycling. In this Example, two similar cells were cycled under identical cycling conditions. One of the cells was put under a pressure of 50 psi, while the second cell was cycled at 0 psi. The first cell also had its lithium anode laminated on a copper current collector while the second one used a free standing lithium foil. Both cells were constructed using the same half-cell, i.e. the same composite cathode laminated to a 30 micron thick electrolyte. The capacity of the cathode was 7 C/cm 2 . The electrolyte was semi-hard with about 30% penetration. The initial impedance of both cells was similar at 60 C. Nevertheless during cycling, the response of the first cell to peak currents was improved compared to the second cell. Similarly, the first cell showed better overall cycling behavior. After 200 cycles, both cells were dismantled and an analysis of the lithium surface roughness showed that the first cell had a better lithium morphology: ±3μ compared to ±12μ for the second cell.
EXAMPLE 7
In a similar arrangement to the previous example, two favorable effects, hardness of the electrolyte and the use of a lithium current collector, were combined to give characteristics of good power and cycling.
In the first cell a membrane of VdB methacrylate (see Table II), 30 microns thick, was used. In the case of the second cell an electrolyte ERM 35 microns thick was used with a current collector on lithium. The electrolytes were 20μ thick and had a hardness equivalent to a deformation less than 20% of their original thickness. The apparatus used was the same as the one used in Example 2 above. Each cell was kept at a pressure of 15 psi. Even after 300 cycles, the lithium surface of the two cells was substantially free of rugosity, i.e., lower than ±1 micron, and this has therefore enabled to disturb the geometrical surface of the SEI to a minimum. The surface of the electrolytes was also kept intact (FIG. 6).
EXAMPLE 8
In another 4 cm 2 cell, a very thin lithium anode (10μ) laminated to a 10μ copper foil against a positive electrode of 6 C/cm 2 was used. This corresponds to an excess of about 20% of the positive electrode capacity. A 25μ hard electrolyte (20% penetration) was used, and the cell was put under a 50 psi pressure. Over 120 cycles were obtained with good retention of capacity and excellent coulombic efficiency (near 100%).
This result shows again that a good choice of material and cycling conditions can improve the cell behavior in an appreciable manner. For any given large generator based on metallic lithium, it is important to reduce the amount of lithium to a required minimum.
By doing so, the safety of the generator is greatly improved especially if an abnormal rise of temperature would take place, for example, above the melting temperature of Li.
EXAMPLE 9
The advantage obtained by combining a hard separator was also verified in a bi-face arrangement corresponding to what follows: positive electrode/electrolyte/lithium electrolyte/positive electrode. The positive electrode had a useful capacity of 5 C/cm 2 and the thickness of the electrolyte was 20μ. The thickness of the central lithium anode was 20μ corresponding to an excess of 0.5. The hardness of the electrolyte was the same as in Example 7 above. After 100 cycles (50 psi) the cell still showed good behavior during cycling and the surface roughness of lithium was less than ±2μ. Lithium preserves a continuous structure which makes it quite suitable to play its role as current collector.
EXAMPLE 10
In this last example, the same positive electrode and the same electrolyte as in Example 8 were used. As an anode, instead of using pure metallic lithium, an alloy of lithium and aluminum containing 1 at. % Al and 99 at. % of lithium was used. This small quantity of aluminum has a direct effect on the hardness of the anode. This alloy can nevertheless be laminated as thin as metallic lithium.
It has been observed that this type of lightly alloyed lithium anodes does not have an adverse effect on the cycling behavior of the anode nor on its impedance. A post-mortem analysis of the lithium surface confirms that the surface remained as smooth as pure lithium.
The combination of the various factors illustrated in the previous Examples, purity, low deformability of SPE, use of pressure or a metallic support which adheres to the electrode of Li, shows that it is possible to optimize the interface Li-polymer electrolyte during cycling and thus reduce the excess of lithium mounted in the generator.
The fact that it is possible to produce electrochemical generators with certain dry "polymer electrolytes" and a metallic lithium anode which do not chemically consume lithium led to design experimental conditions and formulations enabling to produce optimized anode/polymer electrolyte and complete electrochemical generators capable of undergoing a large number of cycles of discharge/charge without a significant evolution of the morphology of the lithium anode and without substantial modification of the interface Li o /polymer electrolyte.
Contrary to the prior art, which is mainly interested with liquid electrolytes, it is now established that the evolution of the morphology of lithium during cycling, in the case of a liquid electrolyte, is rather the result of a mechanical operation on the thin film (stress induced by the cycles of discharge and charge) than of a passivation-chemical consumption of metallic Li o . In the present invention one takes advantage of this specific aspect of a solid system by combining the electrolyte and mechanical pressure to keep the lithium anode in compact form during cycling.
The present invention describes the required specifications for polymer electrolytes to ensure the cyclability of lithium anodes, such as with respect to mechanical properties of deformability and their chemical compositions, i.e., low content of movable species which are reactive towards Li, such as protic solvents or low molecular weight polymers including reactive terminal groups Li. The invention also utilizes with advantage the mechanical properties of the separator electrolyte to transmit pressure on the anode of Li.
It has now been established, contrary to prior art, that it is possible to provide optimized Li o /polymer electrolyte assemblies and rechargeable generators in which the excess of lithium with respect to the capacity of the cathode is clearly lower than 3, preferably between 1 and 2 and even lower than 1. | Rechargeable generator consisting of an anode of an alkali metal or a malleable alkali alloy, at least one polymer electrolyte which is conductive with respect to alkali cations and acts as separator, as well as at least one cathode which is reversible to cations of alkali metal and its current collector. The anode comprises a thin metallic sheet, which includes at the surface thereof a passivation film SEI capable of limiting reaction between the metal and the polymer electrolyte and to exchange lithium ions. The polymer electrolyte comprises a homogeneous separator which is capable of transmitting a pressure on the anode to resist against the dendridic strain of the metal of the anode by undergoing a rate of deformation lower than 35% of its thickness. The polymer electrolyte of the separator, contains a maximum amount of species which are reactive towards lithium and which can accumulate at the surface of the anode to permit a preservation of the quality of the ionic exchanges at the interface of the anode and electrolyte and finally, the combination of anode, electrolyte, cathode and collector is maintained under a mechanical strain which is sufficient to ensure that the separator confines the anode sheet in place to preserve the integrity of the lithium-electrolyte interface during consecutive cycles of dissolution/plating. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the storage of machine-readable data. More particularly, the invention concerns a method and apparatus for more efficiently copying source data to a log structured storage target by pre-configuring the target.
2. Description of the Related Art
With the increasing popularity of computers, users are faced with more data than ever to transmit, receive, and process. Data storage is also critically important to many applications. One popular data storage configuration is “log structured storage.” Log structuring is one way to manage units of storage, such as data tracks in an array of magnetic “hard” disks.
With log structured storage, a storage controller classifies storage space as “space-in-use,” “uncollected free space,” and “collected free space.” Space-in-use describes storage space that contains valid data. Uncollected free space describes storage space that does not contain valid data, but is nevertheless unavailable to store data. For example, if data records only occupy part of a logical unit (such as a “track”), the unoccupied part of that logical unit is uncollected free space. Although this space is unused, it is unavailable to store further data because data is stored in track-size segments regardless of whether the entire track is filled. Collected free space describes storage space that is available to store data. This kind of storage space, for example, may have been formerly occupied by valid data that has been deleted or otherwise released.
Typically, storage controllers use linked lists to keep track of the various types of log structured storage. For example, separate linked lists may be used to track space-in-use, uncollected free space, and collected free space. This approach to space accounting is beneficial to many users because it does not require much management overhead. In contrast, with non-log-structured configurations the storage system must be able to receive and process users'requests to allocate storage. This type of storage system first allocates storage of sufficient size to store data, and then stores the data in the allocated storage. Log structured storage systems avoid the need to allocate storage.
Instead of allocating storage in advance, log structured storage stores the data one logical unit at a time. For each logical unit of data to be stored, the storage controller first consults the “collected free space” list to identify a unit of available storage space, and then stores the data in the free space. When there is a small amount of data to write, or a large amount of collected free space, storage is completed rapidly. In many cases, the storage controller is able to maintain a sufficient amount of collected free space in advance by running a collector subprogram to identify suitable data storage and reclassify it as collected free space. This type of collection, called “off-line collection” herein, may be performed periodically, whenever uncollected free space exceeds a certain threshold, etc.
Despite the use of off-line collection, a situation can arise when the data to be written exceeds the collected free space. In this event, the storage controller invokes another collection procedure, referred to herein as “on-line collection.” Namely, when there is no more collected free space, the storage controller performs the following steps for each storage track: (1) identifying a track of uncollected free space, (2) changing status of this track to “collected free space,” (3) writing the data to the freed unit, and (4) changing the reused unit's listing to “space-in-use.” Although on-line collection is beneficial from the standpoint of minimizing overhead, it incurs a significant delay, which may be too much for some users. Chiefly, users may experience excessive delays when there are many write operations to perform, but relatively little collected free space. One situation exemplifying this problem is a full volume copy, a task that copies an entire volume of data to a target storage, and therefore involves many write operations.
An example of this situation is illustrated in FIG. 1, which shows contents of a log structured storage during various stages of a full volume copy. At first, the log structured storage has the contents 100 . The contents 100 include other data 102 (unrelated to the full volume copy), an existing version of the volume being copied 104 , and some collected free space 106 .
When the full volume copy operation begins, it first writes data of the new version to the free area 106 , until this area is full. At this point, the device has contents 103 , including the formerly-free area 108 , now filled with one part of the volume being copied. At this point, the device is full. To continue the full volume copy, then, the on-line collector must be used to examine and collect storage space to make more collected free space. In particular, the on-line collection process is invoked for each track of source data to be stored. This involves searching the log structured array for uncollected free space, and then consolidating, moving, and otherwise reorganizing data to convert the uncollected free space into collected free space. For example, if two tracks are each half-full (i.e., half space-in-use and half uncollected free space), the on-line collection process might relocate data from both tracks together onto a single track, and list the address of the old track as collected free space.
This process continues until the entire volume has been copied, at which time the device has the contents 105 . Specifically, the volume has been completely written, as shown by 108 and 110 . The remainder 112 of the existing version 104 is then subject to eventual off-line collection, or possibly on-line collection if the storage controller writes further data before off-line collection is activated next.
Some users may find the scenario of FIG. 1 to be undesirable because of the time delay involved. The chief delay is incurred by the consolidating, moving, and reorganizing of data to convert uncollected free space into collected free space. Moreover, this process is invoked repeatedly since on-line collection is invoked for each track to be written. When the source data is sizeable and the collected free space is low, data storage efficiency is at its lowest level.
Consequently, the existing on-line collection process is not completely adequate for some applications due to certain unsolved problems, which ultimately slow the overall storage process.
SUMMARY OF THE INVENTION
Broadly, the present invention concerns a method and apparatus for more efficiently copying source data to a log structured storage target by pre-configuring the target. The invention may be practiced in a system including a host, a storage controller, and the log structured target storage. The host maintains metadata identifying logical units of stored data, and the storage controller maintains a directory classifying storage space as being uncollected free space, collected free space, or space-in-use.
First, the host receives input including source data and specification of a logical unit for the source data. In response, the host directs the storage controller to classify any of the log structured storage space that already contains data corresponding to the specified logical unit as uncollected free space. This pre-configures the log structured storage to more efficiently receive the source data. In one embodiment, the host may first consult the directory to determine whether the specified logical unit already exists in storage, and only if so, proceed to re-classify the storage space as uncollected free space. In another embodiment, the host may blindly issue a “space release” instruction for the specified logical unit, which is ignored by the storage controller if the logical unit does not already exist in storage.
After pre-configuration, the host instructs the storage controller to write the source data to the log structured storage. When the storage controller completes the write the controller updates its directory to show the storage space occupied by the source data as space-in-use, and the host changes the metadata to associate the written source data with the specified logical unit.
In one embodiment, the invention may be implemented to provide a method to more efficiently copy source data to log structured storage by pre-configuring the target storage. In another embodiment, the invention may be implemented to provide an apparatus, such as a storage controller or storage subsystem, programmed to more efficiently copy source data to log structured storage by pre-configuring the target storage. In still another embodiment, the invention may be implemented to provide a signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital data processing apparatus to perform method steps for more efficiently copying source data to log structured storage by pre-configuring the target storage.
The invention affords its users with a number of distinct advantages. Chiefly, pre-configuration according to this invention readies the log structured storage to quickly receive the source data without requiring the time-consuming on-line collection process. Accordingly, write operations are completed more quickly, especially when there are many records to write and little collected free space remaining on the storage. One common example of this situation is the “full volume copy” operation. The invention also provides a number of other advantages and benefits, which should be apparent from the following description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the contents of an exemplary log structured data storage space before and after a full volume copy operation, in accordance with the prior art.
FIG. 2 is a block diagram of the hardware components and interconnections of a data storage system in accordance with the invention.
FIG. 3 is a block diagram of a digital data processing machine in accordance with the invention.
FIG. 4 shows an exemplary signal-bearing medium in accordance with the invention.
FIG. 5 is a flowchart of an operational sequence for performing a volume copy with pre-configuration of log structured storage.
FIG. 6 is a block diagram showing the contents of an exemplary log structured data storage space before and after a full volume copy operation with storage pre-configuration, in accordance with the invention.
DETAILED DESCRIPTION
The nature, objectives, and advantages of the invention will become more apparent to those skilled in the art after considering the following detailed description in connection with the accompanying drawings. As mentioned above, the invention concerns a method and apparatus for more efficiently copying source data to a log structured storage target by pre-configuring the target.
HARDWARE COMPONENTS & INTERCONNECTIONS
Storage System Structure
One aspect of the invention concerns a storage system, configured to efficiently copy source data to log structured storage as discussed below. As an example, this system may be embodied by various hardware components and interconnections as described in FIG. 2 . More specifically, the system 200 includes a host computer 202 , also called a “host.” The host 202 is coupled to a primary storage site 204 , a secondary storage site 210 , metadata storage 216 , and a tape storage 218 .
The host 202 may be implemented by various digital processing units, such as a mainframe computer, computer workstation, personal computer, supercomputer, etc. In one specific example, the host 202 may comprise an IBM mainframe computer such as an S/390 machine supporting the MVS operating system.
The metadata storage 216 contains various statistics (called “metadata”) about the data stored by the primary storage site 204 , secondary storage site 210 , and tape storage 218 . For example, the metadata storage 216 may contain high level metadata such as mapping between named datasets and the logical volumes in which they are stored. The metadata storage 216 may be implemented by a disk drive storage, on-board storage of the host 202 , battery powered RAM, or another suitable storage type.
In the illustrated example, the primary site 204 contains a primary controller 206 coupled to a secondary storage 208 . Similarly, the secondary site 210 includes a primary controller 212 coupled to a secondary storage 214 . Each of the primary and secondary storage sites may be embodied, for example, by an IBM brand RAMAC storage subsystem. In this particular embodiment, the storage 208 / 214 comprises magnetic disk drive storage.
In contrast to the disk media of the primary and secondary storage 208 / 214 , the tape storage 218 utilizes magnetic tape media. As such, the tape storage 218 may be suitable for longer term data archival. As an example, the tape storage 218 may comprise an IBM model 3590 tape storage system.
The foregoing example illustrates one hardware environment in which the invention may be applied. This particular setup is especially useful for maintaining backup copies of data for disaster recovery and the like. In this application, the primary storage site 204 is used to store primary or “source” data, with the secondary site 210 and/or tape 218 maintaining backup copies of the source data. In this environment, the host 202 may serve to implement a data mover, such as the IBM Extended Remote Copy (“XRC”) product, which is commercially available and widely known in the art.
Log Structured Storage
One feature of the invention is the copying of data to a target location of log structured storage. For explanatory purposes, the target location is assumed to be the secondary site 210 in the example of FIG. 2 . The copy operation may involve copying of one or more datasets, or a larger scale copy such as a full volume copy operation. Furthermore, these copying operations may be embodied in move, migrate, restore, or other operations that write data to storage and thereby copy the data.
The target storage (i.e., the secondary storage 214 in this example) is configured as log structured storage. Accordingly, the storage controller 212 maintains statistics that classify storage space of the secondary storage 214 as (1) collected free space, (2) uncollected free space, or (3) space-in-use. These statistics are stored in a directory 250 , and may be organized in various forms, such as a linked list, table, database, etc. The controller 212 also maintains map 251 that cross-references the name of each logical unit contained in the storage 214 with the physical space actually occupied by that data.
Digital Data Processing Apparatus
In contrast to the overall data storage system described above, another aspect of the invention concerns a digital data processing apparatus, specifically configured to implement the host 202 .
FIG. 3 shows an example of one digital data processing apparatus 300 . The apparatus 300 includes a processor 302 , such as a microprocessor or other processing machine, coupled to a storage 304 . In the present example, the storage 304 includes a fast-access storage 306 , as well as nonvolatile storage 308 . The fast-access storage 306 may comprise random access memory, and may be used to store the programming instructions executed by the processor 302 . The nonvolatile storage 308 may comprise, for example, one or more magnetic data storage disks such as a “hard drive,” a tape drive, or any other suitable storage device. The apparatus 300 also includes an input/output 310 , such as a line, bus, cable, electromagnetic link, or other means for the processor 302 to exchange data with locations external to the apparatus 300 .
Despite the specific foregoing description, ordinarily skilled artisans (having the benefit of this disclosure) will recognize that the apparatus discussed above may be implemented in a machine of different construction, without departing from the scope of the invention. As a specific example, one of the components 306 , 308 may be eliminated; furthermore, the storage 304 may be provided on-board the processor 302 , or even provided externally to the apparatus 300 .
OPERATION
In addition to the various hardware embodiments described above, a different aspect of the invention concerns a method for more efficiently copying source data to a log structured storage target by pre-configuring the target.
Signal-Bearing Media
In the context of FIGS. 2-3, such a method may be implemented, for example, by operating the host 202 , as embodied by a digital data processing apparatus 300 , to execute a sequence of machine-readable instructions. These instructions may reside in various types of signal-bearing media. In this respect, one aspect of the present invention concerns a programmed product, comprising signal-bearing media tangibly embodying a program of machine-readable instructions executable by a digital data processor to perform a method to more efficiently copy source data to log structured storage target by preconfiguring the target.
This signal-bearing media may comprise, for example, RAM (not shown) contained within the host 202 , as represented by the storage 304 . Alternatively, the instructions may be contained in another signal-bearing media, such as a magnetic data storage diskette 400 (FIG. 4 ), directly or indirectly accessible by the host 202 . Whether contained in the storage 304 , diskette 404 , or elsewhere, the instructions may be stored on a variety of machine-readable data storage media, such as direct access storage (e.g., a conventional “hard drive” or a RAID array), magnetic tape, electronic read-only memory (e.g., ROM, EPROM, or EEPROM), an optical storage device (e.g., CD-ROM, WORM, DVD, digital optical tape), paper “punch” cards, or other suitable signal-bearing media including transmission media such as digital and analog and communication links and wireless. In an illustrative embodiment of the invention, the machine-readable instructions may comprise software object code, compiled from a language such as “C,” etc.
Overall Sequence of Operation
FIG. 5 shows a sequence 500 for copying data to a log structured target, to illustrate one example of the method aspect of the present invention. For ease of explanation, but without any intended limitation, the example of FIG. 5 is described in the context of the system 200 described above. The sequence 500 , which is performed by the host 200 , is initiated in step 502 when the host 202 receives a storage request including source data and specification of a target logical unit for the source data. For example, the step 502 may occur when the host 202 receives a 100 Kb source dataset and specification of a particular volume of the secondary storage 214 as the target logical unit. The target logical unit may be identified by using a name of the associated data, such as a unique file name, volume name, or other dataset name. Alternatively, each logical storage unit may specify a logical volume, group of records, address extent, dataset, record, or another convenient unit of data regarded by the host 202 .
In the present example, where the target storage is the secondary storage 214 , the source data may originate from the primary storage 208 or the tape storage 218 . As an alternative, the source data may arise from another source, such as another computer, a server console or other interface to a human user, an application program running on the host 202 or elsewhere, etc.
After step 502 , the host 202 asks whether the source data meets a minimum threshold size (step 504 ). If this size is met, data storage will be expedited by performing a “space release” action before starting to store the source data, as explained below. The threshold is predetermined, and may be fixed by pre-programming the host 202 , entry by a system administrator, etc. As an example, the threshold may be about one megabyte. This threshold is easily met for large scape copy operations such as a (1) “full volume copy,” which copies an entire logical volume of data from one storage device to another, (2) “full volume restore,” which copies an entire volume of data from backup storage such as the tape storage 218 , (3) “XRC initialization,” which creates a new backup volume by copying an entire primary volume, or (4) other such operations.
If the threshold is not met, then storage of the data is not likely to be any faster with the space release action. In this event, step 504 advances to step 510 , which copies the source data without pre-configuring the target storage. Following step 510 , the sequence 500 ends in step 512 .
In contrast, if step 504 finds that the threshold is met, the host 202 in step 506 asks whether the specified target storage is log structured. If not, then the space release concept (discussed more thoroughly below) is inapplicable, and step 506 proceeds to 510 , which copies the source data without pre-configuring the target storage. The routine 500 then ends in step 512 .
In contrast to the negative exits from step 504 / 506 , step 508 is performed if the threshold is met (step 504 ) and the target storage is log structured (step 506 ). Step 508 involves a “space release” action, which is implemented by the host 202 instructing the secondary controller 212 to classify certain space of the target storage as uncollected free space. Namely, the host 202 directs the secondary controller 212 to reclassify any existing storage space corresponding to the source data as collected free space. This space is amenable to such reclassification (and effective deletion of its contents) because the newly received source data constitutes a new version of the existing data. The space release action is issued specifically for the logical unit of the source data; accordingly, if data corresponding to the space logical unit already exists on the storage 214 , the space release command is effective in deleting the data by reclassifying it as collected free space in the directory 250 . The logical unit of the source data (new) and stored data (old) may comprise a volume serial number (“volser”), for example. To provide a further example, if the space release action (step 508 ) is issued for volser 1FX290-E, and data residing in the storage 214 has the same volser, the space release command is effective in deleting the existing data by reclassifying its storage space as collected free space in the directory 250 . In the illustrated embodiment, the host 202 issues a “space release” I/O command, which is a known command utilized by IBM brand RAMAC storage subsystems.
In the RAMAC system, the storage controller 212 ignores host-issued space release commands if a counterpart to the specified source data does not already reside on the secondary storage 214 . Therefore, there is no need for the host 202 to determine whether a previous version of the source data already exists on the target storage 214 .
In a different embodiment, the host 202 may consult its metadata 216 before issuing the space release command to determine whether a previous version of the specified source data already exists on the target storage 214 . This involves consulting the metadata 216 to ascertain whether the source data's logical unit (e.g., name) is already listed therein. In the illustrated example, where the source data is a full volume, this is performed by consulting the metadata 216 to determine whether the volume serial number (“volser”) of the source data is already listed in the metadata 216 . If not, the host 202 may skip issuance of the space release command.
Following step 508 , the host in step 510 instructs the secondary storage controller 212 to write the source data to the log structured secondary storage 214 . As part of this process, the secondary controller 212 also changes its directory 250 to list the space now occupied by the source data as space-in-use. Also, in step 510 , the secondary controller 212 updates its map 251 to show the storage locations of the source data. This may be performed, for example, by ensuring that the map 251 cross-references the source data's volser to the physical storage space containing the source data. As a further part of step 510 , the host 202 may update its metadata 216 to properly reflect storage of the source data. For example, this update may involve changing the metadata 216 to show the correct volume, cylinder, sector, track, or other logical unit where the source data is stored.
For various reasons, the copying of step 510 can be completed more efficiently than prior techniques. Namely, if the target storage contains uncollected free space due to the space release of step 508 , this space will have a substantial size (since the threshold of step 504 was met). This large amount of uncollected free space is easily converted to collected free space by the on-line collection process, which is invoked by the copy operation of step 510 . Similarly, this uncollected free space may be converted to collected free space if the off-line collection process is invoked before step 510 . Thus, the copy operation is not burdened with the need to reconfigure space-in-use to create larger blocks of uncollected free space as each track of source data is stored to target storage 214 .
After the expedited copy operation of step 510 completes, the routine 500 ends in step 512 .
State of Target Storage: Step-by-Step
FIG. 6 further illustrates the operation of the invention by progressively depicting the state of the secondary storage 214 in several simplified block diagrams. Before performing the routine 500 , the target storage 214 has the contents 600 . The contents 600 include other data 604 (unrelated to the present copy operation), a previous version of the source data being copied 606 , and some collected free space 608 .
After the size threshold is met (step 504 ), and the target storage is found to be log structured (step 506 ), step 508 performs the space release operation, as discussed above. After the space release operation, the target storage 214 has the contents 601 . The To contents 601 include other data 604 (as before), where the remainder is now free space 610 . The free space 610 includes the collected free space 608 and the area 606 (which is now uncollected free space).
When the source data is written in step 510 , it can be efficiently written to the free space 610 , resulting in the contents 602 . Namely, the source data 612 is easily written into the free space 610 . The old source data 606 , first converted to uncollected free space by the space release operation of step 508 , is ultimately converted to collected free space by the off-line collection process, or by the on-line collection process during the copy operation itself (step 510 ).
OTHER EMBODIMENTS
While the foregoing disclosure shows a number of illustrative embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims. Furthermore, although elements of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. | Source data is more efficiently copied to log structured target storage by pre-configuring the target storage. The invention may be practiced in a system including a host, a storage controller, and the target storage. The host maintains a directory identifying logical units of stored data, and the storage controller maintains records classifying storage space as uncollected free space, collected free space, or space-in-use. First, the host receives input including source data and specification of a logical unit for the source data. In response, the host directs the storage controller to classify any storage space of the log target storage containing data of the specified logical unit as uncollected free space. This pre-configures the log structured storage to more efficiently receive the source data. In another embodiment, the host may consult the directory to determine whether the specified logical unit already exists, and only if so, proceed to direct re-classification of the storage space as uncollected free space. In another embodiment, the host may blindly issue a "space release" instruction for the specified logical unit, which is ignored by the storage controller if the logical unit does not already exists in storage. After pre-configuration, the host instructs the storage controller to write the source data to the log structured storage. The storage controller performs the write, and also changes the directory to classify the storage space now occupied by source data as space-in-use. |
BACKGROUND OF THE INVENTION
In the generation of continuous pulse trains, such as the rectangular-wave signal which is commonly used to synchronize the components (e.g., flip-flops, gates, input-output peripherals) of digital computers, wide use is made of sine-wave oscillators followed by clipping and/or other pulse-shaping circuits. Frequently, in order to achieve a high order of stability without costly complications, crystals are incorporated in the circuitry to establish the frequency of oscillation. However, crystal oscillators inherently produce output signals rich in harmonic content. Presuming that what is desired is that the circuit be permitted to issue, for instance, its fundamental frequency only, it is required that there be provision for insuring that it "lock" to the fundamental to the exclusion of all the harmonics. Several ways of accomplishing this are known. Firstly, there may be used a crystal with a lower impedance at the desired harmonic in an oscillator circuit in which that impedance is a critical factor; the disadvantage here is that special precautions must be taken to insure that the crystal has the correct properties and close constraints thereon make it difficult to use production-quality units. Alternatively, additional frequency sensitive networks may be added to the oscillator loop, thereby, usually, adding a large phase shift at any frequency other than that desired; this requires that the rest of the oscillator loop be sensitive to the added phase shift, and may require the inclusion of special provisions to insure that the added phase shift inhibits oscillation. Also the additional frequency sensitive networks are often an inherent part of an amplifier, thus effectively limiting the oscillation frequency to an upper bound; a problem with this approach is that it is difficult to guarantee the upper frequency characteristics of an amplifier unless control is a function of the values of passive components instead of the limitations of active devices. This requires active devices with upper frequency limits certified to be higher than the frequency cutoff of the amplifier, a requirement not always readily accomplished.
If a crystal oscillator is considered in the time domain instead of the frequency domain, i.e., if bounds (upper and/or lower limits) are placed on the period of the output the use of one-shot timers and appropriate gates suggests several advantages. Firstly, circuit structure and operation are ideal for understanding by logicians of the computer field; analog amplifiers, filters, etc. need not be investigated or constructed. Secondly, the components are functionally the same as used in the rest of the logic system; thus, there is no need for special packaging for the clock oscillator circuits, for example. Thirdly, correct harmonic lock-on is assured by the one-shots; there are no phase margins or gain margins to calculate or compensations for any unexpected circuit parameter changes to include in the design.
SUMMARY OF THE INVENTION
This, then, is the approach to oscillator circuitry taken by the present invention. Specifically provided is a crystal oscillator having a pair of gates serially connected in its feedback path and a set of single-shot multivibrators cooperating with the gates. For one embodiment, for which signal period minimization (i.e., low pass) is desired, a pair of gates of the NOR type (Peirce circuits) are employed whereas, for another embodiment, for which signal period maximization (i.e., high pass) is desired, a pair of gates of the NAND type (Sheffer stroke circuits) are employed. Still another aspect of the invention teaches how the aforementioned embodiments may be combined to provide both bounds for the signal period (i.e., band pass).
DESCRIPTION OF THE DRAWINGS
FIGS. 1a and 1b are embodiments of oscillator circuits which include means according to the invention to provide a lower bound on the period of the output signal;
FIG. 2 is a oscillator circuit which includes means to provide an upper bound on the period;
FIG. 3 shows how the technique of the invention may be employed to provide an oscillator with a band pass characteristic; and
FIG. 4 is a set of idealized wave-shape diagrams at various points of FIG. 1 selected to demonstrate its operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the invention depicted in the figures are oscillator circuits in which the frequency-determining element is piezoelectric (a crystal), and oscillations thereof are maintained by a positive feedback path between the two crystal terminals.
Specifically, FIG. 1 is arranged so that elements in the feedback path lock the oscillation period to synchronize with the crystal fundamental and discriminate against, for instance, the odd harmonics which, as well known, crystal oscillators tend to generate readily. Thus, with reference to FIG. 1a, crystal 10 is paralleled by feedback path 12, which contains elements and interconnections required to sustain oscillations manifest at terminal 14. The elements in feedback path 12 comprise, in this case, a pair of gates 16, 18 and a pair of single-shot multivibrators 20, 22. Both gates 16, 18 perform the same logic, namely, the NOR function, according to which output line 24 is at an effective logic level (e.g. + 10 volts) only if both input lines 26, 28 are in coincidence at an ineffective logic level (e.g. 0 volts) and terminal 14 is at 10 volts only if both lines 24, 30 are at 0 volts; this logic may be represented algebraically as 24 = 26' 28' and 14 = 24' 30' , respectively. Single-shots 20, 22 are identical, both triggered by positive-going input transitions, the former form line 24 directly but the latter from line 24 indirectly through inverter 32 and thus actually responsive to negative-going transitions on line 24.
Gates 16, 18 and single-shots 20, 22 (as well as crystal 10) are components which have been well divulged in the engineering art and therefore will not be detailed further here; for instance, reference for the former may be made to chapters 3 and 4 of the book "Logical Design of Digital Computers" by M. Phister, Jr., Wiley, New York, 1958, and for the latter to the application note "The 9601, a Second Generation Retriggerable One-Shot," APP 173, by T. Gray, et al., March 1969, Fairchild Semiconductor, Mountain View, Ca., structured with an R-C network time constant to provide a pulse width slightly less in duration than the period of one half-wave of the fundamental frequency of crystal 10. Further, for an identification of the functions of graphic symbols in the figures, reference may be made to the compilation by the editors of Electronics found in the Apr. 3, 1975 issue thereof.
An example of the computation of the pulse width of single-shots 20, 22, based on the object of preventing circuit oscillations at the third harmonic of the natural fundamental of crystal 10 would specify as follows: ##EQU1## where T = pulse width
f 1 = fundamental
The above assures that each half-period of circuit output is longer than the half-period ##EQU2## of the third harmonic, and thus, output at that frequency is inhibited.
An example of the activity of the circuit shown in FIG. 1a is given in FIG. 4, a set of idealized waveshape diagrams for certain lines and terminals.
The first full-wave output of crystal 10 (line 26) indicates normal, i.e., on fundamental frequency, oscillation of the circuit; the waveshape for terminal 14 illustrates the output of the circuit. It is apparent that the latter "follows" the former and the triggering of single-shots 20, 22 (lines 30, 28, respectively), by the gate 16 signal leading and trailing edges, respectively, does not affect the output, since the single-shots both revert within a half-period.
The next half-cycle output of crystal 10 (line 26), is negative and shortened and, as before, gate 16 triggers single-shot 20 (line 30) at the leading pulse edge of the line 24 waveshape and single-shot 22 (line 28) at the trailing pulse edge. However, the circuit output, at terminal 14, does not switch at the end of the negative half-cycle since the output of single-shot 20 (line 30) is passed through gate 18. The output period is thus extended beyond the half-period of crystal 10 by the difference between the half-period and the pulse width of single-shot 20. Crystal 10 is thus locked at its fundamental for the next full cycle.
The succeeding positive half-cycle is again shown as shortened. This time only single-shot 22 is triggered (line 28), thereby keeping terminal 14 from switching at the negative-going crossover point of the signal on line 26.
From the above, it is apparent that the circuit of FIG. 1a contains provision for imposing a minimum oscillation period (i.e., maximum frequency) on crystal 10; of course, oscillations may occur at a lower frequency, but it has been noted that, if time constant T of single-shots 20, 22 contemplates a maximum frequency between the fundamental and second harmonic of crystal 10, the oscillator can be depended upon to lock on the fundamental.
It will also be noted that included in the circuit is provision for self-start of oscillations, comprising, as is typical in crystal-controlled oscillators which use digital circuitry having built-in amplification, resistor 52 connected between output terminal 14 and the input of gate 18; capacitor 54, connected between gates 16 and 18 provides isolation and coupling.
FIG. 1b shows an alternative arrangement of the FIG. 1a circuit for the accomplishment of the same objective, i.e., the maximization of the oscillation frequency. Operation of this circuit is sufficiently similar to that of FIG. 1a so that the foregoing description thereof will suffice for one skilled in the art; accordingly, it will not be detailed further.
The invention has been extended to a structure which minimizes the frequency at which a circuit may oscillate; for purposes of illustration here, the circuit of FIG. 1b has been chosen. It is apparent, as FIG. 2 shows, that the only modification required is to the logic performed by gates 16, 18 (renumbered as gates 36, 38): the required logic is the NAND function, according to which line 40 is at 0 volts only if both input lines 42, 44 are in coincidence at 10 volts and terminal 14 is at 0 volts only if both lines 40, 46 are at 10 volts. As in the case of FIG. 1b, the operation of the circuit of FIG. 2 is considered clear to those trained in electronics and will not be derived. It should be apparent that single-shots 48, 50 each limit a half-cycle of oscillation to a maximum period: if a half-period tends to extend, a corresponding single-shot cuts it off at a time corresponding to that for which the single-shot time constants have been selected. Obviously, if the selection corresponds to a maximum frequency between the fundamental of crystal 10 and its second harmonic, the fundamental will be locked out and the oscillator will provide output at a higher harmonic.
FIG. 3 shows how the circuits of FIGS. 1 and 2 may be combined to provide an oscillator forced to provide output at a predetermined harmonic (e.g., the fifth) of crystal 10 even though this harmonic is not normally preferred by the crystal-amplifier feedback loop arrangement. Here, the lower and upper constraints on the period are a function of single-shots 56, 58, 60, 62 whereas logical levels and appropriate signal routing to terminal 14 are established by inverter-amplifier 64, OR gates 66, 68 (for which the output is at the effective logic level only if at least one input is at the effective level) and NAND gates 70, 72.
It is recognized that, to some extent, the drawings and this description provide a rather broad teaching of the present invention. It is submitted that this is justified in view of the supplementary information easily available to those skilled in the computer arts. It is submitted that the logic and detailed circuitry may be structured by such practitioners along the guidelines established in the works referenced previously. Also, it will readily be appreciated that this specification implies no structural limitations to those acquainted with computers or logic design; in brief, the present description should be considered exemplary for teaching those skilled in the computer arts and not constrained to the showing herein or in the aforementioned references. | Disclosed is a circuit for locking a harmonic-rich oscillator, such as the crystal-controlled type, to provide as its output, a signal at a designated frequency characterized by minimum harmonic content and high stability. The circuit includes a combination of gates in the oscillatory feedback path controlled by single-shot multivibrators with time constants such that any tendency of the period of the output signal to compress or expand is overridden by the respective expansion or compression thereof by the appropriate single-shots. |
FIELD OF THE INVENTION
This invention relates generally to an automatic temperature control system and more particularly to one which can be user programmed for operation of a shower or bath.
BACKGROUND OF THE INVENTION
Most temperature controls designed for home baths are operated manually, that is, the user must adjust the hot and cold water proportions by feel until an ideal temperature is reached. Because it is difficult to make precise adjustments with manual units, and because the body is sensitive to small differences in temperature, considerable time and water may, be wasted in acquiring the most comfortable water temperature. In addition, as the supply water temperature is affected by the heat sink effect of plumbing pipes and fixtures through which it runs, and generally the user must make adjustments to compensate for this effect. Finally, as the hot water supply approaches depletion, the supply temperature begins dropping off so quickly that many times a constant, comfortable temperature of water is impossible to sustain by manual adjustment.
There is a need, therefore, for a convenient mixing device that quickly and efficiently performs precise adjustments to achieve and maintain a constant temperature output and on a preprogrammed basis.
SUMMARY OF THE INVENTION
In accordance with this invention, hot and cold water are controllably mixed in response to a selected temperature. As one feature of this invention, mixing is performed by a mixing valve having a hollow piston which moves back and forth within a housing through which hot and cold water is introduced. The piston and housing each include ports for accommodating hot water in, cold water in, and mixed water out. The piston input ports are offset from their housing counterparts, and a piston is precisely moved by a reversible electromagnetic force, Such as by a reversible motor, to allow any desired proportion of hot and cold water to enter the hollow piston. Mixed water then exits from the housing to tub or shower outlets. A motor control signal for controlling the motor is derived from a comparator which compares a signal representative of mixed water temperature with a selected temperature signal, thereby providing more or less hot water to effect the selected temperature.
As a further feature of the invention, a selected temperature signal is stored in a memory together with a selected tub/shower selection signal and duration signal as a set. As a further feature, these are programmed to commence execution at a selected future time or times. Execution of a program is effected by a conventional electronic control means such as by a microprocessor which, responsive to water temperature, controls the mixing valve responsive to rub/selector controls selection, and responsive to the duration signal controls on/off water flow.
As still another feature of the invention, measured water temperature is compared with a selected permissible high temperature as a scald protection feature and when a water temperature is detected above the selected temperature, water flow is shut off.
As still another feature of the invention, control means are provided which enables a user to increment or decrement the value of a preselected water temperature while the water is being drawn.
As still another feature of the invention, a digitally addressable switch is employed which must be addressed with a selected digital input before water delivery can be effected.
As still another feature of the invention, the rate of decrease of water temperature is monitored, and if the rate is above a preselected one, an indicator indicates that the hot water supply is being diminished.
As still another feature of the invention, a water temperature signal is converted to an audio signal which is announced by a speaker.
Finally, as a feature of the invention, a display, of selected time or temperature of water, is provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of an embodiment of the invention.
FIGS. 2a and 2b comprise a more detailed schematic illustration of the invention.
FIG. 3 illustrates a sectional view of a mixing valve assembly shown in FIGS. 1 and 2 together with certain interface drive circuitry.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates an example of the basic organization and configuration of the invention. Program and valve control 9, a conventional microprocessor, includes a number of programmable memories as shown which are loaded from key pad 12 and are illustrative of the basic events to be programmed and controlled. Program and valve control 9 is, in addition, controlled by an abbreviated, hand-held control 14 which, for example, may be readily operated while taking a bath, whereas key pad 12 typically would be mounted on a wall. Display 42 selectively displays time (from clock 11 of program and valve control 9), temperature, and temporarily, program selections pending their entry or execution, as the case may be. Key pad 12 includes the standard numeral designation buttons as well as certain special buttons as labelled. Hand-held control 14 has an additional set of buttons, up and down, whose function will be further described.
Water temperature is regulated by mixer valve assembly 10. It includes a slider type mixer valve 24 which is fed by hot and cold inlets 25 and 26, respectively. An outlet or outlets is connected to the inputs of shower/tub solenoid valves 86 and 88, whereby a mixture of hot and cold water is supplied to either. The actual mixture is controlled by the axial positioning of a valve piston driven by D.C. motor 34, in turn powered by a motor driver 36 and controlled by program and valve control 9.
The start/stop water flow is effected by shower solenoid valve 86 and tub solenoid valve 88. Each is selectively powered from solenoid driver 62 pursuant to control signals from program and valve control 9.
Tub drain 98 is controlled by a solenoid valve 40 which is selectively powered by solenoid driver 62, in turn controlled from program and control 9. This particularly enables tub inlet water to be passed through the drain until water temperature comes up to a preselected temperature, as will be explained.
The control of water temperature requires that the temperature of mixed water be measured, and this is effected by a conventional analog temperature sensor circuit 37 (FIGS. 1 and 2b), for example, employing a thermistor. The output of sensor circuit 37 is converted to an eight-bit digital signal by A/D converter 39 and supplied to program and valve control 9. The latter then effects a comparison between the selected and actual temperature values and controls motor driver 36 to cause motor 34 to operate mixer valve 24 to effect an appropriate adjustment in ratio between hot and cold water emitted. A voice synthesizer 44 (FIGS. 1 and 2b) is provided which, responsive to a temperature output of A/D converter 39 converts the temperature signal to an aural signal, which is then reproduced by a speaker 41 to provide a voice presentation of temperature.
FIGS. 2a and 2b together illustrate in somewhat greater detail the organization and operation of the system envisioned by this invention and particularly certain functions performed in program and valve control 9 (FIG. 1). The system is generally divided into storable registers 50 (FIG. 2a), preset program selector 49, discrete program director 51, and discrete valve controls and controlled valves.
Storable program group 50 is illustrative of the memory arrangement of program and valve control 9 (FIG. 1) wherein there is provided a plurality of registers, and specifically a stop signal register 52 and a group of registers 54a-54z, or a lesser number of registers, wherein each would include register space for storing one or more program words and wherein each word would include (1) a portion representative of tub/shower select, (2) a portion representative of temperature of bath water, and (3) a portion representative of duration of a bath. These are represented by the letters S, T, and D, respectively, In the case of three of them, 54x-54z, there is added an "h" for hot, "w" for warm, and "c" for cold opposite the temperature letter T. Thus, if one of these registers is employed, no specific temperature would be programmed.
Where a single sequence bath is involved, only a single word would be programmed into one of the registers, but where a sequence or stages of a bath are desired, then a word would be programmed in that register for each stage, which would then be executed in the sequence in which it was selected or stored. Thus, if it were desired to have as a first sequence a combination of shower, selected temperature, and selected duration followed by a different combination, for example, where a tub stage were employed and/or different temperatures or durations were desired, then an additional word or words would be programmed. Loading of the register would be effected by register load 56 from key pad 12 by operating the enter button in a conventional manner.
The system also provides for programming the start time, or reoccurring start times, for a bath programmed as above. This is effected by the timed selection for execution of the contents of the selected register of register 55a-55z, each being separately programmed by a particular user. To accomplish this, program selector 49 employs registers 55a-55z, each of which stores three discrete bits of data, one, the register R of one of registers 54a-54z wherein that user has previously stored a description of a desired bath as described. Second, under the label Ts, there is stored the time of start of a reoccurring times, such as a certain time each day. This time then controls an included time countdown which enables readout of that register at zero time. Third, each of these registers has a place for the storage of a common but confidential unlocking code, designated C, as a security means for enabling only a permitted user to load one of registers a-z, loading being effected by a conventional load control 61 from key pad 12.
Upon a countdown of time to the prescribed start time of one of registers 55a-55z, for example, e, its register designation is then fed to register selector switch 58, for example, register 54b of storage register 50 might be the one the instant user has previously programmed and would be selected. Selection is effected by supplying a readout to select switch 57. Select switch 57 typically would comprise a group of triggerable gates, whereby, upon activation by selector switch 58, the contents of register 54b would be selectively gated to the output of select switch 57 and then to decoder 59.
Decoder 59 is, at the same time as the preceding event, fed the contents of the C portion of the same register, register 55e. Decoder 59 includes a decoder and gate circuit, the decoder enabling the gate circuit when the correct code is received. When this occurs, the contents of register 54b is passed through to program director 51. As illustrated by T/S, Temp., and Dur. register 53, the data comprises bath duration instruction, a tub/shower instruction, and a temperature instruction as originally stored in registers 54a-54z under D, S, and T. Since the T/S and Temp. instructions are effective for the period of the duration instruction, the first one to be considered is duration. Thus, as shown, the time duration instruction is fed to decoder 64 which sets a countdown timer 66 to commence counting down, at the end of which the other instructions are cancelled and a new instruction word be loaded into register 53.
