text
stringlengths 1.87k
3.49M
| summary
stringlengths 86
3.43k
|
|---|---|
BACKGROUND OF THE INVENTION
The present invention relates to gaseous fuel engines with fuel injectors for introducing gaseous fuel (i.e., fuel that naturally exists in a gaseous state, rather than a liquid state) into intake ports of an internal combustion engine, for example in a passenger vehicle. Gaseous fuels include natural gas (primarily methane) and derivatives thereof, such as butane and propane, but do not include gasoline. Natural gas can be used to power internal combustion engines. Compared to conventional engines, vehicles run on natural gas are environmentally friendly while outputting less engine noise than traditional diesel-powered engines.
SUMMARY OF THE INVENTION
The invention provides, in one aspect, an engine having one or more cylinders configured to receive gaseous fuel for use in combustion. Two gaseous fuel injectors, per cylinder, are directed at each of the plurality of cylinder. A first injector has an injection capacity of a first amount of gaseous fuel per injection. A second injector has an injection capacity of a second amount of gaseous fuel per injection, the second amount being greater than the first amount. The engine is operable in a first mode in which a per-cylinder fuel demand is at or below the first amount, and only the first injector is operable for each cylinder. The engine is operable in a second mode in which the per-cylinder fuel demand is greater than the first amount, and only the second injector is operable for each cylinder.
The invention provides, in another aspect, a method of operating a gaseous fuel engine having one or more cylinders. Two injectors are provided per cylinder: a first injector and a second injector. An engine load is analyzed. In a first mode of operation, gaseous fuel is injected into each cylinder via only the corresponding first injector when the engine load requires an amount of gaseous fuel that is less than or equal to a first amount. In a second mode gaseous fuel is injected into each cylinder via only the corresponding second injector when the engine load requires a second amount of gaseous fuel, greater than the first amount.
The invention provides, in yet another aspect, a method of operating a gaseous fuel engine having one or more cylinders. Two gaseous fuel injectors are provided per cylinder: a first injector and a second injector. The second injector has a higher injection capacity than an injection capacity of the first injector. An intake valve per cylinder is configured to transition between a closed position and an open position. An intake valve opening duration, in which the intake valve is in the open position, is analyzed. Gaseous fuel is injected into each cylinder only within the corresponding intake valve opening duration. The injection of gaseous fuel includes injecting gaseous fuel into each cylinder via only the corresponding first injector in a first mode of engine operation when the intake valve opening duration is greater than a predetermined duration. The injection of gaseous fuel further includes injecting gaseous fuel into each cylinder via only the corresponding second injector in a second mode of operation when the intake valve opening duration is less than the predetermined valve opening duration.
Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a conventional engine having fuel injectors positioned at the downstream ends of individual intake runners.
FIG. 2 is a schematic representation of an engine utilizing a first injector according to one embodiment of the present invention.
FIG. 3 is a schematic representation of an engine utilizing a second injector according to one embodiment of the present invention.
FIG. 4 is a graph illustrating an exemplary group of operational ranges of the engine of FIGS. 2-3 , according to fuel injection quantity and engine speed. The graph illustrates distinct regions of operation for first and second gaseous fuel injectors, according to an exemplary method of the present invention.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
Gaseous fuel engines may begin with an engine designed for more common fuels such as diesel fuel or gasoline. Components of these engines are retrofitted to allow the engine to run on a gaseous fuel. FIG. 1 shows an engine 16 including an intake manifold 20 and a cylinder head 24 of a known configuration. Air enters the intake manifold 20 via the throttle body 28 . A throttle valve 32 located within the throttle body 28 selectively opens and closes to limit or prevent the passage of air through the throttle body 28 . The air within the throttle body is diverted through numerous intake runners 36 (i.e., one intake runner 36 per piston cylinder 56 ). The intake runners 36 align with intake ports 44 within the cylinder head 24 . Fuel is provided from a single gaseous fuel tank or common fuel supply 46 , through a fuel line 50 , to multiple fuel injectors 48 . A fuel injector 48 is outfitted to inject fuel 52 into each of the respective intake ports 44 . The injected fuel 52 mixes with the air to create an air-fuel mixture. An intake valve 40 , located within each intake port 44 selectively prohibits the air-fuel mixture from reaching a piston cylinder 56 when the intake valve 40 is in a closed position. When the intake valve 40 is in an open position (i.e., intake stroke, suction stroke), the air-fuel mixture enters the piston cylinder 56 where combustion occurs. An exhaust valve 42 is located downstream of each cylinder 56 and is configured to open after combustion has occurred.
Certain engines, such as some diesel engines, do not have individual intake runners, but rather include a common intake plenum 160 , such as the engine 116 as shown in FIGS. 2-3 . The common intake plenum 160 is located directly downstream of the throttle body 128 and throttle valve 132 , upstream of the multiple intake ports 144 , and provides a fluid communication path between the multiple piston cylinders 156 . As shown in FIGS. 2 and 3 , the engine 116 can include six intake ports 144 for six piston cylinders 156 , however, the present invention equally applies to any number of piston cylinders 156 of an engine 116 with a number of cylinders (i.e., at least one piston cylinder 156 ), and any number of intake ports 144 per piston cylinder 156 .
A gaseous fuel engine utilizes gaseous fuel injectors 148 A, 148 B. For example, an engine 116 may be retrofitted to run on the gaseous fuel (i.e., natural gas). Fuel is provided from a single gaseous fuel tank or common fuel supply 146 , through a fuel line 150 , to multiple fuel injectors 148 A, 148 B. Fuel injectors 148 A, 148 B, are positioned to inject fuel into the common intake plenum 160 , and are aligned with the intake ports 144 . Therefore, in use, the fuel injectors direct the injected fuel 152 towards the corresponding intake port 144 . Alternatively, the injectors 148 A, 148 B may inject downstream of the common intake plenum yet upstream of a corresponding intake valve 140 . However, with a gaseous fuel 152 and a common intake plenum 160 , it is possible that injected fuel 152 can travel through the common intake plenum 160 to additional intake ports 144 . This can increase the amount of injected gaseous fuel 152 in some intake ports 144 and decrease the amount in others. This inconsistency can lead to poor combustion within the piston cylinders 156 . Therefore, in certain embodiments, open valve injection is implemented.
With open valve injection, fuel 152 is injected towards the intake ports 144 of the cylinder head 124 only when the corresponding intake valve 140 is open. This prevents or at least limits the amount of injected fuel 152 which bounces off a closed intake valve 140 and spreads through the common intake plenum 160 . The fuel 152 mixes with a flow of intake air which is provided through the throttle body 128 , is selectively throttled via the throttle valve 132 , and mixes with the injected fuel 152 in the common intake plenum 160 . However, in order to supply the largest fuel demand of the engine 116 within an intake valve opening duration (i.e., the time that the intake valve 140 is in an open position), a second fuel injector 148 B, distinct from the first injector 148 A, with a sufficiently large flow capacity is provided for each cylinder 156 . The second fuel injectors 148 B may not be suitable for injecting very small amounts of fuel 152 when the engine 116 is running at idle or with a low load. Therefore, an additional injector, a first gaseous fuel injector 148 A is provided.
The injectors 148 A, 148 B may be operated at a variable energizing time which varies the quantity of injected fuel 152 per injection, up to a maximum capacity. For given operating conditions of the engine 116 , the first gaseous fuel injectors 148 A have an injection capacity of a first amount of gaseous fuel per injection and are limited to injecting no more than the first amount. FIG. 2 shows a first operational mode of the engine 116 in which only the first injector 148 A is in operation for each of the cylinders 156 . Under the same operating conditions of the engine 116 , the second gaseous fuel injectors 148 B have an injection capacity of a second amount of gaseous fuel 152 per injection. The second gaseous fuel injectors 148 B are limited to injecting no more than the second amount. FIG. 3 shows a second operational mode of the engine 116 in which only the second injector 148 B is in operation for each of the cylinders 156 . The second amount is greater than the first amount. However, the first and second fuel injectors 148 A, 148 B are not configured to simultaneously inject, rather, a control unit (not shown) determines which fuel injector 148 A, 148 B to use.
As shown in FIG. 4 , injection quantity is plotted against engine speed, for an exemplary set of operating conditions (e.g., 7 bar inlet pressure; 120 crank angle degrees; maximum injection duration). At these conditions, the engine 116 may operate within a specific range 264 . A first mode 248 A, indicated by a diagonal cross-hatch, specifies engine loads at which the first injector 148 A injects a quantity of gaseous fuel 152 . The second injector 148 B is not capable of accurately injecting the amount of gaseous fuel 152 desired in the first area 248 A. A second mode 248 B, indicated by a stippling, specifies engine loads at which the second injector 148 B injects a quantity of gaseous fuel 152 . The first injector 148 A is not capable of injecting the amount of gaseous fuel 152 desired in the second area 248 B. A third mode 248 C, indicated by a cross-hatch, specifies engine loads at which both the first injector 148 A and the second injector 148 B are capable of injecting the requested quantity of gaseous fuel 152 . The control unit determines which fuel injector 148 A, 148 B to use, and the gaseous fuel 152 is injected with one of the two injectors 148 A, 148 B. If the fuel demand falls within the third mode, the control unit (not shown) may default to continue injecting with the injector used in the previous injection.
The line 268 represents a first amount, which is the upper limit of the first injector 148 A, wherein, at the specified conditions, the first injector 148 A is unable to inject more fuel per injection. The line 272 represents a second amount, which is the upper limit of the second injector 148 B, wherein, at the specified conditions, the second injector 148 B is unable to inject more fuel per injection. The line 276 represents a third amount, which is a non-zero lower limit of the second injector 148 B. The third amount is defined as the smallest injection target amount at which the second injector 148 B can meet the target within a predetermined acceptable range (e.g., less than 5 percent deviation from the specified target amount, less than 1 percent deviation from the specified target amount, etc.).
The intake valve 140 of each cylinder 156 transitions between an open position and a closed position in controlled relation to the crankshaft rotation and piston stroke. An intake valve opening duration is a length of time in which each of the intake valves 140 is in the open position. The intake valve opening duration will generally decrease as the operating speed of the engine 116 is increased. This assumes that each intake valve 140 is held open for a consistent number of crank angle degrees, however, this parameter may be variable (e.g., corresponding to an engine equipped with variable valve control). The intake valve opening duration provides a restriction, which limits the amount of fuel 152 which can be provided to the cylinder 140 . As an alternative to, or in combination with engine-load dependent injection, as shown in FIG. 4 , the control unit can determine which fuel injector 148 A, 148 B is appropriate for injecting the gaseous fuel 152 based on the intake valve opening duration.
The first injector 148 A injects gaseous fuel 152 into the respective piston cylinder 156 when the engine 116 is operating with a first intake valve opening duration. The second injector 148 B injects gaseous fuel 152 into the respective piston cylinder 156 when the engine 116 is operating with a second intake valve opening duration, less than the first intake valve opening duration. Therefore, when the intake valve 140 is open for a short duration, in which the first injector 148 A is unable to inject a requested amount of fuel, the second injector 148 B, with a higher injection capacity than the first injector 148 A, injects the gaseous fuel 152 .
When the engine 116 is operating with a third intake valve opening duration, in which either of the first and the second fuel injectors 148 A, 148 B are configured to inject, the control unit determines which fuel injector 148 A, 148 B to use, and the gaseous fuel 152 is injected with one of the two injectors 148 A, 148 B. If the engine 116 is operating with the third intake valve opening duration, the control unit (not shown) may continue injection with the injector used in the previous injection. | An engine includes one or more cylinders configured to receive gaseous fuel for use in combustion. Two gaseous fuel injectors per cylinder, include: a first injector directed at the corresponding cylinder and having an injection capacity of a first amount of gaseous fuel per injection, and a second injector directed at the corresponding cylinder and having an injection capacity of a second amount of gaseous fuel per injection, the second amount being greater than the first amount. The engine is operable in a first mode in which a per-cylinder fuel demand is at or below the first amount, and only the first injector is operable for each cylinder. The engine is operable in a second mode in which the per-cylinder fuel demand is greater than the first amount, and only the second injector is operable for each cylinder. |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent application Ser. No. 11/774,277, filed Jul. 6, 2007, which is incorporated by reference as if fully set forth.
FIELD OF THE INVENTION
[0002] The present invention relates to a method of controlling an uninterruptible power supply apparatus, particularly to an uninterruptible power supply of a simple-phase AC/AC converter having three arms.
BACKGROUND OF THE INVENTION
[0003] Please refer to FIG. 1 which is a circuit diagram of a conventional line-interactive uninterruptible power supply. In FIG. 1 , the conventional line-interactive uninterruptible power supply contains an AC input voltage AC, a switch containing two diodes D 1 and D 2 , a single-phase AC/AC converter 11 , an AC filter 12 containing a filter inductor Lo and a filter capacitor Co, and a load R.
[0004] The single-phase AC/AC converter 11 contains an AC inductor Li, a bus capacitor Cs and three arms. The three arms are respectively a boost arm comprising a switch 51 and a switch S 2 , a common arm comprising a switch S 3 and a switch S 4 and a buck arm comprising a switch S 5 and S 6 .
[0005] An AC input voltage AC directly provides energy to the load R by the line-interactive uninterruptible power supply 1 of FIG. 1 when the AC input voltage AC (mains electricity) is operated normally. The boost arm and the common arm execute a rectifying function. When the AC input voltage functions abnormally, a storing battery (not shown) provides energy to the load R. At this time, the common arm and the buck arm execute an inverting function.
[0006] In fact, two switches S 3 and S 4 of the common arm are controlled by network frequency. The switching frequency is low-frequency switching. Therefore, the boost arm is used as a rectifying device and the buck arm is used as an inverting device.
[0007] In the prior arts, in order to implement regulation of the AC input voltage, several controlling methods could be used. The difference between the controlling methods was to generate bus voltages having different waveforms. The following explanations show two kinds of common methods of controlling the bus voltages having different waveforms.
[0008] Please refer to FIGS. 2( a ) and 2 ( b ) which were waveform diagrams of bus voltages of an uninterruptible power supply of FIG. 1 for different controlling methods. The FIGS. 2( a ) and 2 ( b ) showed respectively waveforms of different bus voltages. The bus voltage of FIG. 2( a ) had a DC voltage waveform while the bus voltage of FIG. 2( b ) had a full-wave rectifying voltage waveform. Certainly, the different bus voltages generated under different controlling methods had advantages and drawbacks.
[0009] In order to obtain the DC bus voltage shown in FIG. 2( a ), the buck arm and the boost arm must be operated under a high frequency pulse-width-modulation mode and the common arm must be operated at low frequency switch state. When the AC input voltage AC was a positive half-wave, the switch S 4 turned off. When the AC input voltage AC was a negative half-wave, the switch S 3 turned off. An unit input power factor was obtained by using a method of calculating an input current and an input voltage so as to obtain a duty cycle of the buck arm of a single-phase AC/AC converter 11 . Therefore, a DC voltage was controlled by controlling an increasing amount of an input reference current.
[0010] A main advantage of this controlling method was that the input current could be controlled to be a sine-wave so as to obtain an unit input power factor. An output voltage could be accurately regulated. A no-load current would decrease. On the contrary, a main drawback was that a switch loss was large and a efficiency was poor (especially under full-load).
[0011] In order to obtain a full-wave bus voltage shown in FIG. 2( b ), when the AC input voltage AC was abnormal, a converter 11 was operated at a boost state, the switches S 1 and S 2 of the boost arm were operated under high frequency pulse-width-modulation mode. When the converter 11 was operated at a buck state, only the switches S 5 and S 6 of the buck arm were operated high frequency pulse-width-modulation mode. Besides, a capacitance of a bus capacitor Cs was small, then a bus voltage having full-wave rectifying voltage waveform shown in FIG. 2( b ) was obtained.
[0012] A main advantage of this controlling method was that the volume could be decreased, reliability of the circuit was enhanced and usage life of the circuit was lengthened by using a high frequency film capacitor as the bus capacitor Cs. Besides, a loss of the switches was small when a design of the controlling unit was simplified.
[0013] A main drawback of this controlling method was a poor dynamic performance, a large reactive current of input, and a large ripple current of the bus capacitor Cs. Because a current flowing through the load R during light-load and no-load periods was small, in order to maintain the full-wave rectifying voltage waveform of the bus capacitor Cs, an inefficient charging and discharging on the bus capacitor Cs was carried out. But, a large loss of the converter 11 was generated during light-load or no-load period.
SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to provide a method of controlling an uninterruptible power supply apparatus for use in a single-phase AC/AC converter of the uninterruptible power supply apparatus having three arms. In prior arts, there were mentioned two kinds of conventional controlling modes, the first was (1) a DC voltage controlling mode for a voltage waveform on a bus line 13 , and the second was (2) a full-wave rectifying waveform controlling mode for a voltage waveform on the bus line 13 . The controlling method of the present invention tries to sustain the advantages of the two conventional controlling modes and to overcome the drawbacks of them in order to obtain better effects.
[0015] According to a main aspect of the present invention, there is provided a method of controlling an uninterruptible power supply apparatus for use in the single-phase AC/AC converter of the uninterruptible power supply apparatus having three arms. According to an analysis of an operation of the AC/AC converter, waveforms on a bus capacitor are controlled by segment division in order to decrease a reactive current generated by the bus capacitor and to decrease a high frequency ripple current through the bus capacitor and, at the same time, to obtain high efficiency under all-input range no matter when the system (the uninterruptible power supply apparatus) is operated in light-load or heavy-load state, when the system can maintain operation under high efficiency.
[0016] According to one aspect of the present invention, there is provided a method of controlling an uninterruptible power supply apparatus having a bus voltage, an AC input voltage, a DC input voltage and a single-phase AC/AC converter including an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm, the method comprising steps of:
[0000] (a) controlling the bus voltage to have a DC voltage and a full-wave rectifying voltage; and
(b) setting a bus voltage parameter K where 0≦K≦1, so that the bus voltage approaches to the DC voltage when K approaches to 0 and the bus voltage approaches to the full-wave rectifying voltage when K approaches to 1;
[0017] wherein when the AC input voltage is normal, the bus voltage is rectified via the single-phase AC/AC converter to output, and when the AC input voltage is abnormal, the DC input voltage is inverted via the single-phase AC/AC converter to output.
[0018] Preferably, the uninterruptible power supply apparatus includes a switch set, an AC filter and a load.
[0019] Preferably, in step (b) when the load is light-load, the bus voltage parameter K is increased to approach to 1, and when the load is heavy-load, the bus voltage parameter K is decreased to approach to 0.
[0020] In accordance with the present invention, the method further comprises a step of (c) setting a duty cycle d 3 of the buck arm, a duty cycle d 1 of the boost arm and a voltage gain M of the single-phase AC/AC converter to meet an equation of d 3 =M(1−d 1 ).
[0021] In accordance with the present invention, the method further comprises a step of (d) defining a wave function F of the bus voltage to meet the following condition: when |sin(wt)|<K, F=|sin(wt)|; and when |sin(wt)|≧K, F=K, wherein w is an angular velocity, and t is a passing time.
[0022] In accordance with the present invention, the duty cycle d 1 of the boost arm, the voltage gain M of the single-phase AC/AC converter, the bus voltage parameter K and the wave function of the bus voltage F meet an equation d 1 =(2−M)KF.
[0023] In accordance with the present invention, the method further comprises a step of (d) controlling one of boost arm and the buck arm to operate under a pulse-width-modulation mode when sin(wt)>1/K, and controlling both of the boost arm and the buck arm to operate under pulse-width-modulation mode when sin(wt)<1/K.
[0024] According to another aspect of the present invention, there is provided a method of controlling an uninterruptible power supply apparatus having a bus voltage, an AC input voltage, a DC input voltage and a single-phase AC/AC converter comprising an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm, the method comprising steps of: (a) controlling the bus voltage and making the bus voltage have a waveform including a low slope segment and a full-wave rectifying segment; (b) setting a bus voltage parameter K representing an amount of an output power, wherein 0≦K≦1; and (c) regulating a proportion of the low slope segment and the full-wave rectifying segment within a full cycle based on a variation of the bus voltage parameter K, the waveform of the bus voltage during the low slope segment having a slope lower than a further slope of the waveform of the bus voltage during the full-wave rectifying segment; wherein, when the AC input voltage is normal, the bus voltage is rectified via the single-phase AC/AC converter to output, and when the AC input voltage is abnormal, the DC input voltage is inverted via the single-phase AC/AC converter to output.
[0025] Preferably, an average voltage value during the full-wave rectifying segment is larger than that during the low slope segment.
[0026] In accordance with the present invention, the method further comprises a step of (d) increasing a duration of the low slope segment and decreasing a duration of the full-wave rectifying segment when the output power decreases.
[0027] In accordance with the present invention, the waveform of the bus voltage is obtained by regulating duty cycles of the boost arm and the buck arm.
[0028] According to another aspect of the present invention, there is provided a method of controlling an uninterruptible power supply apparatus having a bus voltage, an AC input voltage, a DC voltage and an AC/AC converter, comprising steps of: (a) controlling the bus voltage to provide one of a DC voltage and a full-wave rectifying voltage; and (b) setting a bus voltage parameter K, where 0≦K≦1, so that the bus voltage approaches to the DC voltage when K approaches to 1 and the bus voltage approaches to the full-wave rectifying voltage when K approaches to 0.
[0029] The foregoing and other features and advantages of the present invention will be more clearly understood through the following descriptions with reference to the drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a circuit diagram of a conventional line-interactive uninterruptible power supply;
[0031] FIGS. 2( a ) and 2 ( b ) are diagrams showing waveforms of the bus voltage under different controlling methods for the conventional line-interactive uninterruptible power supply shown in FIG. 1 ;
[0032] FIG. 2( c ) is a diagram showing a waveform of the bus voltage applied by using the controlling method for an uninterruptible power supply of the present invention;
[0033] FIG. 3( a ) is a circuit diagram showing an line-interactive uninterruptible power supply of the present invention;
[0034] FIG. 3( b ) is a switch status table showing each main switch is operated under different operational modes in FIG. 3( a ) according to the present invention;
[0035] FIG. 4( a ) is a timing diagram showing a duty cycle of a boost arm under a boost mode according to the controlling method of the present invention;
[0036] FIG. 4( b ) is a timing diagram showing a duty cycle of a buck arm under a boost mode according to the controlling method of the present invention;
[0037] FIG. 5( a ) is a timing diagram showing a duty cycle of a boost arm under a buck mode according to the controlling method of the present invention; and
[0038] FIG. 5( b ) is a timing diagram showing a duty cycle of a buck arm under a buck mode according to the controlling method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0039] The present invention will now described more specifically with reference to the following embodiments. Please refer to FIG. 3( a ) which is a circuit diagram of a line-interactive uninterruptible power supply apparatus on which the controlling method of the present invention is applied. The numerals of FIG. 3( a ) are similar to those of FIG. 1 for the same components. The line-interactive uninterruptible power supply apparatus 3 contains a DC input voltage DC, an AC input voltage AC, a switch set 33 containing diodes D 1 and D 2 , a single-phase AC/AC converter 31 , an AC filter 32 containing a filter inductor Lo and a filter capacitor Co, and a load R.
[0040] The single-phase AC/AC converter 31 contains an AC inductor Li, a bus capacitor Cs and three arms. A arm containing switches 51 and S 2 is called as a boost arm. A arm containing switches S 3 and S 4 is called as a common arm. A arm containing switches S 5 and S 6 is called as a buck arm. Switches SW 1 , SW 2 and SW 3 are respectively used to control three operations of the AC input voltage AC, the DC input voltage DC and a bypass mode.
[0041] Please refer to FIG. 3( b ) which is a switch status table of different operation modes by the main switches in FIG. 3( a ). According to FIG. 3( b ), it is known that for the line-interactive uninterruptible power supply apparatus 3 under operation of the AC input voltage AC (mains electricity), the switch SW 1 is turned on and the switches SW 2 and SW 3 are switched to be turned off so that the bus voltage is rectified by the simple-phase AC/AC converter 31 and output to the load R. When the performance of the AC input voltage AC is abnormal, the switch SW 2 is turned on and the switches SW 1 and SW 3 are switched to be turned off, and the DC input voltage is inverted through the single-phase AC/AC converter to output. When the line-interactive uninterruptible power supply apparatus 3 does not function, the switch SW 3 is turned on and the switches SW 1 and SW 2 are switched to be turned off to let technicians maintain the device.
[0042] A main object of the controlling method of the present invention is to obtain the bus voltage shown in FIG. 2( c ). Similar to the conventional techniques, the bus capacitor Cs has such a small capacitance that a voltage having a full-wave rectifying voltage waveform is obtained. The method of controlling the bus voltage of the present invention which has a DC voltage and a full-wave rectifying voltage is explained as follows.
[0043] As shown in FIG. 2( c ), firstly, a bus voltage parameter K is set between 0 and 1. When the K value approaches to 0, the full-wave rectifying voltage of the bus voltage becomes larger and the waveform of the bus voltage approaches to a waveform of full-wave rectifying voltage. When the K value approaches to 1, the DC voltage of the bus voltage becomes larger and the waveform of the bus voltage approaches to a waveform of a DC voltage. The low slope segment is defined as the segment of the waveform when DC voltage is conductive according to FIG. 2( c ).
[0044] When the line-interactive uninterruptible power supply apparatus 3 is running and the load R is a light-load, the reactive current of the converter 31 occupies a large proportion of the current. The light load here is defined as a small resistance of the load R, and the heavy load is defined as a large resistance of the load R. Then, the K value is correspondently increased to decrease the reactive current. On the other hand, when the load R becomes larger, the main concern is the efficiency of the converter 31 . Then, the K value is correspondently decreased to decrease the loss of each switch and to increase the whole efficiency of the converter 31 .
[0045] In the above controlling method, the mode of the variation of the K value is irrelevant to a load current. A voltage gain determines a duty cycle d 3 of each switch of the buck arm and a duty cycle d 1 of each switch of the boost arm. Furthermore, the switches S 3 and S 4 of the common arm are relevant to a polarity of the AC input voltage AC. When the voltage gain M is smaller than 1, the converter 31 is operated under a buck mode. When the voltage gain M is larger than 1, the converter 31 is operated under a boost mode.
[0046] A wave function F of the bus voltage for the controlling method of the present invention is defined to meet the following condition:
[0000] when |sin( wt )|< K, F =|sin( wt )|; and
[0000] when |sin( wt )|≧ K, F=K; (1)
[0000] wherein w is an angular velocity, and t is a passing time.
[0047] The duty cycle d 3 of the buck arm, the duty cycle d 1 of the boost arm, the voltage gain M of the simple-phase AC/AC converter, the bus voltage parameter K and the wave function of the bus voltage F meet equations:
[0000] d 3= M (1 −d 1); (2)
[0000] d 1=(2 −M ) KF (3)
[0048] When the voltage input from mains electricity (the AC input voltage AC) is lower than the required value, it is necessary to increase the input voltage and the system is under boost mode and the voltage gain M is between 1 to 1.3. It can be known from equations (2)-(3) that it is necessary to control the duty cycle of the switches of the buck arm as shown in FIG. 4( b ) while a duty cycle of the switches of the boost arm at the same time is shown in FIG. 4( a ).
[0049] When the voltage input from mains electricity is higher than the required value, it is necessary to decrease the input voltage and the system is under the buck mode and the voltage gain M is between 0.7 to 1. It can be known from equations (2)-(3) that it is necessary to control the duty cycle of the switches of the boost arm as shown in FIG. 5( a ) while a duty cycle of the switches of the buck arm at the same time is shown in FIG. 5( b ).
[0050] It shall be noted that in view of timing, during a same cycle when sin(wt)>1/k, one of the boost arm and the buck arm is operated under the pulse-width-modulation mode. When sin(wt)<1/k, both of the boost arm and the buck arm are operated under the pulse-width-modulation mode.
[0051] It shall be noted that the examples shown above in the present invention are relevant to a combination of a DC waveform and a full-wave rectifying waveform. But, as to the object of the present invention, a decrease in the slope of the voltage waveform variation during a light-load period can increase the efficiency compared to the original full-wave rectifying waveform.
[0052] Accordingly, the present invention provides a method of controlling an uninterruptible power supply apparatus having three arms for use in the single-phase AC/AC converter. By controlling the voltage waveform on the bus capacitor by segment method, waveforms on a bus capacitor are controlled by segment division in order to decrease a reactive current generated by the bus capacitor and to decrease a high frequency ripple current through the bus capacitor and, at the same time, to obtain high efficiency under all-input voltage range no matter when the system (the uninterruptible power supply apparatus) is operated in light-load or heavy-load state, the system can maintain operation under high efficiency.
[0053] While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures. | A method of controlling an uninterruptible power supply apparatus (UPS) is provided. The UPS apparatus includes at least an AC input voltage, a DC input voltage and a single-phase AC/AC converter. The single-phase AC/AC converter includes an AC inductor, a bus capacitor, a boost arm, a common arm and a buck arm. The method includes steps of: controlling the bus voltage to have a DC component and full-wave rectifying component, and setting a bus voltage parameter K so that the bus voltage approaches to a full-wave rectifying voltage when K approaches to 1, wherein 0<=K<=1. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to adhesives for electronic parts and adhesive tapes using them, which are suitable for use in production of tape carrier packages (TCP), tape BGA (ball grid arrays), CSP (chip size packages), etc. which are suitable for the inclusion of many pins, miniaturization and high density assembly in a fabrication process of semiconductor devices, and particularly are most suitable for use in bonding of semiconductor chips, radiation plates and circuit boards making good used of TAB (tape automated bonding) techniques, which are all used in these packages.
2. Description of the Related Art
In the conventional adhesive tapes for electronic parts, an adhesive layer composed of an aliphatic polyamide resin and an epoxy resin, a polyamide resin, an epoxy resin and a phenol resin, or the like is formed on at least one side of a heat-resistant film as represented by TAB tapes. As the polyamide resin in the adhesive layer, is used nylon, dimeric acid polyamide or the like.
Film carrier tapes represented by the TAB system have been recently required to make fine by narrowing their conductor width and conductor spacing. Therefore, such a conventional adhesive as described above has become insufficient in insulating property and heat resistance. In wire bonding, copper forming a circuit requires to be plated with nickel or gold. Electro-plating has heretofore been used. However, electroless plating is suitable for thin film plating attendant upon the fining. By the way, the above-described adhesives heretofore used in TAB tapes have encountered problems such as lowering of electrical reliability due to lowering of their adhesive strength by a high temperature upon electroless plating and wire bonding failure by adsorption of impurity components such as sulfur in a plating solution.
In recent years, circuit board materials of the additive type, in which a copper layer is formed directly on a polyimide film or the like, have begun to be marketed. Since perforating in the fabrication of a semiconductor device comes to depend on laser and etching, however, they have a demerit that the productivity of semiconductor devices is low. The additive type circuit board material itself also involves a problem of poor productivity, since plating forms its conductor layer.
With such circumstances in view, various kinds of polyimide adhesives have been developed to date. For example, Japanese Patent Application Laid-Open No. 25453/1993 discloses a heat-resistant resin adhesive comprising soluble polyimide siloxanes consisting of an aromatic tetracarboxylic acid component composed mainly of a biphenyltetracarboxylic acid, a diaminopolysiloxane component and an aromatic diamine component, an epoxy compound and an epoxy hardener, and Japanese Patent Application Laid-Open No. 25452/1993 discloses a heat-resistant adhesive in which a bismaleimide resin is additionally added to the above described adhesive. Furthermore, Japanese Patent Application Laid-Open No. 200216/1994 discloses an adhesive film comprising a polyimide resin having silicon units, and an epoxy resin, and describes the polyimide resin to the effect that at least 1 mol % of a divalent aromatic group having a functional group is preferably contained as a component thereof.
SUMMARY OF THE INVENTION
However, the polyimide resins containing silicon units disclosed in these publications do not satisfy both of heat resistance and formability of the layer, and of low-temperature adhesive property. More specifically, when they have high heat resistance, adhesion must be conducted at a temperature higher than the conventional adhesives used in TAB tapes. In such a case, problems such as deterioration of dimensional stability to heat history, curing of a tape for TAB, strength reduction of a copper foil and reduction in the productivity of TAB tapes have arisen. On the other hand, the preparation for use of a polyimide resin which permits adhesion at a low temperature has involved such problems that the heat resistance is insufficient, its properties upon melting become unsuitable for the formation of an adhesive layer, it exhibits uneven adhesive property to become unsuitable for fining, and reduction in the productivity of TAB tapes is caused.
It is therefore an object of the present invention to provide an adhesive for electronic parts, which satisfies both of heat resistance and formability of the adhesive layer, and of low-temperature adhesive property, and an adhesive tape for electronic parts making use of such an adhesive.
In view of the above-described problems, the present inventors have carried out repeated investigations as to adhesives which are improved in low-temperature adhesive property and can solve the above-described problems such as dimensional stability while possessing properties suitable for the fining, such as good heat resistance and stable adhesive property. As a result, it has been found that when at least two specific polyimide resins different in glass transition temperature (Tg) from each other and an epoxy resin are used, an adhesive which can achieve the above object can be provided, thus leading to completion of the present invention.
According to the present invention, there is thus provided an adhesive for electronic parts, comprising, as a resin component, two polyimide resins different in Tg by at least 20° C. from each other, and an epoxy resin, wherein at least one of the two polyimide resins is a reactive polyimide having structural units represented by the following formula (I), structural units represented by the following formula (II) and structural units represented by the following formula (III), and the other is a polyimide having structural units represented by the following formula (I) and structural units represented by the following formula (II), and the reactive polyimide and the epoxy resin are contained in ranges of at least 25 parts by weight and 10 to 100 parts by weight, respectively, per 100 parts by weight of the whole polyimide resin,
wherein W means a single bond, an alkylene group having 1 to 4 carbon atoms, —O—, —SO 2 — or —CO—, Ar 1 denotes a divalent aromatic group represented by the following formula (1) or (2):
in which X is a single bond, an alkylene group having 1 to 4 carbon atoms, —O—, —SO 2 — or —CO—, Y is an alkylene group having 1 to 4 carbon atoms, and Z 1 and Z 2 are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, Ar 2 represents a divalent aromatic group having one or two hydroxyl groups or carboxyl groups, preferably, a divalent aromatic group represented by the following formula (4) or (5):
in which X and Y have the same meanings as defined above, and Z 3 and Z 4 are both hydroxyl groups or carboxyl groups, or one of them is a hydroxyl group or carboxyl group and the other is a hydrogen atom, R 1 and R 6 individually mean an alkylene group having 1 to 4 carbon atoms or a group represented by the following formula (3):
in which Alk is an alkylene group bonded to a silicon atom and having 1 to 4 carbon atoms, R 2 and R 5 individually denote an alkylene group having 1 to 4 carbon atoms, and n stands for an integer of 1 to 32.
In the adhesive for electronic parts according to the present invention, the epoxy resin may preferably be a trihydroxyphenylmethane type epoxy resin. The adhesive for electronic parts according to the present invention may further comprise a novolak type phenol resin or a bismaleimide resin.
According to the present invention, there is also provided an adhesive tape for electronic parts, comprising a substrate and an adhesive layer formed on at least one side of the substrate using the adhesive for electronic parts described above.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The polyimide resins used in the adhesives for electronic parts according to the present invention will be first described. At least one of the two polyimide resins is a reactive polyimide having a functional group (hereinafter referred to as the “epoxy-reacting group”) which reacts with an epoxy group and can be obtained by polycondensing a tetracarboxylic acid dianhydride represented by the following formula (IV) with a siloxane compound represented by the following formula (V), a diamine compound represented by the following formula (VI) and a diamine compound having an epoxy-reacting group represented by the following formula (VII) in an organic solvent, and imidating the resultant polyamic acid by ring closure. The other one can be obtained by polycondensing a tetracarboxylic acid dianhydride represented by the following formula (IV) with a siloxane compound represented by the following formula (V) and a diamine compound represented by the following formula (VI) in an organic solvent in the same manner as described above, and imidating the resultant polyamic acid by ring closure.
H 2 N—Ar 1 —NH 2 (VI)
H 2 N—Ar 2 —NH 2 (VII)
wherein W, Ar 1 , Ar 2 , R 1 to R 6 and n have the same meanings as defined above.
Examples of the tetracarboxylic acid dianhydride represented by the formula (IV) include 2,3,3′,4′-biphenyltetracarboxylic acid dianhydride, 3,4,3′,4′-biphenyltetracarboxylic acid dianhydride, 2,3,2′,3′-biphenyltetracarboxylic acid dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 3,4,3′,4′-benzophenone tetracarboxylic acid dianhydride and 4′,4′-biphthalic acid dianhydride.
Examples of the siloxane compound having amino groups at both terminals thereof represented by the formula (V) include 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxanes (for example, tetramer to octamer of aminopropyl-terminated dimethylsiloxane, etc.), 1,3-bis(3-aminophenoxymethyl)-1,1,3,3-tetramethyldisiloxane, α,ω-(3-aminophenoxymethyl)polydimethylsiloxane, 1,3-bis(2-(3-aminophenoxy)ethyl)-1,1,3,3-tetramethyldisiloxane, α,ω-bis(2-(3-aminophenoxy)ethyl)polydimethylsiloxane, 1,3-bis(3-(3-aminophenoxy)propyl)-1,1,3,3-tetramethyldisiloxane and α,ω-bis(3-(3-aminophenoxy)propyl)polydimethylsiloxane. In the above-mentioned siloxane compounds, those having an average polymerization degree of 1 to 32, preferably 1 to 16 and more preferably 4 to 8 are used in the case of the polysiloxanes.
Examples of the diamine compounds represented by the formula (VI) include 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-dimethyl-4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 3,3′-dimethyl-4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,3′-dimethoxy-4,4′-diaminophenylmethane, 2,2′-bis(3-aminophenyl)propane, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, benzidine, 3,3′-dimethylbenzidine, 3,3′-dimethoxybenzidine, 3,3′-diamino-biphenyl, 1,3-bis(3-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-methyl-4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-chloro-4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3,5-dimethyl-4-(4-aminophenoxy)phenyl]propane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[3-chloro-4-(4-aminophenoxy)phenyl]ethane, bis[4-(4-aminophenoxy)phenyl]methane, bis[3-methyl-4-(4-aminophenoxy)phenyl]methane, 4,4′-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4′-[1,3-phenylenebis(1-methylethylidene)]bisaniline and 4,4′-[1,4-phenylenebis(1-methylethylidene)]bis(2,6-dimethylaniline). Two or more of these diamine compounds may be used in combination.
Examples of the diamine compound having an epoxy-reacting group represented by the formula (VII) include 2,5-dihydroxy-p-phenylenediamine, 3,3′-dihydroxy-4,4′-diaminodiphenyl ether, 4,3′-dihydroxy-3,4′-diaminodiphenyl ether, 3,3′-dihydroxy-4,4′-diaminobenzophenone, 3,3′-dihydroxy-4,4′-diaminodiphenylmethane, 3,3′-dihydroxy-4,4′-diaminodiphenyl sulfone, 4,4′-dihydroxy-3,3′-diaminodiphenyl sulfone, 2,2′-bis[3-hydroxy-4-(4-aminophenoxy)phenyl]propane, bis[3-hydroxy-4-(4-aminophenoxy)phenyl]methane, 3,3′-dicarboxy-4,4′-diaminodiphenyl ether, 4,3′-dicarboxy-3,4′-diaminodiphenyl ether, 3,3′-dicarboxy-4,4′-diaminobenzophenone, 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 3,3′-dicarboxy-4,4′-diaminodiphenyl sulfone, 4,4′-dicarboxy-3,3′-diaminodiphenyl sulfone, 3,3′-dicarboxybenzidine, 2,2′-bis[3-carboxy-4-(4-aminophenoxy)phenyl]propane and bis[3-carboxy-4-(4-aminophenoxy)phenyl]methane. Two or more of these diamine compounds may be used in combination.
In order to obtain the polyimide resin according to the present invention, one of the above-mentioned tetracarboxylic acid dianhydride is allowed to react with the siloxane compound having amino groups at both terminals thereof and the diamine compounds at +20 to 150° C., preferably 0 to 60° C. for several tens minutes to several days in the presence of a solvent to form a polyamic acid, and the resultant polyamic acid is further imidated, whereby the polyamide resin can be prepared. Examples of the solvent include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide and dimethyl sulfone; phenolic solvents such as phenol, cresol and xylenol; and acetone, tetrahydrofuran, pyridine, tetramethylurea, etc.
Methods for the imidation include a method comprising cyclizing the polyamic acid by dehydration with heat and a method comprising chemically cyclizing the polyamic acid by using a cyclization-dehydration catalyst. When the polyamic acid is cyclized by dehydration with heat, the reaction temperature is 150 to 400° C., preferably 180 to 350° C., and the reaction time is several tens minutes to several days, preferably 2 to 12 hours. Examples of the cyclization-dehydration catalyst in the case of the chemical cyclization include anhydrides of acids such as acetic acid, propionic acid, butyric acid and benzoic acid. It is preferable to use pyridine or the like for promoting the ring-closure reaction. The amount of the catalyst used is at least 200 mol %, preferably 300 to 1,000 mol % based on the total amount of the diamines.
In the reactive polyimide used in the present invention, the structural units represented by the formula (I) and the structural units represented by the formulae (II) and (III) are preferably arranged at a molar ratio of 5/95 to 50/50. A proportion of the structural units represented by formula (II) to the structural units represented by the formulae (III) is in a range of 0:100 to 99:1, preferably 80:20 to 95:5, more preferably 50:50 to 95:5 in terms of a molar ratio. The number average molecular weight of the reactive polyimide is preferably in a range of 5,000 to 40,000. In the case of the polyimide having no epoxy-reacting group, the structural units represented by the formula (I) and the structural units represented by the formula (II) are preferably arranged at a molar ratio of 5/95 to 50/50. The number average molecular weight thereof is preferably in a range of 5,000 to 40,000. If the number average molecular weight of each of the above-described polyimides is lower than 5,000, the film-forming property of the resulting adhesive is impaired. On the other hand, any molecular weight higher than 40,000 results in an adhesive deteriorated in solubility in solvents and having poor processability. It is hence preferred that the molecular weight be within above range. Incidentally, the number average molecular weight is a value determined by using tetrahydrofuran as an eluent, Shodex 80M (2 columns, product of Showa Denko K.K.) as a column and polystyrene as a standard reference substance in accordance with the GPC method.
In the adhesives for electronic parts according to the present invention, at least one of the two polyimide resins must be a reactive polyimide having an epoxy-reacting group. In the present invention, these two polyimide resins must differ in Tg by at least 20° C. from each other. The difference in Tg is preferably 25 to 180° C. In this case, the Tg of either polyimide resin may be higher. The combined use of at least two polyimide resins different in Tg by at least 20° C. from each other permits easily adjusting the flexibility that is a feature of the siloxane-modified polyimide resin, so that no adverse influence is exerted on its properties upon melting while making it possible to lower the adhesion temperature. Therefore, an adhesive layer can be formed with ease. More specifically, the resultant adhesive begins to soften at a low temperature, undergoes no rapid change of viscosity and has excellent heat resistance. In addition, an effect that flexibility is imparted to a product cured by the epoxy resin is brought about. If the difference in Tg between these polyimide resins is smaller than 20° C., the resulting adhesive cannot satisfy the requirements on both heat resistance and the ability to form an adhesive layer, and low-temperature adhesive property. If the difference is greater than 180° C. on the other hand, compatibility of the polyimide resins with each other is deteriorated, so that phase separation or the like is caused, resulting in a failure to form an adhesive layer. The Tg was measured by means of a Reovibron (Model DDV-01/25 FP) manufactured by Orientex Co. The measurement was conducted by applying a synthetic wave of 110 Hz under conditions of a sample length of 5 cm, a sample width of 0.2 cm, a sample thickness of generally about 50 μm, a measuring temperature of 25 to 300° C. and a heating rate of 3° C./min, and the maximum value of tan δ was regarded as Tg.
The Tg of each polyimide resins may be optionally designed by changing the kinds of the above-described raw materials, i.e., the tetracarboxylic acid dianhydride, diamine compounds and siloxane compound, and the content of the siloxane units. In general, the Tg tends to lower as the content of the siloxane units increases.
The polyimide resins different in Tg from each other are preferably blended in such a proportion that one polyimide resin is contained in a range of 25 to 400 parts by weight per 100 parts by weight of the other polyimide resin. The reactive polyimide resin having an epoxy-reacting group must be contained in a proportion of at least 25 parts by weight per 100 parts by weight of the whole polyimide resin, with the inclusion in the range of 25 to 75 parts by weight being preferred. If the content thereof is lower than 25 parts by weight, a problem that the heat resistance of the resulting adhesive is deteriorated arises.
In the adhesives according to the present invention, the total content of the polyimide resins must be at least 30 wt. % based on the whole resin component. If the total content of the polyimide resins is lower than 30 wt. %, the flexibility of the resulting adhesive is impaired, and such problems that its adhesive property to organic films and the like is deteriorated arise.
As the epoxy resin which is another main component of the adhesives for electronic parts according to the present invention, any epoxy resin may be used so far as it is publicly known. Examples thereof include bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolak type epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins and glycidylamine type epoxy resins. Trihydroxy-phenylmethane type epoxy resins are particularly preferred. A blending proportion of the epoxy resin is in a range of 10 to 100 parts by weight, preferably 30 to 70 parts by weight per 100 parts by weight of the whole polyimide resin. If the blending proportion of the epoxy resin is lower than 10 parts by weight, the heat resistance of the resulting adhesive cannot be improved. If the proportion exceeds 100 parts by weight on the other hand, the flexibility as the resin is lost.
The adhesives for electronic parts according to the present invention may comprise, if desired, a novolak type phenol resin. Any known resin may be used as the novolak type phenol resin, and bisphenol A type novolak phenol resins and alkylphenol type novolak phenol resins are preferably used. A preferable amount of the novolak type phenol resin used is in a range of 80 parts by weight or less, preferably 10 to 80 parts by weight, more preferably 20 to 70 parts by weight per 100 parts by weight of the whole polyimide resin.
The adhesives for electronic parts according to the present invention may preferably comprise further a maleimide resin. Preferable examples of usable maleimide resins include bismaleimide resins having 2 maleimide groups. Examples of bismaleimides include N,N′-m-phenylenebismaleimide, N,N′-toluylenebismaleimide, N,N′-4,4′-biphenylenebismaleimide, N,N′-(3,3-dimethylphenylmethane)bismaleimide, N,N′-4,4′-dimethylphenylpropanebismaleimide, N,N′-4,4′-dimethylphenyl ether bismaleimide and N,N′-3,3′-dimethylphenyl sulfone bismaleimide. A blending proportion of the maleimide resin is in a range of 50 parts by weight or lower, preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight per 100 parts by weight of the whole polyimide resin.
The adhesives for electronic parts according to the present invention may comprise, if desired, a hardener and a hardening accelerator for epoxy resins. Examples thereof include imidazoles, tertiary amines, phenols, dicyandiamides, aromatic diamines and organic peroxides. Organic and/or inorganic fillers may also be contained. With respect to the organic and/or inorganic fillers, for example, alumina, silicon nitride, boron nitride and the like may be contained for the purpose of imparting insulating property and thermal conductivity to the resulting adhesive, powder of metals such as silver, copper and nickel for the purpose of imparting thermal conductivity to the resulting adhesive, and titanium oxide, calcium carbonate, silica, zinc oxide, magnesium oxide and the like for the purpose of adjusting the dielectric properties, coefficient of thermal expansion, viscoelasticity and tackiness of the resulting adhesive. A preferable content thereof is in a range of 1 to 70 wt. %, preferably 5 to 50 wt. % based on the total solid content of the adhesive.
The adhesive tapes for electronic parts according to the present invention have an adhesive layer formed with one of the above-described adhesives on at least one side of a substrate. Preferable examples of the substrate include releasable films, heat-resistant insulating films, paper sheets the surfaces of which have been subjected to a releasing treatment, metal foils and metal sheets, with heat-resistant insulating films being particularly preferred. Specific examples thereof include films of synthetic resins such as polyethylene, polypropylene, fluorocarbon resins, polyimide and polyethylene terephthalate. Those having a thickness ranging from 10 to 300 μm are preferably used. Examples of the metal foils and metal sheets include those formed of copper, cupronickel, silver, iron, 42 alloy or stainless steel. Those having a thickness ranging from 10 to 1,000 μm are preferably used.
In the formation of the adhesive layer, may be adopted a method in which one of the above-described adhesives for electronic parts is coated on a surface of the substrate, a method in which the adhesive is injection-molded into a film, and the film is then laminated on the substrate, or the like. In the case where the adhesive layer is formed by coating, it is only necessary to form an adhesive layer by using an adhesive solution obtained by dissolving the resin components in, for example, a polar solvent to apply it by any known method. If desired, the adhesive layer formed may be heated into a semi-cured state of the B- stage. A thickness of the adhesive layer is preferably in a range of 5 to 100 μm, more preferably 10 to 50 μm.
In the adhesive tapes for electronic parts according to the present invention, a protective film may be stuck on the surface of the adhesive layer as needed. As the protective film, is used a paper sheet treated with a releasing agent, or a film of a synthetic resin such as polyethylene, polypropylene or polyethylene terephthalate.
In the case where the substrate is a releasable film or a paper sheet the surface of which has been subjected to a releasing treatment, such a substrate may be peeled off from the adhesive layer upon use, and only the adhesive layer is used as an adhesive tape.
The adhesives for electronic parts according to the present invention have the above-described features. Therefore, when such an adhesive is coated on a substrate to form an adhesive layer, the adhesive layer has sufficient flexibility, exhibits uniform low-temperature adhesive property and moreover has sufficient flexibility and excellent heat resistance and dimensional stability to heat history even after the adhesive layer is cured by heating. Accordingly, the adhesives for electronic parts according to the present invention are suitable for use as adhesives for laminating materials of which flexibility is required, such as flexible wiring substrates and copper-clad substrates for TAB and provide excellent TAB tapes in particular.
EXAMPLES
Synthesis Example 1
Polyimide Having No Epoxy-reacting Group (Polyimide Resin A)
A flask equipped with a stirrer was charged with 10.33 g (52 mmol) of 3,4′-diaminodiphenyl ether, 18.23 g (48 mmol) of 1,3-bis(3-aminophenoxymethyl)-1,1,3,3-tetramethyldisiloxane, 32.22 g (100 mmol) of 3,4,3′, 4′-benzophenonetetracarboxylic acid dianhydride and 300 ml of N-methyl-2-pyrrolidone (NMP) under ice cooling, and the mixture was stirred for 1 hour. The resultant solution was then allowed to react at room temperature for 3 hours in a nitrogen atmosphere to synthesize a polyamic acid. To a solution of the thus-obtained polyamic acid were added 50 ml of toluene and 1.0 g p-toluenesulfonic acid, and the resultant mixture was heated to 160° C. While separating water from an azeotrope with toluene, imidation was conducted for 3 hours. Toluene was distilled off from the reaction mixture, and the resultant polyimide varnish was poured into methanol. Precipitate thus obtained was separated, ground, washed and dried, thereby obtaining 54.3 g (yield: 95%) of a polyimide. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 2
Reactive Polyimide (Polyimide Resin a)
A reactive polyimide (62.5 g; yield: 93%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 16.10 g (39 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1.25 g (5 mmol) of 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 21.25 g (56 mmol) of 1,3-bis(3-aminophenoxymethyl)-1,1,3,3-tetramethyldisiloxane, 32.22 g (100 mmol) of 3,4,3′, 4′-benzophenonetetracarboxylic acid dianhydride and 300 ml of N-methyl-2-pyrrolidone (NMP). An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 3
Polyimide Having No Epoxy-reacting Group (Polyimide Resin B)
A polyimide (67.4 g; yield: 92%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 33.65 g (82 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 13.84 g (18 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 29.42 g (100 mmol) of 2,3,3′,4′-biphenyltetracarboxylic acid dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 4
Reactive Polyimide (Polyimide Resin b)
A reactive polyimide (67.8 g; yield: 94%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 30.38 g (74 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2.35 g (8 mmol) of 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 13.84 g (18 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 29.42 g (100 mmol) of 2,3,3′,4′-biphenyl-tetracarboxylic acid dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 5
Polyimide Having No Epoxy-reacting Group (Polyimide Resin C)
A polyimide (78.7 g; yield: 97%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 31.98 g (78 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 16.95 g (22 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 35.83 g (100 mmol) of bis(3,4-dicarboxyphenyl) sulfone dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 6
Reactive Polyimide (Polyimide Resin c)
A reactive polyimide (75.0 g; yield: 93%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 30.38 g (74 mmol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1.12 g (4 mmol) of 3,3′-dicarboxy-4,4′-diaminodiphenylmethane, 16.85 g (22 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 35.83 g (100 mmol) of bis(3,4-dicarboxyphenyl) sulfone dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 7
Polyimide Having No Epoxy-reacting Group (Polyimide Resin D)
A polyimide (47.1 g; yield: 93%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 26.13 g (89 mmol) of 1,3-bis(3-aminophenoxy)benzene, 8.14 g (11 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 20.02 g (100 mmol) of bis(3,4-dicarboxyphenyl) ether dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
Synthesis Example 8
Reactive Polyimide (Polyimide Resin d)
A reactive polyimide (45.6 g; yield: 91%) was obtained in accordance with a process similar to that in Synthesis Example 1 using 23.55 g (81 mmol) of 1,3-bis(3-aminophenoxy)benzene, 2.06 g (9 mmol) of 3,3′-dihydroxy-4,4′-diaminodiphenylmethane, 8.05 g (10 mmol) of an octamer of aminopropyl-terminated dimethylsiloxane, 20.02 g (100 mmol) of bis(3,4-dicarboxyphenyl)ether dianhydride and 300 ml of N-methyl-2-pyrrolidone. An infrared absorption spectrum of this polyimide was determined. As a result, typical absorption attributable to imide was observed at 1718 cm −1 and 1783 cm −1 . The molecular weight, glass transition temperature and thermal decomposition-starting temperature thereof were also determined. The results thereof are shown in Table 1.
TABLE 1
Number
Glass
Thermal
average
transition
decomposition-
Epoxy-reacting
molecular
temperature
starting
Polyamide
group
weight
(° C.)
temperature (° C.)
Syn. Ex. 1
Not contained
27000
185
420
Syn. Ex. 2
Contained
18000
160
421
Syn. Ex. 3
Not contained
28000
80
425
Syn. Ex. 4
Contained
25000
80
425
Syn. Ex. 5
Not contained
22000
50
421
Syn. Ex. 6
Contained
21000
50
420
Syn. Ex. 7
Not contained
17000
100
430
Syn. Ex. 8
Contained
16000
105
425
Example 1
In tetrahydrofuran (hereinafter referred to as “THF”) were dissolved 25 parts by weight of Polyimide Resin A, 25 parts by weight of Reactive Polyimide Resin a, 20 parts by weight of a trihydroxy-methane type epoxy resin (Epikote 1032, trade name; product of Yuka Shell Epoxy K.K.), 20 parts by weight of p-tert-butyl type phenol resin (CKM2432, trade name; product of Showa Highpolymer Co., Ltd.), a bismaleimide resin (EMI-MP, trade name; product of Mitsui Chemicals, Inc.) and 0.1 part by weight of 2-ethyl-4-methylimidazole, thereby preparing an adhesive of 40 wt. % resin solid concentration.
Example 2
An adhesive was prepared in the same manner as in Example 1 except that the amounts of Polyimide Resin A and Reactive Polyimide resin a were changed from 25 parts by weight and 25 parts by weight to 40 parts by weight and 10 parts by weight, respectively.
Example 3
An adhesive was prepared in the same manner as in Example 1 except that Polyimide Resin A was changed to Reactive Polyimide Resin b.
Example 4
An adhesive was prepared in the same manner as in Example 1 except that Polyimide Resin A and Reactive Polyimide Resin a were changed to Polyimide Resin B and Reactive Polyimide Resin d, respectively.
Comparative Example 1
An adhesive was prepared in the same manner as in Example 1 except that Reactive Polyimide Resin a alone was used in an amount of 50 parts by weight as a polyimide resin.
Comparative Example 2
An adhesive was prepared in the same manner as in Example 1 except that Polyimide Resin A alone was used in an amount of 50 parts by weight as a polyimide resin.
Comparative Example 3
An adhesive was prepared in the same manner as in Example 1 except that Polyimide Resin A and Reactive Polyimide Resin a were changed to Polyimide Resin C and Reactive Polyimide Resin c, respectively.
Comparative Evaluation Tests and Results Thereof
Each of the adhesives prepared in accordance with the respective processes was applied to a polyester film having a thickness of 38 μm and dried at 100° C. for 5 minutes to produce a laminate film having an adhesive layer 25 μm thick.
A hole of 1 cm×1 cm was made in the resultant laminate film by perforating, and the film was superimposed on a copper foil (3EC-VLP foil, product of Mitsui Mining & Smelting Co., Ltd.; thickness: 25 μm) in such a manner that the adhesive layer faces a roughened surface of the copper foil, thereby laminating them by a laminator composed of rubber rolls under conditions of a rate of 1 m/min and a linear pressure of 1 kg/cm. The thus-obtained laminate film was investigated as to the degree of embedding of the adhesive in the roughened surface of the copper foil and runout of the adhesive from the hole. The results thereof are shown in Table 2.
TABLE 2
Rate of
change in
Proper range of lamin-
shape by
Difference
ating temperature
hot pressing
in Tg (° C.)
(° C.)
Practicability
(%)
Practicability
Ex. 1
25
145-170
Practicable
2
Practicable
Ex. 2
25
160-180
Practicable
4
Practicable
Ex. 3
80
105-140
Practicable
2
Practicable
Ex. 4
25
90-130
Practicable
6
Practicable
Comp.
0
170
Unpracticable
6
Practicable
Ex. 1
Comp.
0
170-175
Unpracticable
20
Unpractic-
Ex. 2
able
Comp.
0
70-75
Unpracticable
10
Practicable
Ex. 3
The embedding ability was visually judged. With respect to the runout, a degree of runout of the adhesive at the greatest runout part about each side of the hole was determined through an optical reflection microscope of 100 magnifications, and the maximum value among the degrees of runout about 4 sides was regarded as the degree of runout. More specifically, in the above-described procedure, the laminating temperature was raised 5° C. by 5° C. to determine the embedding ability in the copper foil and the degree of runout of the adhesive at the respective temperatures. Since the level of runout allowable for practical use is 100 μm, laminating temperatures at which the embedding was sufficient, and the degree of runout was at most 100 μm were evaluated as a proper range of laminating temperature. The proper range of laminating temperature must extend over 20° C. at the minimum in view of the margin of process for practical use. In the cases of Comparative Examples 1 to 3, however, the proper range of laminating temperature is narrow as shown in Table 2, so that such adhesives were unable to be put to practical use.
When the adhesives are used for TAB tapes, an IC chip is often wire-bonded to a circuit pattern formed on a TAB tape. Therefore, with respect to properties at that time, the resistance to heat and pressure at a high temperature of each adhesive was evaluated as an alternate property. The evaluation method is as follows. The polyester film of each of the above laminate films was removed, and the adhesive alone was heated and cured to prepare a cured adhesive film. This adhesive film was cut into 1-cm 2 , and a cut piece was hot-pressed at 200° C. for 30 seconds under a pressure of 100 kg/cm 2 by a hot press. The area of the cut piece after the hot pressing was measured to determine a rate of change in shape in accordance with the following equation:
Rate of change in shape (%)=100×(area after hot pressing−1)
When the rate of change in shape was 10% or lower, such an adhesive was ranked as one having excellent resistance to heat and pressure and capable of being subjected to wire bonding. For example, when a capillary is brought into contact under pressure with a circuit pattern upon wire bonding, and an adhesive under the pattern undergoes softening or the like, bonding force is absorbed, resulting in a failure to fully bond wires to the circuit pattern. Therefore, it is necessary for the adhesive to have excellent resistance to heat and pressure. As shown in Table 2, the adhesives of Examples 1 to 4 each had excellent resistance to heat and pressure, but the adhesive of Comparative Example 2 had poor resistance to heat and pressure and was of no practical use because no reactive polyimide is used though the Tg of the polyimide resin is high.
As apparent from the results shown in Table 2, the adhesives of Examples 1 to 4 are wide in the proper range of laminating temperature and low in the rate of change in shape, and are hence excellent from the viewpoint of practical use. On the other hand, the adhesive of Comparative Example 1 is a pinpoint in the proper range of laminating temperature and has no practicability. The adhesive of Comparative Example 2 is narrow in the proper range of laminating temperature and high in the rate of change in shape, and hence has no practicability. The adhesive of Comparative Example 3 uses the polyimide resins having the same Tg. Therefore, it undergoes a rapid change of viscosity, is narrow in the proper range of laminating temperature and has no practicability. | The invention provides an adhesive for electronic parts, which satisfies both points of heat resistance and the ability to form an adhesive layer, and of low-temperature adhesive property, and an adhesive tape for electronic parts making use of such an adhesive. The adhesive comprises, as a resin component, two polyimide resins different in glass transition temperature by at least 20deg C. From each other, and an epoxy resin. At least one of the two polyimide resins is a reactive polyimide having structural units represented by the following formula (I), structural units represented by the following formula (II) and structural units represented by the following formula (III), the other is a polyimide having structural units represented by the formula (I) and structural units represented by the formula (II), and the reactive polyimide and the epoxy resin are contained in ranges of at least 25 parts by weight and 10 to 100 parts by weight, respectively, per 100 parts by weight of the whole polyimide resin, wherein W means a single bond, an alkylene group, --O--, --SO 2 -- or --CO--, Ar 1 denotes a divalent aromatic group such as a diphenylmethane group, and Ar 2 represents a divalent aromatic group having OH group(s) or COOH groups. |
TECHNICAL FIELD
[0001] The present invention relates to a plant growth system for growing plants.
BACKGROUND OF THE INVENTION
[0002] It is known to grow plants in a substrate, consisting practically entirely of a monolithic block of mineral wool, as large as the extent of the root system of the plant is expected to be or to become, or even larger, if more than one plant is grown in or on the substrate. As an advantage of such a known technique, control over the plant growth is mainly dependent on product parameters of the specific mineral wool material, employed for manufacturing the block.
[0003] As an alternative it is known to employ a collection or number of smaller mineral wool elements, which can for instance be arranged in a container or pot. Such a known technique has an advantage, that roots can easily grow and penetrate into the space occupied by the mineral wool elements, possibly in the spaces between these elements. With the “loose” arrangement of the mineral wool elements, a good and proper distribution of liquids and air can be achieved. However, a disadvantage of such a system is the coherence of the larger number of mineral wool elements, which coherence is in practice more often than not too low, at least too loose for some plants to be grown.
[0004] It is known from WO 4004/017.718 that a combination of a lower mineral wool slab in a container with a cover layer of instance peat thereon can be used to grow plants. The disc of mineral wool is primarily intended as a kind of fluid buffer to avoid dehydration of the system, for instance in case of drought.
[0005] According to the teachings of U.S. Pat. No. 5,608,989 a substrate for plant growth can be arranged on a mat through which moisture and air can pass.
SUMMARY OF THE INVENTION
[0006] The present invention, in contrast, relates to a plant growth system, comprising a root substrate formed by a number of essentially independent mineral wool elements and a top substrate, comprising at least one essentially unitary or at least coherent mineral wool element.
[0007] In specific embodiments of the invention this combination of features can result in a previously unknown coherence of the essentially “loose” mineral wool elements required for growing plants more efficiently, while the top substrate can be utilized to more effectively also perform other functions, that relate to plant growing, such as fluid distribution and release, fixation of the roots for harvesting, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 a prospective view of the set up of a number of plant growth systems according to the present invention;
[0009] FIG. 2 a cross-section through a plant system according to the present invention;
[0010] FIG. 3 a prospective view of a top substrate employed in an embodiment of a system according to the present invention; and
[0011] FIG. 4 another example or embodiment of a top substrate for a system according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] In certain specific embodiments of the present invention, wherein a container is provided, the top substrate is preferably anchored to the container for stable arrangement of at least the top substrate in the container. Thereby, also the “loose” mineral wool elements can be kept together in a stable manner, providing the desired coherence there between, even though these are loose mineral wool elements. The anchoring means can be embodied in many different ways. For instance, hooks or couplings acting on or between the top substrate and/or the container can be employed. Such a coupling could in an envisaged embodiment, be formed from an inward protrusion at the inner wall of the container, suitable to cooperate with a cut or groove in the circumference of the top substrate. In a preferred embodiment, the top substrate is dimensioned such and in relation to the dimensions of the container, that the top substrate can be placed in a fitting arrangement in the container. By appropriate dimensioning, the anchoring means are thus provided, without having necessarily to provide any additional components, such as a coupling or a hook.
[0013] In a further preferred embodiment of the present invention, a top substrate exhibits specifically a horizontal water distributing capability. Thereby, water can be directed to all positions underneath the top substrate, where water may be required by the growing roots of a plant to be grown.
[0014] In yet a further preferred embodiment of the present inventions the top substrate exhibits a fluid retention capability combined with a regular fluid release capability. Thereby, a substantially continuous throughput or supply of fluid to the root substrate and thereby to the roots of the growing plant can be achieved. Timing of water supply can hereby be enhanced. Preferably, the top substrate also exhibits a resaturization characteristic, enabling good repeated wettability. Thus, a sufficient capability of being resaturated can be provided, and an improved water management can be enabled.
[0015] In another preferred embodiment of the invention the top substrate comprises a disc of mineral wool material. The disc can have any one of a number of circumferential shapes, such as circular, rectangular, symmetrical and elongate, etc. Such shapes are preferably chosen in correspondence with the shape of a container to be used, if a container is actually used. Again, in such an embodiment of the invention, the shape as well as the dimensioning of the mineral wool material top substrate can provide positive placement of the top substrate to achieve a desired degree of coherence within the root substrate, comprising separate mineral wool elements.
[0016] In a preferred embodiment of the invention the top substrate comprises a disc of mineral wool material having at least one hole for passage there through of a plant stem. In such an embodiment, the disc of mineral wool material does not form in any way a barrier for root growth of a plant to be grown in the system. Root growth is, from the hole, directed straight into the root substrate, where root growth is positively enhanced due to the loose nature of the individual mineral wool elements.
[0017] In yet a further embodiment of the present invention, the top substrate comprises at least one hole for accommodating a plug with a seed, a seedling or a young plant, that is planted in the plug. As such, the top substrate also forms a positioning means, wherein the hole indicates a position, where the plug with the seed, seedling or young plant should be placed.
[0018] Further, in yet another preferred embodiment of the present invention, the top substrate can comprise fluid guiding channels for distribution of fluid over or through the top substrate. From the top substrate, the fluid can thereafter be directed into the root substrate in a manner, by which fluid is evenly distributed over the area of the top substrate, where under roots are suspected, expected and intended to grow.
[0019] In a further preferred embodiment of the present invention the top substrate comprises at least one planting position and fluid guiding channels for distribution of fluid of the top substrate, where the channels extend radially away from the at least one planting position. In such an embodiment, fluid supply is directed at a position close to the planting position, from which central watering place the fluid is preferably evenly distributed over and through the area, under which root plants are suspected, expected and intended to grow. A non central fluid supply is also envisaged especially in embodiments where the top substrate is designed for an improved water dispersal.
[0020] In a preferred embodiment of the present invention the top substrate comprises a disc of mineral wool material having a thickness of between 1 and 10 cm, more preferred of 3-5 cm, and most preferably of approximately 4 cm. Dependent on the material properties of the top substrate other thicknesses can also be chosen, in so far as the underlying root substrate of the loose and individual mineral wool elements can hereby be given a degree of coherence, which is desirable for root growth of plants to be grown.
[0021] In yet another preferred embodiment of the invention, the mineral wool material of the top substrate has a density of 40-120 kg/m 3 , more preferred of 50-100 and most preferably approximately 80 kg/m 3 . With a density in these ranges, preferred water retention and release properties can easily be achieved.
[0022] In yet another preferred embodiment of the present invention the mineral wool elements of the root substrate comprise at least one of blocks, balls, cubes, bars, pills, etc. of mineral wool material. A great many number of possible shapes and forms of the mineral wool elements are possible. One such form is the Growcube® of the present assignee.
[0023] Yet further, in a preferred embodiment of the present invention, the mineral wool elements of the root substrate are made from mineral wool material having a density of between 40 and 120 kg/m 3 , more preferred 50-10, and most preferably approximately 80 kg/m 3 . In such an embodiment, the material of the mineral wool elements enables that preferred properties of the root substrate can relatively easily be realized.
[0024] Preferably, the root substrate and the top substrate exhibit a degree of hydrophilicity, which depends upon the species of the plants to be grown with the plant growth system according to the present invention. For this purpose, several measures can be incorporated into the mineral wool material of the root substrate and of the top substrate. Properties thereof like density, fiber length or orientation, fiber diameter, as well as other parameters and variations thereof in radial, transversal or any other direction may serve to achieve the desired effects of water retention, water release, air retention properties, the capacity of roots to penetrate into the mineral wool material, etc. The mineral wool materials can be provided with additives, such as surfactants, clay, organic, natural hydrophilic components (for example cocos, peat, etc.) and other additives, in order to increase or influence the hydrophilicity of the top substrate and the root substrate. The mineral wool can preferably be bonded with a binder in a conventional manner. Also, the binder can be hydrophilic and most preferably it comprises a furan binder, preferably of the type, described in EP-A-0.849.987. The advantage of such binders is that they provide hydrophilicity to the substrates, but are not washed out during wetting and or drying of the mineral wool materials of the top substrate and of the root substrate, and then still maintain a desired degree of hydrophilicity, exhibiting desired water retention and resaturation properties. Further other additives can also be employed.
[0025] Herein below, a preferred embodiment of the present invention will be described, referring to the accompanying drawings, and in which the same reference numbers are used to identify the same or similar aspects and/or components in the different embodiments.
[0026] In FIG. 1 , a prospective view is shown of three systems 1 according to the present invention.
[0027] Shown in FIG. 1 is a holder 2 , in which a number of containers 3 are arranged. Each container 3 is used for and intended to contain a root system of a plant 4 , which is to be grown in the container 3 .
[0028] Further, a water supply system 5 leads to each of the containers 3 to water the plants 4 .
[0029] As shown in FIG. 2 , which represents a cross-section through one of the containers 3 , possibly in an embodiment as shown in FIG. 1 , the container 3 or pot is filled with cubes of mineral wool material. The assembly of these cubes 6 of mineral wool material is designated the root substrate 7 . On top of the root substrate 7 , a top substrate 8 is arranged. The top substrate 8 comprises a disc 9 of mineral wool material.
[0030] The disc 9 of mineral wool material has a circumference shape and size, as a result of which the disc 9 of mineral wool material can be arranged in the container 3 or pot in a close fitting manner. Thus, the loose mineral wool cubes 6 of the root substrate 7 are encapsulated by the container 3 or pot and the top substrate 8 or disc 9 . Thus, even though the mineral wool cubes 6 are loosely arranged in the root substrate, a sufficiently stable base for plant growth can be provided in accordance with the present invention. Moreover, especially when the plants to be grown are flower plants, such as Gerbera, the flowers can more easily be picked of or cut of, when these flowers are harvested, because the plant is placed sufficiently firm in the system 1 according to the invention than what would be the case, if only the loose mineral wool material cubes 6 where used. The more obvious solution of providing a monolithic block of mineral wool material to provide the desired sturdiness is known to exhibit other disadvantages, such as that root growth is not sufficiently promoted or even hindered, when a massive block of mineral wool material is utilized for growing such plants having formerable roots, or of which the roots are not easily grown.
[0031] Further, in the representation of FIG. 2 , a plug 10 is arranged in a central hole 11 in the disc 9 . The plug 10 is used to insert a seed, a seedling or a young plant, the roots of which may penetrate through the plug and enter into the space below the top substrate 8 in the form of disc 9 into the root substrate formed by the mineral wool cubes 6 . The hole 11 in the disc 9 serves to identify a positive position through the plug 10 . The plug 10 may however be omitted and a young plant or seedling may be inserted directly into the hole 11 .
[0032] In FIG. 3 the mineral wool disc 9 is shown in isolation. More clearly herein, the hole 11 is visible. The disc 9 is shown in FIG. 3 to have practically smooth surfaces. In contrast, especially the circumferential surface of the disc can be provided with grooves or the like to enhance positive placement of the disc 9 in the container 3 or pot.
[0033] The disc 9 has a thickness, resulting in a sufficient stiffness to achieve the objectives of the present invention. The material chosen for the disc 9 is a mineral wool material, the parameters of which are also chosen or set in correspondence with the intended purpose thereof and provide the desired strength or sturdiness of the disc 9 . Also the density, fiber orientation, thickness, etc., can be chosen or varied accordingly.
[0034] In FIG. 4 , a further embodiment of a disc 9 is shown to have grooves or channels 12 , extending radially from the hole 11 in an outward direction. The purpose of the grooves 12 is to enhance water distribution of the surface of the disc 9 and therewith also over the roots of the plant, growing underneath the disc 9 , that forms a top substrate 8 . Other measures can also be taken to achieve a desired fluid distribution. A spiraling groove can also be provided. Also, the material characteristics of the mineral wool material within the disc 9 can be varied in a horizontal direction, preferably in a direction radial relative to the hole 11 , which defines a planting position, in which the plug 10 of FIG. 2 can be inserted.
[0035] It is to be noted, that several additional and alternative embodiments of the present invention will be apparent to a person skilled in the art, which are all to be interpreted as within the scope of protection for the present invention, as defined in the accompanying claims. For instance, a hole 11 need not be provided, and the disc can entirely be made of mineral wool material, without a hole. However, promoting root growth through the mineral wool material of the top substrate may, in such an embodiment, be more slow. The plug, which is preferable made of a mineral wool material, that is, for instance as a result of a lower density or other property thereof, preferably more easily penetrated by the roots of a growing plant, can also be incorporated or integrated into the top substrate, leaving no visible or discernable hole, like in the embodiments shown in the accompanying drawings. This would however mean a variation in the material properties of the disc 9 or more general the top substrate 8 .
[0036] Such a variation could very possibly also comprise a top substrate having a variation in density in the thickness direction thereof. For instance, a disc-shaped top substrate could comprise two or more disc shaped layers on top of each other, each having other properties, like density, fiber thickness, fiber orientation, fiber length, etc.
[0037] Additionally or alternatively the top substrate can also be embodied such that root growth there through is promoted in a horizontal direction, s a result of which roots will grow horizontally outward and then downward into the root substrate, thus promoting an improved rood distribution over the top and root substrates. Also a firm assembled system is ensured hereby. | The present invention relates to a plant growth system, comprising a root substrate formed by a number of essentially independent mineral wool elements and a top substrate, comprising an essentially unitary mineral wool element. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from U.S. Provisional Application No. 61/369,897, filed Aug. 2, 2010 in the United States Patent and Trademark Office, the disclosure of which is incorporated herein in its entirety by reference.
BACKGROUND
[0002] 1. Field
[0003] The invention is related to an apparatus and method for preventing the filling compound (gel) optical fiber from ejecting, flowing or protruding out of buffer tubes in fiber optic cables.
[0004] 2. Related Art
[0005] Many utilities, city municipals and telephone companies deploy systems that use fiber optic cable. Many fiber optic cables contain buffer tubes that are manufactured with a filling compound (gel). The purpose of the gel is to protect the fibers and act as a water blocking agent to prevent water from tracking into the buffer tubes and damaging the fibers and or fiber performance. Three of the typical types of cables used are: OPGW: Optical Ground Wire uses both plastic and or stainless steel buffer tubes (Aerial applications); ADSS: All Dielectric Self Supporting cable containing plastic buffer tubes (Aerial applications); and Loose Tube: Multiple cable designs containing plastic buffer tubes (Non-aerial applications).
[0006] Buffer tubes contain a filling compound that allows the fibers to float within the tube. The gel also helps allow the buffer tubes to store an, excess fiber length or “EFL.” EFL is the term used when talking about the length of the fiber within the buffer tube compared to the actual length of the buffer tube. The excess length of fiber within the tube helps determine the point at which the fiber will see strain. The fiber optic cables are typically installed and terminated within a splice enclosure. The splice enclosure is used to help protect the exposed fibers and buffer tubes from all types of elements. An AFL Telecommunications “SB01” splice enclosure is a good example of an enclosure that is used in an aerial application.
[0007] After the fiber optic cable has been secured within the splice enclosure, the buffer tubes are routed within the enclosure and the fibers are then terminated (spliced) within a fiber optic splice tray.
[0008] Fiber optic cable may be deployed in several harsh or non-standard environments world wide. Two such environments are Extreme Heat and Vertical Installations. In rare applications, optical fiber may migrate or flow out the ends of the buffer tubes. The issue is not typical but can occur due to the viscosity of the filling compound (gel), amount of fibers within the buffer tube versus the inner diameter, vertical installation length and extreme or sustained temperatures while in a vertical position. If a fiber optic product shows signs of migration, the gel and fiber will begin to push its way into the splice enclosure and tray. The end result for this action can be the loss of EFL, bending, kinking or breaking of optical fibers and a possible overall failure to the optical system.
[0009] Due to the abundance of fiber optic cable being installed world wide for communications needs, it has become extremely important to maintain and protect the functionally of our fiber optic networks. For this reason, it is vitally important to have a product and procedure in place that will prevent the filling compound and optical fibers from migrating out of the buffer tubes.
SUMMARY
[0010] Exemplary implementations of the present invention address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an exemplary implementation of the present invention may not overcome any of the problems listed above.
[0011] A first embodiment of the invention is an apparatus for connecting buffer tubes including a first bock, a second block, and a fastener for assembling the first and second blocks. The first block includes a pair of tube grooves, a cavity and a hole leading into the cavity. The second block includes a pair of tube grooves, and a cavity.
[0012] In the apparatus, the second block may also include a hole leading into the cavity.
[0013] In the apparatus the second block may be identical to the first block.
[0014] In the apparatus the first and second blocks may each include four fastener holes.
[0015] In the apparatus two of the fastener holes on each of the first and second blocks may be threaded.
[0016] Another embodiment of the invention is a method of connecting buffer tubes that includes cutting a buffer tube into two sections, separating the buffer tube sections, placing the buffer tube sections into a pair of grooves on a first block, placing a second block on top of the first block, wherein the buffer tube sections are placed into a pair of grooves on the second block, fastening the first and second blocks together, filling a sealant through a hole in said first block into a cavity formed between the first and second blocks and allowing the sealant to cure.
[0017] The method may also include cleaning the buffer tube sections and a fiber in the buffer tube prior to placing the buffer tube sections into the pair of grooves in the first block.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of an embodiment of a block.
[0019] FIG. 2 is a plan view of an embodiment of a block.
[0020] FIG. 3 is a cross-section view of an embodiment of a block.
[0021] FIG. 4 is a perspective view an embodiment of two assembled blocks.
[0022] FIGS. 5 and 6 are a plan view and a perspective view an embodiment showing buffer tubes in a block.
[0023] FIG. 7 is a flow chart of an embodiment of a method of the invention.
[0024] FIG. 8 is a graph showing test results of an embodiment of the invention.
DETAILED DESCRIPTION
[0025] The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses and/or systems described herein. Various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will suggest themselves to those of ordinary skill in the art. Descriptions of well-known functions and structures are omitted to enhance clarity and conciseness.
[0026] Hereinafter, the exemplary embodiments will be described with reference to accompanying drawings.
[0027] The invention is a mechanical solution to prevent filling compound (gel) and optical fibers from migrating out of buffer tubes found in fiber optic cable designs. It is a clever way of solving potential issues caused by the flow of gel and optical fibers within a splice enclosure.
[0028] The method can also be used as a retro-fit solution for an existing splice location that has exhibited the migrating issues. The method can potentially be applied without re-routing or re-splicing the optical fibers.
[0029] FIGS. 1-5 show an embodiment of the invention that can be used on a fiber optic buffer tube. Note that while the description describes the invention being used with fiber optic cables, the invention is not limited to fiber optic cable and also be used with wired cables. The apparatus consists of two blocks 1 A and 1 B. In a preferred embodiment, the block is made of aluminum; however, it could be made of other materials, such as plastic, steel, ceramic, glass, rubber, etc. In addition, in this embodiment, blocks 1 A and 1 B are identical, which can reduce manufacture costs. However, the blocks do not have to be identical. In this particular embodiment, the blocks are 30 mm long by 12.7 mm wide by 4.8 mm deep; however, the block is not limited to these dimensions. The block includes four fastener holes, 4 , 5 . In this embodiment, holes 4 are threaded, and holes 5 are not threaded. This allows a fastener 12 , such as an M3 8 mm screw, to be inserted into hole 5 and then screwed into hole 4 when the blocks are assembled. However, all of the holes could be smooth and the blocks could be assembled by nuts and bolts. In addition, other known fastening methods could be used such as hinging one side of the blocks and fastening the other sides of the blocks.
[0030] The block also includes a filling/exit hole 3 and a cavity 7 . When the blocks are assembled, a sealant can be inserted into one filling/exit hole and can exit the other filling/exit hole 3 after the cavity 7 has been filled.
[0031] The cavity in this particular embodiment is approximately 18 mm long by 7.5 mm wide by 1.3 mm deep; however, the cavity is not limited to these dimensions.
[0032] The block also has two tube grooves 6 into which buffer tubes are inserted. The diameter of the grooves 6 are slightly smaller that the diameter of the buffer tubes to ensure a tight fit.
[0033] Next, a method a assembling the block on a buffer tube cable will be explained. See also FIG. 6 .
[0034] Depending on the type of enclosure selected, a decision should be made in determining the distance needed from the enclosure to for ring cut locations. The blocks should be applied at a distance long enough away from the enclosure to prevent long term kinking or damage to the optical units within the enclosure. In step 1 , the buffer tube 10 should be ring cut.
[0035] In step 2 , the buffer tubes 10 should then be pulled apart approximately 20 mm to reveal the fibers. Note that the fibers in the buffer tubes are not cut.
[0036] In step 3 any waterblock gel is removed from the fibers using a standard solvent spray cleaner and cloth. Ensure that the buffer tubes are clean and all fibers are clean and intact. Ensure that the fibers have dried before proceeding to the next step. Note that the invention may work without the buffer tubes and fibers being cleaned; however, long term performance may be comprised due to the lack of adherence between the cured sealant and un-cleaned fibers.
[0037] In step 4 , ensuring that each end of the tube is clean and dry, offer up the first block 1 A to tubes 10 . The ends of the tube should be flush with the edge of the cavity 7 , and the fibers 11 should be straight as shown in FIG. 5 . Alternatively, the buffer tube can be flush with an edge 6 A of the groove.
[0038] In step 5 , position the second block 1 B over the tubes, ensuring that the filling hole is at the opposite end to the first block 1 A. Push the blocks together to trap the buffer tube in place, ensuring the optical fibers are not trapped between the meeting surfaces.
[0039] In step 6 , fasten the blocks together. In this particular embodiment, at each corner of the block insert screws through the plane side of each hole and use an M3 hexagonal key to tighten.
[0040] In step 7 , the cavity 7 is filled with a sealant, such as a 10:1 ratio 2-part silicone sealant with MSDS silicone sealant. A gun applicator can be used to fill the cavity 7 . Prior to filling, a piece of cloth can be pressed against one of the filling/exit holes 3 , blocking that hole. The applicator is then placed in the other filling/exit hole 3 and the cavity 7 is filled with the sealant. There should be a pressure build up at the blocked filling/exit holes and when the cloth is removed, the excess sealant should flow out of the hole. This excess sealant can be wiped away using the cloth. Then lightly pull on the fibers located next to the entrance of the tray to release any possible movement of the fibers that may have occurred during the sealant injection. The sealant is then allowed to cure.
[0041] Once the sealant cures, future tube/fiber migration should be prevented.
[0042] This solution was also tested to see how it would affect the performance of the fibers. The test includes, temperature soaking the migration repair at extreme temperatures of −40° C. and 85° C. and aged by cycling between 37° C. and 49° C. The blocks 1 A and 1 B were assembled and filled with 2-part silicone sealant as per the methods described above.
[0043] The results of the temperature cycling are shown in FIG. 7 . The retro-fit solution was applied to each end of four buffer tubes found within the OPGW cable. Six fibers from each tube were concatenated by means of fusion splices to form an optical loop. The total fiber length under test was approximately 700 m. The cable was temperature cycled as follows:
[0044] Soak @ −40° C. for 24 h
[0045] Soak @ 85° C. for 24 h
[0046] Cycled between 37° C. and 49° C. for 1 week (3 h per cycles)
[0047] Soak @ −40° C. for 24 h
[0048] Soak @ 85° C. for 24 h.
[0049] The change in attenuation per splice was less than 0.05 dB/km and therefore, the retro-fit solution as tested met the requirements of the test both optically and visually, no fiber migration was observed.
[0050] The solution is to be used at splice enclosures where potential fiber migration is expected or observed. If the fiber migration is already present, the application may be applied without breaking the existing fibers.
[0051] As mentioned above, although the exemplary embodiments described above are directed to fiber optic cables, this is merely exemplary and the general inventive concept should not be limited thereto, and could be used with wired cables (e.g., coaxial cables) and corresponding wired cable interface components and equipment. | An apparatus for connecting buffer tubes including a first block, a second block, and a fastener for assembling said first and second blocks. The blocks contain a pair of tube grooves and a cavity and a and a hole leading into the cavity. A sealant is then inserted into the cavities and allowed to cure. |
FIELD OF THE INVENTION
The present invention relates to a high temperature adiabatic cooking device, particularly, to a high temperature adiabatic cooking device having an outer pot which is thermally insulated, and an inner pot removably placed in the outer pot, in which ingredients of foodstuff and water to be boiled are placed in the inner pot, heated there through until boiling and then maintained boiling for an appropriately short period of time depending upon the foodstuff to be cooked, the inner pot is thereafter placed in the outer pot followed with a lid having a high capacity of heat insulating covered thereon, the foodstuff is effectively cooked by the latent heat of the semi-cooked foodstuff in the inner pot adiabatically retained in the outer pot.
BACKGROUND OF THE INVENTION
Conventionally, a cooker, or a cooking device, generally has a pot member adapted to be placed on a furnace or a heater for transferring heat from the heat source to foodstuff contained in the pot member, until the foodstuff is cooked. A cooker provided with a built-in heater is convenient and has become very popular; such a cooker with a built-in heater generally has an inner pot made of thermally conductive material, and an outer pot having a thermally insulated casting, wherein the inner pot is removably placed in the outer pot which is provided with a built-in heater and a control device. In use, foodstuff is placed in the inner pot, which is then placed in the outer pot, and then the built-in heater of the outer pot is turned on to supply heat to the foodstuff in the inner pot. Some conventional electric cookers are provided with a timer or automatic temperature control device to enable users to set an appropriate cooking time. However, even with a sophisticated automatic control device, it is often difficult for an unskilled housewife to cook a foodstuff appropriately with a conventional electric cooker without consulting a cooking manual.
There is a special type of an electric cooker known as a "slow cooker" which is designed to cook foodstuff slowly with a minimum supply of heat (or energy) throughout the cooking process. However, it has been found out by the inventor of this invention that food can be better and easier cooked by initially supplying an ample amount of heat (or energy) for boiling for a short period of time, and then let the semi-cooked foodstuff cooked by its own latent heat thereafter without a continuous supply of heat energy.
SUMMARY OF THE INVENTION
The high temperature adiabatic cooking device of this invention has an inner pot made of thermally conductive material, an outer pot having a thermally insulated construction and being adapted to removably contain the inner pot, an inner lid for covering the inner pot, and an outer lid for covering the outer pot with the inner pot placed therein. The outer pot is particularly designed to exclude a heat supply means which could affect the thermal insulating capabilities of the outer pot. In use, the inner pot is first removed from the outer pot; the foodstuff to be cooked is placed in the inner pot which is then covered by the inner lid and heated with an appropriate heater for a short period until a sufficient amount of heat has been transferred to and absorbed by the foodstuff; then the inner pot with the foodstuff therein is placed in the outer pot. The outer pot with the inner pot placed therein is covered with the outer lid, so as to "seal in" the foodstuff containing a sufficient amount of heat to become cooked by its own latent heat, without receiving additional heat from or losing heat substantially to an external environment, or "adiabatically" in a more technical term.
According to a test, the cooker of this invention is capable of preserving heat of the foodstuff in the cooker, to such extent that the temperature of the foodstuff, one hour, one and a half hours, and two hours after the foodstuff in the inner is heated up to 100° C. and the inner pot with the foodstuff therein is placed in the outer pot and sealed, is maintained at above 93° C., about 90° C., and about 88° C., respectively.
The inner pot has an upper flange and the outer pot has shoulder for receiving the upper flange of the inner pot, such that when the inner pot is placed in the outer pot, the inner pot is "suspended" within the outer pot to maintain a space between the entire outer surface of the inner pot and the entire inner surface of the outer pot.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a high temperature adiabatic cooking device according to the present invention.
FIG. 2 is an exploded view of FIG. 1.
FIG. 3 is a longitudinal sectional view of FIG. 1.
FIG. 4 is an enlarged fragmentary sectional view of FIG. 3.
FIG. 5 is a vertical sectional view of another embodiment of the high temperature adiabatic cooking device according to the present invention.
FIG. 6 is the composite graph of temperature of variation foodstuff in the covered cooking device versus time showing the temperature change of the foodstuff in the covered cooking device with time.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings which illustrate an embodiment of the high temperature adiabatic cooking device of the present invention, the cooking device includes an outer pot 1 having a thermally insulated construction, an inner pot 13 removably disposed in the outer pot 1, an outer lid 20 for covering outer pot 1, and an inner lid for covering inner pot 13.
The outer pot 1 is comprised of an outer shell 2, an inner shell 3, a heat insulating material 5 filled in between the outer shell 2 and the inner shell 3, and a ring frame 4 affixed onto upper edges of outer shell 2 and inner shell 3.
The outer shell 2 is made of a rigid resin material such as acrylonitrile-butadiene-styrene, polypropylene or equivalent, and is formed into a container shape with a bottom. The inner shell 3 is made of metallic material such as stainless steel or a rigid resin material as above mentioned and has a similar shape to that of the outer shell 2. Inner shell 3 has an upper flange to form a shoulder 9 at an upper, inner part of the outer pot 1. Between inner shell 3 and outer shell 2 a spacing of 10-40 mm preferably of 15-35 mm, more preferably of 20-30 mm is maintained to accommodate the heat insulating material 5 having a thermal conductivity (K) less than 0.15 w/m° C., preferably less than 0.10 w/m° C. more preferably less than 0.05 w/m° C., which may be polyurethane foam or glass fiber.
The outer lid 20 has heat insulating capacity and is used to cover the opening of the outer pot 1 in an air tight manner; the inner pot 13 is removably housed in the outer pot 1 and used for containing foodstuff such as grains and water to be cooked; an inner lid 17 is used for covering the opening of the inner pot 13. The outer lid 20 comprises upper lid body 23 made of rigid resin, lower lid panel 24 mounted on the bottom part of the upper lid body 23 and maintained a distance at least between 20 mm and 35 mm from the upper lid body 23; a heat insulating polyurethane foam 25 which fills the space between the upper lid body 23 and the lower lid panel 24; the inner pot 13 is housed and suspended in the outer pot 1 by a flange 14 which is outwardly extended from the top part of the wall of the inner pot 13 resting on a shoulder 9 which is formed on the inner, upper part of the outer pot 1, and thus the outer wall of the inner pot 13 and the inner wall of the inner shell 3 of the outer pot 1, as well as the lower lid panel 24 of the outer lid 20 and the inner lid 17 are maintained in a separate state.
Moreover, the lower lid panel 24 of the outer lid 20 can be further circumferentially mounted with a flexible heat insulating mat 27, which is made of the heat-resistant material such as silicone rubber, having a low thermal conductivity. With the mat 27, the possibility of heat transfer from the lower lid panel 24 to the upper lid body 23 will be reduced to minimum and the air tight sealing between the lower lid panel 24 and the insulating container 1 is enhanced.
Due to the extremely low heat loss of the inner pot to the insulating container and the excellent insulating capacity of the insulating container itself, the cooking device can be utilized for cooking steamed rice, gruel, meats, beans, a variety of vegetables and the like for saving the energy consumed in the process of cooking. Such cooking is easily done (completed) by boiling the food in the inner pot 13 for a short period of time, then placing the inner pot 13 in the outer pot and with the outer lid covered thereupon to convert the food into a sufficiently cooked state.
The present invention will be further described hereinunder in more detail with reference to the accompanying drawings.
The inner shell 3 has an opening with a diameter smaller than that of outer shell 2 so as to maintain a distance between the walls of inner shell 2 and outer shell 3 at least between 20 mm and 30 mm while the inner shell 3 is placed in the outer shell 2. Ring frame 4, which comprises bracket 6, inner flange 7 and outer flange 8, is made of synthetic resin and connects the top parts of the inner shell 3 and the outer shell 2; the inner flange 7 is secured to the shoulder 9, which is outwardly extended from the top of the wall of the inner shell 3, by means of a screw 10, and is used for suspending the inner pot 13. The top part of the outer flange 8 is outwardly extended to form a handle 11 and the lower part of the outer flange 8 is secured to the outer shell 2 by means of a screw 12, the heat insulating polyurethane foam 5 of a thermal conductivity of about 0.05 w/m° C. is made by injecting into the space between the outer shell 2 and the inner shell 3, fully filling the space after solidification into a foam; the foam is preferably at least of 10 mm in thickness in order to ensure sufficient thermal insulation. The thicker the foam, the better the heat insulation, but the accompanying disadvantages such as increased cost should be as well taken into account, and a large cooking body needed to house the foam, therefore, the thickness is preferably below 35 mm, a compromised thickness of the foam for all costs, volume of cooking body and heat insulating capacity is found to be a thickness between 20 mm and 30 mm in accordance with the results of extensive experiments.
The inner pot 13, which is in a cylinderial shape with a bottom, is suspended in the outer pot 1 by means of resting the flange 14, which is outwardly extended from the top part of the wall of inner pot 13, on the shoulder 9 of the inner shell 3 of the outer pot 1, the outer wall of the inner pot 13 and inner shell 3 are therefore maintained in a separate state. A lift-out stem 16 is pivotally attached to a supporting part 15 on the flange 14 and the lift-out stem 16 can be rested on the flange 14 while not in use.
The substantial center of the inner lid 17, which is made of transparent, high temperature resistant glass or metallic material such as stainless steel, is located with a concave part 18 and a knob 19 on the inner lid 17 is fixed across the concave part 18.
The outer lid 20 is comprised of a covered-plate-shape upper lid body 23 made of synthetic resin, a plate-shaped lower lid panel 24 mounted on the bottom part of upper lid body 23 and a heat insulating polyurethane foam 25 which fills the space between the upper lid body 23 and the lower lid panel 24. A concave part 21 and the knob 22 are located on the upper lid body 23 and the space in the concave part is big enough for hand or fingers to handle the outer lid 20 by grasping the knob 22. A concave part 26 in the inner side of the lower part wall of the outer lid 20 is formed between the lower inner wall of upper lid body 23 and the top flat part of lower lid panel 24, therefore, the concave part 26 and the bracket 6 of the flange 4 are packed by the concave-convex mechanism to provide an excellent air tight sealing between the outer lid 20 and the outer pot 1.
Moreover, the heat insulating mat 27, which is made of high temperature resistant, flexible material such as silicone rubber, is circumferentially mounted on the concave part 26 of the outer lid 20 and tightly contacts with the top flat part of the bracket 6 to prevent the heat dissipating from inside of the cooking device. The top flat part of the lower lid panel 24 is clamped with the "U" shaped heat insulating ring 27 and the lower lid panel 24 is fixed on the upper lid body 23 by means of screwing screw 28 through the top flat part of lower lid panel 24 and the heat insulating ring 27, therefore, the heat of the lower lid panel 24 is not transferred onto the upper lid body 23.
In order to avoid the heat of the inner pot 13 being transferred to the inner shell 3 through flange 14, a rigid heat insulating ring 29 (see FIG. 5) is mounted on the shoulder 9 of the inner shell 3; the heat insulating ring 29 is made of a material with a high temperature resistant and high heat insulating capacity such as chloroprene rubber, Bakelite, and phenol rubber. The use of the heat insulating ring 29 therefore further improves the efficiency of heat insulating between the inner pot 13 or the inner lid 17 and outer pot 1.
The following are examples of the cooking procedures and results for preparing variation of foods using the cooking device illustrated in FIG. 1 through FIG. 4:
(I) Gruel
200 g of rice and 1500 cc. of water were placed in the inner pot, rapidly heated to reach boiling within about 9 minutes (23° C. of room temperature), kept boiling for further about 20-30 seconds, covered immediately with inner lid and transferred into the outer pot as well as covered with the outer lid. the rice turned into a swollen state which is ready for eating (the amount of the resulting gruel is enough for a meal of 4-6 people) after 30 minutes. Referring to the curve A of FIG. 6, the temperature of the gruel at the end of cooking is about 96° C. A sticky paste gruel will be formed if the gruel further stands for a longer time.
(II) Cooked Rice
The procedure used and results were similar to that described in (I) except that the amounts of rice and water used were 200 g and 350 cc., respectively, as well as the resulting rice was in a slightly swollen, semi-dry state and suitable for eating.
(III) Beef and Vegetable Soup
Conventionally, the soup is cooked by simmering for a period of time between 90 and 120 minutes. When using present cooking device, beef 3 cm beef dice, vegetables of carrot, cabbage, radish, onion, tomato and potato being in the appropriate size and water were placed in the inner pot, rapidly heated to reach boiling within 10 minutes, kept boiling for further 15 minutes, covered immediately with inner lid and transferred into the outer pot as well as covered with outer lid. The beef and vegetables were well done and suitable for eating after 60 minutes. Referring to the curve B of FIG. 6, the temperature of the soup is dropped to 94° C. at the end of cooking.
(IV) Red Beans Soup
300 g of red beans and 1500 cc. of water were placed in the inner pot, rapidly heated to reach boiling within 9 minutes and kept boiling for further 15 minutes, and immediately housed in the outer pot. The red beans were turned moistened and swollen, suitable for eating after 60 minutes of standing in the outer pot. Referring to curve °C. of FIG. 6, the temperature of the red beans soup is 90° C. at the end of cooking. It should be noted that the red beans can be, of course, presoaked in water at room temperature before heating to shorten the cooking time.
Furthermore, when the present invention is used to prepare steamed rice, rice and water with a ratio as described above can be boiled in the inner pot and then placed in the outer pot covered with the outer lid in the night, the rice will become cooked in the next morning and will has a temperature of 45°-65° C. It should be noted that the cooked rice prepared by using the cooking device of the present invention can be maintained at an elevated temperature for a long period of time without being additionally heated. Meanwhile, the disadvantage that the upper portion of cooked rice prepared by the conventional electric cooker will be yellowed as well as stiffened after a certain period of time will be effectively eliminated.
In conclusion from the above, the inner pot with the inner lid is suspended on the outer pot, and the heat insulating polyurethane foam with thickness ranging from about 15 mm to 35 mm (preferably 20-30 mm) are filled in the space both between the inner shell and the outer shell of the outer pot as well as between the upper lid body of the outer lid and the lower lid panel of the outer lid, therefore, the temperature of food kept in the inner pot of the cooking device can be maintained at a relatively high level such that cooking can be effectively completed without a further supply of heat after the initial cooking, the conservation of energy, the maintaining of the original flavors of the foodstuff after being cooked and the efficiency of cooking can be greatly improved. In the mean time, it can be understood from the above that the present cooking device has advantages of easy operation and greatly reduced operation time. | A cooking device having an outer pot and an inner pot removally suspended in the outer pot is proposed for better and easier cooking of foodstuff. The inner pot is made of thermally conductive, metallic material and is adapted for initially cooking foodstuff with a separate heater for a short period of time. The outer pot is made into a thermally insulated construction and adapted to house the inner pot containing the semi-cooked foodstuff in the outer pot in a thermally insulated manner, so as to allow the semi-cooked foodstuff to complete the cooking by its own latent heat without a further heating by an external heat supply means. |
TECHNICAL FIELD
The present invention relates to tie clips, generally. More particularly, the present invention relates to tie clips for joining the designer label of a tie to a shirt.
BACKGROUND OF THE INVENTION
For a great number of years, ties have been used as an important part of business and formal attire. Once tied, the top of the tie is secured within the user's shirtcollar, and the lower ends of the tie lie adjacent the button edge (the placket) of the user's shirt front. In a standard tie, one of the ends is a wide end and this end rests atop the other, narrower end. Since it is desired to maintain the tie in a centered relationship over the placket of the shirt, a number of devices have been developed through the years so as to affix the tie in its proper position.
Unless the ends of the tie are somehow fastened in place, they can move away from the shirt front and thereby cause numerous problems. On a windy day, the ends can be blown about and cause the user to appear disheveled. While eating, if the user leans forward, the tie can swing outwardly and brush against food and become soiled. Without benefit of a restraining device, the tie may generally become misaligned from its optimum position as a result of the wearer's movements.
Several kinds of necktie holders are available which clamp or attach both to the shirt and the necktie and provide a visible and external connection to the tie on the outer appearing surface such as a tie bar or what is commonly known as a "tie tack". The tie bar, of course, clamps both necktie folds to the shirt front. The tie tack, by means of a pin, is attached to the necktie through both folds. A friction clutch engages the pin and is connected by means of a bar and chain to the shirt front through a button hole.
While a tie bar does not mar the outward appearing surface of the tie material, it does have a tendency to skew, slide, and permit the necktie to bulge. A tie tack, even though ornamental and available in a variety of designs, does result in punched holes, broken threads, raveling, and other damage to the tie. This usually requires that the necktie always be worn with a tie tack to avoid showing the damage of the material. Wearer's of neckties would like to avoid the shortcomings of tie bars and tie tacks and would prefer, in many instances, to use no visibly showing holder to maintain the necktie in position because of the natural beauty of the tie material itself.
It has been known to apply a label to the necktie during the manufacturing thereof. This label can serve as a holder for the interior branch of the tie. While this arrangement prevents separation of the two tie branches, it does not position the entire tie relative to the shirt front. In any event, permanent attachments to the necktie are undesirable and complicate the manufacturing process and add to the cost of the necktie. Where a designer label or loop is attached permanently to the tie, it is impractical to provide a buttonhole in such loop or attachment because this requires a tying of the necktie in a precise manner at each wearing. If the necktie is not tied with great care at each wearing, then the loop attachment will not be aligned with one of the shirt buttons.
In the past, various patents have issued on devices for securing the necktie to the shirt. For example, U.S. Pat. No. 3,474,503, issued on Oct. 28, 1969, to J. W. Less shows a tie anchor connected to the back of the necktie. The tie anchor has a vertically elongated slot therein into which the button of the shirt front of the wearer is inserted. The slot has a vertical height substantially greater than the diameter of the button and a width less than the diameter of the button whereupon the tie can slide up and down on the button during normal movement of the wearer and yet is held adjacent to the shirt front of the wearer. The tie anchor is made of a flexible sheet material. Hook-shaped end portions of the anchor facilitate connecting the anchor to the necktie by slipping the hooked ends through the stitches at the rear of the necktie body.
U.S. Pat. No. 4,219,909, issued on Sep. 2, 1980, to O. V. Anderson shows a combined clasp and tie slide which is designed for use in removably attaching a clasp to a shirt front. The tie slide is adjustable to accommodate neckties of varying widths. This tie slide is adapted so as to hold the necktie in a proper position relative to the front of the shirt.
U.S. Pat. No. 4,827,576, issued on May 9, 1989, to G. W. Prince, Jr. discloses a buttonslot necktie fastener. This fastener is permanently fastened to the back side of a necktie loop/label oriented parallel to the necktie so as to allow the narrow section of the necktie to be captured inbetween the wide section of the necktie and the loop/label. An adhesive material is provided so as to secure to the loop/label. A slot is provided in one section of the fastener so as to be received by a shirt button.
U.S. Pat. No. 5,062,185, issued on Nov. 5, 1991, to R. T. Howard shows a concealable tie clasp which is constructed in a manner such that it attaches to the button hole edge of a shirt and engages the designer label sewn onto the rear surface of the front panel of a four-in-hand necktie. The tie clasp engages the shirt by means of a spring-loaded type of clip. A vertically elongated holding loop is disposed on the forward surface of the clip for engaging the designer label. Once the tie is engaged by the holding loop, the tie remains generally centered above the vertical row of buttons on the shirt, it is permitted limited vertical and horizontal movement.
U.S. Pat. No. 5,109,547, issued on May 5, 1992, to I. A. Abdallah provides an extended neckwear shirt attachment device. This device includes an elongated base member, a button attachment means which is attached in slidable and threaded engagement to the base member so as to form a unitary structure for permitting the slidable movement of the button attachment means along the entire length of the base member. A means is provided so as to fixedly attach the unitary structure to the wide forepart of the extended neckwear. The device is selectively attachable to a button of the shirt of the wearer by engagement of the button attachment means with the button.
It is an object of the present invention to provide a tie clip that is concealed behind the tie during use.
It is another object of the present invention to provide a tie clip which maintains the vertical orientation of the tie during wearing.
It is another object of the present invention to provide a tie clip that allows upward and downward movement of the tie during use.
It is still another object of the present invention to provide a tie clip that is adaptable to a wide variety of tie configurations and shirt configurations.
It is still another object of the present invention to provide a tie clip that is relatively inexpensive and easy to use.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.
SUMMARY OF THE INVENTION
The concept of the present invention was originally disclosed in Disclosure Document No. 281,727, filed on May 14, 1991 with the United States Patent and Trademark Office.
The present invention is a tie clip that comprises a first bar, a second bar extending transversely to the first bar and slidably connected thereto, a first clip affixed to a surface of the first bar, and a second clip affixed to a surface of the second bar. The second bar is generally shorter than the first bar. The second bar is slidable along a longitudinal axis of the first bar. In a preferred embodiment of the present invention, the first bar has a longitudinal slot formed therewithin. The second bar has a portion received within this longitudinal slot. This portion is slidable within the slot. The second bar has one end extending outwardly from one side of the first bar and another end extending outwardly on an opposite side of the first bar. The portion is positioned between the ends of the second bar. The second bar has a thickness generally equal to a thickness of the first bar. The portion within the slot has a thickness less than a width of the slot.
In another embodiment, the second bar has an interior opening formed therewithin. The first bar extends through this opening. The second bar is slidable along an outer surface of the first bar. The first bar has a stop positioned on an end of the first bar opposite the first clip. The first bar and the stop have a thickness greater than the width of the opening.
The first clip has an openable end which is positioned adjacent an end of the first bar. The second clip has an openable end facing the first bar. The first bar and the second bar have a top surface. The first clip is affixed to the top surface of the first bar. The second clip is affixed to the top surface of the second bar. Each of the first and second clips is an alligator clip. This alligator clip has an openable end and an actuating end. The openable end of the first clip is positioned adjacent an end of the first bar. The actuating end of the second clip is positioned adjacent an end of the second bar opposite the first bar.
The first bar has an indented surface formed adjacent one end of the first bar. The first clip is received within this indented surface. The second bar has an indented surface adjacent an end opposite the first bar. The second clip is received within this indented surface.
The first clip has a flat engagement area. This toothed engagement area serves to affix to the designer label (or loop) of a tie. The second clip includes a similar flat linear toothed engagement area for affixing to a placket of a shirt.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a frontal view showing the preferred embodiment of the tie clip of the present invention as attached to the shirt and tie.
FIG. 2A is a frontal view of the preferred embodiment of the tie clip of the present invention.
FIG. 2B is a side view of the preferred embodiment of the present invention.
FIG. 2C is a rearward view of the preferred embodiment of the present invention.
FIG. 3 is a cross-sectional top view of the preferred embodiment of the present invention.
FIG. 4 is an enlarged, partially cut away, view of the clip of the present invention.
FIG. 5 is an enlarged isolated view of the fastener as used with the clip of FIG. 4.
FIG. 6A is a frontal view of a first alternative embodiment of the present invention.
FIG. 6B is a side view of a first alternative embodiment of the present invention.
FIG. 6C is a rearward view of a first alternative embodiment of the present invention.
FIG. 7 is a top cross-sectional view of the first alternative embodiment of the present invention.
FIG. 8A is a frontal view of a second alternative embodiment of the present invention.
FIG. 8B is a side view of the second alternative embodiment of the present invention.
FIG. 8C is a rearward view of the second alternative embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown at 10 the tie clip in accordance with the preferred embodiment of the present invention. It can be seen that the tie clip 10 is configured so as to secure the tie 12 to the shirt 14 of a wearer. The tie 12 includes a forward portion 16 and a narrow rearward portion 18. As can be seen in FIG. 1, the narrow rearward portion 18 of tie 12 extends through loop 20 on the back surface of the forward portion 16. The loop 20 serves to secure the rearward portion 18 against the back surface of the forward portion 16 of tie 12.
The tie clip 10 is configured so as to secure the loop 20 in a proper position adjacent to the forward portion of the placket 22 of shirt 14. The tie clip 10 includes a first bar 30 and a second bar 32. As used herein, the term "bar" can refer to rigid and flexible solid members. The first bar 30 is positioned vertically in parallel alignment with respect to the placket 22 of shirt 14. The second bar 32 extends transversely and horizontally with respect to the first bar 30. As will be described hereinafter, the first bar 30 is secured to the loop 20 through the use of a first clip. Similarly, the second bar 32 is secured to the placket 22 by means of a second clip.
As can be seen in FIG. 1, the first bar 30 is maintained in slidable relationship relative to the second bar 32. As such, when the wearer 14 straightens his posture or moves upwardly, the first bar 30 will slide upwardly relative to the second bar 32. Alternatively when the wearer bends over, then the first bar 30 will slide downwardly relative to the second bar 32. In all instances, the tie clip 10 of the present invention will cause the tie to be maintained in a proper vertical alignment with respect to the shirt 14. The device of the present invention generally prevents side-to-side or swaying motion of the tie 12. The tie clip 10 of the present invention also prevents the tie 12 from dislodgment from the front of the shirt 14.
FIGS. 2A-C show the preferred embodiment of the present invention tie clip 10 of the present invention. As can be seen in FIG. 2A, the tie clip 10 includes a first bar 30 and a second bar 32. Each of the bars 30 and 32 has a generally flat outward surface. The first bar 30 is a longitudinal vertical member having curved ends 34 and 36. The second bar 32 is slidable relative to the longitudinal axis of the first bar 30. The second bar 32 is generally shorter than that of the first bar 30. The second bar 32 has a first end 38 extending outwardly from a side of the first bar 30 and a second end 40 positioned generally adjacent an opposite side of the first bar 30. A narrow portion 42 is formed through the thickness of the second bar 32 so as to provide a guide area for the movement of the second bar 32 through the slot of the first bar 30.
The bars 30 and 32 can be plated with gold, silver, palladium, or nickel. The bars 30 and 32 could also be made entirely of solid gold, silver, or a white metal casting alloy. The bars 30 and 32 could also be made out of aluminum which will allow it to be anodized in various colors. The tie clip of the present invention could also be made from plastic. Since various materials and finishes could be used for the present invention, the scope of the present invention should not be limited by such materials.
As can be seen in FIG. 2B, the tie clip 10 has a slot 44 extending longitudinally along the first bar 30. This slot has a suitable opening so as to receive the portion 42 of the second bar 32. The slot 44 terminates at ends 45 and 47. As such, the slot 44 provides a length of travel for the second bar 32. As can be seen, the second bar 32 has a thickness generally matching the thickness of the first bar 30. The end 40 of the second bar 32 extends outwardly from the side of the first bar 30.
Importantly, in FIG. 2B, it can be seen that the first bar 30 has a first clip 46 positioned on a surface adjacent to end 34. The first clip 46 is an alligator clip which is received within an indentation formed on the top surface 48 of the first bar 30. The first clip 46 has an openable end 50 adjacent the end 34. The first clip 46 includes an actuating end 54 positioned adjacent to the second bar 32. In this configuration, the openable end 50 is suitable for affixing to the loop 20 of a tie 12. The second bar 32 has a second clip 56 affixed to a surface thereof. The clip 56 has a configuration similar to the clip 46. The clip 56 extends in a direction transverse to that of clip 46. The slotted relationship of the bars 30 and 32 provide relative travel between the clips 46 and 56.
FIG. 2C shows a rearward view of the tie clip 10 of the present invention. The clips 46 and 56 are illustrated diagrammatically. As can be seen, the first clip 46 extends so that the openable end 50 is adjacent to the end 34 of first bar 30. The second clip 56 is positioned on the second bar 32 such that the openable end 60 is positioned adjacent to the first bar 30. The actuating end 62 of the second clip 56 is positioned adjacent to the end 38 of the second bar 32. The configuration of the portion 42 serves to maintain the second bar 32 in its transverse alignment with the first bar 30. In normal use, the openable end 60 of the second clip 56 will fasten to the placket of the shirt. The openable end 50 of the first clip 46 will be attached to the loop 20 of tie 12.
FIG. 3 shows a cross-sectional view of the clip 10. In particular, it can be seen that the second bar 32 has a portion 42 which extends through the slot 44 of the first bar 30. End 40 extends outwardly from one side of the first bar 30. The other end 38 extends outwardly from the other side of the first bar 30. Portion 42 extends through the interior of slot 44. As can be seen, the clip 56 is received within indentation 64 formed in a surface of the second bar 32.
Importantly, in FIG. 3, it can be seen that the portion 42 has radiused surfaces 66 which serve to connect the portion 42 with the ends 38 and 40. These radiused surfaces provide for the smooth travel of the portion 42 within the slot 44 of first bar 30. Through experimentation, it has been found that these curved surfaces 66 enhance the stability of the travel, avoids the marring of the surfaces, generally prevents scratching, and enhances the appearance of the tie clip 10.
In FIG. 4, the clip 70 is illustrated. Clip 70 is similar to the previous described clips 46 and 56 of the previous figures. Clip 70 has a first face 72, a second face 74, an actuating end 76, and a toothed engagement end 78. A thin spring 80 serves to provide resistance against the opening of the toothed engagement end 78. The first face 72 is pivotted at a center of rotation 82 with respect to the second face 74. The second face 74 has a flat bottom surface 84 which is affixed within the indentations of the first bar or the second bar. When pressure is applied to the actuating end 76, so as to overcome the resistance of spring 80, the toothed engagement end 78 will open so as to expose the teeth of end 78.
The toothed engagement end 78 provides full tooth contact between the faces 72 and 74. The meshing and linear design of the teeth 78 of the clip 70 provides a stronger gripping surface that does not become dislodged, offset or pivot from awkward movements. This is a significant advantage over non-meshing curvilinear designs of the prior art. The prior art clips can easily pivot because of the relatively small surface area that grips the shirt (or the loop) and the lack of meshing teeth. The low center of rotation 82 of the clip 70 relative to the surface 84 allows for easier placement of the tie clip as compared to the prior art. This low center of rotation allows the clip 70 to be easily opened with just the thumb and forefinger applied to the actuating end 76 of clip 70. The thin spring 80 provides less resistance when opening the clip. The configuration of the clip 70 is appropriate because it does not cut, damage, or leave marks on shirts or designer labels. The clip 70 provides a strong gripping means that does not become dislodged, offset, or pivot.
The surface 84 of clip 70 can be fastened within the indentation of the bars by soldering, spot welding, tack welding, fusion welding, gluing, or any other attachment means. However, the present invention shows the use of a special fastener 86 which is shown as positioned within a hole 88 formed in the bottom surface 84 of clip 70. The fastener 86 is affixed within the indentation of the bars 30 or 32 and extends upwardly therefrom.
FIG. 5 illustrates the fastener 86. Fastener 86 is affixed at the bottom 90 to the surface of the bars. The fastener 86 has a generally cylindrical configuration extending upwardly. A shouldered area 92 is provided adjacent to the surface 90. In normal use, the opening 88 of the clip 70 will be interposed between the surface 90 and the shoulder 92. This configuration serves to retain the clip in its proper position. An angled area 94 extends inwardly and upwardly from the shoulder 92. The angled area 94 serves as a guide for the proper positioning of the clip 70 on the fastener 86. A slot 96 is provided in the cylindrical configuration of the fastener 86. The slot 96 allows the outer surfaces of the fastener 86 to be compressed so as to allow the opening 88 to slide over the angled edge 94 and into the area between shoulder 92 and surface 90. Alternatively, instead of compressing the slot 96, the opening 88 can simply be placed on the outer surfaces of the fastener 86 and pushed into its proper position.
FIGS. 6A-6C show a first alternative embodiment of the present invention. In the embodiment of FIGS. 6A-6C, the tie clip 100 is shown in which the second bar 102 slides over the outer surfaces of the first bar 104. As is illustrated in FIG. 6A, the first bar 104 has a stop member 106 at one end. The second bar 102 extends outwardly transverse to the longitudinal orientation of the first bar 104. The second bar 102 includes an area which extends over the outer surfaces of the first bar 104.
FIG. 6B shows a side view of the configuration of FIG. 6A. In particular, it can be seen that the first clip 108 is affixed within an indentation 110 at one end 112 of the first bar 104. The first bar 104 has a relatively narrow thickness 114 between the clip 108 and the stop 106. This narrow thickness 114 is received within an opening formed in the second bar 102. The second clip 115 is positioned on a surface of the second bar 102 and is arranged in generally transverse relationship with respect to the first clip 108. The combination of the stop 106 and the thickness of the first bar 114 will provide a stop area having a thickness greater than that of the width of the opening in the second bar 102. The second bar 102 will have a length of travel between the stop 106 and the shoulder 116.
In FIG. 6C, it can be seen that the first clip 108 has an openable end 120 adjacent to the end 112 of the first bar 104. Similarly, the second bar 102 has the second clip 115 with an openable end 122 adjacent to the first bar 104. The actuating end 124 of the second clip 115 is adjacent to the end 126 of the second bar 102. As can be seen, the second bar extends over the outer surface of the first bar 104.
FIG. 7 shows a top cross-sectional view of the embodiment of the tie clip 100 as illustrated in FIGS. 6A-6C. As can be seen, the second bar 102 has an opening 128 which receives the narrow thickness 114 of the first bar 104. The opening 128 has a width that is greater than the thickness of the first bar 114. Importantly, the opening 128 includes radiused corners 130 adjacent to the corners of the rectangular cross-section of the first bar 114. The radiused corners 130 serve to minimize friction, prevent marring, and further facilitates the proper orientation of the first bar 104 with respect to the second bar 102. The second clip 115 is illustrated with its openable end 122 generally adjacent to the first bar 104. The second clip 115 is received within indentation 110.
FIGS. 8A-8C shows a second alternative embodiment of the tie clip 150 of the present invention. In FIG. 8A, it can be seen that there is a first bar 152 and a second bar 154. The second bar 154 includes a portion 156 which extends over the outer surface of the first bar 152. In FIG. 8B, it can be seen that the first bar 152 has a slot 158 extending longitudinally therein. The second bar 154 is received within the slot 158 so as to be slidable in relationship to the first bar 152. As can be seen, the second bar 154 has a thickness which is greater than the thickness of the first bar 152. In FIG. 8C, it can be seen that the first bar 152 has a first clip 160 positioned at one end. The second bar 154 has a second clip 162 positioned thereon. The second bar 154 is received within slot 158 so that an end 164 extends outwardly from an opposite side of the first bar 152 from that of the clip 162. As such, the bottom surface of first bar 152 is not covered by the second bar 154.
The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents. | A tie clip having a first bar, a second bar extending transversely to the first bar and slidably connected thereto, a first clip affixed to a surface of the first bar, and a second clip affixed to a surface of the second bar. The second bar is slidable along the longitudinal axis of said first bar. The first bar has a longitudinal slot formed therewithin. The second bar has a portion received within the longitudinal slot and slidable within the slot. The first clip has an openable end positioned adjacent an end of the first bar. The second clip has an openable end facing the first bar. The first clip grips the designer label of a tie. The second clip grips a placket of a shirt. |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 61/467,433, filed on Mar. 25, 2011. The entire disclosure of the above application is incorporated herein by reference.
FIELD
[0002] This disclosure generally relates to containers for retaining a commodity, such as a solid or liquid commodity. More specifically, this disclosure relates to a heat-set, polyethylene terephthalate (PET) container having a cost-effective barrier system for blow-trim applications capable of providing high reuse levels of in-plant regrind and improved container recyclability.
BACKGROUND
[0003] This section provides background information related to the present disclosure which is not necessarily prior art.
[0004] As a result of environmental and other concerns, plastic containers, more specifically polyester and even more specifically polyethylene terephthalate (PET) containers are now being used more than ever to package numerous commodities previously supplied in glass containers. Manufacturers and fillers, as well as consumers, have recognized that PET containers are lightweight, inexpensive, recyclable and manufacturable in large quantities.
[0005] Blow-molded plastic containers have become commonplace in packaging numerous commodities. PET is a crystallizable polymer, meaning that it is available in an amorphous form or a semi-crystalline form. The ability of a PET container to maintain its material integrity relates to the percentage of the PET container in crystalline form, also known as the “crystallinity” of the PET container. The following equation defines the percentage of crystallinity as a volume fraction:
[0000]
%
Crystallinity
=
(
ρ
-
ρ
a
ρ
c
-
ρ
a
)
×
100
[0000] where ρ is the density of the PET material; ρ a is the density of pure amorphous PET material (1.333 g/cc); and ρ c is the density of pure crystalline material (1.455 g/cc).
[0006] Container manufacturers use mechanical processing and thermal processing to increase the PET polymer crystallinity of a container. Mechanical processing involves orienting the amorphous material to achieve strain hardening. This processing commonly involves stretching an injection molded PET preform along a longitudinal axis and expanding the PET preform along a transverse or radial axis to form a PET container. The combination promotes what manufacturers define as biaxial orientation of the molecular structure in the container. Manufacturers of PET containers currently use mechanical processing to produce PET containers having approximately 20% crystallinity in the container's sidewall.
[0007] Thermal processing involves heating the material (either amorphous or semi-crystalline) to promote crystal growth. On amorphous material, thermal processing of PET material results in a spherulitic morphology that interferes with the transmission of light. In other words, the resulting crystalline material is opaque, and thus, generally undesirable. Used after mechanical processing, however, thermal processing results in higher crystallinity and excellent clarity for those portions of the container having biaxial molecular orientation. The thermal processing of an oriented PET container, which is known as heat setting, typically includes blow molding a PET preform against a mold heated to a temperature of approximately 250° F.-350° F. (approximately 121° C.-177° C.), and holding the blown container against the heated mold for approximately two (2) to five (5) seconds. Manufacturers of PET juice bottles, which must be hot-filled at approximately 185° F. (85° C.), currently use heat setting to produce PET bottles having an overall crystallinity in the range of approximately 25%-35%.
[0008] Unfortunately, PET is a poor barrier to oxygen. One of the main factors that limit the shelf life of foods and beverages (herein known as “fills”) in PET containers is the ingress of oxygen through the walls of the container followed by oxidation of the fill. Many strategies have been employed to reduce the amount of oxygen in contact with food in PET containers. Some strategies include using package barrier coatings, such as chemical vapor deposited (CVD) aluminum oxide or silicon oxide. Still further, some strategies include the use of PET barrier additives that create physical barriers to oxygen diffusion through the packaging (e.g., nylon, nanoclays). However, these barrier additives may include a monolayer barrier blend that is incorporated into the entire preform resulting in scrap material, such as from a removed dome or moil portion, having high levels of barrier material. This scrap material having high levels of barrier material is incapable of being reused effectively in the plant to manufacture subsequent containers. That is, the high levels of barrier material in the strap material is generally non-conducive to in-plant recycling, thereby leading to excessive material waste and increased manufacturing costs.
[0009] In some applications, embedded barrier layers have been incorporated in a multilayer construction of the container to overcome penetration of oxygen into the container. However, such embedded barrier layers can often delaminate if the container is trimmed or otherwise cut improperly. That is, in some cases of container manufacturer, additional portions of the container are created that must be removed prior to final construction along a cut interface. These additional portions may include a dome section and/or moil portion. In some cases, manufacturers have only continued the embedded barrier layer to a position below the intended cut interface, thereby preventing the cut interface from exposing the laminated, multilayer configuration. With this option, it is difficult to control the barrier layer to ensure adequate barrier coverage (that is, that the embedded barrier layer does not stop too short from the finish of the container thereby exposing the contents to oxygen) while also preventing delamination caused by trimming through the multiple layers. In some applications, attempts have been made to heat and curl the finish of the container after trimming to prevent delamination. However, such technique adds additional manufacturing steps and required equipment, thereby increasing costs and time.
SUMMARY
[0010] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
[0011] According to the principles of the present teachings, a container is provided having a shoulder portion terminating at an opening and a sidewall portion extending from the shoulder portion to a base portion. The base portion closes off an end of the container. The shoulder portion, the sidewall portion and the base portion cooperate to define a receptacle chamber within the container into which product can be filled. A barrier layer extends continuously along the base portion, the sidewall portion, and the shoulder portion to the opening and is made of a polymer based material.
[0012] According to the principles of the present teachings, a preform for forming a container is provided having a tubular member defining an opening. The tubular member includes a proximal moil-forming section and a distal container-forming section. Barrier material is disposed throughout an entirety of the distal container-forming section and further disposed in a portion of the proximal moil-forming section.
[0013] According to the principles of the present teachings, a container assembly is provided having a moil section and a container section coupled to the moil section and separable therefrom along a trim plane. The container section includes a shoulder portion, a sidewall portion extending from the shoulder portion to a base portion, wherein the base portion closes off an end of the container section. The shoulder portion, the sidewall portion and the base portion cooperate to define a receptacle chamber into which product can be filled. Barrier material extends continuously throughout the container section and into a portion of the moil section and is made of a polymer based material.
[0014] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
DRAWINGS
[0015] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
[0016] FIG. 1 is a schematic cross-sectional view of a plastic container and moil constructed in accordance with some embodiments of the present disclosure; and
[0017] FIG. 2 is a schematic cross-sectional view of a preform constructed in accordance with some embodiments of the present disclosure.
[0018] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0019] Example embodiments will now be described more fully with reference to the accompanying drawings. 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.
[0020] 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 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.
[0021] When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0022] 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.
[0023] Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
[0024] This disclosure provides for a heat-set, polyethylene terephthalate (PET) container having a cost-effective barrier system for blow-trim applications capable of providing improved layer adhesion, improved oxygen scavenging properties, high reuse levels of in-plant regrind and improved container recyclability.
[0025] The present disclosure will be discussed in connection with the construction of the preform and the resultant container. It should be understood, however, that the present teachings should not be regarded as being limited to any particular preform or container shape. That is, the present teachings provide utility for a wide range of preform and container configurations, including containers having a flexible, collapsible, or otherwise configured base, sidewalls, and/or shoulder regions effectively absorbing the internal vacuum forces resulting from a hot-fill operation. Therefore, it should be recognized that variations can exist in the present embodiments.
[0026] As illustrated in FIG. 1 , the present teachings provide a one-piece plastic, e.g. polyethylene terephthalate (PET), container generally indicated at 10 . The container 10 is substantially elongated when viewed from a side. Those of ordinary skill in the art would appreciate that the following teachings of the present disclosure are applicable to other containers, such as rectangular, triangular, pentagonal, hexagonal, octagonal, polygonal, or square shaped containers, which may have different dimensions and volume capacities. It is also contemplated that other modifications can be made depending on the specific application and environmental requirements.
[0027] As shown in FIG. 1 , the one-piece plastic container 10 according to the present teachings defines a body 12 , and includes an upper portion 14 having a cylindrical sidewall forming a finish 20 . Integrally formed with the finish 20 and extending downward therefrom is a shoulder portion 22 . The shoulder portion 22 merges into and provides a transition between the finish 20 and a sidewall portion 24 . The sidewall portion 24 extends downward from the shoulder portion 22 to a base portion 28 having a base 30 . In some embodiments, sidewall portion 24 can extend down and nearly abut base 30 , thereby minimizing the overall area of base portion 28 such that there is not a discernable base portion 28 when container 10 is uprightly-placed on a surface.
[0028] The exemplary container 10 may also have a neck 23 . The neck 23 may have an extremely short height, that is, becoming a short extension from the finish 20 , or an elongated height, extending between the finish 20 and the shoulder portion 22 . The upper portion 14 can define an opening for filling and dispensing of a commodity stored therein.
[0029] The finish 20 of the plastic container 10 may include a threaded region having threads, a lower sealing ridge, and a support ring. The threaded region provides a means for attachment of a similarly threaded closure or cap (not illustrated). Alternatives may include other suitable devices that engage the finish 20 of the plastic container 10 , such as a press-fit or snap-fit cap for example. Accordingly, the closure or cap (not illustrated) engages the finish 20 to preferably provide a hermetical seal of the plastic container 10 . The closure or cap (not illustrated) is preferably of a plastic or metal material conventional to the closure industry and suitable for subsequent thermal processing.
[0030] With continued reference to FIG. 1 , in some embodiments, plastic container 10 can be formed with a moil portion 50 extending above finish 20 . Moil portion 50 can define a portion of the container 10 to be removed following molding of the preform 100 ( FIG. 2 ).
[0031] The plastic container 10 has been designed to retain a commodity. The commodity may be in any form such as a solid or semi-solid product. In one example, a commodity may be introduced into the container during a thermal process, typically a hot-fill process. For hot-fill bottling applications, bottlers generally fill the container 10 with a product at an elevated temperature between approximately 155° F. to 205° F. (approximately 68° C. to 96° C.) and seal the container 10 with a closure (not illustrated) before cooling. In addition, the plastic container 10 may be suitable for other high-temperature pasteurization or retort filling processes or other thermal processes as well. In another example, the commodity may be introduced into the container under ambient temperatures.
[0032] The plastic container 10 of the present disclosure is a blow molded, biaxially oriented container with a unitary construction from multi-layer material. A well-known stretch-molding, heat-setting process for making the one-piece lastic container 10 generally involves the manufacture of a preform 100 of a polyester material, such as polyethylene terephthalate (PET), having a shape well known to those skilled in the art similar to a test-tube with a generally cylindrical cross section. An exemplary method of manufacturing the plastic container 10 will be described in greater detail later.
[0033] As best seen in FIG. 2 , the preform 100 can comprise a multi-layer construction including a polymer-based barrier layer 110 generally layered between one or more adjacent layers 112 . It should also be recognized that the polymer-based barrier material can also be blended with the PET material to define a container not having discrete layers. However, for the purpose of this present discussion, the polymer-based barrier will be referred to as a layer member, such as polymer-based barrier layer 110 .
[0034] In some embodiments according to the present teachings, barrier layer 110 can comprise an oxidizable, polyamide-based material, such as Poliprotect. In some embodiments, barrier layer 110 can comprise an oxidizable, polymeric, oxygen-scavenging material, such as Oxyclear®, Amosorb®, and the like. Barrier layer 110 can be blended with PET to improve layer adhesion between two or more of the barrier layer 110 and the adjacent layer(s) 112 . That is, barrier layer 110 can be made of a blend of PET and an oxidizable, polymeric, oxygen-scavenging material. In some embodiments, the blend can include at least 80% PET and less than or equal to 20% of an oxidizable, polymeric, oxygen scavenging material. In some embodiments, the blend can include at least 99% PET and up to 1% non-PET active scavenger material by weight. This barrier layer can define about 2% to 3% of the thickness of the sidewall portion 24 .
[0035] The barrier layer 110 can be disposed in preform 100 such that it extends along preform body 111 from a distal tip 114 of preform 100 and continues toward a proximal end 116 of preform 100 . In some embodiments, barrier layer 110 extends along preform body 111 to a predetermined position 118 . Predetermined position 118 , in some embodiments, is defined by a position closer to proximal end 116 than a trim line 120 . Trim line 120 can be a plane through which the intermediate container is trimmed to size. The material trimmed from the intermediate container proximal from trim line 120 , which is also known as a moil 50 ( FIG. 1 ), represents scrap material. Accordingly, as seen in FIG. 2 , a portion of preform 100 above trim line 120 may be referred to as a moil-forming section 200 and the portion of preform 100 below trim line 120 may be referred to as a container-forming section 210 . Therefore, it should be appreciated that according to some embodiments of the present teachings, a portion of barrier layer 110 will be contained in the scrap material of the moil-forming section 200 , such as less than 0.5% by weight. Moreover, in some embodiments, barrier layer 110 will extend from distal tip 114 of preform 100 and will extend beyond trim line 120 and will be circumferentially complete thereabout, such that barrier layer 110 extends throughout container-forming section 210 and within a portion of moil-forming section 200 , such as the lowermost 20% by height.
[0036] As described herein, the barrier layer 110 can comprise any one of the following materials or any other desired material. It should be understood that polymer-based barrier materials are better for recycling and reuse than polyamide (nylon) based resin systems. By further using these teachings to limit the amount of barrier material required in the container and scrap material results in a final container with improved recyclability and scrap material that can be reused at higher levels within the plant.
[0000]
TABLE 1
Avg.
mils in
% barrier in
% barrier
Barrier %/matrix
barrier
% barrier in total
finished
in dome
Layer %
% in layer
layer
container
container
scrap*
3.8%
16.0% Oxyclear ®
0.76
0.61% Oxyclear ®
0.74%
~0.014%
84.0% 2300K
(balance PET)
6.0%
12.0% Oxyclear ®
1.20
0.72% Oxyclear ®
0.88%
~0.016%
88.0% 2300K
(balance PET)
8.2%
8.0% Oxyclear ®
1.64
0.66% Oxyclear ®
0.80%
~0.015%
92.0% 2300K
(balance PET)
3.8%
100% Amosorb ®
0.76
3.8% Amosorb ®
0.46%
~0.009%
4020
(0.38%
polybutadiene,
balance PET)
8.2%
100% Poliprotect ®
1.64
8.2% PPAPB
0.50%
~0.009%
APB
(~0.41% nylon,
balance PET)
3.8%
100% Aegis ® HFX
0.76
3.8% Aegis ® HFX
4.64%
~0.087%
(~0.1%
polybutadiene,
~3.7% nylon-6)
*Based on 20% of moil (dome) height for layer height.
[0037] According to the principles of the present teaching, this arrangement provides several benefits not found in the prior art. Specifically, but not limited to, the present arrangement provides improved barrier performance using less barrier material, because the barrier layer extends throughout the entire container 10 . The materials disclosed herein have been found to provide improved adhesion given better inherent adhesion properties of polymer based scavengers to PET. This arrangement and materials thus provide the ability to trim through the barrier layer 110 without significant delamination. Accordingly, this enables one to minimize the amount of barrier material in the scrap material, thus permitting reuse during in-plant manufacturing. The above will result in improved layer adhesion, oxygen barrier performance, better recyclability, and improved use of in-plant regrind.
[0038] An exemplary method of forming the container 10 will be described. A preform version 100 of container 10 includes a support ring, which may be used to carry or orient the preform through and at various stages of manufacture. For example, the preform may be carried by the support ring, the support ring may be used to aid in positioning the preform in a mold cavity, or the support ring may be used to carry an intermediate container once molded. At the outset, the preform may be placed into the mold cavity such that the support ring is captured at an upper end of the mold cavity. In general, the mold cavity has an interior surface corresponding to a desired outer profile of the blown container. More specifically, the mold cavity according to the present teachings defines a body forming region, a moil forming region and an optional opening forming region. Once the intermediate container, has been formed, any moil 50 created by the moil forming region may be severed along the trim line 120 and discarded and/or reused according to the principles of the present teachings.
[0039] In one example, a machine (not illustrated) places the preform heated to a temperature between approximately 190° F. to 250° F. (approximately 88° C. to 121° C.) into the mold cavity. The mold cavity may be heated to a temperature between approximately 250° F. to 350° F. (approximately 121° C. to 177° C.). A stretch rod apparatus (not illustrated) stretches or extends the heated preform within the mold cavity to a length approximately that of the intermediate container thereby molecularly orienting the polyester material in an axial direction generally corresponding with the central longitudinal axis of the container 10 . While the stretch rod extends the preform, air having a pressure between 300 PSI to 600 PSI (2.07 MPa to 4.14 MPa) assists in extending the preform in the axial direction and in expanding the preform in a circumferential or hoop direction thereby substantially conforming the polyester material to the shape of the mold cavity and further molecularly orienting the polyester material in a direction generally perpendicular to the axial direction, thus establishing the biaxial molecular orientation of the polyester material in most of the intermediate container. The pressurized air holds the mostly biaxial molecularly oriented polyester material against the mold cavity for a period of approximately two (2) to five (5) seconds before removal of the intermediate container from the mold cavity. This process is known as heat setting and results in a heat-resistant container suitable for filling with a product at high temperatures.
[0040] Alternatively, other manufacturing methods, such as for example, extrusion blow molding, one step injection stretch blow molding and injection blow molding, using other conventional materials including, for example, high density polyethylene, polypropylene, polyethylene naphthalate (PEN), a PET/PEN blend or copolymer, and various multilayer structures may be suitable for the manufacture of plastic container 10 . Those having ordinary skill in the art will readily know and understand plastic container manufacturing method alternatives.
[0041] 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 invention. 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 invention, and all such modifications are intended to be included within the scope of the invention. | A container comprises a shoulder portion terminating at an opening and a sidewall portion extending from the shoulder portion to a base portion. The base portion closes off an end of the container. The shoulder portion, the sidewall portion and the base portion cooperate to define a receptacle chamber within the container into which product can be filled. A barrier layer extends continuously along the base portion, the sidewall portion, and the shoulder portion to the opening and is made of a polymer based material. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of invention relates to alarm apparatus, and more particularly pertains to a new and improved filter sentry apparatus wherein the same effects actuation of an audible and visual alarm upon a filter requiring replacement or servicing.
2. Description of the Prior Art
Signal apparatus has been utilized in the prior art to effect alert upon plugging of a filter member. Such apparatus is found and may be exemplified by U.S. Pat. No. 4,321,070 to Bede wherein a whistle member is mounted within the filter upon clogging of the filter, whereupon air flow is directed through the whistle to alert an individual of need to replace or service a filter member.
U.S. Pat. No. 4,491,458 to Sunter sets forth a filter monitoring organization for monitoring pressure differentials across a collector to alert an individual relative to clogging of an associated filter.
U.S. Pat. No. 4,153,003 to Willis sets forth an indicator arranged for location of a pressure differential through a fluid system to note need of service of the system.
U.S. Pat. No. 4,445,456 to Nelson sets forth an air filter communication device to indicate a pressure differential resulting from clogged filter relative to the organization.
Accordingly, there continues to be a need for a new and improved filter sentry apparatus as set forth by the instant invention which addresses both the problems of ease of use as well as effectiveness in construction and in this respect, the present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of filter alert apparatus now present in the prior art, the present invention provides a filter sentry apparatus wherein the same sets forth a housing mountable to an associated filter web to indicate clogging of an associated filter through a visual and audible signal organization. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved filter sentry apparatus which has all the advantages of the prior art filter alarm apparatus and none of the disadvantages.
To attain this, the present invention provides an apparatus including a housing secured to a filter web, wherein the housing includes a reciprocating rod directed orthogonally through the housing relative to the filter web, whereupon plugging of the filter web permits the rod to be directed through the housing to effect actuation of a switch therewithin. The rod mounts a magnet to track a plurality of contacts of a switch within the housing to effect actuation of an audible and visual alarm.
My invention resides not in any one of these features per se, but rather in the particular combination of all of them herein disclosed and claimed and it is distinguished from the prior art in this particular combination of all of its structures for the functions specified.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. Those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
It is therefore an object of the present invention to provide a new and improved filter sentry apparatus which has all the advantages of the prior art filter alarm apparatus and none of the disadvantages.
It is another object of the present invention to provide a new and improved filter sentry apparatus which may be easily and efficiently manufactured and marketed.
It is a further object of the present invention to provide a new and improved filter sentry apparatus which is of a durable and reliable construction.
An even further object of the present invention is to provide a new and improved filter sentry apparatus which is susceptible of a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such filter sentry apparatus economically available to the buying public.
Still yet another object of the present invention is to provide a new and improved filter sentry apparatus which provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.
Still another object of the present invention is to provide a new and improved filter sentry apparatus wherein the same sets forth an organization for retrofit to existing filter webbing to provide alert of clogging of such webbing during use.
These together with other objects of the invention, along with 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 the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is an orthographic frontal view of a prior art filter alert apparatus.
FIG. 2 is an orthographic cross-sectional illustration of a prior art filter alert apparatus as set forth in FIG. 1.
FIG. 3 is an isometric rear view of the instant invention.
FIG. 4 is an isometric frontal view of the instant invention.
FIG. 5 is an orthographic cross-sectional illustration of the housing of the instant invention.
FIG. 6 is an orthographic cross-sectional illustration of the housing mounted to an associated filter web.
FIG. 7 is an orthographic frontal view, taken in elevation, of the invention in operative association with the filter web.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, and in particular to FIGS. 1 to 7 thereof, a new and improved filter sentry apparatus embodying the principles and concepts of the present invention and generally designated by the reference numeral 10 will be described.
FIG. 1 illustrates a prior art filter alert organization 1 in association with a filter, wherein a whistle member 2 is mounted through the filter to effect a shrill tone for signalling a clogged condition within the filter webbing.
More specifically, the filter sentry apparatus 10 of the instant invention essentially comprises a housing including a top wall 11, a rear wall 12, a forward wall 9, a bottom wall 8 (see FIG. 5), and spaced side walls, as illustrated. A first elastomeric strap 13 is mounted medially of an intersection of the top and rear wall, with a second elastomeric strap 14 mounted at an intersection of the bottom and rear wall. The first and second straps extend orthogonally beyond the top and bottom walls and include a respective first and second strap hook 13a and 14a for securement of the housing to an associated filter housing 32 (see FIGS. 6 and 7). An indicator light 16 is mounted to the forward wall 9 and in electrical communication with an on/off switch 17 to effect shutting down of the organization when its use is not desired, as well as communication electrically through an actuator switch 24 mounted within the housing. The actuator switch 24 includes an actuator switch first contact leg 25 and a second contact leg 26, wherein the first contact leg is formed of a non-ferro attractive material, such as aluminum, and wherein the second leg 26 is formed of a ferro magnetic material, such as steel and the like. A battery 27 is mounted within the housing in electrical communication with an audible signal device 29, such as a piazza-electric audible generating disk. An actuator rod 18 is slidably mounted through the housing and normally biased in a first position defined by a first spacing between a free terminal end of a signal hook member 15 formed to a rear terminal end of the actuator rod 18 that projects through the rear wall 12 of the housing through a rear wall opening 19a. A forward wall opening 19 is aligned with the rear wall opening 19a, and the forward wall 19 is directed through the forward wall 9, wherein an actuator rod forward terminal end 18a projects beyond the forward wall 19 in an orthogonal relationship, with a captured coil spring 20 mounted between a coil spring plate 21 and the exterior surface of the forward wall 9. The fastener 22 mounts the plate 21 to the actuator rod 18 adjacent the forward terminal end 18a. A magnetic cylinder 23 is mounted in surrounding relationship relative to the rod 18 and positioned within the forward wall opening 19 in the first spacing of the rear terminal end 15a relative to the rear wall. When a filter web 31 is clogged or requires servicing and the housing mounted to the filter housing 32 to an upper and lower lateral legs thereof as illustrated in FIGS. 6 and 7, the filter web 31 will deflect relative to the filter housing 32 and retract the actuator rod 18 within the housing and thereby position the magnetic cylinder 23 adjacent the actuator switch 24 to complete electrical circuitry and direct electrical energy to the indicator light 16 and the audible signal device 29 and thereby displace the rear terminal end 15a to a second spacing spaced from the rear wall 12. It should be noted, as illustrated in FIG. 6, that the housing is mounted confronting air flow directed towards the housing and the filter web to properly orient the filter web when it is deflected to permit actuation of the audible and visual signals of the sentry apparatus.
It should be noted that the audible signal device 29 is mounted within the housing overlying the rear wall and a matrix of bottom wall openings 30 to minimize dirt and the like from contaminating the audible signal device in use.
As to the manner of usage and operation of the instant invention, the same should be apparent from the above disclosure, and accordingly no further discussion relative to the manner of usage and operation of the instant invention shall be provided.
With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | An apparatus including a housing secured to a filter web, wherein the housing includes a reciprocating rod directed orthogonally through the housing relative to the filter web, whereupon plugging of the filter web permits the rod to be directed through the housing to effect actuation of a switch therewithin. The rod mounts a magnet to track a plurality of contacts of a switch within the housing to effect actuation of an audible and visual alarm. |
BACKGROUND OF THE INVENTION
This application is a continuation of application Ser. No. 862,739, filed Dec. 21, 1977, now abandoned, for Fuel Injection Timing and Control Apparatus.
Internal combustion engines are subject to variations in power output, smoothness of operation, economy, emissions, etc., incident to variations in fuel-air ratio, unequal distribution of fuel-air mixture to each combustion chamber, the timing of ignition in relation to the position of the piston in the cylinder, acceleration and deceleration transients, the type and amount of fuel provided, as well as external operating parameters, for example, engine load, R.P.M., ambient air pressure and temperature, etc. In addition to the foregoing parameters, compression ignition engines are faced with the functional need for initial injection of fuel during the compression stroke. Accordingly, the high gas presssure developed in the combustion chamber prior to the start of injection inhibits injection requiring fuel to be injected at a relatively higher pressure. High fuel pressure is typically achieved by pumping fuel from a low pressure rotary or gear pump to a high pressure pump. High pressure pumps may utilize rotary, displacement, or other means to pressurize fuel. A typical high pressure pump comprises a positive displacement piston driven by a cam mounted on an engine-driven camshaft. The camshaft is connected by various means, such as gears, chains, rocker-arms, follower assemblies, etc. to the engine crankshaft. Other known means of pressurizing fuel include electrical, mechanical, hydraulic, and electro-mechanical pump systems which separately, or in combination, develop sufficient fuel pressure to open a valve assembly which in turn injects the fuel into the combustion chamber.
Since compression-ignition occurs at a variable point in time subsequent to injection, the efficiency of the pressure-temperature build-up within the combustion chamber during the compression and expansion cycle in relation to crankshaft position and the consequent useful energy output is sensitive to many variables not the least of which is timing and duration of injection. Present compression-ignition engine fuel injection systems typically rely on direct coupling of the timing mechanism controlling fuel injection to the engine crankshaft by means of said gearing, chains, cams etc. In most cases, fuel injection timing is relatively fixed in terms of crankshaft position, notwithstanding that some variation in the timing of fuel injection in terms of crankshaft position can be achieved by mechanical movements or mechanisms which align relief ports or entry ports or both. It is also known to use helical flow paths on the fuel injector plunger shaft which can be rotated to adjustably meter fuel and/or control timing by selective alignment of the fuel entry port and/or fuel relief port. In other prior art devices, mechanical levers or other mechanisms open or close fuel entry or relief ports in response to fuel pressure variations to accomplish fuel injection metering and timing.
While electric modification of pressure actuation of a diesel injector is known, as taught in Bader et al U.S. Pat. Nos. 4,129,254; 4,129,253; 4,129,255 and 4,129,256, there exists a need for a fuel injection system that is capable of precisely controlling and varying the timing and duration of fuel injection, if any, as well as having the capability of precisely metering the proper quantity of fuel, independently of fuel pressure and in response to the totality of internal and external operating conditions solely in response to an electrical signal.
With respect to metering, most known direct injection systems effect filling of a cavity upstream of the injector nozzle with the exact amount of fuel to be injected. The fuel in the cavity is acted upon by a piston to provide the pressure necessary for injection.
In distribution type injectors, either rotary, displacement, or other means are used to pressurize fuel at which time a selector mechanism directs the high pressure fuel to remote injectors at or near each combustion cylinder. The high pressure fuel flows to each injector nozzle causing the nozzle to open and to inject the fuel until a subsequent pressure drop closes the nozzle. Such known systems exhibit delays and inaccuracies related to the remoteness of the pressurizing means and the injection mechanism and are comparatively inefficient for controlling timing and the quantity of fuel injected.
SUMMARY OF THE INVENTION
The fuel injection system of the instant invention is actuated independently of any mechanical connection to the crankshaft. The high pressure fuel pump is not involved in the timing or metering of fuel injection or actuation of the fuel injection nozzle. Fuel injection timing is related to a precise position of each cylinder and variations in the quantity and rate of injection are computed externally from the fuel injection mechanism by various means which include, but are not limited to, electronic, electro-mechanical, electro-magnetic, opto-electronic, piezoelectric, and other temperature, pressure, and position determining sensors, position switches and devices which measure engine operating and environmental parameters. A multiplicity of parameters involved in the combustion process can be accommodated. These include, but are not limited to, crankshaft position, R.P.M., temperature of the ambient air, coolants, fuel, exhaust, and oil, fuel and air pressures, load, engine torque, vehicle speed, transmission and throttle position, fuel-air ratios, combustion pressures, combustion temperatures, combustion air-mass flow and supercharger pressures.
Moreover, it is contemplated that memory devices, such as random-access-memories (RAMS) and/or read-only-memories (ROMS), can be utilized to store either computed data (in the instance of RAMS) or can be programmed (in the instance of ROMS) to reflect changes in injection timing, meter fuel quantity, or rate of flow of metered fuel for a multiplicity of operating conditions. Furthermore, it is contemplated that merely a change in a programmed memory can render a single injection device usable in different engines.
The invention incorporates an accumulator along with its associated pressure relief and other valving which operates to dispense fuel directly to the engine combustion chamber. Thus, the invention provides a means of utilizing very high fuel injection pressures and fuel injecting pressures which can be varied quickly, almost instantaneously, without the delays normally associated with present devices. These features facilitate improvements in fuel economy and engine operating efficiencies and design improvements in injection spray mechanisms as well as shorter periods of fuel injection, not heretofore practical.
More particularly, the armature of an electromechanical solenoid is utilized as a direct fuel injection control device. The armature is not affected by high fuel pressure heads or dynamic shut-off forces. By virtue of its immersion in fuel, it is self lubricating, cooled and dynamically dampened to inhibit undesirable vibration modes.
The armature may utilize electro-magnetic, spring, or other restoring forces. Since the mechanism does not effect pressurization of the fuel, electromagnetic force and speed requirements need only be proportioned to the operating requirements of the engine, for example, in a sophisticated application, to change the rate of opening of the injection orifice, or in its most simple application, to effect only an "open-close" action. In a preferred embodiment of the invention, the electro magnetic solenoid is housed internally of the fuel accumulator of the injector. In another form of the invention, the solenoid may be disposed externally of the pressurized fuel in the accumulator. More than one electro magnetic solenoid may be utilized either to amplify the forces on the armature, eliminate return springs, or to provide opposing forces to the "open" and "close" action. In some applications, more precise movement and/or speed of armature movement can be realized with more than one solenoid. A variable and controllable pressure relief valve is connected to the high pressure accumulator so as to provide for safety, as well as allow variations in fuel quantity metering.
It is to be noted that the fuel injector 10 can either be retrofit to an existing diesel engine or disigned into new equipment. The injector renders the engine susceptible of electronic control of the timing and duration of fuel injection independently of the mechanical limitations of currently utilized injectors. Control and injection of liquid fuel is independent of the pressure of said fuel as distinguished from the prior art which characteristically uses a pressure threshhold to initiate injection.
Applicant's contribution is also to be distinguished from injectors which use an electric solenoid merely to control a pressure relief valve to thereby control pressure response of the injector.
More specifically, Applicant's electric non-fuel pressure responsive fuel injector comprises an injector housing which may be mounted in the position of a conventional pressure excited fuel injector. A fuel accumulator is provided including a spring loaded piston for maintaining the pressure of liquid fuel therein relatively constant incident to changes in the volume of fuel in the accumulator. A fuel pump adapted to be mechanically driven directly by the conventional cam shaft of the engine is provided for pressurizing fuel in the accumulator. A fuel injection nozzle communicates with the accumulator and the combustion chamber of the diesel internal combustion engine. A sleeve valve having radially directed fuel flow control ports communicating with the accumulator and the injection nozzle effects control of the flow of fuel from the accumulator to the injection nozzle. Fuel ports are orientated relative to the direction of opening and closing of the sleeve valve whereby the pressure of fuel thereon or passing therethrough exerts no opening or closing force on the valve. An electric solenoid controls movement of the valve independently of the pressure of the fuel in the accumulator and of the speed of rotation of the engine. Conventional sensors having an electrical output are provided for energizing the solenoid independently of the fuel pump and pressure in the accumulator in response to selected engine and environmental parameters. If, for example, shutdown of one or more cylinders is desired, mere interruption of energization of the solenoid is required. Obviously, complete and instantaneous shutdown on deceleration or braking of a vehicle is possible.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of an improved fuel injector in accordance with one embodiment of the invention.
FIG. 2 is a cross sectional view, similar to FIG. 1, illustrating a modified embodiment of the present invention utilizing dual solenoids.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawings, a fuel injector 10 in accordance with the present invention comprises a housing 12 having a manifold 14 and a tubular barrel 16. The manifold 14 has conventional fittings 18 and 20 for the acceptance of relatively low pressure fuel into the manifold 14.
The fuel plunger 22 is slidable in a bore 23. The plunger 22 is biased upwardly, as seen in the drawings, by a plunger spring 24. The plunger 22 has a follower portion 26 that is engageable by a cam 28 on a camshaft (not shown) of an engine (not shown).
The plunger 22 has a piston 30 at the lower end thereof which acts against fuel in a pumping chamber 32 to pressurize and pump the fuel past a check valve 34 into a plenum chamber or accumulator 36 interiorly of the barrel 16.
The manifold 14 is provided with an accumulator piston 38 that is slidably disposed in a bore 40. The piston 38 is movable upwardly against the bias of the spring 42 to maintain fuel pressure relatively constant within the accumulator 36 upon injection of fuel into the working cylinder of an engine as will be described.
The chamber 40 is provided with a relief passage 44 that communicates with an outlet line 46 on the back side of a check valve 48. The accumulator chamber 36 has a relief passage 50 that communicates with the high pressure side of the check valve 48 to relieve pressure within the accumulator 36 above a predetermined level. In this manner, high pressure fuel is constantly flowing through the intake manifold 14, accumulator 36, through outlet line 46, outwardly of the manifold 14 to a fuel reservoir (not shown) to provide an adequate supply of fuel for injection into a working cylinder of an engine as well as to effect cooling of the injector 10.
In accordance with the present invention, injection of fuel under pressure into a working cylinder by the fuel injector 10 is controlled by a solenoid 60 comprising a coil 62, a cylindrical outer casing 64, an inner pole piece 66, and a slidable cylindrical or sleeve-like armature 68. The armature 68 is biased to the normally open condition by a spring 70 which is seated on a radial shoulder 72 on the armature 68.
The solenoid 60 is controlled by a conventional state-of-the art electronic assembly 74, such as but not limited to, suitable sensor transducers, an input-output signal conditioning section, a microprocessor or other suitable electronic processing unit, and a driver section to provide sufficient energy and timing to actuate the solenoid and/or other electro-mechanical device in the conventional manner. The electronic assembly 74 senses and correlates the engine and environmental parameters discussed hereinbefore and translates them into an appropriate electrical signal to the solenoid 60.
The lower end of the armature 68 is provided with a pair of transverse bores 80 and 82 which, when aligned with complementary bores 84 and 86 in a fixed central mandril 88, permit flow of pressurized fuel from the plenum 36 downwardly through a central bore 90 in the mandril 88 and outwardly through discharge passages 92 and 94 in a spray tip 96 of the injector 10. The mandril 88 is non-magnetic to insure magnetic efficiency. A nut 104 secures the coil 62, armature 68 and mandril 88 together as a sub-assembly.
Referring to FIG. 2, a modified injector 110 comprises a pair of opposed solenoids 112 and 114 having coils 116 and 118, cylindrical outer casings 120 and 122, pole pieces 124 and 126, respectively and a common slidable cylindrical armature 128. The armature 128 is biased between the open and closed condition by controlled and/or selective energization of the coils 116 and 118. Thus, control of the injector 110 can be effected by an "on-off" signal or by a "proportional" signal.
The lower end of the armature 128 is provided with a pair of transverse bores 130 and 132 which, when aligned with complementary bores 134 and 136 in a lower tip portion 138 on the housing of the solenoid 114, permit flow of pressurized fuel from the accumulator 36 downwardly through a central bore 140 and outwardly through discharge passages 142 and 146 in the tip 138. A lower end portion 148 and an upper end portion 150 of the armature 128 are non-magnetic while center portions 152 and 153 are magnetizable to maximize the efficiency of the solenoids 120 and 122.
From the foregoing it should be apparent that pressurization of fuel within a plenum chamber of the injector is disassociated from timing and duration of fuel injection which is controlled solely by the energization of a solenoid. In this manner, fuel injection is rendered responsible to a number of parameters of engine performance which heretofore have been incapable of integration into the injector control function. | The disclosure relates to a fuel injector for an internal combustion engine and, more particularly, to a fuel injector for a compression-ignition type engine. The fuel injector precisely meters fuel and accurately times the start and duration of fuel injection in response to an electrical signal that is a composite of a multiplicity of engine and environmental operating parameters as opposed to a fuel pressure threshold. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to button or coin shaped secondary batteries and capacitors capable of being reflow soldered and, more particularly, to the structure of secondary battery or capacitor having terminals.
[0003] 2. Description of the Related Art
[0004] Coin or button shaped primary and secondary batteries and capacitors which are used as auxiliary power supplies for backup for clocks and memories of portable devices are generally fitted with terminals for taking leads from the positive and negative electrodes of the batteries in use.
[0005] With respect to their terminal shapes, components have decreased in size in recent years. In a known type, terminals are inserted into a mounting board or substrate provided with holes for terminals, and the terminals are soldered from the rear side of the substrate (FIGS. 1 and 2). Also, the surface mount type (FIGS. 3 - 6 ) is prevalent. In particular, a secondary battery or capacitor fitted with terminals is placed on a substrate intact. Solder-plated portions at the front ends of the terminals are placed on the front surface of the substrate. A soldering operation is performed from this front side of the substrate. The terminals of the surface mount type are so shaped that both positive and negative terminals extend a considerable distance outwardly from the outer surface of a button or coin shaped secondary battery or capacitor, for the following reason. The positive and negative terminals are hand soldered to the substrate and so the secondary battery or capacitor is protected from thermal effects.
[0006] Recently, button or coin shaped secondary batteries and capacitors have been increasingly required to be capable of being reflow soldered in order to streamline mounting operations. In the past, gaskets made of polypropylene were used. Secondary batteries and capacitors which use better heatproof gaskets made of thermoplastic engineering materials such as polyphenylene sulfide and which can be reflow soldered have been devised and put into practical use.
[0007] To surface-mount a secondary battery or capacitor, which can be reflow soldered, to a substrate, it has been necessary to bring the surfaces of the positive and negative terminals into parallel contact with the substrate surface simply if the secondary battery or capacitor having the terminals is placed on the substrate surface. with respect to the terminal shape, where the positive and negative terminals are directed in the same direction (FIGS. 7 and 8), the center of gravity of the secondary battery or capacitor having the terminals has poor balance. This is unsuited for surface mounting. Where positive and negative terminals are directed in opposite directions (FIGS. 3 - 6 ; spaced apart by 180°), both positive and negative terminals easily make parallel contact with a substrate. Therefore, this type is advantageous for surface mounting and has become a mainstream.
[0008] With respect to terminal shapes of surface mount type secondary batteries and capacitors that can be reflow soldered, the shape type in which positive and negative terminals are spaced apart by 180° and directed in opposite directions is mainstream. This shape has the disadvantage that where a secondary battery or capacitor with terminals is surface-mounted to a substrate by a reflow process, the secondary battery or capacitor with terminals occupies a large area on the substrate. As components have been required to be fabricated in smaller size, it is quite important to minimize the area occupied on the substrate by the secondary battery or capacitor with terminals.
SUMMARY OF THE INVENTION
[0009] The present invention provides a structure, where either one of positive and negative terminals is placed within a square that the outer surface of a button or coin shaped secondary battery or capacitor inscribes. This greatly reduces the area taken up on the substrate by the secondary battery or capacitor fitted with the terminals.
[0010] Where the negative electrode side is placed opposite to the substrate surface, the positive electrode can and the negative terminal are brought into contact with each other by the weight of the secondary battery or capacitor after reflow solder. This creates the possibility that the positive and negative electrodes are shorted to each other. To prevent this electrical shorting, at least one step is formed on the negative terminal mounted on the negative electrode can opposite to the substrate surface. Further details of the configuration of the present invention are as follows.
[0011] (1) A secondary battery or capacitor fitted with terminals. The positive and negative terminals are mounted to the secondary battery or capacitor to take leads. Either one of these two terminals is placed substantially within a square that the outer surface of the secondary battery or capacitor inscribes.
[0012] (2) A secondary battery or capacitor fitted with terminals. The positive and negative terminals are mounted to the secondary battery or capacitor. The solder-plated portions of the positive and negative terminals are placed parallel to the substrate surface on which the secondary battery or capacitor is mounted.
[0013] (3) A secondary battery or capacitor fitted with terminals including a terminal opposite to the substrate surface on which the secondary battery or capacitor is mounted. The terminal opposite to the substrate surface has at least one step.
[0014] Generally, many of electronic components mounted on substrates are rectangular in shape. Therefore, where a round secondary battery or capacitor is mounted, dead space is created. As shown in FIG. 15, dead space is often created at the corners of a square 5 n where the outer surface of a secondary battery or capacitor inscribes the square 5 n. Therefore, a terminal 5 c connected with an electrode located on the side of a substrate is preferably made smaller. However, the size can be increased within the range of the square 5 n. If the terminal 5 c is too small, the secondary battery becomes unstable. Therefore, the width 5 L is preferably set to more than 40% of the diameter R of the secondary battery. It is also necessary to set the width 5 L to less than the diameter R of the secondary battery or capacitor so that the outside diameter of the battery or capacitor does not go beyond the inscribed square 5 n.
[0015] Where stability occurring when a secondary battery is placed on a substrate is taken into consideration, the end of the terminal 5 c should not be too close to the center of the secondary battery or capacitor. Where the distance from the end of the terminal 5 c to the outer surface of the secondary battery or capacitor is 5 m and the radius of the battery or capacitor is r, it is important to have 0≦ 5 m <r.
[0016] However, depending on the accuracy at which the terminal is welded, the terminal 5 c may jut a distance equal to about 10% of the diameter of the secondary battery or capacitor out of the square 5 n. This extent is within the scope of the present invention.
[0017] Since a terminal 5 b connected with an electrode located on the opposite side of the substrate juts out of the inscribed square 5 n, the size is preferably made as small as possible. The stability of the secondary battery or capacitor is secured by making the terminal 5 c wide. This makes use of the dead space and allows more substantial high-density packaging. Consequently, the width 5 L of the terminal 5 c, at its end, connected with the electrode on the substrate side and the width 5 k of the terminal 5 b, at its end, connected with the electrode located on the opposite side of the substrate preferably satisfy 5 k < 5 L.
[0018] The terminal 5 b connected with the electrode located on the opposite side of the substrate does not need to be positioned on a line with the terminal 5 c. The packaging efficiency is also effectively increased by slightly tilting the terminal 5 b such that it is located in a dead space at one corner of the inscribed square 5 n. In this case, it is necessary to stabilize the secondary battery or capacitor by placing the center 5 g of the secondary battery or capacitor within a triangle created by the positions 5 h, 5 i at which the ends of the terminal 5 c connected with the electrode on the substrate side are located at corners and by the midpoint 5 j between the ends of the terminal 5 b connected with the electrode on the opposite side of the substrate.
[0019] In this way, the shapes and positions of the terminals 5 b and 5 c are determined as long as they jut out of the secondary battery or capacitor slightly within a tolerable range of stability.
[0020] In the terminal shape of surface mount type terminals of a secondary battery or capacitor which can be reflow soldered, the area occupied on a substrate by the secondary battery or capacitor fitted with the terminals can be reduced greatly by placing the terminal mounted opposite to the substrate surface within a square that the outer surface of the secondary battery or capacitor inscribes provided that the terminal mounted opposite to the substrate surface juts out of the perimeter of the square that the outer surface of the battery or capacitor inscribes. With this terminal shape, the terminal cannot be hand soldered to the substrate, because either one of the positive and negative terminals does not protrude out of the perimeter of the square that the outer surface of the secondary battery or capacitor inscribes. However, the terminal shape in accordance with the present invention permits mounting to the substrate using a reflow process. That is, the secondary battery or capacitor is passed through a reflow furnace to heat the whole battery or capacitor, and solder previously applied to the substrate is used to solder the terminal portions. Where the secondary battery or capacitor is surface-mounted, space savings can be very effectively achieved.
[0021] Where the negative electrode is placed opposite to the substrate surface as shown in FIGS. 14 , the positive terminal can and the negative terminal may be brought into contact with each other by the weight of the secondary battery or capacitor after reflow soldering, thus creating the possibility that the positive and negative electrodes are shorted to each other. This electrical shorting can be effectively prevented by providing at least one step on the negative terminal mounted on the negative terminal can opposite to the substrate surface.
[0022] It is impossible to eliminate variations in height between individual secondary batteries or capacitors for manufacturing reasons. Therefore, where no step is formed on the terminal connected with the electrode located on the substrate side, if the height of the secondary battery or capacitor decreases, the terminal connected with the electrode on the opposite side of the substrate will float off the substrate. As a result, electrical connection with the substrate may not be made. Variations in height between individual secondary batteries or capacitors can be absorbed by an amount corresponding to the step. The step may be set, taking account of the height variations. Where a terminal having a step is used, if the height of the secondary battery or capacitor deviates from a target value, the surface of the terminal that is electrically connected with the substrate may not be parallel to the substrate N In this case, the portion (i.e., a portion bent because of the presence of a step or the end portion of the surface of the terminal that is electrically connected with the substrate) that rises from the surface of the terminal that is electrically connected with the substrate comes into contact with the substrate. During reflow, the solder begins to melt at this location and is electrically connected. It is very advantageous to place solder at this location. The method of placing solder can be dipping, plating, or other method. No limitations are imposed on this method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a plan view of a conventional secondary battery or capacitor fitted with terminals which are designed to be inserted into a substrate;
[0024] [0024]FIG. 2 is a side elevation of the conventional secondary battery or capacitor with terminals, and in which the battery or capacitor has been inserted into the substrate;
[0025] [0025]FIG. 3 is a plan view of a conventional secondary battery or capacitor fitted with terminals;
[0026] [0026]FIG. 4 is a side elevation of the conventional secondary battery or capacitor fitted with terminals, and in which the battery or capacitor has been surface-mounted to a substrate;
[0027] [0027]FIG. 5 is a bottom view of a conventional secondary battery or capacitor fitted with terminals;
[0028] [0028]FIG. 6 is a side elevation of the conventional secondary battery or capacitor fitted with terminals, and in which the battery or capacitor has been surface-mounted to a substrate;
[0029] [0029]FIG. 7 is a plan view of a conventional secondary battery or capacitor fitted with terminals;
[0030] [0030]FIG. 8 is a side elevation of the conventional secondary battery or capacitor fitted with terminals, and in which the battery or capacitor has been surface-mounted to a substrate;
[0031] [0031]FIG. 9 is a bottom view of a secondary battery or capacitor fitted with terminals according to the present invention;
[0032] [0032]FIG. 10 is a plan view of a secondary battery or capacitor fitted with terminals according to the present invention;
[0033] [0033]FIG. 11 is a side elevation of a secondary battery or capacitor fitted with terminals according to the present invention, and in which the battery or capacitor has been surface-mounted to a substrate;
[0034] [0034]FIG. 12 is a plan view of a secondary battery or capacitor fitted with terminals according to the present invention;
[0035] [0035]FIG. 13 is a bottom view of a secondary battery or capacitor fitted with terminals according to the present invention;
[0036] [0036]FIG. 14 is a side elevation of the secondary battery or capacitor fitted with terminals according to the present invention, and in which the battery or capacitor has been surface-mounted to a substrate; and
[0037] [0037]FIG. 15 is a bottom view of the secondary battery or capacitor fitted with terminals according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] Embodiment 1
[0039] In a 414-size capacitor having a diameter of 4.8 mm and a thickness of 1.4 mm, the positive terminal was mounted inside a square that the capacitor inscribed. The negative terminal was mounted at a normal position. Thus, an inventive product (FIGS. 9 - 11 ) in accordance with the present invention was fabricated. With respect to the inventive product and the conventional product (FIGS. 3 - 4 ), the length ( 4 e, 2 e ) between the front end of the positive terminal and the front end of the negative terminal was measured. The lengths were compared (Table 1). FIG. 9 is a bottom view of a secondary battery or capacitor in accordance with the present invention. FIG. 10 is a plan view of the secondary battery or capacitor in accordance with the invention. FIG. 11 is a side elevation of a secondary battery or capacitor in accordance with the invention, and in which the battery or capacitor is mounted on a packaging substrate. Shown in these figures are the secondary battery or capacitor 4 a, a negative terminal 4 b welded to a negative electrode can, a positive terminal 4 c welded to a positive electrode can, and a packaging substrate 4 d on which an electronic circuit is wired. The hatched portions of the terminals 4 b and 4 c are front end portions of the solder-plated terminals 4 b and 4 c and soldered to solder portions on the packaging substrate 4 d. 4 e shown in FIG. 9 is the length between the front end portion of the negative terminal 4 b and the front end portion of the positive terminal 4 c. This length is defined as the total length including the terminals. FIG. 3 is a plan view of a conventional secondary battery or capacitor. FIG. 4 is a side elevation of the conventional secondary battery or capacitor, and in which the battery or capacitor is mounted on a packaging substrate. Shown in these figures are the secondary battery or capacitor 2 a, a negative terminal 2 b welded to a negative electrode can, a positive terminal 2 c welded to a positive electrode can, and a packaging substrate 2 d on which an electronic circuit is wired. The hatched portions of the terminals 2 b and 2 c are front end portions of the solder-plated terminals 2 b and 2 c and soldered to solder portions on the packaging substrate 2 d. 2 e shown in FIG. 3 is the length between the front end portion of the negative terminal 2 b and the front end portion of the positive terminal 2 c. This length is defined as the total length including the terminals.
TABLE 1 (total length including terminals (mm) total length including terminals Inventive Products 7.0 at maximum Prior Art Products 8.3 at maximum
[0040] As indicated in Table 1, the maximum value of the total lengths 4 e of the inventive products including the terminals was 7.0 mm. The maximum value of the total lengths 2 e of the prior art products including the terminals was 8.3 mm. The total length of the inventive products was shorter than that of the prior art products by about 15%. The inventive and prior art products were evaluated whether their positive and negative terminals could be reflow soldered to packaging substrates. The results are indicated in Table 2. A hot air type reflow furnace was used as a reflow furnace.
TABLE 2 (solderability percentage after reflow process) percentage (%) of products that could be soldered Inventive Products 100 Prior Art Products 100
[0041] As can be seen from Table 2, inventive products in which the positive terminals were placed within the perimeter of a square that the outer surface of the capacitor inscribed could be soldered at a success rate of 100% in the same way as prior art products. No issues were found at all.
[0042] Embodiment 2
[0043] In a 414-size capacitor having a diameter of 4.8 mm and a thickness of 1.4 mm, the negative terminal was mounted within the perimeter of a square that the capacitor inscribed. The positive terminal was mounted at a normal position. Thus, inventive products (FIGS. 12 - 14 ) in accordance with the present invention were fabricated. With respect to the inventive products and the conventional products (FIGS. 5 - 6 ), the length ( 4 f, 2 f ) between the front end of the positive terminal and the front end of the negative terminal was measured. Their lengths were compared (Table 3).
[0044] [0044]FIG. 12 is a plan view of a secondary battery or capacitor in accordance with the present invention. FIG. 13 is a bottom view of the secondary battery or capacitor in accordance with the invention. FIG. 14 is a side elevation of the secondary battery or capacitor in accordance with the invention, and in which the battery or capacitor is mounted on a packaging substrate. Shown in these figures are the secondary battery or capacitor 4 a, a negative terminal 4 b welded to the negative electrode can, a positive terminal 4 c welded to the positive electrode can, and the packaging substrate 4 d on which an electronic circuit is wired. The hatched portions of the terminals 4 b and 4 c are front end portions of the solder-plated terminals 4 b and 4 c and soldered to solder portions on the packaging substrate 4 d. 4 f shown in FIG. 12 is the length between the front end portion of the negative terminal 4 b and the front end portion of the positive terminal 4 c. This length is defined as the total length including the terminals. FIG. 5 is a bottom view of a conventional secondary battery or capacitor. FIG. 6 is a side elevation of the conventional secondary battery or capacitor, and in which the battery or capacitor is mounted on a packaging substrate. Shown in these figure are the secondary battery or capacitor 2 a, a negative terminal 2 b welded to the negative electrode can, a positive terminal 2 c welded to the positive electrode can, and the packaging substrate 2 d on which an electronic circuit is wired. The hatched portions of the terminals 2 b and 2 c are front end portions of the solder-plated terminals 2 b and 2 c and soldered to solder portions on the packaging substrate 2 d. 2 f shown in FIG. 5 is the length between the front end portion of the negative terminal 2 b and the front end portion of the positive terminal 2 c. This length is defined as the total length including the terminals.
TABLE 3 (total length including terminals (mm) total length including terminals Inventive Products 6.3 at maximum Prior Art Products 7.6 at maximum
[0045] As can be seen from Table 3, the maximum value of the total lengths 4 f including the terminals of the inventive products was 6.3 mm. On the other hand, the maximum value of the total lengths 2 f including the terminals of the prior art products was 7.6 mm. The inventive product was shorter in total length than the prior art product by about 17%.
[0046] The inventive and prior art products were evaluated whether their positive and negative terminals could be reflow soldered to packaging substrates. The results are indicated in Table 2. A hot air type reflow furnace was used as a reflow furnace.
TABLE 4 (solderability percentage after reflow process) percentage (%) of products that could be soldered Inventive Products 100 Prior Art Products 100
[0047] As can be seen from Table 4, inventive products in which the negative terminals were placed within the perimeter of a square that the outer surface of the capacitor inscribed could be soldered, by a hot air reflow process at a success rate of 100% in the same way as prior art products. No issues were found at all.
[0048] In the present invention, either one of the positive and negative terminal is placed substantially inside the perimeter of a square that the outer surface of a secondary battery or capacitor inscribes. Therefore, where the secondary battery or capacitor fitted with the terminals is reflow soldered to a substrate, the area occupied on the substrate by the secondary battery or capacitor fitted with the terminals can be reduced greatly. Furthermore, the invention is advantageous for miniaturization of portable devices and so on typified by mobile phones using such secondary batteries or capacitors fitted with terminals. Thus, the present invention contributes greatly to the industry. | A secondary battery or capacitor fitted with terminals and occupies less area on a packaging substrate. Either one of the positive and negative terminals is mounted within the outer surface of the secondary battery or capacitor. This reduces the area occupied by the secondary battery or capacitor fitted with terminals on the substrate. At least one step is formed on the terminal positioned opposite to the substrate. This prevents electrical shorting between the positive electrode can and the negative terminal. |
[0001] This Application is a Continuation of U.S. patent application Ser. No. 09/041,901, filed Mar. 13, 1998 and now pending, and incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The semiconductor manufacturing industry is constantly seeking to improve the processes used to manufacture integrated circuits from wafers. The improvements come in various forms but, generally, have one or more objectives as the desired goal. The objectives of many of these improved processes include: 1) decreasing the amount of time required to process a wafer to form the desired integrated circuits; 2) increasing the yield of usable integrated circuits per wafer by, for example, decreasing the likelihood of contamination of the wafer during processing; 3) reducing the number of steps required to turn a wafer into the desired integrated circuits; and 4) reducing the cost of processing the wafers into the desired integrated circuit by, for example, reducing the costs associated with the chemicals required for the processing
[0003] In the processing of wafers, it is often necessary to subject one or more sides of the wafer to a fluid in either liquid, vapor or gaseous form. Such fluids are used to, for example, etch the wafer surface, clean the wafer surface, dry the wafer surface, passivate the wafer surface, deposit films on the wafer surface, etc. Control of the physical parameters of the processing fluids, such as their temperature, molecular composition, dosing, etc., is often quite crucial to the success of the processing operations. As such, the introduction of such fluids to the surface of the wafer occurs in a controlled environment. Typically, such wafer processing occurs in what has commonly become known as a reactor.
[0004] Various reactors have been known and used. These reactors typically have a rotor head assembly that supports the wafer. In addition to introducing the wafer into the processing chamber, the rotor head assembly may be used to spin the wafer during introduction of the processing fluid onto the surface of the wafer, or after processing to remove the processing fluid.
[0005] During processing, the wafer is presented to the rotor head assembly by a robot in a clean environment in which a number of processing reactors are present. The robot presents the wafer in an exposed state to the rotor head assembly in an orientation in which the side of the wafer that is to be processed is face up. The rotor head assembly inverts the wafer and engages and seals with a cup for processing. As the wafer is processed, the wafer is oriented so that the side of the wafer being processed is face down.
[0006] These types of reactors are useful for many of the fluid processing steps employed in the production of an integrated circuit. However, there remains a need for more control and efficiency from the reactor. As such, a substantially new approach to processing and reactor design has been undertaken which provides greater control of the fluid processes and provides for more advanced and improved processes.
SUMMARY OF THE INVENTION
[0007] An apparatus for processing a workpiece in a micro-environment is set forth. The apparatus includes a rotor motor and a workpiece housing. The workpiece housing is connected to be rotated by the rotor motor. The workpiece housing further defines a processing chamber where one or more processing fluids are distributed across at least one face of the workpiece by centrifugal force generated during rotation of the housing.
[0008] In one embodiment, the workpiece housing includes an upper chamber member and a lower chamber member joined to one another to form the processing chamber. The processing chamber preferably generally conforms to the shape of the workpiece and includes at least one fluid outlet at a peripheral region. At least one workpiece support is advantageously provided to support a workpiece in the processing chamber in a position to allow centrifugal distribution of a fluid supplied through an inlet opening into the process chamber. The fluid may be distributed across at least an upper face and/or lower face of the workpiece, when the workpiece housing is rotated. The fluid outlet is positioned to allow extraction of fluid in the processing chamber by centrifugal force.
[0009] In another embodiment, an apparatus for processing a workpiece includes a rotor portion and a process housing attachable to the rotor portion for rotation, and detachable from the rotor portion for transport. The process housing preferably includes a first chamber member and a second chamber, with the fist chamber member engageable with the second chamber member to form a process chamber between them. At least one inlet and at least one outlet extend into the process chamber. The process housing is useful for processing a workpiece, as well as for transporting or storing the workpiece.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] [0010]FIG. 1 is a cross-sectional view of a workpiece housing and a rotor assembly constructed in accordance with one embodiment of the invention.
[0011] [0011]FIG. 2 is an exploded view of a further embodiment of a workpiece housing constructed in accordance with the teachings of the present invention
[0012] [0012]FIG. 3 is a top plan view of the workpiece housing of FIG. 2 when the housing is in an assembled state.
[0013] [0013]FIG. 4 is a cross-sectional view of the workpiece housing taken along line IV-IV of FIG. 3.
[0014] [0014]FIG. 5 is a cross-sectional view of the workpiece housing taken along line V-V of FIG. 3.
[0015] [0015]FIG. 6 is a cross-sectional view of the workpiece housing taken along line VI-VI of FIG. 3.
[0016] [0016]FIGS. 7A and 7B are cross-sectional views showing the workpiece, housing in a closed state and connected to a rotary drive assembly.
[0017] [0017]FIGS. 8A and 8B are cross-sectional views showing the workpiece housing in an open state and connected to a rotary drive assembly.
[0018] [0018]FIG. 9 illustrates one embodiment of an edge configuration that facilitates mutually exclusive processing of the upper and lower wafer surfaces in the workpiece housing.
[0019] [0019]FIG. 10 illustrates an embodiment of the workpiece housing employed in connection with a self-pumping re-circulation system.
[0020] [0020]FIGS. 11 and 12 are schematic diagrams of exemplary processing tools that employ the present invention.
[0021] [0021]FIG. 13 illustrates a batch wafer processing tool constructed in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] [0022]FIG. 1 is a cross-sectional view of one embodiment of a reactor, shown generally at 10 , constructed in accordance with the teachings of the present invention. The embodiment of the reactor 10 of FIG. 1 is generally comprised of a rotor portion 15 and a workpiece housing 20 . The rotor portion 15 includes a plurality of support members 25 that extend downwardly from the rotor portion 15 to engage the workpiece housing 20 . Each of the support members 25 includes a groove 30 that is dimensioned to engage a radially extending flange 35 that extends about a peripheral region of the workpiece housing 20 . Rotor portion 15 further includes a rotor motor assembly 40 that is disposed to rotate a hub portion 45 , including the support members 25 , about a central axis 47 . Workpiece housing 20 is thus secured for co-rotation with hub portion 45 when support members 25 are engaged with flange 35 . Other constructions of the rotor portion 15 and the engagement mechanism used for securement with the workpiece housing 20 may also be used.
[0023] The workpiece housing 20 of the embodiment of FIG. 1 defines a substantially closed processing chamber 50 . Preferably, the substantially closed processing chamber 50 is formed in the general shape of the workpiece 55 and closely conforms with the surfaces of the workpiece. The specific construction of FIG. 1 includes an upper chamber member 60 having an interior chamber face 65 . The upper chamber member 60 includes a centrally disposed fluid inlet opening 70 in the interior chamber face 65 . The specific construction also includes a lower chamber member 75 having, an interior chamber face 80 . The lower chamber member 75 has a centrally disposed fluid inlet opening 85 in the interior chamber face 80 . The upper chamber member 60 and the lower chamber member 75 engage one another to define the processing chamber 50 . The upper chamber member 60 includes sidewalls 90 that project downward from the interior chamber face 65 . One or more outlets 100 are disposed at the peripheral regions of the processing chamber 50 through the sidewalls 90 to allow fluid within the chamber 50 to exit therefrom through centripetal acceleration that is generated when the housing 20 is rotated about axis 47 .
[0024] In the illustrated embodiment, the workpiece 55 is a generally circular wafer having upper and lower planar surfaces. As such, the processing chamber 50 is generally circular in plan view and the interior chamber faces 65 and 80 are generally planar and parallel to the upper and lower planar surfaces of the workpiece 55 . The spacing between the interior chamber faces 65 and 80 and the upper and lower planar surfaces of the workpiece 55 is generally quite small. Such spacing is preferably minimized to provide substantial control of the physical properties of a processing fluid flowing through the interstitial regions.
[0025] The wafer 55 is spaced from the interior chamber face 80 by a plurality of spacing members 105 extending from the interior chamber face 80 . Preferably, a further set of spacing members 110 extend from the interior chamber face 65 and are aligned with the spacing members 105 to grip the wafer 55 therebetween.
[0026] Fluid inlet openings 70 and 85 provide communication passageways through which one or more processing fluids may enter the chamber 50 for processing the wafer surfaces. In the illustrated embodiment, processing fluids are delivered from above the wafer 55 to inlet 70 through a fluid supply tube 115 having a fluid outlet nozzle 120 disposed proximate inlet 70 . Fluid supply tube 115 extends centrally through the rotor portion 15 and is preferably concentric with the axis of rotation 47 . Similarly, processing fluids are delivered from below the wafer 55 to inlet 85 through a fluid supply tube 125 . Fluid supply tube 125 terminates at a nozzle 130 disposed proximate inlet 85 . Although nozzles 120 and 130 terminate at a position that is spaced from their respective inlets, it will be recognized that tubes 115 and 125 may be extended so that gaps 135 are not present. Rather, nozzles 120 and 130 or tubes 115 and 125 may include rotating seal members that abut and seal with the respective upper and lower chamber members 60 and 75 in the regions of the inlets 70 and 85 . In such instances, care should be exercised in the design of the rotating joint so as to minimize any contamination resulting from the wear of any moving component.
[0027] During processing, one or more processing fluids are individually or concurrently supplied through fluid supply tubes 115 and 125 and inlets 70 and 85 for contact with the surfaces of the workpiece 55 in the chamber 50 . Preferably, the housing 20 is rotated about axis 47 by the rotor portion 15 during processing to generate a continuous flow of any fluid within the chamber 50 across the surfaces of the workpiece 55 through the action of centripetal acceleration. Processing fluid entering the inlet openings 70 and 85 are thus driven across the workpiece surfaces in a direction radially outward from the center of the workpiece 55 to the exterior perimeter of the workpiece 55 . At the exterior perimeter of the workpiece 55 , any spent processing fluid is directed to exit the chamber 50 through outlets 100 as a result of the centripetal acceleration. Spent processing fluids may be accumulated in a cup reservoir disposed below and/or about the workpiece housing 20 . As will be set forth below in an alternative embodiment, the peripheral regions of the workpiece housing 20 may be constructed to effectively separate the processing fluids provided through inlet 70 from the processing fluids supplied through inlet 85 so that opposite surfaces of wafer 55 are processed using different processing fluids. In such an arrangement, the processing fluids may be separately accumulated at the peripheral regions of the housing 20 for disposal or re-circulation.
[0028] In the embodiment of FIG. 1, the workpiece housing 20 may constitute a single wafer pod that may be used to transport the workpiece 55 between various processing stations and/or tools. If transport of the housing 20 between the processing stations and/or tools takes place in a clean room environment, the various openings of the housing 20 need not be sealed. However, if such transport is to take place in an environment in which wafer contaminants are present, sealing of the various housing openings should be effected. For example, inlets 70 and 85 may each be provided with respective polymer diaphragms having slits disposed therethrough. The ends of fluid supply tubes 115 and 125 in such instances may each terminate in a tracor structure that may be used to extend through the slit of the respective diaphragm and introduce the processing fluid into the chamber 50 . Such tracor/slitted diaphragm constructions are used in the medical industry in intravenous supply devices. Selection of the polymer material used for the diaphragms should take into consideration the particular processing fluids that will be introduced therethrough. Similar sealing of the outlets 100 may be undertaken in which the tracor structures are inserted into the diaphragms once the housing 20 is in a clean room environment.
[0029] Alternatively, the outlets 100 themselves may be constructed to allow fluids from the processing chamber to exit therethrough while inhibiting the ability of fluids to proceed from the exterior of housing 20 into chamber 50 . This effect may be achieved, for example, by constructing the openings 100 as nozzles in which the fluid flow opening has a larger diameter at the interior of chamber 50 than the diameter of the opening at the exterior of the housing 20 . In a further construction, a rotational valve member may be used in conjunction with the plurality of outlets 100 . The valve member, such as a ring with openings corresponding to the position of outlets 100 , would be disposed proximate the opening 100 and would be rotated to seal with the outlets 100 during transport. The valve member would be rotated to a position in which outlets 100 are open during processing. Inert gas, such as nitrogen, can be injected into the chamber 50 through supply tubes 115 and 125 immediately prior to transport of the housing to a subsequent tool or processing station. Various other mechanisms for sealing the outlets 100 and inlets 70 and 85 may also be employed.
[0030] [0030]FIG. 2 is a perspective view of a further reactor construction wherein the reactor is disposed at a fixed processing station and can open and close to facilitate insertion and extraction of the workpiece. The reactor, shown generally at 200 , is composed of separable upper and lower chamber members, 205 and 210 , respectively. As in the prior embodiment, the upper chamber member 205 includes a generally planar chamber face 215 having a centrally disposed inlet 220 . Although not shown in the view of FIG. 2, the lower chamber member 210 likewise has a generally planar interior chamber face 225 having a central inlet 230 disposed therethrough. The upper chamber member 205 includes a downwardly extending sidewall 235 that, for example, may be formed from a sealing polymer material or may be formed integrally with other portions of member 205 .
[0031] The upper and lower chamber members, 205 and 210 , are separable from one another to accept a workpiece therebetween. With a workpiece disposed between them, the upper and lower chamber members, 205 and 210 , move toward one another to form a chamber in which the workpiece is supported in a position in which it is spaced from the planar interior chamber faces 215 and 225 . In the embodiment of the reactor disclosed in FIGS. 2 - 8 B, the workpiece, such as a semiconductor wafer, is clamped in place between a plurality of support members 240 and corresponding spacing members 255 when the upper and lower chamber members are joined to form the chamber (see FIG. 7B). Axial movement of the upper and lower chamber members toward and away from each other is facilitated by a plurality of fasteners 307 , the construction of which will be described in further detail below. Preferably, the plurality of fasteners 307 bias the upper and lower chambers to a closed position such as illustrated at FIG. 7A.
[0032] In the disclosed embodiment, the plurality of wafer support members 240 extend about a peripheral region of the upper chamber member 205 at positions that are radially exterior of the sidewall 235 . The wafer support members 240 are preferably disposed for linear movement along respective axes 245 to allow the support members 240 to clamp the wafer against the spacing members 255 when the upper and lower chamber members are in a closed position (see FIG. 7A), and to allow the support members 240 to release the wafer from such clamping action when the upper and lower chamber members are separated (see FIG. 8A). Each support member 240 includes a support arm 250 that extends radially toward the center of the upper chamber member 205 . An end portion of each arm 250 overlies a corresponding spacing member 255 that extends from the interior chamber face 215 . Preferably, the spacing members 255 are each in the form of a cone having a vertex terminating proximate the end of the support arm 250 . Notches 295 are disposed at peripheral, portions of the lower chamber member 210 and engage rounded lower portions 300 of the wafer support members 240 . When the lower chamber member 210 is urged upward to the closed position, notches 295 engage end portions 300 of the support members 240 and drive them upward to secure the wafer 55 between the arms 250 of the supports 240 and the corresponding spacing members 255 . This closed state is illustrated in FIG. 5. In the closed position, the notches 295 and corresponding notches 296 of the upper chamber member (see FIG. 2) provide a plurality of outlets at the peripheral regions of the reactor 200 . Radial alignment of the arm 250 of each support member 240 is maintained by a set pin 308 that extends through lateral grooves 309 disposed through an upper portion of each support member.
[0033] The construction of the fasteners 307 that allow the upper and lower chamber members to be moved toward and away from one another is illustrated in FIGS. 2, 6 and 7 B. As shown, the lower chamber member 210 includes a plurality of hollow cylinders 270 that are fixed thereto and extend upward through corresponding apertures 275 at the peripheral region of the upper chamber member 205 to form lower portions of each fastener 307 . Rods 280 extend into the hollow of the cylinders 270 and are secured to form an upper portion of each fastener 307 . Together, the rods 280 and cylinders 270 form the fasteners 307 that allow relative linear movement between the upper and lower chamber members, 205 and 210 , along axis 283 between the open and closed position. Two flanges, 285 and 290 , are disposed at an upper portion of each rod 280 . Flange 285 functions as a stop member that limits the extent of separation between the upper and lower chamber members, 205 and 210 , in the open position. Flanges 290 provide a surface against which a biasing member, such as a spring (see FIG. 6) or the like, acts to bias the upper and lower chamber members, 205 and 210 , to the closed position.
[0034] With reference to FIG. 6, the spring 303 or the like, has a first end that is positioned within a circular groove 305 that extends about each respective fastener 307 . A second end of each spring is disposed to engage flange 290 of the respective fastener 307 in a compressed state thereby causing the spring to generate a force that drives the fastener 307 and the lower chamber member 210 upward into engagement with the upper chamber member 205 .
[0035] The reactor 200 is designed to be rotated about a central axis during processing of the workpiece. To this end, a centrally disposed shaft 260 extends from an upper portion of the upper chamber member 205 . As will be illustrated in further detail below in FIGS. 7 A- 8 B, the shaft 260 is connected to engage a rotary drive motor for rotational drive of the reactor 200 . The shaft 260 is constructed to have a centrally disposed fluid passageway (see FIG. 4) through which a processing fluid may be provided to inlet 220 . Alternatively, the central passageway may function as a conduit for a separate fluid inlet tube or the like.
[0036] As illustrated in FIGS. 3 and 4, a plurality of optional overflow passageways 312 extend radially from a central portion of the upper chamber member 205 . Shaft 260 terminates in a flared end portion 315 having inlet notches 320 that provide fluid communication between the upper portion of processing chamber 310 and the overflow passageways 312 . The flared end 315 of the shaft 260 is secured with the upper chamber member 205 with, for example, a mounting plate 325 . Mounting plate 325 , in turn, is secured to the upper chamber member 205 with a plurality of fasteners 330 (FIG. 5). Overflow passages 312 allow processing fluid to exit the chamber 310 when the flow of fluid to the chamber 310 exceeds the fluid flow from the peripheral outlets of the chamber.
[0037] [0037]FIGS. 7A and 7B are cross-sectional views showing the reactor 200 in a closed state and connected to a rotary drive assembly, shown generally at 400 , while FIGS. 8A and 8B are similar cross-sectional views showing the reactor 200 in an opened state. As shown, shaft 260 extends upward into the rotary drive assembly 400 . Shaft 260 is provided with the components necessary to cooperate with a stator 405 to form a rotary drive motor assembly 410 .
[0038] As in the embodiment of FIG. 1, the upper and lower chamber members 205 and 210 join to define the substantially closed processing chamber 310 that, in the preferred embodiment, substantially conforms to the shape of the workpiece 55 . Preferably, the wafer 55 is supported within the chamber 310 in a position in which its upper and lower faces are spaced from the interior chamber faces 215 and 225 . As described above, such support is facilitated by the support members 240 and the spacing members 255 that clamp the peripheral edges of the wafer 55 therebetween when the reactor 200 is in the closed position of FIGS. 7A and 7B.
[0039] It is in the closed state of FIGS. 7A and 7B that processing of the wafer 55 takes place. With the wafer secured within the processing chamber 310 , processing fluid is provided through passageway 415 of shaft 260 and inlet 220 into the interior of chamber 310 . Similarly, processing fluid is also provided to the chamber 310 through a processing supply tube 125 that directs fluid flow through inlet 230 . As the reactor 200 is rotated by the rotary drive motor assembly 410 , any processing fluid supplied through inlets 220 and 230 is driven across the surfaces of the wafer 55 by forces generated through centripetal acceleration. Spent processing fluid exits the processing chamber 310 from the outlets at the peripheral regions of the reactor 200 formed by notches 295 and 296 . Such outlets exist since the support members 240 are not constructed to significantly obstruct the resulting fluid flow. Alternatively, or in addition, further outlets may be provided at the peripheral regions.
[0040] Once processing has been completed, the reactor 200 is opened to allow access to the wafer, such as shown in FIGS. 8A and 8B. After processing, actuator 425 is used to drive an actuating ring 430 downward into engagement with upper portions of the fasteners 307 . Fasteners 307 are driven against the bias of spring 303 causing the lower chamber member 210 to descend and separate from the upper chamber member 205 . As the lower chamber member 210 is lowered, the support members 240 follow it under the influence of gravity, or against the influence of a biasing member, while concurrently lowering the wafer 55 . In the lower position, the reactor chamber 310 is opened thereby exposing the wafer 55 for removal and/or allowing a new wafer to be inserted into the reactor 200 . Such insertion and extraction can take place either manually, or by an automatic robot.
[0041] [0041]FIG. 9 illustrates an edge configuration that facilitates separate processing of each side of the wafer 55 . As illustrated, a dividing member 500 extends from the sidewall 235 of the processing chamber 310 to a position immediately proximate the peripheral edge 505 of the wafer 55 . The dividing member 500 may take on a variety of shapes, the illustrated tapered shape being merely one configuration. The dividing member 500 preferably extends about the entire circumference of the chamber 310 . A first set of one or more outlets 510 is disposed above the dividing member 500 to receive spent processing fluid from the upper surface of the wafer 55 . Similarly, a second set of one or more outlets 515 is disposed below the dividing member 500 to receive spent processing fluid from the lower surface of the wafer 55 . When the wafer 55 rotates during processing, the fluid through supply 415 is provided to the upper surface of the wafer 55 and spreads across the surface through the action of centripetal acceleration. Similarly, the fluid from supply tube 125 is provided to the lower surface of the wafer 55 and spreads across the surface through the action of centripetal acceleration. Because the edge of the dividing member 500 is so close to the peripheral edge of the wafer 55 , processing fluid from the upper surface of the wafer 55 does not proceed below the dividing member 500 , and processing fluid from the lower surface of the wafer 55 does not proceed above the dividing member 500 . As such, this reactor construction makes it possible to concurrently process both the upper and lower surfaces of the wafer 55 in a mutually exclusive manner using different processing fluids and steps.
[0042] [0042]FIG. 9 also illustrates one manner in which the processing fluids supplied to the upper and lower wafer surfaces may be collected in a mutually exclusive manner. As shown, a fluid collector 520 is disposed about the exterior periphery of the reactor 200 . The fluid collector 520 includes a first collection region 525 having a splatter stop 530 and a fluid trench 535 that is structured to guide fluid flung from the outlets 510 to a first drain 540 where the spent fluid from the upper wafer surface may be directed to a collection reservoir for disposal or re-circulation. The fluid collector 520 further includes a second collection region 550 having a further splatter stop 555 and a further fluid trench 560 that is structured to guide fluid flung from the outlets 515 to a second drain 565 where the spent fluid from the lower wafer surface may be directed to a collection reservoir for disposal or re-circulation.
[0043] [0043]FIG. 10 illustrates an embodiment of the reactor 200 having an alternate configuration for supplying processing fluid through the fluid inlet opening 230 . As shown, the workpiece housing 20 is disposed in a cup 570 . The cup 570 includes sidewalls 575 exterior to the outlets 100 to collect fluid as it exits the chamber 310 . An angled bottom surface 580 directs the collected fluid to a sump 585 . Fluid supply line 587 is connected to provide an amount of fluid to the sump 585 . The sump 585 is also preferably provided with a drain valve 589 . An inlet stem 592 defines a channel 595 that includes a first end having an opening 597 that opens to the sump 585 at one end thereof and a second end that opens to the inlet opening 230 .
[0044] In operation of the embodiment shown in FIG. 10, processing fluid is provided through supply line 587 to the sump 585 while the reactor 200 is spinning. Once the sump 585 is full, the fluid flow to the sump through supply line 587 is eliminated. Centripetal acceleration resulting from the spinning of the reactor 200 provides a pressure differential that drives the fluid through openings 597 and 230 , into chamber 310 to contact at least the lower surface of the wafer 55 , and exit outlets 100 where the fluid is re-circulated to the sump 585 for further use.
[0045] There are numerous advantages to the self-pumping re-circulation system illustrated in FIG. 10. The tight fluid loop minimizes lags in process parameter control thereby making it easier to control such physical parameters as fluid temperature, fluid flow, etc. Further, there is no heat loss to plumbing, tank walls, pumps, etc. Still firther, the system does not use a separate pump, thereby eliminating pump failures which are common when pumping hot, aggressive chemistries.
[0046] [0046]FIGS. 11 and 12 illustrate two different types of processing tools, each of which may employ one or more processing stations including the reactor constructions described above. FIG. 11 is a schematic block diagram of a tool, shown generally at 600 , including a plurality of processing stations 605 disposed about an arcuate path 606 . The processing stations 605 may all perform similar processing operations on the wafer, or may perform different but complementary processing operations. For example, one or more of the processing stations 605 may execute an electrodeposition process of a metal, such as copper, on the wafer, while one or more of the other processing stations perform complementary processes such as, for example, clean/dry processing, pre-wetting processes, photoresist processes, etc.
[0047] Wafers that are to be processed are supplied to the tool 600 at an input/output station 607 . The wafers may be supplied to the tool 600 in, for example, S.M.I.F. pods, each having a plurality of the wafers disposed therein. Alternatively, the wafers may be presented to the tool 600 in individual workpiece housings, such as at 20 of FIG. 1.
[0048] Each of the processing stations 605 may be accessed by a robotic arm 610 . The robotic arm 610 transports the workpiece housings, or individual wafers, to and from the input/output station 607 . The robotic arm 610 also transports the wafers or housings between the various processing stations 605 .
[0049] In the embodiment of FIG. 11, the robotic arm 610 rotates about axis 615 to perform the transport operations along path 606 . In contrast, the tool shown generally at 620 of the FIG. 12 utilizes one or more robotic arms 625 that travel along a linear path 630 to perform the required transport operations. As in the embodiment of FIG. 10, a plurality of individual processing stations 605 are used, but more processing stations 605 may be provided in a single processing tool in this arrangement.
[0050] [0050]FIG. 13 illustrates one manner of employing a plurality of workpiece housings 700 , such as those described above, in a batch processing apparatus 702 . As shown, the workpiece housings 700 are stacked vertically with respect to one another and are attached for rotation by a common rotor motor 704 about a common rotation axis 706 . The apparatus 702 further includes a process fluid delivery system 708 . The delivery system 708 includes a stationary manifold 710 that accepts processing fluid from a fluid supply (not shown). The stationary manifold 710 has an outlet end connected to the input of a rotating manifold 712 . The rotating manifold 712 is secured for co-rotation with the housings 700 and, therefore, is connected to the stationary manifold 710 at a rotating joint 714 . A plurality of fluid supply lines 716 extend from the rotating manifold 712 and terminate at respective nozzle portions 718 proximate inlets of the housings 700 . Nozzle portions 718 that are disposed between two housings 700 are constructed to provide fluid streams that are directed in both the upward and downward directions. In contrast, the lowermost supply line 716 includes a nozzle portion 718 that directs a fluid stream only in the upward direction. The uppermost portion of the rotating manifold 712 includes an outlet 720 that provides processing fluid to the fluid inlet of the uppermost housing 700 .
[0051] The batch processing apparatus 702 of FIG. 13 is constructed to concurrently supply the same fluid to both the upper and lower inlets of each housing 700 . However, other configurations may also be employed. For example, nozzle portions 718 may include valve members that selectively open and close depending on whether the fluid is to be supplied through the upper and/or lower inlets of each housing 700 . In such instances, it may be desirable to employ an edge configuration, such as the one shown in FIG. 9, in each of the housings 700 to provide isolation of the fluids supplied to the upper and lower surfaces of the wafers 55 . Still further, the apparatus 702 may include concentric manifolds for supplying two different fluids concurrently to individual supply lines respectively associated with the upper and lower inlets of the housings 700 .
[0052] Numerous substantial benefits flow from the use of the disclosed reactor configurations. Many of these benefits arise directly from the reduced fluid flow areas in the reactor chambers. Generally, there is a more efficient use of the processing fluid since very little of the fluids are wasted. Further, it is often easier to control the physical parameters of the fluid flow, such as temperature, mass flow, etc., using the reduced fluid flow areas of the reactor chambers. This gives rise to more consistent results and makes those results repeatable.
[0053] The foregoing constructions also give rise to the ability to perform sequential processing of a single wafer using two or more processing fluids sequentially provided through a single inlet of the reaction chamber. Still further, the ability to concurrently provide different fluids to the upper and lower surfaces of the wafer opens the opportunity to implement novel processing operations. For example, a processing fluid, such as HF liquid, may be supplied to a lower fluid inlet of the reaction chamber for processing the lower wafer surface while an inert fluid, such as nitrogen gas, may be provided to the upper fluid inlet. As such, the HF liquid is allowed to react with the lower surface of the wafer while the upper surface of the wafer is effectively isolated from HF reactions. Numerous other novel processes may also be implemented.
[0054] The present invention has been illustrated with respect to a wafer. However, it will be recognized that the present invention has a wider range of applicability. By way of example, the present invention is applicable in the processing of disks and heads, flat panel displays, microelectronic masks, and other devices requiring effective and controlled wet processing.
[0055] Numerous modifications may be made to the foregoing system without departing from the basic teachings thereof. Although the present invention has been described in substantial detail with reference to one or more specific embodiments, those of skill in the art will recognize that changes may be made thereto without departing from the scope and spirit of the invention as set forth in the appended claims. | An apparatus for processing a workpiece in a micro-environment includes a workpiece housing connected to a motor for rotation. The workpiece housing forms a substantially closed processing chamber where processing fluids are distributed across at least one face of the workpiece by centrifugal force generated during rotation of the housing. The housing may also be detached from the motor and moved to another location. The housing consequently serves as a processing chamber, as well as a storage or transport chamber. |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/DE2003/004096, filed Dec. 11, 2003 and claims the benefit thereof. The International Application claims the benefits of German application No. 10257910.5 filed Dec. 11, 2002, both applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] The invention relates to a method for monitoring a pipeline to detect a slow reduction in the free internal cross section with the aid of the position of a control valve in the pipeline, as well as to a position regulator for a control valve to execute the method.
BACKGROUND OF THE INVENTION
[0003] In many areas of process-control and energy technology the fault-free operation of a system depends on the pipelines, especially on their ability to let the relevant process medium pass through them. To avoid costly regular interruptions to operation it would be sensible to be able to detect well in advance whether a pipeline is blocked in process operation or whether the free internal cross section of the pipeline is slowly reducing. Such faults should where possible be detected right at the start, before a blockage of a pipeline can cause the plant to come to a halt. An operating fault could be avoided by a timely advance warning by optimizing maintenance processes and taking countermeasures in good time.
[0004] Previously plant operators were somewhat surprised to find that the flow though a pipeline had been suddenly blocked by a blockage. The mostly unexpected occurrence of a fault then causes production outages and the associated significant costs. One possibility of detecting a reduction in the free pipeline cross section well in advance is an endoscopic investigation of the pipeline, but this can only be done by interrupting the process and thus entails significant effort.
[0005] A method for monitoring exhaust gas transport systems with a control valve as control for a pressure-regulated exhaust emission is known from DE-PS 43 42 554. Based on the characteristic curve of the control valve at the exhaust outlet point, the pressure which would exist of the control valve were fully open is regulated as a function of the current volume stream and the regulated exhaust pressure. The maximum pressure loss occurring at maximum volume stream is determined with reference to the input pressure and the outlet pressure determined on the basis of the characteristic curve with a fully open control valve, presented as a function of time and compared with the maximum permitted pressure loss. When the value of the maximum pressure loss approaches the value of the maximum permitted pressure loss the time for cleaning the exhaust gas transport system is determined. The disadvantage of the method is that it is designed specifically for the requirements of an exhaust gas transport system and cannot simply be used as it is with other pipeline systems. In addition no account is taken of the fact that on determination of the exhaust gas pressure for a fully open control valve on the basis of its characteristic curve, because of the increased volume stream the loss of pressure over the pipeline increases additionally. The monitoring is thus comparatively imprecise.
[0006] A position regulator for a control valve with a position generator for recording the setting of the valve and with a device for evaluating the recorded position is known for example from DE 199 47 129 A1. This patent describes a system for diagnosis of the current valve status on the basis of a recorded sound signal. In particular a leakage in a closed valve is audibly detected.
SUMMARY OF THE INVENTION
[0007] The object of the invention is to find a method for monitoring a pipeline for slow reduction of the internal cross section which can be executed for a plurality of process control systems without any greater outlay as well as to create a position regulator for a control valve which is suitable for executing the method.
[0008] This object is achieved by the claims. The dependent claims describe advantageous further developments of the invention.
[0009] The advantage of the invention is that a pipeline can be monitored for slow blockage or accumulation solely using the means already available with control valves. Only the evaluation unit for the position value of the valve which is recorded by a position generator, which can be viewed as a component of the position regulator, has to be adapted in order to execute the method. Since such evaluation units are usually implemented by a processing unit with suitable software, this merely requires adaptation of the evaluation program to be processed by the processing unit in any event. The monitoring function can be easily deactivated if the requirements for monitoring are not available or not available at the time. Especially for an application of a control valve for checking for constant media flow through a pipeline an essentially constant throughflow of the medium for a major part of the operating time is required. By observing and evaluating the change of the lift position of the control valve over time a slow reduction of the free internal cross section of the pipeline is detected. If with an essentially constant throughflow of a medium the valve has to be opened further than a specifiable threshold, a signal to indicate the fact that the threshold has been exceeded is output. On the basis of this display signal suitable countermeasures can be taken at an early stage. For example the signal can be interpreted as an alerting signal for maintenance required, so that the pipeline can be cleaned or changed when maintenance is next performed on the process system. Operational faults or production outages can thus be avoided.