Assuming that a countdown is in progress for a particular program as just described for the tub/shower select and temperature, instructions for the same would be read out from register 53 for execution. First, with respect to the tub/shower select, the instruction would be decoded by decoder 60 which would include a solenoid driver 62 and place a drive signal output on lead B or B', B for tub and B' for shower. Each of these leads passes through contacts of digital scald protect relay 116 and analog scald protect 118 as shown in FIG. 2b. Lead B, when powered, operates tub solenoid 86, and lead B', when powered, operates shower solenoid 88.
Second, with respect to temperature, at a selected temperature, its instruction is read out to temperature register 68 (FIG. 2a). The temperature in register 68 may be incremented up or decremented down by an up/down button 16 or 18 of control 14. The contents of temperature register 68, as a command temperature signal, is fed to digital comparator 70 (FIG. 2b) together with an output of A/D converter 39 which provides a digital measure of water temperature as described above. The output 72 of comparator 70 being, for example, positive, indicating a low water temperature state; negative, indicating a high water temperature state; or zero, indicating a desired temperature state. This output is fed to motor driver 36 which converts the signal output to a related D.C. supply voltage to the input of motor 35 to operate mixing valve 24 in a direction to correct any error in temperature. The output of comparator 70 is also fed to zero detector 102 for control of drain valve 98, as will be further explained.
FIG. 3 illustrates in some detail mixer 24. In it, there is an outer valve body or housing 200 having a hot water inlet 25 and cold water inlet 26. A central cylindrical .Iadd.solid ep piston 210 is adapted to axially move in a central cavity 212, being held from rotating by guide pin 201 in guide opening 203. Piston 210 has an opening 214 extending from one side to the other and is adapted to differentially couple hot water inlet 25 and cold water inlet 26 to an axially positioned exit opening 216. Opening 216 is coupled via cavity 212 to an opening 218 in housing 24, with opening 218 communicating with a passageway 220 disposed as shown in FIG. 3. Passageway 220 terminates at opposite sides with outlet openings 222. Motor 34, controlled as described above, rotates screw shaft 211 in threaded opening 213 in piston 210 to axially move it in a direction to vary the ratio of hot and cold water admitted. Thus, mixed temperature water from these openings 222 is then supplied to tub on/off solenoid 86 and shower solenoid valve 88 and then through one of these valves which has been selected open for operation (FIG. 2b). Temperature sensor 37 is inserted into an opening 224 whereby the mixed output of water temperature is measured and employed as previously described.
As shown in FIG. 2b, drain solenoid valve 40 is a normally open valve and :is operated closed to close drain 98 under two conditions being present, the tub solenoid being energized to emit water and the temperature of mixed inlet water having risen to the selected temperature. The latter condition closes the normally open enabling contacts 100 via zero detector 102, and the former condition, the energized tub signal B, is thereby permitted to energize solenoid 443 and close drain 98. Actually, zero detector 102 provides a discrete output, for example, 12 volts, when the output of comparator 70 is zero or positive, indicating that the mixed water temperature is equal to or greater than a selected temperature. A latching circuit comprised of components 74 and 76, and an energizing source of power 78 is employed to hold the drain closed after the two conditions are removed, such as would be the situation when the tub finished filling and the tub user were taking a bath. To accomplish this, tub solenoid 40, when energized initially by the closing of contacts 100 and the presence of an energizing signal B, is employed to close normally open contacts 74, which in turn connects energizing source 76 to solenoid 90. To open the drain, normally closed contacts 78 are temporarily opened to break the energizing source 76 from solenoid 40 and thereby open normally open contacts 74 to deenergize the latching circuit and open drain valve 98.
Scald protection is redundantly provided via relays 116 and 118, each having two sets of normally closed contacts, one being in series with tub select B and the other in series with shower select B'. Relay 116 is driven by digital decoder-driver 120 which, responsive to a selected "excessive water temperature signal" from A/D converter 39, provides a relay operating voltage to close either one of solenoids valves delivering either tub or shower water. Relay 118 is directly driven by analog comparator-driver 121 responsive to an "excessive temperature" signal from temperature sensor 37 and operates in the same fashion to shut off a like solenoid valve.
The actual rate of flow or volume (CFM) into either tub or shower is controlled conventionally as with existing manually operated type valves or, for example, by an electrically operated valve and valve control 112 (FIG. 2b) wherein the valve opening is controllable in more than one size or degree of valve opening.
The system also provides for an indication of an approaching depletion of hot water. This is accomplished by temperature drop detector 128 (FIG. 2b) which is connected to temperature sensor circuit 37. Detector 128 comprises an analog differentiator which detects a decline in rate, temperature drop versus time, for example, on the order of 20 seconds, and provides an output to indicator 132 that greater than a selected differential signal has occurred. Indicator 132, for example, may include a tone generator and reproducer. Alternately, where only a tone generator, its output may be applied to speaker 41 as an indicator.
A typical operation of the system may be summarized as follows. To begin operation, the user must, via key pad 12 or hand control 14 (FIG. 2a), load at least one of the instruction registers 54a-54z with one or more instruction words. Typically, several instruction registers would be programmed to provide various options for the user. These programs may be loaded and then prestored in the instruction registers, or, they may be loaded just before or during tub or shower usage.
Typical programs would be as follows. For a time temperature "profile" program, the user would load two or more instruction words into one of instruction registers 54a-54z to program the mixer output water temperature to adjust automatically to each instructed temperature T and maintain that temperature for the instructed duration period D. If it is desired for the system to stop automatically after the last instruction word time period expires, the user would insert a stop command instruction at the end of the instruction word sequence or select via program select switch 57 the stop register 52 at the appropriate point in time. Otherwise the instruction register will continuously cycle the instruction words in sequence until the user sets select switch 57 to select stop command 52.
If the user desires only a single temperature operation, as would be the case in a more conventional use of the tub or shower, then an instruction register of registers 54a-54z would be programmed with only a single instruction word. If the user desires to automatically stop the operation after the instructed period of time, as described before, a stop instruction would be placed after the single instruction word, and the tub or shower operation would cease when the instructed time expired. Again, if continuous operation is desired, the stop instruction would be left out, and the operation of the tub or shower with the selected temperature would continuously repeat until the user sets select switch 57 to stop command 52.
Once the instructions words are loaded or programmed into the instructions registers 54a-54z, operation of the system may be initiated in either of two ways. First, the user may program the system to automatically start by presetting any one of registers 55a-55z of program selector 52 and thereby the time selection of a readout of registers 55a-55z. Each of registers 55a-55z represents a single option for automatic startup, and therefore there will be as many options as there are registers.
If the user desires for an automatic operation of an option to repeat, as would be the situation where the user desired to begin the bath water running at the same time every evening, then that particular option could be programmed to repeat. This also would include the capability to program sequences of repeat functions, as would be the case if the user desired to repeat an option for only a certain number of days in the week, i.e., Monday through Friday, or Tuesday and Thursday of every week. In this situation, the user would program one of registers 55a-55z as before, except that the sequences would be programmed to repeat in intervals as the user desires. Once the user programs a system to start automatically, when the timed portion Ts of the programmed one of registers 55a-55z arrives, the R portion of the instruction would be employed through selector switch 58 to read out the indicated instruction register of registers 54a-54z through select switch 57 to program director 51 as discussed above. This would assume, of course, that the correct code has been supplied decode switch 59 via the C portion of instruction registers 55a- 55z. This feature prevents unauthorized users, such as small children, from tampering with the system and starting it by accident. Where desired, there would also be included a digitally addressable "unlock" feature for setting the clocks 55a-55z such that unauthorized users would also be prevented from tampering with the programmed settings for automatic starts.
Once the system has read the first instruction word into register 51 (FIG. 2a), the system operates as follows. T/S in register 53 is read out and decoded by decoder 60, which then instructs tub/shower select circuit 62 to energize lead B or B' to open solenoid 86 or 88 (FIG. 2b). If the tub is selected, tub drain solenoid 40 will close the tub drain 98 when zero detector 102 detects that the proper mixer water output temperature has been reached according to comparator output 72.
As discussed above, with either solenoid valve 86 or 88 open, hot water and cold water flow into mixer 24. The temperature instruction Temp. of register 53 (FIG. 2a) is read to temperature register 68 and thereby supplied as a digital signal to comparator 70 (FIG. 2b) and thereby compared with the existing digital temperature signal from A/D converter 39. The difference of these two temperatures is an output of a polarity and/or value which motor driver 36 converts to a particular polarity drive signal which, when supplied to motor 34, will drive piston 210 in a direction to produce a selected temperature output 28 of mixer valve 24.
If the user desires to increase or decrease the temperature of the tub or shower water, an up button 16 or down button 18 would be toggled on hand-held control 14 to increment or decrement the selected temperature in register 68. Of course, if a "profile" instruction sequence is being read from one of instruction registers 54a-54z, the next instruction word will send a new instruction temperature to temperature register 53 which will be unaffected by any prior hot/cold adjustments.
As generally discussed above, at the same time that the selected temperature instruction Temp. is loaded into register 68 and the select instruction T/S entered, one of solenoid valves 86 or 88 is operated open, and time instruction Time would instruct timer 66 to begin counting down for the instructed time period. The time instruction in 66 determines the length of time that the temperature instruction in 53 and select instruction in 62 are operative. Alternately, a countdown timer may be employed that does not begin counting down until the proper temperature has been achieved at the mixer output 28. This would save the user from having to consider in his "profile" program the amount of time required for mixer 24 to readjust to each new temperature.
Once the countdown time has elapsed, register 53 is cleared and the next instruction word command is requested by an enable command to the selected register of registers 54a-54z. The next instruction word will be read into register 53, and the operation of the system as described will be repeated until the last instruction word in the program is reached. If there is a stop instruction after the last instruction word, solenoid valve 86 or 88 (FIGS. 1 and 2b) will close, and all but nominal power Will be removed from the circuitry. If no stop instruction is supplied, the first instruction word in the program will be reread into register 53, and the operation as described will continue until the user manually intervenes by entering a stop command via key pad 12 or hand control 14.
When water is flowing through solenoid valve 86 or 88, the user controls the flow volume at the tub or shower by flow control 112 as discussed.
Discrete and analog scald protect devices 120 and 121 (FIG. 2b) provide redundant protection against scalding by the series operation of switches 116 and 118 to shut off solenoid valves 86 and 88.
If the hot water supply temperature measured by sensor circuit 37 (FIGS. 1 and 2b) drops by at least a selected rate, detector 128 will signal indicator 132 and thereby advise the user of a depleting water state.
If the user desires to see the time or mixer output temperature, display 42 (FIG. 1) may be alternately switched to display one of those quantities.
If the user desires to have the temperature audibly pronounced, voice synthesizer 44 and speaker 41 will convert the digital time and temperature information to audio as described. | A bath water control system in which the bath water is selectively supplied a bath or shower outlets, and the water supply is as to both temperature and period of supply. These parameters may be prestored in a memory along with discrete start times whereby a programmed bath will be automatically available at a discrete time or times in the future. As a means of ensuring that water is not accumulated in the tub prior to water temperature rising to a selected value, the tub drain is closed only after input bath water reaches a selected temperature. Further, means are provided for turning off water in the event that water in excess of a selected value appears. Still further, the temperature of water is indicated both digitally and aurally. |
This is a continuation of co-pending application Ser. No. 07/530,837 filed May 30, 1990 now abandoned which is a division of Ser. No. 07/491,061 field Mar. 14, 1990 now U.S. Pat. No. 5,088,910.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to a system and process for making synthetic wood products, such as building materials, including roof shingles, siding, floor tiles, paneling, moldings, structural components, steps, door and window sills and sashes; house and garden items, such as planters, flower pots, landscape tiles, decking, outdoor furniture, fencing, and playground equipment; farm and ranch items, including pasture fencing, posts and barn components; and marine items, for example, decking, bulkheads and pilings, through a process which combines certain wood scrap material, such as cedar fiber waste, and plastic waste materials, such as high density polyethylene, low density polyethylene, polypropylene and mixtures thereof, and equivalent materials.
The starting wood and plastic materials are identified, processed, mixed, and then formed into building material products through use of an extruder and subsequent rolling processes to produce products which have advantages over natural wood and over other synthetic materials, such that products of the present invention are ordinarily less expensive; have excellent insulating properties; are highly resistant to insect infestation, rotting, splitting, cracking, warping, thermal expansion or absorption of moisture; can be easily shaped and machined; and, in many cases, have superior structural integrity.
2. Needs to Which the Present Invention is Directed
By current estimate, the United States generates half of the world's solid and industrial waste. By the year 2000, if present trends continue, the United States will be discarding 192.7 million tons per year. Only about 22% of this waste is projected to be recycled. Landfills are utilized for the disposal of much of this waste. The United States Environmental Protection Agency (EPA) estimates that by the year 2000, 75% of all existing landfills in the United States will be closed.
According to EPA statistics, discarded plastic presently constitutes about 7.3 percent of the U.S. waste stream. Only about 1% of this plastic waste is recycled. By the year 2000, production of plastics in the U.S. is expected to reach 76 billion pounds per year, with discarded plastics expected to make up 10% of the waste stream by weight and up to 1/3 by volume.
There is clearly a pressing need to adopt means by which plastics and other solid waste materials such as wood fiber waste can be recycled into new and useful products. The present invention meets such need.
3. State of the Art Prior to the Present Invention
There have been developed numerous methods for combining waste wood materials and binders. Examples of such methods can be found in the practice of pressboard and extrusion moulding technologies. However, it has been observed that these methods are limited in the raw materials that can be utilized and in the quality and application of the products produced.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a top view of the preferred material preparation auger of the present invention.
FIG. 2 is an end view of the FIG. 1 auger.
FIG. 3 is a view of a blade of the FIG. 1 auger.
FIG. 4 is an exploded perspective view of the preferred extruder of the present invention.
FIG. 5 is a side view of the preferred flying cutoff assembly of the present invention.
FIG. 6 is a downstream end view of the FIG. 5 assembly with the knife of the flying cutoff in the down position.
FIG. 7 is a downstream end view of the FIG. 5 assembly with the knife of the flying cutoff in the up position.
FIG. 8 is a side view of the preferred rolling and cooling conveyor of the present invention.
FIG. 9 is an end view of the FIG. 8 conveyor.
FIG. 10 is a top view of the FIG. 8 conveyor.
FIG. 11 is a side view of the FIG. 8 conveyor.
FIG. 12 is a front view of a preferred roller assembly of the present invention.
FIG. 13 is a side view of the roller assembly of FIG. 12.
SUMMARY OF THE INVENTION
The present invention allows for the utilization of a wide range of raw materials, previously considered economically and technically unfeasible, to produce various products made from recycled materials and which are of acceptable quality for numerous end uses. Furthermore, in many instances, the present invention makes possible the creation of a multiplicity of products with attributes superior to those of conventionally manufactured products.
By the present invention, wood fiber is identified, decontaminated, sized and dried, as appropriate, to achieve a moisture content of less than about 15% by weight. Also, waste plastic material, such as HDPE and LDPE, is identified, cleaned and dried.
The wood fiber is then mixed with the waste plastic material in a range of ratios from about 40% plastic/60% fiber to about 60% plastic/40% fiber by weight, with a 45% plastic/55% fiber mix preferred. The plastic component of the mix may be 100% of one type of plastic or may be a controlled blend of plastics, such as 60% LDPE/40% HDPE by weight blend.
The mix is then mixed, heated and kneaded to a temperature high enough to melt the plastic and enable the melted plastic to encapsulate the wood fiber particles. This temperature is defined as the encapsulation point.
The mix is then fed to a material preparation auger, where it is cut into small chunks suitable for use as a feed to an extruder.
The chunks are then fed to an extruder and formed into a product having various cross sections in accordance with the cross section of a die chosen for use with the extruder. The temperature of the product is maintained by various means.
After extrusion, the product is cut into desired lengths, inspected, rolled, cooled, collected and then either subjected to further processing or assembled for shipment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to the general process steps used to produce the synthetic wood products of the present invention, as well as with reference to examples in which specific starting materials and specific processing parameters are set forth, preferred embodiments of the present invention will be described.
In preferred embodiments of the present invention waste wood fiber and waste plastic are reclaimed and processed into various synthetic wood products such as, for example, building materials, including roof shingles, siding, floor tiles, paneling, moldings, structural components, steps, door and window sills and sashes; house and garden items, such as planters, flower pots, landscape tiles, decking, outdoor furniture, fencing and playground equipment; farm and ranch items, including pasture fencing, posts and barn components; and marine items, for example, decking, bulkheads and pilings.
STEP 1
The first step in the process is the identification and collection of wood fiber starting materials, preferably waste wood materials such as cedar fiber. Once identified and collected, the waste wood starting material is placed into a holding bin or storage area.
Although other wood fibers may be used, cedar fiber is the preferred wood fiber for the present invention. Cedar fiber, as envisioned within the scope of the invention, is presently available as a waste product from cedar oil mills. Raw waste from cedar oil mills usually includes cedar fiber contaminated with rocks, metal and relatively large chunks of wood, all of which must be removed from the raw cedar fiber waste prior to placing the desired cedar fiber waste into a holding bin.
In addition to the other wood fibers being usable as a starting material, mixtures of cedar fiber and other wood fibers may be used as a starting material.
STEP 2
Once identified, the cedar fiber raw feed material is processed to remove contaminants. The preferred decontamination equipment includes screens, shakers, separators and magnets to remove various foreign materials such as stones, metal and large pieces of wood.
All of the decontamination equipment envisioned for use in the present invention are conventional and their use is well known for the stated functions.
In addition to using magnets to remove metallic contaminants found in the raw cedar fiber feed material, or other raw wood fiber feed, it is preferred that additional magnets be used at various locations throughout the processing system for the purpose of removing pieces of metal which might break away from processing apparatus or otherwise become a contaminant during processing.
STEP 3
After contaminant removal, the cedar fiber is subjected to conventional grinders, such as hammermills, and vibrating screens in order to produce a processed fiber feed having maximum size characteristics. The preferred maximum diameter of the wood fiber is one-eighth inch, and, thus, screens sized to yield minus one-eighth inch diameter fibers are preferred. Since much of the wood fiber is in the form of slivers, the screens will allow the passage of fibers having lengths greater than the maximum allowed diameter. The preferred fiber length is less than one inch.
STEP 4 (Proposed)
At this point in the process, it is preferred that the cedar fiber have a certain maximum moisture content by weight. For further processing, the moisture content of the cedar fiber should not exceed about 15% by weight and it is preferred that the moisture content of the cedar fiber be less than about 12% by weight.
It has been found that cedar fiber from cedar oil mills typically has about 15% to 30% moisture by weight, although this percentage can be higher, depending on the circumstances of the cedar oil mill processing and weather conditions, such as relative humidity, recent rainfall, etc.
The moisture content of the cedar fiber may be reduced at different times and/or locations. For example, the cedar fiber may be dried at the cedar oil mills prior to delivery to the synthetic wood product manufacturing site. In such event, the cedar fiber is dried by means of a conventional dryer to a moisture content of less than 15% by weight.
However, because cedar fiber, like other wood fiber, is hygroscopic and tends to pick up moisture the more it is handled and the longer it is held after being subjected to a drying procedure, it is envisioned that a preferred drying step take place at this stage of the process.
A conventional, variable speed in-line wood dryer fueled by waste wood chips or other fuel may be used to reduce the moisture content of the cedar fibers. It is envisioned that any conventional equipment may be used so long as the function of effectively reducing the moisture content of the sized cedar fibers, or their equivalent, is accomplished. It is also envisioned that microwave technology may be used to flash steam off from the sized cedar fiber to achieve the desired moisture content reduction.
The objective of reducing moisture content to less than approximately 15% by weight at this step is considered important because it has been discovered that excessive moisture in the cedar fiber material will cause pitting or bubbling in the finished product.
Thus, whatever the identification of the wood product raw feed material is, it is important to reduce the moisture content to a level which will avoid the problems of pitting or bubbling in the finished product.
STEP 5
The sized, and heat treated, as appropriate, cedar fiber is then conveyed by conventional means, such as a bucket elevator, to a conventional holding bin or storage area.
STEP 6
In parallel with the identification and preliminary processing of the wood fiber, a corresponding identification and preliminary processing of waste plastic material is accomplished.
First, waste plastic raw materials are identified, collected and placed into conventional holding bins. Presently, it is envisioned that high density polyethylene (HDPE) and low density polyethylene (LDPE) are the preferred types of waste plastic materials.
HDPE has a density of greater than approximately 0.94 g/cc measured in accordance with ASTM D1505, and a melt index of less than approximately 1.0 g/10 minutes, measured in accordance with ASTM D1238, Condition 190/2.16. An example of such type material is Marlex polyethylene, resin number EHM 6007, manufactured by Phillips 66, Bartlesville, Okla.
LDPE has a density of less than approximately 0.94 g/cc, measured in accordance with ASTM D1505, and a melt index of greater than approximately 1.0 g/10 minutes, measured in accordance with ASTM D1238, Condition 190/2.16. An example of such type material is Polyethylene 5004 extrusion coating resin manufactured by The Dow Chemical Company, Midland, Mich.
Preferably, the waste plastic materials are segregated into different holding bins according to type.
Numerous sources of waste LDPE and HDPE are available and it is envisioned that waste plastics from any of these sources may be used in the present invention. Also, it is envisioned that other types of plastics may be used within the scope of the present invention. Other plastics which may be considered equivalent for purposes of the present invention are those which can be processed with extrusion equipment of the type disclosed herein and at temperatures which would not adversely affect the wood fiber feed component in terms of producing unacceptable product for a desired end use. Also, of course, any plastic having the appropriate temperature and physical properties must also be relatively inert in that it must be approved for use in environments in which the end product is used, as well as in the manufacturing environment.
Preferred sources of LDPE are floor sweepings from conventional petrochemical plants, commonly referred to as sump LDPE. Sump LDPE is known to have some polypropylene material contaminant mixed in with it and this contaminant has not adversely effected the end products produced with the process of the present invention. Also, "off spec" LDPE purchased as waste product from petrochemical plants is another preferred source of LDPE.
It is envisioned that another source of LDPE will be plastic lining from certain food packaging operations and beverage container operations, as well as other types of plastic coated papers. It is known that the paper in such plastic coated paper items may be recycled through a process in which the paper and plastic are separated from each other, i.e., hydropulping. It has been found that the LDPE resulting from hydropulping is acceptable as a plastic feed material for the current invention so long as the residual paper content is not excessive, that is, does not exceed about 10% by weight.
Preferred sources of HDPE are articles manufactured from HDPE, such as commonly produced containers for milk, distilled water, fruit juices, soft drink concentrates, liquid detergents, bleach, etc. Also, "off spec" HDPE purchased as waste product from petrochemical plants is another preferred source of HDPE.
STEP 7
The raw plastic material feed is then cleaned, if necessary, to remove unwanted foreign or contaminant material. The contamination removal step employs conventional screens, shakers, magnets and washing equipment, as is well known. Even though it is believed that most sources of LDPE and HDPE are essentially contaminant free, it is preferred that, as a precaution, all plastic feed material introduced into the process be subjected to cleaning or contaminant removal.
STEP 8
The cleaned plastic feed material is then dried to remove any residual moisture from the aforementioned washing procedure. The dried plastic feed material preferably has 0% moisture content by weight, however, trace amounts of moisture may remain with the dried plastic feed material without significantly adversely affecting subsequent processing steps. The preferred drying operation is accomplished through conventional use of a conventional, vertical, in-line spin air dryer.
STEP 9
The dried plastic feed material is then conveyed to holding bins and classified into various bins according to each type of plastic feed material.
STEP 10
Treated fiber from Step 5 and treated plastic from Step 9 are then weighed in accordance with a desired, predetermined mix ratio by introducing such fiber and plastic into a hopper equipped with scales for determining the weight of each component. Conventional means, such as screw conveyors or bucket elevators, may be used to convey the wood fiber and plastic material from their holding bins to the hopper.
The preferred ratio of the cedar fiber to plastic in the mix is 45% plastic and 55% fiber, by weight. It has been found that the ranges within which usable product may be achieved are from about 40% plastic and 60% fiber to about 60% plastic and 40% fiber by weight.
The particular mixture of ingredients is chosen as a function of the characteristics of the final product desired, the type of plastic and type of fiber chosen. For example, in a preferred mix formulation, 100% LDPE is used as the 45% plastic component and 100% cedar fiber as the 55% wood component. In another preferred mix formulation, a 60/40 blend by weight of LDPE and HDPE, respectively, is used as the 45% plastic component and 100% cedar fiber as the 55% wood component.
During the step of preparing the mixture, the fiber and plastic may be fed to the hopper in any order. For example, if a 55% fiber to 45% plastic mix is desired, 550 lbs. of fiber could be added to the hopper, then 450 lbs. of plastic could be added, or vice versa.
After the entire weight of fiber and plastic is conveyed to the hopper, then the entire weight, in this example 1000 lbs., would be discharged for further processing in accordance with the present invention.
In this example, if the plastic were totally LDPE, 450 lbs. of LDPE would be added to the hopper. If the plastic were 60% LDPE and 40% HDPE, then 270 lbs. of LDPE and 180 lbs. of HDPE would be added to the hopper.
It has been found that a relatively stronger end product can be produced by inclusion of HDPE in the mix formulation. For example, when the products made with the two preferred mix formulations mentioned above, i.e., the first with 100% LDPE plastic and the second with the 60 LDPE/40 HDPE plastic blend, are compared for the force required to pull a screw from each type, approximately 42% more lbs. force is required to pull a screw out of the product containing HDPE than to pull an identical screw, identically mounted, out of the product containing all LDPE as its plastic component.
STEP 11
After weighing the desired amounts of fiber and plastic to achieve the predetermined mix and total weight desired, the mixture in the hopper is unloaded and discharged into a conventional, cleated belt conveyor to a batch holding bin.
STEP 12
From the holding bin the cedar fiber and plastic mix are gravity fed through a chute into a conventional compounding machine for heating, mixing and kneading. Although numerous conventional machines may be utilized, the preferred compounding machine is a modified sigma blade, double arm mixer which is insulated and jacketed for heating with hot oil up to temperatures of about 500° F.
The processing objectives to be met within the compounding machine are to heat the fiber/plastic mixture to a temperature high enough to melt the plastic and to thoroughly mix the wood fiber with the molten plastic so that the molten plastic will bond with and encapsulate the wood fiber. As mentioned earlier, this temperature is defined as the encapsulation point. This processing step yields a homogeneous mass having the consistency of a ball or lump of sticky cookie dough.
Depending upon the plastic or combination of plastics chosen, the encapsulation point to which the fiber plastic mixture should be raised within the compounding machine will vary. For instance, if the plastic is comprised of only LPDE, the temperature of the fiber/plastic mixture should be raised to approximately 310° F. If the plastic is comprised of 60% LDPE and 40% HDPE, the mixture should be raised to approximately 350° F.
In practice, the oil in the jacket of the compounding machine is heated to within the range of approximately 400° F. to 500° F., preferably 450° F., prior to introduction of the fiber/plastic mixture. Then the fiber/plastic mixture is introduced into the compounding machine and the temperature of the fiber/plastic mixture is monitored until it reaches the desired level, at which time the mixture is discharged from the compounding machine.
Because different fiber/plastic mixtures must be heated to different encapsulation points to achieve adequate processing within the compounding machine, processing time within the compounding machine varies. Generally, with all other factors being constant, the higher the encapsulation point, the longer the processing time will be.
STEP 13
After processing in the compounding machine, the bonded fiber/plastic mixture is then conveyed from the compounding machine to a heated mixture holding bin by conventional means such as a cleated belt conveyor.
The holding bin is heated by conventional means and maintains the mixture in a hot, malleable state.
The heated mixture holding bin level can be automatically controlled by conventional means and the temperature of the bin and its mixture is maintained by a conventional hot oil jacket system. The heated mixture holding bin is maintained at a temperature sufficient to keep the material within its proper processing temperature and consistency range. This range will vary depending upon the make-up of the mixture itself. For instance, if the mixture is 55% fiber and 45% plastic, with the fiber being solely cedar fiber and the plastic being solely LDPE, the temperature range is preferably 280° F. to 320° F. If the mixture is 55% fiber and 45% plastic, with the fiber being solely cedar fiber, but with the plastic being a blend of 60 parts LDPE and 40 parts HDPE, the temperature range is preferably 320° F. to 360° F.
If the mixture cools below a certain lower limit, which will vary according to mixture, it will not extrude properly in a subsequent processing step. Also, the mixture must not be permitted to rise to a temperature above a certain maximum temperature, which will also vary according to the mixture, because the mixture will not extrude properly in a subsequent processing step. For a 55% cedar fiber/45% LDPE mixture, this minimum temperature is approximately 250° F. and the maximum temperature is approximately 350° F. For a 55% cedar fiber/45% plastic blend with 60 parts LDPE and 40 parts HDPE, the minimum temperature is approximately 290° F. and the maximum temperature is approximately 390° F.
STEP 14
The mixture is then fed from the holding bin to a material preparation auger which forms the mixture into chunks, preferably approximately the size of golf balls. With reference to the preferred material preparation auger, as illustrated in FIGS. 1-3, hot fiber/plastic mixture is fed from the heated holding bin by means of gravity through a chute into the material preparation auger 20 near its upstream end 22.
The mixture is then moved toward the downstream end 24 of the material preparation auger housing 26 by the rotation of the material preparation auger shafts 28, 30 which have a plurality of material preparation auger blades 32 attached thereto. An individual blade 32 is illustrated in FIG. 3. The shafts 28, 30 are rotated inwardly by conventional means such as a motor, not illustrated. The action of the blades on the mixture sizes the mixture into pieces approximately the size of golf balls as the material is moved toward the downstream end 24 of the material preparation auger housing 26. These pieces of mixture are discharged from the material preparation auger through the discharge opening 34 in the bottom of the material preparation auger housing near its downstream end and conveyed to the extruder.
The shafts have a plurality of blades 32 affixed thereto. The first few upstream blades 32, approximately three, on each shaft are mounted at an angle of approximately 15° to the direction of travel of the mixture. The remaining blades are mounted at an angle of approximately 30° to this direction. The material preparation auger performs the function of creating a uniformly-sized feed stock for use in downstream extruding equipment. This feed stock can be introduced into the extruder at a consistent rate to minimize surging during the extrusion process.
STEP 15
The uniformly sized chunks of feed stock are then conveyed to a compounding extruder 36, as shown in FIG. 4, preferably by means of a conventional 12" diameter screw conveyor.
Although the preferred conveying means is a 12" diameter screw conveyor, it is believed that a cleated belt conveyor may be used for this purpose. It is believed that a cleated belt conveyor may be advantageous in that it will reduce residue within the conveyor which otherwise could harden and contaminate subsequent batches of malleable fiber/plastic mixture.
Although, as presently practiced, the preferred process feeds chunks of malleable material directly to an extruder 36, it is envisioned that a conventional compounding roll mill may be incorporated into the system prior to the extruder so that other material, such as a fire retardant, U.V. stablizers, strength inducers, compatibilizers, engineered resins and other substances having advantageous properties may be introduced into the mixture prior to extrusion.
STEP 16
The mixture is extruded through a predetermined die and formed into a product having a predetermined configuration.
The preferred extruder 36 is a standard compounding extruder, having a barrel tapered from a 12" diameter to a 6" diameter , and powered by a 40 hp, 800 rpm electric motor. The extruder has been modified so that its barrel and screw have been shortened to 36" and it has been equipped with a water jacket 38, with port 40 for cooling the mixture during extrusion.
It has been discovered that cooling is required to prevent the mixture from becoming too hot as it is extruded due to the friction and sheer created by the mixture as it is forced through the extruder. A mixture of 55% cedar fiber and 45% LDPE should not be allowed to reach a temperature of greater than approximately 450° F. at this stage. A similar mixture with the plastic component of 60 parts LDPE and 40 parts HDPE should not be allowed to reach a temperature greater than approximately 500° F. at this stage. These mixtures have a tendency to ignite when their respective stated temperatures are exceeded.
With reference to FIG. 4, the extruder 36 is equipped with a bolster 42 and interchangeable dies, one of which, die 44, is shown, whereby the product profile configuration may be changed upon changing the dies. The bolster 42 which holds the die is equipped with electrical heating elements not shown, which pass through ports 46 for use in heating the die during extrusion. It is important that the surface temperature of the mixture must be sufficiently high at the point where the mixture exits the extruder 36 to create a uniform surface for the extruded product. If proper surface temperature is not maintained, the surface of the mixture may tear as it exits the extruder die.
In some cases additional heat is required at the dies and this additional heat is provided by the heating elements on the bolster. The preferred surface temperature at the exit of the extruder is approximately 425°-450° F. for a 55% cedar fiber/45% LDPE mixture and 450°-475° F. for a similar mixture with a plastic component of 60 parts LDPE and 40 parts HDPE. Temperature sensors are placed inside the bolster through ports 48.
During operation of the extruder 36, fiber/plastic mixture is introduced into the mixture inlet 50 of the extruder 36.
The mixture is forced through the extruder barrel outlet 52 by means of a conventional screw mechanism within the extruder driven by a conventional motor and gear mechanism, not shown, within the motor and gear housing 54.
The mixture exits the extruder barrel through the extruder barrel outlet 52. The extruder housing and extruder barrel are water jacketed for cooling as shown at 38.
As the mixture exits the extruder barrel it is forced, in turn, through the fiber alignment plate 56, the extruder bolster 42 and then the extruder die 44. The fiber alignment plate 56 has the configuration shown in FIG. 4 so that it will function to straighten out and align the mixture for passage through the bolster 42 and die 44. It has been found that without the fiber alignment plate 56, this mixture has a tendency to retain the orientation given it by the extruder screw and not maintain proper alignment as it passes through the die.
The fiber alignment plate 56 configuration shown is the preferred configuration for extrusion of a 55% cedar fiber/45% LPDE mixture, as well as a similar mixture with the plastic component thereof comprised of 60 parts LPDE and 40 parts HDPE. It is envisioned that the fiber alignment plate configuration may be varied for other fiber/plastic formulations.
The bolster 42 holds and supports interchangeable dies 44 for the extrusion of desired products having different profiles or configurations. The bolster 42 also has heating element ports 46 for the insertion of heating elements, not shown, so that the mixture may be heated as it exits the die 44. These heating element ports 46 are preferably provided so that separate heating elements may be inserted and controlled proximate the top, bottom and both sides of the die to facilitate uniform heating of the die.
The bolster is also provided with temperature sensor ports 48 for the insertion of temperature sensors, such as conventional thermocouples, so that the temperature of the bolster may be monitored and controlled.
The extruder die 44 is affixed within a recess 56 in the downstream end of the bolster. The die 44 shown forms the mixture into an L-shaped configuration as the mixture is forced therethrough. The die is preferably comprised of two separate components, a top half 58 and a bottom half 60 for ease of insertion into and extraction from the extruder bolster 42.
STEP 17
The extruded product is cut into desired lengths as it exits the extruder 36. The cutting operation is performed by a custom flying cutoff assembly 62 as shown in FIGS. 5-7, equipped with an electric eye sensing device 64.
As product 90 is forced out of the extruder 36, it slides continuously and successively onto and across the entry tray 66 of the flying cutoff knife assembly 62, the product support plate 130 of said assembly, and the exit tray 140 of said assembly. The product then slides onto the conveyor belt 72 of the inspection table assembly 74.
An adjustable electric eye sensing device 64 is provided on the inspection table 76 so that when a leading edge of product is sensed by the device 64, a signal is transmitted to a processor which activates the two air cylinders, 78, 84 as further described. Assuming that the knife 80 of the flying cutoff knife assembly is in the down position, as shown in FIG. 6, the air cylinder 78 attached to the knife is activated to move upwardly so that the product is severed by the upper cutting edge 82 of the steel knife 80. Simultaneously, the horizontal air cylinder 84 of the assembly 62 is activated to move the flying cutoff knife housing in the direction of the flow of product at the same speed at which the product is moving. This allows the product to be cut into pieces while it is continuously flowing from the extruder without the piece of product on the upstream side of the knife blade ramming into the blade as a cut is being effectuated.
Once a cut is completed, the piston of the horizontal air cylinder 84 retracts, returning the flying cutoff knife housing 86 to its starting position.
As is shown in the end view drawings, FIGS. 6 and 7, a product opening 88 is provided in the flying cutoff knife 80 so that product can continue to flow through the flying cutoff knife housing while the knife is in its up position. When the knife is in such up position as shown in FIG. 7, the next product cut is made by the lower cutting edge 91 of the knife 80 when the void between the trailing edge of the most recently cut piece of product and the immediately following leading edge of the product stream is sensed by the sensing device 64 and the attached processor activates the air cylinder 78 attached to the knife 80 to return the knife 80 to its down position shown in FIG. 6. Of course, at the same time, the processor activates the horizontal air cylinder 84 to move the flying cutoff knife housing 86 as described above for the upward stroke of the knife 80.
This procedure is then continued for as many product cuts as desired.
As also shown in FIG. 5, product 90 is shown positioned within the flying cutoff knife assembly 62 and on inspection table 76. The assembly 62 has a housing 86, side frame 92, top frame 94, product stop block screw 96, product support plate screw 98, and bottom frame 100. Product guide 102 is positioned to guide the product 90 and has guide rod holder 104 and guide rod holder support 106 connected thereto. Cylinder 84 is mounted at mount 108 and has piston 110. The assembly 62 is movable along shaft 112 on linear ball cage bearing 114 between urethane bumpers 116, 118. The inspection table assembly 122 includes the table 76, conveyor belt roller 124, and belt tensioner 126.
Referring to FIGS. 6 and 7, the piston 128 for cylinder 78 is shown in FIG. 7. Shown in FIG. 6 is product support plate 130 and adjustable product guide rod 132, product guide 134, with metal brace, made of UHMW plastic or Teflon coated material. Also shown is blade guide 136, product stop block 137, guide clamp 138, product exit tray 140, knife holder 142, shaft support 144, horizontal support frame 146, back stop plate 148, leg 150 and base 152.
With regard to the operation of the flying cutoff knife the following items should be noted:
(a) Preferably the product guides 134 and the product entry tray 66 and exit tray 140 are constructed of UHMW plastic or Teflon coated material to facilitate the sliding of the product thereacross.
(b) The exit port of the extruder 36 is aligned with the entry tray 66, support plate and exit tray 140 of the knife housing assembly which are in turn aligned with the top of the inspection table 76 so that the product moves in a straight line.
(c) The product stop block 136 holds the product 90 in place as the knife is moved upwardly through the product and through a slot 133 in the stop block 137. It has been found that this is desirable since at the cutting stage the product is pliable and has a tendency to bend as it is being cut. The product support plate 130 performs the same function when the knife is cutting in the downward direction.
(d) The product support plate 130 has a slot therein to allow for passage of the knife therethrough.
(e) The speed at which the flying cutoff knife housing 86 moves horizontally is adjustable so that varying speeds of product flow can be accommodated.
(f) The electric eye sensor 64 on the inspection table 76 is adjustable so that the lengths of the product being cut may be varied as desired.
(g) The speed of the conveyor belt on the inspection table is preferably maintained at a speed approximately 15% faster than the flow rate of the product so that cut pieces of product will be moved away from the product stream at a rate faster than the flow rate of the product stream itself.
(h) An activation switch, not shown, preferably provided on a foot pedal, is provided to allow a person at the inspection table to cut product before it reaches a pre-set length. This allows for a shorter length of product to be rejected if a defect is noticed in the product thereby reducing waste from the process.
STEP 18
The cut lengths of hot product 90 are then conveyed by conventional means, such as a belt conveyor, across an inspection table and sent to a custom rolling and cooling conveyor.
At the inspection table, any reject material is removed from the process.
STEP 19
Acceptable, hot extruded product 90 is then passed through an adjustable, variable speed rolling and cooling conveyor 154, as illustrated in FIGS. 8-13. The rolling and cooling conveyor 154 functions to maintain the profile configuration of the lengths of hot, extruded product 90 in their predetermined configuration so as to avoid deformation upon cooling. The guides 156 and rollers 158 of the rolling and cooling conveyor 154 may be adjusted to accommodate different product configurations. Of importance in the particular application of the present invention, the pressure exerted by the rolling and cooling conveyor on the hot, extruded product 90 is held to a minimum so that the hot product will cool and contract substantially independently of pressure exerted by the conveyor. It has been found that if pressure is exerted on the product at this stage by the conveyor, stresses can be induced into the product and the final product weakened.
Referring to FIGS. 7-9, operation of the rolling and cooling conveyor will be described. The product is conveyed from the inspection table 122 to the first set of rollers 158 of the rolling and cooling conveyor 122. The bottom rollers 160 of the conveyor are turned by a chain drive mechanism powered by a conventional power source, preferably a variable speed electric motor 162.
The bottom rollers 160 convey the product through the conveyor assembly for a distance sufficient to allow the product to cool to a temperature at which the product is adequately cured for handling, i.e., less than 180° F. The speed of the rollers may be varied to conform with the speed of the conveyor belt on the inspection table so that a continuous flow of product pieces may be maintained. The distance of conveyor travel for adequate cooling varies with atmospheric conditions, speed of the rollers and configuration of the product. In practice, it is preferred to provide for excess travel so that one is assured that the product has adequately cooled. For an L-shaped product configuration made up of 1.5 lbs./ft. of mixture, it has been found that 200 feet of travel at a roller speed of 30 ft./min. is sufficient for adequate cooling.
The side view FIG. 8 of a section of the rolling and cooling conveyor shows ten roller assemblies. Counting from left to right, the first, third, fifth, seventh and ninth roller assemblies move the product pieces in a rightwardly direction. As will be explained, the direction of the product pieces is reversed and the tenth, eighth, sixth, fourth and second roller assemblies move the product pieces in the leftwardly direction.
To reverse the direction of the pieces of product, a reversing table 164 is provided as shown in FIGS. 10 and 11. The reversing table 164 is equipped with powered rollers 166 as shown in the side and top views of FIGS. 11 and 10, respectively, as well as an electric eye sensing device 168 and a product ram 170. When the device senses a product piece which is being conveyed in the rightwardly direction in FIG. 10, a signal is transmitted to a processor which activates the air cylinders 172 of the product ram 170 which extends to push the product pieces onto opposite, flanged rollers which move the product pieces in the opposite direction.
Sections of conveyor and reversing tables may be assembled as required in an area which would not accommodate a straight-line conveyor to provide enough conveying distance for proper product cooling.
Once cooled, the product pieces exit the last section of the conveyor for further processing or shipment.
With regard to the operation of the rolling and cooling conveyor, the following items should be noted:
(a) The roller assemblies are adjustable to accomodate product pieces of differing thickness. Also, the rollers may be interchanged to accommodate product pieces having different configurations.
(b) The conveyor is equipped with product guides 174 to facilitate proper alignment of the product pieces as they are being conveyed. The product guides are preferably constructed of UHMW or Teflon coated material to reduce frictional resistance between the product pieces and guides as they come in contact during the movement of the product pieces.
(c) The rollers are knurled, as shown in FIG. 12, preferably with a coarse, knurled pattern. It has been found that this makes the rollers self-cleaning and reduces the amount of contact surface between the product pieces and the rollers, thereby facilitating the cooling of the product pieces.
Referring to FIG. 8, the conveyor 156 is shown having chain drive 178, idler sprocket 180, idler sprocket mount 182 and support bearing 184.
Referring to FIG. 9, the conveyor 156 has gear box 186, chain 178, shaft support bearing 184, drive sprocket 190, driven sprocket 192, bottom frame 196, shaft 194, guide rod 198, guide rod holder support 200, guide rod holder 210, guide clamp 212, product guide 174, bracket 214, idler sprocket 216, side frame 218, leg 220, and adjustable pad 222.
Referring to FIGS. 10 and 11, the reversing table 164 is also shown having air cylinder 172, electric eye sensor 168, ram 170, drive chain 224, bottom frame slat 226, and ram guide rod 228.
Referring to FIGS. 12 and 13, the roller assembly is also shown as including adjustable top roller supports 230 having threaded adjustable sleeves 232, adjusting screws 234 and lock nuts 236. The top rollers 237 are provided with top roller flanges 238, top roller sizing segments 240, and top roller knurl sections 242. Roller bearing 244 and roller locking collars 246 also support rollers 237. Bottom knurled rollers 248 are supported on shafts 250 and have locking collars 252 positioned as shown. Top rollers 237 rotate around shafts 254 as shown in FIG. 13.
STEP 20
After cooling, the lengths of product are collected and assembled for shipment or further processing, such as sawing, machining, painting and forming into desired products such as previously mentioned. Such further processing may also include milling and finishing operations for purposes such as smoothing the surface areas of the lengths and adding features such as grooves and/or slots to the product.
EXAMPLES
In accordance with the above described process steps, the following examples are set forth below to illustrate specific processes, specific starting materials, specific processing parameters and specific blends of plastic/wood starting materials.
EXAMPLE 1
In accordance with the steps outlined above, a 1000 lb. batch of mixture having 550 lbs. of cedar fiber of an 8% moisture content and 450 lbs. of LDPE plastic was made.
This mixture was dumped and conveyed to a compounding machine in which the hot oil jacket temperature was approximately 475° F. The initial inside wall temperature of the compounding machine was approximately 410° F. The mixture was kept in the compounding machine for approximately 1 hour and then transferred to a heated holding bin. The surface temperature of the material at the time it was transferred to the holding bin was approximately 310° F.
The mixture was processed through the material preparation auger and then transferred to the extruder and extruded into a product having an L-shaped configuration as shown in FIG. 4. In this particular example, the configuration resulted in a product yield of one and one-half lbs. per foot of extruded product. The speed of the extruder was set at approximately 25 lbs. per minute. The barrel of the extruder was cooled by means of a water jacket so that the temperature of the barrel did not exceed approximately 250° F. The extruder pressure was maintained at approximately 500 psi. The extruder die temperature was maintained at approximately 725° F. by means of the electrical heating elements in the die bolster. The surface temperature of the mixture as it exited from the extruder was approximately 430° F.
After exiting the extruder, the hot product was then cut into lengths of 5 feet inspected and then passed through the rolling and cooling conveyor equipment where it was cooled to room temperature.
EXAMPLE 2
In accordance with the steps outlined above, a 1000 lb. batch of mixture having 550 lbs. of cedar fiber of a 7% moisture content and 450 lbs. of a plastic blend comprising 270 lbs. of LDPE and 180 lbs. of HDPE was made.
This mixture was dumped and conveyed to a compounding machine in which the hot oil jacket temperature was approximately 475° F. The initial inside wall temperature of the compounding machine was approximately 410° F. The mixture was kept in the compounding machine for approximately 11/2 hours and then transferred to a heated holding bin. The surface temperature of the material at the time it was transferred to the holding bin was approximately 350° F.
The mixture was processed through the material preparation auger then transferred to the extruder and extruded into a product having an L-shaped configuration as shown in FIG. 4. In this particular example, the configuration resulted in a product yield of one and one half lbs. per foot of extruded product. The speed of the extruder was set at approximately 25 lbs. per minute. The barrel of the extruder was cooled by means of a water jacket so that the temperature of the barrel did not exceed approximately 250° F. The extruder pressure was maintained at approximately 500 psi. The extruder die temperature was maintained at approximately 725° F. by means of the electrical heating elements in the die bolster. The surface temperature of the mixture as it exited from the extruder was approximately 450° F.
After exiting the extruder, the hot product was then cut into lengths of 5 feet, inspected and then passed through the rolling and cooling equipment where it was cooled to room temperature.
VARIATIONS IN PROCESSING STEPS
There may be some variation in the process depending on a number of circumstances. For example, if the extruder die is changed to produce a product profile having an increased yield in terms of lbs. per foot, the rolling and cooling conveyor equipment downstream must be adjusted, that is, its speed must be reduced to accommodate a slower through-put in terms of feet per minute of product, assuming that the extruder speed is held constant. On the other hand, with a constant extruder speed, if a die is chosen so that the yield is fewer lbs. per foot, then the speed of the downstream equipment must be increased correspondingly.
It is envisioned that numerous alternate processing steps and alternate embodiments of the present invention may be envisioned by one of ordinary skill in the art. It is intended that all such alternatives and alternate embodiments are included within the scope of the present invention which is defined by the hereby appended claims. | A flying cutoff blade assembly for cutting a hot pliable extruded plastic and wood fiber composition product including product entry and exit trays, a housing having a knife with upwardly and downwardly facing edges to cut the product in alternating upward and downward cutting directions, a support plate and upper product stop block each having a slot for passage of the knife for non-deforming non-stick contact support of the product during cutting wherein the housing is moved back and forth of the product at a speed sufficient to permit cutting of the product without the product ramming into the knife during cutting. |
BACKGROUND OF THE INVENTION
The invention relates to an ice making machine of the hollow cylinder type, more particularly to the sizing of the ice harvested therefrom.
An example of this type of ice making machine is set forth in U.S. Pat. No. 3,228,202 issued Jan. 11, 1966 to R. J. Cornelius. The ice is formed within an ice making cavity in the form of cylinder and when harvesting is desired, the cylindrical ice sheet is forced through an opening in the top of the cylinder by internal force provided by a translating piston. As the ice leaves the cylinder it is forced against a plurality of fixed ice breaking fins, spaced around a circular ice breaking head thereby causing the ice to be broken in generally uniformly-sized flakes or pieces as it leaves the ice maker.
While this and other similar methods produce reasonably satisfactory ice, they have one general and important drawback: the size of the ice harvested is fixed in size; it cannot be altered.
Recent developments in cup vending machines provide for vending various size cups of liquid, as well as various types of liquid. These developments are creating requirements for ice making equipment to vend different sizes of harvested ice to provide a more enjoyable iced liquid. Currently the changing of harvested ice size requires the changing of the ice making device to a larger or smaller size unit.
For medical applications where ice size requirements are various, ice produced by standard ice making machines must be crushed prior to its use.
Thus, there is a continuing need for improved ice making machines and particular ice making machines which the size of the harvested ice can be selectively varied.
SUMMARY OF THE INVENTION
The above problem encountered in the state-of-the-art ice making machines and dispensing equipment is solved by the adjustable ice breaker head of the instant invention.
The ice making device to which the ice breaker head of the instant invention is applicable has a hollow cylinder lined with a plurality of narrow protrusions or ribs with the outer surface wrapped with a conventional refrigerant coil. The bottom surface of the cylinder is sealed by a base member which serves as a drain pan and a mounting surface for supporting an upper head assembly. Three stand-off rods extend from the base member to the upper head assembly. One of the three stand-off rods is hollow and also supplies ice making fluid to the upper head assembly. The upper head assembly contains a chamber and spray head for coating the inner cylinder walls with ice forming fluid and a vertically adjustable ice spreader or breaker. An ice harvesting piston translates within the cylinder by any conventional linear activating means conforming to the inner surface and protrusions or ribs of the cylinder.
In operation, ice forming liquid is supplied through the hollow stand-off rod to a hollow chamber in the upper head assembly where peripheral openings direct the flow of liquid down along the inside surface of the cylinder which has been pre-cooled by the refrigerant coil in a conventional manner. Ice is then formed by a layering effect on the inner surface of the cylinder, initially between the protrusions or ribs and then, depending on the desired ice thickness, over the protrusions or ribs. The harvesting piston is then translated, causing the ice to move out of the cylinder toward the upper head assembly. As the ice leaving the cylinder is forced against the ice spreader or breaker, the ice is fractured or cracked into semi-uniform, multi-faceted fragments which are then dispensed from the ice maker. The head portion carrying the ice spreader or breaker is vertically adjustable from an initial position, wherein the smallest of desired size fragments of ice are produced, to a maximum position away from the cylinder ice dispensing opening, where the largest desired size fragments of ice are produced. The head portion carrying the ice spreader or breaker can be selectively translated away from and toward the cylinder ice dispensing opening to any desired location between the smallest ice size position and the largest desired ice size position.
The adjustable positioning of the head is shown as having discrete incremented steps for ease of explanation and not by way of limitation.
The result is that the ice maker produces desirable selective sizes of ice which is hard and clear and has a desirable appearance in a glass or cup.
Details of the invention, and the preferred embodiment and process thereof, will be further understood upon reference to the drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded schematic representation, partially cutaway, of the ice maker and the adjustable head of the instant invention;
FIG. 2 is a showing of the upper portion of FIG. 1 with the ice harvesting piston translated and the head assembly in an intermediate position;
FIG. 3 is a perspective exploded view of the upper portion of the ice making cylinder and the translatable head assembly;
FIG. 4 is a showing of FIG. 3 taken along line 4--4;
FIG. 5 is a showing of FIG. 1 taken along line 5--5;
FIG. 6 is a showing of FIG. 1 taken along line 6--6;
FIG. 7 is a showing of the upper portion of FIG. 1 with ice making liquid being sprayed on the inner surface of the ice making cylinder and the head in a maximum ice size position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a body portion 12 of an ice maker generally takes the shape of a hollow cylinder. It should be understood, however, that body portion 12 may take other configurations and yet be suitable to practice the invention. The body portion 12 may be constructed of any suitable material, such as, but not limited to, stainless steel, brass, copper or similar heat conductive material. The outer surface of wall 20 of body portion 12 is wrapped with a plurality of spaced apart tubing 16. This tubing may be constructed from copper, aluminum, or the like material that can be easily and permanently around the body portion. The ends of tubing 16 are connected to a conventional refrigerant unit so that the tubing operates as the evaporator of the unit. The space between adjacent coils of tubing 16 is filled, and the outer surface of the tubing is covered with a suitable insulation material 17 to direct the temperature of the refrigerant passing through the coils to the body portion and to prevent energy loss externally therefrom.
The inner surface of wall 20 of body portion 12 has a plurality of longitudinally directed protrusions or ribs 22 extending substantially the entire length of interior chamber 14 of the body portion.
A base member 24 and a head assembly 26 are positioned at ends 28 and 30 respectively of body portion 12.
Base member 24 is configured to form an abutting seal with end 28 of body portion 12 when secured thereto, as hereinafter described. Base member 24 has three apertures 32 (only one is shown in FIG. 1) for receiving three respective assembly rods 34 (best shown in FIGS. 5 to 7), a drain aperture 36, and a central aperture 38 for receiving in a sealed relationship a linear translating assembly 40.
Linear translating assembly 40 is a hydraulic linear activator which is operated by the same water source which supplies the ice making liquid. Translating assembly 40 comprises a cylinder 42, a piston 44, and a piston rod 46. The piston 44 includes a conventional "O" ring type seal 48. Hydraulic lines 50 and 52 connect to a valving system and a source of water under suitable pressure, generally in the range of from 15 to 70 psi.
An ice harvesting piston 54 conforms to the walls and protrusions or ribs and is fixedly attached to a top end 56 of piston rod 46. The attachment shown is by way of a bolt 58 which passes partially through an ice harvesting piston 54 and threadedly engaging a threaded aperture 60 in end 56 of rod 46. The piston rod has sufficient length to translate the ice harvesting piston from end 28 to end 30 of body portion 12.
Referring now specifically to FIGS. 2 to 4, it is seen that head assembly 26 includes a base 62, a collar 63, an ice spreader 64, and an end cap 66.
The base includes a plurality of notches 68 around its lower periphery, three spread apart apertures 69 for receiving rods 34 , and a center post 70 which forms an extension of the base's upper surface. The center post is threaded at its upper end, has a plurality of vertical ribs or keys 71 either formed as an integral portion thereof or added thereto, and a locking groove 72 located intermediate the upper base surface and the lower terminus of the posts. The vertical ribs or keys are of different lengths and increase in height sequentially by substantially the same amount of increase. Six keys 71 are shown. The heights are shown to increase and equal in a counterclockwise direction. The increase in height could alternatively be in a clockwise direction if desired. A typical example of the amount of height increase would be in 1/8 inch increments. In this increase example the shortest post would be 1/8 inch, the next 1/4, the next 3/8, etc.
Collar 63 is formed with an open lower portion 51 (FIG. 2) and an open upper portion 53. The central portion between the lower and upper portions includes an aperture 55. The lower portion below aperture 55 has an enlarged countersunk surface 59 for receiving an "O" ring seal 61. When collar 63 is in position, aperture 55 slides over center post 70, whereby the "O" ring seal is positioned partially in the countersunk surface and the transition member is then forced against the upper surface of base 62 to form a liquid seal therebetween. Collar 63 is held in this position by a lock ring 57 captured within groove 72. When in place, the lower portion 51 of the collar forms a water tight reservoir 73 which interconnects with assembly rod 34.
Ice spreader 64 comprises a plurality of ice breaker fins 65 equally spaced around the outer periphery thereof. While eight fins are shown, it should be understood that more or less may be used in practice, depending upon the general widths of ice chips desired. Inner surface 67 (FIG. 4) of ice spreader 64 has a plurality of slots or keyways 74 that mate with keys 71 when the spreader is positioned on center post 70. Keys 74 are equal in number and height of each of the posts 71. That is, when the ice spreader is in a initial position each one of the keys nests against the upper surface of a respective slot 74. This is the smallest ice chip position.
According to the preferred embodiment shown, the ice spreader can be positioned in five different elevations from its initial position by rotating the ice spreader counter-clockwise relative to the posts, one slot at a time, until it again returns to its initial position. The length variations of the posts and slots can be any convenient equal incremental length, for example, and not by way of limitation as hereinbefore mentioned, one-eighth inch increments. This would provide a five-eighths variation in height of the ice breaker relative to base 62. As the separation of the breaker from the base increases, sequentially larger ice chips are harvested.
When the ice spreader is positioned on the base (all posts and slots engaged) a threaded end cap 66 (FIG. 3) is tightened on threads 81 and the ice spreader and base are held in their selected relative position.
Assembly rods 34 are secured to base 62 with the end of rod 34, which is hollow, extending into and having a sealed relationship with watertight reservoir 73 between the base member and transition member for the purpose of delivering ice making liquid to this reservoir. Rods 34 pass through apertures 75 in ice harvester piston 54, pass through apertures 32 (FIG. 1) in base member 24, and are secured at their threaded lower ends to base member 24 by nuts 76 (one shown) which allow easy disassembly. One of hollow rods 34, in addition to being secured by nut 76, is connected to a source of ice making liquid via supply line 51.
When the various components making up the ice maker are assembled, base end 28 is sealed to base member 24 and head assembly 26 is supported in a spaced relationship from interior 14 and head end 30 so that ice formed on the inner wall of the body portion can be forced out of end 30, as hereinafter described in detail.
OPERATION OF THE PREFERRED EMBODIMENT
For operation, the ice maker is assembled as shown in FIG. 1 and placed in an upright position, that is, the head end of the body is upright and the assembly is substantially plumb. Piston 44 is in a stowed position against the lower end of cylinder 42 as indicated by arrow 80, placing the ice harvester piston 54 substantially against the upper surface of base member 24. The refrigeration unit is activated and the refrigerant passing through coils 16 reduces the interior temperature of the chamber below the freezing temperature of the ice making liquid. Liquid is then supplied from a sump tank, in response to pressure from a pump, through line 51 and a hollow assembly rod 34, into reservoir 73 where liquid is sprayed through notches 68 in the periphery of base 62 to the wall surface of interior chamber 22 wherein ice is formed by a layering effect, first between and then over the protrusions or ribs 22 to a desired thickness. The liquid flow into the reservoir is then terminated. Hot gas is then circulated through coils 16 momentarily in a well known manner from the refrigerant source so as to release the ice from the cylinder wall. The formation of frozen liquid by a layering effect with the use of a circulating liquid, well known in the art, ensures clear, hard ice with a heat of fusion equal to substantially 144 BTU per pound.
When the freezing cycle is completed, by conventional control of time and/or temperature, a solid tube or cylinder of ice exists with deep grooves on its outer surface, corresponding to ribs 22.
Water under normal line pressure is now applied through hydraulic line 52 and hydraulic line 50 is vented to the sump tank, both functions being accomplished with known valve means. Ice harvesting piston 54 now translates upward in the direction of arrow 78 and is guided by assembly rods 34, aperture 38, and ribs 22. The translation of piston 54 causes the ice, which has mechanical stress lines along the protrusion or rib grooves, to be forced upward against ice breaker fins 65 carried by the ice spreader 64, where the ice fractures or cracks into multifaceted fragments. The ice leaves the interior of the body for deposit in a collection hopper (not shown). The general size of the random multifaceted cracked ice is determined in part by elevation of ice spreader 64 relative to base 62. The greater the relative displacement of the ice spreader and base, the greater the overall size of the cracked ice fragments. As hereinbefore mentioned, the displacement range between the ice spreader and base of the preferred embodiment is from approximately one-eighth of an inch to three-quarters of an inch.
This random, multifaceted shape of the cracked ice, together with its high heat of fusion, allows it to maintain its configuration, without remelting and fusing together, much longer than conventional cubed or flaked ice. This feature is primarily due to the small and random surface contact areas available for adjacent fragment joining.
After the ice is removed from the inner body portion, hydraulic line 50 admits ice making liquid (water) under line pressure to the opposite side of piston 44 and hydraulic line 52 is vented to the sump tank, both operations being performed by conventional valve means. Ice harvesting piston 54 now returns in the direction of arrow 80 to its original position against the lower inner surface of body portion 12. The cycle is then repeated as required. It should be noted that any excess liquid in the interior of the body portion is drained through aperture 36 and drain line 33 and returned to the sump tank for reuse.
Other variations, ramifications and applications of this invention will occur to those skilled in the art upon reading this disclosure. These are intended to be included within the scope of this invention, as defined by the appended claims and their legal equivalents. | An ice breaking head for an ice producing machine is adjustable for producing harvested ice of selected sizes. The ice making machine has a cylinder, the inner surface of which produces commercial sheet ice. The ice is harvested by forcing the ice from out of the cylinder toward an ice breaking head. The position of ice breaking head is adjustable to vary the size of the ice harvested. The head has an ice breaking surface which contains fins for facilitating the breaking of the ice sheet. It is journalled on a mounting post which has keys or ribs of increasing heights which match corresponding keyway slots in the bore of the head so that the spacing of the head, and hence the size of the ice harvested, can be adjusted by changing the rotational position of the head on its mounting post. |
DESCRIPTION
1. Technical Field
This invention relates to a method of making a fuel cell stack, and more particularly, to a method for making a monolithic solid oxide fuel cell stack.
2. Background Art
Fuel cell systems which use a fused solid ceramic electrolyte are known in the prior art, and are collectively referred to as solid oxide fuel cell systems. The geometry of the prior art solid oxide fuel cell systems is varied, from cylindrical configurations, to corrugated plate configurations, to more conventional flat plate configurations. The cylindrical configurations and corrugated plate configurations have inherently complicated reactant manifolding systems which are the direct result of the geometry of the cell structures.
The prior art flat plate solid oxide fuel cell stacks, such as shown in U.S. Pat. No. 4,476,196 Paeppel et al., utilize a more conventional cross flow pattern for the reactants which is identical to that used in the prior art acid fuel cell stacks, and thus the reactant manifolding is rendered much simpler and less complex in a stack such as is shown in the U.S. Pat. No. 4,476,196 patent, as compared to the cylindrical or corrugated solid oxide stacks. Theoretically, the fuel cell stack structure shown in the above-noted patent should provide exemplary power density, however, such is not the case when following the teachings of the patent. The problems arise because the fuel cell stack shown in the U.S. Pat. No. 4,476,196 patent is formed from extruded arrays of anode and cathode materials in pliant or green form, while the thinner layers of electrolyte and interconnect materials are tape cast. The tapes from which the electrolyte and interconnect layers are initially formed are also green, unsintered materials. The various green constituent layers are then stacked on top of each other, appropriately oriented, to form the stack structure. The resultant stack structure is made up of all green, or unsintered, constituent parts. As noted, the components of the stack are made of different materials, and the patent cautions one to try to match the coefficient of thermal expansion and firing shrinkage for the different materials as closely as possible to one another to minimize separation problems. Despite taking all precautions advised, stacks as shown in the U.S. Pat. No. 4,476,196 patent which are made of green precursors which are all cosintered as taught by the patent display undesirably poor performance due to micro-cracks which occur in the various layers as a result of the cosintering step. Experience has shown that a cosintered stack will only produce about 10-30% of its theoretical current density due to mixing of reactant gases which is the direct result of the micro-cracks in the stack.
DISCLOSURE OF THE INVENTION
This invention relates to a method for making a solid oxide fuel cell stack which has the configuration of that shown in the U.S. Pat. No. 4,476,196 patent, but which will display remarkably improved performance as compared to a stack made according to the procedures described in the aforesaid patent. A stack formed in accordance with this invention is made from preformed, presintered subassembles, of which there are two different kinds. One of the subassemblies is an electrode subassembly, and includes an electrolyte layer which is formed from a green tape and then sintered prior to any further processing step. After the electrolyte layer has been sintered, a finished anode layer will be formed on one face of the electrolyte layer, and a finished cathode layer will be formed on the opposite face of the electrolyte layer. The two electrode layers can be plasma sprayed onto the electrolyte layer, or can be separately laid down as green tapes and sintered in situ. This three layer sintered and densified component will serve as the electrode subassembly of the fuel cell stack. The other subassembly which is similarly preformed is the combined separator-flow field subassembly. This second subassembly is formed by providing a green tape preform of interconnect material for the separator layer, and sintering that preform tape to its final fused and densified form. After performing the sintering step, the ribbed cathode and anode flow field layers are formed on opposite sides of the separator layer. These flow field layers can be formed by plasma spraying; or with green tapes which are then sintered and densified in an appropriate manner; or by some other similar step. The ribs in the flow field layers can be formed with tape strips, by plasma spraying through a mask or stencil, or by an etching or grooving step. The stack is formed by stacking these prefinished subassemblies on top of each other in the proper order and in proper orientation. The final forming step involves heating the stacked subassemblies to a subsintering temperature which is high enough to soften the presintered structures so that they will form intimately conforming interfaces through the phenomenon known as creep flattening. Edge sealed joints can be formed in this creep flattening step, and, if necessary, thin layers of conductive braze, such as platinum, or the like can be applied to the abutting surfaces of the subassemblies prior to the staking step. The result of the creep flattening step is a monolithic stack substantially as shown in the U.S. Pat. No. 4,476,196 patent, but without the myriad of micro-cracks which will be found in the stack formed by the procedure described in the patent.
It is therefore an object of this invention to provide a method for making an improved solid oxide fuel cell stack which is amenable to simple reactant feeding and manifolding.
It is a further object of this invention to provide a method of the character described which results in a stack that is relatively free from micro-cracks in its component layers.
It is another object of this invention to provide a method of the character described which allows for assembly line production of the stacks from preformed subassemblies.
It is an additional object of this invention to provide a method of the character described wherein each layer of each subassembly can be individually formed to final specifications under conditions which are most beneficial to achieving the respective final specifications.
These and other objects and advantages of the invention will become more readily apparent from the following detailed description thereof, when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a fuel cell stack formed in accordance with the invention showing the reactant manifold system used;
FIG. 2 is a fragmented perspective view of the gas separator-flow field subassembly used to build the stack of this invention;
FIG. 3 is a perspective view of the basic electrode subassembly used to build the stack of this invention;
FIG. 4 is a fragmented sectional view of the two subassemblies joined together to form a cell; and
FIG. 5 is a schematic flow sheet describing the manufacturing procedure used to produce the fuel cell power system of this invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to FIG. 1, there is shown the exterior of a solid oxide fuel cell stack which is constructed in accordance with this invention and which has been manifolded for passage of the reactants through the stack with basically the same type of side manifolds which are used in conventional acid or alkaline fuel cell stacks. The stack, denoted generally by the numeral 2, is formed from flat, square components which allows side manifolds to be used to provide the flow of reactant gases. For example, the manifold 4 can be the hydrogen inlet manifold and the manifold 6 can be the hydrogen outlet or exhaust manifold. Likewise, the manifold 8 can be the oxygen inlet manifold and a manifold (not shown) on the opposite side of the stack 2 can be the oxygen outlet or exhaust manifold.
Referring to FIG. 2, there is shown the gas separator-reactant flow field subassembly, denoted generally by the numeral 10, which is used in constructing the power system of this invention. This subassembly 10 is formed from a core gas separator plate 12 and two ribbed flow field plates 14 and 16. The separator plate 12 has a thin central web portion 18, a first opposed pair of edge sealing flanges 20 (only one of which is shown) and a second opposed pair of edge sealing flanges 22 (only one of which is shown). It will be noted that the pairs of sealing flanges 20 and 22 seal off side edges of the reactant flow field against lateral gas diffusion out of the flow field. The central web portion 18 is made from a green Mg doped LaCrO 3 sheet cut to size, and the seal flanges 20 and 22 are formed from strips of the same green sheet material which are laid on the edges of the sheet and overlaid to obtain the desired sealing rib thicknesses. This green composite member is then sintered in a hydrogen atmosphere at a temperature in the range of about 1650° C. to about 1750° C., preferably at 1650° C. to a density of 94%-96% of theoretical density. The ribbed flow field plate 14 provides the hydrogen flow field. The plate 14 is formed from nickel oxide zirconia anode electrode material, which is deposited on the separator plate web 18 after the separator plate has been sintered. Preferably the plate 14 will be deposited by plasma spraying the anode electrode material. The entire surface of the web 18 is thus coated with a basal layer 15 of anode electrode material approximately 3-10 mils in thickness, and then the ribs 13 are built-up on this basal layer. The ribs 13 can be formed by plasma spraying the anode electrode material through a mask or stencil. They could also be formed by machining or etching a thicker layer of the material, but plasma spraying with a mask is preferred. The flow field plate 16 provides the oxygen or air flow field and is formed from strontium doped lanthanum manganate cathode electrode material. The oxygen flow field plate 16 will be formed preferably by plasma spraying the cathode material in the same manner described for the hydrogen flow field plate 14 with ribs 17 built up on the basal layer. The flow field plates will have densities in the range of 20% to 50% of theoretical density and preferably about 30%.
Referring now to FIG. 3, the electrode subassembly, denoted generally by the numeral 24, is shown. The electrode subassembly 24 includes an electrolyte plate 26, an anode electrode layer 28, and a cathode electrode layer 30 (See FIG. 4). The electrolyte plate is formed from a green cut and sized tape of yttria stabilized zirconia electrolyte material. The green tape is sintered in an air (oxidizing) atmosphere at a temperature in the range of about 1400° C. to about 1600° C., preferably at 1400° C. to approximately 94%-96% of theoretical density, and creep flattened. The anode electrode layer 28 is nickel oxide zirconia which is plasma sprayed onto the sintered electrolyte plate 26 and the cathode electrode layer 30 is strontium doped lanthanum manganate which is plasma sprayed on the opposite side of the plate 26. It will be noted that an electrode-free skirt 32 will be left at the edges of the plate 26 for sealing purposes as will be pointed out hereinafter. The anode and cathode material will have a density in the range of 20%-50% of theoretical density and preferably about 30%.
Referring now to FIG. 4, a portion of an assembled monolithic stack is shown. It will be noted that the subassemblies 10 and 24 are merely stacked one atop another in proper orientation to form the stack. Glass sealing gaskets 34 are used to seal the flanges 20 and 22 to the skirt edges 32 of the electrolyte plates 26 and layers of platinum paste 36 may be used to improve the bond and electrical conductivity between the ribs and electrode layers of the subassemblies 10 and 24 in the active area thereof. The assembled stack is then heated to a temperature in the range of about 1000° C. to about 1200° C., preferably 1000° C., for up to an hour, and is subjected to a light compressive load in the range of about 1 to about 10 psi to bond the subassemblies together, and to ensure conformity of all contact surfaces between the subassemblies by creep flattening. The phrase "creep flattening" refers to a conforming of the contacting surfaces, into intimate flat contact with each other which occurs when the assembled stack is heated to temperatures which soften its component parts.
It will be noted from FIG. 4 that the ribs 13 on the hydrogen flow field plate 14 are higher than the ribs 17 on the oxygen flow field plate 16. This relationship will be utilized when the power module is intended for use in space, as for example, in orbiting vehicles, and will be run on relativley pure hydrogen and relatively pure oxygen, rather than hydrocarbon fuel and air. In such a case, the hydrogen will serve as the fuel gas and will also serve as the coolant for the stack. The oxygen, on the other hand, does not serve a dual function, thus the oxygen flow channels can be made more shallow. This allows compaction of the stack, and allows more cells be placed in any given height increment of the stack. Shorter conductance paths are also created, thus lowering iR losses. This unequal flow field geometry cannot be achieved using the prior art corrugated electrode sheets and thus optimum performance cannot be realized when a corrugated cell system is used in an environment where the hydrogen will be the coolant as well as the fuel.
It will be noted that the ability to form the stack components as separate subassemblies has another advantage. As set forth above, the sintering temperature of the gas separator plate is substantially higher than the sintering temperature of the electrolyte, and the plasma spraying temperatures. When the several cell components are co-sintered in one operation, as with the corrugated and cylindrical solid oxide cell structures, the co-sintering tends to stimulate diffusion of the lanthanum manganate cathode material into the zirconia electrolyte, which is an undesirable phenomenon. This will not occur with the fabrication techniques made possible by the cell structure of this invention. The retention of the basal layer of the electrode material in the bottoms of the reactant flow channels provides additional in-plane conductivity for the flow field plates and compensates for the poor conductivity of the gas separator plate. This also lowers iR losses.
The preferred thicknesses of the various layers of cell material are as follows: 2-10 mils for the gas separator plate; 40 mils for the hydrogen and oxygen flow field plates if both are the same thickness; and 40 mils for the hydrogen flow field plate with 5 mils for the oxygen flow field plate when the hydrogen is both fuel and coolant; 1-5 mils for the basal layer in both of the flow field plates; 2-4 mils for the electrolyte plate; 1-3 mils for the anode electrode; and 1-3 mils for the cathode electrode.
Referring now to FIG. 5, there is shown schematically a production format for producing and assembling the subassemblies and the stacks according to this invention. The two subassembly production lines can be operated in parallel, and can be merged at the stack monolith forming station. When produced in accordance with this invention, each part can be individually inspected and tested before proceeding to the next step. Such a procedure cannot be followed with the corrugated or cylindrical geometries of the prior art, or with the procedure described in U.S. Pat. No. 4,476,196 since there are no sintered parts until the entire monolith has been sintered. This ability to perform a complete and thorough inspection of all of the components is another advantage of using subassemblies to form the solid oxide fuel cell modules in accordance with this invention.
Another significant advantage which accrues from the use of subassemblies to form the solid oxide fuel cell stack is the opportunity to employ different fabrication processes for each layer. For example, the electrolyte and interconnect layers can be formed by plasma spraying, chemical vapor or arc deposition onto a fugative substrate rather than tape casting and sintering. Electrode material layers can be screen printed, slurry cast as well as plasma sprayed. This allows fabrication by the most cost effective method.
Since many changes and variations of the disclosed embodiments of the invention may be made without departing from the inventive concept, it is not intended to limit the invention otherwise than as required by the appended claims. | The fuel cell stack is made from two basic finished component subassemblies which are stacked repetitively atop each other in alternating fashion. One of the components is an electrode subassembly, and the other is a separator plate-flow field subassembly. The subassemblies are formed from several different material layers which are sintered and shrunk to operating size and density prior to the stack being assembled. The finished subassemblies are layered atop each other to form the stack and then heated to an elevated subsintering temperature and subjected to a light compressive load so that abutting surfaces of the adjacent subassemlies are creep flattened into intimate adherent contact with each other thereby forming a monolithic stack assembly. |
[0001] This application is a division of U.S. application Ser. No. 09/331,574 filed Aug. 9, 1999, which was the National Stage of International Application No. PCT/EP97/06500, filed Nov. 20, 1997.
FIELD OF THE INVENTION
[0002] The invention concerns a custom cutting apparatus for cutting fabric, a device for feeding said fabric to cutting apparatus and a process for the use of such equipment.
BACKGROUND OF THE INVENTION
[0003] A device for the feed of fabric to a textile machine has been disclosed by EP-A-0 589 089. The device is designed as a trough with a driven surface, so that fabric rolls lying in the trough are set into rotation by friction and thereby unwind themselves. The so unwound fabric length is laid upon a conveyor belt assigned to said unwinder and by means of this conveyor belt is transferred to another additional and separate conveyor belt which is dedicated to feeding a cutting machine. These operations, taken all together, provide the assembly with the name of a feeding device.
[0004] Conventional equipment of this kind has not proven itself as optimal, since it is difficult for such equipment to bring out a fold-free, straight line issue of the fabric. Furthermore, the exactness with which the custom cutting of said fabric is carried out is limited.
SUMMARY OF THE INVENTION
[0005] The purpose of the present invention is to make available a custom cutting apparatus, which overcomes the above named deficiencies of the existing state of the technology. This purpose includes the formulation of a process for said custom cutting, corresponding to the operation of said feeder and cutting apparatus. The invention further provides an improved fabric feeding device.
[0006] This purpose will be achieved by a custom cutting apparatus which exhibits the following:
[0007] at least one fabric unwinding device for a fabric roll,
[0008] a conveyor belt for the transport of the unwound fabric,
[0009] a custom cutting apparatus which cuts the fabric while said fabric is still on the transport band, whereby the transport band extends at least from the position where the fabric is deposited by the unwinder device up to the operational area of the custom cutter and
[0010] the fabric band lies directly on the conveyor belt or on one or more thereupon lying fabric bands.
[0011] Because of the use of the conveyor belt, with a through movement, the control of the fabric custom cutting apparatus has available very precise data in regard to the position of the fabric in the operational zone of the custom cutter. In addition, this movement eases the issuing of fold-free and straight line character of the fabric. Consequently, the pattern can be more exactly positioned in relation to the material, so that the custom cutting can be done with greater precision.
[0012] In the state of the technology up to now, the cutting off of the fabric at the end of a pattern or at the fabric roll end, is, in general, done by the said cutting apparatus. In yet another embodiment of the present invention, the fabric unwinder device is equipped with a fabric cut-off device. In the case of several unwinding devices, these are each advantageously and respectively equipped with a fabric cut-off device. These measures, on the basis of the increased precision of the conveying belt position, enable the cut-off operations at the pattern, or end of a fabric roll, to be carried out at the respective unwinding device. This increases the operational speed, since it makes possible the relieving of the custom-cutting apparatus from the cutoff operation, and provides a faster change of the fabric roll. The custom cutting apparatus permits a simple removal of fabric ends, although not cut off at the custom cutter, but at the unwinding device.
[0013] Fundamentally, these remainder pieces can also run on with the conveyor belt. The cutoff fabric remainders have, usually, a length of 0.2 m to 1 m and can be rolled up and discarded by an operating person or by the custom cutter apparatus (see below).
[0014] In yet another embodiment of the present invention, the fabric unwind device is equipped with fabric stretch loading apparatus or fabric tension loading apparatus, which holds the fabric firmly upon cutoff with the fabric cutoff device.
[0015] In order to attain an especially fast exchange of the fabric to be cut, the fabric unwinding device, of which there may be several, is so designed, that it can, in a self-acting manner, rewind the remainders on the fabric rolls (or on a winding shell). This enables an especially fast change-over to a new fabric roll. The cutoff of the fabric can, as already noted, be exercised for two different reasons. The first possible reason is the reaching of the end of a pattern cut, when the subsequent pattern must cut from a different material, i.e. a different color or a different pattern. The necessary cutoff signal emanates from the control of the fabric feed device, which possesses data on the pattern which is to be used. The second reason lies in the reaching of the end of the material which was originally in the fabric roll.
[0016] In yet another embodiment of the present invention, the material unwinding device, of which there may be more than one, is equipped with a material end sensor or fabric end sensor, which detects the approach or the reaching of the fabric end, advantageously upon the sensing of the complete or nearly complete unwinding of the fabric roll. Differently, in yet another embodiment of the present invention, the fabric end sensor is designed from a light-relay, through the beam of which the fabric band is run, proximal to the unwinder. The control of the cutting is stopped and simultaneously, the unwinding is interrupted as soon as the end of the fabric strip is recognized. With this action cutoff is instituted for the fabric. Because of the traveling conveyor belt, the control senses, with great exactness, the arrival of the fabric end at the custom cutter apparatus and can, therefore, synchronize the cutting operation accordingly.
[0017] The advantages of the invention can be especially effectively put to use, when—in yet another embodiment of the present invention—two or more unwinding devices are provided, preferably one unwinding device following the other winding device. This arrangement, achieves, for instance, a substantial reduction of the idle time of the custom cutting apparatus and besides, enables a significant increase of the effective speed of operation is possible. As has been explained above, there is an obvious requirement that a fabric roll must be changed frequently, because of necessary switches in color or pattern specifications.
[0018] Yet another embodiment of the present invention provides for such changes in the fabric roll, practically without interruption in the operation, since after the cutoff of a fabric with the existing cutoff device for the respective fabric roll, the control of the equipment immediately acts so that the remnant fabric roll is rewound and the unwinding of fabric from other textile rolls is carried out subsequently so that the layout of the material on the transport belt and the conveyance of the “new” fabric to the custom cutting device is immediately effected.
[0019] Because of the continuous conveyor belt, the arrival of the fabric band end at the custom cutter can be precisely calculated. Yet another embodiment of the present invention permits an interruption of the control of the custom cutter process at the latest, when the calculated arrival of the said fabric band end at the custom cutter takes place and sets the control back in operation by a “Start-again” signal upon the arrival of a subsequent fabric band. The computing of the arrival time is carried out advantageously with reference to the speed of the conveyor belt and the difference in distance between the fabric cutoff device or the fabric-end sensor and the custom cutter. The fabric end sensor can, because of the use of the continuous conveyor belt be disposed proximally to the unwinding device (and not the custom cutter, although this would also be possible and would lead to a self actuating recognition of a fabric end.)
[0020] The control can also automatically compute the arrival time of the lead edge of another fabric band at the custom cutter, after the said restart of the unwinder. The valid basis for this is again the continuity of the conveyor belt.
[0021] Alternatively, the determination of the arrival of a fabric band in the near proximity to the operation area can be done without being on the basis of a computation, but by direct detection of the leading edge of said fabric band. This can be accomplished, for instance, by optical means. For this purpose, the conveyor belt can be made in a specific color, which contrasts itself from the generally used fabric colors. An optical sensor is sensitive to the light reflected from the conveyor belt (which light necessarily has the color of the conveyor belt). Upon the arrival of the leading edge of the fabric, (which has a different color) the intensity of the detected reflected light is diminished, whereupon the arrival signal has been received. Another possibility of the recognition of the fabric rests upon an optical difference in distance measurement. The vertical spatial interval between an instrument above the conveyor belt and its visible surface diminishes itself, namely when fabric lies on the conveyor belt. This diminishing of the vertical interval permits the detection of the presence of fabric. The measurement rests, for instance, on the fact that light is focused on the conveyor belt and the reflected light from that surface is detected. The presence of the fabric implies, that the focus point lies under the reflecting surface (here the fabric), which condition manifests itself in an obvious lessening of the detected reflected light intensity. Both measuring methods can be used alternatively or in combination.
[0022] In yet another embodiment of the present invention, on the basis of this detection, a self actuated zero point reset for the pattern cutter in the moving direction of the fabric band occurs for the next-in-sequence, custom cutting procedure. This zero point lies in the longitudinal direction at a pre-specified distance (for instance, 2 cm) from the fabric band leading edge, and is offset toward the center of the fabric band. Along with the zero-point setting, a restart signal for the cutting procedure could also advantageously be made.
[0023] A selvedge for fabric rolls of differing width, found at a right angle, or hereinafter “cross”, to the direction of conveyor travel must be considered when setting the zero point. The selvedge is that fabric edge area which differs from the remainder of the material in color and/or pattern. More exactly said, the cross zero point must be set at a specified distance from the inner edge of the selvedge toward the center of the fabric band, i.e. remote from the edges. The detection of the inner edge of the selvedge can fundamentally be done automatically by optical means. Preferred is, however, a half-automatic setting of the cross zero point in yet another embodiment of the present invention. This is based on an automatic fabric roll follower guide, which compensates for unequal windings of the fabric across the band. At the start of an unwinding for a new roll, an operator defines the position of the cross-zero point relative to the edge of the fabric. If the cross zero point should lie, for example, 1 cm within the inner edge of the selvedge, then the operator, in case of a 2 cm selvedge, sets the cross zero point 3 cm within the actual fabric edge.
[0024] The roll follower guide transversely slides the fabric roll automatically during the unwinding in such a manner, that the cross zero point comes to lie at an established cross position of the conveyor belt (the cross-zero point position) . In yet another embodiment of the present invention, the determination of the fabric band edge position, which is necessary for the described action, is carried out by a fabric band edge sensor with an optical light relay system. Such a system would encompass one or more light sources which directly illuminate the fabric edge after the unrolling and one or more sensors for the spatial detection of the light interrupted by the fabric and/or the light falling on the fabric band.
[0025] In the case of the fabric custom cutting, in accord with the invention, the control, because of the positioning of the conveyor belt, can precisely predetermine whether a pattern to be cut exceeds the available length of the remaining fabric. In accord with yet another embodiment of the present invention, it is even possible, that the control selects only those patterns for a pattern, which, before running out of fabric, can be completely cut out. The control stores in memory those pattern cutouts, which cannot be completely cutout and then permits, that these cutouts are automatically called back into action after operation begins with new (and sufficient) fabric. From the standpoint of control technology, it is possible as shown in yet another embodiment of the present invention, that in case a fabric roll reaches an end at a pattern cutter, this will be cut as determined by the control. Such patterns as could not be cut from said roll completely, are automatically recognized and after automatic recognition of the zero point in the direction of the conveyor belt travel, will be cut out of the next fabric rolls. These measures enable a substantial reduction of the spoilage.
[0026] The single cutouts must frequently be provided with additional seams and quilting. This can be the case, for example, in upholstery covering, in which the cover folds are made by the sewing of the single patterns before the complete sewing together of the covering is done. In this case, it is advantageous that the patterns are provided with markings, along which the seam or quilt lines can be set. In order not to have to mark each cutout, these markings were advantageously placed on the not yet cut fabric band. For the later processing of the cut-outs, in general, markings must be made on the fabric. For instance, such markings show where later quilting is to be made.
[0027] In yet another embodiment of the present invention, for this purpose a marking device has been provided. In the state of the technology, one uses for this purpose a marking head (that is, a spray head) which is installed on the custom cutting apparatus and, indeed more exactly, on the available, bidirectionally movable support which also carries the cutting head of the custom cutting apparatus. The work-up of the fabric is done in the manner of the state of the technology, in general so, that first, by an appropriate procedure of the supports, the necessary markings on the fabric are applied. When that is accomplished, once again, by corresponding movements of the support, the required fabric cutting can proceed.
[0028] Alternatively, in yet another embodiment of the present invention a controllable marking apparatus, separately placed away from the custom cutting apparatus and independent thereof, is provided. The cutting and the marking are executed simultaneously. Advantageously, the marking apparatus is located between the unwinding device and the cutting apparatus. By marking the fabric directly after the unwinding from the fabric rolls, the fabric bands come to the cutting apparatus in a prepared state. Since the cutting apparatus now serves only the one cutting function, the operational speed is increased by a factor of 2.
[0029] In a case of disturbance with the cutting apparatus or the marking apparatus, a custom cutting machine of the state of the technology must, in general, be brought to a stand still, until the difficulty is corrected. In order to avoid production down-time of this kind, by means of an improvement of the above described system, in yet another embodiment of the present invention, the marking apparatus is equipped with a custom cutting means (for example) a cutting head, and/or the custom cutting apparatus is provided with a means for marking (for instance, a marking head). The control of the equipment is so designed, that at an emergency-run operation—at what would be a shut down for conventionally operating cutting or marking means—in accord with the present invention, custom cutting is possible with the cutting means placed on the marking equipment, or, in reverse, marking continues with the marking means located on the cutting apparatus. Further, roll exchange can be carried out simultaneously. In the case of a complete breakdown of either of the two apparatuses, a more extensive emergency-run operation is foreseen, in which both functions are taken over by the non-disabled apparatus (i.e. custom cutting and marking). In the first mentioned case there is effected a continuation of operation with simultaneous cutting and marking without loss of time. In the second case, what occurs is a non-simultaneous cutting and marking, which allows continued operation at perhaps half the speed of the normal operating rate.
[0030] The unwinding of the fabric and its conveyance on the conveyor belt can be done continuously or discontinuously. In the first case, the fabric is drawn from the roll without interruption or delay and during its movement, is cut and, if necessary, marked. Control-wise, however, a forward impulse movement is simpler, in which the unwinding device and the conveyor belt are at times held back for a cutting of a “cutting window” and, if necessary, for the marking of a “marking window”.
[0031] In yet another embodiment of the present invention, the fabric custom cutting apparatus exhibits a marking head, which is movable in the transport direction of the conveyor belt or at right angles thereto. This marking head can be outfitted with a spray device, which applies line-like markings on the fabric band. In this way, dry powder can be ejected thereon, which, after the further work-up of the material can be brushed away. The spray, or ejected substance can also be of a retentive nature, such as a dye, which, without the aid of technical means (fluorescent lamps), is invisible. In the case of another preferred embodiment, the marking apparatus is formed from a marking head, which, in similar manner to a plotter, applies the markings by means of a movable vertical rod moving along the lines to be marked. The rods can be chalk pieces or other customary marking means. In this way, a single rod can be employed. Even a supply magazine can be provided, out of which the marking head can select a rod. The latter form has the advantage, that, first, the rods are exchangeable upon wear without long resetting periods, and second, several rods for varied colored markings are immediately accessible to the marking head. The movement of the marking head is, advantageously, regulated by a control unit which possesses a microprocessor. This control can be, for instance, from a tool machine issue such as the well known CNC or DNC Control units.
[0032] The input quantity of the control includes the placement of the markings to be made on the individual patterns as well as the arrangement of the pattern. In order to be able to load in these data, the said control possesses an interface, to which is connected either:
[0033] a central control unit for the regulation of the fabric guidance formed from the unwinding device and the conveyor belt and the custom cutting apparatus, or
[0034] by means of which central control the data from another computer could be taken over, for instance, the control of the cutter apparatus.
[0035] Compatible data formats are preferred, such as in textile work, the customary formats, *.DXF AAMA or formats such as ISO 6983, wherein the data, in general, are produced with the aid of CAD-systems. A matching to each optional data format is possible. The control of the equipment can be the proprietary format of another machine manufacturer, such as, the proprietary format of the French firm “Lectra Systems”, which can be installed and worked with. The program for the control of the marking head can either be input through the interface for the location data of the markings, or be input to a stable memory, for instance an EPROM or even to an electrical erasable and rewriteable EEPROM.