[0010] Preferably the first position of the control valve at the beginning of the operation of the process system, when the pipeline is still free of deposits, can be determined and stored. On regulation for constant throughflow this produces a degree of opening of the valve which can differ depending on the design of the plant.
[0011] Advantageously the method can be adapted to the relevant application by specifying the threshold value depending on the first position. The threshold value is set here in the range between full opening of the valve and the first position. The optimum position is again dependent on the relevant application, especially of the speed of depositing and the time intervals between the maintenance cycles. It has proved advantageous and suitable for many applications to output a display signal for a threshold value being exceeded, if the setting range remaining beyond the first setting to the opening of the valve is 80% used. This means that the signal is displayed at a point at which there is still a sufficiently safe interval before the onset of regulation problems, that is before regulation to a constant throughflow is no longer possible because the deposits in the pipeline are too large.
[0012] Since a long-term monotonously progressing deposit process is accompanied by a corresponding long-term monotonous shift in the position of the control valve, short duration peaks in the shift, which can be caused by pressure variations for example, can be suppressed by a lowpass filter, especially by forming a floating average, as regards their effect on the result of the diagnosis. This avoids a premature triggering of the pipeline monitoring and a premature output of a display signal for such fluctuations. Naturally other options can be applied for checking the plausibility of the relationship between the valve opening and material being deposited in the pipeline.
[0013] In addition or as an alternative to direct threshold comparison the change over time in the position of the control valve can be determined and the point in time estimated at which the position of the control valve is likely to exceed the specifiable threshold value. This has the advantage of allowing maintenance to be better planned, since not only the current blockage state of the pipeline, but also the speed of the reduction of the free internal cross section is taken into account.
[0014] To avoid a display signal being output prematurely for a threshold being exceeded It can be advantageous to determine the pressure of the medium in the pipeline and, if a permitted average value of the pressure is exceeded to interrupt the monitoring of the pipeline for blockage. The media pressure in the pipeline can for example be checked with a simple pressure switch at a feed point beyond a pump. Usually there are pressure converters in any event in process control systems, preferably at the ends of pipelines, for which the measured value can easily be included in the evaluation.
[0015] If however certain pressure changes are unavoidable and this could lead to an all too frequent interruption of monitoring, it is advantageous, to suppress the influences of pressure fluctuations on the position of the valve, to undertake pressure compensation which can be performed using a predetermined dependency of the valve position on the media pressure.
[0016] The invention, along with its embodiments and advantages is explained in greater detail below with reference to the drawings in which an exemplary embodiment of the invention is shown.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The figures show:
[0018] FIG. 1 a basic diagram of a control valve built into a pipeline and
[0019] FIG. 2 the basic sequence of the valve setting as the blockage of the pipeline increases.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In accordance with FIG. 1 , a valve 2 is built into a pipeline 1 with pipeline sections 1 a and 1 b of a process control system not shown in any greater detail, which by a corresponding lift of a closure element 4 operating in conjunction with a valve seat 3 , controls the throughflow of a medium 5 . The lift is generated by a pneumatic drive 6 transmitted by means of a valve stem 7 to the closure element 4 . The drive 6 is connected via a yoke 8 to the housing of the valve 2 . A position regulator 9 is arranged on the yoke 8 . The relevant position x of the valve is recorded by a position generator 10 and fed to an evaluation unit 11 , which compares it with required value fed in via a data interface 12 from a field bus with digital or analog data transmission and on the output side controls the pneumatic drive 6 in the sense of controlling the regulation difference. The required value is prespecified by a controller not shown in the Figure so that an essentially constant throughflow of the medium 5 through the pipeline 1 and thus through the valve 2 is set. In the exemplary embodiment shown a pump 13 is additionally built into the pipeline 1 which creates the required flow pressure. A pressure switch 14 taps the media pressure obtaining in the flow direction beyond the pump 13 in the pipeline 1 and delivers a signal 15 to the evaluation unit 11 , which indicates whether a permitted deviation from an average value of the pressure has been exceeded. So that smaller variations in the valve position, which could have a very wide variety of causes, do not lead directly to the pipeline monitoring system responding, the position signal is additionally generated for direct feeding to the evaluation unit 11 via a lowpass 16 on the evaluation unit 11 . This lowpass filter, shown separately in the exemplary embodiment, which implements a floating average, can of course be implemented alternately by the evaluation unit 11 itself with suitable programming.
[0021] To explain the functional principle of the invention, in the area of the pipe section 1 a , at the valve 2 and in the area of pipe section 1 b , the pressure differences arising at a first point in time as the medium flows through the pipe Δp 1 , Δp 5 or Δp 2 and the pressure differences arising at a second, later point in time Δp 3 , Δp 6 or Δp 0 are plotted in FIG. 1 . The pressure difference Δp 0 designates the overall pressure difference which arises over the pipeline 1 with the two pipeline sections 1 a and 1 b as well as via the valve 2 by the flow of the medium at a constant speed of flow. The pipeline is monitored for slow reduction of a free internal cross section A by determination and evaluation of the change over time of the position x of the valve 2 recorded with the position generator 10 , by the evaluation unit 11 of the position regulator 9 chronologically archiving and evaluating the floating average value of the valve position over time. If a specifiable threshold value is exceeded a warning message is output as a telegram via the field bus attached to the data interface 11 or a current or voltage signal is output to a control center. This signals an impending total blockage of the pipeline 1 . The relationship between the blockage of the pipeline 1 and the position x of the valve 2 will be explained below:
[0022] In the operation of a process-control system the control valve regulates the flow through the pipeline 1 for a pressure difference Δp 0 which is predetermined by the layout of the system and which is largely constant to a, mostly constant value, required by a process controller or control system. In this case the value of the pressure difference Δp 0 at a first point in time, preferably when the system is commissioned and the pipeline is fully free of deposits, is equal to the sum of the pressure differences Δp 1 , Δp 5 and Δp 2 . This means that:
Δ p 1 +Δ p 2 +Δ p 5 =Δ p 0 .
[0023] In this case the pressure differences Δp 1 and Δp 2 are determined by the relevant flow resistance in the pipeline section 1 a or 1 b and the pressure difference Δp 5 is determined by the flow resistance of the valve at the first point in time. The pressure difference Δp 5 is dependent on the relevant setting of the valve 2 which is recorded by the position generator 10 and the throughflow that applies at the first point in time. If the valve 2 is used in the regulation circuit for controlling a specifiable, essentially constant, throughflow the valve setting is adjusted by the drive 6 such that the actual throughflow of the medium 5 through the pipeline 1 corresponds at least approximately to the predetermined value.
[0024] If deposits form over time on the inner walls of the pipeline sections 1 a and 1 b of the pipeline 1 , flow resistance and pressure differences increase. For a pressure difference Δp 3 or Δp 0 applying at a second, later point in time in the pipeline sections 1 a and 1 b for the same throughflow value, the following thus applies:
Δ p 3 +Δ p 4 >Δ p 1 +Δ p 2 .
[0025] If the output of pump 13 remains the same and the process is also unchanged in other respects, the overall pressure difference Δp 0 over the pipeline 1 and the valve 2 is essentially constant.
[0026] This means that a lower pressure difference Δp 6 must be set by the valve 2 at the second point in time, in order to maintain the essentially constant flow of the medium 5 through the pipeline 1 . The position x of the valve 2 is thus changed in the direction of an increase of the valve opening. The relevant position x of the valve 2 , is, as already explained above, recorded by the position generator 10 and forwarded to the evaluation unit 11 both directly as well as via the lowpass 16 . Storage of the floating average of the valve position undertaken by the evaluation unit 11 , preferably at regular intervals, enables the tendency for a blockage of the pipeline to develop to be determined. If the valve position, which reflects the opening of the valve 2 , exceeds a predetermined threshold value, a signal is output to indicate this value being exceeded via the interface 12 on the field bus. This can be interpreted in a higher-ranking control system as a warning signal, so that suitable measures can be taken in good time before faults can arise in the process system. With the aid of a suitable evaluation of the progress of the setting values the point in time can be determined at which the pipeline must be cleaned or exchanged. The costs associated with an unforeseen system outage are thus avoided. In addition no endoscopic pre-inspections entailing considerable effort, are required. The pressure output by the pump 13 is recorded with the pressure switch 14 . With this pressure switch 14 a signal 15 is created indicating that the pressure value has exceeded a permitted deviation from a predetermined average pressure value. Time ranges in which this value is exceeded can be taken from the evaluation of the position values for monitoring the pipeline on reduction of the free internal cross section A. Alternatively it is of course possible to replace the pressure switch 14 by a pressure sensor which delivers process values of the pressure to the evaluation unit 11 . In this case the influence of variations of the pump pressure on the monitoring result can be eliminated by the relationship between the position of the valve 2 and pressure of the pump 13 being determined and the influence balanced out by insertion of a suitable compensation element in the evaluation unit 11 .
[0027] FIG. 2 shows a graph of the values typical in practice for the position x of a valve with increasing deposits in the pipelines of a process system. The time t is plotted at the abscissa, the position x of a valve at the ordinate with a scaled range of values from 0 to 1. A position x=0 corresponds to a closed valve, a position x=1 to a fully open valve. At a first point in time t 1 , preferably when the process system is commissioned, a value x 1 =0.5 of the valve position is recorded and stored. During the later operation of the system further values of the position are measured at regular intervals and stored, so that the curve shown in the diagram is produced. Depending on the value x 1 =0.5 of the valve position measured on commissioning a threshold value s is calculated, which if exceeded, prompts the assumption that the deposits in the pipelines must be so great that a cleaning or an exchange of the pipeline is required in the next maintenance cycle. In the exemplary embodiment shown the threshold value s is defined at 80% of the remaining setting range available until further opening of the valve. The threshold s is thus set to the value 0.9. Values of the valve setting determined at later times, for example a setting x 2 at a second point in time t 2 , are compared with the threshold value s predetermined in the described manner. An indicator signal generated if the threshold value s is exceeded is interpreted as a requirement for maintenance of the pipeline system. A period between the times t 3 and t 4 , in which increased pressure variations were defined in the monitored pipeline, is hidden in the monitoring of the pipeline for slow reduction of the free internal cross section, since here no simple conclusion can be drawn about the current position of the valve for the blockage of the pipeline. At a point in time t 5 the measured value of the valve setting exceeds the threshold values s, so that a corresponding display signal is created here. In the subsequent maintenance cycle at a point in time t 6 the blocked pipeline is exchanged. After maintenance has been completed essentially the same flow through the pipeline can again be set with a valve which is much less open.
[0028] It can be clearly seen from the graph shown that alternatively or in addition to the evaluation of an actual threshold being exceeded described above, the point in time at which the threshold is expected to be exceeded can be determined on the basis of a trend analysis and output. | The invention relates to a method for monitoring a pipeline in order to detect the slow reduction of the free inner cross-section by means of the position of a control valve in the pipeline. When the flow rate is essentially constant, a first position is determined and stored at a first moment. According to at least one second position of the control valve, determined at a second, subsequent moment, the point at which the position of the valve exceeds a pre-determinable threshold value for a valve opening is determined, and optionally a signal is emitted to indicate that the threshold value has been exceeded and/or the time at which it was exceeded. As a result, suitable maintenance measures can be introduced, before faults occur in the process system. |
COPYRIGHT NOTICE
[0001] Contained herein is material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction of the patent disclosure by any person as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all rights to the copyright whatsoever.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to the field of online commerce. More particularly, the invention relates to information presentation and management in an online trading environment, such as an online shopping site, an online auctioning site, an online e-commerce site, an online person-to-person trading site, or the like.
[0004] 2. Description of the Related Art
[0005] More and more Internet users are realizing the ease and convenience of buying and selling online by way of person-to-person online trading pioneered by eBay Inc., the assignee of the present invention. As a result, collectors, hobbyists, small dealers, unique item seekers, bargain hunters, and other consumers, are able to buy and sell millions of items at various online shopping sites.
[0006] The success of an online shopping site depends upon its ability to provide an enjoyable shopping experience and an easy-to-use environment in which buyers and sellers can conduct business efficiently. Current online shopping sites have certain limitations in the manner in which they present information to users. With reference to FIG. 1 , a typical item listing will briefly be described. A textual list of items 105 representing the results of a user query is presented within a web page format 100 to the user (e.g., a prospective buyer) on his/her computer system In this example, the web page format 100 presented to the prospective buyer includes items 110 that are currently available for sale on a particular page 170 within a particular category 160 . Each item 110 includes a hypertext link 115 having a title (or brief-description) of the item for sale, an indication 120 of whether or not an image of the item is available, the current minimum bid 130 , the number of bids received 140 , and an auction ending time 150 . Based upon the item titles, prospective buyers can decide whether or not to view more detailed information on a particular item. In order to view detailed information on a particular item of interest, the buyer is required to select the hypertext link 115 associated with the item. A new page is then presented with more detailed information regarding the item selected. The more detailed information may include, among other things, the item's starting price, a username associated with the seller of the item, a username associated with the current high bidder, a detailed description of the item in text or HTML format, and an image the seller has associated-with-the item, for example. To continue-browsing other items of interest, the prospective buyer must return to the previously viewed listing, using the browser's “Back” function, for instance, and select the hypertext link 115 associated with the next item of interest. While associating an image with an item, such as a digitized picture of the item, has the advantage of allowing the prospective purchaser to make a more informed decision, the iterative process of individually selecting items to view their images can be very time consuming and even frustrating.
[0007] In light of the foregoing, it is desirable to provide an improved user interface for online commerce sites. In particular, it would be advantageous to enhance the online trading experience by providing buyers with a mechanism to more quickly preview items for sale. Additionally, the trading experience of sellers may be improved by automating certain aspects associated with item registration.
BRIEF SUMMARY OF THE INVENTION
[0008] A method and apparatus for information presentation and management in an online trading environment are described. According to one aspect of the present invention, person-to-person commerce over the Internet is facilitated by providing prospective buyers the ability to quickly preview items for sale. Images are harvested from a plurality of sites based upon user-supplied information. The user-supplied information includes descriptions of items for sale and locations from which images that are to be associated with the items can be retrieved. Thumbnail images are created corresponding to the harvested images and are aggregated onto a web page for presentation at a remote site.
[0009] According to another aspect of the present invention, a user may submit a query to preview items for sale. After receiving the query, thumbnail images corresponding to items that satisfy the user query are displayed, each of the thumbnail images previously having been created based upon a user-specified image.
[0010] Other features of the present invention will be apparent from the accompanying drawings and from the detailed description which follows.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
[0012] FIG. 1 is an example of a prior interface to an online person-to-person trading site that employs text-based item listings.
[0013] FIG. 2 is a simplified view of an exemplary client-server environment in which online commerce may take place.
[0014] FIG. 3 is an example of a computer system upon which one embodiment of the present invention may be implemented.
[0015] FIG. 4 is a high level illustration of the interaction among various devices according to one embodiment of the present invention.
[0016] FIG. 5 conceptually illustrates high level item maintenance processing according to one embodiment of the present invention.
[0017] FIG. 6 is an exemplary form that may be used during item registration.
[0018] FIG. 7 is a flow diagram illustrating image harvesting processing according to one embodiment of the present invention.
[0019] FIG. 8 is a flow diagram illustrating item presentation processing according to one embodiment of the present invention.
[0020] FIG. 9 is an example of an item presentation format for an online person-to-person trading site according to one embodiment of the present invention.
[0021] FIG. 10 illustrates memory mapped file access to the thumb database according to one embodiment of the present-invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] A method and apparatus for information presentation and management in an online trading environment are described In the following description, for the purposes of explanation, 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 of these specific details. In other instances, well-known structures and devices are shown in block diagram form.
[0023] As will be described in greater detail below, the present invention includes features for enhancing the online trading experience for both buyers and sellers. When sellers register an item for sale, they provide information about the item. For example, the seller may associate a textual description, an image, shipping terms, and other information with the item. Advantageously, according to one aspect of the present invention, to associate an image with an item for sale, the seller is not required to provide the image in a particular format or size; rather, the method and apparatus of the present invention automatically harvest images and transform them to an appropriate format for use with the system. According to another aspect of the present invention, prospective purchasers visiting an online commerce site employing the present-invention need not navigate to a separate web page for each item to view images associated with the items; rather, thumbnail images for multiple items are aggregated onto a web page to allow quick preview by the prospective purchaser. In the context of this application, the term “thumbnail” or “thumbnail image” generally refers to a new image that is a miniature version of the original, user-supplied image. Typically, the thumbnail image will be approximately 1 inch×1 inch or smaller. According to one embodiment, thumbnail images are approximately 96 pixels×96 pixels.
[0024] In the preferred embodiment, the steps of the present invention are embodied in machine-executable instructions. The instructions can be used to cause a general-purpose or special-purpose processor which is programmed with the instructions to perform the steps of the present invention. Alternatively, the steps of the present invention might be performed by specific hardware components that contain hardwired logic for performing the steps, or by any combination of programmed computer components and custom hardware components.
[0025] The present invention may be provided as a computer program product which may include a machine-readable medium having stored thereon instructions which may be used to program a computer (or other electronic devices) to perform a process according to the present invention. The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnet or optical cards, or other type of media/machine-readable medium suitable for storing electronic instructions. Moreover, the present invention may also be downloaded as a computer program product, wherein the program may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals embodied in a carrier wave or other propagation medium via a communication link (e.g., a modem or network connection).
[0026] Importantly, while embodiments of the present invention will be described with respect to an online person-to-person trading environment, the method and apparatus described herein are equally relevant to other applications in which image data is collected from disparate sources and presented to a user and/or other e-commerce environments, such as online shopping sites, auctioning sites, and the like.
[0000] Client-Server Environment
[0027] FIG. 2 is a simplified view of an exemplary client-server environment, such as the World Wide Web (the Web), in which online commerce may take place. The architecture of the Web follows a conventional client-server model. The terms “client” and “server” are used to refer to a computer's general role as a requester of data (the client) or provider of data (the server). Web clients 205 and Web servers 210 communicate using a protocol such as HyperText Transfer Protocol (HTTP). In the Web environment, Web browsers reside on clients and render Web documents (pages) served by the Web servers. The client-server model is used to communicate information between clients 205 and servers 210 . Web servers 210 are coupled to the Internet 200 and respond to document requests and/or other queries from Web clients 205 . When a user selects a document by submitting its Uniform Resource Locator (URL), a Web browser, such as Netscape Navigator or Internet Explorer, opens a connection to a server 210 and initiates a request (e.g., an HTTP get) for the document. The server 210 delivers the requested document, typically in the form of a text document coded in a standard markup language such as HyperText Markup Language (HTML).
[0000] Exemplary Computer System
[0028] A computer system 300 representing an exemplary server in which features of the present invention may be implemented will now be described with reference to FIG. 3 . Computer system 300 comprises a bus or other communication means 301 for communicating information, and a processing means such as processor 302 coupled with bus 301 for processing information. Computer system 300 further comprises a random access memory (RAM)or other dynamic storage device 304 (referred to as main memory), coupled to bus 301 for storing information and instructions to be executed by processor 302 . Main memory 304 also may be used for storing temporary variables or other intermediate information during execution of instructions by processor 302 . Computer system 300 also comprises a read only memory (ROM) and/or other static storage device 306 coupled to bus 301 for storing static information and instructions for processor 302 .
[0029] A data storage device 307 such as a magnetic disk or optical disc and its corresponding drive may also be coupled to computer system 300 for storing information and instructions. Computer system 300 can also be coupled via bus 301 to a display device 321 , such as a cathode ray tube (CRT) or Liquid Crystal Display (LCD), for displaying information to a computer user. Typically, an alphanumeric input device 322 , including alphanumeric and other keys, may be coupled to bus 301 for communicating information and/or command selections to processor 302 . Another type of user input device is cursor control 323 , such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 302 and for controlling cursor movement on display 321 .
[0030] A communication device 325 is also coupled to bus 301 for accessing remote servers via the Internet, for example. The communication device 325 may include a modem, a network interface card, or other commercially available network interface devices, such as those used for coupling to a Ethernet, token ring, or other type of network. In any event, in this manner, the computer system 300 may be coupled to a number of clients and/or other servers via a conventional network infrastructure, such as a company's Intranet and/or the Internet, for example.
[0000] System Overview
[0031] FIG. 4 is a high level illustration of the interaction among various devices according to one embodiment of the present invention. According to the embodiment depicted, an online commerce site 400 may comprise a listing server 410 , a thumb serve 430 , and a thumb building machine 450 . Briefly, the listing server 410 includes a listing management process 415 and a listing database 420 . The listing management process interacts with sellers to allow new items to be added to the listing database 420 and with prospective purchasers to provide them with information about items in which they are interested. As will be described further below, the listing management process 415 supports both a text-based item listing format, such as that illustrated in FIG. 1 , or a Gallery™ presentation format, such as that illustrated in FIG. 9 , that includes thumbnail images of the items for sale (Gallery is a trademark of eBay Inc. of San Jose, Calif.). According to one embodiment, depending on a user-selected mode, e.g., text mode or photo mode, the listing management process 415 provides HTML appropriate for the text-based item listing format or the Gallery presentation format, respectively.
[0032] The thumb building machine 450 includes a harvesting process 455 and a database 460 . As will be described further below, the harvesting process 455 periodically harvests images that sellers have associated with items in the listing database 420 . After a set of images have been harvested and thumbnailed, the harvesting process 455 notifies the thumb server 430 that new thumbnails are available.
[0033] The thumb server 430 includes a thumbnail management process 435 , a thumb database 440 and one or more backup databases 445 . Clients 470 interact with the thumbnail management process 435 to receive image data associated with the Gallery format. When new thumbnails are available, the thumbnail management process 435 makes a backup copy of the current thumb database 440 , receives a copy of a new database from the thumb building machine 450 , and begins serving thumbnail images from the new database.
[0034] Importantly, as one feature of the present embodiment, thumbnail images are not stored as individual files; rather, they are stored in an efficient database format that will be described further below. However, at this point, a justification for such an approach is worth mentioning. In the context of an online commerce site that may processes tens of thousands of new items every day, efficiency and stability are key considerations. The practicality of storing and maintaining thousands upon thousands of individual compressed thumbnail image files is questionable at best. It is thought that existing operating systems would become unstable and/or fail to work properly if millions of thumbnail images were stored in various places on the disk as individual files cluttering the file system. Therefore, rather than maintaining a complex file structure with potentially millions of separate files, according to one embodiment of the present invention an efficient database is maintained that is designed to get information into memory quickly to provide fast access to the thumbnail images stored therein.
[0035] Note that in this description, in order to facilitate explanation, the thumb building machine 450 , the listing server 410 , and the thumb server 430 are generally discussed as if they were each a single device. However, each of the thumb building machine 450 , the listing server 410 , and the thumb server 430 may actually comprise multiple physical and/or logical devices connected in a distributed architecture, and the various functions performed may actually be distributed among multiple devices. Additionally, in alternative embodiments, the functions performed by the various servers may be consolidated and/or distributed differently than as described. For example, any function can be implemented on any number of machines or on a single machine. Also, any process may be divided across multiple machines.
[0000] Item Maintenance
[0036] Having briefly described exemplary interactions among various devices in which features of the present invention may be implemented, item maintenance processing will now be described with reference to FIG. 5 . In general, item maintenance comprises three activities: creating and modifying items, harvesting images to be associated with the items, and presenting items to prospective buyers.
[0037] At step 510 , depending upon user interactions with the various servers, appropriate processing is performed. If a user request is received to add a new item, then processing continues with step 520 . If a user query is received, e.g., a query specifying a category and a page, then processing continues with step 540 . Various events may also trigger item maintenance processing. For example, according to the embodiment illustrated, upon expiration of a predetermined harvesting interval, processing continues with step 530 . In alternative embodiments, harvesting may be performed on a periodic basis or continuously.
[0038] At step 520 , item registration processing is performed. According to one embodiment, an HTML form, such as the one illustrated in FIG. 6 , is supplied to the user. When the completed form is submitted to the listing server 410 , the listing management process 415 updates the listing database 420 to include the new item.
[0039] At step 530 , the harvesting process 455 downloads user-specified images associated with newly listed items to its local database 460 . New items may be identified, for example, by a periodic scan of the listing database by either of the listing management process 415 or the harvesting process 455 . The harvesting process 455 may also periodically reload images and update thumbnails associated with items that are not new to accommodate subsequent user modification. For example, a user may change the originally specified image or provide a new URL to be associated with an item for sale. Further details regarding harvesting are described below.
[0040] At step 540 , item presentation processing is performed. According to one embodiment responsive to a user request, e.g., a query specifying a category and a page number, the listing management process 415 generates HTML describing to the user's browser how to gather and compose the web page. As will be described further below, the HTML may contain image tags referencing thumbnail images stored in the thumb database 440 . An exemplary Gallery format, an item presentation format that incorporates thumbnails for fast preview, is illustrated in FIG. 9 .
[0000] Item Registration
[0041] FIG. 6 is an exemplary registration form 600 that may be used during item registration. To sell an item on an online commerce site, typically the seller first registers the item to be sold. In this context, the act of registering simply refers to the process of supplying information about the item so that the information may be presented to prospective purchasers responsive to their requests and/or queries.
[0042] Upon receiving a request to add a new item, the listing management process 415 may respond with an HTML form, such as registration form 600 . The registration form 600 may include a variety of standard HTML form interface elements, including text input fields, checkboxes, radio buttons, and popup menus, for example. The most important piece of information for purposes of this application is the picture URL 650 . The picture URL 650 text input field allows a seller to specify an image of his/her choice to be associated with the item being registered. Note, that no additional information regarding the image is necessary. Advantageously, in this manner, the user need not worry about supplying an image in a particular format or one that is limited to a particular size. As will be described further below, the harvesting process 455 automatically downloads the specified image, converts it to the appropriate format, and scales it to the appropriate size that is appropriate for use with the Gallery presentation mechanism.
[0043] The seller also provides his/her user ID or email address 605 and a password 610 in form 600 . According to this example, the seller additionally submits a descriptive title 615 for the item and a geographical location 620 of the item. Providing the location 620 of the item allows prospective buyers to evaluate potential costs relating to shipping, etc. In order for the item to show up in user queries for a particular category, the seller also selects one of a number of categories 625 and chooses the most specific sub-categories from a predefined list in a popup menu, for example. Finally, the seller may specify acceptable payment methods 630 , shipping terms 640 , the quantity 655 of items of this type that are available, a minimum bid 660 per item, and the duration 665 of the offer. When the item is posted to the listing database 420 a unique item number is generated and associated with the item. The item numbers may be sequentially numbered as new items are posted to the listing database 420 , for example.
[0044] The present invention is not limited to any particular implementation of registration processing or to the specific information that may be associated with an item for sale. Importantly, the registration form 600 is intended only to illustrate some of the many types of information that may be associated with an item that is posted to the listing database 420 . In alternate embodiments, more or less information may be associated with items.
[0000] Image Harvesting
[0045] FIG. 7 is a flow diagram illustrating image harvesting processing according to one embodiment of the present invention.
[0046] At step 710 , image location information is retrieved from the listing database 420 for a set of images that will be downloaded concurrently. According to one embodiment, the image location information is a URL. However, other mechanisms are envisioned for specifying an image location, such as a directory path, etc.
[0047] At step 720 , an attempt is made to convert erroneous user-supplied data to “legal” data For example, the user-supplied data for the image location may be massaged to have correct URL syntax. URLs follow the syntax described in Request for Comments (RFC) 1738, Uniform Resource Locators (URL), December 1994. According to RFC 1738, a URL contains the name of the “scheme” being used (e.g., http, ftp, gopher, etc.) followed by a colon and then a string, the “scheme-specific part” whose interpretation depends on the scheme. URLs are, therefore, written as follows:
[0048] <scheme>:<scheme-specific part>
[0049] For example, the eBay home page is currently located at the following URL: “http://www.ebay.com”. The scheme is “http” and the scheme-specific part is “www.ebay.com”.
[0050] At step 730 , multiple image downloads are started using a sockets-based interface. Prior to starting the downloads, it may be necessary to attempt a variety of option configurations in order to establish communication with a particular server.
[0051] At any rate, assuming communication has successfully been established with the servers that have the desired image data, in one embodiment, 500 downloads are performed concurrently. After the downloads have begun, the status of the downloads is polled periodically (step 740 ). If an error arose in one or more of the downloads, processing continues with step 750 . If one or more of the downloads has completed, then processing continues with step 760 .
[0052] At step 750 , error handling is performed. Attempts may be made to determine whether or not an error has in fact occurred. For example, it is not uncommon for a server to incorrectly identify a file size thereby causing a mismatch between the actual size of the downloaded file and the expected file size. In situations like these, the image can be salvaged; however, other situations may require the download to be restarted.
[0053] At step 760 , the one or more images that have been downloaded successfully are thumbnailed and stored for later inclusion in the thumbnail database 440 . According to one embodiment, the process of thumbnailing an image is performed with an imaging tool kit, such as ImageGear98 Gold Pro of Accusoft. Thumbnailing an image may be broken down into three steps: (1) first, decompression is performed from the harvested image's source format; (2) then, the decompressed image is converted to a thumbnail that will fit within a predetermined space. For example, the largest dimension of the source image may be scaled to fit the corresponding dimension of the predetermined space, then the other dimension of the source image may be scaled proportionately; (3) finally, the thumbnail is recompressed into a predetermined output format, e.g., Joint Photographics Expert Group (JPEG).
[0054] Preferably, for convenience of the users, the thumbnailing process may receive one of many different image formats. According to one embodiment, the source format and the output format are one of the following: Tagged Image File Format (TIFF), JPEG, JPEG 12 Lossy, JPEG 12-8 Lossless, P-JPEG, Audio Video Interleave (AVI), (JPEG File Interchange Format) JFIF, Dehrin Winfax, PCX (ZSoft Paint format), TGA (Truevision (Targa) File Format), Portable Network Graphics (PNG), DCX, G3, G4, G3 2D, Computer Aided Acquisition and Logistics Support Raster Format (CALS), Electronic Arts Interchange File Format (IFF), IOCA, PCD, IWF, ICO, Mixed Object Document Content Architecture (MO:DCA), Windows Metafile Format (WMF), AT7, Windows Bitmap Format (BMP), BRK, CLP, LV, GX2, IMG(GEM), IMG(Xerox), IMT, KFX, FLE, MAC, MSP, NCR, Portable Bitmap (PBM). Portable Greymap (PGM), SUN, PNM, Portable Pixmap (PPM), Adobe Photoshop (PSD), Sun Rasterfile (RAS), SGI, X BitMap (XBM), X PixMap (XPM), X Window Dump (XWD), AFX, Imara, Exif, WordPerfect Graphics Metafile (WPG), Macintosh Picture (PICT), Encapsulated PostScript (EPS), Graphics Interchange Format (GIF). Of course, as new image formats are introduced, it would be advantageous to provide support for those as well.
[0000] Item Presentation
[0055] FIG. 8 is a flow diagram illustrating item presentation processing according to one embodiment of the present invention. The assignee of the present invention has observed that in the context of item presentation only a small amount of information actually needs to be changed in the HTML that is generated for various user queries. For an item presentation format, such as that illustrated in FIG. 9 , the information that varies is essentially limited to: the item title, the current minimum bid, the image, and the auction ending time. The remainder of the web page comprises HTML interface elements that remain constant regardless of the result of the user's query. Consequently, according to one embodiment, a predefined page format (referred to as the Gallery template) is employed into which the information that varies can be inserted on the fly as data is retrieved from the databases.
[0056] At step 810 , the predefined page format, e.g., the Gallery template, is obtained.
[0057] At step 820 , the listing management process 415 retrieves information from the listing database 420 corresponding to the items that will be displayed for the category and page requested, for example.
[0058] At step 830 , the predefined page format is populated based upon the information retrieved in step 820 . At this point it should be noted that according to one embodiment of the present invention, thumbnail images are accessed from the thumb server 430 by item number. As one feature of this embodiment, references to the thumbnail images stored on the thumb server 430 may be generated on the fly by the listing management process 415 based upon the image format and the item number. For example, an inline image tag can be generated having the general form: <img src=path/item_number.jpg>. In this manner, no additional space is required in the listing database 420 for image file names. Another option would have been to represent the image reference in the form of a query, e.g., http://cgi.ebay.com/cgi/DBAPI.dll?GetImage&item=item_number. However, while the former representation would be cached by caching proxy servers, the latter representation is not typically cached by caching proxy servers. Therefore, hiding the underlying queries to the thumb database 440 from caching proxy servers by representing the thumbnail images in the HTML as if they were stored as individual files has the benefit of causing the caching proxy servers to perform more efficiently thereby generally reducing the load on the site and making the experience better for all users. Additionally, users that access the listing server 410 and the thumb server 430 by way of a caching proxy server, such as those on America Online, for example, will have enhanced performance as a result of the thumbnail images being cached because the data for rending the web pages will be available much faster.
[0000] Gallery Presentation Format
[0059] FIG. 9 is an example of an item presentation format for an online person-to-person trading site according to one embodiment of the present invention. The Gallery presentation page format 900 of the present embodiment includes a text mode button 975 and a photo mode button 980 allowing the user to switch between the text-based item listing format and the Gallery presentation format. In response to a user query, such as a request for a particular page 970 within a particular category 960 , a list of items 905 is displayed to the users. In this example, each individual item 910 includes a thumbnail image 920 , a title 915 , a current minimum bid 930 , and the auction ending time 950 . Advantageously, in this manner, the Gallery presentation page format 900 allows a prospective buyer to quickly scan the thumbnails for items of interest. Such a feature becomes critical in an online commerce environment in which thousands of unique items are for sale, for example.
[0060] According to another feature of the present embodiment, by displaying all images in a predetermined, fixed-size display area 921 , the listing management process 415 doesn't need to have detailed knowledge about the individual images. For example, according to an embodiment described previously, the listing management process 415 can simply use the item number to generate references, e.g., inline image tags, for the desiredthumbnail images.
[0000] Thumb Database Access
[0061] FIG. 10 illustrates memory mapped file access to the thumb database 1020 according to one embodiment of the present invention. According to the embodiment depicted, rather than maintaining a complex file structure with potentially millions of separate files, a simple and efficient thumb database 1020 is maintained that is designed to get information into memory quickly to provide fast access to the thumbnail images stored therein, Briefly, the goal is to keep the thumb database 1020 reasonably sized so that it can be completely loaded into a virtual address space 1015 and accessed as a memory mapped file.
[0062] According to one embodiment, each database entry comprises a length field and image data. The length field may identify the length of the entry or the length of the image data. The image data represents the compressed thumbnail image. For purposes of this example, it is assumed the thumb server has a 4 Gigabyte virtual address space and that the thumb database 1020 can be compressed into a single 1 Gigabyte file. When the thumbnail management process 435 opens the thumb database 1020 for reading; rather than using file system calls that would not provide sufficient caching, it opens the thumb database 1020 as a memory mapped file. As a result, the thumb database is loaded completely into a continuous block 1025 of the virtual address space 1015 . Accessing an individual entry of the database may then be accomplished by selecting an offset corresponding to the desired image from an array of relative offsets, such as index 1010 . Advantageously, after the thumb database 1020 is loaded into virtual address space 1015 , disk I/O can be avoided for subsequent accesses thereby enhancing the speed at which images can be served to clients.
[0063] In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. | A method includes loading a plurality of thumbnail images into a virtual address space having a first address, and retrieving a specific thumbnail image of the plurality of thumbnail images from the virtual address space by indexing into the virtual address space at a location defined by an offset, the offset corresponding to the specific thumbnail image. |
RELATED APPLICATIONS
[0001] This application is a divisional of co-pending U.S. patent application No. 11/763,594 filed on Jun. 15, 2007, the entire content of which is incorporated herein by reference.
BACKGROUND
[0002] The present invention relates to a water heater support base for supporting components of a water heater in their proper position and in a manner that elevates an outer jacket of the water heater and still provides sufficient space for insulation between a water tank and the outer jacket.
[0003] As conventionally constructed, a water heater typically has a water tank adapted to hold a quantity of water to be heated, an outer jacket outwardly circumscribing the vertical water tank sidewall portion and forming an annular insulation space between the jacket and the water tank. A quantity of insulation is typically disposed in this annular space. A bottom end of the water tank and jacket is typically placed into a bottom pan structure and suitably secured to the pan. The bottom pan must be both durable and structurally sound to support and properly position the water heater components.
[0004] A common method of placing insulation in the annular space surrounding the water tank, after a bottom portion of the water tank and outer jacket structure are secured within the bottom pan, is to simply inject liquid foam insulation into the annular space and let the injected foam cure after injection. One of the functions of the bottom pan is to hold the base of the water tank and outer jacket in position during the foam injection and curing process, to prevent the water tank from wandering around within the outer jacket as the foam expands.
SUMMARY
[0005] In one embodiment of the invention, a water heater is provided with a support base for supporting a water tank and an outer jacket surrounding the water tank. The support base comprises a circular lip coupled to an angled middle portion for supporting the water tank at a junction of the lip and the middle portion. The junction is preferably formed as a circular trough where the lip is coupled to the angled middle portion which projects upwardly from the lip in a non-vertical direction. The trough provides a structurally robust platform for positioning and supporting the water tank. The angled middle portion is coupled at its upper end to a top portion extending in a generally vertical direction from the upper end of the angled middle portion such that the top portion provides support for the outer jacket. The angled middle portion and the top portion intersect to form a support surface for the outer jacket such that the outer jacket is elevated vertically above the level of the trough. The support base may be formed from a flat strip of metal that is corrugated or crimped into a shape that can be readily formed into a circular jacket base.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a simplified fragmented section view showing a prior art construction of a water heater utilizing a typical prior art support base;
[0007] FIG. 2 is a section view showing a water heater utilizing a support base of the present invention and illustrating insulation in relation to an inner water tank and a surrounding outer jacket for the water heater.
[0008] FIG. 3 is a section view showing the construction of a preferred embodiment of a support base for supporting a water heater in accordance with the present invention.
[0009] FIG. 4 is a section view of the support base of FIG. 3 with certain other water heater components also shown in section view.
[0010] FIG. 5 is a partial elevation view of a portion of a support base formed with a corrugation construction.
DETAILED DESCRIPTION
[0011] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
[0012] Referring now to the drawings and, more particularly, to FIG. 1 , there is shown generally at 10 a basic prior art construction of a water heater. The water heater 10 comprises a water tank 22 in which water is heated by a heating device, shown in dashed outline at 13 , such as electric resistive elements in the a lower portion of the interior of the water tank 22 , as is well known in the art. The water tank 22 is provided with pipe fittings 12 or other fittings such as 12 ′, which lead to the internal resistive elements 13 . The water tank 22 is typically provided with a dome shape bottom wall 14 and the water tank sits on an insulating support base 15 , which has formed in it a circular trough in which the bottom edge of the water tank 22 sits. The insulating support base 15 is positioned as a flat layer in a pan 16 about which is secured an outer jacket 28 . A top cover 18 is secured over a top end of the outer jacket 28 . The outer jacket 28 is provided with a side wall that is spaced apart from an outer wall of the water tank 22 to provide an insulating space 19 . As foam insulation expands within the insulating space 19 , the tank 22 is prevented from wandering within the jacket 28 by the insulating base 15 . A similar construction is illustrated in U.S. Pat. No. 5,154,140.
[0013] In FIG. 2 , a water heater 10 is shown in a structure that incorporates the present invention. A ring-shaped support base 30 supports the water tank 22 and centers it in the jacket 28 the foam insulation injection and curing process.
[0014] Referring now to FIGS. 3 and 4 there is shown a cross-section of the one construction of the support base 30 . It should be understood that a range of dimensions and angles can be utilized in the practice of the invention. The specific selection of surface size, angles and dimensions is a matter of choice for those skilled in the art. In the embodiment shown, the support base 30 is formed in three separate sections, as viewed in a cross-section. These three sections comprise a lip 32 , an angled middle portion 34 and a top portion 38 . To form these three sections, a single piece of metal material can be transformed into the three sections using various metal shaping techniques. It is also possible to form the support base 30 by coupling three separate structures. Alternatively, non-metallic materials can be utilized such as plastic. Various other non-metallic materials and means of construction may also be utilized.
[0015] Referring again to FIGS. 3 and 4 , in the embodiment shown the angled middle portion 34 constitutes the largest cross-section and greatest surface area of the three sections. The angle 31 of this middle portion 34 in comparison to a surface or floor on which it will stand may be, for example, 45 degrees or another angle suitable for a particular construction. The angled middle portion 34 can be either straight or curved when viewed in cross-section.
[0016] The angled middle portion 34 is coupled to or formed to be integral with the lip 32 at its lower end and the top portion or vertical portion 38 at its upper end. The lip 32 is typically coupled to the angled middle portion 34 at something less than a 90 degree angle (for example, 85 degrees) between the two parts as shown at 33 in FIG. 3 . At this junction or intersection between the lip 32 and the angled middle portion 34 , there is formed a trough 36 that extends around the circumference of the support base 30 to define a trough circle. The diameter of the trough circle is the same as the diameter of the bottom edge of the water tank 22 so that the bottom edge of the water tank 22 fits snugly within the trough 36 . It can be readily appreciated that this trough 36 provides a suitable platform and positioning device for the water tank 22 .
[0017] At its other end, the angled middle portion 34 is coupled to or integral with the top portion 38 . In the embodiment shown, the top portion 38 is generally angled in a vertical or nearly vertical direction. Consequently, the angle between the top portion 38 and the angled middle portion 34 will generally be more than 90 degrees, and typically about 135 degrees. Again, this angle can be varied over a range.
[0018] At an intersection or junction between the top portion 38 and the angled middle portion 34 , there is provided a support surface 40 that supports a lower end or lower edge of the outer jacket 28 . It can be readily appreciated that this support surface 40 is elevated a distance off the floor equal to the rise 100 of the triangle. Compared to prior art water heater constructions in which the jacket extends all the way to the floor, the present invention enables use of a shorter outer length jacket and consequently saves an amount of jacket material equal to the rise 100 multiplied by the circumference of the jacket 28 .
[0019] It can also be appreciated that elevation of the outer jacket 28 means that space 24 is reduced by a volume about equal to the triangle extending all the way around the base 30 . The reduction in space 24 gives rise to a savings in insulation material 25 required to fill the space 24 . Another cost savings provided by the support base 30 of the present invention compared to prior art flat pans is that the base pan 30 does not extend across the entire bottom of the water tank 22 , but instead is ring-shaped with a hole in the middle under the tank 22 . The material savings in this regard are roughly equal to the surface area under the water tank 22 .
[0020] Another advantage of the present invention is apparent from FIGS. 3 and 4 . It is desirable to position the water tank 22 centrally within outer jacket 28 so that the water tank is supported to remain centered within the outer jacket 28 during the process of filling space 24 with foam. This is desirable because adequate and uniform insulation space is provided around an outer surface of water tank 22 without any inadequate or thin insulation spaces. This also means that the weight of the water tank 22 and the weight of the water tank 22 when filled with water, remains centered within outer jacket 28 and centered on the support base 30 .
[0021] Referring now to FIG. 5 , an embodiment of the invention is shown that uses a specific construction method to form the support base 30 . The support base in FIG. 5 is made with corrugations that provide structural rigidity. Additionally, the corrugated structure is relatively easy to manufacture. Corrugations ease the process of manufacturing because an initially flat strip of metal can be bent, shaped and formed with appropriate bends and angles to transform a flat strip of metal into a support base 30 with a lip 32 , an angled middle portion 34 and a top portion 38 . The corrugations take up the material along the inner radius (i.e., at the lip 32 ) of the base support 30 , which is smaller than the outer radius (i.e., at the top portion 38 ). By properly spacing and sizing the corrugations, the radius of a strip of material can be adjusted such that when the two ends are joined together to form a circular band, the trough 36 circle has a diameter equal to the bottom edge of the water tank 22 it is intended to support.
[0022] Additional forms of construction may also be utilized to form the support base 30 . For example, crimps may be utilized to transform a flat strip of metal into a curved, circular band that can be shaped into the proper construction to form the support base 30 . Various other forms of manufacturing, forming and shaping will be apparent to those skilled in the art.
[0023] An alternate embodiment of the invention comprises a water heater support base being formed as an integral extension of the outer jacket. In this embodiment, the base is formed from the same material as the outer jacket and can be formed from the same sheet stock. In a profile view, the support base, the lip and the outer jacket will appear as a single part. The lip is formed as an extension of the outer jacket material. In this alternate embodiment, the outer jacket length is increased over the length shown in previous embodiments. However, since the support base is integral with the outer jacket, the result can be a net material savings. Additionally, manufacturing steps may be simplified.
[0024] Thus the invention provides, among other things, a water heater support base that positions and supports a water tank and an outer jacket to provide adequate and uniform insulation space around the water tank and such that the lower end of outer jacket is elevated vertically.
[0025] Various features and advantages of the invention are set forth in the following claims. | A method of making a circular support base for a water heater in which a sheet of material having two ends is formed with corrugations such that the corrugations are progressively more pronounced towards one longitudinal edge thereby creating a generally circular shape out of the formerly straight sheet material, the two ends are connected to form an unbroken circular shape, the corrugated material is shaped to form a lip at an inner circumferential region, and the circular lip intersects with an outer circumferential region of the support base to form a circular trough for supporting and positioning a water tank of the water heater. |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 11/283,125, filed Nov. 18, 2005, now U.S. Pat. No. 7,241,750.
This application claims priority to U.S. Provisional Application No. 60/630,007, filed Nov. 22, 2004.
BACKGROUND OF THE INVENTION
This invention relates to vitamin D compounds, and more particularly to 2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol and its pharmaceutical uses.
The natural hormone, 1α,25-dihydroxyvitamin D 3 and its analog in the ergosterol series, i.e. 1α,25-dihydroxyvitamin D 2 are known to be highly potent regulators of calcium homeostasis in animals and humans, and their activity in cellular differentiation has also been established, Ostrem et al., Proc. Natl. Acad. Sci. USA, 84, 2610 (1987). Many structural analogs of these metabolites have been prepared and tested, including 1α-hydroxyvitamin D 3 , 1α-hydroxyvitamin D 2 , various side chain homologated vitamins and fluorinated analogs. Some of these compounds exhibit an interesting separation of activities in cell differentiation and calcium regulation. This difference in activity may be useful in the treatment of a variety of diseases such as renal osteodystrophy, vitamin D-resistant rickets, osteoporosis, psoriasis, and certain malignancies.
Another class of vitamin D analogs, i.e. the so called 19-nor-vitamin D compounds, is characterized by the replacement of the A-ring exocyclic methylene group (carbon 19), typical of the vitamin D system, by two hydrogen atoms. Biological testing of such 19-nor-analogs (e.g., 1α,25-dihydroxy-19-nor-vitamin D 3 ) revealed a selective activity profile with high potency in inducing cellular differentiation, and very low calcium mobilizing activity. Thus, these compounds are potentially useful as therapeutic agents for the treatment of malignancies, or the treatment of various skin disorders. Two different methods of synthesis of such 19-nor-vitamin D analogs have been described (Perlman et al., Tetrahedron Lett. 31, 1823 (1990); Perlman et al., Tetrahedron Lett. 32, 7663 (1991), and DeLuca et al., U.S. Pat. No. 5,086,191).
In U.S. Pat. No. 4,666,634, 2β-hydroxy and alkoxy (e.g., ED-71) analogs of 1α,25-dihydroxyvitamin D 3 have been described and examined by Chugai group as potential drugs for osteoporosis and as antitumor agents. See also Okano et al., Biochem. Biophys. Res. Commun. 163, 1444 (1989). Other 2-substituted (with hydroxyalkyl, e.g., ED-120, and fluoroalkyl groups) A-ring analogs of 1α,25-dihydroxyvitamin D 3 have also been prepared and tested (Miyamoto et al., Chem. Pharm. Bull. 41, 1111 (1993); Nishii et al., Osteoporosis Int. Suppl. 1, 190 (1993); Posner et al., J. Org. Chem. 59, 7855 (1994), and J. Org. Chem. 60, 4617 (1995)).
2-substituted analogs of 1α,25-dihydroxy-19-nor-vitamin D 3 have also been synthesized, i.e. compounds substituted at 2-position with hydroxy or alkoxy groups (DeLuca et al., U.S. Pat. No. 5,536,713), with 2-alkyl groups (DeLuca et al U.S. Pat. No. 5,945,410), and with 2-alkylidene groups (DeLuca et al U.S. Pat. No. 5,843,928), which exhibit interesting and selective activity profiles. All these studies indicate that binding sites in vitamin D receptors can accommodate different substituents at C-2 in the synthesized vitamin D analogs.
In a continuing effort to explore the 19-nor class of pharmacologically important vitamin D compounds, analogs which are characterized by the presence of a methylene substituent at carbon 2 (C-2), a hydroxyl group at carbon 1 (C-1), and a shortened side chain attached to carbon 20 (C-20) have also been synthesized and tested. 1α-hydroxy-2-methylene-19-nor-pregnacalciferol is described in U.S. Pat. No. 6,566,352 while 1α-hydroxy-2-methylene-19-nor-homopregnacalciferol is described in U.S. Pat. No. 6,579,861 and 1α-hydroxy-2-methylene-19-nor-bishomopregnacalciferol is described in U.S. Pat. No. 6,627,622. All three of these compounds have relatively high binding activity to vitamin D receptors and relatively high cell differentiation activity, but little if any calcemic activity as compared to 1α,25-dihydroxyvitamin D 3 . Their biological activities make these compounds excellent candidates for a variety of pharmaceutical uses, as set forth in the '352, '861 and '622 patents.
SUMMARY OF THE INVENTION
The present invention is directed toward 2-methylene-19-nor-17-ene-vitamin D analogs, and more specifically toward 2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol, their biological activity, and various pharmaceutical uses for these compounds.
Structurally these 2-methylene-19-nor-17-ene-vitamin D analogs are characterized by the general formula I shown below:
where X 1 and X 2 , which may be the same or different, are each selected from hydrogen or a hydroxy-protecting group. The preferred analog is 2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol which has the following formula Ia:
The above compounds I, and particularly Ia, exhibit a desired, and highly advantageous, pattern of biological activity. These compounds are characterized by relatively high binding to vitamin D receptors, but very low intestinal calcium transport activity, as compared to that of 1α,25-dihydroxyvitamin D 3 , and have very low ability to mobilize calcium from bone, as compared to 1α,25-dihydroxyvitamin D 3 . Hence, these compounds can be characterized as having little, if any, calcemic activity. It is undesirable to raise serum calcium to supraphysiologic levels when suppressing the preproparathyroid hormone gene (Darwish & DeLuca, Arch. Biochem. Biophys. 365, 123-130, 1999) and parathyroid gland proliferation. These analogs having little or no calcemic activity while very active on differentiation are expected to be useful as a therapy for suppression of secondary hyperparathyroidism of renal osteodystrophy.
The compounds I, and particularly Ia, of the invention have also been discovered to be especially suited for treatment and prophylaxis of human disorders which are characterized by an imbalance in the immune system, e.g. in autoimmune diseases, including multiple sclerosis, lupus, diabetes mellitus, host versus graft rejection, and rejection of organ transplants; and additionally for the treatment of inflammatory diseases, such as rheumatoid arthritis, asthma, and inflammatory bowel diseases such as celiac disease, ulcerative colitis and Crohn's disease. Acne, alopecia and hypertension are other conditions which may be treated with the compounds of the invention.
The above compounds I, and particularly Ia, are also characterized by relatively high cell differentiation activity. Thus, these compounds also provide a therapeutic agent for the treatment of psoriasis, or as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer, skin cancer and prostate cancer. In addition, due to their relatively high cell differentiation activity, these compounds provide a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of these compounds thus not only results in moisturizing of skin but also improves the barrier function of skin.
The compounds of the invention of formula I, and particularly formula Ia, are also useful in preventing or treating obesity, inhibiting adipocyte differentiation, inhibiting SCD-1 gene transcription, and/or reducing body fat in animal subjects. Therefore, in some embodiments, a method of preventing or treating obesity, inhibiting adipocyte differentiation, inhibiting SCD-1 gene transcription, and/or reducing body fat in an animal subject includes administering to the animal subject, an effective amount of one or more of the compounds or a pharmaceutical composition that includes one or more of the compounds of formula I. Administration of one or more of the compounds or the pharmaceutical compositions to the subject inhibits adipocyte differentiation, inhibits gene transcription, and/or reduces body fat in the animal subject.
One or more of the compounds may be present in a composition to treat the above-noted diseases and disorders in an amount from about 0.01 μg/gm to about 1000 μg/gm of the composition, preferably from about 0.1 μg/gm to about 500 μg/gm of the composition, and may be administered topically, transdermally, orally or parenterally in dosages of from about 0.01 μg/day to about 1000 μg/day, preferably from about 0.1 μg/day to about 500 μg/day.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-6 illustrate various biological activities of 2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol, hereinafter referred to as “VIT-I,” as compared to the native hormone 1α,25-dihydroxyvitamin D 3 , hereinafter “1,25(OH) 2 D 3 .”
FIG. 1 is a graph illustrating the relative activity of VIT-I and 1,25(OH) 2 D 3 to compete for binding with [ 3 H]-1,25-(OH) 2 -D 3 to the full-length recombinant rat vitamin D receptor;
FIG. 2 is a graph illustrating the percent HL-60 cell differentiation as a function of the concentration of VIT-I and 1,25(OH) 2 D 3 ;
FIG. 3 is a graph illustrating the in vitro transcription activity of 1,25(OH) 2 D 3 as compared to VIT-I;
FIGS. 4 and 5 are bar graphs illustrating the bone calcium mobilization activity of 1,25(OH) 2 D 3 as compared to VIT-I. Each graph represents a separate batch of vitamin D-deficient animals. The results depicted in FIG. 5 are not vehicle-controlled, but rather each animal serves as its own control because the animals were bled pre- and post-dose; and
FIG. 6 is a bar graph illustrating the intestinal calcium transport activity of 1,25(OH) 2 D 3 as compared to VIT-I.
DETAILED DESCRIPTION OF THE INVENTION
2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol (referred to herein as VIT-I) was synthesized and tested. Structurally, this 19-nor analog is characterized by the general formula Ia previously illustrated herein, and its pro-drug (in protected hydroxy form) by the formula I.
The preparation of 2-methylene-19-nor-1α-hydroxy-17-ene-homopregnacalciferol having the structure Ia as well as analogs I can be accomplished by a common general method, i.e. the condensation of a bicyclic Windaus-Grundmann type ketone II with the allylic phosphine oxide III to the corresponding 2-methylene-19-nor-17-ene-vitamin D analog IV followed by deprotection at C-1 and C-3 to provide Ia:
In the structures III and IV, groups X 1 and X 2 are hydroxy-protecting groups, preferably t-butyldimethylsilyl, it being also understood that any functionalities that might be sensitive, or that interfere with the condensation reaction, be suitably protected as is well-known in the art. The process shown above represents an application of the convergent synthesis concept, which has been applied effectively for the preparation of vitamin D compounds [e.g. Lythgoe et al., J. Chem. Soc. Perkin Trans. I, 590 (1978); Lythgoe, Chem. Soc. Rev. 9, 449 (1983); Toh et al., J. Org. Chem. 48, 1414 (1983); Baggiolini et al., J. Org. Chem. 51, 3098 (1986); Sardina et al., J. Org. Chem. 51, 1264 (1986); J. Org. Chem. 51, 1269 (1986); DeLuca et al., U.S. Pat. No. 5,086,191; DeLuca et al., U.S. Pat. No. 5,536,713].
The hydrindanone of the general structure II is not known. It can be prepared by the method shown on the Scheme herein (see the preparation of compound VIT-1).
For the preparation of the required phosphine oxides of general structure III, a synthetic route has been developed starting from a methyl quinicate derivative which is easily obtained from commercial (1R,3R,4S,5R)-(−)-quinic acid as described by Perlman et al., Tetrahedron Lett. 32, 7663 (1991) and DeLuca et al., U.S. Pat. No. 5,086,191.
The overall process of the synthesis of compounds I, Ia, II, III and IV is illustrated and described more completely in U.S. Pat. No. 5,843,928 entitled “2-Alkylidene-19-Nor-Vitamin D Compounds” the specification of which is specifically incorporated herein by reference.
As used in the description and in the claims, the term “hydroxy-protecting group” signifies any group commonly used for the temporary protection of hydroxy functions, such as for example, alkoxycarbonyl, acyl, alkylsilyl or alkylarylsilyl groups (hereinafter referred to simply as “silyl” groups), and alkoxyalkyl groups. Alkoxycarbonyl protecting groups are alkyl-O-CO— groupings such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, tert-butoxycarbonyl, benzyloxycarbonyl or allyloxycarbonyl. The term “acyl” signifies an alkanoyl group of 1 to 6 carbons, in all of its isomeric forms, or a carboxyalkanoyl group of 1 to 6 carbons, such as an oxalyl, malonyl, succinyl, glutaryl group, or an aromatic acyl group such as benzoyl, or a halo, nitro or alkyl substituted benzoyl group. The word “alkyl” as used in the description or the claims, denotes a straight-chain or branched alkyl radical of 1 to 10 carbons, in all its isomeric forms. Alkoxyalkyl protecting groups are groupings such as methoxymethyl, ethoxymethyl, methoxyethoxymethyl, or tetrahydrofuranyl and tetrahydropyranyl. Preferred silyl-protecting groups are trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, dibutylmethylsilyl, diphenylmethylsilyl, phenyldimethylsilyl, diphenyl-t-butylsilyl and analogous alkylated silyl radicals. The term “aryl” specifies a phenyl-, or an alkyl-, nitro- or halo-substituted phenyl group.
A “protected hydroxy” group is a hydroxy group derivatised or protected by any of the above groups commonly used for the temporary or permanent protection of hydroxy functions, e.g. the silyl, alkoxyalkyl, acyl or alkoxycarbonyl groups, as previously defined. The terms “hydroxyalkyl”, “deuteroalkyl” and “fluoroalkyl” refer to an alkyl radical substituted by one or more hydroxy, deuterium or fluoro groups respectively.
More specifically, reference should be made to the following description as well as to Scheme 1 herein for a detailed illustration of the preparation of compound VIT-I.
(i) O 3 , C 5 H 5 N, MeOH; NaBH 4 , 81%. (ii) TsCl, C 5 H 5 N, 98%. (iii) TESOTf, 2,6-lutidine, CH 2 Cl 2 , 84%. (iv) NaHCO 3 , DMSO, 76%. (v) t-BuOK, t-BuOH, O 2 , 62%. (vi) MeMgBr, THF, 82%. (vii) 2M HCl:THF (1:1), 46%. (viii) PDC, CH 2 Cl 2 82%. (ix) 10, PhLi, THF 41%, (x) TBAF, THF, 61%
Des-A,B-23,24-dinorcholane-8β,22-diol (2). A flame dried 1000 mL two necked flask was charged with ergocalciferol 1 (5 g, 12.6 mmol), pyridine (5 mL), and anhydrous MeOH (400 mL). The solution was cooled to −78° C. in an argon atmosphere. O 3 was bubbled through the solution until a deep blue colour developed and persisted (about 1 h). The solution was treated with O 2 until the blue colour faded (15 min). Then NaBH 4 (1.5 g, 39.7 mmol) was added. After 15 min. second portion of NaBH 4 (1.5 g, 39.7 mmol) was added and the reaction was allowed to warm to rt. Then the third portion of NaBH 4 (1.5 g, 39.7 mmol) was added and reaction was left over night. The reaction was quenched by adding water (50 mL) drop wise. Methanol was evaporated in vaccuo and residue was dissolved in ethyl acetate. The organic phase was washed with 1N aqueous solution of HCl (100 mL), saturated NaHCO 3 solution (100 mL) and brine (100 mL). The organic phase was dried (Na 2 SO 4 ), filtered and evaporated. Purification by silica gel chromatography (25% ethyl acetate/hexane) afforded 2.18 g (10.3 mmol, 81%) of diol 2 as a white solid. Mp 110-111° C.; 1 H NMR (400 MHz, CDCl 3 ) δ: 4.09 (1H, m), 3.64 (1H, dd, J=10.5 and 3.2 Hz), 3.38 (1H, dd, J=10.5 and 6.7 Hz), 1.03 (3H, d, J=6.6 Hz), 0.96 (3H, s); 13 C NMR (100 MHz, CDCl 3 ) δ: 69.2, 67.8, 52.9, 52.4, 41.8, 40.2, 38.2, 33.6, 26.6, 22.6, 17.4, 16.6, 13.6; MS m/z (relative integration): 212 (M + , 2), 194 (15), 179 (18), 125 (43), 111 (100); exact mass calculated for C 13 H 22 O ([M-H 2 O] + ) is 194.1671, found 194.1665.
Des-A,B-22-(p-toluenesulfonyloxy)-23,24-dinorcholane-8β-ol (3). A solution of diol 2 (1 g, 4.71 mmol) in anhydrous pyridine (12 mL) was cooled to −25° C. and a precooled solution of tosyl chloride (1.08 g, 5.66 mmol) in anhydrous pyridine (2 mL) was added dropwise. The reaction mixture was stirred at that temperature for 4 h and allowed to warm to 0° C. and stirred at that temperature for additional 20 h. The mixture was diluted with CH 2 Cl 2 (50 mL) and washed with saturated CuSO 4 solution (30 mL), 1N HCl (30 mL), water (50 mL). The organic phase was dried (NaSO 4 ), filtered and concentrated. Purification by silica gel chromatography (25% ethyl acetate/hexane) yielded 1.7 g (4.64 mmol, 98%) of hydroxyl tosylate 3. 1 H NMR (400 MHz, CDCl 3 ) δ: 7.78.(2H, d, J=8.2 Hz), 7.35 (2H, d, J=8.2 Hz), 4.06 (1H, m), 3.95 (1H, dd, J=9.2 and 3.0 Hz), 3.8 (1H, dd, J=9.2 and 6.2 Hz), 2.45 (3H, s), 0.96 (3H, d, J=6.6 Hz), 0.89 (3H, s); 13 C NMR (100 MHz, CDCl 3 ) δ: 144.7, 133.0, 129.8, 127.9, 75.6, 69.0, 60.4, 52.2, 41.9, 40.1, 35.7, 33.5, 26.4, 22.4, 21.6, 17.3, 16.7, 13.41 MS m/z (relative integration): 366 (M+, 6), 194(14), 179(16), 125(30), 111(100).
Des-A,B-8β-(triethysilyloxy)-22-(p-toluenesulfonyloxy)-23,24-dinorcholane (4). To a −50° C. cooled solution of hydroxyl tosylate 3 (1.7 g, 4.64 mmol) in anhydrous CH 2 Cl 2 (20 mL) was added 2,6-lutidine (0.64 mL, 5.57 mmol) followed by TESOTf (1.26 mL, 1.47 g, 5.57 mmol). The solution was stirred at 0° C. for 15 min and water (10 mL) was added. The mixture was extracted with CH 2 Cl 2 (3×40 mL), and combined organic phases were washed with 1N aqueous solution of NaOH (40 mL) dried (Na 2 SO 4 ), filtered and concentrated. The residue was purified by silica gel column chromatography (5% ethyl acetate/hexane) to give 1.87 g (3.89 mmol, 84%) of O-silylated tosylate 4. 1 H NMR (400 MHz, CDCl 3 ) δ: 7.77 (2H, d, J=8.2 Hz), 7.33 (2H, d, J=8.2 Hz), 4.01(1H, m) 3.95(1H, dd, J=9.2 and 3.0 Hz), 3.78 (1H, dd, J=9.2 and 6.4 Hz), 2.43 (3H, s), 0.94 (3H, d, J=7.0 Hz), 0.93 (9H, t, J=7.9 Hz), 0.85 (3H, s), 0.53 (6H, q, J=7.9 Hz); 13 C NMR (100 MHz, CDCl 3 ) δ: 144.5, 133.1, 129.7, 127.9, 75.7, 69.1, 52.7, 52.4, 42.1, 40.4, 35.7, 34.5, 26.5, 22.9, 21.6, 17.5, 16.7, 13.4, 6.9, 4.9; MS m/z (relative integration): 480 (M + , 30), 437 (50), 279 (49.), 257 (49), 257 (84), 177 (100); exact mass calculated for C 26 H 44 SSi (M + ) is 480.2730, found 480.2741.
Des-A,B-8β-(triethylsilyloxy)-23,24-dinorcholane-22-al (5). A solution of O-silylated tosylate 4 (1.8 g, 3.75 mmol) in DMSO (5 mL) was added to a suspension of NaHCO 3 (1.42 g, 16.8 mmol) in DMSO (20 mL) at rt. The mixture was heated to 150° C. under argon for 15 min and cooled to rt. Water (50 mL) followed by ethyl acetate (50 mL) were added and aqueous phase was extracted by ethyl acetate (3×30 mL). The combined organic phases were dried (Na 2 SO 4 ), filtered and concentrated. The residue was purified by column chromatography (2% ethyl acetate/hexane) to afford 0.92 g (2.83 mmol, 76%) of O silylated aldehyde 5. 1 H NMR (500 MHz, CDCl 3 ) δ: 9.58 (1H, d, J=3.2 Hz), 4.06 (1H, m), 2.35 (1H, m), 1.09 (3H, d, J=6.8 Hz), 0.96 (3H, s), 0.95 (9H, t, J=8.1 Hz), 0.55 (6H, q, J=8.1 Hz); 13 C NMR (100 MHz, CDCl 3 ) δ: 205.5, 69.0, 52.3, 51.7, 49.2, 42.6, 40.5, 34.5, 26.2, 23.3, 17.6, 13.9, 13.3, 6.9, 4.9; MS m/z (relative integration): no M + , 295 (M + -C 2 H 5 , 41), 163 (100), 135 (35), 103 (72); exact mass calculated for C 17 H 31 O 2 Si ([M-C 2 H 5 ] + ) is 295.2093, found 295.2095.
Des-A,B-8β-(triethylsilyloxy)-pregnan-20-one (6). A flame dried flask was charged with KO-t-Bu (1.55 g, 13.9 mmol) and anhydrous t-BuOH (30 mL). O 2 was bubbled through the solution for 15 min. A solution of O-silylated aldehyde 5 (0.9 g, 2.78 mmol) in anhydrous t-BuOH (15 mL) was added to the reaction mixture and O 2 was bubbled through the solution for additional 10 min. The solution was quenched with water (15 ml) and extracted with ether (3×30 mL). The combined organic phases were dried (Na 2 SO 4 ), filtered and concentrated. The residue was purified by column chromatography (3% ethyl acetate/hexane) to give 0.53 g (1.7 mmol, 62%) of the O-silylated 20-ketone 6. 1 H NMR (500 MHz, CDCl 3 ) δ: 4.07 (1H, m), 2.46 (1H, t, J=9.0 Hz), 2.09 (3H, s), 0.94 (9H, t, J=8.0 Hz), 0.85 (3H, 3), 0.55 (6H, q, J=8.0 Hz); 13 C NMR (100 MHz, CDCl 3 ) δ: 209.6, 68.9, 64.5, 53.2, 43.7, 39.9, 34.4, 31.5, 23.1, 21.8, 17.6, 15.3, 6.9, 4.9; MS m/z (relative intensity): 310 (M+, 12), 281 (100), 267 (59), 103 (98); exact mass calculated for C 18 H 34 O 2 Si (M + ) is 310.2328, found 310.2325.
Des-A,B-20-methyl-8β-(triethylsilyloxy)-pregnan-20-ol (7). To a solution of Ketone 6 (0.5 g, 1.61 mmol) in dry THF (10 mL) was added 3M solution of methylmagnesiumbromide in diethyl ether (1.3 mL, 0.48 g, 4.03 mmol) at 0° C. under argon atmosphere. The reaction was allowed to come to room temperature and allowed to stir at that temperature for 2 h. Then it was quenched with saturated ammonium chloride solution. The mixture was extracted with ethyl acetate (3×20 mL). The combined organic extracts were washed with water (30 mL) and brine solution (30 mL). It was dried (Na 2 SO 4 ), filtered and concentrated. The residue was purified by column chromatography (10% ethyl acetate/hexane) to give 0.42 g (1.29 mmol, 80%) of the tertiary alcohol 7. 1 H NMR (400 MHz, CDCl 3 ) δ: 4.05 (1H, m), 2.05 (1H, m), 1.29 (3H, s), 1.17 (3H, s), 1.10 (3H, s), 0.95 (9H, t, J=7.9 Hz), 0.55 (6H, q, J=7.9 Hz); 13 C NMR (100 MHz, CDCl 3 ) δ: 73.1, 69.0, 60.1, 52.6, 42.5, 40.7, 34.1, 30.5, 29.5, 22.3, 21.7, 17.2, 14.9, 6.5, 4.5; MS m/z (relative intensity): 326 (M+, 2), 311 (4), 297 (31), 279 (100); exact mass calculated for C 17 H 33 O 2 Si ([M-C 2 H 5 ] + ) is 297.2250, found 297.2246.
Des-A,B-20-methyl-pregnan-17(20)-ene-8β-ol (8). A mixture of compound 7 (0.150 g, 0.46 mmol), 2M hydrochloric acid (5 mL) and THF (5 mL) were refluxed at 70° C. for 1 h. THF was evaporated in vaccuo and the aqueous phase was basified using 2.5M NaOH solution. The aqueous phase was extracted with ethyl acetate (3×30 mL). The combined organic phases were washed with water (50 mL) and brine (30 mL). The organic phase was dried (Na 2 SO 4 ), filtered and concentrated. The residue was purified by column chromatography (12% ethyl acetate/hexane) followed by HPLC (9.4 mm×25 cm zorbax-sil column, 4 ml/min) using hexane:IPA (95.5:0.5) solvent system. Pure alcohol 80.041 g (0.21 mmol, 46%) was eluted at R v =56 mL. 1 HNMR(500 MHz, CDCl 3 ) δ: 4.16 (1H, m), 2.28 (2H, m), 2.18 (1H, m), 1.70 (3H, s), 1.55 (3H, s), 1.10 (3H, s).
Des-A,B-20-methyl-pregnan-17(20)-ene-8-one (9). To a solution of alcohol 8 (0.020 g, 0.10 mmol) in anhydrous CH 2 Cl 2 (5 mL) was added PDC (0.054 g, 0.14 mmol) at rt. After stirring the reaction for 3 h under argon atmosphere the solution was passed through a pad of celite with ethyl acetate. The filtrate was concentrated and applied on a Sep-Pak cartridge and eluted with ethyl acetate/hexane (6%) to give ketone as colourless oil. The ketone was purified on HPLC (6.2 mm×25 cm zorbax-sil column, 4 ml/min) using 4% ethyl acetate/hexane solvent system. Pure ketone 9 15.4 mg (0.08 mmol, 78%) was eluted at R v =42 mL as colorless oil. 1 H NMR (500 MHz, CDCl 3 ) δ: 2.57 (1H, m), 1.74 (3H, s), 1.59 (3H, m), 0.083 (3H, s), MS m/z (relative intensity): 192 (M+, 98), 177 (88), 159 (100), 149 (91), 107 (89); exact mass calculated for C 13 H 20 O (M + ) is 192.1514, found 192.1521.
1α-hydroxy-20-methyl-2-methylene-17(20)-ene-19-nor-pregnancalciferol (12). To a solution of phosphine oxide 10 (0.030 g, 0.05 mmol) in anhydrous THF (500 μL) at −25° C. was slowly added PhLi (34 μL, 5 mg, 0.061 mmol) under argon with stirring. The solution turned deep orange. The mixture was stirred at that temperature for 20 min and cooled to −78° C. A precooled (−78° C.) solution of ketone 9 (0.004 g, 0.02 mmol) in anhydrous THF (100 μL) was added slowly. The mixture was stirred under argon atmosphere at −78° C. for 3 h and at 0° C. for 18 h. Ethyl acetate was added and organic phase was washed with brine, dried (Na 2 SO 4 ) and evaporated. The residue was applied on a Sep-Pak cartridge, and eluted with 1% ethyl acetate/hexane to give the 19-nor protected vitamin derivative (1 mg of unreacted ketone was recovered). The vitamin was further purified by HPLC (6.2 mm×25 cm zorbax-sil column, 4 ml/min) using hexane/ethyl acetate (99.05:0.05) solvent system. Pure compound 11, 3.6 mg (0.0067 mmol, 41%) was eluted at R v =28 mL as colourless oil. UV (in hexane): λmax 244, 252, 262 nm; 1 H NMR (500 MHz, CDCl 3 ) δ: 6.21 and 5.87 (1H and 1H, each d, J=11.4 Hz), 4.97 and 4.92 (2H, each s), 4.43 (2H, m), 2.80 (1H, m), 2.53 (1H, dd, J=13.8 and 5.6 Hz), 2.452 (1H, dd, J=8.2 and 5.6 Hz), 1.71 (3H, s), 1.58 (3H, s), 0.9, 0.84 (9H and 9H, each s), 0.74 (3H, s), 0.027, 0.050, 0.068, 0.081 (Each 3H, each s).
The protected vitamin 11 (0.0036 g, 0.0067 mmol) was dissolved in anhydrous THF (500 μL) and treated with TBAF (66 μL, 18 mg, 0.067 mmol) and stirred at rt in dark for overnight. The solvent was removed in vaccuo and residue was applied on Sep-Pak cartridge, and eluted with 30% ethyl acetate/hexane to get the deprotected vitamin. The vitamin was further purified by HPLC (6.2 mm×25 cm zorbax-sil column, 4 ml/min) using hexane/IPA (90/10) as solvent system. Pure vitamin 12, 1.3 mg (0.0036 mmol, 61%) was eluted at R v =26 mL. UV (in ethanol): λ max , 243, 251, 261 nm; 1 H NMR (500 MHz, CDCl 3 ) δ: 6.35 and 5.92 (1H and 1H, each d, J=11.3 Hz), 5.10 and 5.13 (1H and 1H, each s), 4.48 (2H, m), 2.88 (1H, dd, J=13.3 and 4.5Hz), 2.78 (1H, dd, J=12.6 and 3.6 Hz), 2.58 (1H, dd, J=12.7 and 3.6 Hz), 2.13 (1H, m), 1.71 (3H, s), 1.61 (3H, s), 0.739 (3H, s); MS m/z (relative intensity): 328 (M + , 100), 313 (23), 310 (15), 295 (11), 277 (8), 243 (35), 229 (41), 149 (83); exact mass calculated for C 22 H 3 O 2 Na ([MNa] + ) is 351.2300, found 351.2304.
BIOLOGICAL ACTIVITY OF 2-METHYLENE-19-NOR-1α-HYDROXY-17-ENE-HOMOPREGNACALCIFEROL
The introduction of a methylene group to the 2-position, the introduction of a double bond between the 17 and 20 positions, and the elimination of carbons 23, 24, 25, 26 and 27 in the side chain of 1α-hydroxy-19-nor-vitamin D 3 had little or no effect on binding to the full length recombinant rat vitamin D receptor, as compared to 1α,25-dihydroxyvitamin D 3 . The compound VIT-I bound equally well to the receptor as compared to the standard 1,25-(OH) 2 D 3 ( FIG. 1 ). It might be expected from these results that compound VIT-I would have equivalent biological activity. Surprisingly, however, compound VIT-I is a highly selective analog with unique biological activity.
FIG. 6 shows that VIT-I has very little activity as compared to that of 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ), the natural hormone, in stimulating intestinal calcium transport.
FIGS. 4 and 5 demonstrate that VIT-I has very little bone calcium mobilization activity, as compared to 1,25(OH) 2 D 3 .
FIGS. 4-6 thus illustrate that VIT-I may be characterized as having little, if any, calcemic activity.
FIG. 2 illustrates that VIT-I is almost as potent as 1,25(OH) 2 D 3 on HL-60 cell differentiation, making it an excellent candidate for the treatment of psoriasis and cancer, especially against leukemia, colon cancer, breast cancer, skin cancer and prostate cancer. In addition, due to its relatively high cell differentiation activity, this compound provides a therapeutic agent for the treatment of various skin conditions including wrinkles, lack of adequate dermal hydration, i.e. dry skin, lack of adequate skin firmness, i.e. slack skin, and insufficient sebum secretion. Use of this compound thus not only results in moisturizing of skin but also improves the barrier function of skin.
FIG. 3 illustrates that the compound VIT-I has transcriptional activity in bone cells, albeit lower than 1α,25-dihydroxyvitamin D 3 . This result, together with the cell differentiation activity of FIG. 2 , suggests that VIT-I will be very effective in psoriasis because it has direct cellular activity in causing cell differentiation and in suppressing cell growth. These data also indicate that VIT-I may have significant activity as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer, skin cancer and prostate cancer.
The strong activity of VIT-I on HL-60 differentiation and in vitro transcription suggests it will be active in suppressing growth of parathyroid glands and in the suppression of the preproparathyroid gene.
Experimental Methods
Vitamin D Receptor Binding
Test Material
Protein Source
Full-length recombinant rat receptor was expressed in E. coli BL21 (DE3) Codon Plus RIL cells and purified to homogeneity using two different column chromatography systems. The first system was a nickel affinity resin that utilizes the C-terminal histidine tag on this protein. The protein that was eluted from this resin was further purified using ion exchange chromatography (S-Sepharose Fast Flow). Aliquots of the purified protein were quick frozen in liquid nitrogen and stored at −80° C. until use. For use in binding assays, the protein was diluted in TEDK 50 (50 mM Tris, 1.5 mM EDTA, pH7.4, 5 mM DTT, 150 mM KCl) with 0.1% Chaps detergent. The receptor protein and ligand concentration were optimized such that no more than 20% of the added radiolabeled ligand was bound to the receptor.
Study Drugs
Unlabeled ligands were dissolved in ethanol and the concentrations determined using UV spectrophotometry (1,25(OH) 2 D 3 : molar extinction coefficient=18,200 and λ max =265 nm; Analogs: molar extinction coefficient=42,000 and λ max =252 nm). Radiolabeled ligand ( 3 H-1,25(OH) 2 D 3 , ˜159 Ci/mmole) was added in ethanol at a final concentration of 1 nM.
Assay Conditions
Radiolabeled and unlabeled ligands were added to 100 mcl of the diluted protein at a final ethanol concentration of ≦10%, mixed and incubated overnight on ice to reach binding equilibrium. The following day, 100 mcl of hydroxylapatite slurry (50%) was added to each tube and mixed at 10-minute intervals for 30 minutes. The hydroxylapaptite was collected by centrifugation and then washed three times with Tris-EDTA buffer (50 mM Tris, 1.5 mM EDTA, pH 7.4) containing 0.5% Titron X-100. After the final wash, the pellets were transferred to scintillation vials containing 4 ml of Biosafe II scintillation cocktail, mixed and placed in a scintillation counter. Total binding was determined from the tubes containing only radiolabeled ligand.
HL-60 Differentiation
Test Material
Study Drugs
The study drugs were dissolved in ethanol and the concentrations determined using UV spectrophotometry. Serial dilutions were prepared so that a range of drug concentrations could be tested without changing the final concentration of ethanol (≦0.2%) present in the cell cultures.
Cells
Human promyelocytic leukemia (HL60) cells were grown in RPMI-1640 medium containing 10% fetal bovine serum. The cells were incubated at 37° C. in the presence of 5% CO 2 .
Assay Conditions
HL60 cells were plated at 1.2×10 5 cells/ml. Eighteen hours after plating, cells in duplicate were treated with drug. Four days later, the cells were harvested and a nitro blue tetrazolium reduction assay was performed (Collins et al., 1979; J. Exp. Med. 149:969-974). The percentage of differentiated cells was determined by counting a total of 200 cells and recording the number that contained intracellular black-blue formazan deposits. Verification of differentiation to monocytic cells was determined by measuring phagocytic activity (data not shown).
In vitro Transcription Assay
Transcription activity was measured in ROS 17/2.8 (bone) cells that were stably transfected with a 24-hydroxylase (24Ohase) gene promoter upstream of a luciferase reporter gene (Arbour et al., 1998). Cells were given a range of doses. Sixteen hours after dosing the cells were harvested and luciferase activities were measured using a luminometer.
RLU=relative luciferase units.
Intestinal Calcium Transport and Bone Calcium Mobilization
Male, weanling Sprague-Dawley rats were placed on Diet 11 (0.47% Ca)+AEK for one week followed by Diet 11 (0.02% Ca)+AEK for 3 weeks. The rats were then switched to the same diet containing 0.47% Ca for one week followed by two weeks on the same diet containing 0.02% Ca. Dose administration began during the last week on 0.02% calcium diet. Four consecutive ip doses were given approximately 24 hours apart. Twenty-four hours after the last dose, blood was collected from the severed neck and the concentration of serum calcium determined by atomic absorption spectrometry as a measure of bone calcium mobilization. The first 10 cm of the intestine was also collected for intestinal calcium transport analysis using the everted gut sac method.
Interpretation of Data
VDR binding, HL60 cell differentiation, and transcription activity. VIT-I (K i =1.9×10 −10 M) is nearly equivalent to the natural hormone 1α,25-dihydroxyvitamin D 3 (K i =7.8×10 −11 M) in its ability to compete with [ 3 H]-1,25(OH) 2 D 3 for binding to the full-length recombinant rat vitamin D receptor ( FIG. 1 ). There is also little difference between VIT-I (EC 50 =1.3×10 −8 M) in its ability (efficacy or potency) to promote HL60 differentiation as compared to 1α,25-dihydroxyvitamin D 3 (EC 50 =6.2×10 −9 M) (See FIG. 2 ). Compound VIT-I (EC 50 =6.0×10 −9 M) has transcriptional activity in bone cells but noticeably lower than 1α,25-dihydroxyvitamin D 3 (EC 50 =2.2×10 −10 M) (See FIG. 3 ). These results suggest that VIT-I will be very effective in psoriasis because it has direct cellular activity in causing cell differentiation and in suppressing cell growth. These data also indicate that VIT-I will have significant activity as an anti-cancer agent, especially against leukemia, colon cancer, breast cancer, skin cancer and prostate cancer, as well as against skin conditions such as dry skin (lack of dermal hydration), undue skin slackness (insufficient skin firmness), insufficient sebum secretion and wrinkles. It would also be expected to be very active in suppressing secondary hyperparathyroidism.
Calcium mobilization from bone and intestinal calcium absorption in vitamin D-deficient animals. Using vitamin D-deficient rats on a low calcium diet (0.02%), the activities of VIT-I and 1,25(OH) 2 D 3 in intestine and bone were tested. As expected, the native hormone (1,25(OH) 2 D 3 ) increased serum calcium levels at all dosages ( FIG. 4 ). FIG. 4 and FIG. 5 show that VIT-I has little, if any, activity in mobilizing calcium from bone. Administration of VIT-I at 780 pmol/day for 4 consecutive days did not result in mobilization of bone calcium, and increasing the amount of VIT-I to 2340 pmol/day and then to 7020 pmol/day was also without any substantial effect.
Intestinal calcium transport was evaluated in the same groups of animals using the everted gut sac method ( FIG. 6 ). These results show that the compound VIT-1 does not promote intestinal calcium transport when administered at 780 pmol/day, 2340 pmol/day or 7020 pmol/day, whereas 1,25(OH) 2 D 3 promotes a significant increase at the 780 pmol/day dose. Thus, it may be concluded that VIT-I is essentially devoid of intestinal calcium transport activity at the tested doses.
These results illustrate that VIT-I is an excellent candidate for numerous human therapies as described herein, and that it may be particularly useful in a number of circumstances such as suppression of secondary hyperparathyroidism of renal osteodystrophy, autoimmune diseases, cancer, and psoriasis. VIT-I is an excellent candidate for treating psoriasis because: (1) it has significant VDR binding, transcription activity and cellular differentiation activity; (2) it is devoid of hypercalcemic liability unlike 1,25(OH) 2 D 3 ; and (3) it is easily synthesized. Since VIT-I has significant binding activity to the vitamin D receptor, cell differentiation activity, and gene transcription activity but has little ability to raise blood serum calcium, it may also be particularly useful for the treatment of secondary hyperparathyroidism of renal osteodystrophy.
These data also indicate that the compound VIT-I of the invention may be especially suited for treatment and prophylaxis of human disorders which are characterized by an imbalance in the immune system, e.g. in autoimmune diseases, including multiple sclerosis, lupus, diabetes mellitus, host versus graft rejection, and rejection of organ transplants; and additionally for the treatment of inflammatory diseases, such as rheumatoid arthritis, asthma, and inflammatory bowel diseases such as celiac disease, ulcerative colitis and Crohn's disease. Acne, alopecia and hypertension are other conditions which may be treated with the compound VIT-I of the invention.
The compounds of the invention of formula I, and particularly formula Ia, are also useful in preventing or treating obesity, inhibiting adipocyte differentiation, inhibiting SCD-1 gene transcription, and/or reducing body fat in animal subjects. Therefore, in some embodiments, a method of preventing or treating obesity, inhibiting adipocyte differentiation, inhibiting SCD-1 gene transcription, and/or reducing body fat in an animal subject includes administering to the animal subject, an effective amount of one or more of the compounds or a pharmaceutical composition that includes one or more of the compounds of formula I. Administration of the compound or the pharmaceutical compositions to the subject inhibits adipocyte differentiation, inhibits gene transcription, and/or reduces body fat in the animal subject. The animal may be a human, a domestic animal such as a dog or a cat, or an agricultural animal, especially those that provide meat for human consumption, such as fowl like chickens, turkeys, pheasant or quail, as well as bovine, ovine, caprine, or porcine animals.
For prevention and/or treatment purposes, the compounds of this invention defined by formula I may be formulated for pharmaceutical applications as a solution in innocuous solvents, or as an emulsion, suspension or dispersion in suitable solvents or carriers, or as pills, tablets or capsules, together with solid carriers, according to conventional methods known in the art. Any such formulations may also contain other pharmaceutically-acceptable and non-toxic excipients such as stabilizers, anti-oxidants, binders, coloring agents or emulsifying or taste-modifying agents.
The compounds of formula I and particularly VIT-I, may be administered orally, topically, parenterally, rectally, nasally, sublingually or transdermally. The compound is advantageously administered by injection or by intravenous infusion or suitable sterile solutions, or in the form of liquid or solid doses via the alimentary canal, or in the form of creams, ointments, patches, or similar vehicles suitable for transdermal applications. A dose of from 0.01 μg to 1000 μg per day of the compounds I, particularly VIT-I, preferably from about 0.1 μg to about 500 μg per day, is appropriate for prevention and/or treatment purposes, such dose being adjusted according to the disease to be treated, its severity and the response of the subject as is well understood in the art. Since the compound exhibits specificity of action, each may be suitably administered alone, or together with graded doses of another active vitamin D compound—e.g. 1α-hydroxyvitamin D 2 or D 3 , or 1α,25-dihydroxyvitamin D 3 —in situations where different degrees of bone mineral mobilization and calcium transport stimulation is found to be advantageous.
Compositions for use in the above-mentioned treatments comprise an effective amount of the compounds I, particularly VIT-I, as defined by the above formula I and Ia as the active ingredient, and a suitable carrier. An effective amount of such compound for use in accordance with this invention is from about 0.01 μg to about 1000 μg per gm of composition, preferably from about 0.1 μg to about 500 μg per gram of composition, and may be administered topically, transdermally, orally, rectally, nasally, sublingually or parenterally in dosages of from about 0.01 μg/day to about 1000 μg/day, and preferably from about 0.1 μg/day to about 500 μg/day.
The compounds I, particularly VIT-I, may be formulated as creams, lotions, ointments, topical patches, pills, capsules or tablets, suppositories, aerosols, or in liquid form as solutions, emulsions, dispersions, or suspensions in pharmaceutically innocuous and acceptable solvent or oils, and such preparations may contain in addition other pharmaceutically innocuous or beneficial components, such as stabilizers, antioxidants, emulsifiers, coloring agents, binders or taste-modifying agents.
The compounds I, particularly VIT-1, may be advantageously administered in amounts sufficient to effect the differentiation of promyelocytes to normal macrophages. Dosages as described above are suitable, it being understood that the amounts given are to be adjusted in accordance with the severity of the disease, and the condition and response of the subject as is well understood in the art.
The formulations of the present invention comprise an active ingredient in association with a pharmaceutically acceptable carrier therefore and optionally other therapeutic ingredients. The carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulations and not deleterious to the recipient thereof.
Formulations of the present invention suitable for oral administration may be in the form of discrete units as capsules, sachets, tablets or lozenges, each containing a predetermined amount of the active ingredient; in the form of a powder or granules; in the form of a solution or a suspension in an aqueous liquid or non-aqueous liquid; or in the form of an oil-in-water emulsion or a water-in-oil emulsion.
Formulations for rectal administration may be in the form of a suppository incorporating the active ingredient and carrier such as cocoa butter, or in the form of an enema.
Formulations suitable for parenteral administration conveniently comprise a sterile oily or aqueous preparation of the active ingredient which is preferably isotonic with the blood of the recipient.
Formulations suitable for topical administration include liquid or semi-liquid preparations such as liniments, lotions, applicants, oil-in-water or water-in-oil emulsions such as creams, ointments or pastes; or solutions or suspensions such as drops; or as sprays.
For nasal administration, inhalation of powder, self-propelling or spray formulations, dispensed with a spray can, a nebulizer or an atomizer can be used. The formulations, when dispensed, preferably have a particle size in the range of 10 to 100μ.
The formulations may conveniently be presented in dosage unit form and may be prepared by any of the methods well known in the art of pharmacy. By the term “dosage unit” is meant a unitary, i.e. a single dose which is capable of being administered to a patient as a physically and chemically stable unit dose comprising either the active ingredient as such or a mixture of it with solid or liquid pharmaceutical diluents or carriers. | This invention discloses 2-methylene-19-nor-17-ene vitamin D analogs, and specifically 2-methylene-19-nor-1a-hydroxy-17-ene-homopregnacalciferol and pharmaceutical uses therefor. This compound exhibits pronounced activity in arresting the proliferation of undifferentiated cells and inducing their differentiation to the monocyte thus evidencing use as an anti-cancer agent and for the treatment of skin diseases such as psoriasis as well as skin conditions such as wrinkles, slack skin, dry skin and insufficient sebum secretion. This compound also has little, if any, calcemic activity and therefore may be used to treat autoimmune disorders and inflammatory diseases in humans as well as renal osteodystrophy. This compound may also be used for the treatment or prevention of obesity. |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of and priority to U.S. Provisional Application No. 60/437,092 entitled “Morsi Balloon Graft” and filed Dec. 30, 2002
BACKGROUND OF INVENTION
1. Field of Use
The invention pertains to a graft design that combines the minimal size and increased flexibility in its deliverable form which allows for successful navigation of torturous, stenotic blood vessels, aneurysms and other body passages with an in situ increase in size and rigidity, thus improving upon the current covered stent in treatment of various diseases such as atherosclerosis and aneurysms. The invention can be utilized in both the cerebral or peripheral circulatory system.
2. Prior Art
Inflatable devices for opening stenotic blood vessels are known. Devices such as angioplasty balloons, however, are unsuitable for permanent placement since the balloon component is fused to the catheter. Removal of the catheter will cause the collapse of the balloon. Further, the balloon itself may obstruct the lumen of the artery. Further, the procedure usually requires two separate steps; the first clearing of the occlusion and, second, the placement of a reinforcing stent with increased risk of embolization and the risk of restenosis. Currently metallic stents covered with a membrane are often installed as the second step.
Devices for treatment of aneurysms may not provide sufficient wall support or, alternatively, have material properties hindering their deployment within the affected portion of a vessel. Other devices may be subject to dislocation by the mechanics of fluid flow and pressure. Further, other devices of treating aneurysms, such as coils, are not suitable for certain types of aneurysms, e.g., wide neck or fusiform aneurysms. They may also be subject to incomplete olbitration of the aneurysm or coil compaction which may result in re-growth of the aneurysm and future rupture. Devices that are of a braid type construction are subject to variations of the longitudinal length in relation to radial expansion.
SUMMARY OF INVENTION
The invention pertains to a method and apparatus for the repair of stenotic vessels utilizing an inflatable device that can open the occlusion with minimized occurrence of residue breaking free within the blood flow, thereby risking injury to another part of the body, while simultaneously creating a smooth interior walled lumen but with an undulating or corrugated outer wall surface to facilitate secure placement within the intended portion of the vessel. The device also can be moved into position while in a collapsed state, thereby minimizing disruption or irritation of the lumen, and subsequently inflated to create a substantially flexible but stiff walled shent capable of contouring to the shape of the lumen without collapse or buckling.
The device subject of the invention decreases the risk of distal embolization by providing a single system that performs both balloon angioplasty and delivery of the graft in a relatively easy fashion. The flexible nature of the device during deployment allows precise positioning and with no risk of shortening as the length of the graft remains fixed during expansion and deployment. In addition, the device subject of the invention can be retrievable and is compatible with MRI diagnostic testing.
The invention also pertains to a method and apparatus for repairing aneurysm vessels by providing a graft design that, when deployed across the aneurysm, will effectively exclude the aneurysm from circulation and reinforce the weak blood vessel wall. This minimizes possible re-growth or recanalization. It will be appreciated that the operation of the invention reinforces the blood vessel wall both at the location of the aneurysm and in the proximate surrounding area.
The method taught be the invention further decreases the time and cost of the procedure. The method further permits good visualization of the graft during and after deployment through the use of radio-opaque inflating materials. The device and method of the invention also decreases the risk of intimal hyperplasia and resenosis.
Other benefits of the invention will also become apparent to those skilled in the art and such advantages and benefits are included within the scope of this invention.
SUMMARY OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention. These drawings, together with the general description of the invention given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1A illustrates the duel lumen catheter utilized to install the device.
FIG. 1B illustrates a cross sectional view of the catheter.
FIG. 1C illustrates a cross sectional view of the invention.
FIG. 1D is a perspective view of the invention.
FIG. 1E is an axial cross sectional view of the inflated device showing internal webbing.
FIG. 1F is a circumferential cross sectional view of the inflated device.
FIG. 2A illustrations the use of the catheter for inflating the invention.
FIG. 2B illustrates a cross sectional view of the catheter.
FIG. 2C illustrates a cross sectional view of the device during deployment.
FIGS. 3A , 3 B & 3 C illustrate the catheter and the invention in the process of inflation.
FIGS. 4A , 4 B & 4 C illustrate the catheter and invention after completion of the inflation step.
DETAILED DESCRIPTION OF INVENTION
The above general description and the following detailed description are merely illustrative of the subject invention and additional modes, advantages and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention.
FIG. 1A illustrates the system of the invention, being composed of a distal segment 1 , which represents the expandable graft and a proximal segment 2 , which represents the delivery catheter. The catheter 2 has a double lumen shaft 3 . FIG. 1B illustrates a cross sectional schematic of the catheter at a vector arrow BB in FIG. 1A . As shown in FIGS. 1A and 1B , the larger lumen 5 has an aperture proximally 7 , and opens distally 8 into the lumen 18 of the distal segment that provides an artificial flow path for the body lumen. Through this lumen, a guiding wire (not shown) can be inserted to facilitate proper positioning of the graft at the desired location in the cerebral or peripheral circulatory system and also to maintain the elongated shape of the graft during insertion.
The smaller catheter lumen 6 has an aperture proximal 9 that can be attached to an inflating device. Distally it is attached to, and in fluid communication with, the fluid tight chambers 16 within segments 17 A, 17 B, 17 C, 17 D 17 E inside the graft 1 through a detachable check valve 10 .
FIG. 1C is a cross sectional schematic view of the collapsed graft at vector arrow CC in FIG. 1A . The graft is completely deflated and folded to a circumference 3 A equal to the diameter 3 of the catherter in FIG. 1B . FIG. 1C also illustrates the inner wall 13 of the graft, the outer wall surface 12 , folds 28 of the outer graft wall, the collapsed chambers 16 and the lumen 18 of the graft. The longitudinal orientation of the folds 28 of the graft is shown in one segment 17 B of FIG. 1A .
The graft 1 , in its preferred embodiment is a double walled graft made of a bio-compatible, non-compliant non-porous material from a variety of suitable polymers, such as polyethylene, polyurethane, TFE, PTFE and ePTFE. In the preferred embodiment of the invention, the device, when inflated, forms a predetermined shape and size without becoming distorted. However, it will be appreciated that in other applications, a controlled elasticity of the device in one or more directions with inflation may be desirable. The double wall construction of the device is illustrated in FIGS. 1D , 1 E and 1 F discussed below.
In the preferred embodiment of the invention as illustrated in FIGS. 1D , 1 E and 1 F, the outer wall 12 is circumferentially 605 and longitudinally 690 larger than the inner wall 13 . This is particularly illustrated in FIG. 1F , which also illustrates the internal support struts or webs 20 within the chamber 16 . Again, it is within these chambers that that the inflating fluid 21 is deployed. The construction of the inner and outer wall described above allows the inner wall 13 to retain a relatively smooth surface facilitating unimpeded blood flow and the outer wall surface 13 to form a corrugated surface facilitating the shent device to adhere to the vessel wall. These contrasting surfaces 12 13 are illustrated in FIG. 1D .
The two walls 12 13 are completely sealed together both distally and proximally to form the fluid tight chambers 16 that is only attached to, and in fluid communication with, the smaller lumen of the delivery catheter through a detachable check valve 10 . Each graft segment 17 comprising the invention contains a fluid tight chamber 16 interconnected by pathways 19 and through which the inflating fluid 21 is conveyed.
The walls are also interconnected by network of integral radially oriented support or retention webs. The radial 680 orientation of the web structure 20 is illustrated in FIGS. 1E and 1F . The radial oriented web network is preferably of equal length through out the whole length of the individual chamber 16 except at the periphery of the chamber where the web structure tapers in length toward the non-expansive junction. The graft design allows a significant portion of the graft wall to be stiffened with the fluid, thereby providing desired strength from collapse of the body lumen.
FIGS. 1D and 1F further illustrate the inner and outer walls to be circumferentially joined together at multiple restricted or non-expandable junctures 14 . These fused juncture may be spaced equally throughout the length of the graft 1 , thus dividing the inner chamber of the graft into the multiple smaller fluid tight chambers 16 which may of equal linked segments 17 A, 1 B, 17 C, 17 D 17 E. Each chamber is connected with, and in fluid communication with, the adjacent chamber through one of more valves or holes 19 located in the fused junctures. These fluid communication channels may, or may not, have a common longitudinal orientation. ( FIG. 1D illustrates an embodiment having common longitudinal orientation.)
FIG. 1D illustrates the fully deployed graft. The outward radial expansion of the individual segments 17 A, 1 B, 17 C, 17 D 17 E has been exaggerated for clarity of illustration. Also illustrated are vector arrows or lines showing the longitudinal 690 orientation, radial 680 orientation, and circumferential 605 orientation of the invention as described in this specification.
FIG. 1E illustrates an axial cross section of a chamber of the invention, illustrating the multiple webs 20 that may be used to join the two walls together throughout the circumference of the chamber. This configuration ensures that the graft thoroughly inflates to a pre-selected shape without distortion; with a smooth inner surface, a thin film-like lumen, and a corrugated outer surface, which will anchor the graft to the inside of the blood vessel and prevents the drag force of the flowing blood through the graft form displacing the graft.
FIG. 1F illustrates a longitudinally oriented cross section of a chamber showing the tapered length of the web structure 20 , the fused juncture 14 of the inner 13 and outer 12 wall. It will be appreciated that the inflation/stiffing fluid 21 fills the interstitial space
FIG. 1F also illustrates the junctures 14 to be very small in width (about one millimeter 29 . The juncture is formed by the outer wall 12 fused to the inner wall 13 . The outer wall 12 forms an acute angle with the inner wall 13 at the fused juncture 14 as shown if FIG. 1F . They serve both as conduit that connects the adjacent chambers 16 through multiple holes 19 within, and as bending areas (as they do not expand or pressurized when the graft is fully inflated) thus giving the graft some flexibility between the fully inflated segments 17 A 17 B 17 C, 17 D, 17 E; allowing it to conform to the shape of the blood vessel without the risk of kinking or distortion. They also provide a space on its outer surface for neointimal growth that will further help anchoring and stabilizing the graft. It will be appreciated that the design selection of the segments and junctures may facilitate deployment of the device within varying vessel diameters, tissue structure or architecture. In other embodiments, side fenestrations may be created at selected locations of the invention to allow deployment of across bifurcating blood vessels without compromising blood flow.
It will be further appreciated that the material may selectively include fiber reinforcement, particularly in applications where the device may be subjected to repetitively varying pressures. Such fiber may be presumably installed in a circumferential orientation, but other designs may be found advantageous.
FIGS. 1A and 1C illustrate the graft at the start of deployment and during that portion of the procedure for placing the graft in the selected location within the body lumen. The graft is completely deflated and evacuated from any air and folded throughout its length in longitudinal folds 28 around the lumen 18 in a radial fashion to a circumference 3 A approximating the circumference 3 of the delivery catheter 2 , illustrated in FIG. 1B . A very thin sheath (not shown) can cover the outer surface of the graft; alternatively, the edges 28 of the longitudinal folds can be loosely adherent together to help maintain the longitudinal shape and smooth outer surface of the graft during insertion.
The proximal end of the graft is tightly packed into a groove (not shown) on the opposing end of the delivery catheter wall.
FIGS. 2A , 2 C, 3 A, 3 C 4 A and 4 C sequentially illustrated the deployment of the graft in a selected location by the addition of a specified fluid 21 through the catheter 2 . The graft has an elongated cylindrical shape when fully inflated and pressurized and has a lumen 18 therein, which provides an artificial flow path for the body lumen (not shown). It is composed of an outer wall 12 , and an inner wall 13 , wherein the filler material 21 is provided between the two walls to inflate the graft into its predetermined inflated size and shape. Also illustrated is the fluid communication pathway 19 existing between segments 17 A, 1 B, 17 C, 17 D 17 E. The fluid can be a curable resin system, thereby providing additional stiffening reinforcement to the vessel walls. In addition, the fluid system may also adhere to the inner walls of each segment comprising the invention.
FIGS. 2 , 3 , & 4 explain the method of the invention. Using fixed radio-opaque markers at both ends of the graft 24 , the graft can be perfectly positioned at the desired location within the human lumen (not shown). The graft is deployed by injecting a fluid or gel material of contrast media, monomer, or uncrossed polymer through a pressure monitoring inflation device attached to the proximal end of the small lumen of the delivery catheter, which gradually fills the small catheter lumen 21 , and flows across the detachable valve into the chambers of the graft in a successive fashion 22 . The fluid may be a curable polymer resin system.
As the chambers of the graft fill gradually, the graft starts to unfold 23 and expand 25 in a radial fashion outward. After the graft expands to its predetermined shape and size 26 , a slight increase in the amount of the injected material will lead to increased pressure inside the graft, and exert a sufficient radial force outward, thus becoming axially and sealingly fixed to the inside of the blood vessel.
The graft can then be detached from the delivery catheter 27 through the detachable valve leaving the graft fully expanded and pressurized. This graft design functions as a covert stent graft for treating diseases such as atherosclerosis and aneurysms.
This specification is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and describe are to be taken as the presently preferred embodiments. As already stated, various changes may be made in the shape, size and arrangement of components or adjustments made in the steps of the method without departing from the scope of this invention. For example, equivalent elements may be substituted for those illustrated and described herein and certain features of the invention may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the invention.
Further modifications and alternative embodiments of this invention will be apparent to those skilled in the art in view of this specification. | A method and apparatus for repair of stenotic and aneurysmic vessels utilizing in situ deployment of an inflatable tubular shaped device ( 1) having a longitudinally oriented annulus ( 17). When inflated, the size and rigidity of the device ( 1) is increased, thereby providing supplemental strength to the vessel wall and a lumen ( 8) for the passage of fluid. |
This is a divisional of application Ser. No. 08/643,642, filed May 6, 1996, now U.S. Pat. No. 5,768,002.
BACKGROUND OF THE INVENTION
The present invention relates generally to fiber optic communication, and more particularly to modulation of light for use with fiber optics in fiber optic communication schemes.
With the advent of dispersion compensating fibers, erbium doped fiber amplifiers, high speed amorphous silicon detectors, and all optical demultiplexing, fiber optic transmission speed is limited principally by the modulation speed of the optical transmitter.
High speed modulators have been invented that take advantage of the properties of superconducting materials. Superconducting materials are in there "superconducting" state if the current density in the material, and the temperature of the material, and the magnetic field around the material are all below certain critical values. The critical current density (J c ), critical temperature (T c ), and the critical magnetic field (H c ) are all dependent on the chemical composition of the material and on the presence or absence of defects and impurities. If any of these quantities rise above the critical values the material leaves its superconducting state and enters its "normal" state. The material has properties similar to a semiconductor in it's normal state and is characterized by a normal-state resistivity. The superconducting state has many of the properties of a theoretically perfect conductor. The electrical resistance is zero and electromagnetic fields are reflected by it. Thus in the superconducting state a superconducting thin film acts like a mirror with 100% reflectivity 1, 2!. In the normal state light is partially transmitted 3!. The bracketed end note reference numbers 1, 2! and all other such end notes and reference numbers cited herein appear at the end of this specification along with the reference notes themselves.
U.S. Pat. No. 5,210,637 which is incorporated herein by reference issued May 11, 1993 to Puzey for "High Speed Light Modulation" discloses a device for the high speed modulation of light wherein a layer of superconducting film is used to modulate the light. U.S. Pat. No. 5,036,042 which is incorporated herein by reference issued Jul. 30, 1991 to Hed for "Switchable Superconducting Mirrors" and discloses a device that can be used for the high speed modulation of light.
FIG. 1 herein illustrates one embodiment of U.S. Pat. No. 5,210,637 as indicated by reference numeral 10. A DC power supply 15 is connected to a light source 13 to provide constant light output. A superconducting film 14 is placed in the path of the optical output and its reflectivity is altered by a modulating circuit 16 which switches the film between its superconductivity and non-superconductive states, as described In the Puzey patent. The altered reflectivity results in optical pulses 20 which are carried away by an optical fiber 25. The superconducting film is kept cool by placing it in a dewar 22 which is cooled by means of a refrigerating device 26.
A key drawback of device 10 and the corresponding device in the Hed Patent is that they are both limited to creating optical pulses in the far infrared range (approximate wavelength of 14 microns). This is because at higher frequencies the photon energy of the light is high enough to break the binding energy of the Cooper electron pairs responsible for the phenomena of superconductivity. In order for the device to work properly the photon energy of the light must be less than the binding energy (or energy gap) of the cooper pairs. This relation is given by the formula below:
hv<2Δ {1}
Where h is Planck's constant, v is the frequency of light, and 2Δ is the energy gap of the superconductor. The energy gap of the superconductor can be found from Mattis-Bardeen 4!.
2Δ=8 k T {2}
Where k is Boltzman's constant, and T is the critical temperature of the superconducting material. High critical temperature Thallium compounds have critical temperatures around 128 Kelvin. Plugging this into equations {1} and {2}, the operation of the device is limited to light with a wavelength around 14 microns.
The attenuation of light in silica glass fiber (the most common material for long haul fibers) can be calculated from the formula below.
α=Ae.sup.-a/λ +B/λ.sup.4 { 3}
Where α is the attenuation; A, a, and B are constants that are material dependent. λ is the wavelength. The attenuation of 14 micron light in silica glass fiber is approximately 7.32×10 10 dB per km using formula {3} and data from reference 5!. Therefor, applicant has found that the attenuation of 14 micron light in glass fiber is to high to be useful for telecommunication. Modern telecommunication systems are optimized for wavelengths around 1.3 or 1.55 microns and have attenuation around 0.15 dB per km. Unfortunately, light at these wavelengths (i.e. at these higher photon energies) are not compatible with the devices described in the Puzey and Hed Patents. The present invention to be described hereinafter provides a solution to this problem which has remained unsolved since as long ago as December 1988, the filing date of the '042 Hed patent.
SUMMARY OF THE INVENTION
The present invention provides an apparatus and method for the modulation of light. A layer of superconducting material is placed in the optical path of a light source. The light source emits light with a wavelength which in a preferred embodiment is long enough that the energy of the individual photons is less than the superconducting gap of the superconductor. At least a portion of the superconducting layer is then switched between a substantially non-transparent superconducting state and a partially transparent non-superconducting state by predetermined means. The optical pulses transmitted through the portion of the superconducting layer are then converted from the original wavelength to a different wavelength, a shorter wavelength in the preferred embodiment, by a frequency converting device. The shorter wavelength in the preferred embodiment has been chosen to allow an optical fiber to efficiently carry the optical pulses without significant attenuation or dispersion.
In a specific embodiment of the present invention, the predetermined switching means is designed for switching a particular portion of the superconducting layer between its superconducting and nonsuperconducting states using a modulating circuit that intermittently raises the current density in the particular portion above the critical current density of the superconducting material, or raises the magnetic field of the portion above the critical field of the superconducting material, or raises the temperature of the portion above the critical temperature of the superconducting material. The frequency converting device can be a parametric amplifier, parametric oscillator, Nth harmonic generator, four wave mixer, frequency upconverter, or any other frequency converting device. Means for keeping the superconducting layer below its critical temperature can be provided by placing the device in a dewar where at least a portion of the dewar is transparent to the longer wavelength and the dewar is actively cooled by a cryogenic refrigerator.
The present invention may also include certain other features described below. The present invention can include an optical fiber, optically coupled to the frequency converting device to conduct the optical pulses away from the device, for example to a receiver, optical demultiplexer, or other useful device. The present invention can include a number of fiber optic links used to provide input data for the modulating circuit. This is useful because glass optical fibers conduct less heat than metal electrical wires. Alternatively, free space optical links may be used to provide data to the modulating circuit, eliminating a heat conducting path into the dewar all together.
It is an object of the present invention to provide an improved light modulation device which increases the range of wavelengths which can be modulated at an increased rate.
It is another object of the present invention to increase the rate at which data bits can be transmitted on a fiber optic link.
It is another object of the present invention to create high speed optical pulses that are not limited to wavelengths with photon energies lower than the superconducting gap of the superconducting material.
It is an object of the present invention to reduce the amount of heat introduced by incoming data sent to the modulating circuit.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a prior art light modulation device employing superconducting material.
FIG. 2 is a diagrammatic illustration of a light modulating system designed in accordance with the present invention and employing a superconducting layer and frequency converting device to modulate light.
FIGS. 2A and 2B are diagrammatic illustrations of modified light modulating systems designed in accordance with the present invention;
FIGS. 3A-3H are detailed enlarged, not to scale diagrammatic illustrations of one embodiment of the superconducting layer shown in FIG. 2.
FIGS. 4A-4H are detailed enlarged, not to scale diagrammatic illustrations of an alternative embodiment of the superconducting layer shown in FIG. 2.
FIG. 5 is a diagrammatic illustration of an alternative embodiment for the superconducting layer.
FIGS. 6A and 6B are diagrammatic illustrations of still other alternative embodiments of the superconducting layer.
DETAILED DESCRIPTION
Turning to the drawings, attention is immediately directed to FIG. 2, inasmuch as FIG. 1 was discussed above. FIG. 2 shows a light modulation system 10' designed in accordance with one embodiment of the present invention. This system includes most of the components described above in conjunction with FIG. 1 (designated by the same reference numbers primed) plus additional components to be described hereafter. With particular regard to the superconducting arrangement 14', as stated in the Puzey patent electrical current of a certain minimum critical level can be used to switch superconducting arrangement 14' from its superconducting state to the normal state. Removing the electrical current allows arrangement 14' to return to its superconducting state. When the current is below the critical current, the arrangement 14' is in the superconducting state and the optical output 20' is zero because of the 100% reflectance. When the current is above the critical current the material is in the normal state and the optical output 20' is non-zero, that is some measurable level. Thus electrical current pulses can be used to amplitude modulate the light from an optical source 13'. Note that this modulator has the ideal extinction ratio of zero.
Still referring to FIG. 2, in system 10', a plurality of fiber optic transmitters 31 and 32 are arranged to transmit light pulses in parallel to a plurality of receivers 35 and 36 through individual optical fibers 33 and 34, see Van Zehgbroeck 6!. The optical transmitters 31 and 32 may be current modulated laser diodes or LEDs. The receivers 35 and 36 may be MSM (metal semiconductor metal) detectors. The electrical data from the signals are then read in parallel and serialized via a high speed shift register 16'. The shift register is made from Josephson Junction circuitry, see Martens et. al. 7!. A light source 13' is used to generate light which is then amplitude modulated by arrangement or device 14' under the control of the serialized signals from the shift register 16'. Electrical energy is supplied to the light source 13' by a power supply 15'. The light source 13' may be an LED, laser, etc., as is commonly known in the art. The modulating device 14' will be described in more detail later.
The optical pulses 20' from the modulating device 14' enter a frequency converting device 41 which replicates the incoming pulses 20' in a different frequency of light 42 in accordance with one feature of the present invention. The frequency converting device 41 may be a parametric amplifier, parametric oscillator, Nth harmonic generator, four wave mixer, frequency upconverter, etc., some of the principles of which are described in Yariv 8! and Saleh and Teich 9!. The frequency converting device 41 should be made from material that is transparent at the wavelength of the modulated light 20' and the desired wavelength of the outgoing pulses 42, and has a high nonlinear conversion efficiency. The incoming pulses 20' are preferably on the order of 14 microns so as to be compatible with superconducting device 14'. The outgoing pulses 42 are on the order of about 0.5 to 2 microns, preferably on the order of 1.3 or 1.5 microns so as to be compatible with silica glass fibers. Suitable materials for the frequency converting device 41 are GaAs, ZnGeP 2 , AgGaSe 2 , Tl 3 AsSe 3 , CdSe, AgGaS 2 , Ag 3 AsS 3 . These new pulses 42 then enter an optical fiber 25' which carries the pulses and is typically made of silica glass. The pulses 44 exiting the fiber are then received by an optical receiver 45. By way of illustration and not limitation, the optical receiver 45 may be a high speed amorphous silicon detector or an all optical demultiplexer and a plurality of low speed detectors. Such techniques have resulted in 100 Gb/s receiver capability, see Ronson et. al. 10!.
A dewar 22' is used in accordance with another feature of the invention to thermally isolate the device 14' and shift register 16' from the outside room temperature. The dewar 22' must be at least partially transparent to the optical energy 20' or have a window that is substantially transparent to the optical energy 20'. A second window could be used to direct pulses to detectors 35 and 36 in lieu of optical fibers 33 and 34 which extend into the dewar or the dewar could be entirely transparent. A cryogenic cooler 26' is used to keep the temperature in the dewar below the critical temperature. The cryogenic cooler may be a sterling cycle refrigerator, Gifford-McMahon refrigerator, tank of liquid nitrogen, etc.
FIGS. 3A-3H show an embodiment of the superconducting arrangement 14'. The modulator 14' is made by depositing a thin superconducting layer 50 on a transparent or partially transparent substrate 49 such as silicon or diamond 11!. A film thickness of 480 angstroms transmits 6% of the incident light 3!. The critical current of the film depends on the product of the width, thickness, and critical current density. For a 480 angstrom thick layer with a 100 micron bridge width and a critical current density of 10,000 Amps per square centimeter the critical current would be 480 micro Amps. This switch current would lead to dissipative heating of about 96 nW for the same bridge 100 microns long with a normal resistivity of 200 micro Ohms per centimeter. The switching speed of the film is limited by Abrikosov vortices nucleation. The modulation speed is given by 12!
t.sub.s-n =3t.sub.D (W/2Ω)(I.sub.c /I).sup.2, {4}
where t s-n is the superconducting to normal switching time, t D is the order parameter relaxation time, W is the bridge width, Ω is the depairing ratio, I c is the critical current, I is the switching current. Kozyrev estimates t s-n to be on the order of a picosecond for a 70 micron bridge. The FWHM spectral width of a transform limited pulse is the reciprocal of the FWHM temporal width. For a pulse width of about a ps this gives a spectral width of a nanometer or so.
Still referring to FIGS. 3A-3H, substrate 49 which is at least partially transparent to the optical pulses 20' is used to support the thin film of superconducting material 50 which is H shaped so as to include legs 50a and a bridge 50b. At the same time, segments 49a of substrate 49 remain exposed in FIG. 3C. A dielectric layer 51 is used to electrically isolate the superconducting layer 50 from a reflective layer 52 which covers segments 49a along with most of layer 51 as best seen in FIGS. 3G and 3H. A conducting layer 53 which is elongated in configuration is placed over and in direct contact with each leg 50A of material 50 and is used to provide electrical contact to the device 14'. The substrate 49 may be made from MgO, silicon, diamond, etc. The superconducting layer 50 may be made from niobium, yttrium, thallium, or mercury based superconductors. Preferably the superconducting layer 50 is made from a superconducting material with a high critical temperature, low normal resistivity, and low critical current density. The dielectric layer 51 may be composed of silicon dioxide, spin on glass, polyimide, etc. The reflective layer 52 is composed of a material that reflects optical energy 20' such as gold, copper, silver, metal, good conductors, etc. The reflective layer 52 prevents light from "leaking" around the superconducting bridge 50b. The conducting layers 53 are used to make a good electrical contact between the shift register 16' and the superconducting layer 50 via leads 54. The conducting layer 53 may be the same material used for the reflecting layer 52. The conducting layer 53 should have low electrical resistance and be substantially unreactive. Gold is a suitable material for both the reflecting layer 52 and conducting layer 53.
Superconducting material only superconducts when the temperature of the material is below a certain temperature (called the critical temperature) and the magnetic field passing through the material is below a certain value (called the critical magnetic field) and the electrical current density passing through the material is below a certain value (called the critical current density). Raising any of these three parameters above the critical value causes the superconductor to enter a non-superconducting state. In the superconducting state the superconducting material 50 is very conductive and thus highly reflective. Electromagnetic energy is reflected in this state. In the non-superconducting state the superconducting material 50 has properties similar to a semiconductor.
FIG. 2, which has been described, illustrates the use of the critical current density to control device 14'. FIGS. 2A and 2B illustrate the use of a critical magnetic field and a critical temperature respectively to control the superconducting device 14'. Referring to FIG. 2A, element 56 is a magnetic coil which is placed in proximity to device 14'. This magnetic coil 56 when provided with electrical current from shift register 16 via leads 54 raises the magnetic field above the critical magnetic field of material 50 causing it to enter a non-superconducting state. Removal of the current from shift register 16 allows the material 50 to re-enter a superconducting state. Similarly referring to FIG. 2B, element 57 is a resistor or other heating element placed in close proximity to device 14'. This resistor 57 heats the material 50 above its critical temperature when provided with electrical current from shift register 16 via leads 54. Removal of the current from shift register 16 allows the material 50 to re-enter its superconducting state. In the non-superconducting state electromagnetic energy can be transmitted through the material 50. In the superconducting state material 50 substantially blocks transmission. Thus by placing the superconducting layer 50 in the path of the light from the light source 13' the superconducting layer 50 can be used to control the transmission or reflection of light under the influence of the electrical signals from the shift register 16'. Recall that light is an electromagnetic wave.
An alternative embodiment of the modulating device 14' is shown in FIGS. 4A-4H. A substrate 49' that is substantially opaque to the optical energy 20' is used to support H shaped superconducting layer 50. Substrate 49' may be either highly reflective or absorptive. The substrate 49' may be made from sapphire, lanthanum aluminate, gallium arsenide, or the like. The superconducting material may be any superconducting compound such as the niobium, yttrium, thallium or mercury based superconductors. An area 49c of the substrate under the bridge 50b of superconducting material 50 is at least partially removed to allow optical energy 20' to be transmitted through this area 49c. The substrate material may be removed by ion milling, chemical etching, drilling, etc. A conducting layer 53 is used to provide a low resistance electrical contact between the legs 50a of superconducting layer 50 and the shift register 16' as before.
Returning to FIG. 2, the addition of the frequency converting device 41 allows the present system to overcome the problem of large attenuation described above. A parametric amplifier as device 41 can be used to take the high speed pulses 20' at 14 microns and convert them to high speed pulses 42 at a wavelength with lower attenuation and dispersion characteristics (such as 1.3 microns or 1.55 microns). Parametric amplifiers are capable of reproducing even femtosecond pulses. Other devices may be used to perform this frequency conversion as mentioned earlier.
Using the fiber optic arrangement (31, 32, 33, 34, 35, 36) to communicate signals to be multiplexed reduces heat loss as glass does not conduct as much heat into the dewar as copper electrical wires would. In addition, the fiber optic arrangement has better bandwidth, lower crosstalk, and avoids ground-level feed through. An alternative embodiment that eliminates the optical fibers 33 and 34 is also advantageous. A free space optical communication link is established through the transparent dewar (or a transparent window of the dewar). This eliminates heat loss because there is no physical link to carry heat into the dewar. A vertical cavity surface emitting laser (VCSEL) array and charged coupled device (CCD) array would be especially desirable in this type of arrangement.
Returning to FIGS. 3A-3H and 4A-4H the "H" configuration of the superconducting layer 50 provides several advantages. The two legs 50a of the H shape allow for low resistance electrical contact with the shift register 16'. The narrower bridge 50b part of the H allows this part of the superconducting layer to switch faster. The switching speed is linearly related to the width of the bridge as shown by equation {4}. In addition, the narrower bridge reduces the amount of current required to switch the switch to its partially transparent non-superconducting state. This reduces the dissipative heating in the switch.
A more detailed explanation of the current flow through the modulating device 14' is given below. The following dimensions concern the superconducting layer 50.
W1 is the width of the first contact segment 50a.
L1 is the length of the first contact segment 50a.
T1 is the thickness of the superconducting thin film in the first contact segment 50a.
W2 is the width of the light impinging segment 50b.
L2 is the length of the light impinging segment 50b.
T2 is the thickness of the superconducting thin film in the light impinging segment 50b.
W3 is the width of the second contact segment 50a.
L3 is the length of the second contact segment 50a.
T3 is the thickness of the superconducting thin film in the second contact segment 50a.
A good conductor (such as gold) is deposited on the surface of the first and second contact segments 50a. The layer of gold should at least partially cover the surface area of the superconductor defined by (W1×L1) for the first contact segment and (W3×L3) for the second contact segment. This provides a low resistance contact to the superconducting layer.
The critical current density J is defined by the electrical current I flowing through a cross sectional area (W1×L1) A. Initially the current flows substantially vertically through the area defined by the gold-superconductor contact. Then the current travels substantially in a horizontal direction through a cross section of area (W1×T1). The current then enters the light impinging segment 50b. In at least one embodiment the width w2 of the cross sectional area of the light impinging segment 50b is substantially smaller than the width w1 of the contact segment 50a and the thickness of the films are the same (T1=T2). Thus the cross sectional area A in the light impinging segment 50b (W2×T2) is smaller and since I is conserved J increases. This increase in J is due to the restriction of the cross sectional area and causes the light impinging segment to enter its non-superconducting state at a lower electrical current than the contact segments. The electrical current then moves into the second contact segment traveling substantially in a horizontal direction through a cross sectional area (W3×T3). The current then moves substantially in a vertical direction into the gold through the area where the gold and superconductor are in contact. This area at least partially covers (W3×L3).
In addition, the present system is compatible with wave division multiplexing (WDM) and soliton transmission.
Another alternative embodiment of the present invention uses different shapes in the light impinging section of layer 50 to allow for discrete regions to switch. An example of this is shown in FIG. 5 which illustrates a modified H shaped configuration 50'. Here the legs of the H shape 50a' serve as contact areas in the same manner as legs 50a. The bridge 50b' is divided into discrete sections 1, 2 and 3, as shown. This allows amplitude shift keying (ASK). ASK allows a single pulse to carry multiple bits of information. By way of illustration and not limitation, when the electrical current passing through the superconducting layer is low, the light output is zero and this can be used to represent the bit string "00". Notice that section 1 has the most restricted width and therefore constricts the electrical current to a smaller cross sectional area increasing the critical current density in this region for a given amount of electrical current. The current can then be raised to a level just high enough to cause section 1 (but not the other sections) to enter its non-superconducting state, allowing only the light impinging section 1 to pass light. This small amount of light could be used to represent the bit string "01". An even higher current could cause section 2 and section 1 to enter its non-superconducting state. Then only light impinging section 1 and 2 would pass light. This greater amount of light could be used to represent the binary string "10". Finally an even greater current could be used to cause section 3 to enter its non-superconducting state, preferably this current is not high enough to cause section 50a' (the contact section) to switch. Light would then pass through sections 1, 2, and 3 which could be used to represent the binary string "11". Thus current pulses with different magnitude can be used to create light pulses with different magnitude.
Yet another alternative embodiment of the present invention uses different shapes in the light impinging segment to allow for continuous regions to switch, examples of which are shown in FIGS. 6A and 6B. This allows analog control of the light amplitude sent. It can be seen from FIGS. 6A and 6B that the amount of area in section B that is in its nonsuperconducting state increases with an increase in the current passing through the superconducting layer. Thus the amount of light allowed to pass through the superconducting layer is proportional to the current passing through the superconducting layer and can be varied in a continuous or analog manner.
REFERENCES
1. Collins, R. T. et.al. "Infrared Studies of the Normal and Superconducting States of YBa 2 Cu 3 O 7-x ." IBM Journal of RES.&DEV. vol.33, no.3, May 1989, pgs 238-244.
2. Schlesinger, Z. et.al. "Infrared Studies of the Superconducting Energy Gap and Normal-State Dynamics of the high-T c Superconductor YBa 2 Cu 3 O 7 ." Physical Review B, vol. 41, no. 16, Jun. 1, 1990, pgs 11237-11259.
3. Tanner, D. B. "Far-Infrared Transmittance and Reflectance Studies of Oriented YBa 2 Cu 3 O 7-d ." Physical Review B, vol. 43, no. 13, May 1, 1991, pgs 10383-10389.
4. Mattis, D. C., Bardeen J. Phys Rev 111, 412 (1958).
5. Lines, M. E., Nassau K. "calculations of scattering loss and dispersion related parameters for ultralow-loss optical fibers." Optical Engineering vol. 25 no.4, April 1986, Pgs 602-607.
6. Van Zoeghbroeck, B. "Optical Data Communication between Josephson-Junction Circuits and Room-Temperature Electronics." IEEE Transactions on Applied Superconductivity, Vol.3, No. 1, March 1993, pgs 2881-2884.
7. Martens, Jon S. et. al. "High-Temperature superconducting shift registers operating at up to 100 Ghz." IEEE Journal of Solid State Circuits, Vol. 29, No. 1, January 1994, pgs 56-62.
8. Yariv, A. Optical Electronics, 4th edition, chapter 8, HRW press 1991.
9. Saleh & Teich, Photonics, chapter 19.
10. Ronson, K. et.al. "Self-Timed Integrated-Optical Serial-to-Parallel Converter for 100 Gbit/s Time Demultiplexing.", IEEE Photonics Technology Letters, Vol. 6 No. 10, October 1994, pgs 1228-1231.
11. Harshavardhan, K. S. "High T c Thin Films Deposited by PLD onto Technologically important Substrates." AIP Conference Proceedings 288 New York, AIP Press, 1994, pgs 607-612.
12. Kozyrev, A. B. "Fast Current S-N Switching in YBa 2 Cu 3 O 7-x Films and It's Application to an Amplitude Modulation of Microwave Signal." Sverkhprovodimost April 1993, pgs 655-667. | A method and apparatus for modulating light, wherein a light source provides light of a certain wavelength to be modulated. A light modulating device is placed in the optical path of the light source. The resulting optical pulses transmitted through the light modulating device are converted from the original wavelength to a lower wavelength by a frequency converting device. |
FIELD OF THE INVENTION
[0001] This invention relates generally to a treatment for scoliosis and more specifically to the instruments, implants, distracting trial spacers, and surgical methodology used in the treatment and correction of scoliosis.
BACKGROUND OF THE INVENTION
[0002] The bones and connective tissue of an adult human spinal column consists of more than 20 discrete bones. These more than 20 bones are anatomically categorized as being members of one of four classifications: cervical, thoracic, lumbar, or sacral. They are coupled sequentially to one another by tri-joint complexes that consist of an anterior intervertebral disc and the two posterior facet joints. The anterior intervertebral discs of adjacent bones are cushioning cartilage spacers.
[0003] The spinal column of bones is highly complex in that it includes these 20 bones coupled to one another (and others), and it houses and protects critical elements of the nervous system having innumerable peripheral nerves and circulatory bodies in close proximity. In spite of these complications, the spine is a highly flexible structure, capable of a high degree of curvature and twist in nearly every direction.
[0004] Genetic, congenital and/or developmental irregularities are the principle causes that can result in spinal pathologies in which the natural curvature of the spine lost. Scoliosis is a very common one of these types of irregularities, resulting in a sequential misalignment of the bones and intervertebral discs of the spine. Major causes of scoliosis are idiopathic (i.e., unknown cause), congenital developmental anomalies and neuromuscular disorders such as cerebral palsy. The misalignment usually manifests itself in an asymmetry of the vertebral bodies, such that, over a sequence of spinal bones, the spine twists and/or bends to one side. In severe cases, neurological impairment and/or physiological disability may result.
[0005] The present surgical technique for treating scoliosis (as well as other spinal conditions) includes the implantation of a plurality of hooks and/or screws into the spinal bones, connecting rods to these elements, physically bracing the bones into the desired positions, and permitting the bones to fuse across the entire assembly. This immobilization often requires anterior plates, rods and screws and posterior rods, hooks and/or screws. Alternatively, spacer elements are positioned between the sequential bones, which spacers are often designed to permit fusion of the bone into the matrix of the spacer from either end, hastening the necessary rigidity of the developing bone structure. Spacers allow bone fusion to grow into or around them. There are two classes of intervertebral spacers: horizontal cages such as the BAK™ and Ray cages, as described and set forth in exemplary U.S. Pat. Nos. 5,015,247 to Michelson and 5,026,373 to Ray et al., respectively, and vertical cages such the Harms cages, as described and set forth in exemplary U.S. Pat. No. 4,820,305.
[0006] Similar techniques have been employed in other spinal infirmities, including collapsed disc spaces (failure of the intervertebral disc), traumatic fractures, and other degenerative disorders. While the present invention has many applications, such applications include the treatment of any spinal disorder in which the space between vertebral bones needs to be surgically separated (the bones distracted), realigned and then fused to one another.
[0007] A variety of systems have been disclosed in the art which achieve immobilization and/or fusion of adjacent bones by implanting artificial assemblies in or on the spinal column. The region of the back that needs to be immobilized, as well as the individual variations in anatomy, determine the appropriate surgical protocol and implantation assembly. With respect to the failure of the intervertebral disc, and the insertion of implants and/or height restorative devices, several methods and devices have been disclosed in the prior art.
[0008] Restoring the appropriate height and orientation of the vertebral bones and the intervertebral space is the first step in the surgical strategy for correcting this condition. Once this is achieved, one class of surgical implantation procedures involves positioning a device into the intervening space. This may be done through a posterior approach, a lateral approach, or an anterior approach. Various implant devices for this purpose include femoral ring allograft, cylindrical metallic devices (i.e., cages), and metal mesh structures that may be filled with suitable bone graft materials. Some of these implant devices are only suitable for one direction of approach to the spine. All of these devices, however, are provided with the intention that the adjacent bones will, once restored to their appropriate alignment and separation, then grow together across the space and fuse together (or at least fuse into the device implanted between the bones).
[0009] Most recently, the development of non-fusion implant devices, which purport to permit continued natural movement in the tri-joint complex have provided great promise. The instrumentation and methods for the implantation of these non-fusion devices, as well as the implantation of the fusion devices catalogued previously, therefore should integrate the functions of restoring proper anatomical spacing and easy insertion of the selected device into the formed volume.
[0010] It is, therefore, an object of the present invention to provide a new and novel treatment for scoliosis, as well as for the treatment of spinal pathologies in general.
[0011] It is, correspondingly, another object of the present invention to provide an intervertebral distraction trial tool which more accurately and easily separates collapsed intervertebral spaces.
[0012] It is further an object of the present invention to provide an intervertebral distraction trial tool which more can be used to correct scoliosis and/or restore normal alignment to the spine.
[0013] It is further an object of the present invention to provide an instrument that proficiently and simply manages the insertion, rotation, and removal of the intervertebral distraction trial tools.
[0014] It is further an object of the present invention to provide an implantable spacer device that permits more anatomically appropriate and rapidly osteogenic fusion across the intervertebral space.
[0015] Other objects of the present invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.
SUMMARY OF THE INVENTION
[0016] The present invention is directed to a method of treatment of scoliosis and other spinal disorders. This method of treatment further includes several new and novel instruments, implantable trial distraction elements, and intervertebral spacer implants. Inasmuch as the description of the new and novel method cannot be complete without a description of each of these integral members, the following includes ample explanation of these elements as well as description of the surgical techniques.
[0017] First, the patient spine is exposed through an anterior approach (i.e., the surgeon creates an access hole which permits direct interaction with the anterior and/or anterio-lateral portion of the intervertebral bodies). In the case of scoliosis, as well as in other disorders in which the intervertebral space requires distraction and/or repositioning, the surgeon removes the intervertebral disc material, usually leaving some portion of the annulus (the cylindrical weave of fibrous tissue which normally surrounds and constrains the softer cartilage cushion of the disc material). The surgeon then, in succession, inserts a series of intervertebral trial spacers of defined width. Each of the series of spacers is of a progressively wider thickness, resulting in the continual widening of the space until restoration of the proper disc height has been achieved. Proper disc height restoration is determined by surgical experience, and by observation of the annulus. (Often, the tightening of the annulus indicates that the proper disc height has been reached, inasmuch as the annulus is much less likely to be distorted by the same disruption that caused the intervertebral disc to collapse in the first place.)
[0018] More particularly, with respect to the specific instruments disclosed herein, a series of solid trial spacer elements and an instrument for their insertion and removal is now provided. Each trial spacer is a generally cylindrical disc having a deep annular groove at its midpoint, which forms a central trunk and radial flanges at each end of the trunk. Stated alternatively, two cylindrical upper and lower halves of the disc are held in a closely coaxial spaced apart association by the central trunk, which forms a coaxial bridge between the upper and lower halves. The annular groove is particularly useful for holding the spacer using the spacer insertion instrument of the invention, described below, in that the holding end of the insertion instrument fits within the groove.
[0019] A variety of features of embodiments of the trial spacer elements are disclosed. In some embodiments, such as the first and second embodiments described below, support portions (the portions that are in contact with the adjacent vertebral bodies when the spacer is disposed between the bodies) of the top and bottom surfaces are parallel. Spacers having this feature are generally described herein as “constant thickness” trial spacers. In other embodiments, such as the third and fourth embodiments described below, the support portions are not parallel, providing an overall taper to the spacer at an angle. Spacers having this feature are generally described herein as “tapered thickness” trial spacers. The tapered thickness trial spacers are particularly useful for treating scoliosis, as described below.
[0020] Other features of embodiments of the trial spacer elements include beveled flanges and non-parallel annular groove walls. More specifically, in some embodiments, such as the second and fourth embodiments described below, the flanges are radially beveled in that an outer edge of the top surface of the disc is tapered toward an outer edge of the bottom surface of the disc. In other embodiments, such as the first and third embodiments described below, the flanges are not radially beveled in this manner. The radial beveling feature can be particularly useful for easing the insertion of the spacer in between collapsed vertebral bodies, as described below. Further, in some embodiments, such as the first and third embodiments described below, the walls of the annular groove are parallel, such that the floor of the groove is as wide as the opening of the groove. In other embodiments, such as the second and fourth embodiments described below, the walls of the annular groove are tapered toward one another with the increasing depth of the groove, such that the floor of the groove is narrower than the opening of the groove. Each type of annular groove is useful, depending on the particular surgical application and on the particular embodiment of the spacer insertion instrument that is used to insert the spacer.
[0021] Collections of trial spacer elements are provided by the invention. Preferably, each spacer in a particular set maintains the same diameter as the other spacers in the set. (It shall be understood that different collections of spacers may be provided such that the diameter of the selected collection of trial spacers is appropriate for the specific patient being treated.) Also preferably, each spacer in a particular set has a predetermined depth that differs from the depth of the other spacers in the set. The predetermined depth is provided in that while each spacer in the set shares the same annular groove dimensions (so that each can be held by the same insertion instrument), each spacer has a different flange thickness (in sets where the spacers are constant thickness spacers). For sets of tapered thickness spacers, the predetermined maximum depth and predetermined minimum depth (the two depths providing the overall taper) are provided in that while each spacer in the set shares the same annular groove dimensions (so that each can be held by the same insertion instrument), each spacer has a different maximum flange thickness and a different minimum flange thickness. Preferably in sets of tapered thickness spacers, the overall taper angle is the same for each spacer in the set. The usefulness of providing sets of spacers similar in most respects except for the depth dimension will be described in greater detail below.
[0022] With regard to the instrument for the insertion and removal of the trial spacer elements, a first embodiment (particularly useful for inserting constant thickness trial spacers) of a spacer insertion tool includes an elongated shaft and a handle at one end of the shaft. The distal end of the shaft includes semi-circular hook that is adapted to hold a trial spacer within an enclosure formed by the hook. The angle swept out by the hook is slightly greater than 180 degrees, but the inner diameter of the hook is only slightly larger than the central trunk of the trial spacer. Therefore, the trial spacer may be snapped into the enclosure, but maintains complete rotational freedom within its grasp. A loading tool may be provided to assist in the loading and unloading of the trial spacer from the trial spacer insertion instrument of this embodiment. This loading tool comprises a forked hook having two curved tines separated by a notch that engages the shaft of the insertion tool as the tines engage the flanges of the trial spacer, to force the trial spacer into the enclosure. Alternatively and/or additionally, the same device may be utilized to remove the spacer from the enclosure, by reversing the position of the forked hook relative to the insertion tool and the spacer.
[0023] The insertion tool of this embodiment can be used to insert a series of constant thickness trial spacers (some of which may have beveled flange edges for easing the insertion between the collapsed bones and into the space to be distracted). More specifically, thinner trial spacers can initially be inserted into the spacer, followed successively by thicker trial spacers until the desired spacing is achieved. Once the appropriate spacing has been achieved, immobilization of the spine by fixation, fusion, or non-fusion techniques and devices, such as those set forth in co-pending U.S. patent application Ser. No. 09/789,936, 09/______, 09 /______, entitled “An Intervertebral Spacer Device”, “An Intervertebral Spacer Device Having a Wave Washer Force Restoring Element”, and “An Intervertebral Spacer Device Having a Spiral Wave Washer Force Restoring Element”, respectively, as well as U.S. Pat. No. 5,989,291, entitled “An Intervertebral Spacer Device”, each of which has been assigned to the same assignee as this present invention, the specifications of which are all fully incorporated herein by reference, may be desirable.
[0024] While simple distraction to a constant height across the intervertebral space is appropriate for standard disc compression pathologies, in the case of scoliosis, simple constant thickness distraction is insufficient to remediate the pathological condition. What is necessary is the distraction of the sequence of spaces, each to an appropriate angle and height, such that the overall spinal configuration is anatomically correct. Tapered trial spacers, such as those disclosed in the present application, are the first such distraction tools to provide such a tailored correction of the misangulation of the spinal bones.
[0025] More particularly, the surgeon inserts the tapered trial spacers into the intervertebral space (presumably from the anterior, or anterio-lateral, approach) with the narrow edge of the trial spacer forming a wedge and sliding between the adjacent bones. By utilizing either a second or third embodiment of the spacer insertion tool, described more fully below, the surgeon may turn the spacer around its axis within the intervertebral space to find the most appropriate rotational position (corresponding to the most desirable straightening effect on the spinal column). Stated alternatively, each of the tapered trial spacers has an overall wedge shape that generally corresponds to the pathological tapering of the adjacent bones that characterizes scoliosis. By rotating the wedge-shaped spacer after it has been placed between the adjacent bones, the overall disc alignment may be compensated, restoring appropriate anatomical status. It should be understood that additional rotation of the spacer may restore lordosis to the spine, and that over-rotation (if the particular spine is flexible enough) of the spacer would result in a pathological curvature in the opposite direction.
[0026] This second embodiment of the spacer insertion tool includes a handle and an elongated dual shaft, the dual shaft culminating in a trial spacer grasping pincer, rather than the simple hook of the first embodiment. This pincer differs from the hook of the first embodiment of the trial spacer insertion tool described above, inasmuch as the dual shaft includes a fixed shaft and a selectively engagable shaft which, together, form pincer. More specifically, the fixed shaft includes a semicircular hook portion of the pincer at its distal end, having an enclosure within which a trial spacer can be placed. The selectively engagable shaft includes the complementary portion of the pincer, which moves toward the hook portion to grasp and hold the trial spacer when the engagable shaft is engaged, and moves away from the hook portion to release the trial spacer when the engagable shaft is disengaged. (The spacer can be unloaded and loaded when the engagable shaft is disengaged.) The engagement action prevents the spacer from moving relative to the tool, and therefore permits the surgeon to rotate the tapered spacer in between the vertebral bodies (by contrast, the first embodiment of the trial spacer insertion instrument permitted the spacer to rotate freely in the enclosure of the hook). There are alternative insertion and rotating instruments that may be designed, so long as they selectively and alternatingly release or hold the trial spacer securely against rotation (the spacer cannot be permitted to rotate freely if it must be turned in the intervertebral space). The tapered trial spacers themselves can include angle markers that clearly indicate to the surgeon the amount of rotation that was necessary for the correction of the spinal deformity. Such angle markers can also serve as a guide for the implantation of a secondary bone graft (e.g., a femoral ring) or another intervertebral spacer device.
[0027] Once the surgeon has determined the appropriate geometry for the surgical implants via the trial spacers, he or she is ready to immobilize the spine in that position. While multiple ways for immobilizing the spine are disclosed in the prior art, any one of which and others may be suitable for the specific surgical patient's treatment, three alternative ways are herein described.
[0028] First, the trial spacers may be left in the patient while rod fixation apparatuses (anterior or posterior) are mounted to the spine, thereby holding the spine in its desired orientation even after the trial spacers are subsequently removed. Alternatively, surface plating and/or intervertebral cage devices may be mounted to the spine to promote fusion without the need for bulky rod assemblies. (While this approach may seem more surgically desirable, questions regarding the long term stability of these constructs have led some surgeons to chose combinations of rodding and cages.)
[0029] A third approach to immobilizing the corrected spine is to insert a shaped bone graft, or suitably contoured porous metal spacer, into the properly distracted intervertebral space, and either plating or using rod fixation to hold the construct stable as the spine fuses. The insertion of a femoral ring allograft, or porous metal implant, into an intervertebral space is described more fully in co-pending U.S. patent application Ser. No. 09/844,904, and 09/______ respectively entitled “A Porous Interbody Fusion Device Having Integrated Polyaxial Locking Interference Screws”, and “Porous Intervertebral Distraction Spacers”, assigned to the same assignee as the present invention, the specifications of each being fully incorporated herein by reference.
[0030] The tapered trial spacers may also serve as precursors (measuring instruments) for another spacer (e.g., a porous metal spacer), similarly shaped, which is inserted into the intervertebral space by the same instrument.
[0031] Therefore, the present invention, in its many embodiments and components, is directed to a surgical treatment for restoring a proper anatomical spacing and alignment to vertebral bones of a scoliosis patient. In one desired embodiment, the present invention comprises a surgical method, which in a first embodiment, comprises: 1. determining an angular misalignment associated with at least one pair of adjacent vertebral bones; 2. sequentially inserting and removing a series of progressively wider cylindrical spacer elements into the corresponding intervertebral space between said at least one pair of adjacent vertebral bones until the proper anatomical spacing between the pair of adjacent vertebral bones is restored; 3. for each intervertebral space, inserting a diametrically tapered cylindrical spacer element into the intervertebral space between said corresponding pair of adjacent vertebral bones; and 4. rotating said diametrically tapered cylindrical spacer element such that the rotational orientation of the tapered cylindrical spacer element introduces the appropriate counter offset to the intervertebral space of the previously misaligned scoliotic vertebral bones, thereby restoring the proper anatomical alignment of the vertebral bones.
[0032] It shall be understood that each of said progressively wider cylindrical spacer elements includes substantially parallel upper and lower surfaces. The method may also include the additional step of affixing immobilizing instrumentation to the vertebral bones of the patient to hold the restored vertebral bones rigidly in position to facilitate fusion, and positioning bone fusion material adjacent to the restored vertebral bones. It shall be understood that other equivalent (or alternatively efficacious) means for facilitating healing, such as including positioning a non-fusion intervertebral spacer device between the restored vertebral bones so that a proper anatomical motion may be possible.
[0033] The surgical treatment set forth above should be further refined inasmuch with respect to the diametrically tapered cylindrical spacer elements, such that each has a width along its central cylindrical axis substantially equivalent to the axial width of the final cylindrical spacer element utilized in the step of sequentially inserting and removing the series of progressively wider cylindrical spacer elements to restore the proper anatomical spacing between the pair of adjacent vertebral bones.
[0034] It shall be understood that each progressively wider cylindrical spacer element and/or diametrically tapered cylindrical spacer element may comprise solid or porous metal, or a porous or non-porous organic implantable material.
[0035] For clarity, this embodiment of the surgical method includes exposing an intervertebral space between adjacent vertebral bones, distracting the space by sequentially inserting therein and subsequently removing therefrom a plurality of intervertebral spacers, each having a predetermined thickness, the thicknesses incrementally increasing from one spacer to another at an increment acceptable for safely distracting the space to a desired distance, and when adjustment of an angular misalignment of the adjacent vertebral bones is necessary, inserting, and when necessary rotating, in the intervertebral space, at least one diametrically tapered intervertebral spacer having a thickness along its central cylindrical axis sufficient to maintain the desired distance between the adjacent vertebral bones, and a diametrical angle sufficient to reorient the adjacent bones to the desired configuration, when rotational adjustment of the angular misalignment is necessary, rotating said tapered intervertebral spacer within the space until the desired alignment is established.
[0036] In an alternative embodiment, in which porous spacers are utilized, the surgical method of the present invention may comprise: determining an angular misalignment associated with at least one pair of adjacent vertebral bones; sequentially inserting and removing a series of progressively wider cylindrical spacer elements into the corresponding intervertebral space between said at least one pair of adjacent vertebral bones until the proper anatomical spacing between the pair of adjacent vertebral bones is restored; for each intervertebral space, inserting a diametrically tapered cylindrical porous spacer element into the intervertebral space between said corresponding pair of adjacent vertebral bones; rotating said diametrically tapered cylindrical porous spacer element such that the rotational orientation of the tapered cylindrical porous spacer element introduces the appropriate counter offset to the intervertebral space of the previously misaligned scoliotic vertebral bones, thereby restoring the proper anatomical alignment of the vertebral bones; and stabilizing the pair of adjacent vertebral bones to permit infused growth of bone into the diametrically tapered cylindrical porous spacer element.
[0037] As shall be readily understood, in its most basic form, the method of the present invention principally consists of sequentially inserting and removing a series of progressively wider cylindrical spacer elements into the intervertebral space between adjacent vertebral bones until the distance between the vertebral bones is anatomically appropriate.
[0038] More particularly, with respect to the various spacers of the present invention, in its most basic form, the spacers comprise a plurality of sequentially axially wider disc spacer elements, the sequential insertion and removal of which, into an intervertebral space effects a widening of the intervertebral space, such that a desired anatomical spacing of adjacent vertebral bones may be restored. These spacers may include beveled upper and lower circumferential radial edges which facilitate the application of the desired spreading force to the adjacent vertebral bones. For the ease of surgical use, these spacers may each include an engagement locus which couples with a corresponding insertion and removal tool to facilitate the same. This locus comprises an axially medial groove into which said insertion and removal tool can be seated. In two alternative embodiments, the medial groove may comprises a constant width, such that each disc spacer element may rotate freely within the corresponding insertion and removal tool. Alternatively, the groove may be a radially widening groove, such that each disc spacer element may be prevented from rotating freely with respect to the corresponding insertion and removal tool by a clamping action thereof, thereby permitting the controlled rotation of the corresponding disc spacer element within the intervertebral space by manipulation of the insertion and removal tool.
[0039] Tapered spacers, for use in reorienting as well as distracting the alignment of the adjacent vertebral bones may be used. These tapered spacers comprise diametrically tapered upper and lower surfaces. Ideally, for surgeon measurement purposes, each of the disc spacer elements includes at least two relative angle designation marks on at least one of said upper and lower surfaces such that a surgeon user may readily visually determine the rotational angle of said disc spacer element relative to a known reference.
[0040] It shall be understood that the intervertebral spacers each have a unique axial thickness, the thicknesses increasing sequentially from one spacer to another, the increasing thicknesses increasing incrementally, said plurality of spacers being particularly useful for gradually distracting adjacent vertebral bones in an anatomically appropriate manner.
[0041] A critical feature of the present invention is the potential for using porous spacers to distract and potentially reorient the spine, and that the spacers may be implanted permanently into the space between the vertebral bones such that bone ingrowth and solid fusion may occur across the intervertebral space.
[0042] As introduced above, insertion tools are additional components of the present invention. In a first embodiment, the instrument for inserting and removing an intervertebral spacer into and out from an intervertebral space between adjacent vertebral bones, the spacer having a trunk portion having a longitudinal axis and flange portions at each longitudinal end of the trunk, the instrument comprises: a shaft having a proximal end and a distal end; said proximal end including a handle; and a holding structure provided at the distal end, which holding structure includes an enclosure within which the trunk of the spacer may be selectively introduced and maintained therein, the holding structure having an opening leading to the enclosure and through which opening the trunk of the spacer may be selectively passed to when forced therethough. More specifically, the trunk of the spacer has a first width, the opening has a second width which is incrementally smaller than the first width, and the enclosure has a third width which accommodates the first width, such that selective introduction of the trunk through the opening and into the enclosure requires a force to elastically widen the opening such that the trunk may pass through the opening and into the enclosure, the restoration of the opening providing an occlusion which maintains the trunk within the enclosure. As suggested above, the trunk is generally cylindrical and, therefore, the holding structure includes a hook having a curvate extent which forms a partial-circular enclosure, and which curvate extent fits between the flanges when the trunk is maintained within the enclosure.
[0043] In such an embodiment, the intervertebral spacer is selectively snapped into and out of the enclosure through the opening, and such that the intervertebral spacer may be rotationally freely held within the enclosure. In order to snap the spacer into and out of the enclosure, a second element is often utilized. This second helper tool comprises a handle portion at one end, and a bifurcated pair of spaced apart curvate hook-shaped tines at the other. The times have a radius of curvature greater than that of each of the spacers, such that when the first and second elements engage one another (at a fulcrum point at the point of bifurcation of the spaced apart curvate hook-shaped tines and a point between the handle and enclosure ends of the first element), the introduction and removal of the distraction member from the enclosure is facilitated.
[0044] In a second embodiment, which is more suited for the insertion, rotation and removal of the tapered spacers, the tool comprises a shaft having a proximal end and a distal end, said proximal end forming a handle and the distal end forming a spacer member engaging subassembly; said spacer member engaging subassembly including at least one selectively expanding and contracting enclosure into which the central core may be introduced when the engaging subassembly is in the expanded state, and which holds the spacer member so that it cannot move when the selectively expanding and contracting enclosure is rendered into the contracted state; and an actuating mechanism, extending from the proximal end to the distal end, by which the spacer member engaging subassembly may be selectively expanded and contracted. More specifically, the spacer member engaging subassembly comprises a fixed curvate hook defining a portion of the enclosure, a second, selectively advanceable and retractable, portion adjacent the fixed hook portion and said first and second portions forming said selectively expanding and contracting enclosure. Stated alternatively, the selectively expanding and contracting enclosure is formed by at least two members which are maintained in selectively slideable association with each other, at least one of said at least two members including a tapered edge thereof.
[0045] The instrument of this embodiment includes an actuating mechanism including a trigger element disposed in the handle portion, which trigger is actionably coupled to advancing and retracting cams which are coupled to the second portion to advance and retract the second portion in accordance with selective manipulation of the trigger. In more detail, the spacer member engaging subassembly comprises a fixed member and a selectively moveable member which, together, form said selectively expanding and contracting enclosure, and wherein said actuating mechanism comprises a trigger which is mechanically coupled to said selectively moveable member, the mechanical coupling including a rod, a plate having a protrusion, and a lever having a slot, the rod being connected at one end to the selectively moveable member and at another end to the plate, the protrusion engaging the slot, the lever being attached to the trigger, so that when the trigger is engaged, the lever pulls the plate protrusion by the slot, the plate pulls the rod, and the rod moves the selectively moveable member toward the fixed member.
[0046] In a third embodiment, the tool comprises a shaft having a proximal end forming a handle, and a distal end forming a claw subassembly for holding said spacer, said claw subassembly including a first pincer which is fixed at the distal end of the shaft and a second pincer which is selectively rotateable into and out of spacer holding association with said first pincer to hold and release, respectively, the spacer; and an actuation mechanism for selectively rotating the second pincer. The second pincer is rotateably mounted to the shaft and is spring biased away from the first pincer.
[0047] In this embodiment the actuation mechanism comprises a sliding member mounted to the shaft which is selectively moveable in the distal direction by a force sufficient to overcome the bias of the spring, the distally directed movement of the sliding member thereby causing the second pincer to move toward the fixed first pincer, and the subsequent retraction of the sliding member in a proximal direction causes the sliding member to disengage the second pincer and the permits the pincers to separate under the bias of the spring. In order to facilitate this action, the second pincer includes a tapered surface which is engaged by a corresponding surface of the sliding member, said engagement causes the second pincer to rotate relative to the first pincer.
[0048] More specifically, the intervertebral spacer comprises a cylindrical member having an annular groove defining a central axial core portion and a pair of flange portions at opposing ends thereof; and the claw subassembly engages the spacer at the central axial core.
[0049] Stated alternatively, this third embodiment comprises a pair of pincers, a first of this pair being fixed, and a second being coupled to the first in open-biased opposition thereto, and a sliding element which may be selectively translated into and out of engagement with said second pincer to close and open the pair of pincers, respectively. The pair of pincers define an intervertebral spacer grasping enclosure having an access opening through which the intervertebral spacer can be passed for placement into the enclosure when the sliding element is out of engagement with the second pincer, and the spacer is securely maintained between the first and second pincers when the sliding element has been translated into engagement with the second pincer. Ideally, the first and second pincers are mounted at the distal end of a common shaft, and the sliding element is translateable along said shaft; and wherein the second pincer has a portion thereof which is engaged by the sliding element to close the pair of pincers. In addition, the second pincer is mounted to the common shaft by a pivot joint, and the portion of the second pincer which is engaged by the sliding element is a tapered surface, the angle of which tapered surface, when engaged by the sliding element, causes the second pincer to rotate about the pivot joint, closing the first and second pincers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] [0050]FIGS. 1 a - c illustrates a first embodiment of an intervertebral trial spacer of the invention is illustrated in side, top and side cutaway views, respectively.
[0051] [0051]FIG. 1 d illustrates a first set of intervertebral spacers of the invention in a side view.
[0052] [0052]FIGS. 2 a - c illustrate a second embodiment of an intervertebral spacer of the invention in side, top and side cutaway views, respectively.
[0053] [0053]FIG. 2 d illustrates a second set of intervertebral spacers of the invention in a side view.
[0054] [0054]FIGS. 3 a - c illustrate a third embodiment of an intervertebral spacer of the invention in side, top and side cutaway views, respectively.
[0055] [0055]FIG. 3 d illustrates a third set of tapered intervertebral spacers of the invention in a side view.
[0056] [0056]FIGS. 4 a - c illustrate a fourth embodiment of an intervertebral spacer of the invention in side, top and side cutaway views, respectively.
[0057] [0057]FIG. 4 d illustrates a fourth set of tapered intervertebral spacers of the invention in a side view.
[0058] [0058]FIG. 5 a illustrates a first embodiment of a spacer insertion tool 500 of the invention in a side view.
[0059] [0059]FIG. 5 b is a cutaway view of the insertion tool of FIG. 5 a holding the spacer of FIGS. 1 a - c.
[0060] [0060]FIG. 6 a - b illustrates an embodiment of a loading accessory for a spacer insertion tool of the invention in side and top views, respectively.
[0061] [0061]FIG. 6 c shows the loading accessory of FIGS. 6 a - b in operation to load the spacer of FIG. 1 a - c into the spacer insertion tool of FIG. 5 a.
[0062] [0062]FIG. 6 d shows the loading accessory of FIGS. 6 a - b in operation to unload the spacer the spacer insertion tool of FIG. 5 a.
[0063] [0063]FIG. 7 a illustrates another embodiment of a spacer insertion tool of the invention in a side view.
[0064] [0064]FIG. 7 b is a cutaway view of the insertion tool of FIG. 7 a holding the spacer of FIGS. 4 a - c.
[0065] [0065]FIGS. 8 a - b illustrates yet another embodiment of a spacer insertion tool of the invention in open and closed side views, respectively.
[0066] [0066]FIG. 8 c is a cutaway view of the insertion tool of FIGS. 8 a - b holding the spacer of FIGS. 4 a - c.
DETAILED DESCRIPTION OF THE INVENTION
[0067] While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments and methods of implantation are shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while achieving the functions and results of this invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. Like numbers refer to similar features of like elements throughout.
[0068] First, the patient spine is exposed through an anterior approach (i.e. the surgeon creates an access hole which permits direct interaction with the anterior and/or anterio-lateral portion of the intervertebral bodies). In the case of scoliosis, as well as in other disorders in which the intervertebral space requires distraction and/or repositioning, the surgeon removes the intervertebral disc material, usually leaving some portion of the annulus (the cylindrical weave of fibrous tissue which normally surrounds and constrains the softer cartilage cushion of the disc material). The surgeon then, in succession, inserts a series of intervertebral trial spacers of defined width. Each of the series of spacers is of a progressively wider thickness, resulting in the continual widening of the space until restoration of the proper disc height has been achieved. Proper disc height restoration is determined by surgical experience, and by observation of the annulus. (Often, the tightening of the annulus indicates that the proper disc height has been reached, inasmuch as the annulus is much less likely to be distorted by the same disruption that caused the intervertebral disc to collapse in the first place.)
[0069] More particularly, with respect to the specific instruments disclosed herein, a series of solid trial spacer elements and an instrument for their insertion and removal is now provided. Each trial spacer is a generally cylindrical disc having a deep annular groove at its midpoint, which forms a central trunk and radial flanges at each end of the trunk. Stated alternatively, two cylindrical upper and lower halves of the disc are held in a closely coaxial spaced apart association by the central trunk, which forms a coaxial bridge between the upper and lower halves. The annular groove is particularly useful for holding the spacer using the spacer insertion instrument of the invention, described below, in that the holding end of the insertion instrument fits within the groove.
[0070] A variety of features of embodiments of the trial spacer elements are disclosed. In some embodiments, such as the first and second embodiments described below, support portions (the portions that are in contact with the adjacent vertebral bodies when the spacer is disposed between the bodies) of the top and bottom surfaces are parallel. Spacers having this feature are generally described herein as “constant thickness” trial spacers. In other embodiments, such as the third and fourth embodiments described below, the support portions are not parallel, providing an overall taper to the spacer at an angle. Spacers having this feature are generally described herein as “tapered thickness” trial spacers. The tapered thickness trial spacers are particularly useful for treating scoliosis, as described below.
[0071] Other features of embodiments of the trial spacer elements include beveled flanges and non-parallel annular groove walls. More specifically, in some embodiments, such as the second and fourth embodiments described below, the flanges are radially beveled in that an outer edge of the top surface of the disc is tapered toward an outer edge of the bottom surface of the disc. In other embodiments, such as the first and third embodiments described below, the flanges are not radially beveled in this manner. The radial beveling feature can be particularly useful for easing the insertion of the spacer in between collapsed vertebral bodies, as described below. Further, in some embodiments, such as the first and third embodiments described below, the walls of the annular groove are parallel, such that the floor of the groove is as wide as the opening of the groove. In other embodiments, such as the second and fourth embodiments described below, the walls of the annular groove are tapered toward one another with the increasing depth of the groove, such that the floor of the groove is narrower than the opening of the groove. Each type of annular groove is useful, depending on the particular surgical application and on the particular embodiment of the spacer insertion instrument that is used to insert the spacer.
[0072] Collections of trial spacer elements are provided by the invention. Preferably, each spacer in a particular set maintains the same diameter as the other spacers in the set. (It shall be understood that different collections of spacers may be provided such that the diameter of the selected collection of trial spacers is appropriate for the specific patient being treated. For example, the diameters of the trial spacers in a collection that is suitable for use with pediatric patients would be smaller than the diameters of the trial spacers in a collection that is suitable for use with adult patients.) Also preferably, each spacer in a particular set has a predetermined depth that differs from the depth of the other spacers in the set. The predetermined depth is provided in that while each spacer in the set shares the same annular groove dimensions (so that each can be held by the same insertion instrument), each spacer has a different flange thickness (in sets where the spacers are constant thickness spacers). For sets of tapered thickness spacers, the predetermined maximum depth and predetermined minimum depth (the two depths providing the overall taper) are provided in that while each spacer in the set shares the same annular groove dimensions (so that each can be held by the same insertion instrument), each spacer has a different maximum flange thickness and a different minimum flange thickness. Preferably in sets of tapered thickness spacers, the overall taper angle is the same for each spacer in the set. The usefulness of providing sets of spacers similar in most respects except for the depth dimension will be described in greater detail below.
[0073] Referring now to FIGS. 1 a - c, a first embodiment of an intervertebral trial spacer 100 of the invention is illustrated in side, top and side cutaway views, respectively. The spacer 100 is a cylindrical disc with an annular groove 102 that forms a central trunk 103 and radial flanges 104 , 106 at each end of the trunk 102 . In this embodiment, support portions 108 , 110 of the top and bottom surfaces 112 , 114 of the disc are parallel. Further in this embodiment, the walls 120 , 122 of the annular groove 102 are parallel, such that the floor 124 of the groove 102 is as wide as the opening 126 of the groove 102 . Further in this embodiment, the spacer 100 has a central bore 128 .
[0074] Referring now to FIG. 1 d, a set of intervertebral spacers 100 a - l of the invention are illustrated in a side view. Each spacer 100 a - l is formed generally similarly to the intervertebral spacer 100 of FIGS. 1 a - c, except that each spacer 100 a - l has a predetermined depth (denoted by the preferred dimension identified adjacent each spacer) provided in that while each spacer 100 a - l shares the same annular groove dimensions as the other spacers, each spacer 100 a - l has a different flange thickness dimension. For example, the flanges 104 l , 106 l are thicker than the flanges 104 a, 106 a.
[0075] Referring now to FIGS. 2 a - c, a second embodiment of an intervertebral spacer 200 of the invention is illustrated in side, top and side cutaway views, respectively. Similarly to the spacer 100 , the spacer 200 is a cylindrical disc with an annular groove 202 that forms a central trunk 203 and radial flanges 204 , 206 at each end of the trunk 202 . However, in this embodiment, the flanges 204 , 206 are radially tapered in that support portions 208 , 210 of the top and bottom surfaces 212 , 214 of the disc are parallel, while an outer edge 216 of the top surface 212 is tapered toward an outer edge 218 of the bottom surface 214 . Further in this embodiment, in contrast to the spacer 100 , the walls 220 , 222 of the annular groove 202 are tapered toward one another with the increasing depth of the groove 202 , such that the floor 224 of the groove 202 is more narrow than the opening 226 of the groove. Further in this embodiment, the spacer 200 has a central bore 228 .
[0076] Referring now to FIG. 2 d, a set of intervertebral spacers 200 a - l of the invention are illustrated in a side view. Each spacer 200 a - l is formed generally similarly to the intervertebral spacer 200 of FIGS. 2 a - c, except that each spacer 200 a - l has a predetermined depth (denoted by the preferred dimension identified adjacent each spacer) provided in that while each spacer 200 a - l shares the same annular groove dimensions as the other spacers, each spacer 200 a - l has a different flange thickness dimension. For example, the flanges 2041 , 2061 are thicker than the flanges 204 a, 206 a.
[0077] With regard to the instrument for the insertion and removal of the trial spacer elements, a first embodiment (particularly useful for inserting constant thickness trial spacers) of a spacer insertion tool includes an elongated shaft and a handle at one end of the shaft. The distal end of the shaft includes semi-circular hook that is adapted to hold a trial spacer within an enclosure formed by the hook. The angle swept out by the hook is slightly greater than 180 degrees, but the inner diameter of the hook is only slightly larger than the central trunk of the trial spacer. Therefore, the trial spacer may be snapped into the enclosure, but maintains complete rotational freedom within its grasp. A loading tool may be provided to assist in the loading and unloading of the trial spacer from the trial spacer insertion instrument of this embodiment. This loading tool comprises a forked hook having two tines separated by a notch that engages the shaft of the insertion tool as the tines engage the flanges of the trial spacer, to force the trial spacer into the enclosure. Alternatively and/or additionally, the same device may be utilized to remove the spacer from the enclosure, by reversing the position of the forked hook relative to the insertion tool and the spacer.
[0078] Referring now to FIG. 5 a, a first embodiment of a spacer insertion tool 500 of the invention is illustrated in a side view. The insertion tool 500 includes an elongated shaft 502 and a handle 503 at one end of the shaft 502 . At the other end of the shaft 502 , the insertion tool 500 includes a semi-circular hook 504 that is adapted to hold an intervertebral spacer of the invention within an enclosure 506 of the hook 504 . The central trunk of the spacer can be snapped into the enclosure 506 of the hook 504 so that the extent of the hook 504 fits loosely within the annular groove of the spacer and is flanked by the flanges of the spacer. The central trunk of the spacer can also be snapped out of the enclosure 506 .
[0079] In this regard, the hook 504 has an opening 508 that temporarily expands when the central trunk of the spacer is forced through the opening 508 . That is, the outer diameter of the central trunk is greater than the width of the opening 508 , so that the central trunk cannot pass through the opening 508 without force. The application of a force sufficient to cause the opening 508 to expand when confronted with the central trunk causes the central trunk to pass through the opening 508 . After the central trunk has cleared the opening 508 , the opening 508 will contract. The temporary expansion in this embodiment is provided by the hook 504 being formed of a material having a low elasticity and the hook 504 being provided with a stress notch 510 on the extent (preferably located opposite the opening 508 for maximum efficiency) to ease the expansion.
[0080] Once the spacer is loaded into the enclosure, the opening 508 , having contracted back to its resting width, prevents the central trunk from exiting the enclosure radially through the opening, because, as stated above, the outer diameter of the central trunk is greater than the width of the opening 508 . Further, by flanking the extent of the hook 504 , the flanges of the spacer prevent the spacer from exiting the enclosure laterally. The hook 504 therefore holds the spacer loosely in the enclosure so that the spacer can rotate about the cylindrical axis of the central trunk while being held by the hook 504 .
[0081] Referring now to FIG. 5 b, a cutaway view of the insertion tool 500 of FIG. 5 a holding the spacer 100 of FIGS. 1 a - c, shows the extent of the hook 504 in cross-section and fitting within the annular groove of the spacer. It can be seen that to enable the spacer 100 to be loosely held in the enclosure, the width of the extent is smaller than the width of the annular groove, and the depth of the extent is less than the depth of the annular groove if it is desirable for the flanges to fully flank the extent. Preferably, as shown, the outer diameter of the hook 504 is substantially equal to the outer diameter of the spacer 100 .
[0082] Referring now to FIG. 6 a - b, an embodiment of a loading accessory 600 for a spacer insertion tool of the invention is illustrated in side and top views, respectively. The loading accessory 600 can be used to ease the passing of the central trunk of the spacer through the opening of the spacer insertion tool, both for loading the spacer into the enclosure and unloading the spacer from the enclosure. The loading accessory 600 includes an elongated shaft 602 and a forked hook 604 at an end of the shaft 602 . A notch 606 having a base 608 separates the tines 610 , 612 of the forked hook 604 .
[0083] The width of the notch 608 separating the tines 610 , 612 is wide enough to accommodate the width of the hook 504 of the insertion tool 500 and the width of the shaft 502 of the insertion tool 500 , but narrow enough so that the tines 610 , 612 can engage the edges of the flanges of the spacer. Preferably, as shown, the curvature of the tines 608 , 610 follows the curvature of the edges of the flanges.
[0084] Referring now to FIG. 6 c, the loading accessory 600 of FIGS. 6 a - b is shown in operation to load the spacer 100 of FIG. 1 a - c into the spacer insertion tool 500 of FIG. 5 a. Initially, the spacer 100 is positioned adjacent the opening 508 of the insertion tool 500 . Then, the tines 610 , 612 of the loading accessory 600 are passed on either side of the shaft 502 of the insertion tool 500 such that the notch 606 accommodates the shaft 502 and until the base 608 of the notch 606 contacts the shaft 502 . Then, the loading accessory 600 is rotated, using the contact between the shaft 502 and the base 608 as a fulcrum, to cause the tines 610 , 612 to engage the flanges 104 , 106 of the spacer 100 and push them into the enclosure 506 of the tool 500 . Applying a force to the rotation, sufficient to cause the opening 508 of the tool 500 to expand when confronted with the central trunk of the spacer, causes the central trunk to pass through the opening 508 .
[0085] Referring now to FIG. 6 d, the loading accessory 600 of FIGS. 6 a - b is shown in operation to unload the spacer 100 of FIG. 1 a - c from the spacer insertion tool 500 of FIG. 5 a. Initially, with the spacer 100 held by the tool 500 , the tines 610 , 612 of the loading accessory 600 are passed on either side of the shaft 502 of the insertion tool 500 such that the notch 606 accommodates the shaft 502 and until the base 608 of the notch 606 contacts the shaft 502 . Then, the loading accessory 600 is rotated, using the contact between the shaft 502 and the base 608 as a fulcrum, to cause the tines 610 , 612 to engage the flanges 104 , 106 of the spacer 100 and push them out of the enclosure 506 of the tool 500 . Applying a force to the rotation, sufficient to cause the opening 508 of the tool 500 to expand when confronted with the central trunk of the spacer, causes the central trunk to pass through the opening 508 . The width of the notch 606 accommodates the width of the hook 504 as the spacer 100 is being pushed out of the enclosure 506 .
[0086] The insertion tool of this first embodiment can be used to insert a series of constant thickness trial spacers (some of which may have beveled flange edges for easing the insertion between the collapsed bones and into the space to be distracted). More specifically, thinner trial spacers can initially be inserted into the spacer, followed successively by thicker trial spacers until the desired spacing is achieved. Once the appropriate spacing has been achieved, immobilization of the spine by fixation, fusion, or non-fusion techniques and devices, such as those set forth in co-pending U.S. patent application Ser. No. 09/789,936, 09/______, 09 /______, entitled “An Intervertebral Spacer Device”, “An Intervertebral Spacer Device Having a Wave Washer Force Restoring Element”, and “An Intervertebral Spacer Device Having a Spiral Wave Washer Force Restoring Element”, respectively, as well as U.S. Pat. No. 5,989,291, entitled “An Intervertebral Spacer Device”, each of which has been assigned to the same assignee as this present invention, the specifications of which are all fully incorporated herein by reference, may be desirable.
[0087] While simple distraction to a constant height across the intervertebral space is appropriate for standard disc compression pathologies, in the case of scoliosis, simple constant thickness distraction is insufficient to remediate the pathological condition. What is necessary is the distraction of the sequence of spaces, each to an appropriate angle and height, such that the overall spinal configuration is anatomically correct. Tapered trial spacers, such as those disclosed in the present application, are the first such distraction tools to provide such a tailored correction of the misangulation of the spinal bones.
[0088] More particularly, the surgeon inserts the tapered trial spacers into the intervertebral space (presumably from the anterior, or anterio-lateral, approach) with the narrow edge of the trial spacer forming a wedge and sliding between the adjacent bones. By utilizing either a second or third embodiment of the spacer insertion tool, described more fully hereinafter with respect to FIGS. 7 a - c and 8 a - c respectively, the surgeon may turn the spacer around its axis within the intervertebral space to find the most appropriate rotational position (corresponding to the most desirable straightening effect on the spinal column). Stated alternatively, each of the tapered trial spacers has an overall wedge shape that generally corresponds to the pathological tapering of the adjacent bones that characterizes scoliosis. By rotating the wedge-shaped spacer after it has been placed between the adjacent bones, the overall disc alignment may be compensated, restoring appropriate anatomical status. It should be understood that additional rotation of the spacer may restore lordosis to the spine, and that over-rotation (if the particular spine is flexible enough) of the spacer would result in a pathological curvature in the opposite direction.
[0089] Referring now to FIGS. 3 a - c, a third embodiment of an intervertebral spacer 300 of the invention is illustrated in side, top and side cutaway views, respectively. Similarly to the spacer 100 , the spacer 300 is a cylindrical disc with an annular groove 302 that forms a central trunk 303 and radial flanges 304 , 306 at each end of the trunk 303 . However, in this embodiment, support portions 308 , 310 of the top and bottom surfaces 312 , 314 of the disc are not parallel, providing an overall taper to the spacer 300 at an angle. Still, similarly to the spacer 100 , the walls 320 , 322 of the annular groove 302 are parallel, such that the floor 324 of the groove 302 is as wide as the opening 326 of the groove 302 . Further in this embodiment, the spacer 300 has a central bore 328 .
[0090] Referring now to FIG. 3 d, a set of tapered intervertebral spacers 300 a - j of the invention are illustrated in a side view. Each spacer 300 a - j is formed generally similarly to the intervertebral spacer 300 of FIGS. 3 a - c, except that each spacer 300 a - j has a predetermined maximum depth (denoted by the preferred maximum depth dimension identified adjacent each spacer) and a predetermined minimum depth (denoted by the preferred minimum depth dimension identified adjacent each spacer), each provided in that while each spacer 300 a - j shares the same annular groove width dimension as the other spacers, each spacer 300 a - j has a different maximum flange thickness dimension and a different minimum flange thickness dimension. For example, the flanges 304 j, 306 j have a thicker maximum flange thickness dimension and a thicker minimum flange thickness dimension than the flanges 304 a, 306 a.
[0091] Referring now to FIGS. 4 a - c, a fourth embodiment of an intervertebral spacer 400 of the invention is illustrated in side, top and side cutaway views, respectively. Similarly to the spacer 200 , the spacer 400 is a cylindrical disc with an annular groove 402 that forms a central trunk 403 and radial flanges 404 , 406 at each end of the trunk 403 . However, in this embodiment, support portions 408 , 410 of the top and bottom surfaces 412 , 414 of the disc are not parallel. Still, similarly to the spacer 200 , the flanges 404 , 406 are radially tapered in that an outer edge 416 of the top surface 412 is tapered toward an outer edge 418 of the bottom surface 414 . Further in this embodiment, similarly to the spacer 200 , the walls 420 , 422 of the annular groove 402 are tapered toward one another with the increasing depth of the groove 402 , such that the floor 424 of the groove 402 is more narrow than the opening 426 of the groove. Further in this embodiment, the spacer 400 has a central bore 428 .
[0092] Referring now to FIG. 4 d, a set of tapered intervertebral spacers 400 a - j of the invention are illustrated in a side view. Each spacer 400 a - j is formed generally similarly to the intervertebral spacer 400 of FIGS. 4 a - c, except that each spacer 400 a - j has a predetermined maximum depth (denoted by the preferred maximum depth dimension identified adjacent each spacer) and a predetermined minimum depth (denoted by the preferred minimum depth dimension identified adjacent each spacer), each provided in that while each spacer 400 a - j shares the same annular groove width dimension as the other spacers, each spacer 400 a - j has a different maximum flange thickness dimension and a different minimum flange thickness dimension. For example, the flanges 404 j, 406 j have a thicker maximum flange thickness dimension and a thicker minimum flange thickness dimension than the flanges 404 a, 406 a.
[0093] It should understood that the various features of the different embodiments of the intervertebral spacer of the invention discussed above can be used in various combinations and permutations to form the illustrated embodiments and other embodiments of the intervertebral spacer of the invention. In some embodiments, the walls of the annular groove are parallel. In other embodiments, they are not parallel. In some embodiments where they are not parallel, they are tapered toward one another with the increasing depth of the groove. In other embodiments where they are not parallel, they are tapered toward one another with the decreasing depth of the groove. In some embodiments, the support portions of the top and bottom surfaces are parallel. In other embodiments, they are not parallel. In some embodiments, the flanges are radially tapered in that the outer edge of the top surface is tapered toward an outer edge of the bottom surface. In other embodiments, the flanges are not radially tapered. In some embodiments, the spacer has a central bore. In other embodiments, the spacer does not have a central bore.
[0094] It should be understood that while in the illustrated embodiments where spacers in a set have an overall taper, the angle of the overall taper of each spacer in the set is the same as the angle of the overall taper of the other spacers in the set, the invention encompasses a set of spacers in which the angle of the overall taper of each spacer in the set is different than the angle of the overall taper of at least one other spacer in the set.
[0095] It should be understood that while in the illustrated embodiments where the spacer has an overall taper, the angle of the overall taper can be predetermined, such that the maximum flange thickness and the minimum flange thickness can be selected to achieve a desired overall taper angle.
[0096] It should be understood that while in the illustrated embodiments the spacers are shown as having a cylindrical shape, it should be understood that in other embodiment, the spacers can have oval, square, or rectangular cross-sections, or cross-sections of other shapes, provided that any comers are rounded as necessary to prevent damage to surrounding tissue.
[0097] As suggested previously, the insertion, rotation and removal of the tapered trial intervertebral spacers requires an alternate spacer insertion tool. This second embodiment of the spacer insertion tool includes a handle and an elongated dual shaft, the dual shaft culminating in a trial spacer grasping pincer, rather than the simple hook of the first embodiment. This pincer differs from the hook of the first embodiment of the trial spacer insertion tool described above, inasmuch as the dual shaft includes a fixed shaft and a selectively engagable shaft which, together, form pincer. More specifically, the fixed shaft includes a semicircular hook portion of the pincer at its distal end, having an enclosure within which a trial spacer can be placed. The selectively engagable shaft includes the complementary portion of the pincer, which moves toward the hook portion to grasp and hold the trial spacer when the engagable shaft is engaged, and moves away from the hook portion to release the trial spacer when the engagable shaft is disengaged. (The spacer can be unloaded and loaded when the engagable shaft is disengaged.) The engagement action prevents the spacer from moving relative to the tool, and therefore permits the surgeon to rotate the tapered spacer in between the vertebral bodies (by contrast, the first embodiment of the trial spacer insertion instrument permitted the spacer to rotate freely in the enclosure of the hook).
[0098] Referring now to FIG. 7 a, another embodiment of a spacer insertion tool 700 of the invention is illustrated in a side view. The insertion tool 700 includes an elongated shaft 702 and a handle 704 at one end of the shaft 702 . The insertion tool 700 further includes a compression assembly that is adapted to hold an intervertebral spacer of the invention at the other end of the shaft 702 so that the spacer cannot move when held. The insertion tool 700 further includes a release assembly that is adapted to release the spacer from being held.
[0099] The compression assembly includes a semicircular hook 706 at the other end of the shaft 702 and a compression surface 708 adjacent the hook 706 . The hook 706 has an enclosure 709 defined by the extent of the hook 706 and an opening 710 through which the central trunk can pass freely to be placed into the enclosure 709 . That is, the width of the opening 710 is greater than the diameter of the central trunk. When the central trunk is placed within the enclosure 709 , the extent of the hook 706 fits loosely within the annular groove of the spacer.
[0100] The compression assembly further includes a compression trigger 712 mechanically connected to the hook 706 such that as the compression trigger 712 is placed in an engaged position, the hook 706 is pulled toward the compression surface 708 . The mechanical connection includes a rod 714 connected at one end to the hook 706 and at the other end to a plate 716 . A rod 718 protruding from the plate 716 is engaged by a slot 720 in a lever 722 attached to the compression trigger 712 . When the compression trigger 712 is engaged, the rod 714 of the lever 722 pulls the plate 716 by the slot 720 . The plate 716 in turn pulls the rod 714 , which in turn pulls the hook 704 toward the compression surface 708 .
[0101] When the hook 706 is pulled toward the compression surface 708 when the central trunk of the spacer is in the enclosure 709 , the central trunk is compressed within the enclosure 709 between the hook 706 and the compression surface 708 so that the spacer cannot move.
[0102] The release assembly includes a spring 724 biasing the compression trigger 712 to a disengaged position. Therefore, after the compression trigger 712 is released, it moves to the disengaged position. However, so that the central trunk remains compressed within the enclosure even after the compression trigger 712 is released (e.g., so that the surgeon does not need to continue holding the compression trigger 712 to effect the compression), the compression assembly further includes teeth 726 on the rod 714 and corresponding teeth 730 that confront the rod teeth 726 to prevent the rod 714 from retreating, to maintain the compression.
[0103] The release assembly further includes a release trigger 732 that can be engaged to release the rod teeth 726 from the corresponding teeth 730 to allow the rod 714 to return to its rest position, thereby alleviating the compression. More specifically, the release trigger 732 has the corresponding teeth 730 and the release assembly further includes a spring 734 that biases the release trigger 732 toward a position in which the corresponding teeth 730 engage the rod teeth 726 . This arrangement allows the release trigger 732 to be engaged by pressing the release trigger 732 with a force great enough to overcome the bias of the spring 734 , so that the corresponding teeth 730 are disengaged from the rod teeth 726 . Therefore, when the release trigger 732 is pressed, the compression is alleviated, and the central trunk of the spacer can be freely passed through the opening 710 to be taken out of the enclosure 709 .
[0104] Referring now to FIG. 7 b, a cutaway view of the insertion tool 700 of FIG. 7 a holding the spacer 400 of FIGS. 4 a - c shows the extent of the hook 706 in cross-section and fitting within the annular groove of the spacer as the spacer is compressed between the compression surface 708 and the hook 706 . It can be seen that the width of the extent of the hook 706 is smaller than the width of the annular groove, and the depth of the extent is less than the depth of the annular groove if it is desirable for the flanges to fully flank the extent. Preferably, as shown, the outer diameter of the hook 706 is substantially equal to the outer diameter of the spacer 400 .
[0105] Referring now to FIGS. 8 a - b, yet another embodiment of a spacer insertion tool 800 of the invention is illustrated in open and closed side views, respectively. The insertion tool 800 includes an elongated shaft 802 and a handle 804 at one end of the shaft 802 . The insertion tool 800 further includes a compression assembly that is adapted to hold an intervertebral spacer of the invention at the other end of the shaft 802 so that the spacer cannot move when held. The insertion tool 800 further includes a release assembly that is adapted to release the spacer from being held.
[0106] The compression assembly includes a claw 806 at the other end of the shaft 802 having opposing pincers 807 a, 807 b, each providing one of opposing compression surfaces 808 a, 808 b . The claw 806 has an enclosure 809 defined by the extents of the pincers 807 a, 807 b and an opening 810 through which the central trunk can pass freely to be placed into the enclosure 809 when the claw 806 is open (i.e., when the opposing pincers 807 a, 807 b are separated). That is, the width of the opening 810 is greater than the diameter of the central trunk when the claw 806 is open. When the central trunk is placed within the enclosure 809 , the extents of the pincers 807 a, 807 b fit loosely within the annular groove of the spacer.
[0107] The compression assembly further includes a compression slide 812 that when moved to an engaged position (here, a forward position shown in FIG. 8 b ) closes the claw 806 . The closure of the claw 806 by the compression slide 812 is effected as follows. One of the pincers 807 a is in a fixed position relative to the elongated shaft 802 whereas the other pincer 807 b is adapted to rotate about an axis transverse to the shaft 802 . In this embodiment, the rotation is provided by a pin 813 passing through each pincer at a rotation point along the transverse axis. One position of the movable pincer 807 b along the rotation path (shown in FIG. 8 a ) defines the opened claw 806 in that the pincers 807 a, 807 b are separated. Another position of the movable pincer 807 b along the rotation path (shown in FIG. 8 b ) defines the closed claw 806 in that the pincers 807 a , 807 b are brought together. When the pincers 807 a, 807 b are separated, an engagement surface 814 of the movable pincer 807 b is placed in an available compression path of an engagement surface 816 of the compression slide 812 . The engagement surface 814 is tapered so that when the compression slide 812 is moved to the engaged, the engagement surface 816 of the compression slide 812 moves along the available compression path and engages the tapered surface 814 to push the surface 814 aside and thereby cause a rotation of the movable pincer 807 b to the position defining the closed claw 806 .
[0108] When the pincers 807 a, 807 b are thereby brought together to close the claw 806 when the central trunk of the spacer is in the enclosure 809 , the compression surfaces 808 a, 808 b come to bear on the central trunk to compress it within the enclosure 809 so that the spacer cannot move.
[0109] The release assembly includes a spring 818 biasing the movable pincer 807 b to the rotation path position defining the open claw 806 . Therefore, when the compression slide 812 is moved to a disengaged position (here, a backward position), the engagement surface 816 of the compression slide 812 moves along an available release path (here, a backtracking along the compression path) and frees the engagement surface 814 of the movable pincer 807 b to allow the engagement surface 814 to return to a place in the available compression path by the biasing action of the spring 818 . When the claw 806 is open, the compression is alleviated and the central trunk of the spacer can be freely passed through the opening 810 to be taken out of the enclosure 809 .
[0110] The release assembly further includes at least one barrier 820 a, 820 b that limits the biasing action of the spring 818 by preventing the movable pincer 807 b from rotating beyond the position that places the engagement surface 814 in the available compression path. In this embodiment, confrontation surfaces 822 a, 822 b on the movable pincer 807 b confront the barriers 820 a, 820 b as the pincer 807 b rotates toward the rotation path position defining the open claw 806 under the biasing force of the spring 818 . When the engagement surface 814 is returned to the place in the available compression path, the barriers 820 a, 820 b prevent the confrontation surfaces 822 a, 822 b from advancing further. The spring 818 and the barriers 820 a, 820 b maintain the movable pincer 807 b in this position until the compression slide 812 is advanced toward the engaged position by a force great enough to overcome the biasing force of the spring 818 .
[0111] Referring now to FIG. 8 c, a cutaway view of the insertion tool 800 of FIGS. 8 a - b holding the spacer 400 of FIGS. 4 a - c shows the extents of the pincers 807 a, 807 b in cross-section and fitting within the annular groove of the spacer as the spacer is compressed between the compression surfaces 808 a, 808 b. It can be seen that the width of each extent is smaller than the width of the annular groove, and the depth of each extent is less than the depth of the annular groove if it is desirable for the flanges to fully flank the extents. Preferably, as shown, the outer diameter of the claw 806 is substantially equal to the outer diameter of the spacer 400 .
[0112] There are alternative insertion and rotating instruments that may be designed, so long as they selectively and alternatingly release or hold the trial spacer securely against rotation (the spacer can't rotate freely if it is to be turned in the intervertebral space). The tapered trial spacers themselves can include angle markers that clearly indicate to the surgeon the amount of rotation that was necessary for the correction of the spinal deformity. Such angle markers can also serve as a guide for the implantation of a secondary bone graft (e.g., a femoral ring) or another intervertebral spacer device.
[0113] Once the surgeon has determined the appropriate geometry for the surgical implants via the trial spacers, he or she is ready to immobilize the spine in that position. While multiple ways for immobilizing the spine are disclosed in the prior art, any one of which may be suitable for the specific surgical patient's treatment, three alternative ways are herein described.
[0114] First, the trial spacers may be left in the patient while rod fixation apparatuses (anterior or posterior) are mounted to the spine, thereby holding the spine in its desired orientation even after the trial spacers are subsequently removed. Alternatively, surface plating and/ or intervertebral cage devices may be mounted to the spine to promote fusion without the need for bulky rod assemblies. (While this approach may seem more surgically desirable, questions regarding the long-term stability of these constructs have led to some surgeons to choose combinations of rodding and cages.)
[0115] A third approach to immobilizing the corrected spine is to insert a shaped bone graft, or suitably contoured porous metal spacer, into the properly distracted intervertebral space, and either plating or using rod fixation to hold the construct stable as the spine fuses. The insertion of a femoral ring allograft, or porous metal implant, into an intervertebral space is described more fully in co-pending U.S. patent application Ser. No. 09/844,904, and 09/______, entitled “A Porous Interbody Fusion Device Having Integrated Polyaxial Locking Interference Screws”, and “Porous Intervertebral Distraction Spacers”, assigned to the same assignee as the present invention, the specifications of each being incorporated herein by reference.
[0116] The tapered trial spacers may also serve as precursors (measuring instruments) for spacer (e.g., a porous metal spacer), similarly shaped, which is inserted into the intervertebral space by the same instrument. | An orthopedic device set, including: a plurality of intervertebral spacer elements, each spacer element having a different axial thickness from each other element, the axial thicknesses being selected to increase by an increment from one element to another; and an instrument for holding ones of the intervertebral spacer elements, the instrument comprising a shaft having a distal end, a selectively grasping subassembly for alternatively rigidly holding each spacer element at the distal end so that the spacer element cannot move relative to the instrument, and releasing the spacer element. |
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention is directed, in general, to integrated circuit metrology and, more specifically, to a probe having a nanotube stylet and to a method of manufacturing and mounting same for use in integrated circuit metrology.
BACKGROUND OF THE INVENTION
[0002] A conventional stylus nanoprofilometer employing a probe stylet of quartz or diamond may be used to measure integrated circuit features down to approximately 100 nm line width. However, below 100 nm line width features, i.e., at about 80 nm, problems are encountered that are aggravated by the length and diameter of the probe stylet. A conventional quartz stylus has a Young's Modulus of Elasticity of approximately 70 gigapascals (GPa) [1 GPa=1×10 9 Pa]. As feature sizes continue to shrink, the 1 3 /r 4 portion of the deflection equation degrades, forcing a major change in the Young's Modulus required of the material being used.
[0003] One promising material form that could substitute for quartz, yet has a higher Young's Modulus than quartz, is the carbon nanotube. Carbon nanotubes were discovered in 1986 as a discharge material byproduct from a carbon arc. They are actually sheets of graphite where opposing edges have become attached to each other creating a tube. They have exhibited extraordinary material properties including a Young's Modulus approaching a terapascal, i.e., 1 terapascal=1000 Gpa=1×10 12 Pa. However, no material is problem free, and in the case of carbon nanotubes, the problems are associated with orienting and manipulating them due to their extremely small size. While carbon nanotubes may range from approximately 5 nm to 100 nm in diameter and from about 500 nm to about 5000 nm in length or longer, by their very size, manipulating and orienting them becomes a problem.
[0004] Nanotube material is now commercially available having diameters of ranging from about 10 nm to about 80 nm. A diameter nominally smaller than the feature size is preferable for probe stylets. Slightly larger or smaller diameter nanotubes can also be used depending upon the semiconductor technology, i.e., feature sizes of 160 nm, 120 nm, or 100 nm, etc., being investigated. Carbon nanotubes are extremely hard to manipulate and therefore, to orient, to tolerances within less than about 10 degrees to 20 degrees of the angle desired. While some efforts have been made to use a carbon nanotube as a probe tip for atomic force microscopes, all nanotube-based probes have heretofore been manufactured by attaching a carbon nanotube to an existing probe body by fastening the nanotube tip with an adhesive to the probe body tip. The method, in some cases consists of projecting the nanotubes against a probe body tip and literally hoping that one sticks in the correct orientation. The problem with this procedure is clearly in orientation, reproducibility and cost. For integrated circuit metrology, this is totally unacceptable due to common features having sidewalls within 1 degree of normal.
[0005] Accordingly, what is needed in the art is an alternative probe having a microstylet suitable for measuring semiconductor features having on the order of 160 nm or less line widths, and a method of manufacturing the probe.
SUMMARY OF THE INVENTION
[0006] To address the above-discussed deficiencies of the prior art, the present invention provides a probe comprising a probe body having a body longitudinal axis and a shoulder, and a microstylet mechanically coupled to the shoulder, and a method of manufacturing the same. In a preferred embodiment, the microstylet extends from the shoulder and has a microstylet longitudinal axis coincident the body longitudinal axis with the microstylet having a cross section substantially smaller than a cross section of the probe body.
[0007] Therefore, the present invention incorporates the positive attributes of a material having a higher Young's Modulus and extremely small diameter, while dispensing with the problems of manipulating and attaching such a small particle to a probe body in an exact orientation.
[0008] The foregoing has outlined preferred features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a more complete understanding of the present invention, reference is now made to the following detailed description taken in conjunction with the accompanying FIGURES. It is emphasized that various features may not be drawn to scale. In fact, the dimensions of various features may be arbitrarily increased or reduced for clarity of discussion.
[0010] [0010]FIG. 1A illustrates an elevation view of one embodiment of a tube preparatory to forming a probe body of a probe manufactured according to the principles of the present invention;
[0011] [0011]FIG. 1B illustrates the tube of FIG. 1A with one end sealed and an opposite end open;
[0012] [0012]FIG. 1C illustrates a suspension of microstylets in a menstruum in the tube of FIG. 1B;
[0013] [0013]FIG. 1D illustrates the tube of FIG. 1B, at least a portion of which was filled with the suspension as shown FIG. 1C, after evaporation of the menstruum;
[0014] [0014]FIG. 2 illustrates the tube of FIG. 1D preparatory to drawing;
[0015] [0015]FIG. 3 illustrates the resultant tube after drawing and just before tube collapse;
[0016] [0016]FIG. 4 illustrates the necked portion of FIG. 3 after collapse of the tube;
[0017] [0017]FIG. 5A illustrates an elevational view of the shank being subjected to a chemical etchant for a first etch;
[0018] [0018]FIG. 5B illustrates an elevational view of the shank after the first etch;
[0019] [0019]FIG. 5C illustrates an elevational view of the probe body being subjected to a chemical etchant for a second etch; and
[0020] [0020]FIG. 6 illustrates an elevational view of a completed probe manufactured according to the principles of the present invention.
DETAILED DESCRIPTION
[0021] Referring initially to FIG. 1A, illustrated is a sectional elevation view of one embodiment of a tube 100 preparatory to forming a probe body of a probe manufactured according to the principles of the present invention. In an advantageous embodiment, the tube 100 comprises a glass tube 110 having an inner wall 120 and a longitudinal axis 130 . However, other non-glass materials may also be used in place of the glass tube 110 . The glass tube 110 is prepared by sealing an end 111 , preferably by melting the glass. A melting point tube may work well, as will a pulled pipet or a small capillary tube. FIG. 1B illustrates the tube 110 of FIG. 1A with the end 111 sealed and an opposite end 112 open. The tube 100 is therefore suitable to hold a liquid with particulate matter, i.e., microstylets, in suspension. FIG. 1C illustrates a suspension 140 of microstylets 150 in a menstruum 160 in the tube 100 of FIG. 1B. In a preferred embodiment, the microstylets 150 are carbon nanotubes. More specifically, the carbon nanotubes may be either single-walled carbon nanotubes or multi-walled carbon nanotubes. Alternatively, the microstylets 150 may be acerate microparticles 150 such as: carbon whiskers, metal needles, or diamond. Tungsten needles are among suitable metal needles available.
[0022] In a particularly advantageous embodiment, multi-walled carbon nanotubes are used as the acerate microstylets 150 because of their size and Young's Modulus. Base carbon nanotube material is now commercially available and multiwalled carbon nanotubes with a diameter of approximately 60 nm to 80 nm may work particularly well for the present invention. Slightly larger or smaller nanotubes may be used depending upon the semiconductor line widths, e.g., 160 nm, 120 nm, 100 nm, etc. It should be noted that commercially available, multi-walled, carbon nanotubes come in bundles that must be separated before used as set forth herein.
[0023] The suspension 140 is prepared by adding the commercial carbon nanotube bundles to the menstruum 160 . The menstruum 160 is selected from among liquids that: (a) evaporate quickly, (b) are extremely clean, and (c) will not damage the carbon nanotube structure itself. Suitable menstrua may include low carbon number alcohols, e.g., methyl alcohol, ethyl alcohol and isopropyl alcohol. The microstylets 150 are placed in suspension in the menstruum 160 so that separation into individual microstylets 150 can occur. Dilution of the menstruum 160 by volume will help to decrease the concentration of the mirostylets 150 . After preparing the suspension 140 , it is poured into the hollow glass tube 110 sealed at one end 111 as shown in FIG. 1C.
[0024] Referring now to FIG. 1D, illustrated is the tube 110 of FIG. 1B, at least a portion 113 of which was filled with the suspension 140 as shown FIG. 1C, after evaporation of the menstruum 160 . The menstruum 160 chosen because of its highly volatile nature, evaporates quickly. As the menstruum 160 evaporates, the microstylets 150 which are not soluble in the menstruum 160 attach to the inner wall 120 of the glass tube 110 , leaving the condition illustrated in FIG. 1D. Of course, each of the microstylets 150 will attach themselves randomly to some point on the inner wall 120 .
[0025] Referring now to FIG. 2, illustrated is the tube 100 of FIG. 1D preparatory to drawing of the tube as further described. The open end 112 of the tube 110 is secured to a fixed location 210 , preferably a bench or other substantially fixed object, and a free weight 220 , or other device that may exert a pulling force against tube 110 , such as a person's hand, is attached to the closed end 111 . Heat is applied to the portion 113 of the tube 110 wherein the microstylets 150 are attached to the inner wall 120 . Heat may be applied using a circular filament 230 located circumferentially about the tube 110 at the portion 113 having microstylets 150 therein. Using gravity to an advantage, the tube 110 is axially loaded with the free weight 220 applying a force F along the tube longitudinal axis 130 while heat is applied proximate the portion 113 . Heat is applied until the combination of heat and longitudinal force F causes the glass tube 110 to be drawn and necked at the portion 113 . The portion 113 proximate the circular filament 230 will decrease in diameter as the heat and force F are continuously applied until of the tube 110 collapses on itself in that portion 113 . One who is skilled in the art is familiar with the process of heating and drawing glass tubing into a capillary or pipette and the ultimate result of the radial collapse of the tube on itself.
[0026] Referring now to FIG. 3, illustrated is the resultant tube 110 after drawing and just before tube collapse. As the glass tube 110 of FIG. 2 is heated, the microstylets 150 attached to the inner wall 120 become embedded in the viscous, semifluid glass of the glass tube 110 . When heated and combined with the axial force F, the longitudinal axes of the microstylets 150 align with the pulling direction 240 , that also coincides with the longitudinal axis 130 of the glass tube 110 . It is important that this heating and drawing process not be continued to the point at which the tensile strength of the tube 110 in its semifluid state is exceeded. The objective is to narrow the tube 110 and to therefore align the microstylets 150 with the longitudinal axis 130 of the tube 110 without breaking the tube 110 . The tube 110 now comprises first and second tubular portions 310 , 320 and a necked portion 330 . Microstylets 150 in the necked portion 330 are aligned with the longitudinal axis 130 of the tube 110 . The necked portion 330 is then purposely fractured at points 331 and 332 .
[0027] Referring now to FIG. 4, illustrated is the necked portion 330 of FIG. 3 after collapse of the tube 110 . In a preferred embodiment, the necked portion 330 comprises solid amorphous glass 410 on the order of 50,000 nm to 200,000 nm in diameter 420 wherein there are embedded microstylets 150 spaced apart along the longitudinal axis 130 as a function of the previously described pulling process. That is, the microstylets 150 become integrally bound to the glass 410 , in contrast to the prior art that has sought to adhesively bond nanotubes to a probe body. One of the microstylets 150 will form a microstylet that is substantially smaller in cross section than the necked portion 330 that will be used as a shank 330 for a microprobe to be completed in accordance with the principles of the present invention. A microprobe is defined as a probe that is revealed by or has its structure discernible only by microscopic examination.
[0028] For the purpose of this discussion, isotropy is the property of the material, e.g., glass, to etch at the same uniform rate in all axes when subjected to a chemical etchant. Referring now to FIG. 5A, illustrated is a sectional elevational view of the shank 330 being subjected to a chemical etchant 510 for a first etch.
[0029] As a basis for the etchant, a basic oxide etchant (BOE) is prepared that, may comprise in parts by volume for example:
[0030] 615 parts ammonium fluoride (NH 4 F),
[0031] [0031] 104 parts hydrofluoric acid (HF) (49%), and
[0032] [0032] 62 parts deionized water (H 2 O).
[0033] In addition to the BOE, the chemical etchant 510 may further comprise hydrofluoric acid, distilled water and acetone in ratio concentrations to control the etch rate. A typical solution chemistry for the chemical etchant may comprise, for example:
[0034] 5 parts BOE,
[0035] 5 parts hydrofluoric acid (HF) (49%),
[0036] 1 part distilled water (H 2 O), and
[0037] 1 part acetone (CH 3 COCH 3 ).
[0038] Of course, various formulations may be employed with varying results; that is, the rate of etch may be controlled by the etchant formulation and concentration. The etchant detailed above is suitable for etching when the shank 330 is glass. In those embodiments where the shank 330 is comprised of a non-glass material, etching chemistries appropriate for those materials should be used. The above formulation has been successfully used to complete the first chemical etch of the shank 330 . In the case of this etchant, a typical fast radial etch rate of about 45 nm/sec and slow etch rate of about 1 nm/sec have been achieved.
[0039] When a portion 510 of the shank 330 is placed in the etchant solution 520 , a meniscus 521 forms about the shank 330 . The purpose of the first chemical etch is to create a region 511 that has a taper proportional to a height 522 of the meniscus 521 . As a function of the concentration of the etchant 520 , thicker etchant causes more extensive etching. Therefore, in area 513 , where the etchant 520 is thinner, less chemical action occurs, while in area 514 , where the etchant 520 is thicker, more etching action occurs, resulting in a morphology that is a right circular cone as indicated by surface 530 .
[0040] Referring now to FIG. 5B, illustrated is an elevational view of the shank 330 after the first etch. Thus, the result of the first chemical etch is a tapered cone 530 located about a central axis 130 wherein spaced apart microstylets 150 are located along the central axis 130 . A specific microstylet 540 within the apex 531 of the cone 530 now becomes the microstylet that will be exposed by a second etch. A main portion 550 of the shank 330 , not etched by the etchant 520 , may now be referred to as a probe body 550 . The transition from the probe body 550 to the cone 530 forms a shoulder 560 .
[0041] Referring now to FIG. 5C, illustrated is a sectional elevational view of the probe body 550 being subjected to a chemical etchant 510 for a second etch. Once the tapered conical shape 530 has been formed, a greater portion of the probe body 550 including the conical shape 530 is placed in the etchant 520 . As the etchant continues to etch the glass isotropically, material is removed from the probe body 550 and the conical shape 530 at areas 532 and 533 . As before, the etching results in a conical shape about the central axis 130 . Again, in area 533 , where the etchant 520 is thinner, less chemical action occurs, while in area 532 , where the etchant 520 is thicker, more etching action occurs.
[0042] Referring now to FIG. 6, illustrated is a sectional elevational view of a completed probe 600 manufactured according to the principles of the present invention. The probe body 550 , subjected to a thinner etch in area 533 has not etched as much as area 532 where the etchant 520 was thicker. This difference in etching rates has resulted in a morphology that is a tapering, right circular cylinder 610 . However, because the glass material of the conical shape 530 comprises less mass than the probe body 550 , the shoulder 560 (FIG. 5C) decreases in circumference as the etch proceeds reforming the shoulder 560 . The transition from the surface 610 to a new conical shape 630 demarks a transition from a conical slope of one portion 610 to a conical slope of a second portion 630 . This transition may be referred to as a fastigiate shoulder 660 in so much as the tapering, right circular cylinder 610 transitions to the right circular cone 630 which tapers to an apex 631 . The process of the second etch has exposed a portion of the specific microstylet formerly within the apex 531 of the cone 530 of FIG. 5B. Thus, the microstylet 540 , a portion 641 of which is secured mechanically within the conical shape 630 and coincident with the longitudinal axis 130 is formed. This is in contrast to that of the prior art in which a microstylet would be adhesively attached to a shank with a poor chance of being co-aligned with the shank longitudinal axis. Such a microprobe may be used as a field emitter, a micromanipulator or a microinjector in a variety of tools, e.g., scanning electron microscope, stylus nanoprofilometer, etc., or in laboratory procedures.
[0043] Therefore, a microprobe has been described as the present invention incorporating a microstylet, in the form of a single- or multi-walled nanotube, directly into the probe body itself and thereby eliminating any gluing or attachment of the microstylet to a probe body. It also aligns the microstylet directionally with respect to the central axis of the glass tube being used as a shank or probe body.
[0044] Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form. | The present invention provides a probe comprising a probe body having a body longitudinal axis and a shoulder, and a microstylet mechanically coupled to the shoulder, and a method of manufacturing the same. The microstylet extends from the shoulder and has a microstylet longitudinal axis coincident the body longitudinal axis with the microstylet having a cross section substantially smaller than a cross section of the probe body. |
RELATED APPLICATIONS
This application is a continuation application of U.S. patent application Ser. No. 11/057,960, filed Feb. 15, 2005 now U.S. Pat. No. 7,537,377, which in turn is a divisional application of U.S. patent application Ser. No. 091075,392, filed May 8, 1998, (U.S. Pat. No. 7,133,726 ), which is a continuation of PCT/US98/06189, filed Mar. 30, 1998, which claims benefit of U.S. Provisional Application No. 60/046,122, filed May 9, 1997, and claims benefit of U.S. Provisional Application No. 60/041,754, filed Mar. 28, 1997.
FIELD OF THE INVENTION
This invention pertains to the field of computer controlled instruments for performing the Polymerase Chain Reaction (PCR). More particularly, the invention pertains to automated instruments that perform the reaction simultaneously on many samples and produce very precise results by using thermal cycling.
BACKGROUND OF THE INVENTION
The background of the invention is substantially as stated in U.S. Pat. No. 5,475,610 which is herein incorporated by reference.
To amplify DNA (Deoxyribose Nucleic Acid) using the PCR process, it is necessary to cycle a specially constituted liquid reaction mixture through several different temperature incubation periods. The reaction mixture is comprised of various components including the DNA to be amplified and at least two primers sufficiently complementary to the sample DNA to be able to create extension products of the DNA being amplified. A key to PCR is the concept of thermal cycling: alternating steps of melting DNA, annealing short primers to the resulting single strands, and extending those primers to make new copies of double-stranded DNA. In thermal cycling the PCR reaction mixture is repeatedly cycled from high temperatures of around 90° C. for melting the DNA, to lower temperatures of approximately 40° C. to 70° C. for primer annealing and extension. Generally, it is desirable to change the sample temperature to the next temperature in the cycle as rapidly as possible. The chemical reaction has an optimum temperature for each of its stages. Thus, less time spent at non optimum temperature means a better chemical result is achieved. Also a minimum time for holding the reaction mixture at each incubation temperature is required after each said incubation temperature is reached. These minimum incubation times establish the minimum time it takes to complete a cycle. Any time in transition between sample incubation temperatures is time added to this minimum cycle time. Since the number of cycles is fairly large, this additional time unnecessarily heightens the total time needed to complete the amplification.