[0036] In yet another embodiment of the present invention, the custom cutting apparatus exhibits a cutting head, which is movable in the cross direction and, if required, in the direction of conveyor belt travel and the position of which as well as the cutting activity is controllable from the control of the general equipment. The cutting head control is advantageously designed in the same way as the above described marking head control. The two controls can use one and the same or separate microprocessors. Further the two head control components can be the control of the entire fabric cutting equipment, which possesses a single common microprocessor.
[0037] The cutting head can possess a cutting knife, which, for instance, is designed as an electronically driven circular knife. In other embodiments, the cutting knife is designed as a pinion cutter, which advantageously is activated supersonically, whereby the assurance is given that even in the case of fast forward movement, the cutting force is vertical to the fabric band. The cutting head can also be built as a die, which stamps the patterns out of the fabric band.
[0038] In a preferred embodiment, the cutting head is a laser beam cutting head. This type of cutting head possesses a laser beam source and a corresponding focusing optical system, which focuses the laser beam on the fabric band. To avoid undesirable oxidation, an additional protective gas jet can be provided, which pushes away from the cutting position the oxygen containing air by means of inert gases, i.e. nitrogen or other inactive gases. Especially, where artificial fiber containing textiles are concerned, a fume removal system can be provided, which, during the cutting, sucks away the vaporized substances in order to uphold the required working place environmental regulations (MAK-values).
[0039] Finally, the cutting head can also fulfill its function as a water stream, which exhibits a water jet, from which a high pressure water stream issues for cutting the fabric. In this case, the custom cutting apparatus possesses on the side remote from the cutting head, an appropriate collection system for the cutting water stream. An advantageous arrangement is one of the above mentioned mechanical cutting or stamping methods combined with a laser beam cutting device or with a high pressure water jet custom cutting apparatus.
[0040] In order to cut out several similar patterns in a single work operation, it is known in the state of the technology to lay several layers of fabric bands, one on top of the other. These laminated arrangements of fabric are brought to the cutting apparatus, and with one penetrating cut, are all custom cut together (see EP-A-0 589 091 referred to previously). With the conventional marking apparatuses (see DE-U-295 03 230) only the top layer of this multiple layered fabric structure can be so marked.
[0041] In yet another embodiment of the present invention, the fabric cutting apparatus is so designed, that on the conveyor belt, two or more layers of fabric can be laid out on top of one another. For this purpose, a corresponding number of fabric unwinding devices are used. Because of the continuously moving conveyor belt, the fabric bands can be very precisely positioned over one another.
[0042] In yet another embodiment of the present invention, each of the unwinding devices is provided with a marking device.
[0043] The marking apparatuses are so arranged, that they are able, respectively, before the deposition of a further fabric band layer, to apply a marking on the existing band. The marking apparatuses are controllable in respect to time and position in such a way, that the markings of the finally stacked fabric layers are positioned congruently, one on the other. This pre-customized, multiple layered fabric band is then conducted to the cutting apparatus. On the now cutout patterns, the marking guides are still in alignment. The last marking apparatus (if there are more than one) is advantageously located between the last unwinding device and the custom cutting apparatus. It marks respectively the unwound fabric band layer from the assigned unwinding device before the next layer can be placed by the adjacently located unwinding device.
[0044] After the stacking and so that the markings of the individual layers are congruently aligned, the marking apparatuses and the withdrawal speed of the individual unwinders are time synchronized and controlled. Preferably, all marking apparatuses operate simultaneously, wherein each handles one window in the timely sequence of the fabric output. The marking windows can belong to one or to various cutout patterns. After the work-up of respectively one marking window, the fabric band is moved forward, so that the respective marking window next in line is presented. In regard to control, the marking windows are so synchronized, that in the finished, custom cut packet the marking lie congruently, one under the other. In the case of a discontinuous operation, the second marking apparatus carries onto the second layer of fabric exactly the same marking pattern, which, in a previous step, the first marking apparatus applied on the first fabric layer. The markings of the first and second material layers, lie congruent, one on top of the other. Alternatively, a continuous forward movement is possible. The fabric bands were, during the marking, pulled under the marking apparatuses.
[0045] Advantageously, the fabric custom cutting equipment is equipped with at least one coating material dispensing device placed after the unwinding device, which lays down a top layer on the fabric band. In this way, on the uppermost fabric band layer, a covering material is laid for the formation of a vacuum sealing means.
[0046] A fabric band with such a covering coating as described, upon later cutting, can, because of low pressure at the conveyor belt, be so pressed against the said conveyor belt, that the risk of a relative slipping of the single fabric band layers during the cutting is lessened. An appropriate covering material can be a plastic foil, a paper layer, or another foil-like material. The permeability to air of the covering material is advantageously less than that of the fabric band layers, so that a sufficient anchorage due to the vacuum formation is made. In the case of other embodiments, the suction is effected without a cover on the top fabric layer. A sufficient suction can be achieved by the relatively small air permeability of the fabric band layers to be cut.
[0047] In the case of more simple and more economical embodiments, the conveyor belt is provided with a rough and/or adhesive coating, which, without the vacuum effect is enabled to hold the fabric band(s) securely. This is accomplished advantageously by a felt coating. This obviates first, the relatively expensive suction arrangement and second, makes the coating of the fabric band obsolete.
[0048] In order to cut with greater precision and to hold the scrap rate to a minimum, there are various measures for freedom from folding in the depositing of the fabric on the conveyor belt or on other fabric layers. Thus, in yet another embodiment of the present invention, the progressive movement of the unwinding device or the fabric tension loading apparatus (which can be multiple) is somewhat slower than the forward motion of the conveyor belt. This causes the fabric to be laid on the conveyor belt with a certain degree of tension. In yet another embodiment of the present invention the fabric band is subjected to pressure, namely by a pressure roll which presses the band against the conveyor belt.
[0049] In the state of the technology, where custom cutting was involved, frequently in the edge areas of the pattern, so-called “clipping” was observed. What was involved here were three cornered cutouts, which indicated to the sewing person during the subsequent sewing of the fabric pattern, where the seams which were to be installed began or ended. In order to shorten the fabric work-up time even more, in yet another embodiment of the present invention the recognizable characteristic mark for seam ends or seam beginnings, instead of being marked with cutout “clips”, such guiding markings are applied in the form of (colored) marking on the material itself. This is done advantageously by the above mentioned marking apparatus, which operates simultaneously with the custom cutting apparatus. Since the custom cutting apparatus is more heavily loaded than the marking apparatus, the substitution of the cutout clippings (optically recognizable) by markings would bring with it a more well balanced loading and therewith as a whole, an increase of profitable working time.
[0050] The marking system(s) can, advantageously, also be employed for other markings on the fabric pieces. Such markings, for instance, can be symbols assigning different fabric pieces to a specific, for instance, furniture piece. This is particularly valuable, when the fabric pieces belonging to a specific furniture piece come from different patterns. This would be the case if the furniture piece was to have a multicolored covering. Further such marking would be helpful if the fabric, because of roll end changes, was cut from an old and a new fabric roll. In yet another embodiment of the present invention, this assignment information, or other information can be carried out with the marking apparatus on an separate piece for sew-on addition. In this case a fabric piece is involved which is to be sewed on at a later time. The information can be presented in coded or uncoded form.
[0051] The fabric cutting equipment—alternatively or additionally—can possess a label application device, which provides the individual cutouts of a pattern or different patterns with labels, so that the cutouts, by further working, can be properly assembled together. The label application device can, for this service, be located either before or after the cutting apparatus and can be controlled by the complete system controller.
[0052] The unwinding device is advantageously designed as a rodless device, wherein the fabric rolls are found upon an underlying support, and for the unwinding of the fabric are set into rotation by a tangential motion imparted against their outer surface.
[0053] The fabric custom cutting apparatus can also possess a take-away belt, which transports the already cut and possibly marked cutouts to various assigned receiving baskets. The take-away belts can also be located as an extension of the main conveyor belt.
[0054] Advantageously, the said fabric custom cutting apparatus also has a monitor, upon which the cutting design and/or the markings to be made are visible. As mentioned previously, in accord with the state of the technology, one employs separate equipment for the fabric feed and the custom cutting, which are assembled at the operating site. The above described arrangement of the fabric cutting apparatuses are also advantageous for such separate equipment, even if fully optimal results are not achieved, which optimal results would be expected of a fabric cutting apparatus designed as a unified entity. Existing in the textile working countries are a large number of such installations assembled from various parts and these are capable of useful production for many years to come. In order to allow these existing installations to enjoy the profitability of the invented designs, it is proposed that the custom cutting apparatus be retained, but to replace the feeding apparatus with a fabric forwarding feed system in accord with one or more of the above assemblies. In yet another embodiment of the present invention, such a fabric feeding device and system is proposed with at least one fabric unwinding device for a fabric roll, one belt conveyor for the transport of the unwound fabric, wherein the unwinding device lays the fabric band directly on the conveyor belt or upon one or more fabric bands already thereon, whereby the fabric feed equipment possesses one or more of the features of the fabric feed equipment found in the embodiments of the present invention previously described. Insofar as a fabric custom cutting apparatus is mentioned, the separate custom cutter component is not excluded from within the meaning of the term. In some cases, the separate custom cutter component can be controllably coupled with the fabric feed equipment of the invention, so that, for instance, the object of defining and operating on the cut out patterns prior to the end of the fabric roll is advantageous to the highest degree with the feed apparatus of the invention along with an existing, conventional custom cutting apparatus. Particularly advantageous is yet another embodiment of the present invention in which a multi-layered marking is made possible. From this, the existing cutting system can profit in the greatest measure if it is operated together with a feed system as outlined above.
[0055] Finally, the invention presents a procedure for custom cutting of fabric, including the steps of laying out at least one layer of a fabric on a conveyor belt by the unwinding of a roll of fabric from an unwinding device and directing deposition on the continuing or discontinuing movable conveyor belt or on one or more layers of fabric already deposited thereon, transporting the laid out fabric on the conveyor belt to a custom cutting apparatus and automatic cutting out of a desired pattern form with the custom cutting apparatus. In accord with one or more of the above formulations, the procedure can be developed and extended whereby the conveyor belt is continuous at least from the fabric deposition point to the operating area of the custom cutting apparatus. In regard to the details reference is made to explanations for fabric cutting and fabric transport, which give attention to the process and its embodiments.
[0056] Other objects and features of the invention will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawings illustrating the invention, of which there are eight sheets of four embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] [0057]FIG. 1 is a side view of a fabric custom cutting apparatus with two unwinding devices, however, without a marking apparatus,
[0058] [0058]FIG. 2 is a plan view of the cutting apparatus of FIG. 1,
[0059] [0059]FIG. 3 is a side view of a fabric custom cutting apparatus, similar to FIG. 1, however with the additional equipment of two marking apparatuses and a removal belt,
[0060] [0060]FIG. 4 is a plan view of the fabric cutting apparatus shown in FIG. 3,
[0061] [0061]FIG. 5 is a schematic presentation of a fabric band with pattern cutouts and blanks to be cut,
[0062] [0062]FIG. 6 is a schematic cutout, the patterns for which were divided onto two separate fabric bands,
[0063] [0063]FIG. 7 is a side view of a fabric custom cutter apparatus which is similar to FIG. 1, which is made secure against down time due to loss of the cutting facility and the marking apparatus, and
[0064] [0064]FIG. 8 is a side view of a fabric unwinding device, which is similar to that of FIG. 3, however, not equipped with a custom cutting apparatus.
[0065] In the drawings, the same reference number is given to components with identical functions or definitions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0066] The fabric custom cutting apparatus, as shown in FIGS. 1, 2, exhibit two unwinding devices 1 , 1 ′. Respectively, a fabric roll 7 lies in a V-notch shaped, belt arrangement 8 of the unwinding device, which latter has three rolls 9 . The belts are driven preferably by means of the center roll 9 . The traveling force of the said belt arrangement 8 is communicated by friction to the fabric rolls 7 , which are thereby rotated and unwind themselves.
[0067] The fabric custom cutting apparatus is equipped with a conveyor belt 5 , which extends itself from the position where the fabric from the first unwinding device 1 is laid down to the operational area of the custom cutter 3 . As to the term “first unwinding device”, that unwinding device is to be understood which is most remote from the said custom cutting apparatus 3 . The fabric band is laid down from the unwinding devices 1 , 1 ′directly upon the conveyor belt 5 . The direction of travel of the progressing conveyor belt is characterized in the drawing(s) by an arrow.
[0068] In accord with the presentation in FIG. 1, the second unwinding device 1 ′is active. The first unwinding device is idle. The custom cutting apparatus 3 , accordingly, cuts fabric which is respectively discontinuous by the length of a cutting window as drawn from the fabric roll 7 of the second unwinding device 1 ′.
[0069] The unwinding devices 1 , 1 ′ are respectively equipped with a fabric-end sensor 30 . This is comprised, for example, of a light emitter/receiver unit and a reflector. This light relay unit can be so arranged, that the light beam runs over the two outer rolls 9 of the belt arrangement 8 , so that the fabric rolls interrupt the light path of the light relay. When the diameter of the fabric roll, on the other hand, reduces itself below a given threshold, the light beam passes freely to the receiver, thus making a fabric end signal to a control instrument 6 a . This signal initiates a cutoff of the fabric band already on the conveyor from the remainder wound on the fabric roll 7 . At this point, the fabric band is retained by a tensioner apparatus 10 and is cut off by a subsequently placed fabric cutoff apparatus 12 . Both the tensioner 10 and the cutoff apparatus 12 are installed on the unwinding device 1 , 1 ′ in an area in which the already unwound fabric has not yet reached the conveyor belt 5 . After the cutoff, the fabric remainder on the second fabric roll 1 ′ (the active roll) is rewound thereon.
[0070] Although the end of the fabric band, now laid upon the conveyor belt 5 , is to be cut by the custom cutting apparatus 3 , the first unwinding device 1 is already unloading onto the same conveyor belt 5 . With a doubled belt advancement, the fabric from the first unwinding device 1 is already within the operational area of the custom cutting apparatus 3 , so that a fabric roll switch is achieved with only a small break in the continuous operation. The operating person can now remove the fabric roll from the second unwinding device 1 ′ and replace it with a new fabric roll.
[0071] For the continuing of the cutting procedure with the new material, a zero point positioning is required. In the progressive direction of the conveyor belt, this zero-point setting is fully automatic since a travel-direction, zero point sensor 11 detects the forward edge of the fabric in the operational area of the custom cutting apparatus. The detection is based on an optical recognition of the color of the fabric which differs from the color of the conveyor belt and/or by means of an optical detection of a spatial difference between fabric bands. In the cross direction, the zero point setting occurs half-automatically. And indeed, the unwinding devices 1 , 1 ′are slidable at right angles to direction of belt travel by means of a cross directed drive 31 . This cross drive is equipped with a subsequent signal controller 33 , which, acting upon a signal from the optical fabric band edge sensor, moves the unwinding roll laterally so that the unwound fabric band edge comes to a constant cross position on the conveyor belt. This avoids that an uneven unwinding of the fabric leads to angled pushing of the laid down fabric band on the conveyor belt. The position of the unwound fabric located across the belt, which was automatically set by the follow-up control, can be adjusted in individual cases by an operating person as fabric rolls are changed. This is necessary, since the breadth of the so called fabric band edge 13 , does not coincide from side to side. For this adjustment there serves a determinable cross directional zone ( 14 ) i.e. selvedge, free of zero point.
[0072] The cross directional zero point adjustment also encompasses the fact that the operating person, after the insertion of a new roll of fabric, sets the zero point at a specified spatial offset (for instance 1 cm) inside of the inner selvedge limit. By this means, assurance is given, that the cross directional drive automatically controls the position of the unwinding devices 1 , 1 ′ in such a manner, that the adjusted cross zero point is always laid at the same cross position of the conveyor belt.
[0073] This cross zero point adjustment can be undertaken previous to the actual start of operations of a unwinding device and so would engender no interruption in the continuity of work.
[0074] The custom cutting apparatus 3 encompasses a sliding support 16 , movable parallel to the conveyor belt, possessing a cross-traverse 17 upon which a cutting head 18 is movable. Where the cutting head 18 is concerned, this could be, among other choices, a laser-cutting head.
[0075] The control equipment has stored in memory, the patterns to be cut. On a monitor 6 , (among other things) these patterns are presentable in virtual cutouts. Using these the stored patterns as a basis, the control equipment controls:
[0076] the remnants from the unwinding devices 1 , 1 ′,
[0077] the automatic relocation of the zero points in belt travel direction,
[0078] the motion of the cutting head 18 in belt travel and cross directions,
[0079] the cutting activity of said cutting head 18 ,
[0080] the cutoff of the fabric at approaching roll end, and
[0081] the exchange from one unwinding device to the other because of input from the cutting specification for a change in from one fabric to another or because of an approaching end of a fabric band.
[0082] More detail on this will be provided below in connection with FIGS. 5, 6.
[0083] A fold-free lay-out of the fabric on the conveyor belt 5 is to be achieved, first, in that the tensioning device 10 for stretching the fabric permits only a somewhat lesser forward motion of the fabric in comparison to that of the conveyor belt 5 . Thereby, the fabric is under a certain tension when laid down on the conveyor belt 5 .
[0084] Second, proximal to each unwinding device, 1 , 1 ′, a pressure rider roll 19 is provided, which presses the fabric against the conveyor belt 5 .
[0085] The said conveyor band 5 is provided with a felt like surface. The fabric clings to the material of this surface so well, that it does not slide even during the cutting process.
[0086] The fabric custom cutting in accordance with FIGS. 3, 4 permit the marking and the cutting of multi-layer fabric bands. The above detailed explanations for the FIGS. 1 and 2 are also valid for such multi-layer bands in the same custom cutting apparatuses. Additionally, on the cutting apparatus, after each unwinding device 1 , 1 ′ is found respectively, a marking apparatus 2 , 2 ′ which applies on the just unwound fabric band, line markings for quilting or sewing to be carried out later. The marking are comprised, for instance of a self volatilizing substance, which can only be seen in ultraviolet or infrared spectrums. The marking apparatuses 2 , 2 ′, correspond in construction to the above described custom cutting apparatus 3 , and indeed, they exhibit a support 16 , slidingly movable parallel to the conveyor belt carrying a traverse bar 17 and a marking head 20 thereon. The latter is, for instance, a spray head which ejects the marking substance in the course of the spray head movement and thereby applies line-like markings of optional line form in the fabric.
[0087] After the first layer of the fabric band is laid down by the first unwinding device 1 , has been marked by the first marking apparatus, and has been transported further by the conveyor belt 5 , then the second unwinding device 1 ′ lays down a second layer of fabric. This will be marked by the second marking apparatus 2 ′. The marking procedure is so controlled, that at the end of the marking, the markings on successive layers of fabric band are congruent. The conveyor belt transports the ready-to-cut, multilayer fabric band to the custom cutter apparatus 3 , where the collected layers are cut in a common operation.
[0088] A vacuum box 21 in the operational area of the custom cutting apparatus 3 , located underneath upper strand of the endless conveyor belt sucks air through the conveyor belt and the superimposed fabric bands. This causes a sufficient compression of the fabric bands onto the conveyor band to exclude any slippage of same during the cutting operation.
[0089] On the monitor 6 , in this embodiment, not only the virtual cutout lines are visible, but also the marking lines.
[0090] Behind the custom cutting apparatus 3 —“downstream”, relative to the belt travel—is appended a removal belt 22 , which is formed from an extended portion of the conveyor belt 5 . By means of said removal belt 22 , either the finished cut out fabric pieces can be sorted by the operational persons, or an automatic arrange and sort system can be added. Also, at this point, error cuts can be sorted out.
[0091] [0091]FIG. 5 shows a fabric band ahead of the custom cutting. On the longitudinal edge, is found the selvedge 14 , which normally has a width of 2 cm. The (virtual) zero point 23 finds itself in a cross direction, somewhat inside of the inner edge of said selvedge 14 (about 0.2 mm), as well as in the direction of travel of inside of the forward fabric edge (for instance, about 1 cm). On the fabric are seen the cutting lines of the patterns 24 yet to be cut out. This presentation of the lines serves only for information, because in reality, the lines are virtual, and exist only in the data memory of the cutter control. Along these virtual cutting lines, is moved the marking head 20 of the custom cutting apparatus 3 , so that said custom cutting apparatus 3 excise the presented cutouts. Likewise, marking lines 25 are drawn in. These are first likewise in the memory of the control equipment, but after the application of the markings, however, they become visible on the fabric in the here presented form. In the area of the cutting lines, also triangular markings 26 are to be seen. These are likewise applied by the marking apparatus 2 , 21 ′. The triangular marking serve for the later work-up of the fabric as recognition signals for seam ends or seam beginnings. Finally, the marking apparatus 2 , 2 ′ sprays in the specified seam locations of the cutouts 24 , data 27 such as commission or cutout number, so that after the cutting, an assignment of the single cutouts to their proper place is made easier.
[0092] When the length of a cutting pattern, as is presented, for example, in FIG. 5 exceeds the length of the working range of the custom cutter 3 , then the virtual cutting pattern is apportioned into several virtual parts, which correspond to the workable lengths. The control of the equipment is so designed, that after a progressive movement of the conveyor belt to the extent of the length of a “cutting window”, to allow that the next window to be processed, the result is that the presented cutting pattern shown in FIG. 5 is cut piece-wise.
[0093] [0093]FIG. 6 shows a pattern for cutting in an apportionment to demonstrate three cutting windows. In the presented example, the fabric band end comes to lay in the middle of the center cutting window. The control of the equipment determines immediately, which of the virtual proposed cutouts can be made from this cutting window in their entirety, and for which this is not the case. The control then allows the cutting of the partial cutout 24 ′ from the fabric band which is coming to its end, and allows, from the next new fabric band, the excising of the cutout 24 ″ which is now an incomplete but complementary cutout to 24 ′. Previously, the control had automatically reset the zero point 23 on the new fabric band. This measure allows, that the scrap waste is reduced to the minimum and upon fabric band change work can continue, practically without interruption.
[0094] The demonstrated fabric custom cutting equipment is modular in its construction. Thereby, components other than those here presented in example embodiments, may in a simple way, be used in combination with other functional units. Particularly advantageous is, for example, an embodiment for single layer fabric working, similar to FIG. 1, which, however, possesses behind the second unwinding devices 1 ′, a marking apparatus of the kind shown and described in FIG. 3. Such an embodiment is shown in FIG. 7. With this embodiment, single layer marking and custom cutting can be carried out, whereby, because of the doubled unwinding devices available, and the simultaneous carrying out of the marking and cutting, very high speed operation can be achieved. The fabric cutting apparatus of FIG. 7 corresponds to the remaining, not mentioned features in the FIGS. 1 to 4 .
[0095] Other than shown in FIGS. 3, 4, by an increase in durability and resistance against downtime, the marking apparatus 2 (where more marking apparatuses are present, then as in FIGS. 3 , 4 —the last marking apparatus) is provided with a cutting head 18 ′. Correspondingly, the custom cutting apparatus 3 is equipped with a marking head 20 ′. Respectively, a vacuum box is found in the working areas of the marking and cutting apparatuses.
[0096] In normal operation the additional heads 18 ′ and 20 ′ are not employed. In case of a breakdown of one of the normally used heads 18 , 20 , then, respectively, one of the additional heads 18 ′, 20 ′ is put to use. Now as to the roll exchange: The custom cutting apparatus 3 takes over the marking operation, the marking apparatus the cutting. In this emergency switching operation, the marking continues after the cutting, the already cutout pieces of fabric are also marked. Because of the before and after simultaneous method of operation, the operational speed can be maintained at its normal level. In the case of a total breakdown, a further emergency run stands available for the custom cutting apparatus 3 and the marking apparatus 2 . The emergency operation is as follows:
[0097] The still operable apparatus 2 or 3 , by the activation of the marking head 20 ′ or the cutting head 18 ′, marking and cutting now are done one after the other. The equipment can then, in spite of total breakdown, still operate, whereby, because of the now no longer simultaneous method of operation, the working speed is diminished.
[0098] [0098]FIG. 8 shows a fabric feed apparatus, which corresponds to that presented in FIG. 3 with the custom cutting apparatus. The single difference therefrom is that this embodiment has no custom cutting apparatus 3 (and also no subsequent removal area 22 ). Much more, the conveyor belt 5 ends in this case directly after the last marking apparatus 2 ′. This depicted arrangement in FIG. 8 is designed to be combined with a separate (partially shown in the FIG. 8) custom cutting apparatus 3 ′, which has its own conveyor belt 5 ′. Composite embodiments to the FIG. 1 through 7 are adaptable also for this fabric feed equipment. The shown embodiment permits, as does that of FIG. 3, a collection of multilayer, marked fabric windows, before the cutouts are excised in common from the fabric band packet.
[0099] While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims. | An apparatus for cutting fabric includes at least one fabric wind-off device ( 1, 1 ') for one fabric bolt ( 7), a conveyor belt ( 5) for conveying the unwound fabric, and a cutting device ( 3) which cuts a piece of fabric to a given shape from the length of fabric deposited on the conveyor belt ( 5). Said conveyor belt ( 5) extends without interruption from at least that point where the fabric is deposited by the wind-off device ( 1, 1 ') to the working area of the said cutting device ( 3). The wind-off device ( 1, 1 ') places the length of fabric directly onto the conveyor belt ( 5) or onto one of more lengths of fabric already deposited on the said conveyor belt. An apparatus control automatically feeds the unwound fabric to the cutting device and directs the cutting of the unwound fabric by the cutting device. |
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates generally to methods for controlling data flow in a Direct Access Storage Device (DASD) channel, and more specifically, to an efficient Count-Key-Data (CKD) DASD channel control system employing a Predictive Track Table.
2 Discussion of the Related Art
Use of Direct Access Storage Devices (DASDs) in a data processing system requires performance of certain Input/Output (I/0) functions. Data must be transferred between the DASD and the host processor. Such DASDs are often connected to a host processor through an I/O channel. The host Central Processing Unit (CPU) operating system initiates data transfer with a command to the I/0 channel. This shifts control to a series of Channel Command Words (CCW's) that are sent from the CPU over the channel to the DASD controller for effectuating data movement across the interface.
The channel forwards each CCW to the controller for a selected DASD. Once the channel passes a command to a particular controller, the command must be interpreted and the elements of the command must be executed by the DASD. The various functions of channel, controller and command interpretation can be integrated with the host processor or distributed between the host and the mechanical storage components of the DASD.
The DASD controller performs several functions, including the interpretation and execution of CCW's forwarded by a channel from the host CPU. Seek commands position a DASD access mechanism. Search commands cause comparison between data from main CPU storage and data stored on specified DASD areas. Write commands cause data to be transferred from main CPU storage to specified DASD areas. Read commands cause data copies to be transferred from DASD storage to main CPU storage and checked for validity.
Another important function of the DASD controller is the prescription of data storage format for the DASD. Such a format includes provisions for certain "non-data" information such as the track address, record address, and so forth. There are also unused spaces and error correction codes prescribed for the DASDs commonly encountered in widespread use.
Conventional track formats include an index point on each track of the recording surface indicating the physical beginning of the track. Also, on each track, there is normally one Home Address (HA) that defines the physical location of the track and the condition of the track. The HA normally contains the physical track address, a track condition flag, a cylinder number (CC) and a head number (HH). The combination of the cylinder number and head number indicates the track address is commonly expressed in the form CCHH. The HA contains the "physical" track address, which is distinguished from a "logical" track address. The physical and logical track addresses may differ for records stored in the DASD tracks.
The first record following the HA is commonly a track descriptor record, sometimes referred to as R0. One or more user data records follow R) on the track. The first part of each user record is an "address marker" that enables the controller to locate the beginning of the record when reading data from DASD. Each user record is commonly formatted in either a "count-data" (CD) or a "count-key-data" (CKD) format. The only difference between the CD and CKD formats is the presence of key fields and key length data in the CKD formatted record. Both are herein henceforth referred to as CKD records.
The CKD record consists of a count field, an optional key field and a variable-length data field. The typical count field is of the form CC (two bits of cylinder number), HH (two bytes of head number), R (one byte of record number), KL (one byte of key length), and DL (two bytes of data length). Thus, each CKD record is self-identifying. The CCHH in the count field (called "logical" CCHH) is typically the same as the cylinder and head numbers in the HA for the track containing the record (called "physical" CCHH), although not necessarily. Thus, a CKD track consists of the track header (HA and RO) followed by some number of CKD records. The CKD record numbers (R) may, but need not, increment along the track in a monotonic pattern of one, two, three, etc.
In the typical situation, user data is written or read in a data field of a CKD record in some track on some DASD. The channel specifies the device and the track within the device of interest. The channel may also specify the rotational position on the track from which to begin searching for the record having the data field to be read or written. This is accomplished by specifying a search parameter (five bytes in the form CCHHR) for use by the DASD controller to match against count fields in the track of interest. When the DASD controller finds a CKD record on the track with a count field that matches the search parameter, it then either reads or writes the corresponding data field, which is provided by the host through the channel for record writes. The fundamental feature of importance to this disclosure is that the disk controller is not permitted to read or write until it has verified the existence of a count field in the track that matches the channel search parameter. This means that a write command will force the channel to wait until the matching record is actually located on the rotating DASD medium. Of course, such a read wait state is reasonable because a CKD record cannot be read until located, but the only overriding reason for holding the CPU channel merely to locate the proper record for updating is to ensure error recovery.
The prior art is replete with methods for reducing and eliminating the host CPU wait states necessitated by DASD accesses for read and write. A DASD cache is a high-speed buffer store used to hold portions of the DASD address space contents in a manner that reduces channel wait states. In U.S. Pat. No. 4,603,380, Malcolm C. Easton, et al, disclose a method for DASD cache management that reduces the volume of database transfers between DASD and cache, while avoiding the complexity of managing variable length records in the cache. Easton et al, achieve this by forcing the starting point for staging a record to the beginning of the missing record and, at the same time, allocating and managing cache space in fixed length blocks.
Some DASD controllers known in the art, such as the IBM 3990 DASD controller, have some amount of relatively fast Non-Volatile Store (NVS) for storing records that have been written by the host system but not yet written to the DASD medium by the DASD controller. The NVS is additional to the high-speed cache buffer store commonly included in the typical disk controller. DASD controllers having both cache and NVS are said to perform "fast-write" operations.
A fast-write operation proceeds as follows. If a track record to be updated is already in cache (that is, a record count field is found in cache that matches the search parameters provided by the host computer), the cache copy of the record is updated in cache and another updated copy is made in NVS. The two copies of modified records are maintained for error recovery purposes to avoid single points of failure. After copying to NVS, the DASD controller returns a completion signal to the host system, freeing the host CPU to proceed with the next channel operation. Such an operation is called a "fast-write hit" and is completed well before the updated record is actually written to the DASD medium. At some later time, the DASD controller asynchronously destages the updated record to disk from the cache and then removes the record from both cache and NVS.
This explanation, made in terms of a single record, actually is better understood in terms of a single track. DASD controller cache memory is generally organized in fixed block sizes. Because a single track is often a fixed size while single records are not, the typical practice is to stage and destage data from cache to DASD and back again in single track increments.
With a "fast-write hit", the DASD controller can eliminate the disk access time from the channel write operation as perceived by the host CPU. The actual destage of the modified record from cache to disk can be accomplished at a more convenient time; for example, when the DASD controller is idle, or when there is other work to be done against the same track or cylinder as the one holding the modified record.
If the record to be updated was not originally located in cache, however, the "fast-write" operation becomes a "fast-write miss" and the DASD controller must then locate the record on a disk before releasing the channel. That is, a fast-write miss is treated as if there is no cache. After the disk controller locates the track, it must search the count fields of records in the track starting at any specified rotational position, and search for a matching count field. Once the matching count field is located, the DASD controller updates the corresponding data field on the DASD medium and, only then, returns a completion signal to the host CPU. The controller may also read the entire track into cache at the same time in anticipation of subsequent updates to records on the same track.
It will be appreciated that a "fast-write miss" is much slower than a "fast-write hit" because it includes a disk access delay as part of the response time seen by the host CPU. Thus, although the "fast-write" is a useful technique commonly used in DASD controllers to improve the performance of write operations from the host system, the effectiveness of this technique depends on the number of "fast-write hits". This is because the controller functions as slowly on a fast-write miss as it does without the fast-write capability. Thus, for applications exhibiting poor write-hit ratios, use of DASD controllers with fast-write capability will not materially improve DASD channel efficiency.
In U.S. Pat. No. 4,875,155, James L. Iskiyan, et al, disclose a cache and a DASD backing store in which CKD records are staged and destaged to provide a "fast-write" capability. Iskiyan, et al teach the use look-up tables for indicatinq whether cache record images are modified with respect to the DASD-stored versions of the same records. While the Iskiyan, et al technique improves the read and write access efficiency for a "fast-write" type of system, their technique does nothing to avoid the "fast-write miss" delays described above. There is a strongly felt need in the art for a technique that will make available the benefits of the "fast-write" caching scheme to applications exhibiting poor write-hit ratios. The related unresolved problems and deficiencies are clearly felt in the art and are solved by this invention in the manner described below.
SUMMARY OF THE INVENTION
This invention is a new technique for reducing the host CPU wait time associated with fast-write misses in a cached DASD store. The method of this invention is premised on the unexpected observation that a significant fraction of all CKD formatted DASD tracks contain records having substantially equal-size data fields and no key fields. These records are usually organized along the track in monotonically increasing record number order. The invention provides for storage of a Predictive Track Table (PTT) in high-speed RAM for use in predicting the location of records on such well-organized "predictive tracks". By storing two copies of the host-updated record and by predicting the precise DASD track location of the updated record, the DASD controller can immediately release the host CPU channel without risk of data loss and without waiting for verification of the actual record location in the target DASD track.
Examination of CKD formatted system usage in the data processing industry has led to the unexpected discovery that certain host operating systems almost always ensure that the logical record CCHH is identical to the physical CCHH location of CKD records in the DASD track. It was also discovered that the preponderance of CKD tracks are "predictive" in that the CKD records have no key fields, have substantially equal-size data fields and have record numbers in the track that increase monotonically from unity. Examination of channel programs widely used in the art has led to the unexpected observation that most host update writes are to predictive tracks. Thus, improved performance of such update writes to predictive tracks will lead to a significant overall improvement to system performance without actual improvement of cache fast-write hit ratios.
It is an objective of this invention to improve the efficiency of applications that exhibit poor write-hit ratios without a concomitant increase in DASD cache size or complexity. It is another object of this invention to accommodate variations in the proposed predictive track configurations.
It is an advantage of this invention that, for CKD formatted DASD control units, the method eliminates DASD access time components from the host response time for most update write requests. Controllers such as the IBM 3990 already eliminate DASD access time from host CPU service time if the accessed record is found in cache, but not otherwise. Therefore, it is a significant advantage of this invention that applications having poor write-hit ratios, including many of the newer applications, are made more efficient by the method of this invention.
This method has other additional advantages when applied to Fixed Block (FB) DASD controllers known in the art for emulating CKD storage functions. This method eliminates a DASD access normally required for such FB/CKD emulation. It is another advantage of this invention that, when applied to CKD emulation in which all the CKD records are packed tightly into FB sectors, the FB DASD controller can be operated at twice the normal speed because of improved update efficiency.
It is yet another advantage of the method of this invention that certain FB DASD FB/CKD emulation techniques can be simplified by eliminating, for predictive tracks, the normal requirement to store emulated count fields on the FB sectors of the DASDs. This is possible because the Predictive Track Table is defined to comprise sufficient information to recreate the necessary count fields for predictive tracks.
The foregoing, together with other features and advantages of the present invention, will become more apparent when referring to the following specifications, claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this invention, reference is now made to the following detailed description of the embodiments illustrated in the accompanying drawings, wherein:
FIG. 1 shows a CKD DASD channel and controller configuration known in the prior art;
FIGS. 2A-B, illustrate the CD and CKD record formats known in the prior art;
FIGS. 3A-E, show a series of variations on the predictive track formats proposed for this invention;
FIGS. 4A-E, show the Predictive Track Table formats of this invention corresponding to the predictive track formats of FIGS. 3A-E; and
FIG. 5 shows an illustrative example of a flow chart for the method of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Existing Art
FIG. 1 illustrates the typical memory hierarchy and typical Direct Access Storage Devices (DASDs) CPU control paths well-known in the art. The upper portion of FIG. 1 shows a CPU 10 interfacing with a high-speed CPU cache 12 and therefrom to a main memory 14. Main memory 14 is then connected to an exemplary DASD 16, which is shown having a DASD cache 18, a DASD Non-Volatile Storage (NVS) 20, and a plurality of tracks on a rotating disk 22. It will be appreciated that other archival memory devices may be attached to DASD 16 as well.
The lower portion of FIG. 1 illustrates the data and control paths known in the art for CPU references to lower elements in the memory hierarchy. CPU 10 is connected through a plurality of channels exemplified by channel 24 and a group of DASD controllers exemplified by controller 26 to a switch 28 serving to select one of several available DASDs exemplified by the DASD 30. DASD 30 can be the same device illustrated above as DASD 16. CPU 10 passes Channel Command Words (CCWs) through channel 24 to controller 26 for use in selecting and controlling the disposition of read and write references to DASD 30 in one of many useful ways known in the art.
Among the many DASD architectures known in the art, the IBM Count-Key-Data (CKD) and Extended CKD (ECKD) are particularly useful. See, for instance, Marilyn Bohl, "Introduction to IBM Direct Access Storage Devices", Science Research Associates, Inc., 1981, for a detailed description of the CKD architecture. The CKD format permits variation in record sizes and numbers on each DASD track, as compared with the Fixed Block Architecture (FBA) also well-known in the art.
FIGS. 2A-B show the details of the CD and CKD formats known in the art. In FIG. 2A, the CD track begins at index point 32 and, after a brief physical Gap (G), first contains the Home Address Area (HA) 34. FIG. 2B shows the contents of HA 34, which includes Physical Address (PA), Flag (F), Cylinder Number (C) and Head Number (H) (generally written in combination as CCHH), and Cyclic Checksum (CC). The cylinder and head numbers written in HA 34 are denonimated the "logical" cylinder and head location of the track.
Returning to FIG. 2A, the CD track next contains a Track Descriptor Record (R0) containing Count Area 36 and Data Area 38. There is no provision for a Key Area in R0 as will be appreciated by referring to FIG. 2B. Otherwise, R0 may contain either system or user data or a combination of both.
Inspection of FIG. 2B will reveal that the only difference between the CKD format in FIG. 2B and the CD format in FIG. 2A is the presence of a Key Area (KA) 46. Thus, as used herein, "CKD format" is intended to encompass the CD format and the CKD format, unless specifically noted otherwise.
Each track contains anywhere from zero to some maximum number (n) subsequent user data records followed by blank space. Referring to FIG. 2A, for instance, the remainder of the CD formatted track contains a series of user data records (Rl-Rn), each such record having an Address Marker (A) 40, a Count Area (CA) 42 and a Data Area (DA) 44. The first part of each record in FIG. 2B is an address marker (A) exemplified by A 40. The content of this two-byte area is supplied by the DASD controller as the record is written and enables the controller to locate the beginning of the record when searching and reading data from the DASD.
FIG. 2B shows the detailed contents of Count Area (CA) 42, which exemplifies the CA in every record. CA 42 consists of a Physical Address field (PA), a Flag (F), a record identifier consisting of cylinder and head number (CCHH) followed by a Record number (R), a Key Length (KL), a Data Length (DL), and a Cyclic Checksum (CC). Generally, the PA field in each record is the same as the PA field in Home Address 34 and represents the "physical" cylinder and head location of the track. Also, generally, the CCHH field in each record count area is the same as the CCHH field in HA 34, representing the "logical" track number for the record.
In FIG. 2A, the Key Length is always zero because there is no Key Area 46. When the Data Length field is set to zero, this indicates an end of file record. Finally, as is known in the art, the contents of KA 46 may be repeated in DA 44.
The logical CCHH in CA 42 is typically the same as the physical address (PA) although it is not required to be so. The record number (R) fields in each of the records on the track are not constrained to proceed in any particular pattern, but often are monotonic starting with the number 1 and proceeding to some maximum number n, which must be no greater than 255 for a single byte (R) field.
The typical channel program known in the art functions to either read or write a CKD record data field on some track in some DASD. Such a channel program specifies the DASD and the cylinder within the DASD of interest. It also typically specifies a rotational position on the track from which to begin looking for the record whose data fields is to be referenced. Next, it specifies a search parameter in the form of CCHHR for use by the DASD controller to match against the relevant portion of the Count Areas in the track of interest. When the DASD controller locates a CKD record on the track with a matching Count Area, the controller then either reads or writes the referenced Data Field. The notable feature of this process relevant to this disclosure is that the DASD controller does not perform a read or write reference until it has accessed the DASD and verified the existence on the track of a Count Area with the matching search parameters.
To better appreciate the significance of this requirement, reference is made to FIG. 1. DASD controller 26 is shown having some amount of DASD NVS 20 for storing records that have been written by host CPU 10 but have not yet been written to DASD 16 by controller 26. Such controllers are said to perform "Fast-Write" operations. Controller 26 also has access to optional DASD cache 18 for storing records in track-sized blocks or lines from the attached rotating medium.
For example, the IBM 3990 disk controller is typical of such apparatus, having both cache and NVS. The IBM 3990 disk controller performs an update write operation as follows. If the referenced track and record are already in cache and a record that matches the search parameters is found by cache reference alone, the cache record is updated and a copy is made to NVS to avoid single points of failure. The controller then returns "done" to the host CPU. Such an operation is called a "Fast-Write Hit". At some later time, the IBM 3990 controller asynchronously destages the updated record or track to disk from cache, removing the record or track from both cache and NVS. With a Fast-Write Hit, the 3990 controller can eliminate the disk access time normally required to write a record to disk from the response time as seen by the host system. The actual destaging of the modified record from cache to disk can be accomplished at a more opportune time; for example, when the disk is idle or when there is other work to be performed against the same track of cylinder. If the record accessed was not originally in cache, however, the resulting "Fast-Write Miss" forces the 3990 controller to first access the physical track on disk before releasing the host CPU.
With a Fast-Write Miss, after track access is accomplished, the controller must search the count areas of each record in the track, beginning at any specified rotational position, until a matching count area is found. Once the matching count area is found, the corresponding data field is updated and "done" is returned to the host CPU. This description clearly shows that a Fast-Write Miss is much slower than a Fast-Write Hit, because it includes a physical disk access in the response time presented to the host CPU.
Accordingly, for higher write-hit ratios, the Fast-Write procedure results in significant improvements in DASD channel efficiency. However, because the controller operates as if Fast-Write capability is unavailable on a write-miss, any applications exhibiting poor write-hit ratios will not benefit from Fast-Write controller procedures.
The Invention
Examination of actual system usage in the art has demonstrated that many operating systems normally ensure that the logical CCHH in the Count Areas of CKD records is always the same as the physical cylinder and head number on the which CKD record is stored (the physical CCHH). Also, it has been determined that a preponderance (75%) of such CKD tracks are "predictive". A predictive track is defined herein as having characteristics permitting the prediction of count areas on the physical track. For example, such a definition may be one in which records have no key fields, have the same size data fields, and in which the record numbers R of the records along the track increase monotonically from unity. Examination of existing channel programs has revealed that most (95%) update writes are to such predictive tracks. Thus, it was discovered that unexpected and significant efficiency improvements are available through any measure designed to improve the performance of update writes to predictive tracks.
In the exemplary predictive track defined above, knowledge of the last record number stored on the track is sufficient to determine the presence of a particular record having a particular Count Area on the track. For example, consider that cylinder 100, head 50 is a predictive track and that the last record number on the track is known to be 20. When the channel program provides (100, 50, 7) as the CCHHR search parameter, knowledge of the last record on the track is sufficient to determine that the reference record 7 is present, without actually referring to a cache copy of the records on the track. Similarly, it is unambiguously known that other search parameters, such as (100, 50, 25) or (100, 40, 7), will not be satisfied because the record number exceeds the maximum in the first example or the head number is different in the second example.
The method of this invention requires the maintenance of a Predictive Track Table (PTT) in high-speed memory, either within the DASD controller or within the main memory of the channel. The PTT is configured to specify whether the accessed track is predictive and, for such predictive tracks, whether a specified record is present in the track. Also, the nature of CKD architecture requires inclusion in the PTT of the Data Length value common to all the records in the track for use as a check for channel access errors.
In operation, the method of this invention is illustrated by the following example, which may be appreciated by referring to the exemplary flow charts in FIG. 5. Consider an update write to cylinder 100, head 50 of some DASD. If a DASD cache store is provided (this is not necessary), it is first searched for the referenced track. If the referenced track is located in cache, the procedure then becomes identical to that described above for a Fast-Write Hit. If the track is not located in cache, the PTT is next consulted to determine if the subject track is predictive. If the track is not predictive, the process then proceeds as was described above for a Fast-Write Miss. If the track is predictive, the PTT is consulted to obtain the last record number on the track (e.g., 20) and for the Data Length (e.g., 1000 bytes). If, for example, the search parameter is (100, 50, 9), the controller can proceed to accept the record from the host channel, storing one copy in NVS and another copy in cache. At acceptance, the update record data is checked to ensure that it is exactly 1000 bytes in size (referring to well-known rules for CKD controllers in the event that either more or less than 1000 bytes is provided by the host channel). After Data Length verification and storage in NVS and cache, the channel is immediately released by the DASD controller.