In some previous automated PCR instruments, sample tubes are inserted into sample wells on a metal block. To perform the PCR process, the temperature of the metal block is cycled according to prescribed temperatures and times specified by the user in a PCR protocol file. The cycling is controlled by a computer and associated electronics. As the metal block changes temperature, the samples in the various tubes experience similar changes in temperature. However, in these previous instruments differences in sample temperature are generated by non-uniformity of temperature from place to place within the sample metal block. Temperature gradients exist within the material of the block, causing some samples to have different temperatures than others at particular times in the cycle. Further, there are delays in transferring heat from the sample block to the sample, and those delays differ across the sample block. These differences in temperature and delays in heat transfer cause the yield of the PCR process to differ from sample vial to sample vial. To perform the PCR process successfully and efficiently, and to enable so-called quantitative PCR, these time delays and temperature errors must be minimized to the greatest extent possible. The problems of minimizing non-uniformity in temperature at various points on the sample block, and time required for and delays in heat transfer to and from the sample become particularly acute when the size of the region containing samples becomes large as in the standard 8 by 12 microtiter plate.
Another problem with current automated PCR instruments is accurately predicting the actual temperature of the reaction mixture during temperature cycling. Because the chemical reaction of the mixture has an optimum temperature for each of its stages, achieving that actual temperature is critical for good analytical results. Actual measurement of the temperature of the mixture in each vial is impractical because of the small volume of each vial and the large number of vials.
SUMMARY OF THE INVENTION
According to the invention, there is provided an apparatus for performing the Polymerase Chain Reaction comprising an assembly capable of cycling samples through a series of temperature excursions, a heated cover and a computer to control the process.
The invention further encompasses a sample block with low thermal mass for rapid temperature excursions. The sample block is preferably manufactured from silver for uniform overall heat distribution and has a bottom plate for uniform lateral heat distribution. In addition, to further offset heat losses and resulting temperature gradients from the center to the edges, a center pin is used as a conducting path to a heat sink.
The invention also provides a method and apparatus for achieving rapid heating and cooling using Peltier thermoelectric devices. These devices are precisely matched to each other. They are constructed using die cut alumina on one side to minimize thermal expansion and contraction. The devices are constructed of bismuth telluride using specific dimensions to achieve matched heating and cooling rates. They are designed using minimal copper thicknesses and minimal ceramic thicknesses to further reduce their heat load characteristics and are assembled using a specific high temperature solder in specified quantities.
The invention is also directed to a heatsink constructed with a perimeter trench to limit heat conduction and losses from its edges. Furthermore, the heatsink has an associated variable speed fan to assist in both maintaining a constant temperature and in cooling.
The invention is also directed to a clamping mechanism to hold the sample block to the heat sink with the thermoelectric devices positioned in between. The mechanism is designed to provide evenly distributed pressure with a minimal heat load. The design allows the use of thermal grease as an interface between the sample block, and the thermoelectric devices and between the thermoelectric devices and the heatsink.
There is also provided a perimeter heater to minimize the thermal non-uniformity across the sample block. The perimeter heater is positioned around the sample block to counter the heat loss from the edges. Power is applied to the heater in proportion to the sample block temperature with more power applied when the sample block is at higher temperatures and less power applied when the sample block is at lower temperatures.
There is also provided a heated cover, designed to keep the sample tubes closed during cycling and to heat the upper portion of the tubes to prevent condensation. The heated cover applies pressure on the sample tube cap perimeter to avoid distorting the cap's optical qualities. The cover is self-aligning, using a skirt which mates with a sample tube tray.
The invention is also directed to a method and apparatus for determining an ideal temperature ramp rate which is determined so as to take advantage of sample block temperature overshoots and undershoots in order to minimize cycle time.
The invention also includes a method and apparatus for characterizing the thermal power output from the thermoelectric cooling devices to achieve linear temperature control and linear and non-linear temperature ramps.
The invention is further directed to a method for predicting the actual temperature of the reaction mixture in the sample vials at any given time during the PCR protocol.
The invention also includes a method and apparatus for utilizing calibration diagnostics which compensate for variations in the performance of the thermoelectric devices so that all instruments perform identically. The thermal characteristics and performance of the assembly, comprised of the sample block, thermoelectric devices and heatsink, is stored in an on-board memory device, allowing the assembly to be moved to another instrument and behave the same way.
The invention further includes a method and apparatus for measuring the AC resistance of the thermoelectric devices to provide early indications of device failures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a portion of the sample block according to the invention.
FIG. 2 is an enlarged, isometric view of a thermoelectric device constructed according to the invention.
FIG. 2A is a side, elevational view of a thermoelectric device constructed according to the invention.
FIG. 3 is a cut-away, partial, isometric view of the heatsink according to the invention.
FIG. 4 is an exploded view of an assembly including a sample block, thermoelectric devices and heatsink.
FIG. 5 is an isometric view of the heated cover in accordance with the invention.
FIG. 6 is a chart depicting the Up Ramp (heating rate) vs. Power.
FIG. 7 is a chart depicting the Down Ramp (cooling rate) vs. Power.
FIG. 8 is a chart for predicting and compensating for temperature overshoots and undershoots in accordance with the invention.
FIG. 9 is a block diagram of the AC resistance measurement circuit of the invention.
FIG. 10 shows a perimeter heater and its location surrounding the sample block.
FIG. 11 is a detailed view of the perimeter heater of FIG. 10 .
FIG. 12 shows the power applied to the perimeter heater as a function of the temperature of the sample block.
FIG. 13 shows a thermal model of a sample in a sample vial.
FIG. 14 is an illustration of the initial conditions of the thermal model of FIG. 13 .
FIG. 15 shows the sample block and a seal designed to protect the thermoelectric devices from the environment.
DETAILED DESCRIPTION OF THE INVENTION
Generally, in the case of PCR, it is desirable to change the sample temperature between the required temperatures in the cycle as quickly as possible for several reasons. First the chemical reaction has an optimum temperature for each of its stages and as such less time spent at non-optimum temperatures means a better chemical result is achieved. Secondly a minimum time is usually required at any given set point which sets a minimum cycle time for each protocol and any time spent in transition between set points adds to this minimum time. Since the number of cycles is usually quite large, this transition time can significantly add to the total time needed to complete the amplification.
The absolute temperature that each reaction tube attains during each step of the protocol is critical to the yield of product. As the products are frequently subjected to quantitation, the product yield from tube to tube must be as uniform as possible and therefore both the steady-state and dynamic thermal uniformity must be excellent across the block.
Heat-pumping into and out of the samples is accomplished by using Peltier thermoelectric devices. These are constructed of pellets of n-type and p-type bismuth telluride connected alternately in series. The interconnections between the pellets is made with copper which is bonded to a substrate, usually a ceramic (typically alumina).
The amount of heat-pumping required is dependent on the thermal load and the ramp rate, that is, the rate at which the temperature is required to change. The sample tube geometry and sample volumes are not variables as the sample tubes are established as an industry standard, fitting into many other types of instruments such as centrifuges. The sample volume is defined by user need. Therefore the design variables primarily affect the sample block, thermoelectric devices, heatsink, fan and the thermal interface media between the thermoelectric devices and both the heatsink and the sample block.
The block geometry must also meet the necessary thermal uniformity requirements because it is the primary contributor to lateral conduction and therefore evens out any variation in thermal uniformity of the thermoelectric coolers themselves. The conflicting requirements of rapid ramp rates (indicating low thermal mass) and high lateral conduction (indicating a large material mass) are met by concentrating the bulk of the block structure in a base plate and minimizing the thermal mass of the upper portion of the block which holds the sample tubes. The optimal material for block fabrication is pure silver which has relatively low thermal mass and very good thermal conduction. Silver also lends itself well to electroforming. In practice the optimal block geometry has a light electroformed upper portion to hold the sample tubes fixed to a relatively thick base plate which provides lateral conduction. The thermal mass of the block is concentrated in the base plate where the material contributes the most to thermal uniformity. The electroformed portion of the block has a minimum thickness which is defined by two parameters: first, the material cannot be so thin as to make it too delicate for normal handling; second, the wall thickness is required to conduct heat out of the upper regions of the sample tube. Circulation in the sample itself is achieved by convection inside the tube and sample temperature is relatively uniform along the height of the tube, but good thermal conductivity between the tube walls and the base plate increases the effective surface area available for conduction of heat between the sample and the base plate. The base plate thickness has a minimum value defined by lateral conduction requirements which is a function of the thermal uniformity of the thermoelectric coolers and structural rigidity.
Another contributor to the thermal mass is the alumina ceramic layers which form part of the structure of the thermoelectric cooler itself. There are two alumina layers in the construction of the thermoelectric cooler, one on the sample block side and another oil the heatsink side. The thickness of the layers should be minimized as much as possible, in this case the practical limit of thinness for the alumina thickness is defined by the manufacturing requirements of thermoelectric cooler fabrication. This particular layer of ceramic could in principal be replaced by a different layer altogether such as a thin sheet of Kapton which would reduce the thermal mass even more, but at the present time although coolers are available with this structure, reliability is unproven. It is anticipated that once the technology has been developed further, then a cooler of such a design may be preferred. However, the thin alumina layers also contribute to system reliability.
The copper conductors within the cooler are a significant thermal load and are not overlooked in the design of the system. The thickness of the copper traces is defined by the requirement of carrying current through the device. Once the current is known the required copper thickness can be calculated.
Sample Block
FIG. 1 shows a cross sectional view of a portion of the sample block 36 which typically has 96 wells 20 , each for receiving a sample vial. The sample block is constructed of silver and comprises an upper support plate 21 and the sample wells 20 electroformed as one piece fastened to a base plate 22 . The base plate 22 provides lateral conduction to compensate for any difference in the thermal power output across the surface of each individual thermoelectric device and for differences from one thermoelectric device to another.
There are always boundary losses in any thermal system. In a rectangular configuration there is more heat loss in the corners. One solution is to use a round sample block, but the microtiter tray format that is in common usage is rectangular and this must be used to retain compatibility with other existing equipment. Once the edge effects have been eliminated using all standard means, such as insulation etc., there remains a tendency for the center of the sample block to be warmer than the corners. Typically it is this temperature difference that defines the thermal uniformity of the sample block. In accordance with the invention, the center temperature is reduced by providing a small thermal connection from the center of the sample block to the heat sink. By using a pin 24 which acts as a “heat leak” in the center of the sample block, the temperature gradient across the sample block can be reduced to an acceptable level. The amount of conduction required is quite small and a 1.5 mm diameter stainless steel pin has been found to be sufficient. Moreover, a pin made of the polymer ULTEM, manufactured by General Electric may also be used. As more fully described below, the pin also serves to help position and lock into place components of the assembly illustrated in FIG. 4 .
Peltier Thermoelectric Devices (TEDs)
Thermal uniformity of the sample block is critical to PCR performance. One of the most significant factors affecting the uniformity is variations in the thermoelectric device performance between devices. The most difficult point at which to achieve good uniformity is during a constant temperature cycle far from ambient. In practice this is a constant temperature cycle at approximately 95° C. The thermoelectric devices are matched under these conditions to make a set or devices for each heatsink assembly which individually produce the same temperature for a given input current. The thermoelectric devices are matched to within 0.2° C. in any given set, this value being derived from the maximum discrepancy that can be rectified by the lateral conduction of the sample block baseplate.
FIG. 2A shows a side view of a typical Peltier thermal electric device 60 . The device is composed of bismuth telluride pellets 30 , sandwiched between two alumna layers 26 . The pellets are electrically connected by solder joints; 28 to copper traces 29 plated onto the alumina layers. One alumina layer has an extension 31 to facilitate electrical connections. The thickness of the extended areas is reduced to decrease the thermal load of the device.
FIG. 2 shows an isometric view of a typical Peltier thermoelectric device. The alumina layer 26 that forms the outer wall of the thermoelectric device, expands and contracts during temperature cycling at a different rate than the sample block 19 . The motion of the alumina is transmitted directly to the solder 28 connecting the internal bismuth telluride pellets 30 . This motion can be reduced dramatically by cutting the alumina into small pieces 32 called die so that the field of expansion is small. The minimum size of the die is defined by the size of the copper traces required to carry current through the thermoelectric device and the requirements that the device retain some strength for handling.
Using thin alumina layers in the thermal electric device (of the order of 0.508 mm) not only reduces the thermal load but also means that for a given required heat pumping rate the temperature that the ends of the pellet reaches is reduced due to the increase in thermal conductivity k. This enhances reliability by reducing the thermal stress on the solder joint.
Generally in PCR the reaction temperatures are above ambient and in the range 35 to 96° C. In the most important cases the block is heated or cooled between two above ambient temperatures where the flow of heat due to conduction is from the block to the heat sink. The key to optimizing the system cycle time, given an optimized block configuration, is to balance the boost to the ramp rate when cooling provided by the conduction, against the boost provided to the heating ramp rate by the Joule effect of resistance heating.
If the cross-section of the bismuth telluride pellets in a glen thermoelectric device were considered constant, the heating ramp rate would be increased by increasing the height of the pellet. This is because the conduction path through the thermoelectric device would be made longer thereby decreasing k. This also has the effect of reducing the current required to maintain a given block temperature in the steady state. During the down ramp, i.e. cooling the block, the decreased k means that the conduction contribution will be reduced and so the down ramp rate will be reduced.
Conversely, if the height of the bismuth telluride pellet were to be decreased for a given cross-section, then k would be increased. This would increase the current required to maintain an elevated temperature in the steady state and would increase the cooling ramp rate. Heating ramp rates would be reduced as a larger portion of the heat in the block would be conducted directly to the heat sink. Decreasing the bismuth telluride pellet height also increases the holding power required for a given temperature due to the losses through the thermoelectric devices and reduces the thermal load, increasing the maximum possible ramp rate for given power. Therefore the optimized thermoelectric device can be derived by adjusting the height of the Bismuth Telluride pellets until the heating rate matches the cooling rate.
The ratio 1:A for the pellets also defines the resistance of the device i.e.
R=nr(h/A)
where n is the number of pellets, r is the resistivity of the Bismuth Telluride being used, h is the height of the pellet and A is the cross-sectional area.
The resistance must be measured as an AC resistance because of the Seebeck effect. Because the geometry defines the resistance of the device, another design boundary is encountered in that the device must use a cost effective current to voltage ratio because too high a current requirement pushes up the cost of the amplifier. The balanced solution for the silver electroformed block described above is:
Pellet height=1.27 mm Pellet cross-sectional area=5.95 mm 2
If the thermal cycler was to be used as part of another instrument, e.g. integrated with detection technology, then it may be more convenient to use a different current source which would lead to a modified thermoelectric device geometry. The current source in the present embodiment consists of a class D type switch-mode power amplifier with a current sensing resistor in series with the device and ground.
Because the thermoelectric devices are soldered together, excess solder can wick up the side of the bismuth telluride pellets. Where this occurs, k is increased which results in a local cold spot, also called a mild spot. These cold spots are reduced in number and severity by application of the minimum amount of solder during the assembly process of the thermal electric device. For the same reason, it is also necessary to ensure that the solder used to attach the connecting wires to the thermoelectric device does not contact the pellet
High temperature solder has been shown to not only have improved high temperature performance but it is also generally more resistant to failure by stress reversals and hence is most appropriate in this application. The solder used in this invention may be of the type as described in U.S. Pat. No. 5,441,576.
Heatsink
FIG. 3 shows the heatsink 34 assembled with the thermoelectric devices 39 and the sample block 36 . A locating frame 41 is positioned around the thermoelectric devices to align them with the sample block and the heatsink to ensure temperature uniformity across the sample block. The frame is composed of Ultem or other suitable material and has tabs 43 at its corners to facilitate handling. The heatsink 34 has a generally planer base 34 and fins 37 extending from base 35 . The thermal mass of the heat sink is considerably larger than the thermal mass of the sample block and samples combined. The sample block and samples together have a thermal mass of approximately 100 joules/° K and that of the heat sink is approximately 900 joules/° K. This means that the sample block clearly changes temperature much faster than the heat sink for a given amount of heat pumped. In addition the heat sink temperature is controlled with a variable speed fan as shown in FIG. 9 . The temperature of the heat sink is measured by a thermistor 38 placed in a recess 40 within the heatsink and the fan speed is varied to hold the heat sink at approximately 45° C. which is well within the normal PCR cycling temperature range, where maintaining a stable heat sink temperature improves the repeatability of system performance. When the block temperature is set to a value below ambient then the heat sink is set to the coolest achievable temperature to reduce system power consumption and optimize block thermal uniformity. This is accomplished simply operating the fan at full speed.
The heat sink temperature measurement is also used by the thermoelectric device control algorithm described below in linearizing the thermal output power from the thermoelectric devices.
The heatsink temperature uniformity is reflected in the uniformity of the block temperature. Typically the heatsink is warmer in the middle than it is at the edges and this adds to other effects that lead to the corners of the block being the coldest. A trench 44 is cut into the heat sink outside the perimeter of the thermoelectric device area to limit the conduction of heat and decreases edge losses from the area bounded by the trench.
Thermal Interface and Clamping Mechanism
Thermoelectric device manufacturers recommend that thermoelectric devices be held under pressure to improve life-expectancy. (The pressure recommended is often defined by the thermal interface media selected.) The pressure that is recommended varies from manufacturer to manufacturer but is in the range of 30 to 100 psi for cycling applications.
There are many thermal interface media available in sheet form which can be used to act as a compliant layer on each side of the thermoelectric devices, but it has been demonstrated that thermal grease gives far superior thermal performance for this application. Unlike other compliant sheets which have been shown to require 30 psi or more even under optimal conditions, thermal grease does not require high pressure to ensure that good thermal contact has been made. Also thermal grease acts as an effective lubricant between the expanding and contracting silver block and the thermoelectric device surface, enhancing life-expectancy. Thermalcote II thermal grease manufactured by Thermalloy, Inc. may be used.
Because the silver block is relatively flexible and sort it cannot transmit lateral clamping pressure very effectively. However, because the thermal interface media is thermal grease, the clamping force required is low.
FIG. 4 shows an exploded view of the assembly with the preferred embodiment of the clamping mechanism. Each clamp 46 is made up of a series of fingers 48 extending from a spine 49 . The fingers 48 are sized, shaped and spaced so as to fit between the wells 20 of the sample block 36 and thus apply pressure at a corresponding series of points on the base plate 22 of the sample block 36 . The open honeycomb structure of the electroformed sample wells allows the fingers to be inserted some distance into the block, thereby applying the pressure more evenly than an edge clamping scheme would. These fingers apply pressure at a series of local points to minimize the contact area between the mass of the clamp and the sample block so that the clamp does not add significantly to the thermal load. The clamps are molded from a glass filled plastic which has the necessary rigidity for this application. The pressure is applied by deforming the fingers with respect to mounting posts 50 which may be separate clamp structures, but are preferably integrally formed with the clamps 46 . The clamps 46 are held flush to the surface of the heat sink with a series of screws 52 extending through corresponding hole 53 in clamps 46 and then into threaded holes 55 in heatsink 34 . This scheme eliminates the necessity to set the pressure with adjustment screws as the clamps can simply be tightened down by standard torquing techniques.
The resulting even pressure distribution ensures that the full area of the thermoelectric devices is in good thermal contact with the block and the heatsink reducing local thermal stresses on the thermoelectric devices.
FIG. 4 shows other important features of the invention. A printed circuit board 82 includes a memory device 96 for storing data and surrounds the thermoelectric devices and provides electrical connections. Alignment pins 84 are seated if holes 86 in the heatsink and protrude through alignment holes 88 to align the printed circuit board with the heatsink. The locating frame 41 is positioned around the thermoelectric devices and has a cross beam 90 with a through hole 92 . Pin 24 (shown in FIG. 1 ) fits into a hole (not shown) in the sample block, extends through hole 92 in the locating frame and further extends into hole 94 in the heatsink.
Perimeter Heater
In order to bring the temperature uniformity across the sample block to approximately ±0.2° C., a perimeter heater is positioned around the sample block to eliminate heat losses from its edges. Preferably, the heater is a film type, having low mass with inside dimensions slightly larger than the sample block. FIG. 10 shows the perimeter heater 74 and its approximate location surrounding the sample block 36 . The heater is not fastened in place, it is simply positioned in the air around the perimeter of the sample block in order to warm the air in the immediate vicinity.
FIG. 11 shows a detailed view of the perimeter heater 74 . The heater is rectangular as determined by the dimensions of the sample block and is manufactured so that it has separate power densities in specific areas to reflect the varying amounts of heat loss around the perimeter of the block. Matching lower power density regions 76 (0.73 W/in 2 ) are located in the center portions of the short sides of the rectangle and matching higher power density regions 78 (1.3 W/in 2 ) are located in the longer sides, extending into the shorter sides.
As shown in FIG. 12 , the power applied to the perimeter heater is regulated to correspond to the temperature of the sample block, with more power applied to the heater at higher block temperatures and less applied at lower block temperatures.
Heated Cover:
FIG. 5 shows the heated cover 57 . The heated cover applies pressure to the sample vial caps to ensure that they remain tightly closed when the sample is heated.
Further, pressure transferred to the vials assures good thermal contact with the sample block. The cover is heated under computer control to a temperature above that of the sample to ensure that the liquid does not condense onto the tube cap and instead remains in the bottom of the tube where thermal cycling occurs. This is described in U.S. Pat. No. 5,475,610, mentioned above. The heated platen 54 in the present invention does not press on the dome of the cap but instead presses on the cap perimeter. The platen has a surface shaped in this manner so that optical caps are not distorted by the application or pressure. Thus, tubes that have been cycled can be directly transferred to an optical reader without the need to change the cap.
Because the heated platen has recesses 56 in it to clear the cap domes, there is a need to align the platen to the tube positions before applying pressure to avoid damage to the tubes. This is accomplished by use of a “skirt” 58 around the perimeter of the platen which aligns to the microtiter tray before the platen touches the tube caps. The cover has a sliding mechanism similar to that used on the PYRIS Differential Scanning calorimeter by the Perkin Elmer Corporation allowing the cover to slide back to allow sample vials to be inserted into the sample block and forward to cover the sample block and move down to engage the vials.
Determining the Ideal Ramp Rate:
The optimized ramp rate has been empirically determined to be 4° C./sec. Any system which has a higher block ramp rate than this cannot fully utilize the benefits of temperature overshoots and consequently achieves an insignificant reduction in cycle time.
FIG. 6 is a chart depicting the Up Ramp (heating rate) vs. Power and FIG. 7 is a chart depicting the Down Ramp (cooling rate) vs. Power.
When heating the block to a temperature above ambient, the Joule heating and the Seebeck heat pumping both act to heat the sample block against conduction. When cooling the block between two temperatures above ambient, the Seebeck heat pumping and conduction act against the Joule heating. During cooling, significant power is required to hold the block temperature steady against the flow of heat out of the block by conduction. Therefore even with zero power applied, the block will cool at a significant rate. As the current is increased, the Seebeck effect increases the cooling obtained. However as the current is increased further the joule effect, which is proportional to the square of the current, quickly starts to take over acting against the Seebeck cooling. Therefore a point is reached where applying additional power acts against the required effect of cooling. In the heating mode these two effects act together against conduction and no ceiling is reached. In practice the heating power vs. input current is approximately linear. This is why the design criteria centers around meeting the cooling rate requirements; the heating rate can always be achieved by the application of more power.
Characterizing, the Output of the TED's
The following equation describes the total heat flow from the cold side of a thermal electric cooler.
0=½ *R ( t avg )* I 2 +t c *S ( t avg )* I −( k ( t avg )*( t c −t h )+ Q c )
where t c =cold side temperature of cooler t h =hot side temperature of cooler t avg =average of t c and t h R(t)=electrical resistance of cooler as a function of temperature S(t)=Seebeck coefficient of the cooler as a function of temperature K(t)=Conductance of cooler as function of temperature I=electrical current applied to cooler Q c =total heat flow from the cold side of the cooler
Given a desired heat flow, Q c and the hot and cold side temperatures, t c and t h , the equation is solved for I, the current required to produce Q c . The solution of this equation is used for three purposes:
1) To achieve linear temperature transitions or ramps.
For linear temperature transitions, constant thermal power is required. To maintain constant thermal power when temperatures t c and t h are changing, it is necessary to solve for I in equation 1 periodically. The result is the current then applied to the coolers. To compensate for errors a proportional integral derivative (PID) control loop is applied where:
Error input to PID=Set point Rate−Actual Rate
and Output from the PID is interpreted as percent Q
2) To achieve a linear PID temperature set point control algorithm over the desired temperature range:
Input to the PID control is the error signal t c −Set point.
Output from the PID control is interpreted as a % of Q max .
Equation 1 is used to determine the current value, I, which will result in the % of Q max output by the PID control, under the current temperature conditions.
3) To achieve non-linear temperature transitions or ramps where temperature transitions are defined by the derivative of temperature % with respect to time, dT/dt, as a function of block temperature.
This function is approximated by a table containing Block temperature T, dT/dt data points in 5 C increments for cooling and by a linear equation for heating. The small effect of sample mass on dT/dt profiles, although measurable, is ignored. Knowing the total thermal mass, MC p (joules/° K), involved during temperature transitions, the amount of thermal power, Q (joules/see), required to achieve the desired rate profile, dT/dt (° K/sec), is given at any temperature by the following equation:
Q=MC p *dT/dt
The solution to equation I is used to determine the current value, I, which will result in the desired Q under the current temperature conditions. This process is repeated periodically during temperature transitions.
Controlling Overshoot and Undershoot
There is a practical limit to the ramp rates and the resulting cycle times that can be achieved. The sample has a time constant with respect to the block temperature that is a function of the sample tube and tube geometry which, because the tube is an industry standard, cannot be reduced. This means that even if the sample tube wall temperature is changed as a step function e.g. by immersion in a water bath, the sample will have a finite ramp time as the sample temperature exponentially approaches the set point. This can be compensated for by dynamically causing the block to overshoot the programmed temperature in a controlled manner. This means that the block temperature is driven beyond the set point and back again as a means of minimizing the time taken for the sample to reach the set point. As the possible ramp-rates increase, the overshoot required to minimize the time for the sample to reach the set point gets larger and a practical limit is soon reached. This occurs because although the average sample temperature does not overshoot the set point, the boundary liquid layer in the tube does overshoot to some extent. When cooling to the priming temperature, too great an overshoot can result in non-specific priming. Therefore the best advantage is to be gained in a system which utilizes this maximum ramp rate combined with optimized overshoots that are symmetrical on both up and down ramps.
FIG. 8 is a chart for predicting and compensating for temperature overshoots and undershoots. In order to drive the block temperature beyond the set point and back again in a controlled fashion the system first measures the block temperature, Tbn+1 and then solves the following equations:
Ts n+1 =Ts n +( Tb n+1 −Ts n )*0.174 /RC
Tsf n =( Tb n −Ts n −mRC )(1 −e −tm/RC )+ mtr n +Ts n
where Tb is the measured block temperature, Ts is the calculated sample temperature, Tsf is the final calculated sample temperature if the block is ramped down at time t n , R is the thermal resistance between the sample block and the sample, C is the thermal capacitance of the sample, m is the slope of a line defined by the points Tb and Tsf and tr is the time for the sample block to return to the set point if the system caused it to ramp toward the set point at the same rate it is was ramping away.
If the resulting Tsf n is within a particular error window around the set point then the system causes the sample block to ramp back to the set point at the same rate it was ramping away. If the resulting Tsf n is outside the particular error window then the system causes the sample block to continue to ramp away from the set point at the same rate. While ramping back toward the set point the same proportional integral derivative (PID) control loop described above is applied.
Determining Sample Temperature
The temperature of a sample in a sample vial is determined by using the model illustrated in FIG. 13 where:
TB 1 k is the measured baseplate temperature; TSmp is the calculated sample temperature; TPlastic is the calculated plastic temperature; TCvr is the measured cover temperature; R 1 is the thermal resistance of the plastic vial between the block and sample mixture; C 1 is the thermal capacitance of the sample mixture; R 2 and R 3 represent the thermal resistance of air in parallel with the plastic vial between the sample mixture and the cover; and C 2 is the thermal capacitance of the plastic vial between the sample mixture and the cover.
The model above is solved for TSmp(t) and TPlastic(t) given that: TB 1 k =mt+TB 1 k 0 , TCvr=K and initial conditions are non-zero. Taking initial conditions and the slope of TB 1 k to be the only variables, as illustrated in FIG. 14 , the equations are refactored giving equations for Tsmp and TPlastic.
Given the following relationships:
g 1=1/ R 1;
g 2=1/ R 2;
g 3=1/ R 3;
a =( g 1 +g 2)/ C 1;
b=g 2/ C 1;
f=g 2/ C 2;
g =( g 2 +g 3)/ C 2;
alpha=−(− g /2 −a /2−(sqrt( g*g −2 *g*a+a*a +4 *f*b ))/2); and
beta=−(− g /2 −a /2+(sqrt( g*g −2 *g*a+a*a +4 *f*b ))/2),
the coefficients for the sample temperature equation become:
coef1=( g 3 /C 2)*(− b /(beta*(alpha−beta))*exp(−beta* T )+ b /(alpha*beta)+( b /(alpha*(alpha−beta)))*exp(−alpha* T ))
coef2=( b /(alpha−beta))*exp(−beta* T )−( b /(alpha−beta))*exp(−alpha* T )
coef3=( g 1 /C 1)*( g /(alpha*beta)+(−alpha+ g )*exp(−alpha* T )/(alpha*(alpha−beta))+(beta− g )*exp(−beta* T )/(beta*(alpha−beta)))
coef4=( g 1 /C 1)*(( g −beta)*exp(−beta* T )/(pow(beta,2)*(alpha−beta))− g /(beta*pow(alpha,2))+(1 +T*g )/(alpha*beta)+(− g +alpha)*exp(−alpha* T )/(pow(alpha,2)*(alpha−beta))− g /(alpha*pow(beta,2)))
coef5=(− g +alpha)*exp(−alpha* T )/(alpha−beta)+( g −beta)*exp(−beta* T )/(alpha−beta)
and the coefficients for the plastic vial temperature equation become:
coef6=( g 3 /C 2)*((beta− a )*exp(−beta* T )/(beta*(alpha−beta))+ a /(alpha*beta)+alpha+ a )*exp(−alpha* T )/(alpha*(alpha−beta)))
coef7=(−beta+ a )*exp(−beta* T )/(alpha−beta)+(alpha− a )*exp(−alpha* T )/(alpha−beta)
coef8=( g 1 /C 1)*( f *exp(−beta* T )/(pow(beta,2)*(alpha−beta))− f /(beta*pow(alpha,2))− f *exp(−alpha* T )/(pow(alpha,2)*(alpha−beta))+ T*f /(alpha*beta)− f /(alpha*pow(beta,2)))
coef9=( g 1 /C 1)*(− f *exp(−beta* T )/(beta*(alpha−beta))+ f /(alpha*beta)+ f *exp(−alpha* T )/(alpha*(alpha−beta)))
coef10 =f *exp(−beta* T )/(alpha−beta)− f *exp(−alpha* T )/(alpha−beta)
and
slope=( TB 1 k−TB 1 k 0)/ T where T is the sampling period (0.174 sec)
Utilizing the model in FIG. 13 then,
TSmp =coef1 *TCvr 0+coef2 *T Plastic0+coef3 *TB 1 k 0+coef4*slope+coef5 *TSmp 0
T Plastic=coef6 *TCvr 0+coef7 *T Plastic0+coef8*slope+coef9 *TB 1 k 0+coef10 *TSmp 0
The coefficients are recalculated at the beginning of each PCR protocol to account for the currently selected sample volume. TSmp and TPlastic are recalculated for every iteration of the control task.
To determine the sample block set point, TB 1 k SP, during a constant temperature cycle, Tb 1 k is determined using the equation for TSmp.
Tb 1 k 0=( Tsmp −coef1 *TCvr 0−coef2 *T Plastic0−coef4*slope−coef5 *TSmp 0)/coef3
When maintaining a constant temperature the slope=0 and Tsmp=Tsmp 0 =TSmpSP (sample temperature set point) and:
TB 1 kSP =( TSmpSP −coef1 *TCvr −coef2 *T Plastic−coef5 *TSmpSP )/coef3
The equation for TB 1 k SP is solved on every pass of the control loop to update the sample block set point to account for changes in temperature of the plastic and cover.
Calibration Diagnostics:
The control software includes calibration diagnostics which permit variation in the performance of thermoelectric coolers from instrument to instrument to be compensated for so that all instruments perform identically. The sample block, thermoelectric devices and heatsink are assembled together and clamped using the clamping mechanism described above. The assembly is then ramped through a series of known temperature profiles during which its actual performance is compared to the specified performance. Adjustments are made to the power supplied to the thermoelectric C devices and the process is repeated until actual performance matches the specification. The thermal characteristics obtained during this characterization process are then stored in a memory device residing on the assembly. This allows the block assembly to be moved from instrument to instrument and still perform within specifications.
AC Resistance Measurement:
The typical failure mode for the thermoelectric devices is an increase in resistance caused by a fatigue failure in a solder joint. This results in an increase in temperature of that joint which stresses the joint further, rapidly leading to catastrophic failure. It has been determined empirically that devices that exhibit an increase in AC resistance of approximately 5% after about 20,000 to 50,000 temperature cycles will shortly fail. The AC resistance of the thermoelectric devices are monitored by the instrument to detect imminent failures before the device in question causes a thermal uniformity problem.
This embodiment automates the actual measurement using a feedback control system and eliminates the need to remove the thermoelectric device from the unit. The control system compensates for the temperature difference between the two surfaces of the thermoelectric device caused by the heat sink attached to one side and the sample block attached to the other. The control system causes the thermoelectric device to equalize its two surface temperatures and then the AC resistance measurement is made. The micro-controller performs a polynomial calculation at the referenced time of the AC measurement to compensate for ambient temperature error.
FIG. 9 shows the sample block 36 , a layer of thermoelectric device 60 and heatsink 34 interfaced with the system microcontroller 62 and bipolar power amplifier 64 . The temperature sensor is already present in the heatsink 38 and an additional temperature sensor attached to the sample block 36 with a clip (not shown) formed of music wire are utilized to determine the temperature differential of the surfaces of the thermoelectric device.
The bipolar power amplifier supplies current in two directions to the device. Current in one direction heats the sample block and current in the other direction cools the sample block. The bipolar power amplifier also has signal conditioning capability to measure the AC voltage and AC current supplied to the thermoelectric device. A band pass filter 68 is incorporated into the signal conditioning to separate an AC measurement signal from the steady state signal that produces a null condition for the temperature difference across the thermoelectric device.
The micro-controller incorporates the necessary capability to process the measurement information and perform the feedback in real time. It also stores the time history of the AC resistance and the number of temperature cycles of the thermoelectric device and displays the information to the operator on the display 70 . The AC measurement is normally done during initial turn on. However, it can be activated when self diagnostics are invoked by the operator using the keypad 72 . An analog to digital and digital to analog converter along with signal conditioning for the temperature sensors and AC resistance measurement is also integrated into the micro-controller in order for it to perform its digital signal processing.
Sealing the Thermoelectric Device Area from the Environment.
The thermoelectric devices are protected from moisture in the environment by seals and the chamber is kept dry with the use of a drying agent such as silica gel. The seal connects from the silver electroform to the surrounding support and as such adds to the edge losses from the block. These losses are minimized by the use of a low thermal conductivity pressure seal 98 and by the use of the perimeter heater described above. The seal 98 has a cross-section generally in the shape of a parallelogram with several tabs 100 spaced about the lower surface of seal 98 for holding seal 98 to the edge of the sample block as shown in FIG. 15 .
The seal 98 is installed by first applying RTV rubber (not shown) around the perimeter 110 of the upper portion of the sample block. The seal 98 is then placed on the RTV rubber. Marc RTV rubber is applied to the perimeter 120 of the seal and then a cover (not shown) is installed which contacts the RTV rubber-seal combination. The cover has a skirt which also contacts a gasket (not shown) on the printed circuit board to effect a more effective seal. | An apparatus comprising an assembly and a cover. The assembly comprises a sample block configured to receive a microtiter tray having a plurality of vials, each vial comprising a cap having a surface and a perimeter. The cover comprises a platen, vertically and horizontally displaceable in relationship to the sample block, the platen having a plurality of recesses. Each recess corresponds to a respective vial and is shaped and arranged to clear the surface of its respective cap when the cover is displaced onto the sample block. The cover includes a skirt in contact with and surrounding a perimeter of the platen. The skirt is configured for mating with a perimeter of a microtiter tray when a microtiter tray is received in the sample block, and also configured such that the cover contacts a microtiter tray when a microtiter tray is received in the sample block. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a hydroponic plant growing apparatus wherein the plant growing tray is provided with a fluid nutrient growing solution from an associate storage chamber.
1. Description of the Prior Art
Hydroponic devices for the growing of agriculture plants are old in the prior art. U.S. Pat. No. 2,674,828 to Tagner, discloses growing trays in an upper layer over tanks containing a nutrient solution in a lower layer. The device utilizes pumping stations to circulate the temperature controlled solution. U.S. Pat. No. 4,603,506 to Powell, Jr. discloses a plant growing tray from which the fluid drains into a lower storage tank from which it is recirculated air pressure. A timer device controls the periodic circulation of the fluid.
SUMMARY OF THE INVENTION
A hydroponic plant growing apparatus providing growing media, light, and water with fertilizer to plants and other vegetation is provided. There is a plurality of growing chambers, each chamber having a porous liner filled with a plant growth media removably placed within. A bottom section of the growing chamber tapers downwardly to a filter section that is part of the chamber. There are a plurality of filters in the filter section. The filters included are a perforated plastic first filter, a second filter comprising a screen having a plurality of openings per square centimeter, an open cell reticulated plastic foam third filter, a fourth filter comprising a screen having a plurality of openings per square centimeter, and a perforated plastic fifth filter. The preferred foam third filter is described by the manufacturer as having 50 to 100 openings per square centimeter. There is a nutrient transfer tube attached to and passing through a port in the filter section and extending downwardly to an air tight plant nutrient tank in the box like structure.
A hydroponic plant growing apparatus may have a first seal, to reduce leakage between the liner and the growing chamber, on the liner; a second seal, to reduce leakage between the transfer tube and the nutrient tank, in the tank; and a third seal, to reduce leakage between an air line extending from an air source to the nutrient tank, around the air line and in the tank. Preferably, a fourth seal is located at the base of the filter section, between the filter section and the transfer tube. The seals may be O-rings as shown in the drawings, grommet or other seals. The third seal is preferably a welded seam as shown in the drawings. The compressed air source, in the box like structure, may pressurize the nutrient tank through the air line and may force nutrients and water through the transfer tube, through the plurality of filters in the filter section, into the chamber, through the liner and into the growth media. There may be a relief valve in a top portion of the plant nutrient tank. There may be at least one electronic timing device to start and stop the compressed air source, such as a compressor, at selected intervals to allow the nutrient tank to be pressurized and depressurized and at least one electric timing device to selectively operate at least one growing light. An amount of water and nutrients may return to the nutrient tank from the growing chamber after the timer turns off the compressed air source and the relief valve opens allowing the nutrient tank to be depressurized. The relief valve may be electronically operated and open and close electronically, at selected intervals, in cooperation with the compressed air supply that pressurizes the nutrient tank. One electronic timing device may operate the compressed air supply, the relief valve and the growing lights.
A hydroponic plant growing apparatus may be enclosed in a box like structure and may have at least one telescopic rod attached to and extending from the box like structure to support a canopy containing at least one electric, plant growing light. There may be a longitudinal, spring loaded, roller containing a pull-down trellis arrangement and extending along a length of a back side of the canopy. A plurality of fasteners, may be connected to a back side of the box like structure to releasably secure the trellis arrangement to the back side of the box like structure.
A method of growing plants and other vegetation has steps which include, among others, providing a box like structure and placing a plurality of growing chambers in the box like structure, and removably placing a porous liner filled with a plant growth media within the chamber. Other steps are providing a bottom section of the growing chamber that tapers downwardly to a filter section that is part of the chamber and placing a plurality of filters in the filter section. The filters included as a part of these steps are: a perforated plastic first filter, a second filter comprising a screen having a plurality of openings per square centimeter, and a perforated plastic fifth filter. The filters may be laminated together for ease of replacement. Further steps are attaching a nutrient transfer tube to the filter section and allowing the tube to pass through a port in the filter section and extending the tube downwardly to an air tight plant nutrient tank in the box like structure.
A method of growing plants and other vegetation may include, among others, such steps as: placing a first seal, to reduce leakage between the liner and the growing chamber, on the liner; placing a second seal, to reduce leakage between the transfer tube and the nutrient tank, in the tank; and placing a third seal, to reduce leakage between an air line extending from an air source to the nutrient tank, around the air line and in the tank. Preferably, a fourth seal is located at the base of the filter section, between the filter section and the transfer tube. Other steps may include pressurizing the nutrient tank through the air line by using the compressed air source, in the box like structure, and forcing nutrients and water in the nutrient tank through the transfer tube, through the plurality of filters in the filter section, into the chamber, through the liner and into the growth media.
Additional steps that may be included are providing a relief valve in a top portion of the plant nutrient tank; using at least one electronic timing device to allow the nutrient tank to be pressurized and depressurized at selected time intervals and providing at least one electric timing device to selectively operate at least one growing light; and returning an amount of water and nutrients to the nutrient tank from the chamber after the timer turns off the compressed air source and the relief valve opens to allow the nutrient tank to be depressurized.
A method of growing plants and other vegetation may also include such steps as: attaching to and extending from the box like structure at least one telescopic rod to support a canopy containing at least one electric, plant growing light; placing a longitudinal, spring loaded, roller containing a pull-down trellis arrangement and extending along a length of a back side of the canopy; and connecting a plurality of fasteners to a back side of the box like structure and releasably securing the trellis arrangement to the back side of the box like structure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially sectioned front view of the hydro apparatus;
FIG. 2 is an end view of the hydroponic apparatus;
FIG. 3 is a sectional elevation view taken through line 1--1 of FIG. 1;
FIG. 4 is a detailed view of the filter section of the hydroponic apparatus;
FIG. 5 is a top rear perspective view of the hydroponic apparatus.
FIG. 6 is a partial cross-sectional view taken along lines 6--6 and partly in elevation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 5 show a hydroponic plant growing apparatus 10 that provides growing media 11, light (not shown, but provided by plant growing lights), and water (not shown) with fertilizer (not shown) to plants (not shown) and other vegetation (not shown) and that has a box like structure 12. The box like structure has a door 22 for access. There are a plurality of growing chambers 13 in the box like structure 12, each chamber 13 having a porous liner 14 filled with a plant growth media 11 removably placed within. A bottom section 15 of the growing chamber 13 tapers downwardly to a filter section 16 that is part of the chamber 13.
There are a plurality of filters in the filter section 16 including a perforated plastic first filter 17, a second filter 18 comprising a screen having a plurality of openings per square centimeter, and an open cell reticulated plastic (a plastic foam) third filter 19. There are also a fourth filter 20 comprising a screen having a plurality of openings per square centimeter, and a perforated plastic fifth filter 21. A nutrient transfer tube 23 is attached to and passes through a port 24 in the filter section 16 and extends downwardly to an air tight liquid plant nutrient tank 25 in the box like structure 12. There is a first seal 26, to reduce leakage between the liner 14 and the growing chamber 13, on the liner 14. There is a second seal 28, to reduce leakage between the transfer tube 23 and the nutrient tank 25, in the tank 25; and a third seal 29, to reduce leakage between an air line 30 extending from an air source 31 to the nutrient tank 25, around the air line 30 and in the tank 25. A fourth seal 52 reduces leakage between the filter section 16 and the transfer tube 23.
As part of the apparatus 10, the compressed air source 31, in the box like structure 12, pressurizes the nutrient tank 25 through the air line 30 and forces nutrients and water through the transfer tube 23, through the plurality of filters 17, 18, 19, 20 and 21 in the filter section 16, into the chamber 13, through the liner 14 and into the growth media 11. There is a relief valve 32 in a top portion 33 of the plan nutrient nutrient tank 25 that opens to depressurize the tank. There is at least one electronic timing device 34, in the box like structure 12, to allow the nutrient tank 25 to be pressurized and depressurized at selected intervals and at least one electronic timing device 50 to selectively operate at least one growing light 35. One of the features of the apparatus 10 is that an amount of water and nutrients returns to the nutrient tank 25 from the chamber 13 after the timer 34 turns off the compressed air source 31 and the relief valve 32 opens to allow the nutrient tank 25 to be depressurized.
At least one telescopic rod 36 is attached to and extends from the box like structure 12 to support a canopy 37 containing at least one electric, plant growing light 35. There is a longitudinal, spring loaded, roller 38 containing a pull-down trellis arrangement 39 and extending along a length of a back side 40 of the canopy 37. A plurality of fasteners 41, connects to a back side 42 of the box like structure 12 and releasably secures the trellis arrangement 39 to the back side 42 of the box like structure 12. There may be a drain plug 43 in an end portion 45 of nutrient tank 25. The plug 43 allows the water and nutrients to be drained from nutrient tank 25 when desired.
A method of growing plants and other vegetation has steps which include, among others, providing a box like structure 12 and placing a plurality of growing chambers 13 in the box like structure, and removably placing a porous liner 14 filled with a plant growth media within the chamber 13. Other steps are providing a bottom section of the growing chamber that tapers downwardly to a filter section 16 that is part of the chamber 13 and placing a plurality of filters in the filter section 16. The filters included as a part of this step are: a perforated plastic first filter 17, a second filter 18 comprising a screen having a plurality of openings per square centimeter, a foam third filter 19, a fourth filter 20 comprising a screen having a plurality of openings per square centimeter, and a perforated plastic fifth filter 21. Further steps are attaching a nutrient transfer tube 23 to the filter section 16 and allowing the tube 23 to pass through a port 24 in the filter section and extending the tube downwardly to an air tight liquid plant nutrient tank 25 in the box like structure 12.
A method of growing plants and other vegetation may include, among others, such steps as: placing a first seal 26, to reduce leakage between the liner 14 and the growing chamber 13, on the liner 14; placing a second seal 28, to reduce leakage between the transfer tube 23 and the nutrient tank 25, in the tank; and placing a third seal 29, to reduce leakage between an air line 30 extending from an air source 31 to the nutrient tank 25, around the line 30 and in the tank 25. A fourth seal 52 reduces leakage between the filter section 16 and the transfer tube 23. Other steps may include pressurizing the nutrient tank 25 through the air line 30 by using the compressed air source 31, in the box like structure 12, and forcing nutrients and water through the transfer tube 23, through the plurality of filters 17, 18, 19, 20 and 21 in the filter section 16, into the chamber 13, through the liner 14 and into the growth media 11.
Additional steps that may be included are providing a relief valve 32 in a top portion 33 of the plan nutrient tank 25; using at least one electronic timing device 34, in the box like structure 12, to allow the nutrient tank 25 to be pressurized and depressurized at selected time intervals and at least one electronic timing device 50 to selectively operate at least one growing light 35; and returning an amount of water and nutrients to the nutrient tank 25 from the chamber 13 after the timer 34 turns off the compressed air source 31 and opening the relief valve 32 to allow the nutrient tank 25 to be depressurized.
A method of growing plants and other vegetation may also include such steps as: attaching to and extending from the box like structure 12 at least one telescopic rod 36 to support a canopy 37 containing at least one electric, plant growing light 35; placing a longitudinal, spring loaded, roller 38 containing a pull-down trellis arrangement 39 and extending along a length of a back side 40 of the canopy 37; and connecting a plurality of fasteners 41 to the back side 42 of the box like structure 12 and releasably securing the trellis arrangement 39 to the back side 42 of the box like structure 12. | A hydroponic apparatus providing a controlled environment for plant growth including artificial light and periodic flushing with a liquid nutrient. Plant growing containers filled with growth media mounted horizontally on a box like structure containing an air tight storage container for liquid plant nutrient extending beneath the enclosures containing the plant containers. Compressed air admitted to the storage tank forces the nutrient liquid up, through the laminated filter section, into the plant container from which the nutrient drains back into the storage tank. A canopy over the assembly contains electric growth lamps and a roll up trellis. |
This is a divisional of co-pending application Ser. No. 06/893,196 filed on Aug. 4, 1986 now abandoned.
BACKGROUND
The invention is directed to the broad field of apparatus for purging closed fluid piping or other flow systems of air or other corrosive gases. In particular, water source heat pumps of the type where a liquid, for example, water or brine is used to exchange heat to and from a heat pump. Such a heat pump is known in the art and is typical of that utilized for heating and cooling living or working space. A water source heat pump (WSHP) evaporates refrigerant liquid which absorbs heat from water circulating through pipes and a heat exchanger. An electric motor driven compressor pressurizes refrigerant vapor, raising its temperature and delivers it to the condenser coil in the space where heat from condensation is released and transferred to circulating air. A reversing valve changes the flow of refrigerant through the water heat exchanger to change from heating to a cooling cycle.
This invention is directed to a WSHP system wherein the circulating water pipes comprise a sealed closed loop of high strength plastic pipe which is buried in the ground or in communication therewith either through vertical bores and/or horizontal trenches adjacent and/or surrounding the house or other location being affected. Typically, such a closed loop of piping will consist of as much as four hundred to five hundred feet per ton (of heat pump rating) of piping depending upon the size of the system, the size and type of pipe and the ambient climate conditions.
The problem with such an earth coupled system is in the start-up procedures wherein the piping is to be first filled or thereafter to be refilled. In order to prevent possible freezing most systems use brine as the heat exchange liquid. Thus, because part of the heat exchange system within the heat pump is subject to corrosion, it is necessary to purge the air from the piping system to substantially minimize such corrosion.
SUMMARY OF THE INVENTION
This invention has as its primary object to provide a system for purging air from the circulating water or brine used with a WSHP wherein the water circulates through pipes buried or otherwise in communication with the ground.
Another object of the invention is to provide plastic purge valves connected to the circulating water piping which provides a means to fill the piping with the circulating liquid and to purge substantially all of the air therefrom.
In particular, the invention is directed to a manifold and valve system whose only purpose is for purging air from a closed loop of plastic piping used with a WSHP. In further particular The piping is directly in communication with the ground by being buried therein and/or in communication with the earth via a vertical bore. The piping includes an inlet header and an outlet header connected respectively to the inlet and outlet to and from the WSHP. An inlet purge valve in accordance with this invention and an identical outlet purge valve are connected respectively to the inlet and outlet headers. Each of these valves comprises a cylindrical body having a central cavity that is in communication with each respective header. One end of the cavity is in closable communication with the cavity or with a means to fill and purge the piping. A valve means is provided within the cavity to open and close same as a part of the process of filling and purging the piping.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective/schematic view describing the invention in combination with a WSHP and a means to fill and purge the circulating liquid piping.
FIGS. 2-4 represent various forms of ground supported and ground communication circulating liquid flow systems used with a WSHP.
FIG. 5 is a sectional view of the valving and manifold system of the invention.
DETAILED DESCRIPTION
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.
A water source heat pump (WSHP) 10 is schematically shown and which normally includes, not shown, a heat exchanger in communication with the refrigerant liquid to deliver heat to and therefrom, by way of an inlet 12 and an outlet 14 connected respectively by way of conduits 16 and 18 on the inlet side and by conduit 20 on the outlet side. Between the inlet lines 16 and 18 is provided a suitable shut-off valve 22, such as the type known as a Grundfos Isolation valve, and an optional flow meter 24. Inlet line 18 is connected to an outlet header 26 while the outlet conduit 20 is connected to an outlet header 28. The system which has been previously described is aptly contained either within the house within which the air is being conditioned or in a suitable contiguous enclosure 30 shown by the dotted lines.
The inlet header 26 is connected to the inlet flow piping 32 while the outlet flow header 28 is connected to the outlet piping 34. Piping 32 and 34 comprise an extensive connected loop of piping or series of piping which are either buried in the ground horizontally as shown in FIG. 4 or are connected in parallel in a plurality of vertical bores 36 which provides communication with the ground temperature, as is described in FIG. 2. FIG. 3 is descriptive of another system using a plurality of vertical bores 38 in the ground wherein the circulating liquid flows in series from the inlet 32 to the outlet 34.
Referring again to FIG. 1 it becomes necessary in the original start up of the circulating liquid system and occasionally for maintenance purposes to fill and purge the circulating flow system encompassing the closed loop piping 32 and 34 and its associated circulating conduits. As shown in FIG. 1 a purge motor and pump 40 delivers liquids via conduit 42 to purge valve 44A to fill the system, including the closed loop or loops 32 and 34, so that the entire conduit system through the heat exchanger of the WSHP is filled with liquid with the excess exiting from purge valve 44B into conduit 48 for return to the supply tank 50.
The purge valves 44A and 44B are identical and best described with reference to FIG. 5. In this FIGURE, header 26, used in this example, is connected to the purge valve 44A and comprises a body having a central cavity 52 which in one position is in communication with the opening 54 and conduit 32 via passageway 56. Normal flow of liquid through the WSHP occurs through threaded sleeve 55 via threaded connectors 58-A and hose connection means 60.
Threads 62 in the purge valve body are adapted to receive the threaded plug 64 or in the alternative, during the fill and purge cycle, a connector 63 having matching threads 65 and hose connections 67. At the other end of the cavity 52 is a valve 68 which is adapted to be rotated on threads 69 to abut against valve seat 70 and thus close passageways 54 and 56. Means are provided at 72 to receive a wrench or other means for rotating the valve body 68 outward to the open position as shown by dotted line.
When it is desired to fill and purge the liquid circulating system, a purge motor and pump 40 and liquid storage are connected to the purge valves 44 and 46 in the manner shown in FIG. 1. Plug 64 of purge valve 44A is removed and replaced by hose connectors 63A and then connected to purge flow line 42. A similar plug is removed from purge valve 44B and replaced by hose connector 63B and then connected to purge flow line 48. Valves 62A and 72B are rotated to open the central cavity 52 of each purge valve. The valve 22 is closed to inhibit flow through the WSHP via flow lines 16, 18 and 20. Motor/pump 40 is started forcing liquid from reservoir 50 via flow line 42 through connector 63A and purge valve 44A into piping 32, thence through the various loops such as shown in FIGS. 2, 3 and 4 and return via piping 34 to purge valve 44B. Because valve 72B is open flow continues out connector 63B into return flow line 48 back to reservoir 50. Once the operator is satisfied that the piping and connected loops are filled and purged of air, valve 22 is opened to permit flow via lines 18, 16 and 20 to fill and purge the heat transfer tubing directly connected in the WSHP system. Again once the operator is satisfied that the system is filled and purged of air the motor/pump is shut down. Valves 72A and 72B are closed. Respective hoses connectors 42/63A, and 48/63B are removed and replaced by plugs 64 in each purge valve. At this point the WSHP system becomes operational.
The invention is particularly adaptable to the use of polyolefin pipe used in the various ground loop circulating liquid system, fittings, connection and purge valves. This is to include PE 3408 polyethylene
Although the invention has been described with particular reference to the water/brine source type heat pump, the valve 44 is applicable to other flow systems handling corrosive liquids. | A manifold and valve system is disclosed for purging air from a closed brine filled loop piping used in conjunction with a water source heat pump. The valves are T-shaped with a closure member or valving member in the top portion which connects with the purge flow conduit. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to self-locking fasteners and, in particular, to bolts, nuts, washers and the like having serrated bearing surfaces that provide resistance against the fastener becoming loosened unintentionally after it has been seated. The self-locking fastener of the present invention can be used to particular advantage for workpieces having relatively soft bearing surfaces whereby marring of the workpiece surface is minimized.
2. Description of the Prior Art
A serious problem in joints secured together by threaded members is the possibility of joint separation due to a nut backing-off from a bolt or a bolt backing-out from a nut or other internally threaded member. Generally, this result can occur when the joint is subjected to vibrations.
Various proposals have been suggested in the past to either eliminate or greatly reduce the unintentional loosening of threaded members. Because of the wide variety of applications in which this undesirable result can occur, many different types of locking devices have been developed. One approach has been to treat the bearing surface of the fastener in such a manner that the resistance to relative rotation between the fastener and a workpiece in which the fastener is installed is greater than the resistance to relative movement between the mating threads. As a result, the resistance to rotation between the mating threaded parts no longer is the critical factor in determining whether the threaded parts will turn relative to each other.
One important requirement of these fasteners is that the "off" torque (torque required to loosen a tightened fastener) be greater than the "on" torque (torque required to seat a fastener properly.)
Because the bearing surface of these fasteners, for the most part, are serrated or are provided with teeth or the like which are arranged to dig into the workpiece to create resistance to relative rotation between the fastener and the workpiece, some damage or marring of the workpiece bearing surface will occur as these fasteners are seated and removed. Such damage to the workpiece causes it to weaken. Hence, a second important requirement of these fasteners is that the effect of marring or damage to the workpiece is minimized.
Generally, most prior art fasteners provided with a locking characteristic in the bearing surface fail to satisfy concurrently these and other requirements. Those fasteners available at the present time having improved "off" torque to "on" torque ratios dig into the workpiece in such a manner or to such an extent as to weaken greatly the workpiece. "Notch" effect (the build up of stress concentrations) is a common result and may cause fatigue failure of the clamped parts. This problem becomes more acute as the thickness of the workpiece is reduced. Those fasteners available at the present time having reduced adverse effect on the workpiece provide insufficient "off" torque.
The drawbacks of this type of prior art fastener are overcome in a fastener such as that disclosed in commonly assigned U.S. Pat. No. 3,605,845. This patent discloses a self-locking fastener which provides a resistance to unintended rotation between the fastener and the workpiece and yet causes a minimum amount of marring of the workpiece surface with which the fastener bearing surface is in contact. This is accomplished by providing a smooth surface annular ring about a plurality of radially disposed serrations which, upon engagement with the workpiece, opposes further penetration of the serrations and controls the extent of penetration of the serrations.
A similar improved fastener is also disclosed in commonly assigned U.S. Pat. No. 3,825,051. This patent discloses a self-locking fastener having a polygon shaped workpiece bearing surface, such as a hex-head, where the serrated segment is formed within an annular segment so that circumferentially discontinuous smooth-faced outer bearing surfaces are formed across adjacent flats of the polygon configuration.
Thus, it is an object of the present invention to provide a new and improved self-locking fastener having a locking mechanism included in the bearing surface of the fastener and which is also provided with a stress regulating configuration within the locking mechanism to control the extent of penetration of the fastener into the workpiece.
It is another object of the present invention to provide a self-locking fastener of this type which provides improved resistance to unintended rotation between the fastener and a workpiece and yet causes a minimum amount of marring of the workpiece surface with which it is in contact.
It is a further object of the present invention to provide a self-locking fastener which is relatively simple in construction and inexpensive to fabricate.
SUMMARY OF THE INVENTION
The self-locking fastener of the present invention has a bearing surface with a plurality of serrations. The serrations, when viewed along a cylinder concentric with the longitudinal axis of the fastener, have the appearance of teeth. Between two teeth are a plurality of intermediate surfaces. The level of the intermediate surfaces, relative to the teeth, is between the crest and root of the teeth. In one preferred embodiment each section comprises an inclined plane starting at the crest of a tooth and proceeding downwardly in the direction of tightening to an intermediate level forming the intermediate surface, which can be considered generally parallel to the bearing surface, and then a second inclined plane extending downwardly in the direction of tightening from the intermediate surface to the root of the tooth. The intermediate surface reduces the marring of the workpiece by the teeth, yet sufficient resistance to vibration exists to prevent unintentional loosening of the fastener.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a perspective view of a self-locking bolt constructed in accordance with the present invention.
FIG. 2 provides an enlarged portion of the perspective view of the self-locking bolt shown in FIG. 1.
FIG. 3 provides an enlarged portion of a cross sectional view of one embodiment of the plurality of serrations between two teeth of the self-locking bolt of FIGS. 1 and 2.
FIG. 4 provides an enlarged portion of a cross sectional view of another embodiment of the plurality of serrations between two teeth. Both FIGS. 3 and 4 show an intermediate surface which minimizes any marring damage.
FIG. 5 provides a perspective view of a self-locking nut constructed in accordance with the present invention.
FIG. 6 provides a perspective view of a self-locking washer constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The aforementioned objects and other objects of the present invention will be more fully understood after consideration of the following description taken in connection with the accompanying drawngs.
Referring to FIG. 1, a self-locking bolt constructed in accordance with the present invention includes a threaded shank 10, and a bolt head 11 at one end of shank 10. Bolt head 11 has a bearing flange 12. The bearing surface of flange 12, that is the surface to be placed in bearing contact against a workpiece (not shown), is provided with a plurality of outwardly disposed serrations 13. In this embodiment the serrations form sets of preferably two, for example serrations 14, which are parallel to each other leaving a wedge-shaped portion, for example 15, between the sets. Serration sets are defined as the surfaces represented in FIG. 1 by four parallel lines.
In another embodiment (not shown) the bearing surface of flange 12 may include a plurality of radially disposed serrations rather than the parallel serration sets 14.
Referring to FIG. 2, which is an enlarged portion of the perspective view of the self-locking bolt shown in FIG. 1, the bolt head 11 is formed at one end of threaded shank 10 and includes bearing flange 12 and the direction of tightening is indicated by the arrow A. The bearing surface of flange 12 has, in this embodiment, outwardly disposed serrations. When viewed along a cylinder concentric with the longitudinal axis of the fastener, the crest of a tooth is represented by 16. A downwardly inclined surface 17 starts at crest 16 and ends at one end of an intermediate parallel surface 18. Surface 18 can be considered generally parallel to the bearing surface of flange 12 or the non-bearing top surface 19 of flange 12. A second downwardly inclined surface 20 starts at the other end of parallel surface 18 and extends downwardly in the direction of tightening to a root 21 of the next tooth. Root 21 of the next tooth is connected by a wall 22, which is generally parallel to the longitudinal axis of the bolt, to the crest 24 of that tooth. Because the serrations in this embodiment are parallel to each other, a pie-shaped wedge 23 separates successive parallel sets. Three pie-shaped wedges 23 are shown to illustrate this feature of the first embodiment. Each pie-shaped wedge 23 is at the same plane as root 21. Although wall 22 can generally be considered to be 90° to the plane of the bearing surface, variations from 90° are acceptable.
FIG. 3 is an enlarged cross sectional view of one set of serrations shown in FIG. 2. From the crest 16 of the tooth, downwardly inclined surface 17 proceeds in the direction of tightening to one end of intermediate parallel surface 18. As previously described, the surface 18 is generally parallel to bearing flange 12. The surface 18 is at a shallower depth, compared to crests 16 or 24, than the greater depth of root 21. From the other end of intermediate parallel surface 18, an inclined surface 20 extends downwardly in the tightening direction to root 21 of the adjacent tooth. The wall 22 extends from the root 21 to the crest 24 of the adjacent tooth. The surfaces 17, 18, 20, 21 and 22 along with the crest 16 can be considered as one set of serrations. When viewed at a right angle to the surface 18, the set consists of four parallel lines.
FIG. 3 also shows another feature of the present embodiment of the invention. The root 21 is connected to wall 22 by a radius or fillet 25, which is not considered essential to the present invention. The crests 16 and 24 are also preferably radiused rather than having sharp edges.
FIG. 4 is an enlarged cross sectional view of one set of serrations of another embodiment of the invention. The embodiment of FIG. 4 differs from the one shown in FIG. 3 in that the crests 26 and 27 of the teeth are truncated with small flats. A downwardly inclined surface 28 starts at a truncated crest 26 and extends in the direction of tightening to the one end of an intermediate surface 29 that is generally parallel to the bearing surface of flange 12. The intermediate surface 29 is at a level between that of crest 26 and a root 31. Another downwardly inclined surface 32 begins at the other end of surface 29 and extends in the direction of tightening to root 31. Surfaces 26, 28, 29, 31, 32 and 33 can be considered as one set of serrations in this embodiment. Also shown in FIG. 4 is a fillet 34 which connects a root 31 with a wall 33 that is generally perpendicular to the surface of flange 12. Fillet 34, however, is not considered essential to this embodiment of the invention.
FIG. 5 shows the invention described above in the form of a nut 40.
FIG. 6 shows the invention described above in the form of a washer 50.
In general, the present invention provides means for limiting the fastener's serrations from penetrating too deeply into the mating surface of the workpiece (not shown) while still providing "off" torques which are greater than "on" torques. This control is provided by the intermediate shallower parallel surfaces (for example 18 in FIG. 3, and 29 in FIG. 4). As the fastener is seated, the crests 16, 26 of the serrations engage the mating surface of the workpiece (not shown) and begin to penetrate the workpiece. Penetration continues until parallel surfaces 18, 20 contact the mating surface of the workpiece. At this point the total bearing area in contact at the mating surface will be sufficient to resist further penetration.
Parallel surfaces 18, 29 can be considered intermediate surfaces which are closer in the axial direction of the fastener to the non-bearing surface 19 of the bolt than are the crests of the teeth and which are further in the axial direction of the fastener from the non-bearing surface of the bolt than are the roots of the teeth. As a result of the relative location of the intermediate surfaces, the teeth are adapted to penetrate into a mating workpiece surface in which the bolt is being installed, and the intermediate surfaces are adapted to control and limit the extent of penetration of the teeth into the workpiece surface when the fastener is operationally installed with the roots of the teeth not bearing against the workpiece surface.
In particular the fasteners of the present invention are more suitable for use on workpieces consisting of soft material such as cast-aluminum or non-heat-treated carbon steel.
While the serrations have been disclosed and described as originating from the same point on the longitudinal axis of the fastener, or as being parallel to each other in sets with each set being separated by a pie-shaped wedge, it is to be expressly understood that different orientations for the disclosed serrations of present invention may also be employed with equally beneficial results. | A self-locking fastener having a bearing surface comprising a plurality of sets of serrations arranged to penetrate a workpiece such that, while a resistance to the loosening of the fastener from the workpiece is created, the marring of the workpiece surface is minimized. Use of the fastener is particularly advantageous if the workpiece consists of soft materials such as cast-aluminum or non-heat treated carbon steels. Each set of serration, when viewed as a profile, includes a downwardly inclined surface, a relatively deeper serration and a relatively shallower intermediate serration. The intermediate serration controls the depth of the penetration into a workpiece. |
PRIORITY CROSS REFERENCE
[0001] This is a continuation of U.S. provisional patent application No. 61/175,588
DESCRIPTION
Field of the Invention
[0002] This invention relates, in general, to the post treatment of wood extracts from forest products plants. This treatment specifically converts and separates the soluble fraction of extracted woody material to industrial grade alcohol, alkaline acetate and water.
BACKGROUND
[0003] Forest products industry effluents contain dissolved or mechanically separated wood extract components. The major wood components are lignin, hemicelluloses and cellulose. The current pulping processes preferably separate the lignin with some loss of hemicelluloses. Dissolved lignin and hemicelluloses are burned for process energy and chemical recovery in the most pulping processes. Some or all dissolved wood components from the processes end up in the effluent treatment plant. The recovery, separation, and upgrade of the degraded hemicelluloses into chemicals and derivatives are not practiced. Most common treatment consists of activated sludge wastewater treatment from which the sludge is land filled or burned.
[0004] Specifically, the steam explosion process dissolves predominantly hemicelluloses in temperatures above 160 degrees C. Hemicelluloses removed in this process is termed “extract”. The wood chips are released through a pressure reducing valve, commonly termed “blow valve” and are used in the production of medium and hard density board. A concentration of the extract through evaporation is energy intensive, although it is currently practiced to produce molasses.
[0005] Previous research indicates that ethanol, acetic acid and their byproducts can be derived from the wood extract. Especially, predominantly hardwood, produces an extract rich in acetic acid and sugars as taught by Amidon et al. in (U.S. Patent Application No. 2007/0079944 A1, Apr. 12, 2007).
[0006] Reverse osmosis membranes achieve only 40% rejection of acetic acid according to Perry's Chemical Engineering Handbook (6th ed. p. 17-26). However, 98% rejection of sodium acetate was reported by the same source. Bartels et al. (U.S. Pat. No. 5,028,336, Jul. 2, 1991) discloses alkalizing water-soluble organic acids and removing them by nanofiltration to reduce aqueous effluent dissolved organic solids. No attempts to purify the retentate were reported.
[0007] Nothing in the prior art teaches the process to convert acetyl groups to acetic acid in the hydrolysate, evaporate and recover pure alkaline acetate using reverse osmosis membrane. The present application discloses, amongst other things, a process wherein the hemicelluloses in the wood extract can be converted to chemical products in an energy efficient process.
SUMMARY
[0008] The present disclosure relates to, inter alia, a process for the production of alcohol and acetic acid derivatives from wood extract. Treatment of hemicelluloses in the extract through hydrolysis, evaporation, reverse osmosis, fermentation and distillation steps is used to recover and concentrate purified water, alcohol and acetate products. The process may be integrated with the host plant to reuse water and minimize process energy and water consumption.
BRIEF DESCRIPTION OF THE DRAWING
[0009] A more complete understanding of the present invention may be obtained by reference to the following detailed description when read in conjunction with the accompanying drawing wherein:
[0010] FIG. 1 . illustrates a typical general arrangement of the unit/system/plant operations for wood extract from a steam explosion process. Other wood extract streams are possible. It is a flow diagram example of the invention process. Process steps may be in other sequences and steps may be omitted.
DETAILED DESCRIPTION OF THE INVENTION
[0011] This disclosure is of a system, plant for production and a method. The disclosure below is directed primarily to methods of carrying out the invention, but the methods also encompass a system or plant for carrying out the method.
[0012] Wood chips are charged in a batch or continuous reactor vessel, commonly termed “digester” together with steam or hot water and heated to a pressure of 5 to 30 atmospheres to treat the wood chips. In some digesters extract from the wood is removed during this treatment process. The treated wood chips are drained or blown through a valve commonly termed “blow valve” then washed with water to recover the majority of dissolved wood components into the wash filtrate; alternatively dilute wash filtrate may be used in lieu of water. The extract and the wash filtrate are collectively termed “wood extract”. The remaining wood chips are subjected to a manufacturing process, where the wood chips are converted to the final product.
[0013] The wood extract contain dissolved xylan, glucan, mannan, arbinan, galactan and acetyl groups in oligomers of hemicelluloses as well as lignin. The wood extract has low organic solids concentration of 0.1% to 12% or more. The majority of water must be removed before an economic treatment of hemicelluloses is possible.
[0014] A possible first step of the process is low solids evaporation. FIG. 1 Step 1. The wood extract is concentrated preferably by evaporation, preferably using mechanical vapor recompression evaporation, to a concentration of 1% to 25% or more. If the wood extract initial concentration is over approximately 5%, this step may be omitted. When the pH is below the acetic acid dissociation point of pH 4.8, some acetic acid is split to the evaporator condensate. Under the appropriate economic criteria, this first step could be done with steam evaporation.
[0015] A second step of the process is hydrolysis. FIG. 1 Step 2. A mineral acid, preferably sulfuric acid, or enzymes is used to hydrolyze the sugars in the concentrated wood extract from the low solids evaporation step 1. Oligomer hemicelluloses are converted into monomer sugars and acetyl groups are released. The pH of the hydrolyzate from hydrolysis is controlled to maintain acetic acid in unassociated form.
[0016] A third step of the process is post hydrolysis evaporation. FIG. 1 Step 3. Hydrolyzate from step 2 is concentrated by evaporation, preferably using mechanical vapor recompression evaporation, up to 25% solids. More of the remaining acetic acid and water is evaporated in this step. Under the appropriate economic criteria, this third step could be done with steam evaporation.
[0017] A fourth step of the process is membrane filtration. FIG. 1 Step 4. Hydroxide, carbonate or bicarbonate of sodium, potassium, calcium or magnesium is added to evaporation condensates from steps 1 and 3 to convert acetic acid in the condensates to acetate. The pH of the solution should be such that nearly all acetate ions are associated, but preferably between pH 5 and 10. Acetate associated with such element produces a membrane impermeable acetate salt that is filterable in a membrane, preferably reverse osmosis membrane, with high efficiency. Because the combined condensate from evaporation contains very little impurities, the membrane permeate is a high degree of recovery as high quality water suitable for example as boiler feed water.
[0018] A fifth step of the process is acetate concentration. FIG. 1 Step 5. The retentate from the membrane in step 4 is concentrated by evaporation, preferably using mechanical vapor recompression evaporation, up to 50% solids. An industry standard finisher or crystallizer can be used to further concentrate to saleable form as may be required by the market.
[0019] A sixth step of the process is fermentation of wood sugars. FIG. 1 Step 6. Sugars in the concentrated hydrolyzate from step 3 post hydrolysis evaporation are fermented in continuous or batch tanks with one or more micro-organisms capable of converting five and six carbon sugars into alcohol and carbon dioxide. The majority of acetic acid, which may inhibit fermentation, was removed in the previous evaporation steps 1 and 3. Some additional acetic acid may be formed during fermentation. Nutrients and pH adjustment chemicals as well as make-up fermentative organism are added in the fermenters as and if needed. Carbon dioxide is removed from the fermenters and scrubbed with cool water for alcohol recovery and the purified gas can be further compressed and sold as industrial grade carbon dioxide. The fermentation broth, commonly termed “beer”, from the fermentation step is sent to step 7, distillation.
[0020] A seventh step of the process is distillation of alcohol. FIG. 1 Step 7. The beer from the step 6 fermentation is sent to a beer distillation column to separate the ethanol from the solids and residual sugars. Alcohol leaving as the overhead from the distillation column is recovered at approximately 50 mass-% strength. The final concentration of the alcohol product is performed in a rectifying column and drying system, preferably a molecular sieve, to obtain over 99 mass-% alcohol.
[0021] An eighth step of the process is the solids concentration from the stillage. FIG. 1 Step 8. The solids, commonly termed “stillage” from the beer distillation column bottom in step 7 can be further evaporated in an optional concentrator, preferably a mechanical vapor recompression-concentrator, to achieve zero-liquid discharge operation. If the sludge from the optional concentrator is burned, the process may become self-sufficient in its thermal energy needs. The condensate from this step is returned to the reverse osmosis feed in step 4.
[0022] It will be appreciated that a combination of all or any of the steps in considered part of this invention and steps may be omitted and still constitute an invention. In the preferred embodiment all disclosed steps are employed.
[0023] Integration of the biorefinery with the host forest products plant.
[0024] An energy integration analysis of the proposed process indicated that utilizing mechanical vapor recompression evaporators achieves the minimum need for cooling water. The heat generated in the process is absorbed into the product water stream, which can be utilized in the host forest products plant. Furthermore, the reverse osmosis water from step 4 is pure enough to be used in the boiler feed water makeup. This results in a reduction of the energy used in the water heating in the host forest products plant as well as unloading its waste water treatment plant operation.
[0025] The claims below form part of this disclosure and are incorporated into the detailed description without repeating the text.
[0026] The description of the invention and its applications as set forth herein is illustrative and is not intended to limit the scope of the invention. Variations and modifications of the embodiments disclosed herein are possible, and practical alternatives to and equivalents of the various elements of the embodiments would be understood to those of ordinary skill in the art upon study of this patent document. These and other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention. | A system or plant and method for the production of pure alcohol, acetic acid or its derivatives from the extract containing hemicelluloses filtered after extraction of woody biomass or directly extracted from woody biomass. The process can be integrated with the host plant process to minimize the effect of loss of heat value from the extracted hemicelluloses and reduce the loading to the effluent plant. |
BACKGROUND OF THE INVENTION
The present invention relates to chairs, particularly office furniture chairs. Many types of chairs are sold in the office furniture industry. So called "shell chairs" are characterized by a visible shell of some sort which is three dimensional and curvilinear in configuration, resembling a clam shell or egg shell and encompassing both the seat and back areas of the chair. A sling type chair is characterized by spaced side rails, either visible or readily apparent, which support some type of upholstery slung thereby. Wire rod chairs, characterized by a visible, relatively thin wire rod are also popular. Plastic stacking chairs having plastic seats and back supported on some sort of tubular frame are also sold in the office furniture industry.
A manufacturer of office furniture must offer a variety of different types of chairs such as those discussed above. Unfortunately, it is expensive to offer such alternatives since different components and tooling are required for each line of each different type of chair.
SUMMARY OF THE INVENTION
The present invention makes possible two different lines of two different types of chairs for significantly less than one might expect. A sling type of chair and a shell type of chair can be produced using many common components and common tooling.
The chair system of the present invention employs a pair of spaced side rails mounted on the ends of a stretcher which in turn is mounted on a base, each of the side rails being suitable for finishing whereby they can be exposed if a sling type chair is desired. A formed plastic supporting seat and back means secured at each side to the spaced side rails includes a rear surface which is suitable for exposure to view at least in the back portion, in the event that a sling type chair is desired. A first upholstery and cushion means is shaped and adapted to cover the front surfaces of the supporting seat and back means without covering the side rails at the rear of the seat and back supporting means. By using the above components and the first upholstery and cushion means, a sling type chair can be produced. A second upholstery and cushion means shaped and adapted to cover the front surfaces of the supporting seat and to wrap around to the rear surfaces thereof, generally covering the spaced side rails, is provided if a shell type chair is desired. A molded plastic shell is secured to and covers the rear of the chair, including the spaced side rails and the rear surfaces of the supporting seat and back.
In connection with the present invention, the problem of securing a shell to a shell type chair is also solved in a most expedient and inexpensive manner. In the prior art, nonload bearing trim shells have been secured to load bearing structural shells or their equivalent by screws located at the periphery of the outer shell, the screw heads being covered by a plastic trim member. The present invention eliminates the need to fool with a plastic trim member because the shell includes a groove in the rear surface thereof. The fastener screws for securing the shell to the chair are located down in the groove and the groove is sufficiently deep and narrow that the screws are not readily visible except upon very careful inspection of the chair.
These and other objects, advantages and features of the invention will be more fully understood and appreciated by reference to the written specification and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sling type chair made in accordance with the chair system of the present invention;
FIG. 2 is a perspective view of a shell type chair made in accordance with the chair system of the present invention;
FIG. 3 is a perspective view of the stretcher and spaced side rails employed in the present invention;
FIG. 4 is a bottom plan view of the stretcher and spaced side rails;
FIG. 5 is a perspective view of the assembled, common components of both the sling and shell type chair of the present invention, with the exception that the particular arms and particular base of the sling type chair are shown;
FIG. 6 is a fragmentary view taken at the lower front corner of the chair, from the undersurface thereof, at the corner identified by Arrow VI in FIG. 5;
FIG. 7 is a fragmentary view of the upper rear corner of the chair, taken from the rear of the chair, at the point indicated by Arrow VII in FIG. 5;
FIG. 8 is a fragmentary cross sectional view taken along plane VIII--VIII of FIG. 5;
FIG. 9 is a rear elevational view of the juncture of the supporting seat and back of the chair at the area shown in FIG. 8;
FIG. 10 is a generally rear perspective view of the upholstered inner back member of the sling type chair;
FIG. 11 is a generally bottom perspective view of the upholstered inner seat member of the sling type chair;
FIG. 12 is a cross sectional view taken along plane XII--XII of FIG. 1;
FIG. 13 is a cross sectional view taken along plane XIII--XIII of FIG. 1;
FIG. 14 is a cross sectional view of the upper portion of the shell type chair without the shell attached, taken along plane XIV--XIV of FIG. 2;
FIG. 15 is a bottom plan view of that portion of the shell type chair shown in FIG. 14;
FIG. 16 is a side elevational view of the shell of the shell type chair;
FIG. 17 is a rear elevational view of the shell;
FIG. 18 is a fragmentary cross sectional view taken along plane XVIII--XVIII of FIG. 2; and
FIG. 19 is an exploded perspective view of the various components employed in the shell type chair of the system of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a preferred embodiment sling type chair while FIG. 2 shows a preferred embodiment shell type chair, both made using the basic system of the present invention. The sling type chair shown in FIG. 1 is so called because it has the characteristic spaced side rails so often seen in such chairs. Technically, the FIG. 1 chair is a marriage of a sling type chair, which usually includes a loose fabric slung between the spaced side rails, and a stacking type of chair in which molded plastic seat and back members are secured to some sort of frame. The sling type chair as shown in FIG. 1 is itself disclosed and claimed in my prior U.S. Pat. No. 3,947,068.
In the present invention, I take advantage of some of the basic components of the chair of my previous invention to create the two chair system of the present invention. Thus, the construction of that chair will again be explained in this patent as it relates to the sling type chair and, as certain of the components relate to the shell chair employed in the chair system of the present invention.
In the preferred embodiment, both chairs 1 and 2 comprise a stretcher 20 operably mounted on a base 10 for supporting at its ends a pair of spaced side rails (FIG. 3). Secured to side rails 30 are a formed plastic supporting seat 40 and a formed plastic supporting back 50 (FIG. 5) each having at its side edges side channels 41 and 51 respectively which are seated over side rails 30 (FIGS. 5, 6 and 7).
Alternative chair 1 of the system is upholstered and cushioned by upholstered seat and back pads 60 and 80 (FIGS. 1, 10 and 11). Secured to seat 40 is a formed plastic inner seat 60 having a configuration conforming generally to that of supporting seat 40 and being covered by upholstery covering 70 (FIGS. 1, 11 and 12). Secured to back 50 is a formed plastic inner back 80 which is covered by back upholstery covering 90 (FIGS. 1, 10 and 13). The arms 100 of chair 1 may be optionally attached to the chair by securement to stretcher 20 (FIGS. 1 and 4).
Chair 2 disclosed in FIG. 2 is a shell type chair in which the upholstered inner seat and back members 60 and 80 are eliminated and a different type of upholstery assembly 210 and 220 are employed to upholster and cushion the supporting seat and back members 40 and 50. Basically, cushion members are adhered to the inner seat and back members and an upholstery covering is wrapped around to the rear sides of the supporting seat and back members 40 and 50 so that it covers the spaced side rails 30. Shell 230 is then secured to the rear of the chair by means of fasteners 232 located in the rear of shell 230 (FIGS. 17 and 18).
COMPONENTS COMMON TO BOTH THE SHELL CHAIR AND SLING CHAIR
Base 10 is a pedestal type of base having a post 11 with a plurality of legs 12 projecting outwardly from generally the bottom thereof and with a chair tilter control 13 or other mounting mechanism positioned generally at the top of post 11 (FIG. 1). Stretcher 20 includes an enlarged, generally square shaped central mounting pan 21 to which control 13 is fastened by bolts or like fasteners.
Stretcher 20 is formed of stamped steel. Projecting outwardly from each side of central mounting pan 21 are a front strut 22 and a rear strut 23 (FIGS. 3 and 4). Bent over along the front of stretcher 20 is a front wall 24 which extends downwardly across the front edge of mounting pan 21 and across the leading edge of both front struts 22. Projecting downwardly from the rear edge of stretcher 20 is rear wall 25 which extends along the rear edge of mounting pan 21 and along the rear edges of rear struts 23. In a similar fashion, a side wall 26 extends downwardly and runs along the side edges of mounting pan 21 and extends outwardly along the inside edges of front and rear struts 22 and 23 which face each other. All of these downwardly depending walls 24, 25 and 26 help to hide from view the control 13 of base 10 and its securement to stretcher 20. Also, the downwardly depending walls give added strength to stretcher 20. Finally, in extending along struts 22 and 23, these walls give the struts a generally downwardly opening channel shaped configuration which facilitates the mounting of arms 100 or 200 to the struts 22 and 23 of stretcher 20. Preferably, the front defined by front strut channels 22 and front wall 24 are formed as one piece, the rear defined by rear strut channels 23 and rear wall 25 are formed as one piece and mounting pan 21 is formed as one piece. These three pieces are then welded together to form an integral stretcher 20.
Stretcher 20 also includes an upwardly protruding dome 27 generally in the center of mounting pan 21 which leaves clearance space for the top of control 13 of base 10. Dome 27 also provides a support for supporting seat 40. The distance between the bottom of supporting seat 40 and the top of dome 27 is about 3/8 inch. It is sufficiently small distance that when a person sits on the chair, supporting seat 40 comes to rest on the top of dome 27 before sufficient stress is put on channels 41 to cause them to unwrap from or, in other words, be pulled off of side rails 30. In essence, dome 27 serves as a support so that at least some of the load imposed on the chair is transmitted directly axially downwardly onto dome 27 and from thence to the column 11 of base 10.
The side rails 30 which are welded to the ends of struts 22 and 23 are tubular steel members bent to define a seat supporting portion 31 and a back supporting portion 32 (FIG. 3). They can be bent into any of a number of different configurations to give the sling type chair 1 a particular aesthetic or ornamental appearance.
Supporting seat 40 is formed by injection molding of a polypropylene copolymer (approximately 13% polyethylene). Other plastics and other forming methods can be used. Seat 40 should be quite rigid, having a thickness of approximately 5/32 inch. When supported on side rails 30, supporting seat 40 serves to support a person seated in the chair. While the shape of supporting seat 40 is to some extent dictated by comfort considerations, the ornamental designer does have some leeway and can affect the design theme of chair 1 by varying the shape to be given seat 40, particularly at the front, rear and side edge portions. Of course, such changes have no significant bearing in the appearance of shell chair 2.
The channels 41 which are formed at each side of seat 40 are raised generally with respect to the rest of seat 40 so as to define a well 42 between the spaced channels 41 (FIG. 12). It is not essential that the entire surface of seat 40 be below the level of the tops of channel 41 (it will be noticed that seat 40 raises somewhat towards the middle) but it is preferable that there be a well-like depression at least in the area adjacent the side channels 41. In this manner, when the upholstered inner seat 60 is secured to supporting seat 40, its edges will be positioned fairly closely adjacent the inside wall of the raised channels 41 and it will be more difficult to get underneath the seat upholstery pad 60 and pry it upwardly. This is not imperative with respect to shell chair 2.
At the underside of seat 40, at each front corner of seat 40, each side channel 41 terminates in a recessed pocket 49 into which the forward end of side rail 30 extends (FIG. 6). This not only serves to hide the end of side rail 30, but also serves to secure supporting seat 40 in place at the front of the chair.
Back 50 is formed by injection molding of a polypropylene copolymer (approximately 13% polyethylene). Other plastics and other forming methods can be used. Back 50 should be quite rigid, having a thickness of approximately 5/32 inch. When supported on side rails 30, supporting back 50 serves to support a person leaning back in the chair. As with seat 40, the shape of supporting back 50 is to some extent controlled by comfort considerations. However, the designer has some leeway for purely ornamental considerations, particularly along the top, bottom and side portions. The channels 51 are formed at each side of back 50 so as to define a well 52 between the spaced channels 51 (FIG. 13). It is not essential that the entire surface of back 50 be below the level of the tops of channel 51, but it is preferable that there be a well-like depression at least in the area adjacent the side channels 51. In this manner, when the upholstered inner back 80 is secured to supporting back 50, its edges will be positioned fairly closely adjacent the inside wall of the raised channels 51 and it will be more difficult to get underneath the back upholstery pad 80 and pry it upwardly. Again, this is important only with respect to sling type chair 1, not shell chair 2.
At the backside of back 50, at each top corner of back 50, each side channel 51 terminates in a recessed pocket 59 into which the upper end of side rail 30 extends (FIG. 7). This not only serves to hide the end of side rail 30, but also serves to secure back 50 in place at the back of the chair.
The side channels 41 of seat 40 include projecting portions or seat channel projections 43 which project rearwardly and upwardly from the rear edge of seat 40 towards back 50 (FIGS. 5 and 9). Similarly, the side channels 51 of back 50 include projecting portions or back channel projections 53 which project downwardly from the bottom of back 50 towards seat 40. Channel projection 43 terminates in a channel shaped flange 44 while channel projection 53 terminates in a channel shaped overlying flap 54. Flap 54 overlaps flange 44 so that the side channels 41 and 51 meet in such a way as to align channel projections 53 and 43 and to define a continuous, smooth flowing surface with only a slight line being visible at the junction. Once flap 54 is seated over flange 44, a screw is passed through a screw hole 54a in the inside of channel projection 53 (FIGS. 8 and 9), above flap 54, and is threaded into underlying side rail 30. Similarly, a screw is passed through screw hole 44a in the inside of channel projection 43 and is threaded into underlying side rail 30. This positively locks supporting seat 40 and supporting back 50 in place at their rear and bottom respectively so that once the ends of side rails 30 are in place in the pockets 49 and 59 of seat 40 and back 50 respectively and once the projecting side channel portions 43 and 53 are in their proper overlapping condition and secured by screws through holes 54a and 44a, the back 50 and seat 40 are firmly secured to side rails 30.
THE SLING TYPE CHAIR
The first type of upholstery and cushioning used in the system comprises an upholstered inner seat 60 and an upholstered inner back 80. This first system is employed in the sling type chair.
Inner seat 60 is preferably injection molded of basically the same plastic of which supporting seat 40 and supporting back 50 are made and has a thickness of approximately 1/8 inch. It should have sufficient thickness and rigidity that it will hold its shape when secured to supporting seat 40 and such that it will not be bent out of shape when it is covered with upholstery covering 70. It is molded to have a configuration conforming generally to the configuration of the inside of supporting seat 40 within well 42 (FIGS. 11 and 12). Inner seat 60 is approximately as wide as the distance between the inwardly facing walls of side channels 41 of supporting seat 40.
For securing inner seat 60 to supporting seat 40, seat 40 is rolled over along its front edge 45 and includes three integrally molded buttons 47 projecting from its front edge 45 at spaced intervals therealong (FIG. 5). Projecting from the rear edge 46 of seat 40 are three spaced integrally molded tabs 48. In a somewhat similar manner, four integrally molded buttons 58 project upwardly at spaced intervals from the rolled over top edge 56 of back 50 and three integrally molded buttons 57 project downwardly from the rolled over bottom edge 55 of back 50. These integrally molded projecting buttons and tabs facilitate securement of the upholstered inner seat 60 and inner back 80 to seat 40 and back 50 respectively. Inner seat 60 is rolled over along its front edge to define a front lip 61 and it is turned sharply over along its rear edge to define a rear lip 62. Front lip 61 includes three spaced holes 63 therein, whose positions correspond generally to the front projecting buttons 47 of seat 40. In this manner, inner seat 60 is secured along the front edge of supporting seat 40 by snapping the enlarged heads of projecting buttons 47 through the holes 63 of inner seat 60. Rear lip 62 includes three spaced slots 64 (FIG. 11) spaced at intervals corresponding to the spacing of tabs 48, and each having a length corresponding approximately to the width of a tab 48, so that the rear of inner seat 60 is secured in place by snapping rear lip 62 over the rear edge 46 of supporting seat 40 with tabs 48 projecting into slots 64.
Inner back 80 is similarly molded of basically the same plastic of which supporting seat 40 and supporting back 50 are molded and has a thickness of approximately 1/8 inch. As with inner seat 60, inner back 80 must have sufficient thickness and rigidity to hold its shape during the covering process and to hold its shape when secured to supporting back 50. Inner back 80 is molded to have a configuration corresponding generally to the configuration of the front surface of supporting back 50 in the area of the well 52 of back 50 (FIGS. 10 and 13). Inner back 80 is approximately as wide as the distance between the inwardly facing walls of side channels 51 of supporting back 50. Inner back 80 includes a rolled over bottom lip 81 and a rolled over top lip 82 which fit over the bottom edge 55 and top edge 56 of back 50 respectively. Top lip 82 includes four spaced holes 84 therein which receive the four spaced top projecting buttons 58 of back 50 and bottom lip 81 includes three spaced bottom holes which are spaced to correspond to buttons 57 and into which snap the heads of bottom buttons 57. The bottom holes are formed in a manner similar to holes 84.
Inner seat 60 is covered with an upholstery covering composite 70 which includes a layer of cushioning material 71 and suitable upholstery material 72 (FIGS. 11 and 12). The cushioning material is adhered to the top surface of inner seat 60 with a suitable adhesive. Similarly, the upholstery 72 is adhered to the cushioning material 71 by suitable adhesive. Additionally, the upholstery 72 is wrapped around all of the edges of inner seat 60 and is attached by adhesive or possibly by other fastening means along the upholstery edges to the rear surface of inner seat 60. FIG. 11, which is a view of inner seat 60 from the underside, is helpful in illustrating the manner in which the upholstery 72 is wrapped around the edges of inner seat 60 and adhered to the rear undersurface thereof.
Back upholstery covering composite 90 is similar and includes a layer of cushioning material 91 which is adhered to the front surface of inner back 80 and a layer of upholstery 92 which covers cushioning 91 (FIG. 13). Upholstery 92 is wrapped around all of the edges of inner back 80 and is attached to the rear surface thereof as above. FIG. 10 is a generally rear perspective view of inner back 80 and shows the manner in which upholstery 92 is wrapped over its edges and adhered to the rear surface thereof.
Arms 100 of the present chair are an optional attachment (FIGS. 3 and 4). Each arm 100 is a bar of metal such as cast aluminum, formed sheet steel, or the like which is generally U-shaped in configuration and which includes a forward end portion 101 and a rear end portion 102 which project inwardly toward the center of the chair, out of the generally vertical plane of the remainder of the generally U-shaped arm 100. The forward projecting end portion 101 fits snugly into the channel defined by front strut 22 of stretcher 20 and the rear end portion 102 fits snugly into the channel defined by rear strut 23. Each end portion includes a pair of spaced threaded bolt holes 103 therein whereby a suitable bolt fastening can be used to secure the end portions 101 and 102 to their respective struts 22 and 23. It will be noted that matching holes 104 are provided in all of the struts to facilitate passing of the bolts through the struts.
In assembly, the inner seat 60 and inner back 80 are covered with cushioning 71 and 91 respectively and upholstery 72 and 92 respectively in the manner indicated above. Arms 100 may be added optionally to the struts of stretcher 20. The supporting seat 40 and supporting back 50 are then secured to the side rails 30 in the manner indicated above and the covered inner seat and inner back are secured to the supporting seat and supporting back respectively in the manner indicated above. The completed assembly is then secured to base 10.
THE SHELL TYPE CHAIR
The second type of upholstery and cushioning employed in the system of the present invention comprises a seat upholstery and cushion assembly 210 and a back upholstery and cushion assembly 220 (FIG. 14). An urethane foam pad 211 of relatively firm density is glued directly to supporting seat 40. Glued to it is a less dense material 212 and laying on top of it is a top pad 213 which is approximately the same density as layer 212, but which lies loosely on top of layer 212 whereas layer 212 itself is glued to the bottom pad 211. All of this generally conventional cushioning is in turn covered with an upholstery layer 214 which is wrapped around the edges of supporting seat 40 and is stapled, glued or both to the rear surface of supporting seat 40 as shown in both FIGS. 14 and 15. It will be noted by reference to FIG. 15 and FIG. 18 that the spaced side rails 30 are completely covered by the upholstery material 214.
In a similar manner, the upholstery and cushion assembly 220 which covers supporting back 50 includes a bottom pad or cushion 221 of relatively firm density which is loosely covered by a less dense pad 223. The bottom edges of these upholstery pads are simply allowed to project through the space between supporting seat 40 and supporting back 50. An upholstery covering 224 covers these pads and is wrapped around the top and side edges of supporting back 50 and is glued and/or stapled to the rear of supporting back 50 in such a way that the spaced side rails 30 are covered.
The bottom edge of upholstery material 224 is pulled down through the opening between supporting seat 40 and supporting back 50 and is wrapped around and stapled or glued to the underside of supporting seat 40 along its rear edge (FIGS. 14 and 15). It is actually lapped over the top of the rear edge of upholstery covering 214. In this way, the supporting seat 40 and back 50 are covered in a continuous manner as though they were a single unit, and no space shows between the two in the finally assembled chair. This is in contrast to the sling type chair where a space between the upholstered supporting seat 40 and back 50 is clearly visible and is part of the design.
One advantage to having the space between the supporting seat and back is the ability to easily pull the bottom of covering 224 through the space and secure it to the rear edge of supporting seat 40, thereby creating a neat tuck or seam appearance at the juncture of the seat and back of the shell type chair. Another advantage is that while the lumbar region is clearly supported by the supporting back 50, the rear of the buttocks of a person seated in the shell type chair are more softly received and supported by that portion of the back cushion assembly which projects through the space between supporting seat 40 and back 50, thereby providing a softer comfort in that area of the body.
Shell 230 is a molded plastic shell with integral seat and back covering portions (FIGS. 16, 17 and 19). It is molded of a material such as polypropylene, polyethylene or the like of a softer, more flexible grade so that it will give or yield slightly when it comes into contact with an article of furniture.
Molded into shell 230 is a groove 231 which opens to the rear and bottom of the chair. It extends generally along the top and side edges of the shell, spaced a short distance in from the edge of the shell. The depth of groove 231 is approximately 3/4 inch, although at some points it is shallower, particularly at the points where the arms are to be secured to the chair, along the side of the seat covering portion of shell 230 (FIGS. 16 and 19). Groove 231 is also relatively narrow, approximately 1/4 inch, although it is slightly wider at the top than at the bottom to facilitate withdrawal of shell 230 from the mold. Because of the depth and narrowness, it serves to conceal from casual view the small fastener screws 232 which are used to secure shell 230 to the rest of the chair 2.
Specifically, shell chair 2 is assembled by first assembling the basic components shown in FIG. 5 (excluding arms 100 and base 10). The upholstery and cushion assemblies 220 and 210 are then secured to supporting back 50 and supporting seat 40 as explained above. Shell 230 is then located to the rear of the assembly shown in FIG. 14 and is secured to spaced side rails 30 by means of fastening screws 232 (FIGS. 18 and 19). The screws 232 are located within groove 231 at various points along the seat and back portions of spaced side rails 232. For good measure, one or two fastening screws 232 may be located in that portion of groove 231 which runs along the upper back of the chair, with the fastening screws 232 extending into inner supporting back 50. A similar arrangement could be employed along the front of the seat, although it is not necessary. In fact, no groove 231 is provided along the front edge of shell 230 in the preferred embodiment.
An alternative set of arms 200 may also be secured to shell type chair 2. In assembly, the alternative arms 200 would be secured prior to securing shell 230. Arms 100 could be used if the outer shell was modified to provide greater clearance in notch 233 (FIGS. 16 and 19), but the use of the alternative arm 200 adds further variety to the two different lines of chairs. Arm 200 is an oval type arm with a flange 201 including inwardly projecting mounting portions 203 which bolt within the channels defined by the struts 22 and 23 of stretcher 20, just as the ends of arms 100 fit into and are bolted to struts 22 and 23 (see FIGS. 4 and 6). The inwardly protruding groove 231 is reduced or eliminated and shell 230 is notched slightly at 233 to accommodate the passage of flange 201 and projections or mounting portions 203 through shell 230 and into the receiving channels defined by struts 22 and 23. A suitable arm cap assembly 202 is also provided as a further decoration.
Just as arms 200 are different from arms 100 employed in the sling type chair, so too a different base 10a can also be employed in the shell type chair (FIG. 19). Once shell 230 is assembled to the chair, the entire assembly can be secured to base 10a. A suitable aperture 234 is provided in the bottom of shell 230 to allow the passage of the upper pan of chair control 13 of base 10a through shell 230 and to facilitate its securance to stretcher assembly 20.
CONCLUSION
As a result of the system of the present invention, a manufacturer can offer two completely different types of chairs, shell and sling, using some common components and common tooling. While I have specifically employed a sling type chair made in accordance with my earlier invention, U.S. Pat. No. 3,947,068, and while I have designed a particular shell type chair as part of the system, it will be apparent to those skilled in the art that various changes and alterations can be made to both the sling chair design employed and the shell chair design employed without departing from the spirit and broader aspects of the invention as set forth in the appended claims. | The specification discloses a chair system wherein two different types of chairs, a shell chair and a sling chair, can be made using the same basic components and tooling. Spaced side rails support a separately molded plastic seat and back which can be upholstered with upholstery pads which do not cover the side rails to create a sling type chair, or which can be upholstered with a wrap-around type of upholstering and covered on the rear surface by a shell when a shell type chair is desired. |
This is a divisional of copending application Ser. No. 200,917 filed on Feb. 22, 1994 which is a File Wrapper Continuation of Ser. No. 949,783 filed on Sep. 22, 1992 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a thermoplastic preform, apparatus and process for blow molding the preform into biaxially oriented, shaped articles and, more particularly, to annealing returnable polyethylene terephthalate bottles which are subjected to washing and reuse.
2. The Prior Art
Refillable plastic bottles reduce landfill and recycling problems of disposable plastic beverage bottles and, more particularly, those bottles formed from polyethylene terephthalate or PET.
A refillable plastic bottle must remain aesthetically pleasing and functional over numerous washings and refillings as discussed by U.S. Pat. Nos. 4,755,404, 4,725,464 and 5,066,528. Cracks, color changes, volume or structural change must be minimized.
U.S. Pat. No. 4,385,089, teaches how hollow biaxially oriented shaped articles are formed from intermediate products which may be sheets or other shapes when thermoformed or parisons or preforms when injection molded, injection blown or extrusion blown. The preform may be prepared and immediately used hot or may be stored and reheated later to a temperature having sufficient elasticity to be shaped into a bottle or other form by drawing and blowing in a cooled mold to obtain the final shape of the article. The preform is next often subjected to a heat treatment at well above the glass transition temperature of the thermoplastic to increase the articles strength and resistance to gas loss. Heat treatment also prevents distortion when the bottle is reused, including distortion during a hot caustic wash.
For other heat treating patents, see U.S. Pat. No. 4,233,022 and patents cited therein. The '022 patent teaches use of a blow mold comprising four sectional members each separated by insulating portions used to heat treat blown bottles at a temperature within the range of 150° C. to 220° C.
U.S. Pat. No. 5,085,822, teaches it is old to blow in a mold at 130°C. and cool to 100°C. to prevent deformation on removal of the container from the mold. Also taught is to retain a container in the blow mold and heat to remove stress and thereafter transferring the deformable container to a separate cooled mold to solidity. The "822" patent holds the molded container for a predetermined period of time to heat set the container followed by introducing a cooling fluid into the bottle. Also disclosed is heat setting a blown container in a separate mold.
U.S. Pat. No. 4,505,664, teaches transporting the blowing cavity and blown article to a second station where medium is circulated through the article.
U.S. Pat. No. 4,488,279, biaxially orients the article which can then be heat set.
U.S. Pat. No. 5,080,855, teaches blow molded articles which may be heat set in a second mold. Also, see also U.S. Pat. No. 4,485,134, 4,871,507 and 4,463,121 which discuss heat treating biaxially oriented bottles.
U.S. Pat. No. 4,572,811, teaches heat treating a PET container to form a spherulite, opaque texture which we have found leads to stress cracking when bottles are recycled.
U.S. Pat. No. 4,588,620, teaches preforms having a thinner bottom wall and which permit longer or deeper stretch of the shoulder and sidewall portions.
While it is known to biaxial stretch a preform using pressure, we have found the annealing of-the blown preform to be a critical factor in producing carbonated beverage bottles that are refillable.
SUMMARY OF THE INVENTION
The present invention presents a unique preform designed to form a refillable bottle, and a method and apparatus that applies three unique temperatures on the inner wall of a warm blow mold to precisely anneal a blown article such as a beverage container.
A hot preform, about ≈90° C. to 110° C., is rapidly expanded against the inner surface of the warm mold and held there by internal pressure until the temperature of the shaped container reaches the annealing temperature of the mold wall in the case of at least the neck-shoulder and body portions of the bottle. The bottom heel portion which is relatively thick and amorphous is cooled as rapidly as possible to reduce the base temperature to below the body wall annealing temperature.
Portions of the mold section have channels for passing warm water through the mold wall to control the wall temperature and anneal the blown article at the desired temperature.
Each portion substantially abuts and often contacts adjoining portions so that the temperature of the mold wall near the edge of each portion exhibits a gradual temperature profile and avoids sharp temperature differences which can stress the bottle and result in bottle failure during reuse. The body section of the mold is maintained at about 80° C. using 80° C. warm water. The neck-shoulder area is maintained at 70° C. or below normally about 60° C. using warm water. These temperatures rapidly reduce the blown thermoplastic temperature for PET from just above the glass transition temperature to 80° C. on the side wall and 60° C. on the upper wall section, thus, annealing the container and reducing stress. The bottom heel portion of the molded article is cooled with cold water to rapidly reduce the thicker base to below 80° C. normally below 70° C..
The preform is designed with an inside and outside uniformly tapered wall which increases the wall thickness from the neck to side or body portion of the preform at least two fold.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a preform having taper wall, prior to blow-molding and annealing.
FIG. 2 shows a blow-mold section in which, when closed with another opposing section, the preform is rapidly expanded and illustrates the three temperature controlled portions of the mold used for annealing.
FIG. 3 is a block diagram illustrating the various steps of the process and features of the apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a preform, and an apparatus and method for annealing a blown molded thermoplastic article immediately after the preform is blown to the shape of the blow-mold. Rather than using a hot mold for heat treatment, where stickage can result, or a cold mold to rapidly cool the blown article, where stress can be developed, the side or body portion of the mold walls, upper bottle or neck-shoulder portion of the mold walls and the bottom and shoulder portion of the mold walls are each regulated to reduce and control the wall temperature or anneal the bottle wall which reduces and equalizes stress created during the biaxial stretching of the preform to the bottle shape. The annealing temperature is cool enough to allow the bottle to be removed from the mold without deformation.
The bottle herein described is a 1.5 liter carbonated beverage bottle which can be further treated or allowed to cool, stored and be later filled with product. The bottle may be cleaned using hot caustic and reused. Various size bottles are possible by making commensurate changes in the size of the preform and blow mold.
The preform 1 is shown in FIG. 1 where one-quarter of the preform has been cut in a plane perpendicular to the paper shown as A-A and within the plane of the paper exposing the quadrant marked 3 having relatively thin screw cap area 5 which becomes the neck portion 63 of FIG. 2, a tapered portion shown as 7 and 13 which when drawn and blown into a bottle forms the slowly tapering bottle surface apparent in FIG. 2 at 27 of the neck-shoulder portion 22 of the mold. There is a relatively long wall 9 which are drawn and blown into the long bottle wall contacting 28 shown in body portion 20 of the mold in FIG. 2. The preform base 11 may initially contain less thermoplastic than the side wall 9 but after being blow molded into a bottle is relatively thicker than the side walls and more difficult to cool and would contact surface 29 in the bottom and shoulder portion 24 of the mold shown in FIG. 2. The degree of taper of the inside 13 surface and outside 7 surface of the preform of FIG. 1 is extensive and sufficient to increase wall thickness at least 2 fold from neck to body.
For the 1.5 liter bottle the top of the neck or cap 2 of the preform of FIG. 1 has a thickness of 2.1 mm and the neck has a length of 28 mm prior to the beginning of the tapered portion. The thickness at the beginning of the taper at 4 is 2.75 mm and 6.9 mm shown at 6 on the body wall thickness. The tapered portion is 20 mm long and the constant circumference length of the body portion is 94 mm. The wall thickness at the narrowest portion of the bottom of the preform is 4 mm.
Referring now to FIG. 2, there is shown a mold section 21 having four mold portions 20, 22, 24 and 60 which are in cooperative and normally adjacent relationship to at least one of the other mold portions and comprise one-half of a female mold which, when closed, forms the general shape shown by the line marked 25, 27, 28 and 29 which outlines a cavity surface generally shown as 62, 42, 26, and 52. The cavity is normally formed by preparing a mold section in the shape of the bottle as if the bottle were cut along its axis B-B into two equal volumes. Of course more sections could be employed, if desired, as long as when closed they form a cavity having the shape of the desired bottle.
Certain surface ornamentation can be added as shown in 31, 33 and 35. Small openings 37 to remove gases may or may not be noticeable in the final blown and annealed container.
Warm water cooling channels, one of which is shown at 30, are equally spaced about the body portion 26 of the cavity in FIG. 2. These channels are connected to a warm water supply containing 80° C. water which is circulated throughout the metal body mold section shown as 20. Each channel may be connected to each other in either series or parallel relationship and maintain the surface of the mold cavity 26 at about 81° C. during operation, the wall being slightly hotter than the water supply resulting from contact with the hotter blown preform. Hot water is conducted through 32 and up through the channel 30 and out through 34 to another channel not shown in series operation or to a manifold, not shown for parallel operation. The size of the channels is governed by the amount of heat to be removed and the heat transfer characteristics of the mold and can be determined by one of ordinary skill in the art.
The neck-shoulder portion of the mold section shown at 22 including the upper wall surface 42 is maintained at about the temperature of the warm cooling water. Warm water below 70° C. and normally about 60° C. is conducted throughout the cooling channels generally shown as 40 by dotted lines. Inlet 44 and outlet 46 can be connected in parallel or series as desired. The neck-shoulder portion 22 is normally cooled to about 60° C. which allow the bottles removal from the mold without deformation.
The bottom heel portion 24 of the mold section 21 is also cooled by cold water passed through channels shown as 50 in a manner similar to the other portions of the mold. Cold water is used to lower the bottle wall in contact with surface 52 as quickly as possible to reduce the thermoplastic wall temperature to below 80° C., preferably below 70° C..
A fourth mold section 60 is shown about the neck portion of the preform which is not normally heated or cooled and remains cool and amorphous. If desired, heating or cooling channels or equivalent heating or cooling means may be provided.
Obviously, mold portions 60, 20, 22, and 24 of mold section 21 can be contained within an outer hydraulic mold system surrounding at least a portion of the mold section 21 outer wall shown as 70. If desired, channels for controlling mold wall temperature may be contained in the outer mold system in addition to or alternatively to the channels in the mold portions 60, 20, 22 and 24.
The mold portions are normally affixed to each other or an-outer mold system by means well known to the art and not shown. The mold portions generally substantially abut and often touch each other at 74, 76 and 78, without use of insulation, which allows the metal in adjacent mold sections to reach a temperature which gradually changes in the area of 74, 76 and 78 preventing stresses caused by the difference in bulk temperature of sections 20, 22, 24 and 60,
While water is described as the usual heat transfer fluid, any appropriate oil or other fluid might be used. Other appropriate heating or cooling means known in the art can be used in place of and in conjunction with the heat transfer fluid. Resistance heating may be employed, for example, in the body area. The cooling channels may be of any desired shape and configuration but are generally circular and are straight through the mold portion. If the channel is made to abut another portion of the mold, other shapes can be easily formed like those shown as 50 in FIG. 2.
In operation the annealing process may be employed as part of a rotary or linear blow molding process. We prefer a linear configuration of stationary molds because of the ease of feeding heat transfer fluid through stationary piping and the limited number of bottles under manufacture should there be mechanical failure or problems. However, rotary annealing configurations can be employed if desired and provide higher output of bottles for a given factory area.
Referring now to FIG. 3, room temperature preforms 81 are conveyed to a preform feed unit 80. The preforms are gripped by the neck 5 of FIG. 1 and placed on transport mandrels at 82. The preforms are passed through infrared quartz heaters at 84 to bring the sidewalls and bottom 7, 9 and 11 of FIG. 1 to proper temperature for blowing usually between about 90 to 110° C. The preforms are allowed to equilibrate at 86 so that the heat is allowed to flow throughout the preform reducing the high surface temperature and adjusting the preform temperature throughout its wall thickness. From there the preforms are transferred to a blow station 88 where they are blown using high pressure air or other gas against two closed mold one shown as 21 in FIG. 2. The axial direction is also generally stretched by mechanical means such as push rods which drive the closed end of the preform to the bottom of the blow mold. The blown article is annealed in the blow mold 88 to below 95° C., preferably about 65° C. to 85° C., preferably about 80 20 C. in the body portion 20 of FIG. 2, below 70° C. and usually controlled at 60° C. at the neck-shoulder portion 22 of FIG. 2, and below 70° C. in base and shoulder portion 24 of FIG. 2. Usually up to 25 seconds, preferably up to 10 seconds is required to maintain the expanded thermoplastic against the segmented mold portions to properly reach the desired wall temperature of 80° C. for the main wall surface 26 in portion 20 of FIG. 2, below 70° C. in the upper wall surface 42, preferably 60° C. in portion 22 of FIG. 2 and below 70° C. in the base and heel surface 52 of portion 24 of FIG. 2. The bottles 89 in FIG. 3 exit the blow station and go on to further treatment, for example, air cooling and storage preparatory to filling. The mandrels 87 are returned to the loading station.
In a rotary system the preforms are fed to the loading station. At the loading station the preforms are loaded onto the transport mandrel. A rotating heater is equipped with a number of stations holding the transport mandrels as they pass in front of the heating units. The preforms can be rotated on their own axis to insure uniform heating. Infra-red quartz lamps are controlled separately to obtain the desired temperature profile for each preform. While the bulk of the body side wall should be at a temperature of about 90° C. to 110° C. for PET, adjustments in temperature can be made to insure best preform blowing conditions.
The preform temperature is next equalized by passing the preforms to an equalizing wheel which may have neck cooling to insure the neck area is cool for blowing. The object of the equalization wheel is to allow time for the temperature to become even or equilibrated across the wall thickness. From the equalizing wheel the heated preforms are transferred and are locked into position in each of a number of water cooled mold stations. Mold halves are pneumatically actuated and locked into place. The preform is stretched using a stretch rod while high pressure air at 400 to 600 psi is used to rapidly expand the preform against the inner mold surfaces. The blown bottle is maintained against the segmented mold portions shown in FIG. 2 up to 25 seconds, preferably up to 10 seconds and normally about 2 to 6 seconds to bring the bottle wall temperature to the desired annealing temperature.
In the linear version of the process the molds are stationary and the preforms indexed into the mold which is mechanically or hydraulically closed.
The process can be applied to a variety of thermoplastic materials such as amorphous or only slightly crystalline material which do not crystallize substantially during monoaxial or biaxial blowing such as polyamides or saturated polyesters like polyesters of lower alkylene glycols and terephthalic acid such as ethylene glycol terephthalate or polymers that are amorphous prior to blowing and crystallize during biaxial stretching such as saturated polyesters like polyesters of aromatic acids such as terephthalic acid, naphthalene dicarboxylic acids or hydroxybenzoic acids with diols such as lower alkylene glycols, for example, ethylene glycol, propylene glycol or the like and mixtures and copolymers thereof.
The process is particularly useful for polymers which are generally blown from amorphous to crystalline state such as mono and copolymers of ethylene-glycol-terephthalic acid-esters generically known as polyethylene terephthalate or PET.
Biaxial orientation of the articles, particularly bottles useful for still or carbonated beverages, is accomplished by stretching the thermoplastic material, such as PET, in the axial and hoop directions simultaneously as the article is being formed. Often stretching in the axial direction is assisted by a mechanical rod used to force the closed end of a preform to the base of a mold as high internal pressure is applied to the preform causing stretching in both the hoop and axial directions. The preform is forced against the outer mold surfaces to shape the article and anneal the article at about 95° C. or below which further strengthens it and prevent stress cracking and other problems.
Biaxial orientation provides excellent properties such as strength and resistance to gas loss to the article. However, the stretching with immediate cooling (or stretching in a high temperature mold for heat setting by developing further crystallization) leaves the article under high stress which causes excessive shrinkage on reuse. Areas that have a thicker shell, such as the bottom heel and neck have less or no orientation and crystallinity and the contrast between amorphous and crystalline areas causes stress cracking on reuse of such bottles. This problem is overcome by using annealing. Preforms are also often heat profiled at different temperature to improve the wall thickness distribution of the final article and this causes further stress in the walls of the blown article.
This invention is directed to a process and apparatus for reducing wall stress in articles such as bottles by subjecting the blown thermoplastic article to direct and immediate annealing by regulating and controlling the wall temperature of the blow mold so that the body or main wall portion of the article, which has undergone the most biaxial stretching and crystallization is lowered to about 95° C. or below, preferably to 65° C. to 85° C. and more preferably about 80° C. by maintaining the mold wall in contact with that portion of the article at that temperature. The upper portion of the wall near the neck, referred to herein as the Deck-shoulder portion is lowered to 85° C. or below, preferably 70° C. or below usually about 60° C. while the lower or bottom portion of the bottle referred to herein as the bottom heel portion is reduced to below 85° C. and preferably below 70° C. using cold water since the bottle is thickest at this point and most difficult to cool.
The thermoplastic material is normally blown at a temperature which will vary depending on the polymer but which is generally between 90° C. and 110° C. for PET. This means that usually substantial heat must be removed from the article by cooling the mold to the desired annealing temperature. The bottle wall annealing temperature is that temperature where the bottle can be removed from the mold without deformation. One might refer to our process as warm blowing since the mold surfaces are warm in the body and neck-shoulder region. Normal processes employ a cold mold cooled as rapidly as possible.
We have found that annealing the blown bottle at about 65° C. to 85° C., depending on the area of the bottle, allows one to reuse the bottles, including cleaning them at 60° C., without losing the strength developed during biaxial stretching and the annealing treatment. The annealing process, in addition to reducing thermal stress and biaxial stress differences, also strengthens the bottle, makes it more resistant to stress cracking and improves gas barrier properties.
The period of contact between the warm mold and the hollow shaped hot article is dependent on the thickness of the walls and the time necessary to reduce the wall temperature to the desired 65° C. to 85° C. a range. Up to 25 seconds residence time is sufficient with 1 to 10 seconds preferred. Usually from 3 to 6 seconds is sufficient to lower the base-shoulder region of the wall (the thickest part) to 70° C. or below.
Various portions of the segmented mold may be cooled, usually by warm water with the base heel portion cooled with cold water. While other cooling fluid could be used, as well as any known techniques for rapidly and effectively removing heat, we have found water to work well.
The process of this invention can be employed on any thermoplastic article where annealing is required and where reuse is likely. The process anneals the thermoplastic article at a temperature above that likely to be employed for washing the article; generally at least 5° C. or 10° C. above the highest contemplated washing temperature. In general, for PET, the temperature of the article body is reduced to 85° C., preferably about 80° C. while the neck-shoulder portion is lowered to about 70° C. and the base and shoulder portion lowered to 70° C. or below.
The process of this invention can also be employed on multilayer articles containing thermoplastic materials especially PET.
The process of this invention maintains high transparency, relieves stress, prevents stress cracking, and improves dimensional stability in the temperature range used for filling or cleaning the shaped articles. | An apparatus for annealing biaxially oriented articles is disclosed, particularly blow molded articles prepared from unique tapered preforms which are immediately annealed using warm fluid in a segmented mold. Portions of the segment mold, used to form the articles, are temperature controlled at various temperatures by passing warm water through conduits in the neck-shoulder portion and body portion of the mold segment and cold water through the bottom and shoulder portion of the mold to bring the temperature of the article wall to about 65deg C. To 85deg C. For PET bottles. The body wall temperature is preferably lowered to about 80deg C. While the neck-shoulder and bottom and shoulder portions are lowered to at least 70deg C. The annealing increases the articles structural strength, removes temperature and biaxial stress, reduces gas permeability, retains transparency and allows for multiple reuse of the article including hot washing thereof. |
CROSS REFERENCE TO RELATED US PATENT
The application is related to U.S. Pat. No. 6,712,203 filed on Sep. 28, 2001 and granted on Mar. 30, 2004.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a compact disc (CD) tray and CD trays which are bound into a bundle to allow compact discs to be stored in an ordered fashion.
2. Description of the Related Art
A compact disc is a device employing a laser beam technology for retrieving data signals recorded along micro tracks on a plastic diskette, and is commonly called a CD. Since Phillips and Sony first introduced prototypes in the late 1970s, CDs have improved rapidly as a reliable storage system for all types of data, as well as video images, audio signals, etc.
In spite of its indisputable merits, however, sheltering of the CD in a cassette was a difficult problem to be resolved. Therefore, a flip-open type case, which was adopted at the beginning, still dominates its market. In this regard, the conventional flip-open type cases by their nature hardly allow their storage as a bundle binding, and so are required to be used separately. The conventional flip-open type cases are tremendously inconvenient to use, such as for indexing, archiving, publishing, and so on. Thus, the conventional flip-open cases are often replaced with other bundle housing types, such as CD pouches, CD cabinets, CD frames, etc. Therefore, if there were some simple ways capable of allowing the CD cases to be book-bound, it would be most ideal for suffering computer users.
While there have been various excellent ideas on the market up to now, they are not yet successful in terms of practical usage, manufacturing, pricing or archiving, in particular, in digital publishing or large or small scale categorized storage of CDs.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to eliminate one side covering of a CD case by means of book-binding.
Unlike the conventional CD cases, the present invention focuses on the protection of a CD's data-written land by overlaying one tray over another into the shape of a booklet, which will overcome the CD shortcomings as stated above.
Further, the present invention includes other various detailed features and thereby solves the problems of the conventional flip-open type CD cases.
Moreover, the present invention is also ideally suited to digital publishing and archiving by its peculiar bookbindability. As well, by employing this idea, a blank CD with a reasonable extra cost for a casing can expand its market range to a great extent.
In one embodiment, a CD tray according to the invention consists of two major characteristics. One is a tray body with a thinnest possible thickness, which has a circular basin with a minimal depth to accommodate a compact disc, and the other is a fingertip opening, that is, a release opening which is defined adjoining a center hole of a CD holder plate. Holder fins, that is, clip pegs are formed on an inner edge of the CD holder plate, which defines the center hole.
At least one side end surface of the CD tray is made flat so that the CD tray can be book-bound using an adhesive tape or any other suitable means, whereby CD trays bound can be flipped one by one like ordinary book pages. As a consequence, any selected CD on a tray can be released instantly by pushing a non-data land portion of the CD with one fingertip through the release opening.
Since the fingertip opening of the CD holder plate according to the present invention is shaped in a unique manner, even a woman's fingertip with a long nail can release the CD without any difficulty.
BRIEF DESCRIPTION OF THE DRAWINGS
The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with the drawings, in which:
FIG. 1 is a plan view illustrating a state wherein a compact disc is accommodated in a CD tray in accordance with an embodiment of the present invention;
FIG. 2 is a bottom view of FIG. 1;
FIG. 3 is a front longitudinal cross-sectional view of FIG. 1;
FIG. 4 is a front view illustrating a state wherein a plurality of CD trays according to the present invention are stacked one upon another and book-bound using an adhesive tape and a lock band;
FIG. 5 is a plan view of FIG. 4;
FIG. 6 is a bottom view independently illustrating the lock band; and
FIG. 7 is a partial front view illustrating a state wherein an upper flip member is opened from the book-bound CD trays.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
Referring to FIG. 1, there is shown a plan view illustrating a state wherein a compact disc is accommodated in a CD tray in accordance with an embodiment of the present invention. The CD tray comprises a CD holder plate 1 . A circular depression 3 in which the compact disc 2 is accommodated is formed on an upper surface of the CD holder plate 1 . The CD holder plate 1 is defined, at a center portion thereof, with a hole 4 . Clip pegs 5 are formed on an inner edge of the CD holder plate 1 , which defines the hole 4 , in a manner such that they are spaced apart one from another in a circumferential direction. A release opening 6 is defined adjacent to and communicated with the hole 4 .
The CD holder plate 1 according to the present invention can be made of a suitable material, for example, plastic as in the conventional art. In the case of storing compact discs which are used for special purposes such as long-term keeping of a data base, broadcast recording, and the like, the CD holder plate 1 can be made of metal.
The standard compact disc 2 has marginal portions at inner and outer edges thereof so that a central data-written land is protected. The marginal portions serve as non-data disc lands 7 .
In FIGS. 1 through 3, the compact disc 2 is illustrated in a state wherein it is accommodated in the circular depression 3 of the CD holder plate 1 according to the present invention. The compact disc 2 loaded onto the CD tray is securely maintained in the circular depression 3 , that is, a circular basin, with a minimum gap defined between a circular rim delimiting the circular depression 3 and the outer edge of the compact disc 2 , so that the compact disc 2 cannot be released from the CD holder plate 1 unless a portion of the non-data disc land 7 of the compact disc 2 is pushed with a fingertip through the release opening 6 . The hole 4 defined at the center portion of the CD holder plate 1 will help the fingertip to easily find the release opening 6 even in dark circumstances.
Referring to FIGS. 1 through 3, four engagement projections 8 are respectively formed at four corners and on an upper surface of the CD holder plate 1 , and four engagement grooves 14 are defined below the engagement projections 8 . Therefore, the engagement projections 8 of one CD holder plate 1 can be respectively engaged into the engagement grooves 14 of another CD holder plate 1 . Consequently, when the CD holder plates 1 are stacked one upon another, they are locked one to another and prevented from being unintentionally moved in a horizontal direction, which ensures a well arranged book shape.
At least one side end of the CD tray is formed as a flat surface. Hence, when several CD trays are stacked one upon another, one side end surfaces are arranged in line. In this state, by affixing an adhesive tape 11 to one side end surfaces of the CD trays and joining a flip member 9 and a cover member 10 to upper and lower ends of the adhesive tape 11 , respectively, the CD trays can be effectively bound in the shape of a booklet. A lock band 12 is provided on the other side ends of the CD trays to connect distal ends of the flip and cover members 9 and 10 with each other. In order to ensure that the lock band 12 is attached to the distal ends of the flip and cover members 9 and 10 , Velcro-brand hook and loop fastener strips 13 are stitched to a lower surface of the lock band 12 adjacent to both ends thereof. A person skilled in the art will readily appreciate that complementary Velcro-brand hook and loop fastener strips can be stitched to the distal ends of the flip and cover members 9 and 10 .
Adjacent to the other side end, a slightly recessed portion 15 is formed between two engagement projections 8 of each CD holder plate 1 , so that a label or the like can be attached to the recessed portion 15 . Therefore, since a CD categorizing position is fixed, an archiving task can be implemented in an efficient manner.
As can be readily seen from FIGS. 4 and 7, because flip motion of the CD tray is permitted substantially in a vertical direction, CD surfaces are kept from being scratched or damaged in a transverse direction.
As apparent from the above description, the CD tray according to the present invention, constructed as mentioned above, provides advantages in that, differently from the conventional flip-open type case, by simply turning over a CD holder plate as in the case of a booklet, a desired compact disc can be easily found.
Specifically, due to the presence of a release opening, the compact disc can be easily released from the corresponding one of the CD holder plates bound in the shape of the booklet. As a consequence, the CD tray according to the present invention will appeal to publishers of software, music, a DVD, a digital book, etc.
Due to the fact that the CD trays according to the present invention can be easily bound in the shape of the booklet, papers for additional information or book-wrappers can be easily provided to the resultant bundle. Further, the CD trays according to the present invention can be stored and displayed on a book shelf without requiring a separate archiving system, whereby convenience is rendered upon filing or indexing contents.
Upon producing the CD tray according to the present invention, it is sufficient to add or remove some parts without changing the entire existing production system and/or packaging system.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims. | Disclosed is a housing device for compact disks. The housing device includes stackable and bookbindable CD trays, each of which has clip pegs with a hole defined at a center portion of each CD tray. A compact disc can be released by pushing a non-data portion thereof through a release opening defined adjoining the hole in each CD tray. An adhesive tape can be affixed to one side ends of the CD trays and a lock band can be attached to the other side ends of the CD trays, to bookbind the CD trays together. |
TECHNICAL FIELD
[0001] The present invention is directed to an expandable core chuck suitable for engaging the interior surface of a cylindrical core or other article having an inwardly facing cylindrical surface.
BACKGROUND OF THE INVENTION
[0002] Many products are manufactured from elongated sheet or stock material or wire that is shipped and stored in the form of a roll or coil. Continuous strips or webs of thin, flexible material or wire are commonly provided wound on cores to provide rolls of material. The rolls of material are subsequently unwound for production of items made from the materials. Examples of these materials are plastic film, metal foil, tissue, paper and wire.
[0003] During the manufacturing process, the cores carrying the material are commonly transported to various stations within the manufacturing facility. For instance, cores of fresh material are received and transferred to unwind stations. Cores that have material removed are transported to storage facilities, core cleaning stations, or other processing stations. Core chucks are inserted into the opposed ends of the cores thereby allowing the cores to be lifted for transport and processing without damaging the sheet material contained on the core or the core itself. Different types of product have cores which have different inner diameters. In current practice, the manufacturing plant has core chucks of a variety of diameters designed to match the inner diameter of the cores. Thus, there is a need for an universal core chuck that can be used with cores having varying inner diameters of the inwardly facing cylindrical surface of the core. While this invention is described for use with cores carrying rolls of sheet material or wire, it is not intended to be so narrowly construed as to be limited only to that specific use. The present invention can be utilized to mate with a wide variety of articles having an internal cylindrical surface.
[0004] A universal core chuck or arbor for securing the internal surface of a reel or other article may be found in U.S. Pat. No. 6,494,401. The '401 patent includes a thorough discussion of prior art attempts to solve the problems of sizing chucks to cores having different inner diameters. An arbor disclosed in that patent application has a cylindrical axially extending tube with longitudinal slots. Blades are positioned in the slots and are movable radially outwardly from the tube to a position at which their outer surfaces extend slightly beyond the outer surface of the tube. The blades have an inner surface defining axially spaced apart first cam grooves having inclined wrap surfaces. A cam member includes spaced apart cam followers that include inclined ramp surfaces aligned with the first cam grooves. The cam is reciprocal via a pneumatic actuator from a first position in which the respective blades are retracted to a second position in which the blades are extended slightly outwardly from the outer surface of the tube. The present invention improves upon this complex mechanical structure.
SUMMARY OF THE INVENTION
[0005] The present invention provides an expanding core chuck having a housing extending along an axis with a plurality of slots, preferably four, extending substantially parallel to the longitudinal axis of the housing. A camshaft having a plurality of lobes or cams is positioned in the housing and is rotatable with respect to the axis of the housing in clockwise and counterclockwise direction upon actuation by a pneumatic actuator. Each of the cams has a cam surface which extends at varying radial distances from the axis. Cam rollers or other actuators are attached to expansion plates such that, upon rotation of the cam shaft in one direction, the cam rollers will be actuated by the varying radial distance cam surfaces to move the expansion plates from a position within the housing to a position extending outwardly from the housing and into mating contact with the inner cylindrical surface of the core and, upon rotation in the opposite direction, move the expansion plates back within the housing.
[0006] Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of the core chuck of the present invention with the expansion plates contracted.
[0008] FIG. 2 is a view similar to FIG. 1 showing the core chuck with the expansion plates expanded.
[0009] FIG. 3 is a view similar to FIG. 1 but with the outer shell removed for clarity.
[0010] FIG. 4 is a sectional view of the core chuck of the present invention taken along the longitudinal axis.
[0011] FIG. 4A is an enlarged of a section of FIG. 4 .
[0012] FIG. 5 is a schematic view taken through line 2 - 2 of FIG. 4 , showing the essential structure of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIGS. 1 and 2 there is shown the expandable core chuck 10 of the present invention. The core chuck includes a housing or outer shell 12 extending along an axis A ( FIG. 4 ) from a first end on which is mounted an end cap 14 to a second end on which is fastened a mounting flange 16 (FIG. 5 ). The outer shell has four slots 18 extending longitudinally from a point slightly spaced from the end cap 14 to approximately midway between the end cap 14 and the mounting flange 16 . The outer shell 12 also has four openings 20 generally aligned with the slots 18 and spaced a short distance therefrom toward the end with the mounting flange 16 . The slots 18 and the openings 20 are positioned substantially 90 degrees from adjacent slots and openings.
[0014] Referring to FIGS. 3 , 4 and 5 , housed within the shell 12 is a camshaft 22 extending along the axis A from a bearing 24 secured to the end cap 14 to a second bearing 26 fastened to a coupling 28 . The coupling 28 is also secured to a pneumatic cylinder 44 which, upon actuation, rotates the coupling 28 and the camshaft 22 alternately clockwise and counterclockwise. The cam shaft 22 a plurality of cam members 30 extending radially outwardly. Each cam member 30 has a cam surface 32 which follows a path in a circumferential direction, with the path being closer to the axis A in one area and extending along a smooth gradually outwardly path to other areas progressively further from the axis A. Cam rollers 34 mounted on each of four expansion plates are engaged with each of the cam surfaces 32 . Each expansion plate 36 has one or two radially extending support members 42 , each of which carries the cam roller 34 . Located on the outwardly facing ends of the expansion plates 36 are contact members 38 which engage the inner cylindrical surface of the cores or other articles to be cleaned.
[0015] The expansion plates 38 , support member 42 and cam rollers 34 are slidably engaged with a mounting member 40 and are movable relative thereto in a radial direction from a retracted position shown in FIG. 1 to an expanded position shown in FIG. 2 in response to movement of the cam members 30 relative to the cam rollers 34 . The support members 42 and expansion plates 36 are urged outwardly when the camshaft 22 is rotating in a direction in which the cam surfaces 32 push the cam rollers 34 outwardly. Rotation of the camshaft 22 in one direction will force the cam rollers 34 engaged with the cam surfaces 32 to move radially outwardly away from the axis A.
[0016] FIGS. 4 and 4A show in detail the elastic members 37 that are engaged with the mounting members 40 and the support members 42 through slots 35 . As the cam surfaces 32 push the cam rollers 34 radially outwardly, the elastic members 37 are elongated. When the camshaft 22 is rotated in the opposite direction from that which moves the expansion plates 36 outwardly, the elastic members 37 pull the support members 42 and expansion plates 36 radially inward. Guides 39 , located on the support members 42 are engaged with an edge of the mounting members 40 to ensure that the support members 42 and expansion plates move in a non-skewed manner.
[0017] Upon insertion of the core chuck into the end of the core, the pneumatic cylinder 44 is actuated to rotate the camshaft 22 in a first direction, for example clockwise, to urge the cam rollers 34 outwardly as a result of the outwardly extending cam surfaces moving thereagainst to thereby push the expansion plates 36 outwardly such that the contact members 38 firmly engage the cylindrical interior surface of the core. The expandable core chuck 10 may be removed from the core by actuating the pneumatic cylinder 44 to rotate the camshaft 22 in the opposite direction, for example, counterclockwise, to move the reduced sized portions of the cam surfaces relative to the cam rollers so that the springs of the expansion plates return them to a position within the housing or outer shell 12 .
[0018] This invention has been described in considerable detail with reference to its preferred embodiments. However, as indicated previously, the invention is susceptible to numerous modifications, variations, and substitutions without departure from the spirit and scope of the invention as described in the foregoing detailed description and as defined in the following appended claims. | An expandable core chuck includes a housing having a plurality of slots and a plurality of expansion plates movable radially outwardly from the housing to engage the interior surface of an article to be gripped. Outward movement of the expansion plates is effected by means of a camshaft and rotation of the camshaft. |
BACKGROUND
The present invention relates generally to data management, and particularly to managing data stored hierarchically.
Hierarchical data sets are useful and popular. Such data sets are generally composed of multiple records. In a hierarchical set of records, a record can have multiple “children,” which are related to the record and exist at a lower level of the hierarchy. Such a record is referred to as the “parent” record of the children records. The children of a record may have children, and so on, limited only by the size of the database. Within a set of children of a single record, it is often useful to order the children, such that there is a first child, a second child, and so on.
To date the utility of these hierarchical data sets has been limited by the efficiency of the tools available for managing the data. Conventional methods of storing hierarchical data in a database involve multiple expensive calls to update and/or query the database. For example, in order to select the second grandchild of a record, three queries are necessary. The first query selects the child of the record. The second query selects the first child of the child. The third query selects the second child of the child.
SUMMARY
In general, in one aspect, the invention features a method, apparatus, and computer-readable media for retrieving records in a hierarchical set of the records having a plurality of hierarchical levels and a plurality of hierarchical depths, each of the records having a tag that is unique within the hierarchical set of the records. It comprises identifying one of the records in the hierarchical set of the records; modifying the tag, thereby producing a key; indexing the hierarchical set of the records only once, thereby selecting one or more of the records within the hierarchical set of the records, wherein indexing the hierarchical set of the records only once comprises applying the key to the hierarchical set of the records; and retrieving the selected records.
Particular implementations can include one or more of the following features. Applying comprises selecting those of the records in the hierarchical set of the records having a tag that matches the key. Identifying one of the records comprises receiving a selection of the one of the records from a user; and receiving a command from the user; and wherein modifying the tag is based on the command from the user. Each of the records has one or more fields, and implementations can comprise displaying a field of each of the retrieved records on a display, wherein the position of each of the fields on the display represents the hierarchical depth and hierarchical level of the corresponding one of the retrieved records. Each tag is a number having a plurality of digits; the position of each of the digits represents one of the hierarchical depths; the value of each of the digits represents one of the hierarchical levels; and modifying the tag comprises selecting at least one of the digits according to the command from the user; and changing the value of the selected digits according to the command from the user. Each tag is a number having a plurality of digits; the position of each of the digits represents one of the hierarchical depths; the value of each of the digits represents one of the hierarchical levels; the command from the user requests retrieving the children of the identified record; and modifying the tag comprises selecting the digit corresponding to the hierarchical depth of the identified record; and setting the value of each digit corresponding to a hierarchical depth below the hierarchical depth corresponding to the selected digit to a wildcard value. Each tag is a number having a plurality of digits; the position of each of the digits represents one of the hierarchical depths; the value of each of the digits represents one of the hierarchical levels; the command from the user requests retrieving the parent of the identified record; and modifying the tag comprises selecting the digit corresponding to the hierarchical depth of the identified record; and setting the value of the selected digit to a null value. Each of the records represents one of a message and a folder.
In general, in one aspect, the invention features a method, apparatus, and computer-readable media for adding a new record to a hierarchical set of records having a plurality of hierarchical levels and a plurality of hierarchical depths, each of the records in the hierarchical set of records having a tag that is unique within the hierarchical set of records. It comprises identifying one of the records in the hierarchical set of records as the parent of the new record; modifying the tag, thereby producing a key; adding the key to the new record; and indexing the hierarchical set of records only once, thereby adding the new record to the hierarchical set of records, wherein indexing the hierarchical set of records only once comprises applying the key to the hierarchical set of records.
Particular implementations can include one or more of the following features. Identifying one of the records comprises receiving a selection of the one of the records from a user. Each tag is a number having a plurality of digits; the position of each of the digits represents one of the hierarchical depths; the value of each of the digits represents one of the hierarchical levels; the identified record represents a message; identifying one of the records further comprises receiving a command from the user that requests replying to the message; and modifying the tag comprises selecting the digit corresponding to the hierarchical depth immediately below the hierarchical depth of the identified record; and incrementing the value of the selected digit. Applying comprises selecting those of the records in the hierarchical set of the records having a tag that matches the key. Each tag includes a plurality of digits; the position of each of the digits represents one of the hierarchical depths; and the value of each of the digits represents one of the hierarchical levels.
In general, in one aspect, the invention features a method, apparatus, and computer-readable media for selecting records in a hierarchical set of the records having a plurality of hierarchical levels and a plurality of hierarchical depths, each of the records having a tag that is unique within the hierarchical set of the records. It comprises identifying one of the records in the hierarchical set of the records; modifying the tag; and indexing the hierarchical set of the records only once, thereby selecting one or more of the records within the hierarchical set of the records, wherein indexing the hierarchical set of the records only once comprises applying the modified tag to the hierarchical set of the record.
Particular implementations can include one or more of the following features. Each tag includes a plurality of digits; the position of each of the digits represents one of the hierarchical depths; and the value of each of the digits represents one of the hierarchical levels. Applying comprises selecting those of the records in the hierarchical set of the records having a tag that matches the key.
Advantages that can be seen in implementations of the invention include one or more of the following. Implementations of the present invention permit manipulation of a database representing an indented threaded discussion with only a single access of the database. For examples, messages can be added, deleted, and retrieved through a single database access such as a query or call.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 shows a display of an indented threaded discussion.
FIG. 2 is a flowchart of a process for retrieving the parent of a message in an indented threaded discussion according to one implementation.
FIG. 3 is a flowchart of a process for retrieving the children of a message in an indented threaded discussion according to one implementation.
FIG. 4 is a flowchart of a process for adding a message to an indented threaded discussion according to one implementation.
The leading digit(s) of each reference numeral used in this specification indicates the number of the drawing in which the reference numeral first appears.
DETAILED DESCRIPTION
One common type of hierarchical data is an indented threaded discussion. Originally found only in Internet newsgroups, indented threaded discussions have found increasing popularity as a way to manage and display a discussion among multiple participants. Indented threaded discussion management tools are now found in consumer products such as electronic mail software programs.
FIG. 1 shows a display of an indented threaded discussion. An indented threaded discussion begins when a user posts a message 102 in a forum available to multiple users, where the posted message is not a reply to another message. Such a message is referred to herein as the “origin” message of the discussion. Any origin message constitutes the “head” of a thread. Thus message 102 is both the origin message of a discussion and the head of a thread. All replies to a message are part of the thread. Of course, a forum can have multiple discussions.
When a user posts a reply to a message, the reply is generally displayed underneath the message, and indented once. Any message having replies to it is the head of a thread. Thus a discussion can have many threads. The head of thread is indented once relative to the message to which it replies.
Message 104 is a reply to message 102 . Therefore, reply 104 is displayed underneath message 102 , and indented once, as shown in FIG. 1 . A reply 106 to the reply 104 is indented once further. A reply 108 to the reply 106 to the reply 104 is indented once further still.
When a user posts another reply 110 to origin message 102 , it is shown indented only once, and is shown beneath message 104 and its children 106 and 108 . A subsequent reply 112 to origin message 102 is also shown indented once, and is shown beneath message 110 . A reply 114 to message 112 is shown indented twice and beneath message 112 .
A display such as the display of FIG. 1 allows a user to rapidly understand the structure of the discussion hierarchy and the place each message has in the hierarchy. The place a message has in the hierarchy can be described in terms of two dimensions of the hierarchy: level and depth. The depth of a message is the number of threads that contain the message. For example, referring to FIG. 1 , the depth of message 108 is three because it is contained by the threads headed by messages 106 , 104 and 102 . The depth of an origin message such as message 102 is zero.
The level of a message at a particular depth represents the number of messages at that particular depth that precede that message. For example, referring to FIG. 1 , the level of message 112 is three because it has a depth of one and is preceded by messages 110 and 104 , both also at a depth of one. The order of precedence within each hierarchical depth can be determined by any number of factors or combinations thereof. In a threaded discussion group, the chronological order of the messages, as determined by the time and date of the posting of each message, is most commonly used. When the records in the hierarchical data set represent containers such as folders, the alphabetical order of the names of the folders can be used. In addition, the user of the display may select any field in the records, and thereby cause the contents of that field to determine the order of precedence. The level of an origin message such as message 102 is zero.
Referring again to FIG. 1 , messages at a single hierarchical level, such as messages 104 , 110 , and 112 , are shown in chronological order, while the children of a message (that is, replies to the message, replies to those replies, and so on) are shown beneath the message and above the next message at the same hierarchical level. The messages displayed to the user are generally stored in some sort of database such as a table. Each row of the table represents a message. Each message has multiple fields such as subject, author, text, date of posting, and so on. Each column represents one of the fields.
Conventional tools for managing such indented threaded discussions are notoriously inefficient. Normally either multiple rows of the table must be updated upon the creation of a new message or multiple queries have to be performed to display an indented thread. The number of rows needing updates could be as large as the number of messages in the thread.
Implementations of the present invention associate a tag with each record in a hierarchical set of records, such that the tag is unique within the hierarchical set of records. The tag is generally one of the fields of the records. Table 1 depicts a portion of a database table representing the discussion of FIG. 1 according to one implementation.
TABLE 1
Tag
Depth
Level
Subject
0000
0
0
Bike Rides in the Bay Area
1000
1
1
Old La Honda
1100
2
1
re: Old La Honda
1110
3
1
re: re: Old La Honda
2000
1
2
Page Mill Road
3000
1
3
The Bears Loop
3100
2
1
re: The Bears Loop
Each tag is a number having a plurality of digits, one for each of the depths of the hierarchy. The hierarchy of Table 1 has four depths; thus each tag has four digits. In one implementation, the digits are arranged so that the most significant digit represents the first depth of the hierarchy (that is, the depth of the origin message), the next most significant digit represents the second depth of the hierarchy, and so on. Other implementations employ other arrangements of the digits.
The value of each digit represents a level in the hierarchy. Assume the hierarchy of Table 1 has four levels. Then each digit can have a values ranging from zero to three. A value of zero indicates that the message does not exist at that depth in the hierarchy. Of course, other ranges of levels and depths can be supported, as will be apparent to one skilled in the relevant art after reading this description. One implementation supports 16 levels and 16 depths. In that implementation, the tag is a 16-digit hexadecimal number represented by a “big int,” a signed 64-bit number having values ranging from −2 63 to 2 63 .
Each tag uniquely identifies the position of its record in the hierarchy. For example, the tag “3100” shows that the record is the first child of the third child of the origin message.
One advantage of the disclosed tag is that the tag of a record may be determined quickly and easily, without indexing the database, by modifying the tag of a related record.
FIG. 2 is a flowchart of a process 200 for retrieving the parent of a message in an indented threaded discussion according to one implementation. Process 200 receives a command from a user (step 202 ). The command identifies message 108 and requests retrieving the parent of message 108 . Process 200 modifies the tag of message 108 to produce a key. To do this, process 200 first selects the digit corresponding to the hierarchical depth of message 108 (step 204 ). Referring to Table 1, message 108 has a depth of three. Therefore, process 200 selects the third most significant digit of the tag of message 108 . The depth of each message need not be stored in the table, but can be determined in real time, with knowledge of the hierarchical depth represented by each digit. Where tags have digits arranged according to increasing depths in the hierarchy, such as the tags of Table 1, one can select the digit corresponding to the hierarchical depth of a message by simply select the least significant non-zero digit.
Process 200 then sets the value of the selected digit to a null value (step 206 ). In the tags of Table 1, the null value is zero. Of course, other values can be selected as the null value. The resulting key is “1100”, which is the tag of message 106 , the parent of message 108 . Process 200 then indexes the database only once by applying the key to the database (step 208 ), thereby selecting the record for message 106 . Process 200 then retrieves message 106 (step 210 ) and displays message 106 to the user (step 212 ).
FIG. 3 is a flowchart of a process 300 for retrieving the children of a message in an indented threaded discussion according to one implementation. Process 300 receives a command from a user (step 302 ). The command identifies message 104 and requests retrieving all of the messages in the thread for which message 104 is the head. These messages include the children of message 104 , the children of the children of message 104 , and so on.
Process 300 modifies the tag of message 104 to produce a key. To do this, process 300 first selects the digit corresponding to the hierarchical depth of message 104 (step 304 ). Referring to Table 1, message 104 has a depth of one. Therefore, process 300 selects the most significant digit of the tag of message 104 . Process 300 then sets the value of each digit corresponding to a hierarchical depth below the hierarchical depth of the selected digit to a wildcard value (step 308 ). The resulting key is “1XXX”, where “X” represents a wildcard value that can match any value.
In one implementation, applying a key to the database selects all records in the database having tags that match the key. Process 300 indexes the database only once by applying the key to the database (step 310 ), thereby selecting the records for the messages in the thread headed by message 104 . Referring to Table 1, the key “1XXX” matches the tags for records corresponding to messages 106 and 108 . Process 300 then retrieves messages 106 and 108 (step 312 ) and displays messages 106 and 108 to the user (step 314 ).
Process 300 can also be used to delete a message. When a message is deleted, so are all of its children. Process 300 selects a message and all of its children. The records corresponding to the selected messages are then deleted.
FIG. 4 is a flowchart of a process 400 for adding a message to an indented threaded discussion according to one implementation. Process 400 receives a command from a user (step 402 ). The command identifies message 114 and requests replying to message 114 . Process 400 modifies the tag of message 114 to produce a key. To do this, process 400 first selects the digit corresponding to the hierarchical depth immediately below the hierarchical depth of message 114 (step 404 ). Referring to Table 1, message 114 has a depth of two. Therefore, process 400 selects the third most significant digit of the tag of message 104 . Process 400 then increments the value of selected digit (step 406 ). The resulting key is “3110”. Process 400 then indexes the database only once by adding a record to the database having the key as its tag (step 408 ). The record corresponds to the new message.
The invention can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Apparatus of the invention can be implemented in a computer program product tangibly embodied in a machine-readable storage device for execution by a programmable processor; and method steps of the invention can be performed by a programmable processor executing a program of instructions to perform functions of the invention by operating on input data and generating output. The invention can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. Each computer program can be implemented in a high-level procedural or object-oriented programming language, or in assembly or machine language if desired; and in any case, the language can be a compiled or interpreted language. Suitable processors include, by way of example, both general and special purpose microprocessors. Generally, a processor will receive instructions and data from a read-only memory and/or a random access memory. Generally, a computer will include one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM disks. Any of the foregoing can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).
A number of implementations of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other implementations are within the scope of the following claims. | A hierarchical set of records has multiple hierarchical levels and depths. Each of the records has a tag that is unique within the hierarchical set of records. A method for retrieving a record includes identifying one of the records in the hierarchical set and modifying the tag, thereby producing a key. The hierarchical set of records is indexed only once. A record is selected and retrieved based on the indexing which applies the key to the hierarchical set of the records. |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. patent application Ser. No. 10/758,712, filed on Jan. 15, 2004, entitled, “COMMUNICATION SYSTEM AND PROTOCOL FOR INTERACTIVE PORTABLE DEVICE,” by Lucas et al. and U.S. patent application Ser. No. 10/801,497, filed on Mar. 15, 2004, entitled, “INTERACTIVE MOBILE DEVICE,” by Bartels, both of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to portable interactive computing devices, personal digital assistants, handheld computers, and the like. In particular, the present invention teaches a housing for an interactive device having a multi-purpose carrying clip and an easy to use interface. The clip and interface enable a user to carry and operate the portable interactive device with one hand.
BACKGROUND OF THE INVENTION
[0003] The portable computing device is ubiquitous. Specific examples include cellular telephones and personal digital assistants, as well as inventory, delivery services, and other mobile applications. One primary limitation is the failure of the interface to provide easy operation by a user. For example, the typical interface of the prior art portable computing device requires the use of both hands. The failings of the prior art portable computing device are perhaps no where more evident than in applications where the user is mobile, such as sporting activities, inventory taking, and delivery applications.
[0004] The past decade has invoked a dramatic increase in consumer spending in the field of health and fitness products and sporting equipment. In the United States alone, an estimated 50 million people work out at least 3 times a week, over 27 million people play golf, and approximately 1 million people receive some kind of physical therapy every day. This has resulted in a strong demand for devices and methods that assist individuals in setting and reaching fitness goals. The currently available devices and methods however, fail to meet the needs of average consumers in many ways. This is especially true in the field of portable devices that may accompany an individual during their workout.
[0005] For example, prior art devices capable of being carried with a user on their physical fitness workout are severely limited in function and portability. Many of these devices are incorporated into a wristwatch and are only capable of calculating a runner's speed, time and distance. Other functions may include a heart rate monitor that connects to the wristwatch device. There is little or no feedback from these current devices and methods. Further these devices can only function in one specific mode of operation. See U.S. Pat. No. 6,002,982 that describes a device used to aid a user in their fitness workout.
[0006] More sophisticated prior art devices that do allow for operator interactions are not portable and are usually mounted to the exercise equipment. For example, see U.S. Pat. No. 6,066,075 to Poulton. Poulton's patent details a computer apparatus that provides feedback to an individual while the individual is on a treadmill. The structures and sensors necessary in this type of device are not intended to be portable.
[0007] In addition to the failures of the above devices, conventional portable devices do not provide an adequate means by which the portable device may function or be transported in a variety of manners. For example, a conventional PDA (personal digital assistant) must be held in the hand of the user and cannot operate in a “stand alone” manner. There is also no convenient way to carry or interact with a conventional PDA during some type of physical activity.
[0008] Therefore there is a need for a multi-functional mechanism that would allow for a portable device to be easily transported, provide one hand operation, and function in a variety of modes.
SUMMARY OF THE INVENTION
[0009] The present invention improves on the prior art methods and devices by providing a clip that is mounted on a portable, programmable, interactive device that accompanies an individual. One embodiment of the present invention is a device that comprises a housing configured to be carried by a user, a display for displaying information to the user, an interface operable by the user to select and input data, and a fixed-arm clip mounted on the housing of the device. In preferred embodiments, the user can hold the portable device in one hand while operating the interface with that same hand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side view of a portable interactive device having a fixed-arm clip in accordance with one embodiment of the present invention.
[0011] FIG. 2 is an isometric view of the portable interactive device of FIG. 1 .
[0012] FIG. 3 is an isometric view of a portable interactive device having an adjustable clip in accordance with another embodiment of the present invention.
[0013] FIG. 4 is an isometric view of a portable interactive device being held and operated by one hand according to one aspect of the present invention.
[0014] FIG. 5 shows a first embodiment of the present invention in a docking station.
[0015] FIG. 6 is a schematic diagram of the device according to the present invention.
[0016] FIG. 7 illustrates a clip acting as a stand for a portable interactive device according to another aspect of the present invention.
[0017] FIGS. 8A, 8B , 8 C, and 8 D show different positions of an adjustable clip of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] With reference to FIGS. 1-2 , an interactive device 10 having a fixed-arm clip in accordance with one embodiment of the present invention will now be described. The interactive device 10 includes a housing 12 , a fixed-arm clip 14 , a display 16 , and a push-button interface 19 . The electronics of the device 10 are internal to the housing 12 , one suitable embodiment of the electronics is described below with reference to FIG. 6 . The display 16 may be any suitable electronic display, and may even provide touchscreen capabilities.
[0019] The fixed-arm clip 14 enables the user to simultaneously hold or hang the interactive device 10 and operate the push-button interface 19 with one hand. In certain embodiments the clip 14 has a rubber cover for a secure grip and feel. As shown below in FIG. 7 , the clip 14 may also function as a stand for the device 10 . The display 16 of the device 10 may be easily viewed when the device is placed on a flat surface supported by the clip 14 . This allows the user to operate the device in a “hands free” manner. For example, the individual may practice or perform an exercise while watching a video clip of the exercise being performed.
[0020] Turning to FIG. 2 , the operation of the push-button interface 19 will now be described. As will be appreciated, the push-button interface 19 is one possible configuration, the guiding principle being that the present invention contemplates an interface allowing a user single hand interaction with the device 10 . Of course, other button arrangements may well serve this purpose, and additional controls can be provided on the device 10 as desired.
[0021] The push-button interface 19 includes control buttons and switches 251 , 252 , 253 and 254 , all disposed on top of the device 10 . Button 251 provides inputs for the “on,” “enter,” and “off” functions of the device. Switch 252 performs the “up” and “down” functions of moving a highlight bar throughout the various displays. The appropriate choice, once highlighted, may be selected using button 251 . Button 253 is a “back” button as is conventional for switching to a previous display screen. Button 254 is a “menu” button for allowing the user to jump to a “menu” function as described below.
[0022] In the embodiment of FIG. 2 , button 251 sits above the surface of the housing 12 . Switch 252 is a toggle switch that is mounted below the surface of the device, where the top of the switch sticks up above the surface of the device. The “Back” button 253 is a small bar in-between buttons and also sticks above the surface of the device some. The “Menu” button 254 is level with the surface of the device.
[0023] FIG. 3 illustrates one embodiment of an adjustable clip mounted on a portable programmable interactive device 10 . The device 10 includes a case or housing 12 that contains and houses the necessary electrical components for operation of the device. An adjustable clip 15 is attached to the back of the device 10 which allows the portable device to be easily grasped for carrying or easily fastened to a belt of a user for example. A display 16 is arranged on the front of the case 12 so that the user can view information.
[0024] With further reference to FIG. 3 , control buttons 18 , 20 and 22 are provided for controlling the functions of the device 10 . The device 10 is worn or carried by the user during mobile activity. This portability and ease of use make the device 10 particularly well suited for situations where the user has no access to a desktop PC or the Internet, e.g. Some recreational examples include a gym, a golf course or golf driving range, on a bicycle ride, on a sports ground, etc. Some commercial examples include product inventory, delivery services, doctor's office, etc.
[0025] FIG. 4 illustrates the compact size and portability of the device 10 of either embodiment found in FIGS. 1 or 3 . A user's hand 25 easily grasps the device 10 with the aid of the fixed or adjustable clip 14 or 15 . The clip provides a means to clip onto a user's belt for example. The clip may also be used as a stand in which the user may place the device 10 on a table and view the screen 16 . As will be described below, the clip may be locked into place to allow for a variety of uses, dependent on the mode of operation of the device or the individual's preference.
[0026] According to certain embodiments of the present invention, the device 10 may be plugged into an external computer docking station 26 as shown in FIG. 5 . When in the docking station 26 , the device 10 may communicate with an external computer (not shown) by interconnecting a wire 28 between the external computer and the device 10 . Other embodiments of the present invention include communications with local and remote computers using any of a variety of wired and wireless approaches such as Bluetooth or USB connections. While in docking station 26 , the device 10 is capable of both sending and receiving data to an external computer.
[0027] One advantage of the present invention is that the docking station 26 allows the user access to a host of tools and information made available on the Internet. Instructional and motivational information, update information, contact information, inventory data, delivery data, etc. may be downloaded or uploaded while the device 10 is in the docking station. Once the necessary information is stored locally on the device 10 , the device may be unplugged from the station 26 and again used as a portable device.
[0028] For purposes of this disclosure, the external computer described above is simply any suitable computing device, whether portable or stationary. This definition includes, but is not limited to, electronic books, laptop and handheld computers, and desktop computers. Using wireless types of communications for example, the monitoring device 10 may communicate with a web page running on a remote server via the Internet.
[0029] The device 10 may include cellular or other wireless or wired communication capability so as to interconnect with the Internet either continuously or periodically. For communication with a remote server, the device 10 may also include some type of memory chip or memory module that may be removed from the device 10 and inserted into the external computer for transfer of data. It is also a feature of the present invention that the user with the aid of an external computer may program the device 10 . For example, the user's preferred workout and exercises may be entered via a keyboard connected to the external computer. The information is then transferred from the external computer into the local memory of the device 10 . For more details pertaining to the communications protocols and connections with all types of external computer systems, see copending application Ser. No. 10/758,712 filed Jan. 15, 2004 entitled “Communication System and Protocol For An Interactive Portable Device”, by Lucas et al., attorney docket number 41963-8002.
[0030] Referring now to FIG. 6 , the circuitry contained in the device 10 for one embodiment of the present invention is illustrated schematically. As will be appreciated, the embodiment of FIG. 6 is particularly well suited to a portable device designed specifically for physical fitness and recreational applications. The device 10 includes a processor CPU 30 for processing and controlling the various components and functions. A body activity monitor 32 provides a signal indicative of the body activity of the subject to the CPU. In the one embodiment of the invention, the body activity monitor is a heart rate monitor. The operator interface 34 sends signals to the CPU 30 to perform the intended functions as selected by the user. In one preferred embodiment, the operator interface 34 consists mainly of controlling buttons located on the device itself and operable with one hand. However, in other embodiments a touch sensitive overlay may provide a touch screen interface allowing the user to enter data through touch.
[0031] A memory 36 is provided to store all types of data to perform the desired functions of the device. In the physical fitness or recreational application, this information may include the internal programs necessary for device operations, workout information, instructional information, motivational information and the user's personal statistics. However, the memory 36 will include whatever information is necessary for a given application. The memory 36 typically includes both persistent and transient memory. A battery 38 is also provided to power the device in remote locations. The CPU 30 provides the data to display 40 for viewing by the subject. The memory 36 is interconnected with the CPU 30 and allows storage of data that may be entered by the user through the operator interface 34 or downloaded from an external computer through the external computer interface 44 .
[0032] Communications with external devices is provided through communications interface 44 . This interface may be located in the device itself or may be provided in the docking station 26 as shown in FIG. 6 . The communications interface 44 may also be a wired or wireless interface. An audio output connection 42 is provided for connection of external speakers or headphone for playing audio instructions and music. The circuitry of the device 10 may also include other input devices such as a barcode reader, an infrared port, a scanning device, etc.
[0033] FIG. 7 shows another disposition of the device 10 , wherein the clip acts as a stand for the device. The fixed-arm clip 14 can be designed to act as a stand in its fixed form. Alternatively, the adjustable clip 15 may be adjustable into one or more positions for providing stand support for the device 10 . This is ideal for setting the device 10 on a table for example, and viewing instructional data. This position of the device 10 is also desirable for playing music while working out, for viewing motivational information while performing an exercise, for viewing inventory or delivery data while working, etc.
[0034] FIGS. 8A, 8B , 8 C and 8 D show a first, second, third and fourth positions of the adjustable clip 15 . The first position of the clip 15 shown in FIG. 6A , would be used to attach the device to a belt for example. The second position of the clip 15 shown in FIG. 8B is ideal for aiding the user to grasp the device in his hand. The third position of the clip 15 shown in FIG. 8C would be used to fit the device 10 into the docking station as shown in FIG. 5 . In FIG. 8D the clip operates as a stand for the device 10 . Although these four positions are shown, the adjustable clip 15 may be positioned in any number of positions with varying angles relative to the device 10 in accordance with the individual's needs. As described below the device 10 may function in a variety of modes and these modes may be enacted with the adjustable clip in any position.
[0035] The adjustable clip of the present invention may be in any of the four positions as shown in FIGS. 8A through 8D . Depending on the preference of the user, the user may desire to interact with the main menu function while holding the device in his hand (with the clip in a first position), or the user may interact with the device standing upright, with the clip position adjusted accordingly.
[0036] The described embodiments relating to the clip features of the portable device are to be considered as illustrative and not restrictive. The invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims. | A device is disclosed that provides a multifunctional clip mounted on a portable, programmable, interactive apparatus. One embodiment of the device comprises a housing configured to be carried by a user, a display for displaying information to the user, an interface operable by the user, and fixed-arm clip. The user may hold the device with one hand with the fixed arm clip while operating the interface with the same hand. |
FIELD OF THE INVENTION
Counterbalance systems for vertically movable window sash.
BACKGROUND
This invention improves on a locking shoe and mounting bracket usable with a curl spring window balance system such as explained in U.S. Pat. Nos. 5,353,548, and 5,463,793. The invention adds convenience and reliability to the proposals of those patents.
SUMMARY
The improvements made by this invention include a mounting bracket that can hold its position while being shipped with a shoe cassette holding a curl spring and yet can automatically disengage from the spring shoe when fastened to a sash jamb channel. The shoe cassettes are also preferably formed of identical halves that are unhanded so that a shoe cassette can be deployed on either side of a window sash. The cassette halves are preferably configured to resist relative rotation as they are splayed apart in response to cam action of a tilt lock cam contained within the shoe. The tilt lock cams can be configured to retain headed sash pins, or can have recesses or slots that allow a sash pin to extend more than half way through a locking cam. The improved system also allows locking pads to be inexpensively installed on the shoes to exert increased locking friction when a sash tilts and shoe cams lock the shoes in their channels.
DRAWINGS
FIG. 1 is an isometric view of a shoe cassette including a curl spring, a spring mount, and a sash pin to counter balance one side of a window sash.
FIG. 2 is an isometric view of a shoe cassette, including a curl spring, a spring mount, and optional locking pads to counter balance an opposite side of a window sash.
FIG. 3 is a fragmentary view of an upper region of the cassette of FIG. 2 omitting a curl spring to help illustrate a preferred configuration of shoe mount.
FIG. 4 is a fragmentary cross-sectional top view of the shoe cassette of FIG. 2 partially mounted within a shoe channel of a window jamb to illustrate how the shoe mount (in solid black) clears a tilt latch of a sash.
FIG. 5 is a fragmentary rear view of the mounting bracket and the top of the shoe cassette of FIG. 2 to illustrate how the mounting bracket mounts on the shoe body.
FIG. 6 is an exploded isometric view of the cassette of FIG. 2 showing a curl spring, locking cam, and shoe halves, without a spring mount.
FIG. 7 is an exploded isometric view reversed from the view of FIG. 6 to show that each shoe half includes a rotation resisting projection and recess, and also showing a tilt lock cam with a through channel that can receive a sash pin extending more than half-way through the cam.
DETAILED DESCRIPTION
Shoe cartridges or cassettes 10 , such as illustrated in FIGS. 1 , 2 , 6 and 7 , include shoe bodies 11 that contain curl springs 30 and locking cams 20 . Shoe bodies 11 are preferably molded in halves 11 a and 11 b that are identical and that fit together in an interlock allowing a lower region of the shoe bodies to expand or splay apart in response to rotation of locking cam 20 . Shoe body halves 11 a and 11 b are preferably interconnected at their upper regions by a pair of headed rails or ridges that are formed on each of the body halves to slide into an interconnect with the opposite body half.
An upper edge or top region 12 of shoe body 11 supports mounting bracket 50 . A short length of curl spring 30 is uncurled from shoe body 11 and is attached to mounting bracket 50 , which can hold the assembled shoe body 11 , curl spring 30 , and mounting bracket 50 together for assembly into a window or shipment to a window manufacturer.
Mounting bracket 50 improves on a simpler bracket suggested in the '548 and '793 patents. Bracket 50 is robust enough, and well enough braced and interlocked at the top 12 of shoe body 11 , to hold itself and curl spring 30 in place in an assembled cassette 10 during shipment. This provides the convenience to a window manufacturer of shoe cassettes arriving assembled with mounting bracket 50 ready to secure each cartridge in a shoe channel of a window jamb. All that is necessary is to slide each cassette into a shoe channel to the mount position, and then drive in one or two fastening screws 51 to fasten mounting bracket 50 in place. Two fasteners or mounting screws 51 are preferred so that mounting bracket 50 can resist a torque or turning force applied by curl spring 30 . In some jamb channels, mounting bracket 50 can be blocked from rotation by channel walls, making a single mounting screw 51 all that is necessary for securely holding mounting bracket 50 in place.
To accomplish its improvements, mounting bracket 50 preferably includes mounting wall 52 , spring holding wall 53 , and brace 55 , as best shown in FIGS. 3 , 4 and 5 . Mounting wall 52 is preferably flat so that it can be fastened snuggly against back wall 61 of shoe channel 60 . Mounting wall 52 also includes a hole 56 or a hole 56 and a slot 57 to receive one or two mounting screws 51 . Spring holding wall 53 includes a projection 54 oriented to fit into an opening 34 in curl spring 30 , which exerts a downward pull on mounting bracket 50 to hold spring 30 , mount 50 , and body 11 in the assembled position illustrated in FIGS. 1 and 2 . Spring holding wall 53 is preferably normal or perpendicular to mounting wall 52 , and brace 55 preferably extends normal or perpendicular to spring holding wall 53 and parallel with mounting wall 55 . The interrelationship between walls 52 and 53 and brace 55 cooperates with the downward bias of spring 30 , to securely support mount 50 on the top 12 of shoe body 11 .
The top or upper surface 12 of shoe body halves 11 a and b preferably include headed ridge or “dog bone” shaped connectors 13 that hold shoe body halves 11 a and b together in proper alignment. Connectors 13 also allow a superposed attachment of an additional curl spring container mounted on top of shoe body 11 . The headed rail connectors also provide a sturdy interlock with mount 50 , as shown in FIG. 5 .
Mounting wall 52 preferably has an opposed pair of projections 85 that extend under headed connectors 13 to prevent mounting bracket 50 from pivoting out of its position on the top 12 of body 11 . The projection 85 that is farthest from spring holding wall 53 is especially well positioned to prevent this. Spring holding wall 53 has a downwardly extending projection 58 that overlaps with the adjacent dog bone connector 13 . Brace 55 rests on top of a connector 13 , and has a projection 59 ( FIGS. 1-3 ) that hooks over an edge of the connector 13 on which it rests. All these features ensure that mounting bracket 50 stays reliably in place on top of shoe body 11 , especially when curl spring 30 provides a downward force pulling mounting bracket 50 downward against the top of shoe body 11 .
Headed rail connectors 13 have end notches 14 that allow mounting wall projections 85 to escape from under connectors 13 when mounting wall 52 is fully attached flat against back wall 61 of shoe channel 60 . In the position of mounting bracket 50 as illustrated in FIG. 4 , mounting screw 51 has not been tightened enough to draw mounting bracket 50 snugly against back wall 61 of shoe channel 60 so that mounting bracket 50 has not yet escaped from shoe body 11 via notches 14 in the ends of connector rails 13 . Tightening screw 51 beyond the position illustrated in FIG. 4 to draw mounting wall 52 snugly against panel wall 61 then moves projections 85 into notches 14 of connectors 13 , which allows mounting bracket 50 to escape or separate from the top 12 of shoe body 11 . In practice, this separation occurs when shoe body 11 is pulled downward after mounting bracket 50 is fully secured within channel 60 . In effect, the sturdy interlock between mounting bracket 50 and shoe body 11 that allows shipment of assembled cassettes as illustrated in FIGS. 1 and 2 also automatically disconnects mounting bracket 50 from cassette body 11 when mounting bracket 50 is fully secured in place in a shoe channel 60 .
Since mounting bracket 50 is preferably free to slide along top surface of shoe body 11 when fastened into a shoe channel, as described, it is desirable to allow relative movement between curl spring 30 and spring holding projection 54 . Relative movement at the interconnection between spring 30 and projection 54 allows mounting bracket 50 to slide into mounted position without pulling spring 30 laterally out of its alignment with shoe body 11 . A preferred way of accomplishing such relative movement is to make hole 34 in spring 30 an oval or oblong hole or slot, as best shown in FIGS. 6 and 7 . Projection 54 can then move laterally within oblong hole or slot 34 to leave spring 30 in its aligned position relative to body 11 while mounting bracket 50 slides laterally into a released position engaging wall 61 of a shoe channel.
As best shown in FIG. 6 , locking cam 20 preferably has sash pin channels or slots 22 arranged on opposite sides of an annular cam 21 . Each of the cam slots 22 preferably has in turned walls 23 that can capture a head 73 of a sash pin 70 (illustrated in FIG. 1 ). It is also possible, and is preferred in some situations, for locking cam 20 to have a through recess or channel 25 that allows a sash pin to extend more than half way into locking cam 20 (shown in FIG. 7 ). A through channel 25 in cam 20 allows a sash pin to penetrate deeply into cam 20 and is preferred to increase the wind resistance of a sash.
Each body part 11 a and b preferably has a recess 72 formed above the end regions of cam 20 . When a sash supported by cassettes 10 is tilted out of the window plane, cam 20 turns to a locking position that aligns its channel 25 or slots 22 with recesses 72 . This allows the heads 73 of sash pin 70 to be raised upward from cam slots 22 or channel 25 and into recesses 72 to facilitate removing a tilted sash from a window.
Recesses 72 also facilitate replacing a removed sash, because recesses 72 allow extra room above cam 20 to receive sash pin 70 that can then be dropped down into cam slots 22 or 25 . Recesses 72 also provide a somewhat larger area for maneuvering sash pins 70 into shoe bodies 11 a and b before dropping downward into cam channels 25 or slots 22 . The sash pins 70 can have heads 73 that interlock with cam edges 23 to prevent withdrawal of sash pin 70 from shoe cassettes 10 if a window is carried in a suitcase fashion before installation. Sash pins 70 can also be un-headed and long enough to extend deeply into cam 20 for improved wind resistance of a sash. The described arrangement of cam channels 22 and 25 , recesses 72 , and sash pins 70 also allows shoes 11 to be unhanded, so that any shoe can be installed on either side of a sash to be counterbalanced.
Mounting brackets 50 , to the contrary, are preferably handed so that each bracket is arranged to be mounted on only one side of a sash. This preference is to assure that mounting brackets 50 do not interfere with tilt latches of a counter balanced sash. FIG. 4 illustrates one way that this can be accomplished. Tilt latch 75 , which is typically spring loaded to be snapped into latching engagement with channel slot 62 when a tilted sash is moved back to an upright position, runs in slot 62 of channel 60 where it moves up and down with sash 50 to prevent accidental tilting. When latches 75 are moved inward against their spring bias, they allow deliberate tilting of a counter balanced sash.
Brace 55 of mounting bracket 50 is preferably mounted in an orientation that clears tilt latch 75 so that mounting bracket 50 does not interfere with vertical movement of tilt latch 75 past mounting bracket 50 . The left- and right-handedness of mounting bracket 50 as identified by the A and B markings appearing on mounting brackets 50 in FIGS. 1 and 2 ensures that a mounting bracket on each side of a window sash clears the tilt latch 75 .
Lower corners of body parts 11 a and b preferably have molded recesses 82 that can receive locking pads 80 or 81 to increase a frictional locking effect when a balanced sash tilts to pivot cam 20 to a locking position. Locking pads 80 and 81 (schematically shown in FIG. 2 ) are alternatives that can be pressed into a recess 82 to achieve a pressed fit in recess 82 for locking pad 80 or a snap fit in recess 82 for locking pad 81 . Pads 80 and 81 can be surfaced with different materials and given different surface configurations to increase the frictional security of a shoe lock achieved by pivoting of cam 20 to spread shoe bodies 11 a and b somewhat apart within channel 60 .
When locking cam 20 pivots with a tilted sash, its cam surface 21 slides in between lower edges of shoe bodies 11 a and b to splay the shoe bodies apart and lock the shoe cassette in place in a jamb channel. This splaying apart of the lower regions of shoe bodies 11 a and b also produces a force that tends to rotate the shoe bodies relative to each other as they are forced apart by cam surface 21 . Such rotation would tend to diminish the splaying apart of the shoe body halves, and this tendency is overcome by projections 15 and corresponding recesses 16 that are formed in the lower region of each shoe half. As bodies 11 a and b splay apart in response to rotation of cam surface 21 , projections 15 remain engaged with recesses 16 to prevent any relative rotation between shoe halves 11 a and 11 b. Recesses 16 can be formed as inward facing parts of recesses 82 whose outward facing parts can receive locking pads 80 or 81 . Projections 15 and recesses 16 are also preferably alternately formed on each body half 11 a and b so that these halves remain identical to each other while providing a pair of mating recesses 16 and projections 15 . | A curl spring sash shoe cassette improves upon the suggestions of U.S. Pat. Nos. 5,353,548 and 5,463,793 by providing a mounting bracket that holds an uncurled length of the curl spring and is securely mounted on top of the shoe cassette to maintain an assembly of the shoe body, the curl spring, and the mount during shipment to a window manufacturer. The mount can receive two mounting screws to resist torque caused by curl springs and sash weight. The shoe is also improved to facilitate removal and reinsertion of sash pins into the tilt lock cams of the shoes and ensure that shoe body halves do not rotate relative to each other when sash tilting splays the body halves apart to lock them in a shoe channel. |
[0001] The present invention relates to a device for extracting energy from a fluid flow, and more particularly to a fluid power generator generating air pressure variations that may be used to drive an air turbine.
[0002] Recent years have seen the interest in the development of renewable energy sources increase as concern over the impact of carbon emissions on the environment has been heightened. Whilst focus has been primarily on the development of wind and solar power, these technologies have various disadvantages. Wind power generation is reliant upon the presence of driving wind of a given threshold value to move the propeller at sufficient speed to drive a turbine. Wind power also requires a large area of land dedicated to the production of energy and these large ‘wind farms’ are often unsightly and may pose a hazard to the surrounding wildlife. Solar power also has the disadvantages of providing a non-reliable source of electricity and also suffers from low efficiency and high cost.
[0003] Wave or tidal energy devices can overcome many of the disadvantages listed above. They provide a reliable source of energy as they are driven by the force inherent within tidal and ocean waves and also have the potential to be placed in a large number of areas, particularly in coastal areas with large fetch, such as the western coast of Europe.
[0004] A number of differing techniques have been employed to harness wave, tidal or ocean power. Traditional tidal energy devices have centred on a barrier arrangement that when placed within a tidal system fills with water at high tide and releases the water at low tide through a turbine to generate electricity. Concerns have been raised that the use of conventional barrier type tidal energy devices can prove hazardous to wildlife and boats. Additionally, these devices may only be used after each high tide and do not therefore provide a constant supply of energy.
[0005] One example of a wave energy collector is disclosed within EP 1115976. This device utilises the relative rotational movement between pluralities of segments to drive a hydraulic motor.
[0006] One alternative technique is to use the oscillatory nature of waves to compress a volume of air (an Oscillating Water Column device). By submerging a structure with an air chamber and an underwater aperture, an incident surface wave makes the fluid level within the chamber rise, compressing the volume of air within the air chamber. This (adiabatically) compressed air may then be used to drive a turbine, the rotation of which may be used to power a generator. As the water level falls, the air pressure reduces and air is drawn back into the chamber through the turbine. An example of this type of device is shown within EP 0948716 whereby the parabolic wave is focussed into a chamber wherein the air is compressed and used to drive a unidirectional turbine. Another example of an Oscillating Water Column device has been developed by Wavegen and has been named the ‘Limpet’.
[0007] One inherent problem of these devices is the relatively low energy conversion efficiency, coupled to the varying nature of the size and strength of the incident waves, which leads to an uncertain energy output. These devices are also located on or close to the shore to take advantage of the higher parabolic waves at the shore. This again leads to a variation in the production of energy between high and low tides. Additionally, the above devices focus parabolic ocean waves through structural features, for example an upwardly sloped base or a generally upright wall. These devices are also unsuitable in scenarios of constant flow or current, for example tidal flows; thermohaline induced oceanic currents, for example the North Atlantic Drift and the Gulf Stream; and gravity induced fluid flows, for example within rivers.
[0008] The present invention aims to overcome these problems by providing an improved device for extracting energy from a fluid flow.
[0009] It is a further aim of the present invention to provide an improved water power generator. It is a further aim of the present invention to provide a water power device that requires little maintenance.
[0010] According to the present invention there is provided a device for extracting energy from a fluid flow. The device comprises an air compression chamber and an array of valves, operable to open and close to regulate flow of the fluid through associated valve apertures. The valves are operable to close progressively as the fluid flow is incident thereon, thereby focusing flow of the liquid towards the air compression chamber and compressing air therein, and to open on a return flow of liquid from the compression chamber.
[0011] It is an advantage that the device is configured to focus the energy in a flow of liquid to compress the air in an air compression chamber. The device is configured so that this can occur in a cyclical manner. The progressive closing of the valves focuses the flow of fluid to compress the air in the air compression chamber. The liquid, which then flows back out of the air compression chamber, is allowed to flow through the apertures by the opening of the valves. Another compression cycle can then commence by the progressive closing of the valves. Accordingly the device may be used in any flowing liquid, such as a river, or tidal flow or ocean current, to extract energy in the form of compressed air.
[0012] Embodiments of the invention may further comprise an accumulation chamber for storing compressed air that has been compressed in the air compression chamber.
[0013] Advantageously, the device may further comprise a turbine operable to be driven by the compressed air. A decompression chamber may be positioned downstream of the turbine for enhancing a pressure differential across the turbine during the return flow of liquid from the compression chamber.
[0014] In embodiments of the invention, the valves within the array extend in an upward gradient in the direction of the fluid flow.
[0015] The valves may be flap valves. These flap valves may comprise respective buoyant elements. The buoyant elements may have an angular displacement required to close the flap valves, the angular displacement increasing up the gradient. The buoyancy of the buoyant elements may also increase up the gradient and the buoyant elements may comprise tyres.
[0016] In embodiments of the invention the valves comprise spoiler elements to facilitate the deflection of the fluid flow along the upwardly inclined gradient and/or assist the opening of the valves during the return flow.
[0017] Embodiments of the invention further comprise use of the device as a tidal energy device, to drive a water turbine or to pump water to a higher reservoir. Additional embodiments comprise the use of the device as an oceanic or river flow device
[0018] In final embodiments, multiple devices may be arranged or linked together to form a network of devices positioned to optimise utilisation of the fluid flow.
[0019] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0020] FIG. 1 is a perspective view of a device for extracting energy from a fluid flow, prior to submersion in the fluid;
[0021] FIG. 2 is an end-on view of the device of FIG. 1 , showing the array of cutaways and valves in detail;
[0022] FIG. 3 is a cross-sectional view through the line A-A in FIG. 2 after submersion into the fluid flow;
[0023] FIG. 4 is a cross-sectional view as per FIG. 3 and shows the partial closure of the valves due to the incident fluid flow; and
[0024] FIG. 5 is a cross-sectional view as per FIGS. 3 and 4 and shows the complete closure of the valves due to the incident fluid flow, and the subsequent upsurge of fluid into the compression space.
DETAILED DESCRIPTION
[0025] FIG. 1 shows a simplified perspective view of a device 10 for extracting energy from a liquid flow. The device comprises a roof 12 , and side walls 14 that form an opening 16 incident to the flow direction. A top portion 20 of the device 10 , below the roof 12 , houses an arrangement of air chambers, as will be described in more detail below. The roof 12 , side walls 14 and additional structural components may be constructed from concrete, although any material capable of producing a stable, water-tight structure may be utilised, for example metals, including steel. A base section 30 extends from the bottom edge of the opening 16 , and this will be described in more detail below. The size of the device may be optimised for efficiency and/or to optimise the capture of the fluid and may be based on characteristics of the incident flow, as will be further described below.
[0026] The base section 30 of the device 10 comprises alternate sloping backwalls 34 and horizontal floors 33 . FIG. 2 shows an end-on view of the device looking through the opening 16 . An array of apertures 32 on the backwalls 34 are covered by a corresponding array of valves 40 (of which only one column of the array is shown in FIG. 2 ). Additionally, although the array of apertures 32 is shown with a 6×7 arrangement, it may be appreciated that the number of rows and columns of the array may be varied dependent upon the required focussing effect and size of the device. For example, to utilise oceanic or tidal currents the device 10 may feature an array with as many as 200 or more columns and 2000 or more rows. Additionally, multiple devices 10 may be connected together to form a larger structure.
[0027] To simplify the figures and allow viewing of the apertures 32 , only one column of valves 40 is shown in each figure. The valves 40 are shown as flap valves; however it may be appreciated that other valve types may be employed. The structure of the flap valves 40 is explained in detail below with reference to FIG. 3-5 . The purpose of these valves 40 is to channel and regulate the flow of liquid in a manner that will be described in greater detail below. The columns of the valves 40 are shown extending along an upwardly extending gradient in the direction of liquid flow so that each row of valves is located both above and behind the lower row. Although the array is shown with a stepped arrangement, any configuration that provides an upwardly extending gradient may be employed, depending upon the orientation of the device with respect to the incident liquid flow or the required liquid channelling.
[0028] FIG. 3 shows a cross-sectional view through the line A-A marked within FIG. 2 . In this figure, the device has been immersed into a liquid to a level 60 . The valves 40 are open and the level of the liquid 65 within the device is approximately the same as the external level 60 . The top portion 20 includes an air compression chamber 24 , which is open at its bottom so that the liquid level 65 traps the air inside it, an accumulator chamber 22 a , and a decompression chamber 22 b . The pressure of the air trapped within the compression chamber 24 between the roof 12 , side walls 14 , rear wall 18 , chambers 22 a , 22 b and the liquid 65 is also approximately the same as the external air pressure. It may be appreciated that the area and volume of the space 24 may vary depending upon the relative dimensions of the constricting components ( 12 , 14 , 18 , 20 , 22 ) and the height of the water level 65 .
[0029] Within the embodiment shown, the two chambers 20 , 22 are connected to the roof 12 and sidewalls 14 of the device 10 . These chambers act to store air of differing pressure and are connected to each other via a turbine 50 and piping 52 , 54 . Flap valves 21 , 23 interconnect the compression chamber with, respectively, each of the accumulator chamber 22 a , and the decompression chamber 22 b . As the pressure of the air within the compression chamber 24 becomes higher than the pressure in the chamber 22 a , the valve 21 is forced open by the air pressure until the pressure within the chamber 22 a and the compression chamber 24 are equivalent. Conversely, if the pressure within the chamber 22 b is greater than the pressure in the compression chamber 24 , then the valve 23 opens until the pressures are equivalent. These chambers 22 a , 22 b also act as buoyancy tanks to keep the device floating within the water. As shown in FIG. 1 , tether means 11 may be employed to secure the device 10 into position and allow the device to face the incident liquid flow. This tether means 11 may take the form of an anchor, mooring ropes, chains or any other anchorage.
[0030] The operation of the device will now be described in relation to FIGS. 3 , 4 and 5 . Flow lines are shown for reference only. FIG. 3 shows the device in the relaxed or initial position. In this position, the valves 40 are open, the water levels 60 , 65 are approximately level and the pressure of the air within the compression chamber 24 and outside the device are approximately equivalent. An incident flowing liquid or current, represented by the individual flow lines 100 and incident upon the device 10 , flows through the aperture 16 and acts upon the array of valves 40 . The flowing liquid 100 enters the device and acts upon the valves 40 . The valves are arranged so that lowermost row of valves, due to the impulse of the liquid flow 100 , is the first to close against the apertures 32 . Once a valve 40 has closed, the incident liquid flow 100 is deflected in an upwards direction, increasing the impulse of the liquid flow against the second row of valves that are then also closed by the force of the flow 100 . This progressive closing of the valves focuses the flow of the liquid (represented in the figures by the lines of flow 100 ) into the compression chamber 24 , causing the water level 65 within the to rise, and compressing the air within the chamber 24 . This process continues until all the valves 40 are fully closed ( FIG. 5 ). Returning to an intermediate situation ( FIG. 4 ) where (in this representation) 3 of the 7 rows of valves are closed, it is clear that the fluid level 65 within the compression chamber 24 of the device 10 has increased to a level above the external mean level 60 . This increases the air pressure within the compression chamber 24 , closing the valve(s) 23 between the compression chamber 24 and the decompression chamber 22 b and opening the valve 21 between the compression chamber 24 and the accumulator chamber 22 a.
[0031] As may be seen from FIG. 4 , the valves 40 close sequentially along the upwardly inclined gradient of the valve array. This sequential closing is achieved by varying the buoyancy and angle of closure for the valves between the rows within the array. In this case, the lower valves have lower buoyancy than the valves within the row directly above. In the current embodiment, the valves comprise car tyres 42 of differing tyre pressure. Additionally, the angle of the backwall 34 with respect to the vertical increases along the upward gradient towards the compression space 24 . Valve 40 ′ has a tyre 42 ′ with a lower pressure and smaller angle between the backwall 34 ′ and the vertical than valve 40 ″, with tyre pressure 42 ″ and backwall 34 ″.
[0032] FIG. 5 shows the end state of the device when all the valves 40 are fully closed. The progressive closing of the valves 40 results in an increase in the level of the water 65 within the compression chamber 24 . The degree of water level 65 increase is dependent upon the number of valves 40 and the impulse of the incident fluid. Although the present embodiment features seven rows of valves, any number of rows may be utilised dependent upon the depth of the fluid and the degree of surge required. The incident flow of the fluid is now concentrated and directed towards the compression chamber 24 (as shown by the lines of flow 100 ), the volume of which has been reduced by the increasing water level 65 . This reduction in volume creates a corresponding increase in the air pressure within the compression chamber 24 and the accumulator chamber 22 a.
[0033] Once the upward surge of water reaches a maximum, the air pressure within the compression chamber 24 rapidly drops and the inlet valve 21 to the accumulator chamber 22 a closes. At this point there is no net fluid flow within the device 10 . When the device 10 is in this no-flow equilibrium position, both valves 21 and 23 between the compression chamber 24 and the chambers 22 a , 22 b are closed. Due to the operation of the valves 21 , 23 and the relative air pressures of the chamber 24 at varying stages of the operation of the device 10 , the two chambers 22 a , 22 b have differing air pressures. Within the embodiment shown, accumulator chamber 22 a has a greater air pressure than decompression chamber 22 b.
[0034] The two chambers 22 a , 22 b are linked by a turbine 50 and inlet and outlet couplings 52 , 54 . By opening the inlet 52 and outlet 54 couplings to the turbine 50 , the positive pressure air in accumulator chamber 20 is drawn through the coupling 52 , due to the pressure differential between the two bodies of air, into the turbine 50 and through coupling 54 into the decompression chamber 22 . This process drives the turbine 50 and may be used for the generation of electricity via a generator (not shown). Due to the construction of the chambers 22 a , 22 b and the method of coupling to the turbine 50 , the chambers may be used to store the varying pressured air over a number of cycles of the oscillatory water level 65 , building up the pressure difference with each cycle. Once a threshold pressure difference is reached, the coupling to the turbine 50 may be opened and the air moved through the turbine 50 .
[0035] When the device 10 is in the no-flow position the water pressure acting upon the front of the valves 40 is the same as the rear of the valves. The valves therefore begin to open due to the buoyancy of the tyres. As the valve closest to the compression space has the highest pressure or buoyancy, this valve opens first. The water level 65 then begins to fall, causing a backward or downward flow of water over the valves. Due to the spoilers 44 on the top of the valves, the downward force of the water acts to open the valves, until all the valves are open, resetting the device to the situation shown in FIG. 3 . A rail 120 or any other means may be utilised to prevent the valves 40 from opening past a predetermined angle. The device 10 is therefore essentially reset and the process described above is repeated (i.e. the incident fluid flow acts upon, and begins to close, the array of valves).
[0036] As an alternative to the unidirectional turbine 50 described above, the chambers 22 a and 22 b could be omitted and a bidirectional flow turbine connected directly to the compression chamber 24 , for example a Wells turbine that is able to rotate in the same direction irrespective to the incident air flow direction.
[0037] Although the device 10 has been explained with reference to a single device operating in isolation, it may be envisaged that multiple devices may be linked or placed together to form a cellular network of devices capable of supplying a larger quantity of energy. These devices may act independently or may share common elements, for example air compression and decompression chambers and/or turbines and generators to maximise the efficiency of the devices. Additionally, in order to maximise the flow of fluid through the devices, the network may be arranged into a “U” or “V” shape to prevent escape of the fluid flow around the outside of the network. Alternatively, the devices may be arranged within a shape akin to that of a “stealth bomber”, creating an area of low liquid pressure behind the structure. Multiple networks may also be linked or arranged together to optimise utilisation of fluid flow depending upon flow conditions. Although the networks of devices have been described in the orientation described above, any orientation may be utilised to suit the particular flow conditions. In addition, the devices may be arranged in series or stacked to increase the amount of energy that is extracted. The number of devices in the stack may be selected to optimise the return in terms of energy extracted in relation to the construction cost. Also, the stacks may be arranged as a series of devices oriented to receive a flow in one direction, with another series oriented to receive flow in the reverse direction. This arrangement is particularly suitable for use in tidal flows and avoids having to turn the devices around when the tide changes direction. | The invention provides a device for extracting energy from a fluid flow. The device has an air compression chamber and an array of valves, operable to open and close to regulate flow of the fluid through associated valve apertures. The valves are operable to close progressively as the fluid flow is incident thereon, thereby focusing flow of the liquid towards the air compression chamber and compressing air therein. The valves also open on a return flow of liquid from the compression chamber. |
BACKGROUND OF THE INVENTION
Numerous riding garden tractor and lawn mower configurations are known in the prior art. Generally speaking, the prior art machines are manufactured primarily for lawn mowing, but in some cases have the secondary capability for earthworking in the garden. Usually, the engine is located in a forward position relative to the operator and earthworking implements are mounted rearwardly of the operator, making it very difficult for the operator to observe the operation and positioning of implements while driving the tractor. Usually, the prior art machines have minimal ground clearance, restricting their use to the cultivation of only the smallest of row crops, and usually there is no provision for adjustment of wheel tread width which further limits the versatility of the machine for said tilling and cultivating. The customary provision of a gear transmission or differential, or both, increases manufacturing costs as well as the cost of maintenance.
These and other recognized drawbacks of prior art garden tractors are eliminated in the invention in accordance with a principal object of the invention through provision of a much more versatile garden tractor which is more convenient to operate with expected lower maintenance cost over a long period of time. The tractor can mount diverse earthworking implements interchangeably by the mere manipulation of two mounting bolts on a sturdy parallelogram implement frame or lift in clear view of the tractor operator. A lawn mower attachment can also be mounted and driven through a power take-off system by the tractor engine.
A simplified main frame consists essentially of a center longitudinal high ground clearance single beam on which the engine and associated power transfer train are mounted rearwardly of the tractor operator's seat. The tractor has a tricycle configuration with dual traction wheels thereof disposed rearwardly, beneath the engine, and the two wide stance laterally adjustable steering wheels disposed at the front of the machine supporting the front of the main frame. The diverse implement mount is at an intermediate location somewhat forwardly of the operator's seat.
Other features and advantages of the invention will become apparent during the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a riding garden tractor according to the invention.
FIG. 2 is a fragmentary horizontal section taken on line 2--2 of FIG. 1 showing drive train components.
FIG. 3 is an enlarged fragmentary vertical section taken on line 3--3 of FIG. 2.
FIG. 4 is a similar section taken on line 4--4 of FIG. 2.
FIG. 5 is a similar section taken on line 5--5 of FIG. 2.
FIG. 6 is a similar section taken on line 6--6 of FIG. 2.
FIG. 7 is a fragmentary horizontal section taken on line 7--7 of FIG. 1.
FIG. 8 is a side elevation of the tractor depicting the cultivation of a crop row by means of shanks and sweeps.
FIG. 9 is a plan view of the tractor as shown in FIG. 8.
FIG. 10 is an opposite side elevation of the tractor showing a moldboard plow attachment mounted thereon.
FIG. 11 is a similar view of the tractor with a lawn mowing attachment mounted thereon.
FIG. 12 is an exploded perspective view showing a power take-off drive for the lawn mowing attachment.
FIG. 13 is a fragmentary vertica section taken on line 13--13 of FIG. 12.
FIG. 14 is a fragmentary exploded perspective view depicting a modification of the tractor steering mechanism and front wheel tread adjustment.
FIG. 15 is a schematic view of an optional seat pressure responsive safety switch.
FIG. 16 is a fragmentary perspective view of a locking means for holding a forward and reverse clutch operating lever in a neutral position.
DETAILED DESCRIPTION
Referring to the drawings in detail wherein like numerals designate like parts, a garden and lawn tractor according to the invention includes a main frame consisting essentially of a center longitudinal beam or member 25 at a sufficient elevation to provide substantial ground clearance enabling the tractor to pass over various row crops. On a rear sub-frame portion 26, FIG. 12, of main frame member 25 is mounted an engine 27 and associated drive train components, to be described in full detail. The engine and drive components shown particularly in FIGS. 2 and 3 power a preferably dual rear traction wheel 28 of the tractor which is located directly below the engine and support the rear end of frame member 25 including sub-frame 26.
The tractor has a three wheel configuration, FIG. 9, and relatively smaller wide stance laterally adjustable front steering wheels 29 and axle structure, to be described in detail, support the front of frame member 25.
Rearwardly of front steering wheels 29 and substantially forwardly of the engine 27 and rear traction wheels 28 is a mount 30 for diverse earthworking attachments and a lawn mowing attachment, to be described. An operator's seat 31 immediately ahead of the rear engine enclosure 32 is located to position the operator comfortably and efficiently with respect to all controls on the tractor and with a clear view of implements and the lawn mower attachment selectively held by the mount 30.
Power from the engine 27 is delivered to the dual traction wheel 28 without the usual gear transmission and/or differential gear, and consequently without the necessity for shifting gears at any time. The engine 27 includes a power output shaft 33 to which is fixed a sprocket 34, engaged with and driving a chain 35. This chain is driven counterclockwise, FIG. 3, and drives an idler sprocket 36 mounted on a reverse motion shaft 37. The chain 35 also engages and drives another sprocket 38 mounted on a power take-off shaft 39 which also revolves counterclockwise, FIG. 3. The two sprockets 38 and 36 are the forward and reverse prime movers of the tractor drive, respectively.
Mounted forwardly of the engine 27 within the enclosure 32 is a transverse power transfer shaft 40 to which is fixed a sprocket 41. This sprocket drives a chain 42 in FIG. 3, which chain engages a sprocket 43 which, in turn, is fixed to another transverse power transfer shaft 44. Fixed to this shaft 44 is a smaller sprocket 45 engaged by a chain 46 driving a final sprocket 47, fixed to the axle 48 of dual rear traction wheel 28. An idler sprocket 49 is provided in engagement with the chain 46 to take up slack in this chain adjustably.
The foregoing sprocket chain drive shown in FIG. 3 comprises the fixed position components of the drive train for propelling the tractor. For selectively achieving forward or reverse movement of the tractor, a unique pulley and belt mechanism is employed between the forward and reverse motion shafts 39 and 37 and the power transfer shaft 40. This mechanism in its entirety is shown in FIG. 2 and portions of it are shown in FIGS. 5 and 6.
Again referring to FIGS. 2 and 3, a forward and reverse selector lever 50 is provided having a handle 51 which is shown in a neutral position. Forward movement of this handle 50 by the operator engages the forward motion pullies and belts, and rearward movement of the handle engages the reverse movement pullies and belts.
Motion selector lever 50 carries a lower extension 52 rigid therewith which is pivoted at 53 to a frame member 54. At the pivot 53, the lever 50 is held between spring-loaded friction plates 55 which tend to retain the lever in any selected position of adjustment. Movement of the lever 50 forwardly or rearwardly from the illustrated neutral position gradually increases the ground speed of the tractor until the lever reaches an extreme position in either direction.
Rearwardly of pivot 53, a lower yoke 56 is attached at 57 to extension 52. The lower yoke threadedly receives an adjustable actuator rod 58 whose upper end is connected to an upper threaded yoke 59, bolted at 60 to a lever arm 61 fixed to a transverse rotary shifter shaft 62. The shaft 62 is journaled in pillow blocks 63, FIG. 3, and attached to the opposite end of shaft 62 is a shaft lever 64 shown in phantom lines in FIG. 3. The shaft lever is shown in full lines in FIG. 6.
An idler sheave 65 is fixed to the lever 64 at 66. Referring to FIG. 6, the sheave 65 overlies a V-belt 67 which is engaged around a forward motion power take-off pulley 68, fixed to the previously-described forward motion shaft 39, and then engaged with a pulley 69 fixed to take-off shaft 40.
Fixed by bolt 66 to the rear side of sheave 65 is a linkage arm 70 shown in both FIGS. 5 and 6, FIG. 5 being an isolated view of the reversing mechanism. Linkage arm 70 is connected at bolt 71 to an idler sheave 72 which underlies a V-belt 73. The belt 73 engages a reverse motion power take-off pulley 74 fixed to the previously-described reverse motion shaft 37, and then engages a reverse motion take-off pulley 75 which is fixed to the shaft 40.
In operation, when handle 51 is urged forwardly, forward motion idler sheave 65 tightens V-belt 67, as shown in phantom lines in FIG. 6, to transmit the power from forward motion shaft 39 to traction wheels 28 via the drive train previously described. When handle 51 is pulled rearwardly, reversing idler pulley 72 tightens V-belt 73 as shown in phantom lines in FIG. 5 and power is transferred from reversing shaft 37 to traction wheels 28 via the drive train.
Continuing along transfer shaft 40, FIG. 2, and referring to FIG. 4, another pulley 76 is fixed on the shaft 40. This latter pulley is provided to form a mechanical brake on the power transfer shaft 40. A belt section 77, FIG. 4, engages around pulley 76 and is anchored at 78 to an angle member 79 fixed to the main frame 25 of the tractor. The other end of belt section 77 is connected at 80 to a link 81. A threaded connector 82 is connected at 83 to the other end of link 81. A brake return spring 84 is connected between the element 83 and a stationary anchor 85 on main frame 25. A brake control rod 86 is threaded into connector 82 and is fixed to a pedal block 87. The block 87 in turn is fixed to a brake lever 88, pivoted at 89 to a steering cowling 90. A brake pedal 91 is fixed to the lower end of brake lever 88 for applying foot pressure required to slow or stop the tractor at certain times. The pedal 91 is locked when foot pressure is applied to it preventing forward or rearward movement of the tractor. The brake is not used normally in slowing or stopping the tractor, and this is ordinarily accomplished by using the forward/reverse handle 51. The foot operated brake system is for emergency and parking usage. Accordingly, inboard of lever 88, and fixed to shaft 89 is an extension lever 92 equipped with a pivoted pawl 93 which engages a rack bar 94 on frame member 25. When the emergency brake is applied, the rack and pawl arrangement retains the brake in the locked position. A releasing rod 95 is provided which is attached to the pawl 93 and extends through a guide aperture in the cowling 90, whereby the brake locking pawl 93 can be manually released to allow return of the brake lever 88 by the spring 84 to the non-braking position.
Returning to the general construction of the tractor, the operator's seat 31 is hinged at its forward edge by a transverse axis hinge 96 which enables the seat to be swung forwardly nearly 180° when it is desired to open a hood 97 provided on the engine enclosure or cowling 32, the hood having a transverse axis hinge 98. Preferably an upper backrest 99 is provided on the front of the hood 97 to further the comfort of the operator.
Substantially below the operator's seat is the aforementioned implement mount 30 forming an important aspect of the invention. The mount 30 includes a sturdy crossbar 100 rigid with longitudinal frame member 25 and extending equidistantly on opposite sides thereof at right angles thereto, FIG. 9. A pair of angle members 101 are fixed dependingly to each end of crossbar 100 forming a rigid inverted U-frame near the longitudinal center of frame member 25. A pair of transverse tubes 102 are pivotally mounted on the angle members 101 by means of a double-ended hanger strap 103 bolted to each angle member 101. Welded to each end of the upper and lower tubes 102 are parallelogram arms 104 which carry at their forward ends a pair of vertical implement support bars 105. A link 106 is connected diagonally between the lower parallelogram arms 104 and a manual control lever 107 near the side of the operator's seat 31 opposite from the forward/reverse handle 51.
The link 106 is slotted, as shown, and bolted at 108 to enable fine adjustment of the heights of arms 104. The link 106 at its upper end is bolted at 109 to the control lever 107 whose lower end is pivoted at 110 to the tractor frame.
The control lever 107 has a square collar 111 thereon telescopically. This collar carries a tooth-engaging tang 112 urged by a spring 113 into engagement with the teeth of an arcuate toothed sector 114 closely adjacent to the collar 111. This arrangement positively maintains the desired height of the parallelogram implement mount 30 set by the operator by use of the control lever 107. The two right angular handles 115 on the control lever 107 are for the convenience of the operator, and either handle may be utilized to engage or disengage the tang 112 with the teeth of plate or sector 114, whereby the control lever 107 can be swung to a new position to raise or lower the implement mount 30.
A pair of large coil springs 116 is connected between the lower arms 104 and the upper arm 104. These springs preload the implement mount upwardly and greatly aid the operator in overcoming the weight of the mount 30 and any implement attached thereto. Additionally, slots 117 are provided on the upper parallelogram arms 104 to allow adjustment of the bolts 118 at the tops of bars 105, thus enabling some adjustment of the inclination of the bars 105 of the implement mount and, in turn, of the implement attached thereto.
Referring particularly to FIGS. 8 and 9, the tractor steering mechanism is seen to comprise a transverse channel beam 119 fixed to the forward end of longitudinal main frame member 25 and extending equidistantly on opposite sides thereof, at right angles thereto. The beam 119 is secured to the frame member 25 by angles 120 and bolts 121. The cowling 90 forms a housing within which is mounted a vertical axis bearing 122 serving to journal a steering column 123 atop which is welded a U-bracket 124 apertured to receive a crosspin 125 of a bifurcated steering handle 126 arranged for easy grasping by an occupant of the seat 31. The pin 125 forms a transverse axis pivot for the steering handle 126 allowing the latter to be swung forwardly when the seat 31 is swung forwardly on the axis of hinge 96, which in turn makes room for the opening of the hood 97 by swinging it forwardly on the axis of hinge 98.
At its lower end, a steering control arm 127 is welded to the steering column 123. This arm is bolted at 128 to an apertured steering link 129 which in turn is bolted at 130 to right and left hand steering links 131. The links 131 are bolted at 132 to control arms 133 which are fixed to vertically journaled wheel stanchions 134. These stanchions in turn are fixed to depending front wheel support members 135 to which the front wheel axles 136 are secured, rotatably supporting the hubs 137 of front steering wheels 29.
As best shown in FIG. 9, the links 131 are apertured at 138. The steering link 129 is similarly apertured at 139. Also, the front wheels 29 are mounted on laterally adjustable frame members 140 via apertures 141 receiving locking bolts 142. When the tractor is carrying certain attachment implements, to be described, it may be desirable, for example, to position the right front wheel further outwardly from the frame member 25 while the left front wheel is positioned further inwardly from the wheel positions shown in FIG. 9. The described construction allows either or both front wheels 29 to be adjusted inwardly or outwardly from two extreme positions to accommodate the various attachments with which the tractor is provided.
The first of these attachments indicated by the numeral 143, FIG. 1, is a spike tooth harrow with cultivator hoe. This implement is also shown in FIG. 7. It consists of a pair of transverse angle bars 144 and 145. The forward bar 144 carries tines 146 and similar tines 147 carried by the rear bar 145 are staggered laterally relative to the tines 146, FIG. 7
Tool bars 148 are secured to the two bars 144 and 145 by bolts 149. The rear portions of tool bars 148 are angled downwardly at about 45° to the vertical as shown at 150 and these extensions have cultivator hoes 151 fixed thereto by bolts 152.
The tines 146 and 147 are fixed to the angle bars 144 and 145 by welding, and a single pair of bolts 153 is employed to mount the harrow attachment 143 removably on the implement support bars 105 of mount 30. This is a major convenience feature whereby only one pair of bolts requires manipulation in order to mount or demount the various attachment implements. It should be understood that FIG. 7 depicts only one-half of the harrow attachment and the other half thereof is a mirror image of the elements shown in FIG. 7.
FIGS. 8 and 9 illustrate the tractor equipped with a second attachment implement 154 in the nature of a cultivator. This attachment comprises a sturdy tool bar 155 attached by a single pair of mounting bolts 156 to the support bars 105 of the implement mount 30. The tool bar 155 carries cultivator sweeps 157 in spaced relationship, FIG. 9, to straddle a row of crops C. A third cultivator sweep 158 can be placed inwardly and rearwardly of the adjacent front sweep 157 and secured to the tool bar via a bracket means 159.
The arrangement shown in FIG. 9 enables the cultivating of one crop row C, or the sweeps may be positioned on the tool bar 155 to cultivate the entire area between two adjacent crop rows. Earthworking elements other than sweeps may also be mounted on the tool bar to increase the versatility of the attachment. With the cultivator attachment 154 in place on the tractor, the two front wheels 29 are in their maximum width positions, as shown in FIG. 9. The front wheels are straddling two crop rows and the rear traction wheel 28 is between the two rows.
The third attachment implement shown at 160 in FIG. 10 comprises a moldboard plow. This attachment comprises a vertical angle member 161 bolted to implement support bar 105 of implement mount 30. The angle member 161 is attached at bolt 162 to a horizontal mounting bar 163 braced by a strut 164 anchored by bolts 165. Attached to mounting bar 163 is a plow frame member 166 having adjustment apertures 167. Fixed to the frame 166 is the moldboard plow foot 168. Secured by bolts to the plow mounting frame is a member 169 to which are attached dependingly tines 170 in trailing relationship to the plow foot 168 for smoothing out the mound of soil turned up by the plow foot. A forward tool bar 171 remains in place to add strength and rigidity to the parallelogram mount 30. While not shown in FIG. 9, the right front wheel 29 is adjusted to its outermost lateral position in the plowing mode while the left front wheel is in its innermost position. The moldboard plow attachment is on the right hand side of the mount 30.
The final attachment for the tractor shown in FIGS. 11-13 is a lawnmower attachment designated by the numeral 172. Unlike the previous attachment implements, the mower attachment utilizes a power take-off drive from the tractor engine 27 to power the mower blades. Referring to FIGS. 12 and 13, the previously described forward motion shaft 39 driven by sprocket 38 is journaled on pillow blocks 173, as shown. An engage motion pulley 174 journaled on the shaft 39 is engaged by a V-belt 175 which overlies an idler pulley 176 fixed to an engage/disengage lever 177. This lever is provided with a handle 178 which rides in a slot 179 formed in the engine cowling 32. The lever 177 is pivoted at 180 to a fixed stanchion 181 on the sub-frame 26.
The pulley 174 is divided into two halves 182 and 183, the former being keyed at 184 to the shaft 39. The latter pulley half 183 is molded as an integral part of a second pulley 185 which is free to rotate on the shaft 39 via a bushing 186. A third and smaller pulley 187 is fixed to the pulley 185 by bolts 188 and the shaft 39 carries a retaining collar 189 to retain the journaled pulley assembly formed by the union of pulley half 183, full pulley 185 and stop motion pulley 187. The pulley 187 is engaged by a belt 190 which in turn engages a bolted non-rotating pulley 191. The pulley 185 is engaged by a belt 192 which is the driving belt for the blades 193 and 194 of the mower attachment.
In operation, when the forward end of lever 177 is pivoted upwardly the stop belt 190 disengages and the belt 175 imparts rotation from the keyed pulley half 182 of composite pulley 174 and thereby imparts rotation to the free-to-rotate pulley half 183, thus imparting movement to the tool driving belt 192. This belt 192 drives the mower attachment and is guided in its path by a fixed idler pulley 195, then engaging under a sheave 196 journaled on a shaft 197 and then traveling around drive pulley 198 of the mower attachment and then back under an idler pulley 199 adjacent to sheave 196 on shaft 197, and finally, over take-up sheave 200. This take-up sheave is pivoted on a bracket 201 at 202 and a lever 203 is bolted to a notched control arm 204 having a handle 205 by means of which slack take-up pulley 200 can be raised at required times to remove slack from the drive belt. The handle 205, when lifted, can be engaged over a pin, not shown, which pin enters one of the notches of the control arm 204 to releasably lock it.
The drive pulley 198 powers a shaft 206 driving one mower blade 193. A sprocket 207 fixed on shaft 206 and engaged by chain 208 drives a second sprocket 209 journaled at 210 on the mower frame 211. The sprocket 209 drives a second mower shaft 212 which operates the second mower blade 194. A housing 213 encloses the blades 193 and 194. An exit chute 214 for cuttings is provided on the housing.
For additional safety, when desired, a seat pressure actuated switch 221 beneath the seat 31, FIG. 15, is provided. When the operator is seated the ignition circuit to the engine 27 is closed and the engine can be started. When the operator of the tractor leaves the seat without shutting off the engine by means of the manual ignition switch, the seat switch 221 will shut off the engine automatically.
Another optional feature is shown in FIG. 16. This feature comprises a safety neutral lock for the forward and reverse selector lever 50 having handle 51, previously described. For this purpose, a squeeze lever 222 below the handle 51 operates a retractable lock pin 223 which can engage a fixed frame member not shown having a locking aperture corresponding to the neutral position of lever 50. This feature prevents the lever 50 from being accidentally displaced where the tractor engine continues to run while the tractor is stationary.
It can be seen that a highly versatile and convenient garden tractor having lawnmowing capability is provided. Diverse cultivating implements can be quickly mounted and demounted on the implement lift or mount 30 by the mere manipulation of two bolts. All implements are in full view of the operator due to the rear mounted engine and the forward position of the diverse implement mount. Steering is simplified and positive. Easy and flexible control of the tractor is provided by the fixed chain drive between the engine shaft 33 and rear traction wheel 28, while variable speed forward and reverse movement is instantly attainable through the unique intervening friction belt or clutch drive. The comfort and safety of the tractor operator are fully provided for in the invention. Heavy and costly gear transmission and differential gear devices are dispensed with. The many advantages of the invention should be readily apparent to those skilled in the art.
It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts maybe resorted to, without departing from the spirit of the invention or scope of the subjoined claims. | A riding, self propelled tractor primarily for earthworking operations in the garden but also having lawn mowing and lawn care capabilities has a rear mounted engine with a rear traction wheel assembly beneath the engine and front wide stance laterally adjustable steering wheels enabling the tractor to operate along row crops. An implement support near the front of the tractor in clear view of the operator includes a parallelogram lift for diverse easily interchangeable earthworking implements and a lawn mower attachment. A simplified belt transmission having forward and reverse drive capabilities eliminates all gear shifting and foot operated assist clutch pedals. Increased ground clearance is achieved. |
BACKGROUND OF THE INVENTION
The present invention relates to preventing a sudden terrorist attack via a public entrance walkway in particular the entrance for passengers and provisioning access to a cruise ship. Passenger and provisioning access onto a cruise ship when dockside or when anchored is through what is referred to as a shell door located above the waterline of the ship. A gangplank or walkway is extended from the docking platform though the shell door into the ship lower deck vestibule or storage area. The shell door is hydraulically operated and cannot be closed when the gangplank is in place without moving the gangplank, a time consuming operation.
In the present order of things, security of a cruise ship and such other events as sports, air shows, music events rely heavily on the effectiveness of the pre-boarding or pre-entry screening of the individuals entering the activity to insure that weapons metallic or fabricated are not allowed to pass into the protected entry gang plank or access walkway.
The present invention provides an additional security system after pre-entry screening, an instantly closable, high-strength, ballistic resistant portable door system located at the ship gangplank or event entrance after the secured screening area. Closed remotely or locally upon sighting of an overt action, the door closure prevents an immediate presence or threat by forced entry onto a cruise ship gangplank or event entry gate.
The present invention provides a portable door closure system for instantly closing off an entry passage against unwanted or unauthorized intrusion from forced entry.
SUMMARY OF THE INVENTION
In accordance with the present invention, a portable quick close door system is placed immediately inside the shell door of a cruise ship after the ship is docked and the gangplank is put in place. The quick close door system is designed such as to allow the gangplank from the dock to the ship's shell door to be in place passing uninterrupted through the quick door system onto the ship's lower deck. The quick close door system has integral handrails continuing the gangplank handrails to the ships interior. The quick close doors, according to a preferred embodiment of the invention, are situated on opposite sides of the cruise ship at right angles to the gangplank. Kevlar filled doors are each hanging from overhead bars located within the left and right enclosures clamped to the shell door opening. The said door enclosures contain the doors allowing each to slide towards each other, meeting in the middle, closing off the gangplank walkway. The mating doors meet each other as tongue groove fittings providing a minimal grip area for forced opening form the ship's exterior gangplank. The said Kevlar lined enclosures block the shell door opening on each side of the gangplank floor to ceiling from terrorist entry or ballistic attack. The said doors are pulled closed by stretched strings via cable pulley arrangement. Said springs, a bungee type material, allow pre-stretch and door closed tension. Said doors are held open by keepers connected to a common release tube allowing manual door release from either side of the gangplank. Remote door release is possible with the addition of an electric latch solenoid and associated transmitter system.
Visual means such as a video camera placed outside the gangplank provides viewing of potential terrorists from any location on the ship allowing remote door closure. A peephole in the doors provides viewing of the gangplank after door closure.
The quick close door system is designed in separate left and right mating halves that bolt together with a keeper operation connecting rod. Each lightweight quick close door assembly has caster wheels and a handle installed for easy transport to a storage area within the ship.
Specific design configurations in the following descriptions are for purpose of clarity, but various details can be changed to fit applications other than cruise ship requirements within the scope of the present invention.
Modified embodiments of the present invention for other types of access passages, such as sports events, music concerts, and public events are also disclosed.
OBJECTS OF THE INVENTION
An object of the invention is to provide a cruise ship security system for the protection of a cruise ship from terrorists gaining entry on board the ship via storming the passenger gangplank or provisioning gangplank when the ship is docked at its homeport or other and Third World countries' docking locations.
Another object of the invention is to provide quick closure of bullet resistant doors immediately inside the ship's shell or entry doors where the passenger gangplank is installed preventing terrorist access to the ship's interior.
Another object of the invention is to provide a portable or fixed security door closure system for public events as sporting events, music events, indoors or outdoors. The quick close door system is placed after the entry screening process and before main access to the event. The quick close system will provide immediate closure of the event entrance via remote closure when a security guard is not present, and it is dangerous to be in the immediate vicinity or by manual door release keeper actuation by an attendant security guard.
Other and further objects of the invention will become apparent with an understanding of the following detailed description or upon employment of the invention in practice.
DESCRIPTION OF THE FIGURES
FIG. 1 —Long view of an anchored cruise ship with gangplank to dock installed and quick close door system installed in shell door opening.
FIG. 2 —Close up view of quick close door system installed in shell door opening showing quick close door system doors closed.
FIG. 3 —Cruise ship entry gangplank passing through ships shell door opening.
FIG. 4 —View of quick close door system aft door assembly. Forward door assembly is the mirror image of this door assembly except the rotation key tube is only on the aft door.
FIG. 5 —Detailed view from inside of ship of quick close door system installed in ship's shell door opening with gangplank in place.
FIG. 6 —Detailed inside view of quick close door system operational components.
FIG. 7 —Detailed view of quick close door release keeper.
FIG. 8 —Long view of public event area with quick close door system installation.
FIG. 9 —Composite of FIGS. 1-8 .
LIST OF REFERENCE NUMERALS IN FIGURES
1 Inside view of shell door with gangplanks in place.
2 Shell opening in cruise ship hull for loading and unloading.
3 Outside gangplank to dock.
4 Inside ramp to lower deck.
5 Outside hand rail to dock.
6 Ship's shell door latch.
7 Ship's shell door stop plate.
8 Quick close door system forward door assembly.
9 Quick close door system aft door assembly.
10 Quick close door system installation locking bar.
11 Quick close door system transport caster.
12 Quick close door system door assembly transport handle.
13 Quick close door system inside hand rail to lower deck.
14 Quick close door system retracted door, release handle.
15 Quick close door system door closure spring.
16 Quick close door system retracted forward door.
17 Quick close door system retracted aft door.
18 Quick close door system stand off to ship's hull inside.
19 Floating or at port ship's dock area.
20 Ship's hull inside.
21 Quick close door system extended (closed) forward door.
22 Quick close door system extended (closed) aft door.
23 Door assembly outer slide tube.
24 Door assembly inner slide tube.
25 Door closure cable pulley.
26 Door closure cable termination point.
27 Door keeper control tube.
28 Door keeper rotation arm cable termination.
29 Door keeper.
30 Aft/Forward rotation keying tube.
31 Keying tube insertion button.
32 Forward/Aft door system central mating plate.
33 Quick close door system outer casing.
34 Door closure cable.
35 Door keeper release cable.
36 Safety pin.
37 Security pre-screening area of a public event.
38 Quick close door system installation.
39 Public event area.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 of the figures, a cruise ship hull ( 20 ) has numerous entrance doors, called shell doors ( 2 ) located above the waterline shell doors are used to access the ship, via a gangplank ( 3 ) with handrails ( 5 ) leading to a inside ramp ( 4 ) and associated handrail ( 13 ) which terminates on the ship's lower deck inside the ship. These shell doors are used for passenger loading and embarkation from the ship when the ship is at port or anchored at a floating dock ( 19 ). Similar shell doors are also used for loading and unloading ships provisions.
In accordance with the preferred embodiment of the invention, after docking and opening of the ship's shell door ( 2 ) a portable Quick Close Door System ( 8 ) and ( 9 ) herein referred to as “QCDS” is installed inside the ship whereby providing a means to quickly close off access to the ship's interior from a terrorist threat. FIG. 2 shows the shell door opening ( 2 ) with the QCDS doors ( 21 ) and ( 22 ) closed and installed inside the ship as seen from the outside of the ship. The ship's gangplank passes under the doors ( 21 ) and ( 22 ) of the QCDS. The QCDS ( 8 ) and ( 9 ) outer casings ( 33 ) block the shell door opening from access around the gangplank.
Referring to FIG. 3 , the inside hull of the ship ( 1 ) is shown with the shell door opened and the gangplank ( 3 ) installed; the inside ramp ( 4 ) is installed leading onto the lower deck entrance vestibule. The ship's shell door latches ( 6 ) are shown. The ship's shell door stop plates ( 7 ) are also shown.
Referring to FIG. 5 , the quick close door system (QCDS) is comprised of two portable mating sections ( 8 ) and ( 9 ), which using handle ( 12 ) are rolled on casters ( 11 ), up to the open shell door opening FIG. 3 , bolted together at ( 32 ), forward/aft door system central mating plate, with locking bars ( 10 ) in place. FIG. 4 shows the aft QCDS ( 9 ) with door ( 21 ) in the extended or closed position. The fwd QCDS ( 8 ) is essentially the mirror image of the aft ( 9 ) QCDS, an exception being the aft/forward rotation keying tube ( 30 ) shown is replaced in the forward ( 8 ) QCDS with a mating key pin internal to the door keeper control tube ( 27 ). The aft QCDS ( 9 ) is detailed in FIG. 4 . QCDS ( 9 ) is comprised of outer casing ( 33 ), and inner door ( 21 ). The inner door ( 21 ), slides out of the outer casing ( 33 ) closing off the shell door opening ( 2 ). The outer casing ( 33 ) is locked in place by rotating bars ( 10 ) onto latch's ( 6 ) locking the QCDS ( 9 ) to the shell door opening ( 2 ). The QCDS ( 8 ) and ( 9 ) retracted door release handle ( 14 ), releases the spring loaded doors ( 21 ) and ( 22 ) allowing them to extend closing the QCDS opening. Said release handle ( 14 ), releases aft and forward doors simultaneously though the rotation of keying tube ( 30 ) providing immediate closure of both aft ( 22 ) and forward door ( 21 ) of FIG. 2 . Shown in FIG. 4 , is the removable hand rail ( 13 ); the handrail is a continuation of the outside handrail ( 5 ) on the gangplank. Removal of the handrail makes each QCDS lighter weight for portability as well as being readily adapted to various gang plank heights and configurations. The forward ( 8 ) and aft ( 9 ) QCDS are installed with their respective doors in the retracted position with the release handle safety pin ( 36 ) in place. See detailed operation of the preferred embodiment FIG. 6 .
Referring to FIG. 5 , the inside hull is shown as in FIG. 3 with the assembled forward ( 8 ) and aft ( 9 ) FIG. 4 QCDS installed. When installing the QCDS, the QCDS casters ( 11 ) are lifted over the ship's door stop plates ( 7 ). The stop plates retain the said casters ( 11 ) in place preventing the QCDS from being pushed into the ship's vestibule area. Locking bar ( 10 ) is pivotably rotated onto the ship's shell door latches ( 6 ). Standoffs ( 18 ) of a compressible material, as low shore rubber, provides a cushion between the QCDS outer shell ( 33 ) and the ship's hull interior providing compressed rubber pressure on the locking bar ( 10 ) when rotated in position.
Detailed operation of the preferred embodiment of the invention is shown in FIG. 6 and FIG. 7 . Referring to FIG. 6 , the outer casing is not shown for clarity. The door ( 17 ) is shown in the open (retracted) position. Door closure cable ( 34 ) is attached to door closure cable termination ( 26 ) mounted on door outer slide tube ( 23 ) and routed around pulleys ( 25 ). The outer end of cable ( 34 ) is attached to a bungee type material spring ( 15 ). When the door is in the closed (extended) position (not in the outer casing 33 ), the cable length is the length required to apply a preload to the spring ( 15 ) holding the closed door against the central mating plate ( 32 ). Retract door by applying pressure to the door ( 17 ) sliding it into the outer casing ( 33 ) (not shown) on door assembly inner slide tube ( 24 ) urging the door closure cable ( 34 ) to further stretch spring ( 15 ) until the door is fully inserted into the outer casing ( 33 ) and the door keeper ( 29 ) ( FIG. 7 ) can be rotated in the “C” direction, by turning door keeper control tube rotation arm ( 28 ) until said keeper ( 29 ) covers the end of said door outer slide tube ( 23 ) holding said door ( 17 ) open against the spring cable tension “D”.
Door ( 17 ) retraction pressure is then released and the said door ( 17 ) is held in place by said keeper ( 29 ). Door release handle ( 14 ) is in the safety lock position during said door ( 17 ) retraction and cannot be released except by removing the safety pin ( 36 ).
One of the preferred aspects of the invention is that passengers entering the cruise ship on the gangplank and through the QCDS are not aware of its existence. Operation of the QCDS is from inside the ship vestibule area by lifting either QCDS door release handle ( 14 ). Door closure would only be performed in the event of an emergency situation requiring the blocking of the entrance to the ship as in the case of a terrorist attack.
Closing of the QCDS doors is initiated by first removing the associated safety pin ( 36 ) and then lifting either release door handle ( 14 ) on the aft ( 9 ) or forward ( 8 ) QCDS. Lifting said release handle ( 14 ) applies tension to the release cable ( 35 ), which in turn places pressure to the door keeper control tube rotation arm ( 28 ) urging rotation of said arm ( 28 ). Rotation of said arm ( 28 ) allows door outer slide tube ( 23 ) (which is being pulled by spring ( 15 )) to pass by said door keeper ( 29 ) and extend said doors ( 16 ) and ( 17 ) to fully closed position.
The QCDS is made up of mirror image forward ( 8 ) and aft ( 9 ) assemblies bolted together at the central mating plate ( 32 ). Aft/forward rotation keying tube ( 30 ) is slid into place after installation of the said forward ( 8 ) and aft ( 9 ) assemblies using keying tube insertion button ( 31 ) keying said forward ( 8 ) and aft ( 9 ) control tube rotation arms ( 28 ) together.
Activation of either forward of aft QCDS release door handle ( 14 ) will release both forward ( 8 ) and aft ( 9 ) QCDS doors. Said doors ( 8 ) and ( 9 ) meet in the middle when released with a tongue on the aft door leading edge mating with a groove in the forward door leading edge making manual door separation difficult. Door closure pressure is insured by the preload applied to both forward door ( 8 ) and aft door ( 9 ) springs ( 15 ).
Another preferred aspect is the application of the invention. The embodying principles of the invention are applicable to situations other than cruise ship loading and embarkation. FIG. 8 shows a general application, which could apply to various situations as sporting events, concerts, public gatherings, public transportation gating and entrance applications. Entrance area or pre-security screening area ( 37 ) is followed by the installation of either a fixed or mobile (QCDS) ( 38 ) as defined in the preferred embodiment of this invention. The quick close door system provides a way to stop a last minute terrorist attack to a public gathering area defined by ( 39 ).
Various changes may be made to the structure and methodology embodying the principles of the invention. The foregoing embodiments are set forth within are illustrative and not in a limiting sense. Remote operation of the quick close door systems and cameras for visibility of associated areas although not shown are considered to be a part of the invention. The scope of the invention is defined by the claims appended hereto. | A security door closure system for cruise ships and other similar public entrance points to prevent terrorist attack or ship take-over is needed. Cruise ship passenger and ship provisioning entrance gangplanks pass through large hydraulically operated shell doors. The gangplank must be removed to close the shell door. The quick close security door system (Door-Gate) is a portable bullet resistant rapid close door system that is placed in conjunction with the gangplank or other entry system, which when closed prevents forced entry. A single lever either remotely or manually operated immediately closes the doors, which then cannot be forced opened from the entrance side. |
TECHNICAL FIELD
[0001] This disclosure relates generally to alternating current (AC) powered systems that drive direct current (DC) loads or require a DC supply.
BACKGROUND
[0002] FIG. 1 is a schematic diagram of a voltage halving passive valley fill (PVF) circuit 100 . PVF circuit 100 includes a full wave rectifier (FWR) 102 (e.g., diodes DBR 1 -DBR 4 ), diodes D 1 -D 3 , fill capacitors C 2 , C 4 , C 5 and resistor R 1 . In AC powered systems that drive DC loads or require DC supply, PVF circuit 100 can provide power to a load when the rectified AC input voltage approaches zero. PVF capacitors C 2 , C 4 , C 5 are charged in series and discharged in parallel due to diodes D 1 -D 3 . During discharge, the fill capacitors provide half of the peak AC input voltage to the load.
[0003] FIG. 2 is a plot illustrating the rectified AC input voltage, which is output from FWR 102 . Each cycle of the rectified AC input voltage is twice the frequency of the AC input voltage. Each cycle of the rectified AC input voltage arbitrarily starts at the beginning of time period A and ends at the end of time period A′. For discussion purposes, a cycle of the rectified AC input voltage is assumed to start at the beginning of time period B and end at the end of the next time period A.
[0004] FIG. 3 is a plot of output voltage of PVF circuit 100 . PVF capacitors C 2 , C 4 , C 5 charge to the peak input voltage. Because of diodes DBR 1 -DBR 4 in FWR 102 , when the rectified AC input voltage falls below one half of the peak voltage, the combined voltage on PVF capacitors C 2 , C 4 , C 5 , is larger than the AC input voltage and PVF capacitors C 2 , C 4 , C 5 supply current to the load. The combined voltage of PVF capacitors C 2 , C 4 , C 5 falls as the load draws current. Thus, the rectified AC input voltage surpasses the combined voltage on PVF capacitors C 2 , C 4 , C 5 before the end of time period A.
[0005] FIG. 4 is a plot of PVF capacitor current. The current in PVF capacitors C 2 , C 4 , C 5 is shown in FIG. 4 . Line 402 illustrates the resistor limiting the inrush current into PVF capacitors C 2 , C 4 , C 5 and line 400 illustrates a low resistor value R. During time period A, and most of time period A′, PVF capacitors C 2 , C 4 , C 5 supply current to the load. During the end of time periods A, B and B′, the AC input supplies current to the load and current to charge PVF capacitors C 2 , C 4 , C 5 . Because PVF capacitors C 2 , C 4 , C 5 are coupled in series when charging the recharge of PVF capacitors C 2 , C 5 , C 5 occurs when the rectified AC input voltage is near, but prior to, the peak AC input voltage. Because PVF capacitors C 2 , C 4 , C 5 are coupled in parallel during discharge, PVF capacitors C 2 , C 4 , C 5 supply current to the load when the rectified AC input voltage falls below half of peak AC input voltage.
[0006] The current from the AC input is the sum of the current supplied to the load during time periods B and B′ plus the current to charge PVF capacitors C 2 , C 4 , C 5 . For approximately one third of the cycle of the AC input voltage (A and most of A′), the AC input sees no load and the load at the output is supplied by PVF capacitors C 2 , C 4 , C 5 .
[0007] FIG. 5 is a plot of actual AC current (I_ac) versus ideal AC current. For the DC current load (I_load), the actual AC current is a rather rough approximation of the ideal AC current, where “ideal” means having a higher power factor near 1.0. This is for a constant current load, meaning the output power is not constant. For a constant load power, the I_load becomes much worse (worse PF) because the current must increase near the valley to compensate for the decreasing supply voltage, as shown in FIG. 6 .
[0008] FIGS. 7A and 7B are plots illustrating an input voltage waveform of PVF circuit 100 with a resistive load and resistor current limiting. One can observe from FIGS. 7A and 7B , that PVF circuit 100 is limited in its ability to provide a good power factor. The current from the AC input is zero when PVF capacitors C 2 , C 4 , C 5 are conducting. Although the shape of the PVF voltage and current waveforms look better with a resistive load, there is no current drawn from the resistive load for roughly one third of the cycle and there is a current spike near the middle of the cycle to charge the PVF capacitors.
[0009] FIG. 8 is a schematic diagram of a two-stage power factor correction (PFC) converter 200 . Two-stage converter 800 is a conventional solution to the power factor problem described above. First stage 802 of converter 800 includes inductor L 1 , diode D 1 , capacitor C 1 , resistors Ra, Rb, transistor N 2 and integrated circuit IC 1 . Second stage 804 includes the remaining components in FIG. 8 in conjunction with IC 1 . The power factor correction provided by two-stage converter 800 is good but the extra inductor L 1 and the associated losses and costs are not desired.
SUMMARY
[0010] A power converter is disclosed that includes an active valley fill (AVF) capacitor that is actively switched to provide current to a load during a portion of an AC input cycle. The current supplied to the load includes some current supplied by the AC input and some current supplied by the AVF capacitor. Circuitry is configured to regulate the amount of current flowing through the load, including controlling the amount of current supplied by the AVF capacitor. The duty cycle on the AVF capacitor can be adjusted to shape the AC input current waveform. The AVF capacitor can be combined with a floating buck converter for powering the load. The AVF can be used in non-isolated and isolated PFC converter topologies. The isolated topologies can use a winding of an isolation transformer to transfer voltage from the AVF capacitor to the load. The isolated topologies can include an open or closed loop to the secondary side of the transformer. Circuitry can be included on the secondary side of the transformer to rectify the AVF capacitor voltage due to reverse polarity of the winding used to transfer the AVF capacitor voltage to the load.
[0011] In some implementations, a power converter includes a rectifier configured for coupling to an AC input. An AVF capacitor is coupled to an output of the rectifier through a first switch. The first switch is configurable to enable flow of current from the AVF capacitor. An energy storage circuit is coupled to the AVF capacitor and to the output of the rectifier through a second switch. The second switch is configurable to regulate current in the energy storage circuit. A control circuit is coupled to the first switch and the second switch. The control circuit is configurable to control duty cycles of the first and second switches concurrently during a portion of a cycle of the AC input to supply current from the AVF capacitor and AC input to the energy storage circuit.
[0012] In some implementations, a method performed by a power converter comprises: receiving an AC input; rectifying the AC input; configuring a first switch coupled to an AVF capacitor to enable a flow of current from the AVF capacitor; configuring a second switch to regulate current flow in an energy storage circuit; and configuring a control circuit coupled to the first switch and the second switch to control duty cycles of the first and second switches concurrently during a portion of a cycle of the AC input voltage to supply current from the AVF capacitor and AC input to the energy storage circuit.
[0013] Particular implementations disclosed herein provide one or more of the following advantages: 1) input capacitors are maintained on the input side of a power converter, where they can be smaller in high voltage systems, and to which a fast DC-DC converter without bandwidth limitations of conventional active PFC converters can be coupled; 2) improved current shaping that satisfies regulatory harmonic current requirements; 3) significantly lowered part count and system cost of implementing solutions; 4) improved efficiency; and 5) decreased physical area requirements for implementing solutions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic diagram of a voltage halving PVF
[0015] FIG. 2 is a plot illustrating an FWR AC input waveform.
[0016] FIG. 3 is a plot of PVF voltage.
[0017] FIG. 4 is a plot of PVF capacitor current.
[0018] FIG. 5 is a plot of actual AC current versus ideal AC current.
[0019] FIG. 6 is a plot of supply current for a constant power load.
[0020] FIGS. 7A and 7B are plots illustrating a resistive load on a PVF circuit with resistor current limiting.
[0021] FIG. 8 is a schematic diagram of a two-stage PFC converter.
[0022] FIGS. 9A and 9B are schematic diagrams of an exemplary primary side active AVF circuit.
[0023] FIGS. 10A through 10C are plots illustrating AVF voltage waveforms.
[0024] FIGS. 11A through 11C are plots of PVF versus AVF currents.
[0025] FIG. 12 is a schematic diagram of an exemplary AVF circuit with center tap transformer.
[0026] FIG. 13 is a schematic diagram of an exemplary AVF circuit with secondary FWR.
[0027] FIG. 14 is a schematic diagram of an exemplary simplified AVF circuit.
[0028] FIG. 15 is a schematic diagram of an exemplary charge and discharge AVF circuit.
DETAILED DESCRIPTION
[0029] FIG. 9A is a schematic diagram of an exemplary primary side AVF circuit 900 for a primary side Light Emitting Diode (LED) application. While the circuit configuration shown is for an LED application, circuit 900 may be used with other types of applications.
[0030] In the example shown, circuit 900 is a floating buck converter that includes FWR, resistors R 1 , R 2 , diode D 4 , capacitors C 1 , C 2 transistors P 1 , N 1 , integrated circuit IC 1 , load S 1 and an energy storage circuit including diode D 1 and inductor L 1 . When switch N 1 (e.g., NMOS transistor) is driven closed, the current in circuit 900 begins to increase and L 1 drops a voltage. The voltage drop across L 1 counteracts the input voltage and reduces the net voltage across load S 1 , which in this example is an LED string. Over time, L 1 allows the current in circuit 900 to increase slowly by decreasing the voltage it drops and therefore increasing the net voltage seen by S 1 . During this time, L 1 is storing energy in the form of a magnetic field. If N 1 is driven open before L 1 has fully charged, then there will always be a voltage drop across L 1 , such that the net voltage seen by S 1 will always be less than the input voltage source. When N 1 is driven open again, the load from the string S 1 will not flow through the input voltage Vac, the current will begin to drop, causing L 1 to reverse the direction of its voltage and to act like a voltage source. If N 1 is driven closed again before L 1 fully discharges, S 1 will always see a non-zero voltage.
[0031] AVF capacitor C 1 placed in parallel with S 1 helps to smooth out the voltage waveform as L 1 charges and discharges in each cycle. R 2 is an optional resistor to limit inrush current when C 1 is being charged. D 4 is also optional and allows R 2 to be bypassed when the charge from C 1 is being delivered to the load. The gate G 1 of N 1 is driven by IC 1 based on the current through S 1 .
[0032] FIG. 9B is a schematic diagram illustrating the operation of circuit 900 . Switch P 1 (e.g., PMOS transistor) controls the discharge of AVF capacitor C 1 . Because of the parasitic diode (source to drain) inherent in P 1 , C 1 will charge independent of the voltage on the gate G 3 of P 1 . In the discharge phase (when C 1 supplies current to the load) the drain of P 1 will fall below ground and will remain off until G 3 is driven (at least a threshold voltage) below ground. This is the purpose of C 2 and the switches sw 1 , sw 2 and sw 3 . When P 1 is desired off, sw 2 and sw 1 are driven closed and sw 3 is driven open. This switch configuration drives G 3 to zero volts, turning off P 1 , and charges C 2 to the supply voltage (e.g., 12 volts). When P 1 is desired to be on, sw 1 and sw 2 are driven open and sw 3 is driven closed. This switch configuration drives G 3 to approximately a negative supply voltage (e.g., −12V), turning P 1 on.
[0033] When P 1 is off, the FWR voltage is seen at Vfwr. When P 1 is on, the voltage on C 1 is seen at Vfwr. In this manner, circuit 900 can switch between the full-rectified voltage and the voltage on C 1 at any desired time. Circuit 900 is not limited to half the peak voltage as in PVF circuit 100 . In fact, AVF circuit 900 allows for switching back and forth between the FWR voltage and the voltage on C 1 at any time.
[0034] FIG. 10A illustrates a full wave rectified waveform. To aid the comparison of AVF with PVF, the A′ and A part of the cycle will be examined. With AVF, the AVF capacitor C 1 may be engaged at any time. For example, P 1 may be turned on before A′ starts or well after A′ starts. Thus, the time for which the AC input current is drawn can be shortened or lengthened. In FIG. 10B , capacitor C 1 is switched in for the entire A′ and A interval.
[0035] FIG. 10C illustrates the full wave rectified waveform with switching between the voltage on AVF capacitor C 1 and the rectified AC input voltage. The time duration is not representative of the actual time or duty cycle but is shown for illustrative purposes. The advantage of AVF circuit 900 is that current is drawn from the AC input during time A′ and A when both capacitor C 1 and the AC input are supplying current to the load concurrently. If the switching is fast enough, the AC input sees the average current drawn during A′ and A. The circuit can switch back to the AC input for a short amount of time such that the average current follows the AC input waveform. The current drawn by the load can be decreased to zero as the AC input voltage decreases and increased as the AC input voltage increases.
[0036] Referring to FIG. 10C and FIG. 9A , the capacitor C 1 provides current to the load (Vout) during time period A and A′, and the input voltage provides power to the load during time periods B, B′, A and A′. Table 1 below illustrates how the AC input voltage and AVF capacitor provide current to the load during the time periods B, B′, A and A′.
[0000]
TABLE I
Load Current Contributions During AC Input Cycle
Time Period
AC Input
Capacitor C1
B
Sole supplier of current
No current supplied
to the load
to load (C1 charging)
B′
Sole supplier of current
Idle
to the load
A′
Supplies some current
Supplies some current
to the load
to the load
A
Supplies some current
Supplies some current
to the load
to the load
[0037] During time period B, the input voltage supplies power to the load and charges up C 1 . During time B′, C 1 is charged and is idle. The input voltage supplies power to the load. During time A and A′, both the input and C 1 provide power to the load. When input voltage is high (near the start of time period A′), most of the current in the load is supplied by the input and a small amount of current is supplied by C 1 . Consequently, the duty cycle (on time) of switch P 1 is small. When the voltage is low (near the end of time period A′ and the beginning of time period A), most of the current is supplied by C 1 and a small amount of current is supplied by the input. Consequently, the duty cycle on P 1 is high. Effectively, the duty cycle on C 1 increases as the voltage from the input falls and is thus inversely proportional to the FWR voltage. A blowup of time period A′ in FIG. 10C illustrates the duty cycle on C 1 starting low and getting higher (on time is increasing) as the FWR voltage decreases.
[0038] Referring to FIG. 9A , D 1 , L 1 and S 1 are the primary components of the floating buck converter. N 1 , R 1 and IC 1 regulate the current in the floating buck converter. The effect is to create a controlled current in L 1 such that the current in the load S 1 is controlled. The floating buck converter requires a minimum voltage that is greater than the output voltage (Vout) to maintain Vout. Even so, current can still be drawn from the AC input when the AC input falls below this minimum voltage. In this case, instead of adding current to L 1 , the rate at which L 1 current falls is decreased and current is drawn from the AC input as desired to create good PFC.
[0039] In operation, the L 1 current in the floating buck converter increases when N 1 is on and the supply voltage is greater than the Vout. The inductor current decreases when N 1 is off. When the FWR voltage is below Vout, if the AC input voltage is switched from the voltage across C 1 to the FWR voltage there is no change of behavior when N 1 is off (the current decreases). However, when N 1 is on, the L 1 current will still decrease but at a slower rate because the voltage V across L 1 is less and the change in current over time is less (V=L di/dt). As long as C 1 is switched back (by IC 1 through switch P 1 ) to maintain the desired L 1 current, the FWR voltage can be switched into the load by IC 1 through switch N 1 to draw current.
Setting Duty Cycle on Switch P 1
[0040] The circuit configuration that is shown in FIG. 9A uses a floating buck topology to regulate the output voltage (Vout). The duty cycle of switch N 1 increases as the FWR voltage drops and will reach 100% when the FWR voltage is approximately equivalent to Vout. This is the point where AVF capacitor C 1 is used to deliver some of the current to the load. Once the 100% duty cycle is achieved, switch N 1 stays on. Resistor R 1 is used to monitor the current through the floating buck. The circuit configuration is effectively a floating buck converter that switches between two voltages: the voltage on C 1 and the FWR voltage. The switching can be controlled by the duty cycle of switch P 1 . For example, the gate G 3 of transistor P 1 can be driven negative by IC 1 to turn P 1 on.
[0041] In some implementations, it may be desirable to slow or smooth the transition from a floating buck to a conventional buck. This could have the benefit of wave shaping for better power factor correction. For example, the circuit can start switching C 1 at a low duty cycle half way through the time period B′. During the transition phase (before N 1 duty cycle reaches 100%), the circuit can start switching C 1 . The FWR current waveform can be shaped based on when and how the current from C 1 is supplied to the load.
[0042] In some implementations, a comparator (not shown) can be added to the circuit in FIG. 9A that takes as inputs the FWR voltage and Vout. When the input voltage is less than Vout, the comparator outputs a voltage that can be used as a signal to reconfigure the floating buck converter to a conventional buck converter.
[0043] FIGS. 11A through 11C are plots of PVF versus AVF currents. Comparing the current in PVF (for a resistive load) and AVF, the power factor of AVF is significantly improved. AVF provides better power delivery (smaller capacitor C 1 , higher voltage on C 1 ) and better power factor. Compared to a two-stage converter Shown in FIG. 8 , AVF gets nearly as good a power factor (AVF still has the capacitor charging current) and nearly as good a power delivery (two-stage converter places a slightly higher voltage on the capacitor). Finally, AVF eliminates the inductive losses (e.g., magnetic losses and resistive losses) due to the inductor used in the two-stage converter.
Example AVF Circuit Topologies with Isolated Loads
[0044] AVF can be used in isolated or non-isolated designs as shown in FIGS. 12-15 . These example topologies each include a forward FWR; however, other known isolated designs are applicable. Additionally, each circuit includes an open loop to the secondary side. In some implementations, however, feedback may also be used. For example, an opto-isolator or other means can be used to provide feedback on the secondary side of the transformer.
[0045] FIG. 12 is a schematic diagram of an exemplary AVF circuit with a center tap transformer T 1 having four windings T 1 A-T 1 D. AVF is accomplished using winding T 1 D to transfer the voltage from AVF capacitor C 1 to the load. Diode D 1 allows capacitor C 1 to charge to the peak voltage of the FWR input. An optional inrush current limiting resistor (not shown) can be placed in series with D 1 . This configuration acts as a forward converter that transfers energy to the secondary from either the AVF voltage on C 1 or the FWR input. The FWR input energy is transferred in a forward converter manner, by turning on switch N 1 . This forward biases diode D 2 and allows energy to pass to inductor L 1 and capacitor C 2 . When switch N 2 is turned on, energy is transferred through diode D 3 . Since switches N 2 , N 1 are not on at the same time, the sense resistor R 1 can be shared by switches N 2 , N 1 . Diodes D 2 and D 3 rectify the input.
[0046] FIG. 13 is a schematic diagram of an exemplary AVF circuit including a secondary FWR. The AVF circuit is equivalent in function to the AVF circuit in FIG. 12 but includes a secondary FWR comprising diodes D 3 , D 5 on each side of the secondary winding T 1 B to rectify the FWR input. In this topology, the transformer T 1 does not require a center tap. In FIGS. 12 and 13 , the polarity of coil T 1 D of the transformer T 1 is reversed. This guarantees that the voltage on the drain of switch N 2 is positive. As a consequence, the voltage from the AVF capacitor C 1 is inverted, which accounts for the need to rectify in the AVF circuits of FIGS. 12 and 13 .
[0047] FIG. 14 is a schematic diagram of an exemplary simplified AVF circuit. The circuit in FIG. 14 is simplified further from the circuits shown in FIGS. 12 and 13 by including only a single diode D 2 on the secondary side of transformer T 1 . D 2 can be used if the turn ratio of coils T 1 A and T 1 D is at or near one. It is important to keep the parasitic diode in N 2 from turning on. Other than when C 1 is charging, the voltage on C 1 is always greater than the voltage on Vfwr. If the turn ratio is one or less then turning on transistor N 1 will maintain a positive voltage on the drain of N 2 and the parasitic diode of N 2 will remain off. The circuits in FIGS. 12 and 13 do not have the turn ratio requirement because of the polarity of the T 1 D winding.
[0048] FIG. 15 is a schematic diagram of an exemplary charge and discharge AVF circuit. This topology uses coil T 1 D to charge the AVF capacitor C 1 . Diode D 1 is eliminated and the current that is sensed at s 1 (the voltage across R 1 ) represents the total load on the AC input.
[0049] The isolated AVF circuits shown in FIGS. 12-15 have the advantage of using only NMOS transistors N 1 , N 2 for switches and requiring only a positive voltage to turn on the NMOS transistors N 1 and N 2 . Additionally, each of these circuits assumes a positive FWR. In some implementations, a negative FWR could be used by reversing the diodes in the FWR and replacing the NMOS transistors with PMOS transistors and vice-versa.
[0050] While this document contains many specific implementation details, these should not be construed as limitations on the scope what may be claimed, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination. | A power converter is disclosed that includes an active valley fill (AVF) capacitor that is actively switched to provide current to a load during a portion of an alternating current (AC) input cycle. The current supplied to the load includes some current supplied by the AC input and some current supplied by the AVF capacitor. Circuitry is configured to regulate the amount of current flowing through the load, including controlling the amount of current supplied by the AVF capacitor. The duty cycle on the AVF capacitor can be adjusted to shape the AC input current waveform. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a composite substrate for carrying and dissipating heat from fragile articles, and more particularly, a combination carrier strip and heat spreader on which semiconductor die may be mounted with minimum thermal stress during production processing.
2. Description of the Prior Art
Semiconductor packages for power transistors and integrated circuits of the type used in ignition systems for automotive internal combustion engines are disclosed by Taruya et. al. in U.S. Pat. No. 5,288,667. Taruya utilizes a pre-molding strip 11 to hold the pins 3 in proper orientation with the leadframe 1 prior to forming the molded plastic package 5. Taruya explains that some leadframe sections are unnecessary because large portions of the material must be removed. Taruya also discloses the use of wire bonding strips 4 for coupling pads on the transistor or integrated circuit 2 to each of the pins 3. Newer automotive ignition system electronic systems utilize surface mount devices, instead of plastic packaged devices, in order to more efficiently dissipate the heat from the transistor.
Hynes et. al. in U.S. Pat. No. 4,320,412 discloses the use of a composite material, such as KOVAR 24, which is inlaid into a copper leadframe 10 for compensating for the difference in the coefficient of thermal expansion between a transistor 12 and the leadframe 10. As illustrated in FIG. 5, the KOVAR strips 14 may be mounted on opposing faces of the leadframe 10, with the transistor die 12 being mounted on one face. As explained by Hynes et. al. in column 1, the high thermal conductivity and coefficient of thermal expansion of the copper leadframe 10 are not a good match with the relatively lower coefficient of thermal expansion of the semiconductor material, typically silicon. After repeated thermal cycling, the silicon die mounted on the copper surface will break or malfunction as a result of the repeated thermally induced deformations.
As noted by Hynes in column 1, at lines 42 through 56, the use of relatively long lengths of these bi-metallic or layered composite materials result in a bowing or warping in the Z axis when subject to repeated thermal cycling. This bowing or warping will deform the semiconductor chip bonded to the heat spreader or carrier strip, which can result in breakage.
It is, therefore, an object of the present invention to provide a heat spreader of laminated material having a coefficient of thermal expansion that is relatively close to the coefficient of thermal expansion of the semiconductor chip to be mounted thereon. In order to avoid thermal warping along the entire length of this laminated material during the manufacturing process, a thermally stable carrier strip is provided as an integral part of the heatspreader. In order to reduce material costs and to provide a high degree of recycling capability for the materials used, the carrier strip is constructed of an inexpensive, recyclable material such as copper.
A primary advantage of the present invention is that the use of the expensive laminated material for carrying the semiconductor die can be minimized, while a less expensive, thermally stable and recyclable material such as copper, or copper-iron (2.5%), can be used for the carrier strip. This advantage obviates the expensive inlaying process described by Hynes in column 3 at lines 3 through 13.
SUMMARY OF THE INVENTION
This and other objectives are accomplished by providing an intermediate workpiece onto which are mounted a plurality of semiconductor die. The workpiece includes a first strip of material having a coefficient of thermal expansion approximately equal to that of the semiconductor die, and has a high coefficient of thermal conductivity. A second strip of material, that will not bow in response to thermal cycling, is aligned with and abutting the first strip of material, A longitudinal welded section joins abutting sections of the first and second strips substantially along the entire length thereof. The first strip of material is segmented into smaller heatspreader sections, each for receiving a semiconductor die attached thereto. In this manner, the thermal stresses involved in the manufacturing cycles will not cause significant deformations in either the second strip of material or in the heatspreader sections attached thereto.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will be readily apparent from the following description of the preferred embodiment and drawings in which:
FIG. 1 is a perspective view of the strips of heatspreader and carrier materials.
FIG. 2 is a perspective view of the heatspreader and carrier strip materials in close abutment.
FIG. 3 is a perspective view of the heatspreader and carrier strip materials after being welded longitudinally along the abutment line.
FIG. 4 is a top plan view of multiple heatspreaders, each attached to the carrier strip.
FIG. 5 is a cross-sectioned view of the welded substrate material along section lines 5--5 in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a long strip, approximately 8.5 inches long, 1/2 inch wide and 0.020 inches thick, of a composite material constructed by laminating together layers of copper, INVAR, and copper, is illustrated generally as reference numeral 10. While INVAR is described with respect to the preferred embodiment of this invention, other similar composite materials, such as copper laminated with aluminum nitride, beryllium oxide or boron nitride, and having suitable heat conduction and thermal coefficient of expansion characteristics similar to INVAR, may also be used. As used herein, INVAR refers to a low expansion iron alloy metal material having a nominal composition by weight of 36 percent nickel and the balance iron (otherwise denoted as Fe-36Ni). The various characteristics of INVAR and such materials, together with methods of manufacturing, are discussed in detail by, Jha, et. al., in U.S. Pat. No. 5,156,923, which is incorporated herein by reference. In the first preferred embodiment, the composite material comprising laminated strips of copper/INVAR/copper material 10 has a coefficient of thermal expansion of approximately 5.2 PPM per degree Centigrade. This coefficient of thermal expansion is between the coefficients of thermal expansion for a main substrate material and the semiconductor die for reducing the thermally induced stresses therebetween.
As illustrated in the right side of FIG. 5, the composite or laminated strip 10 is composed of sequential layers of copper 12, then INVAR 14, then copper 16. The strips are cold rolled under pressure so that the metallurgical bonds between the metal layers will be transformed to provide the required characteristics of thermal conductivity and coefficient of thermal expansion for the composite material. While FIG. 5 illustrates a single layer of INVAR 14 sandwiched between two layers of copper 12,16, it will be apparent to one skilled in the art that multiple layers of copper, INVAR, copper, INVAR, and copper may be joined in a composite material having the required characteristics. For clarity in the drawings and in this detailed description, the most simplified copper/INVAR/copper arrangement as illustrated in FIG. 5 will be utilized herein.
A second strip comprises a strip of copper material, approximately 8.5 inches long, 1/2 inch wide and 0.020 inches thick, is illustrated in FIG. 1 with the reference numeral 20. As used in the preferred embodiment, the term "copper" is construed broadly enough to include copper-iron (approximately 2.5%) and similar materials that are predominantly copper but which may include trace materials for providing other important characteristics. This copper material is less expensive than the copper/INVAR/copper material 10 by a factor of at least 20% to 30%. Therefore, while the more expensive copper/INVAR/copper material 10 should be used for the heatspreader, it is not necessary or even desirable for this material to be used for the carrier strip 20.
As shown in FIG. 2, the copper/INVAR/copper strip 10 and the copper carrier strip 20 are abutted, generally in a common plane, along adjacent longitudinal edges. In FIG. 3, the abutted sections of the copper carrier strip 20 and the composite material 10 have been welded together using a laser weld in order to create a single flat strip of material. The weld line 50, together with the phantom extension line, is shown as lines in FIG. 3 even though the actual demarcation between the composite strip 10 and the copper strip 20 may not be visible. With reference to FIG. 5, the weld 50 is shown as the central area 50 between the copper strip 20 and the matrix material strip 10. The laser weld 50 continues along the entire length so that each abutting section of the adjacent strips will be welded to the adjacent section. While laser welding has been described as the preferred method for welding the two strips together, one skilled in the art will recognize that other joining methods, such as resistance welding, friction welding, electron beam welding and mechanical compression/crimping may also be used as required by the particular application.
While FIGS. 1, 2, 3 and 5 illustrate that the composite strip 10 is generally of the same thickness as the copper strip 20, it will be apparent to one skilled in the art that different thickness for each of the strips can be used as required by the special circumstances.
Turning now to FIG. 4, the two strips of material, that is, the composite material 10 and the copper material 20 which have been welded together, are formed into a plurality of heatspreaders 60, and a single carrier strip or leadframe 70. The heatspreaders 60 are connected to the carrier strip 70 by two leads, shown generally as 62 and 64. While two leads have been illustrated in FIG. 4, it should be apparent that three or more leads may also be utilized as required by the circumstances of a particular situation. The adjacent leads 62 and 64 define a generally rectangular aperture 66. Leads 62 and 64 generally contain the welded section, shown as 50 in FIG. 3 and the phantom weld line 50 in FIG. 4. Therefore, it is apparent that none of the area originally defined by the copper strip 20 is contained within the area defined by the heatspreaders 60.
The exact shapes of each heatspreader 60, the leads 62 and 64, the aperture 66 and the alignment holes 72 in the carrier strip 70 may be optimized for the requirements of the particular application, and are formed by means of well-known punch and die stamping methods known in the metalworking arts. Further examples of these processes are described by Hynes et. al. in U.S. Pat. No. 4,320,412, which is incorporated herein by reference.
It should be noted again in FIG. 4 that the phantom weld line 50 intersects the leads 62 and 64, and does not communicate through the heatspreaders 60 or the carrier strip 70. Stated another way, the area defined by each heatspreader 60 is contained entirely within the original composite strip 10 shown in FIG. 1, and the area defined by the carrier strip 70 is contained entirely within the original copper strip 20. In this manner, the heatspreader 60 is composed of only the composite material 10, for which the thermal conduction and coefficient of thermal expansion are well known.
With continuing reference to FIG. 4, the resulting carrier strip 70, having the multiple heatspreaders 60 coupled thereon, is processed as a single unit. When heat is applied over the entire length of the carrier strip 70, the copper within the carrier strip 70 does not bow or deform in the Z axis direction. This should be contrasted with the Z axis deformation that would occur if the strip 20 were formed instead from a copper/INVAR/copper laminate, or other similar laminated composite materials, that tend to bow as a result of thermal cycling.
Typical manufacturing operations employing such a thermal cycling operation would be the attachment of a silicon die to the heatspreader shown in FIG. 4. First, the carrier strip 70 is withdrawn by a robotic mechanism from a cassette (not shown) in which multiple carrier strips are stored and moved between separate manufacturing operations. The carrier strip 70 is then heated sequentially in sections as it passes through an oven. As each heat spreader 60 is heated, solder 82 is deposited on the face of the heatspreader 60. After the solder melts, a transistor or other silicon die 80 is tightly pressed against the solder 82 and the heatspreader 60 in order to assure adequate thermal conductivity. Next, the heat is removed from the heatspreader 60, thereby allowing the solder 82 to cool and solidify.
This thermal manufacturing process step will not cause the carrier strip 70 to warp or bend in the Z-axis direction because it is constructed of a solid strip of copper material. While the composite material forming the heatspreader 60 may tend to bow or deform slightly during the temperature cycling process, the relatively small size of the heatspreader 60 will limit the deformation to very small amounts in the Z-axis direction. The silicon die 80 can easily withstand such repetitive temperature cycling processes, and will not be damaged by the small deformation of the heatspreader 60.
On the other hand, a relatively large deformation in the Z-axis direction of the carrier strip 70, especially when multiple carrier strips are stacked within a processing cassette, would jam the automated mechanism from loading and unloading the carrier strips 70 from the cassette. In high volume production environments where millions of these heatspreaders are processed each year, such equipment malfunctions due to preventable jams must be avoided in order to provide maximum up-time and minimum unproductive down-time.
In addition to the foregoing advantages, this construction will allow the copper carrier strip 70 and associated scrap materials to be recycled for subsequent use. Since copper in these quantities is an expensive intermediate production material, this cost savings can be substantial over the long term.
Furthermore, while the use of a standard size and thickness of copper for the carrier strip 70 allows for the use of industry standard, high speed cassette handling and processing equipment, the use of a separate material for the first strip 10 allows for the flexible substitution of different materials, different shapes and sizes, and different thicknesses for the resulting heatspreaders 60 without changing the material handling systems. Finally, the location and structural rigidity of the welded section 50 within the resulting leads 62 and 64 provides additional strength and rigidity when automated die cutting, soldering and shearing equipment are used to process the distended heat spreaders 60 when they are still attached to the carrier strip 70.
After the semiconductor die 80 is soldered to the heatspreader 60, the carrier strip 70 then can be loaded into other automated processing equipment for cutting the heatspreaders 60 from the carrier strip 70. While in some applications it may be desirable to leave extended sections of the leads 62 and 64 for use in coupling to other components or the printed circuit board, in the present application it is desirable to truncate the leads 62 and 64 generally even with the rectangular outline of the heatspreader 60. In this manner, the generally rectangular heatspreader 60 may then be soldered directly to a corresponding space on an underlying circuit substrate (not shown) so that the heat from the silicon die 80 may be transferred directly through the heatspreader 60 and into the circuit substrate for cooling the semiconductor component. Of course, well-known wire bonding techniques and equipment can be used to connect power as well as input and output signals to the silicon die 80.
In an alternate embodiment, the leads 62 and 64, rather than being inset from the corresponding edges of the heatspreader 60 is as illustrated in FIG. 4, would have an outside edge generally aligned with a corresponding outside edge of the heatspreader 60b. This arrangement of the leads provides for an improved resistance against any torque induced, and improves the edge uniformity produced during, the cutting and shearing processes.
While the preferred embodiment of the present invention has been described herein, it will understood by one skilled in the art that various modifications, changes, enhancements and improvements which deviate from the written description in the drawings contained herein may be adopted without departing from the spirit and scope of the present invention in the following claims. | An intermediate workpiece includes a first strip of laminated material exhibiting high thermal conductivity and which is subject to bowing in response to thermal cycling. A second strip of copper material is welded to the first strip along a longitudinal abutting edge of each strip. The first strip is partitioned into smaller heatspreader sections each for having a semiconductor die soldered thereto. Thermal manufacturing cycles will not cause a bowing of the second strip or of the heatspreader sections attached thereto. |
This application is a continuation of application Ser. No. 403,370, filed Sept. 6, 1989 now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an automatic analysis apparatus, and more particularly, to an automatic analysis apparatus provided with the function of keeping the temperature of a row of reaction containers constant.
In a conventional automatic analysis apparatus, an organic sample such as blood is generally measured by means of a photometer after preparing a reaction solution in which the sample and a reagent interact with each other. Measurements of a sample on a large number of analysis items are, for example, performed by using a discrete-type automatic analysis apparatus in which the reaction solution is generated in the reaction container, which is also used as a photometric cell, for each analysis item.
Reaction of the organic samples needs to be performed at a temperature which is kept constant in the vicinity of 37° C. Accordingly, it has been proposed to employ a constant-temperature water bath as a constant-temperature device and to immerse a row of reaction containers in the constant-temperature water. Such an automatic analysis apparatus is disclosed in the specification of Japanese Patent Laid-Open No. 56-168553.
In the above-described type of conventional automatic analysis apparatus in which the constant-temperature water bath is employed as the constant-temperature device, constant-temperature water is circulated between a constant-temperature water supply portion for supplying constant-temperature water and a bath. This requires much space, and therefore increases the overall size of the analysis apparatus.
Furthermore, it is better that a desk-top automatic analysis apparatus employ a constant-temperature air device in place of the constant-temperature water device. However, since the heat capacity of air is smaller than that of water, it takes a long time (e.g., 30 minutes) for a constant-temperature air bath having a heat block therein to raise the temperature of the solution injected into the reaction containers to 37° C., and this results in a prolongation of the overall analysis time.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an automatic analysis apparatus which enables the temperature of the solution injected into a reaction container to be raised to a predetermined degree in a relatively short period of time by the use of a constant-temperature air bath and which enables it to be kept constant thereafter.
To this end, the present invention provides an automatic analysis apparatus which comprises a reaction table for rotating a row of reaction containers, a batch injection means for supplying a sample and a reagent to the reaction containers, a photometric means for measuring the reaction within the reaction containers, a constant-temperature air means for keeping the reaction containers warm, the constant-temperature air means having an annular constant-temperature air chamber which is formed in such a manner as to surround the row of reaction containers, a heat block disposed within the annular constant-temperature air chamber, and a preliminary temperature raising means for heating the reaction containers. The preliminary temperature raising means has an air circulation passage, and a blowing means for blowing constant-temperature air against the reaction containers in a region between a injection position of the injecting means and a measuring position of the photometric means. Furthermore, the preliminary temperature raising means has a ventilating means for temporarily ventilating the air circulation passage.
In the present invention, the temperature of the solution within the reaction container can be raised to a fixed value in a short period of time by means of a constant-temperature air bath, and this results in a reduction in the time required for analysis and an improvement in the sample measurement accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a preliminary temperature raising means of an automatic analysis apparatus, showing an embodiment of the present invention;
FIG. 2 is a schematic view of an automatic analysis apparatus with the preliminary temperature raising means of FIG. 1;
FIG. 3 is a section taken along the line 3--3 of FIG. 2;
FIG. 4 shows a time chart of the analysis process of the automatic analysis apparatus according to the present invention; and
FIG. 5 shows how the temperature of the solution within the reaction container changes in the analysis apparatus according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described below with reference to the accompanying drawings.
Referring first to FIG. 2, an automatic analysis apparatus according to the present invention includes a sample/reagent disk mechanism, a reaction disk mechanism, a batch injection mechanism, and a washing mechanism. The sample/reagent disk mechanism includes a sample table and a reagent table.
Reagent containers 18 are held on the reagent table 17 within a reagent insulating case 19. The sample table 16 is mounted on the reagent table 17 separately from the reagent insulating case 19. Sample containers are aligned in two rows on the sample table 16 in the circumferential direction thereof. Both the reagent table 17 and the sample table 16 are driven by a driving motor (not shown) through the same driving shaft. The reaction disk mechanism includes a reaction table 65, a constant-temperature reaction tank 21, and reaction containers 22. It also includes a washing mechanism 23 for drawing the reaction solutions within the reaction containers 22 and ejecting washing fluid to wash the reaction containers. A peristaltic pump 24 is used to draw the reaction solutions, and ejection of the washing fluid is performed by means of a washing syringe 25.
Between the sample/reagent disk mechanism and the reaction disk mechanism is disposed the batch injecting mechanism 15 for drawing the reagents in the reagent containers 18 and the samples in the sample containers 20 and for conveying them to and ejecting them at an ejection position 60 on the reaction container row. There drawing in and ejecting operations are performed by an injecting syringe 26, which is connected to a probe mounted on the forward end of an arm of the batch injection mechanism 15 through a tube. A probe washing tank 27 is disposed on the rotational locus of the probe on the side of the injection mechanism 15 which is closer to the front of the apparatus, and a fluorometer 28 for measuring the fluorescent radiation emitted by the reaction solutions is disposed within the constant-temperature reaction tank 21 on the rotational locus of the reaction containers 22.
A preliminary temperature raising means 29 shown in FIG. 1 is disposed between the position 60 at which reagents are ejected by the batch injecting mechanism 15 and the fluorometer 28 so as to raise the low temperature of the reagents to 37° C. by the time the reagents rotate clockwise from the position 60 and reach the fluorometer 28. The preliminary temperature raising means has a forced circulation preheating function. Temperature control of the preliminary temperature raising means is performed by a preheating amplifier 30. A printer 10, a CRT 11, an operation panel 12, a floppy disk drive (FDD) 9, an analog/digital converter 32 for processing the signal output from the fluorometer 28, and the preheating amplifier 30 are connected to be controlled by a CPU 34 through an interface 33.
Next, the operation of the automatic analysis apparatus shown in FIG. 2 will be described below. Organic solutions such as blood serums or blood plasmas containing antigen or urea are used as samples. Normally used reagents are employed. In particular, reagent solutions containing a solid phase with an antibody coated thereon are employed for analyzing the immune reaction or like of a virus. First, a large number of sample containers 20 are held on the sample table 16, and the reagent containers 18 are cooled at a predetermined temperature in the reagent insulating case 19. A predetermined amount of sample is drawn from the sample container 20 on the sample table 16 by means of the probe of the batch injection mechanism 15 and is conveyed to and ejected into the reaction containers 22 located at the designated position 60 on the reaction table 65. After the ejection, the probe of the injection mechanism 15 is sufficiently washed by the probe washing tank 27 so as to prevent contamination of the sample solutions. Thereafter, the reaction table 65 is vibrated for a few seconds by a vibration driving means so as to stir the reaction solution, and the row of reaction containers is then rotated.
A sequence of the above-described operations is repeated until a required number of samples are conveyed into the reaction containers 22. This process is indicated by (a) in FIG. 4. Next, the reagent is drawn from the reagent container 18 by the injection mechanism 15 and is conveyed to and ejected into the reaction container 22 located at the ejection position 60. In one injection cycle, reagents in a reagent system are conveyed and batch injected in sequence, starting with the first reagent. The process is indicated by (b) in FIG. 4. Thus, the samples and reagents are batch-injected into the reaction containers 22 while the reaction table 65 is being rotated.
The reaction containers 22 are kept at a predetermined temperature, e.g., 37° C., by means of the constant-temperature reaction tank. Reaction of the samples with the reagents can be performed in a stable state in the constant-temperature tank. This enables highly sensitive measurement of the reaction.
FIG. 3 is a cross-sectional view of the constant-temperature air tank with the preliminary temperature raising means 29 incorporated therein. The constant-temperature air tank 21 has an annular chamber which is formed in such a manner as to surround the reaction container row. The annular constant-temperature air tank is provided near the periphery of and below the reaction table 65. The reaction containers 22 hang into the interior of the constant-temperature air tank 21 in a row. The annular chamber has a form which allows the row of reaction containers to be rotated therealong. The temperature of the entire constant-temperature air tank is kept at 37° C. by means of a metal heat block 35 having a U-shaped cross-section so that it can enclose the reaction containers except for the upper portions thereof. A sheet heater 36 is disposed on the outer periphery of the heat block 35 so as to supply heat.
The temperature of the reaction containers 22 held by the reaction table 65 is kept at 37° C. while the containers are accommodating reaction solutions. The outer periphery of the sheet heater 36 attached on the outer peripheral surface of the heat block 35 is covered by a heat insulating material 37, which is in turn covered by a cover. The reaction table 65 is fixed to a washer 40 mounted on a shaft 39 supported by a driving base 38. A pulley 41 mounted on the other end of the shaft 39 and a pulley 43 mounted on a pulse motor 42 are connected by a timing belt 44 so as to transmit the rotational force of the pulse motor 42 to the reaction table 65. The angle of rotation of the reaction table 65 is detected by a detection plate 45 formed integrally with the reaction table 65 and a photo-interrupter 46.
FIG. 1 is a cross-sectional view of the preliminary temperature raising means 29 having the forced preheating function. The preliminary temperature raising means 29 has an opening in the upper portion thereof. This opening 49 forms part of the accommodating portion or annular chamber 21 that surrounds the row of reaction containers 22. Thus, after the reaction container has received solution at the a solution receiving position 60, it is fed into the opening 49, as the reaction table is rotated, and is forcibly warmed. The temperature raising means 29 has a casing 48 which is opened at the opening 49. The casing 48 is in turn covered by a heat insulating material 47.
In the interior of the casing 48 is disposed a small casing 50. The space between the inner wall of the casing 48 and the outer wall of the small casing 50 forms a substantially circular annular air circulation passage 56. A ventilating hole 70 is opened to the interior of the small casing 50. Air which is introduced is used to control the temperature of the constant-temperature air tank. Air flows into the circulation passage 56 of the preliminary temperature raising means 29 when a lid member 53 mounted on the small casing 50 is opened through a predetermined angle by a driving mechanism (not shown). At the lower limit of the temperature control range, the lid member 53 is closed. Within the circulation passage are disposed a self-regulating type heater 51 such as a ceramic heater, a thermistor 52 for detecting the temperature, and a warmed air circulating fan 54 driven by a motor 55. This keeps the temperature of the air circulated in the circulation passage at 37° C. and keeps the circulated air blown against the reaction containers 22.
Reagent solutions containing an solid phase with the antibody coated thereon are set on the reagent table, and the sample solutions containing an antigen such as a virus are ejected into the reaction containers 22. Subsequently, the reagent solutions are added, and the reagent solutions and the sample solutions are vibrated and thereby stirred by means of the driving means, which includes the pulse motor 42, the pulley 43, the timing belt 44, the pulley 41 and the driving shaft 39, by controlling the driving signal applied to the pulse motor 42. The antigen and the solid phase are brought into contact each other, and the variable portion of the antibody reacts with the antigen. After a predetermined period of time has elapsed, the solid phase is washed away by the washing mechanism 23 (see FIG. 2), i.e., the non-reacted solution which is a source of noise in a highly sensitive measurement is discharged by the nozzle of the washing mechanism 23. Thereafter, the washing water is ejected from another nozzle by the operation of the washing syringe 25 for rewashing. This state is indicated by the process (c) in FIG. 4.
After the solid phase has been washed away, a substrate solution which is an enzyme reaction solution is added. At that time, the temperature of the mixture solution (reaction solution) within the reaction container is lowered below 37° C. After the addition of the substrate solution, the air which is kept at 37° C. by the preliminary temperature raising means 29 is blown against the reaction container 22 to raise its temperature and keep it at 37° C. This state is indicated by the process (d) in FIG. 4. When five minutes have passed after the addition of the substrate solution, the reaction state is measured by the fluorometer 28 so as to analyze the concentration of the components in the sample. This state is indicated by the process (e) in FIG. 4. In the time chart shown in FIG. 4, the reagent injection process (b) is programmed so that the number of processes can be increased or decreased according to the number of reagents required for reaction.
The automatic analysis apparatus according to the present invention may also be used as a diagnosis device for acquired immune deficiency syndrome (AIDS) because of its highly sensitive immune measurement. It is capable of detecting an antigen contained in a sample at a concentration of 10 -6 to 10 -13 mol/l. The analysis apparatus according to the present invention is about 10 6 times more sensitive than the conventional biochemical analysis apparatus which is capable of detecting a antigen contained at a concentration of 10 -6 mol/l. It is therefore essential to raise the temperature of the reaction solution to a predetermined degree as quickly as possible.
The flow of air in the forced circulation preheating function will be described in detail below with reference to FIGS. 1 and 3. The air is blown by the fan 54 in the direction indicated by the arrow B and toward the heater 51. The temperature of the air which has passed through the heater 51 is detected by the thermistor 52. The detection signal of the thermistor 52 is processed by a control circuit and is fed back as a heater voltage which keeps the temperature of the heater at 37° C. The thermistor 52 shown in FIG. 1 is connected to the preheating amplifier 30 shown in FIG. 2. The air which has passed through the heater 51 is blown against the reaction container 22 so as to raise the temperature of the interior of the reaction container to 37° C. in a short period of time. Thereafter, the air is further circulated by the fan 54. When the temperature of the air is raised excessively, the lid 53 is raised in response to the detection signal of the thermistor 52 so as to introduce the air.
FIG. 5 is a graph, showing how the temperature of the solution within the reaction container rises when the reaction container is conveyed to the preliminary temperature raising means after it has received a buffer solution (35° C.) and a substrate solution (about 20° C.) at the solution receiving position 60 on the reaction table 65. The temperature of the solutions accommodated in the reaction containers rises to 37° C. at which measurement by the fluorometer is possible, in five minutes. The temperature changes within the range surrounded by the solid line and the broken line when the ambient temperature is between 15° C. and 32° C.
In the above-described embodiment, the temperature of the solutions can be raised up to 37° C. in a short period of time by the use of the constanttemperature air tank, with the shortcomings of the use of the conventional water bath eliminated. More, specifically, the present embodiment eliminates contamination by the bacteria generated in the water channel which is experienced by the conventional constant-temperature water tank, as well as the troublesome maintenance thereof. It also eliminates the possibility of the water spilling during the exchange of the reaction containers, and thus provides a simple, highly reliably apparatus. | A constant-temperature air type automatic analysis apparatus includes: a reaction table for rotating a row of reaction containers; a batch injecting device for supplying a sample and a reagent into the reaction containers; a photometric device for measuring a reaction within the reaction containers; a constant-temperature air device for keeping the reaction containers warm, the constant-temperature air device having an annular constant-temperature air chamber which is formed in such a manner as to surround the row of reaction containers; a heat block disposed within the annular constant-temperature air chamber; and a preliminary temperature raising device for heating the reaction containers. The preliminary temperature raising device has an air circulation passage, a blowing device for blowing a constant-temperature air against the reaction containers in a region between a injection position of the batch injecting device and a measuring position of the photometric device. Alternatively, the preliminary temperature raising device has a ventilating device for temporarily ventilating the air circulation passage. |
FIELD OF THE INVENTION
[0001] This invention relates to a preparation method for a pharmaceutical compound, specifically, a preparation method of trihydroxyethyl rutoside.
BACKGROUND OF THE INVENTION
[0002] Troxerutin, also called Venoruton, is mainly composed of 7,3′,4′-trihydroxyethyl rutoside (abbreviated as “trihydroxyethyl rutoside” thereafter). The formula is C 33 H 42 O 19 , CAS No. is 7085-55-4, molecular weight is 742.69, and the chemical structure is as below:
[0000]
[0003] Troxerutin is a kind of anticoagulant and thrombolytic drug. Generally, it can be synthesized by reacting rutin with ethylene oxide in methanol and water as medium in the presence of a basic catalyst. Currently, active pharmaceutical ingredient of troxerutin is available on the market, sold at different purities such as 60%, 80% and 88%.
[0004] Trihydroxyethyl rutoside is the active ingredient in troxerutin. The higher its content is in troxerutin, the higher the quality of the drug. However, the current technical approach for preparing troxerutin with high purity is far from ideal.
[0005] The products of troxerutin on the market include injection formulation, oral solution and capsule. Especially for injection, the non-ideal purity of troxerutin produced by current technologies may pose great risk to clinical applications. Actually, injecting such a drug may lead to high prevalence of adverse effects, particularly allergic reactions. Improving the purity of troxerutin, specifically, the purity of the active ingredient trihydroxyethyl rutoside, therefore, has been studied by a great number of researchers.
[0006] The exiting preparation method of troxerutin utilizes a one-step reaction, i.e., direct hydroxyethylation of rutin to complete the reaction. Different hydroxyethylation techniques are based on utilizing different hydroxyethylation agents, reaction media, catalysts, reaction parameters, etc. The following are examples.
[0007] 1. In Patent BG2888B1, trihydroxyethyl rutoside with purity of 85.8% was prepared using water as solvent, ammonium water as catalyst, and ethylene oxide as hydroxyethylation agent.
[0008] 2. In Patent CN1331697 (US6855697), trihydroxyethyl rutoside with purity of 92% was prepared by using water as solvent, alkaline metal as catalyst, and ethylene oxide as hydroxyethylation agent, and by controlling the recrystallization condition.
[0009] 3. In Patent US3420815, troxerutin with chromatographic purity of 87.4%, content of 85.3% and melting point of 181-183° C. was prepared by using sodium hydroxide as catalyst.
[0010] 4. In Patent CN1554353, trihydroxyethyl rutoside with content of 90% was prepared by using organic solvents (methanol and ethanol) as solvent and pyridine as catalyst.
[0011] 5. In Patent CN1814613, trihydroxyethyl rutoside with content of 85% was prepared by using resin to control the pH value of the reaction solution.
[0012] One of the difficulties in preparing trihydroxyethyl rutoside is that rutin has four active hydroxyl groups, all of which can be hydroxyethylated, resulting in a mixture of products. Another difficulty is that natural rutin is mixed with impurities having highly similar structures, making purification difficult. It is challenging to obtain rutin with high purity by using conventional methods. Patent CN200810007927.2 discloses a method for purifying rutin by using complex reverse chromatography, which only gives gram-scale rutin with purity of 98%. In fact, commercially available rutin with low purity is always used as raw materials to prepare troxerutin. The impurities in the raw materials also undergo hydroxyethylation reaction, generating impurities with highly similar properties as trihydroxyethyl rutoside, and such impurities are hard to be removed. Actually, the preparation of trihydroxyethyl rutoside with high purity is highly challenging. Except for the chromatographic method of Jun Li et al. [2004, “Separation of troxerutin as reference substance by preparative liquid chromatography”, Chinese Journal of Pharmaceuticals, 35(5), 285-287] which is capable of preparing trihydroxyethyl rutoside with a purity of 99% as reference substance, no other reports of preparing trihydroxyethyl rutoside with a purity higher than 98% by using conventional methods can be found. Even though a product with a purity of 99% is claimed on the market, the preparation method is not disclosed, and the product is not available. The purity of reference substance prepared by current methods, even after multiple recrystallizations, is only 96-97%.
[0013] In order to solve the problem, this invention provides a preparation method of troxerutin with low content of impurities. Specifically, this method provides troxerutin containing less than 2% of non-troxerutin derivatives and greater than 98% of trihydroxyethyl rutoside. The essence of this invention relies on a two-step reaction to synthesize trihydroxyethyl rutoside with purification of the intermediate, whereby obtaining high-purity product.
SUMMARY OF THE INVENTION
[0014] This invention discloses a new preparation method of troxerutin, including
(1) Preparation of 7-monohydroxyethyl rutoside from rutin; (2) Purification of 7-monohydroxyethyl rutoside; (3) Preparation of trihydroxyethyl rutoside by using purified 7-monohydroxyethyl rutoside; and (4) Purification of trihydroxyethyl rutoside.
[0019] It was discovered that 7-monohydroxyethyl rutoside, as an intermediate for preparing troxerutin, is significantly different in properties in comparison to other impurities contained in the raw materials. Therefore, 7-monohydroxyethyl rutoside can be prepared with a purity of greater than 98%. Comparing with current technologies, this invention can use conventional purification methods, especially recrystallization method. No special expensive equipments or expensive separation chromatographic column is needed. This method thus greatly saves cost for manufacture and makes it possible for industrial production of trihydroxyethyl rutoside. Using conventional method is impossible to obtain trihydroxyethyl rutoside with high purity due to the similarities in properties between the impurities and the final product, even if recrystallization of the final product is performed repeatedly.
[0020] The synthetic approach in this invention can be illustrated as below:
[0000]
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 : HPLC spectrum of 7-monohydroxyethyl rutoside reaction solution in this invention.
[0022] FIG. 2 : HPLC spectrum of 7-monohydroxyethyl rutoside after purification in this invention.
[0023] FIG. 3 : HPLC spectrum of trihydroxyethyl rutoside (98%) in this invention.
[0024] FIG. 4 : HPLC spectrum of trihydroxyethyl rutoside (99%) in this invention.
[0025] FIG. 5 : HPLC spectrum of trihydroxyethyl rutoside as final product in US Patent 6,855,697.
[0026] FIG. 6 : HPLC spectrum of trihydroxyethyl rutoside (96%) as reference substance on the market (Zhongjiansuo 100416-200503)
[0027] The following are illustrative examples only and are not meant to limit the scope of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] In the present method, the preparation of 7-monohydroxyethyl rutoside in step (1) can utilize the technology in U.S. Pat. No. 4,153,788, such as using borax to protect the hydroxyl groups at the 5, 3′, and 4′ positions. Alternatively, preparing 7-monohydroxyethyl rutoside from rutin can also employ the technology in U.S. Pat. No. 3,430,815, i.e., synthesis in organic solvents.
[0029] During the preparation, hydroxyl protecting agent is used to protect the hydroxyl groups of rutin. Then, hydroxyethylation agent is added to the solvent to perform the reaction, wherein rutin can be purchased on the market, the hydroxyl protecting agent is borax, the hydroxyethylation agent is ethylene oxide, the reaction solvent is selected from water, methanol and ethanol, the reaction temperature is 30-50° C., the reaction time is 4-12 h, the reaction solution is let stand after reaction is complete, optionally at low temperature, the solution is made acidic if necessarily, and the resulting precipitate can be used for the next step after filtration.
[0030] The purification of 7-monohydroxyethyl rutoside in step (2) can use any industrially available method such as recrystallization, wherein 7-monohydroxyethyl rutoside is purified to a purity of greater than 95%, preferably greater than 98%, most preferably greater than 99%, and the purified product is used for further reaction.
[0031] The solvent for recrystallization is selected from water, methanol, ethanol, isopropanol and a mixture thereof. The recrystallization step includes dissolution, crystallization and filtration.
[0032] The preparation of trihydroxyethyl rutoside from purified 7-monohydroxyethyl rutoside in step (3) can utilize conventional hydroxyethylation approaches such as hydroxyethylation of 7-monohydroxyethyl rutoside by using ethylene oxide as hydroxyethylation agent. After reaction, the reaction product is passed through cation exchange resin and anion exchange resin to remove salts, or through macroporous resin to remove impurities. Then step (4) is performed.
[0033] In the process, a hydroxyethylation agent is added to react with 7-monohydroxyethyl rutoside, which is dissolved or dispersed in a solvent, wherein the hydroxyethylation agent is ethylene oxide, the reaction solvent is selected from water, methanol, ethanol, pyridine, and a mixture thereof, the reaction temperature is 50-80° C., the reaction time is 3-8 hours, the solution is let stand after reaction is complete, optionally at low temperature, the solution is made acidic if necessarily, and the resulting solution can be used for the next step.
[0034] Said cation exchange resins are selected from strong acidic polystyrene cationic exchange resins such as 007X7(732), 001X12, 001X1 and 001X16, said anion exchange resins are selected from strong basic polystyrene anion exchange resins such as 201X4(711) and 201X7(717). The method of passing the product through resins can be performed as follows: passing the solution through a column of resins, or adding the resins to the reaction solution, stirring the mixture, and then separating the crude product solution.
[0035] Said macroporous resins selected from D101, D201, DAB-8 and D301 can be used for purification in conventional manners, i.e., passing the filtered aqueous solution of the reaction product through a resin column, washing the column with purified water, and further washing with organic solvents of various concentrations in a gradient manner, wherein the organic solvent is ethanol, resulting in a product solution of crude trihydroxyethyl rutoside. The solution of crude product can be subjected to recrystallization after concentration and drying.
[0036] The purification step (4) utilizes recrystallization to prepare purified trihydroxyethyl rutoside, wherein the solvent for recrystallization is selected from water, methanol, ethanol, isopropanol and a mixture thereof, and the recrystallization step includes dissolution, crystallization and filtration.
[0037] Unless otherwise indicated, all the ratios and percentages are weight percentage values, and chromatographic purity refers to the results obtained according to the troxerutin analysis method in European Pharmacopoeia 7.0. Detailed preparation examples can be found in the examples below.
[0038] The advantages of this invention include the following.
[0039] Based on known reports, preparing highly pure trihydroxyethyl rutoside with purity greater than 98% is only possible using preparative chromatographic method, which is extremely expensive, strictly restrained within laboratory research, impossible for large-scale manufacture and wide application. The method disclosed in this invention takes a simpler method to obtain trihydroxyethyl rutoside with high purity, the cost is low and feasibility is great.
[0040] In comparison with current methods, this invention will greatly decrease cost. Especially for trihydroxyethyl rutoside, the cost is significantly decreased. The relevant experimental data are as follows.
[0041] The method in U.S. Pat. No. 3,420,815: according to this method, it is impossible to obtain trihydroxyethyl rutoside with a purity of 98%. The chromatographic purity of the product is 87.4% and the content is 84.2%. The color is dark yellow. Melting point is 178-182 ° C. The cost is 400-500 Chinese Yuan per kilogram. With preparative chromatographic separation, trihydroxyethyl rutoside with a purity of 99% can be obtained. The cost, however, increases dramatically to 5,000-10,000 Chinese Yuan per gram.
[0042] In addition, the relevant data for comparison with the published preparation methods are as follows.
[0043] The method in U.S. Pat. No. 6,855,697: according to this method, it is impossible to obtain trihydroxyethyl rutoside with a purity of 98%. The chromatographic purity of the product is 92.1% and the content is 90.3%. The color is yellow. Melting point is 179-183 ° C. The cost is 500-800 Chinese Yuan per kilogram. With preparative chromatographic separation, trihydroxyethyl rutoside with a purity of 99% can be obtained. The cost, however, increases dramatically to 5,000-10,000 Chinese Yuan per gram.
[0044] This invention provides a preparation of trihydroxyethyl rutoside with purity of 98%. Its color is light yellow, melting point is 185-187° C. and the cost is around 2,000-3,000 Chinese Yuan per kilogram.
[0045] The invention provides a preparation of trihydroxyethyl rutoside with purity of 99%. Its color is light yellow, melting point is 186-188° C. and the cost is around 3,000-5,000 Chinese Yuan per kilogram.
[0046] The products after step (1) and after purification in this invention are analyzed with results as below:
[0000]
Before
After
purification
purification
Result
Component
HPLC %
HPLC %
comparison
7-monohydroxyethyl
91.35
98.72
7.37↑
rutoside
Impurity 1 R f 0.5
2.01
Not detectable
2.01↓
Impurity 2 R f 0.9
0.67
Not detectable
0.67↓
Impurity 3 R f 1.1
2.35
0.73
1.98↓
Impurity 4 R f 1.2
1.64
0.21
1.43↓
Impurity 5 R f 1.3
1.09
0.23
0.86↓
Impurity 6 R f 1.7
0.45
0.11
0.34↓
Impurity 7 R f 1.8
0.26
Not detectable
0.26↓
Note:
R f is the retention time of impurity in reference to the main peak
[0047] According to the table above, it can be seen that the physicochemical property of 7-monohydroxyethyl rutoside is significantly different from the impurities 1-7 in the reaction. The effects of purification are significant
[0048] In order to prove the superiority of this invention, a comparison to the latest technology is also made.
[0049] Trihydroxyethyl rutoside is prepared by the method disclosed in U.S. Pat. No. 6,855,697. After reaction, the trihydroxyethyl rutoside in the reaction solution is purified by the following steps.
[0050] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 732, anion exchange resin 717 to remove salts, then concentrated under reduced pressure, and further spray-dried. With 8,000 ml of methanol added, the solid is heated to dissolve. After active charcoal for refinement of injection is added, the solution is heated at reflux for 30 min, and filtered while hot. The filtrate is let stand at room temperature for 6 h to allow crystallization. After filtration, the solid is dried at 40-50° C. and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 88.2%. The obtained solid was recrystallized from a 20-fold amount of methanol, and dried. The content of trihydroxyethyl rutoside is 90.6%.
[0051] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 732, anion exchange resin 711 to remove salts, then concentrated under reduced pressure, and further spray-dried. With 7,000 ml of methanol-water (37:3) added, the solid is heated to dissolve. After active charcoal for refinement of injection is added, the solution is heated at reflux for 30 min, and filtered while hot. The filtrate is let stand at room temperature for 6 h to allow crystallization. After filtration, the solid is dried at 40-50 ° C. and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 90.1%. The obtained solid was recrystallized from a 20-fold amount of methanol-water (37:3), and dried. The content of trihydroxyethyl rutoside is 91.6%.
[0052] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 001X14, anion exchange resin 717 to remove salts, then concentrated under reduced pressure, and further spray-dried. With 9000 ml of methanol-isopropanol (95:5) added, the solid is heated to dissolve. After active charcoal for refinement of injection is added, the solution is heated at reflux for 30 min, and filtered while hot. The filtrate is let stand at room temperature for 6 h to allow crystallization. After filtration, the solid is dried at 40-50° C. and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 91.7%. The obtained solid was recrystallized from a 20-fold amount of methanol-isopropanol (95:5), and dried. The content of trihydroxyethyl rutoside is 92.4%.
[0053] Trihydroxyethyl rutoside is prepared by the method disclosed in this invention. After reaction, the trihydroxyethyl rutoside in the reaction solution is purified by the following steps.
[0054] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 732, anion exchange resin 717 to remove salts, then concentrated under reduced pressure, and further spray-dried. With 8,000 ml methanol added, the solid is heated to dissolve. After active charcoal for refinement of injection is added and the solution is heated at reflux for 30 min, filtered while hot. The filtrate is then precipitated at room temperature for 6 h. After filtration, the solid is dried at 40-50° C., and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 92.4%. The obtained solid was recrystallized from a 20-fold amount of methanol, and dried. The content of trihydroxyethyl rutoside is 98.2%.
[0055] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 732, anion exchange resin 711 to remove salts, then concentrated under reduced pressure, and further spray-dried. With 7,000 ml methanol-water (37:3) added, the solid is heated to dissolve. After active charcoal for refinement of injection is added and the solution is heated at reflux for 30 min, filtered while hot. The filtrate is then precipitated at room temperature for 6 h. After filtration, the solid is dried at 40-50° C. and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 93.5%. The obtained solid was recrystallized from a 20-fold amount of methanol-water (37:3), refined and dried. The content of trihydroxyethyl rutoside is 98.3%.
[0056] The solution containing trihydroxyethyl rutoside is passed through cation exchange resin 001X14, anion exchange resin 717 to remove salts, then concentrated under reduced pressure, and further spray-dried. After 9,000 ml methanol-isopropanol (95:5) added, the solid is heated to dissolve. After active charcoal for refinement of injection is added, the solution is heated at reflux for 30 min, and filtered while hot. The filtrate is then precipitated at room temperature for 6 h. After filtration, the solid is dried at 40-50° C. and trihydroxyethyl rutoside is finally obtained, in which the content of trihydroxyethyl rutoside is tested to be 95.8%. The obtained solid was recrystallized from a 20-fold amount of methanol-isopropanol (95:5), and dried. The content of trihydroxyethyl rutoside is 98.6%.
[0057] It can be seen from the comparison above that through the same purification method, the present preparation method gave much better result.
[0058] Based on existing technology such as the method in U.S. Pat. No. 6,855,697, the purity of trihydroxyethyl rutoside is 91.3%. Much purer product could not be obtained even by repeated recrystallization from a 20˜25-fold amount of methanol-isopropanol (95:51. as shown below:
[0000]
Number of Recrystallization
Initial
1
3
5
8
Purity
91.77
92.43
93.51
94.36
95.21
EXAMPLE 1
[0059] 1. 328 g (0.86 mol) Borax (Na 2 B 4 O 7 .10H 2 O) is added into 2,500 ml deionized water, and dissolve with stirring. 605 g (0.82 mol) rutin is added and dissolve with stirring at 40-45° C. Clear and transparent solution of rutin-borax complex is obtained. Under 40-45° C., with stirring, 88 g (2.0 mol) ethylene oxide is gradually introduced into the reaction solution followed by a reaction for about 6 h. The reaction is complete based on
[0060] HPLC analysis. The pH value of the solution is adjusted to 2.0 by using 5N HCl and further let stand for 12 h at 3-5° C. After filtration, the solid cake is obtained, in which contains 504 g 7-monohydroxyethyl rutoside and the yield is 95%.
[0061] 2. 1,460 g 7-monohydroxyethyl rutoside obtained from 1 above is added into 4,750 ml deionized water and heated to 60° C. with stirring. When full dissolution reached, the solution is filtrated and the filtrate stands at 3-5° C. for overnight. The predicated solid is obtained by filtration and further dried at 40-50° C. for 12 h. 450g 7-monohydroxyethyl rutoside is obtained. The content by anhydrous count is 98.3%. The chromatographic purity is 98.6%. The yield is 89.3% and the total yield is 84.8%.
[0062] 3. 490 g (0.7mol) 7-monohydroxyethyl rutoside obtained from 2 above and 5.6 g sodium hydroxide are added into 1,880 ml deionized water, heated to and kept at 75-80° C. with stirring. 92 g (2.1 mol) ethylene oxide is gradually introduced into the reaction solution followed by a reaction reacting for 5-6 h. When the fraction of trihydroxyethyl rutoside reaches 75%-78% based on HPLC analysis, the supply of ethylene oxide is stopped. At the same time, nitrogen is introduced into the reaction and the temperature is rapidly lowered down. When the temperature is lower than 40° C., the pH value is adjusted to 5.0±0.2 by using 3N HCl. The reaction solution is respectively passing through cation exchange resin column 732 and anion exchange resin column 717, followed by concentration under reduced pressure, and spray-dried. Solid powder of 520 g is obtained. The content of trihydroxyethyl rutoside is 92.3%. The melting point is 180-183° C. The yield is 98% and the total yield is 83.1%.
[0063] 4. 500 g solid powder as obtained from 3 above is added into 10,000 ml methanol. After an addition of 1.0 g active charcoal for refinement of injection, the solution is heated at reflux for 30 min, and filtered while hot. After a natural crystallization of filtrate at room temperature for 6 h, the solid is obtained by filtration and further dried at 40-50° C. 410 g of trihydroxyethyl rutoside is obtained. The content is 96.8%. The yield is 82% and the total yield is 68.1%.
[0064] 5. 410 g of the solid powder obtained from 4 above is added into 9,500 ml methanol. The solid is heated for dissolve. The solution is heated at reflux for 30 min and filtrated while hot. The filtrate gets through a natural precipitation of crystal at room temperature for 6 h. The solid is obtained after filtration and further dried at 40-50° C. under vacuum. 338 g of trihydroxyethyl rutoside is finally obtained. The content is 98.2%. The chromatographic purity is 98.4%. The melting point is 184-186° C. The yield is 82.5% and the total yield is 56%.
EXAMPLE 2
[0065] 1. 164 g (0.43 mol) Borax (Na 2 B 4 O 7 .10H 2 O) and 12 g (0.3 mol) sodium hydroxide are added into 2,000 ml deionized water, and dissolve with stirring. With an addition of 605 g (0.82 mol) rutin, the solution is heated to and kept at 40-45° C. On the condition of stirring, 88 g (2.0 mol) ethylene oxide is gradually introduced into the reaction solution followed by a reaction for about 12 h. The reaction is complete based on HPLC analysis. The pH value of the solution is adjusted to 2.0 by using 5N HCl and further let stand for 12 h at 3-5° C. After filtration, the solid cake is obtained, in which contains 510 g of 7-mono hydroxyethyl rutoside and the yield is 96%.
[0066] 2. 510 g 7-monohydroxyethyl rutoside obtained from 1 above (total weight is 1,450 g containing 940 g water) is added into 2,000 ml deionized water and heated to 40 ° C. under stirring. Saturated sodium bicarbonate solution is dropwise added until solid is fully dissolved. The solution is filtrated and the pH value of the filtrate is adjusted to 4.0 by using 0.1 N HCl. The filtrate is let stand at 3-5° C. for overnight. The solid is obtained by filtration and further dried at 40-50° C. for 12h. 433 g 7-monohydroxyethyl rutoside (total weight 470 g) is obtained. The content by anhydrous count is 98.6%. The chromatographic purity is 98.8%. The yield is 85% and the total yield is 81.6%.
[0067] 3. 433 g (0.67mo1) 7-monohydroxyethyl rutoside obtained from 2 above and 5.6 g ammonium water are added into 1,880 ml deionized water, heated to and kept at 75-80° C. with stirring. 92 g (2.1 mol) ethylene oxide is gradually introduced into the reaction solution followed by a reaction for 5-6 h. When the fraction of trihydroxyethyl rutoside reaches 75-78% based on HPLC analysis, the supply of ethylene oxide is stopped. At the same time, nitrogen is introduced into the reaction and the temperature is rapidly lowered down. When the temperature is lower than 40° C., the reaction solution is directly loaded onto the pre-treated macroporous resin D101 for purification, in which a total weight of 20 kg resin is used. When the loading is finished, deionized water is used for washing until the eluent is neutral and the chloride detection by silver nitrate is negative. Then 60% ethanol is used for washing until the eluent is colorless. Eluent is collected and concentrated to 2500 ml under reduced pressure. 465 g solid powder is obtained after spray drying. The content of trihydroxyethyl rutoside is 92%. The yield is 86% and the total yield is 70.2%
[0068] 4. 465 g solid powder as obtained from 3 above is added into 8000 ml methanol and heated to dissolve. After an addition of 1.0 g active charcoal for refinement of injection and a refluxed for 30 min, the solution is filtered while hot. After crystal precipitation of filtrate at room temperature for 6 h, the solid is obtained by filtration and further drying at 40-50° C. The content is 97.2%. The yield is 82% and the total yield is 57.6%.
[0069] 5. 381 g of the solid powder obtained from 4 above is added into 10500 ml methanol, and heated for dissolve. The solution is heated at reflux for 30 min and filtered while hot. The filtrate is let stand for a natural precipitation of crystal at room temperature for 6 h. The solid is obtained after filtration and further dried at 40-50° C. under vacuum. 314 g of trihydroxyethyl rutoside is finally obtained. The content is 98.3%. The chromatographic purity is 98.3%. The melting point is 184-186° C. The yield is 82.5% and the total yield is 47.5%.
EXAMPLE 3
[0070] 1. 328 g (0.86 mol) Borax (Na 2 B 4 O 7 .10H 2 O) is added into 2,000 ml deionized water, and dissolve with stirring. 605g (0.82 mol) rutin is added and dissolved at 40-45° C. with stirring. Clear and transparent solution of rutin-borax complex is obtained. 88 g (2.0 mol) ethylene oxide is gradually introduced into reaction solution. After a reaction for about 12 h, the reaction is complete based on HPLC analysis. The reaction solution is directly loaded onto the pre-treated macroporous resin D101 for purification, in which a total weight of 25 kg resin is used. When the loading is finished, deionized water is used for washing until the eluent is neutral. The column is firstly washed by 10% ethanol, further washed by 10,000 ml 60% ethanol and finally washed by 90% ethanol. The eluent from 60% ethanol washing is collected and concentrated under reduced pressure until no smell of alcohol. The solution is diluted with water to a volume of 12,000 ml and stands at 3-5° C. for overnight. After filtration, the solid cake is further washed by icy water. 473 g trihydroxyethyl rutoside (total weight of 1,440 g) is obtained. The content by anhydrous count is 99.3%.The chromatographic purity is 99.3%. The yield is 89.3%.
[0071] 2. 1,440 g solid containing water obtained from 1 above is added into 4,750 ml deionized water and heated to 60° C. under stirring. After full dissolution, the solution is filtered. Then, the solution is filtered and the pH value of the filtrate is adjusted to 2.0 by using 3N HCl. The filtrate is let stand at 3-5° C. for overnight. The solid is obtained by filtration and further dried at 40-50° C. for 12h. 463 g of 7-monohydroxyethyl rutoside (containing 8% water) is obtained. The content by anhydrous count is 99.5%. The chromatographic purity is 99.5%. The yield is 90.1% and the total yield is 80.5%.
[0072] 3. 463 g (0.71 mol) 7-monohydroxyethyl rutoside obtained from 2 above and 5.6 g sodium hydroxide are added into 1,880 ml deionized water, heated to and kept at 75-80° C. with stirring. 92 g (2.1 mol) ethylene oxide is gradually introduced into the reaction solution followed by a reaction for 5-6 h. When the fraction of trihydroxyethyl rutoside based on HPLC analysis reaches 75%-78%, the supply of ethylene oxide is stopped. At the same time, nitrogen is introduced into the reaction and the temperature is rapidly lowered down. When the temperature is lower than 40° C., the pH value is adjusted to 5.0±0.2 by using 3N HCl. The reaction solution is respectively passed through cation exchange resin column 732 and anion exchange resin column 717 to remove salts, followed by concentration under reduced pressure, and spray-dried. Solid powder of 531 g is obtained. The content of trihydroxyethyl rutoside is 85%. The melting point is 180-183° C. The yield is 85% and the total yield is 68.4%.
[0073] 4. 465 g solid powder as obtained from 3 above is added into 8,000 ml methanol and heated to dissolve. After an addition of 1.0 g active charcoal for refinement of injection, the solution is heated at reflux for 30 min, and filtered while hot. After a natural precipitation of crystal precipitation at room temperature for 6 h, the solid is obtained by filtration and further drying at 40-50° C. 531 g of trihydroxyethyl rutoside is obtained. The content is 95.8%. The yield is 82% and the total yield is 56%.
[0074] 5. 435 g of the solid powder obtained from 4 above is added into 10,500 ml methanol, and heated to dissolve. The solution is heated at reflux for 30 min, and filtrated while hot. After a natural crystal precipitation at room temperature for 6 h, the solid is obtained after filtration and further dried at 40-50 ° C. under vacuum. Finally, 354 g trihydroxyethyl rutoside is obtained. The content is 98.4%. The chromatographic purity is 98.4%. The melting point is 184-186° C. The yield is 81.5% and the total yield is 45.6%.
EXAMPLE 4
[0075] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0076] 2. 510 g (0.71 mol) 7-monohydroxyethyl rutoside obtained from 1 above and 5.6 g sodium hydroxide are added into the mixture solution of 1,000 ml deionized water and 800 ml ethanol. The solution is heated to and kept at 70-75° C. under stirring. 92 g (2.1 mol) ethylene oxide is gradually introduced into reaction solution followed by a reaction for 10-13 h. When the fraction of trihydroxyethyl rutoside reaches 75-78% based on HPLC analysis, the supply of ethylene oxide is stopped. At the same time, nitrogen is introduced into the reaction and the temperature is rapidly lowered down. When the temperature is lower than 40° C., the pH value is adjusted to 5.0±0.2 by using 3N HCl. The ethanol is recycled by vacuum distillation. The reaction solution is respectively passed through cation exchange resin column 732 and anion exchange resin column 717 to remove salts, followed by spray drying. Solid powder of 480 g is obtained. The content of trihydroxyethyl rutoside is 93.4%. The melting point is 181-184° C. The yield is 85%.
[0077] 3. The obtained solid from 2 above was recrystallized according to the method in EXAMPLE 1 by using methanol. 323 g of trihydroxyethyl rutoside is obtained. The chromatographic purity is 98.6%. The melting point is 185-186° C. The total yield is 53.5%.
EXAMPLE 5
[0078] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0079] 2. 510 g (0.71 mol) 7-monohydroxyethyl rutoside and 5.6 g sodium hydroxide are added into the mixture solution of 1,000 ml deionized water and 800 ml methanol.
[0080] The solution heated to and kept at 60-70° C. under stirring. 92 g (2.1 mol) ethylene oxide is gradually introduced into reaction solution followed by a reaction for 10-13 h. When the fraction of trihydroxyethyl rutoside reaches 75-78% based on HPLC analysis, the supply of ethylene oxide is stopped. At the same time, nitrogen is introduced into the reaction and the temperature is rapidly lowered down. When the temperature is lower than 40° C., the pH value is adjusted to 5.0±0.2 by using 3N HCl. The reaction solution is respectively passed through cation exchange resin column 732 and anion exchange resin column 717 to remove salts. The methanol is recycled by vacuum distillation. 474 g of solid powder of is obtained after spray drying. The content of trihydroxyethyl rutoside is 94.5%. The melting point is 181-184° C. The yield is 84%.
[0081] 3. The solid as obtained from 2 above was recrystallized according to the method 1 in EXAMPLE 2 by using methanol. 317 g of trihydroxyethyl rutoside is obtained. The chromatographic purity is 98.7%. The melting point is 185-186° C. The total yield is 52.5%
EXAMPLE 6
[0082] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0083] 2. Within a 5,000 ml autoclave, 510 g (0.71 mol) 7-monohydroxyethyl rutoside, 10 ml trimethylamine, 2,000 ml methanol, and 132 g (3.0 mol) ethylene oxide at last are added. Once the addition is finished, the autoclave is sealed immediately and heated to and kept at 75-80° C. under stirring followed by a reaction for 2-3h. When the temperature is lower than 40° C. and the pressure is released, the reaction solution is filtrated. The filtrated solution is respectively passed through the cation exchange resin 732 column and the anion exchange resin 717 column. The pH value of the solution is adjusted to 5.0±0.2 by using 5N HCl. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration and the solid cake of 380 g is obtained.
[0084] 3. The solid cake obtained from 2 above is re-dissolved in a 20-fold amount of hot methanol. The solution is heated at flux for 30 min and filtered. The filtrate is let stand for 6-8 h at room temperature. After filtration, the crystal is dried under vacuum at 40-50° C. The content of trihydroxyethyl rutoside is 98.1%. The melting point is 185-186° C. The yield is 58%.
EXAMPLE 7
[0085] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0086] 2. Within a 5,000 ml autoclave, 510 g (0.71 mol) 7-monohydroxyethyl rutoside, 10 ml diethylamine, 2,000 ml methanol, and 132 g (3.0 mol) ethylene oxide as the last are added. Once the addition is finished, the autoclave is sealed immediately and heated to and kept at 75-80° C. under stirring followed by a reaction for 2-3h. When the temperature is lower than 40° C. and the pressure is released, the reaction solution is filtered. The filtrate is respectively passed through the cation exchange resin 732 column and the anion exchange resin 717 column. The pH value of the solution is adjusted to 5.0±0.2 by using 5N HCl. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration and a solid cake of 375 g is obtained.
[0087] 3. The solid cake obtained from 2 above is re-dissolved in a 20-fold amount of hot methanol-isopropanol (37:3). The solution is heated at reflux for 30 min, and filtered. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration followed by vacuum drying at 40-50° C. A solid powder of 302 g is obtained. The content of trihydroxyethyl rutoside is 98.3%. The melting point is 184-186° C. The yield is 57%.
EXAMPLE 8
[0088] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0089] 2. Within a 5,000 ml autoclave, 510 g (0.71 mol) 7-monohydroxyethyl rutoside, 30 ml ammonium water, 2,000 ml methanol, and 154 g (3.5 mol) ethylene oxide are added. Once the addition is finished, the autoclave is sealed immediately and heated to and kept at 75-80° C. with stirring followed by a reaction for 2-3 h. When the temperature is lower than 40° C. and the pressure is released, the reaction solution can be filtered.
[0090] The filtrated solution respectively passes through the cation exchange resin 732 column and the anion exchange resin 717 column. The pH value of the solution is adjusted to 5.0±0.2 by using 5N HCl. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration and 360 g of solid cake is obtained.
[0091] 3. The solid cake obtained from 2 above is re-dissolved in a 20-fold amount of hot methanol. The solution is heated at reflux for 30 min and is filtrated. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration followed by vacuum drying at 40-50° C. 290 g of solid powder is obtained. The content of trihydroxyethyl rutoside is 98.2%. The melting point is 184-186° C. The yield is 55%.
EXAMPLE 9
[0092] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0093] 2. Within a 5,000 ml autoclave, 510 g (0.71 mol) 7-monohydroxyethyl rutoside, 10 ml pyridine, 1,600 ml methanol, 400 ml methanol and 154 g (3.5 mol) ethylene oxide as the last are added. Once the addition is finished, the autoclave is sealed immediately and heated to and kept at 75-80° C. under stirring followed by a reaction for 2-3 h. When the temperature is lower than 40° C. and the pressure is released, the reaction solution is filtered. The filtrate is respectively passed through the cation exchange resin 732 column and the anion exchange resin 717 column. The pH value of the solution is adjusted to 5.0±0.2 by using 5N HCl. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration and 420 g of solid cake is obtained.
[0094] 3. The solid cake obtained from 2 above is re-dissolved in a 20-fold amount of methanol-ethanol (95:5) and heated to dissolve. The solution is heated at reflux for 30 min and filtrated. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration followed by a vacuum drying at 40-50° C. The 336 g of solid powder is obtained. The content of trihydroxyethyl rutoside is 98.2%. The melting point is 184-186° C. The yield is 64%.
EXAMPLE 10
[0095] 1. The preparation of 7-monohydroxyethyl rutoside is the same as descried in EXAMPLE 1.
[0096] 2. Within a 5,000 ml autoclave, 510 g (0.71 mol) 7-monohydroxyethyl rutoside, 10 ml pyridine, 2,000 ml methanol, and 154 g (3.5 mol) ethylene oxide as the last are added. Once the addition is finished, the autoclave is sealed immediately and heated to and kept at 75-80° C. with stirring followed by a reaction for 2-3h. When the temperature is lower than 40° C. and the pressure is released, the pH value of the solution is adjusted to 5.0±0.2 by using 5N HCl. The filtrate stands for 6-8 h at room temperature. Crystal is obtained after filtration and 410 g of solid cake is obtained.
[0097] 3. The solid cake obtained from 2 above is re-dissolved in a 20-fold amount of methanol and heated to dissolve. The solution is heated at reflux for 30 min and filtrated. The filtrate is let stand for 6-8 h at room temperature. Crystal is obtained after filtration followed by vacuum drying at 40-50° C. A solid powder of 310 g is obtained. The content of trihydroxyethyl rutoside is 98.3%. The melting point is 184-186° C. The yield is 61%.
EXAMPLE 11
[0098] 1. 100 g trihydroxyethyl rutoside with a purity of 98.7% as obtained from EXAMPLE 5 is added into 3,000 ml methanol-ethanol. The solution is heated at reflux for 30 min, and filtrated. After filtration, the crystal is dried under vacuum at 40-50° C. 80.2 g of trihydroxyethyl rutoside is obtained. The chromatographic purity is 98.8%. The content is 98.8%. The melting point is 186-188° C.
[0099] 2. 80 g trihydroxyethyl rutoside with a purity of 98.8% as obtained above is added into 2,400 ml methanol-isopropanol (95:5). The solution is heated at reflux for 30 min, and filtrated while hot. The filtrate is let stand for 6-8 h at room temperature. After filtration, the crystal is dried under vacuum g at 40-50° C. 64.3 g trihydroxyethyl rutoside is obtained. The chromatographic purity is 99.2%. The content is 99.2%. The melting point is 187-189° C. | The present invention relates to a preparation method of trihydroxyethyl rutoside. In the method, rutin is firstly prepared into 7-monohydroxyethyl rutoside with a purity of greater than or equal to 98% by weight, and then 7-monohydroxyethyl rutoside is hydroxyethylated to give troxerutin having less than 2% of non-hydroxyethylated rutoside derivatives. The amount of 7,3',4'-trihydroxyethyl rutoside in troxerutin is more than 80% by weight. The product is further purified so that 7,3',4'-trihydroxyethyl rutoside with a purity of greater than or equal to 98% by weight could be obtained. |
This is a divisional of application Ser. No. 08/104,890 filed on Aug. 10, 1993, now U.S. Pat. No. 5,372,319, which was a divisional of application Ser. No. 07/693,718, filed on Apr. 30, 1991, now abandoned, which was a continuation of application Ser. No. 07/416,301, filed on Oct. 3, 1989, now abandoned.
SUMMARY OF THE INVENTION
This invention relates to a method for loading and unloading workpieces for use in a manufacturing process. The invention is primarily directed to a method for loading and unloading armature assemblies for fractional horsepower electric motors into and out of an armature winding machine but may be useful in other manufacturing processes.
There are many manufacturing processes where a workpiece is to be supplied from a remote supply point to a processing machine along a predetermined axis and, after being processed, removed from the processing machine and replaced by the next workpiece to be processed. For example, a double flier armature winding machine has a collet for gripping the shaft of an armature assembly while coils of wire are being wound on the assembly. Unwound armature assemblies must be advanced along a predetermined axis for insertion into the collet. After the winding process is completed, the newly wound armature assembly is removed from the collet and the shaft of another, unwound, armature assembly is inserted into the collet. To meet high speed production requirements, the loading and unloading of the armature assemblies must be carried out quite rapidly.
An object of this invention is to provide an improved method for loading workpieces into and unloading workpieces from a workpiece processing machine. More specifically, it is an object of this invention to provide an improved method for loading armature assemblies for fractional horsepower electric motors (hereinafter called "armature assemblies") into and unloading such armature assemblies from an armature winding machine.
A further object of this invention is to provide an improved method for moving workpieces such as armature assemblies from a load and unload station of a workpiece conveyor system into and out of processing machine. Maufacturing lines using pallet conveyor systems offer certain advantages over automatic production lines having workpiece handling systems that are dedicated to the handling of workpieces of but one configuration. For example, automatic workpiece handling apparatus used to supply armature assemblies to armature winding machines in automatic armature production lines are usually dedicated to the manufacture of armatures having a single set of specifications, such as size, number of coils, and so forth. Automatic armature production lines are essentially inflexible; any change in the armature specifications or one of the processing steps usually necessitates the shutting down of the entire line for substantial retooling of the line.
Conveyor systems using workpiece-suppporting pallets have been developed for manufacturing processes wherein each pallet carries a single workpiece, such as an armature assembly. The pallets are moved along a conveyor line and presented sequentially to a processing machine, such as an armature winding machine. After the processing of a workpiece is completed by the machine, the workpiece is returned to the conveyor system for further processing by other machines adjacent the conveyor system or else for delivery to a loading and Unloading device. A pallet system can be more flexible than the typical, dedicated automatic manufacturing line because different pallets can carry workpieces of different configurations and processing machines can be "stand-alone" machines which are not tied to other machines by automatic workpiece handling apparatus that is restricted for use with workpieces of but one configuration. Stand alone processing machines may be retooled or added to, or removed from, the processing line without interference with the operation of the conveyor system or with the other processing machines to which workpieces are supplied by the pallet conveyors. However, to meet high speed production requirements, there is a need to be able to rapidly load and unload the conveyor-delivered workpieces into and out of the processing machines so that the machines will be operated with maximum efficiency.
When using a stand-alone machine that processes parts delivered by a conveyor system, it is desirable to provide a substantial area of free space around the machine in order to provide convenient access to the machine for maintenance or retooling. However, there is usually a competing need for manufacturing machines to occupy as little floor space as possible to provide room for other manufacturing machines. A further object of this invention is to provide an apparatus for supplying workpieces, such as armature assemblies, rapidly to a workpiece processing machine that requires a reasonably small area while yet providing a substantial area of free space between a workpiece supply conveyor and the processing machine.
In accordance with this invention, apparatus for successively loading workpieces, such as unwound armature assemblies, along a predetermined axis into a workpiece processing machine, includes an elongate main beam, means mounting the main beam for movement in a first path parallel to said axis, main beam drive means for reciprocally moving the main beam along said path generally toward and away from the processing machine, a support carriage mounted on the main beam for movement of the carriage relative to the main beam in a second path parallel to said axis and said first path, carriage drive means for reciprocally moving the support carriage-along said second path toward and away from the processing machine, an armature staging assembly mounted on the support carriage for movement along a third path perpendicular to said axis, and staging assembly drive means for reciprocally moving the staging assembly along said third path. The staging assembly has two workpiece holders or grippers, a first holder or gripper for parts that have been processed and a second for parts that are to be processed.
In operation of the load and unload apparatus of this invention, the main beam and the staging assembly move to a retracted position whereat a part to be processed located on a pallet at a load and unload station is clamped to the first workpiece holder of the staging assembly. The staging assembly is then moved laterally to deliver a processed part from the second workpiece holder to the same pallet. That pallet is carried away by the conveyor assembly while the main beam and the staging assembly are moved to an extended position with the empty, first workpiece holder in position to receive the part then being processed by the processing machine. Meanwhile, a fresh pallet carrying a part to be processed enters the load and unload station so that the foregoing operations may be repeated.
Other objects and advantages will become apparent from the drawings and the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, perspective view of a workpiece loading and unloading apparatus made in accordance with this invention shown used with a pallet conveyor assembly including a pallet supporting an unwound armature assembly. FIG. 1 also fragmentarily shows a portion of a double flier armature winding machine with an armature in position to be wound.
FIG. 2 is a fragmentary, side elevational view with parts shown in cross section and parts broken away of the load and unload apparatus of FIG. 1.
FIG. 3 is a fragmentary, transverse cross-sectional view of the load and unload apparatus taken along line 3--3 of FIG. 2.
FIG. 4 is a fragmentary, cross-sectional view of a shaft clamping device forming part of the load and unload apparatus taken along line 4--4 of FIG. 3.
FIG. 5 is a fragmentary, cross-sectional view of a portion of the pallet conveyor assembly shown with an unwound armature assembly supported by a pallet.
DETAILED DESCRIPTION
With reference to FIG. 1, a workpiece loading and unloading apparatus in accordance with this invention is generally designated 10. The apparatus 10 is diagrammatically shown associated with a double flier armature winding machine, generally designated 12. The apparatus 10 is also shown associated with a conveyor assembly, generally designated 14, of a commercially available type that functions to deliver pallets, such as that generally designated 16, to a load and unload station which is the location of the pallet 16 shown in FIG. 1, and to remove the pallets 16 from the load and unload station. Although only one pallet 16 is shown in FIG. 1, it will be understood that there will normally be several pallets either queued up or moving along the conveyor assembly 14.
The pallets 16 each carry an unwound armature assembly, generally designated 18, to the load and unload station. The load and unload apparatus 10 delivers the unwound armatures to the winding machine 12. The load and unload apparatus also delivers wound armatures from the winding machine 12 back to the load and unload station. The wound armature assembly is then loaded onto an empty pallet 16 which is then removed from the load and unload station by the conveyor assembly 14.
With reference to FIGS. 1 and 5, the armature assembly 18 includes a coil-receiving core 20 and a commutator 22 mounted on an armature shaft 24. The representations of the armature assembly 18 in FIGS. 1 and 5 are somewhat simplified, the armature assembly 18 being merely representative of workpieces with which this invention may be used.
With reference again to FIG. 1, the armature winding machine 12 may be entirely conventional and forms no part of this invention. An example of such a machine is shown in U.S. Pat. No. 4,633,577, granted Jan. 6, 1987, to Alvin C. Banner. The parts of the winding machine 12 shown in FIG. 1 include an armature shaft-gripping collet 26 which grips an armature shaft 24 during at least portions of the operation of the winding machine 12. At the beginning of the operation of the winding machine 12, the shaft 24 of an armature 18 is moved toward the collet 26 along the axis, designated 28, of the collet 26 and the collet 26 is then actuated to grip the shaft 24. In operation, wires (not shown) guided by rotating fliers 30 and winding forms 32 are laid into coil receiving slots of the armature core 20 to form coils of wire therein.
With continued reference to FIG. 1 and also to FIG. 5, the illustrated pallet conveyor assembly 14 is representative of conveyor assemblies or other workpiece handling devices with which the load and unload apparatus 10 of this invention may be used. The particular conveyor assembly 14 may be assembled from components supplied by Robert Bosch GmbH of Stuttgart, Germany and is illustrated in a highly simplified form. It includes an incoming conveyor generally designated 34, an outgoing conveyor 36, and an intermediate conveyor 38. The incoming conveyor 34 includes a pair of mutually parallel, spaced, pallet conveying endless belts 40 that are looped around a pair of spaced shafts 42, one of which is rotatably driven by a motor (not shown) so that the upper courses of the belts 40 travel together at the same speed in the direction of the arrows 44 in FIG. 1. As shown in FIG. 5, the top courses of the belts 40 are supported for sliding movement from beneath by plates 43. With this arrangement, a pallet 16 may be loaded onto the upstream end of the conveyor 34 and carried by the belts 40 toward the downstream end of the conveyor 34.
The load and unload station is located along the course of a transversely-extending conveyor generally designated 46 located to one side of the incoming conveyor 34. A transfer elevator device 48 is provided for lifting a pallet 16 from the incoming conveyor 34 and transferring it onto the tranverse conveyor 46. The transverse conveyor 46 includes a pair of drive belts 50 driven by a reversible drive motor and gear assembly 52 for delivering a pallet to the load and unload station and return it from the load and unload station. In FIG. 5, it will be noted that the upper course of the transverse conveyor belts 50 is higher than the incoming conveyor belts 40. By raising the transfer elevator 48 above the incoming conveyor 34, as by an air actuator (not shown) to the level of the upper course of the transverse conveyor belts 50, a pallet 16 can be smoothly transferred to and from the transverse conveyor 46.
The return conveyor 36 is used to carry wound armatures to be unloaded. The intermediate conveyor has no purpose in the conveyor assembly shown. It may, however, be "extended" or else aligned with another conveyor or conveyors to carry armatures assemblies wound by the winding machine 12 to other processing machines for further handling. In more elaborate conveyor systems, it could also be used to carry unwound armatures to other winding machines. A second transfer elevator 54 is located in the intermediate conveyor 38 in line with the transverse conveyor 46 and the transfer elevator 48 for transferring wound armatures to the return conveyor 36. Both transfer elevators 48 and 54 may have reversible drive belts 56 for transferring the pallets 16 as needed.
With reference to FIGS. 1 and 5, each pallet 16 includes a base plate 60 and a mutually spaced pair of upstanding armature supports 62 and 63 having V-shaped notches for supporting the armature assembly 18 by its shaft 24. Each pallet 16 further includes an upstanding locating pin 64 positioned to be engaged by the end of the armature shaft 24 most remote from the commutator. The armature assembly 18 is so located on the pallet 16, either manually or by a suitable mechanism (not shown), that the armature shaft 24 engages the locating pin 64 and the commutator 22 engages the confronting face of the support 63. In consequence, the armature assembly 18 is accurately positioned on the pallet 16 when it arrives at the load and unload station. At this time, an elevator 66 operates to engage the pallet base plate 60 and raise the pallet 16 with the unwound armature 18 thereon above the transverse conveyor 46 to a position wherein it may be gripped by the load and unload apparatus 10 as will be described below.
With reference to FIGS. 1, 2, and 3, the load and unload apparatus 10 of this invention comprises an elongate main beam 70, mounted for movement along a horizontal path lying in a vertical plane parallel to vertical plane of the collet axis 28. For this purpose, a pair of linear bearing rails 72 affixed as by bolts (not shown) to the main beam 70 are slidably mounted in linear bearings 74 affixed to a main beam mounting plate 76 connected to a mounting base plate 78 by spacers 80. The base mounting plate 78 is bolted to a vertical stanchion 82 that is supported by a floor mounting plate 84 (FIG. 1). The main beam 70 is reciprocably driven along its horizontal path of movement by a drive motor 86 affixed to the support stanchion 82 having a drive gear 88 meshing with a rack gear 90 affixed to the bottom of the main beam 70. The main beam 70 is preferably substantially surrounded by a housing including a front plate 92, side plates 94, and a rear plate 96 (shown in cross section in FIG. 2). The front plate 92 and the rear plate 96 are affixed as by bolts to the main beam 70 so that they move therewith. (The relative terms "front" and "rear", and terms of similar import, are used arbitrarily herein as if the "front" of the load and unload apparatus 10 faces the pallet conveyor assembly 14 and its "rear" faces the armature winding machine 12.)
As shown best in FIGS. 2 and 3, the load and unload apparatus 10 further comprises a longitudinally movable staging assembly support carriage, generally designated 100, including a vertical carriage plate 102 connected by spacers 104 to a vertical carriage mounting plate 106 to which linear bearings 108 are connected that slide on linear bearing rails 110 affixed to the side of the main beam 70 most remote from the support stanchion 82 and opposite the side of the main beam 70 to which the first mentioned linear bearings 72 are connected.
The carriage mounting plate 106 is connected by a clamp assembly, generally designated 112, to a timing belt 114 that encircles the main beam 70 and extends around pulleys 116 mounted for rotation about vertical axes at each end of the main beam 70. The clamp assembly 112 includes a clamp base plate 118 facing a clamp top plate 120 having teeth 122 that mesh with the teeth of the timing belt 114. The timing belt 114 is also clamped by a similar clamp assembly 124 affixed to the main beam mounting plate 76. The connection of the timing belt 114 to the staging assembly support carriage 100 and also to the main beam mounting plate 76 produces a motion doubler; the staging assembly support carriage 100 moves along a horizontal path parallel to the path of movement of the main beam 70, but moves twice as far and twice as fast as the main beam 70. Accordingly, a relatively short movement of the relatively massive main beam 70 produces a relatively long movement of the carriage 100.
The staging assembly support carriage 100 further includes a horizontal carriage plate 126 and a pair of gusset plates 128 welded to the vertical carriage plate 102. An armature staging assembly, generally designated 130, is mounted for sliding movement in a horizontal path that is perpendicular to the path of movement of the staging assembly support carriage 100 and to the vertical plane of the pallet axis 28. To this end, the staging assembly 130 comprises a horizontal, transversely movable gripper assembly support carriage plate 132 suspended from the horizontal carriage plate 126 by a bearing assembly including a pair of linear bearing rails 134 affixed to the bottom of the horizontal carriage plate 126 and a pair of linear bearings 136 affixed to the top of the horizontal gripper assembly support carriage plate 132.
Referring to FIG. 3, the staging assembly 130 is reciprocably driven along its tranverse, horizontal path by means of an air actuator 138 mounted on top of the horizontal carriage plate 126 by a threaded support bracket 140 and having a piston rod 142 connected by a vertical drive link 144 to the gripper assembly support carriage plate 132. The air actuator 138 may move the staging assembly 130 to the right as shown in FIG. 3 toward the main beam 70 until a stop plate 146 carried thereby engages an adjustable stop 148 on the horizontal carriage plate 126. The stop 148 is adjusted to accurately locate the right-most position (as viewed in FIG. 3) of the staging assembly 130 for reasons which will become apparent. The left-most position of the staging assembly 130, which is the position shown in FIG. 3, is adjustably fixed by a threaded connection (not shown) between the air actuator 138 and its mounting bracket 140.
Referring to FIGS. 1, 2, and 3, the staging assembly 130 further comprises a pair of side-by-side armature shaft-gripping assemblies, generally designated 150 and 152, respectively. The gripping assembly 150 comprises a gripper carriage 154 mounted for sliding movement in a horizontal path parallel to the path of movement of the main beam 70 and the vertical plane of the collet axis 28 by a linear bearing rail 156 and a linear bearing 158 mounted, respectively, on the underside of the gripper assembly support carriage plate 132 and the top surface of the gripper carriage 154. As best shown in FIGS. 2 and 4, the gripper carriage 154 is generally in the form of an inverted U-shaped body having a depending rear leg 160 with a rearwardly projecting gripper jaw-support piece 162 on which a relatively fixed gripper jaw 164 and a relatively movable or pivotal gripper jaw 166 are mounted. The gripper jaws 164 and 166 have mutually confronting shaft-gripping surfaces 164A and 166A, respectively (FIGS. 3 and 4) constructed to grip the end of an armature shaft 24 therebetween. For this purpose, the movable gripper jaw 166 is mounted for pivotal movement about a pivot pin 170 and has a notch 172 in which a clevis-mounted roller element 174 at the end of the piston rod 176 of an air-operated gripper actuator 178 is received. As apparent, short reciprocal movements of the roller element 174 cause the movable jaw 166 to be pivoted about the pivot pin 170 so that its shaft-gripping surface 166A moves into and out of an armature shaft-gripping relation with respect to the fixed jaw 164. The piston of the gripper actuator 178 is double-ended so that its piston rod 176 extends both forwardly and rearwardly therefrom. The forward end of the piston rod is surrounded by a coil spring that biases the rod 176 such that the movable gripper jaw 166 will be in a shaft-gripping position in the event the air supply to the gripper actuator 178 is interrupted. The gripper assembly 152 has the same construction and mounting as the gripper assembly 150 and like numbers are used to refer to like parts thereof.
Referring to FIG. 3, the shaft-gripping surfaces 164A of the fixed jaw 164 comprise a horizontal top surface and an adjacent vertical surface forming therewith a fixed V-groove that faces downwardly along an axis extending at an angle of 45° with respect to vertical and the gripper jaw pivot pin 170 extends at an angle of 45° with respect to vertical and perpendicular to the axis along which the fixed jaw 164 faces. Furthermore, the area below the fixed gripper jaw 164 is open. Accordingly, when the movable shaft-gripping surfaces 166A pivot away from the fixed jaw 164, an armature shaft 24 may be elevated along a vertical path into engagement with the clamping surfaces 164A of the fixed jaw 164. In addition, it will be noted in FIG. 4 that there is an open pocket 167 forwardly of the fixed gripper jaw 64 that may receive the shaft locating pin 64 on the pallet 16 when, as will be described below, the pallet 16 is raised to deliver an unwound armature assembly to the shaft-gripping assembly 150. Accordingly, it is seen that, by virtue of the construction of the gripper assemblies 150 and 152, they can be used to grip armature shafts that are moved vertically up or down without additional motions of the gripper assemblies or of the shafts that otherwise would be necessary to avoid interference with parts of a pallet or an armature assembly when an armature shaft is either gripped or released.
The gripper assemblies 150 and 152 may be moved relative to the gripper assembly support carriage plate 132 by operation of gripper-extending air actuators 182 and 184, respectively, having piston rods 186 and 188, respectively, that are used to advance the gripping assemblies 150 and 152 toward the winding machine collet 26, respectively, to deliver an unwound armature thereto and to remove a wound armature therefrom, as will be further described below. With reference to FIG. 2, the piston rod 186 is shown threadedly connected to a sleeve 187 slidably received within a bore in the front leg of the gripper carriage 154 and a coil spring 189 is coiled about the piston rod 186 and abuts a nut 186A thereon. This arrangement enables a limited resilient lost motion of the gripper assembly 150 as it advances an armature toward the collet 26 to avoid damage that might otherwise occur to the armature assembly or to the collet 26 if the gripper assembly drive were completely rigid.
The representation of the load and unload apparatus 10 is somewhat simplified. Those familiar with the art will recognize that electrical, such as limit switches or proximity control devices, will be provided as needed to control the movements of the various parts of the apparatus. The electrical connections for the several air actuators and for proximity sensors and the like are located within an electical box 190 mounted on the carriage 100. Electrical and pneumatic lines may be held by a flexible cable tray 192, as well known to those familiar with the art. Suitable safety stops may also be provided. One such stop is shown by block 194 in FIGS. 1 and 2 which is used to prevent accidental overtravel of the carriage 100.
In operation of the load and unload device 10, the left gripper assembly 150 (as shown in FIG. 1) holds only unwound armature assemblies and the right gripper assembly 152 holds only wound armature assemblies. The location of a pallet 16 at the load and unload station on the transverse conveyor 46 is such that an unwound armature assembly 18 is held with the axis of its shaft lying in the same vertical plane as the plane containing the collet axis 28. In operation, the armature staging assembly 130 is located at its right-most position (as viewed in FIG. 3), closest to the main beam 70, when the main beam 70 is retracted away from the winding machine 12 to a position wherein the staging assembly 130 can grip an unwound armature assembly. When the main beam 70 is thus retracted, the elevator 66 engages and lifts a pallet 16 to a position wherein the shaft of the unwound armature assembly 18 carried thereby engages the shaft-clamping surfaces 164A of the fixed jaw 164. The associated movable gripper jaw 166 is moved into its shaft-gripping position by operation of the actuator 178 of the gripper assembly 150. The elevator 66 is then lowered, leaving the unwound armature assembly in the jaws of the gripper assembly 150 so that the pallet 16 is empty. The staging assembly 130 is then transversely shifted to its left-most position by the air actuator 138 and the elevator 66 is raised again, this time to position the empty pallet 16 with its armature supports 62 and 63 engaging the shaft of the newly wound armature. The gripper assembly 152 is then actuated to release the wound armature onto the elevated pallet 16. As soon as this task is accomplished, the elevator is again lowered to return the pallet to the transverse conveyor 46 whereupon the pallet conveyor system takes over to remove the pallet 16 with the freshly wound armature thereon from the transverse conveyor 46. Shorty thereafter, the pallet conveyor delivers another pallet carrying an unwound armature to the load and unload station.
As the pallet 16 is being lowered, the main beam 70 is extended, by operation of the beam drive motor 86, toward the armature winding machine 12 with the empty gripper assembly 152 aligned with the collet axis 28. The gripper assembly 152 is thereby moved quite close to the winding area of the winding machine 12 and the parts of the load and unload apparatus pause, awaiting the completion of the winding of an armature.
When the winding is completed, the wound armature gripping assembly 152 is advanced by operation of its gripper-extending actuator 184 into a position wherein its fixed gripping jaw engages along the top of the shaft of the newly wound armature assembly. Its movable jaw is then actuated into engagement with the same shaft, the grip of the armature shaft by the winding machine collet 26 released, and the gripping assembly retracted by reverse operation of its gripper-extending actuator 184 so that it removes the newly wound armature from the winding machine 12. The staging assembly 130 is then transversely moved by the air actuator 138 to position the gripper assembly 150 with the unwound armature carried thereby aligned with the collet axis 28, the latter gripper assembly 150 is then extended to insert the unwound armature assembly in the winding machine, its shaft being gripped by the collet 26. The gripper assembly 150 releases its grip on the unwound armature and is retracted from the winding machine. Simultaneously or sequentially, the main beam 70 is retracted from the winding machine whereupon the unwound armature gripping assembly 150 is again positioned over the pallet at the load and unload station in readiness to receive another unwound armature assembly. The foregoing process may then be repeated indefinitely for the continuous production of wound armature assemblies.
Because the staging assembly 130, holding an unwound armature, is closely adjacent the armature winding machine 12 while the winding of another armature is in progress, minimal time is needed to remove the newly wound armature and replace it with the unwound armature.
By employing a relatively massive main beam 70 and the motion multipying arrangement between the main beam 70 and the carriage 100, not only is there substantial available room around the winding machine 12 but also the accuracy of the location of the staging assembly 130 relative to the collet axis is assured. Those familiar with the art will recognize that the relative positions of the load and unload apparatus 10 and the winding machine 12 must be accurately preset upon installation of the machines. This may be done in conventional ways, such as by the use of a tie plate (not shown).
The main beam drive motor 86 is preferably a programmable servo motor so that it can readily be converted for use with armatures having different shaft lengths. A simpler-machine could use a different drive motor. For example, a relatively inexpensive air-operated actuator, although not readily programmable, could be used to drive the main beam.
While the invention has been described with reference to the winding of armature assemblies, it will be apparent that, in its broader aspects, the invention may be used in other manufacturing processes.
Although the presently preferred embodiment of this invention has been described, it will be understood that within the purview of the invention various changes may be made within the scope of the following claims. | A method and an apparatus for successively loading workpieces, such as unwound armature assemblies, along a predetermined axis into a workpiece processing machine using an elongate main beam and a staging assembly with workpiece grippers connected to the main beam by a motion multiplier. |
RELATED CASES
This is a continuation-in-part of application Ser. No. 08/850,378 filed May 2, 1997 now U.S. Pat. No. 5,947,368.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates generally to folding paperboard cartons and, more particularly, to a carton blank used for assembling a carton having an enhanced appearance and novel reclosure means.
2. Brief Description of the Prior Art
Folding cartons are well known in the packaging art. These cartons are constructed from flat blanks which are pre-cut and pre-scored on paperboard sheets. Carton blanks have five main panels which are adapted to form the cover, top, rear, bottom and front of an assembled carton. Each panel has a pair of end flaps which are hingedly connected by score lines formed in the paperboard.
Carton blanks are typically produced on large paperboard sheets in a multiple configuration. Individual blanks are internally “nested” on three sides to minimize the amount of excess or wasted paperboard. During the blanking operation, score lines are provided to facilitate a pre-selected flap-folding sequence. Perforations are also die-cut in the paperboard to form art-recognized tear-away and breakaway features. Score lines and perforations are created by die-stamping and die-cutting the paperboard blanks in a single, downward direction.
The carton blanks are folded over and secured with known adhesives to form carton sleeves which are typically used for packaging semi-solid consumables. During the form-filling operation, packaging machinery is used to form, fill and seal fully assembled cartons according to the prescribed folding sequence and adhesive pattern.
Numerous carton designs for packaging ice cream and the like are available. For example, commercial products of the type described in U.S. Pat. Nos. 4,679,694, 4,712,689, 4,712,730, 4,749,086, 4,756,470, 4,757,902, 4,819,864, 4,826,074, 4,838,432, 4,872,609, 5,033,622, 5,160,082 and Re. 33,204 (incorporated by reference herein) are manufactured and sold by Fold-Pak Corporation, Newark, N.Y. under the HI TECH® trade designation.
Additional carton designs are presented in U.S. Pat. Nos. 5,288,012, 5,351,881, 5,409,160, 5,411,204, 5,474,231, 5,484,102 and 5,588,584 (all incorporated herein by reference) which describe state-of-the-art blanks used to assemble a rectangular, top opening carton. Containers of the type-described in these patents are manufactured and sold under license from Fold-Pak Corporation.
To construct such a carton, first and second ends are closed by folding the bottom panel end flaps first, front panel end flaps second, top panel end flaps third and rear panel end flaps fourth and last. Prior to folding in the fourth down flap, single lines of adhesive are deposited on the previously folded end flaps. All four end flaps are secured by single glue lines to form a smooth, continuous wall at first and second ends of the carton.
In the form-filling operation, end flaps disposed adjacent a first end are folded in and adhesively secured to form one end of a carton. A filler head is aligned with the second, open end to dispense ice cream or the like, in a semi-solid state, into the partially constructed carton. Once filled, the end flaps of the open end are closed and adhesively secured to form a sealed carton.
To facilitate opening of a sealed carton and subsequent reclosure, a horizontal tear-away strip is die-stamped on the cover panel and breakaway corner tabs are similarly cut on rear panel end flaps during the blanking operation. When the cover panel is glued to the front panel to form a carton sleeve, care is taken to avoid adhesion of the tear-away strip so that it is readily removed by a consumer. During form-filling, care is taken to ensure adhesion of the breakaway corner tabs to corresponding top panel end flaps.
A consumer opens a sealed carton by removing the tear-away strip from the cover panel along pre-cut perforations. The carton seal is broken as the lid (comprised of the top and cover panels) is lifted away from the remainder of the carton, and the breakaway corner tabs (adhered to top panel end flaps) are separated from their respective rear panel end flaps.
Problems are sometimes encountered because the lid does not provide secure reclosure after the initial opening. With extended freezer storage a gap may develop between the body of the carton and the lid. This gap may lead to “freezer burn” or loss of freshness for a stored food product. In addition, the detached tear-away strip leaves behind two rows of unsightly “sawtooth” edges which do not aid reclosure or contribute aesthetic appeal.
Form failure problems can also arise if a partially filled carton collapses because of structural instability. It has been discovered that structural instability is partially caused by attaching the edge of the cover panel to the front panel so that the tear-away strip can be easily removed. And, the frequency of form failure depends on where the tear-away strip is positioned relative to the front panel.
The rectangular, top-opening cartons described above are cheaper to produce than bucket or pail-type ice cream barrels. As a result, bucket-type barrels are used to package “premium” or “upscale” products which can absorb the added costs. An advantage of the present invention is a hinged lid with the “look” of more expensive circular lids for bucket-type barrels.
This disclosure presents a paperboard blank configured to produce a carton which entirely eliminates the form failure attributed to tear-away strips. It also describes a unique reclosure means for easy handling during end use application of a carton.
OBJECTS OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a carton for packaging semi-solid consumables such as ice cream and the like.
Another object of the present invention is to provide a plurality of interlocking reclosure means for easy opening, improved reclosure, reseal and durable storage of a paperboard carton.
Yet another object of the present invention is to provide a plurality of reclosure means constructed entirely from paperboard which is die-cut during the blanking operation.
A further object of the present invention is to provide a blank with unique top panel and rear panel end flaps which cooperate to avoid paperboard buildup in the end walls and facilitate form-filling into a carton.
Yet another object of the present invention is to provide a rectangular, top opening carton having a hinged lid with an up-scale appearance and the “look” of a separate, premium lid.
A still further object is to provide a rectangular, top opening carton having a hinged lid with an up-scale appearance and the “look” of a separate, premium lid with the added benefit of reinforced corner posts.
Other objects of the present invention will be apparent to those skilled in the relevant art.
SUMMARY OF THE INVENTION
One aspect of the present invention is a foldable blank for assembling a carton. The blank comprises an in-folding flap hingedly connected to a cover panel which is, in turn, hingedly connected to left and right cover panel end flaps. Left and right cover panel end flaps are also referred to as left and right posts, respectively.
The left and right junctures further connect the in-folding flap to the left and right cover panel end flaps, respectively. The left juncture is adapted for folding over onto the left cover panel end flap and the right juncture is adapted for folding over onto the right cover panel end flap, when the blank is assembled to form the inventive carton.
The left juncture has a first edge, the left cover panel end flap has a second edge, the right juncture has a third edge and the right cover panel end flap has a fourth edge. The first edge is adapted to align with the second edge, and the third edge is adapted to align with the fourth edge, when the blank is assembled to form the carton.
The left and right junctures each have a paperboard thickness of one unit, and the left and right cover panel end flaps each has a paperboard thickness of one unit. Each juncture and its corresponding cover panel are adapted to form a thickness of two units when the blank is assembled to form the carton.
The blank described above is also formed into the carton via an intermediate sleeve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows blank A of the first embodiment featuring a locking edge, flange lip and elliptical sealing surfaces in their original condition.
FIG. 2 is a top perspective view of sleeve A′.
FIG. 3 is a fragmentary perspective view of one, open end of partially assembled carton A″ ready for a form-filling operation.
FIG. 4 is a top perspective view of fully constructed and. sealed carton A″ with cooperating top panel and rear panel end flaps.
FIG. 5 illustrates carton A″ with a flange lip and sealing surfaces in their sheared condition.
FIG. 6 displays carton A″ with lid components described as top panel, cover panel and posts.
FIG. 7 shows carton A″ with a flange lip and sealing surfaces in their sheared condition.
FIG. 8 is a fragmented, side elevational view emphasizing the relationship between the top panel and rear panel end flaps.
FIG. 9 is a cross-sectional view taken along line 9 — 9 in FIG. 8 showing the front panel end flap disposed between the bottom panel and rear panel end flaps.
FIG. 10 is a fragmented view of carton A″ with its cover panel adhered to its front panel. This figure emphasizes the spatial relationship between an illustrative, elliptical sealing surface and a flange lip which are both shown in phantom lines.
FIG. 11 is a cross-sectional view taken along line 11 — 11 in FIG. 10 showing the flange lip engaged to the locking edge to be described below.
FIG. 12 shows blank B of the second embodiment featuring a releasable lock tab and its corresponding anchoring area.
FIG. 13 is a top perspective view of sleeve B′.
FIG. 14 is a fragmentary perspective view of one, open end of partially assembled carton B″ ready for a form-filling operation.
FIG. 15 is a top perspective view of carton B″.
FIG. 16 illustrates carton B″ shown in FIG. 15, with its seal broken and lid opened to reveal the releasable lock tab adhered to the front panel.
FIG. 17 shows carton B″ featuring the lock tab released from its perforated border and adhered to the front panel.
FIG. 18 is a fragmented front view showing the releasable lock tab anchored to the front panel.
FIG. 19 is a cross-sectional view taken along line 19 — 19 in FIG. 18 showing the spatial orientation of the lock tab with reference to the cover panel and front panel.
FIG. 20 shows blank C of the third embodiment featuring a male tab and its corresponding locking edge.
FIG. 21 shows carton C″ with its seal broken and lid opened to display the male tab of the third embodiment as well as sheared sealing surfaces disposed on the front panel.
FIG. 22 shows carton C″ with its seal broken and lid opened to display the male tab of the third embodiment as well as sheared sealing surfaces disposed on the front panel and underlying outer surface of the in-folding flap.
FIG. 23 is a front fragmented view showing the male tab engaged to the locking edge which are both shown in phantom lines.
FIG. 24 is a cross-sectional view taken along line 24 — 24 in FIG. 23 showing the male tab engaged to the locking edge.
FIG. 25 shows blank D of the fourth embodiment featuring a plurality of releasable lock tabs and their corresponding anchoring area.
FIG. 26 shows carton D″ featuring the lock tabs released from their perforated borders and adhered to the front panel.
FIG. 27 is a fragmented front view showing a releasable lock tab of the fourth embodiment adhered to the front panel.
FIG. 28 is a cross-sectional view taken along line 28 — 28 in FIG. 27 showing the spatial orientation of a lock tab of the fourth embodiment with reference to the cover panel and front panel.
FIG. 29 shows blank E of the fifth embodiment featuring a plurality of male tabs and their corresponding locking edge.
FIG. 30 illustrates carton E″ with its seal broken and lid opened to display the male tabs of the fifth embodiment as well as sheared sealing surfaces disposed on the front panel.
FIG. 31 illustrates carton E″ with its seal broken and lid opened to display the male tabs of the fifth embodiment as well as sheared sealing surfaces disposed on the front panel and underlying outer surface of the in-folding flap.
FIG. 32 shows blank F of the sixth embodiment featuring a die-cut appendage-formed in the score line disposed between the cover panel and in-folding flap. The male tabs and locking edge of the fifth embodiment are also shown.
FIG. 33 illustrates carton F″ with its seal broken and lid opened to display the die-cut appendage as well as the male tabs of the fifth embodiment.
FIG. 34 illustrates carton F″ with its seal broken and lid opened to display the die-cut appendage as well as a sheared sealing surface disposed on the underlying outer surface of the in-folding flap.
FIG. 35 shows blank G of the seventh embodiment featuring junctures which connect the in-folding flap with cover panel end flaps, and which are adapted to be folded into reinforced corner posts.
FIG. 36 is a top perspective view of sleeve G′.
FIG. 37 is a fragmentary perspective view of one, open end of partially assembled carton G″ ready for a form-filling operation.
FIG. 38 is a top perspective view of fully constructed and sealed carton G″ with cooperating top panel and rear panel end flaps.
FIG. 39 illustrates carton G″ with its lid open.
FIG. 40 shows the interior of the lid to carton G″.
FIG. 41 is a fragmented, side elevational view emphasizing the relationship between the in-folding flap, a juncture, the corresponding post and a top panel end flap.
FIG. 42 is a cross-sectional view taken along line 42 — 42 in FIG. 41 showing the cross-sectional relationship between a juncture, a post and a top panel end flap.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the first embodiment of the present invention will now be described. Carton blank A is comprised of five main panels, cover panel 20 , top panel 30 , rear panel 40 , bottom panel 50 and front panel 60 . Cover panel 20 is hingedly connected by score lines 21 and 29 to cover panel end flaps 22 and 23 , respectively. Cover panel 20 is also hingedly connected by score line 25 to in-folding flap 24 . In-folding flap 24 terminates at locking edge 26 .
The plan view surface of blank A shown in FIG. 1 is the outer print side which typically displays colorful graphics identifying the contents of a filled carton. The opposite side (not shown) is the inner unfinished side which constitutes the lining of a form-filled carton. As used herein, the term “in-folding” refers to flap 24 which folds at score line 25 so that the unfinished side of in-folding flap 24 meets the unfinished side of cover panel 20 for adhesive attachment.
Top panel 30 is hingedly connected by score lines 31 and 39 to top panel end flaps 32 and 33 , respectively. Top panel end flaps 32 and 33 have smooth edges 34 and 35 . Disposed adjacent smooth edge 34 is relief notch 36 , and adjacent smooth edge 35 is relief notch 37 . Rear panel 40 is hingedly connected by score lines 41 and 49 to rear panel end flaps 42 and 43 . Rear panel end flaps 42 and 43 have smooth edge portions 44 and 45 .
Bottom panel 50 is shown hingedly connected by score lines 51 and 59 to respective bottom panel end flaps 52 and 53 . Front panel 60 is shown hingedly connected by score lines 61 and 69 to front panel end flaps 62 and 63 . Front panel 60 is connected to flange lip 66 by joint line 110 formed as a solid score or perforation. Front panel end flaps 62 and 63 are connected with respective joint lines 120 and 130 to lips 64 and 65 . Additionally, front panel 60 is shown with two die-cut sealing surfaces 67 and 68 .
FIG. 1 shows five main panels hingedly connected to each other by score lines 70 , 80 , 90 and 100 stamped into the paperboard. Each main panel is hingedly connected to end flaps 22 , 32 , 42 , 52 and 62 by score lines 21 , 31 , 41 , 51 and 61 , and end flaps 23 , 33 , 43 , 53 and 63 are hingedly connected to respective main panels by score lines 29 , 39 , 49 , 59 and 69 , similarly stamped into the paperboard. All score lines are formed by die-stamping the blanks in a single, downward direction using scoring rules. Score line 25 connecting in-folding flap 24 to cover panel 20 is also die-stamped in the same direction to allow in-folding of the unfinished inner surface of flap 24 so that it can be glued to the unfinished inner surface of cover panel 20 .
Carton blank A has a substantially uniform paperboard thickness. Perforations are formed by die-cutting in the same blanking operation which produces the die-stamped score lines. The perforations are cut through the entire thickness of the paperboard in a pattern having intervening spaces of preselected length, for example, one-eighth of an inch. Sealing surfaces 67 and 68 are also formed in the single blanking operation which produces the score lines and joint lines. But, the die-cuts defining sealing surfaces 67 and 68 have a depth which is approximately one-half the thickness of the paperboard blank.
FIG. 2 shows sleeve A′ which is formed by first folding the blank at score line 25 and gluing the unfinished inner surfaces (not shown) of in-folding flap 24 to the unfinished inner surface of cover panel 20 . The blank is next folded at score lines 80 and 100 and lip 66 (shown in FIG. 1) is folded so that its outer print surface joins the outer print surface of front panel 60 . Adhesive is then deposited on sealing surfaces 67 and 68 of front panel 60 and the underlying outer surface of in-folding flap 24 is glued to surfaces 67 and 68 to form sleeve A′.
FIG. 10 is a fragmented view of cover panel 20 adhered to front panel 60 . It shows the spatial relationship between sealing surface 68 (shown mostly in phantom lines with a portion displayed by partial cutaway view AA through cover panel 20 ) and lip 66 (shown with phantom lines).
FIG. 11 is a cross-sectional view taken along line 11 — 11 in FIG. 10 . This figure emphasizes the engagement of locking edge 26 to flange lip 66 . In-folding flap 24 is folded at score line 25 and the unfinished inner surface of in-folding flap 24 is shown glued to the unfinished inner surface of cover panel 20 . Lip 66 connected to front panel 60 is bent at joint line 110 so that the finished surface of lip 66 joins the outer print surface of front panel 60 . In this configuration, locking edge 26 on in-folding flap 24 substantially engages flange lip 66 connected to front panel 60 .
Referring back to FIG. 2, lips 64 and 65 are folded inward along joint lines 120 and 130 and tucked in between the top panel and bottom panel end flaps during a form-filling operation.
FIG. 3 shows an open end of a partially constructed carton ready for filling. After filling, the open end is closed by folding bottom panel end flap 52 first, then front panel end flap 62 second with lip 64 bent inward along joint line 120 and over bottom panel end flap 52 . Top panel end flap 32 is folded third so that lip 64 is tucked in between bottom panel end flap 52 and top panel 30 . A single line of adhesive is deposited on the folded end flaps, then rear panel end flap 42 is folded down fourth and last to form a smooth, continuous end wall.
FIG. 4 shows a fully sealed carton A″. Relief notch 37 is shown engaged to rear panel end flap 43 . Smooth edge 45 in combination with relief notch 37 against rear panel end flap 43 provides a flat, co-planar end wall with no paperboard build-up or protrusions.
FIG. 5 illustrates the carton shown in FIG. 4 . The seal is broken and lid 10 is open. To break the seal of carton A″, a consumer inserts a digit under cover panel 20 and lifts it away from front panel 60 . According to the first embodiment, this action shears approximately half a layer of paperboard along the die-cuts defining sealing surfaces 67 and 68 , leaving behind sheared sealing surfaces 67 A and 68 A having depths which are approximately half the thickness of the paperboard stock.
The illustrative shape of the ellipse provides for easy opening. The tapered ends are sheared away easily with shear gradually increasing as the wider mid-point of the ellipse is approached.
FIG. 7 shows sheared sealing surfaces 67 B and 68 B that are formed during opening. In this example, sheared sealing surfaces 67 B and 68 B are formed from a half layer thickness of paperboard substrate, but one skilled in the art could readily adapt alternative depths to this embodiment of the present invention.
Lid 10 is shown in FIG. 6 . It is comprised of cover panel 20 with posts 22 and 23 , as well as top panel 30 with end flaps 32 and 33 and their smooth edges 34 and 35 . FIG. 7 shows that lid 10 is twice the thickness of the paperboard where cover panel 20 is glued to the unfinished inner surface of in-folding flap 24 . As shown in FIGS. 6 and 7, lid 10 has the “look” of more expensive circular lids for bucket-type barrels. Aesthetic appeal is created by hinged lid 10 which looks like a separate structure with smooth edges 34 and 35 accentuating the spatial separation from the ends of carton A″.
FIG. 6 also shows the relationship between smooth edge 35 and smooth edge portion 45 at one end of open carton A″. FIG. 8 is a fragmented side view showing the relationship between smooth edge 34 and smooth edge portion 44 at the opposite end, of the opened carton. FIG. 9 is a cross-sectional view taken along line 9 — 9 in FIG. 8 . It shows front panel end flap 62 disposed between bottom panel end flap 52 and rear panel end flap 42 . Lip 64 is shown folded along joint line 120 and over bottom panel end flap 52 . Top panel 30 is adapted to be lowered so that top panel end flap 32 fits into the pocket between the front panel end flap 62 and rear panel end flap 42 when lid 10 is reclosed.
FIG. 7 shows flange lip 66 connected to front panel 60 by means of joint line 110 . Locking edge 26 on in-folding flap 24 is also displayed. As will be appreciated by skilled artisans, flange lip 66 retains its paperboard “memory” from initial manufacture until the seal of the carton is broken. This paperboard memory allows flange lip 66 to provide bias against the underlying outer surface of in-folding flap 24 and to lock against edge 26 on in-folding flap 24 .
FIG. 10 shows a fragmented view of locking edge 26 engaged to flange lip 66 in phantom lines beneath cover panel 20 . FIG. 11 shows the cross-sectional view of locking edge 26 on in-folding flap 24 substantially engaged to flange lip 66 which is connected to front panel 60 . The combination of the bias provided by flange lip 66 against the underlying outer surface of in-folding flap 24 and the flange-type locking arrangement between locking edge 26 and flange lip 66 provide one embodiment of the reclosure mechanism of the present invention.
The second embodiment of this invention will now be described in connection with FIGS. 12-19. Blank embodiment B shown in FIG. 12 comprises cover panel 20 , top panel 30 , rear panel 40 , bottom panel 50 and front panel 60 . Cover panel 20 is hingedly connected by score line 25 to in-folding flap 24 . On the edge of in-folding flap 24 is releasable lock tab 200 which is formed by perforated border 201 . FIG. 12 shows the outer print surface of blank B. Artwork displayed on this outer surface is ordinarily printed with acrylic pigments. Anchoring area 220 is patterned out of the artwork so that releasable lock tab 200 can be adhesively secured without interference from acrylic pigments.
In connection with blank embodiment B, rear panel end flaps 42 and 43 include breakaway tabs 202 and 203 which are formed in the flaps by perforation lines 204 and 205 . Lip 266 is connected to front panel 60 by joint line 210 , while front panel end flaps 62 and 63 are connected to lips 64 and 65 by joint lines 120 and 130 .
In-folding flap 24 is bent at score line 25 and the unfinished inner surface of flap 24 is glued to the unfinished inner surface of cover panel 20 , with care being taken to avoid adhesive on the unfinished inside surface of releasable lock tab 200 . Sleeve B′, shown in FIG. 13, is next formed by folding blank B at score lines 80 and 100 and placing adhesive substantially on the outside surface of lock tab 200 with care being taken to avoid adhesive on the remainder of the outer surface of flap 24 , so that only releasable lock tab 200 is glued to the outer print side of front panel 60 .
FIG. 18 is a fragmented view showing releasable lock tab 200 (shown in phantom lines) adhered to front panel 60 . FIG. 19 is a cross-sectional view taken along line 19 — 19 in FIG. 18 . FIG. 19 shows releasable lock tab 200 situated between cover panel 20 and front panel 60 in assembled carton B″. The inside surface of releasable lock tab 200 is free of adhesive and rests on the surface of cover panel 20 , while the outside surface of releasable lock tab 200 is glued to the surface of front panel 60 .
Referring back to FIG. 12, lips 64 , 65 and 266 are folded inward along joint lines 120 , 210 and 130 during the form-filling operation. Lips 64 and 65 are then tucked in between the top panel and bottom panel end flaps, and lip 266 is tucked in between the top and front panels. For example, FIG. 14 shows one open end of partially formed carton B″ ready for filling. The open end is closed by folding bottom panel end flap 52 first, then bending lip 64 inward along joint line 120 and next folding front panel end flap 62 over bottom panel end flap 52 while tucking lip 64 under top panel 30 . Top panel end flap 32 is folded next and adhesive is deposited on the folded flaps. Rear panel end flap 42 is folded down last so that breakaway tab 202 is adhered to top panel end flap 32 .
FIG. 15 shows carton B″ with a fully sealed end wherein breakaway tab 203 of rear panel end flap 43 is shown adhered to top panel end flap 33 . To open carton B″, a consumer inserts two digits under cover panel 20 on either side of releasable lock tab 200 and lifts away lid 10 . FIG. 16 shows carton B″ with its seal broken and lid 10 in the open position. In this condition, releasable lock tab 200 is detached from in-folding flap 24 and adhered to front panel 60 .
FIG. 17 shows open lid 10 with perforated border 201 on in-folding flap 24 from which releasable lock tab 200 was detached as the seal of carton B″ was broken. On carton B″, perforated border 201 and tab 200 comprise interlocking means. When lid 10 is lowered for resealing, releasable lock tab 200 (now adhered to front panel 60 ) fits tightly into perforated border 201 which acts as a locking edge.
The third embodiment of this invention will now be described in connection with FIGS. 20-24. FIG. 20 shows blank embodiment C which has flange lip 366 connected to front panel 60 by joint line 310 . Joint line 310 is shown as a die-cut perforation having a pattern which includes at least one male tab 315 . The perforated pattern is cut through the entire thickness of paperboard with intervening areas of pre-selected lengths including, for example, uncut areas on either side of tab 315 . Alternatively, the depth of the die-cut forming male tab 315 can be less than the entire paperboard thickness, preferably, between about one quarter to about three-quarter deep. One skilled in the art will also appreciate that joint line 310 can be formed as a solid score having within it a die-cut male tab of varying depth.
FIG. 20 also shows in-folding flap 24 of blank C terminating at locking edge 226 and front panel 60 having two die-cut sealing surfaces 367 and 368 on its outer print surface. Sealing surfaces 367 and 368 have a depth which is approximately half the thickness of paperboard blank C.
Blank C is folded, filled and assembled into carton C″ in the same manner described for blank B and corresponding carton B″—except for the alignment of tab 315 with locking edge 226 and the gluing of sealing surfaces 367 and 368 during sleeve formation. In-folding flap 24 of blank C is bent at score line 25 and the unfinished inner surface of in-folding flap 24 is glued to the unfinished inner surface of cover panel 20 . Intermediate sleeve C′ is next formed by folding blank C at score lines 80 and 100 and placing adhesive on sealing surfaces 367 and 368 while avoiding adhesive deposits on the remainder of the outer surface of front panel 60 , so that only sealing surfaces 367 and 368 are glued to the underlying outer surface of in-folding flap 24 .
FIG. 23 is a fragmented view showing cover panel 20 adhered to front panel 60 on carton C″. It shows the spatial relationship between sealing surface 368 (shown partially in phantom lines with a portion displayed by cut-away view CC through cover panel 20 ) and male tab 315 (shown with phantom lines). FIG. 24 is a cross-sectional view taken along line 24 — 24 in FIG. 23 . It emphasizes the engagement of male tab 315 to locking edge 226 .
FIG. 21 shows carton C″ with its seal broken and lid 10 open. Lip 366 is connected to front panel 60 by bent, joint line 310 . Male tab 315 is perpendicular to the plane of front panel 60 and positioned to function as a locking tab when lid 10 is lowered for resealing. To break the seal of carton C″, the end-user inserts a digit under cover panel 20 and lifts it away from front panel 60 . As previously explained, this action shears away half a layer of paperboard along die-cuts forming sealing surfaces 367 and 368 , leaving behind sheared sealing surfaces 367 A and 368 A which are half the thickness of the paperboard stock. FIG. 22 shows sheared sealing surfaces 367 B and 368 B now adhered to in-folding flap 24 . By way of illustration, they are formed from the other half thickness of paperboard.
FIG. 24 shows a cross-sectional view of locking edge 226 engaged to male tab 315 under top panel 30 . The space between locking edge 226 and top panel 30 provides a slot which is occupied by male tab 315 in the locked position. The bias provided by tab 315 against locking edge 226 as lid 10 is opened and closed provides yet another embodiment of the locking/reseal mechanism of the present invention.
It is not necessary to center male tab 315 along joint line 310 . Nor is this embodiment limited to a single male tab. Similar benefits can be achieved using a plurality of male tabs which engage locking edge 226 at pre-selected locations.
The fourth embodiment of this invention will now be described in connection with FIGS. 25-28. Blank embodiment D shown in FIG. 25 is similar to embodiment B illustrated by FIG. 12, with the exception of having two releasable lock tabs 300 and 400 on the edge of in-folding flap 24 . Releasable lock tabs 300 and 400 are formed by perforated borders 301 and 401 , respectively. In-folding flap 24 is bent at score line 25 and the unfinished inner surface of in-folding flap 24 is glued to the unfinished inner surface of cover panel 20 , with care being taken to avoid adhesive deposits on the unfinished inner surfaces of releasable lock tabs 300 and 400 .
A sleeve is next formed by folding blank D at score lines 80 and 100 and placing adhesive on the outside surfaces of releasable lock tabs 300 and 400 while avoiding adhesive on the remainder of the underlying outer surface of in-folding flap 24 , so that only releasable lock tabs 300 and 400 are glued to the outer print surface.of front panel 60 .
FIG. 27 is a fragmented view showing releasable lock tab 300 (in phantom lines) adhered to front panel 60 . FIG. 28 is a cross-sectional view taken along line 28 — 28 in FIG. 27 . FIG. 28 shows releasable lock tab 300 situated between cover panel 20 and front panel 60 in an assembled carton. The inside surface of releasable lock tab 300 is free of glue and rests on the surface of cover panel 20 , while the outside surface of releasable lock tab 300 is secured to the surface of front panel 60 .
To open carton D″, a consumer inserts a digit under cover panel 20 on either side of releasable lock tabs 300 and/or 400 . Lid 10 is then lifted away from the receptacle portion or body of the carton. FIG. 22 shows carton D″ with its seal broken, lid 10 in the open position with releasable lock tabs 300 and 400 detached from in-folding flap 24 and now adhered to front panel 60 . Open lid 10 has perforated borders 301 and 401 on in-folding flap 24 from which releasable lock tabs 300 and 400 were detached as the seal of carton D″ was broken. With respect to carton D″, perforated borders 301 and 401 , in conjunction with releasable lock tabs 300 and 400 , comprise the interlocking means. When lid 10 is lowered for resealing, releasable lock tabs 300 and 400 cooperate with perforated borders 301 and 401 to effect a seal.
The fifth embodiment of this invention will now be described in connection with FIGS. 29-31. Blank embodiment E shown in FIG. 29 is similar to embodiment C illustrated by FIG. 20, except for the plurality of male tabs 415 and 515 . FIG. 29 shows blank embodiment E with flange lip 466 connected to front panel 60 by joint line 410 . Line 410 is shown as a die-cut perforation having a pattern which includes at least one male tab.
In FIG. 29, joint line 410 is cut through the entire thickness of paperboard with intervening areas of pre-selected length (for example, one-eighth of an inch) between cuts. Male tabs 415 and 515 can be formed by die-cuts through the paperboard or by shallow incisions ranging from about one-quarter to about three-quarters of the paperboard thickness.
FIG. 29 also shows in-folding flap 24 of blank E terminating at locking edge 226 . Front panel 60 is shown having two die-cut sealing surfaces 367 and 368 on its outer print surface. Sealing surfaces 367 and 368 have depths which are approximately half the thickness of paperboard blank E. The folding sequence of blank E is identical to that of blank C—except for the alignment of male tabs 415 and 515 with locking edge 226 .
FIG. 30 shows carton E″ with its seal broken and lid 10 open. Lip 466 is connected to front panel 60 by means of bent joint line 410 . In this configuration, male tabs 415 and 515 are perpendicular to the plane of front panel 60 . They are positioned to function as locking tabs when lid 10 is brought back down for resealing. As on carton C″, a space between locking edge 226 and top panel 30 provides a slot for male tabs 415 and 515 in the locked position. As lid 10 is opened and closed, the bias provided by male tabs 415 and 515 against locking edge 226 constitutes another embodiment of the locking mechanism of the present invention. For additional detail, FIG. 31 shows sheared sealing surfaces 367 B and 368 B attached to in-folding flap 24 . As previously described, they are sheared to a half layer thickness of paperboard when the carton is opened.
The sixth embodiment of this invention will now be described in connection with FIGS. 32-34. Referring to FIG. 32, foldable blank F is shown with die-cut appendage 230 formed in score line 25 connecting in-folding flap 24 to cover panel 20 , On blank F, in-folding flap 24 also terminates at locking edge 226 . Male tabs 415 , 515 and 615 are die-cuts in joint line 410 which connects flange lip 466 to front panel 60 . Line 410 is shown in FIG. 32 as a die-cut perforation having a pattern which includes the male tabs. The depth of the die-cuts forming male tabs 415 , 515 and 615 can be less than the entire paperboard thickness, preferably between about one quarter to about three-quarters deep. One skilled in the art will also appreciate that joint line 410 can be formed as a solid score having within it die-cut male tabs of varying depth.
FIG. 32 also shows front panel 60 having die-cut sealing surface 369 on its outer print surface. Sealing surface 369 has a depth which is approximately half the thickness of paperboard blank F. During sleeve assembly, the underlying outer surface of in-folding flap 24 is glued to sealing surface 369 on front panel 60 .
Referring to FIG. 33, carton F″ is shown with its seal broken and lid 10 open. Bent lip 466 is connected to front panel 60 by joint line 410 . In this configuration, male tabs 415 , 515 and 615 are perpendicular to the plane of front panel 60 . They are positioned to function as reclosure means when lid 10 is lowered. A space between locking edge 226 (not shown in FIG. 33) and top panel 30 provides a slot for male tabs 415 , 515 and 615 in the closed position. As lid 10 is opened and closed, the bias provided by male tabs 415 , 515 and 615 against locking edge 226 constitutes another reclosure embodiment of the present invention.
FIG. 33 also shows appendage 230 formed in score line 25 connecting in-folding flap 24 (not shown) to cover panel 20 in carton F″. Appendage 230 is shown tangential to the plane of cover panel 20 . It is used by a consumer to lift lid 10 as an aid to breaking the seal of carton F″, leaving behind sheared sealing surface 369 A having a depth approximately half the thickness of the paperboard. FIG. 34 shows sheared sealing surface 369 B now attached to in-folding flap 24 . As previously explained, sheared sealing surface 369 B has a depth which approximates half the paperboard thickness.
Referring to FIG. 35, the seventh embodiment of the present invention will now be described. Carton blank G is comprised of five main panels, cover panel 20 , top panel 30 , rear panel 40 , bottom panel 50 and front panel 60 . Cover panel 20 is hingedly connected by score lines 21 and 29 to cover panel end flaps 22 and 23 , respectively. Cover panel end flaps 22 and 23 are also referred to as “posts” 22 and 23 , respectively, throughout this disclosure. With respect to the seventh embodiment, carton G″ (FIGS. 38-42) posts 22 and 23 are also referred to as “reinforced corner posts” 22 and 23 , respectively. Top panel 30 is hingedly connected by score lines 31 and 39 to top panel end flaps 32 and 33 , respectively. Other general features with respect to the blank have been reiterated hereinabove.
Carton blank G has a substantially uniform paperboard thickness. When the paperboard is folded over onto itself, a double layer of board is formed which is twice as thick (and strong) as the single layer thickness. Referring again to FIG. 35 with particularity to the seventh embodiment, blank G features junctures 700 and 700 ′ which connect in-folding flap 24 with posts 22 and 23 , respectively, and which features are adapted to be folded into reinforced corner posts.
FIG. 36 is a top perspective view of sleeve G′. From this perspective, junctures 700 ′ and 700 cannot be seen as they are beneath posts 23 and 22 , respectively, and were placed there during the formation of sleeve G′ as has been generally reiterated hereinabove for other sleeve embodiments.
FIG. 37 is a fragmentary perspective view of one, open end of partially assembled carton G″ ready for a form-filling operation. FIG. 38 is a top perspective view of fully constructed and sealed carton G″ with cooperating top panel and rear panel end flaps. From this perspective also, junctures 700 ′ and 700 cannot be seen. For instance, juncture 700 ′ is now folded and concealed beneath post 23 .
FIG. 39 shows carton G″ with lid 10 partially open. FIG. 40 shows lid 10 completely open exposing the interior “underside” of the lid to carton G″. Taking FIGS. 39 and 40 in combination, as lid 10 is opened, posts 23 and 22 are subject to shearing stress as the outward force separating lid 10 from the body of carton G″ pulls on the two junctures formed by the two relevant corners of top panel 30 , top panel end flaps 33 and 32 , and the cover panel 20 .
Junctures 700 and 700 ′ have been found to be beneficial in protecting the corner posts′ points of adherence to end flaps 32 and 33 and the overall integrity of lid 10 from the shear stress upon opening. For instance, FIG. 41 is a fragmented, side elevational view emphasizing the relationship between one relevant corner of top panel 30 , in-folding flap 24 , juncture 700 , post 22 and top panel end flap 32 . FIG. 42 is a cross-sectional view taken along line 42 - 42 in FIG. 41 and shows the cross-section between juncture 700 , post 22 and top panel end flap 32 . As illustrated, juncture 700 of “one” paperboard thickness is folded over onto post 22 also of “one” paperboard thickness thereby forming a double layer of paperboard which is twice as tick (and strong) as the single layer thickness.
The edge of juncture 700 aligns with the edge of top panel end flap 32 as shown in FIG. 42 thereby extending the double layer of paperboard contiguous with top panel end flap 32 . Juncture 700 reinforces corner post 22 so that it is protected from the shear stress which it is subjected to upon opening of lid 10 .
Various modifications and alterations to the present invention may be appreciated based on a review of this disclosure. These changes and additions are intended to be within the scope and spirit of this invention as defined by the following claims. | An ice cream carton blank foldable into a flat sleeve for transportation and storage and erectable into a carton which includes a top cover having left and right top cover end flaps hingedly connected thereto, a cover panel extending downwardly from the top cover having left and right cover panel end flaps hingedly connected thereto, a cover panel extending downwardly from the top cover having left and right cover panel end flaps hingedly connected thereto, an in-folding flap folded under and adhesively adhered to the cover panel and left and right junctures connecting the in-folding flap with the left and right cover panel end flaps folded into abutting relation to the left and right cover panel end flaps, the cover panel end flaps being secured in abutting relation to the top cover end flap with the junctures strengthening the corners defined thereby. |
FIELD OF THE INVENTION
[0001] The present invention relates to an improved roof solar panel, embodying photovoltaic cells, that can be readily and easily installed into a conventional sloping roof and that integrates with a conventional roof covering so as to provide, inter alia, an attractive low profile with improved water shedding, wind resistance, and thermal regulation properties. Further, the invention relates to a kit comprising, inter alia, said roof solar panel, and to a method of installing said roof solar panel.
BACKGROUND
[0002] Both non-structural and structural roof elements incorporating solar collectors such as an array of photovoltaic cells are well known. However, structural roof panels are generally of specialized and costly configuration and installation, often complex and/or heavy and requiring modification or replacement of existing conventional roof structures. The combination of non-structural substrates and solar panels is also well known as substitutes for roofing materials such as shingles and tiles, but such are also typically costly and requiring specialized installation. Solar panels for installation over existing roof components are also well known, but such pose undesirable profile and aesthetic factors, and challenges for mounting securely on the roof without compromising existing roof components or their function.
[0003] In addition, as the temperature of a photovoltaic cell increases, its power output drops. As such, it is important to ensure that photovoltaic cells are kept cool to ensure an optimal operating environment.
[0004] PCT/CA2012/050305 describes a modular roof solar which is mounted onto conventional modular roof sheathing. This integration reduces the complexity, and cost of incorporating a photovoltaic cell, while still providing a highly secure integration into a conventional roof structure. However, this modular panel is still somewhat heavy, and the roof sheathing acts as an insulator against the back of the photovoltaic cell, increasing the difficulty in maintaining an optimal operating temperature.
[0005] There is therefore a need for a low cost, easy to install roof solar panel offering highly secure integration into conventional roof structures and consequent functional and aesthetic advantages while maintaining proper temperature control for the solar panel.
SUMMARY OF THE INVENTION
[0006] In a first aspect, the invention provides a modular roof solar panel for installation on a sloping roof, the panel comprising a rigid photovoltaic panel, a rectangular frame and a retainer trim. The frame comprises a width and lower surface respectively configured for mounting of the solar panel on a plurality of adjacent roof trusses, the trusses having construction industry standard separation. In addition, the frame has an inside support, preferably a recessed perimeter ledge, on which the photovoltaic panel is mounted, and an outside support, preferably a recessed perimeter ledge, for mounting of an overlapping part of a roof covering. The frame has a maximum thickness which is about the same as a combined thickness of a roof sheathing and roof covering of an adjacent part of the roof. The retainer trim is mounted on top of the frame and overlapping the photovoltaic panel so as to secure the photovoltaic panel on the inside support, and also overlaps the outside support for securing the overlapping part of the roof covering when the modular roof solar panel is installed on a roof.
[0007] In a preferred embodiment the photovoltaic panel is sealingly secured to the inside support using a sealing adhesive, preferably a urethane sealer. Additionally, when the panel is installed on a roof, the retainer trim is preferably sealingly secured to the photovoltaic panel, frame and roof covering using a sealing adhesive, preferably a silicone sealer.
[0008] In yet another preferred embodiment, the frame and retainer trim are made of aluminum.
[0009] In yet another preferred embodiment, the retainer trim further comprises fasteners for securing the retainer trim to the frame.
[0010] In yet another preferred embodiment the solar panel comprises a spacer between the frame and the retainer trim.
[0011] In yet another preferred embodiment, the roof covering comprises either shingles or steel roofing.
[0012] In a second aspect, the invention provides a kit of parts for the installation of a modular roof solar panel on a sloped roof, the kit comprising the above described solar panel, one or more roof truss braces for providing extra structural support to the panel and roof trusses, mounting hardware for assembling and attaching the panel to the roof trusses and finally, shingle strips for placement in the outside support of the frame during a shingled installation.
[0013] In a third aspect, the invention also provides a method for installing the modular roof solar panel described above onto a sloping roof. The method comprises the following steps: selecting an area for mounting the modular roof solar panel; installing mounting spacers on roof trusses around a perimeter of the area; mounting the panel onto the roof trusses of the area; securing the roof covering over the outside support and adjacent mounting spacers; and mounting the retainer trim on the frame, roof covering, and photovoltaic panel.
[0014] In a preferred embodiment the method of installation also includes, after installing the mounting spacers, installing roof truss braces between the roof trusses and preparing the roof truss braces for contact with the photovoltaic panel.
SUMMARY OF THE DRAWINGS
[0015] In drawings which illustrate preferred embodiments of the invention:
[0016] FIG. 1 is a side perspective view of the roof solar panel according to the invention, installed on a roof;
[0017] FIG. 1 a is a front perspective view of a roof solar panel according to the invention, installed on a roof;
[0018] FIG. 2 is a cross section view from side to side of the inventive roof solar panel installed on a roof using steel roofing;
[0019] FIG. 2 a is a close-up, cross section view of the right side of the inventive solar panel installed on a shingled roof;
[0020] FIG. 3 is a cross section view through abutting sides of a pair of adjacent roof solar panels according to the invention, installed on a roof;
[0021] FIG. 4 is a cross section view of a retainer trim component of the invention;
[0022] FIG. 5 is a cross section view of the frame component of the invention;
[0023] FIG. 6 is a cross section view of an acrylic foam connecting strip component of the invention;
[0024] FIG. 7 is a sequence diagram illustrating steps for installing an intermediate roof solar panel on a roof so as to provide an installed roof solar panel, according to the invention;
[0025] FIG. 8 is a plan view of a pair of adjacent roof solar panels according to the invention, showing particulars of preferred shingle integration along the lower edge of the roof solar panels before installation of the retainer trim component; and
[0026] FIG. 8 a is a cross section view of the bottom (lower) end of one of the roof solar panels of FIG. 8 , after installation of the retainer trim component.
DETAILED DESCRIPTION OF THE INVENTION
[0027] There is disclosed herein a prefabricated modular roof solar panel that is configured to be installed onto conventional roof trusses, a kit of parts for the installation, of such a roof solar panel, and a method of installing such roof solar panel. The roof solar panel is described as modular as its width is specifically chosen to allow for easy installation on a roof using construction industry standard size roof trusses at construction industry standard separation. This choice of size reduces the complexity involved in installing the roof solar panel.
[0028] The modular roof solar panel is comprised of a frame, preferably made of aluminum. The frame is preferably rectangular in shape, i.e. with four sides (upper, lower and two lateral sides). Each side of the frame preferably has a width, approximately 30 mm, and a lower surface which, as shown in FIG. 3 , is configured to allow for the lateral sides of two adjacent frames to be securely attached, side by side, to a single underlying construction industry standard size roof truss (approximately 3.8 cm (1½″) wide) with each lateral side overhanging the edge of the truss. The frame is also configured to have a total width which allows for each lateral side to be attached to a separate roof truss, when the trusses are at an industry standard separation (approximately 40.6 cm center to center (16″ center to center)). For example, as shown in FIG. 2 , a frame configured to span four roof trusses would attach to the first roof truss at approximately the midpoint of that truss, extend over three truss separations, two trusses, and attach to a fourth roof truss at the midpoint of that truss While the exemplified values reflect North American construction industry standards, the invention may also be modified for use with a roof built according to different standards or requirements.
[0029] The frame has an inside support and an outside support, preferably a recessed inside perimeter ledge and a recessed outside perimeter ledge respectively. The recessed inside perimeter ledge supports a rigid photovoltaic panel comprised of a conventional photovoltaic cell array sealed onto much of its upper surface and covered by a rigid, transparent protective sheet such as glass, plexiglass, or most preferably low iron glass. Such protective sheet is for protecting the array from the usual physical stresses caused by weather (wind, water, snow etc.) and atmospheric debris, while allowing sunlight to pass through to the surface of the photovoltaic array for conversion into electricity. Preferably the photovoltaic panel is mounted to the recessed inside perimeter ledge with a sealing adhesive, preferably urethane. The recessed outside perimeter ledge provides a surface on which a standard roof covering may be mounted, so that it is flush with an adjacent roof sheathing panel which is covered with the same roof covering
[0030] Preferably the roof covering comprises either shingles or steel roofing. Either of these roof coverings may be installed over standard roof sheathing, although steel roofing does allow for some roofs which do not require an underlying layer of sheathing. In such installations, additional strapping would be secured to the trusses adjacent to the frame to provide for an adjacent mounting surface which is flush with the recessed outside perimeter ledge of the frame.
[0031] Finally, the roof solar panel comprises a retainer trim, preferably made from aluminum, which is mounted on the frame and overlaps the photovoltaic panel and roof covering so as to secure both when the panel installation is complete.
[0032] During installation on a shingled roof, after the modular roof solar panel has been secured to the trusses, a preferably single shingle layer (preferably a shingle strip prepared from a shingle by cutting away a show surface of the shingle) is secured around the top and sides of the aforementioned recessed outside perimeter ledge of the frame. The shingle layer is also sized so that it overlaps onto adjacent regular roof sheathing. Along the lower side of the roof solar panel, shingles are installed so that their upper edges overlap the recessed outside perimeter ledge of the frame, preferably subject to cutting them so as to avoid overlap of the shingle strips at the sides of the roof solar panel near and at the bottom thereof. Sealer (e.g. silicone) is applied over the shingle strips along the sides and top of the roof solar panel, the upper ends of the regular shingles along the bottom of the roof solar panel, and the frame and photovoltaic panel, after which the retainer trim is then mounted. After installation of the retainer trim, conventional shingling of the roof to points abutting the retainer trim at the sides and top, and under the shingle along the bottom of the roof solar panel is performed. During an installation using steel roofing, the steel roofing is similarly secured to the frame following which the retainer trim is attached. With steel roofing there is no need to prepare shingle strips as detailed above.
[0033] It is noted that the inventive roof solar panel has the advantage of allowing a solar panel to be quickly and easily installed on a conventional existing roof, or on a new roof construction without the usual time consuming aspects of adapting a solar panel for installation over existing conventional roof panels and coverings. Also, use of familiar materials requires less training, skill and cost for installation compared to other systems.
[0034] The present invention further does not require mounting brackets and is integrated with the roof covering so as to provide a low profile on the roof (see FIG. 1 ). Thus, this provides superior water shedding and is less affected by wind compared to higher or more complex profiles. This further provides a more aesthetically pleasing appearance.
[0035] Further, by using the inventive solar panel significant weight reductions are achieved compared to prior art systems and solar panels, thereby allowing for easier placement and installation.
[0036] The preferred use of urethane as an adhesive allows for a more flexible control over expansion and contraction between the construction materials in the modular roof solar panel.
[0037] Finally, since the bottom surface of the photovoltaic panel exposed is to the air inside the roof (in contrast to installation on the surface of a roof), the panel is in contact with a large volume of air allowing for improved temperature regulation of the photovoltaic array.
[0038] The modular roof solar panel, its installation on a roof and the kit of parts for installation of the modular roof solar panel will now be described with reference to the Figures.
[0039] FIGS. 1 and 1 a illustrate the inventive roof solar panel installed on a roof. The perspective view of FIG. 1 conveys the low profile of the roof solar panel as well as its integration into the surrounding conventional shingles. While these Figures illustrate a single roof solar panel so installed, two or more inventive roof solar panels may be installed on the roof either separated from or, more preferably, abutting each other.
[0040] FIGS. 2 and 2 a illustrate the components of the inventive roof solar panel when installed on a roof. Conventional sheathing 8 and the inventive roof solar panel 9 are mounted on roof trusses 1 using fasteners, e.g. screws. Roof solar panel 9 has photovoltaic panel 3 (having silicon photovoltaic cells and tag wires) mounted on the recessed inside perimeter ledge 4 of the frame 2 . Preferably, the photovoltaic panel 3 is sealed to the recessed inside perimeter ledge 4 using sealing adhesive 12 . Sealing adhesive 12 is preferably urethane. Wiring of the array is attached to a control box on the underside of the panel (not shown) which may be easily accessed from the area under the roof.
[0041] In some embodiments roof truss braces 7 may be installed between the roof trusses 1 using appropriate fasteners 10 , preferably screws. The roof truss braces 7 are preferably notched 11 at either end and fitted with a flexible tape 11 a to allow for the roof truss braces 7 to support the photovoltaic panel 3 and roof trusses 1 against an increased load, or to conform with local building code requirements. One example of where roof truss braces 7 might be appropriate is for a roof in an area which has a significant snowfall during the winter.
[0042] As shown in FIG. 2 a , during a shingled installation, shingle strips 6 , which preferably are cut from conventional shingles, are mounted during installation of the roof solar panel 9 on the roof, preferably in a single layer on the sides and top of the roof solar panel 9 on the recessed outside perimeter ledge 17 of the frame 2 and over the abutting areas of the adjacent sheathing 8 . In contrast, FIG. 2 shows a continuous adjacent roof covering 16 , such as steel roofing, overlapping the recessed outside perimeter ledge 17 of the frame 2 . Once again referring to the shingled installation shown in FIG. 2 a , along the sides and top of the roof solar panel 9 , retainer trim 5 is mounted (during installation of the roof solar panel 9 on the roof), on the shingle strips 6 , the frame 2 , and photovoltaic panel 3 . Along the bottom area of the roof solar panel, retainer trim 5 is mounted (also during such installation on the roof) on a conventional shingle 30 , the frame 2 and the photovoltaic panel 3 (see FIG. 8 a ). Preferably, retainer trim 5 is so mounted using sealing adhesive, preferably silicone 13 . Also preferably, the retainer trim 5 has fastener openings for installing fasteners, preferably screws, through the retainer trim 5 , and into the underlying frame 2 as shown in FIG. 3 .
[0043] In FIG. 3 there is shown in cross section across abutting sides, a preferred configuration of a pair of adjacent roof solar panels according to the present invention. Thus, instead of a shingle strip 6 or continuous adjacent roof covering 16 covering the joint 14 between the abutting panels (as in FIGS. 2 a and 2 respectively), there is a resilient strip 15 , preferably water impermeable and preferably made of an acrylic foam, mounted over and along the length of such joint with adhesive sealant. The retainer trim 5 is mounted, when the abutting roof solar panels are being installed on the roof, over such resilient strip 15 in the place of shingle strips 6 or continuous adjacent roof covering 16 along the abutting recessed outside perimeter ledges 17 of each frame 2 (as well as the frames 2 , and photovoltaic panels 3 as described above).
[0044] FIG. 4 shows a preferred configuration of the retainer trim 5 for use in the roof solar panel of the present invention. Preferably such retainer trim 5 is made of aluminum. The retainer trim 5 is shown having a height (preferably 3.5 mm tall) and a width (preferably 26.5 mm wide), adapted for sealing engagement with the top of the frame 2 , photovoltaic panel 3 , and the roof covering ( FIGS. 2 and 2 a ). In one embodiment a spacer (not shown) may be placed between the retainer trim 5 and the frame 2 to provide for a proper engagement when a thicker photovoltaic panel 3 or roof covering is used.
[0045] FIG. 5 shows a preferred configuration of the frame 2 , which is preferably made of aluminum and is preferably about 30 mm wide and 12 mm high. The recessed inside perimeter ledge 4 is preferably about 8 mm wide and 7 mm high while the recessed outside perimeter ledge 17 is preferably about 7 mm wide and 2 mm high. These preferred dimensions allow for the recessed outside perimeter ledge 17 of the frame 2 to be approximately level with a standard thickness adjacent sheathing 8 (approximately 0.95 cm (⅜″) in order to facilitate the placement and integration of the roof covering which is mounted on the frame 2 with the adjacent roof covering on the adjacent sheathing 8 . These values may be adjusted to accommodate integration with other sheathing or roof coverings of other standard, or even non-standard thickness.
[0046] FIG. 6 shows a preferred configuration of the resilient strip 15 , preferably of made of an acrylic foam and preferably about 13 mm wide and 2 mm high.
[0047] The inventive method of installation of the subject roof solar panel on a roof is illustrated in FIG. 7 . While this illustrates the mounting of three abutting roof solar panels, the process for mounting a single roof solar panel is similar, as will be indicated in the following discussion when appropriate.
[0048] Thus, in step 1 , the planned configuration of three roof solar panels is shown on a roof section in which the vertical lines represent trusses, a peak of the roof is at the top and bottom edge of the roof is at the bottom. In a shingled installation, the location of the bottom edge of the roof solar panels between the top and bottom of the roof section is preferably at a distance above the bottom edge of the roof section which is approximately a whole multiple of the height (distance from lower to upper edges) of the finished showing surface of a shingle for the roof. This is to provide for a full shingle showing surface in the first row of shingles abutting the lower edge of the recessed outside perimeter ledge 17 along the bottom of the roof solar panel. In Step 2 , a border for the roof solar panels is marked, as illustrated, on the trusses to ensure correct positioning of the panels to be mounted. In Step 3 , mounting spacers are mounted onto the roof trusses around the marked opening for the roof solar panels. In a shingled installation, or an installation using steel roofing and roof sheathing, the mounting spacers comprise regular roof sheathing, which is mounted onto the trusses around the marked opening for the roof solar panels. If steel roofing is being used without underlying roof sheathing the mounting spacers comprise strapping on the trusses to provide for an adjacent mounting surface which is flush with the recessed outside perimeter ledge 17 of the frame.
[0049] In Step 4 , in appropriate situations, the installation of roof truss braces 7 to roof trusses that will be under intermediate areas of the first roof solar panel to be installed is shown. Although this is preferably performed after installation of the mounting spacers, the roof truss braces may be installed at any time after the area for mounting the modular roof panel has been selected. In Steps 5 and 6 , mounting of the first solar panel is shown. In Step 5 the roof solar panel is placed into position. In Step 6 the roof solar panel is attached to the underlying roof trusses. Preferably, the frame 2 comprises a number of holes for receiving screws to attach the roof solar panel to the underlying roof trusses (as shown in FIGS. 3 and 5 ). Preferably, after the roof solar panel is in place, a sealing adhesive is applied into each of said holes. A screw is then installed in such holes, beginning with each of the four corners of the roof solar panel, followed by any other such holes, further preferably providing each of such holes with a tapered opening for the screw head. Steps 4 - 6 are repeated to install the other two roof solar panels.
[0050] In Step 7 , which shows the other two panels also mounted in position, a resilient strip ( 15 in FIG. 3 ), preferably made of acrylic foam, is mounted along the join between abutting roof solar panels. (This is not applicable to when a single roof solar panel is being installed—no such resilient strip is needed in the latter case.) Preferably, the resilient strip 15 is mounted over silicon sealant applied between the respective recessed outside perimeter ledges 17 of adjacent roof solar panels. Also preferably, such resilient strip 15 extend from the lower ends of the upper recessed outside perimeter ledges 17 to the upper ends of the lower recessed outside perimeter ledges 17 (to allow for roof covering to be installed on the upper and lower recessed outside ledges 17 of each of the adjacent roof solar panels).
[0051] Steps 8 through 10 detail installation procedures specific to a shingled installation. In Step 8 a preferred method of preparing shingle strips 6 for installation around the outermost sides and top, perimeter areas of the three roof solar panels is shown. (If there is just one roof solar panel, then these shingle strips 6 are for installation around both sides and top perimeter areas of the roof solar panel.) This involves cutting away the normally exposed part of the shingle (i.e. when conventionally installed on a roof) at about one inch below the normal glue line, to leave intact a shingle strip 6 preferably about from 20 to 21 cm high (about 8 inches) i.e. from the lower to upper edge if conventionally orientated. In Step 9 is shown the installation of shingle strips around the top and side perimeter areas of the roof solar panels. Preferably, the glue side of the shingle is mounted on the recessed outside perimeter ledge 17 . In multiple solar panel installations employing the resilient strip 15 , the shingle strip is cut so as to butt up against a side of the part of the resilient strip 15 that extends to the lower end of the upper recessed outside perimeter ledges 17 .
[0052] In Step 10 , regular shingles 30 and 16 a are shown installed from the bottom edge of the roof 25 up to the edge of lower recessed outside perimeter ledge 17 of the frame 2 (best shown in FIGS. 8 and 8 a ), also configured to butt up against the lower edges of the resilient strips 15 . In preparation for installation of the retainer trim 5 , preferably silicon sealant is applied around the perimeter areas of all the solar panels, i.e. over the shingle strips 6 , the frames 2 , photovoltaic panels 3 , the resilient strips 15 and the shingles at the bottom adjacent the flashing strip. Also, preferably roof sealer is applied to all butt joints out 2 inches from the solar panel. In Step 11 , the retainer trim 5 is mounted in position over the frames 2 , shingles 6 , photovoltaic panels 3 , and, for multiple solar panel installation, resilient strips 15 . Fasteners, preferably screws and silicon sealer, are then installed through the retainer trim 5 , into the underlying frame 2 (as shown in FIG. 3 ). Finally, shingling of the roof is performed in which conventional shingles 16 a butt up against the retainer strip 5 .
[0053] In a steel roofing installation the steel roofing would be laid across the roof and mounted on the recessed outside perimeter ledge 17 of the frame 2 . The retainer trim 5 would then be mounted as described above.
[0054] FIG. 8 shows a preferred shingle integration along the lower edge area of a pair of abutting roof solar panels. A normal shingling process is used from the lower edge of the roof 25 upwards to the lower edge of the solar panels 26 , the latter of which has been preferably pre-arranged to be located from the former at a distance which is an increment of 6½″ from the former. The shingle below said lower end of the resilient strip 15 can be seen between the solar panels where it butts up against said end. In FIG. 8 a (which is a schematic representation, not to scale) the lower area of FIG. 8 is shown in cross-section but with the retainer trim 5 in position. The top-most, shingle 30 is configured against the upper edge of the lower recessed outside perimeter ledge 17 , beneath the retainer trim 5 . The first and second adjacent shingles 16 a from the roof edge 25 are also shown.
[0055] In a preferred commercial embodiment of the invention, the roof solar panel 9 is prepared to a pre-installation condition without the retainer strip 5 sealed in place. This is because, as may be appreciated from the foregoing description of the installation method, the retainer trim 5 can only be fully installed once the roof covering, and resilient strips 15 if applicable (i.e. for multiple panel installations), have been installed over the recessed outside perimeter ledge 17 of the frame 2 and adjacent sheathing 8 , or strapping in the case of a steel roofing installation without an underlying sheathing. Thus, such pre-installation condition of the subject roof solar panel may be sold as such, preferably in kit form with shingle strips 6 , roof truss braces 7 and mounting hardware, for later installation on a roof in combination with the retainer trim 5 .
[0056] While the foregoing describes most preferred embodiments of the subject invention, a person skilled in the art will appreciate that variations of such embodiments will be feasible and, still be within the scope of the teachings herein. Thus, the substitution of different materials (e.g. metals, plastic, adhesives etc.) for those specifically indicated may be expected to occur to such person, and variations in shapes and configurations of the different components involved may be made while sustaining the functions of components actually shown herein, such all being within the intended scope of the present invention. | There is provided an improved roof solar panel, embodying a photovoltaic panel mounted on a frame for easy installation onto a conventional sloped roof and integration with conventional roof coverings. Such panel includes a roof covering mounting surface on an outside support of the frame, a photovoltaic panel mounting surface on an inside support of the frame, and when installed on the roof, a retainer trim for securing the roof covering and photovoltaic panel mounted on said supports while mounting to the frame, The frame also serves to provide means for securing the panel onto roof trusses. Integration with the conventional roof covering provides, inter alia, an attractive low profile with improved water shedding, wind resistance, and thermal regulation properties. The invention also relates to a kit comprising, inter alia, said roof solar panel, and to a method of installing said roof solar panel. |
RELATED APPLICATIONS
[0001] This application is a continuation of copending U.S. application Ser. No. 12/569,826, which was filed on Sep. 29, 2009, which is a continuation of U.S. application Ser. No. 11/842,145, which was filed on Aug. 21, 2007, now U.S. Pat. No. 7,594,740, which is a continuation of U.S. application Ser. No. 11/542,072, which was filed on Oct. 3, 2006, now U.S. Pat. No. 7,306,353, which is a continuation of U.S. application Ser. No. 10/789,357, which was filed on Feb. 27, 2004, now U.S. Pat. No. 7,114,931, which is a continuation of U.S. application Ser. No. 09/693,548, which was filed on Oct. 19, 2000, now U.S. Pat. No. 6,712,486, which claims the benefit of U.S. Provisional Patent Application Nos. 60/160,480, which was filed on Oct. 19, 1999 and 60/200,531, which was filed on Apr. 27, 2000. The entirety of each of these related applications is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is in the field of light emitting diode (LED) lighting devices and more particularly in the field of an LED lighting module having heat transfer properties that improve the efficiency and performance of LEDs.
[0004] 2. Description of the Related Art
[0005] Light emitting diodes (LEDs) are currently used for a variety of applications. The compactness, efficiency and long life of LEDs is particularly desirable and makes LEDs well suited for many applications. However, a limitation of LEDs is that they typically cannot maintain a long-term brightness that is acceptable for middle to large-scale illumination applications. Instead, more traditional incandescent or gas-filled light bulbs are often used.
[0006] An increase of the electrical current supplied to an LED generally increases the brightness of the light emitted by the LED. However, increased current also increases the junction temperature of the LED. Increased juncture temperature may reduce the efficiency and the lifetime of the LED. For example, it has been noted that for every 10° C. increase in temperature, silicone and gallium arsenide lifetime drops by a factor of 2.5-3. LEDs are often constructed of semiconductor materials that share many similar properties with silicone and gallium arsenide.
SUMMARY OF THE INVENTION
[0007] Accordingly, there is a need in the art for an LED lighting apparatus having heat removal properties that allow an LED on the apparatus to operate at relatively high current levels without increasing the juncture temperature of the LED beyond desired levels.
[0008] In accordance with an aspect of the present invention, an LED module is provided for mounting on a heat conducting surface that is substantially larger than the module. The module comprises a plurality of LED packages and a circuit board. Each LED package has an LED and at least one lead. The circuit board comprises a thin dielectric sheet and a plurality of electrically-conductive contacts on a first side of the dielectric sheet. Each of the contacts is configured to mount a lead of an LED package such that the LEDs are connected in series. A heat conductive plate is disposed on a second side of the dielectric sheet. The plate has a first side which is in thermal communication with the contacts through the dielectric sheet. The first side of the plate has a surface area substantially larger than a contact area between the contacts and the dielectric sheet. The plate has a second side adapted to provide thermal contact with the heat conducting surface. In this manner, heat is transferred from the module to the heat conducting surface.
[0009] In accordance with another aspect of the present invention, a modular lighting apparatus is provided for conducting heat away from a light source of the apparatus. The apparatus comprises a plurality of LEDs and a circuit board. The circuit board has a main body and a plurality of electrically conductive contacts. Each of the LEDs electrically communicates with at least one of the contacts in a manner so that the LEDs are configured in a series array. Each of the LEDs electrically communicates with corresponding contacts at an attachment area defined on each contact. An overall surface of the contact is substantially larger than the attachment area. The plurality of contacts are arranged adjacent a first side of the main body and are in thermal communication with the first side of the main body. The main body electrically insulates the plurality of contacts relative to one another.
[0010] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
[0011] All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an LED module having features in accordance with the present invention.
[0013] FIG. 2 is a schematic side view of a typical pre-packaged LED lamp.
[0014] FIG. 3 is a top plan view of the LED module of FIG. 1 .
[0015] FIG. 4 is a side plan view of the apparatus of FIG. 3 .
[0016] FIG. 5 is a close-up side view of the apparatus of FIG. 3 mounted on a heat conductive member.
[0017] FIG. 6 is another sectional side view of the apparatus of FIG. 3 mounted onto a heat conductive flat surface.
[0018] FIG. 7 is a side plan view of an LED module having features in accordance with another embodiment of the present invention.
[0019] FIG. 8 is a side plan view of another LED module having features in accordance with yet another embodiment of the present invention.
[0020] FIG. 9 is a perspective view of an illumination apparatus having features in accordance with the present invention.
[0021] FIG. 10 is a side view of the apparatus of FIG. 9 .
[0022] FIG. 11 is a bottom view of the apparatus of FIG. 9 .
[0023] FIG. 12 is a top view of the apparatus of FIG. 9 .
[0024] FIG. 13 is a schematic view of the apparatus of FIG. 9 mounted on a theater seat row end.
[0025] FIG. 14 is a side view of the apparatus of FIG. 13 showing the mounting orientation.
[0026] FIG. 15 is a side view of a mounting barb.
[0027] FIG. 16 is a front plan view of the illumination apparatus of FIG. 9 .
[0028] FIG. 17 is a cutaway side plan view of the apparatus of FIG. 20 .
[0029] FIG. 18 is a schematic plan view of a heat sink base plate.
[0030] FIG. 19 is a close-up side sectional view of an LED module mounted on a mount tab of a base plate.
[0031] FIG. 20 is a plan view of a lens for use with the apparatus of FIG. 9 .
[0032] FIG. 21 is a perspective view of a channel illumination apparatus incorporating LED modules having features in accordance with the present invention.
[0033] FIG. 22 is a close-up side view of an LED module mounted on a mount tab.
[0034] FIG. 23 is a partial view of a wall of the apparatus of FIG. 21 , taken along line 23 - 23 .
[0035] FIG. 24 is a top view of an LED module mounted to a wall of the apparatus of FIG. 21 .
[0036] FIG. 25 is a top view of an alternative embodiment of an LED module mounted to a wall of the apparatus of FIG. 21 .
[0037] FIG. 26A is a side view of an alternative embodiment of a lighting module being mounted onto a channel illumination apparatus wall member.
[0038] FIG. 26B shows the apparatus of the arrangement of FIG. 26A with the lighting module installed.
[0039] FIG. 26C shows the arrangement of FIG. 26B with a lens installed on the wall member.
[0040] FIG. 26D shows a side view of an alternative embodiment of a lighting module installed on a channel illumination apparatus wall member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0041] With reference first to FIG. 1 , an embodiment of a light-emitting diode (LED) lighting module 30 is disclosed. In the illustrated embodiment, the LED module 30 includes five pre-packaged LEDs 32 arranged on one side of the module 30 . It is to be understood, however, that LED modules having features in accordance with the present invention can be constructed having any number of LEDs 32 mounted in any desired configuration.
[0042] With next reference to FIG. 2 , a typical pre-packaged LED 32 includes a diode chip 34 encased within a resin body 36 . The body 36 typically has a focusing lens portion 38 . A negative lead 40 connects to an anode side 42 of the diode chip 34 and a positive lead 44 connects to a cathode side 46 of the diode chip 34 . The positive lead 44 preferably includes a reflector portion 48 to help direct light from the diode 34 to the lens portion 38 .
[0043] With next reference to FIGS. 1-5 , the LED module 30 preferably comprises the five pre-packaged LED lamps 32 mounted in a linear array on a circuit board 50 and electrically connected in series. The illustrated embodiment employs pre-packaged aluminum indium gallium phosphide (AlInGaP) LED lamps 32 such as model HLMT-PL00, which is available from Hewlett Packard. In the illustrated embodiment, each of the pre-packaged LEDs is substantially identical so that they emit the same color of light. It is to be understood, however, that nonidentical LEDs may be used to achieve certain desired lighting effects.
[0044] The illustrated circuit board 50 preferably is about 0.05 inches thick, 1 inch long and 0.5 inch wide. It includes three layers: a copper contact layer 52 , an epoxy dielectric layer 54 and an aluminum main body layer 56 . The copper contact layer 52 is made up of a series of six elongate and generally parallel flat copper plates 60 that are adapted to attach to the leads 40 , 44 of the LEDs 32 . Each of the copper contacts 60 is electrically insulated from the other copper contacts 60 by the dielectric layer 54 . Preferably, the copper contacts 60 are substantially coplanar.
[0045] The pre-packaged LEDs 32 are attached to one side of the circuit board 50 , with the body portion 36 of each LED generally abutting a side of the circuit board 50 . The LED lens portion 38 is thus pointed outwardly so as to direct light in a direction substantially coplanar with the circuit board 50 . The LED leads 40 , 44 are soldered onto the contacts 60 in order to create a series array of LEDs. Excess material from the leads of the individual pre-packaged LED lamps may be removed, if desired. Each of the contacts 60 , except for the first and last contact 62 , 64 , have both a negative lead 40 and a positive lead 44 attached thereto. One of the first and last contacts 62 , 64 has only a negative lead 40 attached thereto; the other has only a positive lead 44 attached thereto.
[0046] A bonding area of the contacts accommodates the leads 40 , 44 , which are preferably bonded to the contact 60 with solder 68 ; however, each contact 60 preferably has a surface area much larger than is required for adequate bonding in the bonding area 66 . The enlarged contact surface area allows each contact 60 to operate as a heat sink, efficiently absorbing heat from the LED leads 40 , 44 . To maximize this role, the contacts 60 are shaped to be as large as possible while still fitting upon the circuit board 50 .
[0047] The dielectric layer 54 preferably has strong electrical insulation properties but also relatively high heat conductance properties. In the illustrated embodiment, the layer 54 is preferably as thin as practicable. For example in the illustrated embodiment, the dielectric layer 54 comprises a layer of Thermagon® epoxy about 0.002 inches thick.
[0048] It is to be understood that various materials and thicknesses can be used for the dielectric layer 54 . Generally, the lower the thermal conductivity of the material used for the dielectric layer, the thinner that dielectric layer should be in order to maximize heat transfer properties of the module. For example, in the illustrated embodiment, the layer of epoxy is very thin. Certain ceramic materials, such as beryllium oxide and aluminum nitride, are electrically non-conductive but highly thermally conductive. When the dielectric layer is constructed of such materials, it is not as crucial for the dielectric layer to be so very thin, because of the high thermal conductivity of the material.
[0049] In the illustrated embodiment, the main body 56 makes up the bulk of the thickness of the circuit board 50 and preferably comprises a flat aluminum plate. As with each of the individual contacts 60 , the main body 56 functions as a heat conduit, absorbing heat from the contacts 60 through the dielectric layer 54 to conduct heat away from the LEDs 32 . However, rather than just absorbing heat from a single LED 32 , the main body 56 acts as a common heat conduit, absorbing heat from all of the contacts 60 . As such, in the illustrated embodiment, the surface area of the main body 56 is about the same as the combined surface area of all of the individual contacts 60 . The main body 56 can be significantly larger than shown in the illustrated embodiment, but its relatively compact shape is preferable in order to increase versatility when mounting the light module 30 . Additionally, the main body 56 is relatively rigid and provides structural support for the lighting module 30 .
[0050] In the illustrated embodiment, aluminum has been chosen for its high thermal conductance properties and ease of manufacture. It is to be understood, however, that any material having advantageous thermal conductance properties, such as having thermal conductivity greater than about 100 watts per meter per Kelvin (W/m-K), would be acceptable.
[0051] A pair of holes 70 are preferably formed through the circuit board 50 and are adapted to accommodate a pair of aluminum pop rivets 72 . The pop rivets 72 hold the circuit board 50 securely onto a heat conductive mount member 76 . The mount member 76 functions as or communicates with a heat sink. Thus, heat from the LEDs 32 is conducted with relatively little resistance through the module 30 to the attached heat sink 76 so that the junction temperature of the diode chip 34 within the LED 32 does not exceed a maximum desired level.
[0052] With reference again to FIGS. 3 and 5 , a power supply wire 78 is attached across the first and last contacts 62 , 64 of the circuit board 50 so that electrical current is provided to the series-connected LEDs 32 . The power supply is preferably a 12-volt system and may be AC, DC or any other suitable power supply. A 12-volt AC system may be fully rectified.
[0053] The small size of the LED module 30 provides versatility so that modules can be mounted at various places and in various configurations. For instance, some applications will include only a single module for a particular lighting application, while other lighting applications will employ a plurality of modules electrically connected in parallel relative to each other.
[0054] It is also to be understood that any number of LEDs can be included in one module. For example, some modules may use two LEDs, while other modules may use 10 or more LEDs. One manner of determining the number of LEDs to include in a single module is to first determine the desired operating voltage of a single LED of the module and also the voltage of the power supply. The number of LEDs desired for the module is then roughly equal to the voltage of the power supply divided by the operating voltage of each of the LEDs.
[0055] The present invention rapidly conducts heat away from the diode chip 34 of each LED 32 so as to permit the LEDs 32 to be operated in regimes that exceed normal operating parameters of the pre-packaged LEDs 32 . In particular, the heat sinks allow the LED circuit to be driven in a continuous, non-pulsed manner at a higher long-term electrical current than is possible for typical LED mounting configurations. This operating current is substantially greater than manufacturer-recommended maximums. The optical emission of the LEDs at the higher current is also markedly greater than at manufacturer-suggested maximum currents.
[0056] The heat transfer arrangement of the LED modules 30 is especially advantageous for pre-packaged LEDs 32 having relatively small packaging and for single-diode LED lamps. For instance, the HLMT-PL00 model LED lamps used in the illustrated embodiment employ only a single diode, but since heat can be drawn efficiently from that single diode through the leads and circuit board and into the heat sink, the diode can be run at a higher current than such LEDs are traditionally operated. At such a current, the single-diode LED shines brighter than LED lamps that employ two or more diodes and which are brighter than a single-diode lamp during traditional operation. Of course, pre-packaged LED lamps having multiple diodes can also be employed with the present invention. It is also to be understood that the relatively small packaging of the model HLMT-PL00 lamps aids in heat transfer by allowing the heat sink to be attached to the leads closer to the diode chip.
[0057] With next reference to FIG. 5 , a first reflective layer 80 is preferably attached immediately on top of the contacts 60 of the circuit board 50 and is held in position by the rivets 72 . The first reflector 80 preferably extends outwardly beyond the LEDs 32 . The reflective material preferably comprises an electrically non-conductive film such as visible mirror film available from 3M. A second reflective layer 82 is preferably attached to the mount member 76 at a point immediately adjacent the LED lamps 32 . The second strip 82 is preferably bonded to the mount surface 76 using adhesive in a manner known in the art.
[0058] With reference also to FIG. 6 , the first reflective strip 80 is preferably bent so as to form a convex reflective trough about the LEDs 32 . The convex trough is adapted to direct light rays emitted by the LEDs 32 outward with a minimum of reflections between the reflector strips 80 , 82 . Additionally, light from the LEDs is limited to being directed in a specified general direction by the reflecting films 80 , 82 . As also shown in FIG. 6 , the circuit board 50 can be mounted directly to any mount surface 76 .
[0059] In another embodiment, the aluminum main body portion 56 may be of reduced thickness or may be formed of a softer metal so that the module 30 can be partially deformed by a user. In this manner, the module 30 can be adjusted to fit onto various surfaces, whether they are flat or curved. By being able to adjust the fit of the module to the surface, the shared contact surface between the main body and the adjacent heat sink is maximized, improving heat transfer properties. Additional embodiments can use fasteners other than rivets to hold the module into place on the mount surface/heat sink material. These additional fasteners can include any known fastening means such as welding, heat conductive adhesives, and the like.
[0060] As discussed above, a number of materials may be used for the circuit board portion of the LED module. With specific reference to FIG. 7 , another embodiment of an LED module 86 comprises a series of elongate, flat contacts 88 similar to those described above with reference to FIG. 3 . The contacts 88 are mounted directly onto the main body portion 89 . The main body 89 comprises a rigid, substantially flat ceramic plate. The ceramic plate makes up the bulk of the circuit board and provides structural support for the contacts 88 . Also, the ceramic plate has a surface area about the same as the combined surface area of the contacts. In this manner, the plate is large enough to provide structural support for the contacts 88 and conduct heat away from each of the contacts 88 , but is small enough to allow the module 86 to be relatively small and easy to work with. The ceramic plate 89 is preferably electrically non-conductive but has high heat conductivity. Thus, the contacts 88 are electrically insulated relative to each other, but heat from the contacts 88 is readily transferred to the ceramic plate 89 and into an adjoining heat sink.
[0061] With next reference to FIG. 8 , another embodiment of an LED lighting module 90 is shown. The LED module 90 comprises a circuit board 92 having features substantially similar to the circuit board 50 described above with reference to FIG. 3 . The diode portion 94 of the LED 96 is mounted substantially directly onto the contacts 60 of the lighting module 90 . In this manner, any thermal resistance from leads of pre-packaged LEDs is eliminated by transferring heat directly from the diode 94 onto each heat sink contact 60 , from which the heat is conducted to the main body 56 and then out of the module 90 . In this configuration, heat transfer properties are yet further improved.
[0062] As discussed above, an LED module having features as described above can be used in many applications such as, for example, indoor and outdoor decorative lighting, commercial lighting, spot lighting, and even room lighting. With next reference to FIGS. 9-12 , a self-contained lighting apparatus 100 incorporates an LED module 30 and can be used in many such applications. In the illustrated embodiment, the lighting apparatus 100 is adapted to be installed on the side of a row of theater seats 102 , as shown in FIG. 13 , and is adapted to illuminate an aisle 104 next to the theater seats 102 .
[0063] The self-contained lighting apparatus 100 comprises a base plate 106 , a housing 108 , and an LED module 30 arranged within the housing 108 . As shown in FIGS. 9 , 10 and 13 , the base plate 106 is preferably substantially circular and has a diameter of about 5.75 inches. The base plate 106 is preferably formed of 1/16 th inch thick aluminum sheet. As described in more detail below, the plate functions as a heat sink to absorb and dissipate heat from the LED module. As such, the base plate 106 is preferably formed as large as is practicable, given aesthetic and installation concerns.
[0064] As discussed above, the lighting apparatus 100 is especially adapted to be mounted on an end panel 110 of a row of theater chairs 102 in order to illuminate an adjacent aisle 104 . As shown in FIGS. 13 and 14 , the base plate 106 is preferably installed in a vertical orientation. Such vertical orientation aids conductive heat transfer from the base plate 106 to the environment.
[0065] The base plate 106 includes three holes 112 adapted to facilitate mounting. A ratcheting barb 116 (see FIG. 15 ) secures the plate 106 to the panel 110 . The barb 116 has an elongate main body 118 having a plurality of biased ribs 120 and terminating at a domed top 122 .
[0066] To mount the apparatus on the end panel 110 , a hole is first formed in the end panel surface on which the apparatus is to be mounted. The base plate holes 112 are aligned with mount surface holes and the barbs 116 are inserted through the base plate 106 into the holes. The ribs 120 prevent the barbs 116 from being drawn out of the holes once inserted. Thus, the apparatus is securely held in place and cannot be easily removed. The barbs 116 are especially advantageous because they enable the device to be mounted on various surfaces. For example, the barbs will securely mount the illumination apparatus on wooden or fabric surfaces.
[0067] With reference next to FIGS. 16-19 , a mount tab 130 is provided as an integral part of the base plate 106 . The mounting tab 130 is adapted to receive an LED module 30 mounted thereon. The tab 130 is preferably plastically deformed along a hinge line 132 to an angle θ between about 20-45° relative to the main body 134 of the base plate 106 . More preferably, the mounting tab 130 is bent at an angle θ of about 33°. The inclusion of the tab 130 as an integral part of the base plate 106 facilitates heat transfer from the tab 130 to the main body 134 of the base plate. It is to be understood that the angle θ of the tab 130 relative to the base plate body 134 can be any desired angle as appropriate for the particular application of the lighting apparatus 100 .