In cases where no DASD controller cache is provided, two copies of an update record can be stored in NVS to avoid single points of failure. In such a system, all references from the host CPU would be treated as Fast-Write Misses. The first step of the non-cache method of this invention is to refer to the PTT to determine if the referenced track is predictive. Following PTT reference, the controller then proceeds according to the above example. In either the cache or the non-cache example discussed above, the method of this invention eliminates this excess time from host response time for most update writes. The actual destage of the updated record from cache/NVS to disk occurs asynchronously with respect to the host channel. For uncached controllers, performance for most update writes is improved. For cached controllers, performance for most update writes that miss the cache is improved.
The method of this invention discussed above is illustrated in FIG. 5. The exemplary flow chart in FIG. 5 is sufficient to permit the preparation of a suitable computer program embodiment of this method by a practitioner knowledgeable in the computer science arts.
FIGS. 3 and 4 present variations on the concept of a "Predictive Track" format suitable for use in the method of this invention. Illustrative Predictive Track Table formats suitable for use with the predictive track definitions in FIG. 3 are illustrated in FIG. 4. FIG. 3A is the preferred definition of a predictive track, requiring only the identifier field and data length field PTT elements shown in FIG. 4A. This embodiment provides a simple and compact PTT, which can be referenced with relatively simple logic to determine the presence or absence of a referenced record in a predictive track. Because each predictive track is filled with the same number n of user records, and because each track begins with record number R=1, any host update record reference can be immediately examined to determine if the referenced record number falls between (1-n). The DL field is then checked for CKD error states in a manner well-known in the art by reference to PTT Data Length field.
The other variations in FIGS. 3 and 4 can be understood by analogy to the discussion above and the discussion in connection with FIGS. 3A and 4A. For the predictive track definition illustrated in FIG. 3A, the last record number n can be calculated from DL and track capacity. For example, if the track capacity is 50 KB and the DL equals 4 KB, then the last record number n equals 12, because we can store twelve 4 KB records with 2 KB unusable track space. According to this predictive track definition, a track having only 3 such records, numbered 1-3, is not considered a predictive track because it does not store the maximum records number n.
FIG. 3B expands the predictive track definition to include tracks with less than the maximum number of records. This is illustrated by showing record numbers Rl and R2 followed by a series of empty address markers (A). The advantage of the embodiment of FIG. 3B is that the number of predictive track hits is increased to include those references to partially empty predictive tracks. The disadvantage of this method is illustrated in FIG. 4B, which shows the necessary addition of a Last Record number (LR) field for each predictive track. The PTT in FIG. 4B requires the DASD controller to compute a new record number range for each predictive track in addition to the other computations discussed in connection with FIG. 4A.
FIG. 3C illustrates a predictive track having identical non-zero key field lengths in all records on the track. In this case, as shown in FIG. 4C, this constant Key field Length (KL) must be stored in the PTT for each such predictive track. This is necessary because the channel program may update both key and data fields together and KL is necessary together with DL to perform CKD length checksum procedures. The embodiment illustrated in FIGS. 3C and 4C is not particularly interesting because it increases the size of the PTT with little concomitant increase in predictive track hit rate.
FIG. 3D illustrates yet another predictive track definition wherein the track is defined as predictive even if the logical track address CCHH in the HA and CAs is different from the physical CCHH (PA) in HA and CAs. In this case, for each such predictive track, the PTT in FIG. 4D requires the storage of an additional Logical Address (LA) field for the logical CCHH. Storage of LA increases the PTT space requirement but offers the additional advantage of supporting host operating systems such as VM that typically use different logical CCHH and physical CCHH. Note that FIG. 3D illustrates a monotonic sequence of record numbers from Rl through Rb followed by a series of unused address markers (A), indicating that such tracks need not be full.
An additional variation of this method can be implemented as a method in which the physical track address can be determined from the location or index of the PTT entry for a given track. Such PTT entries need not explicitly store the physical track address, thereby providing some storage economy. This variation can be further varied into two other methods. In one such variation, the logical track address is stored in the PTT entry and need not be equal to the physical track address. In a second such variation, the logical track address is constrained to always equal the physical track address and may also be omitted from the PTT, thereby economizing on storage.
This additional variation requires an unambiguous mapping from each physical track address to a single PTT entry for which many suitable schemes are known in the art. Most of such schemes may increase PTT size if the PTT is sparse with respect to contiguous physical track address, although segmented or multi-staged PTT organizations can minimize the space occupied by empty entries. Thus, this variation is perhaps most useful in situations where most tracks are predictive and thus represented in the PTT or where most of the contiguously-addressed tracks within sub-PTT groups are predictive and therefore represented in the PTT. In such cases, this variation leads to reduced PTT space requirements and smaller PTT entries without significant numbers of empty entries.
Rather than completely eliminating the physical CCH from the PTT, it is perhaps more useful to store a compacted version of the physical track number. For instance, storing CC*15+HH, where 15 is the number of tracks per cylinder, requires only two bytes instead of the normal four bytes. Alternatively, the low-order byte of the result of the computation of CC*15+HH can be stored in the PTT entry, thereby saving three bytes of PTT space. Storage of even a single byte is useful for providing a cross-check of the controller microcode that points to the particular PTT entry for a given CCHH, thereby providing confidence that the proper PTT entry has been accessed.
By extension of the above discussion, it will be appreciated that the method of this invention may also be used for predictive tracks that have a first record number not equal to 1, as illustrated in FIG. 3E. Such predictive tracks must contain a monotonic sequence (increasing or decreasing) of record numbers Ra-Ra+n, but need not begin with record number Rl. The PTT embodiment illustrated in FIG. 4E requires an additional First Record (FOR) field to identify the record number a. It will be really appreciated that the presence of both first and last record number fields, FR and LR, now permits the computation of the presence or absence of an updated record reference in any predictive track stored in PTT.
Another useful variation of an efficient PTT embodiment that will function with any of the variations discussed above is the implementation of a PTT compaction procedure whereby contiguous ranges of predictive tracks are combined into a single PTT entry. For example, if all tracks on the device are predictive and each have 12 4 KB records, then the PTT need only store the number 12 and size 4 KB to describe all tracks on the device. This method is particularly effective in situations where the logical CCHH differs from the physical CCHH such as for VM mini-disks. For such a mini-disk, a single staring physical CCHH and a single starting logical CCHH will suffice for the entire mini-disk PTT.
Such a scheme will work well in practice because many systems typically format entire cylinders with the same format. However, this extension of the method of this invention adds some complexity to PTT maintenance when, for example, a track in the middle of a similarly formatted range is reformatted differently from its neighbors. In such a case, a single entry in PTT to describe the entire range must be expanded to three entries; (1) to describe the early range up to the modified track, (2) to describe the modified track, and (3) a final entry to describe the range of tracks following the modified track.
Referring to FIG. 1, the entire PTT can be stored in memory (not shown) associated with controller 26. Alternatively, the portion of a PTT that is associated with a particular DASD 30 can be stored in a random access memory (not shown) associated with DASD.30. With the former approach, controller 26 must reserve sufficient memory to hold PTTs for all DASDs that may be attached to controller 26. In the latter case, whenever a new DASD is attached to controller 26, the new DASD brings enough RAM with it to hold its portion of PTT. The disadvantage with this latter scheme is that controller 26 must communicate with DASD through switch 28 to access PTT. Thus, the storage of PTT in memory (not shown) associated with controller 26 or with channel 24 is preferred.
It is preferable that PTT not be lost when controller 26 is powered off or experiences a power failure. One solution to this problem is the storage of PTT in a non-volatile RAM to survive power failures. Another suitable solution is to store the PTT in a RAM that is powered by battery for survival during power loss.
In such a case, a disk copy of the PTT can be made in addition to the RAM copy. A simple and suitable method for insuring validity of the PTT disk copy is to maintain an IML or token number appended to the end of the PTT. During normal controller operation, the disk copy would not be updated at every update of the RAM copy of the PTT, to avoid the performance penalties associated with frequent PTT dumps to disk. However, a current token value appended to the disk copy whenever the working PTT is written to disk serves to distinguish the continually-updated RAM PTT from the static PTT disk copy if the RAM PTT token is incremented at the first update following dump to disk.
At IML time, the controller immediately increments the token and then verifies that the PTT disk copy is valid before reloading to RAM from disk. At each IML, the controller IML number is first incremented and the PTT is then loaded from disk. During loading, the IML number field in the PTT disk copy is checked to ensure that it is exactly one less than the current IML number value. If so, the PTT is verified as the correct copy made to disk at the end of the previous IML session and may be reused. If not, the PTT disk copy is outdated and the PTT must be recovered from RAM or recreated by some suitable means such as a complete DASD scan or piecemeal recreation during normal DASD operation.
If the PTT in RAM has been updated and the controller then fails before the RAM PTT is saved to disk, the controller will discover at the next IML that the disk copy PTT token is valued two (2) less than the current IML value (one count at the disk dump and one count at controller recovery) and thus find the disk copy PTT invalid with respect to the RAM PTT conditions immediately before controller failure.
Two copies of the PTT should be maintained in controller 26 memory (not shown) to avoid single failure points. Also, the PTT can be organized to contain a "valid" byte for each track entry in the table. Thus, upon a host system request to reformat a track, the PTT entry corresponding to that track is first marked invalid. Following the completion of the formatting operation, the PTT entry for that track is updated with new values for DL and LR if the track remains predictive. Finally, the entry for the track is remarked as valid. This prevents the loss of PTT integrity that could result from system failures occurring during format write operations.
In addition to saving the PTT on disk as discussed above, the controller may also operate to save the PTT during DASD subsystem shutdown procedures, including shutdown occasioned by loss of external primary power. The process is the same in that the controller writes the RAM PTT copy to disk, appends the current token, and shuts down, thereby ensuring no further updates to the RAM PTT. If RAM PTT is retained using battery backup or other non-volatile support, the unchanged token is retained in the RAM PTT. As noted above, when the controller restarts following shutdown, it increments the separately-preserved PTT token value and tests the initial PTT copy from RAM or disk for a token value of one (1) less than the now-current controller token.
The method of this invention can be applied to controllers for CKD-emulation on FB systems. In one method known for CKD-emulation, each CKD record is stored starting at a new FB sector boundary. In such a method, both the count field and the start of the key or data field for each CKD record are stored in the same FB sector and these fields may span multiple sectors. Upon a request to update the data field of a record stored on a predictive track, if the track is not in cache, the sectors containing the records must first be copied into the controller buffer memory. Those portions of the sectors that contain the data field to be updated must then be changed. Finally, the updated sectors must be written back to the FB disk on the second revolution. With a Predictive Track Table, the update write requires only one disk revolution because the entire record is rewritten to the disk, including the count field of the record generated using PTT information and the data field received from the host channel. Therefore, in addition to eliminating disk access time from host response time, this PTT method also eliminates a disk access for this CKD/FB emulation technique.
This PTT method is also useful with another technique known for CKD-emulation in which all CKD records are packed tightly into FB sectors. In this technique, the PTT can eliminate a disk access for sequential track update writes such as those performed by DB2 logging. DB2 logging updates the data fields of every user record on the track (whole track update write). With PTT, the entire track can be recreated and written without a requirement for reading any portion of the track. Without PTT, the old value of the track must be read in a first revolution to permit reconstruction of the count fields and the write is then accomplished during a second revolution. This means that DB2 logging can be emulated at the speed of the FB device instead of at one-half speed of the native device as is normally required to permit each track to be first read and then written. The PTT method works because (a) the entire track is written at once, except for R0, and (b) the CKD-emulation scheme assigns a separate sector to R0 and packs user records only together on a track. This advantage of the method of this invention will be fully appreciated with reference to the Bohl reference cited above.
Finally, use of a PTT for CKD-emulation is found to eliminate the requirement for storage of the typical emulated count fields on FB disk sectors. This is possible because sufficient information exists in the PTT to recreate the count fields as necessary. Removing the count field storage requirement saves disk space and may also lead to improved performance.
However, if the PTT is employed to eliminate the usual requirement for storing emulated count field values, then the PTT reliability over time and during catastrophic DASD sub-system failures must be at least equal to the reliability of the data recorded on the DASD. If the PTT is employed to keep the only copy of essential DASD information, then the loss of PTT content could result in actual DASD data loss rather than a mere performance degradation. Recall that in the PTT method variations discussed above for enhancing DASD subsystem performance, loss of PTT contents leads only to normal non-PTT DASD performance levels until the PTT can be reconstructed by the DASD subsystem. Thus, reliance on PTT entries to recreate DASD count fields for FB disk sectors introduces a new risk of actual data loss that may not be acceptable to the system user.
Obviously, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of this teachings. Therefore, this invention is to be limited only by the following claims, which include all such obvious embodiments and modifications when viewed in conjunction with the above specification and the accompanying drawings. | A method for managing cache accessing of CKD formatted records that uses a Predictive Track Table to reduce host delays resulting from cache write misses. Because a significant portion of CKD formatted DASD tracks contain records having no key fields, identical logical and physical cylinder and head (CCHH) fields and similar-sized data fields, a compact description of such records by record count and length data, indexed by track, can be quickly searched to determine the physical track location of a record update that misses the cache. The Predictive Track Table search is much faster than the host wait state imposed by access and search of the DASD to read the missing track into cache. If the updated record that misses cache is found within the set of records in the Predictive Track Table, then the update may be immediately written to cache and to a Non-Volatile Store (NVS) without a DASD read access. This update then may be later destaged asynchronously to the DASD from either the cache or the NVS. Otherwise, if not found in a predictive track, the update record is written directly to the disk and the cache, subject to the LRU/MRU discipline, incurring the normal cache write-miss host wait state. |
BACKGROUND OF THE PRESENT INVENTION
Generally, the present invention relates to the field of document transfer over a computer network. More specifically, the present invention relates to a system and method for the automated transmission of documents and data over a computer network, including the Internet, in order to simplify the user tasks of retrieving and working with documents and data relating to retrieved documents.
DESCRIPTION OF THE RELATED ART
The prior art has long recognized the potential of computer networks for transfer of documents between a central document store and remote document users. Further, the prior art has recognized the desirability of the remote document user being able to work with any received document. That is, the user being able to readily print the received document on the user's local printer, and to edit the received document or to input data into the received document.
A few examples of document and data transfer include an individual downloading tax forms at home from a central IRS site, completing the downloaded tax forms and returning the completed tax form to an IRS processing center; a software retailer's offering downloadable updates for software; and a corporate sales manager distributing informational announcements to a field sales force. Prior art methods to accomplish these document and data transfers, however, are complex and often fraught with a plurality of steps and software applications that frustrate users and deter users from the end goal of document and data transfer.
As a specific example, consider downloading IRS documents. The IRS Web site offers many documents (forms, instructions, etc.) for downloading. To retrieve an available document one must first select a file format (e.g. PDF, PCL, PostScript, and SMGL). Most Internet users are not aware that PCL and PostScript refer to printer control languages, nor do they generally know how to view or print these documents. PDF documents are a specialized file format supported by Adobe (trademark) and require the use of a piece of secondary software, Adobe Acrobat Reader (trademark) to view the document.
At the IRS Web site, after a user selects a file format and the particular document the user desires, a new Web page is presented. The page may advise the user that the desired document is available in several formats depending on printer type and paper size. The Web page also advises the user that after receiving the file, the user must decompress the file by typing the filename and pressing enter; that the file must be run under DOS; for systems other than DOS, that PKUNZIP can be used to decompress the file. Many users find these steps impossible.
Users who do determine and select the appropriate document file to download are presented with yet another window asking if the file should be downloaded. If downloading is desired, the user must specify a path to store the file locally. After the file is downloaded the user must locate the document at the previously specified path and decompress the file using appropriate software.
In addition to this process being overwhelming, the resulting document may be of limited use. If the PDF format is used, that file may not be editable. PCL or PostScript files may only be printable on the printer and paper size for which the document file was specifically designed.
Thus, prior art systems require users to download and install special document reader programs and decompression programs. These programs take up hard drive space and add a further level of complexity to the document transfer process. Documents transferred via FTP or bulletin board sites present similar difficulties.
Further, document users, as exemplified by Internet users, often have disparate needs and capabilities. The prior art, while attempting to address the broad range of user needs and skills, has resulted in a variety of generally complex systems and methods to accommodate document transfer. This variety in sum results in computer network users being presented with expensive, complex, and difficult-to-learn alternatives. The absence of a flexible, easy-to-operate document transfer system often results in users simply abandoning the document transfer effort.
OBJECTS OF THE INVENTION
An object of the present invention is to overcome some of the disadvantages of the prior art systems by providing for automated transmission of documents and data over the Internet and over Intranets.
It is a further object of the present invention to provide a novel method of providing a remote user access to forms and other formatted or graphic documents across all major computing platforms without the need for secondary formatting software.
It is yet a further object of the present invention to provide a novel method of transferring selected formatted documents over a computer network.
It is still a further object of the present invention to provide a novel document transfer system utilizing a central service providing access to plural documents from remote user stations which allows a user to locate, retrieve and print fully formatted documents in user-designated formats.
It is another object of the present invention to provide a novel, non-technical system adapted to access formatted documents over a computer network which obviates the need to use specialized formats such as Adobe Acrobat Reader.
It is yet a further object of the present invention to provide a document transfer system having an operating capability within an Internet browser to permit selection and retrieval of documents without the need to install a browser plug-in, helper applications, decompression programs, and to obviate the requirement for a user to specify a document save location through a ‘save’ window.
It is yet another object of the present invention to provide a novel method of transferring documents and related data between a central server and one or more remote users.
It is a still further object of the present invention to provide a novel method and system of providing for government agencies and other services or goods purchasers, procurement electronically over computer networks and to eliminate much of the required paper-form procurement documents of the prior art procurement methods.
These and other objects and advantages of the present invention will be apparent to those of skill in the art from a perusal hereof.
SUMMARY OF THE INVENTION
The present invention offers a user-friendly system that sends user-selected documents, which may also include related data, from a central server to a remote user automatically over a computer network utilizing a server gateway interface script to directly attach the selected document and any related data to an e-mail message directed to a designated e-mail address. The invention also provides for the return of documents and information from the user to the central server.
The documents may be of any format, including forms, instructional materials, newsletters, and databases. The server gateway interface may be the Common Gateway Interface (“CGI”). The related data may include user-personal information, form-specific data, and user preferences.
The invention includes a central server upon which the server gateway interface script and the available documents and data reside.
The documents are made available in plural formats, which may include but are not limited to Microsoft Word (trademark), Corel WordPerfect (trademark), Lotus 123 (trademark), Microsoft Excel (trademark), and ASCII Text.
An computer network document transfer system of the present invention includes a CGI sending script which instructs a network server to send an e-mail to a user e-mail address and to attach to the e-mail a user-selected document in a user-selected document format.
The present invention also includes a provision for a security screen to maintain, manage, rename, update and remove the available documents.
The various embodiments of the present invention include both methods and systems which provide user-friendly methods and systems that send user-selected documents, optionally including related data and data entry points, from a central server to a remote user automatically over a computer network. These embodiments include host sites such as the IRS and other government agencies as well as private corporate hosts providing selectable documents and services from a central server such as tax forms, application forms such grant applications, business and tax forms and reporting forms, and publications such as government reports, books, and instructions.
In these embodiments, users log onto a web-site, select and download a document file. The downloaded document file may be saved, data entered in data fields of the documents, printed, and e-mailed back or conventionally returned, e.g., faxed or mailed back to the document sender.
By using the invention on a secure server, digital commerce such as procurement and consumer purchasing is advanced.
Further, the invention is suitable both for automatic e-mailing of selected documents to individual users and groups of users alike. The invention provides for mailing in a broadcast e-mail mode wherein selectable e-mail lists determine who, and in what format, documents such as printable magazines or forms are sent. Such electronic mail broadcasting saves both sender costs but further environmental policies but avoiding the use of paper mail.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of an embodiment of the document transfer system of the present invention.
FIG. 2 is a flow chart of a method of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1, an embodiment of the present invention is a computer network document transfer system 10 which includes a CGI sending script 20 residing on a network server 30 together with documents (or document files) 40 . The CGI sending script 20 instructs the network server 30 to send an e-mail 50 and to attach to the e-mail a selected document 60 in a selected document format from the documents 40 residing on the server 30 .
The CGI sending script 20 is an e-mail generating tool that avoids any need to pass information to an e-mail application or to invoke an e-mail application. The CGI sending script 20 accepts a destination e-mail address, a desired document 60 , and a desired document format and then generates and sends, via network server 30 , the generated e-mail 50 to the user e-mail address together with the desired document 60 as an e-mail attachment. The CGI sending script inputs may be taken from a database file 70 or solicited from a user. When inputs are solicited from a user, the CGI sending script interprets the user responses and attaches the selected document in the selected format to an outgoing e-mail sent to the user's e-mail address.
The CGI scripts and the documents both normally reside in the CGI bin of the server. However, either or both the CGI scripts and the documents may reside outside the CGI bin.
An embodiment of the present invention may operate in either an Internet or Intranet environment. In each network, a user selects and retrieves a desired document 60 in a desired format from the network server 30 .
In such an embodiment the user may be at a user terminal 80 that is connected to the network server 30 via the Internet (depicted by two-way lines 90 ) or an Intranet (also depicted by two-way lines 90 ). The user selects documents by first accessing the appropriate document server Web page, e.g., www.docs-r-us.com, which triggers a listing process script 100 of this invention.
The listing process script 100 of this invention determines the document files 45 available and provides the user with a list of available document files 45 and a list of available formats 112 for available document files 45 . For the purpose of interacting with a Web browser and network server, the listing process 100 of the invention is written as a CGI script.
The listing process script 100 solicits input from the user by a request form 110 . The request form 110 includes input region for the user e-mail address 111 , allows the user to select a particular document 60 , e.g., doc 3 from list of available document files 45 , and also allows the user to select a document format 112 , e.g., format 3 . The user responses to the request form 110 are submitted via network server 30 to the CGI sending script 20 .
In a system embodiment, the network server 30 hosts plural documents 40 . The CGI listing script 100 first provides a user at a user terminal 80 a list of available documents 45 from the plural documents 40 residing on the network server 30 . Additionally, for the available documents 40 , the CGI listing script 100 also provides the user a list of available document formats 112 . The CGI listing script 100 further solicits from the user the user e-mail address 111 , a document-select input indicating the selected document 60 to be transferred from the list of available documents 45 , and a selected document-format input indicating the selected document format from the list of available document formats 112 .
The CGI sending script 20 instructs the network server 30 to send the e-mail 50 to the user e-mail address 111 and to attach to the e-mail 50 the selected document 60 indicated by the document-select input in the selected format 112 indicated by the document-format input.
In the above embodiments, the network server 30 may be part of an Intranet, the Internet, or both an Intranet and the Internet.
With reference to FIGS. 1 and 2, the present invention includes a method of transferring documents on a computer network. The invention provides a CGI sending script 20 residing on a network server 30 sending instructions to the network server 30 to send an e-mail 50 to a user e-mail address 111 and to attach to the e-mail 50 a selected document 60 in a selected document format.
The invention allows a network user (including an Internet or an Intranet user) to user-select and download a desired document 60 from a remote network server 30 .
In an embodiment of the method of the invention, the CGI sending script 20 and a CGI listing script 100 reside on network server 30 together with documents 40 .
The method utilizes the CGI listing script 100 to provide a user at a user terminal 80 a list of available documents 45 from the documents 40 residing on the network server 30 (step 10 ). Further the CGI listing script provides a list of available document formats 112 (step 20 ).
The CGI listing script 100 also solicits from the user the user e-mail address 111 (step 30 ), a document-select input indicating the selected document to be transferred from the list of available documents (step 40 ), and a selected document-format input indicating the selected document format from the list of available document formats (step 50 ). Note that steps 10 - 50 need not be performed in the listed order but may be performed in any suitable order.
Utilizing the input from steps 30 - 50 , the CGI sending script 20 instructs the network server to send an e-mail 50 to the user e-mail address 111 and to attach to the e-mail 50 the selected document 60 indicated by the document-select input of step 40 in the selected format indicated by the document-format input of step 50 (step 60 ).
Upon receipt of the CGI sending script instructions, the network server 30 sends the e-mail 50 with attached selected document 60 (step 70 ).
In the method and system of the invention, a user at a user terminal 80 logs onto a network, e.g., the Internet, and onto the appropriate document server web page, e.g., www.docs-r-us.com which calls the CGI listing script 100 on network server 30 .
The CGI listing script 100 need not communicate with other application programs that are running on the server as the CGI listing script 100 itself determines the available documents 45 and the available document formats 112 and instructs the network server 30 to communicate this information to the user at user terminal 80 through request form 110 .
Again, without the aid of any other application programs, the CGI listing script 100 , via request form 110 , solicits input from the user. Request form 110 inputs are submitted via the network server 30 to the CGI listing script 100 .
In turn, the CGI listing script 100 communicates with the CGI sending script 20 also located on the network server
The CGI sending script directs the network server 30 to send an e-mail 50 to the user at the user's e-mail address 111 and to attach the selected document 60 in the selected format. Responsively, the network server 30 sends an e-mail 50 with attached thereto the selected document 60 in the format selected from format list 112 attached thereto to the user at the e-mail address provided by the user.
Advantageously, selected document 60 arrives on user terminal 80 in an format selected by the user and for which the user has appropriate software. As the selected document 60 is in a format selected by the user, the user can edit and print the selected document 60 with normally used software resident on the user's terminal (computer). Software formats may include available word processors, spreadsheets, databases, and others.
Advantageously, use of the CGI does not restrict programming languages in which the CGI scripts can be written. Any language which receives data from the network server 30 and sends data or instructions back to the network server 30 can be used for executing the CGI script.
On a UNIX platform, Perl is one preferred language for writing the CGI scripts. C, C++, Tcl, and Python are also preferred for UNIX servers. On Macintosh servers, Applescript, C, and C++ are preferred. On Windows servers, Visual Basic, Perl, C, and C++ are preferred.
Request input form 110 may include the use of an appropriate conventional input means such as a “Browse” button, check boxes, radio buttons, and scroll boxes as input means.
In an alternative embodiment, the user is not required to provide all required inputs. For example, browser cookies may be used to provide a user e-mail address 111 .
In embodiments of the invention utilizing cookies to pass user-side information may optionally include information concerning document file formats 112 of interest to the user. For example, a particular user may use both Microsoft Word version 7 and WordPerfect version 5.1 for DOS available, as well as Microsoft Excel.
The CGI listing script 100 solicits the user's cookies and thereby knows that Microsoft Word version 7 and WordPerfect version 5.1 for DOS as well as Microsoft Excel are possible document formats for this user. Responsively, these document formats may be shown on request input form 110 as the first two document formats of format list 112 , or, alternatively, as the only two document formats listed in format list 112 .
In yet another embodiment of the invention, browser cookies store persistent data such as user e-mail address 111 and user preferred document formats so that the user is not prompted for this information. For example, a user who has used the system before has provided an e-mail address 111 ([email protected]) and selected MS Word 7 as a preferred format. This information is stored in the user's browser cookies and is retrieved by the listing script 100 when the request input form 110 is displayed. In this embodiment, the user simply selects the desired file as the CGI listing script 100 has retrieved the other required information from the browser cookies.
In addition to the present invention providing means for a user to select and transfer a single e-mail document from a network server, the present invention provides that a user may select a list of e-mail recipients to receive a document. In this embodiment, the CGI sending script 100 instructs the network server 30 to send an e-mail 50 to each of a plurality of user e-mail addresses 111 and to attach to each of the e-mails 50 a selected document 60 in a selected document format. The e-mail addresses 111 are available in e-mail lists 120 residing on the network server 30 .
This embodiment includes a CGI listing script 100 which solicits from the user a desired e-mail listing 112 ′ which includes the e-mail addresses and selected document format for each e-mail addressee. The CGI listing script 100 displays request form 110 ′ which includes available document files 45 ′ and available e-mail lists 112 ′. The various available e-mail lists 112 ′ are selected from e-mails lists 120 residing on the network server 30 .
As an example use of this embodiment, a headquarters manager can broadcast mail a copy of a new product description (document 2 which is available in a variety of formats) to each of the field sales representatives listed in e-mail listing 3 by selecting these from form request window 110 ′.
In this example, the manager at a user terminal 80 logs onto a network, e.g., a company Intranet, and onto the appropriate document server web page, e.g., www.co-docs.com which calls the CGI listing script 100 on network server 30 .
As with the other embodiments, the CGI listing script 100 need not communicate with other application programs that are running on the server as the CGI listing script 100 determines the available documents 45 ′ and the available e-mail lists 112 ′ and instructs the network server 30 to communicate this information to the manager at user terminal 80 through request form 110 ′.
Again, without the aid of any other application program, the CGI listing script 100 , via request form 110 ′, solicits input from the manager. In this embodiment, request form 110 ′ inputs include the selected document 60 to be sent to each field representative listed in the selected one of the e-mail lists 112 ′. The inputs are submitted via the network server 30 to the CGI listing script 100 .
The CGI listing script 100 communicates with the CGI sending script 20 also located on the network server 30 . In some embodiments the CGI listing script 100 and the CGI sending script 20 comprise a single script.
The e-mail list comprises records each with an e-mail address entry and a selected format entry. Thus, the selected formats for each e-mail addressee need not be entered with each broadcast mailing.
The CGI sending script 20 reads each record entry of the selected e-mail list and directs the network server 30 to send an e-mail 50 to entry's e-mail address 111 and to attach the selected document 60 in the entry's selected format. Thus, the network server 30 sends an e-mail 50 with attached thereto the selected document 60 in the format taken from format list 112 ′ attached thereto to each addressee of the selected mailing list.
With reference to FIGS. 1 and 2, in another embodiment of the present invention, data relating to a selected document may concurrently be sent to the user's e-mail address 111 with a selected document 60 . An insurance company agent sending a form to a client's e-mail address with data relating to a particular client included in the e-mail, would be an exemplary use of this embodiment.
In this embodiment, the network server 30 also hosts plural documents 40 and a database file 70 related to the plural documents 40 . The CGI listing script 100 provides the agent a list of available documents 45 from the plural documents 40 residing on the network server 30 (step 10 ). The CGI listing script 100 also provides the agent a list of available document formats 112 (step 20 ).
The CGI listing script 100 solicits from the agent an e-mail address for the client (step 30 ). By way of a document-select input, the agent indicates the selected document 60 to be transferred from the list of available documents 45 to the client (step 40 ). The agent also selects, via a selected document-format input, the selected document format from the list of available document formats 112 (step 50 ).
The CGI sending script 20 reads data from the database file 70 relating the selected document 60 . This data may also relate to the e-mail address 111 . In this way the e-mail to be sent will include both information appropriate for the form (document) being sent as well as information specific to the client associated with the provided e-mail address 111 .
The CGI sending script 20 instructs the network server 30 to send the e-mail 50 to the client e-mail address 111 , to attach to the e-mail the selected document 60 indicated by the document-select input in the selected format indicated by the document-format input, and to include in the e-mail the data obtained from the database (step 60 ).
The agent's client will receive the form via the Internet. The client then can read and edit the form with software on the client's computer. The data from the database may be merged into the selected document either by the CGI sending script 20 or by the client with software resident on the client's computer.
Once the client completes editing the received form, for example, by inserting data into data fields, the client can return the form to the network server 30 .
Network server 30 includes a CGI data extracting script 130 . The extracting script 130 reads the data entered into the data fields. The extracting script 130 then acts upon the data read from the data fields. The extracting script 130 may update database file 70 with the extracted data by opening and amending the database file. Advantageously, the extracting script 130 extracts the data and updates the database file 70 without the use of any non-CGI application program.
Features of each of the embodiments may be used together. For example, the insurance agent may want to send the same form to each of his clients. In this embodiment, the insurance agent accesses request form 110 ′ displaying various e-mail lists 112 ′ and document list 45 ′.
The insurance agent selects the form (document) to be sent from document list 45 ′. The insurance agent also selects the desired e-mail list which comprises records of his clients, their preferred document formats, and his clients' e-mail addresses. The sending scrip 100 reads the selected e-mail list to determine the e-mail address 111 for each e-mail, the preferred document format for that e-mail address, and, optionally, the client name associated with that e-mail address.
If data is associated with the selected form, the sending script 100 uses the client name (or another appropriate field value such as the e-mail address) to access a database file 70 which includes data relating to the selected form.
The sending scrip 100 then directs the network server 30 to send an e-mail to each client using the e-mail list for each e-mail address 111 and preferred document format, and using the database file 70 to obtain related data specific to that client.
In a procurement embodiment of the invention, both request forms 110 and 110 ′ are utilized. The invention advantageously provides to the requirement of selectively distributing the various procurement process announcement and bid documents.
Whether private or governmental, procurement involve numerous instructional and informational documents as well as application form and bidding documents. Some documents go to but a single addressee, while other documents are distributed to many addressees. For example, request form 110 is utilized when sending a document to an individual addresses, such as sending to the apparent low bidder of a procurement solicitation a list of further requirements for the bidder to be awarded the contract. Similarly, request form 110 ′ is utilized when sending a bid package to a list of bidders displayed in e-mail lists 112 ′.
In such a computerized method of procurement, the invention provides a network server 30 connected Internet and hosting the various procurement documents. The network server also hosts a CGI sending script 20 designed and adapted to send instructions to the network server to send an e-mail 50 to a user e-mail address 111 and to attach to the e-mail a selected procurement document 60 in a selected document format.
The procurement method also provides a CGI listing script 100 on the network server to provide a user, such as a contracting officer working at an Internet-connected computer, a list of available procurement documents 45 . The contracting officer provides via request form 110 , a user e-mail address (the low bidder's e-mail address), a document-select input indicating the selected procurement document to be transferred from the list of available procurement documents to the low bidder, and a selected document-format input indicating a procurement document format from the list of available procurement document formats appropriate for that bidder.
The CGI sending script instructs the network server to send the e-mail 50 to the user (low bidder) e-mail address 111 and to attach to the e-mail the selected procurement document indicated by the document-select input in the selected procurement document format indicated by the document-format input.
Often the contracting officer needs to send the same document, such as a bid package, in a variety of formats to a number of prospective bidders. The invention provides that the CGI listing script 100 provides e-mail lists 112 ′ in a request form window 110 ′. The contracting officers inputs the user e-mail address list associated with the prospective bidders. Advantageously, the contracting officer need not indicate a selected document-format of the bidding package for each bidder as the e-mail list includes data in a record field indicating a procurement document format associated with the solicited user e-mail address. That is, the user e-mail address list comprises records, each record comprising a e-mail address field data and a selected document-format field data indicating the selected document format associated with the e-mail address field data of that record.
In a procurement embodiments the CGI listing script 100 and the CGI sending script 20 may comprise a single script.
Similar to the insurance agent embodiment, the procurement embodiment may utilize documents which include data field for the bidders to enter data. The completed documents, e.g., bid documents, can be sent by regular mail, by fax (although not generally considered secure) or by return e-mail. In procurement embodiments, the network server may include security precautions.
While preferred embodiments of the present invention have been described, it is to be understood that the invention is to be defined by the appended claims when read in light of the specification and accorded their full range of equivalence, with changes and modifications being apparent to those of skill in the art. | A system and method for transmission of documents including word processing, spread sheets, and other formatted documents, over a computer network with no need for additional formatting software by using a CGI sending script to send e-mail with the selected document, in its native format, as an attachment to e-mail submissions or obtained directly from websites using standard word processing programs, with end user prerequisites for using the method and system being standard word processing software and e-mail capability; the form may returned to the server in electronic form, and the accompanying data posted to one or more databases, or automatically stored on disk, printed, or routed to other e-mail addresses. |
FIELD OF THE INVENTION
The present invention relates to a manufacturing method for a semiconductor device, and particularly to a manufacturing method for a semiconductor device having an epitaxial layer selectively grown on the contact portion of a semiconductor substrate to improve the reliability of the semiconductor device.
BACKGROUND AND RELATED ART
With the progress of microtechnology in the semiconductor manufacturing field, the physical dimensions of semiconductor devices are becoming increasingly smaller. As these devices become smaller, the contact area has been reduced to dimensions below 1 μm. However, due to the reduction of the contact area, contact resistance increases. Further, a step coverage defect may occur at the stepped portion due to a high aspect ratio, which is caused by microscale processing.
Meanwhile, since dynamic RAM semiconductor devices are being manufactured in densities of mega-bit order, various capacitor structures have been proposed to obtain sufficient capacitances in a limited space. Particularly, in the semiconductor devices of a 4Mbit scale, a stacked capacitor (STC) structure is generally used because it is simple to manufacture and it has a high immunity against soft errors.
The conventional STC has a capacitor structure stacked on an access transistor which is formed on a semiconductor substrate. The capacitor consists of a storage node (i.e., a lower electrode), a dielectric film and an upper electrode. The storage node contacts the source (diffused or ion-implanted region) of the access transistor and usually is formed of polycrystalline silicon doped with an impurity.
However, the conventional STC has several drawbacks. First, the defects of the polycrystalline silicon are distributed over the source (doped region), which cause current leaks at the contact portion. Accordingly, the reliability of the semiconductor device is reduced. Further, the conventional STC has a structural characteristic wherein its capacitance decreases as its density increases. As a result, 4Mbit devices form a limit in conventional semiconductor manufacturing techniques.
Therefore, to manufacture a 16Mbit or a 64Mbit device, the limited space must be utilized more effectively. Accordingly, multi-layer structures, built in the upward direction above the substrate, or in the downward direction in a trench etched in the substrate, have been proposed to increase the effective total area of the capacitor. However, in the case where a multi-layer structure is formed in the upward direction, the contact hole of the drain (doped region) of the access transistor is deepened, thereby making it difficult to contact a bit line to the drain (diffused or ion-implanted region).
SUMMARY OF THE INVENTION
The present invention is intended to overcome the above described disadvantages of the conventional techniques.
Therefore, it is an object of the present invention to provide a method for manufacturing a semiconductor device which solves the problems arising from the increasingly reduced dimensions of the semiconductor contact portion.
It is another object of the present invention to provide a method for manufacturing a dynamic cell semiconductor device wherein electric current leakage from the contact portion between the access transistor and the capacitor is effectively eliminated.
In achieving the above objects, the method for manufacturing a semiconductor device according to the present invention includes selectively doping an impurity into the surface of a semiconductor substrate. An insulating layer is deposited and selectively etched to form a contact hole through which an area of the impurity-doped region is exposed. An epitaxial layer is then grown using the exposed surface of the impurity doped region as a seed. Finally, a conductive layer is deposited upon the epitaxial layer.
The conductive layer is made of a polycrystalline silicon formed upon the impurity doped region and is applicable to all contacting type semiconductor devices.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects and other advantages of the present invention will become more fully apparent by the following description of the preferred embodiment of the present invention with reference to the attached drawings in which:
FIG. 1 is a sectional view of the semiconductor device according to the present invention;
FIGS. 2A to 2D are sectional views showing the manufacturing process of the semiconductor device of FIG. 1;
FIGS. 3A to 3I are sectional views showing the manufacturing process of the stacked capacitor type dynamic RAM semiconductor device according to the present invention;
FIGS. 4A to 4C are sectional views showing a part of the manufacturing method for the combined stack-trench capacitor-type dynamic RAM semiconductor device according to a preferred embodiment of the present invention;
FIGS. 5A to 5D are sectional views showing a part of the manufacturing process for a modified stacked capacitor type dynamic RAM semiconductor device according to the present invention; and
FIGS. 6A to 6D are sectional views showing a part of the manufacturing process for another modified stacked capacitor type dynamic RAM semiconductor device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a sectional view showing an embodiment of the semiconductor device according to the present invention. A diode (for example, a PN-coupled diode) is illustrated wherein a second conduction type (for example, N+ type) impurity-doped region 2 is coupled to a first conduction type (for example, P type) semiconductor substrate 1. An insulating layer 3 (for example, an SiO 2 layer) is formed on the semiconductor substrate 1, and contact hole 4 is formed therein in the impurity-doped region 2. An epitaxial layer 5 is provided within the contact hole 4 and a conductive layer 6 (i.e., a polycrystalline silicon layer) is formed upon the epitaxial layer 5.
In the above described structure, crystal defects of the conductive layer 6 are prevented from contacting the impurity-doped region 2 due to the epitaxial layer 5. Therefore, current leakage, as seen in conventional devices, is prevented.
FIGS. 2A to 2D are sectional views showing the manufacturing process for the semiconductor device having the above described structure. In FIG. 2A, an N+ type impurity is selectively doped via a doping mask into a region 2 of the surface of a P type semiconductor substrate 1. After doping, the doping mask is removed and an insulating layer 3 is deposited on substrate 1 as illustrated in FIG. 2B. A contact hole 4 is then formed by selectively removing via a contact mask a part of the insulating layer 3 formed on the impurity-doped region 2.
As shown in FIG. 2C, an epitaxial layer 5 is grown via a chemical vapor deposition method (CVD) using the surface of the exposed impurity doped region 2 as a seed.
In FIG. 2D, a conductive layer 6 (e.g., a polycrystalline silicon layer) is formed and patterned above the epitaxial layer 5. The conductive layer 6 can be formed almost simultaneously with the epitaxial layer 5 by lowering the selection ratio.
The method of the present invention is preferably applicable to the manufacturing of a dynamic RAM. As the density of the dynamic RAM increases, the memory cell region is proportionally narrowed, and the contact area reduced. In conventional devices, the contact hole has a deep depth and a narrow cross sectional area, contributing to the problems discussed above.
However, according to the method of the present invention, the epitaxial layer is grown from the interior of the contact hole. As a result, contact failure is eliminated and the height of the step of the contact portion is considerably reduced, thereby improving the reliability and the manufacturing yield of the dynamic RAM. Further, given the improvements of the present invention, the contact size is reduced.
Several different embodiments of the manufacturing method for several modified capacitor structures of the dynamic RAM will now be described with reference to FIGS. 3 to 6.
EXAMPLE I
FIGS. 3A to 3I are sectional views showing a method for manufacturing a stacked capacitor type dynamic RAM semiconductor device according to the present invention.
As shown in FIG. 3A, a P type well 12 is formed on a semiconductor substrate 10. A field oxide layer 16 is formed according to the LOCOS (local oxidation of silicon) method to define an active region 14. Although not shown, a P+ channel stopper layer may also be formed under the field oxide layer 16.
In FIG. 3B, a gate oxide layer 18 is provided, followed by a depositing of a first conductive layer 20 of polycrystalline silicon. The first conductive layer 20 is deposited in a pattern to define a gate electrode of the access transistor or a word line. In this Figure, the first conductive layer 20 formed upon the field oxide layer 16 is a word line connected to the gate electrode disposed between the adjacent cells.
As illustrated in FIG. 3C, source and drain regions 22a, 22b of the access transistor are formed by doping the active region 14 of well 12 with an N+ type impurity according to ion implantation or diffusion methods. The field oxide layer 16 and the pattern of the first conductive layer 20 are employed as a mask to help define these regions 22a, 22b.
In FIG. 3D, a first insulating layer 24 is formed via the CVD process. The first insulating layer 24 is then selectively etched on the source region 22a, thereby forming a first contact hole 26 (i.e., a buried contact hole).
As shown in FIG. 3E, an epitaxial layer 28 is grown through the first contact hole 26 using the substrate surface of the source region 22a as a seed.
In FIG. 3F, a second conductive layer 30 (i.e., a polycrystalline silicon layer) is formed upon the whole surface of the epitaxial layer 28 and the first insulating layer 24. The second conductive layer 30 is doped with an N+ type impurity and then patterned as the lower electrode of the cell capacitor through the use of a photo-etching process.
As illustrated in FIG. 3G, a dielectric layer 32 (i.e., ONO layer (oxide layer/nitride layer/oxide layer)) is formed on the whole surface of the second conductive layer 30 and the first insulating layer 24. A third conductive layer 34, (i.e., a polycrystalline silicon layer) is formed upon the dielectric layer 32 and then doped with an N + type impurity via an ion implanting process or a POCL doping process. The dielectric layer 32 and the third conductive layer 34 are simultaneously etched to the illustrated pattern through the use of a photo-etching process. The third conductive layer 34 defines the upper electrode of the cell capacitor.
In FIG. 3H, a second insulating layer 36 (i.e., an oxide layer) is formed by a CVD process. The first and second insulating layers 24, 36 formed upon the drain region 22b are selectively etched to form a second contact hole 38 (i.e., a direct contact hole).
In FIG. 3I, a fourth conductive layer 40 (i.e., a polycrystalline silicon layer) is deposited on the whole face immediately following the formation of the contact hole, and doped with an N+ type impurity. The fourth conductive layer 40 is patterned in bit lines. Thereafter, a flattening layer 42 (e.g., a BPSG (borophosphorosilica glass) layer) is deposited.
EXAMPLE II
FIGS. 4A to 4C are sectional views showing a method for manufacturing the stack-trench combination capacitor type dynamic RAM semiconductor device according to the present invention. The descriptions of the steps identical to those of Example I are omitted.
In FIG. 4A, the substrate is etched through the first contact hole 26 to a depth of several hundred nm to several μm to form a trench 50. This etching step occurs after the formation of the first contact hole 26 described in FIG. 3D.