[0068] A cut out portion 136 of the base plate 106 is provided surrounding the mount tab 130 . The cut out portion 136 provides space for components of the mount tab 130 to fit onto the base plate 106 . Also, the cut out portion 136 helps define the shape of the mount tab 130 . As discussed above, the mount tab 130 is preferably plastically deformed along the hinge line 132 . The length of the hinge line 132 is determined by the shape of the cut out portion 136 in that area. Also, a hole 138 is preferably formed in the hinge line 132 . The hole 138 further facilitates plastic deformation along the hinge line 132 .
[0069] Power for the light source assembly 100 is preferably provided through a power cord 78 that enters the apparatus 100 through a back side of the base plate 106 . The cord 78 preferably includes two 18 AWG conductors surrounded by an insulating sheet. Preferably, the power supply is in the low voltage range. For example, the power supply is preferably a 12-volt alternating current power source. As depicted in FIG. 18 , power is preferably first provided through a full wave ridge rectifier 140 which rectifies the alternating current in a manner known in the art so that substantially all of the current range can be used by the LED module 40 . In the illustrated embodiment, the LEDs are preferably not electrically connected to a current-limiting resistor. Thus, maximum light output can be achieved. It is to be understood, however, that resistors may be desirable in some embodiments to regulate current. Supply wires 142 extend from the rectifier 140 and provide rectified power to the LED module 30 mounted on the mounting tab 130 .
[0070] With reference again to FIGS. 9-12 , 16 and 17 , the housing 108 is positioned on the base plate 106 and preferably encloses the wiring connections in the light source assembly 100 . The housing 108 is preferably substantially semi-spherical in shape and has a notch 144 formed on the bottom side. A cavity 146 is formed through the notch 144 and allows visual access to the light source assembly 100 . A second cavity 148 is formed on the top side and preferably includes a plug 150 which may, if desired, include a marking such as a row number. In an additional embodiment, a portion of the light from the LED module 30 , or even from an alternative light source, may provide light to light up the aisle marker.
[0071] The housing 108 is preferably secured to the base plate 106 by a pair of screws 152 . Preferably, the screws 152 extend through countersunk holes 154 in the base plate 106 . This enables the base plate 106 to be substantially flat on the back side, allowing the plate to be mounted flush with the mount surface. As shown in FIG. 17 , threaded screw receiver posts 156 are formed within the housing 108 and are adapted to accommodate the screw threads.
[0072] The LED module 30 is attached to the mount tab 130 by the pop rivets 72 . The module 30 and rivets 72 conduct heat from the LEDs 32 to the mount tab 130 . Since the tab 130 is integrally formed as a part of the base plate 106 , heat flows freely from the tab 130 to the main body 134 of the base plate. The base plate 106 has high heat conductance properties and a relatively large surface area, thus facilitating efficient heat transfer to the environment and allowing the base plate 106 to function as a heat sink.
[0073] As discussed above, the first reflective strip 80 of the LED module 30 is preferably bent so as to form a convex trough about the LEDs. The second reflector strip 82 is attached to the base plate mount tab 130 at a point immediately adjacent the LED lamps 32 . Thus, light from the LEDs is collimated and directed out of the bottom cavity 146 of the housing 108 , while minimizing the number of reflections the light must make between the reflectors (see FIG. 6 ). Such reflections may each reduce the intensity of light reflected.
[0074] A lens or shield 160 is provided and is adapted to be positioned between the LEDs 32 and the environment outside of the housing cavity 108 . The shield 160 prevents direct access to the LEDs 32 and thus prevents harm that may occur from vandalism or the like, but also transmits light emitted by the light source 100 .
[0075] FIG. 20 shows an embodiment of the shield 160 adapted for use in the present invention. As shown, the shield 160 is substantially lenticularly shaped and has a notch 162 formed on either end thereof. With reference back to FIG. 18 , the mounting tab 130 of the base plate 106 also has a pair of notches 164 formed therein.
[0076] As shown in FIG. 16 , the lens/shield notches 162 are adapted to fit within the tab notches 164 so that the shield 160 is held in place in a substantially arcuate position. The shield thus, in effect, wraps around one side of the LEDs 32 . When the shield 160 is wrapped around the LEDs 32 , the shield 160 contacts the first reflector film 80 , deflecting the film 80 to further form the film in a convex arrangement. The shield 160 is preferably formed of a clear polycarbonate material, but it is to be understood that the shield 160 may be formed of any clear or colored transmissive material as desired by the user.
[0077] The LED module 30 of the present invention can also be used in applications using a plurality of such modules 30 to appropriately light a lighting apparatus such as a channel illumination device. Channel illumination devices are frequently used for signage including borders and lettering. In these devices, a wall structure outlines a desired shape to be illuminated, with one or more channels defined between the walls. A light source is mounted within the channel and a translucent diffusing lens is usually arranged at the top edges of the walls so as to enclose the channel. In this manner, a desired shape can be illuminated in a desired color as defined by the color of the lens.
[0078] Typically, a gas-containing light source such as a neon light is custom-shaped to fit within the channel. Although the diffusing lens is placed over the light source, the light apparatus may still produce “hot spots,” which are portions of the sign that are visibly brighter than other portions of the sign. Such hot spots result because the lighting apparatus shines directly at the lens, and the lens may have limited light-diffusing capability. Incandescent lamps may also be used to illuminate such a channel illumination apparatus; however, the hot spot problem typically is even more pronounced with incandescent lights.
[0079] Both incandescent and gas-filled lights have relatively high manufacturing and operation costs. For instance, gas-filled lights typically require custom shaping and installation and therefore can be very expensive to manufacture. Additionally, both incandescent and gas-filled lights have high power requirements.
[0080] With reference next to FIG. 21 , an embodiment of a channel illumination apparatus 170 is disclosed comprising a casing 172 in the shape of a “P.” The casing 172 includes a plurality of walls 174 and a bottom 176 , which together define at least one channel. The surfaces of the walls 174 and bottom 176 are diffusely-reflective, preferably being coated with a flat white coating. The walls 174 are preferably formed of a durable sturdy metal having relatively high heat conductivity. A plurality of LED lighting modules 30 are mounted to the walls 174 of the casing 172 in a spaced-apart manner. A translucent light-diffusing lens (not shown) is preferably disposed on a top edge 178 of the walls 174 and encloses the channel.
[0081] With next reference to FIG. 22 , the pop rivets 72 hold the LED module 30 securely onto a heat conductive mount tab 180 . The mount tab 180 , in turn, may be connected, by rivets 182 or any other fastening means, to the walls 174 of the channel apparatus as shown in FIG. 23 . Preferably, the connection of the mount tab 180 to the walls 174 facilitates heat transfer from the tab 180 to the wall 174 . The channel wall has a relatively large surface area, facilitating efficient heat transfer to the environment and enabling the channel wall 174 to function as a heat sink.
[0082] In additional embodiments, the casing 172 may be constructed of materials, such as certain plastics, that may not be capable of functioning as heat sinks because of inferior heat conductance properties. In such embodiments, the LED module 30 can be connected to its own relatively large heat sink base plate, which is mounted to the wall of the casing. An example of such a heat sink plate in conjunction with an LED lighting module has been disclosed above with reference to the self-contained lighting apparatus 100 .
[0083] With continued reference to FIGS. 22 and 23 , the LED modules 30 are preferably electrically connected in parallel relative to other modules 30 in the illumination apparatus 170 . A power supply cord 184 preferably enters through a wall 174 or bottom surface 176 of the casing 172 and preferably comprises two 18 AWG main conductors 186 . Short wires 188 are attached to the first and last contacts 62 , 64 of each module 30 and preferably connect with respective main conductors 186 using insulation displacement connectors (IDCs) 190 as shown in FIG. 23 .
[0084] Although the LEDs 32 in the modules 30 are operated at currents higher than typical LEDs, the power efficiency characteristic of LEDs is retained. For example, a typical channel light employing a neon-filled light could be expected to use about 60 watts of power during operation. A corresponding channel illumination apparatus 170 using a plurality of LED modules can be expected to use about 4.5 watts of power.
[0085] With reference again to FIG. 23 , the LED modules 30 are preferably positioned so that the LEDs 32 face generally downwardly, directing light away from the lens. The light is preferably directed to the diffusely-reflective wall and bottom surfaces 174 , 176 of the casing 172 . The hot spots associated with more direct forms of lighting, such as typical incandescent and gas-filled bulb arrangements, are thus avoided.
[0086] The reflectors 80 , 82 of the LED modules 30 aid in directing light rays emanating from the LEDs toward the diffusely-reflective surfaces. It is to be understood, however, that an LED module 30 not employing reflectors can also be appropriately used.
[0087] The relatively low profile of each LED module 30 facilitates the indirect method of lighting because substantially no shadow is created by the module when it is positioned on the wall 174 . A higher-profile light module would cast a shadow on the lens, producing an undesirable, visibly darkened area. To minimize the potential of shadowing, it is desired to space the modules 30 and accompanying power wires 186 , 188 a distance of at least about ½ inch from the top edge 178 of the wall 174 . More preferably, the modules 30 are spaced more than one inch from the top 178 of the wall 174 .
[0088] The small size and low profile of the LED modules 30 enables the modules to be mounted at various places along the channel wall 174 . For instance, with reference to FIGS. 21 and 24 , light modules 30 must sometimes be mounted to curving portions 192 of walls 174 . The modules 30 are preferably about 1 inch to 1½ inch long, including the mounting tab 180 , and thus can be acceptably mounted to a curving wall 192 . As shown, the mounting tab 180 may be separated from the curving wall 192 along a portion of its length, but the module is small enough that it is suitable for riveting to the wall.
[0089] In an additional embodiment shown in FIG. 25 , the module 30 comprises the circuit board without the mount tab 180 . In such an embodiment, the circuit board 50 may be mounted directly to the wall, having an even better fit relative to the curved surface 192 than the embodiment using a mount tab. In still another embodiment, the LED module's main body 56 is formed of a bendable material, which allows the module to fit more closely and easily to the curved wall surface.
[0090] Although the LED modules 30 disclosed above are mounted to the channel casing wall 174 with rivets 182 , it is to be understood that any method of mounting may be acceptably used. With reference next to FIGS. 26A-C , an additional embodiment comprises an LED module 30 mounted to a mounting tab 200 which comprises an elongate body portion 202 and a clip portion 204 . The clip portion 204 is urged over the top edge 178 of the casing wall 172 , firmly holding the mounting tab 200 to the wall 174 as shown in FIG. 26B . The lens 206 preferably has a channel portion 208 which is adapted to engage the top edge 178 of the casing wall 174 and can be fit over the clip portion 204 of the mount tab 200 as shown in FIGS. 26B and 26C . This mounting arrangement is simple and provides ample surface area contact between the casing wall 174 and the mounting tab 200 so that heat transfer is facilitated.
[0091] In the embodiment shown in FIG. 21 , the casing walls 174 are about 3 to 4 inches deep and the width of the channel is about 3 to 4 inches between the walls. In an apparatus of this size, LED modules 30 positioned on one side of the channel can provide sufficient lighting. The modules are preferably spaced about 5-6 inches apart. As may be anticipated, larger channel apparatus will likely require somewhat different arrangements of LED modules, including employing more LED modules. For example, a channel illumination apparatus having a channel width of 1 to 2 feet may employ LED modules on both walls and may even use multiple rows of LED modules. Additionally, the orientation of each of the modules may be varied in such a large channel illumination apparatus. For instance, with reference to FIG. 26D , some of the LED modules may desirably be angled so as to direct light at various angles relative to the diffusely reflective surfaces.
[0092] In order to avoid creating hot spots, a direct light path from the LED 32 to the lens 206 is preferably avoided. However, it is to be understood that pre-packaged LED lamps 32 having diffusely-reflective lenses may advantageously be directed toward the channel letter lens 206 .
[0093] Using LED modules 30 to illuminate a channel illumination apparatus 170 provides significant savings during manufacturing. For example, a number of LED modules, along with appropriate wiring and hardware, can be included in a kit which allows a technician to easily assemble a light by simply securing the modules in place along the wall of the casing and connecting the wiring appropriately using the IDCs. Although rivet holes may have to be drilled through the wall, there is no need for custom shaping, as is required with gas-filled bulbs. Accordingly, manufacturing effort and costs are significantly reduced.
[0094] Individual LEDs emit generally monochromatic light. Thus, it is preferable that an LED type be chosen which corresponds to the desired illumination color. Additionally, the diffuser is preferably chosen to be substantially the same color as the LEDs. Such an arrangement facilitates desirable brightness and color results. It is also to be understood that the diffusely-reflective wall and bottom surfaces may advantageously be coated to match the desired illumination color.
[0095] Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically-disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the invention have been shown and described in detail, other modifications, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed invention. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow. | A modular light emitting diode (LED) mounting configuration is provided including a light source module having a plurality of pre-packaged LEDs arranged in a serial array. The module includes a heat conductive body portion adapted to conduct heat generated by the LEDs to an adjacent heat sink. As a result, the LEDs are able to be operated with a higher current than normally allowed. Thus, brightness and performance of the LEDs is increased without decreasing the life expectancy of the LEDs. The LED modules can be used in a variety of illumination applications employing one or more modules. |
This application is a continuation-in-part of U.S. application Ser. No. 09/374,976, filed Aug. 16, 1999, now U.S. Pat. No. 6,250,517, which is a continuation of application Ser. No. 08/959,399, filed Oct. 28, 1997, now U.S. Pat. No. 5,971,231.
FIELD OF THE INVENTION
This invention generally relates to hand-held plastic containers for storing and dispensing particulate matter. More particularly, it relates to such containers with a cover having a plurality of flaps for enclosing, respectively, a plurality of openings in the cover. More particularly, it relates to containers for foodstuffs having a shaker opening with a plurality of holes and/or a spooning opening with a large opening adapted to receive a common household spoon.
BACKGROUND OF THE INVENTION
Plastic caps and receptacles for the disposable container industry suffer from certain incompatibilities. Generally speaking, they are considered interchangeable, since they have standard threads and standard major diameters. For this reason, one can expect a nominal “63 mm” cap to handily screw onto a “63 mm” receptacle. Beyond this, however, one cannot be assured of compatibility. Commercial receptacles or bottles typically have recessed shoulders adjacent to their open threaded ends to receive the threaded skirt of the cap. The goal is to screw a cap with an outer circular diameter onto a bottle with the same unrecessed outer diameter, thereby providing a cylindrical container with a constant outer diameter over its entire height. As a result, when one screws a random cap onto a random bottle, the skirt of the cap may interfere with the unrecessed portion of the bottle before the cap is screwed down. This will prevent the cap from being screwed completely down, thereby preventing the sealing surfaces of the cap from completely engaging the sealing surfaces of the bottle.
In addition to this incompatibility, the diameter and width of the sealing surfaces of the bottle and cap are often different, even when they have the same nominal thread pitch and major diameter. If a manufacturer wishes to make a cap (or bottle) that can be used with the greatest range of bottles (or caps) by other manufacturers, he is compelled to make as wide a sealing surface as possible. Unfortunately, this requires additional plastic.
There is another problem when manufacturing caps with wide sealing flanges: the propensity of the bottle top to buckle when screwed down too tightly. A wide flange permits force to be applied evenly to the top of bottles with warped sealing surfaces. These bottles have sealing surfaces at their mouths that are not truly circular, but are oval. By screwing a cap down firmly onto the bottle, such as with an automatic capping machine, the oval top begins to buckle, with some portions of the bottle bending inward, and some portions of the bottle bending outward. U.S. Pat. No. 4,693,399, which issued to Hickman (Sep. 15, 1987) purported to solve the ovality problem by providing the cap with a wide, flat sealing surface that was wide enough to accommodate a warped, oval-topped bottle. By providing a wide, flat surface against which the bottle could seal, the top of the bottle could be quite oval, yet there would still be sufficiently wide, flat surface against which it could seal. Unfortunately, this arrangement merely accommodated the out-of-roundness of a warped bottle. The tops of the bottles remained warped. This was an effective solution for hand-tightened caps, but was of quite limited value for machine-attached and tightened caps. Machines for attaching caps to bottles operate at high speeds. It is quite difficult to adjust them to provide a constant tightening torque. As a result the torque applied to seal a cap on bottle will vary significantly in a single production run. Given this wide range of tightening torques, the wide flange of the '399 patent can actual cause bottles to buckle during capping.
As the cap is tightened, the oval rim of the bottle slides against the wide, flat sealing flange, reducing friction between the rim and the wide sealing flange, making it easier to move axially inward or outward, toward or away from the central axis of the bottle. As a result of this reduced friction, the oval rim of the bottle tends to increase in ovality as the bottle is over-tightened until it either disengages from the threads or the bottle collapses.
What is needed is an improved cap that can accommodate a wide range of bottle mouth diameters. What is also needed is a cap that can correct (and not accommodate) bottles with warped oval mouths and sealing surfaces. It is an object of this invention to provide such a cap.
SUMMARY OF THE INVENTION
In accordance with a first embodiment of the invention, a circular plastic cap having a longitudinal axis is disclosed, the cap including an end cover, at least one flap integrally formed with the end cover, a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt. Each sealing surface may have an axial width substantially equal to or less than an average thickness of the cap. The sealing ring may include a plurality of substantially right cylindrical surfaces coaxial with the cap disposed between adjacent sealing surfaces.
Each right cylindrical surface may have a greater diameter the preceding right cylindrical surface as one approaches the open end of the skirt. The sealing ring may be fixed to the end cover. The sealing ring may or may not be fixed to the skirt.
In accordance with a second embodiment of the invention, a container is disclosed, the container including a receptacle including a right cylindrical sidewall having an externally threaded upper end and a lower end, a bottom integrally formed with the sidewall and enclosing the lower end of the sidewall, wherein the upper end of the receptacle defines a mouth having a mouth sealing surface, and a circular plastic cap having a longitudinal axis, wherein the cap further comprises an end cover, at least one flap integrally formed with the end cover, a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt, wherein one of the plurality of sealing surfaces is engaged with the mouth sealing surface and at least one of the plurality of sealing surfaces is not engaged with the mouth sealing surface. The end cover and the at least one flap may be configured to provide the cap with a substantially flat planar end surface. The at least one flap may be recessed into and flush with the end cover. The cap may further comprise a second flap, wherein the second flap is integrally formed with the end cover. The second flap may be recessed into and flush with the end cover. Each sealing surface may have an axial width substantially equal to or less than an average thickness of the cap. The sealing ring may include a plurality of substantially right cylindrical surfaces coaxial with the cap disposed between adjacent sealing surfaces. Each right cylindrical surface may have a greater diameter than a preceding right cylindrical surface as one approaches the open end of the skirt. The sealing ring may be fixed to the end cover. The sealing ring may not be fixed to the skirt.
In accordance with a third embodiment of the invention, a method of attaching an sealing a cap to a bottle is disclosed, wherein the cap comprises an end cover; a cylindrical skirt integrally coupled to the end cover at one end and having a second open end configured to receive the mouth of a receptacle, and a circular sealing ring disposed inside the skirt and adjacent to the end cover, the sealing ring having a plurality of planar sealing surfaces, axially spaced apart, such that each sealing surface has a greater diameter the closer that sealing ring is to the open end of the skirt, and wherein the bottle comprises a right cylindrical sidewall having an externally threaded upper end and a lower end, a bottom integrally formed with the sidewall and enclosing the lower end of the sidewall, wherein the upper end of the receptacle defines a mouth having a mouth sealing surface, wherein the method includes gripping the bottle in an automatic capping machine, gripping the cap in an automatic capping machine, rotating the cap clockwise with respect to the bottle while advancing the cap toward the bottle, engaging the external threads on the bottle to the internal threads on the cap, rotating the cap until the mouth sealing surface engages a first of the plurality of sealing surfaces, further rotating the cap until the mouth sealing surface engages a second of the plurality of sealing surfaces, wherein the second of the plurality of sealing surfaces has a smaller diameter than the first of the plurality of sealing surfaces, and sealing the container against the second of the plurality of sealing surfaces. The step of further rotating the cap may include the step of guiding at least a portion of the mouth sealing surface inwardly toward the axis of the cap. The step of further rotating the cap may include the step of deforming the mouth sealing surface into a more circular shape.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional side view of a container including a cover and receptacle in accordance with the current invention showing the flaps in an open position and as dashed lines in a closed position;
FIG. 2 is an orthogonal view of the cover of FIG. 1, showing the flaps in an open position;
FIG. 3 is a cross-sectional view of the container of FIG. 1 showing the angled orientation of the flap skirts;
FIG. 4 is a top view of the cover of FIG. 1 with the flaps in an open position;
FIG. 5 is a bottom view of the cover showing the circular sealing surfaces;
FIG. 6 is a partial plan view of the sealing ring of the cap (not to scale) showing each of the sealing surfaces enlarged in exaggerated form together with the rim of the receptacle, wherein the rim of the receptacle is oval and the rim has just contacted the sealing ring during tightening;
FIG. 7 is a partial cross-sectional side view of the sealing ring and receptacle rim of FIG. 6 in cross-section wherein the cutting plane for the cross section is coplanar with the longitudinal axis of the receptacle and sealing ring;
FIG. 8 is a partial plan view of the sealing ring of the cap (not to scale) showing each of the sealing surfaces enlarged in exaggerated form together with the rim of the receptacle as in FIGS. 6 and 7, but after the cap has been tightened and the rim has been drawn down into the sealing ring and the ovality of the rim corrected;
FIG. 9 is a partial cross-sectional side view of the sealing ring and receptacle rim of FIG. 8 wherein the cutting plane of the cross-section is coplanar with the longitudinal axis of the sealing ring and the receptacle; and+
FIGS. 10-12 are fragmentary cross sections of the cover and receptacle along a section line that is planar with the major elliptical axis of the warped receptacle shown in FIGS. 6-9 as the cap is tightened on the receptacle.
DETAILED DESCRIPTION OF THE INVENTION
Before explaining at least one embodiment of the invention in detail it is to be understood that the invention is not limited in its application to the details of construction in the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
FIG. 1 illustrates a container 10 having a receptacle 12 and a cap or cover 14 . Cover 14 includes a shaker flap 16 , called a shaker flap because it covers (when closed) shaker openings 18 disposed in planar top portion 20 of the cover. Cover 14 also includes a spooning flap 22 that similarly covers a larger spooning opening 24 also disposed in top portion 20 .
The cover as best seen in FIG. 2, is in the form of a substantially cylindrical portion 26 , and top portion 20 which is coupled to an upper end of cylindrical portion 26 to enclose cylindrical portion 26 . Referring to FIG. 1, which shows a portion of the cover in cross-section with the receptacle attached, threads 28 are provided on the inner surface of cylindrical portion 26 for coupling cylindrical portion 26 to the outside of the top of receptacle 12 . As seen in FIG. 1, mating threads are disposed on an outer indented top portion of receptacle 12 to engage threads 28 . Alternatively, cylindrical portion 26 may be equipped with an inner detent or a raised ring to allow it to be snap connected to the top portion of receptacle 12 . Referring to FIG. 2, an elongate recess 19 is provided in which shaker flap 16 will fit when flap 16 is in a closed position, to provide a substantially flat upper surface of top portion 20 on which a similar container can be stacked.
Referring back to FIG. 1, receptacle 12 includes a substantially planar bottom portion 30 that is adapted to engage a lip 32 of cover 14 . There is a significant advantage to this feature: since the bottom portion 30 is adapted to engage lip 32 , then a plurality of containers identical to the one pictured in FIGS. 1 and 2 can be stacked one atop the other, lip 32 serving to orient the bottom of the next higher container and so keep the containers in proper alignment when stacked. In FIG. 1, two identical containers are shown in this stacked arrangement, the bottom of the upper container being shown as dashed line 34 engaging rim 32 when the flaps of the lower container are in a closed position (shown in FIG. 1 as dashed lines when in their closed positions). It can be seen that bottom portion 30 (and hence identical bottom portion 34 ) and top portion 20 with lip 32 are adapted to engage one another. Lip 32 is disposed at an outer edge of cover 14 to engage a recess 36 at the junction of bottom 30 and wall 38 of receptacle 12 . By disposing both lip 32 and recess 36 to engage each other near the outer periphery of the container, study has shown that the containers are more easily stacked, and when stacked tend to self-center. A portion of lip 32 is preferably disposed on shaker flap 16 , spooning flap 22 as well as on the non-hinged sides of top portion 20 as can be best seen in FIG. 4 . Each of these portions is preferably disposed at an outer edge of cover 14 and have substantially the same diameter. Other designs, provide orienting means disposed more closely to the center of the container, such as by providing an indentation at or near the center of the receptacle bottom that engages with an upwardly extending protrusion located near the center of the cover on which it is stacked, are more difficult to stack accurately and also tend to tip more easily. In addition, it is harder to hold tolerances on an inner indentation than an outer indentation as shown in FIG. 1 . These designs have the added disadvantage of requiring an internal recess to be formed in the center of the receptacle bottom, requiring additional machining to manufacture.
Referring to FIGS. 1 and 2, a plurality of oval shaker openings 18 , preferably substantially circular as shown here, are provided to allow foodstuffs within the container to be shaken out when shaker flap 16 is opened. These openings are preferably arranged not along a straight line, but along an arc. On the underside of shaker flap 16 is an arcuate flange 40 adapted to engage and seal central shaker opening 18 . This flange extends for about 30 degrees around the periphery of its mating opening 18 when in a closed position. Flange 40 engages the inner surface of opening 18 and holds the shaker flap closed.
FIG. 3 shows cover 14 in cross-section along a diametral line of the cover. The cross section is perpendicular to both the shaker flap hinge 50 and the spooning flap hinge 58 . Flange 40 does not extend perpendicularly from the underside of shaker flap 16 , but downward and outward at an angle of between 9 and 25 degrees, and more preferably of between 5 and 20 degrees with respect to the longitudinal axis of container 10 . This angular relationship is particularly beneficial in that it allows the cover, including the flaps, to be readily and integrally molded as a single monolithic piece. In addition, this angle allows flange 40 to releasably lock into central opening 18 when shaker flap 16 is closed.
Shaker flap 16 also includes a skirt 46 that extends downwardly from shaker flap 16 . Skirt 46 is disposed an outer edge of shaker flap 16 . Skirt 46 is indented into the cap to provide, together with the outer surface of cylindrical portion 26 a substantially right circular cylindrical wall.
Skirt 46 has an indentation 48 disposed at a central outer portion of skirt 46 and is configured to receive a finger or finger nail of the user. This allows the user to grasp shaker flap 16 and readily open container 10 by lifting upward on the indentation.
Skirt 46 preferably extends around cover 14 for an arcuate length of between 60 and 120 degrees (see FIG. 4 ). From an outward appearance, therefore, skirt 46 would appear to form between 60 and 120 degrees of the circumference of the upper part of cover 14 . This provides a significant advantage in the design of cover 14 .
Since skirt 46 is arcuate, rather than straight, it is less likely to be bent over when the cover is grasped and opened, and further distributes the grasping load more evenly around the outer edge of shaker flap 16 . This allows shaker flap 16 to be made thinner and therefore to require less plastic when manufactured.
Referring to FIG. 3, when the shaker flap 16 is closed, flange 40 engages an outer portion of shaker opening 18 to thereby releasably lock shaker flap 16 to top portion 20 in a closed position. While only a single flange 40 is shown in cross section in FIG. 4, each of the other openings 18 may also have a flange (not shown) to provide additional engagement surfaces and thereby hold the shaker flap closed even better.
Shaker flap 16 is coupled to top portion 20 by a flexible and integrally formed hinge 50 preferably extending the entire length of shaker flap 16 .
Spooning flap 22 is coupled to top portion 20 by a flexible and integrally formed hinge 58 preferably extending the entire length of spooning flap 22 . Note that, unlike certain prior art covers with hingeable flaps, hinges 50 and 58 are disposed adjacent to a diametral line of cover 14 to allow the flaps to hinge upward and toward the middle of cover 14 . In prior art covers, the hinges were formed along an outer edge of the cover, which allowed the flaps to be opened upward and outward. This caused the flap to dangle in its open position. As a result, the flap was often in the way of the material being shaken out of the container, causing the flap to be covered with the foodstuffs or other materials inside.
Spooning flap 22 covers spooning opening 24 . Spooning flap 22 has a flange 52 depending from a lower surface of spooning flap 22 that engages and locks against the inside of opening 24 . As with flange 40 on the shaker flap, Flange 52 does not extend perpendicularly from the underside of spooning flap 22 , but extends at an angle, preferably between 9 and 25 degrees outward and downward away from the underside of the spooning flap.
As with flange 40 of the shaker flap, by disposing flange 52 at this angle, cover 14 can be manufactured in a single piece with spooning flap 22 formed integrally with cover 14 . Flange 52 preferably has an arcuate length of between 20 and 180 degrees (shown as 20 degrees here). Over this length, flange 52 engages the inside edge of spooning opening 24 to releasably lock spooning flap 22 to top portion 20 when spooning flap 22 is in a closed position.
Spooning flap 22 also includes a skirt 60 like skirt 46 of the shaker flap. Like skirt 46 , skirt 60 extends downwardly from spooning flap 22 near an outer edge of spooning flap 22 and has an arcuate shape to define an outer substantially vertical surface of cover 14 when spooning flap 22 is in a closed position. Skirt 60 has an indentation 61 disposed at a central outer portion of skirt 60 and is configured to receive a finger or fingernail of the user. This allows the user to grasp spooning flap 22 and readily open container 10 . Skirt 60 preferably extends around the circumference of cover 14 when in the closed position for an angle pi of between 100 and 150 degrees (see FIG. 4 ). From an outward appearance, therefore, skirt 60 would appear to form between 100 and 150 degrees of the circumference of the upper part of cover 14 . As with skirt 46 of shaker flap 16 , since skirt 60 is arcuate, rather than straight, it has greater structural strength and it is less likely to be bent over when its flap is grasped and opened, and further distributes the grasping load more evenly around the outer edge of spooning flap 22 . This allows spooning flap 22 to be made thinner and therefore to require less plastic when manufactured. Note that the arcuate length of skirt 60 is preferably greater than the arcuate length of skirt 46 . This additional arcuate length of skirt 60 therefore provides additional strength to spooning flap 22 when the user attempts to open spooning flap 22 .
A recess 62 is provided in the cylindrical portion of cover 14 to receive skirt 46 of shaker flap 16 . By providing recess 62 , skirt 46 can be set into an outer surface of cover 14 when shaker flap is closed, thereby reducing the risk that skirt 46 will be accidentally jostled and caught, shaker flap 16 opened and the contents of container 10 spilled. Similarly, a recess 64 is provided in cover 14 on the opposite side of cover 14 from recess 62 to similarly receive skirt 60 of spooning flap 22 for the same reason. The effect of skirts 46 and 60 being recessed is that the skirts form a smooth and contiguous part of the outer surface of the cylindrical portion of cover 14 .
The rim 70 of receptacle 12 has an upper sealing surface 72 that abuts sealing ring 74 of the cover when the cover is screwed onto the receptacle. Sealing ring 74 has several separate and distinct sealing surfaces 76 . These surfaces are flat and extend normal to the longitudinal axis of the cap. Each sealing surface is separated from adjacent sealing surfaces by cylindrical walls 78 that are circular and parallel to the longitudinal axis of the cap. Each sealing surface defines a plane that is substantially perpendicular to the longitudinal axis of the receptacle and cover. Each of these planes intersects the longitudinal axis at a different point along its length.
The wide sealing surface of the '399 patent discussed briefly in the Background of the Invention is intended to accommodate rather than correct the ovality of the bottle openings. By providing a wide sealing surface, the bottle opening can be quite oval, yet will engage around its entire periphery with the sealing surface, thus providing a good, although oval seal. As we noted above, this may be effective for hand-tightened caps but not for machine-tightened caps. As torque is applied to a cap with an oval bottle opening and bottle sealing surface, the walls of the bottle at its mouth that are distorted inward toward the central axis of the bottle will collapse and be forced inward. In a similar fashion, the walls of the bottle at its mouth that are distorted outward away from the central axis of the bottle, will collapse and be forced outward. Thus, when the cap is over tightened on the bottle, the mouth of an oval bottle becomes even more oval until it finally collapses. In contrast to this, the sealing surfaces of the present invention are designed to prevent the collapse of the bottle's mouth by forcing the mouth of the bottle into a circular shape. Alternatively, the mouth of the bottle becomes ever more oval as the cap is over-torqued onto the bottle. This causes the threads adjacent to the minor axis of the oval bottle mouth to pull away from the mating threads on the caps. This disengagement, in turn, causes the cap to pop off.
The stepped sealing surfaces are preferable to that of the prior art since they force warped, non-circular container mouths into a circular shape as the cap is screwed down, unlike the wide sealing surface of the '399 patent.
In FIGS. 6 and 7, a warped bottle with an oval rim 70 and sealing surface 72 of FIGS. 6-7 has just been screwed into cover 14 of FIGS. 6 and 7 by an automatic capping machine. Rim 70 just contacts the outermost sealing surface 76 of cover 14 having the largest inner and outer diameter (a slight gap is shown for convenience). In a typically manufacturing line, the automatic capping machine would rotate the cover until it reached this position, at which a certain (minimal) initial resistance to rotation would exist due to contact at points 78 and 80 .
The top of the bottle is in the form of an ellipse or oval and therefore rim 70 has a major axis and a minor axis. The first parts of the bottle sealing surface to contact ring 74 are the portions of the sealing surface at the opposing ends of the major axis. The endpoints 82 , 84 of the minor axis of the sealing surface do not even contact the cover, but are suspended in space.
The tightening process does not stop with this initial contact at points 78 , 80 , however. The torque applied by automatic capping machines has not reached its preset torque limit, and hence continues rotating, tightening the cover even more firmly to the receptacle.
Since there are several independent sealing surfaces 76 on the cap, arranged in a stair step fashion, the bottle contacts the cap initially at only two small points on the rim as shown in FIGS. 6 and 7. As a result of this relatively high load on two small points of rim 70 , the capping machine's additional torque causes rim 70 to deflect and bend slightly.
As the cover is further screwed down, endpoints 78 , 80 of the major axis of sealing surface 72 are deflected inward under the increasing pressure between the cover and receptacle. Eventually, rim 70 and its sealing surface 72 assume a more circular shape. As the cover is screwed down further, the endpoints 78 , 80 of the major axis are pushed inward toward the central axis of the cover and receptacle, and the endpoints 82 , 84 of the minor axis are deflected outward, away from the central axis. Eventually, the rim itself is circular enough (i.e. the major axis is small enough) that the rim collapses into the next smaller diameter sealing ring 76 .
This new position is shown in FIGS. 8 and 9. Note that the rim is more circular, and is completely supported on the next smaller sealing surface 76 . Since the diameter of the sealing surface 72 on rim 70 is substantially the same as the diameter of the sealing surface 76 on the cover, the cover cannot be screwed any further onto the receptacle without collapsing or bending the entire rim of the receptacle. As additional torque is applied by the capping machine to rotate the cover onto the receptacle, there is no further collapse of the rim, and the torque rises quite rapidly to the torque limit of the automatic capping machine.
During this final period of rotation, the two abutting sealing surfaces rotate with respect to each other. It is this relative rotation and slippage that applies the additional torque. As a result, the friction between the surfaces is reduced to sliding friction and the rim slides with respect to sealing surface. In the device of the '399 patent, there is nothing to stop the deflection from causing rim 70 to warp into an extremely oval shape. As a result, the threads often pull apart and the cover pops off.
In the present invention, however, there is a mechanism to prevent the additional torque from causing more ovality. The cylindrical wall 79 between sealing surfaces 76 a and 76 b of the cover prevents rim 70 from deflecting outward as the final torque is applied. Rim 70 is nested inside this cylindrical surface, and therefore cannot move outward into a more out-of-round condition. If it starts to move outward, it abuts cylindrical surface 79 and stops while it is still substantially circular, and before the threads of the cover and the receptacle pull away from each other and disengage.
FIGS. 10-12 show how a receptacle rim collapses to a smaller diameter along the major axis of the receptacle's rim. FIG. 10 shows rim 70 as it approaches sealing surface 76 of cover 14 . Point 78 is one of the end points on the major diameter of the oval-topped warped receptacle. Threads 28 a on the receptacle engage threads 28 b on the cover. As the cover and receptacle are rotated with respect to each other receptacle 12 moves until it is in the position shown in FIG. 11, the second of the three FIGURES. In this position, the rim just contacts the sealing surface 76 (a slight gap is shown to make the drawing easier to understand). As additional torque is applied to the cap, it rotates further until it is in the position of FIG. 12 and point 78 of rim 70 collapses to the next smaller diameter sealing surface 76 . Note that the threads 28 a and 28 b move slightly apart. At this stage, the entire sealing surface 72 of the rim contacts sealing surface 76 of cover 14 (a slight gap is shown to make the drawing easier to understand). The rim cannot collapse inward any further when additional torque is applied, since the minor axis has increased (as shown in FIGS. 8-9) so that it abuts cylindrical surface 79 between two adjacent sealing surfaces 7 b.
The FIGURES show how a single receptacle with a single rim diameter is sealed against the cover. The cover is not limited to a single rim diameter, however. Since there are several sealing surfaces on the cover (four of them in the embodiments illustrated herein), each having a slightly smaller diameter, the cover can be screwed onto four different receptacles with four different rim diameters. For each of these receptacles, the operation would be the same as described above: initial contact with a first sealing surface at two points on the major diameter, collapse to the next smaller sealing surface on the cover's sealing ring, and the application of a final tightening torque while the cylindrical surface prevents the rim from deflecting outward. With four different sealing surfaces and three different cylindrical surfaces between them, this cover can accommodate at least three different receptacle rim diameters—three different receptacles. The only difference in operation is that receptacles with smaller rim diameters will rest on sealing surfaces 76 that also have smaller diameters. Receptacles with larger diameter will nest on sealing surfaces 76 with larger diameters.
The system therefore accommodates a variety of receptacle mouth sizes by providing several sealing surfaces against which they can seal. It also corrects the shape of warped bottles used with automatic capping machines by forcing the bottles to collapse inward until the entire sealing surface at the rim of the bottle assumes a circular shape.
Thus, it should be apparent that there has been provided in accordance with the present invention an improved container that fully satisfies the objectives and advantages set forth above. Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. | A plastic cap has one or more hinged flaps that cover openings in the cap, as well as a stepped sealing ring against which the top of a plastic bottle seals. The sealing ring is stepped, much like the rows of seats in a circular stadium. This stepped arrangement permits the cap to be used with many different bottle rim diameters and automatically corrects any ovality of the bottle rim by forcing it to flex into a more circular shape as it engages the steps of the stepped ring. |
BACKGROUND OF THE INVENTION
The present invention generally relates to signal pickup devices in rotary recording medium reproducing apparatuses, and more particularly to a signal pickup device capable of controlling the tracking accurately and efficiently. The tracking control is performed in a manner such that a cantilever rotates to displace a reproducing element which reproduces recorded signals from a rotary recording medium in a direction perpendicular to the longitudinal direction of tracks of the rotary recording medium to follow and trace the same.
Heretofore, there have been apparatus of the designed type. For example, a rotary disc (referred to as "disc" hereinafter) has a video signal recorded on a spiral track as variations in the geometrical shapes corresponding to an information content. A reproducing element is caused to trace over the spiral track and reproduce the recorded video signal. In a pickup device of this character, it is necessary for the signal pickup device to trace the track accurately. For this reason, it is necessary to provide means for detecting any tracking deviation of the signal pickup device relative to the track. In response to this error, the position of the signal pickup device is controlled so that it will trace accurately over the track thereby accomplishing a tracking control.
The present applicant has previously described in a commonly assigned U.S. patent application. Ser. No. 885,579, filed Mar. 13, 1978 (U.S. Pat. No. 4,170,783) by Osamu Tajima, and entitled "Signal pickup device for reproducing an information signal recorded on a track of a rotary recording medium" a signal pickup device in which a permanent magnet member of a rectangular parallelepiped shape and having magnetic poles on the opposite lateral faces thereof is fixed to the proximal end of a cantilever, the cantilever is supported by an elastic support member at a separated point in front of the permanent magnet so as to be rotatable, and a tracking coil is disposed in the rear position with respect to the elastic support member so as to surround the permanent magnet member. On tracking control operation, a torque is produced to act on a cantilever assembly comprising the cantilever, the reproducing element, and the permanent magnet member.
A positional relationship between the permanent magnet member, the elastic support member, and the tracking coil causes a center of the torque to be located at a position which is far apart backwards (in a direction opposite to the reproducing element) with respect to the point where the elastic support member supports the cantilever.
In this connection, the torque for tracking control acts on the elastic support member is an extending (or axial) direction thereof, and the tracking control inevitably accompanies compression and stretching deformation in the axial direction of the elastic support member.
This signal pickup device is accompanied by various problems such that 1 the elastic support member is brought into resonance at a specific frequency, whereby a tracking servo system is subjected to phase delay, thus deteriorating tracking accuracy, and 2 a large torque sufficient to compress and stretch the elastic support member is required, which results in a substantial decrease in efficiency of the tracking control operation.
SUMMARY OF THE INVENTION
Accordingly, a general object of the present invention is to provide a novel and useful signal pickup device in a rotary recording medium reproducing apparatus, in which the above described problems have been overcome.
Another and more specific object of the present invention is to provide a signal pickup device in a rotary recording medium reproducing apparatus in which an elastic support member is disposed at a position of a permanent magnet magnetized in a longitudinal direction thereof, and tracking coils are disposed at both forward and rearward positions with respect to the elastic support member so as to confront opposite magnetic poles respectively. According to the present invention, a center of rotational torque produced on the cantilever assembly due to reaction on the permanent magnet on tracking control operation coincides with a point where the cantilever assembly is supported by the elastic support member, whereby tracking control operation is effected with high accuracy and efficiency.
Other objects and further features of the present invention will be apparent from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view, partly in horizontal section, of an embodiment of a signal pickup device according to the present invention;
FIG. 2 is a vertical section taken along the line II--II in FIG. 1 as viewed in the arrow direction;
FIG. 3 is an elevational view, in section, showing the signal pickup device in a state where a pickup cartridge is to be loaded;
FIG. 4 is an exploded perspective view of an embodiment of a signal pickup device of FIGS. 1 and 2;
FIG. 5 is a plan view showing an essential part of the signal pickup device of FIG. 1; and
FIG. 6 is a simplified diagram for explaining how rotational force acts on the cantilever assembly.
DETAILED DESCRIPTION
In FIGS. 1 through 4, a signal pickup device 10 is provided within a carrier 12 which moves in a radial direction of a disc 11. A reproducing stylus 13 traces relatively the spiral track of the disc 11 rotating in the direction indicated by arrow A and reproduces an information signal therefrom.
The signal pickup device 10 substantially comprises a cartridge 15, a guide member 16 for receiving and rotating the cartridge 15, and a fixed coil mounting member 17 mounted with a coil group. The cartridge 15 comprises a case 18, a lid 19, and a cantilever assembly 20 mounted with a reproducing stylus 16.
In the cantilever assembly 20, the reproducing stylus 13 is mounted at the tip end of a plate-shaped holder 21. The rear end of the holder 21 is mounted to the tip end of a cantilever 22 constructed from a pipe made of light metal such as aluminum. A permanent magnet 23 having a cylindrical shape and magnetized in a longitudinal or axial direction thereof, is insertedly fixed to a space part at the rear end of the cantilever 22. The ring-shaped part 24a of an elastic support member (suspension) 24 made of rubber, is insertedly connected to the rear end outer periphery of the cantilever 22. A pair of arms 24b and 24c unitarily extend in a direction perpendicular to the longitudinal direction of the cantilever 22, which are provided at both sides of the ring-shaped part of the support member 24.
The cantilever assembly 20 of the above described consturction is accommodated within the case 18, wherein the arms 24a and 24b of the support member 24 are pushed and inserted into slots 25a and 25b of the case 18. The lid 19 is mounted freely rotatable on the case 18, and when the signal pickup apparatus is not used, the lid 19 is in a rotated position where the reproducing stylus 13 is protected. On the other hand, when the signal pickup apparatus is being used, the lid 19 is rotated to a position where the reproducing stylus is not interfered.
The guide member 16 comprises grooves 26a and 26b for receiving the cartridge 15, and is ortatably mounted on the carrier 12 by a shaft 27. A coil 28 for elevating stylus is screwed by a screw 29 onto the lower surface of the guide member 16. Further, onto the upper surface of the guide member 16 is screwed a lid 30 by a screw 31. The lid 30 is made of a metal plate and is hinged on the shaft 27. A gap dimension a between the lid 30 and the guide member 16 is appropriately determined by adjusting a screw-in amount of an adjust screw 32 through an opening 30a of the lid 30 and then by screwing the set screw 31.
The coil mounting member 17 is fixed to the carrier 12, and comprises four tracking control coils 35a, 35b, 36a, and 36b, and a single jitter compensation coil 37 mounted thereon. These tracking control coils are classified into a pair of tracking control coils 35a and 35b, and another pair of tracking control coils 36a and 36b, which are mounted inside arms 17a and 17b of the coil mounting member 17 to project inwardly therefrom so as to confront with each other. A first pair of tracking control coils 35a and 35b and a second pair of tracking control coios 36a and 36b are arranged with separated with each other in the forward and rearward directions, that is, in the axial direction of the cantilever 22. Further, the tracking control coils 35a, 35b, 36a, and 36b are respectively provided on nonmagnetic bobbins 38a, 38b, 39a, and 39b which are embeddedly mounted to the arms 17a and 17b at the inside thereof.
Next to be described is how the cartridge 15 is loaded to a predetermined position. Loading operation comprises two steps, that is, insertion and rotation.
Referring to FIG. 3, upon loading, the lid 30 is rotated together with the guide member 16 to a substantially upright open position. The cartridge 15 is inserted, in the arrow direction B, into the guide member 16, with lateral side flanges of a top plate of the case 18 engaged into guide grooves 26a and 26b of the guide member 16. This insertion brings the permanent magnet 23 of the cantilever assembly 20 to confront the stylus elevating coil 28.
Then, the lid 19 of the cartridge 15 is rotated clockwise to open, and the lid 30 is rotated, in the arrow direction C, to be closed. The lid 30 is latched at a horizontal closed state thereof by a latch 40, as indicated in FIG. 2.
When the lid 30 is closed, the cartridge 15 (that is, the cantilever assembly 20) is rotated, with being held in the guide member 16, about the shaft 27, and the arms 24b and 24c of the elastic support member 24 are respectively brought downwards in the spaces formed between the coils 35a and 35b, and the coils 36a and 36b.
Furthermore, the cartridge 15 is finally positioned with respect to the fixed coil mounting member 17. That is, positioning slots 41a and 41b on side walls of the case 18 are respectively engaged with the bobbins 39a and 39b at narrow parts with flanges 39a-1 and 39b-1 thereof, and further make contact with the flanges of the narrow parts 39a-1 and 39b-1, whereby the case 18 is positioned with respect to the directions of arrow X and Y as viewed in FIG. 1. The slots 41a and 41b may be engaged with a part of the coil mounting member 17 instead of the bobbins 39a and 39b. Furthermore, the top plate of the case 18 abuts against studs 42a and 42b, whereby the case 18 is positioned with respect to the direction of arrow Z as viewed in FIG. 2. The metal-plate lid 30 is latched by the latch 40, with free end thereof being forcibly deflected downwards by an amount determined by the gap dimension a. Spring force generated by this deflection serves to press the case top plate against the studs 42a and 42b.
Accordingly, the cartridge 15, that is, the cantilever assembly 20 is positioned with respect to the directions of arrow X, Y, and Z, that is, in both horizontal and vertical planes. The arms 24b and 24c of the elastic support member 24 are respectively inserted in the spaces formed between the coils 35a and 36a, and the coils 35b and 36b. Moreover, a metal ribbon 43 which is connected at one end thereof to the reproducing stylus 13 makes press-contact with a central conductor 45 of a cavity resonator 44.
Accordingly, the signal pickup device 10 now assumes an operable state as indicated in FIGS. 1 and 2.
As to positioning of the cartridge 15, a modification will be made so that an opening 46 of the case top plate engages with a semi-spherical projection 42b-1 and the top plate around the opening 46 presses against an annular top surface of the stud 42b, as indicated by two-dot chain lines in FIG. 2. This construction causes the case 18 to be positioned in the horizontal plane and the height direction simultaneously.
In this signal pickup device 10, two pairs of tracking coils 35a and 35b, and 36a and 36b are arranged so that the axes thereof are aligned in a direction parallel to the disc 11 and perpendicular to the magnetized direction of the permanent magnet 23. A pair of tracking coils 35a and 35b is disposed at a position nearer to the reproducing stylus (that is, forwards) with respect to the elastic support member 24, to have axial edge surfaces of the tracking coils 35a and 35b located near the S pole of the permanent magnet 23. Another pair of tracking coils 36a and 36b is disposed at a position further from the reproducing stylus (that is, rearwards) with respect to the elastic support member 24, to have axial edge surfaces of the tracking coils 36a and 36b located near the N pole of the permanent magnet 23.
The axis of the coil 27 is arranged in the same direction as the magnetized direction of the permanent magnet 23.
In a state in which current is not applied to the coil 28, the cantilever 22 is supported by the support member 24, and the reproducing stylus 13 is positioned at a height where the reproducing stylus 13 does not make contact with the disc 11. Upon reproduction, when current is applied to the coil 28, the cantilever 22 receives a downward force, and rotates downwards while twisting the support member 24. Accordingly, the reproducing stylus 13 is applied with a predetermined stylus pressure, and makes contact with the disc 11.
By flowing a current having a level and direction respective of the tracking error signal through the tracking control coils 35a, 35b, 36a, and 36b, opposite magnetic polarities are introduced at the edge surfaces of the opposing coils. Hence, repulsive force is introduced on the hand, and on the other, attractive force is introduced between the magnetic polarities of the permanent magnet 23. Accordingly, the cantilever 22 is displaced by a predetermined quantity in a direction the tracking deviation is to be compensated, in the radial direction of the disc 11 shown by arrow Y of FIG. 1.
When the tracking control coils 35a, 35b, 36a and 36b generate magnetic polarities as indicated in FIG. 5, for example, forces P and R are generated at opposite magnetic polarities of the permanent magnet 23, as indicated in FIG. 6. These forces P and R, which act as a couple on the permanent magnet 23, generate a torque. As a result of this torque, the cantilever 22 rotates in the direction of arrow, and the reproducing stylus 13 is thereby displaced in the radial direction toward the disc center. Conversely, when the tracking control current flows in the opposite direction, the forces opposite to the above described forces P and R are generated at the opposite magnetic polarities of the permanent magnet 23 to rotate the cantilever 22 in a direction opposite to the arrow. The reproducing stylus 13 is displaced toward the outside periphery of the disc 11. Thus, a tracking control is accomplished so that the reproducing stylus 13 traces along the track. The forces P and R depend upon the winding turns of the coils 35a, 35b and 36a, 36b, and the amount of the tracking control current supplied to the coils.
The factors of the coils 35a, 35b, 36a and 36b and the cantilever assembly 20 are determined so that the center of the torque due to the forces P and R coincides with a support point O where the cantilever assembly 20 is supported by the elastic support member 24 (i.e., a center line of the cylindrical arms 24b and 24c).
Next to be described is how the above factors are determined in the signal pickup device 10.
In order for the center of the rotational torque due to the forces P and R coinciding with the support point O, the cantilever assembly 20 must satisfy the following physical impulsive force equations:
M·u=R-P
Io·ω=P(X.sub.G -z)+R(h-X.sub.G +z)
u=ω·z
where:
M is the mass of the cantilever assembly 20;
P and R are forces acting on the axial edges of the permanent magnet 23;
u is the moving speed of center of gravity of the cantilever assembly when the forces P and R are applied thereto;
Io is the moment of inertia of the cantilever assembly 20 about the support point O;
is the angular speed of the cantilever assembly 20;
ω is the angular speed of the cantilever assembly 20;
z is the distance between the support point O and the center of gravity G;
h is the distance between the opposite magnetic poles of the permanent magnet 23; and
X G is the distance between the free end of the permanent magnet 23 and the center of gravity G.
By eliminating factors u and ω, the equation (1) is rearranged as follows;
[R(X.sub.G -z)+R(h-X.sub.G +z)]z·M=(R-P)Io (2)
Moreover, the relationship of moment of inertia is expressed by a following equation;
Io=I.sub.G +M·z.sup.2 (3)
where, I G is the moment of inertia of the cantilever assembly 20 about the center of gravity G.
From equations (2) and (3), is obtained a following equation (4). ##EQU1##
Accordingly, when the winding turns, resistance and disposition with respect to the permanent magnet 23 of the tracking coils 35a, 35b, 36a and 36b, and mechanical various factors of the cantilever assembly 20 are determined so as to satisfy the above given equation (4), the torque on the cantilever assembly 20 induced by the coils 35a, 35b, 36a and 36b is generated as a torque about the support point O as a center thereof.
The dimension and position of the ring-shaped part 24a and the arms 24b and 24c of the elastic support member 24 is determined so that when the ring-shaped part 24a and the cantilever 22 are assembled together, with projected edge 24a-1 of the ring-shaped part 24a coinciding with the edge face of the cantilever 22 (or permanent magnet 23), the distances X G and z are determined inevitably so as to satisfy the equation (4) in connection with the predetermined forces P and R. Accordingly, after assembly, no adjusting operation is required.
In the signal pickup device 10 thus assembled, the torque to be applied on the cantilever assembly 20, upon tracking control operation, is generated as a torque exactly about support point O. On the arms 24b and 24c of the elastic support member 24, is thereby applied only the bending force. No axial force is applied to the cylindrical arms 24b and 24c. In this connection, the force counter to the tracking control operation is limited to bending drag of the elastic support member 24, which ensures that the tracking control operation is accomplished with small torque. Moreover, the tracking control operation is not accompanied by axial compression and stretching deformation of the arms 24b and 24c of the elastic support member 24. This deformation becomes a cause of resonance of the cantilever assembly 20. As a result, the actual tracking control operation is accomplished with high efficiency and accuracy, without accompanying any energy absorption and phase delay due to resonance.
In the present embodiment of the invention, each pair of tracking coils is disposed at the front and rear sides of the support member 24. In this arrangement, magnetic flux of the permanent magnet 23 is utilized more efficiently, thus ensuring more efficient tracking control operation. In principle, a structure wherein a single tracking coil is disposed respectively at front and rear sides may be adopted, this structure is involved within the scope of the present invention.
The bobbins 38a, 38b, 39a and 39b are made of ferromagnetic material, which results in more effective utilization of magnetic flux of the permanent magnet 23. Accordingly, tracking control operation is carried out with higher efficiency. In place of the whole ferromagnetic bobbins, bobbin structure may be used wherein ferromagnetic material constitutes a part of the bobbin such that an iron rod is embedded in the center of the bobbin and the iron column occupies the bobbin at a side aparted from the permanent magnet.
Furthermore, when a jitter compensation current having a level and polarity respective of the jitter which is to be compensated, is passed through the jitter compensation coil 37, a magnetic field is introduced between the permanent magnet 23 and the coil 37. When a magnetic polarity which is the same as that of the permanent magnet 23 is introduced at the edge surface of the coil 37 opposing the permanent magnet 23, repulsive force is introduced between the coil 37 and the permanent magnet 23 and displaces the cantilever 22 in the direction shown by an arrow X1, to compensate for the jitter. On the other hand, when a magnetic polarity which is opposite to that of the permanent magnet 23 is introduced at the edge surface of the coil 37 opposing the permanent magnet 23, attractive force is introduced between the coil 37 and the permanent magnet 23 and displaces the cantilever 22 in the direction shown by an arrow X2, to compensate for the jitter.
In the above described signal pickup device 10, the cantilever assembly 20 (i.e., cartridge 15) is positively positioned at a predetermined position with respect to the coils, which ensures that tracking control and jitter compensation are carried out accurately. The coils 35a, 35b, 36a, 36b and 37 are respectively mounted on not a rotatable mounting member but the stationally mounting member 37. In this connection, even though the reaction to the force for moving the cantilever assembly 20 is applied on each coil, the coils do never wobble but are held steady, which also ensures the accurate tracking control and jitter compensation.
Further, this invention is not limited to these embodiments but various variations and modifications may be made without departing from the scope of the invention. | A signal pickup device in a rotary recording medium reproducing apparatus comprises a cantilever having at a free distal end thereof a reproducing element for reproducing recorded signals from tracks of a rotary recording medium, a permanent magnet magnetized in an axial direction of the cantilever and fixed to the cantilever at proximal end thereof, an elastic support member extending perpendicular to a longitudinal direction of said tracks and supporting the proximal end of the cantilever so that the cantilever is rotatable, accompanied by elastic deformation of the elastic support member, and tracking control coil device supplied with a tracking control current to attract and repulse the permanent magnet to cause the cantilever to rotate. The reproducing element is displaced in a direction perpendicular to the longitudinal direction of the recording tracks of the rotary recording medium to tracks. The tracking control coil device comprises at least a single rear-side tracking coil disposed at a position opposite to the reproducing element with respect to the elastic support member to confront a magnetic pole of the permanent magnet and at least a single front-side tracking coil disposed at a position toward the reproducing element with respect to the elastic support member to confront an opposite magnetic pole of the permanent magnet, with axes of the rear-side and front-side tracking coils being arranged in a direction perpendicular to an axial direction of the cantilever. |
FIELD OF THE INVENTION
The present invention is generally related to digital computer systems.
BACKGROUND OF THE INVENTION
One of the important features of integrated circuits deigned for portable applications is their ability to efficiently utilize the limited capacity of the battery power source. Typical applications include cellular telephones and personal digital assistants (PDAs), which might have a Lithium ion battery or two AAA alkaline batteries as the power source. Users have come to expect as much as three to four weeks of standby operation using these devices. Standby operation refers to the situation where the cellular phone, handheld device, etc. is powered on but not being actively used (e.g., actively involved in a call). Generally, is estimated that that the integrated circuits providing the functionality of the device is only performing useful work approximately 2% of the time while the device is in standby mode.
Removing the power supply from selected circuits of a device during standby is a technique employed by designers for battery powered applications. The technique is generally applied only to circuit blocks outside of the central processing unit (CPU). A primary reason for not applying this technique to CPUs, has been the difficulty in being able to retain the current processor state information necessary to continue execution after coming out of the standby mode. One solution for this limitation involves saving the current processor state information to external storage mechanisms (e.g., such as flash memory, a hard disk drive, etc.). In such a case there is the overhead required in transferring the state to and from the external storage mechanism. Even if the battery powered device had a hard disk drive, and many don't, the time consuming state transfer would not meet the real time response requirements of the application when the device needs to wake up to respond to a new event.
Other issues are presented when the functionality of a device is implemented by a system-on-a-chip (SOC) integrated circuit. For example, when the core of a system-on-a-chip CPU is temporarily powered down (e.g., deep sleep mode), some of the outputs that connect to assorted peripherals (e.g. LCD display, SPI interface, SDIO, Hard-disk, etc.) should be held in an idle state to avoid having to reprogram the peripheral or lose existing context in the peripheral. This causes a problem since some peripherals need particular values to be set at their inputs (which are connected to the outputs of the SOC) to hold a safely inactive state. For example, if a device is connected to a SOC that is clocked on the falling edge of a clock signal, and the SOC is powered down with that signal as a logic 1, but the power down state is a logic 0 (e.g., ground), it will cause a spurious clock on that signal.
This problem is further exacerbated by the heavy use of pin-muxing or sharing, in which a single pin can have multiple functions in different designs by different customers. In one design a pin may be set to act as part of an SPI interface that wants to be held low when in sleep mode, while the same pin in another design, perhaps by a different customer may be used as a UART pin which would need to be held high when the CPU is put to deep sleep mode. While pin-muxing provides a way to put more features in each chip and allows the chip to be more suitable for a wide range of designs, it precludes knowing exactly at IC design time what each pin will be used for. A more flexible method of configuring the power down states is needed.
One solution to this problem would be to have a software defined register for each pin that drives the pin to any one of the allowed number of states, such as: Input, output 0, output 1, output Hi-Z, open drain, etc. This is a workable solution, but has a problem that since normally the signals that control these functions come from the core of the CPU, they will not be present when the core is powered down in deep sleep mode. To overcome this, a second set of registers on the SOC will have to be in the special power domain.
The special power domain is configured to always have power on (AO), even in the deep sleep mode. The special power domain allows the state information of these IO pads to be preserved. However the big problem is that it requires multiple signals from the portion of the chip that is in the special power domain to each pad, this can cause traces to be required. For example, with 300 signal pads and 3 wires per pad, as many as 900 traces have to be routed on the integrated circuit die, which is a large number at the top level of an integrated circuit die layout. These pad control signals must also be powered by the AO rail, which complicates the distribution of this AO rail or the routing of these pad control signals. Standard interrupt mechanism from the peripheral should result in an answer from the processor whatever is it's current state (e.g., active or standby). The benefits of a low power strategy cannot be fully realized if this mechanism is not transparent to the external environment.
Thus, what is needed is a solution for powering down a CPU for reduced standby power consumption while retaining the integrity of the operating state. What is further needed is a solution for powering down the CPU without imposing burdensome trace routing requirements on the integrated circuit die layout.
SUMMARY OF THE INVENTION
Embodiments of the present invention provides a method and system for powering down an integrated circuit device for reduced standby power consumption while retaining the integrity of the operating state. Embodiments of the present invention further provide a solution for powering down the integrated circuit device without imposing burdensome trace watering requirements on the integrated circuit die layout.
In one embodiment, the present invention is implemented as a circuit for maintaining asserted values on an input output pin (e.g., pad, etc.) of an integrated circuit device when one or more functional blocks of the device are placed in a sleep mode. The circuit includes an interface for coupling a functional block of a processor to an input and output pin and an output storage element coupled to the interface for storing a current value (e.g., logical one, logical zero, etc.) of the input output pin. The circuit further includes a sleep mode enable for controlling the output storage element to store the current value of the input output pin. The current value (e.g., as generated by the functional block) is stored prior to the functional block entering a sleep mode. The output storage element causes the current value of the input output pin to remain asserted after the functional block is in sleep mode. The sleep mode enable is also configured to deactivate the storage element when the sleep mode is exited, thereby allowing the input output pin to resume being driven by the awakened functional block. In one embodiment, the deactivation is performed independently among the different functional blocks. The integrated circuit device can be a CPU (central processor unit), a system-on-a-chip, and embedded computer system, or the like. The input output pin can be coupled to a peripheral device (e.g., display screen, USB interface, etc.) for providing functionality to a user.
In this manner, the signal state of the input output pins can be maintained as one or more functional blocks of the integrated circuit device are powered down. Upon exit from sleep mode (e.g., wake up), the input output pins can resume being driven by the one or more functional blocks. Additionally, this capability is provided without requiring the routing of multiple signals from a special power domain to the input output pin, which greatly reduces signal trace routing requirements. For example, embodiments of the present invention enabled a wake-up when one of a designated set of inputs transitions state. This allows the integrated circuit device to use the same pins that are used to recognize events during normal operation as wake pins to transition the device out of deep sleep.
In one embodiment, different voltage rails are provided to accommodate the different peripheral voltages. For example, a camera can work at one voltage while a WiFi chipset within the camera is working at another voltage. Waking-up from the standard signal of a peripheral (e.g., such as an interrupt) avoids creating additional pads just for this function, which would require a specific voltage choice and voltage translators on the board. So some few selected pads are used as a generic input in the processor active mode but as a wake-up in the processor standby mode, thus at the correct voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements.
FIG. 1 shows a computer system in accordance with one embodiment of the present invention.
FIG. 2 shows an overview diagram of a flexible pin configuration system in accordance with one embodiment of the present invention.
FIG. 3 shows a circuit diagram of a flexible pin configuration component in accordance with one embodiment of the present invention.
FIG. 4 shows a circuit diagram showing an input output capture component 400 in accordance with one embodiment of the present invention.
FIG. 5 shows a circuit diagram showing an implementation where multiple capture components are utilized to capture a variety of different input output signals for an integrated circuit device in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of embodiments of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the embodiments of the present invention.
Notation and Nomenclature:
Some portions of the detailed descriptions, which follow, are presented in terms of procedures, steps, logic blocks, processing, and other symbolic representations of operations on data bits within a computer memory. These 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. A procedure, computer executed step, logic block, process, etc., is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as “processing” or “accessing” or “executing” or “storing” or “rendering” or the like, refer to the action and processes of a computer system (e.g., computer system 100 of FIG. 1 ), or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Computer System Platform:
FIG. 1 shows a computer system 100 in accordance with one embodiment of the present invention. Computer system 100 depicts the components of a basic computer system in accordance with embodiments of the present invention providing the execution platform for certain hardware-based and software-based functionality. In general, computer system 100 comprises at least one CPU 101 , a system memory 115 . A graphics processor unit (GPU) 110 can optionally be included, or any number of special function units. As shown in FIG. 1 , the CPU 101 includes a special “always on” power domain 120 for managing the entry and exit of the computer system 100 into and out of a sleep mode. Similarly, the GPU 110 can also include an always on power domain 121 . The CPU 101 can be coupled to the system memory 115 via a bridge component/memory controller (not shown) or can be directly coupled to the system memory 115 via a memory controller (not shown) internal to the CPU 101 . The GPU 110 is coupled to a display 112 .
System 100 can be implemented as a programmable system-on-a-chip integrated circuit device, where for example, the CPU 101 , memory 115 , and GPU 110 are fabricated as a single integrated circuit die, with the display 112 being coupled as a peripheral device. Similarly, the system 100 can be implemented as an embedded computer system within, for example, a handheld device (e.g., PDA, cell phone, etc.). Alternatively, system 100 can be implemented as, for example, a desktop computer system or server computer system, having a powerful general-purpose CPU 101 coupled to a dedicated graphics rendering GPU 110 . In such an embodiment, components can be included that add peripheral buses, specialized graphics memory, IO devices, and the like. Similarly, system 100 can be implemented a set-top video game console device such as, for example, the Xbox®, available from Microsoft Corporation of Redmond, Wash., or the PlayStation3®, available from Sony Computer Entertainment Corporation of Tokyo, Japan.
Embodiments of the Invention:
Embodiments of the present invention implement a method and system for powering down an integrated circuit device for reduced standby power consumption while retaining the integrity of the operating state. Embodiments of the present invention enable the reliable powering down and waking up of the integrated circuit device without imposing burdensome trace routing requirements on the integrated circuit die layout.
FIG. 2 shows an overview diagram of a flexible pin configuration system 200 in accordance with one embodiment of the present invention. As depicted in FIG. 2 , system 200 includes a processor 210 including a plurality of functional blocks 211 - 214 . These functional blocks are each communicatively coupled to an always on power domain 230 . System 200 also includes a flexible pin configuration component 240 that is configured to dynamically manage the connectivity of one or more input output pins to communicatively connect the functional blocks 211 - 214 to the multiple peripheral devices 250 .
In the FIG. 2 embodiment, the flexible pin configuration component 240 is the interface that enables the multiple functions provided and implemented by the multiple functional blocks 211 - 214 to share a limited number of input output pins. For example, in one embodiment, via the interface provided by the flexible pin configuration component 240 , the multiple functional blocks 211 - 214 can share a single input output pin to deliver their functionality to the peripheral devices 250 , which may themselves also be sharing the single input output pin.
It should be noted that processor 210 can be used to implement a central processor unit, such as, for example, CPU 101 of FIG. 1 , or a GPU such as the GPU 110 of FIG. 1 . The processor 210 can also be part of a programmable system-on-a-chip device. Similarly, the processor 210 can be used to implement an integrated circuit device where the functions of a CPU and the functions of a GPU are combined.
The power domain 230 provides a mechanism for waking up the processor 210 from a sleep mode. For example, in one embodiment, the power domain 230 is configured to consistently have power applied to its constituent circuits. For example, the constituent circuits of the power domain 230 can be configured to receive a clock signal in an uninterrupted manner so that it can execute sequential state machine logic, instructions, etc. while the rest of the processor 210 is powered down. This can allow, for example, an internal state machine within the power domain 230 to detect wake event signals, the signals indicating a wake up from the sleep mode. For example, in one embodiment, the wake event signals are detected by the AO block (e.g., AO functional block 230 ). This block is on the AO rail. The one or more of the functional blocks 211 - 214 that normally process the events are powered down. Once power is returned, the functional blocks 211 - 214 can process the event, and resume normal operation.
In accordance with embodiments of the present invention, the one or more input output pins between the flexible pin configuration component 240 and the peripheral devices 250 will have their state reliably maintained even though the functional blocks of the processor 210 are powered down. The state will be maintained such that the entry and exit from sleep mode will be completely transparent to the peripheral devices 250 .
In one embodiment, different voltage rails are provided to accommodate the different peripheral voltages. For example, a camera can work at one voltage while a WiFi chipset within the camera is working at another voltage. Waking-up from the standard signal of a peripheral (e.g., such as an interrupt) avoids creating additional pads just for this function, which would require a specific voltage choice and voltage translators on the board. So some few selected pads are used as a generic input in the processor active mode but as a wake-up in the processor standby mode, thus at the correct voltage. While some parts of the processor are powered off in standby, the system should be able to power them up again automatically after detecting a wake-up event. In one embodiment, this is done by a hardware control circuit on the AO voltage rail (e.g., AO functional block 230 ).
FIG. 3 shows a circuit diagram 300 of a flexible pin configuration component in accordance with one embodiment of the present invention. As depicted in the diagram 300 embodiment, the pin configuration component includes an output multiplexer for pin sharing 301 , an output enable multiplexer 311 , an input enable multiplexer 312 , and an input signal line for pin sharing 302 . The multiplexer 301 is coupled a common input output pin (e.g., pad 330 ) via an output buffer 321 . The input buffer 322 drives the input 302 for pin sharing (e.g., shared by multiple functional blocks). The multiplexers 301 , 311 , and 312 allow multiple functional blocks of a processor (e.g., functional blocks 211 - 214 of FIG. 2 ) to selectively control the input output pin 330 . For example, the multiplexers 301 , 311 , and 312 can allow the flexible pin configuration component to dynamically change control of the input output pin 330 between any of a number of different multiple functional blocks. In one embodiment, the selective allocation of the input output pin 330 can be placed under software control, for example as in a case where a control utility or the like executes on the processor to allocate control of the input output pin 330 . The control allocation can be implemented on an as needed basis depending upon whatever function the device might be performing.
FIG. 4 shows a circuit diagram showing an input output capture component 400 in accordance with one embodiment of the present invention. The capture component 400 includes a flexible pin configuration component operating in conjunction with an output storage element and an input enable storage element in accordance with one embodiment of the present invention.
In normal operation, the selected function drives the output via the output multiplexer 301 as described above. The output of the multiplexer 301 is coupled to the input output pin 330 via a multiplexer 411 and the buffer 321 as shown. Similarly, in normal operation, the output enable 311 turns on the buffer 321 via the multiplexer 412 as shown. During sleep mode, a sleep mode enable 430 in conjunction with a capture signal 420 causes the storage element 401 and the storage element 402 to store the current value (e.g., logical one, logical zero, etc.) of the output multiplexer 301 and the current value of the output enable signal (e.g., the output enable multiplexer 311 as described above). This causes the input output pin 330 to be driven by the output of the storage element 401 , which would be the previously stored current value from the multiplexer 301 . Thus, after sleep mode entry, the functional blocks driving the inputs of the multiplexer 301 can be inactive. Additionally, in the FIG. 4 embodiment, the output enable signal itself can be inactive, since its value is stored within the storage element 402 . Upon exit from sleep mode, the sleep mode enable 430 causes the input output pin 330 to resume being driven by the multiplexer 301 , thereby deactivating the storage element 401 and 402 .
With respect to the input enable 312 , the input enable 312 has its current value saved by the storage element 403 in accordance with the capture signal 420 and the sleep mode enable 430 . Thus, the input enable 312 can control the input buffer 322 even though the functional block that generates the input enable signal 312 is in sleep mode. The input 302 routes signals from the input output pin 330 to be shared by the appropriate functional blocks.
Thus, embodiments of the present invention limit the use of a central register to store state data for the input output pins of the device. Embodiment of the present invention utilize storage element as described above to enable each pad or input output pin to recall it's last state. For example, when the software executing on the chip wishes to put the chip in deep sleep mode, it simply cleanly tells each interface (e.g. UART, SPI, HDD, USB etc.) to enter it's inactive state (if it is not already there) and then asserts a HW signal (e.g., sleep mode enable) to each of the pads to capture their current value (e.g., input, output 0, output 1, hi-Z, open drain, etc.) and hold that value without the core of the chip being awake. Once this is done, the core can safely be powered down into a deep sleep mode. It should be noted that the constituent logic for performing the state retention function is comparatively small, and is located near each signal input output pin. Thus, very few top level signals are required to clock these storage elements, as these signals can be shared for all affected input-output pins, and don't need to be point to point routed from the always on the core (e.g., core 230 of FIG. 2 ), thereby minimizing trace routing requirements. The entry and exit for sleep mode is transparent to the peripheral devices. From an external devices' point of view, nothing has happened. The external devices' do not know the CPU has gone to deep sleep, as their inputs are not affected at all.
It should be noted that in one embodiment, the system 400 is configured such that the output enable 311 is not used to exit the sleep mode. In such a configuration, a separate control register can be utilized to disable the sleep mode on an interface by interface basis. The use of separate control registers to disable the sleep mode provides an advantage in that there can be less impact on signal timing.
FIG. 5 shows a circuit diagram 500 showing an implementation where multiple capture components 501 - 505 are utilized to capture a variety of different input output signals for an integrated circuit device in accordance with one embodiment of the present invention.
The FIG. 5 embodiment shows a case where multiple capture components 501 - 505 are used to capture signals around the integrated circuit device for different selected interfaces. This enables an application where the integrated circuit device can “unlock” just a single selected interface, or group of interfaces. be useful in applications such as where only the LCD needs to wake up to update the time on the display without needing to wake up all other interfaces. This aspect is illustrated in FIG. 3 where the capture components 501 - 503 are part of a first interface, Capture_A, and the Components 504 - 505 are part of a second interface, Capture_B. FIG. 5 also shows how to connect multiple pads with this feature to avoid routing a large number of signals around the integrated circuit die, with the input/output and I/O enable signals 520 for each to component 501 - 505 being as illustrated in FIG. 4 .
In one embodiment, the de-assertion to re-assertion of the output enable signal for each capture component would switch each output from driving the latched idle state to the value driven from the core once software had reinitialized the peripheral controller to match the idle state. This is necessary for interfaces where the reset state of the controller may not match the idle sate.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | In an integrated circuit device, a circuit for maintaining asserted values on an input output pin of the device when a functional block of the device is placed in a sleep mode. The circuit includes an interface for coupling a functional block of a processor to an input and output pin and an output storage element coupled to the interface for storing a current value of the input output pin. The circuit further includes a sleep mode enable for controlling the output storage element to store the current value of the input output pin prior to the functional block being entering a sleep mode and cause the current value of the input output pin to remain asserted after the functional block is in sleep mode. The sleep mode enable is also to deactivate the storage element when the sleep mode is exited. |
CROSS REFERENCE TO RELATED APPLICATION
The subject matter of the present application is related to that of application Ser. No. 08/662,011 of Toshihiro SUZUKI et al. entitled AUTOMATIC LINE DISTRIBUTION EQUIPMENT AND CONNECTION-PIN INSERTING-AND-EXTRACTING APPARATUS filed Jun. 12, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a connection pin handling device which selectively inserts or extracts a connection pin (hereinafter, insertion/extraction devices) and methods for selectively inserting or extracting a connection pin (hereinafter, inserting/extracting a connection pin). More particularly, the present invention relates to a connection pin insertion/extraction device and a method using the device in which an arbitrary line is connected/disconnected by inserting/extracting a connection pin into/from a matrix switch board.
Recently, demands have been increased for convenient methods for obtaining a telephone circuit by connecting/disconnecting conductor patterns at arbitrary points in the field of telephone switchboards. In one such method, which is currently dominating the field, a connector pin is inserted in a crossing point of a plurality of conductor patterns formed on a matrix switch board.
In the above method, the matrix switch board includes a plurality of conductor patterns located on both sides so as to cross over each other at the same coordinate. The connection between the conductor patterns is carried out by inserting a cross-shaped connection pin having two metallic protruding portions into a through-hole provided with a crossing point.
Also, the connection between the conductor patterns may be disconnected by extracting the connection pin inserted in the through-hole. The insertion/extraction operation of the connection pin may be automatically carried out by a robot, which is controlled by a computer, comprising a connection pin insertion/extraction device. It is necessary to accurately detect the position of the through-hole relative to the robot in order to precisely insert the connection pin in the through-hole. Thus, a position detection mechanism may necessarily be provided with the robot.
The above-mentioned connection pin insertion/extraction device may be applied to, for example, an automatic line distribution equipment which connects a switch board line with a subscriber line. In this case, two conductor patterns are used as the switch board line and the subscriber line, respectively. One of the switch board lines may be connected to one of the subscriber lines by inserting the connection pin in a through-hole formed at a crossing point of the two conductor patterns.
FIGS. 1A and 1B are diagrams showing the structure of a conventional connection pin insertion/extraction device. FIG. 1A is a diagram showing a front view of the device and FIG. 1B is a diagram showing a side view of the device. The connection pin insertion/extraction device shown in the figures may be mounted on an arm of a robot 1, which is capable of moving in the X, Y and Z directions, so that the device may be freely transferred between two matrix switch boards 2. In each of the matrix switch boards 2, a plurality of conductor patterns are formed so as to cross each other, and a corresponding through-hole is formed at a crossing point of the conductor patterns. The connection pin insertion/extraction device inserts a connection pin 3 in the through-hole formed in the matrix switch board 2 so as to connect the conductor patterns.
The connection pin insertion/extraction device shown in FIG. 1A and 1B is comprised of an optical sensor 4, a handling mechanism 5, an insertion-strength restriction mechanism 6 and a reversal mechanism 7.
The optical sensor 4, which is mounted on the handling mechanism 5, irradiates a laser beam from a laser port 4a onto a standard mark formed on the matrix switch board 2 and determines a positional relationship between the connection pin insertion/extraction device and the matrix switch board by detecting the strength of reflected laser light from the standard mark.
FIG. 2 is a diagram for explaining a detection method of the standard mark by the optical sensor 4. A standard mark 2a which has a high reflectivity is provided near a through-hole formed on the matrix switch board 2. In this case, the positional relationship between the through-hole and the standard mark 2a may be accurately determined by using the same patterning mask for the through-hole and the standard mark 2a.
The optical sensor 4 irradiates a laser beam onto a region of the standard mark 2a while moving in the directions indicated by the arrows in FIG. 2. At this time, the position of the standard mark 2a is determined by detecting the border lines between the standard mark 2a and the matrix switch board 2 from the strength of the reflected laser beam. Since the positional relationship between the standard mark 2a and the through-hole is accurately defined, the positional relationship between the through-hole and the robot may also be precisely determined.
As shown in FIG. 1A, the handling mechanism 5 is comprised of two rotary hooks 5a, a push rod 5b and an electromagnet 5c. The handling mechanism 5, which may be mounted on the insertion-strength restriction mechanism 6, carries out a holding/releasing operation of the connection pin 3. For example, the handling mechanism 5 with the rotary hooks 5a opened may be moved to the connection pin 3 and when it contacts the pin 3, the push rod 5b starts to move upward in the figure.
As the push rod 5b moves upward, a flange 5d which is formed on the push rod 5b closes the rotary hooks 5a, and at the same time, the push rod 5b contacts the electromagnet 5c. When the push rod 5b contacts the electromagnet 5c, the electromagnet is magnetized and the connection pin 3 is held by the rotary hooks 5a. Thus, the connection pin 3 may be extracted from the through-hole by moving the handling mechanism 5 in the upward direction.
The insertion-strength restriction mechanism 6 is operated so as to restrict the insertion strength of the connection pin 3 when the pin 3 is inserted in a through-hole. For instance, a certain force is required for inserting the connection pin 3 in the matrix switch board 2. However, the connection pin 3 may be damaged if too much force is applied to the pin 3. Therefore, a mechanism by which the insertion strength of the pin 3 may be restricted is necessarily provided with the connection pin insertion/extraction device.
The insertion-strength restriction mechanism 6, which is mounted between the handling mechanism 5 and the reversal mechanism 7, may be comprised of an insertion-strength generating spring 6a, a slider 6b, a rail 6c, a sensor 6d and a masking plate 6e. The rail 6c is fixed to the robot 1 via the reversal mechanism 7, and the handling mechanism 5 is mounted on a side surface of the slider 6b. The masking plate 6e is fixed on the upper surface of the slider 6b so that it may be moved with the slider 6b in the up and down directions. Also, the insertion-strength generating spring 6a, which is provided on the upper surface of the slider 6b, generates a stress (insertion strength) when the slider 6b moves in the up and down directions.
A light beam is ejected in the transverse direction in the sensor 6d. The sensor 6d determines a movement of the slider 6b when the slider 6b moves in the up or down direction and the masking plate 6e interrupts the light beam. That is, the sensor 6d detects that the insertion-strength generating spring 6a is contracted by a predetermined distance. The insertion-strength generating spring 6a is formed so that its insertion strength reaches a maximum limit when it is contracted by the predetermined distance in the above operation.
When the robot 1 is moved to a through-hole in order to insert the connection pin 3, the rail 6c and the slider 6b move in the downward direction in the figure. When the connection pin 3 starts to contact the through-hole, the insertion-strength generating spring 6a is deflected and generates an insertion force which is appropriate for inserting the connection pin 3 in the through-hole. After that, the robot 1 continues its movement and when the sensor 6d which is mounted on the rail 6c detects the masking plate 6e of the slider 6d, the insertion strength applied to the connection pin 3 reaches maximum and the insertion operation is terminated.
The reversal mechanism 7, which is provided between the insertion-strength restriction mechanism 6 and the robot 1, rotates the optical sensor 4, the handling mechanism 5 and the insertion-strength restriction mechanism 6 by 180 degrees so as to enable a both-side insertion/extraction of the connection pin 3.
However, according to the conventional connection pin insertion/extraction devices, the position of a through-hole is determined relative to the standard mark 2a on the matrix switch board, which is detected by the light beam. Thus, it is required to provide, additionally, the optical sensor 4 which optically detects the standard mark 2a with the connection pin insertion/extraction device. Also, it is necessary to additionally provide the reversal mechanism 7 with the connection pin insertion/extraction device in order to perform an insertion/extraction operation of the connection pin 3 for both sides of the matrix switch board.
Accordingly, it is not easy to reduce the size and the manufacturing cost of the conventional connection pin insertion/extraction device.
Moreover, in the conventional connection pin insertion/extraction device, since the optical sensor 4, which forms a position detection mechanism, is provided a certain distance away from the position of a connection pin, it is necessary to correct the position of a through-hole corresponding to the distance. This may become one of the error factors in the through-hole position detection operation and may cause an erroneous insertion of the connection pin.
SUMMARY OF THE INVENTION
It is a general object of this invention to provide a connection pin insertion/extraction device in which the above-mentioned problems are eliminated.
It is also a general object of this invention to provide a method for inserting/extracting a connection pin by which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a connection pin insertion/extraction device of reduced size which may be manufactured at low cost.
It is another object of the present invention to provide a connection pin insertion/extraction device by which a position of an object may be detected with high accuracy.
It is still another object of the present invention to provide a method for inserting/extracting a connection pin by which a position of a through-hole may be accurately detected and a connection pin may be precisely inserted therein.
The objects described above are achieved by a connection pin insertion/extraction device comprising: two sleeves, each of the sleeves being provided on the same axis and having an inlet facing the outside of the connection pin insertion/extraction device so as to be engaged with a connection pin; two push rods, each of the push rods being slidably provided in one of the corresponding sleeves so as to push the connection pin; and a spring provided between the two push rods which spring generates an insertion force for the connection pin, whereby the connection pin insertion/extraction device performs an insertion/extraction operation of the connection pin on both sides of the connection pin insertion/extraction device.
The objects described above are also achieved by the connection pin insertion/extraction device further provided with two hooks, each one of the hooks being provided around the axis so as to enable the hooks to hold the connection pin.
According to the above connection pin insertion/extraction device, it is possible to carry out an insertion/extraction operation for the connection pin for both sides of the connection pin insertion/extraction device without using a reversal mechanism which is usually used in a conventional connection pin insertion/extraction device. Also, since the hooks and the spring may be shared by a handling mechanism for handing the connection pin at right and left hand sides, the size of the device may be decreased and the cost required for constructing the device may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein the two hooks are formed as one member which moves parallel with respect to a vertical direction of the axis and may perform an opening/closing operation on a respective side of the connection pin insertion/extraction device.
According to the above device, since the two hooks are formed as one member and performs an opening/closing operation on both sides of the connection pin insertion/extraction device, it is possible to perform an insertion/extraction operation for the connection pin for both sides of the device without using a reversal mechanism which is usually used in a conventional device. Also, since the hooks and the spring may be shared by a handling mechanism for handing the connection pin at right and left hand sides, the size of the device may be decreased and the cost required for constructing the device may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, further comprising: a detection portion which detects a sliding distance of the two push rods, the detection portion including a first member which is fixed to the back portion of one of the two push rods; a second member which is fixed to the back portion of the other one of the two push rods; and a first circuit which outputs different signals in accordance with the movement of one of the first member and the second member, wherein the movement of the push rod for pushing the connection pin may be stopped by a signal from the first circuit when the push rod is moved a first predetermined distance, and a presence of an object may be detected by a signal from the first circuit when the push rod is moved a second predetermined distance after the push rod contacts the object.
According to the above device, an insertion force applied to a connection pin by the push rod may be controlled by the push rod, the spring and the detection portion and the presence of an object may also be detected. That is, an insertion force restriction mechanism and a position detection mechanism may be formed by using the identical construction parts. Also, a part (the push rod and the spring) of the mechanism may be included in the handling mechanism. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced compared with a conventional connection pin insertion/extraction device in which the insertion force restriction mechanism and the position detection mechanism are independently added thereto.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein the two sleeves, the two push rods, the spring, and the two hooks form a connection pin handling mechanism, and the two push rods, the spring, and the detection portion form a monitor mechanism which monitors an insertion strength of the two push rods and a presence of the object, the connection pin handling mechanism and the monitor mechanism being provided on substantially the same axis.
According to the above device, the monitor mechanism comprising the two push rods, the spring, and the detection portion and the handling mechanism are provided on substantially the same axis. That is, the insertion force restriction mechanism and the position detection mechanism, each of which forms the monitor mechanism, are formed on substantially the same axis of the handling mechanism. Thus, the insertion force may be transmitted efficiently without loss and an error associated with a position detection operation may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein each of the first member and the second member is formed of a masking plate, and the first circuit included in the detection portion is comprised of a photoelectric switch using a light beam, wherein the light beam may be interrupted by the movement of the first member and the movement of the second member so that the photoelectric switch may output different signals in accordance with the movement of the two push rods.
According to the above device, the detection portion may be formed by using simple construction parts. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein each of the first member and the second member is formed of a dog, and the first circuit included in the detection portion is comprised of a mechanical switch, wherein the mechanical switch may be actuated by the movement of the first member and the movement of the second member so that the mechanical switch may output different signals in accordance with the movement of the two push rods.
According to the above device, the detection portion may be formed by using simple construction parts. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced.
The objects described above are achieved by a connection pin insertion/extraction device comprising: a sleeve which is provided with an inlet facing the outside of the connection pin insertion/extraction device so as to be engaged with a connection pin; a push rod which is slidably provided in the sleeve so as to push the connection pin; a spring which generates an insertion force for the connection pin by pushing the push rod; a hook being provided around a central axis of the sleeve so as to enable the hook to hold the connection pin; and a detection portion which detects a sliding distance of the push rod, the detection portion including a first member, which is fixed to the back portion of the push rod, and a first circuit, which outputs different signals in accordance with the movement of the first member, wherein the movement of the push rod for pushing the connection pin may be stopped by a signal from the first circuit when the push rod is moved a first predetermined distance, and a presence of an object may be detected by a signal from the first circuit when the push rod is moved a second predetermined distance after the push rod contacts the object.
According to the above device, an insertion force applied to a connection pin by the push rod may be controlled by the push rod, the spring and the detection portion and the presence of an object may also be detected. That is, an insertion force restriction mechanism and a position detection mechanism may be formed by using the identical construction parts. Also, a part (the push rod and the spring) of the mechanism may be included in a handling mechanism. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced compared with a conventional connection pin insertion/extraction device in which the insertion force restriction mechanism and the position detection mechanism are independently added thereto.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein the sleeve, the push rod, the spring, and the hook form a connection pin handling mechanism, and the push rod, the spring, and the detection portion form a monitor mechanism which monitors an insertion strength of the push rod and a presence of the object, the connection pin handling mechanism and the monitor mechanism being provided on substantially the same axis.
According to the above device, the monitor mechanism comprising the push rod, the spring and the detection portion and the handling mechanism are provided on substantially the same axis. That is, the insertion force restriction mechanism and the position detection mechanism, each of which forms the monitor mechanism, are formed on substantially the same axis of the handling mechanism. Thus, the insertion force may be transmitted efficiently without loss and an error associated with a position detection operation may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein the first member is formed of a masking plate, and the first circuit included in the detection portion is comprised of a photoelectric switch using a light beam, wherein the light beam may be interrupted by the movement of the first member so that the photoelectric switch may output different signals in accordance with the movement of the push rod.
According to the above device, the detection portion may be formed by using simple construction parts. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced.
The objects described above are also achieved by the connection pin insertion/extraction device, wherein the first member is formed of a dog, and the first circuit included in the detection portion is comprised of a mechanical switch, wherein the mechanical switch may be actuated by the movement of the first member so that the mechanical switch may output different signals in accordance with the movement of the push rod.
According to the above device, the detection portion may be formed by using simple construction parts. Thus, the size and the cost of the connection pin insertion/extraction device may be reduced.
The objects described above are achieved by a method for inserting a connection pin in a through-hole formed on a board using a connection pin insertion/extraction device comprising steps of: (a) moving the connection pin insertion/extraction device holding the connection pin by a hook towards the board so as to push the connection pin to the board; (b) stopping the movement of the connection pin insertion/extraction device in response to a change in a signal from a first circuit so as to apply an insertion force not greater than a predetermined value to the connection pin; (c) opening the hook; and (d) moving the connection pin insertion/extraction device backward, wherein the connection pin insertion/extraction device comprises: at least one push rod which is slidably formed and pushes the connection pin towards the board with an insertion strength corresponding to a sliding distance thereof; at least one hook which is capable of holding the connection pin; a first member which is fixed to the back portion of the corresponding at least one push rod; and a detection portion which detects a sliding distance of the push rod, the detection portion including the first circuit which outputs different signals in accordance with the movement of the first member.
According to the above method, an insertion force larger than a predetermined value is not applied to a connection pin. Thus, it is possible to avoid a danger in which the connection pin is destroyed by an excessive insertion force.
The objects described above are achieved by a method for extracting a connection pin inserted in a through-hole formed on a board using a connection pin insertion/extraction device comprising steps of: (a) moving the connection pin insertion/extraction device including an opened hook towards the connection pin inserted in the board so as to push the connection pin by a push rod which slides in an opposite direction to the board upon contact with the connection pin; (b) stopping the movement of the connection pin insertion/extraction device in response to a change in a signal from a first circuit of a detection portion which is caused by the movement of a first member fixed to the push rod so that the connection pin insertion/extraction device stops at an appropriate position for holding the connection pin by the hook; (c) closing the hook; and (d) moving the connection pin insertion/extraction device backward so as to extract the connection pin from the board, wherein the connection pin insertion/extraction device comprises: at least one push rod which is slidably formed and pushes the connection pin towards the board with an insertion strength corresponding to a sliding distance thereof; at least one hook which is capable of holding the connection pin; and a detection portion which detects a sliding distance of the push rod, the detection portion including the first member which is fixed to the back portion of the corresponding at least one push rod and the first circuit which outputs different signals in accordance with the movement of the first member.
According to the above method, the connection pin insertion/extraction device is controlled to stop at an appropriate position for the hook to hold a connection pin. Thus, it is possible to prevent a collision of the hooks with a board. Also, the hook may properly hold the connection pin.
The objects described above are achieved by a method for detecting the presence and position of an object on a board using a connection pin insertion/extraction device comprising steps of: (a) moving the connection pin insertion/extraction device above the object with a predetermined pitch; and (b) contacting a push rod to the object by moving the connection pin insertion/extraction device a predetermined distance in up and down directions with respect to the board for every movement of the connection pin insertion/extraction device with the predetermined pitch, wherein the presence of the object is detected by the change in signal from a first circuit of a detection portion, which is caused by the movement of a first member of the detection portion when the push rod contacts the object, and the position of the object is determined by measuring a transfer distance of the connection pin insertion/extraction device, the connection pin insertion/extraction device comprising: at least one push rod which is slidably formed and pushes the connection pin towards the board with an insertion strength corresponding to a sliding distance thereof; the detection portion which detects the sliding distance of the push rod, the detection portion including the first member which is fixed to the back portion of the push rod and the first circuit which outputs different signals in accordance with the movement of the first member, and a transfer distance measurement portion which measures a transfer distance of the connection pin insertion/extraction device.
According to the above method, the presence and the position of an object may be detected by making the push rod contact the object. Thus, the accurate position of a through-hole may be detected by making the push rod contact a standard pin when the standard pin is provided on a board with a predetermined positional relationship to the through-hole.
The objects described above are achieved by a method for detecting the position of a connection pin insertion/extraction device in a height direction on a board comprising steps of: (a) setting the current position of the connection pin insertion/extraction device as a base position; and (b) contacting a push rod to the board by moving the connection pin insertion/extraction device towards the board, wherein a first member of a detection portion is moved when the push rod contacts the board so as to change the output from a first circuit of the detection portion, and the distance between the connection pin insertion/extraction device and the board is determined by measuring the transfer distance of the connection pin insertion/extraction device, the connection pin insertion/extraction device comprising: at least one push rod which is slidably formed and pushes the connection pin towards the board with an insertion strength corresponding to a sliding distance thereof; a detection portion which detects a sliding distance of the push rod, the detection portion including the first member which is fixed to the back portion of the push rod and the first circuit which outputs different signals in accordance with the movement of the first member, and a transfer distance measurement portion which measures a transfer distance of the connection pin insertion/extraction device.
According to the above method, the distance between the connection pin insertion/extraction device and the board may be accurately measured by making the push rod contact the board.
The objects described above are achieved by a method for detecting a failure of an insertion/extraction operation for a connection pin by a connection pin insertion/extraction device comprising steps of: (a) storing a position of the connection pin insertion/extraction device at which the output from a first circuit of a detection portion is changed in a normal insertion/extraction operation in advance, and (b) comparing the position of the connection pin insertion/extraction device at which the output from the first circuit is changed with the position stored in the step (a), wherein an insertion/extraction operation is determined to be a failure when an error larger than a predetermined value is detected in the step (b), the connection pin insertion/extraction device comprising: at least one push rod which is slidably formed and pushes the connection pin towards the board with an insertion strength corresponding to a sliding distance thereof; at least one hook which is capable of holding the connection pin; a detection portion which detects a sliding distance of the push rod, the detection portion including the first member which is fixed to the back portion of the push rod and the first circuit which outputs different signals in accordance with the movement of the first member, and a transfer distance measurement portion which measures a transfer distance of the connection pin insertion/extraction device.
According to the above method, it is possible to determine if an insertion or extraction operation of the connection pin insertion/extraction device is a failure or not by detecting the position of the connection pin insertion/extraction device at which the output from the first circuit is changed during the insertion or extraction operation.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanied drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a diagram showing a front view of a conventional connection pin insertion/extraction device;
FIG. 1B is a diagram showing a side view of the conventional connection pin insertion/extraction device;
FIG. 2 is a diagram for explaining a conventional detection method of a standard mark by an optical sensor of the connection pin insertion/extraction device;
FIG. 3 is a structural diagram showing a connection pin insertion/extraction device according to the present invention;
FIG. 4 is a diagram showing a portion of a handling mechanism of the connection pin insertion/extraction device shown in FIG. 3 in a magnified scale;
FIG. 5A is a diagram for explaining an extraction/insertion operation of a connection pin by the connection pin insertion/extraction device according to the present invention;
FIG. 5B is a diagram for explaining an extraction/insertion operation of a connection pin by the connection pin insertion/extraction device according to the present invention;
FIG. 5C is a diagram for explaining an extraction/insertion operation of a connection pin by the connection pin insertion/extraction device according to the present invention;
FIG. 5D is a diagram for explaining an extraction/insertion operation of a connection pin by the connection pin insertion/extraction device according to the present invention;
FIG. 5E is a diagram for explaining an extraction/insertion operation of a connection pin by the connection pin, insertion/extraction device according to the present invention;
FIG. 6A is a diagram showing a perspective view of a detection portion of a monitor mechanism;
FIG. 6B is a diagram showing a side view of the detection portion of the monitor mechanism;
FIG. 6C a diagram showing a front view of the detection portion of the monitor mechanism;
FIG. 7 is a diagram for explaining a position detection method for an object on a matrix switch board;
FIG. 8A is a diagram showing a second embodiment of the detection portion of the monitor mechanism;
FIG. 8B is a diagram showing a third embodiment of the detection portion of the monitor mechanism;
FIG. 9A is a diagram showing a side view of the connection pin insertion/extraction device according to the present invention;
FIG. 9B is a diagram showing a front view of the device shown in FIG. 9A; and
FIG. 9C is a diagram showing a top view of the device shown in FIG. 9A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A description will be given of embodiments according to the present invention with reference to the accompanied drawings.
First, a handling mechanism of a connection pin insertion/extraction device according to the present invention will be explained with reference to FIGS. 3 through 5. FIG. 3 is a structural diagram showing a connection pin insertion/extraction device according to the present invention. FIG. 4 is a diagram showing a portion of a handling mechanism of the connection pin insertion/extraction device shown in FIG. 3 in a magnified scale. FIGS. 5A through 5E are diagrams for explaining an extraction operation of a connection pin by the connection pin insertion/extraction device according to the present invention. The operation of a monitor mechanism for a position detection mechanism and an insertion-strength restriction mechanism is also shown in FIGS. 5A through 5E.
In FIG. 3, it is shown that the connection pin insertion/extraction device according to the present invention is located between two matrix switch boards 2. The connection pin insertion/extraction device is mounted on an end of a robot 1 which may move in the X, Y, and Z directions. Thus, the connection pin insertion/extraction device may move freely between the two matrix switch boards 2.
The connection pin insertion/extraction device shown in FIG. 3 includes a handling mechanism 30 for handling a connection pin 3 at each of right and left hand sides. However, no reversal mechanism is provided with the connection pin insertion/extraction device. The handling mechanism 30 is mainly comprised of a frame 30a, screw shafts 32 and 34, hooks 35 and 36, a push rod 37 and a sleeve 38. The screw shafts 32 and 34 are supported by the frame 30a and the hooks 35 and 36 are moved by the screw shafts 32 and 34 in the up and down directions (i.e., as viewed in the orientation of FIG. 3). The push rod 37 contacts an object and the sleeve 38 is engaged with the connection pin 3.
A motor 31 is fixed to the frame 30a of the handling mechanism 30. The motor 31 drives the screw shafts 32 and 34 via a motor pinion 31a and an idler gear 33.
As shown in FIG. 4, the connection pin 3 is comprised of a base portion 43 of substantially a cross-shape and two pins 42 projecting from the base portion 43. The base portion 43 may be made of a resin while the two pins 42 may be made of a metal. The two pins 42 are electrically disconnected in the base portion 43.
Also, as shown in FIG. 4, conductor patterns 81 and 82 are provided on the upper surface and the lower surface, respectively, of the matrix switch board 2 so as to cross each other. In practice, the two conductive patterns 81 on the upper surface may be used for a subscriber line and the two conductive patterns 82 on the lower surface may be used for a switch board line. A through-hole 83 is formed in each crossing point of the conductor patterns 81 and 82.
Accordingly, the two conductor patterns on the upper surface and the two conductor patterns on the lower surface may be connected simultaneously by inserting the two pins 42 of the connection pin 3 in the two through-holes 83. That is, the subscriber line and the switch board line may be connected arbitrarily. On the other hand, the connected lines may be disconnected when the connection pin 3 is pulled out from the matrix switch board 2.
Next, an extraction operation of the connection pin 3 from the matrix switch board 2 will be explained in detail.
When the motor 31, which is fixed to the frame 30a of the handling mechanism 30, is rotated in the direction indicated by an arrow in FIG. 3, the rotating force generated is transferred to the screw shaft 32 via the motor pinion 31a. At this time, the direction of the rotating force applied to the screw shaft 32 is changed to opposite to be that of the motor 31, and hence the hook 36, in which the screw shaft 32 is driven, moves in the upward direction.
At the same time, the rotating force of the motor 31 is transferred to the screw shaft 34 via the idler gear 33. Since the rotating direction of the screw shaft 34 is the same as that of the motor 31, the hook 35, in which the screw shaft 34 is driven, moves in the downward direction. Thus, the hooks 35 and 36 are opened (refer to the state shown in FIG. 5A).
In this state, the push rod 37 contacts the connection pin 3 when the robot 1, on which the frame 30a of the handling mechanism 30 is mounted, is moved in the left direction (refer to FIG. 5B). At this time, the push rod 37 is pushed by the connection pin 3 and moves in the backward direction with a spring 41 being bent (compressed). As the handling mechanism 30 moves further toward the connection pin 3, the connection pin 3 having the base portion 43 of the cross-shape is contained in the sleeve 38 which includes a spring having a slit of a corresponding cross-shape (refer to FIG. 5C).
When the motor 31 is rotated in the opposite direction in this state, the hooks 35 and 36 are closed (refer to FIG. 5D) and, at the same time, a stopper 36a formed with the hook 36 is inserted, with a little spare space, on the left side of a flange 37a fixed to the other end of the push rod 37.
When the robot 1 is moved in the right hand direction in this state, the base portion 43 of the connection pin 3 is hooked by the hooks 35 and 36 and the connection pin 3 may be extracted (refer to FIG. 5E). Also, since the flange 37a fixed to the push rod 37 is hooked by the stopper 36a, the push rod 37 is fixed with the spring 41 being compressed.
Although the extraction operation of the connection pin 3 inserted in the left-hand-side matrix switch board 2 is explained in the above, it is understood that the extraction operation of the connection pin 3 inserted in the right-hand-side matrix switch board 2 may be carried out in same manner. Also, the insertion operation of the connection pin 3 may be performed by reversing the above-mentioned extraction operation.
As mentioned above, according to the connection pin insertion/extraction device of the present invention, it is possible to carry out the insertion/extraction operation of the connection pin 3 for the matrix switch boards located on both sides of the device without using the reversal mechanism. Also, the hooks 35 and 36, the motor 31 and the spring 41 are commonly used or shared by the handling mechanism 30 for handing the connection pin 3 on the right and left hand sides. Thus, the number of construction parts for the device may be decreased and hence the manufacturing cost of the device may be lowered. Also, the size of the connection pin insertion/extraction device may be reduced.
Next, the insertion-strength restriction mechanism and the position detection mechanism of the connection pin insertion/extraction device according to the present invention will be described with reference to FIGS. 3 through 5.
In the conventional connection pin insertion/extraction device shown in FIG. 1, the insertion-strength restriction mechanism 6 and the optical sensor 4 (the position detection mechanism) are additionally provided with the handling mechanism of the device. However, according to the connection pin insertion/extraction device of the present invention, the insertion-strength restriction mechanism and the position detection mechanism are formed in the monitor mechanism and, moreover, a portion of the monitor mechanism is included in the above-mentioned handling mechanism 30. Also, the monitor mechanism is formed along substantially the same axis as that of the handling mechanism 30.
The monitor mechanism of the connection pin insertion/extraction device according to the present invention is comprised of two push rods 37, the spring 41, two masking plates 39 and a photoelectric switch 40. As shown in FIG. 3, the two push rods 37 are provided so as to oppose each other on the right and left hand sides of the device. The spring 41 is located between the two push rods 37 and the masking plate 39 is fixed to the back of each of the push rods 37. The masking plates 39 and the photoelectric switch 40 form a detection portion of the monitor mechanism. The push rods 37 and the spring 41 are commonly used in the above-mentioned handling mechanism 30 and the monitor mechanism.
The monitor mechanism monitors the insertion strength of the push rods 37 for the operation of the insertion-strength restriction mechanism and the presence of an object for the operation of the position detection mechanism.
The detection portion of the monitor mechanism comprised of the photoelectric switch 40 and the masking plates 39 will be described in detail with reference to FIGS. 6A through 6C. FIG. 6A is a diagram showing a perspective view of the detection portion of the monitor mechanism, FIG. 6B is a diagram showing a side view of the detection portion of the monitor mechanism, and FIG. 6C is a diagram showing a front view of the detection portion of the monitor mechanism.
As shown in the figures, the photoelectric switch 40 has a concave shape and a light beam 45 is ejected in the direction indicated by an arrow in FIG. 6B. The masking plates 39 are provided at right and left hand sides of the photoelectric switch 40 so as to be parallel to each other. Both of the right and left side masking plates 39 have a predetermined length.
When the push rods 37 move in the right and left directions, the two masking plates 39 cross the light beam 45 of the photoelectric switch 40 without contacting each other. When the light beam 45 of the photoelectric switch 40 is interrupted by the masking plates 39, a high-level signal (H-level signal) is output from the photoelectric switch 40. On the other hand, a low-level signal (L-level signal) is output from the photoelectric switch 40 when the light beam 45 is not interrupted.
Next, the insertion-strength restriction mechanism of the connection pin insertion/extraction device according to the present invention will be explained.
In the connection pin insertion/extraction device shown in FIG. 3, the photoelectric switch 40 outputs a L-level signal when the push rods 37 are not in contact with anything (corresponds to the state shown in FIG. 5A). When the left-side push rod 37 starts to contact an object (corresponds to the state shown in FIG. 5B), the left-side masking plate 39 interrupts the light beam 45 and the photoelectric switch 40 outputs a H-level signal.
After that, when the push rods 37 are further pushed by the object (corresponds to the state shown in FIG. 5C), the left-side masking plate 39 having the predetermined length as mentioned above, passes over the light beam 45, and hence the signal level is changed to L from H. At this time, the push rods 37 receive a certain stress from the spring 41. The stress corresponds to the insertion strength for the connection pin 3 during an insertion operation.
In this state, when the movement of the push rods 37 are controlled so as to be stopped, the insertion strength exerted by the push rods 37 may be restricted to a predetermined value. Thus, the insertion strength greater than the predetermined value is not applied to the connection pin 3. The predetermined value may be determined by the property of the spring 41 and the position of the masking plates 39.
Next, an extraction operation of the connection pin 3 based on the output information from the photoelectric switch 40 will be explained with reference to FIGS. 5A through 5E. As mentioned above, in the state shown in FIG. 5A, the hooks 35 and 36 are opened and the robot 1 is moved to the matrix switch board 2. In the state shown in FIG. 5B, the output of the photoelectric switch 40 is changed to H-level from L-level. When the robot 1 is moved further, the output of the photoelectric switch 40 is changed to L-level from H-level as shown in FIG. 5C. At this moment, the robot 1 is stopped and the hooks 35 and 36 are closed as shown in FIG. 5D.
Then, as shown in FIG. 5E, the robot 1 is moved in the backward direction so that the connection pin 3 may be pulled out from the matrix switch board 2. At this time, the push rods 37 are moved toward the connection pin 3 relative to the frame 30a with a distance corresponding to the space between the flange 37a fixed to the push rods 37 and the stopper 36a formed with the hooks 35 and 36. Therefore, the output of the photoelectric switch 40 is changed to H-level again. This is the holding (handling) state of the connection pin 3.
Next, an insertion operation of the connection pin 3 based on the output information from the photoelectric switch 40 will be explained with reference to FIGS. 5A through 5E. The insertion operation of the connection pin 3 may be performed by reversing the above sequence for the extraction operation.
In the holding state of the connection pin 3 shown in FIG. 5E, the robot 1 is moved to the matrix switch board 2. When the connection pin 3 contacts the through-hole 83, the push rod 37 pushes the base portion 43 of the connection pin 3 with an insertion force obtained from the spring 41. The output of the photoelectric switch 40 is H-level in this state.
As shown in FIG. 5D, when the connection pin 3 is completely inserted in the through-hole, the push rod 37 moves to the opposite direction of the connection pin 3 with respect to the frame 30a and hence the output of the photoelectric switch 40 is changed to L-level from H-level. When this change of the output level is detected, the movement of the robot 1 is stopped. According to the above operation, it is possible to prevent the insertion force of the push rod 37 applied to the connection pin 3 from becoming greater than the predetermined limitation value. Thus, the danger that the connection pin 3 may be damaged by the applied insertion force may be eliminated according to the present invention.
Then, the hooks 35 and 36 are opened as shown in FIGS. 5C through 5A and the robot 1 is moved in the backward direction so that the insertion operation of the connection pin 3 may be completed. At this time, the output of the photoelectric switch 40 is changed to H-level from L-level and then changed to L-level from H-level. Thus, the termination of the insertion operation of the connection pin may be confirmed by the detection of the above change in the output level of the photoelectric switch 40.
Next, the position detection mechanism of the connection pin insertion/extraction device according to the present invention will be explained in detail. In the position detection mechanism also, the above-mentioned monitor mechanism used in the insertion-strength restriction mechanism may be employed. According to the position detection mechanism, the distance from the robot 1 to an object may be measured by detecting a contact state of the push rod 37 with the object when the robot 1 is transferred. The contact state of the push rod 37 with the object may be easily detected by the change in the state shown in FIG. 5A to the state shown in FIG. 5B.
The moving distance of the robot 1 may be measured (or calculated) by monitoring the driving pulse for the robot 1. The circuit used for measuring the moving distance of the robot 1 is well known in the prior art and the explanation thereof will be omitted.
First, a method for measuring the height direction with respect to the robot 1 and the matrix switch board based on the output information from the photoelectric switch 40 will be explained. After initializing the current position of the robot 1, the robot 1 is moved to the matrix switch board 2. When the push rod 37 touches the matrix switch board 2, the output of the photoelectric switch 40 is changed to H-level from L-level as explained above. The number of the driving pulses required for the movement of the robot 1 till the output of the photoelectric switch 40 is changed to H-level corresponds to the distance between the initial position of the robot 1 and the matrix switch board 2. Likewise, the distance between the robot 1 and an object on the matrix switch board 2 may be measured.
Next, a method for detecting a position of an object on the matrix switch board based on the output information from the photoelectric switch 40 will be explained.
FIG. 7 is a diagram for explaining a position detection method for an object on the matrix switch board. In FIG. 7, the output waveform of the photoelectric switch 40 is shown in accordance with the movement of the push rod 37.
As shown in FIG. 7, the robot 1 is moved straightforward with a short pitch in the region of an arbitrary object provided on the matrix switch board. Every time the robot 1 moves with a predetermined pitch, the push rod 37 is moved toward the object a predetermined distance. At this time, the presence of the object may be detected when change in the output level of the photoelectric switch 40 is detected. Also, by moving the robot 1 in a cross shape on the object, it is possible to measure the size and the center point of the object.
As shown in FIG. 4, at least two standard pins 61 are provided around the through-hole 83 instead of the standard marks used in the conventional position detection mechanism. The through-hole 83 and the hole for the standard pins 61 may be simultaneously formed and their positional relationship may be determined precisely.
According to the connection pin insertion/extraction device of the present invention, the position of each of the standard pins 61 may be accurately measured by using the above-mentioned position detection mechanism and contacting the standard pin 61 by the push rod 37. Thus, the position of a specific through-hole 83 may also be accurately determined.
Particular to the position detection mechanism of the connection pin insertion/extraction device of the present invention, the position of an object may be detected using the push rod 37 which is located on a central axis extended from the handling mechanism. Thus, an error in distance may be eliminated between the optical sensor and the handling mechanism associated with the conventional connection pin insertion/extraction device in which the optical sensor is not located on the central axis of the handling mechanism. Therefore, the connection pin insertion/extraction device of the present invention may perform the measuring operation of the position of an object more accurately.
Next, a method for detecting a failure of an inserting/extracting operation of the connection pin based on the output information of the photoelectric switch 40 will be explained. In this method, the distance in a height direction of the robot 1 at which the output signal of the photoelectric switch 40 is changed is stored in a memory in advance. When the failure of the inserting/extracting operation of the connection pin is caused, the position of the robot 1 at which the output signal of the photoelectric switch 40 is changed is different from the one stored beforehand.
According to the above method, when the above-mentioned shift in position of the robot 1 at which the output signal of the photoelectric switch 40 is changed is observed, it is assumed that the operation was not successful. For instance, when the metallic pins 42 of the connection pin 3 are not correctly inserted in the corresponding through-holes 83 in the inserting operation, the output signal of the photoelectric switch 40 is changed to H-level from L-level before the robot 1 reaches the predetermined position. Thus, the inserting operation may be determined to be a failure.
As mentioned above, according to the connection pin insertion/extraction device of the present invention, it is possible to form the inserting-strength restriction mechanism and the position detection mechanism (optical sensor), both of which are additionally provided with the conventional connection pin insertion/extraction device, in the same monitor mechanism. Also, a part of the monitor mechanism may be included in the handling mechanism. Therefore, the number of construction parts for the device may be decreased and the manufacturing cost of the device may be lowered. Moreover, the size of the connection pin insertion/extraction device may be reduced.
Further, since the insertion-strength restriction mechanism and the position detection mechanism are formed along substantially the same axis of the handling mechanism, the transfer operation of the insertion force may be efficiently performed without having a loss and the error associated with the position detection operation may be reduced.
In addition, the switch which may be used in the monitor mechanism of the connection pin insertion/extraction device is not restricted to the photoelectric switch 40.
FIG. 8A is a diagram showing a second embodiment of the detection portion of the monitor mechanism and FIG. 8B is a diagram showing a third embodiment of the detection portion of the monitor mechanism. In FIG. 8A, the detection portion is comprised of a dog 50 and a mechanical switch 51 instead of the photoelectric switch 40. The dog 50 is fixed to an end portion of the flange 37a of the push rod 37.
In the operation of the detection portion, the push rod 37 moves in a right direction and the output signal of the switch 51 is change to H-level from L-level when the dog 50 pushes down a knob 52 of the switch 51 in the right direction. When the push rod 37 further moves in the right direction and the dog 50 completely passes over the knob 52, the knob 52 is returned to the original position and the output signal of the switch 51 is changed to L-level from H-level. Accordingly, the dog 50 and the switch 51 may operate in the same manner as the masking plate 39 and the photoelectric switch 40.
Also, although the knob 52 is pushed down in the right or left direction in the above-mentioned switch 51, it is possible to employ a knob 52' which moves in the up and down directions as shown in FIG. 8B.
FIG. 9A through 9C show an embodiment of a connection pin insertion/extraction device according to the present invention. FIG. 9A is a diagram showing a side view of the connection pin insertion/extraction device, FIG. 9B is a diagram showing a front view of the device and FIG. 9C is a diagram showing a top view of the device.
According to the embodiment shown in the figures, the rotary driving force generated by the motor 31, which is fixed to the frame 30a of the handling mechanism 30, is transferred to the screw shafts 32 and 34 via the pinion 31a and the idler gear 33. Sliders 71 and 74 in which the screw shafts 32 and 34 are driven, respectively, move along a shaft 73 as a guide and open the corresponding hooks 36 and 35, each of which is fixed to the sliders 71 and 74, respectively. The above-explained handling mechanism, insertion-strength restriction mechanism and position detection mechanism are used in the connection pin insertion/extraction device.
The present invention is not limited to the above embodiments, and variations and modifications may be made without departing from the scope of the present invention. | A connection pin handling device has first and second sleeves mounted on a common axis and having corresponding first and second inlets disposed respectively at first and second opposite sides of the device, each inlet alignable with a selected connection pin on the corresponding side of the device. First and second push rods are slidably mounted for movement along the common axis in the first and second sleeves, respectively, to engage, by a selected one of the first and second push rods, a selected, aligned connection pin disposed at the respective, corresponding side of the connection pin handling device. A spring is disposed between the first and second push rods and exerts an insertion force on the selected push rod which applies a force to, and moves, the selected connection pin engaged thereby for performing an insertion or an extraction operation thereon. |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation under 35 U.S.C. §120 of co-pending and commonly-assigned U.S. Utility patent application Ser. No. 12/784,466, filed on May 20, 2010, by Sri R. Narayan and Charles C. Hays, entitled “NANOSTRUCTURED PLATINUM ALLOYS FOR USE AS CATALYST MATERIALS,”, which application claims the benefit under 35 U.S.C. Section 119(e) of the following and commonly assigned patent applications:
U.S. Provisional Patent Application Ser. No. 61/222,429, filed on Jul. 1, 2009, by Sri R. Narayan and Charles C. Hays, entitled “NANOSTRUCTURED PLATINUM ALLOYS FOR USE AS CATALYST MATERIALS IN FUEL CELLS,”; and
U.S. Provisional Patent Application Ser. No. 61/346,428, filed on May 19, 2010, by Charles C. Hays and Sri R. Narayan, entitled “NANOSTRUCTURED PLATINUM ALLOYS FOR USE AS CATALYST MATERIALS,”;
all of which applications are incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention described herein was made in the performance of work under NASA contract No. NAS7-1407, and is subject to the provisions of Public Law 96-517 (35 U.S.C. 202) in which the Contractor has elected to retain title.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a new composition for use as a catalyst or electro-catalyst material.
2. Description of the Related Art
(Note: This application references a number of different publications as indicated throughout the specification by one or more reference numbers within brackets, e.g., [x]. A list of these different publications ordered according to these reference numbers can be found below in the section entitled “References.” Each of these publications is incorporated by reference herein.)
Platinum metal, as a discreet nanoparticle or as a film on a nanoparticle support, is the dominant catalyst material for a wide range of catalytic reactions under extreme conditions; e.g., at high temperatures or under acidic environments. Consider the use of Pt catalysts in the Platforming process, first developed in 1949, which enabled the synthesis of gasoline without the addition of lead to the gasoline. Efforts to make the synthesis of gasoline more green include the development of Pt or PtRe catalysts with higher activity or lower Platinum group metal (PGM) loading. In the modern refinery, the Pt-containing catalysts are regenerated once in a six to twenty four month period. The catalyst can be regenerated perhaps 3 or 4 times before it must be returned to the manufacturer for recycling of the PGM catalyst.
In order to reduce vehicle emissions, better catalysts are needed for catalytic converters. In the state-of-the-art (SOA) 3-way catalytic converter, the Pt-based catalysts simultaneously break down the harmful byproducts present in the hot exhaust streams of automobiles exhausts, including: 1) reduction of nitrous oxides to nitrogen and oxygen; 2) oxidation of carbon monoxide to carbon dioxide; and 3) oxidation of unburned hydrocarbon (HCs), according to the following reaction:
2CO+2NO→2CO 2 +N 2
In a 3-way catalytic converter, the Pt or Pt-alloy particles are placed on a high surface area support that is maintained at high temperatures and Pt-based alloys with greater microstructural stability at these temperatures will improve the converter performance over time.
Fuel cells are widely regarded as an alternative to internal combustion engines, and will play a dominant role in a hydrogen economy as power sources for portable power, transportation, and stationary power applications. However, to meet the future requirements outlined by the US Department of Energy, a new class of catalytic materials is required to improve the performance of electrodes used in advanced fuel cell applications [1]. As such, extensive government and industrial research has been performed in an attempt to commercialize fuel cells. In SOA polymer electrolyte membrane fuel cells (PEMFCs) using an acid polymer electrolyte, platinum (Pt) and platinum group metal (PGM) alloy catalysts are used as the cathode material for the reduction of oxygen, and as the anode material for the oxidation of the hydrogen gas fuel.
In either application, the high cost of Pt is an impediment to their use. A significant amount of research is under way to reduce the Platinum group metal (PGM) content in catalytic converters and fuel cells.
Some challenges limiting the widespread application of PEMFCs, that utilize PGM catalysts are: 1) slow kinetics for oxygen reduction; 2) long-term durability issues manifest by metallurgical effects (e.g., Ostwald particle ripening, and surface area loss due to corrosion); and 3) the high cost of platinum.
The reduced PEMFC durability observed in SOA fuel cell systems is driven in large part by the metallurgical changes in the Pt metal used as the cathode for the oxygen reduction reaction (ORR). During fuel cell operation; grain growth (i.e., Ostwald particle coarsening), corrosion of Pt crystals, and the corrosion/gasification of carbon supports under electrochemical polarization are observed, which collectively result in severe cathode degradation. In addition, the optimal performance of SOA PEMFCs is limited by the sluggish kinetics of the ORR on Pt and its alloys; e.g., a large activation potential (i.e., an over-potential V over ˜300 mV) exists even for the SOA catalysts. In new the alloyed catalysts, such as Pt 3 Co, the durability of polymer electrolyte cell membrane is reduced due to poor corrosion resistance of the cell electrodes, where Co is corroded from the catalyst surface (cathode), and ultimately crosses over into the membrane [2].
In this application, embodiments of the present invention teach a new class of Pt-based catalyst materials. In the description of the catalyst performance, focus on the use of these materials as the cathode material in a PEMFC, and the results presented show that their performance far exceeds that demonstrated by SOA Pt materials, with a greatly reduced Pt content or Pt loading. However, other applications are also disclosed.
SUMMARY OF THE INVENTION
There is provided in the practice of embodiments of this invention, a series of binary and ternary Pt-alloys, that promote the important reactions for catalysis at an alloy surface; oxygen reduction, hydrogen oxidation, and hydrogen and oxygen evolution. The first two of these reactions are essential when applying the alloy for use in a PEMFC.
To overcome the limitations in the prior art described above, and to overcome other limitations that will become apparent upon reading and understanding the present invention, the present invention discloses a platinum (Pt) metal containing alloy composition useful as a catalyst electrode, comprising a film comprising a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table.
The film may comprise a continuous film on a nanoparticle support, a continuous film on a hollow spherical nanoparticle (e.g., nanoshell) support, a continuous film on a micron-sized metallic or non-metallic support, or a continuous film on a wire or wire-gauze support, for example.
There may be less than 50% Atomic % (At. %) Pt in the compound.
Element A may comprise at least one valve metal element of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb). A may comprise at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B may comprise at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe), and with at least one PGM element of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
The Pt-containing compound may further comprise at least one late transition metal B, thereby forming a Pt—B-A alloy. For example, A may comprise at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B may comprise at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe). The alloy may be (Pt 3 Co) 100-y Zr y with 0≦y≦30 (At. %). The alloy may comprise (Pt 100-x Co x ) 100-y Zr y with 0≦x≦80 and 0.5≦y≦60.
The Pt-containing compound may further comprise at least one platinum group metal (PGM), thereby forming a Pt-PGM-B-A alloy, wherein the PGM element comprises at least one of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
The alloy may be crystalline, for example, nanocrystalline with a grain size of no more than 100 nm, or nanocrystalline with a preferred grain size of less than 10 nm. The alloy may have a (111) crystallographic orientation.
An amount of A and an amount of Pt in the film may be such that that the film is at least 2 times more electrochemically active, in an oxygen reduction reaction (ORR), than Pt. An amount of A and the amount of Pt in the film may be such that the film is electrochemically stable, with no decrease in electrochemical activity of the film used with an electrolyte. To determine the durability of said alloy, the electrochemical activity is characterized by conducting multiple cyclic voltammograms (CV) over a potential range of 0.0 to at least 1.2 Volts (vs. NHE), with a potential scan rate of the order 100 mV/sec, and a total number of cycles exceeding N=1000. For durable compositions, the current density at 0.9 V (vs. NHE) should not decrease on electrochemical cycling, within the measurement accuracy (e.g., +/−10 microamps).
The electrolyte may be an acid electrolyte. The acid electrolyte may be a mixture of perchloric acid in water (HClO 4 /H 2 O) (e.g., a 1 molar perchloric acid concentration in water (HClO 4 /H 2 O)), or mixture of sulfuric acid in water (H 2 SO 4 /H 2 O) (e.g., a 1 molar sulfuric acid concentration in water (H 2 SO 4 /H 2 O). The acid electrolyte may saturate a polymer exchange membrane electrolyte (e.g. Nafion).
For example, synthesized Pt—Co—Zr thin films are stable in 1 M perchloric acid and are electrochemically active for the oxygen reduction reaction, with kinetic currents at 0.9 V (that greatly exceed those of Pt, by amounts as great as thirty times [30×]).
The present invention further discloses a platinum (Pt) metal containing alloy composition useful as a catalyst electrode, comprising a nanoparticle comprising a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table.
The present invention further discloses a platinum (Pt) metal containing alloy composition useful as a catalyst electrode, comprising a metallic nanocrystalline cluster or quantum dot on a nanoparticle support, wherein the metallic nanocrystalline cluster or quantum dot comprises a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
FIG. 1 is a fuel cell comprising electrodes according to the present invention;
FIGS. 2 a - 2 g are schematics of co-sputtering, electron beam evaporation, vapor phase condensation, atomic layer deposition, melt spinning and melt extraction, gas atomization, and rotary atomization processes, that may be used to fabricate the compositions of the present invention;
FIG. 3 is a photograph of an 18 electrode Pt—Co—Zr thin film array, showing electrodes upon which samples E11-E36 are deposited;
FIGS. 4 a and 4 b show X-ray diffraction results for Pt 3 Co to Pt 53 Co 20 Zr 27 films, and Pt 100-x Zr x films, respectively, and FIG. 4 c is a secondary electron scanning electron microscope (SEM) image of the top surface of sample E33, a Pt 69 Co 20 Zr 11 as deposited thin film (50,000× magnification), showing single phase microstructure, with uniform grain size (40-50 nm resolved at 100,000× magnification), wherein the PtCoZr film's grain size and crystallographic orientation (111) are comparable to the grain size of the underlying Au-film on which it was deposited;
FIG. 5 a is an image of an electrochemical measurement set up and FIG. 5 b is a schematic of a typical electrochemical half cell;
FIG. 6 shows voltammograms (CV), plotting current (amps) as a function of voltage applied to PtCoZr and PtCo films (voltage with respect to a normal hydrogen electrode defining 0 volts), for samples E11, E13, E23, E33 and E14 using the PtCoZr multi-electrodes array of FIG. 3 and the multi electrode half cell set up of FIG. 5 a , wherein the voltage is scanned at a 100 mV/second scan rate and the curves shown are the last cycle plots obtained after 100 cycles; the surfaces were prepared by conducting 100 cycles at 200 mV/second scan rate over the same potential range;
FIG. 7 is a durability plot for a Pt 67 Zr 33 film, showing multiple cyclic voltammograms taken after the film has been electrochemically prepared (by e.g., by cycling voltage over 100 cycles), with the individual voltammograms shown after conducting N=2, 50, 100, 250, 500, and 1000 cycles;
FIG. 8 shows nearly potentiostatic polarization curves in the kinetic region for the ORR, for various PtCoZr and PtCo compositions, wherein current density (microamps/cm 2 ) is plotted as a function of voltage applied to the PtCoZr and PtCo films (voltage with respect to a normal hydrogen electrode defining 0 volts), the voltage is ramped from 1.05 V to 0.25 V at a 1 mV/second scan rate, and the measurements of FIG. 8 are taken after the surface of the films has been prepared by performing 100 voltage cycles over 0 V to 1.2 V at a 200 mV/second scan rate;
FIG. 9 shows ORR current density (at 0.9 V vs. NHE) for different alloy compositions of the present invention, wherein the ORR current density for a Pt thin film (Pt-TF) is also shown;
FIG. 10 is a schematic of the binary Pt 3 Co composition showing the 111 plane;
FIG. 11 a is a graph showing the binary phase diagram for the Pt—Zr alloy series, at which various Pt 100-x Zr x compositions occur, wherein the ellipse shows compositions with high electrochemical performance, and FIG. 11 b is a schematic showing the D0 24 crystal structure for the Pt 3 Zr composition;
FIG. 12 is a flowchart illustrating a method of fabricating and using a Pt metal alloy composition as a catalyst;
FIG. 13 is an image of a multi electrode NSTF Array, wherein the scale bar shows 50% to 35% (At %) Pt-content;
FIG. 14 shows active area (μC/cm 2 ) as a function of Pt content (At %), for PtCoZr, PtZr and Pt; and
FIG. 15 shows activity relative to Pt for ORR, for PtCoZr and PtZr as a function of Pt content (At %).
DETAILED DESCRIPTION OF THE INVENTION
In the following description of the preferred embodiment, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
Technical Description
Two series of Pt-based alloys, in thin film form, have been prepared by co-sputtering. As examples, the present invention shows that members of two platinum-metal containing composition manifolds are stable in acid solutions, and exhibit electro-catalytic performance that meets or exceeds that of pure Pt metal. Examples of the two platinum metal containing composition manifolds are A) (Pt 100-x Co x ) 100-y Zr y 0≦x≦80, and 0.5≦y≦60 (At. %); and B) Pt 100-x Zr x , 8<x<33 (At. %).
Thus, the compositions of the present invention may be useful in any applications that would benefit from electro-catalytic performance. For example the new Pt-based alloy catalysts of the present invention may be useful as electrodes in a fuel cell, as illustrated in FIG. 1 . The fuel cell typically comprises an electrolyte between the anode and the cathode. The composition of the present invention may be used as a cathode and/or an anode in the fuel cell.
Fabrication
Combinatorial film deposition methods, as described in [1], were used to simultaneously prepare a wide range of Pt—Co—Zr compositions for evaluation. Using a high-throughput, co-sputtering, synthesis technique, an array of thin film specimens in the ternary alloy series (Pt 3 Co) 100-x Zr x , 0≦x≦30 (At. %), were simultaneously prepared.
FIG. 2 a shows a schematic of the co-sputtering process. All films were co-sputtered from two targets, each made from research grade materials, with minimum purities of 99.99%; Pt 3 Co and Zr (Kurt J. Lesker). A typical co-sputtering procedure comprises evacuating the sputtering chamber to a base chamber pressure of <1×10 −6 Torr, followed by film deposition carried out under an Argon gas pressure of 15 mTorr.
A multi-electrode array comprising of 18 thin film electrodes were deposited using a three-step physical masking method. First, an 18-segment current collector array was fabricated using a nanostructured Au thin film over a Ti adhesion layer. The average Au grain size was 40-50 nm. The Au/Ti films were sputtered through a patterned mask onto a polished borosilicate glass substrate, with nominal dimensions of 4″×5″×⅛″. The Au films were strongly oriented, with a (111) crystallographic orientation.
The Pt—Co—Zr catalyst films were co-sputtered after physically masking off an equally spaced array of ⅛″×⅛″ openings, each placed above the Au current collector structure. The individual films were deposited onto an 18-segment current collector structure comprised of nanostructured Au thin films, with average Au grain size of 40-50 nm.
FIG. 2 b illustrates an electron beam evaporation apparatus [12] that can be used to deposit the Pt films of the present invention, comprising a heatable substrate holder, quartz crystal, shutter, crucible, and 4-pocket e-beam evaporator.
FIG. 2 c illustrates a vapor phase condensation apparatus [6] that can be used to synthesize the Pt alloys of the present invention in particulate form, comprising a vacuum chamber with computerized process control comprising a heating element (e beam evaporator), power supply, powder, quenchant gas. Powder collection and final packaging is also shown.
FIG. 2 d illustrates an atomic layer deposition (ALD) apparatus [7] (fluidized bed ALD reactor schematic) that can be used to deposit the Pt films of the present invention, comprising Mass Flow Controllers (MFC), Nitrogen Source N 2 , reagent reservoirs A and B, vibrational motors, fluidized bed reactor, and vacuum pump.
FIG. 2 e illustrates an melt spinning and melt extraction apparatus [8] that can be used to synthesize the Pt alloys of the present invention in thin ribbon or fine wire form, comprising melt spinning, double roller, melt drag, free flight, taylor wire, and melt extraction.
FIG. 2 f illustrates Gas Atomization apparatus [9] that can be used to synthesize the Pt alloys of the present invention in powder form, comprising gas and metal source.
FIG. 2 g illustrates a centrifugal atomizer [10] that can be used to synthesize the Pt alloys of the present invention in powder form, comprising turbine drive air and coolant exhaust air, collectors, deflector shield, manifold, 2 nd nozzle, 1 st nozzle, recirculator, heat exchanger, and cyclone separator.
FIG. 3 shows the collector structure 300 comprising 18 thin film electrodes 302 of Au thin films disposed in an array, with different PtCo and PtCoZr samples 304 deposited thereon. The samples 304 , labeled E-ab depending on their position on the array, comprise different compositions having different amounts of Pt, Co and Zr, where “a” corresponds to the row number 306 and “b” corresponds to the column number 308 . For example, sample E-11 is positioned in the first row and first column.
Experimental Characterization of the Films
Structure
FIGS. 4 a and 4 b illustrate X-ray diffraction (XRD) data for a platinum (Pt) metal containing alloy composition for use as a catalyst electrode, comprising a film including a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table. In this example, the Pt-containing compound further comprises at least one late transition metal B, thereby forming a Pt—B-A alloy.
FIG. 4 a shows the Au films were strongly oriented, with a (111) crystallographic orientation. Also shown in FIG. 4 a are the XRD patterns for six films from the array, wherein nominal compositions from Pt 3 Co (16) to Pt 53 Co 20 Zr 27 (11 or E-11) are shown. Each of the Pt—Co—Zr thin films exhibits a (111) crystallographic orientation. Some additional lines in the spectra indicate the presence of some grains with differing orientation. The decreased intensity for Pt 53 Co 20 Zr 27 is consistent with the reduced thickness of the films in this part of the array. As shown in FIG. 4 a , the X-ray spectra reveal that there appears to be a smooth increase in the lattice parameter with increasing x, moving from Pt 3 Co (a=2.245 Å, Cu 3 Au structure type) to Pt 62 Co 24 Zr 14 (a=2.294 Å). For x>14%, the lattice parameter decreases.
As shown in FIG. 4 b , the X-ray spectra for Pt 100-x Zr x reveal that there appears to be a smooth decrease in the lattice parameter with decreasing x, moving from ˜Pt 3 Zr (a=3.964 Å, Ni 3 Ti structure type) to Pt 93 Zr 7 (a=3.923 Å, Pt-ric, Pt 4 Zr structure type [i.e., Cu 3 Au type]).
FIG. 4 c shows SEM images of the compositions of the present invention, showing single phase microstructure, with uniform grain size (40-50 nm).
Electrochemical Properties
The electrochemical properties of the (Pt 3 Co) 1-x Zr x films were measured using a high-throughput, multi-electrode, screening technique developed at Nasa's Jet Propulsion Laboratory. This technique enables the simultaneous evaluation of polarization behavior, active area, and durability for multiple thin film specimens.
FIGS. 5 a and 5 b illustrate electrochemical measurement set ups used for the measurements of the present invention [11].
The results of these electrochemical measurements show that a wide range of compositions within the (Pt 3 Co) 100-x Zr x composition manifold are stable in acid solutions (e.g., 0.1 M HClO 4 /H 2 O electrolytes). This stabilization has been achieved by the addition of early transition-metal (ETM) elements from groups IVB and VB of the periodic table (e.g., Ti, Zr, Hf, and Nb). The addition of the ETM element(s) also enables the addition of late transition metal (LTM) moieties (e.g., Ni, Co, and Fe), thereby reducing the Pt-metal content further.
In order to exhibit electro-catalytic behavior, the films of the present invention were electrochemically prepared by applying a voltage to the films (with respect to a normal hydrogen electrode (NHE) defining 0 volts), wherein the voltage was ramped from 0 to 1.2 V and the ramping was repeated or cycled over a sufficient number of cycles (approximately 100 cycles). After sufficient number of cycles (e.g., 100 cycles), the film exhibits electrochemical characteristics.
Anodic Behavior
The films of the present invention may be used as an anode to catalyze a hydrogen oxidation reaction.
Electro-catalytic behavior is demonstrated by the results presented in FIG. 6 , which shows a cyclic voltammogram (CV), taken using the set ups in FIGS. 5 a and 5 b , for the compositions E11, E13, E23, E33 and E14 which exhibit a (111) crystallographic orientation. This CV was conducted at a scan rate of 100 mV/sec, in a de-aerated 0.1 M HClO 4 /H 2 O electrolyte. Note that the hydrogen oxidation peaks 600 are those associated with the Pt(111) or PtCo(111) crystal faces [active Pt-site area values in Table-1].
The hydrogen oxidation reaction (HOR) peak is a direct measurement of the oxidation of hydrogen to produce electron(s) (e − ) and a hydrogen nucleus (H + ), catalyzed by the composition of the present invention acting as an electrode (anode), and according to the reaction:
H 2 →2H + +2 e −
This is the reaction typically catalyzed by an anode, for example in a fuel cell, in the presence of hydrogen (in this case, the hydrogen is the fuel). The area under the peaks labeled HOR in FIG. 6 (active area A active ) is directly proportional to the amount of charge (electrons) generated by the reaction and catalyzed by the Pt sites at the anode, and therefore is a good figure of merit for the anodic performance of the composition of the present invention. The larger the area under the peaks (e.g. HOR), the more charge (or electrons) generated, and the better the performance as an anode. More specifically, the active area represents charge resulting from the underpotential deposition of hydrogen (H upd ) onto the composition acting as an anode.
Table 1 lists the active areas for various compositions of the present invention, as calculated by integrating the curves, between 0 and 0.4 V vs. NHE, in FIG. 6 , and dividing by the geometric surface area of the film being used as an electrode.
TABLE 1
Charge for H upd region
Film
Composition
Sample
Active Area (A active )
thickness (nm)
Pt 56 Co 24 Zr 20
E-11
397.66 μC/cm 2
88.3
Pt 68 Co 23 Zr 9
E-13
550.32 μC/cm 2
105.9
Pt 66 Co 24 Zr 10
E-23
741.64 μC/cm 2
137.8
Pt 69 Co 20 Zr 11
E-33
343.41 μC/cm 2
123.7
Pt 77 Co 23
E-14
367.63 μC/cm 2
160.4
A active for a Pt film containing only Pt (pure Pt) is 210 μC/cm 2 . Thus, the data in Table 1 and FIG. 6 illustrate the films of the present invention have greater A active as compared to a pure Pt film. Moreover, FIG. 6 shows the remarkable result that reducing the amount of Pt in the alloy electrode may increase the electrochemical performance of the Pt alloy electrode.
Durability (Non-Corrosive Properties)
FIG. 7 is a durability plot for a Pt 67 Zr 33 film, illustrating that compositions of the present invention do not corrode (to within the measurement accuracy) over a period of more than 1000 cycles. FIG. 7 compares the voltammogram taken after the film has been electrochemically prepared (by e.g., by cycling voltage over 100 cycles), with the voltammogram taken after 1000 cycles. The voltammograms are identical, to within the measurement accuracy of the experiment.
The durability of these compositions may exceed that of pure Pt, as the arrays have been extensively cycled (n>10 3 cycles) over the potential range 0.0 to 1.2 V, with no degradation of the electrode surface or decrease in electrochemical performance observed. Although not reported, representative electrodes of the Pt—Co—Zr thin films prepared have been cycled over the potential range 0.6-1.2 V, at a scan rate of 200 mV/sec, for at least 3000 cycles with no degradation in performance. These results suggest that alloys in Pt—Co—Zr composition manifold can be as active as Pt catalysts, although with much reduced Pt-loadings; i.e., with just ˜50% of the amount of platinum metal.
Cathodic Behavior
The films of the present invention may be used as a cathode in the presence of, e.g., oxygen, to catalyze the reduction of the oxygen in an oxygen reduction reaction (ORR) (reacting the oxygen with, e.g., hydrogen ions produced at the anode).
For example, FIG. 8 illustrates the (Pt 3 Co) 100-x Zr x thin film compositions synthesized are also electrochemically active for the ORR, a key point for application as a cathode material in an advanced fuel cell. FIG. 8 shows the results of potentiostatic polarization measurements conducted in a fully oxygenated 0.1 M HClO 4 /H 2 O electrolyte, using the set up of FIGS. 5 a and 5 b.
The ORR current is measured as a function of voltage applied to the film (voltage with respect to a normal hydrogen electrode defining 0 volts), in the presence of the oxygen in the electrolyte, wherein the voltage is swept at 1 mV/sec, from 1.05 V to 0.25 V (cathodic sweep). Large values for the ORR current density (μA/cm 2 ) at 0.9 V (vs. NHE), is indicative of better cathodic performance. The cell current is divided by the geometric surface area of the film being used as an electrode to obtain current density. The data shown are for the ORR kinetic region of the polarization measurement and are taken after the surface of the films has become electrochemically active by performing 100 voltage cycles over 0 V to 1.2 V at a 200 mV/second scan rate. The ORR data were quite reproducible for the alloys shown, with independent measurements providing nearly identical results.
FIG. 9 shows ORR current density for a voltage of 0.9 V vs NHE, for different alloy compositions of the present invention, wherein the ORR current density for a Pt thin film (Pt-TF) is also shown. The current density is normalized to the geometric area of the electrodes. FIG. 9 shows that the (111) oriented Pt 66 Co 24 Zr 10 surface is ˜30 times more active than the (111) Pt film measured in the same cell. The (111) Pt 53 Co 20 Zr 27 surface is still ˜17 times more active than Pt. The Pt 3 Co current densities in this array, ˜83 μAmps/cm 2 , are ˜22 times greater than (111) Pt, in agreement with the literature. This behavior may be related to the intraalloy electron transfer between Pt/Co and Zr, and the d-band filling with x in these new ternary alloys.
While FIG. 9 shows that Pt—Co—Zr compositions with approximately 10% Zr are the best performers, given the high cost of Pt (˜$2000 per ounce currently), for some applications it may be advantageous to use less Pt, such as Pt 53 Co 20 Zr 27 (sample E-31 with 53% Pt content), which still shows approximately 17 times enhancement over a pure Pt thin film cathode. The present invention illustrates that a cost vs. performance trade-off may be considered depending on the application.
Binary Compound
In a parallel study, the present invention has examined the properties of specific compositions in the binary alloy series, Pt 100-x Zr x , 8<x<33 (At. %). The present invention has synthesized two compositions, in thin film form, via co-sputtering. Both chemical compositions; e.g., 1) x=8; and 2) x=33, illustrate the great potential of alloys in this binary series. As with the Pt—Co—Zr thin film compositions prepared, the Pt 100-x Zr x alloys are stable in 0.1 M Perchloric acid and are electrochemically active for the ORR, with kinetic currents at 0.9 V that exceed elemental Pt. The 0.9 V (vs. NHE) enhancements of the ORR geometric current densities for Pt 100-x Zr x , are ˜2.5× greater for x=33, and 5.5× greater for x=8, respectively.
FIG. 10 is a schematic illustrating the atomic positions of the Pt and Co in the Pt 3 Co crystal. Also shown in FIG. 10 is the (111) plane.
The chemical stability for the binary Pt 100-x Zr x alloys (with x=8 and x=33) is manifest in cyclic voltammograms much like those shown in FIG. 6 , and for x=33 in FIG. 7 .
The present invention has also synthesized a Pt 3 Co (sample E-13). The Pt 3 Co sample also shows a good ORR kinetic current that is approximately 24 times greater than the ORR of a pure Pt film of comparable thickness, at 0.9 V vs. NHE.
FIG. 11 a is a graph showing the binary phase diagram for the Pt—Zr alloy series, at which various Pt 100-x Zr x compositions occur, wherein the ellipse shows compositions with high electrochemical performance, and FIG. 11 b is a schematic showing the D0 24 crystal structure for the Pt 3 Zr composition.
Process Steps
FIG. 12 illustrates a method of fabricating a platinum (Pt) metal containing alloy composition useful as a catalyst electrode.
Block 1200 represents selecting a substrate. The step may comprise selecting a crystalline structure and grain size of the substrate. The substrate may be crystalline or nanocrystalline. The substrate may be a nanoparticle support. The substrate may be a hollow spherical nanoparticle (e.g., nanoshell) support, with typical diameter of 100 nm or larger. The substrate may be a micron-sized metallic or non-metallic support (e.g.−325 mesh). The substrate may be a porous support having open areas. The substrate may be a wire or wire-gauze support. The substrate may include a metal (e.g., Ti, Au) and a current collector structure and the metal's grain size is on a nanoscale (e.g., 100 nanometers or less).
Block 1202 represents selecting early transition metal A, A and B, or A, B and PGM. The amount of A or A and B and Pt may be such that the film has a microstructure ranging between an amorphous and a nanocrystalline microstructure. A may be at least one valve metal element of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), for example. The step may comprise selecting the amounts of early transition metal, valve metal A, and Pt such that the film has a microstructure ranging between an amorphous or nanocrystalline microstructure, or with a mixture of both phases.
Block 1204 represents depositing Pt and the at least one early transition metal element A, or A and B onto the substrate.
A nanoparticle wash may be applied to the open areas of the porous support, wherein the nanoparticle wash includes a compound of Pt and at least one early transition metal element A, from group IVB or VB of the Periodic table. The nanoparticle wash may be heat-treated or fired to promote adherence to the surface of the porous support.
The alloy may be prepared by sputtering onto a support (or substrate). The sputtering may be from single alloyed target onto a support (or substrate). The sputtering may be co-sputtering from multiple targets onto a support (or substrate). The alloy may be deposited onto a support of any type, geometry, or size by hollow core magnetron sputtering.
The alloy may be prepared by electron beam evaporation from multiple targets onto a support (or substrate).
The alloy may be prepared by electron beam evaporation from a single alloyed target onto a support (or substrate).
Discreet nanoparticle forms of the alloy may be prepared by vapor-phase condensation in a high-vacuum chamber.
The alloy may be deposited onto a support by Atomic-Layer-Deposition (ALD) processing.
The alloy may be prepared by mechanical alloying (ball milling).
The alloy may be prepared by gas-atomization processing to yield an alloy in powder form.
The alloy may be prepared by centrifugal atomization processing to yield an alloy in powder form.
The alloy may be prepared by rapid solidification rate processing to yield an alloy with a nanostructured or amorphous atomic arrangement or microstructure. For example, the alloy may be prepared by the melt-spinning process to yield a thin-foil geometry product, wherein the alloy has a nanostructured or amorphous atomic arrangement or microstructure. The alloy may be prepared by the melt-extraction process to yield a wire-geometry product, wherein the alloy has a nanostructured or amorphous atomic arrangement or microstructure.
The alloy may be prepared by wet chemistry techniques resulting in the formation of small particles or nanoparticles. For example, the alloy may be prepared by the co-precipitation wet chemistry technique resulting in the formation of nanoparticles. The alloy may be prepared by the colloidal synthesis wet chemistry technique resulting in the formation of nanoparticles. The alloy may be prepared by the any wet chemistry technique involving PARR bomb processing at high temperatures resulting in the formation of nanoparticles.
The step may further comprise depositing the Pt, A and at least one late transition metal B on the substrate, wherein A includes at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B includes at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe), and with at least one PGM element of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir), for example. Alternatively, A may include at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B may include at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe), for example.
The step may further comprise depositing the Pt, A, B, and at least one platinum group metal (PGM), wherein the PGM element includes at least one of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
Block 1206 represents the composition fabricated using the method, a platinum (Pt) metal containing alloy composition for use as a catalyst (e.g., electrode). The Pt metal containing alloy composition may comprise a film (e.g. continuous) including a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table. The Pt metal containing alloy composition may comprise a nanoparticle; e.g., with nominal particle size 10 nm or less, including a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table. The Pt metal containing alloy composition may comprise a metallic nanocrystalline cluster or quantum dot on a nanoparticle support, wherein the metallic nanocrystalline cluster or quantum dot includes a compound of Pt and at least one early transition metal element A from group IVB or VB of the Periodic table. The composition may comprise less than 50% At. % Pt in the compound.
A may comprise at least one valve metal element of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb).
The Pt-containing compound further comprises at least one late transition metal B, thereby forming a Pt—B-A alloy.
A may include at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B includes at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe).
The Pt-containing compound may further comprise at least one platinum group metal (PGM), thereby forming a Pt-PGM-B-A alloy, wherein the PGM element includes at least one of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
A may include at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B includes at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe), and with at least one PGM element of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
A may include at least one of Zirconium (Zr), Titanium (Ti), Hafnium (Hf), and Niobium (Nb), and B includes at least one of Cobalt (Co), Nickel (Ni), and Iron (Fe), and with at least one PGM element of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
Examples of embodiments of the alloy composition include Pt 66 Co 24 Zr 10 (Atomic %), Pt 68 Co 23 Zr 9 (Atomic %), Pt 53 Co 20 Zr 27 (Atomic %), Pt 92 Zr 8 (Atomic %) and Pt 67 Zr 33 (Atomic %).
The film may be a continuous film on a nanoparticle support, on a hollow spherical nanoparticle support, or on a micron-sized metallic or non-metallic support, or on a wire or wire-gauze support, for example.
The Pt-containing compound may further comprise at least one late transition metal B, thereby forming a Pt—B-A alloy. For example, the Pt-containing alloy composition may be (Pt 3 Co) 100-y Zr y with 0≦y≦30 (At. %) or (Pt 100-x Co x ) 100-y Zr y with 0≦x≦80 and 0.5≦y≦60.
The Pt-containing compound may further comprise at least one platinum group metal (PGM), thereby forming a Pt-PGM-B-A alloy, wherein the PGM element includes at least one of Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Rhenium (Re), Osmium (Os), and Iridium (Ir).
The film may be crystalline with a grain size such that, when the film is used as the cathode catalyst, an active area of the cathode is above 218 μf/cm 2 (see also FIG. 4 a , FIG. 6 , and Table 1, for example). The film may be sputtered on the substrate. The alloy composition may be crystalline (e.g., with a (111) crystallographic orientation), nanocrystalline with a grain size of no more than 100 nm, nanocrystalline with a preferred grain size of less than 10 nm.
Block 1208 represents using the composition formed in Block 1206 as a catalyst.
The alloy may be used as a catalyst in a catalytic convertor for a internal combustion engine burning gasoline or diesel fuel.
The alloy may be used as a replacement catalyst for Pt catalysts used in the Platforming process, which enables the synthesis of gasoline without the addition of lead to the gasoline.
The alloy may be used as the anode in a hydrogen-air fuel cell or hydrogen-oxygen fuel cell.
The alloy may be used as the cathode in a hydrogen-air fuel cell, hydrogen-oxygen fuel cell, or direct methanol fuel cell (DMFC). In this application, the amount of A and an amount of Pt in the alloy may be such that that the alloy may be at least 2 times more electrochemically active, than Pt, as the cathode material for the oxygen reduction reaction (ORR).
The alloy may be used as the anode in a direct methanol fuel cell (DMFC).
In one embodiment, the alloy composition is Pt 66 Co 24 Zr 10 (Atomic %), and may be used as the cathode in a hydrogen-air fuel cell. In this embodiment, the alloy as a cathode may be at least 31 times more electrochemically active at 0.9 V (vs. NHE) than Pt, when used as the cathode material for the oxygen reduction reaction (ORR).
In one embodiment, the alloy composition is Pt 68 Co 23 Zr 9 (Atomic %), and may be used as the cathode in a hydrogen-air fuel cell. In this embodiment, the alloy as a cathode may be at least 30 times more electrochemically active at 0.9 V (vs. NHE) than Pt, when used as the cathode material for the oxygen reduction reaction (ORR).
In another embodiment, the alloy composition is Pt 53 Co 20 Zr 27 (Atomic %), and may be used as the cathode in a hydrogen-air fuel cell. In this example, the alloy cathode may be at least 16 times more electrochemically active at 0.9 V (vs. NHE) than Pt, when used as the cathode material for the oxygen reduction reaction (ORR).
In another embodiment, the alloy composition is Pt 92 Zr 8 (Atomic %), and may be used as the cathode in a hydrogen-air fuel cell. In this example, the alloy as a cathode is at least 5 times more electrochemically active at 0.9 V (vs. NHE) than Pt, when used as the cathode material for the oxygen reduction reaction (ORR).
In another embodiment, the alloy composition is Pt 67 Zr 33 (Atomic %), and may be used as the cathode in a hydrogen-air fuel cell. In this example, the alloy cathode may be at least 2 times more electrochemically active at 0.9 V (vs. NHE) than Pt, when used as the cathode material for the oxygen reduction reaction (ORR).
An amount of A and the amount of Pt in the film may be such that the film is electrochemically stable, with no decrease in electrochemical activity of the cathode, when the electrochemical activity is characterized by conducting multiple cycles of a cyclic voltammogram (CV) over the potential range 0.0 to at least 1.2 Volts (vs. NHE) to determine the durability of said alloy: measuring a current flowing between the film and an anode, in a electrochemical ½-cell, in response to a voltage applied to the film that is ramped from 0.0 to at least 1.2 Volts at a scan rate of at least 10 mV/second, wherein the voltage is ramped from the 0.0 Volts to the at least 1.2 Volts at least 1000 times (over 1000 cycles); and the current not varying by more than the measurement accuracy (+/−10 microamps).
When the alloy is used as the cathode or anode in a hydrogen-air fuel cell, hydrogen-oxygen fuel cell, or direct methanol fuel cell (DMFC), the electrolyte may comprise an acid electrolyte, the acid electrolyte may comprise a mixture perchloric acid in water (HClO 4 /H 2 O) (e.g., a 1 molar perchloric acid concentration in water (HClO 4 /H 2 O)), the acid electrolyte may comprise a mixture of sulfuric acid in water (H 2 SO 4 /H 2 O) (e.g., a 1 molar sulfuric acid concentration in water (H 2 SO 4 /H 2 O)). The acid electrolyte may saturate a polymer exchange membrane electrolyte (e.g. Nafion).
The film may be crystalline with a grain size such that, when the film is used as the cathode catalyst in a hydrogen-air or hydrogen-oxygen fuel cell, and the measured Pt-active area from the hydrogen-oxidation-reaction (HOR) of the cathode is greater than that of polycrystalline Pt, A Pt =210 μC/cm 2 .
Further Results
FIG. 13 is an image of a multi electrode NSTF Array, wherein the scale bar shows Pt-content in the Array of 50% to 35%.
FIG. 14 shows active area (μC/cm 2 ) as a function of Pt content (At %), for PtCoZr, PtZr, and Pt.
FIG. 15 shows activity for ORR for PtCoZr and PtZr as a function of Pt content (At %).
TABLE 2
Composition Range on Electrode Array
E-11
E-12
E-13
E-14
Pt 49.9 Co 37.4 Zr 12.7
Pt 47.3 Co 35 Zr 17.7
Pt 40 Co 35 Zr 25
Pt 33.8 Co 32.7 Zr 33.5
E-15
E-16
E-21
E-22
Pt 32.5 Co 28.6 Zr 38.9
Pt 35.8 Co 30 Zr 34.2
Pt 52.1 Co 36.5 Zr 11.4
Pt 45.1 Co 36.9 Zr 18
E-23
E-24
E-25
E-26
Pt 39 Co 35.3 Zr 25.7
Pt 33.4 Co 33.6 Zr 34
Pt 32 Co 30.1 Zr 37.9
Pt 37.5 Co 29.2 Zr 33.3
E-31
E-32
E-33
E-34
Pt 50.5 Co 33.2 Zr 16.3
Pt 44.7 Co 35 Zr 20.3
Pt 39.2 Co 36.6 Zr 24.2
Pt 33.4 Co 32.8 Zr 33.8
E-35
E-36
Pt 35.1 Co 28.5 Zr 36.4
No whiskers
Possible Modifications
The compositions of the present invention may be fabricated by methods other than co-sputtering, including for example, e-beam deposition.
The compositions of the present invention may be used for various applications where catalytic properties are useful. For example:
1. The present invention may be used to replace Pt gauze in a nitrogen fertilizer application.
2. The present invention may be used in a catalytic converter.
3. The present invention may be used in a hydrogen fuel cell or an hydrogen and air fuel cell, or in a fuel cell that uses a PEM membrane electrode. The present invention may be used as an anode and/or a cathode.
4. The present invention could be used in a nanofuel cell, wherein the nanofuel cell is surrounded by microcatalytic compositions of the present invention.
5. Various crystal forms of the present invention, as well as various compositions, may be tailored for particular applications.
Advantages and Improvements
Technical issues in the current state of the art, coupled with the high-cost and limited availability of Pt metal, have motivated the present invention to search for new Pt-based, transition metal alloy catalysts that are stable in acid and electrochemically active for the oxygen reduction reaction (ORR).
The scientific methodology of the present invention has employed the following key concepts in materials design, chemical physics, and electrochemistry, to achieve improvements associated with the following metrics for fuel cell cathode materials:
1) controlled alloy design methods used to obtain improved corrosion resistance and increased stability in acid solutions;
2) thin film synthesis (co-sputtering unique) used to obtain a wide range of multi-component Pt-based, binary- and ternary-alloys, thin film form;
3) thin film synthesis, coupled with modulations of chemical composition, enables control of the microstructural length scale of the materials prepared (amorphous to nanocrystalline microstructures);
4) d-band engineering (i.e., filling of the transition metal d-band) used to control the relative position of the Fermi energy, ε f , and the density of states at the Fermi energy, (ε f ), thereby enabling controlled reductions in the ORR activation potential (i.e., reduced over-potential V over results in increased ORR current density);
5) control of the microstructural length scales can be used to exploit the occurrence of quantum size effects in small- or nanocrystalline-particles; which can result in controllable shifts in the relative position of the Fermi energy, ε f , thereby enabling another means to obtain reductions in the ORR activation potential.
The results of the present invention suggest that in order to endow an enhanced corrosion resistance to Pt-based alloys, while maintaining a high catalytic activity, addition of group IVB, VB valve metal elements appears to be of value. The present invention is also able to achieve at least 2-10 times electrochemical (ORR and Hydrogen oxidation) performance as compared to a pure Pt electrode. The present invention also shows that reducing the amount of Pt in the alloy electrode may increase the electrochemical performance of the Pt alloy electrode, as shown in FIGS. 6-9 .
REFERENCES
The following references are incorporated by reference herein.
[1] J. F. Whitacre, T. I. Valdez, and S. R. Narayanan, “A high-throughput study of PtNiZr catalysts for application in PEM fuel cells,” Electrochemica Acta 53, 3680 (2008). [2] “Advanced Cathode Catalysts and Supports for PEM Fuel Cells,” fuel cell presentation on catalysts by Mark Debe at the 2009 Annual Merit Review Proceedings for the U.S. Department of Energy Hydrogen Program, http://www.hydrogen.energy.gov/pdfs/review09/fc — 17_debe.pdf. [3] Kathi Epping Martin, John P. Kopasz, and Kevin W. McMurphy, “Fuel Cell
Chemistry and Operation”, Chapter 1, pp 1-13, ACS Symposium Series, Vol. 1040, 2010 American Chemical Society.
[4] V. R. Stamenkovic et al, Nature Materials 6, 241 (2007). [5] J. K. Stalick, R. M. Waterstrat, J. Alloys and Compounds 430, 2123 (2007). [6] Quantum Sphere Corporation, http://www.qsinano.com/tech_process.php, (2010). [7] S. M. George, Chemical Vapor Deposition, Vol. 11, page 420 (2005). [8] G. Haour and H. Bode, page 111 of Rapid Solidification Technology Source Book, American Society for Metals (1983), Metals Park, Ohio, R. L. Ashbrook (Editor). [9] R. E. Marienger, p. 121 of Rapid Solidification Technology Source Book, American Society for Metals (1983), Metals Park, Ohio, R. L. Ashbrook (Editor). [10] B. H. Kear et. al., “On the Microstructure of rapidly solidified In-100 Powders,” page 66 of Rapid Solidification Technology Source Book, American Society for Metals (1983), Metals Park, Ohio. [11] Charles C. Hays PhD Thesis, “A Mott-Hubbard/Fermi-Liquid Systems La 1-x Sr x TiO 3 ,” University of Texas at Austin, Austin Tex. (1997). [12] A. Biswas et. al., Applied Physics Letters, Vol. 88, 013103 (2006).
CONCLUSION
This concludes the description of the preferred embodiment of the present invention. The foregoing description of one or more embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. | A series of binary and ternary Pt-alloys, that promote the important reactions for catalysis at an alloy surface; oxygen reduction, hydrogen oxidation, and hydrogen and oxygen evolution. The first two of these reactions are essential when applying the alloy for use in a PEMFC. |
CROSS REFERENCE TO RELATED APPLICATIONS
This invention is a continuation-in-part of my copending application Ser. No. 468,364, filed Jan. 22, 1990 U.S. Pat. No. 4,999,753.
FIELD OF THE INVENTION
This invention relates to a portable device for attracting visual attention, especially suited for use in potentially explosive environments, such as underground mines, but also useful for cyclists, joggers, pedestrians, children and the like.
BACKGROUND OF THE INVENTION
There are many situations where it is desirable to provide an object with a high degree of visibility. For example, pedestrians, cyclists and children are particularly vulnerable to vehicle accidents at night, especially on roads with no sidewalk. It is common practice for such persons to wear reflective clothing or arm bands, but these can only be seen when the person is sufficiently close to the oncoming vehicle for enough light to be reflected.
Sometimes people will carry a conventional flashlight, but this can often only be seen in one direction and generally portable flashlights have a short lifetime, which means that they soon start to fade and become less visible.
Problems also arise in industrial environments where visibility is obscured due to dust or darkness, such as in underground mines, open pit mines, construction sites and the like. In such environments, there is often a danger of personnel being run over or caught by moving machinery, and it is vitally important to make the machinery as visible as possible so as to give the personnel sufficient time to move out of its way.
In all these situations, the warning time for the person in danger or operator of the vehicle is of the essence. For example, in the case of a fast-moving vehicle, a fraction of a second can make the difference between life and death. A vehicle moving at 60 miles an hour covers about 30 meters in one second.
Strobe lights, such as are found near road works, are known. These generally require substantial amounts of power and are therefore not conveniently portable and cannot be left unattended for prolonged periods. They are also not suitable for attachment to personnel, largely as a result of their bulk and weight.
Devices with flashing lights are known. For example, one such device is described in U.S. Pat. Nos. 3,944,803 and 3,134,548. These devices are unsatisfactory because the incandescent bulbs they employ consume a large amount of power and they therefore have a short lifetime. When incandescent bulbs are periodically switched on and off their lifetime is considerably shortened.
A problem with all such devices is how to find a safe, longlasting, high energy power pack. Lithium batteries provide a convenient source of high energy power, but can be extremely dangerous if allowed to discharge too rapidly. Their high energy density can cause them to explode if shorted either directly or as a result of the ingress of moisture.
An object of the present invention is to alleviate the aforementioned problems and provide a portable safety device with high visibility and longevity.
SUMMARY THE INVENTION
According to the present invention there is provided a portable power pack comprising a pair of terminals supplying DC power, at least one high energy battery, and current limiting means in series with said terminals, said current limiting means preventing the current supplied by said terminals from exceeding a predetermined safe value, and said at least one battery and said current limiting means being completely encapsulated in solidified flowable material with only said terminals exposed, whereby shorting of said exposed terminals will not result in the passage of a current exceeding a safe limit.
The high energy battery is preferably a lithium battery, and desirably four batteries connected is series are employed. The solidified flowable material is preferably epoxy resin.
The power pack can be connected to a flashing circuit consisting of a low intensity light-emitting diode with an integrated circuit driver incorporated therein. The change in resistance of the low intensity light-emitting diode as it switches on and off, and therefore the change in voltage across its terminals, causes the high intensity diodes to switch in synchronism with it. This is a convenient low cost way of causing the high intensity light-emitting diodes to flash.
The current limiting means preferably comprises a pair of resistors arranged in parallel. Ideally the current should be limited to a maximum of half an amp, which for a nine volt battery means that the combined resistance of the resistors has to be 18 ohms. The advantage of using two resistors in parallel, each having a higher resistance such that the parallel combination has a resistance of 18 ohms, is that if one resistor fails the other resistor is still able to provide current at a reduced level. In case of a short circuit, a half amp fuse is connected in series with the battery, which cuts off the power completely.
The power pack can be provided with an end cap, which after the power pack has come to the end of its useful life can be used to short out the terminals and safely discharge any residual current remaining in the power pack.
To make the device safe for use in explosive environments, the complete device can be mounted in a rigid container with a window, which may be in the form of a lens, through which the light-emitting diodes are visible. The latter are preferably arranged in a line. It has been found that three such light sources arranged about half an inch apart are most effective at attracting attention.
Ideally the light output of the high intensity light-emitting diodes should be at least 2000 mcandela.
When carried by pedestrians, the safety device can be seen at a distance of approximately 1600 to 4000 feet, depending on the brightness of the light-emitting diodes and the environmental conditions. The minimum legal requirement for such devices is that a person be seen at 500 feet, which gives enough time for reaction and braking. The safety device can therefore exceed the minimum requirement by a factor of three to eight depending on the conditions. In tests, a device powered by one lithium battery has flashed continuously for over three weeks, and with normal intermittent use can last for six months or more.
The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a safety device in accordance with the invention;
FIG. 2 is a illustration of a trip lamp for use in mines and similar environments;
FIG. 3 is an illustration of a safety band incorporating a safety device in accordance with the invention; and
FIG. 4 is an illustration of a hazard warning triangle incorporating a safety device in accordance with the invention;
FIG. 5 shows an omni-directional safety light;
FIG. 6 shows in more detail a practical embodiment of a one-directional safety light for use in mines; and
FIG. 7 shows the safety light with the front cover pivoted open;
FIG. 8 is a diagrammatic illustration of a four-lithium battery power pack; and
FIG. 9 is a diagrammatic illustration of a further embodiment of a lithium battery power pack.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows three high intensity, super bright light-emitting diodes (LEDs) 1 with a 2000 mcandela light output, having a rating of 1.85 volts at 20 m amps.
The LEDs 1 are connected in series with a standard low intensity, blinking light-emitting diode 2 incorporating a MOS integrated circuit driver and a red LED within a T-5 mm 13/4 inch plastic LED housing.
The LEDs 1 are supplied by the Tandy Corporation under product designation 276-087™ and the LED 2 under product designation 276-036C™.
The LEDs 1, 2 are connected in series through a switch 3 with a power supply consisting of a battery 5, comprising four 9 volt lithium batteries in parallel, a parallel pair of resistors 6, each having a 39 ohm resistance and 0.5 watt rating, and a 0.5 amp fuse 4. Three or four lithium batteries are preferred, although any suitable number can be combined in parallel.
The circuit is activated by closing switch 3. The internal integrated circuit causes the standard low intensity LED 2 to start flashing, and as it does so it changes from low to high resistance, and hence low to high voltage, causing the main voltage drop to be applied across the series arrangement of high intensity LEDs 1, which in turn are caused to turn on. The high intensity LEDs 1 therefore flash in synchronism with the low intensity LED 2, even though the LEDs 1 do not incorporate internal drivers.
In the event of one of the resistors 6 becoming an open circuit, the remaining resistor limits the current to approximately half its previous value. While the intensity of light output falls, the safety device nonetheless continues to operate at an effective level. To ensure complete safety in the event of one or both of the resistors 6 becoming short circuited, the 0.5 amp fuse 4 is present.
The battery 5, consisting of four lithium batteries in parallel, parallel arrangement of resistors 6, and fuse 4 together make up the power supply. This is provided within a rigid metal or plastic box 12, completely sealed with epoxy resin such that the battery 5, resistors 6, and fuse 4 are fully encapsulated.
Turning now to FIG. 2, the miner's trip lamp has a hermetically sealed steel or plastic casing 7 with a removable lid 8 bolted to the casing 7 by bolts 10 and sealed by means of a rubber seal 13.
The casing 7 contains the battery container 12 and a further steel or plastic box 11 in which is encapsulated the flasher unit consisting of the LED 2. The box 11 is mounted such that the high intensity LEDs 1 protrude therefrom and are mounted just below a plastic lens 9 sealed in the lid 8 of the casing 7. The three LEDs 1 are arranged in a line and spaced about half an inch apart.
The trip lamp shown in FIG. 2 is particularly adapted for use in explosive environments, such as underground mines and the like. The casing 7 is completely hermetically sealed and the flasher unit 2 is hermetically sealed inside the box 11, mounted within the casing 7, as is the battery pack mounted within the container 12. Since the flashing circuit is entirely solid state, there is no risk of spark generation, even though any such sparks generated would be sealed both within the containers 11 and 12 and the casing 7.
The safety device is therefore useful for placement in mine shafts and, for instance, on the front of underground vehicles.
FIG. 3 shows schematically an arm band or the like for use by pedestrians. The three light-emitting diodes 1 are mounted on the arm band and are connected by wires (not shown) to a lightweight battery pack (not shown) carried by the wearer. Since there is no risk of explosion, the battery power supply can be made very small and light. Although described as a lithium battery, other suitable batteries, such as alkaline or carbon-zinc batteries can be employed.
FIG. 4 shows a hazard warning triangle 17 with three rows of LEDs 1, one for each side of the triangle. Such a warning triangle is considerably more effective than the passive type, yet the safety device adds little to the overall weight and is reliable even after long periods of inactivity.
Such safety devices, when incorporated into articles of clothing, such as belts as shown in FIG. 3, or other types of articles such as protective vests and the like, can be of very great value in enhancing safety of personnel. The extremely high visibility is an obvious benefit, but also the ability to continue flashing for long periods with a light and portable power source is also of great significance.
There are many examples of situations where such a device can be usefully employed. Some have been already mentioned, but others are joggers, walkers, cyclists, hunters, fishermen, motorcyclists, snowmobilers, A.T.V.s, adventurers, climbers, skiers, and explorers.
In a professional environment, the devices can be used at traffic check points, for ambulance attendants, firemen, tow truck attendants, search and rescue personnel, forest and game rangers, E.M.O., police, sailors, oil rig personnel, freight and cargo handlers, linesmen, military personnel, utility works, miners, railway yard and terminal operators, trip lamps, airport traffic directors (commercial, private), military, parking lot attendants, offshore life-saving capsules, marine survival suits, hazardous and disabled vehicles.
The device can also be applied to children's Halloween costumes to significantly enhance safety on Halloween.
The following is a comparative table of features of reflective devices, incandescent type devices and devices in accordance with the present invention.
TABLE 1______________________________________PRODUCT FEATURE COMPARISONS REFLEC- TIVE BULB LEDFEATURES DEVICES TYPE TYPE______________________________________DEVICE TYPE PASSIVE ACTIVE ACTIVEDAYTIME VISIBILITY GOOD N/A N/ANIGHTTIME VISIBIL- POOR GOOD EXCITYADVERSE ENVIRON- POOR GOOD EXCMENTSWATERPROOF N/A POOR EXCVIBRATION RESIST- N/A POOR EXCANCEIMPACT RESISTANCE N/A POOR EXCVISIBILITY DISTANCE 500 Ft. 1/2 mi 1/2-3/4 mi (DAY) (APPROXIMATELY)POWER SOURCE SIZE N/A LARGE SMALLPOWER SOURCE N/A HEAVY NEGLIGI-WEIGHT BLEPRODUCT/LONGEV- N/A 8 HOURS 10 WEEKSITY/(CONT.)BULKINESS CUMBER- BULKY NEGLIGI- SOME BLEPRODUCT WEIGHT NEGLIGI- HEAVY NEGLIGI- BLE BLE______________________________________ Abbreviation Legend: N/A = Not Applicable EXC = Excellent Ft. = Feet mi. = Miles FREQ. = Frequently CONT. = Continuously ON
The safety device in accordance with the invention can be made completely waterproof, dustproof, shockproof and impact resistant very easily in view of the fact that there a a minimum number of parts and the integrated circuit is not susceptible to shock, especially when encapsulated in the stout container.
In the case of devices intended for attachment to articles of clothing, many methods of attachment can be employed, such as clips, tape, bolts, glue etc., and the device can be attached to almost any article of clothing, such as jackets, pockets, or helmets, or other equipment such as bicycles, or parked or stationary machinery.
One of the important features of the product is its ability to operate with very low power consumption at high intensity for long periods. The high intensity LEDs employed, while having a light output some 2000 times the output of a conventional low power LED, draw about the same current. In many cases, when the device is switched off while not in use, it can last many years before requiring a change of battery.
The number of components required for the device described is extremely low, and this low component count translates into extremely good reliability. In the preferred embodiment, the three light sources are arranged in a straight line about half an inch apart and flash in synchronism. This combination has been found to be most effective at attracting attention.
The described safety device has good penetration of rainy, snowy, foggy, smokey and dusty environments. The light is reflected off the microscopic particles in the air, producing a glow from the surrounding particles. This phenomenon is especially useful for firemen in a burning building, for example, where visual contact may be very short and only enhancement of lighting conditions is extremely useful.
High intensity light-emitting diodes have significant advantages over conventional bulbs. Incandescent bulbs are intolerant to flashing and can consume up to ten times the rate of current in the turn on phase. By contrast, LEDs consume very low current and when switched on consume even less. They are extremely tolerant of flashing, can have a life span of over 100,000 hours and be virtually shockproof and impact proof.
When applied to warning triangles on motor vehicles, LEDs have a significant advantage over flares, which deteriorate over time. Flares are susceptible to environmental conditions, such as wind, rain and snow, and they are not always dependable. Also, they can be dangerous, especially if someone inadvertently trips over one.
A particular application for the safety device is as a trip lamp for use in underground mines. A trip lamp is attached to the front of a train or vehicle that takes coal, material or personnel throughout the mine. The trip lamp gives notice to personnel that the vehicle is approaching. Conventional trip lamps with lead acid batteries last for only eight to ten hours, and in many cases replacement is so time-consuming that lamps have not been replaced due to the nuisance aspect, leading to unfortunate accidents.
A further important application of the device is for use on life rafts and the like.
The device shown in FIG. 5 is similar to the device shown in FIG. 2, but comprises an array of LEDs on each of its five faces, except for the lower face. This provides an omni-directional device that is suitable, for instance, to be mounted on the top of an emergency life raft, such as might be carried by boats or aeroplanes.
A smaller version of the device can be used on personal life vests. In this regard, it should be mentioned that commercial life vests generally employ a glass encapsulated light source supplied by a lithium battery. If the glass breaks and the battery becomes exposed to sea water, the energy density in the battery is such that it will actually explode, presenting a serious danger to the wearer. The light source of the present invention will avoid this difficulty due to the fact that the lithium battery and current limiting means are encapsulated such that the lithium battery per se cannot be exposed directly to the water.
The invention as described represents an important advance generally in safety technology. Lithium batteries have generally come into widespread use for powering portable electronic devices because of high energy density, high voltage, high ampere capacity, very wide operating temperature range, long shelf life and flat discharge curve.
While the high energy density is useful for giving a long shelf life, one of the problems is that the high energy density is also capable of supplying a very high current. If the battery becomes shorted or even exposed to water or moisture, it can explode and be very dangerous. In one instance, a lithium battery employed in a cellular telephone exploded due to moisture causing injury to the user.
The present invention makes use of the fact that the high energy density is generally required only to supply a moderate current for a long period, rather than a high current for a short period. Furthermore, lithium does not need an air vent, and by encapsulating the battery with a current limiting device, absolute safety is ensured because only the terminals of the composite power supply are exposed. If the exposed terminals are directly shorted by moisture or even wire, the composite power supply will not supply a current sufficient to cause a dangerous explosion, or even a spark.
The combination of a fuse in association with the current limiting device within the epoxy is particularly desirable. If a fuse alone were used, since the fuse has to be completely encapsulate with the battery, if the fuse blew the power pack would become useless. The presence of the current limiting resistance within the epoxy and in series with the battery and fuse ensures that even if the battery is immersed in water or the leads shorted for a short period, the battery pack would not be damaged and could be reused. The resistance should be set at a value such that even in the event of a direct short no explosion will occur. The resistors should have a wattage such that a short circuit can be handled without damage. The described safety power supply thus has application in other safety areas, such as cellular telephones and the like.
The safety light is shown in more detail in FIGS. 6 and 7. The casing 7 is of corrosion resistance stainless steel with a front cover 7 1 attached to it by means of a piano hinge 7 11 . The lens 9 is a 44.5 mm diameter Lexan™ window. The casing is held shut by means of glass 20 on all three sides fixed to the casing by means of tamperproof screws 21. The rear of the casing 7 provided a mounting plate 22.
FIG. 8 is a portable power pack for use with the described safety light and for other portable applications, such as cellular telephones.
Four lithium batteries 30 are tightly packed and connected in parallel by wires 31, 32, which are connected respectively to exposed terminal plates 33, 35. Wire 31 interconnecting the positive terminals of the batteries is connected to terminal plate 33 through housing 34 containing the parallel combination of current-limiting resistors 6, and the fuse 4.
The entire package, apart from the exposed terminal plates 33, 35 is encapsulated in a two-part epoxy resin, which is allowed to set to from a completely sealed unit. As a result of this arrangement, a direct short across the exposed terminals will not give rise to a dangerous current liable to cause an explosion. Since the battery terminals are never exposed, they do not give rise to any danger.
The advantage of this arrangement is use is made of the desirable properties of lithium batteries, namely their ability to produce a steady moderate current for long periods without the concomitant disadvantage that the high energy density causes, namely the risk of explosion to a sudden release of stored energy.
Another problem with lithium batteries is environmental. Their safe disposal causes a problem because after discharge a significant amount of stored energy often remains in the battery. This has caused batteries to explode at dump sites, or it can cause an explosion hazard in the presence of flammable gases due to the risk of sparking. In accordance with a further feature of the invention, a metallic end cap 35 is provided, which is inserted over the power pack terminal after the battery has come to the end of its useful life. This allows a gradual discharge of the residual current in the battery to occur in a safe manner since the current limiting means prevents a rapid discharge from occurring.
In FIG. 8, the metallic end cap fits over opposite ends of the power pack to short terminals 33, 34. In FIG. 9, which has positive and negative terminals located at the same end of the power pack, the end cap fits over the top end of the power pack.
It has been found that power packs can also be conveniently made with three 3.6 volt lithium batteries in series and two 47 ohm, 5 watt resistors in parallel and a 0.5 amp fuse, all encapsulated in epoxy resin. Alternatively, three volt lithium batteries can be employed.
It has been found that in the case where such a power pack is used to power the flashing light unit, two extra LED's can be added for each 3.6 volt lithium battery. The resistance has to be increased commensurately, but the life of the power pack remains essentially the same. | A portable safety device for attracting visual attention, comprises an array of flashing light sources, comprising high intensity light-emitting diodes having a light output of at least 500 mcandela. The light sources are connected in series with a solid state flashing circuit and a power supply. The power supply comprises a high energy battery and current limiting means in series therewith. The current limiting means prevents the current supplied by the battery externally of the power supply from exceeding a predetermined safe value. The solid state flashing circuit is periodically switchable between a low resistance state characterized in that the voltage across the series arrangement of high intensity light-emitting diodes exceeds a threshold voltage thereof, and a high resistance state characterized in that the voltage across the series arrangement of high intensity light-emitting diodes falls below the threshold voltage. The high intensity light-emitting diodes flash brightly to provide a low current attention-attracting device visible at lone range. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Non-Provisional (Utility) patent application of provisional application Ser. No. 60/572,263 filed May 18, 2004 and provisional application Ser. No. 60/572,315 filed May 18, 2004.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to test equipment, and more particularly to test equipment for circuit boards.
2. Description of the Related Art
Circuit board testers are used for testing a variety of circuit boards or similar devices to assure that the circuit boards operate as intended. In at least one type of circuit board tester, such as Agilent Model No. 3070, Series 3, a separate device, referred to as a fixture, is used to position the circuit board such that a plurality of electrically conductive probes (which are part of, or coupled to, the tester) contact predetermined components or positions of the circuit board. The particular components or positions that are contacted by the test or probes depend on the tests that are desired. When the probes are in contact with the desired locations on the circuit board, electrical signals with predetermined parameters (e.g., predetermined magnitudes or patterns of current, voltage frequency, phase and the like) are applied by the tester, typically under control of a computer, to certain of the probes. Some or all of the probes are used to measure the performance or response of the circuit board (i.e., to measure electrical parameters at some or all of the probes contacting the circuit board). In this way, it is possible to rapidly perform a number of tests or measurements characterizing the performance of the circuit board while simulating the conditions the circuit board would have, or could have, during actual use. Although it is possible to use these types of tests (and testing devices) for a variety of possible purposes (such as “spot checking” selected circuit boards at a production facility, testing circuit boards which may be malfunctioning, testing prototype circuit boards as part of a design program and the like), in at least some applications, circuit board testing is used to provide quality assurance on all or substantially all products of a given type or class which are produced by a company. Even with the relatively rapid test procedures which can be achieved by in circuit testing, it is not unusual for desired testing of each circuit board to require on the order of 30 seconds to 90 seconds or more.
Because, in at least some applications, circuit board testing is performed on substantially all devices on a production line or production facility, speed and reliability of testing can be especially important since delay or failure at a testing station can delay or interrupt the overall production in a production line or facility. Accordingly, it would be useful to provide a fixture, useable in connection with in-circuit testers, which provides desired speed of positioning the circuit board or other unit under test (UUT) and which achieves a relatively high degree of reliability, e.g., so as to avoid interrupting or delaying production rates at a production line or facility.
The effect of such testing on overall production rates is at least partially related to the rate at which each UUT can be placed in the fixture and the rate at which the fixture can accurately and reliably move the UUT to the desired position or positions. In at least some situations, it is desired to provide a tester with probes at two or more levels (with respect to a direction normal to the plane of the UUT) e.g., by providing some probes having a first height and other probes having a second height. This arrangement affords the opportunity to perform two or more different sets of tests such that the points at which probes contact the UUT during one set of tests are different from (or a subset of) the points at which probes contact the UUT during another set of tests. Typically, in such a “dual stage” testing situation, the UUT is first positioned so as to contact all probes (and perform a first set of tests), and then positioned to contact only the taller set of probes (at points of the UUT which are determined by the location of the tall probes) and a second set of tests are performed using only the taller probes. The order of the tests may be reversed, so that the taller probes contact first, then the shorter probes contact. Although many different testing procedures can be used, as will be understood by those of skill in the art, in at least some situations, the taller probes may be used for functional tests and/or boundary scan tests (such as boundary scan tests as described in IEEE Standard No. 1149.1).
In at least one previous approach, the circuit board is moved in the direction of the probes, typically causing the taller probes, which may be provided with a spring-urged telescoping structure, to partially collapse or telescope, down to the level of the smaller probes, such that substantially both sets of probes (the taller probes and the shorter probes) contact the UUT at desired positions. With the board held in this position, a first set of tests (such as functional tests and/or boundary scan tests) can be performed. After tests are performed using the full set of probes the vacuum is released such that the UUT is positioned to contact only the taller probes (which telescope upwardly) and a second set of tests, (such as tests directed to measuring performance or characteristics of individual components on the UUT) can be performed.
In order for fixtures used in dual stage testing to operate well, especially in the context of a production line or facility, it is also desirable to avoid delays or malfunctions in moving the UUT between the stages. Accordingly, it would be desirable to provide a fixture, useable connection with dual stage in-circuit testing, with a relatively high degree of reliability and operating speed.
In at least one type of fixture, the force of atmospheric pressure is used to move the UUT towards the probes, e.g., by drawing a (partial) vacuum in a sealed area above or near the probes. In these devices, in order to accommodate dual stage testing, such fixtures have, in the past, been provided with a shuttle plate positioned in the area somewhere above the probes and defining one or more standoff structures which engage or contact a surface of the fixture (or of the UUT) to limit the amount of downward movement that the vacuum can effect on the UUT. In this way, the shuttle plate, in a first position, can cause the UUT to be positioned so as to contact only the taller probes. After a first set of tests is performed, the vacuum is at least partially released and the shuttle plate is then moved, typically laterally, such that the standoffs slide against a surface of the fixture sufficiently to become aligned with notches or other openings, allowing the (reapplied) vacuum to pull the UUT down farther, so as to contact the full set of probes (so that a second set of tests can be performed). It is also possible to perform tests with the full set of probes before performing the tests using only the taller probes. In at least one previous device, a shuttle mechanism is located in the lid structure to hold the board down onto the long probes. This device requires pneumatic cylinders, and requires an additional operator connection of compressed air lines to the fixture.
While this arrangement can achieve dual stage positioning, it has been found that such a shuttle plate approach can lead to delays or failures in testing. For example, the shuttle plate approach can provide a relatively high amount of friction when the shuttle plate is moved laterally, particularly when components of the fixture are made of a G10 or similar relatively high-friction material. This can lead to binding (inability of the shuttle plate to move smoothly to the second position or return to the first position). Such binding can not only cause delays and slow down a production line or production facility but can cause failures which may require repairs or replacement of parts, thus creating a substantial interruption of production. Accordingly, it would be useful to provide a fixture that can achieve dual stage testing while avoiding the type of binding, delay, failure, or interruption associated with the use of a shuttle plate.
In at least some systems, pneumatic actuators are used to move the UUT towards the probes. In these types of systems, the pneumatic actuators are configured and/or controlled so as to be movable among three positions, an initial position, a position with the UUT in contact with the taller probes and a position with the UUT in contact with all probes. Pneumatic systems, unfortunately, are associated with certain undesirable qualities. Unlike an atmospheric pressure system, which provides pressure spread over a substantial area, preferably over substantially the entire surface of the UUT, pneumatic systems generally provide pressure only at discrete locations. In general, this leads to a certain amount of flexure of the UUT as it is moved by the pneumatic actuators which can lead to poor contact with the probes in some locations of the UUT and, thus, inaccurate test results. Furthermore, pneumatic systems are generally relatively massive (e.g., such as resulting in fixtures weighing 40 to 50 pounds more than vacuum systems). Generally, this means that changing from one fixture to another (such as for routine maintenance, or to accomplish testing of a different type of UUT) will require two or more workers and/or lifting or positioning equipment, and will typically require more time than changing fixtures in a vacuum system, thus, leading to delays and/or interruptions in a production line or production facility. This is particularly true when the fixture is reinforced in an attempt to reduce the amount of flexure associated with pneumatic systems (although such reinforcement is, typically, only partially successful such that even reinforced systems may have an undesirable amount of flexure). Accordingly, it would be useful to provide a fixture which can be used for dual stage in-circuit testing which has a relatively low weight, e.g., compared with pneumatic-type fixtures, and/or imparts relatively little flexing on the UUT (e.g., compared with pneumatic-type fixtures), and otherwise achieves a low amount or probability of delays or interruptions.
In a prior art system disclosed in U.S. Pat. No. 6,535,008, the UUT, typically supported on a support plate that has perforations corresponding to the probe positions, is held spaced from all of the probes, e.g., by one or more springs. The prior art disclosure uses atmospheric pressure (by drawing a vacuum in the region adjacent the probes) to move the UUT (against one urging of the springs) into a position contacting all of the probes (i.e., both the short probes and the long probes). Such use of atmospheric pressure as a moving force reduces or substantially eliminates flexing of the UUT. In one aspect, in order to move the UUT to a second position, contacting only the tall probes, the vacuum is substantially released but a (preferably actuateable and/or controllable) structure limits the distance the UUT can travel away from the probes (under urging of the springs) so as to position the UUT at the desired location, contacting only the tall probes. Because this movement of the prior art system does not require the lateral sliding of a shuttle plate (or its components), e.g., against a high-friction surface and/or because this movement does not require relative sliding or other contact movement while components are pressed together by atmospheric pressure forces (since the vacuum has already been released, at least partially), there is relatively little tendency for binding during such movement and thus dual stage testing can be achieved with relatively low incidence or probability of delay or failure.
Stated another way, the prior art system of U.S. Pat. No. 6,535,008 uses a retractable arm that, when engaged into a slot, functions as a hard stop to longitudinal motion of the UUT with respect to the probes. At one end of the slot, the UUT is brought into contact with the tall probes, and at the other end, the UUT is brought into contact with the short probes. Any longitudinal motion of the UUT is accomplished by a single stage, driven by a single vacuum feed, and the extent of any longitudinal motion during testing is limited by the engaged retractable arm.
A potential drawback of the prior art system of U.S. Pat. No. 6,535,008 is that it still uses a translatable arm, which increases the complexity of the circuit tester system, and is subject to wear. Accordingly, it would be useful to provide a fixture which can be used for dual stage in-circuit testing which has a relatively low weight, e.g., compared with pneumatic-type fixtures, and/or imparts relatively little flexing on the UUT (e.g., compared with pneumatic-type fixtures), increases reliability by removing any laterally translatable parts, and otherwise achieves a low amount or probability of delays or interruptions.
The testers generally contain a plate as part of the tester that functions as a mechanical stand-off for the fixture. While the fixture is held rigidly in place against the plate, or against rigid stand-offs fastened to the plate, the probes make contact with the circuit board through various holes in the plate. The plates are usually supplied by the tester manufacturer with regularly spaced holes, usually in a rectangular grid, so that a given plate from the tester manufacturer may be used to test a variety of circuits. Even though a circuit generally requires its own custom layout for the probe locations, the plate, because of its standardized hole configuration, may be used relatively independently of the specific locations of the probes, and may also be reused when the tester is reconfigured to test a new circuit. This standardization of the hole locations reduces the number of custom parts required for a tester, and thereby reduces the cost of the system.
The plates are typically molded from a plastic material, such as polycarbonate, so that the array of holes may be built right into the mold. Because they are molded, not drilled, there is no additional cost required for drilling the holes. In addition, the resulting plastic part is non-conducting, which is important for insulation of the electrically conductive probes from each other. These plates are commercially available, and a model that fits the above-mentioned Agilent circuit tester is sold as the “3070 alignment plate”.
A potential drawback to a completely standardized plate is that it generally requires considerable effort to identify particular holes during the final inspection of the tester prior to usage. Typically, a technician will have to verify the location of each probe manually, by counting the row and column values of each probe (seen visually through a hole in the plate), then comparing the values to those in a published list as part of the tester layout drawings. If there are dozens of probes, all specifically located in a rectangular array that contains hundreds of identical-looking holes, this may be a very time-consuming procedure for the technician, and may lead to errors in probe placement if the technician counts incorrectly. Accordingly, it would be useful to provide a plate with simple identification features, so that a technician may readily visually identify which holes are to accept probes.
One prior art solution is to manually mark each hole in the plate that will receive a probe during operation. This solution turns out to be simple in theory, but very labor-intensive, and therefore very expensive. Accordingly, it would be useful to provide a plate with simple identification features that may be identified using the same tools that provide the tester configuration drawings (reducing the possibility of human error in determining the locations.) Additionally, the identification features should be inexpensive, and not require a custom-fabricated plate for each particular circuit under test.
BRIEF SUMMARY OF THE INVENTION
The present embodiment uses a dual-stage translation to bring a unit under test (UUT) into physical and electric contact first with a series of tall probes, then with a series of short probes.
Initially, the UUT is mounted on a support plate, and spaced apart from both the tall and short probes. First, in order to perform a functional test on the UUT, a first vacuum stage is engaged, and atmospheric pressure translates the UUT longitudinally until contact is made with a first hard stop, defining a first position. At this first position, the UUT is in contact with a series of tall probes, and is spaced apart from a series of short probes. After a function test is performed, a second vacuum stage is engaged in addition to, and independent of, the first vacuum stage. Atmospheric pressure translates the UUT longitudinally until contact is made with a second hard stop, defining a second position. At this second position, the UUT is in contact with both tall and short probes (the tall probes being appropriately spring-loaded so as to maintain physical and electric contact with the UUT without damaging the UUT). After an in-circuit test is performed, both vacuum stages are released, and the UUT returns to its initial location, spaced apart from both the tall and short probes. The UUT may be replaced with another part to be tested, and the cycle is repeated.
A further embodiment has a plate with identification features, so that a subset of holes in the plate may be visually identified. A first side of the plate, preferably (although not necessarily) the side facing the fixture and circuit board during operation of the tester, is coated with a thin layer of paint at the factory, so that the area in between all the holes is generally uniformly coated. The paint is preferably colored in contrast to the unpainted color of the plate. A subset of the holes is identified, and the paint surrounding each hole in the subset is removed.
Typically, when a tester is customized to test a particular circuit, a set of drawings is made by a computer assisted drawing (CAD) machine, well-known in the art, and presented to a technician. The technician uses the drawings to configure the tester, and the drawings typically indicate the locations and types of the probes. Alternatively, the CAD machine may generate an automated set of instructions for placement of the probes during assembly of the tester. In the present invention, the CAD machine may generate an additional set of instructions for denoting which holes in the plate are to receive probes. The additional instructions may be used by an automated drilling machine that scrapes off the paint in the area surrounding each hole that receives a probe. The drilling machine uses a drill bit of a larger diameter than the hole, and only drills until the paint is removed; it does not drill substantially into the plate itself and does not increase the diameter of the hole. Once the paint is removed around a particular hole, the hole is readily identified visually, either by eye or by use of a machine vision system. Once the tester is configured, each hole in the subset should contain a probe, and no probes should be present in holes not contained in the subset. Once all the probes are configured, a final visual inspection of the tester is relatively simple, as the technician may simply look at the plate and ensure that each hole in the subset has a probe that extends through it, and that none of the probes extend through holes not in the subset.
The present embodiment has a circuit tester for testing for reliably and repeatedly testing circuit boards in a plurality of different circuit conditions comprising a first circuit board mounting plate; a probe plate aligned with said circuit board mounting plate having a first set of probes of predetermined length and a second set of shorter probes; an adjuster for moving said first plate and said probe plate toward and away from each other along a single axis from a first position wherein none of said probes contact said the circuit board on said mounting plate, to a second position wherein said first probes contact said circuit board and to a third position wherein said first and second probes contact said circuit board so that said circuit board may be tested under different conditions depending upon the probes in contact therewith.
A further embodiment has a method of testing a circuit board on a test bed having a first set of compressible probes and a second set of shorter probes, comprising the steps of: defining an axis of movement for the test bed being generally coaxial with said probes; enclosing said test bed in a first compressible enclosure, said enclosure being capable of moving along said axis to urge said circuit board into contact with at least some of said probes when in a compressed state; enclosing said test bed in a second compressible enclosure at least partly outside of said first enclosure, said second enclosure being capable of moving along said axis to urge said circuit board into contact with at least some of said probes; providing a vacuum source for selectively withdrawing air from said first and second enclosures thereby selectively drawing said first and second sets of probes into contact said circuit board.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates a schematic of a circuit board tester.
FIG. 2 illustrates a schematic of a dual-stage circuit board tester in “rest” position.
FIG. 3 illustrates a schematic of a dual-stage circuit board tester in “functional test” position.
FIG. 4 illustrates a schematic of a dual-stage circuit board tester in “in-circuit test” position.
FIG. 5 is a schematic of a prior art grooved plate with a subset of holes identified manually.
FIG. 6 is a schematic of a grooved plate with a subset of holes identified according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In a manufacturing environment for circuit boards, a final test will often be an electrical test, to ensure that each circuit board performs as required. Such tests are well-known in the industry, and may be performed by commercially available testers, such as Agilent Model 3070.
A basic schematic of a circuit board tester 1 is shown in FIG. 1 . A circuit board, often referred to as a unit under test (UUT) 2 , is mounted on a fixture 3 for the duration of the test, which provides a rugged mechanical mount for the UUT as well as a mechanical interface with other components in the tester 1 . The fixture 3 is positioned on a bed 4 , so that various electrical probes may make contact with specific locations on the UUT 2 and perform the desired tests. The probes may apply and measure voltages or currents at various locations on the UUT 2 , and are controlled mechanically and electrically by the tester 1 . A computer 5 may control the tester 1 and may record data from the tests.
A more detailed view of the mechanical configuration is shown in FIG. 2 . The UUT 2 is removably and rigidly attached to, and is spaced apart from, a support plate or mounting plate 11 via spacer elements 12 . The electrical contacts on the UUT 2 that are to be tested face downward, and are accessible by probes 13 a,b that extend through holes or apertures 14 contained in the support plate 11 . The support plate 11 also has regions that are devoid of holes or apertures 14 . Fingers 15 , attached to a vacuum box which forms a top 16 , hold the UUT 2 on the side opposite the support plate 11 . The support plate 11 may be fastened to the vacuum box 16 by supports 90 (omitted for clarity from FIGS. 3 and 4 ). The vacuum box 16 rests on a set of second seals 17 , and may be evacuated through a vacuum connection 18 , connected via a second valve 19 to a vacuum system 20 . Initially, during the loading and unloading of parts, and before any tests are performed, the second valve 19 is closed (as drawn in FIG. 1 ), and the volume 21 inside the vacuum box 16 is at atmospheric pressure. The second seals 17 may contain springs (not shown) or may contain a compressible material, such as a foam, so that the second seals 17 compress when the vacuum box 16 is evacuated, and retain a generally expanded shape when the vacuum box 16 is at atmospheric pressure.
The second seals 17 rely on atmospheric pressure to change shape; when the second valve 19 is opened, the volume 21 is connected with a vacuum system 20 that pumps it down to a pressure below atmospheric pressure. The difference between atmospheric pressure and the pressure inside the vacuum box 16 is applied uniformly across the area of the vacuum box 16 by the atmosphere, and a net force is applied downward on the vacuum box 16 , compressing the second seals 17 .
With respect to FIG. 1 , the fixture 3 includes the vacuum box 16 , the second seals 17 , the fingers 15 , the UUT 2 , the spacer elements 12 , and the support plate 11 . The fixture is connected to the vacuum system 20 by the vacuum connection 18 . The vacuum connection 18 is typically a hose or pipe, and generally does not offer any mechanical support for the fixture 3 .
The second seals 17 rest upon a series of top plates 22 . The top plates 22 are permanently attached to a probe plate 24 through a series of first seals 23 . The first seals 23 may be similar in composition to the second seals 17 , retaining a generally expanded shape in atmospheric pressure, and compressing under the influence of a vacuum.
The probe plate 24 which sits atop a base which are depicted together as rectangle 24 contains a series of vacuum connections 25 , connected via a first valve 26 to the vacuum system 20 . When the first valve 26 is opened, the vacuum system 20 evacuates a volume, or series of volumes, bounded by the probe plate 24 , the top plates 22 , and the first seals 23 . When these volumes are pumped down to a pressure less than atmospheric pressure, the first seals 23 compress under the influence of negative atmospheric pressure, as described above.
A series of first hard stops 27 is located between the first probe plate 24 and the top plates 22 , typically attached to the probe plate 24 . When the first valve 26 is opened, the first seals 23 compress until the top plates 22 contact the first hard stops 27 . Because an accurate spacing is required between the probe plate 24 and the top plates 22 , this spacing is generally fixed by the thickness of the first hard stops 27 .
The probe plate 24 also contains a series of second hard stops 28 , located between the probe plate 24 and the support plate 11 . Although the second hard stops 28 are generally similar to the first hard stops 27 in composition, they likewise may be fabricated from various materials. The sizes of both first hard stops 27 and second hard stops 28 are determined by the dimensions of the UUT 2 and the specific tests required. Thus the hard stops on all plates are of predetermined dimensions which provide a predicable stop point to the UUT at the various test positions. When both the first valve 19 and second valve 26 are open, both the first seals 23 and second seals 17 compress until the support plate 11 contacts the second hard stops 28 . Note that any or all of the hard stops may be built into the probe plate 24 itself, such as using a series of grooves, stand-offs or depressions.
With respect to FIG. 1 , the bed 4 includes the top plates 22 , the first seals 23 , the probe plate 24 , the first hard stops 27 , the second hard stops 28 , and the probes 13 a,b . The bed 4 is connected to the vacuum system 20 by the vacuum connection 25 , typically a hose or pipe.
Although the probes 13 a,b are drawn in FIG. 2 as attached to the probe plate 24 , the tall probe 13 a being appropriately spring-loaded so as to maintain physical and electric contact with the UUT 2 without damaging the UUT 2 , the probes 13 a,b may in actuality be attached to a mechanism beneath the probe plate 24 , and the probes may extend through holes (not shown) in the probe plate 24 . Although only two probes 13 a,b are shown in FIG. 2 , it will be appreciated that the tester 1 may contain many more probes 13 a,b , perhaps several dozen or more.
FIG. 2 shows the system in a “rest” position, which occurs both before and after any tests are performed. The first valve 26 and the second valve 19 are both closed, and the entire system is generally at atmospheric pressure. Both the first seals 23 and the second seals 17 are extended. The top plates 22 are spaced apart from the first hard stops 27 , and the support plate 11 is spaced apart from the second hard stops 28 . Most importantly, all of the probes 13 a,b are spaced apart from the UUT 2 when the system is in a “rest” position.
FIG. 3 shows the system in a “functional test” position, in which the first valve 26 is open. The first seals 23 are compressed under the influence of the vacuum 20 , as described above. (Note that the second seals are not compressed.) The top plates 22 are brought into contact with the first hard stops 27 . Most importantly, the tall probe 13 a is brought into contact with the UUT 2 , while the short probe 13 b is spaced apart from the UUT 2 . Although only two probes 13 a,b are drawn in FIG. 3 , it will be appreciated that a plurality of both tall and short probes are used in the device, and that in the “functional test” position, all of the tall probes are in physical and electrical contact with the UUT 2 , and all of the short probes are spaced apart from the UUT 2 .
FIG. 4 shows the system in an “in-circuit test” position, in which both the first valve 26 and the second valve 19 are open. Both the first seals 23 and the second seals 17 are compressed under the influence of the vacuum 20 , as described above. The support plate 11 is brought into contact with the second hard stops 28 . The short probe 13 b is brought into contact with the UUT 2 . In addition, the long probe 13 a , which is appropriately spring-loaded, remains in contact with the UUT 2 . Although only two probes 13 a,b are drawn in FIG. 4 , it will be appreciated that a plurality of both tall and short probes are used in the device, and that in the “in-circuit test” position, both the tall and short probes are in physical and electrical contact with the UUT 2 .
Generally, after a UUT 2 is removably attached to the support plate 11 , a functional test is performed (FIG. 3 —note that one valve is open and one is closed, and that only the tall probes are in contact with the UUT), followed by an in-circuit test (FIG. 4 —note that both valves are open, and that both the tall and short probes are in contact with the UUT). The UUT 2 is then detached from the support plate 11 and replaced with another unit to be tested. It will be understood that this sequence of events is a typical embodiment, and may be altered as necessary. Note also that the “functional test”, shown in FIG. 3 , may be performed equally well with either valve open, and the other valve closed.
While the actuating mechanism of FIGS. 2–4 is shown as a vacuum system, it will be appreciated that other methods, such as positive or change in pressure (i.e., the opposite of a vacuum) or non-pressure methods could achieve similar results. For example, a solenoid system could substitute for the vacuum without departing from the spirit of the invention. Likewise, a screw drive, or equivalent mechanical system for raising and lowering the plates would suffice.
Regardless of the type of actuating mechanism used, the actuated motion of the plates is preferably oriented largely parallel to the probes, so that the probes remain aligned with their corresponding test points. The actuated motions of the two stages are preferably substantially coaxial or collinear. In order to ensure coaxial motion, the two stages may slide along common alignment pins or guide pins(not shown), which may preferably be located outside the vacuum chambers, and may preferably constrain the relative motion of the two stages colinearly. Preferably, the common alignment pins lie generally parallel to the probes, along the direction 31 in FIG. 3 . Preferably, the guide pins may be located near the corners of the plates in order to provide optimal stability during motion.
As discussed earlier, the probe plate 24 may contain holes, through which the probes pass. The probe plate is constructed as part of the tester, and is generally not removed or replaced between tests of individual parts. In general, certain holes in the probe plate are marked in some manner before the tester is configured, in order to show which subset of the holes should receive probes.
FIG. 5 shows a prior art probe plate (or simply “plate”) 51 , which contains a first face 56 and a plurality of holes 54 . The holes 54 are drawn in a rectangular array, but it will be appreciated that the holes 54 may be configured arbitrarily on the plate 51 . As used in a circuit board tester, the plate 51 is typically built into the tester, and typically provides a protective and alignment mechanical surface against which parts may be held during the test procedure. (Note that the hard stops 27 and 28 may be incorporated into the plate 51 itself as a series of protrusion 53 .) A fixture that contains a circuit board under test may be placed rigidly in contact against the protrusion 53 on the first face 56 of the plate 51 , and a plurality of electrical probes access various points on the circuit board through various holes 54 in the plate 51 . During the testing procedure, the probes apply and measure various voltages and currents at specific locations in a circuit board under test, generally to ensure that the circuit performs adequately. Typically, a single probe corresponds to a single hole 54 in the plate 51 .
Prior to usage of the tester, the various electrical probes must be configured to test specific locations in a particular circuit. The probe locations are typically generated at the CAD (computer assisted drafting) level, usually by the same tools that lay out the components on the circuit boards. The probe locations may be documented in CAD drawings and communicated to a technician that configures the probes manually, or may be encoded and communicated electronically to an automated device that configures the probes.
Once the tester probes are properly configured and the plate 51 is attached to the tester, a subset 54 a – 54 h of the holes 54 in the plate 51 will receive probes during operation of the tester. The remainder of the holes 54 that are not in the subset 54 a – 54 h do not receive probes during operation of the tester. It will be appreciated that the number and locations of the holes in subset 54 a – 54 h depend on the circuit under test, and are relatively unimportant for the present invention.
The final step in the manufacturing process for the prior art plate 51 is a manual identification of the subset 54 a – 54 h of holes 54 that receive probes. The user identifies the subset 54 a – 54 h of holes 54 , produces a CAD drawing or file describing the locations of the subset 54 a – 54 h , and sends the drawing or file to the plate manufacturer. The manufacturer of the prior art plate 51 then marks each hole 54 in the subset 54 a – 54 h by hand, typically by painting or marking a small area around each hole 54 in the subset 54 a – 54 h on the first face 56 . The paint or ink 55 is preferably in high contrast to the unpainted color of the bare plate 52 . For example, if the bare plate 52 is a dark-colored polycarbonate material, then the paint or ink 55 should be a light color, so that the marked holes are readily visibly detected, by eye or by a machine vision system. Although the marked areas surrounding each hole 54 in the subset 54 a – 54 h are drawn as circular in FIG. 1 , it will be appreciated that the markings may be of any shape or pattern, as long as each marking is readily identifiable with exactly one hole 54 in the subset 54 a – 54 h.
A severe drawback to the manual marking system of the prior art plate 51 is that it is very labor-intensive, and therefore very expensive. For a plate 51 that requires dozens of markings, in an array with hundreds of holes, the marking procedure can be quite significant, and in some cases, can be the greatest expense in producing the plates 51 .
Although one may be tempted to fabricate a new plate for each circuit under test, with holes only where probes are placed, this would be expensive and largely impractical. The prior art plate 51 is generally molded from a plastic material, such as polycarbonate, and has its holes incorporated into the mold itself. A custom prior art plate 51 molded in this manner, with holes only where required by the user, would require a custom mold for each user, which is impractically expensive. Additionally, the drilling of holes in a blank plate, while possible, is also more expensive than the prior art technique of manually marking the holes. Accordingly, there is a need for a plate that has a large number of holes for flexibility, but has a way of inexpensively identifying a subset of the holes to simplify the final inspection of the tester.
FIG. 6 shows a present embodiment of a plate 61 . A coating 65 is applied to a first face 66 of an uncoated plate 62 , preferably in the area between the protrusion 63 . The protrusion 63 may be coated as well, but at the risk of flaking or peeling of the coating 65 . The uncoated plate 62 contains a plurality of holes 64 , and the coating 65 does not fill in the holes 64 . The coating 65 may be a paint, a two-part epoxy, or an other opaque coating, preferably of a color of a high contrast with the color of the uncoated plate 62 . Preferably, the coating 65 is not electrically conductive. For example, if the uncoated plate 62 is dark-colored, a suitable coating 65 may be commercially available “Polane T-White” paint.
Note that it is generally difficult to fabricate a coating 65 that adheres well to a plastic uncoated plate 62 . In preliminary tests, it was found that standard paints did not adhere well to the polycarbonate plate. Often, the standard paints would chip during the hole-identification process so that more than one hole was exposed, effectively rendering the plate useless. These issues were resolved by finding a suitable overcoat material that ensures proper bonding with the uncoated plate.
Note also that the coating 65 may be formed in layers, in order to optimize both adhesion and color contrast with the uncoated plate material. For instance, a layer in closest proximity to the plate may have desirable adhesion properties, and a layer farthest away from the plate may have desirable color characteristics. It will be understood by those skilled in the art that any suitable material, combination of materials, or combination in layers may be used, without limiting the scope of the invention.
In a subset 64 a – 64 h of holes 64 , the coating 65 has been removed in the region around each hole 64 in the subset 64 a – 64 h , exposing the first face 66 underneath. Because the coating 65 contrasts with the color of the uncoated plate 62 , each hole 64 in the subset 64 a – 64 h is readily visually identifiable, whether by eye or by a camera in a machine vision system. The coating 65 may be ablated by appropriate methods, such as scraping, drilling, chipping, peeling, punching, grinding, and the like.
Preferably, the removal of the coating around each hole 64 in the subset 64 a – 64 h is performed by an automated tool, such as an automated drill that receives a set of subset 64 – 64 h locations from a CAD file. The automated drill preferably uses a drill bit larger than the hole 64 diameter, and drills only enough material to completely remove the coating 65 , without substantially drilling through the first face 66 . For example, if the coating 65 has a thickness of roughly 0.1 mm, then the drill may remove roughly 0.5 mm of material. The uncoated plate 62 may be substantially thicker than 0.5 mm. Note that drilling such shallow holes is an inexpensive procedure compared to drilling comparable through holes, and that very little waste material is produced. The hole may be countersunk, if convenient. Additionally, if the user decides to add another hole 64 to the subset 64 a – 64 h , he may mark the added hole by hand, simply by turning a drill bit centered in the hole by hand and grinding for a few seconds; the coating 65 comes off readily.
It will be understood that the protrusion 63 on the plate 61 are not essential for the present embodiment. A similar coating 65 may be applied to an uncoated plate that has physical features other than grooves, such as posts, or has no physical features at all. The coating 65 may be applied to the regions between holes 64 , so that when removed, the hole may be readily visibly identified by eye or by a machine vision system as part of the subset 64 a – 64 f.
As used in a circuit board tester, the plate 61 of FIG. 6 would readily identify the subset 64 a – 64 h of holes 64 that receive probes during operation. Because of the high contrast between the coating 65 and the color of the uncoated plate 62 , the technician easily sees the exposed first face 66 in the regions around each hole 64 in the subset 64 a – 64 h , and can then quickly complete the final inspection of the probe locations prior to operation. If the technician finds any holes 64 in the subset 64 a – 64 h that are missing a probe, or finds a probe in a hole 64 that is not in the subset 64 a – 64 h , he can take corrective actions. Because the entire subset 64 a – 64 h is visible all at once to the technician, without the need for manually counting rows and columns, the efficiency of the inspection process is greatly improved. | A circuit board tester that uses a dual-stage translation to bring a unit under test (UUT) into physical and electric contact first with a series of tall probes, then with a series of short probes. Initially, the UUT is mounted on a support plate, and spaced apart from both the tall and short probes. First, in order to perform a functional test on the UUT, a first vacuum stage is engaged, and atmospheric pressure translates the UUT longitudinally until contact is made with a first hard stop, defining a first position. At this first position, the UUT is in contact with a series of tall probes, and is spaced apart from a series of short probes. After a function test is performed, a second vacuum stage is engaged in addition to, and independent of, the first vacuum stage. Atmospheric pressure translates the UUT longitudinally until contact is made with a second hard stop, defining a second position. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to valve constructions, and more particularly pertains to valve constructions in which a partial vacuum is generated in the course of fluid flow of a main stream for purposes of aspirating fluid in a connecting fluid passageway to a discharge point. In its broader aspects, this invention is directed to systems in which fluids such as hydraulic liquids are positively pumped from hydraulic cylinders or the like by means of hydraulic pumps effecting a true pumping action or by means of a partial vacuum effecting an aspirating action.
2. Description or the Prior Art
Control valves of the type hereinafter described in detail are used throughout the hydraulics and pneumatics industry for directing the flow of oil and air in hydraulic and pneumatic circuits. A common application of these valves is for use in controlling operation of lifting rams or pistons reciprocally movable in hydraulic cylinders. Such hydraulic cylinders which may be used for direct lifting purposes, reinforcing purposes, bracing, pushing and the like may be of one of two general types. These two types are single-acting and double-acting hydraulic cylinders. Single-acting cylinders employ a piston which is hydraulically extended and such extended piston relies upon the load, a spring member or gravity to effect retraction of the extended piston. In double-acting cylinders, however, the hydraulic fluid medium is employed not only for extending the piston but also in retracting the same in the opposite direction whereby the piston may attain its lowermost retracted position. Thus positive force is applied to the piston in opposite directions of movement.
Single-acting hydraulic or pneumatic cylinders encounter many practical difficulties, particularly in heavy duty applications. Heavy duty cylinder and piston systems are normally of a compact size whereby the piston weight is such that it will only force a minimum amount of hydraulic liquid from its housing cylinder. This fact combined with the frictional resistances afforded by the hoses and conduits employed in the supplying of hydraulic liquid to the cylinder and sealing devices used in the construction of the cylinder effectively prevent the weight of the piston from forcing the hydraulic liquid back to a reservoir.
The inability to retract present in typical single-acting cylinders leads to many practical operational difficulties. Thus when employing heavy duty cylinders in confined spaces, the piston in the extended position may create problems in endeavors to remove such cylinders to a new site of use. Obviously in heavy duty applications the extendible piston should be returned to a retracted position, as close as possible to a supporting floor surface so as to obtain maximum work benefits from such cylinder. Also when such cylinder is employed for reinforcing purposes or the like in a confined space, it may be necessary to pry the extended piston into a retracted position to enable such hydraulic cylinder to be removed from its original work position.
The use of pry bars in the prior art in connection with single-acting cylinders not only rendered use of such cylinders cumbersome, but in addition may lead to damage of the extendible piston.
In accordance with this invention an improved retractor valve is provided. In a preferred embodiment a single-acting cylinder is retracted without the need for a return spring or the use of hydraulic liquid application to opposed piston surfaces as is normally applied in double-acting cylinders. The valve embodiment provides retraction of the piston of single-acting cylinders when the cylinder is used in any horizontal or vertical position. In accordance with this invention, a two or three way directional control valve creates a partial vacuum within the valve interior which in turn creates an aspirating action. Such aspirating action performs a pumping function thereby the hydraulic liquid is exhausted in a ready manner from a work cylinder as in a jack construction or the like. In addition, improved retraction performance of spring returned single-acting cylinders is realized because the resistance to flow which slows the retraction of cylinders of this type particularly as the spring forces diminish near the retracted position of the piston are greatly reduced by the aspirating action of the valve.
The prior art has previously employed control valves for use with hydraulic cylinders for controlling the fluid flow into and from cylinders in which an extendible ram is disposed. Thus McClocklin, U.S. Pat. No. 4,049,019 is directed to a rotary valve providing desired fluid control when the extendible piston or ram of a hydraulic cylinder is in the extended or neutral position, is in the process of being extended or is in the process of being retracted. Other prior art control valves comprise Schultz, U.S. Pat. No. 3,677,295, McClocklin, U.S. Pat. No. 3,892,259 and Masuda, U.S. Pat. No. 3,556,151.
In all of the disclosures of these prior art references, however, there is no suggestion of the creation of a partial vacuum by means of fluid flow control so as to aspirate or positively pump hydraulic liquid from a hydraulic cylinder.
Ejector pumps of the type hereinafter described have also been employed in the prior art in a fluid handling environment as disclosed in Howard, U.S. Pat. No. 3,373,688, Stepp, U.S. Pat. No. 3,423,011, Haisma, U.S. Pat. No. 3,496,735, Shexnayder, U.S. Pat. No. 3,882,930, Yamoto, U.S. Pat. No. 4,549,854, Briley, U.S. Pat. No. 4,595,344 and Ise, et al, U.S. Pat. No. 4,600,363. In these references, however, there is no suggestion of the valve structures or systems of the invention hereinafter described in detail.
SUMMARY OF THE INVENTION
It is thus an object of this invention to provide a system whereby hydraulic liquid is positively pumped from a single-acting hydraulic cylinder so as to render such single-acting cylinder comparable in operation to a double-acting cylinder without the need for lines, structure, etc., previously deemed necessary for forcing the extendible piston or ram of such cylinder into the retracted position.
It is a further object of this invention to provide a directional flow control valve which employs a vacuum-generating jet pump for purposes of aspirating liquid from a fluid passageway as a main fluid stream simultaneously passes through the pump.
It is another object of this invention to provide a directional control valve incorporating therein a pilot-piston operated check valve which allows communication between a main hydraulic stream passing to tank, and a fluid line connected to the hydraulic liquid in a hydraulic cylinder. With such valve, the hydraulic liquid of such cylinder may be aspirated by means of a jet pump to tank along with passage of the main hydraulic fluid stream cycling to tank, as will hereinafter be described in detail.
It is a further object of this invention to provide systems in which fluid pumps may be employed in conjunction with a control valve and a single-acting hydraulic cylinder for purposes of rendering operation of such single-acting cylinder similar to that of a double-acting cylinder.
It is yet another object of this invention to provide a valve construction employing a nozzle, an entrainment chamber, a diffuser, and an outlet whereby hydraulic liquid passing from a pumping source to tank passes through said elements creating a reduced pressure zone and hydraulic liquid in a cylinder is exhausted to tank along with the liquid being cycled from a pump.
It is a further object of this invention to provide a novel valve construction having a jet pump for creating suction in a fluid passageway connected to said pump and which jet pump may be readily incorporated in both manual and automatically operated valves.
The above and other objects of this invention will become more apparent from the following detailed discussion when read in the light of the accompanying drawings and appended claims.
In one embodiment of the invention hereinafter described, a rotary valve having a plurality of fluid passageways disposed therein is arranged over an underlying valve block. The valve and block are in communication with a passageway communicating with a work site such as a hydraulic cylinder, and hydraulic liquid under pressure discharged by a pump. In the course of extending a lifting piston in the hydraulic cylinder, the valve guides by appropriate disposition of its passageways the hydraulic liquid passing under pressure from the pump to the cylinder passageway. After the cylinder piston is in the desired extended work or "advance" position, the rotary valve may be rotated to a "neutral" position whereby the hydraulic liquid is confined within the cylinder. When it is desired to retract the cylinder piston, the rotary valve is adjusted into a "retract" position allowing hydraulic liquid pumped from reservoir or tank to cycle through a jet pump in the valve. The jet pump creates a partial vacuum within the valve which is in communication with the passageway leading directly to the hydraulic cylinder. The liquid in the hydraulic cylinder is thus aspirated to the low-pressure zone in the jet pump and to tank along with the main liquid stream being pumped through the rotary valve. The hydraulic liquid previously confined within the cylinder is thus readily exhausted to tank allowing the extendible piston to rapidly drop into a retracted position, ready for a new work cycle and redisposition if necessary in a lowered, retracted position.
Although the various valve embodiments illustrated hereinafter incorporate therein rotary valve members, other valve types such as spool valves, poppet valves, etc. will work to equal advantage by appropriately aligning the fluid passageways in desired relation relative to the vacuum generating jet pump.
In a modification of the provided invention, fluid pumps may be employed for purposes of driving fluids through a control valve with a secondary pump employed for purposes of positively exhausting the fluid from a work site. In a further modified system a bidirectional pump may be employed for purposes of both advancing the piston of the hydraulic cylinder or the like into a work position and retracting such piston as fluid is exhausted from such cylinder, as will hereinafter be described in greater detail.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this invention, reference will now be made to the drawing, wherein,
FIG. 1 is a side elevational view of one embodiment of a control valve made in accordance with the teachings of this invention;
FIG. 2 is a top plan view of the valve of FIG. 1;
FIG. 3 is an elevational view similar to that of FIG. 1 illustrating a valve side opposite to that illustrated in FIG. 1;
FIG. 4 is a front elevational view of the valve of FIGS. 1 through 3;
FIG. 5 is a fragmentary elevational view partly broken away illustrating the interconnection between the upper portions of the valve of FIGS. 1 through 4;
FIG. 6 is an elevational view taken along line 6--6 of FIG. 5;
FIG. 7 is an elevational view partly broken away illustrating upper portions of the valve construction of FIGS. 1 through 5;
FIG. 8 is an elevational view taken along line 8--8 of FIG. 7; FIG. 9 is an elevational view taken along line 9--9 of FIG. 7;
FIG. 10 is a fragmentary sectional view illustrating upper portions of the valve construction of FIG. 1 through 5 in one position of operation;
FIG. 11 is a top plan view of the lower valve block employed in the valve construction of FIGS. 1 through 4 and illustrating recesses therein in phantom line;
FIG. 12 is an end elevational view of the valve block of FIG. 11;
FIG. 13 is a side elevational view of the valve block of FIG. 11;
FIG. 14 is a bottom plan view of the block of FIG. 11;
FIG. 15 is a sectional view taken along line 15--15 of FIG. 11;
FIG. 16 is a sectional view taken along line 16--16 of FIG. 12;
FIG. 17 is a schematic representation of fluid flow in the valve construction of FIGS. 1 through 4, with such valve in a "neutral" position;
FIG. 18 is a schematic representation of fluid flow in the valve construction of FIGS. 1 through 4, with the valve in an "advance" position;
FIG. 19 is a schematic representation of fluid flow in the valve construction of FIGS. 1 through 4, with the valve in a "retract" position;
FIG. 20 is an enlarged fragmentary view, partly in section, illustrating a jet pump employed in the valve of FIGS. 1 through 4;
FIG. 21 is a fragmentary exploded view, partly broken away, of components employed in a modified valve construction made in accordance with the teachings of this invention;
FIG. 22 is a view similar to FIG. 21 illustrating valve components and fluid flow therein when such valve components are in a position to advance a ram or piston in a hydraulic cylinder or the like;
FIG. 23 is a view similar to FIG. 22 illustrating valve components in a position to direct fluid flow therein when a hydraulic ram or piston is to be retracted in a hydraulic cylinder or the like;
FIG. 24 is a top plan view of the valve of FIGS. 21 through 23;
FIG. 25 is a sectional view taken on line 25--25 of FIG. 24;
FIG. 26 is an elevational view taken along line 26--26 of FIG. 25 and illustrating internal passages in phantom line;
FIG. 27 is a fragmentary sectional view illustrated on an enlarged scale of a jet pump which may be employed in the valve construction of FIGS. 21 through 26;
FIG. 28 is a fragmentary exploded view, partly in section, of components of a third embodiment of a control valve made in accordance with the teachings of this invention illustrating fluid flow therein when such valve is in a "neutral" position;
FIG. 29 is a view similar to FIG. 28 illustrating fluid flow in the valve components when such valve is in an "advance" position;
FIG. 30 is a view similar to FIGS. 28 and 29 illustrating the valve components in a disposition whereby the fluid flow therein retracts a ram or piston in a hydraulic cylinder or the like;
FIG. 31 is a transverse sectional view of the valve construction of FIGS. 28 through 30, and
FIG. 32 is a transverse sectional view taken along 32--32 of FIG. 31.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now more particularly to FIGS. 1 through 4, there is illustrated therein a fluid control valve 10 made in accordance with this invention. As illustrated in FIGS. 1 and 2, the valve construction comprises a lower valve block or subplate 12 over which is mounted a valve body 14 and a valve housing 16 in which is disposed a rotary valve body 18. The separate valve body 14 and block 12 may be formed as an integral member if desired. The separate bodies illustrated facilitate element assembly and passageway formation therein.
As illustrated in FIGS. 7 and 8 the valve body 18 is connected to and rotatably driven by rotatable valve cap 20, through connecting stem 22. The rotary valve cap is manually rotatable by means of handle 24 which threadably engages a receiving opening in the valve cap 20. The aforedescribed components are maintained in a state of assembly by means of screws 25, more clearly seen in FIG. 4, which traverse the housing 16, valve body 14 and are threadably anchored in the lower valve block 12 as illustrated in phantom line in FIG. 4, as in threaded openings 13 of FIG. 11.
A spring loaded ball 26, more clearly seen in FIGS. 5 and 7, is mounted in valve cap 20 and is received in appropriate openings disposed in an upper surface portion of stationary valve housing 16 for purposes of positioning the valve rotary valve body 18 relative to the underlying valve body 14 with which valve 18 is in face-to-face contact, as illustrated in FIG. 7. The openings, such as opening 28 illustrated in FIG. 5, precisely position valve 18 relative to underlying valve body 14 in three spaced positions which are determinately spaced apart.
Valve rotor 18 has a plurality of fluid conveying passageways therein. Passageway 32, illustrated in FIGS. 8 and 10, has a terminal end 32T disposed at the periphery of rotor 18. As a result, fluid passing from such terminal end 32T will fall into an underlying annular chamber 34, illustrated in FIGS. 7, 8 and 10. The latter annular chamber is directly connected to a fluid reservoir or "tank" as will hereinafter be explained in greater detail. A resilient O-ring 36 encompasses the liquid chamber 34 and is compressed in fluid sealing engagement between undersurface portions of housing 16 within which rotary valve 18 is disposed and the upper surface of the valve body 18 in the manner clearly illustrated in FIG. 7 of the drawing.
Also disposed in valve rotor 18 are fluid passageways 40 and 42, see FIG. 8. Passageway 40 has opposed terminal ends 43 and 45, and passageway 42 has opposed terminal ends 47 and 49. These passageway terminal ends lie on the face or plane of rotary valve 18 in the manner illustrated in FIG. 8. It is the function of the rotor passageways to communicate with fluid passages in the underlying intermediate valve body 14. It will be noted from FIG. 9 that four main fluid passageways terminate on the surface of valve body 14. These passageways 48, 50, 52 and 54 traverse the thickness of valve body 14 in the manner illustrated in FIGS. 7 and 10. Each passageway is surrounded by a spring-loaded seat S.
The seats S effect tight fluid-seals between each of the passageways 48, 50, 52 and 54 of valve body 14, and aligned passageways of valve rotor 18. Seats S are upwardly biased by means of springs 60 in the manner most clearly seen in FIGS. 7 and 10. Each of the seats S has an O-ring 62 mounted thereon for purposes of effecting a fluid-tight seal within the valve body passageway within which the seat is disposed. The upper annular portions of the seats S effect a desired fluid seal with the engaged surface portions of the rotor 18 in the manner illustrated in FIG. 7. Such seat constructions are known in the art, and per se comprise no part of this invention.
Lower portions of each of the passageways 48, 50, 52 and 54 of the valve body 14 have disposed therein O-ring 64 for purposes of effecting fluid-tight seals with aligned fluid passageways in underlying valve block or base plate 12 illustrated in elevation in FIGS. 1 through 4. Details of the passageways contained therein are illustrated in FIGS. 11 through 16 of the drawing.
Referring now more particularly to FIG. 16 comprising a transverse section of valve block 12, there is illustrated in such section lower entry 48E of a block passageway 48B which communicates with overlying fluid passageway 48 of valve body 14. The lower entryway of passageway 48B is in direct communication with a pump 49 or equivalent source of hydraulic fluid or the like, under pressure, which is directed by valve 10 in the course of passing to a hydraulic cylinder or the like. FIG. 16 also illustrates in section a pressure-limiting valve assembly 64 including a seat member 66, a conical valve member 68, which is spring biased by means of a spring 70 to close the opening in seat 66, and an adjusting screw 72. Screw 72 threadedly engages a recess in the valve block 12 for purposes of applying adjustable, desired compression forces on the engaged spring 70 and thereby determine the force which must be applied to the cone valve 68 to remove the same from its seat 66 upon entry of fluid such as hydraulic liquid or the like into passageway branch 74 communicating with passageway 48B. Accordingly, if the incoming pump pressure exceeds a predetermined limit set by the spring 70 and cone valve 68, such pressure will unseat valve 68 allowing fluid flow through opening 75 into passageway 77 which communicates with tank. Thus, the limiting valve assures that the incoming pressure does not exceed a predetermined value. It will be noted from figures such as FIG. 11 of the drawing that a number of plugs "P" are present in block 12 after the appropriate drilling to form desired fluid passageways therein.
Assuming the valve is in the neutral position wherein no work is being performed, the incoming fluid such as hydraulic liquid passes through passageway 48B in block 12 into overlying passageway 48 of valve body 16 (see FIG. 9) and then into overlying passageway 32 of valve rotor 18 illustrated in FIG. 10. The hydraulic liquid discharges into annular chamber 34 from which the liquid passes from chamber 34 to tank by means of vent-passageway 70 of valve body 14, (FIGS. 6 and 9). The liquid continues to pass from passageway 70 to continuation thereof comprising passageway 70B in lower valve block 12, the latter passageway being seen in FIGS. 11, 13 and 14.
With the valve rotor 18 in a neutral position, entryway 31, see FIG. 8, of rotor passageway 32 is in overlying relationship with passageway 48 of intermediate valve body 14 which is in turn in overlying alignment with passageway 48B in lower valve block 12.
Thus, with valve 10 in neutral, hydraulic fluid is pumped from the tank through the aforementioned aligned passageways out terminal end 32T of passageway 32, as seen in FIG. 10, for discharge into annular chamber 34, from which the liquid passes through the vent-passageway 70 of valve body 14 and continuation thereof 70B in lower block 12 to tank.
Upon indexing the upper rotary valve member 18 to a work position such as a position in which hydraulic fluid is passed to a cylinder for purposes of piston extension, the following fluid flow takes place. Fluid such as hydraulic liquid is pumped into the lower block passageway 48B, through the intermediate valve body passageway 48 and then into the valve rotor passageway 42 by means of entryway 47 (FIG. 8) which in the work or "advance" position will be disposed over passageway 48 illustrated in FIG. 6. It will be noted from FIG. 6 that O-rings 64 surround each of the lower entries to valve body passageways 48, 50, 52 and 54.
The fluid passing into the valve rotor 18 exits via opening 49 of passageway 42 which will be in overlying relationship with passageway 52 of valve body 14 in the "advance" valve condition. Passageway 52 is in overlying relationship with fluid passageway 52B in the lower block 12 illustrated in FIG. 11. The latter block passageway is in communication with work port 75 which is in turn in communication with the bottom entry of a hydraulic cylinder or the like, whereby a ram or piston disposed therein may be extended.
After the cylinder piston has been fully extended, the rotor 18 may be indexed to the neutral position for the desired time period in which the piston is in the extended position. In such valve position the cylinder hydraulic liquid is trapped within the cylinder as any hydraulic liquid attempting to pass through passageway 75 of block 12 engages a blind surface of the rotor 18.
When it is desired to retract a cylinder piston, the rotor 18 is indexed into the "retract" position which allows the following fluid flow. The fluid pump continues to pump hydraulic liquid into the entryway 48B of the block 12, into passageway 48 of the central valve body 14 and into entryway 43 of passageway 40 of the valve rotor 18. Liquid will then exit from end of 45 of passageway 40 which end will be located over passageway 54 of the central valve body 14. Liquid passes from passageway 54 into the opening 54B in the lower valve block 12 in which is disposed a jet pump 53 for generating a partial vacuum. Such pump is most clearly seen in FIG. 15, and comprises an upper nozzle 76 which discharges into underlying diffuser 78 located in the valve block 12, after which the liquid passes to tank. The passage of the main stream of pumped liquid through the nozzle 76 and the underlying diffuser 78 effects a partial vacuum.
Such partial vacuum is communicated to the hydraulic liquid in the cylinder via port 75 in communication with the cylinder hydraulic liquid which in turn communicates with passageway 52B of the cylinder block 12 as illustrated in FIG. 11. The latter passageway is in communication with opening 52 in central valve body 14. In the retract position, passageway 52 will be in underlying relationship with opening 47 of passageway 42 of rotor 18. The other end of passageway 42, i.e., the end 49 thereof will be in overlying relationship with seat "S" of passageway 50 of valve body 14 as illustrated in FIG. 9. The lower end of passageway 50 illustrated in FIG. 6 will be in overlying relationship with passageway 50B in the lower valve block 12 (see FIG. 11). Passageway 50B is a vertical extension passageway 80 seen in FIGS. 11 and 15, which communicates with reduced pressure zone of jet pump 53 in the valve block 12. Thus hydraulic liquid will be aspirated or pulled from the cylinder connected to port 75 of the valve block to the diffusion chamber 78 illustrated in FIG. 15 from which the combination streams of the liquid pumped from tank together with the hydraulic liquid pulled from the hydraulic cylinder will pass to tank in the manner illustrated in FIG. 15.
The foregoing detailed recitations of the fluid passages in the valve "neutral", "advance" and "retract" positions may also be apparent from the schematic FIGS. 17 through 19. Thus FIG. 17 illustrates a neutral position in which the main hydraulic stream is pumped directly to tank, bypassing the jet pump 53, and returning to tank through the vent passage 70B. It will be apparent from FIG. 17 that the hydraulic liquid of the cylinder will be unable to proceed into passageway 75 inasmuch as seat S disposed in valve body 14 and the encompassed passageway 52 will be in engagement with an unapertured, blind surface of the overlying rotor 16, preventing any exit of any hydraulic liquid from the cylinder in the neutral position.
In the FIG. 18 advance position, it will be seen that the hydraulic liquid from pump again bypasses the jet pump 53, passing through the appropriate passages in rotor 18 prior to entering passageway 52 in valve body 14 and underlying aligned passageway 52B of lower valve block 12 prior to entering port 75 in direct communication with the cylinder or other work site.
In the retract position of FIG. 19, the hydraulic fluid passes from the pump through appropriate passageways in the rotor 18, through passageway 54 of the central valve body 14 and into the underlying passageway 54B in which the jet pump 53 comprising the nozzle 76 and the diffuser 78 are disposed. Simultaneously, liquid is pulled from the cylinder through port 75, through connecting passageway 52B into overlying passageway 52 of the intermediate valve body 14. After passing through appropriate fluid passages in the rotor 18, the cylinder fluid enters passageway 50 of valve body 14 and connecting fluid passageway 80, the latter connecting passageway 50B with the diffuser chamber 78.
FIG. 20 is an enlarged view of the jet pump construction of this application illustrating the structure wherein the nozzle 76 has the upper periphery thereof surrounded by an O-ring 64 for purposes of engaging the undersurface of valve body 14 in a fluid-tight engagement. The jet pump 53 may be formed in two separate nozzle and diffuser pieces inserted in receiving recesses of the valve lock, or the pump may comprise a nozzle member arranged over a recess in the valve block in the form of the diffuser. Other structural arrangements are contemplated which generate fluid flow adequate to pull the hydraulic liquid from the cylinder, and are construed to be within the scope of this invention.
FIGS. 21 through 27 are directed to a second embodiment of a flow control valve made in accordance with the teachings of this invention. Such valve 90 is seen in FIG. 25 and includes an upper handle 92, a valve rotor 96 rotatably mounted in a valve housing 98 overlying a valve body 100. The latter valve body has two spring-loaded check valves 102, 104 urged against seats 106 and 108 respectively by springs 110 and 112 respectively. Rotor 96 is located in the three positions of "neutral", "advance" and "retract" by means of the spring-loaded detent ball 114 urged into spaced recesses 116 of rotatable valve cap 118, see FIGS. 24 and 25. Spring 120 illustrated in FIG. 25 urges the ball 114 into its spaced position-defining recesses 116.
As will be noted in FIG. 24, the rotational movement of the rotor 96 in the housing 98 is guided by means of guide pin 121 which is mounted in housing 98. Pin 121 interfits with arcuate slot 122 which rotates with the rotor 96, as handle 92 is manually actuated. Handle 92 is connected to valve rotor 96 by stem 94.
It will also be noted from FIG. 25 that cam plate 124 is secured to the bottom of rotor 96 by means of a screw 125 or the like. The assembly of the rotor 96, housing 98 and valve body 100 may be secured to an underlying base 130 as by means of screws 127, illustrated in FIG. 24, which traverse aligned apertures of the housing 98 and valve body 100 prior to being anchored in the base 130.
The valve embodiment 90 of FIGS. 21 through 27 by virtue of the two check valves employed, eliminates the necessity of the plurality of fluid passageways of the valve embodiment 10. As noted from FIG. 21, when valve 90 is in the neutral position, pressurized flow from a pump traverses the base 130 prior to entering passageway 140 in valve body 100. The passageway 140 terminates at its upper end in illustrated valve seat 142 which is spring biased against the undersurface of rotor 96 in the manner illustrated in FIG. 25 by spring 60. The fluid passes through the passageway 140 and seat 142 into right-angle passageway 144 disposed in rotor 96 for discharge at the periphery of the rotor into underlying annular chamber 146, more clearly seen in FIG. 25. Chamber 146 is surrounded by an O-ring 148. The liquid passing into annular chamber 146 enters the top of jet pump 150, illustrated in FIG. 21, passing through the valve body 100 and base 130 to tank.
When the rotor 196 is indexed to an "advance" position, illustrated in the exploded view of FIG. 22, the liquid flow again passes from the pump through base plate 130 through passageway 140 and valve body 100 to surface seat 142, and then through unidirectional passageway 143 disposed in the valve rotor 96. Passageway 143 has a ball and pin disposed within the interior thereof whereby flow may only take place from passageway entry 143E to the passageway terminus 143T. If flow were attempted from 143T to 143E in the reverse direction, ball valve 147 disposed in passage 143 would seat at the left passageway end, preventing fluid flow out of 143E.
Liquid flow exits the rotor 96 at 143T into underlying seat 149 which is concentric with the passageway end 143T. Seat 149 is disposed at the upper terminus of a fluid passageway 151 disposed in valve body 100. Passageway 151 is intersected by passageway 152 (FIG. 25) which is in communication with a site of hydraulic liquid use, such as a lifting jack hydraulic cylinder.
It will be more clearly seen from FIG. 25 of the drawing, that when valve 90 is in a non-advance position, the ball valve 102 is seated in seat 106 of the passageway 151. However, upon pressurized fluid flow entering seat 149 and passageway 151, ball 102 is removed from its seat 106 in the manner illustrated in FIG. 22 against the action of spring 110, allowing fluid flow to a cylinder or other site of use in the manner illustrated in FIG. 22.
FIG. 23 illustrates the valve 90 in a retract position in which rotor 96 has been indexed to a new position in which the incoming fluid flow passing through seat 142 passes through right angle passageway 154 disposed in the rotor 96, and the fluid discharging at the periphery of the rotor body accumulates in the annular chamber 146 illustrated in FIG. 25 for passage through underlying jet pump 150. With the rotor in the position of FIG. 23, cam plate 126 has been moved into a position to depress ball 158 which is normally disposed in a position located above the surface of valve body 100, as illustrated in FIG. 25. It will be further noted from the latter figure that ball 158 rests atop a plunger pin 160 which in the lowered or depressed position unseats check valve ball 104 from its seat 108 against the action of spring 112, allowing fluid passage from the cylinder through passageways 75, 152 with the ball 104 in its unseated position. Fluid flow passes from the cylinder through passageway 152 through passageway 154, see FIGS. 23 and 26, allowing the fluid in the line 154 from the cylinder to be aspirated into the jet pump 150 as a result of the main flow passage of the hydraulic fluid under pressure from the pump in the manner illustrated in FIG. 23. Thus, fluid, such as hydraulic liquid from a cylinder or the like, will be readily exhausted from the cylinder and aspirated to tank, together with hydraulic liquid being cycled from the pump.
FIG. 27 is an enlarged sectional view illustrating the two discrete pieces which nozzle 53M and diffuser 78M of the jet pump 150 may assume rather than the construction illustrated in FIG. 23.
FIG. 26 illustrates in greater detail the flow path of the hydraulic liquid in valve body 100 from a cylinder or work site to the area above depressed check valve 102, and into the passageway 154, comprising an intake branch of the jet pump 150.
FIGS. 28 through 32 are directed to a second modified control valve construction 170 in which the valve rotor 18 is of precisely the same construction as valve rotor 18 of the first-discussed valve embodiment 10. Also, the intermediate valve body 14 is of precisely the same construction as body 14 of valve 10 with respect to the valve seats and flow passageways therethrough. As is most apparent from the sectional view of FIG. 31, valve construction 170 employs a pilot piston 172 for purposes of engaging and unseating a check valve ball 174 seated on seat 176 in passageway 75. The latter passageway communicates with a hydraulic cylinder or other site of hydraulic liquid or fluid use. Check valve 174 engages seat 176 and is urged into the seated position by means of spring 178. In the normal course of operation, and specifically in the course of cylinder retraction, pilot piston-operated valve 172 will be unseated in the manner hereinafter described in detail.
The normal "neutral", "advance" and "retract" functions of the valve 170 are as follows. Referring now more particularly to FIG. 28, the relationship between the valve rotor 18, intermediate valve body 14 and underlying valve block 180 is as follows. Actuating fluid such as hydraulic liquid passes from a hydraulic pump 49 through passageway 48B in lower valve block 180 into overlying and aligned passageway 48 in valve body 14 for entrance into entryway 31 of fluid passage 32 formed in the valve rotor 18. The liquid discharges from the rotor 18 into the annular fluid chamber 34, see FIG. 31, defined by the rotor 18, its surrounding housing 16 and the underlying valve body 14. The liquid in the chamber 34 then passes into the vent passageway 70 into underlying passageway 70B of the underlying block 180 and then into jet pump 181 mounted in the block 180 in the manner illustrated in FIG. 28. The cycling fluid will then pass to tank as indicated.
In the advance position for the rotary valve 170, illustrated in FIG. 29, the rotor 18 is positioned relative to the underlying valve body 14 and the fluid passageways disposed therein in such manner that the hydraulic liquid or other activating fluid passes from the pump through the passageway 48B in the lower block 180 through passageway 48 of overlying valve body 14 into end 47 of passageway 42 of rotor 18. The fluid exits passageway 42 through end 49 and enters the seat S disposed over passageway 52 of the block 14. The bottom end of passageway 52 is in fluid-sealing engagement with passageway 52B of the block 180 by means of O-ring 64 in the manner illustrated in FIG. 31. The hydraulic liquid or other fluid passing through passageway 52B unseats check ball 174 from seat 176 in passageway 175 as illustrated in FIG. 29. The unseated ball 174 enables the pumped liquid to proceed to the cylinder or other site of use whereat a work piston or ram is extended from a cylinder.
FIG. 30 illustrates the components of the valve embodiment 170 in a relationship assumed for purposes of retracting an extended piston in a hydraulic cylinder. In such position, activating fluid such as hydraulic liquid is pumped through passageway 48B of the lower block 180. The liquid passes into overlying and aligned passageway 48 of valve body 14, into end 43 of passageway 40 in rotor 18, and exits from such passageway at 45 and is returned into the valve body 14 through passageway 54. The liquid then strikes bevelled surface 173 of piston 172 urging the piston and its terminal pin P axially to the right unseating ball 174 from its seat 176 as illustrated in FIG. 30. The liquid then enters into the hollow center 172C of pilot piston 172 mounted in block 180 and is discharged through radial openings 183. (See FIG. 32) After unseating of the ball in opposition to spring 178 fluid flow passing from piston 172 proceeds through passageway 54E in block 180 into the upper conical portion of jet pump 181 whereafter the liquid passes from the pump to tank.
In the course of such pumped liquid passing through the diffuser portion of the jet pump 150 a partial vacuum is created. Such partial vacuum will enable the liquid in a cylinder passing through passageway 75, which is now open because of the unseating of ball valve 174, to pass through passageway 52B in block 180. The liquid from the cylinder then passes through overlying passageway 52 of valve body 14 into overlying and aligned opening 47 of rotor passageway 42, from end 49 of passageway 42 into passageway 50 of valve body 14, and down into underlying aligned passageway 50B of the block 180. It will be clearly seen from FIG. 30 that passageway 50B enters into the side of the jet pump 181, whereby the liquid in passageway 50B is aspirated into the jet pump 181 for discharge to tank along with the main recycled hydraulic liquid stream.
It is believed evident from the above descriptions of the various forms of the rotary valves 10, 90 and 170 that a variety of valve structures may incorporate the inventive features of the provided invention for purposes of positively aspirating or drawing hydraulic liquid or other fluids from a site of use. As is apparent from the embodiment 10 above described, it is not necessary to employ a check valve in conjunction with the fluid passages and jet pump employed for creating an area of low pressure within the valve body. It is also believed apparent from the valve embodiments 90 and 170 that various check valve arrangements and pilot pistons may be employed for controlling the various flows while aspirating liquid from a hydraulic cylinder as the main source of activating liquid is cycled to tank or reservoir. As previously noted, the valves incorporating the jet pumps need not be rotary. Slide valves, poppet valves etc. will work to equal advantage.
Although in the valve embodiments illustrated and described, a valve rotor is adjustable relative to the remaining valve elements; obviously any valve element containing plural passageways may be adjustable relative to the other to form desired passageway combinations. The various combinations may provide varying fluid paths relative to the jet pump, hydraulic cylinders, etc.
In view of the foregoing, it is believed apparent that a number of modifications of the inventive embodiments disclosed may be readily effected by those skilled in the art. Accordingly, this invention is to be limited only by the scope of the appended claims. | Fluid flow control valves are provided having a jet pump or aspirator connected to a plurality of fluid passageways. Fluid flow from one of the passageways through the jet pump creates a partial vacuum enabling fluid flow to be drawn through the other of the fluid passageways connected to the jet pump. Such valves enable hydraulic fluids of a single-acting piston-cylinder unit or the like to be readily exhausted. |
This invention is concerned with a down draft recirculating air filtration system particularly useful in enclosed environments, especially in those wherein airborne contaminates are constantly being generated such as in automobile body and service shops. It is particularly concerned with the removal of health hazardous dust and paint particles.
PRIOR ART
______________________________________PRIOR ART______________________________________U.S. Pat. No. 4,339,250 Thut 7/13/82U.S. Pat. No. 4,603,618 Charles 8/5/86U.S. Pat. No. 4,370,155 Armbruster 1/25/83______________________________________
These patents are concerned with the filtering and re-circulating of air in enclosed environments. However, they do not disclose the particular floor mounted filtering system used by the applicant in conjunction with the uniform controlled distribution of the recirculated air across the ceiling of the enclosed space by means of an elongated duct thereunder.
BACKGROUND
There are many situations where in an enclosed environment suspended particulate matter is being constantly generated which particulate material is often deleterious to the workers in the room and/or the product being produced. Particularly bad offenders in this regard are machine and metal working shops and automobile service areas and body shops. Many systems have been proposed for the filtering of the air in such enclosed environments, but none to date have been entirely satisfactory at a reasonable price. For example, electrostatic precipitators have been hung from a shop ceiling with the air being circulated in series through them to remove the particulate matter and other contaminates. Besides the fact that the electrostatic precipitators at the ceiling level are difficult to service--and they do require regular cleaning--this arrangement requires that the air from the floor of the shop be drawn up past the workers on the floor to the electrostatic units, giving the workers a better opportunity to inhale the contaminated air.
In another system, the filtering unit is placed on the floor and the filtered area air is blown toward the ceiling without proper distribution through a duct. Undue turbulence results and the distribution of the air is not uniformed throughout the enclosed space. When the room is heated, the warmer air tends to collect underneath the ceiling and if proper distribution of the filtered air is not observed, localized air circulation cells may be set up that will draw the contaminated air to the ceiling, rather than allow it to flow along the floor to the filtration unit.
There has been a desideratum therefore for a cost and performance effective air filtration/air distribution system for enclosed environments to purify contaminated air therein. There has been a need for an effective re-circulating air filtration system that is mechanically uncomplicated and easy to service and maintain.
The present invention proposes such a system.
INVENTION
In brief compass, this invention is a down draft re-circulating air filtration system for an enclosed space comprising a filtration unit and a duct receiving air from the air filtration unit and distributing the same through a multiplicity of outlets across and just under the ceiling of the enclosed space. The filtration unit intakes air from the floor of the enclosed space and has a fan to propel the air into and through the duct. Upstream of the fan in the filtration unit there are at least three easily removable filter elements through which the air passes in series.
The first filter is a coarse filter of a non-woven fiber mesh on the outside of the base of the unit. This filter is held largely by the airflow into the unit pushing it against a supporting grid such that it is easily removable for daily shake out or cleaning.
The second filter within the unit consists of a commercially available cap-shaped filter of plastic fibers coated with a tackifier. It removes 95% of all particles in the contaminated air greater than 10 microns. The cap-shaped filter is held on a frame within the unit simply by a hook and loop fabric fastener (Velcro) such that it could be readily removed and replaced. The fibrous filtering mat is preferably of three ply construction of crimped polyester fiber with the outer ply having a coarser more open structure and the inner ply the finest interstices. The middle ply preferably contains a tackifier to assure filter cake build-up.
The third filter is a commercially available bag filter that removes 95% of all particles greater than 1 micron. The bag filter consists of several pockets mounted on a frame or hoop. The hoop, with the filter, can readily be removed from the filtration unit for shaking out or for such other cleaning or replacement as may be desired.
The ducting used for distributing the filtered air is preferably of a reinforced plastic fabric in the form of a tube. It has a multiplicity of openings cut in the tube along its length to direct the air against the ceiling of the enclosed space. The filtered air because it is dispersed at a multiplicity of points directly underneath the ceiling, gently mixes with the warm air layer against the ceiling to form a "blanket" which for any lot of air gently drifts downwardly to the floor of the enclosed space without appreciable turbulence or the formation of localized air circulation cells that would serve to stir up the dust from the floor. This "blanket" when approaching or reaching the floor, gently drifts along the floor to the air intake of the filtration unit.
This down flow or down draft system keeps particulate matter, dust or fumes being generated in an enclosed space from traveling upwardly and/or laterally which if they do, tend to cause worker irritation and perhaps contamination of adjacent work projects. For example, in an auto body shop at one station a car maybe being painted while at an adjacent station, a car maybe being sanded and primed to prepare it for painting. If the dust being generated from the sanding operation were allowed to drift over to the spray painting operation, it could spoil the paint finish.
DRAWINGS
In the drawings:
FIG. 1 illustrates an enclosed spaced or work area to which this invention is applied and,
FIG. 2 is a schematic illustration in cross section of the filtration unit of this invention.
DESCRIPTION
With reference to FIG. 1, an enclosed space 10 e.g. an automobile service area generating particle laden air, contains a filtration unit 11 of this invention. Filtered air from the filtration unit 11 is passed up to the ceiling and along underneath the ceiling by fabric ducting or pipes 12. This ducting has a series of openings cut into it, preferably at 10:00 and 2:00 o'clock in cross section, which allow the filtered air to exit from the ducting up against the ceiling and to flow thereover as indicated by the arrows 13, mixing with the warm air that tends to collect at the ceiling. This pattern of distribution creates a "blanket" of filtered air at the ceiling under a positive pressure with respect to the pressure of the air at the floor of the enclosed space 10. As the filtered air is admitted underneath the ceiling to the "blanket" through a multiplicity of outlets, there is no violent turbulence and swirling and mixing the air as is the case if there is simply but one or two outlets or if the air is being blown up from a filtration unit on the floor without the use of ducting.
Because of the pressure differential that exist between the ceiling and that of the floor, the "blanket" with regard to any one unit of air tends to settle gently towards the floor. The fumes and dust thus being created in the work area are carried downward with this "blanket" to the floor with little turbulence other than that caused by the work going on in the enclosed space. Near or at the floor, the air travels across the floor as indicated by directional areas 14 to the filtration unit 11 of this invention to be cleansed and recirculated.
Filtration unit 11 has a door or upward removable panel 15 that permits access to the filters in the unit. It also preferably has means for observing the pressure drops over the second and third stage filters, which pressure drops may be displayed by gages 16 on the side of the unit. The observing of these pressure drops aid in determining when the filters should be removed and cleaned.
With reference to FIG. 2, the filtration unit of this invention comprises a cabinet 20, having at the top a blower or fan 21 exhaust the air via an outlet 22 which connects to the ducting 12. The ducting can be held on oulet 22 by a suitable clamp 23.
The first or coarse filter 24 is wrapped around the base of the unit on three sides. The filter is supported against a grid 25. Filter 24 consists of a heavy bat of non-woven fibers which is pretty much self supporting. It is held against the grid 25 by means of the incoming air flow indicated by arrows 26. If desired, filter 24 can be held in place by a spring clip or a hook and loop fabric fastener spotted along the circumference.
The second filter is a cap-filter 27 held by a hoop 28 with the hoop being attached to a circumferential frame in the unit as by means of a hook and loop fabric fastener.
Filter 27 preferably consists of a three ply mat of crimped plastic fibers with the fibers being more coarsely layed or more open on the side facing the air flow, indicated by directional arrows 29.
The air exiting filter 27 passes through a bag filter 30 having several pockets mounted on a hoop or framed 31. Hoop 31 again is desirably held within the unit on a rim 32 by means of a hook and loop fabric fastener.
The cap filter and the bag filter can be readily removed by removing access door 15 and simply lifting the filters out.
As previous indicated, the cap filter removes 95% of all particles greater than 10 microns in size, and the bag filter removes 95% of all particles greater than 1 micron in size. If there is no dust or other contamination being continuously generated in enclosed space 10 the constant re-circulation of air through the filtration unit 20 would in short order remove practically all contamination greater than 1 micron in size.
With auto body shops and other operations, there will be paint fumes and blower 21 is desirably explosion proof.
It has been found that as this down draft filtration system of the present invention causes heat collecting at the ceiling to migrate downward to the floor of the enclosed space, there is a substantial savings in heating cost. There is less heat lost through the ceiling of the enclosed space and as the heat is more uniformly distributed the workers feel more comfortable with, consequently, less heat input being required.
The system of the present invention has been installed in several automobile service areas and body shop facilities. The results have been truly impressive. The air in which the workers must work is substantially cleaner and there has been a reduced amount of headaches and absenteeism. Employee moral and efficiency were improved. As indicated above, the heating costs were reduced and there was substantially less grime and dust on the walls of the shops. Purchasers of the systems were pleased with their easy maintenance. Among other things it was not necessary for them to deal with ceiling suspended units. | A down draft air re-circulating filtration system for auto body shops and the like companies a filtration unit intaking air from the floor and having a series of three filters removing particles greater than about 1 micron and a fabric ducting distributing the filtered air at a multiplicity of points just under the ceiling to create a "blanket" of filtered air under positive pressure that settles towards the floor and the filtration unit intake. |
TECHNICAL FIELD
The present invention relates to a detection device for an internal combustion engine which detects inhibitors such as particulate matters.
BACKGROUND TECHNIQUE
In an exhaust system of an internal combustion engine, various sensors such as an air-fuel ratio sensor (A/F sensor) for detecting an air-fuel ratio in the exhaust gas are provided. When inhibitors such as particulate matters in the exhaust gas adhere to a detection unit of these kinds of sensors, the sensors become unable to obtain accurate detection values, and thereby the detection accuracy is deteriorated. As a technique for dealing with this, in Patent Reference-1, there is described a technique which determines, at the time when an operation state of a engine is a static state, whether an output value of an oxygen sensor is smaller than a predetermined value or larger than the predetermined value, and which burns up the particulate matters by increasing temperature of an electrical heater for heating up a detection element of the oxygen sensor at the time when the output value is larger than the predetermined value. In Patent References-2 and -3, there are also described technique which relates to the present invention.
Patent Reference-1: Japanese Patent Application Laid-open under No. H11-82112 Patent Reference-2: Japanese Patent No. 3744486 Patent Reference-3: Japanese Patent No. 3958755
DISCLOSURE OF INVENTION
Problem to be Solved by the Invention
However, by the technique described in Patent Reference-1, it is not clear whether the deviation of the output value supplied from the sensor is caused by adhesions of inhibitors or by deterioration of the sensor itself. In the case where the deviation of the output value is caused by the deterioration of the sensor itself, it is meaningless to burn up the particulate matters.
The present invention has been achieved in order to solve the above problem. It is an object of this invention to provide a detection device for an internal combustion engine which can precisely detect adhesions of inhibitors.
Means for Solving the Problem
According to one aspect of the present invention, there is provided a detection device for an internal combustion engine which is applied to the internal combustion engine including a temperature varying member, which is provided in an exhaust system, and whose temperature varies due to gas flow in the exhaust system, including a temperature correlation value detection unit which detects a correlation value which correlates with the temperature of the temperature varying member, and a variation calculating unit which calculates a variation of the correlation value, in a time period when the gas flow arises, detected by the temperature correlation value detection unit.
The above detection device for an internal combustion engine is preferably applied to the internal combustion engine which includes a temperature varying member, which is provided in an exhaust system, and whose temperature varies due to gas flow in the exhaust system. The detection device for the internal combustion engine is for example an ECU (Electronic Control Unit) and functions as a temperature correlation value detection unit and a variation calculating unit. The temperature correlation value detection unit detects a correlation value which correlates with the temperature of the temperature varying member. The term correlation value herein includes impedance of the temperature varying member, a signal output value such as current and voltage sent from the temperature varying member, and the temperature varying member's own temperature. The variation calculating unit calculates a variation of the correlation value, in a time period when the gas flow arises, detected by the temperature correlation value detection unit. According to whether or not inhibitors adhere to the temperature varying member, levels of the difficulty in cooling the temperature varying member and the difficulty in heating up the temperature varying member vary and the variation of the correlation value also varies. Thus, by calculating the variation of the temperature varying member, it becomes possible to precisely detect whether or not inhibitors adhere to the temperature varying member.
In a preferable embodiment of the detection device for an internal combustion engine, the temperature varying member is an electric heater of a gas sensor, and the temperature correlation value detection unit detects impedance of the electric heater as the correlation value.
In another preferable embodiment of the detection device for an internal combustion engine, the temperature varying member is a temperature sensor, and the temperature correlation value detection unit detects a signal output value supplied from the temperature sensor as the correlation value.
In another manner of the detection device for an internal combustion engine, an exhaust temperature sensor which detects temperature of the gas is provided on a streamline which is approximately same as the streamline where the temperature varying member is provided in the exhaust system, and the variation calculating unit calculates a rate of the variation of the correlation value to a variation of an exhaust temperature detected by the exhaust temperature sensor. Thereby it is also possible to precisely detect whether or not inhibitors adhere to the temperature varying member. Additionally, thereby it becomes possible to detect whether or not inhibitors adhere to the temperature varying member only by keeping the gas flow approximately constant during a predetermined time period when the exhaust temperature varies.
In another manner of the detection device for an internal combustion engine, a filter member is provided in the exhaust system, and the temperature varying member is provided at the downstream side of the filter member. Thereby, it becomes possible to determine whether or not the filter is functioning normally.
In another manner of the detection device for an internal combustion engine, a threshold of the variation is set according to an amount of inhibitors which adhere to the temperature varying member, and the detection device further includes a determining unit which determines whether or not the variation calculated by the variation calculating unit is smaller than the threshold. The determining unit is an ECU for example. Thereby it is possible to determine whether or not the amount of the inhibitors which adhere to the temperature varying member is larger than the amount of inhibitors corresponding to the threshold.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a configuration diagram which shows a configuration of an internal combustion engine in the first embodiment;
FIG. 2 is a cross-section diagram showing a configuration of the A/F sensor;
FIG. 3 shows the graphs indicating the time variation of the temperature of the heater of the A/F sensor;
FIG. 4 is a flow chart indicating the clogging detection method for the A/F sensor;
FIG. 5 is a configuration diagram showing a part of the exhaust passage of the internal combustion engine in the second embodiment;
FIGS. 6A and 6B show the graphs each of which indicates the time variation of each temperature at the heater of the A/F sensor and the exhaust temperature sensor and graphs each of which indicates the relationship between the temperature of the heater and the exhaust temperature.
FIG. 7 shows graphs each of which indicates the time variation of the temperature of the heater of the A/F sensor;
FIG. 8 shows a configuration diagram showing a part of the exhaust passage of the internal combustion engine in the fourth embodiment; and
FIGS. 9A and 9B show the graphs each of which indicates the time variation of the temperature of the heater of the A/F sensor and the graphs each of which indicates the relationship between the temperature of the heater and the exhaust temperature.
BRIEF DESCRIPTION OF THE REFERENCE NUMBER
3 Intake air valve
4 Exhaust valve
5 Fuel injection valve
12 Cylinder
13 Intake air passage
14 Exhaust passage
17 EGR passage
18 Turbocharger
34 Throttle valve
42 A/F sensor
50 ECU
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be explained hereinafter with reference to the drawings.
First Embodiment
The first embodiment of the present invention will be described. FIG. 1 is a configuration diagram which shows a configuration of an internal combustion engine in the first embodiment. In FIG. 1 , the solid arrows show the flows of gas and the broken arrows show the flows of signals.
The internal combustion engine (engine) is, for example, a diesel engine which is mounted as a power source for driving on a vehicle such as an automobile, and includes plural cylinders 12 , an intake air passage 13 and an exhaust passage 14 which are connected to each of the cylinders 12 , and a turbocharger 18 which is arranged in series with the intake air passage 13 and the exhaust passage 14 . It is noted that the internal combustion engine may be a gasoline engine instead of the diesel engine.
On the exhaust passage 14 , there is provided an EGR (Exhaust Gas Recirculation) passage 17 for recirculating a part of exhaust gas from the exhaust passage 14 to the intake air passage 13 . Hereinafter, the part of the exhaust gas recirculated by the EGR passage 17 is referred to as the EGR gas. An EGR cooler 23 for cooling the EGR gas, and an EGR valve 33 for controlling an amount of the EGR gas are provided on the EGR passage 17 . The EGR valve 33 is controlled by the control signal S 33 supplied from the ECU 50 .
On the intake air passage 13 , there are provided an air cleaner 21 , an air flow meter 41 which detects an amount of air (intake air) drawn in from the external, a throttle valve 34 for controlling the intake air amount, a compressor 18 a of the turbocharger 18 , an intercooler 22 , and a surge tank 16 which can store the intake gas (mixed gas of the EGR gas and the intake air). The air flow meter 41 detects the intake air amount and sends the detection signal S 41 corresponding to the detected intake air amount to the ECU 50 . The throttle valve 34 is controlled by the control signal S 34 supplied from the ECU 50 .
On the exhaust passage 14 , a turbine 18 b of the turbocharger 18 , an air-fuel ratio sensor (A/F sensor) 42 , and a filter 24 are provided. The A/F sensor 42 detects an air-fuel ratio in the exhaust gas and sends the detection signal S 42 corresponding to the detected air-fuel ratio to the ECU 50 . The filter 24 collects particulate matters in the exhaust gas. Here, the filter is not limited to what only has the filtering function. Instead, what also has a function of a NOx absorber catalyst which absorbs and reduces NOx in the exhaust gas besides the filtering function may be used.
In the turbocharger 18 , the compressor 18 a and the turbine 18 b are configured to revolve integrally. Here, the turbocharger 18 , as shown in FIG. 1 , may be a variable geometry turbocharger which has a variable nozzle vane 19 and can control the supercharging pressure for example. In the variable geometry turbocharger, the supercharging pressure is controlled by adjusting the opening degree and controlling the amount of the exhaust gas. It is noted that, instead of the turbocharger 18 , another supercharger such as an electrical supercharger can be used as the supercharger.
The intake air passage 13 and the exhaust passage 14 are connected to the combustion chamber 12 b of the cylinder 12 , and a fuel injection valve 5 for injecting fuel in the combustion chamber 12 b is provided on the combustion chamber 12 b . The fuel injection valve 5 is controlled by the control signal S 5 supplied from the ECU 50 . Also, an intake air valve 3 and an exhaust valve 4 are provided on the cylinder 12 . The intake air valve 3 controls the flow and cutoff between the intake air passage 13 and the combustion chamber 12 b by opening and closing. The exhaust valve 4 controls the flow and cutoff between the exhaust passage 14 and the combustion chamber 12 b by opening and closing. In the cylinder 12 , a force which depresses the piston 12 c to the bottom dead center is transmitted to the crank shaft 15 via the connecting rod 12 d , and then the crank shaft 15 rotates. Here, a crank angle sensor 44 is provided near the crank shaft 15 . The crank angle sensor 44 detects the rotation angle (crank angle) of the crank shaft 15 and sends the detection signal S 44 corresponding to the detected crank angle to the ECU 50 .
The ECU (Electronic Control Unit) 50 includes a CPU, a ROM, a RAM, an A/D converter, and input-output interfaces, which are not shown, and controls the engine based on the detection signals supplied from various sensors. Concretely, the ECU 50 receives the detection signals supplied from the air flow meter 41 , the crank angle sensor 44 , and the A/F sensor 42 . The ECU 50 detects operation state of the engine based on the detection signals supplied from these various sensors. The ECU 50 also receives the detection signals according to each of the pedal opening degrees of the accelerator pedal and the brake pedal supplied from the accelerator sensor 45 and the brake sensor 46 . The ECU 50 detects the operation request based on the detection signals supplied from these various sensors. The ECU 50 sends the control signals to the EGR valve 33 , the throttle valve 34 , and the fuel injection valve 5 on the basis of the detected operation state and the detected operation request of the engine.
Here, a description will be given of a configuration of the A/F sensor 42 with reference to FIG. 2 . FIG. 2 is a cross-section diagram showing a configuration of the A/F sensor 42 .
As shown in FIG. 2 , the A/F sensor 92 is a glass-type A/F sensor for example, and includes a sensor element 60 , a cover 65 , and a heater 68 .
The sensor element 60 includes a solid electrolyte 61 , an atmosphere side electrode 62 which is provided on the inner surface of the solid electrolyte 61 , an exhaust side electrode 63 which is provided on the outer surface of the solid electrolyte 61 , and a ceramic coating 64 which covers the exhaust side electrode 63 . The heater 68 is provided at the inside of the atmosphere side electrode 62 .
The solid electrolyte 61 is made of zirconia for example and is configured to function (become activated) as an oxygen ion conductor on a hot condition of equal to or higher than 300 degree for example. The heater 68 is an electric heater, and heats up and activates the solid electrolyte 61 . The heater 68 is controlled by the ECU 50 . The exhaust side electrode 63 and the atmosphere side electrode 62 are porous-platinum electrodes. In the inside of the solid electrolyte 61 , oxygen ions can transfer freely, and if there is a difference (a difference of the oxygen partial pressure) of the oxygen densities in the both ends, the oxygen ions transfer from one side to the other side in order to reduce the density difference. This transfer phenomenon of the oxygen ions become the transfers of electrons and generate electromotive force between the pair of electrodes consisting of the exhaust side electrode 63 and the atmosphere side electrode 62 . This electromotive force becomes the output voltage of the A/F sensor 42 , and the larger the difference of the oxygen densities is, the larger the voltage becomes.
The cover 65 is provided to cover the sensor element 60 and includes an inner cover 66 and an outer cover 67 .
On the cover 65 , small holes are provided to let the exhaust gas pass through. Concretely, as shown in FIG. 2 , small holes 66 a and 67 a are provided on the inner cover 66 and the outer cover 67 , respectively. In the example shown in FIG. 2 , the holes 66 a of the inner cover 66 and the holes 67 a of the outer cover 67 are provided not to overlap with each other. It is noted that the holes 66 a of the inner cover 66 and the holes 67 a of the outer cover 67 may be provided to overlap with each other.
Here, in the holes of the cover 65 , clogging is likely to happen due to adhesions of inhibitors such as particulate matters in the exhaust gas at the time when the exhaust gas passes. For example, in a case where a reductant addition valve is set on the exhaust passage 14 at the upstream side of the A/F sensor 42 , droplets of the reductant adhere to these holes of the cover 65 and the inhibitors adhere to the holes by letting the adherent reductant function as a binder and thereby the clogging in the holes of the cover 65 occurs. Once the clogging in the holes of the cover 65 occurs, it becomes hard for the exhaust gas to reach the sensor element 60 and the detection accuracy of the A/F sensor 42 degrades. For this reason, it is important to know whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
Hence, in the detection method for the internal combustion engine in the first embodiment, the ECU 50 determines whether or not the clogging in the holes of the cover 65 of the A/F sensor occurs based on a temperature variation of the heater 68 in a predetermined time period. A concrete description will be given below.
FIG. 3 shows the graphs each of which indicates the time variation of temperature in the heater 68 of the A/F sensor 42 . The graph 101 indicates a graph in a case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur, and the graph 102 indicates a graph in a case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
At the time t 1 , the temperature of the heater 68 is L 1 in both of the case where the clogging in the holes of the cover 65 does not occur and the case where the clogging in the holes of the cover 65 occurs. At the time t 1 , the ECU 50 stops the fuel injection by the fuel injection valve 5 thereby to stop the combustion in the cylinders 12 and lets the gas pass through the exhaust passage 14 from the intake air passage 13 . In this case, since the cold gas blows down to the A/F sensor 42 , the temperature of the heater 68 decrease bit by bit as time goes on.
Here, compared to the case where the clogging in the holes of the cover 65 does not occur, in the case where the clogging in the holes of the cover 65 occurs, it becomes hard for the gas to pass through the holes, and thereby wind force of the gas to the sensor element 60 of the A/F sensor 42 becomes weak and it is difficult for the heater 68 to be cooled by the gas. For this reason, as shown in FIG. 3 , compared to the case (see the graph 101 ) where the clogging in the holes of the cover 65 does not occur, in the case (see the graph 102 ) where the clogging in the holes of the cover 65 occurs, the amount of the temperature decrease over time becomes smaller. For example, at the time t 2 when a predetermined time period Δt has elapsed since the time t 1 , in the case where the clogging in the holes of the cover 65 does not occur, the temperature of the heater 68 becomes L 2 a as indicated by the white arrow in FIG. 3 . In contrast, in the case where the clogging in the holes of the cover 65 occurs, the temperature of the heater becomes L 2 b (>L 2 a ) as indicated by the black arrow in FIG. 3 .
Hence, in the detection method for the internal combustion engine in the first embodiment, at the time t 2 , the ECU 50 determines whether or not the amount of the temperature decrease of the heater 68 becomes smaller than a clogging criterion value predetermined in advance. Here, the clogging criterion value, for example, is set to the amount |L 2 a −L 1 | (corresponding to the length of the white arrow in FIG. 3 ) of the temperature decrease of the heater 68 in the case where the clogging in the holes of the cover 65 does not occur. The ECU 50 determines that the clogging in the holes of the cover 65 occurs in the case where the amount of the temperature decrease of the heater 68 is smaller than the clogging criterion value, and determines that the clogging in the holes of the cover 65 does not occur in the case where the amount of the temperature decrease of the heater 68 is equal or larger than the clogging criterion value. Thereby the ECU 50 can detect whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
Next, a description will be given of the above clogging detection method which detects the clogging of the cover 65 of the A/F sensor 42 with reference to FIG. 4 . FIG. 4 is a flow chart indicating the clogging detection method.
At step S 101 , the ECU 50 recognizes a request to stop the engine on the basis of the operation state of the engine and then the process goes to step S 102 . The ECU 50 recognizes the request to stop the engine, for example, due to the change to an idle operation state or a motoring time of a hybrid vehicle which mounts the engine.
At step S 102 , the ECU 50 detects the temperature of the heater 68 and determines whether or not the temperature of the heater 68 is equal to or larger than a predetermined temperature. Here, the predetermined temperature is, for example, temperature of the heater 68 at which the A/F sensor 42 is activated. The ECU 50 , for example, measures the impedance of the heater 68 and then can detect the temperature of the heater 68 on the basis of the impedance measured. When the ECU 50 determines that the temperature of the heater 68 is equal to or larger than the predetermined temperature (step S 102 : Yes), the process goes to step S 103 . On the other hand, when determining that the temperature of the heater 68 is smaller than the predetermined temperature (step S 102 : No), the ECU 50 executes a normal control process of stopping the engine and then ends the control process.
At step S 103 , the ECU 50 obtains the temperature L 1 of the heater 68 at this time. After then, the ECU 50 proceeds to the process at step S 104 .
At step S 104 , the ECU 50 executes the preliminary control of stopping the engine. Concretely, by sending the control signal S 5 to the fuel injection valve 5 thereby to stop the fuel injection, the ECU 50 stops the combustion in the cylinder 12 . Also, by sending the control signal S 33 to the EGR valve 33 thereby to let the EGR valve 33 be fully closed, and sending the control signal S 34 to the throttle valve 34 thereby to control the opening degrees, the ECU 50 keeps the gas flow amount in the exhaust passage 14 approximately constant. It is noted that, for a variable geometry turbocharger, the ECU 50 additionally controls the opening degrees of the variable nozzle vane 19 in order to keep the gas flow amount in the exhaust passage 14 approximately constant. Thereby it becomes possible to let the cold gas (air) pass through the exhaust passage 14 from the intake air passage 13 . After this, the ECU 50 proceeds to the process at step S 105 .
At step S 105 , the ECU 50 determines whether or not the predetermined time period Δt has elapsed since the preliminary control of stopping the engine was conducted, and when determining that the predetermined time period Δt has not passed (step S 105 : No), the ECU 50 repeatedly executes the process at step S 105 . On the other hand, when determining that the predetermined time period Δt has elapsed (step S 105 : Yes), the ECU 50 proceeds to the process at step S 106 , and for example by measuring the impedance of the heater 68 , the ECU 50 obtains the temperature L 2 at this time. After this, the ECU 50 proceeds to the process at step S 107 .
At step S 107 , the ECU 50 executes a control of stopping the engine. Concretely, the ECU 50 decreases the number of engine revolution to 0 and thereby stops the engine completely. After this, the ECU 50 proceeds to the process at step S 108 .
At step S 108 , the ECU 50 determines whether or not the temperature difference |L 2 −L 1 | of the temperatures of the heater 68 is smaller than the clogging criterion value ΔLc. Here, the clogging criterion value ΔLc is the amount of the temperature decrease of the heater 68 after the predetermined time period Δt in the case where the clogging in the holes of the cover 65 does not occur. When determining that the temperature difference |L 2 −L 1 | is smaller than the clogging criterion value ΔLc (step S 108 : Yes), the ECU 50 determines that the A/F sensor 42 is functioning normally, i.e., the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur (step S 109 ). On the other hand, when determining that the temperature difference |L 2 −L 1 | is equal to or larger than the clogging criterion value ΔLc (step S 108 : No), the A/F sensor 42 has an abnormality, i.e., the clogging in the holes of the cover 65 of the A/F sensor 42 occurs (step S 110 ). After executing the processes at step S 109 or step S 110 , the ECU 50 ends the control process. It is noted that the ECU 50 may execute the processes at step S 108 to S 110 and the process at step S 107 in the inverse order. Namely, the ECU 50 may execute the control of stopping the engine at step S 107 after executing the processes at step S 108 to S 110 .
As described above, in the detection method for the internal combustion engine in the first embodiment, the ECU 50 lets the cold gas (air) pass through the exhaust passage 14 during the predetermined time period and calculates the amount of the temperature decrease of the heater 68 in the predetermined time period. The amount of the temperature decrease of the heater 68 varies due to whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. Therefore, by calculating the amount of the temperature decrease of the heater 68 , the ECU 50 can detect whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. Also, in the detection method for the internal combustion engine in the first embodiment, since the temperature variation of the heater 68 is used, it is possible to precisely detect whether or not the clogging in the holes of the cover 65 occurs without an influence by the degree of deterioration of the sensor element 60 .
Second Embodiment
Next, the second embodiment of the present invention will be described below.
FIG. 5 is a configuration diagram showing a part of the exhaust passage of the internal combustion engine in the second embodiment. The configuration of the internal combustion engine in the second embodiment has an exhaust temperature sensor 43 on the exhaust passage 14 in addition to the configuration of the internal combustion engine in the first embodiment. Concretely, the exhaust temperature sensor 43 is provided on a streamline which is approximately same as the streamline where the A/F sensor 42 is provided and is exposed to the exhaust gas which has approximately-same temperature as the exhaust gas to which the A/F sensor 42 is exposed. For example, an exhaust temperature sensor for estimating the temperature of the filter 24 , which is originally provided on the exhaust passage 14 at the upstream side of the filter 24 , can be used as this kind of exhaust temperature sensor 43 .
FIG. 6A shows the graphs each of which indicates the time variation of each temperature at the heater 68 of the A/F sensor 42 and the exhaust temperature sensor 43 . The graph 201 indicates the temperature variation of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur, and the graph 202 indicates the temperature variation of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs, and the graph 203 indicates the variation of the temperature which is detected by the exhaust temperature sensor 43 . Hereinafter, temperature which is detected by the exhaust temperature sensor 43 is referred to as “exhaust temperature”.
At the time t 1 , the ECU 50 stops the fuel injection by the fuel injection valve 5 thereby to stop the combustion in the cylinders 12 and lets the gas pass through the exhaust passage 14 from the intake air passage 13 . Temperature which is detected by the exhaust temperature sensor at this time t 1 is expressed as “MO”, and temperature of the heater 68 of the A/F sensor 42 at the time t 1 is expressed as “L 1 ”.
FIG. 6B shows the graphs each of which indicates the relationship between the temperature of the heater 68 and the exhaust temperature. In FIG. 6B , the graphs in FIG. 6A is modified to the graphs each of which indicates the relationship between the temperature of the heater 68 and the exhaust temperature. The graph 301 is a graph which indicates the relationship between the temperature of the heater 68 and the exhaust temperature in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur. The graph 302 is a graph which indicates the relationship between the temperature of the heater 68 and the exhaust temperature in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
As shown in FIG. 6B , whereas the graph 301 is approximately linear, the graph 302 is curved toward the direction where the temperature of the heater 68 becomes higher. As indicated by the graph 301 , in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur, the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature is approximately constant. In contrast, as indicated by the graph 302 , in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs, the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature varies significantly.
For example, in response to the decrease of the exhaust temperature to a smaller value than the temperature MO, the ratio of the temperature decrease of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur becomes approximately constant as indicated by the graph 301 . On the other hand, as indicated by the tangent lines IL 1 , IL 2 to the graph 302 , the gradients of the tangent lines to the graph 302 becomes larger and larger in response to the decrease of the exhaust temperature to a smaller value than the temperature MO. In other words, the ratio of the temperature decrease of the heater 68 , in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs, becomes larger and larger as the exhaust temperature decreases from the temperature MO.
Hence, in the detection method for the in the internal combustion engine in the second embodiment, the ECU 50 calculates the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature and determines whether or not the ratio of the temperature variation is approximately constant. For example, the ECU 50 detects temperature of the heater 68 per a predetermined time period while the exhaust gas varies, and calculates a map, like what is shown in FIG. 6B , which indicates a relationship between the exhaust temperature and the temperature of the heater 68 . Then, by using the map, the ECU 50 calculates the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature and determines whether or not the ratio calculated is approximately constant. When determining that the ratio calculated is approximately constant, the ECU 50 determines that the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur. In contrast, the ECU 50 determines that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs in a case where the ratio calculated is not constant and is changing toward the direction where the temperature of the heater 68 becomes higher over the variation of the exhaust temperature as indicated by the graph 302 . For example, in the case where the ratio of the temperature decrease of the heater 68 becomes larger and larger as the exhaust temperature decreases from the temperature MO, the ECU 50 determines that the temperature of the heater 68 is changing toward the direction where the temperature of the heater 68 becomes higher and that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
As described above, in the detection method for the in the internal combustion engine in the second embodiment, similarly to the detection method for the internal combustion engine in the first embodiment, since the temperature variation of the heater 68 is used, it is possible to precisely detect whether or not the clogging in the holes of the cover 65 occurs without the influence by the degree of deterioration of the sensor element 60 . Furthermore, in the detection method for the internal combustion engine in the second embodiment, the ECU 50 executes the clogging detection process of the cover 65 of the A/F sensor 42 on the basis of the temperature variation of the exhaust temperature which is detected by the exhaust temperature sensor 43 . Therefore, in the detection method for the internal combustion engine in the second embodiment, without stopping the combustion in the cylinders 12 and significantly decreasing the temperature of the gas which flows in the exhaust passage, only by keeping the flow amount of the exhaust gas approximately constant during the predetermined time period when the exhaust temperature is changing, it is possible to precisely detect whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. Thus, in the detection method for the internal combustion engine in the second embodiment, for example, even at the time of an idle operation state, it is possible to detect whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs.
Third Embodiment
Next, the third embodiment of the present invention will be described. The configuration of the internal combustion engine in the third embodiment is the same as the configuration ( FIG. 1 ) of the internal combustion engine in the first embodiment.
FIG. 7 , similarly to FIG. 3 , shows the graphs each of which indicates the time variation of the temperature of the heater 68 of the A/F sensor 42 . The graph 401 indicates temperature variation of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur and each of the graphs 402 to 404 indicates the temperature variation of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. In FIG. 7 , the state of the A/F sensor 42 indicated by the graph 404 has the greatest degree of the clogging in the holes of the cover 65 , and the state of the A/F sensor 42 indicated by the graph 402 has the smallest degree of the clogging in the holes of the cover 65 , out of the all states of the A/F sensor 42 indicated by the graphs 402 to 404 .
At the time t 1 , the temperature of the heater 68 is L 1 in both the case where the clogging in the holes of the cover 65 does not occur and the case where the clogging in the holes of the cover 65 occurs. At the time t 1 , the ECU 50 stops the fuel injection by the fuel injection valve 5 thereby to stop the combustion in the cylinders 12 and lets the gas pass through the exhaust passage 14 from the intake air passage 13 .
At the time t 2 when a time period Δt predetermined has elapsed since the time t 1 , as indicated by the white arrow, the temperature of the heater 68 , in the case where the clogging in the holes of the cover 65 does not occur, becomes L 2 a . In contrast, as indicated by the black arrows, the temperatures of the heater 68 , in the case where the clogging in the holes of the cover 65 occurs, become L 2 b to L 2 d . In other words, the greater the degree of the clogging in the holes of the cover 65 is, the smaller the amount (the length of the black arrow) of the temperature decrease becomes. This is because, the greater the degree of the clogging in the holes of the cover 65 is, the harder it becomes for the gas to pass through the holes.
Hence, in the detection method for the internal combustion engine in the third embodiment, the ECU 50 sets a threshold of the amount of the temperature decrease of the heater 68 in accordance with the amounts of inhibitors which adhere to the holes of the cover 65 and then determines whether or not the amount of the temperature decrease of the heater 68 is smaller than the threshold. Thereby it is possible to determine whether or not the amount of the inhibitors which adhere to the holes of the cover 65 is larger than the amount of inhibitors corresponding to the threshold. For example, by setting in advance the threshold in accordance with the limit amount of inhibitors which can be cleared by cleansing the A/F sensor 42 , the ECU 50 can determine whether or not inhibitors the amount of which can be cleared by the cleansing adhere to the A/F sensor 42 . Concretely, the ECU 50 determines that the inhibitors the amount of which can be cleared by the cleansing adhere to the A/F sensor 42 when the amount of the temperature decrease is smaller than the threshold. At this time, the ECU 50 can inform the driver of the abnormal state where an exchange of the A/F sensor 42 is encouraged, for example, by lighting up a caution-advisory indicator provided on the driving seat.
In the above example, the first embodiment is applied as an example, but the second embodiment and the third embodiment can be combined. In the second embodiment, the ECU 50 determines that the temperature of the heater 68 is changing toward the direction which the temperature of the heater 68 becomes higher and that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs in the case where the rate of the temperature decrease of the heater 68 becomes larger and larger as the exhaust temperature decreases from the temperature MO. The larger the amount of the inhibitors is, the larger the degree of the temperature increase of the heater 68 becomes. Namely, the graph 302 shown in FIG. 6B curves toward the direction where temperature of the heater 68 becomes higher. Thus, similarly to the above example, in the case of letting the exhaust temperature decrease from the temperature MO, by setting the threshold of the rate of the temperature decrease of the heater 68 in accordance with the amount of the inhibitors which adhere to the holes of the cover 65 , the ECU 50 can determine whether or not the amount of the inhibitors which adhere to the holes of the cover 65 is larger than the amount of inhibitors corresponding to the threshold.
Fourth Embodiment
Next, the fourth embodiment of the present invention will be described below.
FIG. 8 is a configuration diagram showing a part of the exhaust passage of the internal combustion engine in the fourth embodiment. As shown in FIG. 8 , in the internal combustion engine in the fourth embodiment, the A/F sensor 42 is provided on the exhaust passage 14 at the downstream side of the filter 24 . Other part of the configuration is similar to the configuration ( FIG. 1 ) of the internal combustion engine in the first embodiment.
The filter 24 has a partition whose pores are open and collects the inhibitors in the exhaust gas by the partition by letting the exhaust gas pass through the partition. In the partition, oxidation catalysts such as platinum (Pt) and cerium oxide (CeO2) are supported and the inhibitors collected is oxidized by the oxidation catalysts. Therefore, when the filter 24 is functioning normally, the inhibitors do not almost adhere to the holes of the cover 65 of the A/F sensor 42 provided on the exhaust passage 14 at downstream side of the filter 24 .
In contrast, in the case where the function of the filter 24 which collects the inhibitors in the exhaust gas has decreased due to cracks of the partition, the inhibitors drains into the exhaust passage 14 at downstream side of the filter 24 . Hence, in this case, the inhibitors adhere to the holes of the cover 65 of the A/F sensor 42 provided on the exhaust passage 14 at the downstream side of the filter 24 and thereby the clogging occurs.
Hence, in the detection method for the internal combustion engine in the fourth embodiment, the ECU 50 calculates the temperature variation of the heater 68 of the A/F sensor 42 provided on the exhaust passage 14 at the downstream side of the filter 24 and, by using the detection method for the internal combustion engine in the first or the second embodiment, determines whether or not the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. Thereby it becomes possible to determine whether or not the filter 24 is functioning normally. Concretely, when determining that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs, the ECU 50 can determine that the function of the filter 24 has decreased, and when determining that the clogging in the holes of the cover 65 of the A/F sensor 42 does not occur, the ECU 50 can determine that the function of the filter 24 is functioning normally.
[Application]
Next, an application will be described below. In each of the above embodiments, the ECU 50 determines whether or not the clogging in the holes of the cover 65 occurs on the basis of the temperature variation of the heater 68 . These detection methods take advantage of the fact that the gas flow amount to the heater 68 in the case where the clogging of the cover 65 occurs is smaller than the gas flow amount to the heater 68 in the case where the clogging of the cover 65 does not occur.
In contrast, the gas flow amount to the heater 68 in the case where cracking in the cover 65 occurs is larger than the gas flow amount to the heater 68 in the case where the cracking in the cover 65 does not occur.
FIG. 9A , similarly to FIG. 3 , shows the graphs each of which indicates the time variation of the temperature of the heater 68 of the A/F sensor 42 . The graph 501 indicates the temperature variation of the heater 68 in the case where both the clogging and the cracking in the cover 65 of the A/F sensor 42 do not occur, and the graph 502 indicates the temperature variation of the heater 68 in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. The graph 503 indicates the temperature variation of the heater 68 in the case where the cracking in the cover 65 of the A/F sensor 42 occurs.
At the time t 1 , the ECU 50 stops the fuel injection by the fuel injection valve 5 thereby to stop the combustion in the cylinders 12 and lets the gas pass through the exhaust passage 14 from the intake air passage 13 .
At the time t 2 when a time period Δt predetermined has elapsed since the time t 1 , the temperature of the heater 68 , in the case where both the clogging and the cracking in the cover 65 do not occur, becomes L 2 a . In contrast, at the time t 2 , the temperature of the heater 68 , in the case where the clogging in the holes of the cover 65 occurs, becomes L 2 b (>L 2 a ) and the temperature of the heater 68 , in the case where the cracking in the cover 65 occurs, becomes L 2 bb (<L 2 a ).
As shown in FIG. 9A , the amount of the temperature decrease of the heater 68 over time becomes large because the amount of the gas flow to the heater 68 , in the case where the cracking in the cover 65 of the A/F sensor 42 occurs, is larger than that in the case where the cracking in the cover 65 does not occur.
Hence, in the detection methods for the internal combustion engine in the applications for each of the above embodiments, the ECU 50 not only determines whether or not the clogging in the holes of the cover 65 occurs but also determines whether or not the cover 65 has cracked on the basis of the temperature variation of the heater 68 .
In the application of the first embodiment, the ECU 50 not only determines whether or not the amount of the temperature decrease of the heater 68 is smaller than a predetermined clogging criterion value but also determines whether or not the amount of the temperature decrease is smaller than a predetermined cracking criterion value. Here, the cracking criterion value is a compatible value calculated by experimental trials and is set to a value which is smaller than the clogging criterion value. The ECU 50 determines that the cracking in the cover 65 occurs in the case where the amount of the temperature decrease of the heater 68 is smaller than the cracking criterion value, and determines that the cracking in the cover 65 does not occur in the case where the amount of the temperature decrease of the heater 68 is equal to or larger than the cracking criterion value. In other words, the ECU 50 determines that both the clogging and the cracking in the cover 65 of the A/F sensor 42 do not occur when the amount of the temperature decrease of the heater 68 is smaller than the clogging criterion value and equal to or larger than the cracking criterion value.
FIG. 9B , similarly to FIG. 63 , shows the graphs each of which shows the relationship between the temperature of the heater 68 and the exhaust temperature. The graph 601 is a graph showing the relationship between the temperature of the heater 68 and the exhaust temperature in the case where both the clogging and the cracking in the cover 65 of the A/F sensor 42 do not occur. The graph 602 is a graph showing the relationship between the temperature of the heater 68 and the exhaust temperature in the case where the clogging in the holes of the cover 65 of the A/F sensor 42 occurs. The graph 603 is a graph showing the relationship between the temperature of the heater 68 and the exhaust temperature in the case where the cracking in the cover 65 of the A/F sensor 42 occurs.
As shown in FIG. 9B , whereas the graph 601 is approximately linear, the graph 603 is curved toward the direction where the temperature of the heater 68 becomes lower. As indicated by the graph 601 , the temperature of the heater 68 , in the case where both the clogging and the cracking in the cover 65 of the A/F sensor 42 do not occur, varies at an approximately constant rate to the variation of the exhaust temperature. In contrast, as shown in the graph 603 , in the case where the cracking in the cover 65 of the A/F sensor 42 occurs, similarly to the case (see graph 602 ) where the clogging in the holes of the cover 65 occurs, the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature varies significantly.
For example, as indicated by the tangent lines IL 1 a , IL 2 a to the graph 603 , the gradient of the tangent line to the graph 603 becomes smaller and smaller as the exhaust temperature decreases from the temperature MO. In other words, as the exhaust temperature decreases from the temperature MO, the ratio of the temperature decrease of the heater 68 , in the case where the cracking in the cover 65 of the A/F sensor 42 occurs, becomes smaller and smaller.
Hence, in the application of the second embodiment, the ECU 50 determines how the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature gradually changes in the case where the ratio of the temperature variation of the heater 68 to the variation of the exhaust temperature is not approximately constant. Concretely, the ECU 50 determines that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs when the temperature of the heater 68 is changing toward the direction where the temperature becomes higher with the change of the exhaust temperature as indicated by the graph 602 . On the other hand, the ECU 50 determines that the cracking in the cover 65 of the A/F sensor 42 occurs when the temperature of the heater 68 is changing toward the direction where the temperature becomes lower with the change of the exhaust temperature as indicated by the graph 603 . For example, the ECU 50 determines that the clogging in the holes of the cover 65 of the A/F sensor 42 occurs in the case where the rate of the temperature decrease of the heater 68 is larger and larger as the exhaust temperature decreases from the temperature MO, and determines that the cracking in the cover 65 of the A/F sensor 42 occurs in the case where the rate of the temperature decrease of the heater 68 is smaller and smaller.
As described above, in the detection method in the application, it becomes possible not only to determine whether or not the clogging in the holes of the cover 65 occurs but also to determine whether or not the cracking in the cover 65 occurs on the basis of the temperature variation of the heater 68 . It goes without saying that in the above application whether or not the clogging in the holes of the cover 65 occurs is also determined, but instead of this, only whether or not the cracking in the cover 65 occurs may be determined.
MODIFICATION
In each of the above embodiments and the application, the ECU 50 detects the temperature of the heater 68 based on the impedance of the heater 68 and determine whether or not the clogging in the holes of the cover 65 (or the cracking of the cover 65 ) occurs on the basis of the amount of temperature variation of the heater 68 . However, instead of by using the temperature variation, by using an amount of impedance variation of the heater 68 , the ECU 50 may determine whether or not the clogging in the holes of the cover 65 (or the cracking of the cover 65 ) occurs. For example, in the first embodiment, instead of determining whether or not the temperature variation between the time t 1 and the time t 2 is smaller than the clogging criterion value, the ECU 50 may determine whether or not the impedance variation between the time t 1 and the time t 2 is smaller than the impedance corresponding to the clogging criterion value.
In addition, the present invention is not limited to what is applied to the A/F sensor, but also can be applied to other various sensors. Further, in each of the above embodiments and the application, the above detection method is executed in order to determine whether or not the clogging in the holes of the cover occurs, but it is not limited to this. Namely, by executing the above detection process for a sensor which does not have a cover, it is also possible to determine whether or not the inhibitors adhere directly to the sensor precisely.
For example, instead of the A/F sensor, the present invention can also be applied to a case where a temperature sensor is used. In this case, by using the detection method in the each of the embodiments and the application, the ECU 50 can determine whether or not inhibitors adhere to the temperature sensor on the basis of the temperature variation detected by the temperature sensor. Here, it goes without saying that the ECU 50 may determine whether or not the inhibitors adhere by using a variation of a signal output value (voltage value and/or current value) correlated with the temperature supplied from the temperature sensor instead of using the temperature variation.
It also goes without saying that the present invention is not limited what is applied to sensors but also applied to a temperature varying member whose temperature varies in response to the gas flow in the exhaust passage.
In addition, the present invention is not limited to the above embodiments and these can be accordingly changed in the range where the changes do not go against the gist or the ideas which can be seen in all of the claims and the specification and the embodiments to which the changes is applied is also included in the technical scope of the present invention.
INDUSTRIAL APPLICABILITY
This invention can be used for an internal combustion engine which includes a temperature varying member such as a sensor which varies in response to an exhaust temperature. | A detection device for an internal combustion engine is preferably applied to the internal combustion engine which includes a temperature varying member, which is provided in an exhaust system, and whose temperature varies due to gas flow in the exhaust system. A temperature correlation value detection unit detects a correlation value which correlates with the temperature of the temperature varying member. The term correlation value herein includes impedance of the temperature varying member, a signal output value such as current and voltage output sent from the temperature varying member, and/or the temperature varying member's own temperature. A variation calculating unit calculates a variation of the correlation value, in a time period when the gas flow arises, detected by the temperature correlation value detection unit. |
FIELD OF THE INVENTION
[0001] The present invention relates to a backlight control circuit with a protecting circuit, the backlight control circuit typically being used in a liquid crystal display (LCD).
GENERAL BACKGROUND
[0002] LCDs are widely used in various modem information products, such as notebooks, personal digital assistants (PDAs), video cameras and the like. Because liquid crystal in an LCD does not emit any light itself, a backlight system is usually needed to enable the LCD to display images.
[0003] A typical backlight system includes a plurality of backlight lamps, and a backlight control circuit. The backlight control circuit is used for feeding back currents of the backlight lamps, and protecting the backlight system when an open circuit occurs in any of the backlight lamps.
[0004] Referring to FIG. 3 , one such backlight control circuit 100 includes a pulse width modulation integrated circuit (PWM IC) 110 , an inverter circuit 130 , a backlight lamp unit 150 , a first feedback circuit 140 , a second feedback circuit 160 , and a protecting circuit 170 .
[0005] The backlight lamp unit 150 includes a first lamp 151 and a second lamp 152 . The first lamp 151 and the second lamp 152 both have a positive end and a negative end. The PWM IC 110 includes a signal output terminal 111 , a current feedback terminal 113 , a protecting output terminal 115 , and a voltage feedback terminal 116 . The signal output terminal 111 is connected to the inverter circuit 130 . The voltage feedback terminal 116 is connected to the first feedback circuit 140 . The current feedback terminal 115 is connected to the second feedback circuit 160 . The protecting output terminal 115 is connected to the protecting circuit 170 .
[0006] The inverter circuit 130 includes a signal input 131 , a first driving terminal 132 , and a second driving terminal 133 . The first driving terminal 132 and the second driving terminal 133 output an AC voltage to the positive ends of the lamps 151 , 152 respectively. A value of the AC voltage can be 1500V. The AC voltage at the first driving terminal 132 has a phase opposite to that at the second driving terminal 133 .
[0007] The first feedback circuit 140 includes two high voltage feedback inputs 141 and a high voltage feedback output 142 . The two high voltage feedback inputs 141 are connected to the positive ends of the lamps 151 , 152 respectively. The high voltage feedback output 142 is connected to the voltage feedback terminal 116 of the PWM IC 110 . The first feedback circuit 140 outputs a first feedback signal to the voltage feedback terminal 116 .
[0008] The second feedback circuit 160 includes a current input 161 and a low-voltage feedback output 162 . The current input 161 is connected to the negative ends of the lamps 151 , 152 . The low-voltage feedback output 162 is connected to the current feedback terminal 113 of the PWM IC 110 . The second feedback circuit 160 outputs a second feedback signal to the PWM IC 110 corresponding to the current at the negative ends of the lamps 151 , 152 .
[0009] The protecting circuit 170 includes a first resistor 171 and a capacitor 172 . One end of the first resistor 171 is coupled with the protecting output terminal 115 of the PWM IC 110 , and the other end of the first resistor 171 is grounded via the capacitor 172 . The first resistor 171 is used for controlling the charging time of the capacitor 172 .
[0010] When an open circuit occurs in any of the lamps 151 , 152 , the current input 161 feeds back the current of the lamps 151 , 152 , and the second feedback circuit 160 outputs a lower second signal to the PWM IC 110 . When the second signal is lower than a first reference voltage, the PWM IC 110 outputs a pulse-time ratio signal to increase the working voltage of the backlight unit 150 through the inverter circuit 130 . At the same time, the first feedback circuit 140 outputs the first signal to the PWM IC 110 . The PWM IC 110 compares the first signal with a second reference voltage. When the first signal is higher than the second reference voltage, the PWM IC 110 outputs a signal to charge the capacitor 172 via the protecting output terminal 115 . When the voltage of the capacitor 172 reaches a predetermined potential, for example 3 V, the PWM IC 110 stops the inverter circuit 130 from driving the backlight lamp unit 150 , so as to protect the backlight lamp unit 150 .
[0011] As described above, the inverter circuit 130 stops the backlight lamp unit 150 after a period of time has elapsed from the time when the PWM IC 110 outputs the signal to charge the capacitor 172 . During this period, the PWM IC 110 continuously increases the voltage difference between the lamps 151 , 152 . The voltage difference between the lamps 151 , 152 may increase and induce a spark discharge. The spark discharge is liable to destroy the backlight lamp unit 150 . Thus, the backlight control circuit 100 has low reliability.
[0012] It is, therefore, desired to provide a backlight control circuit that can overcome the above-described deficiencies.
SUMMARY
[0013] In an exemplary embodiment, a backlight control circuit includes a load, an inverter circuit, a pulse width modulation integrated circuit (PWM IC), a protecting circuit, and a feedback circuit. The load includes a plurality of backlight lamps. Each lamp includes a first terminal. The inverter circuit is configured to drive the load. The PWM IC is connected to the load via the inverter circuit. The PWM IC includes a protecting output. The protecting circuit is connected to the protecting output of the PWM IC. The protecting circuit has a reference voltage. The first feedback circuit is connected to the first terminals of the lamps, the PWM IC, and the protecting circuit. The first feedback circuit is capable of detecting voltage from the first terminals of the lamps. The first feedback circuit is capable of outputting a voltage to the protecting circuit. The output voltage is corresponded to the voltage detected from the first terminals. The protecting circuit is configured to control the PWM IC to stop outputting a backlight adjusting signal to the inverter circuit such that the inverter circuit stops driving the load when the output voltage is higher than the reference voltage of the protecting circuit.
[0014] Other novel features and advantages of the present backlight control circuit will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a diagram of a backlight control circuit according to an exemplary embodiment of the present invention.
[0016] FIG. 2 is a diagram of a backlight control circuit according to another exemplary embodiment of the present invention.
[0017] FIG. 3 is a diagram of a conventional backlight control circuit.
DETAILED DESCRIPTION OF EMBODIMENTS
[0018] Reference will now be made to the drawings to describe preferred and exemplary embodiments of the present invention in detail.
[0019] FIG. 1 is an abbreviated circuit diagram of a backlight control circuit according to an exemplary embodiment of the present invention. The backlight control circuit 200 is typically installed in a backlight system (not shown). The backlight system can be used together with an LCD, both being installed in a product such as a notebook, a PDA, a video camera, etc. The backlight control circuit 200 includes a PWM IC 210 , an inverter circuit 230 , a load 250 , a first feedback circuit 240 , a second feedback circuit 260 , and a protecting circuit 270 . The PWM IC 210 outputs a backlight correction signal to the inverter circuit 230 , and the inverter circuit 230 drives the load 250 to function. The first feedback circuit 240 is connected to the load 250 to feed back signals to the PWM IC 210 and the protecting circuit 270 . The second feedback circuit 260 outputs a signal to the PWM IC 210 corresponding to the current of the load 250 .
[0020] The load 250 includes a first lamp 251 and a second lamp 252 . Each of the lamps 251 , 252 has a first terminal and a second terminal. The PWM IC 210 includes a signal output end 211 , a current feedback end 213 , a protecting output 215 , and a voltage feedback end 216 . The signal output end 211 is connected to the inverter circuit 230 . The current feedback end 213 is connected to the second feedback circuit 260 . The voltage feedback end 216 is connected to the first feedback circuit 240 . The protecting output 215 is connected to the protecting circuit 270 .
[0021] The inverter circuit 230 includes a signal input end 231 , a first driving end 232 , and a second driving end 233 . The signal input end 231 is connected to the signal output end 211 of the PWM IC 230 . The first driving end 232 is connected to the first terminal of the first lamp 251 to supply a high alternating current (AC) voltage, and the second driving end 233 is connected to the first terminal of the second lamp 252 to supply another high AC voltage. A value of each high AC voltage can be 1500V. The two AC voltages have an opposite phase from each other.
[0022] The first feedback circuit 240 includes two high voltage detecting terminals 241 , and a feedback signal output terminal 242 . The two high voltage detecting terminals 241 are connected to the first terminals of the first and second lamps 251 , 252 , respectively. The feedback signal output terminal 242 is connected to the voltage feedback end 216 of the PWM IC 210 .
[0023] The second feedback circuit 260 includes a current voltage detecting terminal 261 . The current voltage detecting terminal 261 is connected to the second terminals of the lamps 251 , 252 .
[0024] The protecting circuit 270 includes a charging branch 1 , and a comparison circuit 272 . The comparison circuit 272 controls the charging branch 1 to be charged or discharged. The charging branch 1 includes a current-limiting resistor 271 , a switch element 278 , and a charging capacitor 279 . One end of the current-limiting resistor 271 is connected to the protecting output 215 of the PWM IC 210 . The other end of the current-limiting resistor 271 is grounded via the switch element 278 and the charging capacitor 279 in sequence. The switch element 278 is typically a diode, which includes a positive terminal connected to the current-limiting resistor 271 , and a negative terminal connected to the charging capacitor 279 .
[0025] The comparison circuit 272 includes a comparator 273 , a first resistance divider R 11 , a second resistance divider R 12 , and a reference voltage input terminal 277 . The comparator 273 has a positive input 274 , a negative input 275 , and an output end 276 . The reference voltage input terminal 277 is grounded via the first resistance divider R 11 and the second resistance divider R 12 . The positive input 274 is connected to a node between the first resistance divider R 11 and the second resistance divider R 12 , and is configured to set a first reference voltage which is greater than or equal to a second reference voltage of the PWM IC 210 . The negative input 275 is connected to the feedback signal output terminal 242 of the first feedback circuit 240 to receive the first feedback signal. The output end 276 is connected to a node between the switch element 278 and the charging capacitor 279 .
[0026] When an open circuit occurs in any of the lamps 251 , 252 of the load 250 , the current of the load 250 decreases. The second feedback circuit 260 sends a signal to the PWM IC 210 corresponding to the current. Then the PWM IC 210 provides a correction signal to the inverter circuit 230 . The inverter circuit 230 outputs a higher voltage to the load 250 . At the same time, the first feedback circuit 240 feeds back the voltage of the first terminals of the lamps 251 , 252 , and outputs voltage feedback signals to the PWM IC 210 and the protecting circuit 270 . While the voltage feedback signal is higher than the second reference voltage of the PWM IC 210 , the PWM IC 210 turns on its over voltage protection function. That is, the protecting output 215 of the PWM IC 210 outputs a charging signal to the charging capacitor 279 via the current-limiting resistor 271 and the switch element 278 . While the voltage feedback signal is higher than the first reference voltage of the comparison circuit 272 , the comparator 273 turns off the switch element 278 to cut off the charging branch 1 . Therefore the protecting output 215 reaches a predetermined potential, for example, 3V, immediately. The PWM IC 210 stops outputting the charging signal to the charging capacitor 279 and stops outputting a backlight adjusting signal to the inverter circuit 230 . The inverter circuit 230 turns off the load 250 to protect the load 250 from spark discharge.
[0027] The backlight control circuit 200 includes the comparison circuit 272 and the switch element 278 . The comparison circuit 272 receives the voltage feedback signal. When the voltage feedback signal is higher than the first reference voltage, the PWM IC 210 consequently stops outputting the backlight adjusting signal to the inverter circuit 230 . The inverter circuit 230 turns off the load 250 according to the dormant PWM IC 210 , so as to protect the load 250 from spark discharge. Therefore the backlight control circuit 200 has high reliability.
[0028] FIG. 2 is a diagram of a backlight control circuit 300 according to another exemplary embodiment of the present invention. The backlight control circuit 300 is similar to the above-described backlight control circuit 200 , only differing in that a charging branch 2 of a protecting circuit 370 includes a current-limiting resistor 371 , a switch element 378 , and a charging capacitor 379 . One terminal of the current-limiting resistor 371 is connected to a protecting output 315 of a PWM IC 310 . The other terminal of the current-limiting resistor 371 is grounded via the switch element 378 and the charging capacitor 379 in sequence. The switch element 378 is typically a negative-channel metal-oxide semiconductor (NMOS) transistor, which includes a source electrode, a gate electrode, and a drain electrode. The source electrode is connected to the comparison circuit 372 , the drain electrode is grounded, and the gate electrode is connected to the charging capacitor 379 . The NMOS transistor performs substantially the same function as the diode (switch element 278 ). Compared with the backlight control circuit 200 , the backlight control circuit 300 can achieve substantially the same function and advantages.
[0029] It is to be understood, however, that even though numerous characteristics and advantages of preferred and exemplary embodiments have been set out in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail within the principles of the present invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | An exemplary backlight control circuit includes a load ( 250), an inverter circuit ( 230), a pulse width modulation integrated circuit (PWM IC) ( 210), a protecting circuit ( 270), and a feedback circuit ( 240). The load ( 250) includes two backlight lamps ( 251, 252) with first terminals ( 241). The PWM IC with a protecting output ( 215) is connected to the load via the inverter circuit. The protecting circuit haves a reference voltage. The first feedback circuit is capable of outputting a voltage to the protecting circuit corresponding to the voltage detected from the first terminals. The protecting circuit is configured to control the PWM IC to stop outputting a backlight adjusting signal to the inverter circuit such that the inverter circuit stops driving the load when the output voltage is higher than the reference voltage of the protecting circuit. |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from German Patent Application No. 202 00 885.1, titled A SYRINGE PUMP HAVING A PISTON BRAKE, filed in Germany on Jan. 22, 2002, the entire contents of which is incorporated by reference herein as though set forth in full.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a syringe pump having a piston brake for controlled discharge of medical syringes.
[0003] From EP 0 566 825 A1 a syringe pump having a piston brake is known, which comprises a first holder for fixing the cylinder of a syringe and a linearly movable second holder for displacing the piston rod of the syringe.
[0004] A stationary piston brake engages the piston rod and, when the piston cylinder is inserted, blocks the piston rod until the piston rod has been gripped by the second holder. Thereby unintentional displacement of the piston rod caused by suction effect or mechanical movement prior to the start of infusion is prevented. Securing the piston rod after an exchange of syringes is of importance in particular for small syringes having small frictional forces.
[0005] Further, syringe pumps are known which allow an automatic exchange of syringes. For this purpose, a syringe holding head is provided which, after insertion of a syringe, scans said syringe and determines the syringe size. On the basis of the syringe size the displacement velocity and other parameters are automatically adjusted.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to provide a syringe pump having a piston brake, which, in the syringe position, requires only a simplified support.
[0007] In the syringe pump according to the invention the brake element is arranged on the syringe-position side opposite the drive rod, i.e., on the outside. The brake element is movable toward a syringe bearing arranged on the drive-rod side in order to impart the brake effect. Consequently, the syringe bearing is located on the drive-rod side which defines the inside. Against this syringe bearing syringes of various sizes may be placed for assuming a defined position suitable for the discharge process.
[0008] According to a preferred aspect of the present invention, the brake element is provided on a syringe holding head which is movable transversely to a syringe in the syringe position. Such a syringe holding head normally engages only the syringe cylinder. It serves as a holder which secures the syringe cylinder against displacement out of the syringe position. According to the invention, this syringe holding head is additionally provided with a brake element which acts upon the piston rod projecting out of the syringe cylinder. One advantage of this measure is that the piston brake is spatially related to the syringe cylinder, i.e., activation and deactivation of the piston brake require only a very small amount of displacement of the brake element. After closing of the syringe holding head and recognition of a proper syringe, the piston brake automatically imparts a braking effect until the motorized drive head has recognized and locked the piston plate of the syringe. Thereafter, the piston brake is released by displacing the brake element, wherein engagement of the syringe holding head with the syringe cylinder is however not released.
[0009] According to a preferred embodiment of the present invention, a linear drive for the brake element extends below the syringe position, wherein a motor is arranged on one side and the syringe holding head on the other side of the drive rod. The linear drive effects adjustment of the brake element from the drive-rod side, wherein the syringe is pulled against the syringe bearing which is also located on the drive-rod side.
[0010] Preferably, the brake element is provided on a syringe holding head, wherein a portion of the syringe holding head engages the syringe cylinder, and the brake element engages the piston rod. In this manner, the functions of syringe holding head and brake element can be combined in one unit.
[0011] According to a preferred aspect of the present invention, an actuating means for the brake element is arranged on a slide which is connected with the syringe holding head, and a sensor detecting the position of the slide is provided for the purpose of determining the syringe size. When the syringe holding head is manually removed to allow the syringe to be inserted, and is then placed against the syringe, the slide carrying the actuating means for the brake element moves together with the syringe holding head. When the syringe is in the syringe position, the sensor provides a position signal indicative of the syringe holding head position and thus the size (diameter) of the inserted syringe.
[0012] Preferably, the slide is connected via a tube with the syringe holding head, through which tube extends an axially movable rod for adjusting the brake element relatively to the syringe holding head. This configuration offers a particularly simple mechanism for adjusting the brake element relatively to the syringe holding head.
[0013] To definedly position the syringe in axial direction when the syringe is inserted into the syringe pump, a positioning means engaging a winglike syringe portion is provided according to a preferred aspect of the present invention, said positioning means being coupled with the syringe holding head such that it presses the winglike syringe portion axially against a stop wall when the syringe holding head radially approaches an inserted syringe.
[0014] The invention further relates to another embodiment of the syringe pump. Here, the brake element defining the piston brake is provided on a syringe holding head which radially presses the syringe cylinder against a syringe bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Hereunder an embodiment of the present invention is explained in detail with reference to the drawings in which:
[0016] [0016]FIG. 1 shows a plan view of a syringe pump with removed syringe holding head and with the locking means in the release position;
[0017] [0017]FIG. 2 shows a section along line II-II of FIG. 1;
[0018] [0018]FIG. 3 shows, in a similar representation as that of FIG. 1, the condition with properly inserted syringe and closed syringe holding head;
[0019] [0019]FIG. 4 shows a section along line IV-IV of FIG. 3;
[0020] [0020]FIG. 5 shows a section along line V-V of FIG. 3 with open arms of the drive head;
[0021] [0021]FIG. 6 shows the drive head of FIG. 5, wherein the arms are locked with the piston rod;
[0022] [0022]FIG. 7 shows a section along line VII-VII of FIG. 3; and
[0023] [0023]FIG. 8 shows a detail of FIG. 1, wherein the locking means for the syringe holding head is in the locking position.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The syringe pump is generally configured like that described in EP 0 566 825 A1 such that a general description of the overall device is omitted here. (EP 0 566 825 A1 was was published on Oct. 27, 1993 and is incorporated in its entirety by this reference.)
[0025] The syringe pump serves for discharging a syringe 10 which comprises a syringe cylinder 11 and a piston rod 12 .
[0026] The syringe cylinder 11 is provided at its open end with a projecting winglike syringe portion 13 , and the piston rod comprises at its end a piston plate 14 . The piston rod 12 has a cruciform profile made from ribs arranged perpendicularly to each other.
[0027] In the syringe position P the syringe 10 is placed against a laterally arranged syringe bearing 15 in such a manner that the winglike syringe portion 13 assumes a specified axial position. In this condition, the piston rod 12 is retracted from the syringe cylinder 11 , and the syringe cylinder 11 is filled with a liquid.
[0028] For moving the piston rod 12 a linearly movable drive head 16 is provided on the syringe pump, said drive head 16 being attached to an elongate drive rod 17 . The drive head can be moved toward the piston plate 14 to receive and lock the latter. According to FIG. 3, the drive head can be moved to the left for discharging the contents of the syringe 10 . On the drive rod 17 side a supporting bearing 18 is located upon which the piston plate 14 can rest when the piston brake is actuated.
[0029] On the drive rod 17 side a motor 20 having a vertical axis is arranged on a slide 19 . The motor 20 drives, via a worm wheel, a helical gear wheel 21 supported on the slide 19 . The gear wheel 21 is provided with a threaded bore which is in engagement with the thread of a spindle rod 22 . By rotating the gear wheel 21 the spindle rod 22 , which is secured against rotation, is axially displaced. Thus the spindle rod 22 defines a linear drive 23 .
[0030] A tube 24 extends, transversely to the longitudinal direction of the syringe 10 and below the drive rod 17 , from the slide 19 , through which tube 24 the spindle rod 22 extends. On the opposite side of the syringe 10 a syringe holding head 25 is fastened to the end of the tube 24 . On the tube 24 a helical spring 26 is located which is supported on the syringe bearing 15 associated with the housing of the syringe pump, and presses the slide 19 out of the syringe position. Since, on the other hand, the tube 24 is connected with the slide 19 , and at the end of the tube 24 the syringe holding head 25 is located, the syringe holding head is pressed against the syringe 10 which is in the syringe position P, thus pressing the syringe against the syringe bearing 15 . The syringe holding head 25 is rotatable about the axis of the tube 24 . The syringe holding head 25 comprises a handle knob 27 by means of which the syringe holding head 25 can be manually pulled away from the syringe and can be rotated.
[0031] The slide 19 is guided, transversely to the longitudinal direction of the syringe 10 in the syringe position P, in guide rails 28 , 29 . Next to this linear guide a sensor 30 configured as a potentiometer 31 is arranged. The tap 32 of the potentiometer 31 is adjusted by a slider 19 a connected with the slide 19 . In this manner, the electric resistance of the potentiometer 31 indicates the position of the slide 19 and thus the position of the syringe holding head 25 . The signal of the sensor 30 thus provides information on the syringe size and/or the syringe diameter with closed syringe holding head 25 .
[0032] The spindle rod 22 extends into the syringe holding head 25 and carries a brake element 33 which is configured as a cutting edge and arranged within the syringe holding head 25 , the tip of the cutting edge facing the syringe cylinder 11 . By operating the motor 20 the brake element 33 is moved between a retraction position (FIG. 1) and an active braking position (FIG. 3). In the braking position the brake element 33 , which moves along the winglike syringe portion 13 , engages the piston rod 12 to block any displacement of the piston rod 12 relative to the syringe cylinder 11 .
[0033] The syringe pump is further provided with an axial positioning means 35 which axially presses the winglike syringe portion 13 against a stop wall 36 . The positioning means 35 comprises a slider 37 which is guided, on two rods 38 , 39 , axially to the syringe 10 . The slider 37 projects into the path of the winglike syringe portion 13 . The slider 37 is fastened to two parallel rods 38 , 39 which extend parallel to the axis of the syringe 10 and are biased, by a spring 40 , toward the front, i.e., toward the outlet end of the syringe cylinder 11 . The rear ends of the rods 38 , 39 are controlled by a control means 41 connected with the slide 19 , since the control means 41 comprises an inclinded surface 42 acting as a cam. When the slide 19 is moved toward the syringe position P, the control means 41 push the plate 37 toward the rear, i.e., away from the stop wall 36 , such that the winglike syringe portion 13 can be positioned into the space created therebetween. When the syringe holding head 25 is then released, such that it is placed against the syringe cylinder 11 , the plate 37 is pulled forward by the spring 40 action, thereby pressing the winglike syringe portion 13 against the stop wall 36 thus causing the syringe cylinder 11 to assume an exact axial position.
[0034] The drive head 16 contains a piston plate sensor 40 which responds to the presence of a piston plate 14 thus communicating to the device that the drive head 16 has been moved to the piston plate 14 of an inserted syringe. The piston plate sensor 40 is arranged in a recess of the drive head 16 . The recess further contains controlled arms 42 , 43 which are pivotable about a pivot pin 44 and are movable toward each other to lock the piston plate 14 on the drive head.
[0035] For inserting a syringe 10 into the syringe pump the syringe holding head 25 is removed by pulling the handle knob 27 . Simultaneously, the positioning means 35 is brought into the open position. Now the syringe cylinder 11 can be inserted. Then the syringe holding head 25 is placed from outside against the syringe cylinder 11 . The spring 26 causes the syringe holding head 25 to press the syringe cylinder 11 against the syringe bearing 15 . When the syringe holding head 25 is placed against the syringe cylinder 11 , the plate 37 of the positioning means 35 presses the winglike syringe portion 13 against the stop wall 36 . When the syringe holding head 25 is released, the syringe is exactly positioned. The sensor 30 detects, on the basis of the position assumed by the slide 19 , the syringe size and provides a corresponding signal to the control means. When the advance velocity is determined, the syringe size is taken into consideration.
[0036] When the syringe holding head 25 is released, the motor 20 is put into operation such that the tip of the brake element 33 is moved out of the syringe holding head 25 and pressed against the piston rod 12 . Thus the piston rod 12 is fixed relatively to the syringe cylinder 11 .
[0037] Then the drive rod 17 is automatically moved such that the drive head 16 approaches the piston plate 14 . When the piston sensor 40 detects that the piston plate is correctly positioned, the arms 42 , 43 are actuated to lock the piston plate in the drive head 16 . Then the motor 20 is put into reverse to remove the brake element 33 from the piston rod 12 . Now the drive head 16 can be moved to discharge the syringe 10 .
[0038] It is further possible to provide a forced limitation of the movement of the slide 19 to secure the inserted syringe on the device. Such securing of the syringe can be particularly appropriate for PCA (patient-controlled analgesia). This is a kind of pain treatment. The securing prevents too high a drug dose from being administered to the patient by his/her own manipulation or manipulation of a third person. Forced limitation is effected by a locking means 47 comprising a shaft 50 which is rotatably supported, parallel to the slide 19 , on housing walls 48 , 49 , the shaft 50 having a rack-type toothing 51 on one side. Said toothing 51 can, by rotating the shaft 50 , be brought into engagement with a tooth segment 52 located on the slide 19 . When the toothed portions are in engagement with each other (FIG. 8), the slide 19 is blocked such that it cannot move. The shaft 50 can be rotated only with the aid of a special wrench which is inserted into a profiled opening (not shown) provided in the front wall 53 .
[0039] Although a preferred embodiment of the present invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made without departing from the spirit and scope of the present invention, as defined in the appended claims. | The syringe pump comprises a receiving position for a syringe. The piston plate of the syringe is moved by a drive head which is fastened to a drive rod. For locking the piston rod prior to fixing the piston plate in the drive head, a braking element is provided on a syringe holding head. The syringe holding head further serves for determining the respective syringe size. After placing the syringe holding head against a syringe cylinder, the brake element is actuated to temporarily engage the piston rod and fix it relatively to the syringe cylinder. |
BACKGROUND OF THE INVENTION
Since at least 1970, much effort has been expended to develop durable catalyst supports, for use in catalytic converters, which supports can be mass produced and which achieve long converter life. In recent years, metal supports have gained favor because they can be fabricated in any shape or size and the converter is about 20% smaller than the equivalent ceramic converter. When temperatures exceed 2000° F., metal converters do not melt down and plug the exhaust flow, as do ceramic converters. Furthermore, the metal supports used in honeycomb cores have approximately 90% open area, whereas ceramic cores have thicker cell walls and typically have approximately 70% open area, which generates a higher pressure drop.
Anticipated future applications will require materials that will withstand cyclic oxidation in exhaust environments in the range of 2300° F. Such future applications include recuperators for gas turbines, planned for automobiles in the late-1990s, catalytic combustors for gas turbines, and converters for spark-ignited internal combustion engines in which the converter is coupled directly to the cylinder head.
Another example of the need for materials which can function at high temperatures is in the area of diesel particulate traps, where the temperature can reach 2400° F. during regeneration, i.e. when carbon particles are burned off.
In addition to the need for supports which withstand high temperatures, there is a need for supports that can withstand oxidation from residual sulfur compounds found in many liquid fuels. Sulfur accelerates oxidation, and causes failure of the support, under hot cyclic conditions.
The prior art that relates to metal supports for catalytic converters culminates in U.S. Pat. No. 4,601,999, which describes a composition for a catalyst support, made by the hot-dip coating process for coating aluminum on ferritic stainless steel strip, which is subsequently rolled to foil. This composition is relatively resistant to hot cyclic corrosion, and it does not interact with the catalyst coating.
Another invention that describes the process for making an aluminium-coated base metal foil, for use as a catalyst support, is disclosed in U.S. Pat. No. 4,686,155, entitled "Oxidation Resistant Ferrous Base Foil and Method Therefore", which is also based on hot-dip coated aluminum on stainless steel.
Methods for making a metal strip into a finished catalytic converter are given in U.S. Pat. No. 4,576,800, "Catalytic Converter for an Automobile" and in U.S. Pat. No. 4,673,553, "Metal Honeycomb Catalyst Support Having a Double Taper". The metal strip is corrugated so that when it is wound into a spiral or folded back and forth upon itself, the corrugations form channels for the flow of gas. Before the strip is wound or folded it is coated with catalytic materials or heat resistant materials, depending on the application.
U.S. Pat. No. 4,711,009, "Process and Apparatus for Making Metal Substrate Catalytic Converters", describes a continuous process for producing converters made with a metal catalyst support.
Both U.S. Pat. No. 4,601,999 and U.S. Pat. No. 4,686,155 contemplate a hot-dipped aluminum coating on a ferritic stainless steel strip at least 0.020 inch thick followed by reduction to foil thickness by rolling the coated strip. This process has a number of disadvantages, which are outlined below. Also noted below are the means by which the present invention overcomes the limitations of the prior art.
1. The hot-dip process sometimes leaves the coated foil with an uneven aluminum coating along its length and across its width. Indeed, the thickness of the coating can be as low as zero, and as high as 400 microinches or more, on the same coil of 0.0025 inch thick foil. The variations in thickness occur in spots or streaks where the aluminum does not cover the underlying steel.
One of the causes for the variation in thickness is that the aluminumis softer than the steel. Because the thickness of the steel varies, the softer aluminum becomes the repository of the initial non-uniformity of both the stainless steel and the aluminum coating. Another cause of a non-uniform aluminum coating is hard spots in the stainless steel, or inclusions, such as lumps of oxide, or the like, that do not roll to foil as readily as the balance of the steel.
In the present invention, the steel is first rolled to foil thickness and then is coated with aluminum by vapor deposition. Hot-dip coating of the foil is not practical because the thin foil would dissolve, at least partly, in the aluminum. The vapor-deposited coating is uniform, even if the surface of the base metal is uneven. This uniformity is analogous to that of a snowfall, which uniformly coats both smooth and rough pavement.
2. In the the hot-dip process no more than 3% aluminum and 1% silicon can be included in the base metal. Otherwise, the base metal is not wetted by molten aluminum. This limitation of the prior art eliminates many high temperature base metals from consideration. According to the present invention, the base metals to be coated need only be (a) thin and in roll-form, (b) reasonably smooth, and (c) able to be heat treated to 1200°-140020 F. to form an aluminum oxide film on the surface. Many base metals, besides ferritic stainless steel, can be used, such as austenitic stainless steel, martensitic stainless steel, superalloys, titanium, and composite materials including composites of metals and ceramics.
3. In the prior art, wherein the hot-dip coating process is used, the foil is work hardened by the many passes through a rolling mill. Intermediate annealing between rolling mill passes is not practical because the aluminum coating would develop an oxide film which is hard and abrasive and unsuitable for rerolling. When the base metal is first rolled to foil thickness and then coated with aluminum, the foil can be bright annealed (in a non-oxidizing atmosphere) before coating it with aluminum. This is important because high performance alloys can be made relatively ductile by a final annealing after they have been rolled to foil thickness.
4. In the hot-dip coating process of the prior art, annealing the aluminum-coated foil before corrugating would oxidize the aluminum coating. The aluminum oxide thus formed would crack and also would abrade the corrugating rolls. The cracks expose the underlayers of the support and thereby open sites of potential corrosion. When the foil is annealed before it is coated with aluminum, the foil is corrugated in a ductile state so that a minimum of stress centers are created in the catalyst support. Further, the aluminum surface does not abrade the corrugating rolls, but instead it serves as a lubricant.
5. In the hot-dip coating process, the thick aluminum-coated steel strip undergoes as many as 10 passes through a rolling mill. During the rolling, the rolls embed in the soft aluminum any dirt that has accumulated on the surface of the rolls. In the finished foil, this embedded dirt becomes the source of corrosion sites, just as do the stress centers mentioned earlier. Oil used in rolling is hard to remove and, if heated, tends to leave a film which lessens the adherence of the catalyst coating.
6. In the hot-dip coating process, the molten aluminum dissolves iron from the strip that is being coated. The amount of iron that is typically alloyed with the molten aluminum is 2-4%, by weight, which subsequently becomes part of the aluminum coating on the same strip. In the end product foil, this results in impurities, which reduce the corrosion resistance. Also, the iron-aluminum coating is less ductile than a pure aluminum coating and is less suitable for corrugating. In the present invention the aluminum used to coat the surfaces of the catalyst support contains no unwanted alloys or impurity.
7. According to the present invention, the base material is not limited to metals, but can include ceramics, high-temperature composite materials comprised of metals, ceramics, silicates, nitrides, borides, and refractory-metal oxides, or a combination, any of which can be coated with aluminum, heated to a temperature high enough to form an aluminum oxide coating (nominally 1400° F.), and subsequently processed to make an end product that heretofore was limited to use of metal alone.
The following is a list of references dealing with the field of the present application. These items, and the patents and patent applications cited above, are incorporated by reference herein:
Oxidation of Metals & Alloys, Butterworths, by Dr. O. Kubaschewski and B. E. Hopkins, 1962.
Handbook On Thin Film Technology, McGraw Hill, Edited by L. I. Maissel & R. G. Lang, 1970.
Source Book On Materials For Elevated-Temperature Applications, American Society for Metals, by E. F. Bradley, 1975.
High-Temperature Protective Coatings, Conference Proceedings, The Metallurgical Society of AIME, Edited by Subhash C. Singhal, 1983
Ferritic Steels for High-Temperature Applications, American Society for Metals, Edited by Ashok K. Khare, 1983
Vapor Deposition, The Electrochemical Society, Inc., Edited by C. F. Powell, J. H. Oxley and J. M. Blocher, Jr., 1983
High Temperature Alloys: Theory and Design, The Metallurgical Society of AIME, Edited by J. O. Stiegler, 1984
High-Temperature Ordered Intermetallic Alloys, Materials Research Society, C. C. Koch, C. T. Liu, N. S. Stoloff, 1984
Thin Films: The Relationship of Structure to Properties, Materials Research Society, Editors Carolyn Rubin Aita and K. S. SreeHarsha, 1985
Engineers' Guide to Composite Materials, American Society for Metals, Edited by John W. Weeton, 1987
SUMMARY OF THE INVENTION
This invention provides a new series of compositions for use as catalyst supports, and a method of making such compositions. The compositions of the invention are useful as honeycomb cores for catalytic converters in automobiles, but can also be used in other contexts. The composition of the invention includes a base material which can be metal or ceramic. The composition can also be a composite material comprising one or more of metal, ceramics, silicates, nitrides, borides, graphite and refractory-metal oxides.
According to the invention, the base material is coated with a thinlayer of aluminum, of substantially uniform thickness, by a process of vapor deposition. A stabilizer, selected from the group consisting of zirconium, yttrium, hafnium, and the rare earth metals, may be added to the aluminum. The vapor deposition technique produces a uniform coating, regardless of the roughness of the base material. Because aluminum vapor can be deposited on a metal of virtually any thickness, it is feasible to roll a base metal to the thickness of a foil before applying the aluminum coating.
Thus, a major advantage of the invention is the elimination of the requirement that the base material be chosen from those materials to which molten aluminum will adhere, or to those materials which can be easily rolled to foil after being coated. The base material need only be a material capable of withstanding the temperatures expected during operation of the catalytic converter or other device.
The present invention is especially useful in making aluminum-coated metal foils for catalytic converters for automobiles. But the invention has uses beyond catalytic converters. The same surface that binds a catalytic coating to it will also bind to itself a heat-resistant coating. Thus, the new composition can be used as cores in products such as diesel traps or recuperators that operate at high temperatures. It can also be used as a catalyst display surface for chemical processes.
It is therefore an object of this invention to provide a new series of compositions for use as catalyst supports.
It is another object to provide a catalyst support that can survive in very high temperatures in corrosive atmospheres.
It is another object to provide a catalyst support in the form of a foil or thin film.
It is another object to provide a catalyst support for use in catalytic convertres for automobiles.
It is another object to provide a catalyst support for making high temperature cores for diesel traps, recuperators and similar products.
It is another object to provide a method of making a catalyst support.
It is another object to expand the number of materials which can be used in making catalyst supports, and thereby to reduce the expense of such supports.
Other objects and advantages of the invention will be apparent to those skilled in the art, from a reading of the following detailed description of the invention and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the invention comprises a metal strip that is made or processed to a thickness of 0.001 to 0.010 inches and then is coated with aluminum or an aluminum alloy. A relatively thick strip can be passed through a rolling mill and rolled to gauge to provide the base material.
There are various methods for forming a metal foil that is to be coated with aluminum. These include the following:
1. A thick strip of metal can be rolled to foil thickness as described above.
2. A curtain of molten metal can be made to impinge on a cooled roller that rotates at high speed. The metal solidifies on the cold surface of the roller to form the foil. The time for solidification is only about one millisecond, and the rate of cooling is about one million degrees centigrade per second. The foil can be as thin as 0.001 inch. The foil is continuously peeled off the cooled roller and is wound into coils. At such high rates of cooling, the metal is amorphous, instead of crystalline, as it would be at slower cooling rates. This method was pioneered for making cores for electric power transformers. Now, it is being used to form foils from alloys that cannot be made by conventional slow cooling.
3. The cooled roller need not have a smooth surface, but instead the surface can be corrugated. This produces a foil that is already corrugated.
The surface of the foil produced by any of these methods can be given increased corrosion resistance by implanting a thin coating of, for example, TiN, TiC, ZrN, CrN, and Al 2 O 3 . The thickness of this coating is only a few micrometers, which is thinner than the aluminum coating to be applied later. One method of implanting these coatings is by the cathodic arc method. To form a coating of TiN, titanium ions are formed at the cathode in low-pressure nitrogen. The titanium ions react with the nitrogen to form the nitride, still ionized, which implants itself in the surface of the catalyst support. Such coatings have been applied to cutting tools and to blades for gas turbines. These coatings are not wetted by molten aluminum, but they can be coatd with aluminum by vapor deposition, according to the invention. In addition to metal foils, other materials that can be coated with aluminum by vapor deposition include screens woven from fibers of metal or ceramic, or both.
Vapor deposition can be done by various means, such as are described in the following examples:
1. A tungsten filament is heated with an electric current, and the heat is radiated into a pool of molten aluminum. This is called thermal vaporization.
2. The pool of aluminum is heated by electrical induction or with an electron beam. This is another example of thermal vaporization.
3. In the process called sputtering, the bulk of the aluminum to be vaporized is not heated, but instead an electric arc is struck from the surface of the aluminum. The arc moves rapidly over the surface of the aluminum, and the spot being heated at any instant is tiny, only a few micrometers in diameter. Metal is evolved from the surface as metal ions, in contrast to thermal vaporization, where the metal is evolved as uncharged atoms. Sputtering occurs at low vacuum, so that the mean free pathof the metal ions is restricted by collisions with the gas molecules. The metal ions do not travel in straight lines to the target that is being coated. Because of this fact, sputtering is a preferred method for coating a rough surface. Thermal vaporization occurs at high vacuum and the metal atoms travel to the target along straight lines.
4. In chemical vapor coating, a compound of the coating metal is decomposed on the surface of the target. This process is not preferred in the present invention because there are no compounds of aluminum that readily decompose to the metal.
All embodiments of the invention comprise coating a thin strip with aluminum by vapor deposition. There are some compositions of aluminum-coated metal foil that can be made by this invention, but which cannot be made by the hot-dip method of the prior art. These compositions comprise:
(1) Metals that cannot be rolled to foil thickness;
(2) Metals that are not wetted by molten aluminum; and
(3) Metals that cannot be rolled to foil thickness, and also are not wetted by molten aluminum.
As explained in U.S. Pat. No. 4,601,999, when the metal to be coated contains more than about 3% aluminum, or more than about 1% silicon, it is not readily wetted by molten aluminum, and it is also difficult to roll the metal down to foil thickness. Therefore, the metals used in the above-cited patent must be limited to alloys which do not exceed these limits.
Another example of a material which is not readily wetted by molten aluminum, and which is not readily rollable to foil, is the class of alloys called "superalloys". Superalloys are used for blades for gas turbines, where temperatures and stresses are increasing year by year. An example of a superalloy is Nimonic 115, and has the following composition:
______________________________________ Weight (%)______________________________________Carbon 0.15Chromium 15.0Cobalt 15.0Molybdenum 3.5Aluminum 5.0Titanium 4.0Nickel balance______________________________________
Such an alloy cannot be rolled to a foil thickness. A foil could be made by solidifying a curtain of the molten alloy on a coated roller, as just described. The foil so formed could be coated by vapor deposition.
The first step in making a catalyst support according to this invention is to select the base material that is to be coated with aluminum. Any of the metals disclosed in U.S. Pat. No. 4,601,999 can be used as a base material. As stated above, the primary criterion for selection of a material is its ability to withstand elevated temperatures. Thus, it is possible to use many other materials, besides those disclosed in the above-cited patent.
While the metals used in the above-cited patent are limited to the ferritic steels (having no significant amounts of nickel), the present invention is not so limited. Stainless steels that contain nickel as well as chromium can be made into catalyst supports by the method of this invention, but not by the hot-dip process of the prior art. The reason is that these steels work harden so rapidly that they must be annealed at least once during the rolling process. Annealing causes the aluminum to combine with the nickel to form a brittle crust that flakes off in the next pass through the rollers.
Nickel-bearing stainless steels can be rolled to foil thickness, with annealing, and then coated with aluminum by vapor deposition. These nickel-bearing stainless steels comprise the austenitic series. Typical compositions are:
______________________________________AISI NO. % Chromium % Nickel______________________________________202 17-19 4-6304 18-20 8-10314 23-26 19-22______________________________________
These austenitic stainless steels have good oxidation resistance, and are promising candidates for catalyst supports, when coated with aluminum. But they must be rolled to foil thickness first and then coated with aluminum, by the method of this invention.
After the base material has been selected, the next step is to coat the material on both sides with a film of aluminum or an aluminum alloy. The preferred process is vapor deposition with thermal vaporization of the aluminum. The aluminum is vaporized continuously under high vacuum. The atoms of aluminum travel in straight lines to the target upon which they are deposited. The thickness of the coating is proportional to the time of exposure and to the rate of metal vaporization. The atoms of vaporized aluminum will travel to the target along straight lines only if they do not collide with residual gas molecules during their flight. There will be no collisions if the pressure of the residual gas is low enough, and this means pressures of about 10 -5 Torr.
The aluminum to be vaporized is fed as a wire to the electrically-heated vaporizer. The wire is vaporized as fast as it is fed, so that the rate of feed determines the rate of vapor generation. The foil being coated is continuously unwound from one reel, and coated and rewound onto a take-up reel. Both reels are normally located inside the vacuum chamber.
The coating deposited by vapor deposition is uniform, even if the surface of the base material is uneven or has hard inclusions in it. The coating of the base material uniformly with aluminum is analogous to that of a snowfall, in which snow uniformly coats both smooth and rough pavement.
The surface to be coated with aluminum must be clean. In the case of coating a metal foil, the foil is cleaned in several steps. The first step is vapor degreasing the foil to remove residual oils from the process of cold rolling to foil thickness. The second step is to mechanically scrub the surface of the foil to remove solid particles, followed by a rinse. Cleanliness of the foil is essential for good coating adherence.
The thickness of the foil used to make a honeycomb is governed by the cell density, which is dictated by the mass transfer and flow considerations and the need for structural rigidity. The following table shows typical foil thicknesses relative to various cell densities of the honeycomb:
______________________________________Cells Per Square Inch Foil Thickness, Inches______________________________________ 20 .010 40 .005 80 .005160 .005320 .0025500 .002______________________________________
The use of aluminum, as an alloying element in base metals to improve their resistance to hot cyclic oxidation, is well established. By the present invention, ceramics, and composites of metal and ceramic, can also be coated with aluminum, as practiced in microelectronic circuitry. The suface coating of aluminum (a) diffuses into the base material when it is heated to about 1400° F. or more, thus anchoring itself to the base material, (b) forms an aluminum oxide surface, which is porous, so that it binds the catalyst coating or some other coating, and (c) serves as a corrosion inhibitor because aluminum oxide does not crack or spall at high temperatures in corrosive atmospheres.
The thickness of the aluminum coating is about 150 to 330 micro-inches with a preferred range of about 220 to 280 microinches. A base metal that contains no aluminum will be given a thicker coat than a base metal that already contains some aluminum. The weight of the aluminum in the starting base metal plus the weight of aluminum in the coating should be about 5-10%, and preferably about 6-8%, of the weight of the coated support.
A feature of the invention is the uniformity of the thickness of the coating. The standard deviation in the thickness is no more than about 10 microinches. Such uniformity is not obtained by the hot dip method of coating.
As described above, the base metal may be coated with a thin layer of TiN, TiC, ZrN, CrN, or Al 2 O 3 , to improve its corrosion resistance.
The base metal, whether or not previously coated as described above, is coated with aluminum, initially of 99.9% purity, alloyed with one or more rare earth metals such as cerium, or with yttrium, hafnium, or zirconium. The metal or metals selected from this group will be referred to as a "stabilizer", because it has the effect of stabilizing the coating chemically and structurally in thermal-cycling environments.
The stabilizer metals are selected such that the the sum of their percentages, by weight, in the aluminum coating, is less than about 1.0%.
U.S. Pat. No. 3,920,583 discloses that yttrium helps to anchor the surface coating of alumina. U.S. Pat. No. 4,277,374 discloses that hafnium can be substituted for yttrium, and is cheaper besides. In both of these patents, the alumina coating was formed from aluminum contained in the base metal core, there being no additional coating of aluminum on the surface. The yttrium or hafnium was also contained in the base metal core, and only that fraction of them that diffused to the surface would help anchor the alumina coating. By including the yttrium or hafnium in the aluminum coating instead of in the base metal core, one expects to obtain the same anchoring effect with less yttrium or hafnium.
The amount of yttrium or hafnium cited in these patents did not exceed about 2%. When the stabilizer is included in the coating, 1% should be sufficient.
The usefulness of stabilizers has been established in the reference literature. Stabilizers have been used successfully for coating aircraft cast parts to prevent degradation in hot cyclic corrosive atmospheres. A cycling temperature is destructive because the coefficients of thermal expansion of the base material and of the aluminum oxide coating are widely different, thus tending to open fissures.
The stabilizer metal need not be soluble in aluminum at room temperature. Thus, it need not be fed to the vaporizer already alloyed with aluminum, in a single wire. Instead, the stabilizer metal can be fed to its own vaporizer as a separate wire or powder.
After a flat foil has been coated with aluminum, it is corrugated with rollers, as described in U.S. Pat. No. 4,711,009, cited above. After being corrugated, the foil is heat treated. The heat treatment serves three functions: (a) to stress relieve the metal so that is holds its shape, and does not relax at the temperatures that it will encounter in use, (b) to oxidize the aluminum coating to form an aluminum oxide layer, and (c) to cause the aluminum to diffuse into and thereby anchor itself to the base material.
The temperature at which the metal is heat treated after it has been aluminum-coated and corrugated is as high as the maximum temperature the end-product will see in service. The metal must see this service temperature for at least 5 seconds before it is finally assembled into the end product. When the service temperature is uncertain, the following heat treat schedule is used:
______________________________________ Holding Time at TemperatureTemperature (°F.) (Minutes)______________________________________1400 1.01600 0.31800 0.1______________________________________
These holding times are approximate and can be varied by about 10%.
If the foil was made by the rapid cooling of molten metal on a corrugated roller, the process is simplified. The foil is already annealed and corrugated, and is ready for coating with aluminum. After the coating step, the foil must be heat treated to oxidize the aluminum coating and form the porous surface that binds the catalyst coating. This heat treatment need not be sufficient to relieve stresses, so that the temperatures can be lower than those given previously.
The base material, thus coated with aluminum, and heat treated, is now ready to be coated with a catalyst. U.S. Pat. No. 4,711,009, cited above, describes a method for applying a catalytic coating to the support. However, the present invention contemplates the application of other coatings for various applications, including temperature resistant coatings consisting of commercially available products containing, for example, various silicates, and adsorbent coatings such as zeolites.
As described above, it is apparent that the invention can be modified in many ways. Many different materials can be coated by a vapor deposition technique. While the preferred embodiment of the invention employs metal as the base material, non-metallic materials can also be used. Other variations in the composition of the base metal, and in the composition of the aluminum coating, can be made. Such modifications are understood to be within the spirit and scope of the following claims. | This invention relates to catalyst supports, such as are used in catalytic converters for vehicles, and in other applications, such as diesel particulate traps. The invention discloses a novel composition for a catalyst support, and a method of making it. The support includes a base material, such as a stainless steel. If the base material is a metal, it can be rolled down to the thickness of a foil and then coated with a layer of aluminum. The coating is done by a vapor deposition technique, so that the aluminum coating is thin and substantially uniform. The base material can be almost any substance capable of withstanding the high temperatures expected in the catalytic converter or other application. Because the material is already of foil thickness when it is coated, it is not necessary to select a material which is capable of being rolled down after being coated with aluminum. Thus, the invention makes it possible to use a much wider variety of materials than have been used in the prior art. |
CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This application claims priority to Swedish Application No. 0900847-5 filed Jun. 23, 2009, which is incorporated by reference herein.
TECHNICAL FIELD
[0002] This disclosure relates to a drilling tool intended for chip removing machining and of the type that includes a basic body having front and rear ends, between which a first center axis extends around which the basic body is rotatable in a given direction of rotation. Further, the drilling tool includes a loose top having front and rear ends, between which a second centre axis extends. The front end of the loose top includes one or more cutting edges. The front end of the basic body includes a jaw between two axially protruding, peripherally situated branches that are elastically bendable and have the purpose of resiliently clamping the loose top in the jaw. Specifically, a pair of inner support surfaces of the branches resiliently presses against a pair of external side contact surfaces of the loose top. Further, the branches have the purpose of transferring torque to the loose top via tangential support surfaces of the branches and cooperating tangential contact surfaces of the loose top. The inner support surface of the individual branch extends between first and second, tangentially separated side borderlines. The first tangentially separated borderline is heading and the second tangentially separated borderline is trailing during rotation of the tool. The individual side contact surface extends between first and second side borderlines. The second side borderline is rotationally trailing and is included in an edge to a trailing part surface, besides which the loose top is axially insertable into the jaw and turnable into and out of an operative engagement with the branches.
[0003] Drilling tools of the kind in question are suitable for chip removing or cutting machining, especially hole making of workpieces of metal, such as steel, cast iron, aluminium, titanium, yellow metals, etc. The tools may also be used for the machining of composite materials of different types.
BACKGROUND ART
[0004] In the discussion of the background that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
[0005] Drilling tools have been developed that, contrary to solid drills, are composed of two parts, including a basic or drill body and a head detachably connected with the same and thereby being replaceable. The head includes the requisite cutting edges. In such a way, the major part of the tool can be manufactured from a comparatively inexpensive material having a moderate modulus of elasticity, such as steel, while a smaller part, the head, can be manufactured from a harder and more expensive material, such as cemented carbide, cermet, ceramics and the like, which gives the cutting edges a good chip-removing capacity, a good machining precision and a long service life. The head forms a wear part that can be discarded after wear-out, while the basic body can be re-used several times, for example, 10 to 20 replacements. A now recognized term for these cutting edge-carrying heads is “loose tops”, which henceforth will be used in this document.
[0006] Loose top type drilling tools have a plurality of desired capabilities, one of which is that torque should be transferable in a reliable way from the rotatable, driven basic body to the loose top. Furthermore, the basic body should without problems be able to carry the rearwardly directed axial forces that the loose top is subjected to during drilling. Further, the loose top should be held centered in an exact and reliable way in relation to the basic body. Also, the loose top is clamped to the basic body not only during drilling of a hole, but also during retraction of the drilling tool out of the same. A user further desires that the loose top should be mountable and dismountable in a rapid and convenient way without the basic body necessarily having to be removed from the driving machine. In addition, the tool, and in particular the loose top manufactured from expensive materials, should be capable of low cost manufacture.
[0007] A loose-top tool intended for drilling and of the initially generally mentioned kind is previously known by EP 1013367. In this case, the two branches of the basic body are arranged to be turned into arched pockets, which are recessed in the rear part of convex envelope surfaces of two bars included in the loose top and separated by chip flutes, and which have a limited axial extension that in turn limits the maximally possible length of the branches. The internal support surfaces of the branches and the external side contact surfaces of the loose top, which are pressed against each other in order to resiliently and securely pinch the loose top in the jaw between the branches, have a rotationally symmetrical basic shape. The external side contact surfaces of the loose top generally have a larger diametrical dimension than the inner support surfaces of the branches in order to bend out the branches elastically or resiliently. In their angle-wise end position of turning, the rotationally heading, torque-transferring tangential support surfaces of the branches should be pressed into close contact against two tangential contact surfaces that form end surfaces in the two pockets in the loose top.
[0008] The tool of EP 1013367 is meritorious in several respects, one of which is that the axial support surface that is situated between the branches and forms a bottom in the jaw of the basic body does not need to be intersected by any slot or cavity in which chips could get caught. Another merit is that the loose top can be made fairly short in relation to its diameter, something that is material-saving and cost-reducing. In addition, the axial contact surface of the loose top as well as the axial support surface of the basic body extends between ends that are peripherally situated. In such a way, these surfaces become ample and thereby suitable to transfer great axial forces.
[0009] A disadvantage of the known tool is, however, that the mounting of the loose top in the jaw of the basic body risks becoming unreliable and cumbersome to carry out. Already when the two branches initially begin to be turned into the appurtenant pockets in the loose top, the branches are subjected to a clamping force that from then on becomes equally great during the entire rotary motion up to the end position in which the branches are pressed against the end surfaces of the pockets. Because the mounting is carried out in a manual way and the branches are held resiliently clamped against the side contact surfaces of the loose top by a force that is equally great during the entire rotary motion, it may become difficult for the operator to determine whether the loose top has reached its end position or not. This decision is made more difficult by the fact that the uniform clamping force has to be fairly great in order for the loose top to be clamped reasonably reliably. This means that the work with the turning-in becomes laborious, and therefore the operator, particularly when in a hurry, may unintentionally finish the turning-in too early, before the loose top has reached its end position in the jaw. Incorrect mounting of the loose top may, among other things, manifest itself in lost centering of the drilling tool in connection with the entering of a workpiece.
SUMMARY
[0010] The present disclosure aims at obviating the above-mentioned disadvantages of the known drilling tool and at providing an improved drilling tool. An object is accordingly to provide a drilling tool, in which the loose top and the cooperating jaw of the basic body are formed in such a way that the operator, in a tactile and/or auditory way, clearly perceives when the loose top reaches its end position during the turning-in. Another object is to provide a drilling tool, the loose top of which can be turned into the jaw of the basic body without the branches constantly subjecting the loose top to a great clamping force and thereby a great, uniform resistance during the entire turning-in operation. Still another object is to provide a drilling tool, the loose top of which is held reliably clamped in the jaw of the basic body, for example, by utilizing the inherent elasticity of the branches in such a way that an optimal grip on the loose top is provided. A further object is to provide a drilling tool, the loose top of which has a minimal length, and thereby a minimal volume, in relation to its diameter, all with the purpose of reducing the consumption of expensive material to a minimum in connection with the manufacture of the loose top. It is also an object to provide a drilling tool where the basic body can transfer great torques to the loose top. Still another object is to provide a drilling tool in which the loose top is centered and retains its centricity in an accurate way in relation to the basic body.
[0011] An aspect of the invention provides a drilling tool for chip removing machining, including a basic body having front and rear ends, between which a first center axis extends around which the basic body is rotatable in a given direction of rotation, and a loose top having front and rear ends, between which a second center axis extends, the front end including one or more cutting edges. The front end of the basic body comprises a jaw between two axially protruding, peripherally situated branches that are elastically bendable. The branches are capable of resiliently clamping the loose top in the jaw by inner support surfaces of the branches being resiliently pressed against external side contact surfaces of the loose top, and capable of transferring torque to the loose top via tangential support surfaces of the branches and cooperating tangential contact surfaces of the loose top. The inner support surface of the individual branch extends between first and second tangentially separated side borderlines, the first tangentially separated side borderline is heading and the second tangentially separated side borderline is trailing during rotation of the tool. The individual side contact surface extends between first and second side borderlines, the second side borderline that is rotationally trailing is included in an edge to a trailing part surface, besides which the loose top is axially insertable into the jaw and turnable into and out of an operative engagement with the branches. A second imaginary diametrical line, which extends perpendicular to the second center axis of the loose top between abutting edges that abut the second side borderline of each of the two side contact surfaces, has a length that is greater than the length of an analogous first diametrical line, which extends the shortest possible distance between the inner support surfaces when the branches are unloaded, and has opposite end points located at tangential distances from the first tangentially separated side borderline and the second tangentially separated side borderline of the respective inner support surface.
[0012] The side contact surfaces of the loose top with edges, in combination with a suitably selected distance between the inner support surfaces of the branches, upon the turning-in provides a successively increasing deflection of the branches up to a predetermined dead or intermediate position. At the predetermined dead or intermediate position the clamping force is maximal, so as to then decrease during the continued turning a short distance further until the end position is reached. During the final phase of the rotary motion between the dead position and the end position, the clamping force in the branches assists in rapidly bringing the loose top to the end position. This may manifest itself in either a tactile perception in the fingers of the operator or a click sound being audible to the ear, or a combination of these manifestations.
[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Particular embodiments of the invention will be described in more detail below, reference being made to the appended drawings, on which:
[0015] FIG. 1 is a sectioned perspective view showing the basic body and loose top of an embodiment of the drilling tool in the composed state,
[0016] FIG. 2 is an exploded perspective view showing the drilling tool of FIG. 1 where the loose top is separated from the basic body,
[0017] FIG. 3 is an enlarged exploded view showing the drilling tool of FIG. 1 where the loose top is shown in a bottom perspective view and the front end of the basic body is shown in a top perspective view,
[0018] FIG. 4 is an exploded view showing the basic body and the loose top of FIG. 1 in side elevation,
[0019] FIG. 5 is an end view V-V in FIG. 4 showing the front end of the loose top,
[0020] FIG. 6 is an end view VI-VI in FIG. 4 showing the basic body from the front,
[0021] FIG. 7 is an end view VII-VII in FIG. 4 showing the loose top from behind,
[0022] FIG. 8 is an enlarged side view of the loose top of FIG. 1 ,
[0023] FIG. 9 is a cross section IX-IX in FIG. 8 ,
[0024] FIG. 10 is a partial perspective view showing the loose top of FIG. 1 inserted into the jaw of the basic body of FIG. 1 in a state when the turning-in of the same is to be started,
[0025] FIG. 11 is a section XI-XI in FIG. 4 ,
[0026] FIG. 12 is a cross section XII-XII in FIG. 4 ,
[0027] FIGS. 13-16 are a series of pictures showing the different positions of the loose top of FIG. 1 in connection with the turning-in of the same into the jaw of the basic body,
[0028] FIG. 17 is a cross section XVII-XVII in FIG. 4 , the loose top being shown in an intermediate position between the branches,
[0029] FIG. 18 is a cross section corresponding to FIG. 17 in which the loose top is shown in its end position of turning,
[0030] FIG. 19 is an extremely enlarged, schematic picture showing different positions of the edge of the loose top of FIG. 1 that bends out a cooperating branch,
[0031] FIG. 20 is an enlarged perspective view of the jaw of the basic body of FIG. 1 ,
[0032] FIG. 21 is a perspective exploded view illustrating an alternative embodiment of the invention,
[0033] FIG. 22 is a cross section showing the loose top according to FIG. 21 in an initial position before turning-in into the jaw of the basic body, and
[0034] FIG. 23 is a cross section showing the loose top according to FIG. 21 in its turned-in, operative position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] In the following description and the claims, a number of cooperating pairs of surfaces of the basic body and the loose top, respectively, will be described. When these surfaces are present on the basic body, the surfaces are denominated “support surfaces”, while the corresponding surfaces of the loose top are denominated “contact surfaces” (for example, “axial support surface” and “axial contact surface”, respectively). Furthermore, it should be pointed out that the loose top includes a rear end in the form of a plane surface, which in the example serves as an axial contact surface for pressing against an axial support surface in the basic body. Depending on the context, this surface will be denominated either “rear end” or “axial contact surface”. Furthermore, an inner support surface of a branch and a side contact surface of the loose top are defined by a pair of side borderlines, one of which moves ahead of the other one during rotation. The borderlines are denominated “heading” and “trailing”, respectively, in order not to be mistaken for the concepts “front” and “rear”. In the drawings, the cooperating surfaces contacting each other in the operative state of the drilling tool are shown by similar surface patterns.
[0036] The drilling tool shown in FIGS. 1 and 2 is in the form of a so-called twist drill and includes a basic body 1 as well as a loose top 2 in which the requisite cutting edges 3 are included. In its composed, operative state according to FIG. 1 , the drilling tool is rotatable around a center axis indicated by C, more precisely in the direction of rotation R.
[0037] In FIG. 2 , it is seen that the basic body 1 includes front and rear ends 4 , 5 , between which a centre axis C 1 specific to the basic body extends. In the backward direction from the front end 4 , a cylindrical envelope surface 6 extends, in which two chip flutes 7 are countersunk that in this embodiment are helicoidal, but that also could be straight as in tap borers. In the example, the chip flutes 7 end in the vicinity of a collar 8 included in a rear part 9 that is intended to be attached to a driving machine (not shown).
[0038] Also the loose top 2 includes front and rear ends 10 , 111 and a center axis C 2 with which two parts 12 of an envelope surface are concentric. The envelope part surfaces 12 are separated by two helicoidal chip flute sections 13 (see also FIG. 3 ), which form extensions of the chip flutes 7 of the basic body 1 when the loose top is mounted onto the basic body. If the loose top 2 is centered correctly in relation to the basic body 1 , the individual centre axes C 1 and C 2 coincide with the centre axis C of the composed drilling tool.
[0039] Reference is now made to FIG. 3 and other drawing figures. In FIG. 3 , it is seen that the basic body 1 in the front end thereof includes a jaw 14 that is delimited between two identical branches or shanks 15 and an intermediate bottom that forms an axial support surface 16 for the loose top. Each branch 15 includes an inner support surface 17 that extends axially rearward from a front end surface 18 of the branch. Furthermore, the individual branch 15 includes a tangential support surface 19 that is facing forward in the direction of rotation, and thus is heading. An opposite, trailing tangential support surface 20 a is included as a front part of the concave surface 20 that is present between two helicoidal borderlines 21 , 22 and delimits the chip flute 7 . In a known way, the individual branch 15 is elastically bendable to be resiliently clampable against the loose top 2 . This is realized by the fact that the material in at least the front portion of the basic body 1 has a certain inherent elasticity, for example, lower modulus of elasticity than the material in the loose top 2 . The material in at least the front portion can include steel. The material in the loose top may, in a traditional way, include cemented carbide, which is hard carbide particles in a binder metal, cermet, ceramics or the like. Advantageously, the axial support surface 16 is plane and extends perpendicular to the center axis C 1 . In addition, the axial support surface 16 extends diametrically between the two part surfaces that together form the envelope surface 6 . Generally the axial support surface has a §-like contour shape.
[0040] As is further seen in FIG. 3 , the rear end of the loose top is represented by an axial contact surface 11 that, like the axial support surface 16 , can be plane and extends perpendicular to the center axis C 2 . The axial contact surface 11 extends between diametrically opposed envelope part surfaces 12 and has a §-like contour shape. Furthermore, the loose top 2 includes a pair of external, diametrically opposed side contact surfaces 23 , against which the inner support surfaces 17 of the branches can be resiliently clamped. In certain embodiments, the contour shape of the surfaces 11 and 16 is identical, whereby complete surface contact is established in the operative state of the tool.
[0041] The front end 10 of the loose top 2 , in which the cutting edges 3 are included, is represented by an end surface that is composed of a plurality of part surfaces (see FIGS. 5 and 8 ), which in this embodiment are identical in pairs and therefore not described individually. Behind the individual cutting edge 3 , as viewed in the direction of rotation, a primary clearance surface 24 is formed, which has a moderate clearance angle and transforms into a secondary clearance surface 25 having a greater clearance angle, via a borderline 26 . Via an additional borderline 27 , the secondary clearance surface 25 transforms into a third clearance surface 28 , which in turn, via an arched borderline 29 , transforms into a chip flute 13 . As may be best seen in FIG. 8 , the concave surface 30 that delimits the chip flute section 13 extends partly up to the individual cutting edge 3 and forms a chip surface for the cutting edge 3 . In the chip surface of the cutting edge, also a convex part surface 31 is included. The design of the front end of the loose top may be modified in miscellaneous ways and is therefore incidental provided that the loose top can carry out chip removing machining.
[0042] Furthermore, it should be observed that adjacent to the envelope part surface 12 , a guide pad 32 (see FIGS. 3 and 5 ) is formed, the main task of which is to guide the drilling tool. The diameter of the drilled hole is determined by the diametrical distance between the peripheral points 33 where the cutting edges 3 meet the guide pads 32 . Also the two cutting edges 3 converge into a tip 34 , which forms the very foremost part of the loose top, and in which there may be included a so-called chisel edge and a minimal centering punch (lack designations).
[0043] Reference is now made to FIG. 8 , from which it is seen that the individual side contact surface 23 of the loose top 2 is laterally delimited between first and second side borderlines 35 , 36 , the first side borderline 35 is heading and the second side borderline 36 is trailing during rotation of the tool. Rearward (downward in the drawing), the side contact surface 23 is delimited by a transverse, rear borderline 37 , while its front limitation includes two oblique borderlines 38 , 39 , the first oblique borderline borders on the secondary clearance surface 25 and the second oblique borderline borders on the third clearance surface 28 . The second side borderline 36 is included in (or forms) an edge, designated 40 , that constitutes a transition between the side contact surface 23 and a rotationally trailing part surface 41 . Although it is feasible to form the edge 40 sharp, most embodiments manufacture the edge 40 as a radius transition, including, for example a convexly rounded, long narrow surface in the transition between the side contact surface 23 and trailing part surface 41 . Also, the trailing part surface 41 in this embodiment is wedge-shaped and borders on the trailing chip flute surface 30 . In particular, the trailing part surface 41 is delimited between the edge 40 and an acute borderline 42 that forms an acute angle with the edge 40 . The edge 40 and the acute borderline 42 diverge in the backward direction.
[0044] At the first side borderline 35 thereof, the side contact surface 23 transforms into a concave recess surface 43 that in turn borders on a tangential contact surface 44 (see FIG. 3 ), against which the individual branch 15 is pressed, in order to transfer torque to the loose top.
[0045] In the illustrated embodiment, the side contact surfaces 23 , like the inner support surfaces 17 of the branches 15 , are essentially plane. As is further seen from the cross section in FIG. 9 , the two opposite side contact surfaces 23 of the loose top 2 diverge at a certain angle α in the direction from the rear end toward the front end. In the reference plane RP 1 , which is situated on a level with the front end 40 a of the edge 40 , the loose top has accordingly a width W 1 that is somewhat greater than the width W 2 in the reference plane RP 2 , which is situated on a level with the rear borderline 37 of the side contact surface. The difference between the width measures W 1 and W 2 can be very moderate, where the angle of divergence α is small. In the illustrated embodiment, W 1 is about 8.00 mm and W 2 is about 7.97 mm, the angle α is about 0.86° (α/2=0.43°). Although this angle of divergence is diminutive, the angle is, however, fully sufficient for bending out the branches 15 so much that the branches subject the loose top to a considerable clamping force.
[0046] In this connection, it should be pointed out that the angle of divergence α may vary upward as well as downward from about 0.86°. However, the angle of divergence α should amount to at least about 0.20° and at most about 2°. In certain embodiments, the angle of divergence α should be within the range of 0.60-1.20°. The size of the angle α depends on the axial length of the inner support surface 17 and side contact surface 23 . Specifically, the angle should be adapted to the length of the surfaces in such a way that surface contact is attained in the operative state of the loose top.
[0047] Because the side contact surfaces 23 diverge in the way described above, the front end 40 a of the edge 40 is located at a greater radial distance from the center axis C 2 of the loose top than the rear end 40 b of the edge 40 . In other words, the front end 40 a will first contact the inner support surface 17 of the individual branch in connection with the turning-in of the loose top into the jaw 14 . Also, the edge 40 in this embodiment is straight.
[0048] Reference is now made to FIG. 20 , which shows that the inner support surface 17 of the individual branch 15 , like the cooperating side contact surface 23 of the loose top, is delimited between first and second side borderlines 51 , 52 . The first borderline 51 is heading and the second borderline 52 is trailing during rotation. Between the inner support surface 17 and the tangential support surface 19 , there is a concave clearance surface 53 having a radius that is greater than the radius of the recess surface 43 .
[0049] In FIG. 10 , the loose top 2 is shown in an initial position in which the loose top has been inserted axially into the jaw between the branches 15 , but has not been turned into its operative end position. In order to coarse-center or provisionally retain the loose top in a reasonably, but not exactly, centered position during the subsequent turning-in, the rear part of the loose top and the inner parts of the branches are formed with cooperating guide surfaces. Each side contact surface 23 (see FIGS. 3 and 4 ) transforms into a convex guide surface 45 being axially behind via an intermediate surface 46 . Between the guide surface 45 and the axial contact surface 11 of the loose top, a clearance surface 47 is present. As is seen in FIG. 7 , the two guide surfaces 45 , which are formed on diametrically opposed sides of a central portion of the loose top, have a rotationally symmetrical shape. The surfaces follow a circle S 2 , the diameter of which is designated D 2 . The circle S 2 , and thereby also the surfaces 45 , are concentric with the centre axis C 2 of the loose top. In the illustrated embodiment, the surfaces 45 are cylindrical, although they could also be conical.
[0050] As is seen in FIG. 3 , in combination with FIGS. 6 and 20 , the two branches 15 are, at the rear ends thereof, formed with a pair of concave, internal guide surfaces 48 , which cooperate with the convex, external guide surfaces 45 of the loose top. Each such guide surface 48 transforms into an inner support surface 17 via an intermediate surface 49 , which is inclined in the inward/rearward direction from the inner support surface 17 . Also the two internal guide surfaces 48 are cylindrical, or alternatively conical, and are defined by an imaginary circle S 1 (see FIG. 6 ), the diameter of which is designated D 1 . The diameter D 1 of the circle S 1 is somewhat greater than the diameter D 2 of the circle S 2 , which means that the guide surfaces 45 , 48 do not contact each other when the loose top is operatively clamped in the jaw of the basic body. The difference in diameter may in practice amount to one or a few tenth of a millimeter. However, it is guaranteed that the loose top is coarse centered and retains an approximate intermediate position between the branches during the turning-in that is carried out from the initial position shown in FIG. 10 . The fact that the diameters D 1 and D 2 are differently great means that the guide surfaces 45 , 48 do not impose requirements of dimensional accuracy in connection with the manufacture.
[0051] The guide surface 45 (see FIG. 8 ) is partially displaced in the tangential direction in relation to the side contact surface 23 , in such a way that the borderline 45 a to the chip flute 13 is displaced rearward in the direction of rotation R in relation to the limiting edge 40 of the side contact surface, which is toward the left in FIG. 8 . During the turning-in of the loose top in the turning direction V, the borderline 45 a will therefore move before the limiting edge 40 . The practical consequence of this will be that the guide surfaces 45 can start to co-operate with the guide surfaces 48 with the purpose of provisionally coarse centering the loose top already before the limiting edges 40 get in contact with the inner support surfaces 17 of the branches 15 .
[0052] Reference is now made to FIG. 11 , in which DL 1 designates a straight, first diametrical line that intersects the centre axis C 1 and extends the shortest possible distance between the inner support surfaces 17 of the branches 15 facing each other, and forms a right angle with the inner support surfaces. The ends of this shortest possible diametrical line DL 1 are designated Ea, Eb. It is evident that any other imaginary diametrical line (lacks designation) drawn between the inner support surfaces 17 and intersecting the centre axis C 1 becomes longer than the shortest diametrical line DL 1 . This applies irrespective of whether the imaginary, longer diametrical line is turned clockwise or counter-clockwise around C 1 in relation to the diametrical line DL 1 shown in FIG. 11 .
[0053] In FIG. 12 , DL 2 designates a second, likewise straight diametrical line that extends between the edges 40 of the two opposite side contact surfaces 23 and intersects the centre axis C 2 of the loose top. The diametrical line DL 2 extends between the front end points 40 a of the edges 40 (see FIG. 8 ). The individual side contact surface 23 forms an acute angle with the diametrical line DL 2 . In the example, the angle β amounts to about 85°. In certain embodiments, the angle β amounts to at least about 75° and at most about 88°. In yet more certain embodiments, the angle amounts are within the range of 80-86°. From the enlarged detailed section in FIG. 12 , it is furthermore seen that the side contact surface 23 and the trailing part surface 41 form an obtuse angle γ with each other. In the example, γ amounts to about 152°. By the fact that the angle γ is obtuse, rather than acute, which would also be feasible, the portion of the loose top that surrounds the edge 40 will become robust and endure forces that act against the edge.
[0054] In certain embodiments, the diametrical line DL 2 is somewhat longer than the diametrical line DL 1 . Because the length difference is small, for example, some hundredths of a millimeter, and not visible to the naked eye, reference is now made to the series of pictures in FIGS. 13-16 , as well as to the enlarged, schematic picture in FIG. 19 . In FIG. 13 , the loose top 2 is shown in an initial position P 1 according to FIG. 10 . FIG. 13 shows how the loose top in this position can be freely inserted axially into the jaw by the fact that the side contact surfaces thereof have no contact with the branches 15 . In this position, the convex guide surfaces 45 of the loose top are partially located between the concave guide surfaces 48 of the branches 15 . In a first step, the loose top is turned into the position P 2 according to FIG. 14 , where the two opposite edges 40 get in contact with the inner support surfaces of the branches. After further turning, the loose top 2 reaches the position P 3 shown in FIG. 15 where the diametrical lines DL 1 and DL 2 coincide. In this position, the edges 40 have reached a dead or intermediate position, in which the clamping force of the branches 15 is maximal. From this dead position P 3 , the loose top is turned further a short distance to reach its end position P 4 according to FIG. 16 . In this position, the edges 40 have passed the dead position P 3 according to FIG. 15 , but without the spring force or tensile capacity of the branches 15 having been exhausted. In the end position P 4 according to FIG. 16 , the side contact surfaces 23 abut against the inner support surfaces 17 at the same time as the torque-transferring tangential support surfaces 19 of the branches are pressed in close contact against the tangential contact surfaces 44 of the loose top.
[0055] In FIG. 19 , the different positions of the edge 40 in relation to the individual branch 15 are illustrated more clearly. In the position P 1 according to FIG. 13 , the edge 40 lacks all contact with the inner support surface 17 of the branch. In the position P 2 , contact has been established with the inner support surface 17 . From this position and on, the edge 40 of the loose top starts to bend out the branch 15 while applying a successively increasing clamping force to the loose top. In the dead position P 3 according to FIG. 15 , the clamping force in the branch has grown to a maximum, because here, the diametrical lines DL 1 and DL 2 coincide. In order to reach its end position P 4 , the loose top is turned further a short distance clockwise around the centre axis C 1 . During the comparatively short move between the positions P 3 and P 4 , when the edge 40 has passed the dead position P 3 , the continued turning of the loose top will entirely or partly be overtaken by the branches 15 as a consequence of the fact that the clamping force in the branches now aims to bring the loose top to the end position in which it no longer can be turned further as a consequence of the fact that the pairs of surfaces 23 , 17 and 19 , 44 are held pressed in close contact against each other. Practical tests carried out using the tool have shown that the concluding turning between the positions P 3 and P 4 is followed by a pronounced tactile sensation in the fingers of the operator, and at times an audible click sound, which confirms to the operator that the loose top has reached its operative end position.
[0056] The exact centering of the loose top in relation to the basic body is initiated in the position P 2 , when the edges 40 of the loose top first get in contact with the inner support surfaces 17 of the branches 15 . As the edges are turned toward their end position P 4 , the centering will become increasingly distinct and exact as a consequence of the increasing clamping force in the branches. The branches 15 retain an ample clamping force in the end position P 4 , even if the clamping force to a certain extent has been reduced in relation to the maximal clamping force in the position P 3 . By suitably adjusting such geometrical factors as the amount of rotary motion between P 3 and P 4 in relation to the selected difference in length between DL 1 and DL 2 , the clamping force in the operative end position can be predetermined. For instance, the clamping force in the end position P 4 can be determined to 50% of the maximal clamping force in the dead position P 3 .
[0057] In FIGS. 17 and 18 , it is illustrated how narrow, although pronounced slits 50 arise between the pairs of cooperating guide surfaces 45 , 48 of the loose top 2 and of the branches 15 , respectively, when the loose top is turned toward its operative end position.
[0058] Further, the drilling tool includes that the side contact surfaces 23 of the loose top 2 are situated near the front end 10 of the loose top, and that the corresponding inner support surfaces 17 of the branches 15 are situated far in front on the branches. Accordingly, the side contact surfaces 23 extend rearward from the two clearance surfaces 25 , 28 that are included as part surfaces in the front end 10 of the loose top. In an analogous way, the inner support surfaces 17 of the branches extend rearward from the edge lines that form transitions to the front end surfaces 18 of the branches. By this location of the side contact surfaces and the inner support surfaces, respectively, there is provided a powerful grip or pinch along the front portion of the loose top adjacent to the cutting edges, because the branches have their greatest bending capacity, and thereby their optimal gripping capacity, in the area of the free, front ends thereof rather than in the vicinity of the rear ends.
[0059] In FIG. 8 , 44 a designates the straight borderline that forms a transition between the part envelope surface 12 and the tangential contact surface 44 of the loose top (see also FIG. 3 ). Said tangential contact surface 44 is inclined in relation to the axial contact surface 11 of the loose top at an angle δ, which in the example amounts to about 76°. The tangential support surface 19 (see FIGS. 10 and 20 ) that cooperates with the individual tangential contact surface 44 is correspondingly inclined. By this inclination of the respective surfaces, a locking element is provided that, in combination with the pinching effect of the branches 15 , counteracts unintentional axial retraction of the loose top out of the jaw 14 , for example, in connection with the retraction of the drilling tool out of a drilled hole. The angle δ may vary upward as well as downward. In certain embodiments the angle amount is at least about 65° and at most about 85°.
[0060] In FIGS. 4 and 5 , it is seen that the loose top 2 includes a key grip in the form of a pair of peripherally situated notches or seats 55 .
[0061] Embodiments of the invention enable the operator to obtain an apparent confirmation of the loose top having reached its operative end position during the turning-in. Further, the resistance of the bendable branches to the turning-in is not constantly great, but maximal only during the short moment when the edges are turned past the dead position. Furthermore, the inherent elasticity of the branches assumes entirely or partly the final turning-in from the dead position to the end position during the final phase of the rotary motion. In other words, the risk that the operator, for example, when in a hurry, unintentionally fails to finish the manual turning all the way up to the absolute end position is counteracted. Additionally, the loose top is securely pinched between the front ends of the branches, where the branches are most bendable and give an optimal clamping force. Furthermore, the loose top may be given a minimal volume in relation to its diameter, whereby the consumption of expensive material in the same is reduced to a minimum. Yet further, the basic body can transfer considerable torques to the loose top because the tangential support surfaces of the branches can be given an optimized length within the scope of the available axial length of the loose top. Furthermore, the loose top can be mounted and dismounted in a simple way with use of a simple key. In addition, the two side contact surfaces of the loose top are well exposed and easy to access if the two side contact surfaces would need to be ground in order to guarantee good centering.
[0062] Reference is now made to FIGS. 21-23 , which illustrate an alternative embodiment in which the inner support surface 17 of each individual branch 15 is formed with a plurality of part surfaces or surface sections 17 a, 17 b and 17 c. The first surface section 17 a extends between the rotationally trailing borderline 52 and the surface section 17 c, which is a concave radius transition to the second surface section 17 b, which in turn connects to the borderline 51 . Via a transition surface 53 that includes three facet surfaces, the surface section 17 b transforms into the tangential support surface 19 . In the embodiment shown, the surface section 17 b has a concave, more precisely part-cylindrical shape, while the surface section 17 a is plane, or possibly slightly cambered.
[0063] Axially behind the inner support surface 17 there is, in the same way as in the previous embodiment, a cylindrical or otherwise rotationally symmetrical guide surface 48 that is included in a thickened, rear portion of the branch 15 , and is separated from the inner support surface 17 via an intermediate surface 49 .
[0064] In analogy with the inner support surface, the cooperating side contact surface 23 of the loose top 2 includes two surface sections 23 a, 23 b, the first surface section 23 a of which is rotationally trailing in relation to the second surface section 23 b. The surface section 23 a extends between a borderline 23 c to the surface section 23 b and between the edge 40 that forms a transition to the rotationally trailing part surface 41 . The surface section 23 b is convex and has the same rotationally symmetrical shape as the concave surface section 17 b of the branch 15 . In certain embodiments, the surface section 23 b has a cylindrical shape. Via the borderline 35 , the surface section 23 b transforms into the recess surface 43 , which in turn transforms into the tangential contact surface 44 . The surface section 23 a is plane, or slightly cambered, like the surface section 17 a included in the inner support surface 17 . Axially behind the two surface sections 23 a, 23 b, there is a convex, cylindrical or otherwise rotationally symmetrical guide surface for cooperation with the concave guide surface 48 .
[0065] In FIG. 22 , the loose top 2 is shown in an initial position before turning-in (P 1 ) into the jaw between the branches 15 , which is similar to the position of the first embodiment shown in FIG. 13 . The two plane surface sections 17 a that are included in the two inner support surfaces of the branches are mutually parallel. A diametrical line DL 1 that intersects the center axis C and is perpendicular to the surface sections 17 a represents the shortest distance between the surface sections 17 a. Said diametrical line DL 1 contacts the surface sections 17 a in points that are situated between their side limitations 17 c and 52 , respectively. DL 2 designates a second diametrical line that extends between the edges 40 along the surface sections 23 a that are included in the two opposite side contact surfaces 23 of the loose top. The second diametrical line DL 2 is some hundredths of a millimeter longer than the first diametrical line DL 1 . However, the radial distance between the center axis C and the edge 40 that forms an end of the diametrical line DL 2 is somewhat smaller than the radial distance between the center axis C and the concave surface section 17 b. This means that the edges 40 of the loose top will clear the concave surface sections 17 b when the turning-in of the loose top is started.
[0066] When the loose top 2 is turned in from its initial position (P 1 ) according to FIG. 22 to the operative end position (P 4 ) according to FIG. 23 , the following occurs. Initially, the edges 40 will freely pass the surface sections 17 b without affecting the branches 15 . When the edges 40 have passed the radius transitions 17 c, the edges 40 will contact the surface sections 17 a and successively start to bend out the branches. When the pair of edges 40 reaches the rotation angle position in which the diametrical lines DL 1 and DL 2 coincide with each other, which is similar to position P 3 in FIG. 15 of the first embodiment, the deflection and thereby the spring forces becomes maximal, as a dead position is passed. In this state, the convex surface section 23 b of the loose top has started to overlap the concave surface section 17 b of the inside of the individual branch 15 . From said dead position, the turning-in of the loose top continues primarily by the spring force in the branches up to the operative end position, which is shown in FIG. 23 and in which the tangential contact surfaces 44 of the loose top have been pressed against the tangential support surfaces 19 of the branches. In the final stage of the turning-in, which includes turning-in between the dead position and the end position, the convex surface sections 23 b of the loose top will be located opposite the concave surface sections 17 b. The spring force in the branches will be transferred to the loose top by surface contact between the surface sections 17 b and 23 b. Simultaneously, the plane surface sections 17 a clear somewhat from the internal, plane surface sections 23 a of the loose top. In other words, the fastening force that the branches exert will be located along an axial plane AP that extends diametrically between the surface pairs 17 b, 23 b according to FIG. 23 .
[0067] The embodiment according to FIGS. 21-23 includes an alternative type of axial locking element for the loose top that includes two seats 54 formed in the rear ends of the branches 15 and two male members 55 on the loose top. The seat 54 is, in this embodiment, a chute that is recessed in the individual branch 15 and situated between tangential support surface 19 thereof and the axial support surface 16 of the basic body. The individual male member 55 is in turn a ridge that is situated axially behind the tangential contact surface 44 of the loose top and connects to the axial contact surface 11 . In other words, the ridge 55 projects laterally in relation to the tangential contact surface 44 , the rear part thereof transforming into the axial contact surface 11 . When the loose top is turned into its operative position, the ridges 55 engage the chutes 54 without the ridges getting surface contact with the chutes. The ridges 55 are therefore activated only if the negative axial forces on the loose top overcome the spring force in the branches.
[0068] Further, the side contact surfaces of the loose top do not necessarily need to be plane. For instance, the side contact surfaces may be slightly cambered or markedly convex and arranged to cooperate with inner support surfaces that have been given a more or less markedly concave shape.
[0069] Although described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departure from the spirit and scope of the invention as defined in the appended claims. | A drilling tool of the loose top type includes a basic body having two bendable branches having inner support surfaces that are resiliently pressable against side contact surfaces of a replaceable loose top. The mounting of the loose top is affected by turning-in from an initial position to an operative end position. An abutting edge along each side contact surface then bends out the branches and subjects the branches to a spring force that reaches a maximum in a dead position so as to then decrease somewhat up to the operative end position. During the final phase of the rotary motion, the operator obtains, in a tactile and/or auditory way, confirmation of the loose top indeed reaching its operative end position. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application under 35 U.S.C. 371 and claims the benefit of PCT Application No. PCT/JP2013/071431 filed 7 Aug. 2013, which designated the United States, which PCT Application claimed the benefit of Japanese Patent Application No. 2012-174930 filed 7 Aug. 2012, and Japanese Patent Application No. 2012-245098 filed on 7 Nov. 2012, the disclosure of each of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a burner for an exhaust purification device, which is used in an exhaust purification device for purifying an exhaust gas from an internal-combustion engine (hereinafter, referred to as an engine) and raises the temperature of the exhaust gas.
BACKGROUND OF THE INVENTION
Conventional diesel engines include an exhaust gas purification device in the exhaust passage, and the exhaust gas purification device includes a diesel particulate filter (DPF), which captures particulates contained in an exhaust gas, and an oxidation catalyst. Such an exhaust gas purification device treats an exhaust gas to raise the temperature in order to maintain the function of purifying an exhaust gas. The treatment regenerates the DPF by burning the particulates captured by the DPF and activates the oxidation catalyst. A burner that performs the treatment for raising the temperature of the exhaust gas is arranged upstream of the DPF and the oxidation catalyst.
One example of the structure of the burner is a multilayer tube structure. In the multilayer tube structure, a plurality of tubular members is overlapped to be coaxial. A burner having the multilayer tube structure is advantageous for saving space and raising the temperature of air for combustion.
For example, Patent Document 1 discloses a combustor that includes a combustion tube including an outer tube and an inner tube, a short auxiliary combustion tube arranged radially inside of the inner tube, and a vaporization tube arranged radially inside of the auxiliary combustion tube. The bottom of each tube is fixed to a base. When the combustor is activated, fuel is injected in the auxiliary combustion tube and is vaporized in a premixing region arranged in the auxiliary combustion tube. The vaporized fuel is mixed with air for combustion supplied from the vaporization tube. A flame occurs in a combustion chamber by igniting a premixed air-fuel mixture, in which the fuel and the air for combustion are mixed. In this way, the premixed air-fuel mixture is combusted. An air flow path, through which air for combustion passes, is provided between the inner and outer tubes. The air for combustion supplied to the flame promotes combustion.
PRIOR ART DOCUMENT
Patent Document
Patent Document 1: Japanese Laid-Open Patent Publication No. 58-160726
SUMMARY OF THE INVENTION
Problem that the Invention is to Solve
Since a flame occurs in a head portion of the inner tube, the inner tube is heated to a high temperature and thermally expands mostly in the direction parallel to the central axis (in the axial direction). There is a space between the outer and inner tubes, and air passes through the space. Therefore, the outer tube has a lower temperature than the inner tube. As described above, because of the premixing region arranged inside of the auxiliary combustion tube, the auxiliary combustion tube has a lower temperature than the inner tube. For this reason, the expansion amount of the inner tube is greater than those of the auxiliary combustion tube and the outer tube during combustion.
In the burner with the multilayer tube structure, a difference of expansion amounts generally occurs between a tube exposed to a high temperature and a tube kept at a relatively low temperature. When the tubes are partially joined to each other by welding and the like, the difference between the expansion amounts of the tubes causes a large stress on the joining portion between the tubes. Even if the tubes are not joined to each other, there is a case, for example, in which the distal end of the inner tube is in a direct and close contact with the distal end of the outer tube as the aforementioned combustor. In this case, due to the radial expansion of the inner tube, the distal portion of the inner tube presses against the inner circumferential surface of the outer tube, and a force acts on the inner tube to hinder expansion in the axial direction. When ignition and extinction of the burner are repeated, each ignition and extinction causes stress on the joining portions, the contacting surfaces, and the like. As a result, depending on the usage conditions, damages such as fatigue and cracks may be occurred. This is not limited to the aforementioned burner, and burners with the multilayer tube structure generally have this kind of problem.
It is an objective of the present invention to provide a burner for an exhaust gas purification device that prevents tubes from being damaged due to a difference between the expansion amounts of the tubes in a multilayer tube structure.
In accordance with one aspect of the present disclosure, a burner for an exhaust gas purification device comprises a base, a first tube, and a second tube. The first tube includes a basal portion and a distal portion, a combustion chamber for combusting air for combustion and fuel, and a discharge port for discharging post-combustion gas. The basal portion is fixed to the base. An air flow path through which air for combustion passes is arranged between the first tube and the second tube. The burner for an exhaust gas purification device further comprises a compressible closing part, which is fixed to the first tube or the second tube and is arranged between the distal portion of the first tube and the second tube. The distal portion of the first tube has a circumference that is entirely, slidably supported by the second tube via the closing part.
According to the present aspect, the air flow path is provided between the second and first tubes. Because of the combustion chamber arranged inside of the first tube, the first tube has a higher temperature than the second tube. Therefore, when combustion starts, the expansion amount of the first tube is greater than that of the second tube. The distal end of the first tube is slidably supported by the second tube via the closing part. The closing part absorbs the radially-outward expansion of the first tube, while allowing the first tube to expand toward the distal end. Moreover, the closing part closes the distal end of an air passage. This suppresses leakage of air for combustion and suppresses damage caused by a difference between the thermal expansion amounts of the first and second tubes.
In another embodiment, the first tube is arranged radially inside of the second tube. The second tube includes a radially-narrowed portion. The closing part is held between the radially-narrowed portion of the second tube and the first tube.
In this case, since the closing part is held between the radially-narrowed portion of the second tube and the first tube, the thickness of the closing part is decreased compared to when the first and second tubes have constant diameters. Further, this decreases the diameter of the closing part compared to when the first tube has an enlarged diameter to reduce a space between the first and second tubes.
In another embodiment, the first tube is arranged radially inside of the second tube. The first tube includes a radially-enlarged portion. The closing part is held between the radially-enlarged portion of the first tube and the second tube.
In this case, since the annular closing part is held between the radially-enlarged portion of the first tube and the second tube, the thickness of the closing part is decreased compared to when the first and second tubes have constant diameters.
In another embodiment, the first tube includes a flange extending from a portion between the distal portion of the first tube and the closing part toward an inner circumferential surface of the second tube.
In this case, the flange arranged in a portion between the distal end portion of the first tube and the closing part closes the distal end of an air flow path at least in part, thereby suppressing leakage of air for combustion.
In another embodiment, the closing part is of a wire mesh. The first tube includes a hook for hooking the wire mesh. The hook projects from the outer circumferential surface of the first tube.
In this case, the closing part of a wire mesh absorbs the radial expansion of the first tube. The first tube also includes the hook for hooking the wire mesh. The hook projects from the outer circumferential surface of the first tube. The hook prevents the wire mesh from falling off and partially blocks an air flow, thereby suppressing leakage of air for combustion from an air flow path.
In another embodiment, the second tube is arranged radially outside of the first tube, so that a flow path of air for combustion is formed between the first tube and the second tube. The burner further comprises a first connecting tube portion and a second connecting tube portion. The first connecting tube portion is connected to the inner surface of the first tube and includes an opening at an end closer to the discharge port. The second connecting tube portion has a lid portion and partitions the combustion chamber from a premixing chamber. The second connecting tube includes a supply hole connected to the combustion chamber. The first connecting tube portion is inserted into the second connecting tube portion while being spaced from the second connecting tube portion.
In this case, the first and second connecting tube portions are overlapped, and a premixed air-fuel mixture has a longer flow path. This promotes mixture of the fuel and the air for combustion. The first tube expands in the axial direction without interference and extends toward the distal end. This suppresses change in the width of the flow path arranged between the first and second connecting tube portions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a burner for an exhaust gas purification device according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along line 2 - 2 in FIG. 1 ;
FIG. 3 is a cross-sectional view taken along line 3 - 3 in FIG. 1 ;
FIG. 4 is a cross-sectional view taken along line 4 - 4 in FIG. 1 ;
FIG. 5 is a schematic view of a burner for an exhaust gas purification device according to a second embodiment of the present invention;
FIG. 6 is a schematic view of a burner for an exhaust gas purification device according to a third embodiment of the present invention;
FIG. 7 is a schematic view of a burner for an exhaust gas purification device according to a fourth embodiment of the present invention;
FIG. 8 is a cross-sectional view of a principal part of a burner for an exhaust gas purification device according to a modification of the present invention; and
FIG. 9 is a cross-sectional view of a principal part of a burner for an exhaust gas purification device according to another modification of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A first embodiment of a burner for an exhaust gas purification device according to the present invention will now be described with reference to FIG. 1 to FIG. 4 .
As shown in FIG. 1 , a diesel engine 1 includes, in an exhaust passage 2 , a DPF 3 , which captures particulates contained in an exhaust gas. The DPF 3 has a honeycomb structure made of a porous silicon carbide, for example, and captures particulates in the exhaust gas. A burner for an exhaust gas purification device (hereinafter, simply referred to as a burner) 10 is arranged upstream of the DPF 3 . The burner 10 carries out a regeneration process of the DPF 3 by raising the temperature of an exhaust gas flowing into the DPF 3 .
The burner 10 is connected to a compressor 7 via an air supply passage 4 and an intake passage 5 of the diesel engine 1 . The compressor 7 rotates with a turbine 6 arranged in the exhaust passage 2 .
An air valve 8 is arranged on the air supply passage 4 . The air valve 8 is capable of changing a flow path cross-sectional area of the air supply passage 4 . Opening and closing of the air valve 8 is controlled by a control unit, not shown. When the air valve 8 is in an open state, some intake air flowing through the intake passage 5 is introduced into the burner 10 from the air supply passage 4 as air for combustion.
The burner 10 will now be described in detail. The burner 10 has a dual tube structure, in which an inner tube 11 as a first tube and an outer tube 12 as a second tube are overlapped to be coaxial. The inner tube 11 made from metal and shaped substantially cylindrical has openings at both ends in the direction parallel to the central axis. The inner tube 11 includes a basal portion as a first end portion in the axial direction or a bottom portion, and a distal portion as a second end portion in the axial direction or a head portion. The opening of the bottom portion is fixed to and closed by a disk-shaped base 13 . The opening of the head portion of the inner tube 11 is open, and a flange 11 F projects radially outward from the entire circumferential rim at the distal edge.
Blades 15 are arranged in the basal portion of the inner tube 11 . As shown in FIG. 2 , the blades 15 are formed by cutting and raising parts of the circumferential wall radially inward in the basal portion of the inner tube 11 . The blades 15 are arranged at equal intervals in the circumferential direction of the basal portion. Forming the blades 15 forms first introduction holes 16 , through which the exterior of the inner tube 11 is connected to the interior.
As shown in FIG. 1 , a plurality of second introduction holes 17 extends through the sidewall of the inner tube 11 in the substantially axial center. The second introduction holes 17 are shaped circular and arranged at equal intervals in the circumferential direction of the inner tube 11 .
An orifice plate 18 is arranged radially inside of the basal portion of the inner tube 11 . The rim of the orifice plate 18 is joined to the inner circumferential surface of the inner tube 11 . An orifice 18 A is arranged in the center of the orifice plate 18 . The basal portion of the inner tube 11 , the base 13 , and the orifice plate 18 define a first mixing chamber 19 for mixing fuel with air for combustion.
A fuel supply port 13 A for fixing the injection port of a fuel supply unit 24 is arranged in the substantially radially-central location of the base 13 . The fuel supply unit 24 is connected to a fuel pump and a fuel valve, neither shown. Opening the fuel valve delivers fuel from the fuel tank to the fuel supply unit 24 . The delivered fuel is vaporized in the fuel supply unit 24 and injected into the first mixing chamber 19 . At this time, the injection direction of fuel is adjusted so that the orifice 18 A is on the line extending in the injection direction.
A disk-shaped burner head 20 is arranged closer to the head portion than the orifice plate 18 in the inner tube 11 . The rim of the burner head 20 is joined to the inner circumferential surface of the inner tube 11 . A large number of air holes 20 A extend through the burner head 20 . The burner head 20 , the inner tube 11 , and the orifice plate 18 define a second mixing chamber 21 . The first mixing chamber 19 and the second mixing chamber 21 , described above, form a premixing chamber 22 for mixing fuel with air for combustion.
A metal mesh 23 for avoiding backfire is arranged at the burner head 20 at a position close to the opening of the head portion. In the present embodiment, the metal mesh 23 is arranged on the upstream face of the burner head 20 , but may be arranged on the opposite face or on the both.
The burner head 20 and the inner tube 11 define a combustion chamber 25 for generating a flame F. An insertion hole is formed in the combustion chamber 25 . The insertion hole is closer to the burner head 20 than the location where the second introduction holes 17 are formed. The insertion hole extends through the inner tube 11 . The ignition portion 27 of a spark plug 26 is inserted into the insertion hole.
The outer tube 12 is made from metal and shaped substantially cylindrical. The outer tube 12 has openings at both ends in the direction parallel to the central axis. The outer tube 12 includes a basal portion as a first end portion in the axial direction or a bottom portion, and a distal portion as a second end portion in the axial direction or a head portion. The opening of the bottom portion of the outer tube 12 is closed by the base 13 . A lid portion 30 is arranged on the opening of the head portion of the outer tube 12 . A discharge port 31 is arranged in the center of the lid portion 30 . The discharge port 31 is connected to the exhaust passage 2 , and supplies a post-combustion gas delivered from the combustion chamber 25 to the exhaust passage 2 .
An air supply port 12 B for fixing the inlet of the air supply passage 4 is arranged in the outer tube 12 at a position close to the opening of the head portion. As shown in FIG. 3 , a guide plate 32 is arranged on the inner circumferential surface of the outer tube 12 at a position near the opening of the air supply port 12 B. The guide plate 32 is fixed to the outer tube 12 in a cantilever-like manner in a state that the lateral face of the guide plate 32 is inclined in the direction along the inner circumferential surface of the outer tube 12 . The guide plate 32 is inclined in the same direction as the blades 15 on the inner tube 11 .
A distribution chamber 35 is arranged between the inner circumferential surface of the outer tube 12 and the outer circumferential surface of the inner tube 11 . The distribution chamber 35 distributes air for combustion to the first mixing chamber 19 and the combustion chamber 25 . As shown in FIG. 2 , the distribution chamber 35 is shaped annular to surround the inner tube 11 . As shown in FIG. 1 , the distribution chamber 35 is connected to the first mixing chamber 19 through the first introduction holes 16 arranged in the basal portion of the inner tube 11 . The distribution chamber 35 is also connected to the combustion chamber 25 through the second introduction holes 17 formed in the substantially center of the inner tube 11 .
As shown in FIG. 1 , the head portion of the outer tube 12 includes a radially-narrowed portion 12 A formed by decreasing the outer and inner diameters. The flow path cross-sectional area is decreased with the radially-narrowed portion 12 A in the distal portion of the distribution chamber 35 . A small gap, which corresponds to a thermal expansion amount, is provided between the radially-narrowed portion 12 A and the flange 11 F of the inner tube 11 .
As shown in FIG. 4 , the wire mesh 33 as a closing part is shaped annular by compression and is supported between the radially-narrowed portion 12 A and the inner tube 11 . The wire mesh 33 is fixed to the outer circumferential surface of the inner tube 11 by spot welding and the like, and comes in contact with the inner circumferential surface of the outer tube 12 . As shown in FIG. 1 , the distal face of the wire mesh 33 is closed by the flange 11 F.
The wire mesh 33 is formed from a metal mesh shaped annular by compression. The metal mesh has a mesh size, which is the distance between the wires, of a few millimeters. When the inner tube 11 radially expands, the wire mesh 33 is compressed to absorb the expansion of the inner tube 11 .
Operation of the burner 10 of the first embodiment will now be described.
When a regeneration process of the DPF 3 starts, the air valve 8 is controlled to be in the open state, and the fuel supply unit 24 and the spark plug 26 are activated. When the air valve 8 is in the open state, some intake air flowing through the intake passage 5 is introduced to the distribution chamber 35 as air for combustion from the air supply passage 4 through the air supply port 12 B. At this time, as shown in FIG. 3 , the guide plate 32 guides the air for combustion, thereby suppressing a flow of the air for combustion in the direction against the inclined direction of the guide plate 32 . As shown by the arrows in FIG. 3 , the air for combustion keeps swirling in a predetermined direction and flows in the direction opposite toward the discharge port 31 .
As shown in FIG. 1 , the wire mesh 33 and the flange 11 F close a gap between the distal portion of the inner tube 11 and the opening of the head portion of the outer tube 12 . This interferes with a flow of air from the air supply port 12 B toward the discharge port 31 and suppresses leakage of air for combustion from the opening of the outer tube 12 .
Some of the air for combustion introduced to the distribution chamber 35 is introduced to the combustion chamber 25 through the second introduction holes 17 . As shown in FIG. 2 , the remaining portion of the air for combustion is introduced to the first mixing chamber 19 through the first introduction holes 16 . As described above, since the guide plate 32 and the blades 15 are inclined in the same direction, the air for combustion does not lose the momentum of swirling. Rather, the air for combustion gains momentum of swirling and is introduced to the first mixing chamber 19 .
The swirling flow generated by the blades 15 flows toward the orifice 18 A while converging to the radially-central region of the inner tube 11 , which is a region to which the fuel supply unit 24 supplies fuel. As described above, since the location of the orifice 18 A corresponds to the fuel injection direction, the center of swirling of the air for combustion overlaps with the fuel injection direction by the fuel supply unit 24 . The fuel is caught in the swirling flow and spreads outward from the center of the swirling flow. A large part of injected fuel passes through the orifice 18 A.
The premixed air-fuel mixture, in which air for combustion and fuel are mixed, keeps a swirling flow in a predetermined direction and is discharged to the second mixing chamber 21 through the outlet of the orifice 18 A. Since the downstream pressure of the orifice 18 A is more reduced than the upstream pressure, the mixed air-fuel mixture spreads throughout the second mixing chamber 21 .
In this way, the premixed air-fuel mixture mixed in the second mixing chamber 21 is introduced to the combustion chamber 25 through the air holes 20 A of the burner head 20 . When the ignition portion 27 ignites the premixed air-fuel mixture flowing into the combustion chamber 25 , a flame F occurs in the combustion chamber 25 . The premixed air-fuel mixture is combusted, and a post-combustion gas is generated. At this time, as shown in FIG. 1 , air for combustion is supplied to near and downstream of the ignition portion 27 from the distribution chamber 35 through the second introduction holes 17 . As a result, the air for combustion and the post-combustion gas are exchanged, and combustion is promoted.
A post-combustion gas generated in the combustion chamber 25 is supplied to the exhaust passage 2 through the discharge port 31 . The temperature of an exhaust gas flowing into the DPF 3 is raised by the post-combustion gas mixed with an exhaust gas in the exhaust passage 2 . In the DPF 3 drawing such an exhaust gas, the temperature rises to the target temperature to burn the captured particles.
When a premixed air-fuel mixture is combusted in the combustion chamber 25 , the post-combustion gas at a high temperature heats the inner tube 11 . For this reason, after combustion starts, heat propagated via the inner tube 11 raises the temperature of air for combustion flowing in the distribution chamber 35 . The air for combustion at the raised temperature is introduced to the first mixing chamber 19 through the first introduction holes 16 . This suppresses liquidation of already vaporized fuel after combustion starts and promotes vaporization of liquidized fuel at that time. Moreover, the air for combustion in the distribution chamber 35 swirls around the inner tube 11 , and has a longer flow path in the distribution chamber 35 than when air for combustion linearly flows toward the first introduction holes 16 in the distribution chamber 35 . Thus, the air for combustion at a higher temperature is introduced to the first mixing chamber 19 .
In this way, while the inner tube 11 is heated by a post-combustion gas and the like, the outer tube 12 is exposed to the air for combustion passing through the distribution chamber 35 . For this reason, after combustion starts, the expansion amount of the inner tube 11 is greater than the expansion amount of the outer tube 12 , which is small. The inner tube 11 expands radially outward, but the radial expansion amount is small compared to the axial expansion amount. For this reason, the radial expansion amount of the inner tube 11 is absorbed by compression of the wire mesh 33 . The inner tube 11 expands toward the discharge port 31 while the wire mesh 33 and the distal end of the flange 11 F contact and slide on the inner circumferential surface of the outer tube 12 .
In contrast, when the outer circumferential surface of the inner tube 11 closely contacts the inner circumferential surface of the outer tube 12 to close the distal portion of the distribution chamber 35 , radially outward expansion of the inner tube 11 presses the distal portion of the inner tube 11 against the inner circumferential surface of the outer tube 12 . Since a force acts on the inner tube 11 to interfere with the axial expansion, the inner tube 11 is not easily extended in the axial direction. However, in the present embodiment, the contact area between the wire mesh 33 and the inner circumferential surface of the outer tube 12 is smaller than, for example, the contact area when the outer circumferential surface of the inner tube 11 closely contacts the inner circumferential surface of the outer tube 12 , and the frictional force is small when sliding. For this reason, the friction between the inner and outer tubes 11 , 12 does not prevent the inner tube 11 from being axially extended by the expansion.
The wire mesh 33 only has to have the substantially same diameter as the inner diameter at the radially-narrowed portion 12 A of the outer tube 12 . If the outer tube 12 has a constant outer diameter from the basal to central portion, the diameter of the wire mesh 33 is smaller than that in a case in which the inner tube 11 has an enlarged diameter to narrow the distal portion of the distribution chamber 35 . Thus, the contact area between the wire mesh 33 and the outer tube 12 can be reduced, and the friction required to slide the inner tube 11 can be further decreased. Moreover, the downsized wire mesh 33 suppresses leakage of air for combustion from the wire mesh 33 , a space between the wire mesh 33 and the outer tube 12 , or the like.
As described above, the following advantages are provided according to the first embodiment.
(1) The distribution chamber 35 is arranged between the outer and inner tubes 12 , 11 . Because of the combustion chamber 25 arranged in the inner tube 11 , the inner tube 11 has a higher temperature than the outer tube 12 . Therefore, when combustion starts, the expansion amount of the inner tube 11 is greater than that of the outer tube 12 . The distal portion of the inner tube 11 is slidably supported relative to the outer tube 12 via the wire mesh 33 . For this reason, while the wire mesh 33 absorbs the radially-outward expansion of the inner tube 11 , the inner tube 11 can expand toward the distal end. Further, the wire mesh 33 closes the distal portion of the distribution chamber 35 . This suppresses damage caused by a difference in the thermal expansion between the inner and outer tubes 11 , 12 , while suppressing leakage of air for combustion.
(2) Since the annular wire mesh 33 is held between the radially-narrowed portion 12 A of the outer tube 12 and the inner tube 11 , the thickness of the wire mesh 33 is decreased compared to when the diameters of the outer and inner tubes 12 , 11 are fixed. Moreover, the diameter of the wire mesh 33 is decreased compared to when the inner tube 11 has an enlarged diameter.
(3) The flange 11 F extends from the distal portion of the inner tube 11 toward the inner circumferential surface of the outer tube 12 . For this reason, the flange 11 F closes at least part of the distal portion of the distribution chamber 35 , and this suppresses leakage of air for combustion.
Second Embodiment
A second embodiment according to the present invention will now be described with reference to FIG. 5 . A burner 10 of the second embodiment only differs from the first embodiment in a part of the inner tube and a part of the outer tube. Like reference characters designate like or corresponding parts and the parts will not be described in detail.
As shown in FIG. 5 , the outer and inner diameters of the outer tube 12 are uniform from the basal to distal end. A radially-enlarged portion 11 B with increased outer and inner diameters is arranged at the distal end of the inner tube 11 . The flow path cross-sectional area in the distal portion of the distribution chamber 35 is decreased with the radially-enlarged portion 11 B. The flange 11 F is formed at the distal end of the radially-enlarged portion 11 B. The annular wire mesh 33 is supported between the radially-enlarged portion 11 B and the outer tube 12 .
Operation of the burner 10 of the second embodiment will now be described.
Similar to the first embodiment, when a premixed air-fuel mixture is combusted in the combustion chamber 25 , the inner tube 11 is heated by the post-combustion gas at a high temperature. The heat propagated by the inner tube 11 raises the temperature of air for combustion flowing through the distribution chamber 35 . The air for combustion at the raised temperature is introduced to the first mixing chamber 19 through the first introduction holes 16 . This suppresses liquidation of already-vaporized fuel after combustion starts, as well as promoting vaporization of fuel liquidized at that time.
Similar to the first embodiment, after combustion starts, the expansion amount of the inner tube 11 is greater than the expansion amount of the outer tube 12 , which is small. At this time, the radial expansion of the inner tube 11 is absorbed by compression of the wire mesh 33 . The inner tube 11 expands in the axial direction toward the discharge port 31 while the wire mesh 33 and the distal end of the flange 11 F contact and slide on the inner circumferential surface of the outer tube 12 .
According to the second embodiment, the following advantage is provided in addition to the advantages (1) and (3) in the first embodiment.
(4) Since the annular wire mesh 33 is held between the outer tube 12 and the radially-enlarged portion 11 B of the inner tube 11 in the second embodiment, the thickness of the wire mesh 33 is deceased compared to when the diameters of the outer and inner tubes 12 , 11 are fixed.
Third Embodiment
A third embodiment of a burner for an exhaust gas purification device according to the present invention will now be described with reference to FIG. 6 . The burner 10 of the third embodiment only differs from the first embodiment in the premixing chamber. Like or corresponding parts will not be described in detail.
The inner tube 11 and the outer tube 12 are fixed to the base 13 of the burner 10 . The lid portion 30 having the discharge port 31 is arranged in the distal portion of the outer tube 12 . The opening of the head portion of the inner tube 11 is open, and the flange 11 F projects radially outward from the entire circumferential rim. The radially-narrowed portion 12 A is arranged in the head portion of the outer tube 12 .
The wire mesh 33 shaped annular by compression is supported between the radially-narrowed portion 12 A and the inner tube 11 . The flange 11 F closes the distal face of the wire mesh 33 .
The premixing chamber will now be described. A connecting wall 60 and a burner head 61 are fixed to the inner surface of the inner tube 11 . The connecting wall 60 is arranged to include a portion between the blades 15 and the burner head 61 in the axial direction of the inner tube 11 . The connecting wall 60 , the base 13 , and the inner tube 11 define a first mixing chamber 71 .
The connecting wall 60 has an end portion in the axial direction, which projects toward the discharge port 31 . An insertion opening is formed at the end portion. A first connecting tube 62 is inserted in the insertion opening. The first connecting tube 62 extends in the axial direction from the connecting wall 60 , and opens toward the discharge port 31 . The inner space of the first connecting tube 62 is a second mixing chamber 72 . The connecting wall 60 and the first connecting tube 62 form a first connecting tube portion.
A connecting hole is formed in the center of the burner head 61 , and a second connecting tube 63 fits into the connecting hole. The burner head 61 and the second connecting tube 63 form a second connecting tube portion. The second connecting tube 63 extends in the axial direction from the burner head 61 toward the discharge port 31 , and the distal end is closed by a closing plate 64 . The second connecting tube 63 , the closing plate 64 , and the opening end of the first connecting tube 62 define a third mixing chamber 73 . The inner circumferential surface of the second connecting tube 63 and the outer circumferential surface of the first connecting tube 62 define a fourth mixing chamber 74 . The connecting wall 60 , the inner tube 11 , and the burner head 61 define a fifth mixing chamber 75 .
The mixing chambers 71 - 75 form a premixing chamber 70 . The second to fifth mixing chambers 72 - 75 have flow path cross-sectional areas different from each other. The inner tube 11 , the second connecting tube 63 , the burner head 61 , and the closing plate 64 define a combustion chamber 77 .
Operation of the aforementioned burner 10 will now be described.
When a regeneration process of the DPF 3 is started, air for combustion flows into the distribution chamber 35 . The air for combustion introduced by the guide plate 32 swirls around the inner tube 11 .
Some of the air for combustion flowing in the distribution chamber 35 is introduced to the combustion chamber 77 through the second introduction holes 17 . The remaining portion of the air for combustion is introduced to the first mixing chamber 71 through the first introduction holes 16 . Similar to the first embodiment, a swirling flow is generated in the first mixing chamber 71 .
In the first mixing chamber 71 , the fuel supply unit 24 supplies fuel toward the swirling flow to produce a premixed air-fuel mixture, in which the air for combustion and the fuel are mixed. The premixed air-fuel mixture flows into the second mixing chamber 72 while swirling.
After passing through the second mixing chamber 72 , the premixed air-fuel mixture turns around in the third mixing chamber 73 , and flows into the fourth mixing chamber 74 . Then, the premixed air-fuel mixture turns around again in the fifth mixing chamber 75 , and flows into the combustion chamber 77 through the supply holes 66 of the burner head 61 .
In the premixing chamber 70 , a flow path is lengthened by the length of the mixing chambers 71 - 75 , and this promotes mixing of air and fuel. Since the mixing chambers 71 - 75 have flow path cross-sectional areas different from each other, abrupt changes in the flow path cross-sectional area further promote mixing of air and fuel.
Ignition of the air-fuel mixture flowing into the combustion chamber 77 generates a flame F, which is an air-fuel mixture in combustion, in the combustion chamber 77 . The flame F generates a combustion gas. Air for combustion is supplied to the flame F through the second introduction holes 17 formed in the inner tube 11 .
The combustion gas generated in the combustion chamber 77 is supplied to the exhaust passage 2 through the discharge port 31 . The combustion gas heats the premixed air-fuel mixture in the fourth mixing chamber 74 via the second connecting tube 63 . This suppresses liquidation of already vaporized fuel and promotes vaporization of non-vaporized fuel.
In this way, while the inner tube 11 is heated by a post-combustion gas and the like, the outer tube 12 is exposed to air for combustion passing through the distribution chamber 35 . The radial expansion of the inner tube 11 is absorbed by compression of the wire mesh 33 . The inner tube 11 expands toward the discharge port 31 while the wire mesh 33 and the distal end of the flange 11 F contact and slide on the inner circumferential surface of the outer tube 12 . As described above, although the inner circumferential surface of the inner tube 11 is connected to the connecting wall 60 and the burner head 61 , the inner tube 11 is expandable toward the discharge port 31 . This suppresses change in the flow path cross-sectional areas of the third mixing chamber 73 and the fifth mixing chamber 75 .
As described above, according to the burner 10 of the third embodiment, the following advantage is provided in addition to the advantages (1) to (3) in the first embodiment.
(5) The premixing chamber 70 of the burner 10 has a portion at which the flow path of the premixed air-fuel mixture is turned around. For this reason, the burner 10 has a longer flow path of the premixed air-fuel mixture than a burner including a premixing chamber not having such a turned-around portion. This promotes mixture of air for combustion and fuel and improves combustion quality of the premixed air-fuel mixture. Thus, the combustion gas contains a less amount of non-combusted fuel. In the outer tube 12 and the inner tube 11 as above, a thermal expansion difference occurs between the tubes. However, since the distal portion of the inner tube 11 is slidably supported by the outer tube 12 via the wire mesh 33 , the inner tube 11 can expand toward the distal end while the wire mesh 33 absorbs the radially-outward expansion of the inner tube 11 . This suppresses change in the flow path cross-sectional area of the premixing chamber 70 .
Fourth Embodiment
A fourth embodiment of a burner for an exhaust gas purification device according to the present invention will now be described with reference to FIG. 7 . The burner 10 of the fourth embodiment only differs from the second embodiment in the premixing chamber. In the fourth embodiment, the premixing chamber of the burner 10 of the second embodiment is modified to the premixing chamber of the third embodiment. Therefore, like or corresponding parts will not be described in detail.
The radially-enlarged portion 11 B with increased outer and inner diameters is arranged at the distal end of the inner tube 11 . The flange 11 F is formed at the distal end of the radially-enlarged portion 11 B. The annular wire mesh 33 is supported between the radially-enlarged portion 11 B and the outer tube 12 .
Operation of the burner 10 of the fourth embodiment will now be described.
Flows of combustion air, fuel, and a premixed air-fuel mixture are the same as those in the third embodiment. The radial expansion of the inner tube 11 is absorbed by compression of the wire mesh 33 . The inner tube 11 expands in the axial direction toward the discharge port 31 while the wire mesh 33 and the distal end of the flange 11 F contact and slide on the inner circumferential surface of the outer tube 12 .
As described above, according to the burner 10 of the fourth embodiment, the following advantage is provided in addition to the advantages (1) and (3) in the first embodiment and the advantage (4) in the second embodiment.
(6) In the distal portion of the inner tube 11 , the annular wire mesh 33 is held between the outer tube 12 and the radially-enlarged portion 11 B of the inner tube 11 having the first to fifth mixing chambers 71 - 75 . Compared to when the diameters of the outer and inner tubes 12 , 11 are fixed, the thickness of the wire mesh 33 is decreased. The inner tube 11 expands toward the discharge port 31 while maintaining a space between the connecting wall 60 and the burner head 61 .
The above embodiments may be modified in the forms described below.
In the above embodiments, the flange 11 F is arranged at the distal end of the inner tube 11 , but the flange 11 F may be omitted. In the initial state before combustion starts, the distal end of the flange 11 F may contact the inner circumferential surface of the outer tube 12 . As shown in FIG. 8 , a hook 11 E for hooking the wire mesh 33 may project from the outer circumferential surface of the inner tube 11 . The hook 11 E extends substantially perpendicular to the outer circumferential surface of the inner tube 11 . A plurality of hooks 11 E is arranged in the axial direction of the inner tube 11 . The hooks 11 E may be successively formed in the circumferential direction of the inner tube 11 to have an annular shape. Alternately, the hooks 11 E may be intermittently formed on the outer circumferential surface to be shaped like sectors of a circle. This fixes the wire mesh 33 more firmly. The hooks 11 E interfere with a flow of air from the air supply port 12 B toward the discharge port 31 , and this suppresses leakage of air from the distribution chamber 35 . As shown in FIG. 9 , as a substitute for the wire mesh 33 , a bellows tube 50 may be arranged between the inner and outer tubes 11 , 12 . The bellows tube 50 is formed substantially cylindrical to entirely surround the inner tube 11 , and the wall has a waved cross-sectional shape. When the inner tube 11 expands radially outward, the bellows tube 50 extends between the inner and outer tubes 11 , 12 to absorb the radial expansion of the inner tube 11 . In the above embodiments, the orifice plate 18 is used to diffuse non-combusted fuel, but a funnel-shaped conduit with the inner diameter continuously decreasing from the inlet to the outlet, a Venturi tube, or the like may be used. The air supply port 12 B may be formed in a portion not close to the head portion such as the central portion of the outer tube 12 . A plurality of air supply ports 12 B may be provided. In the above embodiments, the swirling flow generating portion includes the blades 15 , which is cut and raised radially inward. However, the swirling flow generating portion may include something shaped different such as swirlers arranged on the outer circumference of the inner tube 11 . In the above embodiments, the inner tube 11 as the first tube is arranged radially inside of the outer tube 12 as the second tube. However, the first tube may be arranged radially outside of the second tube. For example, when the first tube overlaps with a second tube, which is shorter than the first tube, the length difference between the tubes forms a space in the head portion of the first tube. A combustion chamber may be arranged in the space. In the above embodiments, the burner includes a premixing chamber, but the burner may be a diffusion combustion type burner. In the above embodiments, the fuel supply unit 24 is a type of device that vaporizes fuel inside, but may be a type of device that sprays liquid fuel into the inner tube 11 . The ignition portion 27 may include a glow plug, a laser spark device, and a plasma spark device in addition to the spark plug as necessary. If the ignition portion 27 can generates a flame F, the ignition portion 27 may include only one of the glow plug, the laser spark device, and the plasma spark device. Not limited to intake air flowing through the intake passage 5 , air for combustion may be air flowing through a pipe connected to a brake air tank or air supplied by a blower for the burner of an exhaust gas purification device. Not limited to the DPF 3 , the exhaust gas purification device may be a device including a catalyst for purifying an exhaust gas. In this case, the burner 10 raises the temperature of the catalyst and therefore, the temperature promptly rises to the activation temperature. The engine including the burner for an exhaust gas purification device may be a gasoline engine.