As shown in FIG. 4B, an epitaxial layer 52 is grown down into the contact hole 26, using the semiconductor substrate of the interior of the trench 50 as a seed. Accordingly, a pattern of a lower electrode of the capacitor (i.e., second conductive layer 30) is obtained as shown in FIG. 4C.
EXAMPLE III
FIGS. 5A to 5D are sectional views showing a part of the manufacturing method for a modified stacked capacitor type dynamic RAM semiconductor device according to the present invention. Again duplicative steps illustrated in Example I are omitted.
In FIG. 5A, a thick first insulating layer 60 (i.e., a BPSG layer) is formed after the formation of the first conductive layer 20 as illustrated in FIG. 3B.
A first contact hole 62 is selectively etched in the flattened first insulating layer 60 in the source region 22a as shown in FIG. 5B.
In FIG. 5C, an epitaxial layer 64 is grown using the substrate surface of the exposed source region 22a as a seed.
According to this embodiment in Example III, since the first contact hole 62 is formed by thickly flattening the first insulating layer 60, a second conductive layer 66 of a depressed capacitor has a lower electrode pattern as shown in FIG. 5D. The total area of the cell capacitor is expanded through the utilization of the first contact hole 62, thereby obtaining a sufficient cell capacitance.
EXAMPLE IV
FIGS. 6A to 6D are sectional views showing a part of the method for manufacturing a modified stacked capacitor type dynamic RAM semiconductor device according to the present invention. Duplicative steps are omitted.
In FIG. 6A, a first contact hole 62 is selectively etched in the flattened first insulating layer 60 formed upon the source region 22a.
In FIG. 6B, an epitaxial layer 70 is grown up to the surface of the flattened layer 60 using the substrate surface of the exposed source region 22a as a seed.
In FIG. 6C, the whole face of the first insulating layer 60 is etched a certain thickness by an etch-back process so that a part of the top of the epitaxial layer 70 is projected in a convex form.
A second conductive layer 72 of a capacitor is formed on the projected epitaxial layer 70 and the first insulating layer 60 and has a pattern as shown in FIG. 6D.
In Examples I to IV described above, it should be understood that an epitaxial layer may be formed using the substrate surface of the exposed drain region 22b as a seed, after the formation of the second contact hole 38 on the drain region.
Further, second conductive layer 30 (i.e. the lower electrode of the capacitor) of FIGS. 3 and 4 can be formed almost simultaneously with the epitaxial layers 28, 52 by lowering the selection ratio during the growing of the epitaxial layers 28, 52 through the first contact hole 26.
According to the present invention as described above, an epitaxial layer is grown at the contact portion to prevent the deposition of defects of the polycrystalline silicon layer to the impurity doped region during the formation of a contact therebetween. Thus, the reliability of the semiconductor device is greatly enhanced while the contact size is reduced.
It is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A method for manufacturing a semiconductor device includes forming contact holes in insulating layers to expose an impurity doped region of a semiconductor substrate. An epitaxial layer is then grown in the contact hole. A polycrystalline silicon layer is formed over the top to provide the lower electrode of a capacitor. Accordingly, the polycrystalline layer is separated from the impurity doped region thereby preventing current leakage. |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/827,700, entitled “Low Profile Magnetic Mount for Electronic Display Devices,” filed May 27, 2013, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] The embodiments described herein relate generally to the field of electronic display device mounts, and more specifically, to a mounting system that can be used to easily mount and unmount electronic display devices to various surfaces.
[0003] There are many known mounting systems for various electronic display devices. These electronic display devices include, but are not limited to tablet computers, smartphones, televisions, and LCD displays. As technology progresses, these devices are becoming thinner and lighter. Along with this, the importance for low profile mounting mechanisms have become more valuable. Current mounting mechanisms can be cumbersome, bulky, and can add considerable weight to the electronic display device. Often, the mounting mechanism that attaches to the desired mounting surface is bulky and aesthetically unpleasing.
[0004] Thus, a need exists to provide a mounting mechanism for mounting electronic display devices to amounting surface without adding significant bulk to the electronic display device or the mounting surface.
SUMMARY
[0005] The disclosure generally relates to a mounting mechanism for mounting an electronic device, such as an electronic display device, to various surfaces, including ferrous surfaces. The mounting mechanism may include friction pads for attachment to the electronic display device. In one implementation a plurality of magnets are embedded within the friction pads. Alternatively, the magnets may be directly attached to the electronic display device and covered by the friction pads. When the mounting mechanism is used to mount the electronic device to a ferrous surface, the magnets and the friction pad respectively provide magnetic and frictional forces so as to enable secure mounting of the electronic display device to the ferrous surface.
[0006] The electronic device may also be mounted to a non-ferrous surface. In this case the mounting mechanism includes a frame, such as a metal frame, which is affixed to the non-ferrous surface using conventional techniques. The metal frame defines a ferrous surface to which the electronic display device may then be mounted using various configurations of magnets and friction pads described hereinafter.
[0007] It is a feature of the disclosed mounting device that a user may easily dismount the electronic display device from a surface to which it had been mounted. Moreover, the mounting mechanism advantageously does not add significant thickness or weight to the electronic display device or the mounting surface.
[0008] In one particular aspect the disclosure relates to a mounting mechanism for mounting an electronic device to a ferrous surface. The mounting mechanism may include a plurality of magnets attached to a surface of the electronic device. The mounting mechanism may further include a high friction pad structure having an inner surface for attachment to the surface of the electronic device. The high friction pad structure may cover the plurality of magnets and have an outer surface which contacts the ferrous surface when the electronic device is mounted to the ferrous surface. The mounting mechanism may further include a frame element for attachment to a non-ferrous surface, the frame element defining the ferrous surface.
[0009] In another aspect the disclosure relates to a mounting mechanism which includes a high friction pad structure having an inner surface for attachment to a surface of an electronic device. The mounting mechanism may further include a plurality of magnets embedded within the high friction pad structure wherein the high friction pad structure includes an outer surface which contacts the ferrous surface when the electronic device is mounted to the ferrous surface. The mounting mechanism may further include a frame element attached to a non-ferrous surface, the frame element defining the ferrous surface.
[0010] The disclosure also pertains to an electronic device configured to be mounted to a ferrous surface. The electronic device includes a housing having a substantially planar surface characterized by high friction properties. The electronic device further includes a plurality of magnets embedded within the housing. The substantially planar surface contacts the ferrous surface when the electronic device is mounted to the ferrous surface. The mounting mechanism may further include a frame element for attachment to a non-ferrous surface, the frame element defining the ferrous surface.
[0011] In yet a further aspect the disclosure relates to a mounting mechanism for securing an electronic device to a ferrous surface. The mounting mechanism includes a plurality of magnets embedded within the electronic device. The mounting mechanism may further include a high friction pad structure having an inner surface for attachment to one or more surfaces of the electronic device wherein an outer surface of the high friction pad structure contacts the ferrous surface when the electronic device is mounted to the ferrous surface. In addition, the mounting mechanism may further include a frame element attached to a non-ferrous surface, the frame element defining the ferrous surface.
[0012] The disclosure further pertains to a mounting mechanism for mounting an electronic device to a ferrous surface. The mounting mechanism includes a case structure having a high friction surface and a plurality of magnets embedded within the case structure. When the electronic device is mounted to the ferrous surface, the case structure at least partially encloses the electronic device and the high friction surface contacts the ferrous surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1A is an exploded perspective view of an electronic display device with a mounting mechanism, according to an embodiment.
[0014] FIG. 1B is a perspective view of the electronic display device with mounting mechanism of FIG. 1A .
[0015] FIG. 2A is a cross-sectional profile view of a portion of an electronic display device with a mounting mechanism, according to another embodiment.
[0016] FIG. 2B is a cross-sectional profile view of a portion of the electronic display device with mounting mechanism of FIG. 2A shown mounted to a ferrous surface.
[0017] FIG. 3A is a perspective view of the electronic display device of FIGS. 1A and 1B shown mounted to a ferrous surface.
[0018] FIG. 3B is a profile view of the electronic display device of FIGS. 1A and 1B shown mounted to a ferrous surface.
[0019] FIG. 4A is a perspective view of a ferrous element attached to a non-ferrous surface.
[0020] FIG. 4B is a perspective view of the electronic display device of FIGS. 1A and 1B mounted to a non-ferrous surface using the ferrous element of FIG. 4A .
[0021] FIG. 4C is a profile view of the electronic display device of FIGS. 1A and 1B mounted to a non-ferrous surface using the ferrous element of FIG. 4A .
[0022] FIG. 5A is a perspective view of the electronic display device with mounting mechanism of FIGS. 1A and 1B illustrating example dimensions of the electronic display device with the mounting mechanism attached thereto.
[0023] FIG. 5B is a top view of the electronic display device of FIGS. 1A and 1B , illustrating example dimensions of the electronic display device.
[0024] FIG. 5C is a top view of the electronic display device with mounting mechanism of FIGS. 1A and 1B illustrating example dimensions of the electronic display device with the mounting mechanism coupled thereto.
[0025] FIG. 6A is a profile view of an electronic display device with a mounting mechanism, according to an embodiment including embedded magnets and frictional surface.
[0026] FIG. 6B is a back view of the embodiment of the electronic display device with mounting mechanism of FIG. 6A .
[0027] FIG. 7A is a profile view of an electronic display device with a mounting mechanism, according to another embodiment including embedded magnets and added friction pads.
[0028] FIG. 7B is a back view of the embodiment of the electronic display device with a mounting mechanism of FIG. 7A .
[0029] FIG. 8A is an exploded perspective view of an electronic display device with a mounting mechanism according to yet another embodiment, showing the electronic display device separated from a case with embedded magnets.
[0030] FIG. 8B is a perspective view of the electronic display device with mounting mechanism of FIG. 8B showing the electronic display device with a case with embedded magnets.
[0031] FIG. 9A is a perspective view of an electronic display device with a mounting mechanism, according to yet another embodiment, with friction pads and magnets aligned to the sides of the electronic display device.
[0032] FIG. 9B is an exploded perspective view of the electronic display device and the mounting mechanism of FIG. 9B .
[0033] FIG. 10A is a front transparent view of the electronic display device with mounting mechanism of FIGS. 1A and 1B , shown mounted to a non-ferrous surface in a portrait orientation using a ferrous element.
[0034] FIG. 10B is a front transparent view of the electronic display device with mounting mechanism of FIG. 10A , shown mounted to a non-ferrous surface in a landscape orientation using a ferrous element.
DETAILED DESCRIPTION
[0035] Devices and methods for a mounting mechanism for an electronic display device to mount the electronic display device to various surfaces are described herein. In some embodiments, an electronic display device includes a mounting mechanism that can include friction pads and magnets attached to a back side of the electronic display device. The friction pads and magnets can be used to mount the electronic display device to a surface. In some embodiments, the magnets are embedded within the friction pads. In some embodiments, the electronic display device includes a friction material and the magnets are embedded within the material of the electronic display device. The mounting mechanism can also permit a user to easily dismount the electronic display device from the mounting surface. A mounting mechanism as described herein can be added to an electronic display device without adding significant thickness or weight to the electronic display device or the mounting surface.
[0036] FIG. 1A is an exploded perspective view of an electronic display device with a mounting mechanism according to an embodiment, and FIG. 1B shows a perspective view of the mounting mechanism coupled to the electronic display device. An electronic display device 100 includes a mounting mechanism 120 coupled to a back side of the electronic display device 100 . The mounting mechanism 120 can be used to mount the electronic display device 100 to a surface. The electronic display device 100 can be, for example, a tablet computer, a smartphone, a television, or an LCD display. In some embodiments, the electronic display device 100 can be an Apple iPad 2. The mounting mechanism 120 includes a pair of high friction pads 122 , and multiple magnets 124 (as shown in FIG. 1A ). The magnets 124 can be made from, for example, rare earth materials. The high friction pads 122 can be formed with, for example, a high friction material. For example, the high friction pads 122 can be made from an elastomeric material, such as, for example, silicone rubber. The magnets 124 can be positioned in such a way that they do not add significant thickness to the electronic display device 100 (see, e.g., FIGS. 2A and 2B ). In some embodiments, the magnets 124 can be coupled to the electronic display device 100 with, for example, a double-sided tape. Other attachment methods such as adhesives, mechanical latches, hinges, or elastic grip can alternatively be used.
[0037] High friction material of the pads 122 in combination with the magnets 124 allows the electronic display device 100 to be mounted magnetically to ferrous surfaces and ferrous objects. When mounted to a ferrous surface as shown in FIG. 3A , each high friction pad 122 can be squeezed between the electronic display device 100 and the ferrous surface by the magnetic force of the magnets 124 to the ferrous surface.
[0038] FIGS. 2A and 2B illustrate another embodiment of an electronic display device 200 with a mounting mechanism 220 that includes friction pads 222 and magnets 224 that can be formed the same as or similar to friction pads 122 and magnets 124 , respectively. In this embodiment, the magnets 224 are embedded in the friction pads 222 as shown in FIGS. 2A and 2B . FIG. 2B shows a cross sectional view illustrating the contact between a ferrous surface 230 , the pads 222 , and the electronic display device 200 .
[0039] As shown in FIGS. 3A and 3B , the electronic display device 100 can be attached to a surface 130 and the force of friction from the pads 124 can maintain the electronic display device 100 attached to the surface 130 . This force of friction can be proportional to the normal force and friction coefficient of the materials. The normal force is the magnetic pull force between the magnets 124 and the ferrous surface 130 . This normal force, in addition to the high friction coefficient of the pads 122 produces an overall force of friction high enough to hold the electronic display device 100 in place, mounted to the ferrous surface 130 . Electronic display device 200 can be mounted to a surface (e.g., surface 230 in FIG. 2B ) in a similar manner as described for electronic display device 100 .
[0040] FIG. 4B shows a perspective view and FIG. 4C shows a side view of the electronic display device 100 mounted to a non-ferrous surface 440 . In this embodiment, a ferrous metal frame 442 (also referred to as “ferrous element”) can be attached to the surface 440 , as shown in FIG. 4A . In some embodiments, the metal frame 442 can be formed with a steel, such as, for example, a Stainless Steel—Grade 430, and the metal frame 442 can be adhered to the wall surface 440 with, for example, a double-sided tape (not shown). Other methods of attaching the metal frame 442 to a surface can be used such as adhesives, screws, or Velcro. FIG. 4C shows a profile view of the electronic display device 100 attached to surface 440 with the mounting mechanism 120 mounted to the ferrous metal frame 442 , which is attached to the wall surface 440 . In this embodiment, the pads 122 of mounting mechanism 120 can be squeezed between the electronic display device 100 and the metal frame 442 creating a friction force sufficient to keep the electronic display device 100 mounted to the non-ferrous surface 440 .
[0041] The mounting mechanisms described herein can provide a method of attaching an electronic display device to a surface while providing a low profile. In other words, when adhered to the surface, the mounting mechanism does not add significant thickness to the electronic display device. FIG. 5A shows a perspective view of the electronic display device 100 with the mounting mechanism 120 attached to the backside of the electronic display device 100 and shown within a dashed-line bounding box B 1 to illustrate the dimensions of the electronic display device 100 with the mounting mechanism 120 attached thereto. The dimensions of the bounding box B 1 are represented by the maximum length L, width W, and thickness T2. The thickness T2 is the total thickness of the electronic display device 100 and the mounting mechanism 120 attached thereto as shown in FIG. 5C . FIG. 5B shows a dashed-line bounding box B 2 , with the thickness of only the electronic display device 100 as T1. In one embodiment, shown in FIG. 5C , the thickness T2 of the combined electronic display device 100 and the mounting mechanism 120 is no greater than 10% thicker than the thickness T1 ( FIG. 5B ) of the electronic display device 100 alone. The width W of the electronic display device 100 remains unchanged. As shown for example, in FIG. 4C , in embodiments in which the metal frame 442 is used, the stack up thickness of the electronic display device 100 , the mounting mechanism 120 and the metal frame 442 does not increase the overall thickness of the electronic display device 100 by more than 15% of the thickness of the electronic display device alone.
[0042] In another embodiment shown in FIGS. 6A and 6B , an electronic display device includes a mounting mechanism 620 that includes multiple magnets 624 that are embedded into the electronic display device 600 . The back surface of the electronic display device 600 can have, for example, high friction properties. The combination of the high friction surface of the electronic display device 600 and the embedded magnets 624 can allow the electronic display device 600 to mount magnetically to ferrous surfaces and ferrous objects.
[0043] In another embodiment shown in FIGS. 7A and 7B , an electronic display device 700 with a mounting mechanism 720 includes multiple magnets 724 that are embedded into the electronic display device 700 . Pads 722 composed of high friction material are attached externally to the electronic display device 700 such that the combination of the magnets 724 and the pads 722 allows the electronic display device 700 to be mounted magnetically to ferrous surfaces and ferrous objects. In this embodiment, the friction pads 722 add a thickness to the electronic display device 700 that is no more than 10% greater than the thickness of the electronic display device 700 alone.
[0044] In yet another embodiment, an electronic display device 800 includes a mounting mechanism that can be in the form of a case that can enclose the electronic display device 800 . FIG. 8A shows a layered perspective view of the electronic display device 800 and a case 845 .
[0045] The case 845 can be made of, for example, a high friction material. Embedded into the walls of the case 845 are multiple magnets 824 . The combination of the high friction material of the case 845 and the embedded magnets 824 allows the electronic display device 800 to be mounted magnetically to ferrous surfaces and ferrous objects. FIG. 8B shows a perspective view of the electronic display device 800 with the mounting mechanism 820 (in the form of case 845 ) coupled thereto.
[0046] FIGS. 9A and 9B illustrate yet another embodiment of an electronic display device 900 with a mounting mechanism 920 . The mounting mechanism 920 includes high friction pads 922 with multiple magnets 924 that align to the sides of the electronic display device 900 . FIG. 9B shows an exploded perspective view and FIG. 9A illustrates the mounting mechanism 920 coupled to the electronic display device 900 . The high friction pads 922 can be attached to the sides of the electronic display device 900 as shown in FIG. 9A . Magnets 924 can be positioned between the electronic display device 900 and the friction pads 922 . The high friction pads 922 extend to the back side of the electronic display device 900 to ensure contact of the pads 922 with the surface to which the electronic display device 900 is mounted. The combination of the high friction pads 922 that extend to the back of the electronic display device 900 and the magnets 924 allows the electronic display device 900 to be mounted magnetically to ferrous surfaces and ferrous objects.
[0047] In each of the embodiments described above, the electronic display device 100 , 200 , 600 , 700 , 800 , 900 can be mounted to a surface in various orientations, such as, in a landscape view, a portrait view or at any angle therebetween. For example, FIG. 10A shows a transparent back view of the electronic display device 100 mounted in portrait view to the non-ferrous surface 440 with the ferrous metal frame 442 and mounting mechanism 120 . FIG. 10B shows a transparent back view of the electronic display device 100 mounted in landscape view to the non-ferrous surface 440 with the ferrous metal frame 442 and the mounting mechanism 120 .
[0048] While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods described above indicate certain events occurring in certain order, the ordering of certain events may be modified. Additionally, certain of the events may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above.
[0049] Where schematics and/or embodiments described above indicate certain components arranged in certain orientations or positions, the arrangement of components may be modified. While the embodiments have been particularly shown and described, it will be understood that various changes in form and details may be made. Any portion of the apparatus and/or methods described herein may be combined in any combination, except mutually exclusive combinations. The embodiments described herein can include various combinations and/or sub-combinations of the functions, components, and/or features of the different embodiments described. | A mounting mechanism for mounting an electronic device, such as an electronic display device, to various surfaces, including ferrous surfaces. The mounting mechanism may include friction pads for attachment to the electronic display device. In one implementation a plurality of magnets are embedded within the friction pads. Alternatively, the magnets may be directly attached to the electronic display device and covered by the friction pads. When the mounting mechanism is used to mount the electronic device to a ferrous surface, the magnets and the friction pad respectively provide magnetic and frictional forces so as to enable secure mounting of the electronic display device to the ferrous surface. The mounting mechanism may also include a frame disposed to be affixed to a non-ferrous surface. The frame defines a ferrous surface to which the electronic display device may then be mounted using various configurations of magnets and friction pads. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Applications Ser. Nos. 60/703,652, filed on Jul. 29, 2005 and 60/793,403 filed on Apr. 19, 2006. The disclosure of the prior applications are considered part of (and are incorporated by reference in) the disclosure of this application.
BACKGROUND
[0002] Structural panels used in applications such as aircraft, buildings and transportation vehicles vibrate and transmit sound due to unavoidable external sources of excitation. Panels used in aircraft applications need to have high specific strength and stiffness and very low weight. Sandwich panels with cores made of honeycomb, balsa or foam often meet these criteria, especially for floors and fuselage.
[0003] However, the same property combination may lead to higher transmission and radiation of airborne noise than expected, based solely on panel mass.
SUMMARY
[0004] Structure and methods to reduce airborne noise across a broadband frequency range transmitted by a vibrating honeycomb sandwich floor panel is described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows a honeycomb sandwich panel;
[0006] FIG. 2 shows an enhancement of the low shear, thin skin, high density core;
[0007] FIG. 3 shows an enhancement of the high shear, thick skin, low density core;
[0008] FIG. 4 shows the flow chart for the design of subsonic panels;
[0009] FIG. 5 shows a graph reflecting the improvement of transmission loss between subsonic and supersonic wave speed panels;
[0010] FIG. 6 shows a graph of the sound transmission loss of airplane floors;
[0011] FIG. 7 shows a graph of the difference between mass law performance of floor panels; and
[0012] FIG. 8 shows a graph with calculated wave speeds for honeycomb sandwich panels.
DETAILED DESCRIPTION
[0013] The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals, are described herein.
[0014] The inventors believe that the reason for the sound transmission is based on the supersonic wave speed for energy waves in the panel. These energy waves efficiently exchange energy with the cabin environment of the airplane or other vehicles.
[0015] The present application describes optimizing the panel to have a subsonic wave speed in the frequency range of interest. This can make the panels more inefficient as transmitters and radiators of sound. Moreover, this provides superior sound attenuation for a given panel mass.
[0016] An embodiment describes a panel design with a core that has a constant subsonic sheer mode for transmitted waves. In the embodiment, the coincidence frequency is shifted to above 8000 Hz. The panel is also optimized to meet other design constraints including mechanical performance constraints and weights. In effect, this forms a passive noise rejection technique which varies skin and core thickness, densities, and elastic moduli.
[0017] FIG. 1 illustrates a first embodiment showing a honeycomb sandwich panel which has predominantly sheer modes over bending modes at most, e.g. more than half, the frequencies of interest. According to the embodiments, the panels become inherently noise attenuated, requiring less damping material. Reduction in the damping material reduces their weight and hence increases payloads. This may be critical and extremely advantageous in commercial aircraft. This also reduces labor costs which would otherwise be required to pack the damping material.
[0018] The panel of FIG. 1 has parameters such that the shear wave speed will remain subsonic at most of these frequencies. The subsonic speed targeted is between ⅔ of Mach 1 and Mach 1. The subsonic speed for waves in the panel makes the panel an inefficient exchanger of energy with the surroundings.
[0019] The predominant subsonic shear wave speed is achieved by using a low-modulus core and an increased skin-to-core thickness ratio. This enhancement of shear motion is shown in FIG. 2 and FIG. 3 . In an embodiment, the core is a sound insulating material, e.g. Nomex® honeycomb with a density that lies between 1.8 pcf and 5 pcf (pounds per cubic foot). The core is also made of Kevlar® honeycombs or balsa wood or forms. The one-side skin-to-core thickness ratio can range anywhere between 0.02 and 0.1. The skin can be of any high modulus fiber/fabric and resin combination like carbon fiber—phenolic or glass fiber—epoxy.
[0020] The density and modulus of the core can be varied to strike a balance between the requisite acoustic performance, mechanical performance and weight constraints. The mechanical properties considered in the optimization include flexural strength, flexural modulus, core shear strength, and compressive strength. The flexural modulus can be tripled by increasing the skin thickness while remaining within the acoustic and weight constraints. Depending upon the core densities, the core strength can be as low as half the value for the lowest density compared to the highest density. The compressive strength can be one-third the value for the lowest density compared to the highest density.
[0021] As an example of the present art, design parameters for 5 panels and a reference panel are described in Table 1 and Table 2. The core densities presented are 1.8 pcf and 3 pcf.
TABLE 1 Panel design parameters. × 10{circumflex over ( )}6 × 10{circumflex over ( )}9 Panel Code kg/m3 m kg/m3 m N/m2 N/m2 X-Reference 144 0.0096 1600 0.0003 750 100 PA −1.8 pcf - 28.8 0.0087 1600 0.00075 450 100 2.5S PB −1.8 pcf - 28.8 0.009 1600 0.0006 450 100 2S PC −3 pcf - 2S 48 0.009 1600 0.0006 450 100 PD −3 pcf - 48 0.0087 1600 0.00075 450 100 2.5S PE −3 pcf - 3S 48 0.0084 1600 0.0009 450 100
[0022]
TABLE 2
Mass, bending stiffness and core shear wave speed.
surface mass
D
C s
Panel Code
kg/m 2
N/m 2
m/s
X - Reference
2.81
1675
666
PA −1.8 pcf - 2.5S
3.14
3816
243
PB −1.8 pcf - 2S
3.17
3151
273
PC −3 pcf - 2S
3.34
3151
350
PD −3 pcf - 2.5S
4.05
3816
314
PE −3 pcf - 3S
4.77
4435
286
D-Bending stiffness C s - Shear speed
[0023] To demonstrate the impact of subsonic wave speed design on the acoustic performance of the panel, transmission loss improvement of panels made according tot eh present system with subsonic wave speed (PA, PB, PD, and PE) with Mach between 0.7 and 1 is compared to a reference panel with supersonic wave speed (X), as shown in FIG. 5 . A sound transmission loss improvement of 507 dB at middle and higher frequencies is demonstrated in the experimental measurements for panel PB, which has significantly subsonic shear wave speed. Panels with incremental shear wave speed show decrement in transmission loss (TL).
[0024] These materials may be used for an airplane floor or wall panels. According to an embodiment, the materials are made of a high modulus fiber laminate skins and an orthotropic Nomex®/Kevlar® honeycomb core. These lightweight panels are optimized for mechanical performance that results in poor acoustic performance. The commercially available floor panels are considerably inefficient in their usage of mass when compared to a single panel of same mass.
[0025] Airborne sound transmission loss (TL) is used to estimate the acoustic barrier properties of these floor panels 1 . The panels have a complicated acoustic behavior that are dependent on the different mechanical motions like panel bending, skin bending and core shear motions 2, 3 . The wave propagations related to these motions and their relation to the speed of sound in ar at different frequency regimes determines the subsequent performance of the panels. The low-frequency region is stiffness-controlled, while the mid-frequency region is mass-controlled. Typically these panels have a critical frequency, which is the lower limiting coincidence frequency corresponding tot eh grazing angle of incidence, between 1-2 KHz. Kurtze and Watters derived the relationships between the mass and mechanical properties of a sandwich panel to the panel wave speeds at different frequency regimes. Their model assumes the existence of three idealized frequency regimes; the first regime is dominated by the total panel bending, the second regime is dominated by the core shear, and the third regime is controlled by the bending of the skins. Their design for inherently quieter sandwich panels emphasized on significantly subsonic core shear wave speeds for the panels in the frequency range of interest. The core modulus influences the core shear wave speed. To make a thin sandwich panel acoustically superior, a low density core would be required. However, this could lower the mechanical performance of the floor panel. 1 Shankar Rajaram, Tongan Wang, Puneet Jain, Steve Nutt, “Noise transmission loss in composite sandwich panels”:, SAMPE, Long Beach, California, May 17-21, 2004 2 Kurtze, G., and Watters, B. G., “New wall design for high transmission loss or high damping”, J. Acoust. Soc. Am., 31, 739-48, 1959. 3 Davis, E. B., “Designing Honeycomb panels for noise control”, American Institute of Aeronautics and Astronautics, AIAA-99-1917, 1999.
[0026] The objective of this application is to design a practical quieter honeycomb sandwich panel based on Kurtze and Watter's theory for floor panel applications.
[0027] Kurtze and Watters Theory
[0028] Kurtze and Watters based their model for acoustics of sandwich panel on wave impedances. The impedance of a symmetric sandwich panel due to the panel mass (Z M ) , bending of the panel (Z b ), skin contribution to the shear of the core (Z sh1 ) , and the core shear (Zsh 2 ) are given consideration.
[0029] Then the total impedance is obtained by combining the above impedances (eqn. 1), analogous to an electrical circuit. The mass terms are connected in series to the stiffness terms. The stiffness terms are connected parallel to each other. The shear stiffness term contains serial contributions from two skins and one core.
Z p = Z m + Z b · ( 2 Z sh 1 + Z sh 2 ) Z b + ( 2 Z sh 1 + Z sh 2 ) Equation 1
[0030] For special cases, the polynomial is reduced to,
c s 4 c b 4 c p 6 + c s 2 c p 4 - c s 4 c p 2 - c b ′4 c s 2 = 0
where
c b 4 = D p ω 2 M p = bending wave speed of the plate ,
c b 4 = 2 D sk ω 2 M p = bending wave s peed of the skins ,
and c s 2 = G c M p = shear wave speed of the core . Equation 2
[0031] The panel bending stiffness (D p ), and skin bending stiffness (D sk ) are given by
D p = E sk J ( 1 - v sk 2 ) ; D sk = E sk t sk 3 12 ( 1 - v sk 2 ) .
[0032] In the above expressions, M p is the mass of the panel, G c is the shear modulus of the core, E sk is the Young's modulus of the skin, υ sk is the Poisson's ratio of the skin material, J is the moment of inertia for the cross section of the sandwich panel, t sk is the thickness of the skin, and G c is the shear modulus of the core.
[0033] Evan Davis normalized the panel wave speed to speed of sound and arrived at the save speeds of the different regimes in the form of panel geometry, mass density and the elastic properties of the materials used from the above polynomial:
c b = [ ω 2 t sk 2 ( 1 + t c / t sk ) 2 4 ( 1 + ρ c t c / 2 ρ sk t sk ) ( E sk ρ sk ( 1 - v 2 ) ) ] 1 / 4 Equation 3 c s = [ 1 ( 1 + 2 ρ sk t sk / ρ c t c ) ( G c ρ c ) ] 1 / 2 Equation 4 c b ′ = [ ω 2 t sk 2 24 ( 1 + ρ c t c / 2 ρ sk t sk ) ( E sk ρ sk ( 1 - v 2 ) ) ] 1 / 4 Equation 5
[0034] C b and c b ′ are proportional to the skin material save speed,
c msk = E sk ρ sk ( 1 - v 2 ) ,
and c s is proportional to the core material wave speed,
c mc = G c ρ c .
The panel wave regimes and the transition zones T I and T II are summarized as:
c b < T I < c s < T II < c b ′ Equation 6 T I 1 π t sk ( 1 ( 1 + t c / t sk ) ) ( ρ c t c / 2 ρ sk t sk ) 2 ( 1 + ρ c t c / 2 ρ sk t sk ) ( c mc 2 c msk ) Equation 7 T II = 3 π t sk ( ρ c t c / 2 ρ sk t sk ) 2 ( 1 + ρ c t c / 2 ρ sk t sk ) ( c mc 2 c msk ) Equation 8
[0035] The mechanical parameter used as a design constraint was the static bending stiffness D given by
D = E sk t sk ( t sk + t c ) 2 2 ( 1 - v sk 2 ) .
[0036] Experimental Procedure
[0037] The sound transmission loss (TL) was tested at a facility that has an asymmetric reverberant source room and a symmetric anechoic receiver room mounted on floating floors. The samples tested had a size of 1.067 m by 1.067 m and was secured in the window between the two chambers using steel slats along the four edges of the test panel. The small-scale reverberant source room had a volume of 15 cubic meters and 9 non-parallel walls. The receiver room was a rectangular shaped anechoic room with a volume of 15 cubic meters. Pink noise was generated in the source room using an omni sound speaker. The spatial average of the incident sound pressure was measured using a pressure microphone mounted on a rotating boom. The transmitted sound was measured using an intensity probe that was mounted on a traverse system. The surface intensity of the transmitted sound was averaged from measurements taken at discrete points on an 11×11 grid. A standard steel panel was used to calibrate the chamber. The chamber was calibrated for all frequency bands above 315 Hz.
[0038] Samples
[0039] Three samples were chosen for the study. All the samples had carbon-phenolic laminates for skins and Nomex® honeycomb for core. Panels A and B were commercial grade airplane floor panels. The design of Panel S was based on Kurtze and Watters model for quieter panels. It was designed to meet the subsonic criteria that core shear speed, c s ˜⅔ speed of sound. The design details of the panels are given in table 3. Table 4 shows the calculated wave speeds of the three panels based on equations 4-8.
TABLE 3 Mechanical and geometrical details of the samples Cell ρ c t c ρ s t s M G × 10 6 E × 10 9 Panel size m kg/m 3 m kg/m 3 m kg/m 2 Nm −2 Nm −2 A 0.004 144 0.0096 1600 0.0003 2.8 108.3 100 B 0.003 80 0.0096 1600 0.0003 2.2 63.25 100 S 0.004 28.8 0.0087 1600 0.00075 3.1 18 100
[0040]
TABLE 4
Wave speed details of the samples based
on Kurtze and Watters formulation
D
Cs
Cb
Cms
CmL
T1
T2
Panel
Nm
m/s
m/s
m/s
m/s
Hz
Hz
A
1675
666
3
867
8439
2643
151052
B
1675
593
3
889
8439
1797
102711
S
3816
243
6
791
8439
248
5411
[0041] Results and discussion
[0042] FIG. 6 shows that the TL of panels A and B have a dip at ˜1600 Hz. This is the coincidence dip caused by the matching of panel speed with the speed of air for the grazing angle of incidence. The TL trend increases after 2 KHz, but the TL values are considerably lower compared to panel S. The TL curve for panel S does not show any dip between 1 KHz and 2 KHz.
[0043] FIG. 7 shows the TL difference, which is the measured TL minus the mass law calculated TL. The TL difference is plotted to get a relative idea of the acoustic performance of the panels for a given mass. Panel A shows the poorest mass law performance above 1 KHz. Panel S. shows the best mass law performance. The negative deviation from mass law above 1 KHz is considerably lower for panel S compared to panel A and B. The TL improvement for the subsonic floor panel is comparable to the SEA predication made by Evan Davis for a similar design.
[0044] The improvement in TL for panel S can be attributed to the supersonic core shear wave speeds for panels A and B, and a subsonic wave speed for panel S, as listed in Table 4. FIG. 8 shows the wave speed plotted for panels A and S calculated using the Kurtze and Watters formulation. It can be seen that the panel wave speed coincides with speed of sound at around 1 KHz for panel A. For panel C, the shear wave speed is about two-thirds the speed of sound for most frequency bands above 1 KHz.
[0045] The static bending stiffness (D) of panel S is almost twice the static bending stiffness of panel A and B as shown in table 4. This increased beam loading capacity for the panel S due to thicker skins is expected to take most kinds of loads that an airplane floor panel is subjected to. Moreover, panel S is only ˜10% heavier than panel A. This shows that such panels can be designed for practical applications.
[0046] The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein.
[0047] Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art. For example, other materials with similar or analog characteristics.
[0048] Also, the inventors intend that only those claims which use the words “means for” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims. The computers described herein may be any kind of computer, either general purpose, or some specific purpose computer such as a workstation. The computer may be a Pentium class computer, running Windows XP or Linux, or may be a Macintosh computer. The computer may also be a handheld computer, such as a PDA, cellphone, or laptop.
[0049] The programs may be written in C, or Java, Brew or any other programming language. The programs may be resident on a storage medium, e.g., magnetic or optical, e.g. the computer hard drive, a removable disk or media such as a memory stick or SD media, or other removable medium. The programs may also be run over a network, for example, with a server or other machine sending signals to the local machine, which allows the local machine to carry out the operations described herein. | Aircraft panels are formed of a honeycomb core material and the skin. The honeycomb core material and the skin are selected to provide subsonic wave speed across the panel, thereby reducing sound transmission. |
BACKGROUND OF THE INVENTION
The invention relates to an electronic ignition system for gasoline internal combustion engines with a Hall sensor for generating the reference signal corresponding to the position of the crankshaft or the pistons in the cylinders wherein the ignition point is electronically controlled in dependence upon the speed and the load.
Electronically controlled ignition systems for gasoline internal combustion engines have been advantageously employed in automotive vehicles for some years. These ignition systems control the ignition coil current in such a way that the latter does not reach its maximum until shortly before the ignition point. In the known systems, the ignition coil current is furthermore limited to a defined maximum value. To identify the position of the motor crankshaft either a Hall or an induction sensor is used. These known ignition systems do not control the ignition point electronically in dependence upon the speed and the load, but rather effect this desired control with the aid of mechanical systems. For example, the speed dependency of the ignition point is achieved by the mechanical adjustment of the ignition distributor with the aid of a centrifugal force system, and the load dependency similarly by a mechanically operating vacuum system.
Furthermore, electronic ignition systems wherein the ignition point is electronically controlled in dependence upon speed and load have recently become known. To this end, the engine-related data are transferred to an electronic data store. These data are processed in a microprocessor according to a predetermined program to provide output data which control the ignition procedure. The store and the microprocessors preferably consist of MOS modules. The output stage amplifier and the control of the primary coil current in the ignition coil are, on the other hand, still realized by bipolar technology. The reason for this is that high demands are made on the ignition system with respect to current and voltage stability. The ignition system should, furthermore, operate temperature independently within a large temperature range.
These relatively new ignition systems, often referred to as "characteristic curve ignition" have the advantage that the formerly commonly used mechanical adjustment devices are replaced by electronic components. The disadvantage of characteristic curve ignition is that the electronic modules of the ignition themselves are comparatively expensive and complicated, with the result that characteristic curve ignition has hitherto only been installed in automobiles of the higher price range.
Substantial cost could be saved with an electronic ignition system without mechanical systems, without store and microprocessor, wherein the speed- and load-dependent ignition point is controlled by an analog bipolar system. This is promoted by U.S. Pat. No. 4,324,216. With this ignition system, the information for control of the ignition point is derived from the signal of an induction sensor whose amplitude and curvature are speed-dependent. The disadvantage of this ignition system is that the ignition point in the idle range changes between two states and the speed-dependent ignition point only depends on the curvature of the induction sensor. The ignition point can, therefore, not be influenced in an engine-related manner in the electronic system.
Furthermore, the unavoidable dispersion of the induction sensors fully affects the speed dependency of the ignition point. There is no load-dependent electronic control of the ignition point in this ignition system.
SUMMARY OF THE INVENTION
The object underlying the invention is therefore to indicate an electronic ignition system for gasoline internal combustion engines wherein the ignition point is speed- and load-dependently influenced with low electronic expenditure without a special curvature of a sensor playing a role in this control mechanism. This object is attained in accordance with the invention in an electronic ignition system of this kind mentioned at the outset by the control information being derived from a reference signal controlled charging and discharging procedure of at least one capacitor and by this information voltage either being compared with a d.c. voltage which is alterable in dependence upon load or it itself being altered in dependence upon load and compared with an unaltered d.c. voltage in order to determine the ignition point.
It is furthermore desirable for the ignition coil current to pass for as short a time as possible through the primary coil at the current maximum. To aid in attaining this object, provision is made in accordance with a further development of the invention for the information voltage to be compared with a second d.c. voltage to obtain the point in time at which the current starts to flow through the primary coil, with this second d.c. voltage being altered in dependence upon the duration of the passage of the primary current through the primary coil at its maximum.
The voltage comparisons are preferably carried out with the aid of conventional type comparators. The output signals of the comparators are linked together via logic circuits in such a way that there is obtained for control of the primary coil current an output signal whose one flank determines the ignition point and whose other flank determines the point in time at which the current starts to flow through the primary coil.
The load-dependently alterable d.c. current may, for example, be set with the aid of a potentiometer controlled by the throttle valve. If the d.c. voltage to be compared with the information voltage is constant, a single capacitor is charged with a load-dependently alterable charging current so that the charging current increases as the load increases, which causes a decrease in the advance of the ignition point.
The invention and its further advantageous output circuitry will now be described in further detail with reference to embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the block diagram of the electronic ignition system according to the invention;
FIG. 2 shows the circuit for the setting of the load-dependent voltage;
FIG. 3 shows the voltage paths at the various circuit points of FIG. 1;
FIG. 4 shows, in addition, the output signal of the circuit according to FIG. 1 and the path of the primary current in the ignition coil;
FIG. 5 shows the closing angle in dependence upon the speed and the battery voltage under the conditions at maximum load;
FIG. 6 shows the advance of the ignition point before the upper dead center in dependence upon the speed and the load in a circuit according to FIGS. 1 and 2;
FIG. 7 shows a circuit for the load-dependent alteration of the saw-toothed voltage path at a capacitor;
FIG. 8 shows this voltage path;
FIG. 9 shows, in turn, the path of the advance of the ignition point before the upper dead center in dependence upon the speed and the load in a circuit according to FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the invention, a Hall sensor whose curvature is a meander as shown in FIG. 3a is used to indicate the position of the crankshaft or the pistons in the engine cylinders. This curvature is independent of the speed and has a low and a high phase per period, with the percentage duration of the respective state in relation to the period duration T being defined, for example, by a rotating cover fixedly coupled with the crankshaft. This input signal U IN in accordance with FIG. 3a is located at the input of an electronic circuit in accordance with FIG. 1. This circuit is preferably realized in bipolar technology.
The rotating cover of the Hall sensor is, for example, coupled with the crankshaft in such a way that the positive flank of the Hall signal, i.e., the jump from the low state to the high state occurs when one of the pistons in the engine cylinder is located at the upper dead center O.T. or, depending on the engine design, in the proximity of the upper dead center. The cover may, for example, be of such design that after 60% of the period T, the signal U IN goes over from the high state to the low state and remains there for the remaining 40% of the period duration.
In accordance with the circuit in FIG. 1, this input signal U IN controls a switch S 1 in such a manner that via this switch in the high phase of the reference signal U IN a charging current I L charges a capacitor unit to the voltage U 1 . In the low phases of the reference signal U IN , on the other hand, the capacitor unit discharges itself with the constant current I E . The capacitor unit consists, for example, of two parallel connected current branches, with the capacitance C 1 connected in one current branch, and the capacitance C 2 and the resistance R 2 connected in series in the other current branch. The path of the voltage U 1 at the capacitor unit is shown in FIG. 3b and in FIG. 4b.
The path of the information voltage U 1 can be influenced in an engine-related manner by the design and dimensions of the capacitor unit in such a way that in accordance with FIG. 6, the advance of the ignition point before the upper dead center does not rise linearly with the speed, but, as desired in certain cases, the advance from idle at approximately 750 r.p.m./min. first rises steeply and then flatter.
The information voltage U 1 at the capacitor unit is fed in accordance with FIG. 1 to the non-inverting input of a comparator K 1 . The d.c. voltage U L is located at the inverting input of this comparator K 1 . In accordance with FIG. 2, this d.c. voltage is set with the aid of a load-dependently alterable resistance R D . The resistance R D is altered, for example, by the throttle valve. The resistance R D increases as the load decreases, which results in an increase in the advance of the ignition point as the load decreases. In FIG. 2, resistance R D is part of a series connection comprising the resistances R 4 , R 3 and R D , with the inverting input of the comparator K 1 being connected to the connection between the resistances R 3 and R 4 . In one embodiment, the resistances have, for example, the following values:
R.sub.4 =9kΩ
R.sub.3 =1kΩ
R.sub.D =800Ω(in idle)
R.sub.D =0Ω(at maximum load).
In FIGS. 3b and 4b, the d.c. voltage U L is depicted by a line. Its point of intersection P with the decreasing flank of the information voltage U 1 determines the ignition point. As is apparent from FIGS. 3b and 4b, the advance t (FIG. 4f) of the ignition point with respect to the upper dead center O.T. increases as the voltage U L increases and the load simultaneously decreases.
In accordance with FIG. 3c, the voltage U 2 appears at the output of the comparator K 1 . This voltage is meander-shaped and has the low state when the information voltage U 1 is smaller than the d.c. voltage U L , and it has the high state when the information voltage U 1 is larger than the aforementioned d.c. voltage U L .
Connected downstream of the output of comparator K 1 is the reference signal U IN controlled switch S 2 which in the high state of the reference signal U IN is closed and in the low state of the reference signal U IN is open. In this way, the hatched area of the high phase of the signal U 2 in FIG. 3c is faded out. There therefore appears at the output of the switch unit S 2 the signal U 3 shown in FIG. 3d and FIG. 4c which has the high state from the negative flank of the reference signal U IN to the ignition point. This signal U 3 is directed to one input of an OR gate G 2 .
As already mentioned, the control signal for the primary current in the ignition coil should be of such configuration that this current remains for as short a time as possible at its maximum. To this end, the information voltage U 1 is fed to the inverting input of a further comparator K 2 , in accordance with FIG. 1, at whose non-inverting input the voltage U I is located. The d.c. voltage U I is illustrated in FIGS. 3e and 4b by a line. Its point of intersection Q with the rising flank of the information voltage U 1 determines the point in time at which the current I pr starts to flow through the primary coil. If the primary current I pr stays at its maximum I prmax (FIG. 4f) too long, the voltage U I increases and the starting point for the primary coil current is delayed. The way in which the duration of the primary coil current at its maximum can be determined is apparent, for example, from German Pat. No. 3,015,939.