DESCRIPTION OF THE REFERENCE NUMERALS
10 : burner; 11 : inner tube as a first tube; 11 B: radially-enlarged portion; 11 E: hooks; 11 F: flange; 12 : outer tube as a second tube; 12 A: radially-narrowed portion; 25 : combustion chamber; 31 : discharge port; 33 : wire mesh as a closing part; 35 : distribution chamber as an air flow path; 60 : connecting wall included in a first connecting tube portion; 61 : burner head included in a second connecting tube portion; 62 : first connecting tube included in the first connecting tube portion; and 63 : second connecting tube included in the second connecting tube portion. | A burner for exhaust gas purification devices, comprising a base, a first pipe section, and a second pipe section. The first pipe section has a base end section, a tip section, a combustion chamber wherein combustion air and fuel are combusted, and a discharge port from which combusted gas is discharged. The base end section is fixed to the base. An air flowpath through which combustion air passes is provided between the first pipe section and the second pipe section. The burner for exhaust gas purification devices also comprises a compressable blocking section fixed to the first pipe section or the second pipe section, and interposed between the tip section of the first pipe section and the second pipe section. The entire perimeter of the tip section of the first pipe section is supported so as to be slidable relative to the second pipe section, via the blocking section. |
[0001] This application is a continuation of U.S. application Ser. No. 13/933,288, filed Jul. 2, 2013, the entire contents of which is hereby incorporated by reference.
BACKGROUND
[0002] This application relates to methods of manufacturing and mounting a printed circuit board in a receiving socket such that electrical leads on the printed circuit board maintain good electrical connections with pins in the receiving socket. In particular, the application is concerned with creating a mounting structure that will ensure good electrical connections are maintained even when the assembly is subjected to significant levels of shock and vibration.
[0003] A printed circuit board (PCB) both mechanically supports and electrically connects electronic components. A PCB may include one or more non-conductive layers which provide mechanical support and electrical separation/insulation for one or more conductive layers. The one or more conductive layers, for example, may include any electrically conductive material such as copper, silver, aluminum, etc. The conductive layers may be formed on the PCB in patterns that allow leads of selected electrical components that are mounted on the PCB to be electrically connected to one another.
[0004] FIGS. 1A and 1B illustrate a related art PCB 1 , and a mounting socket 2 that receives the PCB. The PCB 1 includes a substrate 11 , electronic components 12 , and a plurality of electrical leads 13 formed along the lower edge of the substrate 11 . Electrical components 12 can be formed on both sides of the substrate. Likewise, separate electrical leads 13 may be formed on opposite sides of the substrate. Conductive layers or traces on the substrate electrically connect leads of the electrical components 12 to the electrical leads 13 on the bottom edge of the substrate.
[0005] The PCB is mounted in the socket 2 by pushing the lower edge of the PCB into a slot 22 formed between sidewalls 25 of the socket 2 , as illustrated in FIG. 1B . Electrical contacts or pins in the slot 22 couple to the electrical leads 13 on sides of the bottom edge of the PCB 1 . The socket may also include pivoting locking clips 21 that engage slots 15 on side edges of the PCB to hold the PCB 1 in the socket 2 . When the locking clips 21 are pivoted outward away from the side edges of the PCB 1 , they may exert an upward force on the bottom edge of the PCB 1 that tends to push the PCB 1 out of the slot 22 of the socket 2 .
[0006] Unfortunately, when a PCB 1 and mounting slot 2 arrangement as shown in FIGS. 1A and 1B are subjected to significant levels of shock and vibration, the PCB 1 can move with respect to the mounting socket 2 . This movement of the PCB 1 can cause an electrical connection between the electrical leads 13 on the bottom edge of the PCB 1 and contacts in the slot 22 to be broken temporarily broken or impaired. Although contact between the electrical contacts 13 and the leads in the slot 22 may not be completely broken, movements of the PCB 1 with respect to the mounting slot 22 may cause the electrical resistance of the connection to vary over time. And this change in electrical resistance alone could cause problems for signals traversing the connection. As a result of these factors, when such an assembly is subjected to significant shock and vibration, it is common for an electrical computing system using this arrangement to report faults or errors, or completely stop responding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIGS. 1A and 1B illustrated a background art PCB and mounting socket;
[0008] FIGS. 2A and 2B are perspective views of opposite sides of a first embodiment of a PCB having retention bosses that is positioned above a mounting slot;
[0009] FIG. 3 is a side view of PCB having retention bosses mounted in a mounting slot;
[0010] FIG. 4 is a cross-sectional view of a PCB having retention basses mounted in a mounting slot;
[0011] FIG. 5 is a perspective view of a PCB with discontinuous sections of a retention boss;
[0012] FIG. 6A-6C are cross-sectional views illustrating alternate cross-sectional shapes of retention bosses; and
[0013] FIG. 7 illustrates steps of a method of forming a PCB with retention bosses.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0014] A detailed description of exemplary embodiments is provided with reference to the accompanying drawings. Like reference numerals indicate like parts throughout the drawings.
[0015] FIGS. 2A and 2B illustrate a printed circuit board (PCB) 100 positioned above a mounting socket. FIG. 2A shows a first side 110 of the PCB 100 , and FIG. 2B shows a second, opposite side 120 of the PCB 100 . As described above, a variety of electrical components would be mounted on one or both of the first and second sides 110 , 120 of the PCB 100 . Electrically conductive layers or traces would couple those electrical components to electrical leads 130 formed on the bottom edge of the PCB 100 . For ease of illustration, however, the electrical components and electrically conductive leads and traces are not shown.
[0016] One or more retention bosses are formed on the sides of the PCB 100 . In the embodiment illustrated in FIGS. 2A and 2B , a first retention boss 30 is formed on the first side 110 of the PCB 100 , and a second retention boss 40 is formed on the second side 120 of the PCB. The first and second retention bosses 30 , 40 are formed adjacent the lower edge of the PCB, above the electrical leads 130 . FIG. 3 shows the PCB 100 after it has been inserted into the mounting slot 22 of a mounting socket 2 . Once the PCB 100 is inserted into the mounting slot 22 , lower surfaces 35 , 45 of the first and second retention bosses 30 , 40 abut upper surfaces 25 of the mounting socket 2 on opposite sides of the mounting slot 22 .
[0017] The presence of the first and second retention bosses 30 , 40 helps to stabilize the PCB 100 with respect to the mounting socket 2 when the assembly is subjected to shock and vibration. Because bottom surfaces 35 , 45 of the first and second retention bosses 30 , 40 abut the upper surfaces 25 of the mounting socket 2 , the PCB is less likely to wobble in the slot 22 , or to rotate around the lower edge of the PCB, when the assembly is subjected to shock and vibration. Any rotation of the PCB that does occur is likely to be a pivoting movement around the upper surfaces 25 of the mounting socket 2 , instead of a point lower down where the electrical leads 130 on the PCB are located. As a result, the bottom edge of the PCB and the electrical leads tend to move laterally from side to side against the bias of the electrical contacts 27 in the receiving slot 22 of the mounting socket 2 . These aspects of the design cause any movements of the bottom edge of the PCB to smaller than movements that would occur if the retention bosses 30 , 40 were not present. As a result, the electrical connections between the electrical leads 130 on the PCB and the electrical contacts 27 in the mounting socket 2 are better maintained when the assembly is subjected to shock and vibration.
[0018] The retention bosses 30 , 40 may be any length. In some embodiments, the retention bosses may run along substantially the entire length of the PCB. In alternate embodiments, the retention bosses may only extend along a portion of the length of the PCB. In still other embodiments, two or more discontinuous segments of a retention boss may be formed along a single side of the PCB.
[0019] For example, FIG. 5 illustrates a PCB 100 with three discontinuous segments 50 , 52 , 54 of a retention boss formed on one side of the PCB. The retention boss may be made discontinuous to avoid covering up an electrical component that requires air cooling for proper operation. Alternatively, it may be advantageous to form only a few segments of the retention boss along the length of the PCB to minimize the weight of the assembly, or to reduce material consumption. Several separate segments of a retention boss formed along the length of the retention boss may provide most of the immobilizing benefits as a continuous retention boss formed along the entire length of the PCB.
[0020] In some embodiments, the length of the first retention boss 30 is controlled such that first and second end surfaces 34 , 36 of the first retention boss 30 engage corresponding inner surfaces 24 , 26 of the mounting socket. Likewise, a length of the second retention boss 40 is controlled such that first and second end surfaces 44 , 46 of the second retention boss 40 engage corresponding inner surfaces 24 , 26 of the mounting socket. The engagement between the first and second end surfaces of the retention bosses and the corresponding inner surfaces of the mounting socket 2 may also help to keep the PCB 100 from moving with respect to the mounting socket 2 .
[0021] In some embodiments, an adhesive layer may be formed along the bottom surfaces 35 , 45 of the first and second retention bosses 30 , 40 . When a PCB 100 having this configuration is mounted in a mounting slot 22 of a mounting socket 2 , the adhesive layer bonds to the upper surfaces 25 of the mounting socket 2 on opposite sides of the mounting slot 22 , which helps to further immobilize the PCB with respect to the mounting socket. FIG. 4 shows a cross-sectional view of a PCB 100 having this configuration.
[0022] As shown in FIG. 4 , an adhesive layer 37 is formed on the lower surface of the first retention boss, and an adhesive layer 47 is formed on a bottom surface of the second retention boss 40 . The adhesive layers 37 , 47 bond to the top surfaces 25 of the mounting socket 2 located on opposite sides of the mounting slot 22 . FIG. 4 also illustrates how electrical contacts 27 in the mounting slot 22 contact electrical leads on the bottom edge of the PCB 100 .
[0023] Adhesive layers may also be provided on the end surfaces 34 , 36 , 44 , 46 of the retention bosses. Such adhesive layers would bond to the corresponding inner side surfaces 24 , 26 of the mounting socket 2 to help keep the PCB immobilized with respect to the mounting socket.
[0024] When adhesive layers are provided on surfaces of the retention bosses, the adhesive layers may initially be covered by a removable protective film. When one wishes to mount the PCB in a mounting socket, one would remove the protective film, then insert the PCB 100 into the mounting slot of the mounting socket until the adhesive layers contact and adhere to corresponding surfaces of the mounting socket.
[0025] The width of the bottom surfaces 35 , 45 of the retention bosses 40 , 50 , may be greater than, equal to, or less than a width of the upper surfaces 25 of the mounting socket located on opposite sides of the slot 22 of the mounting socket 2 .
[0026] As illustrated in FIG. 4 , a cross-sectional shape of the retention bosses 30 , 40 may be square or rectangular. However, the retention bosses could also have many other cross-sectional shapes.
[0027] For example, FIG. 6A shows a PCB 100 with retention bosses 60 , 62 having a triangular cross-sectional shape. FIG. 6B illustrates a PCB 100 with retention bosses 64 , 66 having convex side surfaces. FIG. 6C illustrates a OCB 100 having retention bosses with concave side surfaces. Of course, many other cross-sectional shapes are also possible.
[0028] The retention bosses can be formed of any suitable material which does not interfere with the proper operation of the PCB 100 . In some embodiments, it may be desirable for the material of the retention bosses to be electrically insulative, such that the retention bosses do not interfere with or short circuit any of the electrical components, conductive layers or traces that are formed on the PCB.
[0029] In some embodiments, the retention bosses may be formed of a molding resin, such as an epoxy resin. The resin preferably has a relatively high electrical resistivity, which helps to prevent any short circuiting of any electrical components, leads or metal traces covered by the resin.
[0030] In some embodiments, the retention bosses may be formed of a material that is semi-rigid. In these embodiments, it may be desirable to form the retention bosses such that they have a length that is slightly longer than the distance between the interior side surfaces 24 , 26 of the mounting socket. As a result, the retention bosses will be slightly compressed and deformed when the PCB is inserted into the mounting socket. This will provide an interference fit that helps to keep the PCB immobilized with respect to the mounting socket.
[0031] In the embodiments described thus far, retention bosses are formed on opposite sides 110 , 120 of a PCB 100 . However, in alternate embodiments, a retention boss may be formed on only one side of a PCB. Further, if retention bosses are formed on opposite sides of a PCB, the retention boss on a first side of the PCB may have a different configuration than a retention boss on the opposite side of the PCB.
[0032] FIG. 7 illustrates steps of forming a PCB having retention bosses. The method begins in step S 702 , when a PCB is inserted into a mold having one or more cavities that are configured to form the retention bosses. In step S 704 , a molding resin is inserted into the mold cavities. In step S 706 , the resin is allowed to cure. The PCB with the cured resin retention bosses is then removed from the mold.
[0033] In an optional final step S 708 , an adhesive is applied to selected surfaces of the retention bosses. As noted above, the surfaces of the adhesive opposite the retention bosses may be covered with a removable protective film.
[0034] The forgoing exemplary embodiments are intended to provide an understanding of the disclosure to one of ordinary skill in the art. The forgoing description is not intended to limit the inventive concept described in this application, the scope of which is defined in the following claims. | A circuit board that is to be mounted in a connector socket includes a plurality of electrical connectors located along a side edge of the circuit board. Retention bosses are formed on first and second opposite sides of the circuit board, each of the retention bosses protruding from a surface of the circuit board and extending parallel to and adjacent to the first edge of the circuit board. When the first edge of the circuit board is inserted into a slot of a connector socket, contact surfaces of the first and second retention bosses contact top surfaces of the connector socket to help immobilize the circuit board with respect to the connector socket. Adhesive layers on the contact surfaces of the first and second retention bosses may adhere to the top surfaces of the connector socket to help hold the circuit board immobile with respect to the connector socket. |
TECHNICAL FIELD
The invention relates to apparatus for actuating shifting mechanisms in devices having multi-sprocket variable-ratio power transmissions. The invention may be embodied in a bicycle gear changing mechanism.
BACKGROUND OF THE INVENTION
A typical multi-speed bicycle has a chain drive, which connects a pedal-driven crank to a driven wheel. The chain drive may have several front sprockets (chain rings) of different pitch diameters and several rear sprockets of different pitch diameters. The front sprockets are connected to the crank and rotate with the pedals. The rear sprockets are coupled to the driven wheel of the bicycle. A chain couples one of the front sprockets to one of the rear sprockets. Different gear ratios can be selected by moving the chain so that it couples a selected front sprocket to a selected rear sprocket.
Such bicycles typically have cable-actuated front and rear derailleurs. A cyclist can operate the front derailleur to move the chain to a selected one of the front sprockets. The cyclist can operate the rear derailleur to move the chain to a selected one of the rear sprockets.
There are various handlebar mounted mechanisms, which a cyclist can use to operate the front and rear derailleurs to achieve a desired gear ratio. For example, some bicycles have a pivotable lever mounted on each side of the handle bar. One lever is connected to a cable that operates the front derailleur and the other is connected to a cable that operates the rear derailleur. A cyclist can select a desired gear ratio by pivoting the levers.
The GRIP SHIFT™ shifting mechanism provides a pair of handle-bar mounted collars. One collar is mounted to a bicycle's right handlebar and the other to the bicycle's left handlebar. One of the collars is connected to a cable that operates the front derailleur. The other collar is connected to a cable that operates the rear derailleur. A cyclist can rotate the collars relative to the bicycle handlebar to select a desired gear ratio.
Cirami, U.S. Pat. No. 4,201,095, describes a bicycle gear-shifter having a single lever that operates both front and rear derailleurs to yield a progressive and programmed series of gear ratios. The Cirami mechanism has two flat plane cams. Intermediate drive ratios are obtained in consecutive increments ordered from the lowest to the highest drive ratio positions of the lever. Cirami proposes a shift pattern that avoids gear ratios that result in cross chaining.
Ross, U.S. Pat. No. 4,279,174, discloses another bicycle gear shifter which permits a cyclist to operate front and rear derailleurs by manipulating a single control. The Ross shifter requires two types of derailleurs: a spring-biased front derailleur and a “push-pull” rear derailleur. The Ross shifter is constructed to provide a progressive shift pattern. Ross describes a shift pattern in which four changes involve shifting or changing the position of both derailleurs simultaneously to provide a progressive series of gear ratios.
Watarai, U.S. Pat. No. 5,577,969, discloses an electronic apparatus for controlling both the front and rear derailleurs of a bicycle. A cyclist can cause the apparatus to shift between gears by operating a lever.
Brix, U.S. Pat. No. 1,114,400, describes a mechanism for adjusting the positions of rods, which control the spark control, throttle, muffler control and engine clutch of a motorcycle. Each control rod is independently adjusted. The Brix mechanism employs two cylindrical sleeves, which are coupled to, and located within, the motorcycle handgrip. Each sleeve is associated with one of the control rods and features a helical groove in its cylindrical surface. When the rider rotates the handgrip, one sleeve is rotated, while the other is prevented from rotating. A cam follower travels in the helical groove of the rotating sleeve, causing longitudinal movement of the associated control rod.
Savard, U.S. Pat. No. 5, 970,816, describes a bicycle gear shifter, which provides a mechanism for controlling both front and rear derailleurs. The mechanism is operated by rotating one handgrip. A cylindrical barrel is attached to the inner end of the handgrip. The barrel has a track on each of its inner and outer faces. Cables from the front and rear derailleurs are each connected to a corresponding one of a pair of cam followers. The cam followers each slide in one of the tracks. When the barrel is rotated, the members move the derailleur cables to select different gear ratios. The cam followers and follower guides are located close to each other on the outside of the handlebar. This results in a large bulbous assembly on the inboard side of the separate rotatable handgrip. A separate detent mechanism holds the collar in a position corresponding to the selected gear ratio. Like Cirami, Ross, and others, the Savard mechanism may be constructed to provide an optimal shift pattern in which undesirable or redundant gear combinations are avoided. A mechanism like the Savard mechanism is marketed by EGS of France under the trademark SYNCHRO SHIFT™. The SYNCHRO SHIFT™ mechanism is undesirably bulky. Its size makes it incompatible with standard bicycle brake levers.
Socard, U.S. Pat. No. 5,447,475 discloses two separate and quite different bicycle gear shifting mechanisms. The mechanisms provide an optimal shift pattern that avoids cross chaining. The mechanisms are actuated via a cable that links to a handle bar mounted shift mechanism which provides two levers; one for shifting up and the other for shifting down. The mechanisms include a cam which rotates 90 degrees for each shift.
Wechsler, U.S. Pat. No. 4,530,678, discloses a bicycle gear shifting mechanism that uses a cylindrical cam with a cam follower to control a rear derailleur. The cam is integrated into the rear derailleur mechanism and has cam grooves cut into its exterior surface. A second rotary cam is used to control a front derailleur. The second cam is integrated into the front derailleur. There is a cable that mechanically connects the front and rear derailleurs so that as one moves, the other also moves. Wechsler's front derailleur cam is shaped to cause the front derailleur to alternate between a large and small chain ring with each consecutive shift.
Patterson, U.S. Pat. No. 4,900,291 discloses a bicycle gear shifting mechanism which has a rotatable handgrip actuator cam that is coupled via a cable to a derailleur mechanism. Separate independent cams are provided for controlling front and rear derailleurs. A cam surface on an edge of each cam abuts against a fixed post. The cam surface has peaks and valleys and uses cable tension to index the shifter. As a cam is rotated the cam slides longitudinally. An end of the cable is attached to the cam.
Ethington, U.S. Pat. No. 5,681,234, discloses an “Automatic Transmission Shifter For Velocipedes” that employs speed and force sensors as well as a programmable logic controller and two servo motors to automatically shift a bicycle transmission according to operating conditions. Ethington discloses a shift pattern that uses all gears in an ascending sequence. Many of the speed changes involve shifting both front and rear derailleurs simultaneously.
Nier, U.S. Pat. No. 5,803,848, discloses a shifter system that employs a shift pattern that is identical to the one used by Socard and others. This system uses flat radial cams that are linked and rotatably mounted on a handle bar. Nier's system combines a cam which operates the front derailleur by way of a mechanical linkage and two other cams with nodes that actuate electric motors to either pull or release the rear derailleur by predetermined amounts. The use of these three cams in combination results in an optimal shift pattern.
Lahat, U.S. Pat. No. 5,865,062, discloses several mechanisms that control both front and rear derailleurs to achieve an optimal shift pattern. These mechanisms show both single cylinders with two cam surfaces and several arrangements of dual cylinders with single cam surfaces. In all cases the cams and followers are located on the exterior of the handlebar. In some cases, the cam and follower assembly are mounted in a separate casing and are not rotatably mounted on the handlebar. In all cases, the mechanisms are “aimed at synchronously controlling both front and rear derailleurs to achieve a predetermined sequential combinations of front and rear gears.
Despite the long history of bicycle development and the large variety of shifting mechanisms that have been proposed for bicycles, there remains a need for practical gear shifting mechanisms suitable for use in bicycles and other pedal-powered vehicles. There is a particular need for such mechanisms, which permit a user to select a desired gear ratio without needing to separately control two shifting mechanisms.
SUMMARY OF THE INVENTION
This invention provides ratio selecting mechanisms and related methods. The ratio selecting mechanisms may be used in bicycles, and other pedal powered mechanisms. The ratio selecting mechanisms may also be used in other applications, wherein a gear ratio is selected by controlling two mechanisms.
One aspect of the invention provides a gearshift mechanism. The mechanism comprises a rotatable handgrip member with first and second guide paths on an inner surface within its bore. First and second followers are configured to engage the first and second guide paths respectively and first and second cable anchors are coupled respectively to the first and second followers. Rotation of the handgrip member simultaneously adjusts the positions of the first and second cable anchors.
The first and second followers may be on opposing sides of the bore.
The first and second guide paths may comprise grooves on the surface of the handgrip member. One or more of the grooves may comprise a plurality of indentations on one of its sides and the indentations may be located at detent positions. The indentations may be conveniently provided in the groove that controls the operation of a front derailleur. In the alternative, the indentations may be provided in the groove that controls the operation of the rear derailleur or distributed between grooves which control the operations of front and rear derailleurs. In the further alternative, a separate detent mechanism may be provided to hold the handgrip member in positions corresponding to selected gear ratios.
The handgrip member may be rotatably mounted on a hollow handlebar. The first and second followers may be coupled respectively to the first and second cable anchors by members that extend through a bore of the handlebar. With such an embodiment, the first and second followers may extend through longitudinally disposed slots in the handlebar. Each follower may comprise a head portion, which is wider than a corresponding one of the slots and a neck portion, which passes through the corresponding slot. The neck portions of the followers may be elongated relative to the head portions of the followers. Each of the slots may have an enlarged portion, through which the head portion of the corresponding follower can pass. The enlarged portion(s) are located outside of the normal range of motion of the followers.
The handgrip member may also comprise one or more substantially cylindrical cam members. The inside walls of the cam members may bear the first and second guide paths. The cam members may be affixed within a bore of a substantially tubular outer handgrip member. The first and second guide paths may comprise grooves on the surfaces of the one or more cam members. The grooves may penetrate the walls of the one or more cam members.
The cable anchors may project from the members through additional longitudinally disposed slots in the handlebar. The gearshift mechanism may comprise a bracket on each of the cable anchors, the bracket having a width greater than that of the corresponding additional slot.
The gearshift mechanism may be used in combination with a transmission comprising: a plurality of front sprockets, a chain, a plurality of rear sprockets, a cable-actuated front derailleur capable of engaging the chain with a selected one of the front sprockets, a cable-actuated rear derailleur capable of engaging the chain with one of the plurality of rear sprockets, a first cable connecting the first cable anchor to the front derailleur, and a second cable connecting the second cable anchor to the rear derailleur.
The handgrip member may be rotatably mounted on a handlebar and the first and second followers may be coupled respectively to the first and second cable anchors by members, which slide in longitudinally extending recesses in the handlebar.
Another aspect of the present invention provides a gearshift mechanism comprising: a hollow handlebar, a member mounted for longitudinal movement within the handlebar, a cable anchor projecting from the member through a slot in a wall of the handlebar, and an actuating mechanism coupled to move the member longitudinally between a plurality of selected positions.
Another aspect of the invention provides a bicycle, which comprises: a frame, a handlebar, a plurality of front sprockets mounted to the frame, a chain, a plurality of rear sprockets, a cable-actuated front derailleur capable of engaging the chain with a selected one of the front sprockets, a cable-actuated rear derailleur capable of engaging the chain with one of the plurality of rear sprockets, a first cable connected at its first end to the front derailleur, a second cable connected at its first end to the rear derailleur, and a gearshift mechanism. The gearshift mechanism comprises a handgrip member rotatably mounted on the handlebar. The handgrip member has first and second guide paths on a substantially cylindrical inner surface of its bore. A first follower engages the first guide path and is coupled to the first cable at its second end and a second follower engages the second guide path and is coupled to the second cable at its second end. Rotation of the handgrip member relative to the handlebar simultaneously adjusts the front and rear derailleurs.
Another aspect of the invention provides for a method of controlling the positions of a first member and a second member along a longitudinal axis. The method involves locating the first and second members within a bore of a handgrip at first and second angular positions respectively about the longitudinal axis. The first and second members are made to respectively engage first and second guide paths on an inner surface of the handgrip. The method also involves rotating the handgrip about the longitudinal axis, while maintaining the first and second angular positions substantially fixed. In this manner, the positions of the first and second members along the longitudinal axis are independently determined by the shapes of the first and second guide paths.
The method may also comprise adjusting positions of first and second cables, which may be coupled respectively to the first and second members.
Other aspects and features of the invention and descriptions of specific embodiments of the invention are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
In drawings, which depict non-limiting embodiments of the invention,
FIG. 1 is an isometric view of a gear shifting mechanism according to one embodiment of the invention, which is mounted on a bicycle handlebar;
FIG. 2 is a close-up view of the gear shifting mechanism of FIG. 1 ;
FIG. 3 is a partially cut-away view of the gear shifting mechanism of FIG. 1 ;
FIG. 4 is an exploded view of the gear shifting mechanism of FIG. 1 ;
FIG. 5 is a plan view of the gear shifting mechanism of FIG. 1 ;
FIG. 5A is a longitudinal cross-sectional view of the gear shifting mechanism of FIG. 1 in the plane 5 A— 5 A of FIG. 5 ;
FIGS. 6A , 6 B, 6 C and 6 D are transverse cross-sectional views of the gear shifting mechanism of FIG. 1 in the planes 6 A— 6 A, 6 B— 6 B and 6 C— 6 C and 6 D— 6 D respectively of FIG. 6 ;
FIG. 7 is an isometric view of a cam cylinder of a gear shifting mechanism similar to the gear shifting mechanism of FIG. 1 , according to another embodiment of the invention;
FIG. 8 is an isometric view of a portion of the handlebar of FIG. 1 ;
FIGS. 8A and 8B are respectively enlarged views of the portions of FIG. 8 within areas 8 A and 8 B;
FIG. 9 depicts is an enlarged isometric view of a portion of the handlebar of FIG. 1 with the cam follower removed;
FIGS. 9A and 9B are respectively enlarged views of the portions of FIG. 9 within areas 9 A and 9 B;
FIG. 10 is a graph of cable extension as a function of handgrip rotation angle for one embodiment of the gear shifting mechanism;
FIG. 11 is a schematic diagram, which illustrates the operation of a gear shifting mechanism according to an embodiment of the invention and FIG. 11A is a magnified view of the area indicated by reference character 11 A in FIG. 11 ;
FIG. 12A is a view of guide paths in a shifter according to one embodiment of the invention and FIG. 12B is a magnified view of a portion of the guide paths of FIG. 12A ;
FIG. 13 is an elevational view of a shifter according to an alternative embodiment of the invention and FIGS. 13A–13D are cross sections through the gear shifting mechanism of FIG. 13 ; and,
FIG. 14 is an elevational view of a shifter according to an alternative embodiment of the invention and FIGS. 14A–14D are cross sections through the gear shifting mechanism of FIG. 14 .
DETAILED DESCRIPTION
The following description describes embodiments of the invention which are useful for selecting gear ratios in a pedal-powered apparatus. In particular, the following description describes a bicycle having a cable-actuated front derailleur, capable of placing a drive chain onto a selected one of a plurality of front sprockets and a cable-actuated rear derailleur, capable of placing the drive chain onto a selected one of a plurality of rear sprockets. The invention is not limited to such embodiments however.
In this description, a numeral followed by the letter “F” refers to an element that is associated with a front derailleur. The same numeral followed by the letter “R” is a reference to a corresponding element that is associated with the rear derailleur. The same numeral standing on its own refers generally to the elements associated with both the front and rear derailleurs.
FIGS. 1 through 3 show a gear shifting mechanism 10 mounted on a bicycle handlebar 12 . FIG. 4 is an exploded view of mechanism 10 . In FIG. 4 the parts of mechanism 10 have been exploded both radially and axially. As a consequence, members 24 R and 24 F. which are normally within handlebar 12 (as shown, for example, in FIGS. 1 to 3 ) are displayed outside of handlebar 12 in the exploded view of FIG. 4 . Gear shifting mechanism 10 controls front and rear derailleurs (not shown) by way of cables 14 F and 14 R respectively. Mechanism 10 can be operated by rotating a handgrip 16 . As handgrip 16 is rotated in a first angular direction, mechanism 10 moves cables 14 F and 14 R in a coordinated manner, so as to select progressively increasing gear ratios. As handgrip 16 is rotated in a second angular direction opposite to the first angular direction, mechanism 10 moves cables 14 F and 14 R in a coordinated manner, so as to select progressively decreasing gear ratios.
Handgrip 16 may be covered with a resilient material. The outside of handgrip 16 has a shape which can be comfortably gripped. For example, the outside of handgrip 16 may be cylindrical or generally cylindrical. Handgrip 16 preferably has a diameter, which does not exceed about 38 millimetres, so that it can be readily grasped by children and adult users with typical-sized hands. Handgrip 16 includes a cam cylinder 20 , which is coupled to rotate with handgrip 16 relative to handlebar 12 . Cam cylinder 20 may be integral with handgrip 16 or may comprise a separate part. In the illustrated embodiment, handgrip 16 comprises an outer handgrip member 16 A having a bore 16 B. Cam cylinder 20 is received in bore 16 B of outer handgrip member 16 A. Handgrip 16 has a bore 16 C that extends through cam cylinder 20 . Handgrip 16 can be rotated about an axis 17 .
Cam cylinder 20 has a bore 21 , which receives one end of handlebar 12 . An inner end 20 ′ of cam cylinder 20 bears against a surface which prevents cam cylinder 20 from sliding inwardly along handlebar 12 . A pair of guide paths 22 are defined in bore 21 . In the illustrated embodiment, guide paths 22 F and 22 R each comprise a groove. Cam cylinder 20 may comprise an outer sleeve 20 A. In FIG. 4 , cam cylinder 20 and outer sleeve 20 A are shown as being separated axially in FIG. 4 so that guide paths 22 F and 22 R can be seen. Cam cylinder 20 may also have a one-piece construction as shown, for example, in some other Figures.
In the illustrated embodiment (see FIG. 4 ) a gasket 23 of a low friction plastic material such as Delrin™ is provided on the inboard end of cam 20 . Gasket 23 rotates with cam 20 and bears against the flat surface of housing 23 A which in turn bears against brake post 45 which is clamped to handlebar 12 . Gasket 23 prevents cam 20 and housing 23 A from wearing where they rub against one another and provides increased contact surface area with cam 20 and housing 23 A.
The position of each cable 14 is controlled by one of a pair of members 24 (see FIG. 5A ), each of which includes a follower 26 . Followers 26 each engage a corresponding one of guide paths 22 . Members 24 are at fixed circumferential locations relative to handlebar 12 , but are free to travel longitudinally. As handgrip 16 is rotated relative to handlebar 12 , followers 26 move members 24 longitudinally as indicated by arrows 27 F and 27 R. In the illustrated embodiment, followers 26 comprise pins, which project into the groove of the corresponding guide path 22 . Followers 26 are cylindrical and have diameters slightly less than the widths of the grooves into which they project. As best seen in FIG. 6C , the radially outermost ends of followers 26 may be curved to conform with the curves of the bases of guide paths 22 . This permits the area of contact between followers 26 and the surfaces of guide paths 22 to be increased.
Each cable 14 is coupled to a corresponding one of members 24 . In the illustrated embodiment each member 24 has a cable anchor 28 , which receives one of cables 14 .
Cables 14 are attached to cable anchors 28 by any suitable means for attaching the cables to the cable anchors. In the embodiment of FIGS. 8 and 9 , each cable 14 passes through an aperture 29 in the corresponding cable anchor 28 . Cables 14 have enlarged portions 30 (see FIG. 4 ) that will not fit through apertures 29 . Other means could be used for attaching cables 14 to cable anchors 28 . For example, a cable 14 having an enlarged end portion could pass through a slot in a cable anchor or a mechanical clamp could be provided on the cable anchor for the purpose of holding the cable.
Each cable 14 runs within a sheath 32 . The position of a cable 14 relative to its sheath 32 can be adjusted by way of an adjusting nut 34 , which adjustably engages a cable guide 35 . Cable guide 35 may be attached, for example by clamping, to handlebar 12 . In the illustrated embodiment, cable guide 35 is not affixed to handlebar 12 . Cable guide 35 is kept in position by cable 14 which is held in place by cam followers 22 . Allowing cable guide 35 to float somewhat permits mechanism 10 to be displaced so that it can absorb some impacts without suffering damage. Tension in cables 14 holds cable guide 35 snugly against brake post 45 . A cover 36 (see FIG. 2 ) may be provided to protect cable anchors 28 and keep dirt and other contaminants out of the mechanism.
Members 24 are configured so that they do not interfere with one another as they move. This may be achieved by spacing members 24 apart in a circumferential direction. Members 24 may be opposed to one another, as illustrated, or may be more closely spaced around the circumference of handlebar 12 . For example, members 24 could be circumferentially spaced apart by 90 degrees or some other angle.
As shown in FIG. 8 , members 24 are located inside handlebar 12 . Followers 26 project outwardly through slots 33 in handlebar 12 . As shown in FIGS. 8A and 9A , each follower 26 may comprise a head portion 37 , which is wider than the corresponding slot 33 , and a neck portion 38 , which passes through the corresponding slot 33 . Neck portion 38 may be elongated relative to head portion 37 as shown in the illustrated embodiment. Slots 33 may have enlarged portions 33 ′ through which head portion 37 can pass. The illustrated configuration ensures that the followers 26 fully engage guide paths 22 . Enlarged portions 33 ′ are preferably located a small distance distal to the normal range of motion provided by guide paths 22 so that head portions 37 of followers 36 do not encounter enlarged portions 33 ′ during normal operation.
Cable anchors 28 also project through slots 39 in handlebar 12 . In the illustrated embodiment, a bracket 40 is mounted to each of cable anchors 28 . Brackets 40 are configured to receive the enlarged ends 30 of cables 14 . Brackets 40 are wider than slots 39 and prevent cable anchors 28 from slipping radially inwardly through slots 39 . Brackets 40 hold cable anchors 28 in positions such that cables 14 are supported so that they do not rub excessively on surfaces within the bores of adjusting screws 34 and cable guides 35 as gear shifting mechanism 10 is operated. Since each cable 14 passes through a hole in bracket 40 as well as a hole in cable anchor 28 , the cable 14 holds its bracket 40 and cable anchor 28 together when the cable 14 is under tension. Therefore, follower members 24 are constrained to move in the longitudinal direction only. Brackets 40 are not essential to the operation of gear shifting mechanism 10 .
Guide paths 22 follow trajectories, which move followers 26 , and consequently cables 14 , in a longitudinal direction as necessary to control front and rear derailleurs (or other shifting mechanisms), to switch through a sequence of gear ratios as handgrip 16 is turned through its range of motion. The longitudinal travel of a member 24 for a given rotation of handgrip 16 depends upon the helical slope (i.e. longitudinal displacement per unit of rotation) of guide path 22 in the region in question. If a particular angular region of a guide path 22 extends generally circumferentially, then rotation of handgrip 16 while a follower 26 is in that particular angular region causes little or no longitudinal motion of the corresponding member 24 . Conversely, if a follower 26 is in an angular region where the guide path 22 has a greater helical slope, rotation of handgrip 16 causes a greater longitudinal movement of the corresponding member 24 . Front and rear guide paths 22 are, in general, shaped differently from one another. Consequently, rotation of handgrip 16 through a range of angles can cause member 24 F to move through a different distance and/or move in a different direction from member 24 R.
In the illustrated embodiments, guide paths 22 are shaped so that, when handgrip 16 is in any one of a plurality of discrete angular positions, cables 14 are positioned to provide a specific gear ratio corresponding to that angular position.
Gear shifting mechanism 10 preferably includes a detent mechanism whereby, when handgrip 16 is in one of these discrete angular positions, there is some resistance to rotating handgrip 16 in either angular direction. In preferred embodiments, at least one of cables 14 is maintained under tension and a corresponding one of guide paths 20 has indentations 41 located along it. Indentations 41 are at places such that, when handgrip 16 is in one of the discrete angular positions, the follower 26 is engaged in one of the indentations. Indentations 41 are shaped so that follower 26 must be moved to pull on the corresponding cable if handgrip 16 is rotated in either angular direction. Cables 14 are maintained under tension by springs or other bias elements (not shown). The bias elements may be parts of the corresponding front and rear derailleurs or other shifting mechanisms operated by cables 14 . Currently available front and rear derailleurs typically include springs which serve as bias elements. A separate detent mechanism could be present within the mechanism of gear shifting device 10 . A separate detent mechanism is not required in the illustrated embodiment of the invention.
Gear shifting device 10 can be made very compact. As shown in FIG. 2 , gear shifting device 10 may be compact enough that it does not interfere with the use of a typical bicycle brake lever 44 . A post 45 which supports brake lever 44 may be integrated with gear shifting device 10 as shown in FIG. 3 . Post 45 may be part of a standard brake clamp.
A bicycle may have a large number of gear ratios which are available in theory. For example, a bicycle having 3 front sprockets and 8 rear sprockets has, in theory, 3×8=24 distinct gear ratios. With conventional shifters all possible gear ratios are typically available. In practice, not all combinations of a front sprocket and a rear sprocket are desirable for use. Many possible gear combinations provide gear ratios that are redundant and/or result in severe cross chaining conditions. It is desirable to avoid “cross-chaining”. Cross-chaining occurs, for example, where the chain is engaged on the largest front sprocket and the largest rear sprocket (or the smallest front sprocket and the smallest rear sprocket). Further, some different combinations of front and rear sprockets typically provide very similar gear ratios. For a given set of front and rear sprockets, there is typically a set of pairs of front and rear sprockets that provide an optimum shift pattern. For example, Table I shows gear ratios for a bicycle having three front sprockets respectively with 28, 38 and 48 teeth and eight rear sprockets, respectively with 11, 13, 15, 17, 20, 23, 26, and 30 teeth.
TABLE I
GEAR RATIOS
TEETH (FRONT–REAR)
RATIO
INCLUDE
COMMENT
28–30
0.93
Y
1 - Lowest gear
28–26
1.08
Y
2
28–23
1.22
Y
3
38–30
1.27
N
Cross chain
28–20
1.4
Y
4
38–26
1.46
N
Cross chain
48–30
1.6
N
Cross chain
38–23
1.65
Y
5
28–17
1.65
N
Cross chain
48–26
1.85
N
Cross chain
28–15
1.87
N
Cross chain
38–20
1.9
Y
6
48–23
2.09
N
Cross chain
28–13
2.15
N
Cross chain
38–17
2.24
Y
7
48–20
2.40
N
Cross chain
38–15
2.53
Y
8
28–11
2.55
N
Cross chain
48–17
2.82
Y
9
38–13
2.92
N
Cross chain
48–15
3.2
Y
10
38–11
3.45
N
Cross chain
48–13
3.69
Y
11
48–11
4.36
Y
12 - Highest gear
As shown in the “Include” column of Table I, one can achieve a sequence of front-rear sprocket pairs that represents a desirable shift pattern by eliminating front-rear sprocket pairs that have undesirable cross-chaining and front-rear sprocket pairs that provide gear ratios, which are similar to those of other front-rear sprocket pairs. The resulting optimized shift pattern has a reduced number of gear ratios. For example, the shift pattern of Table I includes 12 of the 24 possible front-rear sprocket pairs. Guide paths 22 may be shaped to provide an optimized shift pattern, such as that shown in Table I, in which continued rotation of handgrip 16 in one angular direction progressively operates cables 14 to select, in sequence, the pairs of sprockets included in the optimized shift pattern.
FIG. 10 is a graph depicting the longitudinal displacement (×) of cables 14 F and 14 R for a given rotational angle (⊖) of handgrip 16 . FIG. 10 shows an optimal shift pattern for a 3×7 configuration in which 11 of 21 possible gear combinations are used. It can be seen from FIG. 10 , that the discrete angular positions of handgrip 16 do not need to be equally angularly spaced-apart from one another. It can also be seen from FIG. 10 that guide paths 22 may extend around handgrip 16 by more than 360 degrees such that more than one full revolution of handgrip 16 is required to move through the full range provided by guide paths 22 .
The torque required to turn handgrip 16 increases with the tension in cables 14 and with the displacement (×) through which cables 14 are pulled for a given angular rotation (⊖) of handgrip 16 (i.e. the helical slope of guide paths 22 ). Friction between components also affects the required torque. In general, a user must do more work between discrete angular positions for shifts in which both cables 14 are being pulled (e.g. shifts in which both front and rear derailleurs are moving the chain to a larger sprocket—an example of such a shift is the shift between the 8 th and 9 th gear ratios of the shift sequence shown in both Table I and FIG. 10 , wherein the shift is from the 38-15 sprocket pair to the 48-17 sprocket pair). The torque that a user must apply to make such difficult shifts can be reduced by shaping guide paths 22 , so that hand grip 16 rotates through a larger rotation angle (⊖) when such difficult than it does for shifts which require less mechanical work to accomplish. This shape for guide paths 22 is represented in FIG. 10 by a line having a lesser relative slope. Conversely, guide paths 22 can be shaped such that handgrip 16 rotates through a smaller angle when shifts that require less work are made. This variation in the rotational angle between discrete angular positions permits guide paths 22 to have a variety of helical slopes ranging from more gradual to less gradual depending on the amount of work required.
In some embodiments of the invention, guide paths 22 are shaped such that followers 26 move by no more than 0.06 mm in a longitudinal direction per degree of rotation of handgrip 16 as they traverse the portions of guide paths 22 between adjacent discrete angular positions. In some embodiments followers move by not more than 0.03 mm per degree of rotation averaged over a shift.
FIG. 11 illustrates one specific embodiment of the invention in which a front derailleur 60 F is controlled by cable 14 F and a rear derailleur 60 R is controlled by cable 14 R. A chain 61 can be engaged with a selected one of front sprockets FS- 1 , FS- 2 , and FS- 3 by placing front derailleur 60 F in a corresponding one of its positions FD- 1 , FD- 2 , and FD- 3 . Similarly, rear derailleur 60 R has a number of positions RD- 1 to RD- 7 , which place the chain on a corresponding one of rear sprockets RS- 1 to RS- 7 .
The torque which a user must apply to rotate handgrip 16 can be further controlled by tailoring the shape of guide paths 22 in their portions which control shifts involving changes in the positions of both front and rear derailleurs. As shown in FIGS. 12A and 12B , guide paths 22 may be constructed so that only one derailleur is moved at a time in such shifts. Angular portion 65 corresponds to a shift in which guide path 22 F shifts front derailleur 60 F (see FIG. 11 ) and guide path 22 R shifts rear derailleur 60 R (see FIG. 11 ). As best seen in FIG. 12B , in a first part 66 of angular portion 65 , guide path 22 R angles so that rear derailleur 60 R is shifted while guide path 22 F has no slope so that front derailleur 60 F is not shifted. In a second part 67 of angular portion 65 , guide path 22 F angles so that front derailleur 60 F is shifted while guide path 22 R has no slope so that rear derailleur 60 R is not shifted.
Some particular shifts involve changing the positions of both the front and rear derailleurs. For example, as shown in FIGS. 10 and 11 , the shifts between the 4 th and 5 th gear ratios and the 8 th and 9 th gear ratios involve changing the positions of both front derailleur 60 F and rear derailleur 60 R. In some embodiments of the invention, such multi-derailleur shifts may involve moving one derailleur and then moving the other derailleur. For example, when switching from the 4 th to 5 th gear ratio, the guide paths 22 R and 22 F may be shaped, such that rear derailleur 60 R moves first, so that chain 61 moves from the 4 th rear sprocket (RS- 4 ) to the larger 3 rd rear sprocket (RS- 3 ), and thereafter front derailleur 60 F moves, so that chain 61 moves from the 1 st front sprocket (FS- 1 ) to the larger 2 nd front sprocket (FS- 2 ). The order of movement of front derailleur 60 F and rear derailleur 60 R will be reversed when shifting down from the 5 th to the 4 th gear ratio. Other multi-derailleur shifts may be implemented in a similar manner, such that one derailleur is moved prior to the other.
It can be appreciated that the embodiments described above provide bicycle gear shifters, which may be made in a compact rugged units. One feature that helps to make mechanism 10 compact is that cable anchors 28 are located inboard with respect to brake post 45 while cam cylinder 20 and followers 26 are located out board with respect to brake post 45 . Cam follower members 24 move longitudinally within the normal bore of brake post 45 .
While this invention has been described with reference to illustrative embodiments, the invention is not limited to the embodiments described herein. It will be apparent to those skilled in the art in the light of the foregoing disclosure that many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:
A shifting mechanism according to the invention may be adapted to control “push-pull” derailleurs; The invention may be applied to the selection of ratios in transmissions other than bicycle transmissions. The invention may be applied in pedal-powered vehicles such as pedal-powered tricycles, pedal cars, pedal-powered water craft and the like. The invention may be applied to selecting gear ratios in other apparatus, which include a handgrip and a suitable variable-ratio power transmission; Shifting mechanisms other than derailleurs may be controlled by the gear shifting mechanism. For example, a gear shifting mechanism according to the invention may be used to select a ratio in a transmission which includes a front or rear derailleur and a variable-ratio gear train internal to a hub of the driven wheel; With an additional guide path 22 and associated coupling to a third cable, a gear shifting mechanism according to the invention may be used to select a ratio in a transmission having three shifting mechanisms. For example, a transmission having front and rear derailleurs and an additional variable gear train internal to a hub of the driven wheel; While the gear shifting mechanism 10 is shown in the Figures as being associated with a right handgrip, a gear shifting mechanism according to the invention could be associated with a left handgrip or with a handgrip not mounted on a handlebar; The number of discrete angular positions for each of the gear selecting mechanisms may be varied (i.e. in the illustrated embodiments, the numbers of front and rear sprockets can be varied); and, The particular selection of gear ratios is not critical to the invention. The gear ratios used preferably provide an optimal shift pattern. Determining an optimal shift pattern for any derailleur system is a matter of simply arranging gear ratios in ascending order and selecting a sequence that minimizes cross chaining. This is not difficult for anyone skilled in the art and is an obvious starting point for any integrated shifter design. Instead of being located inside the bore of a handlebar, members 24 may slide in longitudinal grooves 70 on an exterior surface of a handlebar as shown, for example, in FIG. 13 . As a further alternative, handlebar 12 may comprise flattened faces 70 A and members 24 may slide on the flattened faces as shown in FIG. 14 . Instead of using cables 14 to control the operation of derailleurs, a gear shifter according to the invention may comprise hydraulic or pneumatic mechanisms which control the operation of gear shifting devices such as derailleurs in response to movements of followers 26 .
Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims. | An apparatus and accompanying method are disclosed for a handgrip based gear-shifting mechanism used to manipulate the front and rear derailleur cables on a vehicle having a multi-sprocket gear system. The gear-shifter comprises a substantially hollow handgrip member that has first and second cam guide paths in the bore of its substantially cylindrical surface. First and second cam followers, preferably located inside the bore of the handgrip member, engage the first and second cam guide paths respectively. The first and second cam followers are coupled to the front and rear derailleur cables, such that a single rotation of the handgrip simultaneously adjusts the positions of the first and second cam followers and the front and rear derailleur cables. |
This is a continuation of a U.S. patent application (Application No. 09/209,928) filed Dec. 9, 1998, which has matured into U.S. Pat. No.
BACKGROUND
1. Field of the Invention
The present invention relates to the field of bicycle carriers. In particular, the present invention relates to a carrier including one or more adjustable article support members to secure bicycles during transport and to protect against theft.
2. General Background
For many years, a substantial majority of bicycle frames have been manufactured with a generally horizontal top tube, which is connected to the seat tube and the head tube of the frame. In light of these features, rear-mounted bicycle carriers have been designed to hold the top tube of a bicycle frame during transport. For example, both U.S. Pat. No. 4,646,414 and U.S. Pat. No. 5,190,195 disclose standard rear-mounted bicycle carriers, each employing a pair of horizontal, hook-like arms to support the top tube of a bicycle frame. In addition, U.S. Pat. Nos. 5,529,231 and 5,647,521 disclose a rear-mounted bicycle carrier having a horizontal support member upon which V-shaped frame holders are permanently affixed. A single clamping mechanism, when fastened, is used to secure all of the bicycles placed on the V-shaped frame holders. The clamping mechanism is incapable of securing individual bicycles.
It is evident, however, that these rear-mounted bicycle carriers are unable to easily accommodate bicycles with sloped top tubes, which are usually found in ladies' bicycles and in an increasing number of mountain and racing bicycles. Normally, bicycles having sloped top tubes (generally referred to herein as “sloped tube bicycles”) rest in an awkward, unstable position when transported by conventional rear-mounted bicycle carriers. This awkward position can cause damage to the bicycle or cause the bicycle to become partially or completely dislodged from the carrier during transit.
In addition, conventional rear-mounted bicycle carriers are designed so that the spatial distance between bicycle frames placed on the carrier is constant and non-modifiable. This is problematic when bicycles are upgraded with components that increase the width of the bicycle. For example, a bicycle with front-fork shock absorbers would require more spacing between neighboring bicycles than a conventional bicycle. If the additional spacing cannot be provided, some of the bicycles being transported can become damaged. Hence, it is desirable to provide a self-locking carrier that allows the spacing between neighboring bicycles placed on the carrier to be adjusted.
SUMMARY
Briefly, the present invention relates to a carrier comprising a holding member and an article support member. The holding member includes a tubing with a plurality of grooves length-wise down the tubing. The article support member is coupled to the holding member. The article support member includes a tray and a collar. The collar is coupled to the tray and interlocks with the holding member in a plurality of angular orientations. In one embodiment, the interlocking is accomplished by a pivotal release clamp having a protrusion complementary to the groove. The collar enables the tray to be rotatably adjusted with a slope of a selected angular orientation. Also, placed within the interior of the tubing is an integral locking mechanism to ensure that the article cannot be unknowingly removed from the carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the present invention will become apparent from the following detailed description of the present invention in which:
FIG. 1 is a prospective view of an embodiment of a self-locking carrier including adjustable, article support members.
FIG. 2 is a side view of column and holding members of the carrier of FIG. 1 inclusive of a locking mechanism and article support members.
FIG. 3 is a top-down view of an illustrative embodiment of the locking mechanism of FIG. 2 .
FIG. 4 is one of the cables associated with the prospective view of an illustrative embodiment of a locking mechanism of the carrier.
FIG. 5 is a front view of an illustrative embodiment of an article support member mounted on the holding member of FIG. 2 .
FIG. 6 is a prospective view of one illustrative embodiment of an article support member of FIGS. 2 and 5 before attachment of the collar fastening mechanism.
FIG. 7 is a prospective view of the illustrative embodiment of the article support member of FIG. 6 after attachment of the collar fastening mechanism.
FIG. 8 is a prospective view of the article support member of FIG. 7 when placed in a locked state.
FIG. 9 is a prospective view of the article support member of FIG. 7 when placed in an unlocked state.
FIG. 10 is a prospective view of a second embodiment of the locking mechanism.
DETAILED DESCRIPTION
Herein, an embodiment of a carrier comprising one or more adjustable article support members is shown. Each article support member is designed to accommodate articles with different structures such as, for example, any type of bicycle including sloped tube bicycles of varying tube diameters, skis, wheelchairs and the like. While numerous specific details are set forth in order to provide a thorough understanding of the invention, it is apparent to one of reasonable skill in the art that the invention may be practiced without these specific details. In fact, to avoid unnecessarily obscuring the invention, well known features may not be described herein.
Referring now to FIG. 1, a perspective view of an illustrative embodiment of a carrier 100 comprising a plurality of article support members 200 is shown. Carrier 100 comprises a base member 110 , a column member 120 and a holding member 130 . In particular, base member 110 is capable of being securely attached to a hitch receiver of a vehicle through a fold-down receiver footing 140 . Of course, it is contemplated that carrier 100 may be attached to a bumper or chassis of a vehicle in lieu of the hitch receiver. Also, instead of being attached to a vehicle, carrier 100 may be used as a stationary locking apparatus.
As further shown in both FIGS. 1 and 2, column member 130 includes a cylindrical tube having a first end 121 coupled to base member 110 and a second end 122 coupled to holding member 130 . In particular, at the first end 121 , column member 120 is pivotally coupled to base member 110 . This allows column member 120 to be rotated downward for loading and unloading of articles and to remain generally perpendicular to base member 110 during transport. Column member 120 is coupled to holding member 130 at second end 122 as shown in more detail in FIG. 2 .
Referring now to FIG. 2, one embodiment of holding member 130 includes a cylindrical tube having an outer surface 131 featuring a plurality of orientation grooves 150 lengthwise across the tube. For this embodiment, orientation grooves 150 are immediately adjacent to each other and placed around a circumference of outer surface 131 (e.g., each groove occupies about one-twentieth of the circumference of holding member 130 ). This allows a spacing distance (X) between article support members 200 to be adjustable. It is contemplated, however, that grooves 150 may be separated from each other by non-grooved or protruding portions separated by a common distance or by varying distances.
Referring now to FIGS. 3 and 4, in this embodiment, an integral, locking mechanism 170 is implemented within carrier 100 . As shown, locking mechanism 170 includes a plurality of single cable lock at end of collar cables 171 and 172 situated within the cylindrical tubing of holding member 130 and optimally column member 120 . These cables 171 and 172 are made of metal, a hardened plastic or any other material that is difficult to break. Optionally, to avoid wearing cables 171 and 172 , an optional plastic sheath 179 is placed over each cable 171 and 172 .
Cables 171 and 172 are prevented from being completely removed and disconnected from carrier 100 by (i) providing a channel 173 through which cables 171 and 172 can be pulled therethrough, and (ii) securely attaching a clamp 174 at one end 175 and 176 of cables 171 and 172 , respectively. Channel 173 is created, for example, by placing of a pre-manufactured insert 180 within the cylindrical tubing of holding member 130 , placing one or more rivets through holding member 130 at one or more selected locations (not shown) and the like. By sizing clamp 174 to be greater in size than channel 173 , cables 171 and 172 can only be partially removed from holding member 130 , not completely removed.
The opposite ends 177 and 178 of cables 171 and 172 are adapted with a cable lock holder (e.g., plastic eyed hooks) so that a lock 180 may be removably coupled to both cables 171 and 172 . Herein, lock 180 includes a combination or key lock capable of coupling together cables 171 and 172 when secured, although other types of locks may be used. It is contemplated that lock 180 may include a pad lock when loops are placed at ends 177 and 178 of cables 171 and 172 as shown in FIG. 4 . In a locked state, cables 171 and 172 are securely coupled to lock 180 . In an unlocked state, cables 171 and 172 may be separated so that one or more of cables 171 and 172 can be wound around the article nearest a far end 132 of holding member 130 .
It is contemplated that another embodiment of locking mechanism 170 includes a single cable 190 placed with the cylindrical tubing of the holding member 130 and optionally column member 120 as shown in FIGS. 10 and 11. Similarly, at the end of cable 190 , a clamp or other element (not shown) may be used to prevent cable 190 from being completely removed from the tubing of holding member 130 . To lock an article, cable 190 would be partially removed from the tubing of holding member 130 and wrapped either around a portion of the article, or perhaps placed through an aperture of the article. Cable 190 would be attached to article support member 200 . Of course, this would require article support member 200 to include a locking device 195 to receive and secure cable 190 . It is contemplated that the type of locking device 195 includes a tubular lock requiring a key for placement in a locked and unlocked state, although any other type of locking device may be used.
Referring now to FIGS. 5-7, an illustrative embodiment of article support member 200 is shown. Article support member 200 comprises a collar 300 , a tray 400 , a collar fastening mechanism 500 and an article anti-sway mechanism 600 . In one embodiment, article support member 200 is substantially made of a hardened plastic. This allows collar 300 and tray 400 to be molded together as a single structure. Instead of hardened plastic, it is contemplated that article support member 200 may be substantially made of metal in which collar 300 and tray 400 are molded together either as a single structure or attached together through adhesive, welding or any other type of fastening technique.
As shown in FIG. 5, an embodiment of collar 300 comprises a curved collar portion 310 and a curved release clamp 350 placed between a pair of circumferential collar portions 315 and 316 having an inner diameter slightly greater than an outer diameter of the holding member 130 . In particular, curved collar portion 310 includes an end 320 having an aperture 330 for collar fastening mechanism 500 (see FIG. 6 ). In this embodiment, curved collar portion 310 is permanently positioned while release clamp 350 is pivotal about a hinge 390 . Release clamp 350 includes a stationary first segment 360 and a pivotal second segment 370 having an end 375 with an aperture 376 for collar fastening mechanism 500 (see FIG. 6 ). Thus, when placed in a closed state, release clamp 350 is positioned so that aperture 330 is generally aligned with aperture 376 .
In addition, an inner surface 380 of second segment 370 is configured to generally interlock with outer surface 160 of holding member 130 while the remaining inner surface of collar 300 is held on holding member 130 by applied pressure. For example, in this embodiment, second segment 370 of release clamp 350 includes one or more protrusions 377 complementary with the orientation grooves 150 of holding member 130 of FIGS. 1 and 2. Of course, protrusions 377 can possess any geometric shape so long as it is complementary and adaptive to generally interlock with grooves 150 . As a result, once article support member 200 is placed on holding member 130 and rotated as need to accommodate different types and structures of the articles, release clamp 350 is placed in a closed position to present article support member 200 from further unwanted rotation. Herein, when in a closed state, a diameter (ID) of inner surface 380 of collar 300 is measured to be slightly greater than the diameter of holding member 130 of FIG. 2 taken from its outer surface 160 .
Referring to FIG. 6, tray 400 is placed along curved collar portion 310 and stationary 360 segment of release clamp 350 through buttress portions 410 and 420 , respectively. These buttress portions 410 and 420 provide a stable structure to support an article. Tray 400 further includes a generally concave channel 430 which features a plurality of extensions 440 at its ends to prevent the article (not shown) from swaying and/or becoming dislodged during transport. It is contemplated that tray 400 may be configured in a half-rectangular shape to hold skis or in any different shape to hold the article(s). To further prevent swaying of the article during transport, a material (e.g., Kraton) having an acceptable coefficient of friction may be placed on channel 430 and/or one or more of extensions 440 .
Referring now to FIG. 7, fastening mechanisms of article support member 200 include (i) collar fastening mechanism 500 joining collar portion 310 and release clamp 350 (see FIG. 5 ), and (ii) article anti-sway mechanism 600 . An example of collar fastening mechanism 500 includes a quick release lever 510 which, when inserted through apertures 330 and 376 (see FIG. 5) and placed in a locked state provides positive fastening (e.g., pressure and interlocked protrusion(s)/groove(s)) of collar 300 on to holding member 130 . When placed in an unlocked state, article support member 200 can be rotated and moved laterally along holding member 130 .
Referring still to FIG. 7, an example of article anti-sway mechanism 600 includes a cap 610 which conforms with the curvature of channel 430 and is designed to rest over a portion of an article to prevent the article from being dislodged from channel 430 . Cap 610 is secured by inserting fastening straps 620 (e.g., VELCRO® hook and loop fastener straps, canvas straps, etc.) through strap inserts 630 placed on a top surface of cap 610 .
Thus, as shown in FIG. 8, in a locked state, cap 610 is positioned over an article resting in channel 430 . Straps 620 are inserted through inserts 630 and fastened to ensure that cap 610 maintains the article (placed in tray 400 ) from becoming dislodged. In an unlocked state, as shown in FIG. 9, straps 620 are loosened so cap 610 does not rest above the channel to allow the article 700 (e.g., a top-tube of a sloped-tube bicycle) from being removed from the channel of tray 400 .
The present invention described herein may be designed in many different architectures and using many different components. While the present invention has been described in terms of various embodiments, other embodiments may come to mind to those skilled in the art without departing from the spirit and scope of the present invention. The invention should, therefore, be measure in terms of the claims which follow. | A carrier comprised of a holding member and an article support member. The holding member includes a tubing with a plurality of grooves lengthwise down the tubing. The article support member is coupled to the holding member. The article support member includes a tray and a collar. The collar is coupled to the tray and interlocks with the holding member in a plurality of angular orientations. The collar enables the tray to be rotatably adjusted with a slope in accordance with a selected angular orientation of the plurality of angular orientations. An integral locking mechanism allows an article to be locked to the carrier. |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates to a means by which individuals can experience both Visual and Physical immersion (i.e., Total Immersion) into Virtual Environments (VEs) by performing human locomotive characteristics such as walking, running, crawling, jumping, climbing, etc. in a stationary or confined space while visually interacting with a Virtual Reality (VR) system and physically interacting with the Electromagnetic Locomotion Platform (ELP).
VR has been proven to be a very useful and beneficial science and currently is being used to help people overcome the fear of heights, fear of flying, and as training devices for pilots of all kinds of vehicles; tanks, planes, helicopters, etc. Current VR systems are used to allow pilots of vehicles the ability to totally immerse into VEs. These pilots are fortunate because the three most critical senses required for total immersion are already built into the vehicle itself. Sight, sound, and touch are the three most critical--smell and taste could also be considered but are more of a fine sensory stimulus and are to be considered as having a secondary level of impact on the human's immersion believeability factor. For example, all of the following components are necessary for a human to operate a vehicle in the real world:
a) Vehicle--contains the cockpit and permits freedom of movement over terrain or through space depending upon vehicle capabilities (Touch).
b) Cockpit--is the operators compartment in the vehicle and contains all control functions for manipulation of the vehicle in it's environment (Touch).
c) Controls--allows the pilot to input control commands for operation of the vehicle (Touch, Sight & Sound).
d) Windshield--is the pilots window to the external environment and allows him to make decisions for control input based on visual stimulus from the outside environment (Sight).
e) Support Systems--includes all computers, control systems and subsystems, and physics based devices which provide all the ancillary functions to operate the entire vehicle from the operators commands and physical limitations of the vehicle (Sight, Sound & Touch).
As is evident in the above example, for a VE dealing with a human inside a vehicle, all of the interfaces are provided for just by the nature of the situation; the human is stationary in the cockpit of the vehicle, has a graphical interface around him (windscreen, canopy, vision blocks, and the like), and has controls within his reach for manipulation of the vehicle through the VE. However, when trying to replicate these same functions for an infantryman or human navigating over the ground who has no stationary cockpit, no graphical interface (windshield), no control mechanisms, and no vehicle support systems; the problem of immersing this individual becomes much more complicated. A review of the same components for the infantryman as compared to a human operated vehicle breaks out as the following:
a) Vehicle=Mobility Platform: A device which allows the human to have all of their locomotion activities done in one location and allows the human to interact with a VE (Touch).
b) Cockpit=Human Interactive Zone: The human itself is basically the cockpit, because of the controls located on the body and in the Human Interactive Zone (HIZ) (area where the human can perform mobility functions and remain within the control parameters and boundaries of the VE system) (Touch).
c) Controls=Controls: Instead of the controls being mounted to the vehicle they are now an integral part of the human or are located in, on, and/or around the HIZ (Touch, Sight, & Sound).
d) Windshield=Visual Interface: This can be any number of devices such as a Helmet Mounted Display (HMD), rear projection screen, or any means of displaying graphical information to the human's visual senses (Sight).
d) Support Systems=Support Systems: Includes all computers, control systems and subsystems, and all mechanical, electrical, physics based, etc. devices which provide all the ancillary fuinctions to operate the entire VB system i.e.; providing graphics, logic controls, motion controls, timing, sequencing, etc. (Sight, Sound & Touch)
Current technology can provide a fairly good graphical or visual interface by using HMDs or other devices as previously mentioned, the real problem is to provide the foot soldier with a platform and controls. The infantryman is mobile, not confined to a cockpit, and is able to perform a multitude of different physical locomotion movements--his platform is essentially the ground he stands on. Controls for the foot soldier do not exist--he does not interface with any ancillary equipment to move about, he uses his brain and limbs to navigate and be mobile on the battlefield.
BRIEF SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a means by which individuals can experience both Visual and Physical immersion into VEs by performing human locomotive characteristics such as walking, running, crawling, jumping, climbing, etc. in a stationary or confined space while visually interacting with a VR system and physically interacting with a mobility platform system.
A further object of the present invention is to provide a device designed to work in conjunction with a VR system where the user can navigate through different environments, while staying in one place, and view the changes in the environment commensurate with the amount of movement performed on the invention.
A still further object is to provide a system that does not require a VR system to operate, and in such a mode would allow locomotive functions (similar to treadmills) where one can endure locomotive exercise, yet remain in a relatively stationary position.
Another object is to provide an electromagnetically activated plate/platform/surface which will move or translate objects by modifying the power to the electromagnets within the plate.
Still another object is to provide a system that has the ability to apply resistive forces to the user's body or parts of his body to hold his body or part of his body in one place, thus allowing the system to apply resistive forces to locomotive limbs and extract work from the user.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the present invention. As will be realized, the present 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 present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive.
These and other objects are achieved by an electrically operated device which links the locomotion functions of a human with a computer system, which in turn feeds translation motion back to the ELP and supplies data for graphic presentation to various display devices. The soldier navigates on the ELP, using any locomotion characteristic (walking, running, jogging, crawling, etc.) and essentially remains in one place, much like people do when they walk on a treadmill. As the person navigates on the ELP, sensors register his movements and feed this data back to a computer which displays changes in the virtual scenery appropriate to the amount of movement and direction the human has "moved" (in a stationary position). This change in scenery is presented to the human via any number of means such as a Helmet Mounted Display, rear projection screens, multiple monitor screens, etc. This visual stimulus is timed in conjunction with the natural locomotion the human is performing on the ELP and produces what is referred to as (visual) "immersion" into a VE. "Immersion" means the human is fooled into thinking he is moving, operating, and existing in a 3D environment just like in the real world--however, this environment is artificial and is a "synthetically" created realistic 2D or 3D version of the real world. This phenomenon is called "Virtual Reality," making someone feel as if they are really in another place, when actually they have not moved at all.
Immersing the human using visual stimulus is very effective, and when you couple it with physical immersion, the VE becomes even more realistic and believable. Physical immersion is currently achieved for vehicular applications by mounting an operator's cockpit/vehicle on a platform which has six degrees freedom of movement capability. This allows a complete and full range of motions to be imparted into the cockpit and thus to the pilot. They can feel "G" forces, acceleration, banking, braking, turning, etc., all the motions a tank, plane, helicopter, can possibly do; needless to say the effect is very believable and convincing. The present invention can also take advantage of this same proven technology. The present invention is designed to also incorporate the physical immersion effects to the human by applying resistive forces to the limbs and body of the soldier as they are navigating on the ELP. This gives the soldier a feeling of really physically taxing his body, much like he would if in the real world. Resistance can be applied so the soldier thinks he is walking up a sand dune, lifting his body in a vertical climb (even though he may be on a horizontal plane), or any number of similar physical activities which demand effort and energy extraction from humans. The physical immersion is a very important and unique feature of the present invention, as no other mobility platform can provide the same effects to the human body.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic diagram of the present invention.
FIG. 2 is a flow chart of the present invention showing the basic components and their interfaces.
FIG. 3 is a plan view of one embodiment of the electromagnets and ancillary sensors in the ELP.
FIG. 4 is a plan view of another embodiment of the electromagnets and ancillary sensors in the ELP.
FIG. 5 is a sectional view of the ELP showing the position of the electromagnets, the slip plate, the sub-plate, and the attracted object.
FIG. 6 is a plan view of the individual foot steps, their locations, stepping orders, and translations associated with making a complete "virtual step" on the ELP.
FIG. 7 is a logic diagram for completing a step on the present invention.
FIG. 8 is a plan view of the individual foot steps, their locations, and stepping order for an "actual step" in the "real world".
FIG. 9 is a plan view showing the translation of an object by "blinking" of the electromagnets on the ELP.
DETAILED DESCRIPTION OF THE INVENTION
In the prior art, treadmill devices have been used to allow individuals to walk, jog, and run "in place," and currently are being investigated for adaptation into the VR world. However, there are many limits and shortcomings of conventional treadmill design, some of which are; they basically only operate on one axis, in a forward or rearward motion (usually only forward) and require the user to grasp onto a stationary device or be physically restrained in some manner so they can remain on the device while they are operating it. Without this stationary anchor and reference point, it is very difficult to remain on the device while it is running and definitely impossible to stay on if you do not have use of your vision. In addition to these limitations, the treadmill is not representative of true human mobility, since it operates only along one axis, while humans are capable of a full 360 degree mobility on the horizontal plane, and limited mobility on the vertical plane as well. In addition, the treadmill offers no means for a soldier to simulate locomotion on any plane other than the horizontal and slightly angled surfaces of the earth, and is limited by gravitational pull.
Some advanced concepts of omni-directional treadmills are being developed which allow for a two axis mode of locomotion with a series of belts and rollers operating at normal angles to each other. One fault of this omni-directional tread mill is the individual belts or tracks would have to move at exactly the same speeds or the junction of the two would become a shear plane and would disrupt any object placed on the junction between the two belts. These treadmill based concepts appear to be very hardware dependent, bulky, noisy, mechanical nightmares, and generally stretching the envelope of what can be done with traditional and currently available treadmill technologies. In addition they are encumbered by the inherent lag times and momentum problems associated with moving mechanical masses; i.e. belts, motors, wheels, tracks, chains, gears, sprockets, and numerous other mechanical components and devices. All of these mechanical masses make instantaneous direction changes nearly impossible because of their inherent momentum, this causes incongruencies and movements which are "unreal" and "unnatural" to the user; and thus, the seamless immersion effect is degraded or even nullified.
The present invention is designed to solve these deficiencies and add additional capabilities as well. As described below and shown in the figures, the ELP is a structural honeycombed subplate comprising a top plate material having a very low coefficient of friction on its surface, which could be any number of plastics, composites, micro ball bearings, or possibly even an air cushion table (similar to an air hockey table) with electromagnets (EMs) placed underneath it and mounted flush to or near the top surface of the subplate. These EMs are individually controllable in both an on and off status, polarity, etc., as well as the intensity of their magnetic force. The EMs are in very close proximity to each other or can even abut each other. They are laid out in a grid or honeycomb pattern in the subplate under the entire "slip" surface of the ELP. The EMs are closely adjoined with no adverse effects on their performance or capabilities regarding overlapping magnetic fields. In fact, the overlapping magnetic fields prove to be a beneficial feature in attaining smooth and imperceptible translations.
Either the EMs themselves or additional sensors are included with the EMs to allow the computer to sense what the individual is going to do. As the foot, object, or extremity nears the proximity of the sensor, it tells the computer to activate the EMs and apply the current for the desired forces and translations. All of the EMs are linked to a computer system as well as a power source providing activation signals and power to energize and de-energize the EMs. The soldier wears a modified standard military boot with a special sole containing thin flexible metal sheets, bars, or a special ferrous particle impregnated sole which is invisible to the wearer. It thereby allows complete natural movement of a normal boot, yet also serves as the attraction device for the EMs embedded in the ELP. It is also possible to incorporate an active system (permanent magnet or EM for example) in or on the surface of the object being drawn to the ELP's EMs to enhance the attractive force over that of a passive (metal plate, ferrous material, etc.) system, or vice versa, with the added capabilities of having repelling or repulsive forces.
The EMs are controlled by a computer so one's pattern of footsteps, gait, and any other individual idiosyncrasies can be gauged, calibrated, and then be input into a file for each individual. This permits an exact replication template of the operators "footprint", "walkprint", "gaitprint", "jogprint", "runprint", "crawlprint", "jumpprint", etc. and allows a very natural and normal transition onto the ELP. The platform can also mimic jogging, running, and jumping scenarios by simply calibrating the gaits and speeds at which the soldier does these tasks. Since the calibration of running may not be feasible on the ELP because of it's smaller size, a companion strip of sensors would be utilized for this calibration phase called the Calibration Strip (CS). The CS is a long thin strip of material which contains closely abutting sensors beneath the entire surface of the strip. These sensors are based on almost any technology, whether it be optical, pressure sensitive, magnetic, pneumatic, microelectromechanical systems (MEMS) etc., as long as they can switch when the foot hits them. This strip allows the soldier to jog, run, walk, jump, crawl, and do all of the functions he intends to do later on the ELP, however it provides him the physical room in which to do the activity at his normal pace and speed so accurate and realistic data is obtained for each speed and kind of locomotion. All relevant points which contact the CS are recorded and sequenced in the order in which they occur, so as to map out all the body contact points and motions of every particular locomotion entity, from crawling on your stomach to sprinting at your top speed. From this recorded and complied database of "locomotion prints", the ELP can then be programmed for the characteristics which will replicate the same exact movements the soldier will be doing while on the ELP. Since there may be slight variations in the actual locomotive functions, the ELP has a built in compensation feature which adjusts and compensates for deviations outside the calibrated data, a locomotive tolerance band. The ease of calibration allows each soldier his own locomotion print so he does not have to conform to a generalized set of parameters based on generic data, and his natural body motions are replicated exactly as he performs them. They are perfectly matched to each individuals body and mimics their own personal style of body movement. This enhances the ability of the device to become transparent, invisible, and to disappear from the soldiers cognizant world of being on a "mobility platform".
Once the soldier's locomotive steps have been calibrated and input into the computer by the CS, he steps onto the ELP and establishes a starting point at the center of the slip plate which now becomes the "Slip Center" (meaning the center position about which the operator will be based or his "home position"). This starting home position can be anywhere on the plate as long as the computer defines the coordinates. This is established by locking in the coordinates of his feet when placed on the surface of the slip plate.
Since the computer has all of the "locomotion prints" on file, the soldier can replicate any one of his stored movements and the computer will know how to mimic his actions. For example, the following is a brief look at the sequence of events which outline one complete step on the ELP. As the soldier begins to walk, his first step makes contact with the ELP and it energizes the EMs beneath his feet and concomitantly activates sensors (pressure, optical, positional, etc.) indicating the body is moving and changing it's center of gravity (CG). These data are sent to the computer, which immediately begins to activate the EMs on the computed track back to his home position. As the EMs directly beneath his foot release, the ones behind it activate, thus pulling the foot rearward towards the home position, in a continuous and fluid (natural-like) sliding motion. Concomitantly, while this foot is being drawn rearward towards the home position and the body begins to regain center over the first foot, the other foot is lifted for the second step. When the first step is completed, the foot is at the home position and the second foot has just completed it's step. Continuing in this fashion, the soldier can walk "forever to nowhere", since he has stayed in the proximity of the center of the slip plate at all times. The soldier's movements and locomotion data drive the computer which in turn updates the VR environment (as seen through the visual interface by the soldier) and causes this displayed environment to change as the soldier walks through it in real time.
The EMs are an excellent means to gradually and smoothly start to move the foot in a rearward motion so as to be almost imperceptible to the operator. Treadmill drive belts transfer motion along each belt or series of belts in one or two directions only, when the belts are trying to move one foot in a specified vector and the other foot touches these belts, that foot is now also moving in the same direction. With the ELP, each foot or body point is individually controllable, so you could have both feet side by side and move one independently from the other in any direction, a unique and valuable feature.
To achieve seamless immersion in VR, the environments must be "real" and "believable" to the user, and operate in "real time" (no latency or lag periods) across all of the interfaces in the system. The human body and mind are very sensitive to visual and motion incongruities and when these faults are perceived they destroy the mind's and body's ability to believe the immersion is virtually "real". In fact latency and lag time (defined as the time it takes to update the frame rate to what is "real time" in a visual sense and the difference of time between action and reaction of physical objects=haptic lag) are the most critical human elements in VR simulations and cause operators to become ill when exposed to these problems, this is commonly referred to as "motion sickness" or "simulator sickness". The human body is designed to perceive changes in movement on land in relation to the center of the earth, and when anyone of the three human sensory systems (the visual system, the vestibular system, and the proprioceptive system) receive erroneous orientation information, it may propagate sensory illusions which cause spatial disorientation and eventually leads to "motion sickness" of the human.
The ability to change directions on the ELP is facilitated by having sensors (directional, positional, area, etc.) in the boots of the soldier which indicate the orientation of the boot as it is placed on the ELP. If the boot changes direction and orientation from its last position and orientation, the computer then activates the EMs in the general direction of the perceived next step. This puts all the possible EMs "on call" waiting for the signal from the boot to activate and attain proper power levels (attractive forces) for the activity being performed. This allows the soldier the ability to run on the ELP and then change directions quickly, as if running on land. Because of the instantaneous speed of the signals and activation of the EMs, no latency will be noticed by the user. This ability allows the soldier to run and change directions or even allows him to walk backwards or sideways. Also, the soldier can run and stop on a dime without being thrown off by a continuously moving treadmill belt hindered by momentum and braking forces which are not instantaneously altered. The EMs are activated only when needed, and there is no constant motion device like a drive belt imparting energy to the user and no moving parts having momentum forces which would require some lag time to stop, change directions, accelerate, decelerate, etc.
If programmed into the ELP, the soldier would even be able to side step, as if walking on a ledge of a building with a perceived VR 400' drop to the pavement. As the user comes to a stop, the VR environment and feet will simultaneously be brought back to their home position with the soldier being unaware of this movement. This places him in his original starting position from where he can continue his operations. It may not be necessary to return home if the computer can adjust the home position and there are no other conflicts with the ELP or other operators. In a sense, the user is led in a small never ending circle; this is an option if the user perceives the rearward pull back to home position. Nevertheless, this still allows the soldier to operate in a very small confined area, as opposed to the massive amounts of ground covered when performing his normal activities in the real world.
A unique feature of the EMs is their attraction force can be varied by the amount of current being supplied to them. Using this phenomenon allows the resistance between the boot and the ELP to be changed to replicate different surface conditions, based on different coefficients of friction. For example, a snow and ice covered surface has a very low coefficient of friction (and subsequently a very low attraction force supplied by the EMs) and conversely, a hot black top road has a much greater coefficient of friction (and thus a higher attraction force supplied by the EMs). This feature allows the soldier to actually slip and fall, if he doesn't place his foot properly on the "ice covered" slip plate state, yet gives him extremely good traction when on the high coefficient of friction surface state of the hot black top road.
The ELP also permits additional features unavailable to treadmill designs such as the following:
The ELP can simulate an "out-of-bounds" area on obstacles which the user may be negotiating; i.e., if the infantryman is walking along the top of a log balance in the simulated VR environment there may be only a small portion at the top circumference of the log which will permit a footstep capable of negotiating the log. If the subject steps too far to either side he may lose his footing or may fall off entirely. In the case of the ELP, this designated "non-walk" or "out-of-bounds" area could result in the foot being locked to the ELP, or the foot could be pulled to the side indicating or replicating a mis-step or slip on the log balance. Similarly, negotiating a tire obstacle run would be accomplished by predetermining the free travel zones for the foot and the interference zones where the foot would get stuck in the tire. This ability to determine customized zones of "travel" and "no-travel" will add to the realism in the VR world, by enhancing user feedback while negotiating certain obstacles. It will also allow for accurate performance data to be gathered in test and evaluation efforts utilizing man/equipment/environment scenarios.
The EMs are arranged in a grid pattern in very close proximity to each other; this results in a continuous magnetic field which is controlled in any X-Y direction on each ELP regardless of the ELPs orientation. Activation of the EMs is programmed to gradually increase the field of strength and also to gradually translate their attraction fields from one to the next in a wave-like motion; this range of adjustments allows the foot to be moved in a very smooth manner, almost imperceptible to the soldier. Since the holding power of electromagnets decrease in proportion to a reduction in energy supplied (they will loose approximately 75% of their original holding force before it drops to 0 holding force), and attain maximum holding power in the same manner, this allows for a very smooth translation of the attracted objects by a magnetic wave. With timing, attraction intensity correctly adjusted, and control of the EMs synchronized, the soldier is able to walk in one place and feels as if he is traversing the terrain because of being immersed in the VE.
Another benefit of the ELP is that each foot is individually controllable, so if a soldier has his feet placed in different mediums, i.e. sand and rocks, the different movement and slippage perceived by humans is replicated by the ELP. One foot could be on either firm or loose rocks and the other foot might be slipping and sliding on a sand covered base. Gradual slippage and movement is thus incorporated to mimic even the smallest of movements and in any direction. This adds to the realism, believability, and seamlessness of the entire immersion effect.
In all modes of using the ELP, a safety harness or other safety system should be employed to maintain a fall back means of catching the soldier/user either while climbing the vertical, negotiating the horizontal, or using any of the ancillary devices on the ELP to insure their safety. If the system did have a malfunction (i.e. power loss) the individual would then be caught by the safety harness. If the system had a computer malfunction, the operator and user would both have "master kill" switches to shut off all power to the EMs instantaneously rendering them useless.
Another method of ensuring the infantryman's safety is,to have a perimeter of sensing devices around the ELP which monitors the user's position and feeds this back to the computer system. This would watch for any sudden movements or be used as a signaling source to cue the computer of the user's intentions, a second means to anticipate or check the user's movements and direction of travel.
Construction of the ELP is modular so the entire plate can be disassembled into smaller subplates and easily transported (minus the six degree-of-freedom device). The ability to join the panels together and lock them in place, permits the ability to construct the entire slip plate almost anywhere. In addition to being of modular construction, the panels are very durable and lightweight, and with a series of imbedded circuits, conventional wiring is eliminated or reduced significantly. Each EM is individually locked into its receptacle by a simple twist lock coupling, which also completes it's connection into the embedded circuitry back to the main computer. This allows for easy replacement of each individual EM in case of failure. If one EM fails, the computer compensates by increasing the pull of it's adjoining EMs, so the function currently in process is not degraded. This also allows the computer to have a self diagnostic capability to insure proper operation of all the components, and makes replacement easy and efficient. Since the individual panels are small and easily transported the entire system is man-portable.
The power requirements for operation of the ELP are minimal, since there is a need only to energize the areas directly under the feet for the operation the soldier is currently doing and preactivating the EMs in the next anticipated movement area. Thus, only small areas and numbers of EM's are being energized at any one particular time.
One problem in simulating VR worlds is climbing steps; i.e., how do you realistically simulate a man walking up and down stairs while in one place? With the present invention, this is accomplished by having two or more "Live" panel segments. These "Live" segments are capable of rising vertically above the horizontal plane of the ELP to mimic steps (standard step dimensions are about 7" rise and 12" tread depth) or any other vertical surface required. These steps rise and fall as the soldier steps on them, much like a stair stepper device. Steps are manipulated by various mechanical means which provide quick response time and also permit a fill range of activation speeds so the soldier can climb or descend at any rate desired. Another means to simulate steps is to have a designated area of the ELP have an imbedded system of revolving steps similar to a revolving tank tread, treadmill, escalator, or squirrel cage device. This allows the soldier to step vertically as well as horizontally as is done in normal stair stepping. The soldier actually walks to the steps on the ELP, utilizes them, and then is routed and translated back to his home position until the stair device is needed again.
The ability of the ELP to have different specialized function areas is a critical design capability, as it allows the soldier to access many different physical apparatus required to simulate all of the functions and obstacles encountered by a soldier in a real and simulated environment.
Simulation of prone crawling is also accomplished with this device by calibrating in the soldier's motions on the CS. It is also possible to simulate this type of crawling by anchoring the subjects stomach or midsection to the center of the ELP (by means of a metal disk or attractive device located on the soldiers body, probably near the center of the stomach) and then simply let the soldier move his arms and legs in the crawling fashion with the appropriate amount of drag being provided by the EMs at the required body points. In this case, the soldier wears BDUs which have metal disks or attractive devices located at the various body points (elbows, knees, etc.) which make contact with the ELP (the same locations as defined by the CS). However, it may be more realistic to actually allow the soldier to move his entire body forward in one motion and then pull him back by moving all contacted points simultaneously, or "steer" him in a circle as he crawls. If the BDUs incorporate active attractive devices (EM's, permanent magnets, etc.) instead of the passive attractive devices, then it is possible to induce both the push and pull motions for energy extraction and translation purposes. Since the versatility of the present invention is so adaptable to different situations and procedures, it will prove to be a very valuable test bed and tool in determining the requirements of how best to simulate in VR what actually happens in the "Real World".
Another possibility for the present invention is to mimic vertical or near vertical climbing; since the EMs can be of sufficient power to actually hold a body against the ELP, it will work in other elevations as well. EMs generally are 75% less efficient in shear force but this is overcome by the fact the user is not moving as quickly and they would most likely have three points (possibly more) of contact on the ELP at any one time. Plus, the EM's could be located only at points where body contact would be appropriate, i.e., handholds, ladder rungs, outcroppings, etc., and thus would be able to be larger and with more powerfill attractive forces. Given adequate EM strength, the soldier or climber is able to hang from only one point of contact without slipping or breaking the magnetic force holding him against the ELP. This allows the soldier to scale any "virtual" vertical object i.e.; walls, rope ladders, and mountainous rock formations.
When the soldier is climbing a vertical surface, he has to hold a gripping device, glove mechanism, or attraction means, so the ELP can act upon it. In the case of climbing a rope ladder for example, the gripping device (gripper) has a portion of rope which the soldier would grasp; for mountain climbing the gripper mimics a rock hand-hold; and in the case of a metal rung ladder, a metal bar is the gripper device. These devices are located on the vertical ELPs and are accessed by the operator seeing the hand hold grippers through the VR helmet. The gripping devices may require a special designation or enhancement for the soldier to actually locate and grasp them, but once in hand, they become the means to travel up and down whatever the obstacle appears to be. On a rope ladder for example, the only EMs which activate would be the ones located visually within his grasping range, so if he put his hand in a space, and not on a rope, he feels no rope resistance; the same is true for ladders, i.e., only where a rope or rung appears to be. The soldier is able to lift the climbing device by activating a switch mechanism which tells the computer to de-energize that group of EMs. The switch mechanism could be as simple as a button, grip switch, or even as transparent as a switch which operates, when for example, the soldier takes pressure off of the rope device, signaling a potential move by the soldier and thus signaling for de-energization of the EMs to permit free use of the hand gripper for its next move.
In a vertical climbing mode the feet also require a means to place them into and out of the VR ropes. These could be similar to the devices used for the hands yet modified to attach onto the boot's toe and/or sole. They still get the feel of a rope foot hold by designing the release button to activate as the pressure is lifted from the rope. In this case the toe slides in a grooved receiver gripper which allows the boot to ride up and down in a gimbaled device so the foot can get the "feel" of the rope yet still permit attachment to the ELP.
With a special rope laying device, the soldier will also be able to simulate climbing up and rappelling down vertical surfaces. The rope feeds out gradually as the soldier begins climbing and his feet are able to grip the walls. As he moves, his feet are brought back to home position, just as the procedure employed when walking on the horizontal ELP. The technology also permits overhead traversing with strong enough EMs, so it is possible for the soldier to actually maneuver in a 360 degree environment; in fact, with grippers on both feet and hands, the soldier is able to move like an insect on any wall; vertical, horizontal, or even upside down!
The addition of a "tilting" device (means for lifting one or more edges of the ELP) allows the ELP to simulate traversing of hills, slopes, inclines, and depressions, as the entire ELP is positioned at any simple or compound angle. This technology is already utilized in vehicle simulators which have six degree-of-freedom (DOF) motion platforms. This feature places extending and retracting means (E&RM) (like hydraulic cylinders) underneath the platform, and by increasing or decreasing the length of each individual E&RM the angular position of the platform can be oriented in virtually any x, y, & z configuration. This same technology is applied to the ELP for dynamic positioning capabilities of the terrain the human is navigating over. In vehicle simulators it can induce "G" forces, accelerations, braking, tilting, banking, climbing, descending, etc., any number of actions a vehicle would endure in it's mission, and the ELP also benefits from having the same capabilities using a "live" 6 DOF mobility platform where the need requires it.
The addition of a companion vertical wall (which can be adjusted to any angle as well), imparts the added feature of deriving compound angled obstacles for the soldier to negotiate. This capability is very useful in simulating or replicating overhangs and building outcroppings in tactical situations.
To simulate resistance of walls against the shoulders and body of soldiers in tactical situations inside or outside of buildings, the ELP system has a series of vertical walls which could act against metal plates or attractive devices located in various areas around the body. This provides a good tactical feel for snaking against a wall and works for any position on the body. For example, the soldier could crawl on his belly or could crawl on his back; with the present invention he is limited only by his imagination, since the ELP will act upon any body or material which is attracted to the magnetic field. As long as the movements can be calibrated from the CS, then the actions will be able to be replicated on the surfaces of the ELP. The ELP may be able to attract points on the body other than those calibrated on the CS for translating. This would be done to simply impart resistance to the user for physical immersion effects (dynamic resistance) and would not necessarily be used to locomote or translate the soldier, only to apply resistance to his movements.
In addition to providing a very realistic training device for the military, there are a vast array of other uses for the ELP in the commercial world. Since one can program in specific predetermined movement paths, the system can be used to rehabilitate people requiring locomotion rehabilitation. One can make their feet, arms, limbs, hands, fingers, etc., move ti preprogrammed steps to help in the rehabilitation process. This will benefit people who cannot move their limbs on their own, e.g., because of muscular atrophy, injury, deformation, etc. The ELP can move these body parts for them. The present invention can assist in the rebuilding and regenerative process by working the limbs and muscles which are in need of exercise. The ELP can be used as a means of correcting dysuenctional foot or orthopedic abnormalities and can be incrementally adjusted as the progress of rehabilitation develops. The ELP can provide gradual increases in angles and motions critical to the proper development or rehabilitation of the various limbs and will apply just the right amount of incremental correction so as to minimize any undue pain or suffering on the subject. The ELP is so adaptable in function and form that it could be configured at such a micro level as to facilitate movement of individual fingers, toes, or other small shapes. Its versatility in configuration variability makes it easily adaptable to many various different fields and sciences with many current and unforeseen uses yet to be discovered.
The ELP will have many applications in the entertainment industry, especially for VR games, movies, animation, special effects, and featured interactive scenarios. Industry can use this technology in many applications, such as a sorting device, transfer systems, clean room applications, and many other uses. The ELP can be used as a means of moving ferrous metal chips away from manufacturing machines such as mills, lathes, grinders, etc. The ELP will attract the metal chips and then translate them into hoppers or recycling bins for reclamation. Use of the ELP can replace or assist the "wet" method of flooding the area with coolant to flush chips away from the cutting area; it will work very well in applications where the "wet" method would be prohibited, or moving belts would be inappropriate. The ELP can be configured in any shape or contour which would partially enclose or encapsulate metal removing machines and can attract ferrous particles of very small almost invisible proportions; such as are emitted by grinding operations, lapping machines, or any other process which produces fine dust like particles which may become airborne and cause problems in adjacent equipment, clean areas, electronic components, etc., or become trapped in human lung tissue.
The ELP can also work as an anchoring device for Astronauts in space stations where loss of gravity is a problem; it will allow them the ability to move around wherever the ELP was located by attracting their feet, hands, body, etc. to the ELP. It will also help in situations of weightlessness concerning machining operations; it will attract all of the ferrous metal chips, particles, and dust which would otherwise become airborne contaminates and be used as a containment device to trap these floating debris. This will be a very critical problem in space because these small particles could cause serious foreign object damage (FOD) by infiltrating all kinds of electronic and mechanical equipment.
Another commercial use will be to detect, and then attract, ferrous objects (guns, weapons, knives, etc.) in areas of increased security. If a person was attempting to enter a building with a weapon, the magnetic force field would be disturbed; the field would then be increased to attract the weapon to the side of the wall containing the ELP. If the attraction force was large enough, it would not permit the weapon to function, and could then be used to move the weapon away from the user.
This technology can also be applied to game boards where pieces are required to be manipulated by the computer while playing against the human. This will permit a very thin and compact unit because movement of the game pieces would not be dependent upon mechanical linkages and arms to make x-y positional movements.
The sports world will also find this device an excellent conditioning device and will allow people to participate in sports they normally would never try, such as free climbing the side of a mountain, sky diving, or any number of extreme sports people are hesitant to participate in. People could walk or run against various resistance fields in order to develop particular muscular features difficult to currently exercise using conventional methods, or in dangerous situations such as mountain climbing.
Since the basic system is entirely static with no moving parts, it will lend itself very nicely to multiple players or users; on one large ELP, it will be possible to have multiple players using the same ELP and interacting with one another. Since the directions are all computer controlled, one could have soldiers facing each other, side by side, or in any other manner since they only activate EMs in their area. The system is so versatile one could conceivably program in a pattern to actually spin a person around and around in circles by having their feet or body follow the preprogrammed paths. If, for example, the ELP was constructed in a spherical shape the soldier could mimic free fall flight maneuvers (like the HALO jumpers do in the wind tunnel) or simply "fly" around the interior of the sphere. With a teleoperated direct digital control link and a sensing system to control the computer, the soldier would be able to determine his own flight path on the ELP at any time. He would simply communicate where he wanted to go and the EMs would take him there.
Referring now to FIG. 1, a schematic diagram of the present invention is shown. The ELP System 10 comprises Calibration Strip (CS) 20, Computer 30, ELP 40, Power Supply 50, Remote Control Device 60, Visual Interface 70, and external Power Source 80.
CS 20 is a device which collects and transmits positional data from itself to Computer 30. It's function is to collect all of the pertinent locomotive data of subjects maneuvering on CS 20 and send this data to Computer 30 for storage and programming the "locomotive prints" of each user navigating on ELP 40.
Computer 30 receives all of the data from CS 20 and uses it as information on how to operate the control of the EMs in ELP 40. This includes the timing, location, intensity, polarity, and other pertinent data required to allow the navigation of the human body and objects on ELP 40. Computer 30 controls all activation input to the EMs: to energize and de-energize, intensity levels, self diagnostic data, timing, sequencing, polarity, etc., which performs the movement of the Attracted Objects 110 (see FIG. 5) being positioned, translated, and moved around ELP 40. Attracted Objects 110 can be virtually any passive object which would be attracted by a magnetic field, such as metal plates in clothing, modified boots, metal objects, non-metal objects with enough ferrous content to be attracted, etc. These Attracted Objects 110 can also be active in nature, these items could be EMs, permanent magnets, or any thing which can generate positive or negative magnetic fields.
EMs 100 (see FIG. 5) are electromagnets which produce a magnetic field when their coils and windings are excited by electrical current. EM 100 field intensity is variable in proportion to the electrical power supplied to it. The more electrical power delivered to EM 100 results in more magnetic force (up to a designed level) and vice versa; the less power supplied the weaker the magnetic force.
Computer 30 also receives data from the Ancillary Sensors 90 located on ELP System 10; Remote Control Device 60, and Visual Interface 70. This data then is used to change the scenery downloaded to Visual Interface 70 for the visual immersion of the infantryman, and for navigation purposes.
Remote Control Device 60 is a unit which allows the user of ELP System 10 to issue commands to Computer 30 for additional control while navigating on ELP System 10. Initially this input device may be hardwired, but the ideal solution would be to have the communication link be a wireless transmitting system so as to eliminate any tethers or connections to and from the user. This would then allow the soldier complete freedom to move about, just as in real life.
The Visual Interface 70, in this embodiment an HMD, is a helmet which the user wears while being immersed in the VE; it provides simulated images of terrain, objects, and everything visually associated with the real world. The Visual Interface is not limited to using a HMD however, it could be any number of visual devices or systems capable of displaying or presenting graphical images to the user.
ELP 40 is a plate-like structure with internal cavities designed to house and accept EMs 100, Ancillary Sensors 90 (see FIG. 3 & 4), and to form a Sub Plate Structure 115 (see FIG. 5) for supporting Slip Plate 120. ELP 40 has integrated circuitry for all of the individual cavities in Subplate 115 and connects the circuitry for EMs 100 and Ancillary Sensors 90 as well. The main purpose of Slip Plate 120 is to provide a very low coefficient of friction surface on which all of the attracted objects will slide or glide; it is almost like a continuous sheet covered with infinitesimally small ball bearings which allow near frictionless movement. The Sub Plate 115 structure is a rigid housing plate which serves as the basic supportive structure and mounting system for EMs 100, all other Ancillary Sensors 90, and other components associated with ELP 40. Ancillary Sensors 90 refer to all sensors embedded in or around ELP 40 and any sensors carried by the individual or object being translated on ELP 40, since they would have a parent/sibling relationship. These sensors accomplish many things, such as notification of near foot contact, directional changes, pressure sensing, and may include solenoids and any other control linking sensors required for the operation of the ELP System 10.
Power Supply 50 is a unit which supplies the correct proportional electrical inputs to EMs 100, depending upon the input signal from Computer 30. This allows EMs 100 to "blink" on and off very rapidly allowing the Attracted Objects 110 to move smoothly on Slip Plate 120.
The operation of ELP System 10 is performed in the following order:
First, Infantryman 15 (see FIG. 2) performs his array of maneuver functions on CS 20 to record and store all of the moves he will be doing on ELP 40. CS 20 will allow him to perform his physical activities as he normally would at the proper speed, distance, gait, etc. so as to capture all of the locomotion data for use when he is on ELP 40. Once the data has been collected and input into Computer 30, Soldier 15 is now ready to don the specially modified BDUs and boots, get onto ELP 40, and establish a center or home position.
Next Subject 15 will don HMD 70 and any Remote Control Device (RCD) 60 he will require to communicate with Computer 30. RCD 60 may be a hand held unit which signals Computer 30 different functions Subject 15 is performing, or could even be a voice activated wireless control mechanism. A voice actuated telemetry device would be an excellent method for Soldier 15 to communicate with Computer 30 since it would be a hands-off, hands-free method of communicating commands, signals, and instructions to Computer 30. This would eliminate the hindrance caused by hard wires linking and tethering Human 15 to System 10. RCD 60 may include commands such as start, stop, walking speed, running speed, direction, etc. which provides User 15 with his own steering device for navigating on ELP 40. These voice commands would generate a voice recognition system allowing a completely "hands-free" operation of the ELP; this technology is currently being utilized in other "hands-free" VR applications in use today.
The following example of a "Virtual Step" will address only one functional use of ELP System 10; it is, however, representative of the multitude of other scenarios which may be performed on ELP System 10. Refer now to FIG. 6. Soldier 15 will place his feet at the start or home position on ELP 40 and signal Computer 30 (position "A"--L 0 & R 0 ) to enter this position into memory. Once the commands have been given by Soldier 15 he may begin to walk on ELP 40. In position "B"--L 1 & R 1 Soldier 15 has de-energized and lifted his right foot and placed it back onto the surface of Slip Plate 120 of ELP 40 "X" distance from his original stance. Booth feet are now being held by EMs 100 to the surface of Slip Plate 120 of ELP 40. Next, User 15 will deactivate his left foot and move it forward above ELP 40 (as shown by the dashed outline) in position "C"--L 2 & R 2 ; concomitantly, as the left foot is moving in the +Y axis direction the right foot is now being translated backwards in the -Y axis direction. The center of gravity (CG) of his body is now moving in the +Y direction as shown by the CG symbol. In position "D"--L 3 & R 3 his left foot continues to move in the +Y direction and his right foot continues to move in the -Y axis direction. When the step is completed at position "E"--L 4 & R 4 , his left foot is now attracted to ELP 40 and his right foot is also attracted and stationary. The next step is for his right foot to be de-energized and move forward to a parallel position beside his left foot, position "F"--L 5 & R 5 . To complete the entire step the two feet are translated rearward simultaneously back to the home or start position, position "G"--L 6 & R 6 .
User 15 has now completed one entire "Virtual Step"; follow on continuous steps would repeat in a similar fashion (steps L 1 & R 1 through L 3 & R 3 ) and is representative of the type of motion required for the other various locomotive scenarios.
As a baseline comparison to an "Actual Step" in the "Real World" refer to FIG. 8. In this sequence the two feet are on the ground at start position "A"--L 0 & R 0 . Soldier 15 begins the step procedure by lifting and placing his right foot on the ground at position "B"--L 1 & R 1 , distance "X". Next his left foot is lifted and placed on the ground at position "C"--L 2 & R 2 , distance "X". Finally to complete the step, his right foot is lifted and placed on the ground at the final position "D"--L 3 & R 3 , total distance=2X.
As shown in FIG. 6, the total amount of ground traversed in the "Virtual Step" is "0" from start to finish (L 0 & R 0 to L 6 & R 6 respectively), and in the "Actual Step" (FIG. 8) the total is 2X, or two steps. This capability of traversing "zero ground distance" in "Virtual Stepping" is paramount to the use and adaptation of ELP System 10 into the VR world. It allows Soldier 15 the capability to "walk forever to nowhere", meaning he will be stationary about a center point or parameter, yet the VR system will change his mental picture in accordance to the locomotive input he provides on ELP 40. He can virtually walk any where in his mind and physically remain in a very small perimeter.
There are three methods of how ELP 40 will translate objects. The first method is to simply shift the power (and thus attractive force on the EMs) beneath the attracted object in small increments so the object will follow the attractive magnetic field. Refer now to FIG. 9, which shows a simple Attracted Object 1 10 being translated on ELP 40 from a starting position at "A" to a final position at "K". First EMs 100 are activated to hold Object 110 on ELP 40 at the starting position "A", next the magnetic footprint is "blinked" off in position "A" and "blinked" on in a new position "B", thus pulling the Attracted Object 110 to the new location of the magnetic field. This method will require a smart system to know where Object 110 was and where the shift is intended. The magnetic fields can switch almost instantaneously and therefore may allow for an almost imperceptible movement to the user. The quicker and smaller the shift, the less noticeable and more fluid the translation will appear. This "blinking" procedure continues through the rest of the translations until the desired final position is reached at "K". FIG. 9 depicts translations of Object 110) in a +X horizontal mode from "A-C", vertical -Y mode "C-E", combined +X & +/-Y moves in "E-I", and another +X horizontal move in "I-K". The distance between the moves of Object 110 have been shown greatly separated for ease of explanation and clarity. In an actual translation on ELP 40 however, EMs 100 would be shifted in much smaller adjacent type of increments and moves, in order to achieve a very smooth and fluid movement of Object 110. This type of translation is simply called "blinking" translation.
The second method of movement is actually a refinement or modification to the above concept. It accomplishes basically the same function yet allows for the EMs to fade in their intensity of attractive force to allow a much smoother and more controlled flow of the object from position to position. In this operation the EMs are energized and holding the object to the ELP, when the object is to be moved a gradual decrease in the holding EMs force will be replaced by an increased force in the new "positioning" EMs. In other words, some of the EMs are reduced in holding power and some are increased in a vice versa fashion. This may permit additional control and a more refined method of moving objects on the ELP, in what is termed a "fading blink" translation.
The third method of movement is another refinement or modification to the two concepts above. It accomplishes the same functions by allowing the EMs to fade not only in their intensity of attractive force but to change polarity as well. By having an active magnetic system (permanent magnets, permanent magnetic field, or EMs) associated with the attracted object you can take advantage of reversing the current of the EM, which changes its polarity field from a (-) to a (+) or vice versa. The ability to change the EMs polarity is a critical feature, because coupled with a permanent magnetic field (in the attractive object), now allows the EMs to either "push" or "pull" on the object. This depends on whether the EM is attracting an "opposite pole" or repelling a "like" pole, thus the "pull or push" ability. This may allow an even smoother and more controlled flow of the object from position to position. In this operation for example, the EMs are energized and holding the object to the ELP, when the object is to be moved a gradual reverse in the polarity of the holding EMs "pulling" force will now be replaced as a "pushing" force. In other words, some of the EMs holding power is "pulling" and some are "pushing" in a vice versa fashion. This may permit additional control and a more refined method of moving objects on the ELP, in what is termed a "push-pull blink" translation. Note; the EMs can also fade in their attractive intensity as well, during the "push-pull" blink translation. Another benefit to this "push-pull" blink, is that as the EMs reverse polarity and begin to "push" the attracted object, this reduces the coefficient of friction between the Attracted Object 110 and the Slip Plate 120 even further, this results in a smoother and reduced friction translation of the Attracted Objects 110.
Of paramount importance to the translation of objects on the ELP is a very small coefficient of friction between the attracted object and the surface of the ELP itself. With a smooth near frictionless surface it will allow the ELP to move objects, especially humans, with little or no perception of physically moving. Of course this may require a safety device to eliminate injury to the soldier in the case of a power failure or malfunction. The soldier would then be literally standing on a sheet of"ice". To alleviate this problem, a safety belt could be attached to the soldier, yet this inhibits and restrains the soldier and is getting away from the scope of the original intent, which is to be as close to real life as possible. Most soldiers don't run around the battlefield with a safety harness attached to them.
Another option would be to place protective mats around the area where the infantryman is operating, since he requires very little actual locomotive area this may be an acceptable solution. The mats are entirely removed from the soldier, he can't see them, yet they provide protection from falls in the immediate area. Another approach would be a means of making the "ice" turn into "real" ground instantaneously. This would be a more complex system, yet deserves discussion because of its passive, unobtrusive, and desirable hands-off capability. This system would be based on using solenoids (for example), the principal behind it, is to space electrically operated solenoids throughout the ELP, which when de-energized protrude small surfaces (or patterns) just slightly above the surface of the slip plate on the ELP. These surfaces would have a non-slip texture and would facilitate the gripping of the boots or other body parts and provide a secure walking or running surface over the "ice". These solenoids would be sized to impart only enough tread area to be effective, yet not so much as they would impair or hinder the placement and function of the EMs. When power is supplied to them they could be in a retracted mode and when power is shut off they would extend, thus if there is a power failure they automatically spring up and lock. If there was a computer malfunction and the EMs where behaving erratically, the solenoids could also be activated to form the non-slip surface for the safety of the human. The safety systems would not be dependent upon any outside power for activation, only the lack of it.
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 effect various changes, substitutions of equivalents and various other aspects of the present 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
Having thus shown and described what is at present considered to be the preferred embodiment of the present invention, it should be noted that the same has been made by way of illustration and not limitation. Accordingly, all modifications, alterations and changes coming within the spirit and scope of the present invention are herein meant to be included. | The present invention, an Electromagnetic Locomotion Platform (ELP) system, is an electronically powered device which allows human-like activities to be performed in all three axes: x, y, & z, in a confined and localized a for the purpose of attaining total immersion (both visual and physical) into Virtual Environments. The ELP system allows humans the ability to walk, jog, run, crawl, etc. In a stationary position, thus the user can "walk forever to nowhere", similar to the basic function of a treadmill. This feature can be enhanced by having the user wear a helmet mounted display (HMD) which is coupled to a computer generated Virtual Reality (VR) system. The VR system provides external environments to the HMD and when synchronized with the movements of the individual on the ELP, it displays visual changes in the surrounding environment according to the movements generated by the user. This is a system which then can totally immerse someone into a Virtual Environment by allowing body movement to dictate visual changes in the environment, yet keep the subject in essentially the same location. In addition to the visual immersion capability, the ELP also has the ability to physically immerse humans by generating and applying resistive forces which will cause the body to work, this energy expenditure replicates the physical loads experienced by the body in the real world. |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of, and incorporates by reference, U.S. Provisional Patent Application No. 61/456,931 filed Nov. 14, 2010.
BACKGROUND
Fuel gasification and fuel full oxidation by solid state oxygen carriers use flameless technologies that require no direct contact between air and fuel. Said systems oxidize carbonaceous or hydrogen fuels using a solid compound (typically a metal oxide or peroxide) as an oxygen carrier. In past practice, the oxygen carrier is circulated between two reactors. In the first reactor the fuel is oxidized and the oxygen carrier is reduced and in the second reactor the oxygen-depleted (reduced) oxygen carrier is regenerated (oxidized) to an oxygen rich state.
SUMMARY
An oxygen carrier reactor system comprises plural distinct reactors (or reaction zones. The term “reactor” herein shall be construed to include zones where reaction takes place). Reactor I is a fuel oxidation reactor. In this reactor, the fuel is mixed with controlled amounts of an oxygen rich solid state oxygen carrier. The present fuel reactor is a system and process such that oxygen from the oxygen carrier oxidizes completely or partially the volatile component of a solid or liquid fuel or hydrogen component for a gas fuel, while non-volatile or carbon components are substantially unoxidized. An innovative single fuel reactor can be selected to operate in either of two modes, a partial-oxidation mode or a full-oxidation mode. The oxygen carrier is reduced in this process. The product stream from this reactor is substantially pure steam and carbon dioxide in full oxidation mode and a syngas with a minimum of carbon dioxide content in partial oxidation (gasifier mode). The un-oxidized component of the fuel is passed as char or carbon to a second reactor, the burn-off reactor, where it is mixed with a further controlled amount of oxygen rich oxygen carrier and oxidized completely. The burn-off reactor produces a gaseous product stream of substantially pure carbon dioxide or carbon dioxide and steam. The solids from the burn-off reactor, which are substantially reduced oxygen carrier and ash (in the case of a solid fuel), are passed to an oxygen carrier regeneration reactor where the oxygen carrier is restored to a fully oxygenated state via contact with air. The oxygenated oxygen carrier and ash mixed with the oxygen depleted air are conveyed to a separation means where the heavier solids are separated from the oxygen depleted air and ash and returned to the fuel reactor and burn-off reactor. The oxygen depleted air and ash are conveyed to a power production and ash capture section before clean oxygen depleted air is returned to the atmosphere. An innovative feedback control and oxygen rich oxygen carrier distribution system is implemented to: (1) control the amount of oxygen rich oxygen carrier admitted to the fuel reactor in a ratio to the fuel such that the reactor operates in the full oxidation, partial oxidation (gasifier), or an intermediate mode; (2) control, in fully coordinated mode with the fuel reactor control, the amount of oxygen-rich oxygen carrier admitted to the burn-off reactor in a ratio to the unoxidized char or carbon fuel components from the fuel reactor such that all these components are completely oxidized; and (3) isolate the response of the oxygen-rich oxygen carrier distribution system from supply of oxygen-rich oxygen carrier available from the regeneration reactor, such that any controlled amounts of oxygen-rich oxygen carrier demanded by the fuel reactor and burn-off reactor due to changes in load, operation mode, or both can be achieved while maintaining system stability. In a further innovation a feedback control and solid material extraction system is implemented such that a controlled portion of the oxygen carrier solids and heavier ash components circulating in the system is continuously removed. The removed oxygen carrier is cleaned, reconditioned, and returned to the system. This continuous removal and recycle system minimizes the need for prolonged system shut downs for total oxygen carrier removal and replacement. The ash component is treated and sold or disposed of. In a further innovation, a transfer system for transferring a portion of oxidized fuel makes use of an opening or openings with a profile that regulates the residence time of the fuel in the reactor by regulating the rate of flow from the reactor.
DRAWINGS
The file of this patent contains at least one drawing executed in color. Copies of this patent with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.
FIG. 1 schematically depicts a reactor system by which the present system and method may be implemented.
FIG. 1A schematically depicts a separator by which the present system and method may be implemented.
FIGS. 1B and 1C schematically depict a downcomer by which the present system and method may be implemented.
FIG. 2 schematically depicts a reactor system by which the present system and method may be implemented.
FIG. 3 schematically depicts a reactor system and process by which the present system and method may be implemented, along with an example of a product table from the present system and method.
FIG. 4 schematically depicts a feedback control system by which the present system and method may be implemented.
FIGS. 5A-5F schematically depict processes and systems by which the present system and method may be implemented.
DESCRIPTION
The present description relates to technologies for gasification (partial fuel oxidation) and full fuel oxidation by solid state oxygen carriers and oxidation of solid state oxygen carriers in a reactor system for the selectable production of gases for production of heat and power or syngas for biofuels plus heat and power. In the fuel reactor, the fuel is oxidized by the oxygen carrier, which undergoes a corresponding reduction. Because the carrier-borne oxygen is used rather than the oxygen in air, it is sometimes called “air-independent oxidation (AIO).”
The oxygen-depleted carrier is then regenerated (oxidized) in another reactor, typically by exposure to the oxygen in air. The regeneration process restores the carrier to an oxygen-rich state, enabling reuse in the fuel reactor. This process is sometimes called “chemical looping combustion (CLC).”
Products from the fuel reactor can yield heat and power through a thermodynamic cycle. In existing systems, the overall system function is similar to a conventional combustor or gasifier with the advantage that the fuel reactor output flow is free of nitrogen. Because it does not require additional carbon dioxide capture units, CLC technology avoids the energy penalty that traditional fossil fuel fired combustors or gasifiers must pay to produce pure carbon dioxide. In addition, hot air from the regeneration reactor can yield heat and power through a thermodynamic cycle.
In combined heat and power (CHP) and power production alternatives to CLC using boilers, air is introduced by fans or other means to a combustion chamber. Fuel is also introduced to this chamber via pumps or other means. The chamber may be at or near atmospheric pressure or it may be pressurized. In the most common type of atmospheric boiler, just prior to entering the boiler combustion chamber, the air and the fuel are mixed in the burner.
The hot gases from combustion are nitrogen, carbon dioxide (the primary greenhouse gas or “GHG”), and water vapor, along with pollutants such as nitrogen oxides formed from the extraneous nitrogen introduced with the oxygen needed for combustion (by volume air is 80% nitrogen and only 20% oxygen), sulfur oxides formed from fuel contaminants, and carbon monoxide due to incomplete combustion. The water vapor comes both from atmospheric humidity and from combustion. The water from combustion carries with it a portion of the fuel energy which can only be regained by condensing it to a liquid.
The hot post-combustion gases are carried up by their buoyancy and pass through various heat exchange systems that boil the feedwater forming steam. Other heat exchange means superheat the steam. The cooled exhaust gases are then treated or exhausted to the atmosphere.
In an atmospheric fluidized bed boiler, the process is the same except that the fuel and air are mixed in, and combustion occurs in the bed of solids which is fluidized by their passage. A pressurized fluidized bed boiler is similar except that the entire process is contained in a pressurized vessel, and the entering and exiting stream are pressurized. The pressurization reduces the volume of the gases and therefore the size of the equipment needed.
Existing external combustion boiler technologies have numerous problems and shortcomings, many related to the extraneous nitrogen involved. The nitrogen: 1) requires major components (ducts, fans, the boiler itself, post combustion pollution treatment equipment) to be greatly oversized; 2) requires energy to supply it to the process (especially for a pressurized process); 3) carries energy away in the exhaust, as explained more fully below; and 4) results in pollutant (nitrogen oxides) formation.
“Oxy fuel” combustion is an existing technology that partially addresses the issues of energy waste via exhaust. In this process, oxygen from an air separation plant is supplied to the combustion. Two types of air separation processes are cryogenic and pressure swing adsorption (PSA).
Gasification is a technology used to convert a solid fuel into a synthesis gas (“syngas”) that can then be used for other downstream uses such as power production or biofuels production. In the case of power production the syngas is often used as fuel for a gas engine. In the case of biofuel production, the syngas is sent to a catalytic or other process that converts the syngas to liquid fuel products such as mixed alcohols, methanol, ethanol, or through subsequent process to gasoline. Syngas can also be sent to processes such as Fischer Tropsch to produce diesel fuel.
For catalytic processes that convert syngas into fuel, the composition of the syngas is a major factor in the efficiency and life of the conversion catalyst. Many of these catalysts become much less efficient and can be deactivated by high concentrations of carbon dioxide, a major component syngas. In addition, many existing gasifiers generate a high content of tar that can also poison the catalyst.
What is needed is a reactor system that is able to be used to (1) fully oxidize fuel-producing products, including a stream of substantially pure carbon dioxide, for power production, and (2) operate as a gasifier producing syngas for production of biofuels while minimizing carbon dioxide and regulating concentrations of other components in the syngas; producing a stream of substantially pure carbon dioxide; solving problems with using solid fuel vs. gaseous fuel; improving gasification for biofuel production; and that accomplishes these goals with low or no tar formation.
FIG. 1 schematically depicts a system 100 for the selectable production of gases for production of heat and power or syngas for biofuels plus heat and power. In either mode, a separate stream comprising greater than 95% CO 2 or CO 2 and steam by volume is produced. The CO 2 may be recovered from the stream of CO 2 and steam by condensing the steam resulting in a stream of greater than 95% CO 2 by volume. The apparatus and method consist of three or more reactors which are arranged and operate as follows. A fuel reactor 101 is arranged so that a carbonaceous fuel 106 which has been treated (as explained in *Biomass Gasification and Pyrolysis: Practical Design and Theory*, by P. Basu, Academic Press, 2010 for example) to satisfy the requirements of the reactor with regard to variables (e.g., moisture content less than 40% by weight, particle effective diameter 1 millimeter or less, in one embodiment) is introduced by a feeder (including, but not limited to screw feeders, chain feeders, and slurry pumps) through a pipe 107 . In the reactor the fuel is mixed and distributed in a fluidized bed 102 .
Fuel reactor 101 , a bubbling fluidized bed in one embodiment, is arranged to admit a solid, liquid or gaseous, carbonaceous fuel 106 , which has been treated to satisfy the requirements of the reactor for solid carbonaceous feed particles in the size range of 0.5 to 50 millimeters (with a diameter of 5 millimeters in one embodiment), and moisture content in the range of 4 to 40 weight percent (with a moisture content of 4 weight percent in one embodiment). Said carbonaceous fuel is introduced by a feeder that includes, but is not limited to, screw feeders, chain feeders, blowers, and pumps. In the reactor the fuel is mixed with the bubbling fluid bed 211 . Said fluid bed consists of particles in the size range of 100 to 1200 micrometers, with a diameter size of 300 micrometers in a preferred embodiment. Each of said particles is composed of chemically active metal oxides or peroxides chosen from the set of copper oxides, manganese oxides, and barium peroxides. Said oxides (copper oxides in one embodiment) are dispersed throughout and bound to each particle of a support material such as γ alumina, titanium dioxide, or Yttria stabilized zirconia which provides mechanical strength, toughness, and resistance to wear and attrition as the particles are transported around the system. Said particles are suitable for use in past practice chemical looping systems as well as the present novel system.
A fluidizing gas 108 which provides the motive volume and velocity required for bed fluidization is introduced via a pipe 109 creating a fluidized bed 102 of admixed fuel, oxygen rich oxygen carrier, and solid reaction products. The use of both atmospheric pressure and pressurized fluid bed technologies in chemical processes and combustion are well known to those skilled in the art. Pressurized fluid bed technology has been demonstrated and offered for sale at commercial scale. The Tidd Pressurized Fluidized Bed Combustion (PFBC) project. [Anon., “Tidd PFBC Demonstration Project Final Report,” U.S. Department of Energy Contract No. DE-FC21-87 MC-24132.000, August, 1995. and Hatazaki, H., et al, “Development and Construction of World Largest 360MW PFBC Having Hexagon Shaped Furnace,” The Japanese Society of Mechanical Engineers, 1996. Many applications of both pressurized and atmospheric pressurized fluid bed technology are described in the work by Kunii and Levenspiel (Kunii Daizo, and Levenspiel, Octave. Fluidization Engineering. 2nd ed., Butterworth-Heinemann, Boston, Mass., (1991)). The fluidizing gas is steam in one embodiment, but may consist of other gases, such as carbon dioxide, or mixtures of gases. The bed material is separated from the fluidizing gas expansion chamber 104 and supported by a distribution plate 103 which also serves to distribute the fluidizing gas evenly across the fluidized bed. In the fluidized bed, the metallic oxide or peroxide reacts with and gives up oxygen to the fuel. The net process is the oxidation of the fuel to gaseous products and ash while some or all of the copper oxide is reduced to copper. The oxygen carrier substrate is unchanged in the reaction. Some or all of the bed material is entrained in the gaseous products and is conveyed by them into an upper reactor space 158 . These gases and solids are then directed by a duct 148 into a separator 150 for separating the solids from the gases. Separator 150 is a cyclonic separator in one embodiment.
The cyclonic separator or other separation means separates the solids from the gases by centrifugal forces and causes their conveyance by a pipe 151 back to the fuel reactor 101 .
As a consequence of the addition of carbonaceous fuel and oxygen rich oxygen carrier the height of the bed 102 tends to increase. The height of the bed is controlled by a downcomer 105 which removes a controlled portion of the bed material to maintain the desired height and therefore residence time in the bed. A novel flow area entrance 170 to the downcomer 105 , shown in FIG. 1B , is provided such that the flow area available to the flow out of the reactor bed is a desired function of the bed height. This means is chosen from the set of a single and a multiplicity of slots 170 . When said slot or slots are formed in one embodiment with profiled sides 171 said profile is chosen such that the flow area and therefore the downcomer flow varies with bed height such that the residence time, the average time spent by a particle in the reactor, can be controlled. An example of such a control system is that the residence time is constant as solids flow through the reactor changes. As a further illustration, for some weirs and slots, flow through the slot varies as bed height above the slot base 172 raised to the 3/2 power. For this functional dependence of flow with bed height and a slot profile as shown in FIG. 1B , the bed residence time will be constant with regard to total flow into the bed and with regard to any individual flow into the bed for bed heights greater than the distance 173 from the distribution plate 103 to the slot base 172 . Thus there is a minimum mass flow through the reactor above which the residence time is controlled. The functional form of the residence time variation with flow may be controlled to other than constant form, linear for example, by applying different profiles to the slot opening. As will be appreciated by those skilled in the art, slot profiles will be tailored to desired results, and such methods and results are within the scope of this invention. Thus through the present means, the reactor bed residence time may be controlled as a function of any desired reactor flow variable such as one or more reactor flows or a function thereof. Reactor flow variables can include, but are not limited to, oxygen-rich oxygen carrier and carbonaceous fuel in one embodiment. The independent variable may be chosen from a set including, but not limited to, the ratio of oxygen rich oxygen carrier flow to fuel flow, oxygen rich oxygen carrier flow, and fluidizing fluid flow. In a further feature of this means, the height of the downcomer which is free of any flow openings 174 is set to maintain a minimum reactor fluidized bed height at which bed fluidization can be stably and reliably maintained. The bed material entering the burn-off reactor 110 via downcomer 105 includes a portion of the introduced oxygen rich oxygen carrier, oxygen lean oxygen carrier, substantially all of the carbonaceous component of the fuel as char, and ash. It is substantially free of the gaseous products of the reaction of the hydrogen component of the fuel.
In the burn-off reactor 110 , oxygen rich oxygen carrier is admitted at a controlled rate via a pipe 141 . In one embodiment, the rate is controlled via an L Valve 165 , by controlling the pressure and flow of a motive fluid 142 through an aeration pipe 143 . The ratio of the char, any other unoxidized fuel components, and fuel to the oxygen rich oxygen carrier in the bed is maintained at or above the minimum value required for complete oxidation. The height of a fluidized bed 111 is controlled via a downcomer 113 . A novel entrance 175 to the downcomer 113 , shown in FIG. 1C , is provided such that the flow area available to the flow out of the reactor bed is a desired function of the bed height. This means is chosen from the set of a single and a multiplicity of slots 175 in one embodiment. When said slot or slots are formed in one embodiment with profiled sides 176 said profile chosen such that the flow area and therefore the downcomer flow varies with bed height such that the residence time, the average time spent by a particle in the reactor, can be controlled. One example of such a control is that the residence time is constant as solids flow through the reactor changes. As an example, for some weirs and slots, flow through the slot varies as bed height above the slot base 177 raised to the 3/2 power. For this functional dependence of flow with bed height and a slot profile as shown in FIG. 1C , the bed residence time will be constant with regard to total flow into the bed and with regard to any individual flow into the bed for bed heights greater than the distance from the distribution plate 112 to the slot base 177 . Thus there is a minimum mass flow through the reactor above which the residence time is controlled. The functional form of the residence time variation with flow may be controlled to other than constant form, linear for example, by applying different profiles to the slot opening depending on desired characteristics, as will be appreciated by those skilled in the art, and such methods and results are within the scope of this invention. Thus through the present means, the reactor bed residence time may be controlled as a function of any desired reactor flow variable such as one or more reactor flows or a function thereof; chosen from the set including, but not limited to oxygen rich oxygen carrier and carbonaceous fuel in one embodiment. The independent variable may be chosen from a set including, but not limited to, the ratio of oxygen rich oxygen carrier flow to fuel flow, oxygen rich oxygen carrier flow, and fluidizing fluid flow. In a further feature of this means, the height of the downcomer which is free of any flow openings 179 is set to maintain a minimum reactor fluidized bed height at which bed fluidization can be stably and reliably maintained. This system and process is designed and operated to completely oxidize all char and any other fuel or fuel components so that material leaving the bed via a downcomer 113 is substantially composed of oxygen lean oxygen carrier admixed with oxygen rich oxygen carrier and ash. The bed 111 is maintained in a fluidized state via a fluidizing fluid 114 , carbon dioxide in one embodiment, admitted via pipe 115 into an expansion space 116 . This fluid is then distributed by a distributor plate 112 uniformly across the face of the fluid bed. The gaseous products 115 of the oxidation mixed with the fluidizing fluid, flow into the head space 157 of the burn-off reactor and from there to a heat exchange means 159 , continuous tube banks in one embodiment, arranged in the bed and head space of the fuel reactor. When the fuel reactor is operating in other than full oxidation mode, this heat exchange means supplies the heat required to maintain the endothermic gasification reactions. When the fuel reactor is operating in full oxidation mode heat is released by the oxidation reaction and the heat exchange means serves as a pipe or duct only. The burn-off reactor bed material conducted by downcomer 113 flows into an oxygen carrier regeneration reactor 117 , where the solids are dispersed and mixed in a fluidized bed by a fluidizing agent 120 (compressed air in one embodiment), which has been introduced via a pipe 121 . The bed material 118 in the regeneration reactor 117 is separated from the fluidizing gas expansion chamber 122 and supported by a distribution plate 119 which also serves to distribute the fluidizing gas evenly across the fluidized bed.
In the oxygen-carrier regeneration reactor 117 , an oxygen carrier (such as copper metal dispersed on a carrier particle), reacts with, and is oxidized by the oxygen in air to copper oxides. The substrate particle is not changed in the reaction.
Some or all of the bed material is entrained in the gaseous product hot oxygen depleted air and is conveyed with the aid of secondary air 128 introduced through a pipe 129 from an upper reactor space 156 of the regeneration reactor 117 . These gases and solids are then directed by a duct 132 and 133 into a separator 134 , a cyclonic separator in one embodiment, where the solids are separated from the gases by centrifugal forces and are conveyed down through the cyclonic separator converging section 134 A through a duct 161 into a material accumulator 162 . The oxygenated oxygen carrier then passes into a solids-flow regulating means.
The means for separating solids, including heavier ash components, from the lighter ash components, 167 and the solids flow regulating system, 168 are shown in an expanded view FIG. 1A where like numbers correspond to like features.
This solids-flow regulating means is an L-Valve system 168 in one embodiment. Said system comprises an upper L-Valve component 164 including a downcomer 132 , and an aeration tube 138 . As is well known in the art, the amount of solid particles which flow through said L-Valve and into conveying pipe 136 can be regulated by varying the amount of gas 137 , for example steam in one embodiment, introduced through the aeration tube 138 . Greater aeration gas pressure and flow result in greater solids flow. The oxygenated oxygen carrier is then introduced to the fuel reactor through a pipe 136 in accordance with the desired ratio to the carbonaceous fuel 106 . This ratio is controlled so that in oxy-fuel mode it is above the minimum required for full oxidation and in gasification mode, it is below the maximum required for partial oxidation of the volatile or hydrogen fuel component. In transition mode it is changed in a controlled manner to move from one of said modes to the other.
A portion of the oxygenated oxygen carrier along with ash constituents bypasses a first L-Valve component 164 and flows through an opening 139 into a second L-Valve component 165 . There a controlled portion of the flow is directed via motive fluid 142 via aeration tube 143 , steam in one embodiment, into duct 141 and into the burn off reactor 110 to provide the oxygen rich oxygen carrier in a controlled ratio to the char, unreacted fuel, and other unreacted fuel components exiting the fuel reactor 101 via downcomer pipe 105 . This ratio is controlled and maintained above a minimum needed for full oxidation of all char, unreacted fuel, and other unreacted fuel components.
In a further feature, a portion of the bed material bypasses the second L Valve component 165 , and flows into a third L Valve component 166 , through an opening 163 . A controlled portion of this bed material is extracted via a third L-Valve assembly 166 . The amount of extracted material is controlled by varying the pressure and volume of the aeration gas 124 , steam in one embodiment, admitted through the L-Valve aeration tube 125 .
The material 127 that is pushed through a pipe 126 and extracted for treatment consists primarily of oxygenated oxygen carrier and heavier ash components. This oxygenated oxygen carrier is separated from the ash using conventional means. Some ash components such as potassium salts are valuable as additives to fertilizer and can be sold. Others such as sodium salts are sent to disposal. The clean reclaimed oxygen carrier 130 is recycled to the system through pipe 131 .
One example of operating parameters of the fuel oxidation reactor 101 for a pressurized embodiment show that said parameters depend upon whether the system has been selected to operate in partial oxidation (gasification) or full oxidation (oxy-fuel mode):
Fuel Oxidation Reactor Conditions
Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
700° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Fuel to Active
0.44 kg/kg
0.22 kg/kg
Components of
Oxygen Rich Carrier
Oxygen Rich Carrier
4 kg/kg
0 kg/kg
in Accumulator
per kg of Fuel
Product Gas
CO 2 , steam, trace
CO 2 , CO, H2 and trace
Composition
gases
gases
CO
31% volume dry
18 ppmd
CO 2
14% volume dry
98% volume dry
H 2
52% volume dry
41 ppmvd
Steam
14% volume wet
60% volume wet
Trace Gases
3% volume dry
2% vd including CO + H 2
The typical operating conditions of the burn-off reactor 110 for a pressurized embodiment are substantially the same whether the system and process is in partial oxidation (gasification) or full oxidation (oxy-fuel mode):
Burn-off Reactor Conditions
Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
875° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Solids from FR/
0.05 kg/kg
0.09 kg/kg
Oxygen Carrier
Product Gas
CO 2 , steam, trace gases
CO 2 , CO, H2 and trace
Composition
gases
CO
less than 1 ppmd
less than 1 ppmd
CO 2
greater than 99% volume
greater than 99% volume
wet
wet
H 2
less than 1 ppmd
less than 1 ppmd
Steam
less than 1% volume wet
less than 1% volume wet
Trace Gases
less than 1% volume dry
less than 1% volume dry
including CO + H 2
The gaseous products 153 , from the fuel reactor 101 leave the gas solid separator 150 via the duct 152 . The gaseous products 155 from the burn-off reactor 110 leave via a duct 159 , flow through the heat exchanger 160 and duct 154 . The oxygen depleted air 147 from the oxygen carrier regeneration reactor 117 leaves the gas solid separator 134 via the duct 144 . Any solid components of the stream are removed via known separation methods such as electrostatic precipitation 145 . The solid free oxygen depleted air 147 is then exhausted or sent to further processes via a ducting mean 146 .
The hot high-pressure fuel reactor product stream is used for power production using the same equipment for both modes. If the system is operating in gasification mode, the post-power and heat production, cooled, reduced pressure, syngas product stream is sent to a downstream catalytic process for the production of biofuels. By means of the process and systems described above, substantially the entire carbon component of the fuel is conveyed as char into the burn-off reactor. This minimizes the carbon dioxide content of the syngas, and increases the efficiency and biofuel product production of the syngas to liquid biofuel process. When operating in oxy-fuel mode, the cooled reduced pressure product stream consisting substantially of steam, and trace gases with a minimum of carbon dioxide, is sent to a condensing scrubber where the stream is condensed and the trace gases are removed with this condensate. The resulting stream of essentially pure carbon dioxide is mixed with the carbon dioxide from the burn-off reactor.
The burn-off reactor gaseous products is substantially pure carbon dioxide in one embodiment where carbon dioxide is used as the fluidizing fluid. This carbon dioxide is mixed with the aforesaid carbon dioxide from the fuel reactor and is liquefied for sale or sequestration. The electric energy and heat production equipment is the same for both gasification and oxy-fuel operation with the exception of the scrubbing condenser and carbon dioxide liquefaction equipment. Thus, greater than 95% (on a cost basis) of the plant is common to the two modes of operation.
The hot, high-pressure carbon dioxide stream is also used for the production of electric power and heat utilizing means including but not limited to, turbo-expanders, heat-recovery steam generators, gas compressors, gas turbines, and thermo-electric generators. In one embodiment, the turbo-expander is coupled to a carbon dioxide compression means to provide the compressed carbon dioxide needed to operate the burn-off reactor.
The hot, high pressure oxygen depleted air stream may also be used for the production of electric power and heat utilizing existing means such as turbo-expanders, and heat recovery steam generators. The turbo-expander is coupled to an air compression means to provide the compressed air needed to operate the oxygen carrier regeneration reactor.
The means and equipment used for compression and for power generation and heat production is completely common to both modes of operation, since the oxygen carrier regeneration reactor operation is essentially the same for both modes.
In at least one embodiment, the reactor system is entirely self-sustaining on an energy basis. In oxy-fuel and gasification mode both reactors generate high temperature and pressure products for heat and power generation. In gasification mode, the fuel reactor is operated at the same or a lower temperature, 700 C in one example, relative to the oxygen carrier regeneration reactor, 875 C in the example. The solid oxygen carrier flowing from the oxygen carrier regeneration reactor give up sensible heat to the fuel reactor providing some of the energy need for gasification of the fuel. The remainder of the energy is provided by heat transfer from the gaseous products from the burn-off reactor. This method and process is superior to conventional oxygen blown gasification, since the carbon dioxide does not mix with and contaminate the syngas product stream.
The method and means for switching between the two modes is to vary the amount of oxygen rich oxygen carrier stored in the accumulator 162 by varying the amount and pressure of the steam introduced through aeration pipes 137 and 142 . This method also controls the amount of solid material circulating in the fuel, burn-off and oxygen carrier regenerator loop, which is easily seen to be the total solids circulating in the system minus the solids stored in the accumulator. The amount of active components of solids circulating in the system, and the amount of active components (copper oxides in one embodiment) of oxygen rich oxygen carrier stored in the accumulator for both modes of operation is shown above.
Operating conditions of the oxygen carrier regeneration (air) reactor are essentially the same for either fuel oxidation mode:
Oxygen Carrier Regeneration Reactor
Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
875° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Air to Active Components
4.3 kg/kg
3.4 kg/kg
of Oxygen Depleted Carrier
Ratio*
Product Gas
O 2 and N 2
Composition**
O 2
16.5% volume dry
16.6% volume dry
N 2
83.5% volume dry
84.4% volume dry
*Note: Includes air required for heat balance as well as air required for oxygen carrier regeneration
**Note: These compositions do not include the trace amounts of water, argon, and CO 2 which enter with the ambient air.
FIG. 2 schematically depicts a system 200 for the selectable production of gases for production of heat and power or syngas for biofuels plus heat and power. In either mode, producing a separate stream consisting of greater than 95% CO 2 or CO 2 and steam by volume. The CO 2 may be recovered from the stream of CO 2 and steam by condensing the steam resulting in a stream of greater than 95% CO 2 by volume. The apparatus and method can consist of three or more reactors which are arranged and operated as follows:
A fuel reactor 212 , a circulating fluidized bed in one embodiment, is arranged so that a solid, liquid or gaseous, carbonaceous fuel 208 , which has been treated to satisfy the requirements of the reactor for biomass feed particles in the size range of 0.5 to 50 millimeters (with a diameter of 5 millimeters in one embodiment), moisture content in the range of 4 to 40 weight percent (with 4 weight percent in one embodiment). The carbonaceous fuel is introduced by a feeder such as (by way of example but not limited to), screw feeders, chain feeders, and pumps, through a pipe 210 at a rate controlled by a valve 209 . In the reactor the fuel is mixed with a dispersed circulating fluid bed 211 . Said fluid bed consists of particles in the size range of 100 to 1200 300 micrometers, with 300 micrometers being used in one embodiment. Each of said particles is composed of chemically active metal oxides or peroxides chosen from the set of copper oxides, manganese oxides, and barium peroxides. Said oxides (copper oxides in one embodiment) are dispersed throughout and bound to each particle of a support material such as γ alumina, titanium dioxide, or Yttria stabilized zirconia which provides mechanical strength, toughness, and resistance to wear and attrition as the particles are transported around the system.
A fluidizing gas 201 , which provides the flow rate and velocity required for bed fluidization, is introduced via pipes 202 and 206 at a rate controlled by valve 203 creating a fluidized bed of solids 211 comprising admixed fuel, oxygen rich oxygen carrier, and solid reaction products. Said gas is steam in one embodiment, but may consist of other gases, such as carbon dioxide, or mixtures of gases. The bed material is separated from the fluidizing gas expansion chamber 207 and supported by a distribution plate 205 which also serves to distribute the fluidizing gas evenly across the fluidized bed. In the fluidized bed, the metallic oxide or peroxide reacts with and gives up oxygen to the fuel. Through systems and processes explained below, the net process is the oxidation of the hydrogen component of the fuel to gaseous products while some or all of the copper oxide is reduced to copper. The oxygen carrier substrate is unchanged in the reaction. The circulating bed material and the gaseous products are conveyed into an upper reactor space 213 . These gases and solids are then directed by a duct 214 into a means for separating the solids from the gases 215 . This separation means 215 is a cyclonic separator in one embodiment. The cyclonic separator separates the solids from the gases by centrifugal forces and causes their conveyance by pipe 218 into a burn-off reactor 260 . The bed material entering the burn-off reactor by pipe 218 includes a portion of the introduced oxygen rich oxygen carrier, reduced oxygen lean oxygen carrier, substantially all of the carbonaceous component of the fuel as char, and ash. It is substantially free of the gaseous products of the reaction of the hydrogen component of the fuel.
In the burn-off reactor 260 , oxygen rich oxygen carrier is admitted at a controlled rate via pipe 223 . In one embodiment, the rate is controlled via an L-Valve assembly 257 , by controlling the pressure and flow of motive fluid 227 through aeration pipe 226 . Through these means, the ratio of the char plus any other unoxidized fuel components to the oxygen rich oxygen carrier in the bed is maintained at or above the minimum value required for complete oxidation. The height of the bed is controlled via the downcomer 219 and the residence time of reactants in the bed is set by the rate of admission of the material entering the bed via pipes 218 and 223 and the rate of material leaving via the downcomer 219 . A novel entrance 176 to the downcomer 219 , similar to that shown in FIG. 1C , is provided such that the flow area available to the flow out of the reactor bed is a desired function of the bed height. This means is chosen from the set of a single and a multiplicity of slots 176 in one embodiment. When said slot or slots are formed in one embodiment with sides 176 with a profile as shown in FIG. 1C , the bed residence time in the bed is constant with regard to total flow into the bed and with regard to any individual flow into the bed. The functional form of the residence time variation with flow may be controlled to other than constant form, linear for example, by applying different profiles to the slot opening, as will be appreciated by those skilled in the art, and are within the scope of this invention. Thus through the present means, the reactor bed residence time may be controlled as a function of any desired reactor flow variable such as one or more reactor flows or a function thereof, chosen from the set including, but not limited to oxygen rich oxygen carrier and carbonaceous fuel in one embodiment. Various reactor bed residence times may be achieved by various slot shapes. The independent variable may be chosen from a set including, but not limited to, the ratio of oxygen rich oxygen carrier flow to fuel flow, oxygen rich oxygen carrier flow, and fluidizing fluid flow. In a further feature of this means, the height of a downcomer which is free of any flow openings is set to maintain a minimum reactor fluidized bed volume at which bed fluidization can be stably and reliably maintained. Through these systems and process all char and any other fuel or fuel components are completely oxidized so that the material leaving the bed via downcomer 219 is substantially composed of oxygen lean oxygen carrier, oxygen rich oxygen carrier, and ash. The bed 220 is maintained in a fluidized state via a fluidizing fluid 225 , carbon dioxide in one embodiment, admitted via a pipe 224 into an expansion space 261 . This fluid is then distributed by distributor plate 262 uniformly across the face of the fluid bed. The gaseous products of the oxidation mix with the fluidizing fluid 225 , and flow into burn-off reactor head space 259 and from there to a heat exchange means via pipe 222 . In the one embodiment, the heat exchange means is comprised of continuous tube banks 204 arranged in the bed and head space of the fuel reactor 212 . When the fuel reactor is operating in other than full oxidation mode, this heat exchange means supplies some or all of the heat required to maintain the endothermic gasification reactions. When the fuel reactor is operating in full oxidation mode heat is released by the oxidation reaction and the heat exchange means serves as a piping or duct only.
The burn-off reactor bed material 220 flows through a downcomer 219 , via a pipe 229 , and into the oxygen carrier regeneration reactor 237 , where the solids are dispersed and mixed with a circulating fluidized bed. The bed is fluidized by the fluidizing agent 230 , compressed air in one embodiment, which has been introduced via a pipe 231 . The bed material 236 in regeneration reactor 237 is separated from the fluidizing gas expansion chamber 232 and supported by a distribution plate 233 which also serves to distribute the fluidizing gas evenly across the fluidized bed.
In the oxygen carrier regeneration reactor, the oxygen lean oxygen carrier, copper metal dispersed in and bound to a carrier particle in the one embodiment, reacts with, and is oxidized by the oxygen from air to copper oxides. The substrate particle is not changed in the reaction.
Some or all of the bed material is entrained in the fluidizing compressed air and the product hot oxygen depleted air is circulated to an upper reactor space 238 of the regeneration reactor 237 . These gases and solids are then directed by duct 239 into a separation means 240 , a cyclonic separator in one embodiment, where the gases and lighter ash components are separated by centrifugal forces from the remaining solids, substantially composed of oxygenated oxygen carrier and heavier ash components. These solids are conveyed down through the cyclonic separator converging section 134 A through duct 243 into a solids flow regulating system. This solids-flow regulating means is comprised of a material accumulator 256 , an L-Valve component 257 , a second L-Valve component 245 and a third L-Valve component 255 . These components are operated in a coordinated control manner to achieve regulated flows of oxygen rich oxygen carrier to the burn-off reactor, fuel reactor, and solids extraction and treatment system respectively. The upper L-Valve component 257 comprises a downcomer 258 , and an aeration tube 226 . The amount of solid particles which flow through said L-Valve and into conveying pipe 223 can be regulated by varying the flow rate and pressure of a gas 227 , for example steam in one embodiment, introduced through aeration tube 226 . Greater aeration gas pressure and flow result in greater solids flow. The oxygenated oxygen carrier is then introduced to the burn-off reactor 260 through a pipe 223 to provide the oxygen-rich oxygen carrier in a controlled ratio to the char, unreacted fuel, and other unreacted fuel components exiting the fuel reactor via a pipe 218 . This ratio is controlled and maintained above a minimum needed for full oxidation of all char, unreacted fuel, and other unreacted fuel components.
A portion of the oxygenated oxygen carrier along with ash constituents bypasses the first L-Valve component 257 and flows through an opening 228 into a second L-Valve component 245 . There a controlled portion of the flow is directed via motive fluid 246 , steam in one embodiment, into duct 248 and into the fuel reactor 212 in a ratio to the carbonaceous fuel 208 . This ratio is controlled so that in oxy-fuel mode it is above the minimum required for full oxidation and in gasification mode, it is below the maximum required for partial oxidation of the volatile or hydrogen fuel component. In transition mode it is changed in a controlled manner to move from one of said modes to the other.
In a further feature, a portion of the bed material is extracted via another L-Valve assembly 255 . The amount of extracted material is controlled by varying the pressure and volume of the aeration gas 251 , steam in one embodiment, admitted through L-Valve aeration tube 252 .
The material 254 extracted for treatment consists primarily of oxygenated oxygen carrier and heavier ash components. This oxygenated oxygen carrier is separated from the ash using conventional means. Some ash components such as potassium salts are valuable as additives to fertilizer and can be sold. Others such as sodium salts are sent to disposal. The clean reclaimed oxygen carrier 234 is recycled to the system through a feed pipe 235 .
The operation and features of the present system and process may be further understood by an example of system operation conditions, as follows:
The typical operating conditions of the fuel reactor 212 for one pressurized embodiment depend upon whether the system and process is in partial oxidation (gasification) or full oxidation (oxy-fuel mode):
Fuel Oxidation Reactor Conditions
Preferred Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
700° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Fuel to Active
0.44 kg/kg
0.22 kg/kg
Components of
Oxygen Rich Carrier
Oxygen Rich Carrier
4 kg/kg
0 kg/kg
in Accumulator
per kg of Fuel
Product Gas
CO 2 , steam, trace
CO 2 , CO, H2 and trace
Composition
gases
gases
CO
31% volume dry
18 ppmd
CO 2
14% volume dry
98% volume dry
H 2
52% volume dry
41 ppmvd
Steam
14% volume wet
60% volume wet
Trace Gases
3% volume dry
2% vd including CO + H 2
The typical operating conditions of the burn-off reactor 260 for one pressurized embodiment are substantially the same whether the system and process is in partial oxidation (gasification or full oxidation (oxy-fuel mode):
Burn-off Reactor Conditions
Preferred Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
875° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Solids from FR/
0.05 kg/kg
0.09 kg/kg
Oxygen Carrier
Product Gas
CO 2 , steam, trace
CO 2 , CO, H2 and trace
Composition
gases
gases
CO
less than 1 ppmd
less than 1 ppmd
CO 2
greater than 99%
greater than 99%
volume wet
volume wet
H 2
less than 1 ppmd
less than 1 ppmd
Steam
less than 1% volume wet
less than 1% volume wet
Trace Gases
less than 1% volume dry
less than 1% volume dry
including CO + H 2
Gaseous products 217 from the fuel reactor 212 leave the gas solid separation means 215 via the duct 216 . Gaseous products 264 leave the burn-off reactor 260 via duct 222 , flow through the heat exchanger 204 and duct 263 . The oxygen-depleted air 242 from the oxygen carrier regeneration reactor 237 leaves gas-solid separator 240 via a duct 241 .
The hot high-pressure fuel reactor product stream is used for power production using the same equipment for both modes. If the system is operating in gasification mode, the post-power and heat production, cooled, reduced pressure, syngas product stream is sent to a downstream catalytic process for the production of biofuels. By means of the process and systems described above, substantially all of the carbon component of the fuel is conveyed as char into the burn-off reactor. This minimizes the carbon dioxide content of the syngas, and increases the efficiency and biofuel product production of the syngas to biofuel process. When operating in oxy-fuel mode, post power production, the cooled reduced pressure product stream of consisting substantially of steam, and trace gases with a minimum of carbon dioxide, is sent to a condensing scrubber where the stream is condensed and the trace gases are removed with this condensate. The resulting stream of essentially pure carbon dioxide is mixed with the carbon dioxide from the burn-off reactor.
The burn-off reactor gaseous product is substantially pure carbon dioxide in one embodiment where carbon dioxide is used as the fluidizing fluid. This carbon dioxide is mixed with the aforesaid carbon dioxide from the fuel reactor and is liquefied for sale or sequestration.
The electric energy and heat production equipment is the same for both gasification and oxy-fuel operation with the exception of the scrubbing condenser and carbon dioxide liquefaction equipment. Thus, greater than 95% (on a cost basis of the plant is common to the two modes of operation.
The hot, high pressure carbon dioxide stream is also used for the production of electric power and heat utilizing existing means such as turbo-expanders, and heat recovery steam generators. The turbo-expander is coupled to a carbon dioxide compression means to provide the compressed carbon dioxide needed to operate the burn-off reactor. The hot, high pressure oxygen depleted air stream also used for the production of electric power and heat utilizing existing means such as turbo-expanders, and heat recovery steam generators. The turbo-expander is coupled to an air compression means to provide the compressed air needed to operate the oxygen carrier regeneration reactor.
The means and equipment used for compression and for power generation and heat production is completely common to both modes of operation, since the oxygen carrier regeneration reactor operation is essentially the same for both modes.
The present system 200 is entirely self-sustaining on an energy basis. In oxy-fuel and gasification mode both reactors generate high temperature and pressure products for heat and power generation. In gasification mode, the fuel reactor is operated at the same or a lower temperature, 700 C in one example, relative to the oxygen carrier regeneration reactor, 875 C in the example. The solid oxygen carrier flowing from the oxygen carrier regeneration reactor give up sensible heat to the fuel reactor providing some of the energy need for gasification of the fuel. The remainder of the energy is provided by heat transfer from the gaseous products of the burn-off reactor. This method and process is superior to conventional oxygen blown gasification, since the carbon dioxide does not mix with and dilute the syngas product stream.
The method and means for switching between the two modes is to vary the amount of oxygen rich oxygen carrier stored in the accumulator 256 by varying the amount and pressure of the steam introduced through aeration pipes 226 , 247 , and 252 . This method also controls the amount of solid material circulating in the fuel, burn-off and oxygen carrier regenerator loop, which is easily seen to be the total solids circulating in the system minus the solids stored in the accumulator. The amount of active components of solids circulating in the system, and the amount of active components, copper oxides in one embodiment, of oxygen rich oxygen carrier stored in the accumulator for both modes of operation is shown above.
The typical operating conditions of the oxygen carrier regeneration (air reactor are essentially the same for either fuel oxidation mode:
Oxygen Carrier Regeneration Reactor
Preferred Active Oxygen Carrier = CuO and Cu 2 O
Gasification Mode
Oxy-fuel Mode
Temperature
875° C.
875° C.
Pressure
20 atmospheres
20 atmospheres
Air to Active Components
4.3 kg/kg
3.4 kg/kg
of Oxygen Depleted Carrier
Ratio*
Product Gas Composition**
O 2 and N 2
O 2
16.5% volume dry
16.6% volume dry
N 2
83.5% volume dry
84.4% volume dry
Exit Solids Composition
Oxygen Lean Oxygen
Carrier
Oxygen Rich Oxygen
Carrier
Char
Unreacted Fuel
Ash
*Note: Includes air required for heat balance as well as air required for oxygen carrier regeneration
**Note: These compositions do not include the trace amounts of water, argon, and CO 2 which enter with the ambient air.
FIG. 3 schematically illustrates an overview of a system 300 in accordance with the present invention, including both apparatus and method. At a starting step 302 , a carbonaceous fuel, solid, liquid, gas or mixture, such as biomass or biorefinery residue is introduced, at a step 304 , into an air-independent internal oxidation (AIIO) reactor system. AIIO system 304 is capable of operation in either a gasification mode (Mode 1 ) or a production mode concentrating more particularly on combined heat and power (CHP) (Mode 2 ); these discrete modes are schematically illustrated at a step 306 . Note that both modes produce heat and power, as illustrated at a step 308 (and with further specificity as step 332 for power production and 334 for heat production, which are further shown to be outputs of AIIO system 304 ).
From step 308 , system 300 may be selectively operated in either of two optional modes, a Mode 1 312 or a Mode 2 320 . That these are optional alternatives is schematically illustrated by the dashed lines indicating the branches.
If system 300 is selected to operate in Mode 1 , the system shifts to a biofuel process 314 , a catalytic process in the preferred embodiment. In this case, the reactor is operated in gasification mode and produces ethanol (or other biofuel) as the predominating end-product, as illustrated at step 318 . Heat is also produced at a step 316 .
If system 300 is selected to operate in Mode 2 , the system shifts to operate as a direct contact condenser 322 , producing condensed water at a step 324 , and CO2 which goes on treatment, which include liquefaction in the preferred embodiment, at a step 326 , resulting in liquid CO2 at a step 328 , and heat, at a step 330 .
FIG. 4 shows, in a schematic fashion, the feature of a novel system 400 for control of system parameters, in particular the solids flowing in, out, and through the system and carbonaceous fuel entering the aforesaid reactor system. Fuel 449 is introduced to a flow control assembly 450 , comprising a flow controller 451 , an actuator for said controller 452 responsive to a signal 453 received from the supervisory control system 499 . This supervisory control system can be chosen from a set including, but not limited to, input output, adaptive, programmable logic, and model based control systems. Said system is a model-based control system in one embodiment, capable of receiving multiple input signals, processing them and sending multiple output signals to the system actuators to achieve desired results, including but not limited to, flows, temperatures, and pressures. FIG. 4 shows novel features of one embodiment, but some conventional signals are not shown. The signal received by the fuel flow control actuator 452 is a function of input demand signals chosen singly or multiply from a set comprising, but not limited to required heat, electric power, and syngas flow. The fuel then flows through a flow measurer and transmitter 402 which sends a signal in proportion to the flow to the control system. This feedback signal is compared with the desired flow and the fuel flow control signal 453 is adjusted until the difference between the desired flow and the measured flow reaches a programmed level. The fuel is then introduced to the fuel reactor 404 having a residence time τ FR 431 . This residence time is the average time that a particle spends in the fuel reactor before exiting through downcomer 432 and is constant in one embodiment. Oxygen-rich oxygen carrier is introduced to the fuel reactor via pipe 435 in proportion to the fuel. The amount and flow of this oxygen rich oxygen carrier is controlled in a manner described below using steam in one embodiment. The particles leaving the fuel reactor via downcomer 432 and entering the burn-off reactor, after a transit time τ FR-BOR 424 , are comprised of oxygen-rich oxygen carrier, oxygen-lean oxygen carrier, unreacted fuel, carbon, and char particles. The burn-off reactor 405 has a residence time τ BOR 430 , said residence time is constant in one embodiment. In addition to said particles, the burn-off reactor receives oxygen-rich oxygen carrier via pipe 434 ; the amount and flowrate of said oxygen rich oxygen carrier is controlled as discussed below. The particles leaving the burn-off reactor via downcomer 433 and entering the air reactor after transit time τ BOR-AR 425 are comprised of ash, oxygen rich oxygen carrier and oxygen lean oxygen carrier. Air 436 , compressed in one embodiment, is also introduced into the air reactor through flow control assembly 460 and flow measurer and transmitter 436 which operate in the manner describe for fuel flow to achieve a desired air flow amount and air flow rate in proportion to the said particles introduced via downcomer 433 . The air reactor has a residence time τ AR 431 . Particles, comprised of oxygen rich oxygen carrier and ash, then flow from the air reactor via a pipe 443 and are introduced to a solids accumulator 407 after transit time τ AR-ACC 423 . In one embodiment, the solids accumulator is a vessel of sufficient active holding volume 419 , taking into account the volume of oxygen-rich oxygen carrier required by fluctuations in flow rate required for stable operation, the volume of oxygen rich oxygen carrier required by fluctuations in flow rate required when selecting between operating mode requirements, and the volume of oxygen rich oxygen carrier required by simultaneous operating mode switching and stable operation. The amount of oxygen rich oxygen carrier held in the accumulator is monitored by a level transmitter 475 which inputs a signal 476 to the control system. It is a feature of the accumulator that the output flow rate is independent of the input flow rate so that each may fluctuate temporally with no effect on the other. This system and process enables operation in a mode chosen from any of full fuel oxidation, gasification, and transition. As will be appreciated by those skilled in the art, without the accumulator, stable operation in the event of large changes in fuel and other inputs cannot be achieved, as shown by the following example: Step 1: an increase in fuel input in response to control system output 453 demands an increase in oxygen rich oxygen carrier to maintain stable output. Step 2: The first L-Valve assembly directs some or the entire portion of the oxygen rich oxygen carrier entering from pipe 448 to the fuel reactor in response. Step 3: with no or insufficient oxygen rich oxygen carrier entering the burn-off reactor, oxidation of char, unoxidized fuel and ash components stops. Step 4: Said unoxidized components enter the air reactor, initiating flame combustion in air. Step 6: Said flame combustion of carbonaceous fuel components results in excessively high temperatures and undesirable emissions of carbon dioxide, other greenhouse gases, and pollutants to the atmosphere. With the accumulator, the process is as follows: Step 1: an increase in fuel input 453 demands an increase in oxygen rich oxygen carrier to maintain stable output. Step 2: The first L-Valve assembly directs the demanded portion of the oxygen rich oxygen carrier entering from 448 to the fuel reactor in response. Step 3: The amount of oxygen rich oxygen carrier stored in the accumulator decreases to supply the necessary amounts for the fuel reactor and the burn-off reactor. Step 3: An amount of oxygen rich oxygen carrier necessary for oxidation of char, unoxidized fuel and ash components is introduced to the burn-off reactor via a second L-Valve assembly. Step 4: No unoxidized components enter the air reactor, which operates in a normal manner. Step 6: There is no flame combustion of carbonaceous fuel components, no excessively high temperatures, and no undesirable emissions of carbon dioxide, other greenhouse gasses, and pollutants to the atmosphere. Further, with the accumulator in place, for smaller changes in fuel and other inputs, there is no delay in response time to said input demand. Without the accumulator, delays would result in system oscillations due to the multiplicity of residence times and transit times between the fuel input to the fuel reactor (demand) and oxygen rich oxygen carrier input to the first L-Valve assembly (response). With the accumulator in place, the amount of oxygen rich oxygen carrier in said accumulator simply fluctuates as required to respond to demand fluctuation. Therefore, fluctuations fuel and other inputs do not lead to feedback oscillation and other serious operational limitation and instabilities. Thus, this system and process prevents dynamic loop flow disturbances from propagating around the reactor system. A portion of the oxygen-rich oxygen carrier particles flow from said accumulator via pipe 448 and into a first L-Valve assembly 412 . Oxygen-rich oxygen carrier in a desired proportionality to the fuel 402 is sent to the fuel reactor via pipe 435 flowing through flow measurer and transmitter 413 which sends a signal in a proportional relation to the supervisory control system. The amount and flow rate of said oxygen rich oxygen carrier is controlled by a motive fluid 404 which flows through a flow control assembly 470 then through a flow measurer and transmitting assembly 410 these assemblies operate as described above to introduce a controlled amount of the motive fluid into the L-Valve assembly. This motive fluid induces an oxygen-rich carrier flow in proportion to said motive fluid flow into the fuel reactor as described above. By this system and process, the ratio of oxygen rich oxygen carrier to the fuel may be controlled to a desired value. For operation in a gasification mode, the ratio is maintained within a range of 0-3 in one embodiment. For operation in a full oxidation mode, the ratio is maintained within a range of 4-10 in one embodiment. Said ratio is increased or decreased as appropriate to transition between modes. The controlled ratios are in a functional relation to fuel reactor parameters selected from a set comprising, but not limited to, residence time, temperature and pressure. Constant residence time, in one embodiment, results in a desired simplicity of control system design, programming, operation, and cost.
A portion of the oxygen rich oxygen carrier entering the L-Valve assembly (which can include multiple L valves) is introduced to the first L-Valve assembly 412 , via steam in one embodiment, the remainder of the oxygen rich oxygen carrier flows to a second L-Valve assembly 417 . There, as described above, a portion of the flow is sent to the burn-off reactor via pipe 434 through the control of a motive fluid, carbon dioxide 446 in one embodiment. Said portion is controlled in a ratio to the char, any unoxidized fuel, and unoxidized ash forming components, such that all of said components are completely oxidized prior to leaving the burn-off reactor. A final portion of the oxygen rich oxygen carrier and bottom ash is conveyed from a second L-Valve assembly to a third L-Valve assembly, where it flows to a treatment system comprised of conventional components including but not limited to froth flotation units, filters, pumps, and settling tanks. The flow of this final portion of oxygen rich oxygen carrier and ash to said treatment system is accomplished using a controlled flow of a motive fluid 428 , steam in one embodiment. The amount and flowrate of this motive fluid is controlled as described above. The supervisory control system may be operated to perform said operations and actions automatically or in response to manual operator inputs.
FIGS. 5A , 5 B, 5 C, 5 D and 5 F depict more detailed embodiments of a system 500 .
FIG. 5E depicts a biofuel reactor system of the related art.
In the preceding specification various embodiments and aspects of the present invention have been described with reference to specific examples thereof. It will, however, be evident that various modifications and changes may be made without departing from the broader spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. | A reactor system which selectably produces from carbonaceous fuel, combined heat and power (CHP) or syngas and CHP, and in either mode a stream of greater than 95% CO 2 for sale or sequestration. Also included are plurality of reactors, ash separation system, and feedback control system. The reactors comprise 1) a fuel reactor selectably operated in full oxidation mode for production of CHP, or in partial oxidation mode to produce syngas to produce biofuels and CHP; 2) a burn-off reactor fully oxidizes char or carbon from the fuel reactor producing CO 2 ; and 3) an optional regeneration reactor reoxygenating oxygen carrier from the first two reactors which is returned to the fuel reactor. The feedback control system comprises an accumulator and controllable elements to apportion oxygen carrier between fuel and burn-off reactors and extract oxygen carrier and heavy ash. This ash and ash from the regenerator products are sold or disposed. |
BACKGROUND OF THE INVENTION
The present invention is concerned with a key and, more particularly, with a key comprising means enabling to see the last status, open or closed, of the corresponding locks.
DESCRIPTION OF THE RELATED ART
Locks are known, which are provided with a visible marking which can assume two different states, depending on the open or closed status of the lock. This however requires that the user be near the lock to recognize its status. To solve the problem of verifying remotely the status of a lock, the German patent DE 3207998 C2 proposes a key, the head of which is provided with an electrical circuit having a pulse generator and with a source of energy supplying an optical display. When the key is introduced completely into the cylinder, a pressure contact activates the electric circuit. The rotation of the key initiates the displacement of a movable contact by the effect of gravity, and a pulse is generated modifying the status of the optical display. This device makes it possible to solve the above-mentioned problem, but is expensive and complicated to manufacture. Furthermore, this device necessitates a source of energy in the head of the key, for example in the form of a battery and, accordingly, poses problems of reliability when the battery is discharged.
SUMMARY OF THE INVENTION
The purpose of the present invention is to remedy to the above-mentioned drawbacks and to provide a device which is simple to manufacture, which requires no source of energy and which enables the owner of a key to determine, by direct reading of the latter, the last status of the corresponding lock. Furthermore, the device should be inexpensive and capable of adaptation to different types of existing keys. This objective is attained by a key which is characterized by the features set forth in claim 1.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the annexed drawing which represents schematically a non limiting example of an embodiment of the key according to the present invention, wherein:
FIG. 1 is a bottom view of the assembled key according to the present invention.
FIG. 2 is a profile view of the body of the key.
FIG. 3 is a front view of the body of the key illustrated in FIG. 2.
FIG. 4 is a cross-sectional view taken along line A--A of the body of the key illustrated in FIG. 3.
FIG. 5 is a front view of one half of the piece forming the head of the key.
FIG. 6 is a partially cross-sectional view of the key once assembled.
FIG. 7 is a cross-sectional view taken along line B--B of the key shown in FIG. 6.
FIG. 8 is a cross-sectional view identical to that of FIG. 7, but showing another version of the head of the key.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, the key is conformed in a traditional manner in its upper head part 2 and in its lower shank part 1, designed for introduction into the cylinder of the corresponding lock. An opening or window 3 is provided at the center of the head 2 of the key. This transparent window 3 enables a visual determination of the last status of the lock. Thus, a red color will appear, for example, in this window 3 when the corresponding lock is in the closed position and a green color when the same is in the open position. It is obvious that the choice of the colors is arbitrary and can be adapted according to the wishes of the user.
FIG. 2 illustrates the body of the key, of which the upper part is designed for receiving the head 2 which will be described in detail with reference to FIGS. 5 to 8. The lower part 1 of the key provides the shank which can be machined according to the cylinder of the lock for which it is intended. The upper part of the body of the key is comprised of a cylindrical portion 4 of which the central part has a diameter which is slightly smaller. This central part 5 is designed for receiving the information support, which is provided as a self-adhesive rectangular strip 25 of a length corresponding to the circumference of the central part 5. The self-adhesive strip 25 is applied to central part 5 as indicated by the curved arrow of FIG. 2. This self-adhesive strip 25 has one color on one half of its length another color on the other half of its length, this other being selected to allow a discrimination between the two statuses of the lock. When the colored strip is placed on the central part 5, the first covers one half of the circumference of the part 5 over its whole length, the other half being colored by the second color selected. One can also consider the use of a bushing 26 colored with two colors, each color covering over the whole length of the bushing 26 one half of the circumference. This bushing, designed for being slipped over, and to adhere to, the central part 5 of the body of the key, as indicated by the arrow of FIG. 3, is generally made of a plastic material or of polycarbonate. Alternatively, central part 5 may serve as the bushing 26, wherein the central part 5 is colored in printing or the central part can be made of two halves, differently colored.
The upper part of the body has two grooves 6, extending each one over one half of the circumference of the body 4. The upper and lower grooves 6 are mutually offset by 180 degrees, so that they extend each one over an opposite half of the circumference of the body 4. On the axis of symmetry of the body, the grooves 6 end by a bore 7 of which the depth is slightly greater than that of the grooves 6. The body 4 is ended in its upper part by a frustoconical portion 8.
FIG. 3 is a frontal view of the body of the key represented in profile in FIG. 2 and it shows over which portions of the circumference of the cylinder the grooves 6 extend. The cross-sectional view of FIG. 4 shows the depth of the bores 7.
FIG. 5 shows one half of the piece forming the head 2 of the key. This piece is generally made of a plastic material, by molding or injection. This piece illustrated as having a rectangular shape, can obviously be conformed differently according to the visual effect desired and can be, in non-limiting exemplary embodiments, oval or round shaped. The central part of this piece includes a longitudinal semi-cylindrical recess 9, designed for receiving the upper part 4 of the body of the key. One of the two halves of the head of the key has a central rectangular recess 10 providing the display window. This window can be provided with a panel (not illustrated), made of a transparent material. In another version, each one of the two halves of the head of the key will include a display window. When the head of the key includes a display window on each one of its faces, it is necessary that the two windows be offset along the longitudinal axis. In this embodiment, the central part 5 of the cylinder 4 carrying the visual information is separated into two zones. A first zone, facing the first window, has two colors, each one extending over one half of the circumference of the cylinder. A second zone, facing the second display window, also has two colors, each one extending over one half of the circumference. The portions of the circumference of the cylinder 5 carrying the same color are mutually offset by 180 degrees. Accordingly, the same color appears at the same time through each one of the two windows, whatever may be the position of the head of the key relative to its shank.
Two recesses 11, perpendicular to the axis of symmetry of the piece open into the central recess 9. When the head is positioned on the body 4 of the key, the recesses 11 face the grooves 6 of the body 4. These recesses 11 receive, as shown from FIGS. 6 and 7, a friction device comprised of pins 12 and of springs 13. In the service position, i.e. when the head of the key is aligned with the shank, the pins 12 are maintained by the action of the springs 13 at the bottom of the bores 7 of the grooves 6. To simplify the manufacture of the head of the key, the recesses 11 can extend over the whole width of the key and not only over one half thereof as illustrated in the drawings.
The assembling of the key, according to the present invention, is extremely simple. In the first step, the two halves constituting the head of the key are superimposed and then bonded together with an adhesive or by hot soldering. The body 4 of the key is then inserted fully into the head of the key in such a manner as to leave solely the shank 1 protruding. The pin 12 and the spring 13 are then inserted into the upper housing 11, and a slight pressure is applied on the spring 13 by means of an appropriate tool, so as to insert the same completely into the body of the head of the key. A rider or a blocking clip 14 is introduced into the trapezoidal groove formed by the two halves of the head of the key. After rotating the key, the first friction device being maintained by the clip 14, the same procedure is applied to place a friction device 12, 13 into the lower housing. The clip 14 can then be pushed into its final position on the head of the key, as illustrated in FIG. 6. This assembling process offers the advantage that it can be completely automated without requiring any complicated assembly line. Another advantage is that the clip 14 is simply urged into the trapezoidal groove, the shape of the latter preventing the clip from escaping. The clip 14 being removable, it is possible, if necessary, to change the springs 13 and replace them by springs exhibiting other characteristics, should one wish to modify the torque which needs to be applied to disengage the pins 12 from the bores 7.
The blocking clip 14 is generally made of a plastic material, preferably colored in its mass, the coloring making it possible to identify individual keys in a set of otherwise identical keys.
In another version and as illustrated in FIG. 8, the recesses 11 exhibit, at their distal end, a bore of smaller diameter provided with a threading. A screw 15 makes it possible to retain the spring 13 and the pin 12 in their housing. This embodiment makes it possible to adjust manually, the pressure of the pins against the grooves and, accordingly, the torque needed to disengage the pins from the bores. Accordingly, the user can adjust himself this parameter, according to the state of the lock.
Once assembled, the head of the key can undergo a 180 degree rotation relative to the body of the key, in one direction or the other. This rotation is limited by the fact that the grooves 6 extend only over one half of the circumference of the body 4. In the service position, the head of the key is maintained aligned with the shank of the key by virtue of the springs 13 urging the pins 12 into the bottoms of the bores 7 located at the ends of the grooves 6. After introduction of the key into the cylinder of the lock, the user imparts a rotation to the key in one direction or the other, depending on whether he wants to open or close the lock. The head of the key is initially fixed with respect to the body of the key, since the lock offers only little resistance until when the bolt is driven. As soon as the torque applied to the head of the key increases, the pins 12 disengage from the bores 7 and the head of the key rotates by one half of a circle relative to the body of the key, displacing thereby the display window 3 to face the opposite portion of the cylinder 5. Accordingly, the other color chosen for identifying the open or closed status appears in the window 3. After having carried out this rotation of one half of a circle, the head of the key is anew aligned with the shank and fixed with respect to the same, and the pins 12 become engaged again in the bores 7. The continued rotation of the head of the key, produces an actuation of the lock. One should note that the springs 13 are sized so that the torque to be applied to the head of the key be lesser than the one necessary for opening or closing the lock. In this manner, the user is certain that he will not be able to open or close the lock without carrying out beforehand a rotation of one half of a circle of the head of the key with respect to the shank. In the position where the head of the key is aligned with the shank, i.e. when the pins 12 are engaged in the bores 7, the user can realign the barrel of the lock to remove the key for example, without any rotation of the head, the torque needed for realigning the barrel being insufficient for causing the disengagement of the pins 12.
The key, according to the invention, is therefore extremely reliable, a change in the status of the display occurring only as a result of an actual operation of opening or closing of the lock. One can note that the friction device, comprised of the pins 12 and of the springs 13, makes it possible, by cooperating with the grooves 6 and the bores 7, on the one hand, to adjust the torque needed for the rotation of the key relative to its shank and, on the other hand, to limit the rotation of the head of the key to one half of a circle, these two functions being ensured by the same device.
The construction of the key, which is both simple and robust, makes it possible to use this type of key with any existing type of lock. Furthermore, this key can be wholly factory made and requires no operation by the retailer, except for the machining of the shank to correspond to a given cylinder.
By simply inverting the colors of the adhesive strip, provided on the center of the body of the key 5, it is possible to use this key both with locks opened by an anticlockwise rotation and those opened by a clockwise rotation. | The key has a head (2) provided with a window (3) enabling to see a portion (5) of the surface of the cylinder of the body (4) of the key. Two grooves (16) extend each one over one half of the circumference of the body (4), they are mutually offset by 180 degrees and ended by bores (7). In the service position, pins (12) are urged towards the bottom of the bores (7) by a resilient member (13). When the torque applied to the head (2) of the key increases, the pins (12) are expelled from the bores (7) and the head of the key can rotate by 180 degrees relatively to its shank (1), thus showing the opposite portion of the body (4) through the window (3). |
RELATED APPLICATIONS
[0001] This application is a divisional of and incorporates by reference in its entirety, U.S. patent application Ser. No. 08/988,946, entitled, “METHOD OF MOUNTING A MOTHERBOARD TO A CHASSIS,” filed on Dec. 11, 1997. The subject matter of U.S. patent application Ser. No.______, entitled “METHOD OF MOUNTING A MOTHERBOARD TO A CHASSIS,” filed concurrently herewith and having Attorney Docket No. MTIPAT.080C1, and U.S. Pat. No. 6,124,552, entitled “MOTHERBOARD SCREWLESS MOUNTING SPACER,” is related to this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to mounting spacers for circuit boards. More particularly, the invention relates to a device for easily and quickly mounting a motherboard to a computer chassis.
[0004] 2. Description of the Related Art
[0005] During assembly of a computer, the computer motherboard must be fastened to the computer frame or chassis to secure the board during use against undesired movement relative to the chassis. In existing systems, the motherboard is mounted to the computer chassis using screws or bolts which are typically made of electrically conductive metal. The screws are inserted into any of several mounting holes in the motherboard, which are aligned with corresponding holes on the computer chassis. After insertion of the screws, an installer uses a screwdriver to tighten the screws and thereby securely mount the motherboard to the computer.
[0006] The mounting holes on the motherboard are often surrounded by a grounding pad. The grounding pad is a conductive surface that is used as an electrical ground for the motherboard. After mounting, the heads of the metal mounting screws contact the pads on the motherboard and thereby provide an electrical ground interface.
[0007] There are certain drawbacks associated with using screws to mount a motherboard to a computer chassis. One such drawback is the great amount of time it takes for an installer to insert the screws through the multiple mounting holes and then tighten each screw onto the motherboard. This process is tedious and time-consuming. It is also time-consuming to remove the screws in order to remove the motherboard from the chassis for purposes such as repairs or maintenance.
[0008] There is, therefore, a need for a device that may be used to easily and quickly mount a motherboard to a computer chassis. Preferably, the device should secure the motherboard to the chassis without requiring screws. Additionally, the device preferably should be usable with existing motherboard designs and should also be capable of providing an electrical ground interface for the motherboard.
SUMMARY OF THE INVENTION
[0009] The aforementioned needs are satisfied by the present invention. In one aspect of the invention, there is disclosed a method of removably mounting a planar electrical component to a chassis. The method comprises positioning a first fastener of a mounting device adjacent a mounting slot in the chassis, inserting the first fastener of the mounting device through the mounting slot in the chassis, releasing the mounting device so that the first fastener clamps onto the chassis through the mounting slot, positioning a second fastener of the mounting device adjacent a mounting hole on the planar electrical component, and inserting the second fastener of the mounting device into the mounting hole until the second fastener clamps onto the planar electrical component through the mounting hole.
[0010] Another aspect of the invention relates to a method of removably mounting a planar electrical component to a chassis. The method comprises inserting a first fastener of a mounting device into a mounting slot in the chassis so that the first fastener compresses the chassis between the first fastener and a spacer portion of the mounting device, and inserting a second fastener of the mounting device into a mounting hole in the planar electrical component so that the second fastener compresses the planar electrical component between the second fastener and the spacer portion.
[0011] In another aspect of the invention, there is disclosed a method of removably mounting a planar electrical component to a chassis. The method comprises inserting a first fastener of a mounting device into a mounting hole of the planar electrical component so that the first fastener clamps onto the planar electrical component, and inserting a second fastener of the mounting device into a mounting slot in the chassis so that the second fastener clamps onto the chassis to thereby attach the planar electrical component to the chassis.
[0012] In yet another aspect of the invention, there is disclosed a method of removably mounting a planar electrical component to a chassis. The method comprises clamping the chassis between a first fastener and a spacer of a mounting device, and clamping the planar electrical component between a second fastener and the spacer of the mounting device so that the planar electrical component is spaced apart from the chassis by a distance substantially equal to the height of the spacer of the mounting device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features of the invention will now be described with respect to the drawings which are intended to illustrate and not to limit the invention and in which:
[0014] [0014]FIG. 1 is a perspective view of a motherboard mounted onto a computer chassis using the mounting spacers of the invention;
[0015] [0015]FIG. 2 is a side elevational view of one embodiment of the mounting spacer of the invention;
[0016] [0016]FIG. 3 is a front elevational view of the mounting spacer of FIG. 2;
[0017] [0017]FIG. 4 is a top plan view of the mounting spacer of FIG. 2;
[0018] [0018]FIG. 5 is a side view of the mounting spacer illustrating the first step in the process of installing the mounting spacer in a computer chassis;
[0019] [0019]FIG. 6 is a side view of the mounting spacer illustrating that device after installation onto a chassis;
[0020] [0020]FIG. 7 is a side view of the mounting spacer illustrating the first step in the process of installing the mounting spacer onto a motherboard;
[0021] [0021]FIG. 8 is a side view of the mounting spacer illustrating the second step in the process of installing the mounting spacer onto a motherboard;
[0022] [0022]FIG. 9 is a side view of a motherboard mounted onto a chassis using the mounting spacer of the present invention; and
[0023] [0023]FIG. 10 illustrates a material blank that is formed into the mounting spacer of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0024] [0024]FIG. 1 is a perspective view of a planar motherboard 20 mounted onto a frame or chassis 22 of a computer using at least one mounting spacer 24 configured in accordance with one embodiment of the invention. As discussed in detail below, an installer may use the mounting spacers 24 to easily and securely mount the motherboard 20 to the chassis 22 without the use of mounting screws. The motherboard 20 is also easily removed from the chassis 22 and the mounting spacers 24 , during repair, upgrade, or maintenance. Although described herein in the context of a motherboard 20 and computer chassis 22 , it will be appreciated that the mounting spacer 24 may be used to mount a motherboard 20 , or any other planar object, to any of a wide variety of structures having mounting slots.
[0025] As shown in FIG. 1, at least one mounting spacer 24 is used to attach the motherboard 20 to the chassis 22 . In particular, a top end 26 of the mounting spacer 24 mates or couples with a mounting hole 30 that extends through the motherboard 20 . The opposite or bottom end 32 (shown in phantom lines) of the spacer mates or coupled with a corresponding mounting slot 34 (FIG. 5) in the computer chassis 22 so that the motherboard 20 is separated from the chassis 22 by a distance equal to the height of the mounting spacer 24 . The mounting holes 30 in the motherboard 20 are arranged so that they may be aligned with the mounting slots 34 on the chassis 22 . The motherboard 20 and chassis 22 may be equipped with any number of mounting holes 30 and slots 34 , respectively.
[0026] As shown in FIG. 1, a grounding pad 36 is positioned around the periphery of each of the mounting holes 30 in the motherboard 20 . The top end 26 of the mounting spacer 24 contacts the grounding pad 36 . The grounding pad 36 functions as an electrical ground for the motherboard 20 in a manner well known to those skilled in the art. Toward this end, one embodiment of the mounting spacer 24 is manufactured of an electrically-conductive material to provide an electrical ground connection between the mother board 20 and the chassis 22 .
[0027] [0027]FIGS. 2, 3, and 4 are side, front, and top views, respectively, of one embodiment of the mounting spacer 24 of the invention. As shown, the mounting spacer 24 includes a spacer portion 40 comprising a wall that defines a substantially cylindrical shape and defines a hollow space 42 (FIG. 4) therein. The height and diameter of the spacer portion 40 may be varied to provide various spacing distances between the motherboard 20 and chassis 22 .
[0028] As best shown in FIG. 2, the mounting spacer 24 further comprises a thin and elongated clip member 44 having a central portion 46 (shown in phantom) that extends through the hollow space 42 within the spacer portion 40 . In the illustrated embodiment, the central portion 46 extends substantially parallel to the axis of the spacer portion 40 and is aligned slightly offset from the center axis of the spacer portion 40 . As shown in FIG. 4, one end of the spacer portion 40 curves or coils into the hollow space 42 and integrally forms into the central portion 46 of the clip member. The coiled configuration reduces the likelihood of the mounting spacer 24 twisting during use.
[0029] With reference to FIG. 2, the clip member 44 further includes an upper clamp or fastener 50 that extends upward from the upper edge of the central portion 46 so as to protrude from the top of the spacer portion 40 . The upper fastener 50 is configured to removably clamp the mounting spacer 24 to the motherboard 20 , as described more fully below.
[0030] As best shown in FIG. 2, the upper fastener 50 includes a first bend 52 which defines a first arm 54 of the upper fastener 50 that is oriented at an angle θ relative to the central portion 46 . The upper fastener 50 further includes a second bend 56 that defines a second arm 60 that extends downwardly toward the spacer portion 40 substantially parallel to the central portion 46 . The second arm 60 has a lower tip 62 that is positioned flush against the peripheral upper edge of the spacer portion 40 . In one embodiment, the upper fastener 50 is biased or spring loaded so that the lower tip 62 of the second arm 60 is urged to press against the upper edge of the spacer portion 40 . In the illustrated embodiment, the second arm 60 is also bent at the lower tip 62 to provide the lower tip 62 with a rounded edge.
[0031] As shown in FIG. 2, the clip member 44 further includes a lower clamp or fastener 64 that extends downwardly from the bottom edge of the central portion 46 . The lower fastener 64 is configured to removably clamp the mounting spacer 24 to the computer chassis 22 , as described more fully below. The lower fastener 64 includes a first bend 66 which forms a first arm 70 that terminates at a tip 72 extending beyond the periphery of the spacer portion 40 . The first arm 70 of the lower fastener 64 is oriented at an angle a relative to the central portion 46 . The first arm 70 is biased or spring loaded toward the spacer portion 40 . Thus, when the first arm 70 is pulled away from the spacer portion 40 , it automatically springs back toward the spacer portion 40 and assumes its natural orientation, as shown in FIG. 2.
[0032] As shown in FIG. 3, the width of the upper fastener 50 is slightly less than the width of the lower fastener 64 . However, it will be appreciated that the sizes of the upper and lower fasteners 50 and 64 , respectively, may be varied to fit within various mounting holes 30 and mounting slots 34 in a motherboard 20 and in a computer chassis 22 . In one embodiment, the mounting slots 34 slots have dimensions of 0.03″×0.19″.
[0033] Exemplary dimensions of one embodiment of the mounting spacer 24 are as follows. The width of the lower fastener 64 is approximately 0.17 inches and the width of the upper fastener 50 is approximately 0.08 inches. Referring to FIG. 2, the first bend 52 of the upper fastener 50 is spaced approximately 0.07 inches from the upper edge of the spacer portion 40 . The angle θ of the first arm 54 of the upper fastener 50 is approximately 42°. Additionally, the length of the first arm 54 of the upper fastener 50 is approximately 0.22 inches and the length of the second arm 56 of the upper fastener 50 is approximately 0.20 inches.
[0034] Regarding the lower fastener 64 , the angle ∝ is approximately 68°. The first bend 66 in the lower fastener 64 is spaced approximately 0.10 inches from the lower edge of the spacer portion 40 . The length of the first arm 70 of the lower fastener 64 is approximately 0.26 inches. The foregoing dimensions have been found to provide secure fastening characteristics when the mounting spacer 24 is attached to a computer chassis 22 and motherboard 20 . However, it will be appreciated that the foregoing dimensions are merely exemplary and that the dimensions of the mounting spacer 24 may be varied based upon the circumstances.
[0035] FIGS. 5 - 9 illustrate the manner in which the mounting spacer 24 is used to mount the motherboard 20 to the chassis 22 . As shown in FIG. 5, an installer first pulls the first arm 70 of the lower fastener 64 away from the spacer portion 40 and then inserts the first arm 70 of the lower fastener 64 through the mounting slot 34 in the chassis 22 . As shown, the mounting spacer 24 is positioned at an angle relative to the plane of the chassis 22 .
[0036] As shown in FIG. 6, the bias in the first arm 70 forces the mounting spacer 24 to pivot such that it orients substantially vertical relative to the chassis 22 . In this position, the chassis 22 is compressed between the lower fastener 64 and the lower edge of the spacer portion 40 . The mounting spacer 24 is thus secured to the chassis 22 via the lower fastener 64 . It will be appreciated that an installer may easily remove the mounting spacer 24 from the chassis 22 by pulling the lower fastener 64 out of the mounting slot 34 in the chassis 22 .
[0037] As shown in FIG. 7, the installer may then mount the motherboard 20 to the mounting spacer 24 . The installer first inserts the second bend 56 of the upper fastener 50 into the mounting hole 30 of the motherboard 20 . As shown in FIG. 8, the installer then presses the motherboard 20 downward onto the mounting spacer 24 so that the first and second arms 54 and 60 of the upper fastener 50 are compressed toward each other. When so pressed, the first and second arms 54 and 60 are oriented such that the lower tip 62 of the second arm 60 rises relative to the spacer portion 40 , thereby creating a gap 74 between the lower tip 62 of the second arm 60 and the upper edge of the spacer portion 40 .
[0038] As shown in FIG. 9, the installer then continues to push the motherboard 20 downward until the lower tip 62 of the second arm 60 exits the mounting hole 30 . At this point the second arm 60 springs to its natural orientation and the motherboard 20 is positioned within the gap 74 . The motherboard 20 is thus compressed between the lower tip 62 of the upper fastener 50 and the mounting spacer 24 . In this manner, the mounting spacer 24 securely retains the motherboard 20 in connection with the computer chassis 22 . The motherboard 20 may be easily and quickly removed by reversing the previously-described steps.
[0039] [0039]FIG. 10 shows a flat material blank 76 that may be used to form the mounting spacer 24 . The material blank 76 includes a main section 80 and two protrusions 82 . Prior to use, the main section 80 is rolled into the shape of a cylinder to form the spacer portion 40 of the mounting spacer 24 . The protrusions 82 are then folded at the broken fold lines to form the upper and lower fasteners 50 and 64 . The mounting spacer 24 is preferably manufactured of an electrically-conductive material so that the mounting spacer 24 may be used as an electrical ground.
[0040] The mounting spacer 24 may thus be used to easily and securely mount a motherboard 20 to a computer chassis 22 . The mounting spacer 24 eliminates the need for screws and also provides an electrical ground interface for the motherboard 20 . It will be appreciated that the mounting spacer 24 may be used with an existing motherboard and computer chassis without the need for modifications to the motherboard or chassis.
[0041] Hence, although the foregoing description of the invention has shown, described, and pointed out fundamental novel features of the invention, it will be understood that various omissions, substitutions, and changes in the form of the detail of the apparatus and method as illustrated as well as the uses thereof, may be made by those skilled in the art without departing from the spirit of the invention. Consequently, the scope of the invention should not be limited to the foregoing discussion, but should be defined by the appended claims. | Disclosed is a method of removably mounting a planar electrical component, such as a computer motherboard, to a chassis. The method comprises positioning a first fastener of a mounting device adjacent a mounting slot in the chassis, inserting the first fastener of the mounting device through the mounting slot in the chassis, releasing the mounting device so that the first fastener clamps onto the chassis through the mounting slot, positioning a second fastener of the mounting device adjacent a mounting hole on the planar electrical component, and inserting the second fastener of the mounting device into the mounting hole until the second fastener clamps onto the planar electrical component through the mounting hole. |
FIELD OF THE INVENTION
This invention relates generally to a reservoir frame capable of being transported to various geographical areas, placed on or in the ground and able to provide containment for various liquids.
BACKGROUND OF THE INVENTION
Often in various industries is necessary to hold and contain various industrial liquids from process activity. In the oil and gas industry, for example, it is often necessary to contain fracturing fluid, which is a byproduct of drilling activity. Currently, trailers are used to hold and contain this liquid.
To accommodate oil and gas production in the field, a trailer is transported to the site where the liquid is produced. The trailers often have a 500 barrel capacity, so multiple trailers are needed in situations where much liquid is stored.
The cost of trucking trailers to various oil and gas drilling locations is significant. Additionally, transporting said liquid from the production site adds to the already high cost of oil and gas drilling operations. Furthermore, environmental concerns associated with numerous containment trailers for the liquid has generated governmental regulations, including rules regarding environmental quality, transportation, safety and health, etc.
SUMMARY OF THE INVENTION
Accordingly, it is an object of embodiments of the present invention to provide a portable reservoir frame to aid in the storage of liquid materials.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following 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.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention, as embodied and broadly described herein, the invention comprises a portable reservoir frame comprising two or more interlocking panels for deployment on a ground surface, each of said panels having the following: a plate having an outer surface, an inner surface, a top edge, a bottom edge for resting on the ground surface, a first edge and an opposing second edge, said first and said second edges being disposed between said top edge and said bottom edge; a first flange having an inner face, an outer face, and at least one hole having a chosen diameter and perforating said first flange, said first flange attached to said plate and extending beyond the first edge; a second flange having an inner face and an outer face, said second flange attached to said plate and extending beyond the opposing second edge; and at least one peg attached to said second flange and extending in a direction perpendicular to the outer face thereof, each of said at least one peg adapted for insertion into one of said at least one hole.
Benefits and advantages of the present invention include, but are not limited to, providing a reservoir frame, which is portable and can function in a variety of terrains, and accommodate a wide variety of ground surfaces.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:
FIG. 1 illustrates a perspective view of one embodiment of the present invention showing a panel having an outer surface, first and second flanges and top edge.
FIG. 2 illustrates a front view of the top of the embodiment of the present invention shown in FIG. 1 hereof.
FIG. 3 illustrates another perspective view of the embodiment of the present invention shown in FIG. 1 and FIG. 2 hereof, further showing the inner surface, first and second flanges and top edge.
FIG. 4 illustrates a perspective view of yet another embodiment of the present invention as seen from the outer surface, further showing two panels prior to connection of the two panels.
FIG. 5 illustrates a perspective view of yet another embodiment of the present invention as shown in FIG. 4 , further showing two panels connected.
FIG. 6 illustrates a perspective view of yet another embodiment of the present invention as seen from the inner surface, further showing two panels prior to connection of two panels.
FIG. 7 illustrates a perspective view of yet another embodiment of the present invention as shown in FIG. 6 , further showing two panels connected.
FIG. 8A and FIG. 8B illustrate a perspective view of one embodiment the pin connection mechanism which secures connection of the panel flanges.
FIG. 9 illustrates a perspective view of one embodiment of the present invention showing panels fully connected and creating a circular reservoir of interlocking panels.
FIG. 10 illustrates a perspective view of one embodiment of the present invention further showing a liner covering the inner surface of the reservoir frame and the bottom of the reservoir as shown in FIG. 9 .
FIG. 11 illustrates a perspective view of one embodiment of the present invention showing panels having additional support beams.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference characters refer to the same or similar elements in all FIG.s.
FIG. 1 illustrates a perspective view of one embodiment of the present invention showing a panel 1 having plate 5 . As depicted in FIG. 1 , the plate 5 of the panel 1 has an outer surface 10 , a top edge 20 , and a bottom edge 25 . The bottom edge 25 is adapted to be disposed upon a ground surface. The plate 5 is attached to a first flange 40 at the first edge 30 of the plate 5 . The plate 5 is attached to the second flange 60 at the opposing second edge 35 of the plate 5 . FIG. 1 depicts the outer face 50 of the first flange 40 and the outer face 70 of the second flange 60 .
FIG. 1 illustrates the first flange 40 having holes 55 . In one embodiment of the present invention, the holes 55 are unevenly spaced, having a higher density of holes 55 toward the bottom of the first flange 40 . The second flange 60 has pegs 75 . In one embodiment, the pegs 75 extend in direction normal to the outer face 70 of the second flange 60 and are adapted for penetration of the holes 55 . Similar to the holes 55 and in one embodiment of the present invention, the pegs 75 are unevenly spaced with a higher density of pegs disposed at the bottom of the second flange 60 . The higher density of holes 55 and corresponding pegs 75 disposed toward the bottom of the first and second flanges provides for and accommodates more water to be placed in the reservoir. The additional water places more pressure toward the bottom of the flanges and a higher density of holes and pegs stabilize the bottom portion of the structure and further secures the connection between interconnected panels. In many embodiments of the present invention, the pegs 75 are integrally formed with the second flange 60 .
FIG. 1 illustrates crossbars 90 that are used to attach temporarily a panel connector piece of a front end loader or tele-handler for transportation. Thus, a front end loader or tele-handler can easily manipulate and transport a panel during reservoir frame construction. In one embodiment, the crossbars 90 may be attached to the outer surface 10 of the panel 1 . Additionally, FIG. 1 depicts horizontal support beams 95 to further secure and strengthen the panel 1 and plate 5 . The horizontal support beams 95 are generally parallel to the top edge 20 and the bottom edge 25 , and the horizontal support beams are disposed between the first edge 30 and opposing second edge 35 . In another embodiment the crossbars 90 may be attached to the horizontal support beams 95 .
In one embodiment of the present invention the panels have a curvature such that when numerous panels are interconnected via the pegs 75 and holes 55 , a generally circular reservoir frame system is constructed. The curvature is generally convex relative to the outer surface and concave relative to the inner surface.
In various embodiments of the present invention, the first flange 40 is integrally formed with the plate 5 . Likewise, the second flange 60 is integrally formed with the plate 5 , in many embodiments of the present invention.
FIG. 2 illustrates a front view of the top of the embodiment of the present invention as depicted in FIG. 1 . FIG. 2 further depicts the pegs 75 and holes 55 having a higher density of both at the bottom portion of the flange. FIG. 2 shows one embodiment of the present invention wherein the pegs 75 and corresponding holes 55 have a larger diameter toward the bottom portion of the first flange 40 and the second flange 60 . This further secures connection between panels because the lower, larger diameter pegs 75 have additional sheer strength and are able to accommodate greater pressures against the inner surface of the panel 1 .
FIG. 3 depicts the inner surface 15 of the plate 5 of the panel 1 having a top edge 20 and a bottom edge 25 . The plate 5 is attached to the first flange 40 at the first edge 30 . The plate 5 is attached to the second flange 60 at the opposing second edge 35 . FIG. 3 depicts the first flange inner face 45 and the second flange inner face 65 . FIG. 3 illustrates the first flange 40 having holes 55 . The second flange 60 has pegs 75 .
FIG. 4 depicts a perspective view of the outer surface of two panels prior to connection of the two panels. The pegs 75 of the second flange 60 of one panel will penetrate the holes 55 of the first flange 40 of another panel. In this representation of the present invention the second flange outer face 70 is aligned opposite the first flange inner face 45 (not depicted).
FIG. 5 depicts a perspective view of the outer surface after the connection of two panels. In this representation, the outer face 75 of the second flange 60 contacts the inner face (not depicted) of the first flange 40 . The pegs 75 penetrate the holes 55 . Furthermore, FIG. 5 depicts pins 85 penetrating the pegs 75 in order to further secure the interlocking panels.
FIG. 6 depicts a perspective view of the inner surface of two panels prior to the interlocking connection. FIG. 6 is the inside view of the invention shown in FIG. 4 , i.e., prior to connection of panels.
FIG. 7 depicts a perspective view of the inner surface after the connection of two panels. FIG. 7 depicts the inside view of the invention shown in FIG. 5 , i.e., when connection of the panels occurs.
FIG. 8A depicts the pin 85 and the peg 75 with a cut out representation of the eyelet 80 to accommodate penetration of the pin 85 . FIG. 8B more depicts the pin 85 penetrating the peg 75 through the eyelet as show previously in FIG. 8A . The pin 85 goes through the peg 75 via the eyelet 80 (not depicted). In one embodiment of the present invention, the eyelet 80 is at an angle of roughly 45° relative to the bottom edge 25 .
FIG. 9 depicts a top perspective side view of panels fully connected and creating a circular reservoir frame of interlocking panels. The interlocking panels form a variety of shapes in various embodiments, including oval and circles.
FIG. 10 shows a liner 105 covering the inner surface of the reservoir frame and the bottom of the reservoir.
FIG. 11 illustrates a perspective view of one embodiment of the present invention showing panels having vertical support beams 150 . Such vertical support beams further secure and support the reservoir panel 1 and plate 5 in order to hold and contain large amounts of liquid in the reservoir frame.
It is believed that the apparatus of the present invention and many of its attendant advantages will be understood from the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction, and arrangement of the components without departing from the scope and spirit of the invention and without sacrificing its material advantages. The forms described are merely exemplary and explanatory embodiments thereof. It is the intention of the following claims to encompass and include such changes. | A portable reservoir frame composed of interlocking panels secured by a series of flanges having holes and pegs. An inner liner to hold liquid inside the reservoir frame is presented. |
FIELD OF INVENTION
[0001] The present invention relates generally to accessing databases, and in particular, to accessing hierarchical databases from object oriented applications. The Java language incorporating industry standard JDBC (Java Database Connectivity) and SQL (Structured Query Language is one example of an object oriented application. (Java is a trademark of Sun Microsystems, Inc. in the United States and/or other countries.)
BACKGROUND
[0002] Hierarchical databases, such as IBM's IMS (Information Management System), are well known in the art. (IMS is a trademark of International Business Machines Corporation in the United States, other countries, or both.) IMS is a hierarchical database management system (HDBMS) with wide spread usage in many large enterprises where high transaction volume, reliability, availability and scalability are of the utmost importance. IMS provides software and interfaces for running the businesses of many of the world's largest corporations. However, companies incorporating IMS databases into their business models typically make significant investments in IMS application programs in order to have IMS perform meaningful data processing particularly tailored to the needs of their respective enterprises. IMS application programs are typically coded in COBOL, PL/I, C, PASCAL, Assembly Language, or Java.
[0003] The near universal acceptance of web technologies has significantly expanded the pool of programmers with extensive skills in object oriented languages, such as the Java programming language. With escalating demands for new applications, and particularly web-based applications, it is desirable to tap into this talent pool to help meet this demand. However, there are several problems (discussed infra) which interfere with efficient application development when Java is used as the application development language. Today an enterprise may be faced with the undesirable choice of deferring new applications due to a skills shortage or utilizing the available Java programmer resource and accepting extended development cycles because of the inherent inefficiencies when this development platform is utilized for applications accessing hierarchical databases.
[0004] Those of ordinary skill in the art will recognize that Java is an object oriented programming language that requires the creation of object oriented constructs such as classes. Therefore, when accessing hierarchical data from a Java application incorporating JDBC and SQL (hereinafter such applications are referred to as simply Java applications), all of the existing information reflecting existing databases must be transformed from procedural language data structures to object oriented classes. These procedural language data structures comprise database definitions, database views and field definitions.
[0005] Furthermore, when transforming these procedural language data structures to classes, the application developer frequently needs to add additional information to the object oriented classes to take advantage of various features within the Java development environment not available within the legacy programming environment. For example, within the Java environment, names of segments, fields, etc. are not restricted to 8 bytes of length but rather can be expanded to any length to have a meaningful name that conveniently conveys additional information about the named entity. Utilizing this feature of the Java programming language to access hierarchical data can improve programmer efficiency as well as minimize programming errors that occur when restricted length arcane symbols are miscomprehended.
[0006] Currently, when developing Java applications to access hierarchical databases, the Java programmer is required to manually subclass a base class (known as DLIDatabaseView) to create the required classes (known as metadata classes, since the class data represents “data about data”) to reflect the application's view of the hierarchical database. This is an extremely tedious and error prone process that involves manually reading complex IMS constructs (such as PSBs, PCBs, DBDs and Cobol Copylibs) and trying to decipher the relevant information from the syntax embedded within the constructs. In addition, transforming these legacy constructs into the appropriate metadata classes may require the programmer to manually add additional information to take advantage of various desirable features of the Java environment (as briefly discussed supra).
[0007] Once classes, encapsulating required hierarchical database information, are complete, there remains an additional problem of how to use this information within other tools and programming environments. Typically, another object oriented programming tool needing this same information would once again require manual conversion of these legacy hierarchical database data structures into a new object oriented form encapsulating the same hierarchical database information. This “manual data interchange” process is time consuming and has the same risks of introducing additional errors as discussed supra for the conversion process.
[0008] Accordingly, there is a great need for an automated and integrative approach to building, customizing and interchanging the class information required to access legacy hierarchical databases from an object oriented application whereby the deployment of object oriented applications and other object oriented tools required to access hierarchical databases may be accomplished in a more efficient and reliable manner.
SUMMARY OF THE INVENTION
[0009] To overcome these limitations in the prior art briefly described above, the present invention provides a method, program product and apparatus for automatically generating and customizing a class to facilitate access to a hierarchical database from an application program. A database definition, logical database view, extended field definition and control statement information are accessed to build an in-memory representation of selective information contained therein. Utilizing this in-memory representation, a class in one form is automatically generated and customized wherein this class is used to access the hierarchical database responsive to a hierarchical database access request from an application. The utility program performing the above computer implemented steps may be referred to as a “class integrator utility program”.
[0010] The above method for automatically generating and customizing a class further comprises automatic interchange and the method steps further comprise utilizing the in-memory representation to generate an XMI stream of metadata defining the class. In this way the XMI stream may be used to regenerate the class in the same or another form for use with another application requiring access to the hierarchical database.
[0011] In another embodiment of the present invention, the above-described class integrator utility program may be provided as a computer system. The present invention may also be tangibly embodied in and/or readable from a computer-readable medium containing program code (or alternatively, computer instructions.) Program code, when read and executed by a computer system, causes the computer system to perform the above-described method.
[0012] A novel method for accessing a hierarchical database from a Java application program is also disclosed. A class integrator utility program is invoked to automatically generate and customize one or more classes wherein these classes encapsulate information from at least one database definition, at least one database view, at least one extended field definition and at least one control statement. An API is invoked by the Java application to access the hierarchical database wherein, responsive to said API invocation, the one or more classes are utilized to access the hierarchical database.
[0013] In this manner, an object oriented application may utilize automatically generated classes to access hierarchical databases corresponding to the generated classes. In this way, the cumbersome, time-consuming and error prone manual process of reading legacy data structures and coding classes by hand can be eliminated. Utilizing a single invocation of a class integrator utility program, the required classes can be automatically generated and customized in accordance with existing legacy data structures and a programmer's desire to utilize additional features available within the object oriented language development environment.
[0014] Various advantages and features of novelty, which characterize the present invention, are pointed out with particularity in the claims annexed hereto and form a part hereof. However, for a better understanding of the invention and its advantages, reference should be made to the accompanying descriptive matter, together with the corresponding drawings which form a further part hereof, in which there is described and illustrated specific examples in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The present invention is described in conjunction with the appended drawings, where like reference numbers denote the same element throughout the set of drawings:
[0016] [0016]FIG. 1 is a block diagram of a typical computer system wherein the present invention may be practiced;
[0017] [0017]FIG. 2 shows a block diagram summarizing the inputs and outputs of a class integrator utility program in accordance with the present invention;
[0018] [0018]FIG. 3 shows a high level model of an exemplary hierarchical database;
[0019] [0019]FIG. 4 shows an exemplary database definition for the hierarchical database;
[0020] [0020]FIG. 5 shows an exemplary logical database view of the hierarchical database;
[0021] [0021]FIG. 6 shows exemplary control statement syntax;
[0022] [0022]FIG. 7 shows additional exemplary control statement syntax;
[0023] [0023]FIG. 8 is a flow diagram summarizing phase I processing of the class integrator utility program in accordance with one embodiment of the present invention;
[0024] [0024]FIG. 9 is a flow diagram summarizing phase 2 processing of the class integrator utility program in accordance with one embodiment of the present invention; and
[0025] [0025]FIG. 10 is a flow diagram summarizing phase 3 processing of the class integrator utility program in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION
[0026] The present invention overcomes the problems associated with the prior art by teaching a system, computer program product, and method for the automatic generation of classes with an integrated customization and interchange capability. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. Those skilled in the art will recognize, however, that the teaching contained herein may be applied to other embodiments and that the present invention may be practiced apart from these specific details. Accordingly, the present invention should not be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features described and claimed herein. The following description is presented to enable one of ordinary skill in the art to make and use the present invention and is provided in the context of a patent application and its requirements.
[0027] [0027]FIG. 1 is a block diagram of a computer system 100 , such as the S/390 mainframe computer system, in which teachings of the present invention may be embodied. (S/390 is a registered trademark of International Business Machines Corporation in the United States, other countries, or both.) The computer system 100 comprises one or more central processing units (CPUs) 102 , 103 , and 104 . The CPUs 102 - 104 suitably operate together in concert with memory 110 in order to execute a variety of tasks. In accordance with techniques known in the art, numerous other components may be utilized with computer system 100 , such as input/output devices comprising keyboards, displays, direct access storage devices (DASDs), printers, tapes, etc. (not shown). Although the present invention is described in a particular hardware environment, those of ordinary skill in the art will recognize and appreciate that this is meant to be illustrative and not restrictive of the present invention. Those of ordinary skill in the art will further appreciate that a wide range of computing system configurations can be used to support the methods of the present invention, including, for example, configurations encompassing multiple systems, the internet, and distributed networks. Accordingly, the teachings contained herein should be viewed as highly “scalable”, meaning that they are adaptable to implementation on one, or several thousand, computer systems.
[0028] IMS-Java was introduced with IMS V7 R1. The IMS Java Users Guide, SC27-0832, documents a required manual procedure for defining a Java “metadata” class for each application that describes the logical database view of the application's PSB (Program Specification Block). The name of this class is passed to IMS-Java by the application program when the JDBC (Java Database Connectivity) connection to the database is established. IMS-Java uses the class to map the JDBC commands issued by the application to IMS database calls, and to map the segments and fields returned by IMS to the result set returned by IMS Java to the application program.
[0029] The manual procedure to define this metadata class is not trivial. The outer class is derived from a provided superclass, DLIDatabaseView. The user must instantiate variables from other provided classes, DLISegmentlnfo, DLISegment, DLITypelnfo, and DLISecondarylndexlnfo to describe the segment hierarchy and the fields that make up the PSB's logical view. If the PSB contains multiple database PCBs (Program Control Blocks), then multiple hierarchies, one for each PCB, must be described within the outer class. Moreover, the segment layouts must correctly allow for the presence of concatenated segments, field-level sensitivity, and XDFLD “fields” of secondary indexes.
[0030] Finally, the segment layout information from the FIELD macros in DBDs (Database Definitions) may be incomplete, and the user may need to merge information from other sources about additional fields, their lengths, positions in the segment, and data types. This information is typically extracted (again, manually) from fragments of existing high-level language applications, such as COBOL copybooks, and is referred to herein as “extended field definitions”.
[0031] Overall, this manual procedure impacts the usability of the IMS Java facility and the availability of IMS-Java applications, since the manual creation is error-prone and certain errors may only show up at run time. Maintainability is also impacted, since changes to the logical database views may require manual rework of the class definition and requiring use of complex IMS-Java documentation. The manual class creation procedure seriously reduces the potential productivity benefits of Java for IMS application development. The invention disclosed herein addresses these and other problems.
[0032] Furthermore, applications and other products may need the ability to interpret the structure of the same set of IMS databases for their own purposes. For such products, the present invention integrates the creation of an XMI stream along with the automatic class generation of IMS databases. As an example, consider the DB2 Stored Procedure Builder, which, if given the capability to access IMS databases through the IMS-Java JDBC interface, would need to be given information about the set of databases it was to process. It would not be very efficient to analyze native IMS PSBs or DBDs. Rather, the needed information should be provided in a more standard, easy-to-process form.
[0033] Referring now to FIG. 2, block diagram 200 illustrates the inputs and outputs of a class generation utility program. A class generation utility program, with integrated customization and interchange capabilities, is referred to herein as a “class integrator utility program” 290 . Database definition 220 represents a physical description of a hierarchical data base, such as a DBD (Database Definition) in the case of an IMS database. This information typically comprises descriptions of the hierarchical segments, their hierarchical relationships, and searchable fields within the segments.
[0034] Database logical view 210 represents a logical view of one or more hierarchical databases, as required for a particular application using the database. This information typically comprises segments within the physical database that the application is authorized to process and the hierarchical relationship of those segments. In the case of IMS this information is contained within the PSB, which is in turn comprised of one or more PCBs encompassing one or more logical views spanning single or multiple physical IMS databases.
[0035] Since the database definition typically contains field information for just the searchable fields, extended field definitions 230 are also input to class integrator utility program 290 . These extended field definitions provide additional segment mapping detail and are typically contained with high-level language constructs, such as COBOL copybooks.