The output signal U 4 at the comparator K 2 is illustrated in FIG. 3f. The meander-shaped signal U 4 has the high state when the information voltage U 1 is smaller than the voltage U I and has the low state when the information voltage U 1 is larger than U I . This voltage U 4 is fed to the input of a NOR gate G 1 , at whose other input the inverted reference signal U 5 in accordance with FIG. 3g is located. A conventional inverter Inv. is used to invert the reference signal U IN . At the output of the NOR gate G 1 there then occurs the signal U 6 in accordance with FIG. 3h and FIG. 4d which between the point of intersection Q and the negative flank of the reference signal U IN has the high state and during the remainder of the period duration T has the low state.
The voltages U3 and U6 in accordance with FIGS. 3d and 3h and 4c and 4d, respectively, are fed to an OR gate G 2 whose output signal U out is illustrated in FIG. 4e. The low phase of this output signal U out is defined by the points of intersection P and Q, respectively, in accordance with FIG. 4b. Consequently, the output signal U out is in the low state between the points of intersection P and Q and in the high state during the remaining time.
In accordance with FIG. 4f, the rising flank of the output signal U out switches on the primary coil current which shortly before the ignition point remains at its maximum for a short time and is abruptly switched off with the decreasing flank of the output signal U out so that ignition occurs. The limitation of the ignition coil current at its maximum is effected, for example, with the aid of a circuit, as similarly described in German Pat. No. 3,015,939. This known circuit also supplies a control pulse whose pulse width t e corresponds to the duration of the primary coil current at maximum. With this control pulse the d.c. voltage U I at the comparator K 2 can be set such that this duration of the coil current at maximum becomes as short as possible.
In FIG. 5, the closing angle is depicted at maximum load in dependence upon the speed and the battery voltage. By closing angle the relationship between the time in which primary current flows in the ignition coil and the total period duration T is meant. The battery voltage is the voltage which is respectively available when the circuit is in operation, as illustrated, for example, in FIG. 2 of German Pat. No. 3,015,939. FIG. 5 shows the measured closing angle for a 4-cylinder engine with a circuit constructed in accordance with the invention as function of the battery voltage of 6 V to 16 V. Here, a transistor ignition coil with its primary coil current set at 7.5 A was used.
FIG. 6 shows the percentage advance of the ignition point before the upper dead center O.T. in relation to the period duration in dependence upon the motor speed and as function of the load as parameter. The percentage advance was also converted at the ordinate into degrees crankshaft (°CS) for a four-cylinder engine. The advance is independent of voltage from 5 V battery voltage upwards.
As is apparent from the diagram, the advance decreases as the load increases and increases from approximately idle speed with the speed.
In many cases, it is also desirable for the curve branches in accordance with FIG. 6 to extend parallel to one another as the speed increases for different load parameters. Such a path is depicted in FIG. 9. This path is acquired by using instead of the capacitor unit in FIG. 1 only one single capacitance C 1 in accordance with FIG. 7. Here, the charging current I L of this capacitance C 1 is load-dependently altered in such a way that as the load increases the charging current increases and thus the advance of the ignition point before the dead center O.T. decreases. To this end, the circuit in accordance with FIG. 7 consists of a current source with the transistors T 1 and T 2 , and the current of this current source is set with the variable resistance R D . This resistance is, for example, controlled by the throttle valve again and has in idle a value of, for example, 0Ω and at maximum load a value of approximately 5kΩ. The resistance R D is inserted into the emitter section of the transistor T 1 connected as diode. In the collector branch of the transistor T 1 lies a resistance R 7 comprising, for example, 7kΩ. The diode T 1 and the resistance R D are arranged parallel to the resistance R 6 and to the base-emitter section of a transistor T 2 . The resistance R 6 has, for example, a value of 125kΩ. A transistor T 3 which is part of a current mirror circuit comprising the transistors T 3 and T 4 is located in the collector branch of the transistor T 2 . The transistor T 3 is connected as diode and its base is coupled with the base of a transistor T 4 at whose collector there appears the variable output current I L with which the capacitance C 1 is charged. The emitters of the two transistors T 3 and T 4 are coupled with each other and connected to a supply potential. The base of the two transistors T 3 and T 4 is connected via a resistance R.sub. 5 to ground; this resistance has, for example, a value of 96kΩ. The variable information voltage U 1 and the capacitance C 1 is fed to the non-inverting input of the comparator K 1 at whose inverting input an invariable d.c. voltage U L* is applied. The charging current for the capacitance C 1 is, for example, at minimum load 25 μA and at maximum load 33 μA. The discharge current I E of the capacitance C 1 is constant.
From FIG. 8 it is apparent how the ignition point changes with the load. FIG. 8a, in turn, shows the reference signal U IN in accordance with FIG. 3a. The saw-toothed path of the information voltage U 1 when the capacitor unit consists of only one single capacitance C 1 is evident from FIG. 8b. The points P and Q are, in turn, the points of intersection with the invariable d.c. voltage U L* and the d.c. voltage U I dependent on the duration at maximum primary current, respectively. The advance t changes to the value t' when the load is reduced. In this case, the resistance R D becomes smaller so that the charging current for the capacitance C 1 decreases. The voltage path at the capacitance C 1 then takes the course shown in dashed lines in FIG. 8. In the high phases of the reference signal the voltage at the capacitance C 1 is charged to a relatively low value and then discharges itself with the unchanged discharge current I E so that the point of intersection P with the constant d.c. voltage U L* already occurs at an earlier point in time, resulting in the increase in the advance of the ignition point with the time t'. | The invention relates to an electronic ignition system for gasoline internal combustion engines wherein a Hall sensor is used to generate the reference signal corresponding to the position of the crankshaft or the pistons in the cylinders. The ignition point is electronically controlled in dependence upon the speed and the load. In accordance with the invention, control information in the form of an information voltage is generated at at least one capacitor by the charging and discharging procedure controlled by the reference signal. To determine the ignition point, this information voltage is either compared with a d.c. Voltage which is alterable in dependence upon load or it itself is altered in dependence upon load and compared with an unaltered d.c. Voltage. |
FIELD
The present disclosure relates to a privacy display and related techniques for using a privacy display on a mobile device.
BACKGROUND
The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A “user device” refers to a computing device that typically includes a user interface, a display, and a processor. User devices may include non-portable or stationary devices such as a desktop computer. User devices may also include mobile devices such as mobile phones, laptop computers, personal digital assistants, and tablet computers. Mobile devices may selectively communicate via one or more networks, such as a mobile telephone network, the Internet, and the like.
Privacy filters have been used on viewing screens for protecting sensitive information. Specifically, a privacy filter is used to darken side viewing of the display to prevent others from reading information displayed. Privacy filters, however, are often bulky and cumbersome such that they are not incorporated on mobile devices. Further, in some instances, it may be desirable to protect or hide sensitive information that is displayed on only portions of the viewable screen.
SUMMARY
In accordance with some embodiments of the present disclosure, a display device is disclosed. The display device can include a housing, a processor, and a display assembly. The processor can be arranged within the housing. The display assembly can be operably coupled to the processor and arranged within the housing. The display assembly can include a first display, a privacy filter, and a second display. The first and second displays can comprise first and second LCD's, respectively. The first LCD can output a first portion of the display assembly. The second LCD can output a second portion of the display assembly. The privacy filter and the first and second LCD's can be arranged such that the first portion of the display assembly is filtered by the privacy filter to be viewable in a first viewable arc. The second portion of the display assembly can be viewable in a second viewable arc that is different than the first viewable arc. In one example, the display device may be incorporated on a mobile computing device such as a mobile phone, tablet computer or laptop computer for example.
In accordance with various embodiments of the present disclosure, a display device is disclosed. The display device can include a housing, a first display, a privacy filter, and a second display. The housing can have a user interface portion. The first and second displays can comprise first and second LCD's, respectively. The first LCD can be disposed in the housing. The second LCD can be disposed relative to the privacy filter such that the privacy filter is interposed between the first and second LCD's. The first LCD can be configured to display a first output. The second LCD can be configured to display a second output. The first output can be displayed on the first LCD and be viewable through the second LCD only within a viewable arc of the privacy filter.
Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIG. 1 is a front perspective view of a mobile device incorporating a privacy display according to some embodiments of the present disclosure;
FIG. 2 is a sectional view of the mobile device of FIG. 1 illustrating a user viewing the display through a first viewable arc and a pair of bystanders viewing the display through a second viewable arc;
FIG. 3 is a functional block diagram of the mobile device of FIG. 1 according to some implementations of the present disclosure;
FIG. 4 is a plan view of the display of the mobile device of FIG. 1 illustrating a first field “bank.example.com” and a second field “Account Number:” both displayed on a second or public liquid crystal display (hereinafter “LCD”) and a third field “123456789” displayed on a first or private LCD, wherein all of the first, second, and third fields are viewable by the user through the first viewable arc;
FIG. 5 is a plan view of the display of FIG. 4 illustrating the third field as being obscured as viewed through the second viewable arc; and
FIG. 6 is a flow diagram of a technique for using the privacy display according to some implementations of the present disclosure.
DETAILED DESCRIPTION
With initial reference now to FIG. 1 , a display device constructed in accordance to one example of the present disclosure is shown and generally identified at reference numeral 10 . The display device 10 may be a laptop computer, a mobile phone, a tablet computer, or the like. The display device 10 generally includes a housing 12 that incorporates a user interface 14 . The user interface 14 includes a viewable screen or display assembly 20 and a plurality of buttons 22 , as well as a microphone 24 and a speaker 26 . The display assembly 20 may be a touch display as shown, such as a capacitive sensing display. The display device 10 may additionally or alternatively include a physical character layout, e.g., a partial QWERTY-based keyboard. The display assembly 20 may display information to, and receive input from, a user 30 ( FIG. 2 ). For example, the user 30 may input information to the display device 10 via the user interface 14 including the display assembly 20 , the buttons 22 , and/or the microphone 24 .
With continued reference to FIG. 1 and additional reference now to FIG. 2 , the display assembly 20 will be further described. The display assembly 20 generally incorporates a first or private display 32 , a privacy filter 34 , a one-way mirror 36 , and a second or public display 38 . According to the examples shown, the private display 32 may be an LCD display such as a transmissive LCD that incorporates a backlight, however other LCD configurations are contemplated. Moreover, other display types may be additionally or alternatively incorporated such as, but not limited to, LED displays including OLED and AMOLED displays. The privacy filter 34 may include a polarized filter having a material that only permits light to pass through in a limited range of directions, thereby limiting visibility of the information displayed on the private display 32 to a limited viewable arc, as will be described in greater detail herein.
The one-way mirror 36 may be arranged to include or cooperate with a light source 40 disposed in the housing 12 generally adjacent to the one-way mirror 36 . The light source 40 may be configured to scatter light off of the one-way mirror 36 . In one example, the light source 40 may be a set of solid state light emitting diodes (LEDs) disposed around the inner housing 12 . In another example, the light source 40 may be an electroluminescent material that may be configured to illuminate upon application of a voltage. Other configurations are contemplated. The public display 38 may be a transmissive LCD, for example. Other LCD configurations are contemplated. As will become appreciated from the following discussion, the display assembly 20 may be configured to display some information on the public display 38 and other information on the private display 32 . The display assembly 20 is configured to only allow the information displayed on the private display 32 to be viewable through a first viewable arc 46 by the user 30 . Other information displayed on the public display 38 may be viewable through a second viewable arc 48 such as by bystanders 52 and 54 . In this way, the display assembly 20 of the display device 10 may be configured to display sensitive information such as bank account numbers, passwords, and the like on the private display 32 such that the information may only be viewable by the user 30 through the first viewable arc 46 .
Referring now to FIG. 3 , an example of the display device 10 is shown in more detail. The display device 10 may include a user interface module 60 , a processor 62 , a communication module 64 , and a memory 66 . The user interface module 60 can include and control the display assembly 20 . Specifically, the user interface module 60 may generate or manipulate the information to be displayed to the user 30 via the display assembly 20 . The user interface module 60 may receive information from and communicate information to the processor 62 and the communication module 64 . While the display device 10 is shown as generally including the user interface module 60 , the processor 62 , the communication module 64 , and memory 66 , the display device 10 may also include other suitable computing components.
In general, a user 30 may communicate with the display device 10 via the user interface 14 including the display assembly 20 and the buttons 22 . In particular, the display assembly 20 may display information to the user 30 and receive input from the user 30 . The processor 62 may control most operations of the display device 10 . The processor 62 , therefore, may communicate with each of the user interface module 60 , the communication module 64 , and the memory 66 . For example, the processor 62 may perform tasks such as, but not limited to, loading/controlling an operating system of the display device 10 , loading/configuring communication parameters for the communication module 64 and controlling various parameters of the user interface module 60 . The processor 62 may also perform the loading/controlling of software applications, the controlling of memory storage/retrieval operations, e.g., for loading of the various parameters.
The processor 62 may interpret information input by the user 30 through the user interface 14 . The processor 62 may determine a public display portion and a private display portion. The processor 62 may communicate a public display signal 70 to the public display 38 and communicate a private display signal 72 to the private display 32 . In this regard, the processor 62 sends some information identified as suitable for public viewing to be displayed on the public display 38 while sending other information identified as sensitive or private for viewing only by the user 30 to be displayed on the private display 32 . As used herein the term “information” may be characters including letters, numbers, signs and the like. The information may also include graphics, pictures, symbols and the like.
According to one example of the present disclosure, the processor 62 may determine whether certain information is dedicated for sending to the public display 38 as compared to other information that is dedicated to sending to the private display 32 based upon an indicator associated with such information. The indicator may be a tag associated with a given field of information that may identify a password or other protected entry field (HTML5, etc.) that may be associated with protected or otherwise sensitive data. It is contemplated that a user 30 may additionally or alternatively assign information to be displayed on the private display 32 manually. Such information may also be associated with a private indicator through the settings of the display device 10 . In this regard, a privacy setting manager may be incorporated that provides a user with options for assigning a private indicator to certain information. The content of the information can be contact information, location information, account information, browser information or any other information the user deems as private. In other examples, a user may assign a private indicator to individual applications. For example, a user may identify particular applications, such as banking applications for example, that can be selected for all or partial display on the private display 32 . Additionally, the privacy settings manager may include a privacy setting mode that a user can select to associate subsequent information for display on the private display 32 .
The communication module 64 controls communication between the display device 10 and other devices. For example only, the communication module 64 may provide for communication between the display device 10 and other users via a cellular telephone network, and/or between the display device 10 and a wireless network. Examples of wireless networks include, but are not limited to, the Internet, a wide area network, a local area network, a satellite network, a telecommunications network, a private network, and combinations of these.
With reference now to FIGS. 4 and 5 , one example of using the display assembly 20 according to the present disclosure will be described. At the outset, FIG. 4 illustrates the display assembly 20 as viewed by the user 30 through the first viewable arc 46 ( FIG. 2 ). Specifically, the display assembly 20 includes a first field 80 , a second field 82 , and a third field 84 . The first field 80 includes “bank.example.com” communicated by the processor 62 through the public display signal 70 to the public display 38 . Similarly, the second field 82 includes “Account Number:” communicated through the public display signal 70 to the public display 38 . The third field 84 includes “123456789” communicated through the private display signal 72 to the private display 32 . Notably, the third field 84 is still viewable by the user 30 through the first viewable arc 46 . Explained further, the user 30 is able to view through the privacy filter 34 to the private display 32 when the user 30 is in a position within the first viewable arc 46 illustrated in FIG. 2 . It will be appreciated that the public display 38 will be transparent in corresponding areas directly above the third field 84 , or more generally in areas above fields dedicated for private viewing.
With particular attention now to FIG. 5 , the display assembly 20 is configured to display all of the first, second, and third fields 80 , 82 , and 84 as explained above with respect to FIG. 4 . However, in FIG. 5 , the resulting view is of a viewable arc outside of the first viewable arc 46 . For example, the view that results in FIG. 5 may be that of the second viewable arc 48 , outside of the first viewable arc 46 as viewed by one of the bystanders 52 or 54 . In this regard, the information viewable by another bystander that is occupying a position outside of the first viewable arc 46 will view the third field 84 as blacked out or otherwise obscured. The information displayed in the third field 84 (“123456789”) is not viewable by anyone looking toward the display assembly 20 from a viewing angle outside of the first viewable arc 46 . As can be appreciated, the privacy filter 34 disposed intermediate the public display 38 and the private display 32 will preclude viewing of any information displayed on the private display 32 (or in this case, the third field 84 ).
Referring now to FIG. 6 , an example of a technique 100 for using the display device 10 according to one example of the present disclosure is illustrated. At 102 , the processor 62 receives information to display from the user interface module 60 . At 104 , the processor 62 determines from the information, a public display portion and a private display portion. At 106 , the processor 62 communicates the public display signal 70 to the public display 38 . At 108 , the processor 62 communicates the private display signal 72 to the private display 32 .
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known procedures, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “and/or” includes any and all combinations of one or more of the associated listed items. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
As used herein, the term module may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); an electronic circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor or a distributed network of processors (shared, dedicated, or grouped) and storage in networked clusters or datacenters that executes code or a process; other suitable components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip. The term module may also include memory (shared, dedicated, or grouped) that stores code executed by the one or more processors.
The term code, as used above, may include software, firmware, byte-code and/or microcode, and may refer to programs, routines, functions, classes, and/or objects. The term shared, as used above, means that some or all code from multiple modules may be executed using a single (shared) processor. In addition, some or all code from multiple modules may be stored by a single (shared) memory. The term group, as used above, means that some or all code from a single module may be executed using a group of processors. In addition, some or all code from a single module may be stored using a group of memories.
The techniques described herein may be implemented by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions that are stored on a non-transitory tangible computer readable medium. The computer programs may also include stored data. Non-limiting examples of the non-transitory tangible computer readable medium are nonvolatile memory, magnetic storage, and optical storage.
Some portions of the above description present the techniques described herein in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. These operations, while described functionally or logically, are understood to be implemented by computer programs. Furthermore, it has also proven convenient at times to refer to these arrangements of operations as modules or by functional names, without loss of generality.
Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Certain aspects of the described techniques include process steps and instructions described herein in the form of an algorithm. It should be noted that the described process steps and instructions could be embodied in software, firmware or hardware, and when embodied in software, could be downloaded to reside on and be operated from different platforms used by real time network operating systems.
The present disclosure also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored on a computer readable medium that can be accessed by the computer. Such a computer program may be stored in a tangible computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, application specific integrated circuits (ASICs), or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. Furthermore, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability.
The algorithms and operations presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatuses to perform the required method steps. The required structure for a variety of these systems will be apparent to those of skill in the art, along with equivalent variations. In addition, the present disclosure is not described with reference to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present disclosure as described herein, and any references to specific languages are provided for disclosure of enablement and best mode of the present invention.
The present disclosure is well suited to a wide variety of computer network systems over numerous topologies. Within this field, the configuration and management of large networks comprise storage devices and computers that are communicatively coupled to dissimilar computers and storage devices over a network, such as the Internet.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. | A display device can include a housing, a processor, and a display assembly. The processor can be arranged within the housing. The display assembly can be operably coupled to the processor and arranged within the housing. The display assembly can include a first display, a privacy filter, and a second display. The first display can output a first portion of the display. The second display can output a second portion of the display. The privacy filter and the first and second displays can be arranged such that the first portion of the display assembly is filtered by the privacy filter to be viewable in a first viewable arc. The second portion of the display assembly can be viewable in a second viewable arc that is different than the first viewable arc. The first and second displays can be LCD's. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an energy-saving aerodynamic vehicle. More particularly, the invention relates to a vehicle having a structure which causes the fluid (gaseous;liquid) through which the vehicle moves to flow along the sides of the vehicle, and to minimize the flow of such fluid over the top of such vehicle.
The term "vehicle" as used herein is intended to include all types of vehicles which move on land, sea, air, amphibious type, and any other type of vehicle which moves through a fluid medium.
2. Description of Relevant Art
The prior art is replete with all types of attachments for vehicles which are intended to reduce air drag of the vehicle during movement. Such prior art is exemplified by the following:
Weems U.S. Pat. No. 452,741;
Adams U.S. Pat. No. 490,057;
Taylor U.S. Pat. No. 3,451,499;
Edwards U.S. Pat. No. 3,797,879;
U.S. Pat. No. 3,815,948;
Hobbensiefken U.S. Pat. No. 3,929,202;
Servala et al U.S. Pat. No. 3,945,677;
Ensor U.S. Pat. No. 4,095,835;
Greene et al U.S. Pat. No. 4,206,715;
Canning U.S. Pat. No. 4,210,354;
Stone U.S. Pat. No. 4,221,423;
Goize U.S. Pat. No. 4,239,253;
Keedy U.S. Pat. No. 4,257,641;
U.S. Pat. No. 4,269,443;
U.S. Pat. No. 4,269,444;
Front U.S. Pat. No. 4,313,635; and
Alford U.S. Pat. No. 4,355,834.
The prior art attempts to reduce air resistance and air drag and for streamlining the vehicle are, for the most part, complicated, uneconomical, unsightly and/or impractical.
The present invention effectively overcomes the foregoing problems and disadvantages attendant conventional techniques.
SUMMARY OF THE INVENTION
The present invention provides an energy-saving vehicle, comprising a vehicle which includes a first aerodynamic means for urging the fluid through which the vehicle moves to flow only along the sides of the vehicle, and for minimizing the flow of such fluid over the top of the vehicle and under the vehicle.
The energy-saving vehicle also includes an enclosure for a driver of the vehicle. The first aerodynamic means has its forward most portion positioned at or forwardly of the forward most portion of the enclosure for the driver of the vehicle.
It is an object of the present invention to provide an improved aerodynamic shape and means of producing commercial trucks and campers with reduced aerodynamic drag coefficients.
Another object of the present invention is to split the air flow by a vertical edge in order to divide the air flow horizontally and thus reduce the force to approximately 1/2 the force necessary to displace the air flow vertically.
It is another object of the present invention to provide energy-saving vehicles which would, based on a million vehicle truck fleet, save billions of gallons of fuel per year.
The above and further objects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments of the invention, when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a perspective view of a first embodiment of the invention.
FIG. 2 depicts a perspective view of a second embodiment of the invention.
FIG. 3 depicts a perspective view of a third embodiment of the invention.
FIG. 4 depicts a perspective view of a fourth embodiment of the invention.
FIG. 5 depicts a perspective view of a fifth embodiment of the invention.
FIG. 6 depicts a perspective view of a sixth embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1, there is shown a vehicle 10. The vehicle 10 includes wheels 12, a cab or driver enclosure 14 having a windshield 15 and side windows 16, to enable a driver in the cab 14 to view both the exterior of the vehicle 10 and path of travel of the vehicle 10 while steering said vehicle 10.
The vehicle 10 includes a canopy 18 which is wedge shaped. The canopy 18 has a first canopy side 20 and second canopy side 21 which converge to form a canopy edge 22 forward of the driver enclosure 14. The canopy 18 overhangs the driver enclosure roof 24 with the vertical canopy edge 22 preferably lying forwards of the cab 14 and along an imaginary line which preferably bisects the front end of the cab encosure 14.
The vehicle 10 may also include a trailer 28, which trails behind and is higher than the cab 14.
The vehicle 10 moves on wheels 12 through a fluid medium such as air. The canopy edge 22 serves to urge the fluid medium primarily along the sides 23 of the vehicle. However, a substantial portion of air can still flow over the top of the canopy 30. This overflow can result in turbulence at the top 30 which is generally undesirable because turbulence results in drag. To the extent, however, that the air is urged primarily along the sides of the canopy 20 and 21, turbulence is decreased, and so is drag.
The rear of the canopy 36 should be wide so the canopy 18 directs air towards the vehicle sides. Generally the rear of the canopy 36 need be no wider than the width of the trailer front, and the canopy rear can be narrower.
The vehicle 10 depicted in FIG. 2 differs from the vehicle 10 in FIG. 1 by the addition of a visor 32 which is attached to, rests on, and extends over and beyond canopy sides 20 and 21.
Drag forces are generated at least partly by low-pressure, vacuum conditions on localized vehicle surfaces as moving air particles separate from the vehicle surface. In conventional vehicles, air separation effects occur at the grill-hood intersection, and also at the windshield-roof intersection. The air moving relative to the vehicle is not able to closely follow directional changes in the vehicle surface; consequently the air tends to separate from the vehicle surface, creating vacuum forces that exert drag effects on the vehicle.
Although other theories may be applicable, I hypothesize that visor 32 prevents air on windshield 15 from flowing upwardly over visor 32; consequently there is no air separation effect or resultant drag force. The air that would otherwise flow upwardly over cab roof 24, visor 32, or trailer top 28 is instead deflected laterally with the air flowing naturally from the vehicle front to vehicle side surfaces 23.
The enhanced air flow along the vehicle side surfaces due to the forward roof extension or visor 32 provides a more uniform air flow, thereby minimizing air separation effects on the vehicle side surfaces 23.
The FIG. 3 vehicle has a rear cargo section 34. The rear wall 36 of the canopy is attached to the front wall 38 of the cargo section 34.
A vertical, transparent extension 40 of the canopy 18 may descend to the hood 42 of the vehicle to further promote lateral air movement along the vehicle's sides 23 and to further deter the creation of turbulent air flow about the vehicle.
The extension is a transparent material such as plexiglass. A first wall 44 of the extension serves as a continuation of first canopy side 20 and second extension wall 46 serves as a continuation of second canopy side 21. The edge 22A formed by the convergence of first extension wall 44 and second extension wall 46 serves as a continuation of canopy edge 22.
First extension wall 44 may be hinged to first canopy side 20 and second extension wall 46 may be hinged to second canopy side 21. By rotation of first wall 44 and second wall 46 about their respective hinges, the extension 40 may be dropped into place in ront of windshield 16 of cab 14. Conversely, by rotation in the opposite direction, said first wall 44 and said second wall 46 may be raised above cab 14 and secured to canopy 18.
The vehicle 10 of FIG. 4 has a canopy 18 on cab roof 24. The absence of a gap between the canopy 18 and the cab roof 24 serves to facilitate the reduction of drag caused by air turbulence. The canopy 18 may be extended from a first position 48 to a fully extended position 50 or to any intermediate position. Preferably the visor 32 height may be placed at the same height as, or lower than trailer top 28 to minimize turbulence at the trailer top 28.
As depicted in FIG. 5, the extension is accomplished utilizing poles 52 which can telescope in an upward or downward direction. Any gaps 54 created by extending the canopy 18 in an upward direction may be filled utilizing a removable cover (not shown). Alternatively, the upward portion of the canopy 56 may overlap the lower portion of the canopy 58 so that no gaps are created as the upper portion of the canopy 56 moves either up or down.
The telescoping feature allows the canopy 18 to be extended or contracted to accommodate trailers of varying height and size, and to allow adjustment for different wind conditions.
Canopy 18 may also serve as a storage enclosure. A wall 58 of the canopy may have a door 60 provided therein for accessing the enclosure.
In FIG. 6, the embodiment depicted in the canopy 18 includes driver enclosure 14. There is no gap between driver enclosure 14 and canopy 18 thus, air turbulence is reduced. Additionally, base 62 of the canopy slopes in a downward, forward direction. Fenders 64 are flat surfaces which rise upwardly from the forward most area of the vehicle to a plateau 66 contiguous with and perpendicular to canopy side walls. Air turbulence is reduced because there is no grill-hood interface or canopy-cab section gap with this design.
Although there have been described what are at present considered to be the preferred embodiments of the invention, it will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative, and not restrictive. The scope of the invention is indicated by the appended claims rather than by the foregoing description. | Vehicle has wedge shaped frontal structure for urging the fluid through which it travels to pass solely along the vehicle side with minimal or zero turbulence. A visor on the structure further prevents the fluid contacting the front of the vehicle from flowing upwardly and across the vehicle's roof in turbulent fashion. The wedge may be placed above the driver enclosure, the forward vertical edge formed by the convergence of the wedge sides, being forwards of the driver enclosure. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application, filed under 35 U.S.C.§111(a), of PCT Application No. PCT/JP2007/055389, filed Mar. 16, 2007, the disclosure of which is herein incorporated in its entirety by reference.
FIELD
[0002] The embodiments discussed herein are related to a Web service control program, a Web service control apparatus, a Web service control method, and a relay program that control communication between a consumer and a provider in a Web service.
BACKGROUND
[0003] In recent years, a new technical trend has emerged in an SOA (Service Oriented Architecture) that designs a system based on loosely-coupled services. In a conventional Web service system, a provider side estimates the amount of Web service requests that a consumer side will transmit and, based on its peak value, determines the total capacity of servers to be prepared.
[0004] Further, electronic negotiation technology such as WS (Web Service)—Agreement specification standardized by GGF (Global Grid Forum) has been proposed.
[0005] As a conventional art relating to the present invention, there is known a method and apparatus that manage business interaction between the parties. In addition, there is known a method that provides end-to-end service quality negotiation procedure for a distributed multimedia application.
Patent Document 1: Japanese Laid-open Patent Publication No. 2006-146892
Patent Document 2: International Publication Pamphlet No. 2004-537187
[0006] However, in a conventional Web service system, an operator on the provider side estimates the Web service request amount without acquiring a clear utilization plan of each of customers on the consumer side. Further, in the case where the provider-side operator has failed in making the estimation of the Web service request amount, he or she needs to rearrange the installed capacity. Since these operations are carried out by the operator, man-hour may rise, as well as, there may be a risk of errors. Further, in the conventional Web service system, the provider-side operator conducts hearings with customers for planning addition of the installed capacity. However, in the case where the number of customers is greatly increased or the frequency of the hearings is increased, it becomes difficult for the operator to make the estimation.
[0007] Further, there may be a case where the provider side receives the number of requests exceeding the installed capacity. The provider cannot prevent such a case from occurring for technical and contractual reasons, so that servers provided on the provider side may become overloaded and even unstable.
[0008] Further, in the case of a Web service, unlike the case of a scientific computation service where estimation of required resources is easy, it is difficult to estimate the required resources due to existence of a case where the number of requests suddenly increases.
SUMMARY
[0009] According to a aspect of the present invention, a computer readable storage medium stores a Web service control program that allows a computer to execute a process comprising: receiving from a consumer of a Web service a reservation request for a reservation which reserves the Web service and defines a condition for Web service requests for the Web service, the condition including a shortest time interval between Web service requests for the Web service; acquiring a state of a server that can execute the Web service; determining whether or not to accept the reservation according to the condition and the state of the server; accepting the reservation when it is determined to accept the reservation; determining, when receiving from the consumer a Web service request for the Web service after the accepting, a time interval between the received Web service request and a Web service request prior to the received Web service request; determining whether or not the received Web service request satisfies the condition; and transferring, when it is determined that the received Web service request satisfies the condition, the received Web service request to the server.
[0010] The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims.
[0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a block diagram depicting an example of a configuration of a Web service system according to an embodiment of the present invention;
[0013] FIG. 2 is a sequence diagram depicting an example of operation of the Web service system according to the present embodiment;
[0014] FIG. 3 is a table depicting an example of the content of a price list according to the present embodiment;
[0015] FIG. 4 is a table depicting a first example of a utilization plan table according to the present embodiment;
[0016] FIG. 5 is a table depicting a second example of the utilization plan table according to the present embodiment;
[0017] FIG. 6 is a view depicting an example of the content of a reservation request according to the present embodiment;
[0018] FIG. 7 is a view depicting an example of the content of a reservation reply according to the present embodiment;
[0019] FIG. 8 is a table depicting an example of the content of a provider reservation information table according to the present embodiment;
[0020] FIG. 9 is a table depicting an example of the content of a server information table according to the present embodiment;
[0021] FIG. 10 is a table depicting an example of the content of a consumer reservation information table according to the present embodiment;
[0022] FIG. 11 is a table depicting an example of the content of the passage determination information table according to the present embodiment;
[0023] FIG. 12 is a block diagram depicting an example of a configuration of a Web service system according to a second embodiment;
[0024] FIG. 13 is a sequence diagram depicting an example of operation of the Web service system according to the second embodiment;
[0025] FIG. 14 is a graph depicting an example of a service profile according to the second embodiment;
[0026] FIG. 15 is a sequence diagram depicting an example of operation of a Web service system according to a third embodiment;
[0027] FIG. 16 is a block diagram depicting an example of operation of a conventional load balancer;
[0028] FIG. 17 is a table depicting an example of a cookie table retained by the conventional load balancer;
[0029] FIG. 18 is a view depicting an example of a Web service request according to a fourth embodiment;
[0030] FIG. 19 is a flowchart depicting an example of operation of a CK according to the fourth embodiment;
[0031] FIG. 20 is a flowchart depicting an example of operation of a CC according to a fifth embodiment;
[0032] FIG. 21 is a flowchart depicting an example of operation of a CK according to the fifth embodiment;
[0033] FIG. 22 is a time chart depicting an example of the time distribution of Web service requests received by the server in the case where the number of Web service requests per unit time is used as a measure of the Web service request amount;
[0034] FIG. 23 is a time chart depicting an example of the time distribution of the Web service requests received by the server in the case where the MSI according to the fifth embodiment is used; and
[0035] FIG. 24 is a graph depicting an example of a service profile according to the fifth embodiment.
DESCRIPTION OF EMBODIMENTS
[0036] An embodiment of the present invention will be described below with reference to the accompanying drawings.
First Embodiment
[0037] A Web service in a Web service system according to the present embodiment is a service using Web Service/SOAP (Simple Object Access Protocol), REST (Representational State Transfer), HTTP (HyperText Transfer Protocol), and the like.
[0038] Further, in the present embodiment, a Web service system offering a stamp duty service will be described. In the stamp duty service, a provider side receives from a consumer side an electronic receipt issued through an electronic clearing system and appends a stamp duty (time stamp) to the electronic receipt. The consumer side that has received the service makes payment, to the provider, of a service fee charged by the provider together with the amount to be paid to the country. Hereinafter, this service is represented by a service type “TSService”, and functions offered by this service are represented by “stamp” and “check”.
[0039] First, a configuration of a Web service system according to the present embodiment will be described.
[0040] FIG. 1 is a block diagram depicting an example of a configuration of a Web service system according to the present embodiment. The Web service system has, on the consumer side, a CC (Contract Client) 11 (relay apparatus), one or more clients 12 , a planning terminal 13 , and a terminal 14 installed in each department and has, on the provider side, a CM (Contract Manager) 21 , a CK (Contract Keeper) 22 , one or more server 23 , an operator terminal 24 , and a provider terminal 31 . The CM 21 , CK 22 , server 23 , and operator terminal 24 are installed within a data center.
[0041] The client 12 is connected to the CC 11 . The CC 11 is connected to the CM 21 and CK 22 through a network 1 . The CC 11 and client 12 may be incorporated in one apparatus. The planning terminal 13 is connected to the CM 21 through the network 1 . The terminal 14 for each department is connected to the planning terminal 13 . The CM 21 is connected to the CK 22 and server 23 . The CK 22 is connected to the server 23 . The operator terminal 24 is connected to the CM 21 and server 23 .
[0042] The terminal 14 for each department determines service utilization plan in each department on the consumer side. The planning terminal 13 compiles the service utilization plan on the consumer side. The client 12 executes a client program to access the Web service. The operator terminal 24 , which is operated by an operator on the provider side, monitors and controls the server 23 . The provider terminal 31 , which is operated by a person in charge on the provider side, inputs a price list and the like.
[0043] Next, operation of the Web service system according to the present embodiment will be described.
[0044] FIG. 2 is a sequence diagram depicting an example of operation of the Web service system according to the present embodiment. This sequence diagram depicts operations of the terminal 14 for each department, client 12 , planning terminal 13 , and CC 11 on the consumer side and operations of the CM 21 , CK 22 , node, operator terminal 24 , and provider terminal 31 on the provider side. On the provider side, the node denotes one or more servers 23 allocated to a service. The Web service system performs Web service reservation processing (S 11 to S 31 ) and Web service execution processing (S 32 to S 43 ).
[0045] Next, the Web service reservation processing will be described.
[0046] The provider terminal 31 transmits a price list created by a sales representative on the provider side to the CM 21 (S 11 ). The CM 21 transmits the received price list to the planning terminal 13 (S 12 ). The planning terminal 13 transfers the received price list to the terminal 14 for each department (S 13 ).
[0047] A description will be given here of the price list. FIG. 3 is a table depicting an example of the content of the price list according to the present embodiment. This price list depicts the price of the abovementioned “stamp” service of “TSService”. The price list depicts a list of segments of service use time period and unit price of the service for each time period segment. In the “time period” item, the date (year, month and day) representing the service start day and service end day and the number of days from the service start day to service end day are recorded. Further, the time period segment is classified according to the level of the Web service request amount (for example, the time segment is classified into “off season” and “on season” groups). In the “unit price” item, price (yen/case) per one electronic receipt (one request) is recorded. Further, the list may include a maximum number of electronic receipts which represents the upper limits of the number of electronic receipts that can be reserved. The unit price may be classified into reservation time unit price representing the price to be paid at the reservation time and execution time price unit representing the price to be paid at the execution time.
[0048] Then, a person in charge of each department designs service utilization plan of his or her own department based on the received price list and past performance table and the terminal 14 for each department notifies the planning terminal 13 of the service utilization plan (S 14 ).
[0049] The planning terminal 13 then compiles the utilization plans from respective departments to thereby create a utilization plan table and transmits the table to the CC 11 (S 15 ).
[0050] A description will be given here of the utilization plan table. FIG. 4 is a table depicting a first example of the utilization plan table according to the present embodiment. This utilization plan table depicts a list of segments of service use time period, as well as, total amount of reservation requests, increase in reservation requests, unit price, and estimated amount for each time period segment.
[0051] In the “time period” item, the same values as those in the price list are recorded. The “total amount of reservation requests” item represents the total number of Web service requests to be reserved, and “increase in reservation requests” item represents the number of Web service requests to be newly reserved. In the “total amount of reservation requests” item, the total amount of reservation requests before update [case] representing the total amount of requests in a past utilization plan table and total amount of reservation requests after update [case] representing the total amount of requests up to this time are recorded. In the “increase in reservation requests” item, increase in the amount of reservation requests [case] and increase in the amount of reservation requests per one day [case/day] are recorded. In the “unit price” item, the same values as those in the price list are recorded. In the “estimated amount” item, increase in the charge to be paid for the service (increase in reservation requests×unit price) is recorded. The utilization plan table of FIG. 4 is a utilization plan table that has been created first. Therefore, all values for the total amount of reservation requests before update are 0, and the total amount of reservation requests after update and increase in reservation requests are equal to each other.
[0052] The planning terminal 13 can update the utilization plan table even after transmitting the utilization plan table to the CC 11 and transmit the latest utilization plan in the form of a difference from the immediately preceding utilization plan table. FIG. 5 is a table depicting a second example of the utilization plan table according to the present embodiment. The utilization plan table of FIG. 5 is one that has been created after the utilization plan table of FIG. 4 . Therefore, the total amount of reservation requests before update of FIG. 5 corresponds to the total amount of reservation requests after update of FIG. 4 , and the total amount of reservation requests after update of FIG. 5 is a value obtained by adding the increase in the number of reservation requests to the total amount of reservation requests before update.
[0053] The CC 11 then starts electronic negotiation with the CM 21 for service reservation (S 21 ). The CM 21 prepares authentication processing and the like according to a specification of the electronic negotiation (S 22 ). The CC 11 transmits a reservation request to the CM 21 (S 23 , S 25 ). Upon receiving the reservation request, the CM 21 performs reservation determination processing to make determination whether it accepts or rejects the reservation request based on a reservation condition and received reservation request and reservation reply processing to transmit a reservation reply to the CC 11 in accordance with a result of the determination (S 24 , S 26 ).
[0054] Each of the reservation request and reservation reply is a machine-readable agreement conforming to Agreement document format defined in a specification (e.g., GGF WS-Agreement specification) of the electronic negotiation and is described in XML (Extensible Markup Language) or the like. When a reservation reply indicating “acceptance” is transmitted from the CM 21 to CC 11 , the relevant agreement is completed. In this agreement, the provider side represents to the consumer side that it can reject the Web service request different from the reserved request condition.
[0055] A description will be given here of the content of the reservation request. FIG. 6 is a view depicting an example of the content of the reservation request according to the present embodiment. The reservation request describes “target service”, “reservation time period”, and “request amount”. The “target service” is represented by service type (service) and function (term). In this example, the service type is TSService, and function is stamp. The “reservation time period” is represented by start time and end time. The “request amount”, which is a Web service request amount (processing amount), is represented by unit and numerical value. In this example, the unit is RPS (Request/sec), and numerical value is 20.
[0056] A description will next be given of the content of the reservation reply. FIG. 7 is a view depicting an example of the content of the reservation reply according to the present embodiment. The reservation reply describes “target service”, “reservation time period”, “request amount”, and “reception state”. Each of the “target service”, “reservation time period”, and “request amount” has the same value as that of the corresponding reservation request. The “reception state” assumes two values of “accepted” indicating that a reservation request has been accepted and “rejected” indicating that a reservation request has been rejected depending on the result of the reservation determination processing. In the case where a reservation request has been accepted, a reservation described in the reservation request is made and thereby agreement is completed. Then, an agreement ID is given to the agreement by the CM 21 and is described in the reservation reply. In this example, the “reception state” is “accepted” and thus the agreement ID has been described.
[0057] The CM 21 retains a provider reservation information table and, when the reservation is established, registers information of the established reservation in the provider reservation information table. FIG. 8 is a table depicting an example of the content of the provider reservation information table according to the present embodiment. The provider reservation information table has provider reservation information which is information relevant to each established reservation. The provider reservation information has items of “agreement ID”, “request source”, “start time”, “end time”, “target service”, “required capacity”. The “agreement ID” has the same value as that of the “agreement ID” in the reservation reply. The “reply source” is the name of the consumer side. The reservation time period (“start time” and “end time”) and “target service” have the same value as those described in the accepted reservation request. The “required capacity” has the same value as that of the “request amount” described in the accepted reservation request and represents the processing capacity required for executing a reserved service.
[0058] The CM 21 sets the reservation time period described in the received reservation request as a coverage time period and, based on the coverage time period and provider reservation information table, creates a server information table. FIG. 9 is a table depicting an example of the content of the server information table according to the present embodiment. The server information table depicts server information relevant to each server 23 . The server information represents a state of the server 23 in the coverage time period and has items of “retained capacity [RPS]”, “reserved capacity [%]”, and “remaining capacity [%]”. The “retained capacity” is a value representing the maximum value of the processing capacity of the server by the amount of Web service requests on a per-service basis. In this example, stamp of TSService and check of TSService are set as the target service. The “reserved capacity” is a value representing the total sum of the processing capacities that have been reserved in the coverage time period as a ratio [%] relative to the retained capacity. The “remaining capacity”, which is obtained by (100%—reserved capacity), represents the processing capacity that has not been reserved as a ratio [%] relative to the retained capacity.
[0059] The CM 21 then determines whether the content of the reservation request satisfies the reservation condition. In the case where the reservation condition is satisfied, the CM 21 registers the content of the reservation request as the provider reservation information and sends back a reservation reply indicating “accepted” to the client 12 . On the other hand, in the case where the reservation condition is not satisfied, the CM 21 sends back a reservation reply indicating “rejected” to the client 12 . The reservation condition specifies that the request amount in the reservation request be not more than the remaining capacity in the server information table. That is, in the case where the request amount of the received reservation request exceeds the remaining capacity, the CM 21 sends back the reservation reply indicating “rejected”.
[0060] Alternatively, in the case where reservation preparation time period is set and where the CM 21 sets a value obtained by (start time of reservation time period in reservation request—reservation preparation time period) as reservation deadline of the reservation request, the reservation condition may specify that the current time falls within the reservation deadline of the reservation request. That is, in the case where the current time at the time point when receiving the reservation request passes the reservation deadline set for the reservation request, the CM 21 sends back a reservation reply indicating “rejected”.
[0061] The CC 11 retains a consumer reservation information table and, when receiving a reservation reply indicating “accepted”, registers the content included in the reservation reply in the consumer reservation information table. FIG. 10 is a table depicting an example of the content of the consumer reservation information table according to the present embodiment. The consumer reservation information table has consumer reservation information which is information relevant to each reservation reply indicating “accepted”. The consumer reservation information has items of “agreement ID”, reservation time period (“start time” and “end time”), “target service”, and “required capacity” which have the same values as those of the provider reservation information.
[0062] The CM 21 then transmits the provider reservation information to the operator terminal 24 (S 31 ). The operator refers to the provider reservation information displayed on the operator terminal 24 to determine allocation of the nodes.
[0063] Next, the Web service execution processing will be described.
[0064] According to given provider reservation information that has been received from the CM 21 , the operator terminal 24 allocates, as nodes, the number of the servers 23 that can assure the required capacity corresponding to the relevant provider reservation information by the start time of the reservation time period thereof (S 32 ). Further, in the case where the reservation time period of the relevant provider reservation information has ended, the operator terminal 24 releases the number of nodes corresponding to the required capacity of the relevant provider reservation information.
[0065] Then, at the start time of the reservation time of the relevant provider reservation information, the CM 21 transmits the relevant provider reservation information to the CK 22 , and the CK 22 registers the content of the received provider reservation information in a passage determination information table (S 33 ). In the case where the current time has passed the end time of the reservation time period described in passage determination information, the CM 21 deletes the passage determination information from the passage determination information table.
[0066] A description will be given here of the passage determination information table. FIG. 11 is a table depicting an example of the content of the passage determination information table according to the present embodiment. The passage determination information table has passage determination information relevant to each received provider reservation information. The passage determination information is information for the CK 22 to determine the Web service request and has items of “agreement ID”, “request source”, “target service”, and “required capacity”, which have the same values as those of the provider reservation information. Further, the passage determination information table has only passage determination information whose reservation time period includes the current time.
[0067] Then, the client 12 uses a client program of the Web service to transmit a Web service request to a node through the CC 11 and CK 22 . In the case where the Web service request received from the client 12 satisfies an added condition, the CC 11 acquires the corresponding agreement ID from the client reservation information table and adds the agreement ID to the Web service request. Here, the added condition specifies that client reservation information in which the target service is the same as that specified in the Web service request and in which the reservation time period includes the current time exist in the client reservation information table.
[0068] The CK 22 receives the Web service request from the CC 11 and compares the Web service request with passage determination information table. In the case where the Web service request satisfies the passage condition, the CK 22 transfers the Web service request to the node (S 41 , S 42 ). In the case where the Web service request does not satisfy the passage condition, the CK 22 does not transfer the Web service request to the node but transmits a notification representing “rejected” to the client 12 (S 43 ). Here, the passage condition specifies that the passage determination information whose agreement ID is the same as the agreement ID of the received Web service request exist in the passage determination information table, and that the Web service request amount corresponding to the agreement ID be not more than the required capacity in the passage determination information.
[0069] Note that not only a single passage condition, but also a plurality of passage conditions may be set. In this case, different unit prices may be set for a plurality of passage conditions.
[0070] The node executes the service according to the Web service request received from the CK 22 and transmits a result of the execution to the client 12 . The CK 22 transmits the information of the Web service request that the CK 22 allows to pass therethrough to the CM 21 . The CM 21 tallies the information of the Web request service for each request source, each target service, and each time period segment and records it as an achievement information table. This achievement information table is used when the provider side charges the consumer side for a service fee.
[0071] According to the present embodiment, the CK 22 can reject a Web service request that does not satisfy a reserved condition. Further, by enabling the rejection of unfavorable Web service request, it is possible to prevent overload on the node, thereby enhancing stability of the system. Further, a reservation process concerning the Web service request amount can be automatically performed. Therefore, man-hour can significantly be reduced, making it possible to cope with a large number of consumers or frequent updates of reservation concerning the Web service request amount. Further, by setting the reservation preparation time period, it is possible to take some measures before the start of the reservation time period such as enhancement of facility.
[0072] Comparing with a Web service system using an autonomous system, the Web service system according to the present embodiment is easier to control and, further, facility arrangement and cost calculation are also easier.
Second Embodiment
[0073] In the present invention, a Web service system which includes servers laid out in a grid system will be described.
[0074] A configuration of a Web service system according to the present embodiment will first be described.
[0075] FIG. 12 is a block diagram depicting an example of a configuration of the Web service system according to the present embodiment. In FIG. 12 , the same reference numerals as those in FIG. 1 denote the same or corresponding parts as those in FIG. 1 , and the descriptions thereof will be omitted here. As compared to FIG. 1 , it can be seen that the Web service system of FIG. 12 newly includes a grid management server 25 . The CM 21 is connected to the CK 22 and grid management server 25 . The operator terminal 24 is connected to the grid management server 25 . A server group including a plurality of servers 23 constitutes a grid system and is controlled by the grid management server 25 . This server group can be allocated by the grid management server 25 as a node other than one of the Web service according to the present embodiment.
[0076] Next, operation of the Web service system according to the present embodiment will be described.
[0077] FIG. 13 is a sequence diagram depicting an example of operation of the Web service system according to the present embodiment. In FIG. 13 , the same reference numerals as those in FIG. 2 denote the same or corresponding parts as those in FIG. 2 , and the descriptions thereof will be omitted here. As compared to FIG. 2 , it can be seen that FIG. 13 depicts the operation of the grid management server 25 in place of the operation of the operator terminal 24 . The Web service system performs Web service reservation processing (S 11 to S 51 ) and Web service execution processing (S 52 to S 64 ).
[0078] Next, the Web service reservation processing will be described.
[0079] The operations in steps S 11 to S 26 are the same as those in the first embodiment. Then, in the case where the content of a reservation request satisfies a reservation condition, the CM 21 performs server reservation processing for the grid management server 25 . The server reservation processing is reservation processing for allocation of a server 23 that satisfies the reservation condition immediately before start of the reservation time period (S 51 ).
[0080] Next, the Web service execution processing will be described.
[0081] According to the server reservation processing, the grid management server 25 deploys the reserved server 23 as a node of the grid system at the time immediately before the start of the reservation time period (S 52 , S 62 ). When the reservation time period has ended, the grid management server 25 releases the allocated node.
[0082] In the server reservation processing, the CM 21 uses a stable operation threshold value previously set for each server 23 to determine the number of the servers 23 to be reserved. The stable operation threshold value is equal to the above-mentioned retained capacity. FIG. 14 is a graph depicting an example of a service profile according to the present embodiment. The service profile is a graph representing, on a coordinate system, the amount of Web service requests (horizontal axis [RPS]) and processing delay (RTT: Round Trip Time) (vertical axis [sec]) as a curved line. Further, the service profile is measured by a performance test performed before start of the operation of the Web service system. It can be seen from the service profile that at the time point when the Web service request amount exceeds the operation threshold value, the processing delay rapidly increases. Further, an error tolerance, which is a tolerance of error between the performance test time and actual operation time, is defined in this service profile and thus the stable operation threshold value (operation threshold value—error tolerance) is defined so that the Web service request amount does not exceed the operation threshold value.
[0083] In the server reservation processing, the CM 21 reserves the servers 23 based on the server information table such that the Web service request amount for each server 23 becomes not more than the stable operation threshold value (i.e., the Web request amount for each server 23 falls within a stable operation range). For example, assuming that the stable operation threshold vales of all the servers 23 are the same, the CM 21 reserves the smallest integer number of servers 23 but not less than a value obtained by dividing the total sum of required capacities to be reserved by the stable operation threshold value. More specifically, in the case where a first server 23 is reserved by a first reservation and the required capacity in the reservation time period of a second reservation exceeds the stable operation threshold value of the first server 23 , a second server 23 is additionally reserved. Consequently, the grid management server 25 allocates the first server 23 at the start time of the first reservation (S 52 ) and allocates the second server 23 at the start time of the second reservation (S 62 ).
[0084] The operations in steps S 53 , S 61 , S 63 , and S 64 are the same as those in steps S 33 , S 41 , S 42 , and S 43 in the first embodiment, respectively.
[0085] According to the present embodiment, the grid management server 25 can automatically allocate a node in accordance with a reserved required capacity. This reduces a load on the operator and eliminates estimation error of the facility arrangement, thereby enhancing stability of the Web service system. Further, the grid management server 25 can allocate a required node at a required timing, thereby enhancing the utilization ratio of the server 23 .
[0086] The plurality of servers 23 may be provided at a location other than the data center and may be provided at a plurality of locations in a distributed manner.
Third Embodiment
[0087] In the present embodiment, a Web service system which includes servers laid out in a grid system and controls a stable operation threshold value for each server will be described.
[0088] A configuration of the Web service system according to the present embodiment is the same as that according to the second embodiment.
[0089] Operation of the Web service system according to the present embodiment will be described.
[0090] FIG. 15 is a sequence diagram depicting an example of operation of the Web service system according to the present embodiment. In FIG. 15 , the same reference numerals as those in FIG. 13 denote the same or corresponding parts as those in FIG. 13 , and the descriptions thereof will be omitted here. As compared to FIG. 13 , it can be seen that steps S 65 to S 67 are additionally performed in FIG. 15 .
[0091] As described above, the initial value is set lower than a result of the test performed before the actual operation for the purpose of allowance. The operations in step S 11 to S 64 are performed in the similar manner as the second embodiment. Then, the grid management server 25 acquires a load index from a node that is in operation (S 65 , S 66 ) and transmits the acquired load index to the CM 21 (S 67 ). Examples of the load index (load information) include a CPU utilization, network usage, memory usage, and the like. Then, the CM 21 resets the error tolerance and stable operation threshold value based on the actual measurement values concerning the processing capacities, such as values in the provider reservation information table, values in the achievement information table, and load index. The CM 21 then compares a given actual measurement value concerning the processing capacity and current stable operation threshold value. In the case where the stable operation threshold value is considerably larger than the actual measurement value concerning the processing capacity (for example, the actual processing delay with respect to the actual Web service request amount is smaller than the processing delay obtained by the service profile), the CM 21 increases the stable operation threshold value. On the other hand, in the case where the stable operation threshold value is considerably smaller than the actual processing capacity (for example, the actual processing delay with respect to the actual Web service request amount is larger than the processing delay obtained by the service profile), the CM 21 reduces the stable operation threshold value. In the case where the CM 21 has reset the stable operation threshold value, it performs the server reservation processing once again.
[0092] In a conventional Web service system, it has been necessary to set the error tolerance to a larger value due to some undetermined factor for the purpose of allowance. According to the present embodiment, even in the case where the error tolerance has been set to a considerably larger value before start of the actual operation, review of the error tolerance can be made during the actual operation to thereby reduce the error tolerance to an adequate value. Accordingly, the stable operation threshold value becomes larger to reduce the facility arrangement, thereby reducing operation cost. On the other hand, in the case where the load index during the actual operation time becomes worse, the error tolerance is made larger to reduce the stable operation threshold value. This suppresses the Web service request amount to be reserved afterward, thereby prioritizing the stability of the Web service system.
Fourth Embodiment
[0093] In the present embodiment, a Web service system in which the agreement ID is added to plurality of protocol layer information in the Web service request transmitted from a consumer to a provider will be described.
[0094] In the case where the Web service uses SOAP in the above embodiments, the CC 11 adds the agreement ID in SOAP envelope of the Web service request, and the CK 22 detects the agreement ID added in the SOAP envelope. In this case, the CK 22 needs to perform syntax analysis of XML describing the SOAP envelope, which increases the load on the CK 22 .
[0095] The configuration of the Web service system according to the present invention is the same as that of the first embodiment except that the CK 22 is realized using a layer 7 switch. The operation of the Web service system according to the present embodiment is the same as that of the first embodiment except for the operation of CC 11 and CK 22 in steps S 41 , S 42 , and S 43 .
[0096] Here, operation of the layer 7 switch will be described by taking a conventional load balancer constituted by the layer 7 switch as an example.
[0097] FIG. 16 is a block diagram depicting an example of operation of a conventional load balancer. A load balancer 111 is connected to a client 112 and a plurality of servers 113 a , 113 b , and 113 c to relay communication between the client 112 and plurality of servers 113 a , 113 b , and 113 c . The client 112 transmits a first request to the server, and the server 113 a that has received the request transmits a replay into which cookie has been inserted to the client 112 . The replay transmitted at this time is, e.g., as follows.
[0098] HTTP/1.1 200 OK
Set-Cookie: Customer=“WILE_E_COYOTE”;
[0100] The client 112 that has received the cookie inserts the cookie into a series of http requests to be transmitted afterward to the server. The request transmitted at this time is added with, e.g., the following header.
[0101] POST/acme/pickitem HTTP/1.1
Cookie: Customer=“WILE_E_COYOTE”;
[0103] The load balancer 111 extracts the cookie from the request and reply to thereby sort the request including the cookie that has been received from the client 112 to a corresponding server 113 a based on the extracted cookie. FIG. 17 is a table depicting an example of the cookie table retained by the conventional load balancer. The load balancer 111 retains the identifier of a node that has issued cookie as represented by the cookie table. The load balancer 111 refers to the cookie table every time a request having a cookie header passes therethrough to determine a destination node.
[0104] The CK 22 in the present embodiment uses the passage determination information table in place of the abovementioned cookie table and uses the agreement ID in place of the cookie to thereby easily utilize the layer 7 switch.
[0105] In steps S 41 , S 42 , and S 43 , the client 12 uses a client program of the Web service to transmit a Web service request to a node through the CC 11 and CK 22 . In the case where the Web service request received from the client 12 satisfies an added condition, the CC 11 acquires the corresponding agreement ID from the client reservation information table and adds the agreement ID in the SOAP envelope of the Web service request. The CC 11 adds the agreement ID also to an HTTP header outside SOAP envelop of the Web service request.
[0106] FIG. 18 is a view depicting an example of the Web service request according to the present embodiment. In FIG. 18 , the agreement ID is inserted into the SOAP header as “SOAP-wedge-contract-id” and inserted into the HTTP header as “X-wedge-contract-id”.
[0107] Upon receiving the Web service request from the CC 11 , the CK 22 compares the Web service request with the passage determination information table. In the case where the Web service request satisfies the passage condition, the CK 22 transfers the Web service request to the node (S 41 , S 42 ). In the case where the Web service request does not satisfy the passage condition, the CK 22 does not transfer the Web service request to the node but transmits a notification representing “rejected” to the client 12 (S 43 ). Here, the passage condition specifies that the agreement ID exists in at least one of the HTTP header and SOAP envelope of the received Web service request, and that the Web service request amount corresponding to the agreement ID is not more than the required capacity in the passage determination information.
[0108] Next, operation of the CK 22 in steps S 41 , S 42 , and S 43 will be described. FIG. 19 is a flowchart depicting an example of operation of the CK according to the present embodiment. The CK 22 analyzes the HTTP header of the received Web service request (S 111 ) to determine whether the agreement ID in the passage determination information table is included in the HTTP header (S 112 ). In the case where the agreement ID is included (Yes in step S 112 ), the flow shifts to step S 115 . In the case where the agreement ID is not included (No in step S 112 ), the CK 22 analyzes the SOAP envelope of the received Web service request (S 113 ) to determine whether the agreement ID in the passage determination information table is included in the SOAP envelop (S 114 ). In the case where the agreement ID is included (Yes in step S 114 ), the flow shifts to step S 115 .
[0109] In the case where the agreement ID is not included (No in S 114 ), the CK 22 determines that the passage condition is not satisfied (S 121 ), and the flow is ended.
[0110] In the case where the agreement ID is included in step S 112 or S 114 , the CK 22 determines whether the passage determination information including the agreement ID exists in the passage determination information table (S 115 ). In the case where the passage determination information including the agreement ID does not exist in the passage determination information table (No in S 115 ), the flow shifts to step S 121 . In the case where the passage determination information including the agreement ID exists in the passage determination information table (Yes in S 115 ), the CK 22 determines whether the Web service request amount corresponding to the agreement ID is not more than the required capacity in the passage determination information (S 116 ). In the case where the Web service request amount corresponding to the agreement ID is more than the required capacity (No in S 116 ), the flow shifts to step S 121 . In the case where the Web service request amount corresponding to the agreement ID is not more than the required capacity (Yes in S 116 ), the CK 22 determines that the passage condition is satisfied, and the flow is ended.
[0111] HTTP syntax is simpler than XML syntax representing the SOAP envelope, so that less load is required to detect the agreement ID in the HTTP header than to detect the agreement ID in the SOAP envelope. In particular, the layer 7 switch is designed to effectively perform HTTP processing, so that the processing speed of the CK 22 can be increased.
[0112] The CC 11 adds the agreement ID both to the SOAP envelope and HTTP header of the Web service request in the present embodiment. However, according to the abovementioned operation of the CK 22 , even in the case where a CC that does not have a function of adding the agreement ID to the HTTP header exists, it is possible to transfer a Web service request to a node as long as the agreement ID has been added at least to the SOAP envelope of the Web service request.
[0113] Further, although the SOAP is used as a protocol for calling the Web service, and HTTP is used as a protocol for transmitting/receiving data in the lower layer than the SOAP in the above embodiment, any other suitable protocol may be used in place of the SOAP and HTTP. An example of a protocol that can be used in place of the SOAP includes CORBA (Common Object Request Broker Architecture) over http, RST, etc. Further, one or more of the abovementioned embodiments may be combined with the present embodiment.
[0114] According to the present embodiment, the CC 11 adds the agreement ID also to the HTTP header of the Web service request, and CK 22 detects the agreement ID in the HTTP header of the Web service request. With this configuration, the processing load of the CK 22 can be reduced, whereby the processing speed thereof can be increased. Further, by utilizing the existing layer 7 switch to constitute the CK 22 , cost can be reduced.
Fifth Embodiment
[0115] In the present embodiment, a Web service system in which a new measure is used as the amounts of Web service requests will be described.
[0116] In the above embodiments, the number of requests [RPS] (Request/sec) per unit time (one second) is used as a measure of the amount of Web service requests. However, even if this measure is used, there may be a case where it is difficult to achieve tight synchronization between the consumer and provider. Further, even if this measure is used, there may a case where stability of a server is impaired due to burstiness (a large amount of processing is required to be performed in a short period of time) of the Web service request. For example, under an agreement of 100 [RPS], a case where the consumer transmits 99 requests in the first 0.001 seconds of the agreement period may occur, which means the time distribution of the Web service requests is extremely biased.
[0117] In the present embodiment, MSI (Minimum Service Interval) is defined as a new measure of the amount of Web service requests. The MSI represents the lower limit value [msec] of the time interval of two consecutive Web service requests transmitted. In the reservation time of reserving Web service request amount x [msec], transmission of a Web service request made within x [msec] from transmission of the immediately preceding Web service request is rejected.
[0118] The configuration and operation of the Web service system according to the present invention are the same as those of the first embodiment except for the operation of CC 11 and CK 22 .
[0119] In this embodiment, the Web service request amount (request amount, retained capacity, remaining capacity, required capacity, operation threshold value, error tolerance, and stable operation threshold value) represented using the number of Web service requests per unit time as a measure in the above embodiments is represented by using the MSI.
[0120] Here, operation of the CC 11 and CK 22 in the time period for reservation in which the Web service request amount (request amount and required capacity) is set to x [msec] in terms of the MSI will be described.
[0121] First, operation of the CC 11 in steps S 41 , S 42 , and S 43 will be described. The CC 11 receives a Web service request from the client 12 and, when the Web service request satisfies the added condition, acquires a corresponding agreement ID from the client reservation information table and adds the acquired agreement ID to the Web service request.
[0122] The CC 11 has a transmission interval timer for measuring the time interval with which the CC 11 transmits the Web service requests for each agreement ID to the CK 22 and resets the transmission interval timer for a target agreement ID every time the CC 11 transmits the Web service request to the CK 22 . FIG. 20 is a flowchart depicting an example of operation of the CC according to the present embodiment. This flow starts when the CC 11 receives a Web service request from the Client 12 . The CC 11 determines whether the received Web service request satisfies a target service condition (S 131 ). The target service condition specifies that client reservation information corresponding to a target service in the received Web service request exists in the client reservation information table.
[0123] In the case where the target service condition is not satisfied (No in S 131 ), the CC 11 transmits a reply indicating the rejection of the Web service request to the client 12 (S 141 ), and this flow is ended. In the case where the target service condition is satisfied (Yes in S 131 ), the CC 11 determines whether the current time satisfies a reservation time period condition (S 132 ). The reservation time period condition specifies that the client reservation information in which reservation time period includes the current time exists in the client reservation information table.
[0124] In the case where the reservation time period condition is not satisfied (No in S 132 ), the flow shifts to step S 141 . In the case where the reservation time period condition is satisfied (Yes in S 132 ), the CC 11 determines whether the current time satisfies a transmission interval condition (S 133 ). The transmission interval condition specifies that the value of the transmission interval timer corresponding to the agreement ID included in the received Web service request is not less than x [msec]. In the case where the transmission interval condition is not satisfied (No in S 133 ), the flow returns to step S 132 where the CC 11 does not transmit the received Web service request but retains it. In the case where the transmission interval condition is satisfied (Yes in S 133 ), the CC 11 transmits the received Web service request to the CK 22 (S 142 ) and resets the transmission interval timer for the relevant agreement ID (S 143 ), and this flow is ended.
[0125] According to the operation of the CC 11 , the time interval with which the CC 11 transmits the Web service request to the CK 22 is inevitably not less than x [msec] of the reservation amount.
[0126] Next, operation of the CK 22 in steps S 41 , S 42 , and S 43 will be described. The CK 22 has a reception interval timer for measuring the time interval with which the CK 22 receives the Web service requests for each agreement ID and resets the reception interval timer for a target agreement ID every time the CK 22 receives the Web service request from the CC 11 . FIG. 21 is a flowchart depicting an example of operation of the CK according to the present embodiment. This flow starts when the CK 22 receives a Web service request from the CC 11 . The CK 22 determines whether the received Web service request satisfies an agreement ID condition (S 151 ). The agreement ID condition specifies that the passage determination information corresponding to an agreement ID included in the received Web service request exists in the passage determination information table.
[0127] In the case where the agreement ID is not satisfied (No in S 151 ), the CK 22 transmits a reply indicating the rejection of the Web service request to the CC 11 (S 161 ), and this flow is ended. In the case where the agreement ID condition is satisfied (Yes in S 151 ), the CK 22 determines whether the reception time of the Web service request satisfies a reception interval condition (S 153 ). The reception interval condition specifies that the value of the reception interval timer corresponding to the agreement ID included in the received Web service request is not less than x [sec]. In the case where the reception interval condition is not satisfied (No in S 153 ), the flow shifts to step S 161 . In the case where the reception interval condition is satisfied (Yes in S 153 ), the CC 11 transmits the received Web service request to a node corresponding to the agreement ID (S 162 ) and resets the reception interval timer for the relevant agreement ID (S 163 ), and this flow is ended.
[0128] According to the operation of the CK 22 described above, the CK 22 can reject the Web service request received with a time interval less than x [msec] of the request amount, and the time interval with which the CK 22 transmits the Web service request to the server is inevitably not less than x [msec] of the reservation amount.
[0129] Next, a case where the number of Web service requests [RPS] per unit time is used as a measure of the Web service request amount and case where the MSI [msec] is used as a measure thereof are compared. FIG. 22 is a time chart depicting an example of the time distribution of the Web service requests received by the server in the case where the number of Web service requests per unit time is used as a measure of the Web service request amount. In FIG. 22 , the horizontal axis represents time, and vertical axis represents the number of Web service requests. One “X” corresponds to one Web service request. Further, reservation time period is represented by an arrow. In the case where the reservation amount is represented by the number of Web service requests per unit time, bias may occur in the time distribution of the Web service requests, in which, for example, the Web service requests concentrate at the reservation time period start time.
[0130] FIG. 23 is a time chart depicting an example of the time distribution of the Web service requests received by the server in the case where the MSI according to the present embodiment is used as a measure of the Web service request amount. The notation employed here is the same as in the case where the reservation amount is represented by the number of Web service requests per unit time. In this case, the Web service requests reach the server evenly over the reservation time period.
[0131] Next, a case like the second or third embodiment where servers are laid out in a grid system and where the stable operation threshold value is set for each server will be described.
[0132] In the server reservation processing, the CM 21 uses a stable operation threshold value previously set for each server 23 to determine the number of the servers 23 to be reserved. The stable operation threshold value is equal to the above-mentioned retained capacity. FIG. 24 is a graph depicting an example of a service profile according to the present embodiment. The service profile is a graph representing, in the case where the Web service request amount is represented by the MSI, a correlation between the amount of Web service requests and processing delay as a curved line on a coordinate system having the horizontal axis representing MSI [msec] and vertical axis representing processing delay (RTT) [sec]. Further, the service profile is measured by a performance test performed before start of the operation of the Web service system. It can be seen from the service profile that at the time point when the MSI falls below the operation threshold value, the processing delay rapidly increases. Further, an error tolerance, which is a tolerance of error between the performance test time and actual operation time, is defined in this service profile and thus the stable operation threshold value (operation threshold value+error tolerance) is defined so that the MSI does not fall below the operation threshold value.
[0133] In the present embodiment, in the server reservation processing described in the third embodiment, the CM 21 reserves the servers 23 based on the server information table such that the MSI for each server 23 becomes not less than the stable operation threshold value (i.e., the MSI for each server 23 falls within a stable operation range). For example, assuming that the stable operation threshold vales of all the servers 23 are the same, the CM 21 reserves the smallest number of servers 23 but not less than a value obtained by multiplying the total sum of the inverse numbers of the MSIs corresponding to the required capacity to be reserved by the stable operation threshold value. More specifically, in the case where a first server 23 is reserved by a first reservation and the total sum of the inverse number of the MSIs corresponding to the required capacity for the first and a second reservation exceeds the inverse number of the stable operation threshold value of the first server in the reservation time period of the second reservation, a second server 23 is additionally reserved.
[0134] According to the present embodiment, by using the MSI as a measure of the Web service request amount, it is possible to avoid burstiness of the Web service request amount received by the provider, thereby improving stability of the Web service system. Further, as compared to the case where the number of Web service requests is used as a measure of the Web service request amount, it is possible to make simpler the logic of determination on whether the CK 22 allows the Web service request to pass therethrough, thereby reducing the load on the CK 22 . As a result, stability of the CK 22 can be improved, or cost of the CK 22 can be reduced. Further, it is possible to make simpler the definition of the Web service request amount in an agreement.
[0135] Further, a combination with the above embodiments can easily be realized.
[0136] The CC 11 , CM 21 , and CK 22 according to the abovementioned embodiment can easily be applied to an information communication apparatus to thereby increase performance thereof. Examples of the information communication apparatus include a server, a router, a switch, and the like.
[0137] Further, it is possible to provide a program that allows a computer constituting the Web service system to execute the above steps as a Web service control program. By storing the above program in a computer-readable storage medium, it is possible to allow the computer constituting the Web service system to execute the program. Further, it is possible to provide a program that allows a computer constituting the CC to execute the above steps as a relay program. By storing the above program in a computer-readable storage medium, it is possible to allow the computer constituting the CC to execute the program.
[0138] The computer-readable medium mentioned here includes: an internal storage device mounted in a computer, such as ROM or RAM, a portable storage medium such as a CD-ROM, a flexible disk, a DVD disk, a magneto-optical disk, or an IC card; a database that holds computer program; another computer and database thereof.
[0139] A management step corresponds to steps S 22 , S 24 , and S 26 in the embodiments. An adaptation determination step and a transfer step correspond to the processing performed by the CK 22 in steps S 41 to S 43 in the embodiments.
[0140] A reservation request step corresponds to steps S 21 , S 23 , and S 25 in the embodiments. A transmission step corresponds to the processing performed by the CC 11 in steps S 41 to S 43 in the embodiments.
[0141] A management section corresponds to the CM 21 in the embodiments. An adaptation determination section and a transfer section correspond to the CK 22 in the embodiments.
INDUSTRIAL APPLICABILITY
[0142] According to the present invention, it is possible to control the amount of Web service requests to be accepted based on reservation.
[0143] All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiment(s) of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | A computer readable storage medium stores a Web service control program that allows a computer to execute a process comprising: receiving from a consumer of a Web service a reservation request for a reservation which reserves the Web service and defines a condition, the condition including a shortest time interval between Web service requests; acquiring a state of a server; determining whether to accept the reservation; accepting the reservation when it is determined to accept the reservation; determining, when receiving a Web service request for the Web service, a time interval between the received Web service request and a Web service request prior to the received Web service request; determining whether the received Web service request satisfies the condition; and transferring, when it is determined that the received Web service request satisfies the condition, the received Web service request. |
RELATED APPLICATIONS
This application is a divisional of and claims the benefit of priority to Non-provisional U.S. application Ser. No. 11/686,090, filed Mar. 14, 2007, now U.S. Pat. No. 7,952,360 ; which in turn claims the benefit of priority to U.S. Provisional Patent Application No. 60/785,052, filed Mar. 22, 2006, the entire contents of each of which are incorporated herein by this reference. This application further claims the benefit of priority to Non-provisional U.S. application Ser. No. 11/093,075, filed Mar. 28, 2005, now U.S. Pat. No. 7,516,924 B2 of which 11/686,090 is a Continuation-in-Part, the entire contents of each of which are incorporated herein by this reference. All related applications are assigned in common to the assignee of the present divisional application.
FIELD OF THE INVENTION
The present invention relates to a medical boom with one or more articulated arms used to suspend video displays for use in a hospital operating room, and more particularly, to a medical boom having a base cabinet designed to accommodate modular equipment racks and utility cabinets which enable the easy insertion and removal of video processing, computer, electronic and other equipment into or out of the base cabinet.
BACKGROUND OF THE INVENTION
State of the art hospital operating rooms now contain a wide variety of audio, visual and technology tools, such as video cameras, video recorders, microphones and voice recorders, video guided ultrasound imaging systems, lasers, cytoscanners, etc. With delicate surgery for example, a 3D video camera may be placed in or above the surgical area of the patient. The image from the camera is then transmitted to a large display, such as a flat panel, allowing the operating doctor and medical staff to see an enlarged visual of the surgical area. The enlarged image makes it easier for the doctor to perform the surgery compared to relying on the naked eye.
U.S. application Ser. No. 11/093,075, entitled “ARTICULATED BOOM FOR SUPPORTING VIDEO AND MEDICAL EQUIPMENT IN HOSPITAL OPERATING ROOMS”, incorporated herein for all purposes, and assigned to the same assignee of the present application, describes a medical boom used for suspending video and other equipment in a hospital operating room. The medical boom disclosed in the above-mentioned application features articulated arms attached to a structural equipment cabinet that is mounted to the floor or wall of the operating room. Electronic equipment is installed or mounted directly in the cabinet at the factory prior to shipment to customer facility such as a hospital operating room. While the aforementioned medical boom does dramatically lower installation time and cost compared to previously known approaches in the prior art, the requirement of installing electronic equipment in the structural cabinet of the medical boom in the factory, as opposed to on site, is less than ideal. Due to size and weight of the cabinet, the medical boom is typically transported by truck. The cabinet and pre-installed equipment are therefore subject to vibration, shock and adverse temperatures and humidity conditions during transit, all of which could potentially damage the electronic equipment. Alternatively, if the electronic equipment is shipped separately, it has to be installed and configured on site, requiring a team of technicians to travel to the customer facility, adding to the time and expense of the installation.
A medical boom with articulated arms and a base cabinet designed to accommodate modular equipment and utility racks that include video processing, computer, and electronic, and other utility equipment that can be easy inserted and removed from the base cabinet is therefore needed.
SUMMARY OF THE INVENTION
A medical boom with articulated arms and a base cabinet designed to accommodate modular equipment and utility racks that include video processing, computer, and electronic, and other utility equipment that can be easy inserted and removed from the base cabinet is disclosed. The boom includes a stationary base that is configured to be installed into an operating room and one or more boom arms supported by the stationary base and configured to extend over an operating table in the operating room. The structural base includes one or more bays configured to receive a modular rack of electrical equipment. In various embodiments, the structural base cabinet further incorporates wiring to connect the equipment installed in the modular racks to video monitors and other equipment mounted on the articulated booms. The modular racks are preconfigured with a variety of electronic equipment such as computers, video processors and the like. The modular racks are installed in the base cabinet subsequent to the cabinet's structural installation in the operating room and may be readily removed or replaced at a later time. The placement of equipment into preconfigured modular racks allows such equipment to be transported and handled separately from the structural base cabinet while allowing it to be preconfigured as a system. This prevents damage to sensitive equipment during transport and facilitates rapid maintenance and upgrades of the equipment after it is placed in service.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 illustrates medical boom with articulated arms and a base cabinet designed to accommodate modular equipment racks according to the present invention.
FIGS. 2A and 2B illustrate a modular equipment rack for use with the base cabinet of the medical boom of the present invention.
FIG. 3 illustrates a utility module that may be installed in the base cabinet of the medical boom in lieu of a modular equipment rack according to the present invention.
FIGS. 4A-4B illustrate two drawings showing the installation of a modular electronic equipment rack in the base cabinet of the present invention.
FIG. 5 is a cross section diagram illustrating an exemplary routing for the electrical cabling used for the video display and electronics housed in the medical boom of the present invention.
FIGS. 6A-6C illustrate an alternative embodiment of the modular equipment rack in accordance with another embodiment of the invention.
FIG. 7 illustrates retractable arms on the articulated arms of the medical boom in accordance with another embodiment of the invention.
FIGS. 8A-8B illustrate the routing of power and signal wires through the segments and joints of the articulated arm of the medical boom in accordance with the present invention.
FIGS. 9A-9B illustrate a cowling plate used for covering the power and signal wires plugged into the back of the displays of the medical boom in accordance with the present invention.
FIG. 10 illustrates the symmetrical features of the base cabinet of the medical boom according to the present invention.
It should be noted that like reference numbers refer to like elements in the figures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be described in detail with reference to a few preferred embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known operations have not been described in detail so as not to unnecessarily obscure the present invention.
Referring to FIG. 1 , a medical boom with articulated arms and a base cabinet designed to accommodate modular equipment racks according to the present invention is shown. The medical boom 10 includes a base cabinet 100 , one or more articulated arms 200 , and a plurality of video displays 220 suspended from the articulated arms 200 . The base cabinet 100 includes a number of equipment bays 150 . The equipment bays 150 are used for accommodating either equipment racks 300 and/or utility modules 400 . For more details on the design of the base cabinet 100 and articulated arms 200 of the medical boom 10 , see the aforementioned pending U.S. application Ser. No. 11/093,075, incorporated by reference herein for all purposes.
Referring to FIGS. 2A and 2B , a modular equipment rack 300 for use with the base cabinet 100 of the medical boom 10 according to one embodiment is shown. The equipment rack 300 is a rectangular shaped box or cabinet configured to house electronic equipment 310 . The front face of the rack 300 includes a pair of mounting brackets 312 , each with a plurality of threaded holes. As illustrated in FIG. 2B , screws are used to screw or mount the equipment 310 into the mounting brackets 312 of rack 300 . As illustrated in the two figures, one or more pieces of electronic equipment 310 can be housed in the rack 300 . The equipment rack 300 also includes a pair of guides 316 and stops 318 located on opposite sides of the cabinet (in the FIG. 2A , only one groove 316 and stop 318 are visible). The guides 316 are used to install the rack 300 into the equipment bays 150 of the base cabinet 100 , as described in more detail below.
Referring to FIG. 3 , a utility module 400 that may be installed in the base cabinet 10 of the medical boom 10 in lieu of a modular equipment rack 300 according to the present invention is shown. The utility module 400 is also a rectangular shaped box or cabinet configured to store utility medical equipment, such as surgical tools and the like. The utility module 400 includes one or more shelves 410 and one or more drawers 415 . The utility module also includes a pair of guides 316 and stops 318 also located on opposite sides of the cabinet (only one guide 316 and stop 318 are visible in the figure). The guide rails 316 are used to install the utility module 400 into the equipment bays 150 of the base cabinet 100 , as described in more detail below. It should be noted that utility module 400 does not necessarily require a combination of shelves 410 and drawers 415 . In alternative embodiments, the modules 400 may include just one or more shelves 410 or just one or more drawers 415 .
In accordance with one embodiment, the equipment racks 300 and the utility modules 400 are the same size and are inter-changeable. Each can be inserted into any one of the equipment bays 150 of the base cabinet 100 to configure the medical boom 10 in any manner desired. It should be noted, however, that the racks 300 and modules 400 do not necessarily have to be the same size. The bays 150 in the base cabinet 100 can be made of any size and the racks and/or modules 400 can be made the appropriate size to fit into the bays 150 .
Referring to FIGS. 4A and 4B , the installation of a modular equipment rack 300 in the base cabinet 100 of the present invention is illustrated. In FIG. 4A , an equipment rack 300 is shown being positioned for installation into a bay 150 of the base cabinet 100 . In FIG. 4B , a pair of guide rails 155 , provided within each bay 150 , are shown (only one guide rail 155 is visible). The two guides 316 on the opposite sides of either the rack 300 and/or utility module 400 are configured to engage and move along the two guide rails 155 provided in each bay 150 . The stops 318 , located at the end of each of the guides 316 , prevent the rack 300 or utility module 400 from sliding through the back of the base cabinet 100 . A lock 157 is provided within the structure of the base cabinet 100 to lock either the rack 300 or utility module 400 in place once installed in the bay 150 .
FIG. 5 is a cross section diagram illustrating an exemplary routing for the electrical cabling used for the video display and electronics housed in the medical boom 10 of the present invention. The cross section shows the routing of video 210 and power cabling 215 between the video displays 220 suspended by the articulated arms 200 connected to the bays 150 in the base cabinet 10 . The cross section also shows electrical wiring 120 , conduit 130 , and junction boxes 140 between a power supply 125 and the bays 150 . The aforementioned electrical wiring 120 , conduit 130 , and junction boxes 140 are pre-installed in the base cabinet 100 prior to shipment to a customer facility. During installation of the racks 300 and/or modules 400 at the customer facility (an operating room or other medical facility), the video 210 and power cabling 215 are connected along with electrical wiring 120 and conduit wiring 130 to the equipment in the bays 150 .
The medical boom 10 of the present invention thus provides a flexible, self-contained medical video presentation unit that can be quickly and easily installed in an existing operating room. With the bays 150 in the base cabinet, electrical equipment in the equipment racks 300 and other utilities in the utility modules 400 can readily be installed on site in the hospital operating room. In the event the electronic equipment needs to be serviced or repaired, the racks 300 can be readily be removed and the equipment repaired or replaced, with minimum down time.
In the one embodiment, a structural cabinet 100 is shipped to the customer facility along with articulated boom arms 200 . One or more equipment racks 300 and/or utility modules 400 are then configured with electronic equipment 310 and other utility equipment according to customer requirements at a location remote from the customer. After configuration and testing, the racks 300 of equipment 310 and/or modules 400 are then separately shipped to the customer facility, either simultaneously or at a different time as the cabinet 100 . The required video monitors 220 can be either shipped together with either the racks 300 , the boom 10 , or separately.
At the customer facility, the base cabinet 100 is first structurally attached to the facility floor in the desired location. The base cabinet is affixed to the floor or wall of the operating room using any one of a number of known elements such as concrete anchors, bolts, studs, structural adhesives or a combination thereof. Upon completion of the structural installation, the installation of the necessary electrical power or signal cabling is carried out to connect the electrical wiring and conduit in the base cabinet 100 . Next, the articulated boom arms 200 are mounted to the base cabinet 100 and the video monitors 220 are attached to the booms 200 . To complete the installation of the present invention, one or more of the preconfigured equipment racks 300 are installed into the equipment bays 150 of the base cabinet 100 . One or more of the equipment bays 150 may also receive a utility module 400 . As a final step, electrical connections are made to the installed electrical equipment 310 and then the entire system is powered up and tested.
In an alternative embodiment, one or more equipment bays may be configured with protective covers or user-accessible doors to protect the electronic equipment contained therein and to optionally limit user access thereto.
Should service or configuration changes be required after the system of the present invention is placed in service, one or more of the equipment racks 300 can be readily removed, serviced, or replaced with another preconfigured equipment rack. The complete racks 300 can be easily shipped to the factory for service or configuration. A replacement preconfigured rack 300 can be shipped to the customer facility in advance and quickly exchanged in the field with any troubleshooting and configuration being performed offline, resulting in the minimum possible downtime and cost.
Referring to FIGS. 6A-6C , an alternative embodiment of the modular equipment rack is shown. In this embodiment, the equipment rack 600 includes a plurality of trolley wheels 602 , each located at the bottom four corners of the rack 600 . The trolley wheels 602 are designed to allow the equipment rack 600 to be readily rolled around. The trolley wheels 602 also facilitate in the installation of the rack 600 into the bays 150 of the base cabinet 100 of the boom 10 . A plurality of slots 604 are provided in the bay 150 in the bottom of the base cabinet 100 , as best illustrated in FIG. 6A . Although not clearly illustrated in the figure, the slots 604 are provided to accommodate the trolley wheels 602 of the rack 600 . During installation, the rack 600 is rolled into the equipment bay 150 until the trolley wheel 602 drop into the slots 604 of the cabinet 100 . With the trolley wheels 602 in the slots 604 , the rack 600 is “locked” into place within the boom 10 . To remove the rack 600 , a firm pull on the rack is required to pull the trolley wheels 602 out of the slots 604 . The rack 600 can thereafter be rolled out of the equipment bay and readily accessed for repairs or upgrades. FIG. 6B shows the rack 600 inside the bay 150 . FIG. 6C shows an exploded view of one of the wheels 602 of the rack 600 dropped into place within a slot 604 of the base cabinet 100 .
Referring to FIG. 7 , the articulated arms 200 with retractable handles 70 are shown in accordance with another embodiment of the invention. One or more handles 70 are provided on each articulated arm 200 for the purpose of facilitating the movement of the video displays 220 and other supported equipment into position. For the sake of illustration, a first handle 70 A is shown in a retracted position, while handle 70 B is shown in the non-retracted position. When the handle 70 is not in use, it may be partially housed within the articulated arm 220 . When the arm 200 is to be positioned, the exposed portion of the handle is pulled down into the non-retracted position. The handle 70 is then used to move the articulated arm 200 so the display monitors 220 are positioned to a desired location. The handle 70 provides a higher degree of leverage, making it easier to move the articulated arm 200 so the display monitors 220 are positioned to a desired location. The handle 70 provides a higher degree of leverage, making it easier to move the articulated arms 200 into a desired position. It also makes it easier for members of the medical staff in the operating room who are not very tall to be able to move or manipulate the position of the arms 200 and display monitors 220 .
FIGS. 8A-8B illustrate yet another feature of the articulated arms 200 of the present invention. With this embodiment, the articulated arms 200 include a plurality of segments joined together by joints 80 . The segments include recesses that allow for the routing of wires 82 , for example power and signal cabling for the displays 220 . As best illustrated in the cross section diagram of FIG. 8A , the joints 80 are capable of distributing the wires in multiple directions, including through the top and bottom of the joint and forward to the next segment of the articulated arm 200 . FIG. 8B shows two wires 82 a and 82 b protruding out from the top and bottom directions of the joint 80 , allowing equipment to be attached to both the top and bottom of the arms 200 . For example, appendage arms and/or displays 220 can be suspended off the bottom of an arm 200 , while task lighting or other equipment can be attached to the top of the arm 200 . For more details of the segments and the joints 80 of the arm 200 , see the above-identified application U.S. Ser. No. 11/093,075.
FIGS. 9A and 9B illustrate a cowling plate 90 used for covering the power and signal wires plugged into the back of the displays 220 . In FIG. 9A , the cowling 90 is illustrated removed from the back of the display 220 . In FIG. 9B , the cowling 90 is attached to the back of the display 220 , covering the wires. In various embodiments, the cowling 90 can be made from a metal, plastic or any other hard or soft material. It also protects the wires from contaminants and prevents the wires from being inadvertently pulled or removed from the displays 220 , and is more aesthetically pleasing to look at.
Referring to FIG. 10 , the symmetrical nature of the base cabinet 100 is shown. The cabinet 100 is symmetrical for a number of reasons. The articulated arms 200 (not illustrated) can be attached to any one of the four recesses 94 located in the four corners of the top of the cabinet 100 . For the sake of illustration, a wire 82 is shown passing through one of the recesses 90 . If an articulated arm 200 were attached, the wire would be routed through the arm 200 and joints 18 as described above. Within the base cabinet 100 , the wire 82 would be connected to electrical equipment, power transformers, a power supply, etc. The equipment racks 300 and 600 can also be inserted into the equipment bays 150 from either the side of the cabinet 100 , either as shown in the diagram or in the opposing side of the diagram. In this regard, the medical boom 10 does not have a “front” or “back”. On the contrary, the cabinet 100 is symmetrical, allowing the front panel or the equipment contained in the racks 300 and 600 to be exposed through either side of the medical boom, depending on how it was installed. The symmetrical design of the medical boom 10 increases flexibility and allows the base cabinet 100 to be installed into virtually all operating room environments.
While this invention has been described in terms of several embodiments, there are alteration, permutations, and equivalents, which fall within the scope of this invention. For example, the stationary base does not necessarily have to be fastened to the floor of an operating room. It can also be attached to or affixed to the wall of an operating room. Further, while the present invention has been described as a medical boom for use in a hospital operating room, it does not necessarily have to be limited to this environment. Rather the boom of the present invention may be used in a dentist office, examination rooms, veterinary clinics, surgical suites, etc. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention. | The present invention is directed to a medical boom with articulated arms and a base cabinet designed to accommodate modular equipment and utility racks that include video processing, computer, and electronic, and other utility equipment that can be easy inserted and removed from the base cabinet, as well as a method of manufacturing and using the same. The boom includes a stationary base that is configured to be installed into an operating room and one or more boom arms supported by the stationary base and configured to extend over an operating table in the operating room. The structural base includes one or more bays configured to receive a modular rack of electrical equipment. In various embodiments, the structural base cabinet further incorporates wiring to connect the equipment installed in the modular racks to video monitors and other equipment mounted on the articulated booms. The modular racks are preconfigured with a variety of electronic equipment such as computers, video processors and the like. The modular racks are installed in the base cabinet subsequent to the cabinet's structural installation in the operating room and may be readily removed or replaced at a later time. |
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