[0036] Control statements 240 are also input to class integrator utility program 290 . These control statements direct the processing flow according to the desired features and functions to be performed. Additionally, these control statements may be used to customize the generated classes to take advantage of features within a Java or object oriented programming environment not present within the legacy environment. For example, Java alias names may be established for any segment or field; and the name can be any length, as required, to enable the name to convey information about the named entity. Reasonable naming conventions improve programmer efficiency and reduce programmer errors. Additionally, the generated classes can be customized with new field names to accommodate new features or application extensions.
[0037] Class integrator utility program 290 , utilizing selected information from inputs 210 , 220 230 and 240 outputs the generated and customized classes 260 encapsulating hierarchical database metadata for use with object oriented applications, such as Java, required to access the associated hierarchical database. Additionally, if requested by a user, class integrator utility program 290 further outputs an XMI stream 280 representative of all metadata encapsulated within classes 260 . The XMI 280 stream may be utilized by other applications and tools to regenerate this class information into a required form appropriate for their particular usage.
[0038] Class integrator utility program 290 optionally outputs trace data 250 . This information may be utilized for status and debugging purposes, as well as for facilitating additional application development.
[0039] Generally, the novel methods disclosed herein may be tangibly embodied in and/or readable from a computer-readable medium containing the program code (or alternatively, computer instructions), which when read and executed by computer system 100 causes computer system 100 to perform the steps necessary to implement and/or use the present invention. Thus, the present invention may be implemented as a method, an apparatus, or an article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” (or alternatively, “computer program product”) as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. Examples of a computer readable device, carrier or media include, but are not limited to, palpable physical media such as a CD ROM, diskette, hard drive and the like, as well as other non-palpable physical media such as a carrier signal, whether over wires or wireless, when the program is distributed electronically.
[0040] Referring now to FIG. 3, a model 300 of an exemplary hierarchical database is shown. This exemplary hierarchical database will serve as the basis for various other samples of IMS metadata provided as an aid to understanding the concepts taught herein. Dealer segment 310 identifies an automobile dealership selling cars. This segment may contain fields, such as the name of the dealership, and the dealership address.
[0041] Dealers carry car types, each of which has a corresponding Model segment 320 . A model segment may contain fields such as the car model (such as Nissan Maxima), and a model description. Other segments include Order 330 , Sales 340 and Stock 350 representing information pertaining to orders, sales and inventory for each car model, with additional fields defined appropriate to their usage within an application.
[0042] Referring now to FIG. 4 an exemplary hierarchical database definition 400 is shown, in accordance with model 300 discussed supra. In FIG. 5 an exemplary database logical view 500 is shown representing the logical view of an exemplary application requiring access to the hierarchical database defined by database definition 400 . FIG. 6 shows a set of control statements specifying processing options and identifying a logical database view. In addition, an “Include” control statement identifies a second file of additional control statements shown in FIG. 7. The control statements 700 of FIG. 7 further customize database logical view 500 with additional segment and field information. Taken together FIGS. 4 - 7 , along with any extended field definitions (not shown), represent the source data from which class integrator utility program 290 acquires needed information to generate, customize and interchange Java classes.
[0043] Appendix A contains the Java class that is automatically generated and customized by Class Integrator Utility Program 290 when presented with the data sources depicted in FIGS. 4 - 7 . Appendix B contains the XMI data stream of metadata generated by Class Integrator Utility Program 290 to facilitate automatic interchange of metadata encapsulated in the Java class illustrated in Appendix A. Those of ordinary skill in the art will recognize that the teachings contained herein may apply to other object oriented languages and accordingly the generated classes may be classes for any object oriented language in addition to the Java language.
[0044] Continuing with FIGS. 8 - 10 , a preferred embodiment is described for the IMS hierarchical database and Java programming language. Referring now to FIG. 8, flow diagram 800 illustrates the high level flow of the first phase of processing performed by class integrator utility program 290 which builds an in-memory model of the hierarchical database legacy data structures. In step 810 , class integrator utility program 290 reads PSB control statements from an MVS dataset, or from an HFS (Hierarchical File System) file. In one preferred embodiment, the first control statement is an option statement which specifies execution and input/output options (as shown in FIG. 6).
[0045] Next, in step 815 , a PSB source file is read. The PSB is the IMS data structure that represents the logical view of the hierarchical database. The control statement specifies the name of the PSB to be read and processed, and may also optionally specify a Java name to be associated with this PSB. Continuing with step 820 , the PSB source macro statements are parsed and selected information accumulated into the in-memory model representing the hierarchical database metadata.
[0046] In step 825 , the source file of a referenced DBD is read and in step 830 the DBD source macro statements are parsed and selected information accumulated into the in-memory model representing the hierarchical database metadata. The in-memory model captures all information related to segments and fields and their hierarchical relationships. In step 835 , a test is made to determine if additional DBDs are referenced by the PSB. If so, control passes back to step 825 where processing continues as discussed supra. Otherwise, in step 840 , a test is made to determine if additional PSBs are associated with the PSB control statement currently being processed. This may occur where the PSB control statement incorporates a generic name, such as a “wild card” naming convention, wherein all PSBs matching the name form are to be processed. If one or more PSBs remain to be processed, control passes back to step 815 where processing continues as discussed supra.
[0047] Returning now to step 840 , if there are no more PSBs to process for this PSB control statement, then processing continues with step 845 , where a test is made to determine if additional PSB control statements exist. If so, control returns to step 810 and processing continues as discussed supra. Otherwise, in step 850 control passes to the beginning of flow diagram 900 of FIG. 9. Each PSB is reflected individually in the model, with its segments and fields; but if the PSBs share logical or physical databases, only a single instance of each database is added to the in-memory model and shared by the referencing PSBs.
[0048] Referring now to FIG. 9, flow diagram 900 illustrates phase 2 processing of class integrator utility program 290 , where phase 2 operations carry out adjustments to the in-memory model that was built from phase 1 processing. Adjustments may be required because the information available from the database definitions and logical database views may not be sufficient to generate complete classes. Additional information may be required in several areas, including adding additional fields, creating Java-style aliases and establishing formatting information, such as Java data types.
[0049] First, step 910 receives control from step 850 of flow diagram 800 , FIG. 8. Processing continues with step 915 , where a test is made to determine if extended field definitions are present, such as COBOL copybooks. Those of ordinary skill in the art will recognize that this information may be provided in a transformed form produced by an importer, such as an XMI data stream conforming to the HLL language metamodel, or any other intermediary data form. If extended field definitions are present then, in step 920 , this additional field information is merged into the in-memory model before proceeding to the test at step 925 . An extended field definition is related to a particular DBD and physical segment through a Segment control statement. Fields found in the extended field definition that are not yet in the model are added to the segment with their field name, offset, length and data type. If, however, a field in the extended field definition coincides (same starting offset and length) with an existing field in the model, then a new field is not added to the model. Instead, the Java name and the data type in the existing model field are set to the name and data type of the field in the extended field definition. Those of ordinary skill in the art will recognize that many detailed design decisions are possible within the framework of the teachings contained herein. For example, in another embodiment, an error could be generated when extended field definitions coincide with existing fields within the in-memory model.
[0050] Returning now to step 915 , if extended field definitions are not present, processing continues with step 925 where a test is made to determine the presence of additional model related control statements. If additional unprocessed control statements exist, the processing continues with step 930 . Step 930 merges additional control statement information into the in-memory model.
[0051] A ‘PSB’ control statement type allows the user to specify an alias name for a PSB, which determines the name of the generated IMS Java class. A ‘PCB’ control statement type allows the user to specify an alias name for an existing PCB within a PSB. A ‘‘SEGM’ control statement type allows the user to specify an alias Java name for an existing logical or physical segment. A ‘field’ control statement type allows the user to specify a filed in a specified DBD and/or a physical segment, either by its starting offset and length, or by its 8-character IMS name. A new field object is created in the model if not already present. If the field is coincident with an existing field (same 8-character name, or same starting offset and length) then the information in the existing field is overridden by the control statement information. An ‘XDFLD’ statement allows an alias to be provided for an IMS secondary index field already specified within the DBD. A ‘field’ type control statement takes precedence over extended field definitions where conflicts occur.
[0052] Processing continues from step 930 to step 935 , where a Model Adjustment Report is generated summarizing status information accumulated during the building of the in-memory model (the Model Adjustment Report is not shown). In step 940 , control passes to the beginning of flow diagram 1000 , FIG. 10.
[0053] Referring now to FIG. 10, flow diagram 1000 illustrates phase 3 processing of class integrator utility program 290 , where the contents of the in-memory model are written to supported output files. First, step 1010 receives control from step 940 of flow diagram 900 , FIG. 9. Processing continues with step 1015 , where Java class source is generated by traversing the in-memory model for each PSB processed. Each class source is written to a supported output file (such as an HFS file) with the same name as the class, and a suffix of “Java”. If no Java name has been provided, the 8 character IMS PSB name is used. The class integrator utility program 290 builds IMS-Java classes with correct hierarchies and segment field layouts, automatically handling any special situations, such as concatenated segments, noncontiguous key fields, secondary indexing, system related fields and the like. Where available from the model, alias names, data types and type qualifiers are included in the generated classes.
[0054] Processing continues with step 1020 , where a default data type of “CHAR” is used for each unspecified data type. Next, in step 1025 , a test is made to determine if a required type qualifier is missing for any data types. If so, in step 1030 an error condition is generated and class integrator utility 290 terminates processing. Otherwise, in step 1035 , a test is made to determine if an optional XMI metadata stream has been requested by the user of class integrator utility 290 (an exemplary XMI metadata stream is shown in Appendix B). If so, in step 1040 , an XMI metadata stream is generated to facilitate an interchange of metadata whereby the XMI stream is utilized by other applications and tools to regenerate class information into a required form appropriate for their usage. In step 1045 , class integrator utility 290 completes normal processing and terminates.
[0055] Taken in combination flow diagram 800 , 900 and 1000 in conjunction with supporting diagrams and detailed descriptions provide for enhanced reliability and programmer productivity by automatically generating classes with an integrated customization and interchange capability. Although flow diagrams 800 - 1000 use IMS and Java as exemplary platforms, those of ordinary skill in the art will appreciate that the teachings contained herein apply to any hierarchical database and any object oriented language environment. References in the claims to an element in the singular is not intended to mean “one and only” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described exemplary embodiment that are currently known or later come to be known to those of ordinary skill in the art are intended to be encompassed by the present claims. No claim element herein is to be construed under the provisions of 35 U.S.C. § 112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or “step for. ”
[0056] While the preferred embodiment of the present invention has been described in detail, it will be understood that modifications and adaptations to the embodiment(s) shown may occur to one of ordinary skill in the art without departing from the scope of the present invention as set forth in the following claims. Thus, the scope of this invention is to be construed according to the appended claims and not limited by the specific details disclosed in the exemplary embodiments. | A database definition, logical database view, extended field definition and control statement information are accessed to build an in-memory representation of selective information contained therein. Utilizing this in-memory representation, a class in one form is automatically generated and customized wherein this class is used to access a hierarchical database responsive to a hierarchical database access request from an application. |
RELATED APPLICATION DATA
This application is the U.S. National Stage of PCT/IL2007/001632 filed Dec. 31, 2007, the contents of which are herein incorporated by reference for all purposes.
BACKGROUND
Various analyzing devices, such as, for example, medical devices, use various types of connectors that are used as mediators for connecting between the medical device interface (the instruments itself) and external constituents, such as tubes, cannules, and the like that may be of the disposable type. An example of such medical device is a capnograph, which is an instrument for analyzing exhaled breath. A capnograph samples air that is exhaled by a subject by using a small tube, also known as sample line. One end of the sample line may be connected to an air passageway of a respirator or to a cannula attached to, for example, the subject nostril. The other end of the sampling line is connected, through a connector to the instrument itself. The sampling line, including the tube, the connector and other constituents, such as filters, and the like is, in most cases disposable and is replaced for each patient and for each patient type. For example, a subject which is a child will have a sampling line which is different (for example, in size) than a sampling line of an adult subject.
In general, the shape of a connector is standardized throughout the industry, such that tube assemblies of various manufacturers may be interchangeably used with any analyzing instrument. Hence, the manufacturer of a particular type of analyzing instrument has generally no control over which type of tube is used with his instrument. Therefore, to ensure optimal functioning of the instrument, and for commercial reasons, the manufacturer of an analyzing instrument may want to exert such control. In particular, he may want to stipulate that only a certain class, type and/or model of tube assemblies be connected to, and used with, his instrument. Such a class may, for example, consist of tube assemblies that include a specific constituent, such as, for example, a filter, or such that are manufactured directly by him or to his specifications or under his supervision or license.
Enforcing such stipulation may be performed by various means, such as, for example, by using a unique interlocking key arrangement between the connector and the instrument; having a system by which the correct tube assembly would be identified as such by the instrument, whereupon its operation would be enabled, and to disable the instrument otherwise, such as for example, by using electro-mechanical fitting, electrical fitting, and the like. Benefits of such arrangement would be that the instrument would be prevented from operation also when no tube is connected at all or when even a correct tube is improperly connected, thus avoiding damage to sensitive parts of the instrument and also causing incorrect readings. Yet another purpose may be served by such a system, namely identifying the tube assembly as belonging to one of a number of classes and informing the instrument of the particular identity detected, so as to enable it to automatically operate differently for the different classes.
There is thus a widely recognized need for, and it would be highly advantageous to have, a fluid analysis system that includes the capability of determining that a tube assembly has been properly connected to the analyzing instrument and that the tube is of a certain class. Such a capability should be compatible with the standard shape of connectors being used, as well as with the medical environment, and should be reliable and inexpensive.
SUMMARY
The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other advantages or improvements.
Medical analyzing devices may use various types of connectors that may be used for connecting between the medical device and external constituents, such as tubes, cannules, and the like that are usually disposable and are replaced for each patient. In general, the shape of a connector is standardized, such that tube assemblies of various manufacturers may be interchangeably used with any analyzing device. However, to ensure optimal functioning of the device and for commercial reasons, the manufacturer of an analyzing device may want to stipulate that only a certain class, type and/or model of tube assemblies be connected to and used with his instrument. Such stipulation may be achieved by having an identification and verification means between the medical device and the tube attached to the device. Such capability of determining that a tube assembly has been properly connected to the analyzing instrument and that the tube is of a certain class may further ensure optimal functioning of the medical device. Moreover, the identification and verification means may include any type of information that may be encoded on the end face of the tube connector and identified by the medical device. Accordingly, there is thus provided, according to some embodiments, one or more identification and verification means that may allow increased amount of information to be encoded on the end face of the connector and transferred between the connector and the device. The information encoded may improve the safety of using the device, simplify the use of the device and optimize the use of the device by ensuring an optimal operating mode of the device in accordance with the tube connector (and hence the tube/sampling line) attached to the device. For example, the information encoded on the end face of the connector may be used to determine the type/class and/or model of the connector, such as for example the patient interface, patient size, patient specific parameters, and the like. For example, the information may be used to determine if the connector type is a children's connector (a connector of sampling line that is to be used with children), an adult connector (a connector of sampling lines that is to be used with adults), and the like. This information may be used by the medical device to determine the optimized mode of operation for that type/class/model/manufacturer of connectors and patient interface. This may be achieved, for example, by use of optimized software algorithm to be used for that type of connector and sampling line.
According to some embodiments, there is provided a tube connector for connecting between a fluid sampling tube and a fluid analyzer, the tube connector includes an end face adapted to identify the tube connector, said end face comprising a reflecting surface having one or more reflective regions adapted to reflect light at a predetermined range of wavelengths.
According to some embodiments, the surface of the tube connector may be adapted to reflect light at one or more distinct wavelengths. The surface may further be adapted to selectively reflect light having different intensities. The surface may further include one or more reflective regions having distinct reflective properties. The surface may be patterned, wherein the pattern may include geometrical shapes, non-geometrical shapes, horizontal lines, vertical lines or any combination thereof.
According to some embodiments, the fluid analyzer to which the tube connector is connected to may include a capnograph.
According to further embodiments, the fluid analyzer may include a verification system adapted to identify the connector, wherein the verification system may include one or more light sources and one or more optical detectors. The one or more light sources may include a light emitting diode (LED), a lamp or any combination thereof. The one or more optical detector may include an RGB detector.
According to other embodiments, the end face of the tube connector may further include a Radio Frequency Identifier (RFID) tag adapted to provide further identification of the connector type. The end face of the tube connector may further include a barcode tag adapted to provide further identification of the connector type.
According to additional embodiments, the verification system of the fluid analyzer may further include a Radio Frequency Identifier (RFID) reader, a barcode scanner or both.
According to some embodiments there is provided a device for analyzing fluid, the device includes: a device connector adapted to receive a tube connector and a verification system for identifying the tube connector, wherein said system comprises one or more light sources adapted to transmit light towards an end face of the tube connector, one or more optical detectors adapted to detect reflected light from the end face and to produce a signal indicative of the reflected light and a processor adapted to identify the tube connector type based on a signal received from the detector.
According to some embodiments, the tube connector is adapted to connect between a fluid sampling tube and the fluid analyzer.
According to additional embodiments, the end face of the connector includes a reflecting surface having one or more reflective regions adapted to reflect light at a predetermined range of wavelengths. The end face surface may be adapted to reflect light at one or more distinct wavelengths. The surface may be adapted to selectively reflect light having different intensities. The surface may include one or more reflective regions having distinct reflective properties. The surface may further be patterned, wherein the pattern may include geometrical shapes, non-geometrical shapes, horizontal lines, vertical lines or any combination thereof.
According to additional embodiments, the fluid analyzing device may include a capnograph. The one or more light sources of the verification system may include a light emitting diode (LED), a lamp or any combination thereof. The one or more optical detector of the verification system may include an RGB detector.
According to other embodiments, the end face of the tube connector may further include a Radio Frequency Identifier (RFID) tag adapted to provide further identification of the connector type. The end face of the tube connector may further include a barcode tag adapted to provide further identification of the connector type.
According to additional embodiments, the verification system of the fluid analyzer may further include a Radio Frequency Identifier (RFID) reader, a barcode scanner or both.
According to some embodiments, there is provided a verification system for identifying a tube connector attached to a fluid analyzer, the system includes one or more light sources adapted to transmit light towards an end face of the tube connector; one or more optical detectors adapted to detect reflected light from the end face and to produce a signal indicative of the reflected light; and a processor adapted to identify the tube connector type based on a signal received from the detector.
According to additional embodiments, the verification system may be functionally associated with a device connector adapted to receive the tube connector.
According to additional embodiments, there is further provided a method for identifying a tube connector type attached to a fluid analyzer, the method includes transmitting light from one or more light sources towards an end face of the tube connector; detecting reflected light from the end face by one or more optical detectors, producing a signal indicative of the reflected light and identifying the tube connector based on the signal.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the figures and by study of the following detailed descriptions.
BRIEF DESCRIPTION OF THE FIGURES
Examples illustrative of embodiments of the disclosure are described below with reference to figures attached hereto. In the figures, identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. Dimensions of components and features shown in the figures are generally chosen for convenience and clarity of presentation and are not necessarily shown to scale. The figures are listed below.
FIG. 1 —A perspective view of a connector, according to some embodiments;
FIG. 2 A-K—A front view of exemplary end face patterns of a connector, according to some embodiments; and
FIG. 3 —A perspective schematic of a closeup side view of a connector and verification system, according to some embodiments.
DETAILED DESCRIPTION
In the following description, various aspects of the disclosure will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the disclosure. However, it will also be apparent to one skilled in the art that the embodiments may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the invention.
According to some embodiments, there is provided an end face of a connector, the surface of which may have an annular, ring like shape. The surface of the end face of the connector may be an integral part of the connector, or may be permanently attached to the connector. The surface may include a flat, uniform surface. The surface may include a concave and/or convex surface. The surface may include a patterned surface, wherein the patterns may include recurring patterns of any desired shape. The surface may be a discontinuous surface. The surface may be divided to various regions/areas, wherein at last two areas have different characteristics. By characteristics may include different texture, different compositions, different chemical properties, different optical properties, different electrical properties, different magnetic properties, different surface concaveness, and the like.
According to some embodiments, there is provided a connector, such as a tube connector that may be used to connect a tube to a medical device, such as for example a capnograph. Reference is now made to FIG. 1 , which illustrates a perspective view of a connector, according to some embodiments. The connector, such as connector ( 2 ), may include 2 ends: a tube end ( 4 ), which is the end that may be connected to a tube; and a device end ( 6 ), which is the end that may be used to connect the connector to a device/instrument. Connector, such as, connector ( 2 ) may be a male or a female type connector that may be received/connected/attached/to a matching female or male connector (referred to herein as a “device connector”), respectively, located on the device, such as, for example, on the device panel. The connector, such as connector ( 2 ), may have an elongated cylindrical-like shape. Spiral threads, such as threads ( 8 ), may be found at the outer surface of the connector in close proximity to the device end ( 6 ) of the connector ( 2 ) and may be used to secure the connector to its matching connector on the device (the device connector). At the tube end ( 4 ) of the connector ( 2 ), gripping wings, (such as, gripping wings 10 A-B in FIG. 1 ) are located. The end face ( 12 ) of the device end ( 6 ) of the connector ( 2 ) may have a circular, annular shape. The end face may form as an integral part of the connector ( 2 ), or may be an external surface that is permanently attached to the device end ( 6 ) of the connector ( 2 ). The end face ( 12 ) surface may be a continuous or discontinuous surface, which may include at least two regions/areas that are distinct from each other. By distinct from each other may relate to physical, mechanical, electrical, optical, and chemical properties, such as, for example, but not limited to: shape, pattern, texture, color, size, electrical properties, reflectivity, composition, magnetic properties, and the like, and any combination thereof. The distinct regions of the end face of the connector may be used as an identifying means to the medical device to which the connector is to be connected and consequently to affect a decision process in the device and hence the operation mode of the medical device. The distinct regions of the end face of the connectors may be used to encode data that may be read/identified and used by the medical device. The encoded data may include, for example, the type/class of the connector, the model of the connector, manufacturer of the connector, preferred mode of operation with that connector, and the like.
Prior art, such as that described in U.S. Pat. No. 6,437,316 teaches that the annular end face of the device end may be specularly reflective to light. The reflectivity may be obtained, for example, by coating the surface with a suitable reflective layer, by polishing the surface to a glossy, by hot-pressing a reflective foil and the like. In particular, the reflective surface need not extend over the entire width of the end face, but it must form a complete annular ring. However, such a connector may be identified by the device by only one verification way (meaning—reflection of light at one range of wavelengths). There is thus a need to combine additional verification ways in order to allow the connector to be used with various types/models of devices and also to allow increased amount of information to be encoded on the end face of the connector and transferred between the connector and the device. This may allow a more accurate, efficient, simple and safer mode of operation of medical device.
As referred to herein, the term “the end face of the connector” relates to the end face of the device end of a connector, such as connector 2 of FIG. 1 , unless otherwise stated.
As referred to herein, the terms “amplitude” and “intensity” may interchangeably be used.
As referred to herein the term “type”, “model”, “class” of the connector may interchangeably be used and may relate to the interface to be used with the tube connector and/or manufacturer of the tube connector.
According to some embodiments, the end face of the connector may include more than one region with distinct reflectivity characteristics. The regions may be adjacent to each other or may be spatially separated. Each of the regions may be reflective at a different range of wavelength and/or possess different level (amplitude, intensity) of reflectivity and/or may be non-reflective (such as, for example, colored black, which absorb all light and does not reflect back). For example, the end face may include two spectrally distinct reflective regions. Each of the regions may comprise about half of the annular circumference of the end face. For example, one region may be spectrally reflective such that when light is emitted at the end face, this region may reflect at one amplitude, while the second region may reflect at a second amplitude. For example, one region may be spectrally reflective such that when light is emitted at the end face, this region may reflect light at one wavelength (for example, at the green color range of wavelength), while the second region may reflect light at a second wavelength (for example, at the red color range of wavelengths). The reflected lights may be detected by matching detectors located in the medical device and then further processed/analyzed to confirm the connection between the connector and the medical device, as further detailed below herein. The distinct regions of reflectivity of the connector end face may be coated or comprised of various materials that possess different reflectivity characteristics. For example, the distinct regions may have reflective materials that contain dyes or pigments. For example, the distinct regions may be coated with suitable spectral filters. For example, the distinct regions may have different surface areas, such as, for example, a flat surface, a concaved surface, a convex surface or any combination thereof.
According to some embodiments, in addition to determining various wavelength ranges of reflectivity of connectors with more than one reflective region at their end face, the amplitude and the threshold levels of reflectiveness may also be determined. The threshold levels of reflectiveness may be used as an additional data encoding means that may be used to distinguish between various types/models of connectors. For example, a connector that exhibits reflectivity of above a predetermined threshold value may belong to a certain type of connector (for example, connectors of sampling lines that are to be used with children), while connectors with a lower threshold (that may include, for example, at least two distinct regions of reflectivity at the connector end face) may belong to a different type of connector (for example, connectors of sampling line to be used with adults). For example, the threshold levels may be used to distinguish between connectors manufactured by different manufacturers.
According to further embodiments, the end face of the connector may include various patterns that may be distinguished by their characteristics/properties. The patterns may include any shape, such as geometrical shapes (such as circles, triangles, squares, and the like), non-geometrical shapes, such as hearts, droplets, waves, and the like. The patterns may further include any combination of shapes. The shapes may include any size and any number of shapes that may be distributed evenly or non-evenly over the surface of the end face of the connector. The patterns may include recurrent patterns. The patterned regions on the surface of the end face connector may exhibit different characteristics than the non-patterned region surface. Different characteristics may include, for example, optical characteristics, such as, for example, various reflectiveness properties.
According to additional embodiments, the end face of the connector may include any combination of lines, dots, spots and the like that may be distributed evenly or non evenly over the surface of the end face of the connector. For example, the lines may include straight lines, curved lines, checkered lines, and the like. Areas/regions defined by the combination of lines may possess different characteristics than other regions. Different characteristics may include, for example, optical characteristics, such as, for example, various reflectiveness levels, various wavelength ranges of the reflected light, and the like. According to further embodiments, the surface of the end face of the connector may include one or more concave regions and one or more convex regions. The concave regions may focus the reflected light and the convex regions may defocus the reflected light and thus different levels of reflectivity from different regions of the end face of the connector may be obtained.
Reference is now made to FIGS. 2A-K , which illustrate exemplary end faces of a connector according to some embodiments. For example, end face A illustrates an annular end face of a connector with two regions with distinct reflective properties. For example, end face B illustrates an annular end face divided into three equal regions, wherein at least one of the regions has distinct reflective properties. For example, end face C illustrates an annular end face divided into four equal regions, wherein at least one of the regions has distinct reflective properties. For example, end face D illustrates an annular end face of a connector with a reflective surface and spots, at least one of which is with distinct reflective characteristics. For example, end face E illustrates an annular end face of a connector with a reflective surface and circles distributed over the surfaces, at least one of the circles exhibits distinct reflective characteristics. For example, end face F illustrates an annular end face of a connector with a reflective surface and heart shaped regions distributed over the surfaces, at least one of the heart shaped regions exhibits distinct reflective characteristics. For example, end face G illustrates an annular end face of a connector with a reflective surface and squares distributed over the surfaces, at least one of the squares exhibits distinct reflective characteristics. For example, end face H illustrates an annular end face of a connector with a reflective surface and horizontal lines stretched over the surface, at least one of the areas bound between the lines exhibits distinct reflective characteristics. For example, end face I illustrates an annular end face of a connector with a reflective surface and horizontal and vertical lines distributed over the surface, at least one of the areas bound between the lines exhibits distinct reflective characteristics. For example, end face J illustrates an annular end face of a connector divided into two separate, non-continuous regions, wherein at least one of the regions has distinct reflective properties. For example, end face K illustrates an annular end face of a connector divided into three separate, non-continuous regions, wherein at least one of the regions has distinct reflective properties. For example, end face L illustrates an annular end face of a connector divided into four separate, non-continuous regions, wherein at least one of the regions has distinct reflective properties.
According to some embodiments, the medical device may include a verification system that may be used to detect/identify the connector (and hence the tube) attached to the medical device. Identification/detection of the connector that is attached to the medical device may be performed by detection/identification of any of the properties/parameters of the end face of the connector that are described herein. For example, the verification system of the medical device may detect/identify the optical properties (as determined by the reflectiveness properties) of the end face of the connector. The verification system may include one or more optical light source emitters (such as, for example, Light Emitting Diodes (LEDs)) that may emit light at various individual wavelengths and/or at a wide spectral range of wavelengths. For example, the light source may include a Light Emitting Diode (LED) that may emit light at the visible white light spectral range (for example, at the range of 0.4 to 0.7 mm). The verification system may further include one or more optical receivers that may be adapted to receive light reflected from the end face surface of the connector. The optical receivers may be spatially separated from the light source emitters so as to ensure that light detected by the optical receivers is the light reflected from the end face surface of the connector. Spatial separation may be performed, for example by placing an optical barrier between the light source and the optical receiver. The spatial separation may be performed, for example, by use of optical wave guides that may be used to create a channel/chamber, at the bottom of which the optical detector is situated. The use of such a chamber may ensure that only light that is reflected from the end face surface of the connector reaches the optical receiver, while light, such as scattered light from the environment, direct light from the light source, and the like, is prevented from reaching the optical detector. The reflected light from the end face of the connector may be at various wavelengths and at various amplitudes (intensity levels), which may be determined by the reflective properties of the surface of the end face connector. The optical receiver may include any type of light and/or color detector. The optical receiver may include more than one optical receiver, which may be adapted to receive light at the wavelengths, which correspond to the wavelengths of the light reflected from the various regions of the end face of the connector. For example, the optical receiver may include one or more light detectors that may be used to detect intensity of reflected light. The optical receiver may include a light detector that may be further equipped with an optical filter that may allow the optical detector to identify a specific, predetermined range of wavelengths that correspond to the optical filter. For example, the optical detector may include an RGB detector, which is well known in the art. Briefly, an RGB detector may be basically described as a multi-element photodiode coupled to red, green, and blue filters, that enable the photodiode to generate separate response curves for the three colors and hence determine the color (wavelength) and the amplitude (intensity) of the light detected by the photodiode. As such, the RGB color detector that may be used to detect light of various wavelengths (which correspond to different colors) may be reflected from one or more surfaces of the end face of the connector. The RGB detector may further be used to detect the amplitude (level) of the reflected light from one or more surfaces of the end face of the connector. According to additional embodiments, the optical receiver may be adapted to receive light at a wavelength which corresponds to the wavelength of the light reflected from a region of the end face of the connector and to further receive light at a second wavelength, which may correspond to the wavelength of the light reflected from other region(s) of different reflectivity of the end face surface. According to other embodiments, the light reflected from the regions of different reflectivity on the surface of the end face of the connector may be conveyed by the use of, for example, optical fibers that may collect the signals reflected from the individual spots into one optical signal that may be received by the second receiver.
Reference is now made to FIG. 3 , which illustrates a schematic drawing of a close up side view of an end face of a tube connector and the medical device verification system, according to some embodiments. As shown in FIG. 3A , verification system 100 , includes one or more light sources (shown as one light source, 102 ). The light source may include, for example, a LED that may emit light a the white light spectral range. The verification system further includes one or more optical receivers (shown in FIG. 3A as one optical receiver, 104 ). The optical receiver may include, for example an RGB detector. The verification system may further include an optical barrier, such as optical barrier 106 , that may be used to prevent light emitted from a light source (such as light source 102 ) from directly reaching the optical receiver (such as optical receiver 104 ). Also shown in FIG. 3A , the end of connector, (such as connector 108 ) and the end face surface of the connector, (end face 110 ). When operating, the verification system light source may emit light (illustrated as arrow 112 ). The light emitted from the light source may be reflected (illustrated as reflected light (arrow 114 )), depending on the reflectiveness properties of the connector end face ( 110 ). Reflected light 114 may reach the optical receiver 104 , that may consequently determine the optical properties of the reflected light (such as color (wavelength) and amplitude (intensity). According to the determined optical properties of the reflected light, the verification system (as detailed below herein) may determine the type/model of the connector attached and further determine the operation mode of the medical device. As shown in FIG. 3B , verification system 200 , may include one or more light sources (shown as one light source, 202 ). The light source may include, for example, a LED that may emit light at the white light spectral range. The verification system further includes one or more optical receivers (shown in FIG. 3B as one optical receiver, 204 ). The optical receiver may include, for example an RGB detector. The verification system may further include one or more optical guides, such as optical guides 206 A-B that may form a tunnel/chamber, such as chamber 209 , at the bottom of which, optical receiver ( 204 ) is positioned. The optical guides may be used to prevent light emitted from a light source (such as light source 202 ) from directly reaching the optical receiver (such as optical receiver 204 ), as well as other light that is not reflected from the connector end face. Also shown in FIG. 3B is the end of connector, (such as connector 208 ) and the end face surface of the connector, end face 210 ). When operating, the verification system light source may emit light (illustrated as arrow 212 ). The light emitted from the light source may be reflected (illustrated as reflected lights (arrow 214 A-B)), depending on the reflectiveness properties of the connector end face ( 210 ). Only light that is reflected at an acute angle (such as reflected light 214 A) may enter chamber 209 and reach the optical receiver. Other reflected light (such as 214 B) is prevented from reaching the optical receiver. Likewise, light that may originate from other sources, such as scattered light from the environment (demonstrated as arrow 216 ) is prevented from reaching the optical receiver. The optical receiver that may consequently determine the optical properties of the detected reflected light (such as color (wavelength) and amplitude (intensity)). According to the determined optical properties of the reflected light, the verification system (as detailed below herein) may determine the type/model of the connector attached and further determine the operation mode of the medical device. Additional elements/constituents of the verification system that are detailed below herein, such as wires, fibers, power sources, electrical circuits, comparators, integrators, and the like are omitted from drawings 3 A and 3 B for clarification purposes.
According to some embodiments, and as mentioned above herein, the medical device may include a verification system that may be used to de-encode the data encoded on and by the end face of the connector. The verification system may be used to analyze the properties and characteristics of the connector attached to the medical device, and accordingly change the mode of operation of the device. For example, in relation to detection of reflected light by the end face of the connector, the medical device may include the various electrical circuits that may further include various constituents for generating and processing optical signals transmitted to the connector end face and received therefrom and based upon the analyzed results determine if the connector is properly connected to the medical device and identify what is the type, class, model and/or interface of the connector (and hence the tube attached thereto). According to some embodiments, the electronic circuits may include several constituents, such as, for example, but not limited to: one or more light sources (such as, for example, LED adapted to emit light at various wavelengths, Infra Red light source, Ultraviolet light source, laser light source, and the like); photodiodes adapted to receive emitted and reflected light and convert the signal to electrical signal; RGB detector; fibers, such as optical fibers adapted to transfer light (emitted and reflected) between the medical device and the connector; one or more amplifiers adapted to specifically amplify the light reflected from the connector end face; filters, adapted to emit and/or receive reflected light of a specific wavelength; one or more synchronous detectors adapted to synchronize light pulses emitted from the one or more light sources, respectively; one or more integrators adapted to receive a voltage signal from the one or more synchronous detectors and integrate the voltages over a certain time period to yield voltage values (for each of the light sources); one or more comparators/processors which are adapted to compare/process the voltage value obtained by the one or more integrators to predetermined threshold values that correspond to the various light reflections from the connector. The one or more processors may be adapted to process the information received from the detectors and to provide identification of the tube connector based on the signals received from the detector. The one or more comparators/processors may yield a signal that may be used by the medical device to determine if the connector is properly attached to the device and if the connector is of the right type, class and/or model and accordingly modify the operation of the medical device. If, for example, the binary signal received indicates that improper connection is detected between the device and the connector, the device may not operate until the attachment is corrected. For example, if the signal indicates that the connector is attached to a sampling line (tube) adapted for children, than the device may operate accordingly and be adjusted (for example, automatically) to operate under “children” mode. For example, if the calculated/measured signal is indicative that the connector is attached to a sampling line that is to be used with intubated patients, the device may operate accordingly and be adjusted to operate under “intubated patient” mode. In addition, the verification system of the medical device may further include one or more additional detectors/receivers that may be used to detect/sense/measure/receive additional features/characteristics/properties/information that may be encoded on and by the end face of the connector, as further detailed below herein.
According to some embodiments, the identification of the connector (and hence the tube) being attached to the medical device may be performed in various ways, such as, for example, while the connectors are being attached (“on the “fly”), after the connectors have been attached (“final position”) or any combination thereof. For example, the identification (and verification) of the tube connector being attached may be performed on the fly, during the attachment (connection) of the tube connector to its corresponding connector on the device. The connection may be performed, for example by pushing and/or turning and/or screwing the tube connector to its location in the device connector. During the time of insertion, the tube connector may be identified by the verification system by any of the methods described herein, such as, for example, by identifying distinct regions of reflectivity (amplitude and/or wavelength) of the end face of the connector; by identifying recurring changes of reflectivity during the revolving of the tube connector relative to the device connector, and the like. The identification (and verification) of the tube connector attached to the device may be performed after the tube connector is attached to its respective device connector, while the connectors are at their final (resting) position. Such identification may be performed by the verification system of the medical device by any of the methods described herein.
According to some embodiments, the relative final location (alignment) of the end face of the connector with respect to the detectors/receivers of the verification system of the medical device may be determined. For example, the relative location (alignment) of the end face of the connector with respect to its matching device connector may be determined. Determining a desired relative location of the end face of the connector to its matching device connector may be used to allow proper alignment between the respective locations of the two connectors and hence, a desired respective location between the end face of the connector to the verification system of the medical device. Proper alignment may be used to allow matching between regions of the end face of the connector and, for example, respective receivers/detectors (such as, for example, optical receivers) of the verification system of the medical device. Determination of the desired relative location (alignment) between the end face connector and the verification system of the medical device may be performed by various means, such as, for example but not limited to physical barriers, mechanical fitting, visual fitting, manual fitting, and the like. For example, proper alignment may be achieved by matching projection(s) and depression(s) on the end face connectors and its matching device connector; key and lock fittings on the end face connector and its matching device connector; markings on the end face connector and its matching device connector, to which it is to be attached, and the like. For example, the end face connector may include projection at the circumference of the device end of the connector. The device connector may include a matching depression. In order to physically attach the two connectors, the respective projection and depression must match. Matching the respective projections and depression of the connectors ensures the proper relative alignment of the end face of the connector with the corresponding receivers/detectors of the verification system of the medical device. In such a manner, different regions of the end face of the end face connector may be distinguishable and may allow identification and/or verification of the end face and further, the tube being used. For example, the end face connector may include a marking, such as a line, at the circumference of the device end of the connector. Likewise, the connector device may include a marking, such as a line, at the circumference of the device connector. After (or during) attaching the connectors, the two markings on the two connectors must be aligned. Alignment of the markings on the connectors ensures proper relative alignment of the end face of the connector with the corresponding receivers/detectors of the verification system of the medical device. In such a manner, different regions of the end face of the connector may be distinguishable and may allow identification and/or verification of the end face and hence the tube being used.
According to some embodiments, the threshold values may be chosen to be such that would discriminate between integrated voltage values that result from the reflection of light from various regions of the end face of the connector and other sources of light. The threshold values may further be used to discriminate between various types of connectors, such as, for example, between connectors that may have only one reflective region on the end face and connectors that may have more than one reflective region on their end face. In addition, the threshold values may be used to discriminate between connectors that have one or more reflective regions on their end face and connectors that have no reflective regions on their end face. In addition, the threshold values may be used to discriminate between various types, classes and/or models of connectors, that may be adapted for various uses (for example, use with children sampling lines, adults sampling lines, and the like).
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the additional feature may include radioactive labeling of at least a distinct region of the end face. The radioactive labeling may include spots deposited along the annular circumference of the end face of the connector. The radioactive spots may include radioactive labeling using any common radioisotope, such as, for example, deuterium (H 3 ), C 14 , P 32 , S 35 and the like. In addition, the medical device verification system may include an appropriate matching radioactive detector, such as a radioactive counter that may be used to detect radioactive energy emitted from the connector end face.
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the end face of the connector may include an electronic identification means, such as, for example, a Radio Frequency Identification (RFID). RFID is known as an automatic identification method, that stores and remotely retrieves data using RFID tags or transponders. An RFID tag is an identification tag that may be identified wirelessly using radio waves. Most RFID tags include at least two parts: an integrated circuit for storing and processing information, modulating and demodulating a radio frequency signal; and an antenna for receiving and transmitting the signal. In addition, a technology called chipless RFID allows for discrete identification of tags without an integrated circuit. According to some embodiments, an RFID tag may be implemented with the connector. The RFID tag may preferably be implemented at the end face of the connector, for example, by using a chipless RFID that may be printed on at least a region of the end face of the connector. The RFID tag may be of the passive type, which is a tag that does not need an autonomous power supply. The RFID tag may include specific information characteristic of the connector, such as type, class and model of the connector. In addition, the verification system of the medical device may include an antenna and an RFID reader that may identify the RFID tag and read/process the information encoded within the RFID tag. For example, the RFID tag may include information regarding the type, class and model of the connector (for example, for what type of patient it is to be used with: a child or an adult; intubated patient or non-intubated patient; who is the manufacturer that produced the connector, and the like).
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the end face of the connector may include a barcode pattern that may be present on at least one region of the end face of the connector. The barcode may be used to identify the connector type/model to the medical device to which it is to be connected. In addition, the medical device verification system may further include an appropriate barcode reader, such as, for example, a barcode scanner, that may be used to detect the presence of a barcode on the end face and to further interpret the barcode. The bar code may be read “on the fly”, while the connector is being turned/screwed into its location towards its final position. Identification of the barcode by the medical device verification system may allow proper identification of the connector that is connected to the medical device and accordingly, adjust the operation mode of the medical device.
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the end face of the connector may include one or more regions that include distinct magnetic field characteristics. The one or more regions with the distinct magnetic properties may be of any shape and size. The distinct magnetic properties may be achieved by, for example, using a coating, which has magnetic properties, that may be applied to the appropriate region on the end face. In addition, the medical device verification system may further include an appropriate magnetic field detector, that may be used to detect the presence and/or force of the magnetic field created by the one or more regions of the end face.
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the end face of the connector may include one or more regions that include distinct electrical field characteristics. The one or more regions with the distinct electrical properties may be of any shape and size. The distinct electrical properties may include, for example, regions with different electrical conductance, different electrical field, different electrical energy produced thereby, and the like. The distinct electrical properties may be applied by, for example, applying small electrical power to specified one or more regions on the end face. In addition, the medical device verification system may further include an appropriate electrical detector, that may be used to detect the presence and/or force of the electrical energy and/or current and/or conductance and/or electrical filed created by the one or more regions of the end face with distinct electrical properties.
According to some embodiments, the end face of the connector may include an additional distinguishing feature in addition to being reflective. For example, the use of pressure drop detection across the sampling line used may also be used as a verification method to determine if the connector is of the appropriate class, type, an/or model. Detection of pressure drop may be performed, for example, initiating operation of the medical device upon first verification of correct attachment between the connector and the medical device. Then, different pressure drops across the sampling line are created and detected. The different pressure drops, which are characteristics of a sampling line, may be detected and may thus identify the sampling line used with the attached connector. If the pressure drop identifies a connector/sampling line that is not of the required/desired type (such as, for example, not by the desired manufacturer), the operation of the medical device may stop until a proper connector and sampling line are attached to the device.
According to further embodiments, the end face of the connector may include one or more light sources. The light sources may include, for example, one or more LED that may emit light at various, distinct wavelengths. The one or more LED may receive power from an internal power supply, such as, for example, small batteries located within the cavity of the connector. The LEDs may emit light at predetermined wavelength ranges that may match corresponding light detectors, such as, for example, photodiodes, located in the verification system of the medical device. The light detectors may convert the detected light to a binary signal, as detailed above herein to determine the type, class and/or model, of the connector and to determine the correct assembly of the connector to the medical device. If the connector is properly attached to the medical device and is of the appropriate type, the device may operate in an operation mode that is suitable for the detected connector.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced be interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope. | There is provided a tube connector for connecting between a fluid sampling tube and a fluid analyzer, the tube connector includes an end face adapted to identify the tube connector, said end face comprising a reflecting surface having one or more reflective regions adapted to reflect light at a predetermined range of wavelengths. |
PRIORITY CLAIM
This application is related to and claims priority under 35 U.S.C. §119(e) to a commonly assigned provisional patent application entitled “A FLOATING COLLAR CLAMPING DEVICE FOR AUTO-ALIGNING NUT AND SCREW IN LINEAR MOTION LEADSCREW AND NUT ASSEMBLY,” by James E. Tappan., Application Ser. No. 61/027,405 filed on Feb. 8, 2008, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Advances in plasma processing have provided for growth in the semiconductor industry. During substrate processing, conditions of the chamber may have to be closely manipulated to create a processing environment that produces semiconductor devices. In a precision linear motion processing system, manipulation may occur by altering the configuration of the processing chamber.
Consider the situation wherein, for example, a substrate is being processed in a processing chamber of a precision linear motion processing system. The substrate is positioned on top of a lower electrode (e.g., electrostatic chuck). Depending upon the recipe, the lower electrode may be moved vertically, thereby adjusting the substrate in relation to the upper electrode, which is usually positioned above the lower electrode.
To facilitate the vertical adjustment of the lower electrode, a linear motion apparatus may be attached to the lower electrode. The linear motion apparatus may include a leadscrew. To enable the leadscrew to rotate, a motor may be attached to the leadscrew via a shaft. The motorized leadscrew arrangement may be attached to the external wall of the processing chamber via a pair of clamps, which may be fastened to the wall of the processing chamber via a pair of screws.
The linear motion apparatus may also include a nut arrangement. The nut arrangement may include a threaded nut, which may surround the leadscrew to create a concentric relationship between the leadscrew and the threaded nut. The nut arrangement may be attached to a support plate, which is fastened to the threaded nut via a nut bracket. Accordingly, as the leadscrew rotates, the nut arrangement is moved in a vertical direction, thereby causing the support plate to move in the same direction. Since the support plate is attached to the lower electrode, the lower electrode is adjusted by manipulating the linear motion apparatus. In other words, the motorized leadscrew causes the nut arrangement to move in a vertical direction, thereby translating into a vertical adjustment of the lower electrode.
To maximize the life of the linear motion apparatus, the concentricity between the leadscrew and the threaded nut may have to be maintained. However, maintaining concentricity may be a challenge, especially if the linear motion apparatus may have been improperly assembled. In an example, during assembly of the precision linear motion processing system, the leadscrew may have been positioned in a manner slightly out of concentricity. Even if the linear motion apparatus has been assembled properly, leadscrew runout may occur. As discussed herein, leadscrew runout refers to a leadscrew that is not straight due to a manufacture defect, or normal manufacturing tolerances. Regardless if the linear motion apparatus has been improperly assembled or the leadscrew may have runout, the rotation of the leadscrew may cause the threaded nut to apply load to one side of the leadscrew, thereby causing excessive friction and/or premature wearing of the leadscrew and/or the threaded nut.
To address the misalignment, one prior art solution includes employing a set of clearance slots to accommodate the fasteners that may be utilized to mount either hardware (e.g., leadscrew or threaded nut). In an example, a clamp may mount the leadscrew to the wall of the processing chamber. The clamp may be fastened to the wall of the processing chamber via a pair of screws, which may be inserted into a pair of clearance slots located on the clamp. Each clearance slot may have an oblong configuration, thereby enabling an assembler to align the leadscrew in an X direction. However, by using clearance slot to perform alignment, the simple assembly process becomes a time-consuming and more complicated assembly procedure. As a result, a highly-skilled assembler is required to perform the more complicated assembly procedure. In addition, unwanted side loading (i.e., grinding against the side of the leadscrew) may still occur since the clearance slots do not address leadscrew runout.
Another prior art solution includes employing a floating nut, which is a threaded nut with a clearance gap at its mounting holes. In an example, a linear motion apparatus may include a leadscrew surrounded by a threaded nut mounted with holes with clearance gap. In other words, a gap may exist between the mounting screws and the mounting holes of the threaded nut. Accordingly, with a gap, misalignment due to improper assembly and/or leadscrew runout may be accommodated, thereby reducing unwanted side loading. However, the floating nut arrangement may cause the threaded nut to shift in a clockwise and/or counterclockwise direction. As a result, the shifting of the threaded nut may cause loss of positional accuracy that may translate to inability to accurately manipulate the configuration of the processing chamber in order to etch a substrate.
As can be appreciated from the foregoing, premature wearing due to unwanted side loading may require that at least part of the linear motion apparatus, such as the leadscrew and the threaded nut, be replaced. While the worn parts are being replaced, the processing tool is essentially unavailable for processing substrate. Depending upon the time period required to replace the worn parts (which may include shutting down the processing tool, ordering the required parts, disassembling the linear motion apparatus, reassembling the linear motion apparatus with the new parts, recalibrating the processing tool, and the like), the economic loss that a company may suffer due to premature wearing can become quite significant.
SUMMARY OF INVENTION
The invention relates, in an embodiment, an auto-aligning linear motion apparatus. The apparatus includes a leadscrew. The apparatus also includes a nut arrangement configured to surround the leadscrew, wherein the nut arrangement includes at least a nut, a nut bracket, and a floating collar. A shoulder screw is inserted through a nut bracket slot of the nut bracket and a nut slot of the nut to rest at least partially within the floating collar. One dimension of the nut bracket slot is larger than a dimension through a cross-section area of the shoulder screw to enable the shoulder screw to move within the nut bracket slot to adjust the nut arrangement as the leadscrew is rotated to maintain a concentric relationship between the nut arrangement and the leadscrew.
The above summary relates to only one of the many embodiments of the invention disclosed herein and is not intended to limit the scope of the invention, which is set forth in the claims herein. These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 shows, in an embodiment of the invention, an exploded-view of an auto-aligning linear motion apparatus.
FIG. 2 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of inserted shoulder screws.
FIG. 3 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of raised bosses.
FIG. 4 shows, in an embodiment of the invention, an exploded-view of an auto-aligning linear motion apparatus (another view of FIG. 1 ).
FIG. 5 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of inserted shoulder screws (another view of FIG. 2 ).
FIG. 6 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of raised bosses (another view of FIG. 3 ).
DETAILED DESCRIPTION OF EMBODIMENTS
The present invention will now be described in detail with reference to a few 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 process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.
Various embodiments are described hereinbelow, including methods and techniques. It should be kept in mind that the invention might also cover articles of manufacture that includes a computer readable medium on which computer-readable instructions for carrying out embodiments of the inventive technique are stored. The computer readable medium may include, for example, semiconductor, magnetic, opto-magnetic, optical, or other forms of computer readable medium for storing computer readable code. Further, the invention may also cover apparatuses for practicing embodiments of the invention. Such apparatus may include circuits, dedicated and/or programmable, to carry out tasks pertaining to embodiments of the invention. Examples of such apparatus include a general-purpose computer and/or a dedicated computing device when appropriately programmed and may include a combination of a computer/computing device and dedicated/programmable circuits adapted for the various tasks pertaining to embodiments of the invention.
In accordance with embodiments of the present invention, an auto-aligning linear motion apparatus provides a mechanism for a nut to self-align in relation to the configuration of a leadscrew. To facilitate self-alignment, the nut may be attached to a nut bracket and a floating collar via a pair of shoulder screws. In an example, the nut may slide in an X direction due to the shape of the nut bracket slots that have been cut into the nut brackets. In an embodiment, the pair of nut bracket slots may have an oblong shape in the X direction, thereby enabling the inserted shoulder screws to move in an X direction. Since the shoulder screws are also inserted into slots cut into the nut, the sliding of the shoulder screws may also translate into self-alignment of the nut in the X direction.
In another embodiment, the nut is connected to the floating collar via the shoulder screws and a pair of opposing raised bosses, which are raised fixtures located on the floating collar. In an embodiment, the raised bosses are inserted upward into a pair of nut flange slots that have been cut into the nut flange. In one embodiment, the nut flange slots have an oblong shape in the Y direction, thereby enabling the nut to slide in the Y direction.
With the modified nut arrangement, the shoulder screws and/or the raised bosses restrict the nut from rotating while allowing the nut the freedom of self-aligning in the X/Y direction. In an example, the motorized leadscrew is offset to the right in an X direction. As the motorized leadscrew rotates, the nut is able to perform self-alignment to accommodate the offset of the leadscrew by also sliding in the X direction, thereby maintaining concentricity between the nut and the leadscrew and substantially minimizing unwanted side loading. Thus, premature wearing that is usually associated with unwanted side loading may be significantly reduced.
The features and advantages of the present invention may be better understood with reference to the figures and discussions that follow.
FIG. 1 shows, in an embodiment of the invention, an exploded-view of an auto-aligning linear motion apparatus. For an exploded view of FIG. 1 , see FIG. 4 . As aforementioned, a precision linear motion processing system may include a movable lower electrode (not shown) that may be adjusted during substrate processing, thereby enabling an operator to control the height of the lower electrode. To facilitate adjustment, the lower electrode is attached to an auto-aligning linear motion apparatus 100 via a support plate 110 . in an embodiment, auto-aligning linear motion apparatus 100 may include a modified nut arrangement surrounding a leadscrew 102 . Similar to the prior art, leadscrew 102 may be attached to a motor 111 ( FIG. 5 ) thereby enabling leadscrew 102 to rotate when the motor is turned on.
The modified nut arrangement may include a nut bracket 104 , a nut 106 , and a floating collar 108 . Nut bracket 104 is an extension of support plate 110 and connects nut 106 (which may be threaded) to support plate 110 . To join the two components, a pair of shoulder screws ( 112 and 114 ) may be inserted into a pair of opposing nut bracket slots ( 116 a and 116 b ) and a pair of opposing nut slots ( 118 a and 118 b ).
In an embodiment, each shoulder screw ( 112 and 114 ) may include a screw head 122 , a shoulder portion 124 , and a screw portion 126 . In one embodiment, shoulder portion 124 may have a length that is at least equal to the thickness of nut bracket 104 and the thickness of a nut flange 128 , which is the wider portion of nut 106 . When shoulder screw is inserted into the slots, screw portion 126 may extend beyond nut flange 128 . In an embodiment, shoulder screw 112 may be secured into the modified nut arrangement by inserting screw portion 126 into a collar threaded hole 120 a of floating collar 108 . As discussed herein, a floating collar is a ring arrangement that is positioned directly beneath nut flange 128 and fits securely around a nut body 130 of nut 106 .
In the prior art, unwanted side loading, which may lead to premature wearing, may occur when concentricity between a leadscrew and a nut is either not established and/or maintained due to misalignment and/or leadscrew runout. In one aspect of the invention, the inventor herein realizes that concentricity may be maintained if the modified nut arrangement automatically aligns in an X/Y direction to accommodate the configuration of the leadscrew. FIGS. 2 and 3 will be used to illustrate how auto-alignment may be achieved through the modified nut arrangement.
FIG. 2 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of inserted shoulder screws. For an exploded view of FIG. 2 , see FIG. 5 . Shoulder screws 112 and 114 have been inserted into the modified nut arrangement. In an example, shoulder screw 112 has been inserted into nut bracket slot 116 a, nut slot 118 a (not shown), and collar threaded hole 120 a (not shown), thereby joining nut bracket 104 , nut 106 , and floating collar 108 into a single modified nut arrangement.
In an embodiment, the pair of nut bracket slots ( 116 a and 116 b ) may have a larger diameter than the pair of shoulder screws ( 112 and 114 ). In other words, when shoulder screw 112 is inserted into nut bracket slot 116 a , a slight gap may exist between shoulder section 124 and wall of nut bracket slot 116 a . In one embodiment, each of the pair of nut bracket slots ( 116 a and 116 b ) has an oblong shape in an X direction 202 , thereby enabling the inserted shoulder screws to move in X direction 202 when shoulder screw 112 is tightened.
In an embodiment, shoulder sections of the shoulder screws may pass through the corresponding pair of opposing nut slots. In an example, when shoulder section 124 is butted snugly against top surface of floating collar 108 inserted shoulder screw 112 is securely affixed to floating collar 108 . Since inserted shoulder screw 112 is able to slide in X direction 202 , floating collar 108 , consequently, may also inherit the trait and is able to automatically align in the same direction. Accordingly, since nut 106 is constrained in the X direction relative to floating collar 108 via the pair of opposing raised bosses ( 302 and 304 ) and corresponding slots 306 a and 306 b in nut 106 floating collar 108 and nut 106 together may also be automatically aligned in the X direction.
FIG. 3 shows, in an embodiment of the invention, a cut-out view of an auto-aligning linear motion apparatus with a pair of raised bosses. For an exploded view of FIG. 3 , see FIG. 6 . Floating collar 108 may include a pair of opposing raised bosses ( 302 and 304 ), in an embodiment. Pair of raised bosses 302 and 304 may be located on top of floating collar 108 and each may be situated between the pair of opposing collar threaded holes ( 120 a and 120 b of FIG. 1 ).
In an embodiment, pair of opposing raised bosses ( 302 and 304 ) may be inserted upward into a pair of opposing nut flange slots ( 306 a and 306 b ), which may be recessed into nut flange 128 . In one embodiment, pair of opposing nut flange slots ( 306 a and 306 b ) may be slightly larger than larger pair of opposing raised bosses ( 302 and 304 ). In an example, when raised boss 302 is inserted into nut flange slot 306 a , a slight gap may exist between the raised boss and the slot, thereby enabling nut 106 to automatically align in relation to raise boss 302 . In one embodiment, pair of nut flange slots ( 306 a and 306 b ) may have an oblong shape in a Y direction 308 , thereby allowing nut 106 to adjust in a Y direction relative to floating collar 108 .
If modification to nut bracket 104 is not feasible or permissible to create the pair of oblong slots (i.e., pair of nut flange slots) to allow the pair of raised bosses to rise into the pair of oblong slots and translate in the Y direction, then an additional adapter ring run be provided in-between nut flange 128 and floating collar 108 , in an embodiment. The adapter ring may have a pair of opposing oblong slots to facilitate the guiding function of the raised bosses for the translation movement in the Y direction.
As can be appreciated from FIGS. 2 and 3 , the modified nut arrangement enables the nut to automatically self-align in the X/Y direction while the shoulder screws and the raised bosses prevent the nut from rotating, thereby limiting rotation between nut and nut bracket to ensure that no loss of positional accuracy is sacrificed while accommodating the ability to self-align in the X/Y direction. In other words, the nut is able to perform self-alignment in relation to the configuration of the leadscrew, thereby enabling the nut and the leadscrew to maintain a concentric relationship while maintaining good positional accuracy of the linear motion apparatus. In an example, the nut is able to accommodate misalignment of the leadscrew due to improper assembly or manufacturing tolerances resulting in a non-concentric nut to leadscrew relationship. For example, as the motorized leadscrew rotates, the modified nut arrangement may slide in either the X or Y direction to accommodate the position of the leadscrew. Similarly, the modified nut arrangement ability to perform self-alignment in the X/Y direction may also address the unwanted side loading that may occur due to leadscrew runout.
As can be appreciated from one or more embodiments of the invention, the auto-aligning linear motion apparatus provides an arrangement for vertically adjusting a lower electrode while substantially eliminating unwanted side loading of leadscrew nut. Accordingly, by substantially eliminating the unwanted side loading, premature wearing of the leadscrew and the nut may also be correspondingly prevented. With a modified nut arrangement, concentricity between the leadscrew and the nut may be maintained without requiring complicated assembly procedures. Since the arrangement requires fairly inexpensive parts, concentricity may be maintained without incurring expensive costs. Thus, the auto-aligning linear motion apparatus provides a cost effective solution for minimizing economic loss that may have originated from lack of concentricity.
While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents, which fall within the scope of this invention. Although various examples are provided herein, it is intended that these examples be illustrative and not limiting with respect to the invention.
Also, the title and summary are provided herein for convenience and should not be used to construe the scope of the claims herein. Further, the abstract is written in a highly abbreviated form and is provided herein for convenience and thus should not be employed to construe or limit the overall invention, which is expressed in the claims. If the term “set” is employed herein, such term is intended to have its commonly understood mathematical meaning to cover zero, one, or more than one member. 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. | An auto-aligning linear motion apparatus is provided. The apparatus includes a leadscrew. The apparatus also includes a nut arrangement configured to surround the leadscrew, wherein the nut arrangement includes at least a nut, a nut bracket, and a floating collar. A shoulder screw is inserted through a nut bracket slot of the nut bracket and a nut slot of the nut to rest at least partially within the floating collar. One dimension of the nut bracket slot is larger than a dimension through a cross-section area of the shoulder screw to enable the shoulder screw to move within the nut bracket slot to adjust the nut arrangement as the leadscrew is rotated to maintain a concentric relationship between the nut arrangement and the leadscrew. |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 09/704,150, filed Nov. 1, 2000, now U.S. Pat. No. 6,891,838, and entitled “System and Method for Monitoring and Controlling Residential Devices;” U.S. patent application Ser. No. 09/271,517, filed Mar. 18, 1999, now abandoned, and entitled “System For Monitoring Conditions in a Residential Living Community;” and U.S. patent application Ser. No. 09/439,059, filed Nov. 12, 1999, now U.S. Pat. No. 6,437,692 and entitled “System and Method for Monitoring and Controlling Remote Devices.” Each of the identified U.S. patent applications is hereby incorporated by reference in its entirety. This application also claims the benefit of U.S. Provisional Application Ser. No. 60/224,047, filed Aug. 9, 2000, and entitled “Design Specifications for a Personal Security Device (FOB),” which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
The present invention generally relates to remotely operated systems, and more particularly to a computerized system for monitoring and reporting on remote systems by transferring information via radio frequency (RF) signals via a message protocol system.
BACKGROUND
There are a variety of systems for monitoring and/or controlling any of a number of systems and/or processes, such as, for example, manufacturing processes, inventory systems, emergency control systems, personal security systems, residential systems, and electric utility meters to name a few. In many of these “automated monitoring systems,” a host computer in communication with a communication network, such as a wide area network, monitors and/or controls a plurality of remote devices arranged within a geographical region. The plurality of remote devices typically use remote sensors and actuators to monitor and automatically respond to various system parameters to reach desired results. A number of automated monitoring systems utilize computers to process sensor outputs, to model system responses, and to control actuators that implement process corrections within the system.
For example, both the electric power generation and metallurgical processing industries successfully control production processes by implementing computer control systems in individual plants. Home security has been greatly increased due to automated monitoring devices. Many environmental and safety systems require real-time monitoring. Heating, ventilation, and air-conditioning systems (HVAC), fire reporting and suppression systems, alarm systems, and access control systems utilize real-time monitoring and often require immediate feedback and control.
A problem with expanding the use of automated monitoring systems is the cost of the sensor/actuator infrastructure required to monitor and control such systems. The typical approach to implementing automated monitoring system technology includes installing a local network of hard-wired sensor(s)/actuator(s) and a site controller. There are expenses associated with developing and installing the appropriate sensor(s)/actuator(s) and connecting functional sensor(s)/actuator(s) with the site controller. Another prohibitive cost of control systems is the installation and operational expenses associated with the site controller.
Another problem with using automated monitoring system technology is the geographic size of automated monitoring systems. In a hard-wired automated monitoring system, the geographic size of the system may require large amounts of wiring. In a wireless automated monitoring system, the geographic size of the automated monitoring system may require wireless transmissions at unacceptable power levels.
Another problem is that communications within the automated monitoring system can only be initiated by the host computer, some other computing device connected to the host computer via a wide area network, or one of the remote devices being monitored. Individuals associated with the remote devices and/or personnel associated with the automated monitoring system have no additional means of communicating various conditions within the automated monitoring system. For example, in situations where the automated monitoring system is susceptible to emergency situations and/or unforeseen events, it may be beneficial to enable users and other personnel the ability to flexibly initiate communications without having to access the host computer.
Accordingly, there is a need for automated monitoring systems that overcome the shortcomings of the prior art.
SUMMARY OF THE INVENTION
The present invention provides systems and methods for enabling a mobile user to notify an automated monitoring system of an emergency situation. In general, the automated monitoring system may be configured for monitoring and controlling a plurality of remote devices and may comprise a site controller in communication with the plurality of remote devices via a plurality of transceivers defining a wireless communication network. The remote devices may be controlled via a host computer in communication with the site controller via a communication network, such as a wide area network.
The present invention may be viewed as providing a mobile communication device adapted for use with an automated monitoring system. The automated monitoring system may be configured for monitoring and controlling a plurality of remote devices and may comprise a site controller in communication with the plurality of remote devices via a plurality of transceivers defining a wireless communication network and in communication with a host computer via a wide area network. Briefly described, one of many possible embodiments of the mobile communication device comprises: memory, logic, and a wireless transmitter. Memory may comprise a unique identifier associated with the mobile communication device. The logic may be responsive to a transmit command and may be configured to retrieve the unique identifier from memory and generate a transmit message using a predefined communication protocol being implemented by the wireless communication network. The transmit message generated by the logic may comprise the unique identifier and may be configured such that the transmit message may be received by the site controller via the wireless communication network and such that the site controller may identify the mobile identification device and notify the host computer of the transmit message. The wireless transmitter may be configured for communication over the wireless communication network and configured to provide the transmit signal to the wireless communication network.
The present invention may also be viewed as providing a method for enabling a mobile user to notify an automated monitoring system of an emergency situation. Briefly described, one such method involves the steps of: receiving notification that the mobile user desires to initiate transmission of an emergency message to the site controller; determining the identity of the mobile user; and providing an emergency message over the wireless communication network for delivery to the site controller, the emergency message indicating the identity of the mobile user.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a block diagram illustrating one of a number of a number of possible embodiments of an automated monitoring system according to the present invention;
FIG. 2 is a block diagram illustrating one of a number of possible embodiment of the transceiver in FIG. 1 in communication with the sensor of FIG. 1 ;
FIG. 3 is a high level diagram of one embodiment of a personnel communication device according to the present invention that may be used to communicate with the site controller of FIG. 1 ;
FIG. 4 is a block diagram of the architecture of the personnel communications device of FIG. 3 ;
FIG. 5 is a block diagram illustrating one of a number of possible embodiments of the site controller of FIG. 1 ;
FIG. 6 is a table illustrating the message structure of a communication protocol that may be implemented by the automated monitoring system of FIG. 1 ;
FIG. 7 is a table illustrating several exemplary values for the “to” address in the message structure of FIG. 6 ;
FIG. 8 illustrates three sample messages using the message protocol of the present invention; and
FIG. 9 illustrates another embodiment of the automated monitoring system according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Having summarized the invention above, reference is now made in detail to the description of the invention as illustrated in he drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed therein. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
Reference is now made to FIG. 1 , which is a schematic diagram illustrating an automated monitoring system 100 according to the present invention. The automated monitoring system 100 may comprise one or more applications servers 110 (one being shown for simplicity of illustration), one or more database servers 115 , a WAN 120 , one or more repeaters 125 , one or more sensor/actuators 130 , one or more transceivers 135 , one or more sensors 140 , one or more transmitters 145 , and at least one site controller 150 . As further illustrated in FIG. 1 , each of the sensor/actuators 130 and the sensors 140 may be integrated with a suitably configured RF transceiver/repeater 125 , an RF transceiver 135 , or an RF transmitter 145 . Hereinafter, the group including an RF transceiver/repeater 125 , an RF transceiver 135 , and an RF transmitter 145 will be referred to as RF communication devices.
The RF communication devices are preferably small in size and may be configured to transmit a relatively low-power RF signal. As a result, in some applications, the transmission range of a given RF communication device may be relatively limited. Of course, the transmitter power and range may be appropriately designed for the target operating environment. As will be appreciated from the description that follows, this relatively limited transmission range of the RF communications devices is advantageous and a desirable characteristic of the automated monitoring system 100 . Although the RF communication devices are depicted without a user interface such as a keypad, etc., in certain embodiments the RF communication devices may be configured with user selectable pushbuttons, switches, or an alphanumeric keypad suitably configured with software and or firmware to accept operator input. The RF communication device may be electrically interfaced with a sensor 140 or with a sensor/actuator 130 , such as, for example, a smoke detector, a thermostat, a security system, etc., where user selectable inputs may not be needed. It should be noted that the automated monitoring system 100 is being shown in FIG. 1 with a wide variety of components. One of ordinary skill in the art will appreciate that automated monitoring system 100 may include fewer or more components depending on design needs and the particular environment in which automated monitoring system is implemented.
As illustrated in FIG. 1 , one or more sensors 140 may communicate with at least one site controller 150 via an RF transmitter 145 , an RF transceiver 135 , or an RF transceiver/repeater 125 . Furthermore, one or more sensors/actuators 130 may be communicatively coupled to at least one site controller 150 via an RF transceiver 135 or an RF transceiver/repeater 125 . In order to send a command from the applications server 111 to a sensor/actuator 130 , the RF communication device in communication with the sensors/actuators 130 should be a two-way communication device (i.e., a transceiver). One of ordinary skill in the art will appreciate that that one or more sensors/actuators 130 may be in direct communication with one or more site controllers 150 . It will be further appreciated that the communication medium between the one or more sensor/actuators 130 and sensors 140 and the one or more site controllers 150 may be wireless or, for relatively closely located configurations, a wired communication medium may be used.
Alternatively, the RF transceiver 135 may be replaced by an RF transmitter 145 . This simplifies the device structure, but also eliminates the possibility of the site controller 150 communicating with remote devices via the transmitter 145 .
Automated monitoring system 100 may further comprise a plurality of standalone RF transceivers 125 acting as repeaters. Each repeater 125 , as well as each RF transceiver 135 , may be configured to receive one or more incoming RF transmissions (transmitted by a remote transmitter 145 or transceiver 135 ) and to transmit an outgoing signal. This outgoing signal may be another low-power RF transmission signal, a higher-power RF transmission signal, or alternatively may be transmitted over a conductive wire, fiber optic cable, or other transmission media. One of ordinary skill in the art will appreciate that, if an integrated RF communication device (e.g., a RF transmitter 145 , a RF transceiver 135 , or a RF transceiver/repeater 125 ) is located sufficiently close to site controller 150 such that the RF signals may be received by the site controller 150 , the data transmission signal need not be processed and repeated through either an RF transceiver/repeater 125 or an RF transceiver 135 .
As illustrated in FIG. 1 , one or more site controllers 150 may be configured and disposed to receive remote data transmissions from the various stand-alone RF transceiver/repeaters 125 , integrated RF transmitters 145 , and integrated RF transceivers 135 . Site controllers 150 may be configured to analyze the transmissions received, convert the transmissions into TCP/IP format and further communicate the remote data signal transmissions to one or more applications servers 110 or other computing devices connected to WAN 120 . The site controller B 150 may function as either a back-up site controller in the event of a site controller failure or may function as a primary site controller to expand the potential size of the automated monitoring system 100 . As a back-up site controller, the site controller B 150 may function when the applications server 110 detects a site controller failure. Alternatively, the site controller B 150 may function to expand the capacity of automated monitoring system 100 . A single site controller 150 may accommodate a predetermined number of remote devices. While the number of remote devices may vary based upon individual requirements, in one embodiment, the number may be equal to approximately 500 remote devices. As stated above, additional site controllers 150 may increase the capacity of automated monitoring system 100 . The number of RF communications devices that may be managed by a site controller 150 is limited only by technical constraints, such as memory, storage space, etc In addition, the site controller 150 may manage more addresses than devices because some RF communications devices may have multiple functions, such as sensing, repeating, etc. Since the site controller 150 is in communication with WAN 120 , applications server 110 may host application specific software. As described in more detail below, the site controller 150 may communicate information in the form of data and control signals to remote sensor/actuators 130 and remote sensors 140 , which are received from applications server 110 , laptop computer 155 , workstation 160 , etc. via WAN 120 . The applications server 110 may be networked with a database 115 to record client specific data or to assist the applications server 110 in deciphering a particular data transmission from a particular sensor 140 or actuator/sensor 130 .
One of ordinary skill in the art will appreciate that each RF communication device in automated monitoring system 100 has an associated antenna pattern (not shown). The RF communications devices are geographically disposed such that the antenna patterns overlap to create a coverage area 165 , which defines the effective area of automated monitoring system 100 .
As described in further detail below, automated monitoring system 100 may also include a mobile personal communication device (FOB) 170 , which may transmit an emergency message directly or indirectly to a site controller 150 . For example, in certain implementations of automated monitoring system 100 , such as where the remote devices are electric utility meters or personal security systems, it may be beneficial to enable FOB 170 to transmit an emergency message configured to notify the site controller 150 of the occurrence of an emergency situation. In this manner, automated monitoring system 100 may an FOB 170 configured to transmit an electromagnetic signal that may be encoded with an identifier that is unique to the FOB 170 .
Reference is now made to FIG. 2 , which is a block diagram illustrating one embodiment of the transceiver 135 and sensor 130 of FIG. 1 in communication with each other. Sensor 130 may be any type of device configured to sense one or more parameters. For example, sensor 130 may be a two-state device such as a smoke alarm. Alternatively, sensor 130 may output a continuous range of values, such as the current temperature, to transceiver 135 . If the signal output from the sensor 130 is an analog signal, data interface 205 may include an analog-to-digital converter (not shown) to convert signals provided to the transceiver 135 . Alternatively, where sensor 130 provides digital signals, a digital interface may be provided.
In FIG. 2 , the sensor 130 may be communicatively coupled with the RF transceiver 135 . The RF transceiver 135 may comprise a transceiver controller 210 , a data interface 205 , a data controller 215 , memory 220 , and an antenna 225 . As shown in FIG. 2 , a data signal provided by the sensor 130 may be received at the data interface 205 . In situations where the data interface 205 has received an analog data signal, the data interface 205 may be configured to convert the analog signal into a digital signal before forwarding a digital representation of the data signal to the data controller 215 .
The RF transceiver 135 has a memory 220 that may contain a unique transceiver identifier that uniquely identifies the RF transceiver 135 . The transceiver identifier may be programmable and implemented in the form of, for example, an EPROM. Alternatively, the transceiver identifier may be set/configured through a series of dual inline package (DIP) switches. One of ordinary skill in the art will appreciate that the transceiver identifier and memory 220 may be implemented in a variety of additional ways.
While the unique transceiver address may be varied in accordance with the present invention, it preferably may be a six-byte address. The length of the address may be varied as necessary given design needs. Using the unique transceiver address, the RF communication devices and the site controller 150 may determine, by analyzing the data packets, which devices generated and/or repeated the data packet.
Of course, additional and/or alternative configurations may also be provided by a similarly configured transceiver. For example, a similar configuration may be provided for a transceiver that is integrated into, for example, a carbon monoxide detector, a door position sensor, etc. Alternatively, system parameters that vary across a range of values may be transmitted by transceiver 135 as long as data interface 205 and data controller 215 are configured to apply a specific code that is consistent with the input from sensor 130 . As long as the code is understood by the applications server 110 ( FIG. 1 ) or workstation 160 ( FIG. 1 ), the target parameter may be monitored.
FIG. 3 shows a high level diagram of the interaction of the personnel communication device (FOB) 170 and the site controller 150 according to the present invention. The FOB 170 communicates directly or indirectly with the site controller 150 . While the FOB 170 will be described in more detail below, in general the FOB 170 transmits an electromagnetic signal to a site controller 150 and/or an RF communication device. The electromagnetic signal may be encoded with a unique transceiver identifier associated with the FOB 170 . An internal circuit (not shown) may be provided within the FOB 170 to act upon command to transmit the encoded electromagnetic signal 320 . A transmit button 325 may be provided for the user. In the embodiment illustrated in FIG. 3 , the FOB 170 is quite small and may be conveniently attached, for example, to a key ring 330 , clothing (not shown), etc. for ready and portable use. Furthermore, FOB 170 may be integrated with a mobile electronics device. For instance, FOB 170 may be integrated with a handheld computer, such as a personal digital assistant (PDA), a wireless telephone, or any other mobile electronics device.
Indeed, in another embodiment, the single FOB 170 may serve multiple functions. For example, an FOB 170 may be integrally designed with another device, such as an automotive remote, to provide the dual functionality of remotely controlling an automobile alarm along with the functionality of the FOB 170 . In accordance with such an embodiment, a second transmit button 335 may be provided. The first transmit button 325 may be operative to, for example, communicate with the site controller 150 , while the second transmit button 335 may be operative to remotely operate the automobile alarm. One of ordinary skill in the art will appreciate that FOB 170 may be integrated with any of a variety of alternative devices with one or more transmit buttons 335 . Furthermore, it will be appreciated that the frequency and/or format of the transmit signal 320 transmitted may be different for the different applications. For example, the FOB 170 may transmit a unique identifier to the site controller 150 ( FIG. 1 ), while only a unique activation sequence need be transmitted to actuate an automobile alarm or other device.
In use, a user may simply depress transmit button 325 , which would result in the FOB 170 transmitting an electromagnetic signal 320 to the site controller 150 . Preferably, the FOB 170 is low power transmitter so that a user may only need to be in close proximity (e.g., several feet) to site controller 150 or one of the RF communication devices of the automated monitoring system 100 ( FIG. 1 ). The FOB 170 may communicate either directly with the site controller 150 , if in close proximity, or indirectly via the transceivers and/or repeaters of the automated monitoring system 100 . Low-power operation may help to prevent interception of the electromagnetic signals. In alternative embodiments, FOB 170 may be configured such that the transmitted signal may be encrypted for further protect against interception.
The site controller 150 receives and decodes the signal 320 via RF transceiver 340 . The site controller 150 then evaluates the received, decoded signal to ensure that the signal identifies a legitimate user. If so, the site controller 150 sends an emergency message to the applications server 110 ( FIG. 1 ).
Having now presented an overview of the basic operation of FOB 170 , reference is made to FIG. 4 which shows a more detailed block diagram of the components contained within an embodiment of FOB 170 . As previously mentioned, the FOB 170 includes a transmit button 325 , which initiates the data transmission. FOB 170 may include a memory 405 , a data formatter 410 , a controller 415 , and an RF transmitter 420 . Depending upon the desired complexity of the automated monitoring system 100 and FOB 170 , the RF transmitter 420 may be replaced by an RF transceiver.
Controller 415 controls the overall functionality of FOB 170 . The controller 415 is responsive to the depression or actuation of transmit button 325 to begin the data transaction and signal transfer. When a user depresses the transmit button 325 , the controller 415 initiates the data transmission sequence by accessing the memory 405 , which, among other things, stores the transceiver unique identifier. This information is then passed to the data formatter 410 , which places the data in an appropriate and predefined format for transmission to the site controller 150 . One of ordinary skill in the art will appreciate that the data may be retrieved from memory 405 and translated into the predefined format as electronic data or in a variety of other ways. When electronic data is used, the data is sent from data formatter 410 to RF transmitter 420 for conversion from electronic to electromagnetic form. As well known by those skilled in the art, a variety of transducers may perform this functionality. One of ordinary skill in the art will appreciate that FOB 170 may implement any of a variety of communication protocols and data formats for communication with automated monitoring system 100 . In one embodiment, FOB 170 may implement the communication protocol used by automated monitoring system 100 , which is described in more detail below with respect to FIGS. 6-8 .
It will be appreciated by persons skilled in the art that the various RF communication devices may be configured with a number of optional power supply configurations. For example, the FOB 170 ( FIG. 4 ) may be powered by a replaceable battery. Those skilled in the art will appreciate how to meet the power requirements of the various devices. As a result, it is not necessary to further describe a power supply suitable for each device and each application in order to appreciate the concepts and teachings of the present invention.
Having illustrated and described the operation of the various combinations of RF communication devices with the various sensors 140 , reference is now made to FIG. 5 , which is a block diagram further illustrating one embodiment of a site controller 150 . According to the present invention, a site controller 150 may comprise an antenna 510 , a transceiver controller 515 , a central processing unit (CPU) 520 , memory 525 , a network card 530 , a digital subscriber line (DSL) modem 535 , an integrated services digital network (ISDN) interface card 540 , as well as other components not illustrated in FIG. 5 , capable of enabling a transfer control protocol/Internet protocol (TCP/IP) connection to WAN 120 .
The transceiver controller 515 may be configured to receive incoming RF signal transmissions via the antenna 510 . Each of the incoming RF signal transmissions are consistently formatted as described below. Site controller 150 may be configured such that the memory 525 includes a look-up table 545 configured for identifying the various wireless communication devices (including intermediate wireless communication devices) used in generating and transmitting the received data transmission. As illustrated in FIG. 5 , site controller 150 may include an “Identify Remote Transceiver” memory sector 550 and an “Identify Intermediate Transceiver” memory sector 555 . Programmed or recognized codes within the memory 525 may also be provided and configured for controlling the operation of a CPU 520 to carry out the various functions that are orchestrated and/or controlled by the site controller 150 . For example, the memory 525 may include program code for controlling the operation of the CPU 520 to evaluate an incoming data packet to determine what action needs to be taken. In this regard, one or more look-up tables 545 may also be stored within the memory 525 to assist in this process. Furthermore, the memory 525 may be configured with program code configured to identify a remote RF transceiver 550 or identify an intermediate RF transceiver 555 . Function codes, RF transmitter, and/or RF transceiver identification numbers may all be stored with associated information within the look-up tables 545 .
Thus, one look-up table 545 may be provided to associate transceiver identificatiers with a particular user. Another look-up table 545 may be used to associate function codes with the interpretation thereof For example, a first data packet segment 550 may be provided to access a first lookup table to determine the identity of the RF transceiver (not shown) that transmitted the received message. A second code segment may be provided to access a second lookup table to determine the proximate location of the RF transceiver that generated the message by identifying the RF transceiver that relayed the message. A third code segment may be provided to identify the content of the message transmitted. Namely, is it a fire alarm, a security alarm, an emergency request by a person, a temperature control setting, etc. In accordance with the present invention, additional, fewer, or different code segments may be provided to carry out different functional operations and data signal transfers of the present invention.
The site controllers 150 may also include one or more network interface devices configured for communication with WAN 120 . For example, the site controller 150 may include a network card 530 , which may allow the site controller 150 to communicate across a local area network to a network server, which in turn may contain a backup site controller (not shown) to the WAN 120 . Alternatively, the site controller 150 may contain a DSL modem 535 , which may be configured to provide a link to a remote computing system via the public switched telephone network (PSTN). The site controller 150 may also include an ISDN card 540 configured to communicate via an ISDN connection with a remote system. Other communication interfaces may be provided to serve as primary and/or backup links to the WAN 120 or to local area networks that might serve to permit local monitoring of the operability of site controller 150 and to permit data packet control.
Automated monitoring system 100 may implement any of a variety of types of message protocols to facilitate communication between the remote devices, the RF transceivers, and the site controller 150 . FIG. 6 sets forth a message structure for implementing a data packet protocol according to the present invention. All messages transmitted within the automated monitoring system 100 may consist of a “to” address 600 , a “from” address 610 , a packet number 620 , a number of packets in a transmission 630 , a packet length 640 , a message number 650 , a command number 660 , any data 670 , and a check sum error detector (CKH 680 and CKL 690 ).
The “to” address 600 indicates the intended recipient of the packet. This address can be scalable from one to six bytes based upon the size and complexity of automated monitoring system 100 . By way of example, the “to” address 600 may indicate a general message to all transceivers, to only the stand-alone transceivers, or to an individual integrated transceiver. In a six byte “to” address, the first byte may indicate the transceiver type—to all transceivers, to some transceivers, or a specific transceiver. The second byte may be the identification base, and bytes three through six may be used for the unique transceiver address (either stand-alone or integrated). The “to” address 600 may be scalable from one byte to six bytes or larger depending upon the intended recipient(s).
The “from” address 610 may be a six-byte unique transceiver address of the transceiver originating the transmission. The “from” address 610 may be the address of the site controller 150 when the controller requests data, or this can be the address of the integrated transceiver when the integrated transceiver sends a response to a request for information to the site controller 150 .
The packet number 620 , the packet maximum 630 , and the packet length 640 may be used to concatenate messages that are greater than 128 bytes. The packet maximum 630 may indicate the number of packets in the message. The packet number 620 may be used to indicate a packet sequence number for multiple-packet messages.
The message number 650 may be assigned by the site controller 150 . Messages originating from the site controller 150 may be assigned an even number. Responses to the site controller 150 may have a message number 650 equal to the original message number 650 plus one, thereby rendering the responding message number odd. The site controller 150 then increments the message number 650 by two for each new originating message. This enables the site controller 150 to coordinate the incoming responses to the appropriate command message.
The next section is the command byte 660 that may be used to request data from the receiving device as necessary. One of ordinary skill in the art will appreciate that, depending on the specific implementation of automated monitoring system 100 , the types of commands may differ. In one embodiment, there may be two types of commands: device specific and not device specific. Device specific commands control a specific device such as a data request or a change in current actuator settings. Commands that are not device specific may include, but are not limited to, a ping, an acknowledge, a non-acknowledgement, downstream repeat, upstream repeat, read status, emergency message, and a request for general data among others. General data may include a software version number, the number of power failures, the number of resets, etc.
The data section 670 may contain data as requested by a specific command. The requested data may be any value. By way of example, test data may be encoded in ASCII (American Standard Code for Information Interchange) or other known encoding systems as known in the art. The data section 670 of a single packet may be scalable, for example, up to 109 bytes. In such instances, when the requested data exceeds 109 bytes, the integrated transceiver may divide the data into an appropriate number of sections and concatenate the series of packets for one message using the packet identifiers as discussed above.
Checksum sections 680 and 690 may used to detect errors in the transmissions of the packets. In one embodiment, errors may be detected using cyclic redundancy check sum methodology. This methodology divides the message as a large binary number by the generating polynomial (in this case, CRC-16). The remainder of this division is then sent with the message as the checksum. The receiver then calculates a checksum using the same methodology and compares the two checksums. If the checksums do not match, the packet or message will be ignored. While this error detection methodology is preferred, one of ordinary skill in the art will appreciate that other error detection systems may be employed.
One of ordinary skill in the art will appreciate that automated monitoring system 100 may employ wireless and/or wired communication technologies for communication between site controller 150 and the RF transceivers. In one embodiment, communication between site controller 150 and the RF transceivers may be implemented via an RF link at a basic rate of 4,800 bits per second (bps) and a data rate of 2400 bps. All the data may be encoded in Manchester format such that a high to low transition at the bit center point represents a logic zero and a low to high transition represents a logic one. One of ordinary skill in the art will appreciate that other RF formats may be used depending upon design needs. By way of example, a quadature phase shift encoding method may also be used, thereby enabling automated monitoring system 100 to communicate via hexadecimal instead of binary.
Messages may further include a preface and a postscript (not shown). The preface and postscripts are not part of the message body but rather serve to synchronize automated monitoring system 100 and to frame each packet of the message. The packet may begin with the preface and end with a postscript. The preface may be a series of twenty-four logic ones followed by two bit times of high voltage with no transition. The first byte of the packet may then follow immediately. The postscript may be a transition of the transmit data line from a high voltage to a low voltage. It may be less desirable to not leave the transmit data line high after the message is sent. Furthermore, one of ordinary skill in the art will appreciate that the preface and the postscript may be modified as necessary for design needs.
FIG. 7 sets forth one embodiment of the “to” address byte assignment. The “to” address may take many forms depending on the specific requirements of automated monitoring system 100 . In one embodiment, the “to” address may consist of six bytes. The first byte (Byte 1 ) may indicate the device type. The second byte (Byte 2 ) may indicate the manufacturer or the owner. The third byte (Byte 3 ) may be a further indication of the manufacturer or owner. The fourth byte (Byte 4 ) may indicate that the message is for all devices or that the message is for a particular device. If the message is for all devices, the fourth byte may be a particular code. If the message is for a particular device, the fourth, fifth, and sixth bytes (Byte 5 and Byte 6 ) may include the unique identifier for that particular device.
Having described the general message structure of the present invention, reference is directed to FIG. 8 . FIG. 8 illustrates the general message structure for an emergency message. The message illustrates the broadcast of an emergency message “FF” from a central server with an address “0012345678” to a integrated transceiver with an address of “FF.”
Returning to FIG. 1 , the site controller 150 functions as the local communications master in automated monitoring system 100 . With the exception of emergency messages, the site controller 150 may initiate communication with any RF communication device. The RF communication device then responds based upon the command received in the message. In general, the site controller 150 may expect a response to all messages sent to any of the RF communication devices. By maintaining the site controller 150 as the communications master and storing the collected data at the site controller 150 , overall system installation, upkeep costs, and expansion costs may be minimized. By simplifying the RF communication devices, the initial cost and maintenance of the RF communication devices may be minimized. Further information regarding the normal mode of communications can be found in U.S. patent application Ser. No. 09/812,044, entitled “System and Method for Monitoring and Controlling Remote Devices,” and filed Mar. 19, 2001, which is hereby incorporated in its entirety by reference.
As stated above, automated monitoring system 100 may be configured such that other devices, such as FOB 170 and certain RF transceivers, may initiate emergency messages. To accommodate receiving emergency messages, the site controller 150 may dedicate a predetermined time period, for example one-half of every ten-second period, to receive emergency messages. During these time periods, the site controller 150 may not transmit messages other than acknowledgements to any emergency messages. The integrated transceiver 135 may detect the period of silence, and in response, may then transmit the emergency message.
There are typically two forms of emergency messages: from the FOB 170 and from permanently installed safety/security transceiver(s). In the first case of the FOB 170 , the emergency message may comprise a predetermined “to” address and a random odd number. In response to this emergency message, the site controller 150 may acknowledge during a silent period. The FOB 170 then repeats the same emergency message. The site controller 150 may forward the emergency message to the WAN 120 in the normal manner.
Upon receipt of the site controller 150 acknowledgement, the FOB 170 may reset itself If no acknowledgement is received within a predetermined time period, the FOB 170 may continue to re-transmit the original emergency message until acknowledged by the site controller 150 for a predetermined number of re-transmissions.
One of ordinary skill in the art will appreciate that the RF transceivers of the present invention may be further integrated with a voice-band transceiver. As a result, when a person presses, for example, the emergency button on his/her FOB 170 , medical personnel, staff members, or others may respond by communicating via two-way radio with the party in distress. In this regard, each transceiver may be equipped with a microphone and a speaker that would allow a person to communication information such as their present emergency situation, their specific location, etc.
FIG. 9 sets forth another embodiment of automated monitoring system 100 according to the present invention. FIG. 9 illustrates the automated monitoring system 100 of FIG. 1 with an additional sensor 180 and transceiver 185 . The additional sensor 180 and transceiver 185 may communicate with, but outside of, the coverage area 165 of the automated monitoring system 100 . In this example, the additional sensor/transceiver may be placed outside of the original coverage area 165 . In order to communicate, the coverage area of transceiver 185 need only overlap the coverage area 165 . By way of example only, the original installation may be a system that monitors electricity via the utility meters in an apartment complex. Later a neighbor in a single family residence nearby the apartment complex may remotely monitor and control their thermostat by installing a sensor/actuator transceiver according to the present invention. The transceiver 185 then communicates with the site controller 150 of the apartment complex. If necessary, repeaters (not shown) may also be installed to communicate between the neighboring transceiver 185 and the apartment complex site controller 150 . Without having the cost of the site controller, the neighbor may enjoy the benefits of automated monitoring control system 100 .
The foregoing description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the inventions to the precise embodiments disclosed. Obvious modifications or variations are possible in light of the above teachings. When the transceiver is permanently integrated into an alarm sensor or other stationary device within a system, then the application server 110 and/or the site controller 150 may be configured to identify the transceiver location by the transceiver identification number alone. It will be appreciated that, in embodiments that do not utilize stand-alone transceivers, the transceivers may be configured to transmit at a higher RF power level in order to effectively communicate with the control system site controllers.
It will be appreciated by those skilled in the art that the information transmitted and received by the wireless transceivers of the present invention may be further integrated with other data transmission protocols for transmission across telecommunications and computer networks. In addition, it should be further appreciated that telecommunications and computer networks may function as the transmission path between the networked wireless transceivers, the site controllers 150 , and the applications servers 110 . | Systems and methods for enabling a mobile user to notify an automated monitoring system of an emergency situation are provided. The automated monitoring system may be configured for monitoring and controlling a plurality of remote devices and may comprise a site controller in communication with the plurality of remote devices via a plurality of transceivers defining a wireless communication network and in communication with a host computer via a wide area network. Briefly described, one such method comprises the steps of: receiving notification that the mobile user desires to initiate transmission of an emergency message to the site controller; determining the identity of the mobile user; and providing an emergency message over the wireless communication network for delivery to the site controller, the emergency message indicating the identity of the mobile user. |
BACKGROUND
1. Field of the Invention
This invention relates generally to light emitting devices, and more particularly, to producing a self-aligned, self-exposed photoresist pattern on a light emitting diode (LED).
2. Description of Related Art
Semiconductor light-emitting devices such as light emitting diodes are among the most efficient light sources currently available. Materials systems currently of interest in the manufacture of high-brightness LEDs capable of operation across the visible spectrum include Group III-V semiconductors, including binary, ternary, and quaternary alloys of gallium, aluminum, indium, and nitrogen, also referred to as III-nitride materials. Light emitting devices based on the III-nitride materials system provide for high brightness, solid-state light sources in the UV-to-yellow spectral regions. Typically, III-nitride devices are epitaxially grown on sapphire, silicon carbide, or III-nitride substrates by metal-organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial techniques. Some of these substrates are insulating or poorly conducting. Devices fabricated from semiconductor crystals grown on such substrates must have both the positive and the negative polarity electrical contacts to the epitaxially-grown semiconductor on the same side of the device. In contrast, semiconductor devices grown on conducting substrates can be fabricated such that one electrical contact is formed on the epitaxially grown material and the other electrical contact is formed on the substrate. However, devices fabricated on conducting substrates may also be designed to have both contacts on the same side of the device on which the epitaxial material is grown in a flip-chip geometry so as to improve light extraction from LED chip, to improve the current-carrying capacity of the chip, or to improve the heat-sinking of the LED die. Two types of light emitting devices have the contacts formed on the same side of the device. In the first, called a flip chip, light is extracted through the substrate. In the second, light is extracted through transparent or semi-transparent contacts formed on the epitaxial layers.
Fabrication of an LED requires the growth of an n-type layer or layers overlying a substrate, the growth of an active region overlying the n-type layers, and the growth of a p-type layer or layers overlying the active region. Light is generated by the recombination of electrons and holes within the active region. After fabrication, the LED is typically mounted on a submount. In order to create an LED-based light source that emits white light or some color other than the color of light produced in the active region of the LED, a phosphor is disposed in the path of all or a portion of the light generated in the active region. As used herein, “phosphor” refers to any luminescent material which absorbs light of one wavelength and emits light of a different wavelength. For example, in order to produce white light, a blue LED may be coated with a phosphor that produces yellow light. Blue light from the LED mixes with yellow light from the phosphor to produce white light.
One way to produce a phosphor-converted LED is to apply a conformal coating of phosphor over the LED after mounting on the submount. A conformally-coated phosphor-converted LED is described in more detail in application Ser. No. 09/879,547, titled “Phosphor-Converted Light Emitting Device,” and incorporated herein by reference. If the conformal coating of phosphor is not uniform, undesirable inconsistencies in the light generated by the phosphor-converted LED can result. Conventionally, an LED was conformally coated by using photo-masking techniques developed for planar semiconductors, where masks are used to define the size and shape of patterns to be printed in photoresist deposited on the LED and submount. The printed photoresist layer defines which areas are covered with phosphor.
The application of conventional masking techniques to three-dimensional structures such as an LED mounted on a submount is fraught with problems including stray reflected light and depth of field artifacts in the resulting image; and imperfect alignment, both of which can result in nonuniform coating of the LED. For example, light reflected from the surfaces of the three dimensional LED structure, including the surface of the photoresist layer used for masking, may introduce exposure artifacts. Also, depth-of-field problems may lead to distortions and loss of dimensional accuracy in the image produced by the mask. Additionally, not all LEDs will have a perfect shape or be perfectly aligned with other LEDs in an array of LEDs. Shape and alignment imperfections can result in nonuniform coating. Masks cannot fully compensate for the process and object variations normally seen in a manufacturing environment, leading to imperfections and yield losses.
SUMMARY
In accordance with an embodiment of the invention, a method of forming a photoresist mask on a light emitting device is disclosed. A portion of the light emitting device is coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed, removing either the exposed photoresist or the unexposed photoresist. In one embodiment, the photoresist mask may be used to form a phosphor coating on the light emitting device. The light emitting device is attached to a submount, and the light emitting device and submount are coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed to remove the exposed photoresist. A phosphor layer is deposited overlying the light emitting device, then the unexposed portion of photoresist is stripped. In some embodiments, the light exposing the photoresist is produced by electrically biasing the light emitting device, by shining light into the light emitting device through an aperture, or by shining light into the light emitting device by a steered, focussed laser.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1F illustrate an LED connected to a submount at various stages during phosphor coating.
FIG. 2 illustrates an embodiment of self-exposing photoresist.
FIG. 3 illustrates an alternative embodiment of self-exposing photoresist.
FIGS. 4A-4C illustrate an alternative embodiment of phosphor coating an LED.
DETAILED DESCRIPTION
In accordance with embodiments of the invention, light from an LED is used to expose photoresist, resulting in a photoresist pattern that is self-aligned with the LED. The process may eliminate depth-of-field, scattering, and mask alignment problems associated with the use of conventional masks, as well as problems resulting from non-uniformly sized LEDs.
FIGS. 1A-1F illustrate an embodiment of conformally coating an LED with phosphor using a self-aligned photoresist mask. FIG. 1A illustrates an LED 18 mounted on submount 10 . LED 18 includes a substrate 16 , an n-type region 15 , an active region 14 , and a p-type region 13 . A p-contact 12 is attached to p-type region 13 . An n-contact 11 is attached to n-type region 15 . LED 18 may be attached to submount 10 by, for example, solder (not shown) between contacts 11 and 12 and submount 10 . Other methods of attaching LED 18 to submount 10 are described in more detail in application Ser. No. 09/469,657, titled “III-Nitride Light-Emitting Device With Increased Light Generating Capability,” and incorporated herein by reference. Usually, substrate 16 is transparent, and submount 10 is opaque.
In FIG. 1B, LED 18 and submount 10 are coated with a layer of photoresist 20 . Photoresist layer 20 may be, for example, a positive photoresist, meaning that when photoresist 20 is exposed to electromagnetic radiation, the radiation breaks the chemical bonds in photoresist layer 20 , making it soluble in a developer solution. The portions of photoresist 20 that are not irradiated are not soluble in a developer solution, and are therefore left behind when photoresist layer 20 is developed. Photoresist 20 may be, for example, a dry film photoresist applied by a heated vacuum coater, a liquid film photoresist, an electrophoretically deposited photoresist, a screen printed photoresist, or any other suitable photoresist. Generally, photoresist 20 is a positive acting photoresist.
In FIG. 1C, photoresist layer 20 a is exposed to light from LED 18 . Photoresist layer 20 b is not exposed to light from LED 18 . FIGS. 2 and 3 illustrate two embodiments of exposing photoresist layer 20 a . In an embodiment illustrated in FIG. 2, LED 18 is electrically biased in order to generate light 24 . Light 24 may be internally reflected off the photoresist covered surfaces of LED 18 , exposing the photoresist covering those surfaces. Usually, contacts 11 and 12 (shown in FIG. 1A) are highly reflective, which aids the scattering of light 24 within LED 18 . The internally reflected light 24 produces a self-aligned exposed layer of photoresist, including an annulus of controlled thickness 20 c surrounding LED 18 .
LED 18 of FIG. 2 may be electrically biased in two ways. First, a voltage may be applied to contacts (not shown) on the underside 26 of submount 10 . The contacts on underside 26 of submount 10 are electrically connected to solder bumps 28 , which are connected to contacts 11 and 12 (shown in FIG. 1A) of LED 18 . The voltage causes LED 18 to emit light 24 from the active region of LED 18 . In one embodiment, submount 10 is part of an undiced wafer of submounts with an LED attached to each submount on the wafer. A series of probes are connected to each row of submounts on the wafer. Each probe then provides a series of short voltage bias pulses, until a minimum required level of light exposure flux necessary to expose photoresist 20 has been produced in LED 18 . Second, LED 18 may be electrically biased by RF excitation. LED 18 may produce light by rectified coupling to RF fields, when submount 10 and LED 18 are placed in proximity to an RF radiator or antenna.
In an embodiment illustrated in FIG. 3, LED 18 is optically pumped in order to generate light 24 . As shown in FIG. 3, a mask 30 , such as, for example, a dark field dot mask, is aligned over LED 18 . Mask 30 includes an aperture 35 . Aperture 35 is much smaller than LED 18 , in order to simplify alignment of aperture 35 over LED 18 . Aperture 35 need not be located in the center of LED 18 . Aperture 35 may be of any shape. A collimated beam of light 24 is applied to mask 30 . The light source used may be, for example, a flood light producing collimated light with a divergence less than 30°, a fiber optic cable connected to a remote light source, or a laser light source. A focussed laser light source may be used, and the laser may be steered to expose the photoresist coating multiple LEDs mounted on an undiced wafer of submounts. The light source first exposes the portion of photoresist under aperture 35 . Light 24 transmitted through aperture 35 and the photoresist layer enters LED 18 , where light 24 is reflected off the photoresist covered surfaces of LED 18 , exposing the photoresist covering those surfaces. In one embodiment, the photoresist is developed to remove the photoresist layer exposed by aperture 35 . Light is then shown through aperture 35 and the gap in the photoresist layer, and reflected off the walls of LED 18 to expose the remaining photoresist coating LED 18 . Thus, if LED is optically pumped, two cycles of photoresist exposure and developing may be required. Alternatively, LED may be a III-nitride device with an InGaN active region, and the collimated light beam may be UV light, which excites shallow UV emissions from the active region or any other layer of LED 18 . In one embodiment, the diameter of aperture 35 may be about 100 μm. LED 18 may have a top area of (1000 μm) 2 . Photoresist 20 (FIG. 1B) may have a high absorption to prevent light 24 from being transmitted through photoresist 20 a and 20 b.
In the embodiments illustrated in both FIGS. 2 and 3, the amount of light exposure (i.e. the exposure time and exposure intensity) necessary to develop photoresist 20 depends on the photoresist used. If a highly absorbing photoresist is used, the exposure time may be increased. The wavelength of light required to expose the photoresist also depends on the photoresist used.
After exposure to light from LED 18 , exposed photoresist 20 a is removed by application of a photoresist developer solution, such as a standard liquid developer. Exposed photoresist 20 a is soluble in the developer solution, while unexposed photoresist 20 b is not soluble in the developer solution. The developer used depends on the composition of photoresist 20 . After developing, the structure shown in FIG. 1D remains.
A layer of phosphor 22 is then deposited over portions of the structure shown in FIG. 1D, as shown in FIG. 1 E. Phosphor 22 may be selectively deposited by, for example, screen printing or electrophoretic deposition, both of which are described in more detail in “Phosphor-Converted Light Emitting Device,” previously incorporated by reference. After phosphor deposition and fixation, unexposed photoresist 20 b is stripped away. The structure shown in FIG. 1F results. In one embodiment, photoresist 20 is selected such that unexposed photoresist 20 b has a conductivity that is low enough to be an effective mask for electrophoretic deposition without a “hard-bake” which would further fix photoresist 20 b , making photoresist 20 b difficult to strip once phosphor 22 is deposited. In one embodiment, photoresist 20 is selected such that the hard-bake temperature is less than the maximum temperature allowed by LED 18 and submount 10 during phosphor coating and any curing steps required to set the phosphor coating.
Once each LED 18 on the wafer of submounts is coated with phosphor, the submounts may be tested by probing. The wafer is then diced into individual submounts, each attached to an LED. The submounts are sorted, die-attached to a package, and encapsulated with an encapsulant. Probing, dicing, sorting, die attaching, and encapsulating steps are well known in the art of packaging light emitting diodes.
In accordance with embodiments of the invention, the use of a self-exposed and self-aligned method of exposing photoresist may offer several advantages. First, since the photoresist is self-exposed by light from within LED 18 , no mask, other than possibly dot mask 30 shown in FIG. 3, is required. Dot mask 30 may be a simple inexpensive alignment jig, which will work for any size or shape of LED mounted on the submount centers of the submount wafer. Thus, costly high precision alignment of a mask with the submount wafer is avoided. The elimination of patterning by a precision mask reduces variation in the phosphor thickness caused by variations in the size, shape, placement, and mounting height of LEDs 18 relative to the mask pattern. Second, depth of field and light scattering errors in the photoresist pattern are eliminated. Third, the width of annulus 20 c can be controlled by light exposure, reducing variations in the light output of the final packaged conformally coated LED caused by variations in the annular thickness. In one embodiment, annulus 20 c has a width that is no greater than the thickness of the photoresist coating 20 . In one embodiment, the width of annulus 20 c is less than 100 microns wide.
FIGS. 4A-4C illustrate an alternative method for creating a self aligned photoresist layer on an LED. In FIG. 4A, LED 18 is mounted on submount 10 , resulting in the same structure as shown in FIG. 1 A. The structure is then coated with a layer of photoresist 40 , as shown in FIG. 4 B. Photoresist 40 may be a negative photoresist filled with phosphor, fluorescent dyes, or other photoluminescent materials. In FIG. 4C, light is introduced into LED 18 by one of the method described in the text accompanying FIGS. 2 and 3. The light exposes portion 40 a of photoresist layer 40 . Portions 40 b are unexposed. Since photoresist 40 is a negative photoresist, when photoresist 40 a and 40 b is developed, portions 40 b of the photoresist are removed, leaving portion 40 a . The structure shown in FIG. 1F results.
The above-described embodiments of the present invention are merely meant to be illustrative and not limiting. For example, the invention is not limited to III-nitride devices, and may be applied to devices made from III-phosphide or other materials systems. It will thus be obvious to those skilled in the art that various changes and modifications may be made without departing from this invention in its broader aspects. Therefore, the appended claims encompass all such changes and modifications as falling within the true spirit and scope of this invention. | A method of forming a photoresist mask on a light emitting device is disclosed. A portion of the light emitting device is coated with photoresist. A portion of the photoresist is exposed by light impinging on the interface of the light emitting device and the photoresist from inside the light emitting device. The photoresist is developed, removing either the exposed photoresist or the unexposed photoresist. In one embodiment, the photoresist mask may be used to form a phosphor coating. After the photoresist is developed to remove the exposed photoresist, a phosphor layer is deposited overlying the light emitting device. The unexposed portion of photoresist is stripped. In some embodiments, the light exposing the photoresist is produced by electrically biasing the light emitting device, or by shining light into the light emitting device through an aperture or by a focussed laser. |
This is a division of application Ser. No. 09/906,696, filed Jul. 18, 2001 now U.S. Pat. No. 6,727,099, which claims the benefit of priority under 35U.S.C. §119 of Korean Application No. 2001-25970, filed May, 12, 2001, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for monitoring the progress of membrane fouling that occurs on pores as well as on the surface of a membrane by means of variations of zeta potential (ζ) of a hollow-fiber membrane measured according to time passage of filtration of a suspension, wherein colloid particles, biopolymers and other inorganic particles are dispersed, and the method thereof. Moreover, the present invention also relates to a method to identify the effect of concentration polarization layer and cake layer which can vary according to the axial position of a hollow-fiber and the subsequent developing progress of a membrane fouling by measuring the position-dependent zeta potential of the hollow-fiber membrane.
2. Description of the Related Art
In conventional methods, measurements of streaming potential of a membrane have been implemented by employing either a flat-plate type or a tubular membrane and the related studies have been largely restricted to charged property of membrane surface or electrokinetic phenomena. Therefore, there is a need for the development of a technology that can interpret the fouling progress of a given membrane via changes in zeta potential according to time passage of filtration as well as measurement of streaming potential of a hollow-fiber membrane.
Zeta potential, being defined based on electrostatic and electrokinetic principles, is known to provide useful real-time information on the surface property and the interaction between membrane and particles in actual operational situations and physicochemical conditions without incurring structural change of membrane or disturbance of flow condition. That is, zeta potential can not only provide information on electrostatic field when the membrane surface is in contact with a flowing solution but can be also an important physical quantity related to a criterion of membrane fouling resulted from adsorption or deposition of particles thus determining the property and performance of a membrane.
In the present invention, electrodes were installed both inside and outside of an inlet and an outlet of a hollow-fiber membrane, respectively, to measure the streaming potential. The difference between streaming potentials perceived simultaneously at these electrodes were used to evaluate the value of zeta potential.
The conventional apparatus and methods related to the present invention are described hereunder.
Ricq et al. [ Journal of Membrane Science , 114(1996), 27-38]studied the properties of the initial virgin and the fouled membranes after filtration of a tubular inorganic membrane by measuring zeta potential and analyzing permeate flux. They installed platinum electrodes such that they penetrated the internal channel of a membrane and measured the streaming potential difference and permeate flux, however, the membrane used was not a hollow-fiber membrane but a tubular membrane and also the measurements were not made at various positions but at the inlet.
Japanese Pat. No. 62-47545 discloses a method to measure streaming potential as a way to identify the property of zeta potential inside of a hollow-shaped cylindrical tube. This method relates to the measurement of streaming potential of the internal wall of a cylindrical tube, a kind of a pipe, unlike the apparatus of the present invention which relates to a hollow-fiber having membrane pores. This method enables to measure the zeta potential of the internal wall since a given solution can flow through the cylindrical tube, however, it cannot measure the property of membrane pores located on the radial wall of a hollow-fiber as shown in the present invention.
Japanese Published Pat. Appln. No. 11-197472 discloses a method to analyze fouling in a given separation membrane as a way to identify the fouling of a reverse osmosis membrane. This method enables to identify the fouling of a flat-plate reverse osmosis membrane by comparing the zeta potentials on membrane surface before and after the fouling and also sets up the washing conditions of the membrane. However, this method is only related to the application of the result of zeta potential to the observation of membrane fouling and is not related to the method or the apparatus of measuring streaming potential. The example 2 of the present invention also shows that the zeta potential changes according to the membrane fouling.
Szymczyk et al. conducted a study on zeta potential according to the change in ionic concentration of electrolytes by installing an Ag/AgCl electrode at each given point on both an upper and a lower region of plane inorganic membrane [ Journal of Membrane Science , 134(1997), 59-66].
Japanese Published Pat. Appln. No. 8-101158 discloses a method to measure streaming potential of porous materials and Japanese Published Pat. Appln. No. 10-38836 discloses an apparatus to measure streaming potential.
These methods and apparatus, being designed for porous materials, cannot be applied to a hollow-fiber membrane and also cannot be used in measuring zeta potentials at local positions.
SUMMARY OF THE INVENTION
It is essential to provide fine installments of electrodes which carry out measurements of minute streaming potential difference in order to obtain the membrane zeta potential. A hollow-fiber membrane is not advantageous in that it has a very narrow internal diameter unlike a flat-plate or a tubular membrane, and this results in difficulty when installing internal electrodes and also becomes liable to damage the hollow-fiber or disturb the liquid flow. Moreover, the cross-flow filtration enables to generate a concentration polarization layer as the filtration is run along the axial direction and the continued permeation results in change in particle concentrations as well as the pressure drop, according to the axial position.
The present invention installed electrodes both inside and outside of an inlet and an outlet of a hollow-fiber membrane, respectively, and also provided a device to sense the minute change of streaming potential difference generated by the minute pressure difference across the membrane pores.
The present invention succeeded in monitoring the progress of membrane fouling over time by evaluating the zeta potential of a hollow-fiber membrane by continuously measuring the streaming potential in two given positions according to time passage of filtration of a given suspension.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram that shows a concentration polarization layer as well as a cake(or gel) layer generated inside a hollow-fiber membrane by cross-flow filtration and the resulting difference in local streaming potential.
FIG. 2 is a schematic diagram of the apparatus of the present invention that enables to measure the difference in local streaming potential of a hollow-fiber membrane by cross-flow filtration.
FIG. 3 shows an exploded view of a hollow-fiber membrane module used in the apparatus of the present invention measuring streaming potential difference.
FIG. 4 is a graph that shows zeta potential at an inlet and an outlet of a hollow-fiber membrane measured according to the change of pH under a constant ion concentration of a symmetric monovalent electrolyte.
FIG. 5 is a graph that shows the change in zeta potential at an inlet and an outlet of a hollow-fiber membrane measured according to the time passage under a constant pH as well as a constant ion concentration of a symmetric monovalent electrolyte while performing filtration of a biopolymer protein solution.
[Code Explanation]
1. thermostated feed tank 2. solvent delivery pump 3. conductance meter 4. pH meter 5. connecting part of membrane module 6. main body of membrane module 7. clamping part of membrane module 8. internal electrode of a hollow-fiber membrane 9. external electrode of a hollow-fiber membrane 10. hollow-fiber membrane 11. minute flow-control valve 12. multi-channel digital multi-meter 13. computer 14. pressure gauge 15. pressure gauge connecting aperture 16. sealing ring 17. epoxy resin potting
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to an apparatus and the method of measuring local streaming potential for monitoring the progress of membrane fouling over time in the course of filtration with hollow-fiber membrane.
To achieve the above-mentioned goal, the inventors of the present invention prepared an apparatus which comprises a feed tank to reserve feed solution in a state of colloidal suspension; a membrane module with several hollow-fibers as well as a connecting part and electrodes to measure streaming potential; a means to deliver feed solution from the feed tank to the inside of the hollow-fiber membranes; a means to measure physical properties of said feed solution; a means to measure the transmembrane pressure differences between the inside and the outside of a hollow-fiber at both an inlet and an outlet of a membrane module and a means to control the transmembrane pressure differences; a means to simultaneously measure and record the differences in local streaming potential being obtained from the above electrodes; and a means to obtain the value of zeta potential (ζ) of a hollow-fiber membrane by using the physical properties, transmembrane pressure difference and the difference in streaming potential.
This invention will be better understood with the following figures.
FIG. 1 shows a diagram that depicts a concentration polarization layer as well as a cake layer generated inside a hollow-fiber membrane due to cross-flow filtration and the resulting local streaming potential difference.
FIG. 2 is a schematic diagram of the apparatus of the present invention that can measure local streaming potential difference of a hollow-fiber membrane due to cross-flow filtration. As shown in FIG. 2 , the apparatus of measuring streaming potential according to the present invention comprises a thermostated feed tank 1 to reserve feed solution in a state of colloidal suspension; two means 3 and 4 to measure physical properties of said feed solution; the body of membrane module 6 equipped with electrodes 8 and 9 to measure streaming potential difference as well as a hollow-fiber membrane 10 ; a fine flow-control valve 11 to adjust transmembrane pressure difference present between the inside and outside of the hollow-fiber 10 ; a pressure gauge 14 that measures the transmembrane pressure difference both at an inlet and an outlet of a membrane module; connecting parts 5 and 7 which are parts of membrane module that link between membrane module and flow channel; two means 12 and 13 to display and record data being obtained from the above-mentioned measuring means; and a means to calculate the value of zeta potential (ζ) of the hollow-fiber membrane 10 .
FIG. 3 is an exploded view of the connecting part between membrane module and the flow channel, which shows a connecting part 15 , electrodes 8 and 9 to measure streaming potential difference, a clamping part 14 of membrane module, a sealing ring 16 to prevent fluid leakage at the connecting part, the hollow-fiber membrane 10 wherein the actual filtration takes place, a potting region 17 cured by epoxy resin to separate the permeate from the feed solution, and the body 6 of cylindrical membrane module containing the above-mentioned parts.
The relative cooperation of the respective parts of the membrane module is set forth hereunder.
An Ag/AgCl (or platinum) wire-type electrode 8 with 0.25 mm in diameter, which takes about 6% of the internal cross-sectional area of a hollow-fiber, is installed inside the hollow-fiber membrane 10 , where the actual filtration of feed solution takes place, to allow undisturbed liquid flow while a spiral electrode 9 made of the same material is installed on the corresponding external positions of the hollow-fiber so that it can sense the minute streaming potential difference according to the minute pressure difference.
The permeation of suspension due to pressure difference results in change in ionic fluid flow and charge distribution within a solution in the hollow-fiber membrane pores. Therefore, it generates a difference in streaming potential between the upper and the lower regions of membrane pores and the difference can be detected by a pair of electrodes consisting of an internal electrode 8 and the external electrode 9 . The internal electrode 8 is inserted into the inside of the hollow-fiber membrane mounted on the cylindrical membrane module by means of the clamping part 7 of the membrane module, and the varying values detected in each electrode are measured by using multi-channel digital multi-meter 12 .
The method of measuring streaming potential can be further delineated as follows. A given solution is supplied from the thermostated feed tank 1 of feed solution through the membrane module connecting part 5 to the hollow-fiber membrane 10 by means of a solvent delivery pump 2 , and subsequently the respective conductance and pH are measured by using a conductance meter 3 and a pH meter 4 .
The pressure is generally proportional to the flow rate, and thus the transmembrane pressure can be properly adjusted by using a minute flow-control valve 11 . The minute flow control valve 11 , installed at an outlet of a concentrate, may be able to precisely control the flow rate to the extent of 0.3% of the maximum flowrate.
The streaming potential (ΔV) generated between the upper and the lower regions of membrane pores at a given position of the hollow-fiber membrane is measured by using a multi-channel digital multi-meter 12 via Ag/AgCl electrodes 8 and 9 installed inside and outside of the given position, respectively, and recorded in a computer 13 .
The zeta potential can be obtained by plugging the values of streaming potential (ΔV), generated from a given pressure difference (ΔP), dielectric constant ∈, conductivity of a solution λ, and viscosity of a solution η into the following Helmholtz-Smoluchowski equation (1).
Δ V Δ P = ɛ ζ λ η ( 1 )
This invention is explained in more detail based on the following examples, however, they should not be construed as limiting the scope of this invention.
Example 1
A given solution can have various pH values in the course of filtration of the hollow-fiber membrane. In measuring zeta potential according to pH change, it is usually quite essential to measure an isoelectric point. After installing several hollow-fiber ultrafiltration membranes (Model PM100, Internal diameter; 1.0 mm, KOCH Membrane System Inc., MA, USA) made of polysulfonate having asymmetric membrane pores, pH was modified in the presence of 1.0 mM aqueous solution of potassium chloride, a symmetric monovalent electrolyte. Then, streaming potential was measured at two different positions, at an inlet and at an outlet of a hollow-fiber membrane, under the pressure difference of less than 0.4 kg f /cm 2 across the membrane pores.
The results of the application of the above equation (1) were reliable when the zeta potential difference of the membrane was less than 5% between two directions, wherein one of the flow directions of permeate was directed outside from the inside of the hollow-fiber membrane while the other is directed in the opposite way. As the pH increased, according to the results, the zeta potential of a hollow-fiber membrane changed from negative to positive and the isoelectric point was formed around pH 9.4.
The absolute value of zeta potential at an outlet of a hollow-fiber membrane was lower than that at an inlet and this is ascribed to the fact that the permeation of a given solution is continued while the flow of feed solution is directed to the axial direction of the hollow-fiber membrane and thus the flow rate becomes to decrease as it goes to the outlet and also the amount of the charged ions become depleted. The results are shown in the FIG. 4 .
Example 2
As a way to monitor the change in zeta potential of a given solution according to time passage of filtration, wherein particles are suspended in feed solution, several hollow-fiber ultrafiltration membranes (Model PM100, Internal diameter; 1.0 mm, KOCH Membrane System Inc., MA, USA) made of polysulfonate having asymmetric membrane pores were installed on membrane modules. Then, an aqueous solution containing a biopolymer of 300 ppm of bovine serum albumin (BSA) was filtered and then streaming potential was measured at two different positions both at an inlet and at an outlet of a hollow-fiber membrane. The pressure difference across the membrane pores was less than 0.2 kg f /cm 2 , the concentration of potassium chloride as an electrolyte was 1.0 mM and the pH of the solution was 6.0. It is already known that, at pH 6.0, the pores of a hollow-fiber membrane are positively charged as in the example 1 while the surface of BSA is negatively charged.
The FIG. 5 shows the result of filtration progress, which reveals that the absolute value of the zeta potential was higher at the inlet than that at the outlet and this is consistent with the example 1. The zeta potential changed from positive to negative about 20 min after the start of the filtration and this indicates that the properties of the charged membrane must have been changed during the filtration process due to the adsorption or deposition of BSA particles, which were negatively charged at pH 6.0, onto the surface of the membrane. The absolute value of zeta potential decreases as the filtration proceeds and even a faster decreasing rate at the outlet; this appears to be due to the weakened electrokinetic flow resulted from the narrowed membrane pores due to the continued adsorption or deposition of BSA particles.
Comparative Example 1
The zeta potentials according to filtration progress and the location of a membrane were measured by using the apparatus in the example 1 as shown in the examples 1, 2, and FIGS. 4 and 5 , however, there are no reports on these results in the prior art.
As mentioned above, the present invention provides a novel apparatus and a novel method to obtain zeta potential influenced by a concentration polarization layer and a cake (or gel) layer which can vary according to the axial position in a given hollow-fiber membrane. The ability to obtain the zeta potential in the present invention in the course of filtration of a given suspension with a hollow-fiber according to time passage can also help to identify the characteristics of physicochemical interactions on membrane pores and on membrane surface as well as to monitor the progress of membrane fouling. These are essential in studying the downstream for the highly efficient filtration with a hollow-fiber membrane. Further, the present invention can also provide critical data that can be used in studying the electrokinetic properties, charged characteristics, hydrophilicity and the level of substituted functional as well as ionic groups according to modifications. | The present invention relates to an apparatus for monitoring the progress of membrane fouling that occurs on pores as well as on the surface of a membrane by means of variations of zeta potential (z) of a hollow-fiber membrane according to time passage of filtration of a suspension, wherein colloid particles, biopolymers and other inorganic particles are dispersed, and the method thereof. Moreover, the present invention also relates to a method to identify the effect of concentration polarization layer and cake layer which can vary according to the axial position of a hollow-fiber and the developing progress of a membrane fouling by measuring the position-dependent zeta potential of the hollow-fiber membrane. |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention pertains to crop harvesting devices such as combines and more particularly to a fan device to be removably installed at the discharge from a combine and which will distribute the chaff from that end in a safe manner and over a neatly prescribed area.
Nearly all farm combines now discharge straw, stalk, chaff and the like from an opening located at the rear of the combine. This material is somewhat distributed by a horizontally rotating beater device adapted to break up clumps of material. Frequently these beaters are used in pairs sometimes with meshed blades. However, even with the overlap, much chaff and finer particles fall through the blades.
By the present invention an auxiliary spreading device is provided. Particularly in fields subject to "no-till" or "minimum till" farming, it is very desirable to have the most nearly possible, even division of waste material. When a field is plowed, this material is readily disposed of regardless of spreading. However, when seed is to be planted in unplowed ground on top of last year's refuse as it is in "no-till" farming, it becomes highly desirable to have a relatively even distribution of that refuse.
To accomplish the distribution, a secondary distribution is desirable, and for that purpose, added devices to accomplish the desired result have been used. The present invention is for an improved secondary distribution device. The novel device is readily mounted and removed, is flexibly adjustable for best distribution and is constructed so as to be safer than the normal distributing devices.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of the spreader mounted on an axle of a combine,
FIG. 2 is a side elevational view of the spreader from line 2--2 of FIG. 1,
FIG. 3 is a partial end elevational view of the spreader and a part of its attaching mechanism, and
FIG. 4 is a detailed view of the adjustment device allowing swingable adjustment of the spreader.
DESCRIPTION
Briefly this invention comprises an auxiliary device for a farm combine which is readily attachable to the combine, truly adjustable as to position near the waste outlet of the combine, and relatively safe in its operation because of its construction.
More specifically and referring to the drawings, the spreader device is adapted for attachment to the rear axle 10 of a combine mounted on wheels 11. A support arm 12 is clamped to the axle 10 by means of clamping plates 13. This arm 12 in turn is fitted with a pair of indexing plates 14, one above and one below the arm 12.
A swing arm 15 is pivotally attached to the support arm 12 through a pivot pin 16 extending through the plates 14 and the swing arm 15. For the sake of any disassembly, the pin 16 may be simply slipped through the arm 15 and the plates, or, it may be held in place by having a nut threaded onto its lower end or a cotter key may extend through the pin. These latter expedients are common and well known in the art.
To hold the spreader rotor, later described, in an adjusted position, series of holes 18 (FIG. 4) extend through the plates 14. These holes are arranged in an arcuate pattern on the plates and thus are in position to register with a hole extending through the swing arm 15. By extending an indexing pin 19 through one opposing pair of holes 18 in the plates 14 and through the hole in the arm 15, the arm can thus be held in one of a plurality of swingable positions relative to the support arm 12.
At its outer end, the swing arm 15 carries a cross member 20 (FIG. 1). This cross member 20 combined with the arm 15 provides a framework to which a safety guard may be attached. The guard illustrated includes a pair of rings 23 formed on a diameter large enough to surround the rotor described later. Further guards in the form of arcuate plates 24 may be attached to the rings 23 if it is deemed desirable to keep the chaff away from certain parts of the ring. For example, a plate 24 is preferably placed near the juncture of the rings 23 with the swing arm 15 to keep chaff away from the pivot pin 16 and indexing pin 19 and from the holes into which those pins extend.
The spreading fan is pivotally mounted within the rings 23 and on the framework provided by the swing arm 15 and cross member 20. The fan comprises a disc 26 and a series of flexible bats 27, preferably made of rubber, attached to that disc. The disc is attached to the spindle 28 of an hydraulic motor 29 which is fixed to the swing arm 15. Hydraulic hoses 30 lead from the hydraulic system of the combine through proper controls (not shown) to the motor 29 allowing that motor 29 to be controlled as needed from the cab of the combine.
In use, the cleaner is attached to the combine. On large machines, it is quite possible to use two of the cleaners fastened to opposite sies of the axle 10. The necessary hydraulic connections to the combine are made for power and control so that the cleaners will rotate. At that point it is a simple matter to swing the swing arm 15 to the optimum position to receive material not properly spread by the regular beaters on the combine and to pin the swing arm in its adusted position. Then, as the machine runs through the field, the motor 29 can be started and the spreader will receive material from the combine and sling it out onto the ground.
It will be apparent that with the flexible bats 27 and the guard rails 23, that this device is relatively safe. Also, because of the adjustability of the swing arm 15, the spreader can be readily adjusted for best efficiency. | A chaff spreader for attachment to a farm combine. The spreader rotates to spread chaff discharged from the combine and is readily removable and adjustable to the discharge opening in the combine. Novel safety rings are provided on the rotating spreader to protect operators or others who might come into contact with the rotor. |
BACKGROUND
[0001] Electrical receivers are used in a variety of applications. For example, next generation automotive vehicles may have multiple onboard systems and sensors that send data to a centralized computer module. Such data may include, for example, pressure data from a tire pressure monitoring system, as well as information from entertainment, air conditioning, or other such systems. Such a wireless communication system may benefit from a receiver that can receive multiple channels simultaneously. One channel may be used to continuously provide data (e.g., tire pressure data) and another channel may be used more intermittently such as for entertainment or air conditioning control data. Such channels may be generally unrelated with respect to their input power level, channel raster, modulation, information content, and instantaneous phase. Separation between the center frequencies of the channels may be arbitrarily close or far apart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] For a detailed description of various examples, reference will now be made to the accompanying drawings in which:
[0003] FIG. 1 shows a system in which multiple devices wirelessly communicate simultaneously over different channels to a common receiver in accordance with various examples;
[0004] FIG. 2 shows an example of a frequency spectrum including two such channels in accordance with various examples;
[0005] FIG. 3 illustrates the receiver in accordance with various examples;
[0006] FIG. 4 shows an example of the front-end architecture for a low noise amplifier used in the receiver which splits the input signal at a low impedance point;
[0007] FIG. 5 shows an example of the circuit schematic for a low noise amplifier used in the receiver which splits the input signal at a low impedance point;
[0008] FIG. 6 shows an example where the low impedance split point can be implemented at low frequency (baseband); and
[0009] FIG. 7 illustrates a technique for automatic gain control in accordance with various embodiments.
DETAILED DESCRIPTION
[0010] Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, different companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct wired or wireless connection. Thus, if a first device couples to a second device, that connection may be through a direct connection or through an indirect connection via other devices and connections.
[0011] Some multichannel receivers may use a high bandwidth, high resolution analog-to-digital converter (ADC) as well as high speed signal processing in digital logic to perform signal processing in the back-end after limited front-end amplification and downconversion. Such systems unfortunately are characterized by a relatively high level of power consumption as they operate over higher bandwidth than that is occupied by the sum of information content from individual channels. In accordance with the disclosed embodiment, however, a low power receiver is disclosed that splits a received signal in a radio frequency (RF) front-end into multiple signal paths that are concurrently active and process signals in a narrowband manner by processing a bandwidth that equals to the sum of the information content of individual channels. The channels may be transmission channels and each transmission channel may contain any one or more of commands, data, control information, and other types of information as desired. The split of the received signal may occur at a relatively low impedance point (e.g., between about 40 and about 100 ohms). By splitting the received signal at a low impedance point, the disclosed architecture maximizes bandwidth and reduces the level of loading on the signal itself. A low impedance split also provides a current mode interface in the architecture that enhances linearity of the signal processing blocks as they process small signal swings. The separate signal paths downstream of the split point are essentially copies of each other and thus fully modular in nature, containing all of the frequency content of the wireless transmitted signals. That is, each signal path includes multiple channels of data on different carrier frequencies. The frequency of each split signal path may be separately downconverted to a different baseband frequency level (the frequency of one of the channels) and converted to the digital domain by a relatively low resolution, low speed ADC. These requirements may also lead to improvement in the area of the ADC, leading to overall optimization of area. As a result, the disclosed receiver consumes less power than conventional wideband multichannel receivers. By using a combination of frequencies and phases, multiple channels with variable center frequency separation can be received and processed. An RF amplifier in the disclosed receivers uses a configurable single-ended or differential input and provides the low impedance point to split the RF signal. Baseband filters also are used that employ bandwidth boosting techniques to cover the dynamic range of data rates.
[0012] The disclosed techniques are applicable to automotive applications, but are applicable as well to other applications. In one example of an automotive application, a tire pressure monitoring system (TPMS) uses one channel to continuously transmit (e.g., twice per second) tire pressure data to the receiver. Another channel may operate at a different frequency and may be used to transmit other automotive-related data such as data from the entertainment system, air conditioning, etc.
[0013] FIG. 1 shows an example of a communication system 50 in accordance with various embodiments. The system 50 includes one or more monitoring devices or sensors 80 , 82 , and 84 which wireless transmit data to a receiver 100 through antennas 90 and 95 . Although three monitoring devices 80 , 82 , 84 are shown, any number of such devices are possible. The function performed by each such monitoring device can be any of a variety of functions. In the example of FIG. 1 , device 80 is a tire pressure monitoring system (TPMS) for an automobile and device 82 is the automobile's entertainment system which may be used to control music, air conditioning and other functions of the automobile.
[0014] Each such device 80 - 84 may encode data on a carrier signal of a particular frequency to form a channel. The frequency used by each device 80 - 84 may be different than the frequency of the other devices. That is, the TPMS 80 may transmit on one frequency, while the entertainment system 82 may transmit on a different frequency. FIG. 2 shows an illustrative frequency band usable in connection with the communication system 50 of FIG. 1 . The various devices 80 - 84 may communicate within a specified frequency band defined between frequencies F 1 and F 2 . In one example, F 1 is 312 MHz and F 2 is 315 MHz. In this example, therefore, the frequency band for the communication system 50 is from 312 MHz to 315 MHz. In another embodiment, data on three frequencies may be transmitted with the center frequency used for the continuous transmission of data (e.g., TPMS data), and frequencies symmetrically located on either side of the center frequency for other data (e.g., non-continuous data).
[0015] Within the defined frequency band for use by the communication system 50 , one or more channels are provided for use by the various devices 80 - 84 . Channel A, for example, may be used by device 80 , while Channel B may be used by device 82 . The devices may communicate using their respective channels and may do so concurrently. That is, devices 80 and 82 may transmit their data through antenna 90 simultaneously over two different frequency channels to receiver 100 . Such channels may be completely unrelated with respect to their input power level, channel raster, modulation, information content, and instantaneous phase. Separation between the center frequencies of the channels may be arbitrarily close or far apart. The amplitude of the signals of Channels A and B may be the same (as shown) or different from each other.
[0016] The receiver 100 receives the multichannel wireless signal from its antenna 95 and extracts the various channel data for further processing by an electronic control unit (ECU) 105 . The ECU 105 may be a computer module and contain a processor, memory, and other components to process and respond to data wirelessly received over the various channels from the various devices 80 - 84 . The ECU 105 may control one or more operational aspects of a vehicle (e.g., automobile). In one example, one channel of the multichannel wireless signal may contain tire pressure data which the ECU may use to monitor tire pressure and generate and alert if a tire pressure is below a threshold. Another channel may be used to transmit data of an entertainment system 82 of the vehicle.
[0017] FIG. 3 shows an example of an implementation of the receiver 100 in accordance with various embodiments. In this example, the receiver 100 includes a low noise amplifier (LNA) 102 , mixers, baseband filters, ADCs and a modem 110 . Other components may be included as well, and the architecture may be different from the particular architecture shown in FIG. 3 . The wirelessly received signal is amplified by the LNA 102 and converted to differential signals at the output. The mixers are employed in quadrature phases, where a broadband phase shift is obtained from the input to the output by the use of quadrature signal phases. Such quadrature signals can be used for polyphase signal processing, for example, to cancel blockers at a specific frequency of interest.
[0018] The received signal is split at a low impedance point within the LNA 102 (as detailed below) to produce two pairs of differential signals 103 and 104 , respectively, as shown. The first differential signal 103 is processed via a first signal conditioning circuit 106 , and the second differential signal 104 is processed via a second signal conditioning circuit 108 which is in parallel with the first signal path. The first signal conditioning circuit 106 extracts Channel A from I/Q signals 103 . The second signal conditioning circuit 108 extracts Channel B from I/Q signals 104 . The extracted signals are extracted at baseband frequencies which are substantially lower than their carrier frequencies. Once extracted, the Channel A I/Q signals and the Channel B I/Q signals are provided to a modem 110 for further processing, and then on to the ECU 105 . In some embodiments, the signal can be split to create at least three copies of the signal. Two of the copies of the signal are provided to the first and second signal conditioning circuits 106 and 108 , respectively, and the system may include at least a third signal conditioning circuit in parallel with the first and second signal conditioning circuits to receive a third copy of the split signal.
[0019] Each mixer accepts two signals as inputs—a large signal called the “local oscillator” (LO) and a smaller signal called the “RF signal.” The LO signals are generated and provided to the mixers by the frequency phase selector 107 . Each mixer multiplies its received RF signal (e.g., differential signals 103 and 104 ) by the local oscillator to generate an output “IF” signal. The IF signal may carry essentially the same information as the RF signal but at a much lower frequency. Thus, the mixers used in the embodiment of FIG. 3 may downconvert the frequency of their input RF signals. The mixers thus permit the received signals to be processed at much lower frequencies than the original Channel A and B signal frequencies.
[0020] The mixers in the first signal conditioning circuit 106 include MIX 1 -I for the in-phase signal (I) and MIX 1 -Q for the quadrature signal (Q). For the second signal conditioning circuit 108 , two cascaded mixer stages are included as shown. The first mixer stage includes mixers MIX 2 -I and MIX 2 -Q for the I and Q signals, respectively. The second mixer stage includes mixers MIX 3 -I,Q as shown. The first mixer stage (MIX 2 -I and MIX 2 -Q) downconverts the frequency of the input I and Q signals 104 to a low intermediate frequency, and the second stage of mixers provides the remainder of the frequency shift such that the baseband filters (indicated by BBF) and the ADC hardware are identical to each other and a fully modular baseband design can be utilized. As an example, two channels present at 312 MHz and 315 MHz in the RF band are downconverted with an LO frequency of 310 MHz. Thus, the first set of mixers in the first signal conditioning circuit 106 in the first channel provide (i.e., MIX 1 -I/Q) an output signal at 2 MHz, and the first set of mixers of the second signal conditioning circuit 108 in the second channel (i.e., MIX 2 -I/Q) provide an output at 5 MHz. The second set of mixers MIX 3 I/Q in second channel uses another LO frequency of, for example, 3 MHz, so the low frequency baseband output from the second set of mixers in the second channel (MIX 3 -IQ) is also at 2 MHz, and a fully modular baseband filter and ADC hardware can used, where they all operate with respect to a 2 MHz bandwidth. In general, the mixers (MIX 1 -I/Q) of the first signal conditioning circuit 106 are clocked or driven with a LO signal at the same frequency as the first stage mixers (MIX 2 -I/Q) of the second signal conditioning circuit 108 , and the second stage mixers of the second signal conditioning circuit are clocked or driven with an LO signal at a frequency that is synchronously derived from the common frequency used to clock the mixers MIX 1 -I/Q and MIX 2 -I/Q.
[0021] Each of the first and second signal conditioning circuits 106 , 108 includes baseband filters (BBF 1 -I, BBF 1 -Q, BBF 2 -I and BBF 2 -Q) as shown. The BBF 1 / 2 -I/Q may be the same hardware in some embodiments. The various baseband filters are designed to provide variable gain to the downconverted signal at the baseband frequency and they may provide wide tunability to accommodate a wide variation of the frequency and amplitude of the IF input signal to the filters. The signal processing by the baseband filters is inherently low-pass in nature which means that the filters can be used in conjunction with a direct conversion or a low IF architecture. While processing continuous time bandwidth-limited signals at the baseband, direct conversion offers maximum bandwidth, while low IF offers a response which may be immune to DC impairments. In at least some embodiments, both architectures may be implemented by adjusting the LO frequency to the downconverting mixers.
[0022] After channel filtering by the baseband filters, signal digitization is performed using the analog-to-digital converters ADC 1 -I, ADC 1 -Q, ADC 2 -I and ADC 2 -Q. Such ADCs may utilize the same hardware and achieve low power and low area. The digitized results are then provided to a modem 110 and through the modem to the ECU 105 .
[0023] Referring still to FIG. 3 , each pair of the differential output signals of output signals from the LNA 102 (i.e., signals 103 and 104 ) is provided to the quadrature mixers. The clock (or LO signal) to each mixer is generated by a frequency and phase selector 107 . The frequency and phase selector 107 may derive the clock for each mixer from a single phase lock loop (PLL) system after employing dividers along with duty cycle shaping (25% or 50% depending on the application).
[0024] The first stage mixers (MIX 2 -I/Q) of the second signal conditioning circuit 108 is clocked or driven with the same LO frequency as the mixers MIX 1 -I/Q of the first signal conditioning circuit 106 . The second stage mixers (MIX 3 -I/Q) of the lower signal conditioning circuit 108 are clocked or driven with an LO signal of a frequency approximately equal to the magnitude of the difference of the carrier frequencies of the two channels to be received. This frequency may be derived synchronously from a higher frequency clock signal. As such, the first signal conditioning circuit 106 may employ single frequency conversion, while the second signal conditioning circuit 108 may employ two stage mixing architecture.
[0025] FIG. 4 shows an embodiment of the receiver similar to that of FIG. 3 but with a different second signal conditioning circuit. The second signal conditioning circuit (designated as circuit 116 in FIG. 3 ) provides the second stage of mixers (MIX 3 -I/Q) implemented in the modem 110 as digital gates in the modem. Implementation of the mixer hardware completely in digital may result in superior phase accuracy for the signal processing. The baseband filters in the signal conditioning circuit 116 (BBF 2 -I/Q) may not be the same hardware as the baseband filters BBF 1 -I/Q in the first signal conditioning circuit 106 . The BBF 2 -I/Q filters may be implemented using biquadratic stages to provide filtering that is either of bandpass or low pass in nature. Hence, bandpass filters constructed using the same structure as the BBF 1 -I/Q filters while tapping different points in the filter architecture. The ADCs in both signal conditioning circuits 106 , 116 may be same hardware as was the case for the embodiment of FIG. 3 .
[0026] FIG. 5 illustrates an embodiment of the LNA 102 . In general, using a single LNA to drive mixers simultaneously corresponding to two different receive channels can lead to loss in the signal power and also degradation in sensitivity of both the receive channels compared to the case where the LNA is driving only mixers in one receive channel at any given time. The disclosed LNA 102 overcomes such problems while not increasing current consumption. LNA 102 includes a capacitive cross-coupled, common gate input differential transistor pair 150 . This differential transistor pair includes transistors M 1 and M 2 which are cross-coupled via capacitors C 1 and C 2 . Capacitor C 1 is connected between the gate of M 1 and the source of M 2 , and similarly, capacitor C 2 is connected between the gate of M 2 and the source of M 1 . The differential transistor pair 150 can be driven from an antenna in either a single ended manner without employing a balun or in a differential manner if required at nodes NINP and NINM. The capacitive cross coupling used in the common gate differential pair boosts the pair's small signal transconductance gain while also keeping the gain constant over a wide frequency bandwidth. This gain can be enhanced further by using bulk cross-coupling as shown. The LNA 102 uses the enhanced transconductance and resulting larger signal current to feed two additional capacitive, cross-coupled common gate output differential transistor pairs 160 and 170 . Cross-coupled differential transistor pair 160 includes transistors M 3 and M 4 and cross-coupling capacitors C 3 and C 4 . Cross-coupled differential transistor pair 170 includes transistors M 5 and M 6 and cross-coupling capacitors C 5 and C 6 .
[0027] Point 180 in the LNA 102 represents a relatively low impedance point for the differential signals, and it is at this low impedance point 180 , that the signals are split to be provided to each differential transistor pair 160 and 170 . More than two splitting points may also be used at the low impedance point so that the architecture may be scalable. The signal split that occurs as a result of simultaneously feeding the two transistor pairs 160 , 170 happens at a low impedance point providing the advantage that the wide bandwidth of the input differential transistor pair 150 is not compromised. The two differential pairs 160 , 170 are cascoded on top of the base differential transistor pair 150 . Differential pairs 160 , 170 can be configured independently to reuse partly or completely the total DC and signal current consumed by the base differential pair 150 . Such configuration of the differential pairs 160 , 170 may be performed by adjusting the bias voltage at nodes N 1 and N 2 . As differential transistor pairs 160 , 170 themselves use capacitive cross-coupling, they are gain-boosted which in turn helps each of them to drive mixers of the separate receive channel (i.e., signal conditioning circuits 106 , 108 ) simultaneously without incurring significant loss in signal power. This configuration also provides isolation and reduces or eliminates cross-talk between the two receive channels.
[0028] Each of the two differential transistor pairs 160 , 170 use capacitive elements to function as feedforward signal paths. Transistor pair 160 includes capacitive elements C 1 and C 2 , and transistor pair 170 includes capacitive elements C 7 and C 8 . These capacitive elements partially function as feedforward paths for the signal coming from the base differential pair while also acting to suppress the noise generated by the transistors M 3 , M 4 , M 5 , and M 6 across which the capacitive elements act as shunt elements. This configuration therefore allows the LNA 102 to drive the two receive channels without impacting the sensitivity of either of the receive channels.
[0029] FIG. 6 shows another embodiment of the receiver. In the embodiment of FIG. 6 , the low impedance split point is not internal to the LNA 102 , and instead is at point 220 as shown. In this implementation, only one set of mixers 219 is used at the RF frequency, leading to lower loading from the LO distribution network. The first set of mixers provide the maximum frequency shift to translate the signals to IF frequency, and the second set of mixers simply process the offset frequency
[0030] At least some radio receivers employ Automatic Gain Control (AGC) to control the strength of the received signal such that the stages through which the signal passes do not saturate. In accordance with various embodiments, a particular AGC scheme is employed at the interface between the LNA 102 and each of the first stage mixers (MIX 1 -I/Q and MIX 2 -I/Q). The mixers used in some embodiments may comprise passive mixers. An example is shown in FIG. 7 of a passive mixer which is resistively degenerated by resistors R 1 and R 2 for the purposes of providing improved second order linearity performance. In the degenerated configuration, a linear resistor is placed in series with the nonlinear transistor to reduce nonlinearity generated from the mixer. However, the resistors R 1 and R 2 also provide a resistive impedance seen in to the mixer, which comprises transistors M 11 -M 14 . This property is exploiting for AGC purposes as well. A cascaded capacitive attenuator 200 including capacitors C 10 -C 26 provides attenuation steps of a fixed ratio in conjunction with the resistive impedance provided by R 1 and R 2 . The capacitive attenuator 200 in turn provides a constant impedance to the LNA 102 irrespective of the attenuation chosen through the various attenuation selection inputs (gmix_maxdB, gmix_m06 dB, gmix_12 dB, gmix_m18 dB, gmix_24 dB, and gmix-m30 dB). The capacitance attenuator 200 can be incorporated into, or subsumed within, the capacitance that is at the output of the LNA 102 which is usually tuned for setting the frequency at which the LNA 102 is to operate.
[0031] In integrated circuits and systems, built-in self-calibration permits the cost of testing to be reduced, power consumption to be reduced, and permits easy testing anytime during the product's lifetime to enhance robustness. Such implementations of built-in-self-calibrations require minimum hardware to be placed in silicon. In the present embodiments, since there are multiple parallel channels to simultaneously receive signals, one of the channels may be configured to operate as a transmitter, thereby enabling loopback calibration. In another embodiment, two channels may be simultaneously activated with respect to different LO frequencies and baseband bandwidth so that the hardware dedicated to one receiver may be used to calibrate the main receiver. This implies that during the calibration phase out of N simultaneous channels, one channel can be configured to receive a reference signal, while the other(s) may be reconfigured to operate as a calibration receiver to calibrate an electrical characteristic of the receiver, examples of which may include filter center frequencies, impedances, gains etc.
[0032] The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. | A system of multiple concurrent receivers is described to process multiple narrow bandwidth wireless signals with arbitrary bandwidth and center frequency separation. These multiple receivers may provide a downconverted signal at the baseband frequency to process signal bandwidth using the lowest power consumption while using fully modular signal processing blocks operating at the low frequency. The concurrent receivers may operate from a single high frequency amplifier and may be derived from a low impedance point to reduce loading and improve scalability. The center frequency and bandwidth of each of the channels as well as phases of each of the channels may be independently reconfigured to achieve scalability, and on-chip test and calibration capability. |
FIELD OF THE INVENTION
This invention relates to a heat-sensitive recording material, and more particularly to a heat-sensitive recording material used in high-speed recording heat-sensitive facsimiles.
BACKGROUND OF THE INVENTION
Heat-sensitive recording materials record images by using physical or chemical changes that occur to objects due to thermal energy, and a great number of processes have been studied for these materials. A heat-sensitive recording material that uses a physical change of an object caused by heat has long been known as "wax type" heat-sensitive recording paper. This type of paper is currently used for electrocardiograms or the like. Several color forming mechanisms have been proposed for a heat-sensitive recording material which utilize a heat-induced chemical change, and a typical example is known as "two-component color forming system based heat-sensitive recording sheet." This sheet is made by coating a base with a dispersion of fine particles which include two heat-reactive compounds that are separated from each other by a binder or the like. One or both of the compounds are melted so that they contact each other and cause a color forming reaction by which a record is produced. The two heat-reactive compounds are generally called electron donor and electron acceptor compounds. A great number of combinations of these compounds are known. However, they basically consist of those which form a metal compound image and those which form a dye image.
The two-component color forming system based heat-sensitive recording sheet (1) depends on primary color formation and requires no development step, (2) has a texture similar to that of plain paper and (3) is easy to handle. In addition to these advantages, one which uses a colorless dye as an electron donor compound (4) achieves high color density and (5) permits easy manufacture of heat-sensitive recording sheets forming various hues of color. For these reasons, the two-component color forming system based heat-sensitive recording sheet is most commonly used as heat-sensitive recording material.
The heat-sensitive recording sheet having the unique features described above has recently begun to draw researchers' attention as paper that is suitable for recording the received image in facsimile communications. When a heat-sensitive recording sheet is used as recording paper for a facsimile, no development is needed. Accordingly, a facsimile receiver of simplified construction can be used. The fact that the recording paper is the only consumable is advantage with respect to the maintenance of the equipment. However, the use of such a sheet is disadvantageous in that it relies on thermo-recording and therefore has a slow recording speed. The slow recording speed is due to the slow heat response of the thermo-recording head and the heat-sensitive recording material used. With the recent advance in technology, thermo-recording heads having good heat response characteristics have been developed. However, no heat-sensitive recording material that fully meets this requirement has been devised.
Therefore, one object of this invention is to provide a heat-sensitive recording material having good heat response characteristics that enables high-speed recording. More specifically, the invention intends to provide a heat-sensitive recording material which is distinct from prior art recording material that uses a heat pulse of a width of about 5 ms (milli second). It is an object of this invention to produce a material which achieves satisfactory color density with a heat pulse of a width of less than 2 ms (milli second). To achieve this object, the temperature at which color is formed in the heat-sensitive recording material must be decreased. Conventionally, color is formed at a desired temperature by using a colorless electron donor compound (hereunder referred to as a color former) and an electron acceptor compound (hereunder referred to as a developer) at least one of which has a low melting point. We previously proposed in U.S. patent Ser. No. 58,399 and GB No. 2,033,594 A a developer made of a condensate of phenol and aldehyde. Japanese Patent Publication No. 4160/68 teaches the addition of a heat-fusible substance to a combination of color former and developer that forms color at a desired temperature. The heat-fusible substance is added in order to satisfy all other requirements for a heat-sensitive recording material, e.g., white background, long keeping quality of the color forming system, low cost and good hue of color. This substance must be miscible with either the color former or developer or both when it is melted. Because of its purpose, the heat-fusible substance is generally made of a compound that has a lower melting temperature than the color former and developer. However, in most cases, the recording material forms color at a temperature significantly lower than the melting point of the heat-fusible substance. This is perhaps because the heat-fusible substance forms a partial eutectic mixture with the color former or developer and the melting point of the blend is reduced to the eutectic point. For example, in a system wherein the color former is crystal violet lactone (m.p. 178° C.), the developer is 2,2-bis(p-hydroxyphenylpropane) (m.p. 158° C.) and the heat-fusible substance is stearic acid amide (m.p. 140° C.), the recording material forms color at about 80° C. In this sense, the heat-fusible substance need not be a compound whose melting point is lower than that of both the color former and developer, and any compound that causes a reduction in the melting point can be used.
Although the heat-sensitive recording material described above forms color at a desired low temperature, it possesses a disadvantageous characteristic. For instance, a fairly long heating period is necessary for providing satisfactory color density. The reason is that a heat-sensitive recording material containing a heat-fusible substance forms color by going through the following steps: (1) the melting of the heat-fusible substance, (2) the dissolution of the coupler and developer into the heat-fusible substance, and (3) the color forming reaction between the color former and developer; and step (2) governs the rate of the color forming reaction. Therefore, in spite of its satisfactorily low color forming temperature, the heat-sensitive recording material is still unsatisfactory for use as high-speed heat-sensitive recording material that is in increasing demand these days.
In order to solve this problem, a first method involves minimizing the size of the particles of the color former, developer and the heat-fusible substance. By reducing the particle size, the melting and dissolution speeds are increased making high-speed heat-sensitive recording possible. However, a great deal of energy is required to crush the color former, developer and heat-fusible substance into small particles. In addition, the small particles require the use of an increased amount of binder when applying a coating of the mixture onto a base.
The second method, developed from the first method described above, is characterized by forming a homogeneous mixture of the heat-fusible substance with either the color former, developer or both. Specifically, a uniform melt of the color former or developer and the heat-fusible substance is cooled to a solid. Alternatively, the color former or developer and the heat-fusible substance are dissolved in a solvent, followed by evaporation of the solvent or mixing with a precipitation solvent to form a precipitate. This method is very effective in forming a high-speed heat-sensitive recording material because the time required for the color former or developer to dissolve in the heat-fusible substance can be assumed to be almost zero. However, to provide a uniform mixture, the developer and heat-fusible substance must first be melted and then cooled to a solid before it is crushed and even pulverized. Alternatively, the three ingredients must be dissolved in a large quantity of solvent. All of these procedures are unsuitable for practical application. Furthermore, heat-sensitive recording material prepared by these procedures is likely to fog during handling.
We have made various efforts to devise an alternative process for producing a high-speed heat-sensitive recording material and, as a result, have accomplished this invention.
Therefore, another object of this invention is to provide a simple method for producing a developer that melts at a desired color forming temperature allowing it to enter into a color forming reaction with a color former, as well as a heat-sensitive recording material that uses such a developer.
The objects of this invention can be achieved by using as a developer for heat-sensitive recording an organic acid having fusion-bonded thereto a heat-fusible substance having a melting point in the range of from 60° C. to 150° C.
DETAILED DESCRIPTION OF THE INVENTION
The term "fusion bonding" as used herein means heating the heat-fusible substance so that it is broughtinto contact with the developer. According to the two preferred embodiments, the developer is covered with the heat-fusible substance and particles of the heat-fusible substance are dispersed on the surfaces of the developer particles. Specifically, a dispersion medium having a heat-fusible substance dissolved therein is prepared and fine particles of an organic acid are dispersed in the medium. The dispersion is then spray-dried to cause fusion bonding between the heat-fusible substance and the organic acid. Alternatively, a melt or solution of a heat-fusible substance is dropped in the form of a curtain and particles of an organic acid are injected onto the curtain to fusion-bond the two substances. Many other methods are known for causing fusion bonding and they are described in Wolfgang Sliwka, Angewandte Chemie, International Edition, Vol. 14, pp. 539-550 (1975), etc. To prepare a developer for heat-sensitive recording paper, a heat-fusible substance having a melting point in the range of from 60° C. to 150° C. and an organic acid having a higher melting point than the heat-fusible substance is dispersed in a water-soluble polymeric dispersion medium. The resulting dispersion is heated under conditions which cause the formation of a turbulent flow. The dispersion is then cooled to ordinary temperatures. This way, an organic acid to which the heat-fusible substance is fusion-bonded is obtained more easily than by the methods described above.
Specific examples of the water-soluble polymer used as the dispersion medium include a synthetic water-soluble polymer such as polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol, styrene-maleic anhydride copolymer, ethylene-maleic anhydride copolymer, or isobutylene-maleic anhydride copolymer; a natural water-soluble polymer such as hydroxyethyl cellulose, starch derivative, gelatin or casein; and modified products thereof. These water-soluble polymers are used in the form of an aqueous solution having a concentration of 1 to 20 wt%, preferably 3 to 10 wt%. If the concentration is less than 1 wt%, the dispersed particles are so labile that they may agglomerate during the subsequent heating step. If the concentration is more than 20 wt%, the dispersion medium has such a high viscosity that excessive energy is spent in forming a uniform dispersion.
The organic acid is desirably a compound that is solid at ordinary temperatures and which has a melting point of 80° C. or more. Preferred compounds are phenols and aromatic carboxylic acid derivatives. Preferred phenols include p-octylphenol, p-tert-butylphenol, p-phenylphenol, 1,1-bis(p-hydroxyphenyl)-2-ethyl-butane, 2,2-bis(p-hydroxyphenyl)propane, 2,2-bis(p-hydroxyphenyl)pentane, 2,2-bis(p-hydroxyphenyl)hexane, and 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane. Bisphenols are particularly preferred since they achieve high color density and have fairly good keeping quality. Preferred bisphenols are represented by the formula ##STR1## wherein R 1 and R 2 each represents a hydrogen atom or an alkyl group containing 1 to 12 carbon atoms or R 1 and R 2 combine to form a carbocyclic ring; or derivatives thereof.
Preferred aromatic carboxylic acid derivatives include p-hydroxybenzoic acid, ethyl p-hydroxybenzoate, butyl p-hydroxybenzoate, 3,5-di-tert-butylsalicylic acid, 3,5-di-α-methylbenzylsalicylic acid, and polyvalent metal salts of free carboxylic acids.
The heat-fusible substance may be a compound that is solid at ordinary temperatures and which when melted is missible with the organic acids described above. A compound having a melting point in the range of from 60° C. to 150° C. is preferred. If the melting point is lower than 60° C., the resulting heat-sensitive recording material forms color and fogs during storage. If the melting point is higher than 150° C., the resulting heat-sensitive recording material often fails to have the color forming temperature required for the high-speed sensitive recording material. In order to achieve better results in fusion bonding, the heat-fusible substance preferably has high miscibility with the organic acid, and a compound that dissolves at least 20 wt% of the organic acid under molten conditions is particularly preferred. The heat-fusible substance desirably has a lower melting point than the organic acid used as developer. Furthermore, it is preferable if the heat-fusible substance is fusion-bonded to the organic acid at a temperature lower than the melting point of the organic acid. In practice, it is preferable if the two compounds are fusion-bonded at a temperature lower than the melting point of the heat-fusible substance. Specific examples of the heat-fusible substance include higher aliphatic acid amides (e.g., stearic acid amide, palmitic acid amide, erucic acid amide and oleic acid amide), ethylene bisstearoamide, acetanilide, acetoacetamide and derivatives thereof. Straight chain higher aliphatic acid amides having 12 to 24 carbon atoms are particularly preferred.
The organic acid and heat-fusible substance are generally used in a weight ratio in the range of from 10:1 to 1:5, preferably from 5:1 to 1:2. They are put into an aqueous solution of water-soluble polymer in a solid content of 5 to 40 w/v % and are dispersed by a propeller stirrer, homogenizer, dissolver or other suitable means. The dispersed particles may be of any size unless they are excessively large. Specifically, the dispersed particles should have a volume average size of several millimeters, preferably less than one millimeter.
The dispersion is then heated while it is stirred with a disperser to give a shear (stirring) sufficient to form a turbulent flow. The temperature to which the dispersion is heated varies with the type of organic acid and heat-fusible substance. In general, a temperature lower than the melting point of the heat-fusible substance will serve the purpose. Subsequently, the dispersion is quenched to room temperature with cold water or by other suitable means. When the dispersion is agitated by a propeller stirrer having relatively low dispersing ability, developer particles having a size of 10 to 30 μm are produced. If a dissolver or other machine having great dispersing ability is used, a particle size of 3 to 10 μm is obtained. When observed under a scanning electron microscope, the dispersed particles thus-produced look entirely different from the particles obtained by dispersing either the developer or heat-fusible substance alone.
The method of this invention provides a large quantity of dispersion in a very short period of time as compared with the method of using a ball mill, sand mill, etc. The dispersion obtained is highly stable and the dispersed particles will not agglomerate or precipitate upon standing for several days. Another advantage is that the dispersion step is simplified since the developer and heat-fusible substance can be dispersed in a single step.
When the particles of the developer to which the particles of heat-fusible substance are fusion-bonded are large, they may be reduced in size as in the preparation of ordinary heat-sensitive recording papers by a ball mill, sand mill, attritor, colloid mill, or other suitable means. However, if a more powerful dispersing means is used, finely dispersed particles as small as several microns in size can be produced in a single step, so no separate pulverizing step is required. Accordingly, a desired dispersion can be prepared in a period of time that is from several tens to several times shorter than has been required in preparing the conventional coating solution for heat-sensitive recording material. Any developer particle having a particle size of 10 μm or less prepared in this manner exhibits satisfactory performance for use as a component of high-speed heat-sensitive recording material. Furthermore, they need not be further reduced in size.
To prepae the heat-sensitive recording material of this invention, the developer having the heat-fusible substance fusion-bonded thereto that has been produced by the novel method described above is blended with a color former, inorganic or organic oil-absorbing pigment, binder. Other ingredients which may be added include a release agent, an agent such as a binder that makes the recording material waterproof, a UV absorber, wax and a dispersant. A coating of the mixture is applied onto a base.
Typical examples of the color former that can be combined with the developer of this invention include (1) triarylmethanes, (2) diphenylmethanes, (3) xanthenes, (4) thiazines, and (5) spiropyran compounds. Specific examples are given in U.S. patent Ser. No. 58,399 and GB No. 2,033,594 A. Many of the compounds of the groups (1) and (3) achieve high color density and hence are preferred. These color formers may be used individually or in admixture. The color former is generally dispersed by a ball mill or the like in an aqueous solution of the water-soluble polymers described above. The dispersion of fine particles of the color former is then mixed with the dispersion of the developer to which the heat-fusible substance has been fusion-bonded. The color former is mixed with the developer in a ratio of from 1:20 to 1:1, preferably from 1:5 to 1:2.
A preferred inorganic or organic oil-absorbing pigment is such that it aborbs at least 50 ml of oil per 100 g as measured in accordance with JIS K5101. Specific examples include kaolin, calcined kaolin, talc, pyrophyllite, diatomaceous earth, calcium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium carbonate, titanium oxide, barium carbonate, urea-formalin filler and cellulose filler.
The coating solution thus formed is spread on paper, plastic or other suitable bases and dried. The coating amount of the solution is from 0.1 g/m 2 to 0.7 g/m 2 , preferably from 0.2 g/m 2 to 0.5 g/m 2 in terms of the weight of the color former.
This invention is now described in greater detail by reference to the following examples which are given here for illustrative purposes only and are by no means intended to limit the scope of the invention.
EXAMPLE 1
A mixture of 10 g of 2,2-bis(p-hydroxyphenyl)propane and 10 g of stearic acid amide was put in 100 g of a 5% aqueous solution of polyvinyl alcohol (degree of polymerization=500, saponification value=98%) and the resulting dispersion was heated to 85° C. under vigorous agitation with a propeller mixer. After the dispersion was held at 85° C. for 10 minutes, it was cooled to room temperature. When the dispersion was heated to 85° C., it turned milk white and the particles of 2,2-bis(p-hydroxyphenyl)propane could not be clearly distinguished from those of stearic acid amide. The melting point of 2,2-bis(p-hydroxyphenyl)propane was 158° C. and its average particle size was 180 μm, and the melting point of stearic acid amide was 140° C. and its average particle size was 110 μm. In contrast, the developer consisting of the fusion-bonded particles of 2,2-bis(p-hydroxyphenyl)propane and stearic acid amide had a melting point of 87° C. and an average particle size of 18 μm. The dispersion was stirred with a ball mill for 5 hours to provide dispersed particles having an average size of 6 μm. Separately from the developer, a color former was prepared by stirring a dispersion of 3 g of crystal violet lactone in 15 g of 5% polyvinyl alcohol in a ball mill for 24 hours until the dispersed particles of the lactone had an average size of 3 μm. The developer and color former dispersions were mixed and to the mixture, 20 g of calcium carbonate powder and 100 g of 5% aqueous polyvinyl alcohol solution were added to make a heat-sensitive coating solution. The solution was spread on raw paper (basic weight=50 g/m 2 ) to give a coating weight of 5 g/m 2 , dried and calendered under a pressure of 10 kgw/cm at a speed of 1 m/sec. Recording was made on the resulting heat-sensitive paper with an exothermic recording head adjusted in order to apply a power of 25 w/mm 2 at a pulse width of 1.5 ms (milli second) and 3.0 ms (milli second). The density of the background before the recording and the color density after the recording were measured with a Macbeth RD-514 type reflection densitometer (using a visual filter). The recorded image was left to stand in an atmosphere (50° C., 90% RH) for 16 hours, and the density of the background and that of the recorded image were measured. The results are shown in Table 1 below.
EXAMPLE 2
A mixture of 100 g of 2,2-bis(p-hydroxyphenyl)propane and 100 g of palmitic acid amide was put in 1 kg of a 5% aqueous sodium caseinate solution, and the mixture was stirred with a propeller mixer to make a dispersion. After heating to 90° C., the dispersion was further stirred with a dissolver for 10 minutes and then, under continued stirring with the dissolver, the dispersion was quenched by cooling the dispersion vessel. The resulting particles of 2,2-bis(p-hydroxyphenyl)propane to which palmitic acid amide was fusion-bonded had a diameter of 5.5 μm and a melting point of 76° C. Heat-sensitive paper was prepared using this developer according to the procedure of Example 1, and the color density, whiteness of the background and keeping quality of the paper were evaluated as in Example 1. The results are shown in Table 1 below.
COMPARATIVE EXAMPLE 1
(A) A mixture of 10 g of 2,2-bis(p-hydroxyphenyl)propane and 10 g of stearic acid amide was put in 100 g of a 5% aqueous polyvinyl alcohol solution, and stirred in a 300 ml ball mill for 24 hours. The resulting dispersion comprised particles having a volume average size of 6 μm.
(B) The dispersion was stirred for an additional 48 hours to obtain a volume average particle size of 3 μm.
A dispersion of 3 g of crystal violet lactone in 15 g of 5% polyvinyl alcohol was prepared as in Example 1, and added to the dispersions (A) and (B) of 2,2-bis(p-hydroxyphenyl)propane and stearic acid amide, respectively. To each dispersion mixture, 20 g of fine calcium carbonate powder and 100 g of a 5% aqueous polyvinyl alcohol solution were added to make a heat-sensitive coating solution. The solution was spread on raw paper having a basis weight of 50 g/m 2 , dried and calendered under a pressure of 10 kgw/cm at a speed of 1 m/sec to make heat-sensitive recording paper. The color density, whiteness of the background and keeping quality of the paper were evaluated as in Example 1. The results are shown in Table 1 below.
COMPARATIVE EXAMPLE 2
A mixture of 10 g of 2,2-bis(p-hydroxyphenyl)-propane and 10 g of stearic acid amide was put into a glass beaker which was placed in an oil bath at 200° C. to fuse the compounds completely. Then the beaker was put into water for quenching. The resulting 1:1 eutectic mixture of 2,2-bis(p-hydroxyphenyl)propane and stearic acid amide was crushed to an average particle size of 300μ and put into 100 g of a 5% aqueous polyvinyl alcohol solution and stirred with a 300 ml ball mill for 24 hours to obtain a dispersion having an average particle size of 6μ. To the dispersion, a dispersion of color former, fine calcium carbonate powder and an aqueous polyvinyl alcohol solution were added as in Example 1 to make a heat-sensitive solution. The solution was spread on raw paper, dried, calendered, had a color formed, and subjected to the measurement of density and keeping quality as in Example 1. The results are shown in Table 1 below.
TABLE 1______________________________________ Recording Pulse Keeping Quality Width Image Back- Image Back- (ms (milli Den- ground Den- groundRun No. second)) sity Density sity Density______________________________________Example 1 1.5 1.31 0.08 1.20 0.10 3.0 1.35 1.28Example 2 1.5 1.33 0.08 1.24 0.08 3.0 1.36 1.31Comparative 1.5 0.67 0.08 0.33 0.10Example 1 3.0 0.96 0.69(A)Comparative 1.5 1.02 0.10 0.77 0.14Example 1 3.0 1.29 1.17(B)Comparative 1.5 1.28 0.12 1.09 0.18Example 2 3.0 1.34 1.26______________________________________
As shown in Table 1, the heat-sensitive recording material according to this invention achieves high color density in high-speed recording, and has a background with a high degree of whiteness that is maintained even in a hot and humid atmosphere. Comparison between the Examples and Comparative Examples shows that a dispersion of developer particles can be obtained by the method of this invention in a period only a fraction of that required by the conventional technique.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | A heat-sensitive recording material comprising a heat-sensitive color forming layer on a base is disclosed. The color forming layer contains an electron donating colorless dye and an organic acid to which a heat-fusible substance having a melting point in the range of from 60deg to 150deg C. Is fusion-bonded. A process for producing such recording material by applying to a base a coating solution containing a developer for heat-sensitive recording is also disclosed. The developer is prepared by the steps of dispersing in a dispersion medium a heat-fusible substance having a melting point in the range of from 60deg C. To 150deg C. And an organic acid, heating the resulting dispersion under conditions that form a turbulent flow, and cooling the heated dispersion to ordinary temperatures. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a cutting tool for cutting building materials, for example vinyl or polyvinyl chloride (PVC) flooring. More specifically, this invention relates to a cutting tool including a base with a pair of support supporting a cam rotatably connected to the pair of supports and a blade holder with a blade, the blade holder pivotally connected to the pair of supports to move in an arc and movable downward by rotating the cam.
[0003] 2. Discussion of Related Art
[0004] Various tools are currently used to cut building materials, however most are bulky, heavy, require power to be operated, produce large amounts of dust during the cutting process, and/or result in uneven or splintered cuts. Accordingly, there is a need for an improved cutting tool for cutting building materials. There is a need for a portable, non-power operated cutting tool capable of cutting building materials, particularly vinyl and PVC flooring, in a predictable and straight fashion without splintering, cracking or similar problems and without creating dust.
SUMMARY OF THE INVENTION
[0005] The present invention provides a portable, non-power operated cutting tool for cutting sheets of building materials, for example, but not limited to, vinyl and polyvinyl chloride (PVC) flooring, in a clean, straight manner without tearing, splintering or cracking.
[0006] According to an embodiment of this invention, the cutting tool includes a base with a support surface for supporting the building material that is to be cut. The support surface preferably further includes a guide rail for aligning the material. The guide rail may be adjustable, allowing the building material to set at a range of angles to the blade in a horizontal plane. The base further includes a pair of supports extending vertically from the base. The supports are preferably positioned on either side of the base with a blade holder and a cammed axle extending between the supports.
[0007] The blade holder is preferably connected with a pivot connection to the supports and spaced from the support surface to allow the building material to slide under the blade holder. In a preferred embodiment, the blade holder includes a main body with arm extending from the main body. The main body preferably includes a slot with a threaded connection for connecting a blade to the blade holder. The threaded connection allows for the blade to be removed for replacement or repairs. Alternatively, the blade may be connected with any type of connection, such as an adhesive or weld connection. In another embodiment, the blade holder and the blade may be integrally formed together. The arm extends from the main body and includes a connection for a pivot connection to the pair of supports. In a preferred embodiment, the connection comprises an axle connection between each support and each arm. With the axle connection the blade moves in an arc, where the arc includes a radius equal to a distance between the axle and the blade. The circular motion of the arc improves the ability of the cutting tool to cut through building materials such as vinyl and PVC flooring.
[0008] The cammed axle is rotatably connected to the supports and positioned over and in contact with the blade holder. The blade holder and the blade are moveable between an open position, where the blade is separated from the base, and a closed position, where the blade is in contact or nearly contacting the base, by rotating the cammed axle. In the open position, the cammed axle contacts the blade holder at a relatively small radius of the cam, as the cam rotates, the cammed axle contacts the blade holder at a gradually increasing radius forcing the blade holder downward until the blade contacts a blade stop, the closed position. In a preferred embodiment, a spring is positioned between the base and the blade holder. The spring biases the blade holder in the open position and is compressed as the blade holder moves downward. In a preferred embodiment, a handle is connected to the cammed axle to assist in rotating the cam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of a cutting tool in a closed position according to one embodiment of this invention.
[0010] FIG. 2 a is a side view of the cutting tool shown in FIG. 1 in an open position.
[0011] FIG. 2 b is a close-up of the side view shown in FIG. 2 a with elements of the cutting tool removed for explanatory purposes.
[0012] FIG. 3 a is a side view of the cutting tool shown in FIG. 1 in the closed position.
[0013] FIG. 3 b is a close-up of the side view shown in FIG. 3 a with elements of the cutting tool removed for explanatory purposes.
[0014] FIG. 4 a is a rear view of the cutting tool shown in FIG. 1 in the closed position.
[0015] FIG. 4 b is a rear view of the cutting tool shown in FIG. 1 in the open position.
[0016] FIG. 5 is a top view of the cutting tool shown in FIG. 1 .
[0017] FIG. 6 is a bottom view of the cutting tool shown in FIG. 1 .
DESCRIPTION OF THE INVENTION
[0018] FIG. 1 shows a perspective view of a cutting tool 10 according to one embodiment of this invention. The cutting tool 10 as described is preferably used to cut building materials, not shown, such as, but not limited to, vinyl and PVC flooring materials. The cutting tool 10 utilizes an arc cutting motion which easily severs the building material and prevents damaging the building materials during cutting.
[0019] As shown in FIGS. 1-6 , the cutting tool 10 includes a base 14 , a support surface 16 , a pair of supports 12 , a blade holder 18 , blade 20 , and a cam 22 with a handle 24 . As best shown in FIG. 6 , the base 14 comprises an “I” shape with cross braces to provide rigidity and stability for the cutting tool 10 , however the base 14 is not limited to this shape and may comprises any shape that provides a stable base for the cutting tool 10 . The base 14 may be formed of steel, aluminum or another material with durable qualities capable of withstanding the force required to cut the building materials.
[0020] In an embodiment, the support surface 16 is mounted on the base 14 with threaded connections. In an alternative embodiment the support surface 16 and the base 14 may be integrally formed as a single component. The support surface 16 preferably includes a textured or a high friction, non-slip surface that prevents the building material from slipping or moving during cutting process. The support surface 16 is preferably made of lightweight and durable materials, such as plastic, rubber, metal and composite materials, but may be made of any material capable of supporting the building materials and withstanding the cutting force. The base 14 and support surface 16 are preferably sized to accommodate standard sizes of materials, such as a vinyl and PVC flooring tiles, and may correspond in width to such materials.
[0021] The support surface 16 preferably includes a guide rail 26 on support surface 16 that can be used to align the building materials to the blade 20 . In an alternative embodiment, the guide rail 26 may be adjustable to cut the material at a range of angles to the blade 20 . The guide rail 26 may further include a ruler for measuring the material to be cut.
[0022] In a preferred embodiment of this invention, the pair of supports 12 are connected to the base 14 and extend generally perpendicular to a plane of the support surface 16 . In this embodiment, the pair of supports 12 are connected to the base with a threaded connection and are positioned on either side of the base 12 at a width sufficient to accommodate the material to be cut. The pair of supports 12 may be formed of durable materials such as, but not limited to, steel, aluminum or similar rigid materials which are capable of withstanding the force created during cutting. In other embodiments, the pair of supports 12 can be welded to or integrally formed to the base 14 or connected in any other means known to one of skill in the art.
[0023] As best shown in FIGS. 4 a - b , the blade holder 18 is positioned between the pair of supports 12 and below the cam 22 with a blade holder pivot connection 28 which allows the blade holder 18 to move in an arc pattern from the open position to the closed position. As best shown in FIGS. 2 b and 3 b , the blade holder 18 includes a main body 30 and an arm 32 extending from the main body 30 . The blade holder pivot connection 28 preferably comprises an axle which extends through a distal end of the arm 32 opposite the blade 20 and through the support 12 . In this embodiment, the axle comprises a pair of axles, one for each of the supports 12 . Alternatively, the axle may comprise a single axle extending through the arm of the blade holder 18 and both pairs of supports 12 . In a preferred embodiment, the blade 20 moves in an arc pattern having a radius of the distance between the blade 20 and the blade holder pivot connection 28 . This arc pattern provides a clean cut through various building materials, especially vinyl and PVC flooring. The blade holder 18 may be formed of durable materials such as, but not limited to, steel, aluminum or similar rigid materials which are capable of withstanding the force created during cutting.
[0024] In a preferred embodiment, the blade 20 is attached to the blade holder 18 with a threaded connection. With this arrangement, the blade 20 can be removed from the blade holder 18 for repairs, sharpening and to select a specialty blade for a type of material. In an alternative embodiment, the blade 20 can be integrally formed with the blade holder 18 . The blade 20 is preferably formed of steel or another material capable of repeatedly cutting the building material.
[0025] As shown in FIGS. 4 a - b , the cam 22 is positioned between the pair of supports 12 and over and in contact with the blade holder 18 . In a preferred embodiment of the invention, the cam 22 contacts the blade holder 18 in proximity to the blade 20 . The cam 22 preferably includes an axle 34 which extends through the pair of supports 12 to provide a rotatable connection between the cam 22 and the supports 12 . Alternatively, any type of connection may be used to provide a rotatable connection. As best shown in FIGS. 2 b and 3 b , the cam 22 includes a cam edge 36 with a gradually increasing radius from a small radius 38 to a large radius 40 . As the cam 22 rotates, the increasing radius of the cam edge 36 forces the blade holder 18 downwards from the open position, see FIG. 2 b , to the closed position, see FIG. 3 b . In an embodiment, at least one of the cam 22 and the blade holder 18 may include a low friction durable surface to minimize the friction between the cam 22 and the blade holder 18 , as the cam is rotated. In another embodiment, a bearing or other low-friction device may be used.
[0026] In a preferred embodiment, the cutting tool includes the handle 24 which is connected to the cam 22 to assist a user to rotate the cam 22 . A distal end of the handle 24 preferably includes a hand grip for the user to manually grab or engage. In an alternative embodiment, the handle 24 may be adjustable and/or extendible to provide additional assistance to cut through tough-to-cut materials.
[0027] In an embodiment of this invention, as shown in FIGS. 2 b and 3 b , the base 14 may include a blade stop 42 with a contact element 44 and a brace 46 . The contact element 44 is preferably manufactured of a softer material that causes minimal damage to an edge of the blade 20 such as, but not limited to, nylon. The brace 46 is preferably manufactured of a durable material such as, but not limited to, steel and aluminum. Preferably, the contact element 44 and the brace 46 are connected to the base 14 with a threaded connection that allows the contact portion 44 to be easily replaced as it wears. In an alternative embodiment, the blade stop and the contact element may be manufactured from a durable material such as, but not limited to, steel and aluminum to withstand the impact of the blade.
[0028] According to a preferred embodiment, the blade holder 18 is biased upward into the open position by a spring 48 . As shown in the figures, the spring 48 is positioned between the base 14 and the blade holder 18 and maintained in position with a pair of alignment pins 50 . The strength and configuration of the spring 48 may be adjusted depending on the desired application.
[0029] In operation, the cutting tool 10 of this invention starts in the open position as shown in FIGS. 2 a - b and 4 b . In the open position, the spring 48 biases the blade holder 18 and the blade 20 upward and the cam 22 contacts the blade holder 18 at the relatively small radius 38 , this provides an opening between the blade 20 and the blade stop 42 of the base 14 . The material to be cut is placed onto the support surface 16 of the base 14 and through the opening formed between the blade 18 and the blade stop 42 . To cut the material, the handle 24 is lowered to rotate the cam 22 . By rotating the cam 22 , a gradually increasing radius of the cam edge 36 pushes the blade holder 18 and blade 20 downward through the material until the relatively larger radius 40 of the cam 22 contacts the blade holder 18 and the blade 20 contacts the blade stop 42 thereby severing the material. The resulting cut is optimally free of splinters and a resulting cut end of the material is otherwise clean and straight.
[0030] While in the foregoing specification this invention has been described in relation to certain preferred embodiments thereof, and many details have been set forth for purpose of illustration, it will be apparent to those skilled in the art that the material cutter is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention. | A cutting tool for cutting building materials, such as vinyl and PVC flooring, in a straight and predicable manner using an arc cutting motion. The cutting tool utilize a cam to force a pivot connected blade holder with a blade downward through a piece of building material placed under the blade. |
FIELD OF THE INVENTION
The present invention relates to a fuel recovery system for recovery leaks that occur in fuel supply piping in a retail fueling environment.
BACKGROUND OF THE INVENTION
Managing fuel leaks in fueling environments has become more and more important in recent years as both state and federal agencies impose strict regulations requiring fueling systems to be monitored for leaks. Initially, the regulations required double walled tanks for storing fuel accompanied by leak detection for the tanks. Subsequently, the regulatory agencies have become concerned with the piping between the underground storage tank and the fuel dispensers and are requiring double walled piping throughout the fueling environment as well.
Typically, the double walled piping that extends between fuel handling elements within the fueling environment terminates at each end with a sump that is open to the atmosphere. In the event of a leak, the outer pipe fills and spills into the sump. The sump likewise catches other debris, such as water and contaminants that contaminate the fuel caught by the sump, thereby making this contaminated fuel unusable. Thus, the sump is isolated from the underground storage tank, and fuel captured by the sump is effectively lost.
Coupled with the regulatory changes in the requirements for the fluid containment vessels are requirements for leak monitoring such that the chances of fuel escaping to the environment are minimized. Typical leak detection devices are positioned in the sumps. These leak detection devices may be probes or the like and may be connected to a control system for the fueling environment such that the fuel dispensing is shut down when a leak is detected.
Until now, fueling environments have been equipped with elements from a myriad of suppliers. Fuel dispensers might be supplied by one company, the underground storage tanks by a second company, the fuel supply piping by a third company, and the tank monitoring equipment by yet a fourth company. This makes the job of the designer and installer of the fueling environment harder as compatibility issues and the like come into play. Further, it is difficult for one company to require a specific leak detection program with its products. Interoperability of components in a fueling environment may provide economic synergies to the company able to effectuate such, and provide better, more integrated leak detection opportunities.
Any fuel piping system that is installed for use in a fueling environment should advantageously reduce the risk of environmental contamination when a leak occurs and attempt to recapture fuel that leaks for reuse and to reduce excavation costs, further reducing the likelihood of environmental contamination. Still further, such a system should include redundancy features and help reduce the costs of clean up.
SUMMARY OF THE INVENTION
The present invention capitalizes on the synergies created between the tank monitoring equipment, the submersible turbine pump, and the fuel dispenser in a fueling environment. A fluid connection that carries a fuel supply for eventual delivery to a vehicle is made between the underground storage tank and the fuel dispensers via double walled piping. Rather than use the conventional sumps and low point drains, the present invention drains any fuel that has leaked from the main conduit of the double walled piping back to the underground storage tank. This addresses the need to recapture the fuel for reuse and to reduce fuel that is stored in sumps which must later be retrieved and excavated by costly service personnel.
The fluid in the outer conduit may drain to the underground storage tank by gravity coupled with the appropriately sloping piping arrangements, or a vacuum may be applied to the outer conduit from the vacuum in the underground storage tank. The vacuum will drain the outer conduit. Further, the return path may be fluidly isolated from the sumps, thus protecting the fuel from contamination.
In an exemplary embodiment, the fuel dispensers are connected to one another via a daisy chain fuel piping arrangement rather than by a known main and branch conduit arrangement. Fuel supplied to a first fuel dispenser by the submersible turbine pump and conduit is carried forward to other fuel dispensers coupled to the first fuel dispenser via the daisy chain fuel piping arrangement. The daisy chain is achieved by a T-intersection contained within a manifold in each fuel dispenser. Fuel leaking in the double walled piping is returned through the piping network through each downstream fuel dispenser before being returned to the underground storage tank.
The daisy chain arrangement allows for leak detection probes to be placed within each fuel dispenser so that leaks between the fuel dispensers may be detected. The multiplicity of probes causes leak detection redundancy and helps pinpoint where the leak is occurring. Further, the multiple probes help detect fuel leaks in the outer conduit of the double walled piping. This is accomplished by verifying that fuel dispensers downstream of a detected leak also detect a leak. If they do not, a sensor has failed or the outer conduit has failed. A failure in the outer piping is cause for serious concern as fuel may be escaping to the environment and a corresponding alarm may be generated.
Another possibility with the present invention is to isolate sumps, if still present within the fuel dispenser, from this return path of captured leaking fuel such that contaminants are precluded from entering the leaked fuel before being returned to the underground storage tank. In this manner, fuel may potentially be reused since it is not contaminated by other contaminants, such as water, and reclamation efforts are easier. Since the fuel is returned to the underground storage tank, there is less danger that a sump overflows and allows the fuel to escape into the environment.
Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention.
FIG. 1 illustrates a conventional communication system within a fueling environment in the prior art;
FIG. 2 illustrates a conventional fueling path layout in a fueling environment in the prior art;
FIG. 3 illustrates, according to an exemplary embodiment of the present invention, a daisy chain configuration for a fueling path in a fueling environment;
FIG. 4 illustrates, according to an exemplary embodiment of the present invention, a fuel dispenser;
FIG. 5 illustrates a first embodiment of a fuel return to underground storage tank arrangement;
FIG. 6 illustrates a second embodiment of a fuel return to underground storage tank arrangement; and
FIG. 7 illustrates a flow chart showing the leak detection functionality of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
Fueling environments come in many different designs. Before describing the particular aspects of the present invention (which begins at the description of FIG. 3 ), a brief description of a fueling environment follows. A conventional exemplary fueling environment 10 is illustrated in FIGS. 1 and 2 . Such a fueling environment 10 may comprise a central building 12 , a car wash 14 , and a plurality of fueling islands 16 .
The central building 12 need not be centrally located within the fueling environment 10 , but rather is the focus of the fueling environment 10 , and may house a convenience store 18 and/or a quick serve restaurant 20 therein. Both the convenience store 18 and the quick serve restaurant 20 may include a point of sale 22 , 24 , respectively. The central building 12 may further house a site controller (SC) 26 , which in an exemplary embodiment may be the G-SITE® sold by Gilbarco Inc. of Greensboro, N.C. The site controller 26 may control the authorization of fueling transactions and other conventional activities as is well understood. The site controller 26 may be incorporated into a point of sale, such as point of sale 22 if needed or desired. Further, the site controller 26 may have an off-site communication link 28 allowing communication with a remote location for credit/debit card authorization, content provision, reporting purposes or the like, as needed or desired. The off-site communication link 28 may be routed through the Public Switched Telephone Network (PSTN), the Internet, both, or the like, as needed or desired.
The car wash 14 may have a point of sale 30 associated therewith that communicates with the site controller 26 for inventory and/or sales purposes. The car wash 14 alternatively may be a stand alone unit. Note that the car wash 14 , the convenience store 18 , and the quick serve restaurant 18 are all optional and need not be present in a given fueling environment.
The fueling islands 16 may have one or more fuel dispensers 32 positioned thereon. The fuel dispensers 32 may be, for example, the ECLIPSE® or ENCORE® sold by Gilbarco Inc. of Greensboro, N.C. The fuel dispensers 32 are in electronic communication with the site controller 26 through a LAN or the like.
The fueling environment 10 also has one or more underground storage tanks 34 adapted to hold fuel therein. As such the underground storage tank 34 may be a double walled tank. Further, each underground storage tank 34 may include a tank monitor (TM) 36 associated therewith. The tank monitors 36 may communicate with the fuel dispensers 32 (either through the site controller 26 or directly, as needed or desired) to determine amounts of fuel dispensed and compare fuel dispensed to current levels of fuel within the underground storage tanks 34 to determine if the underground storage tanks 34 are leaking.
The tank monitor 36 may communicate with the site controller 26 and further may have an off-site communication link 38 for leak detection reporting, inventory reporting, or the like. Much like the off-site communication link 28 , off-site communication link 38 may be through the PSTN, the Internet, both, or the like. If the off-site communication link 28 is present, the off-site communication link 38 need not be present and vice versa, although both links may be present if needed or desired. As used herein, the tank monitor 36 and the site controller 26 are site communicators to the extent that they allow off site communication and report site data to a remote location.
For further information on how elements of a fueling environment 10 may interact, reference is made to U.S. Pat. No. 5,956,259, which is hereby incorporated by reference in its entirety. Information about fuel dispensers may be found in commonly owned U.S Pat. Nos. 5,734,851 and 6,052,629, which are hereby incorporated by reference in their entirety. Information about car washes may be found in commonly owned U.S. patent application Ser. No. 10/430,689, filed 06 May 2002, entitled SERVICE STATION CAR WASH, which is hereby incorporated by reference in its entirety. An exemplary tank monitor 36 is the TLS-350R manufactured and sold by Veeder-Root. For more information about tank monitors 36 and their operation, reference is made to U.S. Pat. Nos. 5,423,457; 5,400,253; 5,319,545; and 4,977,528, which are hereby incorporated by reference in their entireties.
In addition to the various conventional communication links between the elements of the fueling environment 10 , there are conventional fluid connections to distribute fuel about the fueling environment as illustrated in FIG. 2 . Underground storage tanks 34 may each be associated with a vent 40 that allows over-pressurized tanks to relieve pressure thereby. A pressure valve (not shown) is placed on the outlet side of each vent 40 to open to atmosphere when the underground storage tank 34 reaches a predetermined pressure threshold. Additionally, under-pressurized tanks may draw air in through the vents 40 . In an exemplary embodiment, two underground storage tanks 34 exist—one a low octane tank ( 87 ) and one a high octane tank ( 93 ). Blending may be performed within the fuel dispensers 32 as is well understood to achieve an intermediate grade of fuel. Alternatively, additional underground storage tanks 34 may be provided for diesel and/or an intermediate grade of fuel (not shown).
Pipes 42 connect the underground storage tanks 34 to the fuel dispensers 32 . Pipes 42 may be arranged in a main conduit 44 and branch conduit 46 configuration, where the main conduit 44 carries the fuel to the branch conduits 46 , and the branch conduits 46 connect to the fuel dispensers 32 . Typically, pipes 42 are double walled pipes comprising an inner conduit and an outer conduit. Fuel flows in the inner conduit to the fuel dispensers, and the outer conduit insulates the environment from leaks in the inner conduit. For a better explanation of such pipes and concerns about how they are connected, reference is made to Chapter B13 of PIPING HANDBOOK, 7 th edition, copyright 2000, published by McGraw-Hill, which is hereby incorporated by reference.
In a typical service station installation, leak detection may be performed by a variety of techniques, including probes and leak detection cables. More information about such devices can be found in the previously incorporated PIPING HANDBOOK. Conventional installations do not return to the underground storage tank 34 fuel that leaks from the inner conduit to the outer conduit, but rather allow the fuel to be captured in low point sumps, trenches, or the like, where the fuel mixes with contaminants such as dirt, water and the like, thereby ruining the fuel for future use without processing.
While not shown, vapor recovery systems may also be integrated into the fueling environment 10 with vapor recovered from fueling operations being returned to the underground storage tanks 34 via separate vapor recovery lines (not shown). For more information on vapor recovery systems, the interested reader is directed to U.S. Pat. Nos. 5,040,577; 6,170,539; and Re. 35,238, and U.S. patent application Ser. No. 09/783,178 filed Feb. 14, 2001, all of which are hereby incorporated by reference in their entireties.
Now turning to the present invention, the main and branch fuel supply conduit arrangement of FIG. 2 is replaced by a daisy chain fuel supply arrangement as illustrated in FIG. 3 . The underground storage tank 34 provides a fuel delivery path to a first fuel dispenser 32 , via a double walled pipe 48 . The first fuel dispenser 32 is configured to allow the fuel delivery path to continue onto a second fuel dispenser 322 via a daisy chaining double walled pipe 50 . This process repeats until an nth fuel dispenser 32 n is reached. Each fuel dispenser 32 has a manifold 52 with an inlet aperture and an outlet aperture as will be better explained below. In the nth fuel dispenser 32 n , the outlet aperture is terminated conventionally as described in the previously incorporated PIPING HANDBOOK.
As better illustrated in FIG. 4 , each fuel dispenser 32 comprises a manifold 52 with a T-intersection 54 housed therein. The T-intersection 54 allows the fuel line conduit 56 to be stubbed out of the daisy chaining double walled pipe 50 and particularly to extend through the outer wall 58 of the daisy chaining double walled pipe 50 . This T-intersection 54 may be a conventional T-intersection such as is found in the previously incorporated PIPING HANDBOOK. The manifold 52 comprises the aforementioned inlet aperture 60 and outlet aperture 62 . While shown on the sides of the manifold 52 's housing, they could equivalently be on the bottom side of the manifold 52 , if desired. Please note that the present invention is not limited to a manifold 52 with a T-joint, and that any other suitable configuration may be used that allows fuel to be supplied to a fuel dispenser 32 and allows to continue on as well to the next fuel dispenser 32 until the last fuel dispenser 32 is reached.
A leak detection probe 64 may also be positioned within the manifold 52 . This leak detection probe 64 may be any appropriate liquid detection sensor as needed or desired. The fuel dispenser 32 has conventional fuel handling components 66 therein, such as a fuel pump 68 , a vapor recovery system 70 , a fueling hose 72 , a blender 74 , a flow meter 76 , and a fueling nozzle 78 . Other fuel handling components 66 may also be present as is well understood in the art.
With this arrangement, the fuel may flow into the fuel dispenser 32 in the fuel line conduit 56 , passing through the inlet aperture 60 of the manifold 52 . A check valve 80 may be used if needed or desired as is well understood to prevent fuel from flowing backwards. The fuel handling components 66 draw fuel through the check valve 80 and into the handling area of the fuel dispenser 32 . Fuel that is not needed for that fuel dispenser 32 is passed through the manifold 52 upstream to the other fuel dispensers 32 within the daisy chain. A sump (not shown) may still be associated with the fuel dispenser 32 , but it is fluidly isolated from the daisy chaining double walled pipe 50 .
A first embodiment of the connection of the daisy chaining double walled pipe 50 to the underground storage tank 34 is illustrated in FIG. 5 . The daisy chaining double walled pipe 50 connects to a casing construction 82 , which in turn connects to the double walled pipe 48 . A submersible turbine pump 84 is positioned within the underground storage tank 34 , preferably below the level of fuel 86 within the underground storage tank 34 . For a more complete exploration of the casing construction 82 and the submersible turbine pump 84 , reference is made to U.S. Pat. No. 6,223,765 assigned to Marley Pump Company, which is incorporated herein by reference in its entirety, and the product exemplifying the teachings of the patent explained in Quantum Submersible Pump Manual: Installation and Operation , also produced by the Marley Pump Company, also incorporated by reference in its entirety. In this embodiment, fuel captured by the outer wall 58 is returned to the casing construction 82 such as through a vacuum or by gravity feeds. A valve (not shown) may allow the fuel to pass into the casing construction 82 and thereby be connected to the double walled pipe 48 for return to the underground storage tank 34 . The structure of the casing construction in the ' 765 patent is well suited for this purpose having multiple paths by which fuel may be returned to the outer wall of the double walled pipe that connects the casing construction 82 to the submersible turbine pump 84 .
A second embodiment of the connection of the daisy chaining double walled pipe 50 to the underground storage tank 34 is illustrated in FIG. 6 . The casing construction 82 is substantially identical to the previously incorporated U.S. Pat. No. 6,223,765. The daisy chaining double walled pipe 50 however comprises a fluid connection 88 to the double walled pipe 48 . This allows the fuel in the outer wall 58 to drain directly to the underground storage tank 34 , instead of having to provide a return path through the casing construction 82 . Further, the continuous fluid connection from the underground storage tank 34 to the outer wall 58 causes any vacuum present in the underground storage tank 34 to also be existent in the outer wall 58 of the daisy chaining double walled pipe 50 . This vacuum may help drain the fuel back to the underground storage tank 34 . In an exemplary embodiment, the fluid connection 88 may also be double walled so as to comply with any appropriate regulations.
FIG. 7 illustrates the methodology of the present invention. During new construction of the fueling environment 10 , or perhaps when adding the present invention to an existing fueling environment 10 , the daisy chained piping system according to the present invention is installed (block 100 ). The pipe connection between the first fuel dispenser 32 1 and the underground storage tank 34 may, in an exemplary embodiment, be sloped such that gravity assists the drainage from the fuel dispenser 32 to the underground storage tank 34 . The leak detection system, and particularly, the leak detection probes 64 , are installed in the manifolds 52 of the fuel dispensers 32 (block 102 ). Note that the leak detection probes 64 may be installed during construction of the fuel dispensers 32 or retrofit as needed. In any event, the leak detection probes 64 may communicate with the site communicators such as the site controller 26 or the tank monitor 36 as needed or desired. This communication may be for alarm purposes, calibration purposes, testing purposes or the like as needed or desired. Additionally, this communication may pass through the site communicator to a remote location if needed. Further, note that additional leak detectors (not shown) may be installed for redundancies and/or positioned in the sumps of the fuel dispensers 32 . Still further, leak detection programs may be existent to determine if the underground storage tank 34 is leaking. These additional leak detection devices may likewise communicate with the site communicator as needed or desired.
The fueling environment 10 operates as is conventional, with fuel being dispensed to vehicles, vapor recovered, consumers interacting with the points of sale, and the operator generating revenue (block 104 ). At some point a leak occurs between two fuel dispensers 32 x and 32 x+1 . Alternatively, the leak may occur at a fuel dispenser 32 x+1 (block 106 ). The leaking fuel flows towards the underground storage tank 34 (block 108 ), as a function of the vacuum existent in the outer wall 58 , via gravity or the like. The leak is detected at the first downstream leak detection probe 64 (block 110 ). Thus, in the two examples, the leak would be detected by the leak detection probe 64 positioned within the fuel dispenser 32 x . This helps in pinpointing the leak. An alarm may be generated (block 112 ). This alarm may be reported to the site controller 26 , the tank monitor 36 or other location as needed or desired.
A second leak detection probe 64 , positioned downstream of the first leak detection probe 64 in the fuel dispenser 32 x−1 , will then detect the leaking fuel as it flows past the second leak detection probe 64 (block 114 ). This continues, with the leak detection probe 64 in each fuel dispenser 32 downstream of the leak detecting the leak until fuel dispenser 32 1 detects the leak. The fuel is then returned to the underground storage tank 34 (block 116 ).
If all downstream leak detection probes 64 detect the leak at query block 118 , that is indicative that the system works (block 120 ). If a downstream leak detection probe 64 fails to detect the leak during the query of block 118 , then there is potentially a failure in the outer wall 58 and an alarm may be generated (block 122 ). Further, if the leak detection probes 64 associated with fuel dispensers 32 x+1 , and 32 x−1 both detect the leak, but the leak detection probe 64 associated with the fuel dispenser 32 x does not detect a leak, that is indicative of a sensor failure and a second type of alarm may be generated.
Additionally, once a leak is detected and the alarm is generated, the fueling environment 10 may shut down so that clean up and repair can begin. However, if the double walled piping system works the way it should, the only repair will be to the leaking section of inner pipe within the daisy chaining double walled pipe 50 or the leaking fuel dispenser 32 . Any fuel may caught by the outer wall 58 is returned for reuse, thus saving on clean up.
Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. | A fueling environment that distributes fuel from a fuel supply to fuel dispensers in a daisy chain arrangement with a double walled piping system. Fuel leaks that occur within the double walled piping system are returned to the underground storage tank by the outer wall of the double walled piping. This preserves the fuel for later use and helps reduce the risk of environmental contamination. Leak detectors may also be positioned in fuel dispensers detect leaks and provide alarms for the operator and help pinpoint leak detection that has occurred in the piping system proximate to a particular fuel dispenser or in between two consecutive fuel dispensers. |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 09/133,243, filed Aug. 13, 1998; abandoned entitled “Laminator Assembly Having a Pressure Roller with a Deformable Layer” by Roger S. Kerr.
FIELD OF THE INVENTION
The present invention relates to the art of color proofing, and in particular, to an improved lamination assembly and roller for preparing prepress color proofs, such as by the use of pressure and heat to laminate media together.
BACKGROUND OF THE INVENTION
Prepress color proofing is a procedure that is used by the printing industry for creating representative images of printed material to check for color balance and other important image quality control parameters, without the high cost and time that is required to actually produce printing plates and set up a printing press to produce an example of an intended image. These intended images may require several corrections and may be reproduced several times to satisfy or meet the requirements of the customers, resulting in a large loss of profits and ultimately higher costs to the customer.
Generally speaking, color proofs sometimes called “off press” proofs or prepress proofs, are one of three types: namely (1) a color overlay that employs an image on a separate base for each color; (2) a single integral sheet process in which the separate color images are transferred by lamination onto a single base; and (3) a digital method in which the images are produced directly onto or transferred by lamination onto a single base from digital data.
In one typical process for a prepress color proofing system used in the printing industry, a multicolor original is separated into individual transparencies, called color separations, the three subtractive primaries and black. Typically a color scanner is used to create the color separations and in some instances more than four color separations are used. The color separations are then used to create a color proof sometimes called an “off press” proof or prepress proof as described above.
A Kodak Color Proofing Laminator can be used to bond lamination sheets to receiver stock as a part of a color proofing system. The lamination sheets include a carrier and a layer of material to be applied to the receiver stock, which, in the case of the Kodak Color Proofing Laminator, is a color donor. A lamination sheet is laid upon the receiver stock with the color donor side sandwiched between the carrier and the receiver stock forming a lamination sandwich.
FIG. 1 shows a laminator 12 as described in U.S. Pat. No. 5,478,434. As shown in FIG. 1, a lamination sandwich 10 sits on an entrance table 20 . A leading edge of lamination sandwich 10 is fed into a laminator 12 which includes an upper heated pressure roller and a lower heated pressure roller. Lamination sandwich 10 passes completely through the upper heated pressure roller and the lower heated pressure roller. Lamination sandwich 10 thereafter exits the upper heated pressure roller and the lower heated pressure roller and comes to rest on an exit table 14 undisturbed until the trailing edge is cool to the touch; whereupon the top-most carrier can be peeled away from receiver stock and from the transferred color donor. With the configuration of an upper heated pressure roller and a lower heated pressure roller as described above, the laminator is called a straight-through laminator. Further details of this type of lamination/de-lamination system can be found in the above patent. As an additional reference U.S. Pat. No. 5,203,942 describes a lamination/de-lamination system as applied to a drum laiminator.
While the above-described laminator works well for a some materials and in limited conditions, there are many conditions and materials that cannot be laminated successfully using the above-described laminator. One problem is the intended image shifting from one color to another such that the dots/image from one color to the next are not overlaid correctly causing a misregistration of the intended image. Also damage to the media may occur in the form of speckle, freckle, image wave or creases commonly know as rivers or valleys. Any of the above mentioned problems can render the intended image unacceptable to the customer.
The aforementioned problems are for the most part due to the heated pressure rollers and there application. The upper heated pressure roller and the lower heated pressure roller have hollow cores that are typically made of metal. The hollow portion of the core is for accepting a heating rod or lamp while a rubber layer or shell typically of silicone rubber is formed around the outside of core. Typically one of the heated pressure rollers will have a different durometer. Typically one heated pressure rollers of this type has a 50-60 SHORE A durometer and the other a 65-80 SHORE A durometer and in some cases they are the same SHORE A durometer. When the upper heated pressure roller and the lower heated pressure roller are pressed together they form a nip or indentation which is typically 7-10 mm wide and varies considerably along the length of the heated pressure rollers at a pressure of 40-80 PSI . Within the nip formed by the upper heated pressure roller and the lower heated pressure roller, lateral shear stresses and overdrive conditions are formed. These lateral sheer stresses and overdrive conditions act upon the media being laminated together to cause the intended image to shift from one color to another color. These lateral sheer stresses and overdrive conditions can also cause a defect in the final lamination in the form of creases commonly known as a rivers or valley, as described above. These lateral sheer stresses and overdrive conditions can also cause image growth which can be different with each color, causing the intended image to be misregistered from one color to the next color or to be larger than the original image or printed image. Also these lateral sheer stresses and overdrive conditions can cause the bond that holds the rubber on the core to fail letting the rubber to delaminate from the core.
SUMMARY OF THE INVENTION
An object of the present invention is to provide for an apparatus and method that overcome or reduces the drawbacks noted above
The present invention provides for a laminator and heated pressure roller arrangement that overcomes lateral shear stresses and overdrive conditions, and allows the use of low durometer rubber or of a compressible rubber.
The present invention further provides for a heated pressure roller that allows the use of a wider nip, and permits a wider range of media to be laminated.
The present invention further provides for a heated pressure roller that allows a wider range of conditions for lamination, and permits a wider range of media thicknesses to be laminated.
The present invention also provides for a heated pressure roller that overcomes or reduces image growth and overcomes or reduces image shift from one color to another. Additionally, the present invention provides for a heated pressure roller that overcomes or reduces defects such as creases, rivers or valleys.
According to a feature of the present invention, a laminating system for bonding, to a paper receiver stock, a thermal print media of the type including a carrier and a material to be applied to the paper receiver stock, includes an improved pair of heated pressure rollers through which a sandwich of thermal print media and paper receiving stock is fed. The pair of heated pressure rollers have been improved by adding, to at least one of the heated pressure rollers, a metal or plastic belt or tube over a rubber layer of the heated roller. This serves to prevent lateral stresses or overdrive conditions from acting on the thermal print media or paper receiving stock.
The present invention relates to a laminator assembly which comprises a first roller located on a first side of a media passage; and a second roller located on a second side of the media passage so as to oppose the first roller. A nip portion is defined between the first and second rollers so as to apply pressure to media in the media passage which passes through the nip portion. Each of the first and second rollers is a heated roller that comprises a heating core and a substantially solid layer which surrounds the heating core. At least one of the first and second rollers comprises a first deformable layer which surrounds the substantially solid layer and a second deformable layer which surrounds the first deformable layer and forms an outer surface of the “at least one” first and second rollers.
The present invention also relates to a laminating roller assembly for a laminator which comprises first and second opposing rollers; wherein one of the first and second opposing rollers comprises a heater core, a substantially solid or compressible layer which surrounds the heater core, a first deformable layer which surrounds the substantially solid or compressible layer and a second deformable layer which surrounds the first deformable layer and forms an outer surface of the one of the first and second opposing rollers.
The present invention also relates to a laminator assembly that comprises a first roller located on a first side of a media passage; and a second roller located on a second side of the media passage so as to oppose the first roller. A nip portion is defined between the first and second rollers so as to apply pressure to media in the media passage which passes through the nip portion; wherein at least one of the first and second rollers comprises a first deformable layer and a second deformable layer which surrounds the first deformable layer and forms an outer surface of the at least one of the first and second rollers to contain the rubber to prevent lateral sheer stresses and over drive conditions.
The present invention also relates to a laminator assembly that comprises a first roller located on a first side of a media passage; and a second roller located on a second side of the media passage so as to oppose the first roller. A nip portion is defined between the first and second rollers so as to apply pressure to media in the media passage which passes through the nip portion; wherein at least one of the first and second rollers comprises a first deformable layer and a second deformable layer which surrounds the first deformable layer and forms an outer surface of the at least one of the first and second rollers to contain the rubber to prevent the first deformable layer from destroying the bond and coming off the roller core.
The present invention further relates to a laminating method which comprises the steps of forming at least one deformable layer on at least one of first and second pressure rollers so as to increase a width of a nip portion between the first and second pressure rollers; and passing a media to be laminated between the first and second pressure rollers and through the nip portion having the increased width.
The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiments presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which:
FIG. 1 is a perspective view showing a laminator known in the related art;
FIG. 2 is a perspective view showing the loading operation of a laminator according to a preferred embodiment of the present invention;
FIGS. 3-5 are schematic side elevation views showing progressive stages of operation of the laminator of FIG. 2; and
FIGS. 6-8 are schematic side elevation views showing alternative details of the heated pressure rollers according to the present invention of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The present description will be directed, in particular, to elements forming part of, or cooperating more directly with, an apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art. For the sake of discussion, but not limitation, the preferred embodiment of the present invention will be illustrated in relation to a laminating apparatus for making image proofs on a paper receiver stock, since the usual proofing practice is to make a hard copy of the image proof on paper. The present invention, however, is not limited to making hard copies of proof images on paper, since it can produce hard copies of images on a wide variety and thicknesses of media that may be used in the printing process.
Referring now to the drawings, wherein like reference numerals represent identical or corresponding parts throughout the several views, FIG. 2 shows a pair of rollers, in the form of an upper heated pressure roller 16 and a lower heated pressure roller 18 of a laminator 120 according to the present invention. Upper heated pressure roller 16 is provided with a roller cover 22 to protect the operator. The remainder of the laminator 120 has been omitted from the illustration for clarity, As shown in FIG. 2, media in the form of an assembled lamination sandwich 100 is made up of thermal print media 24 and paper receiving stock 26 . Thermal print media 24 can include a transfer layer, on an image bearing side of thermal print media 24 facing paper receiving stock 26 , which is to be applied to paper receiving stock 26 when heat and pressure are applied to lamination sandwich 100 .
Referring now to FIGS. 3-5, lamination sandwich 100 made up of thermal print media 24 positioned on paper receiving stock 26 travels along a media passage 200 to a nip portion 32 between heated pressure rollers 16 and 18 . Upper heated pressure roller 16 and lower heated pressure roller 18 can each contain a heating element 30 (see FIGS. 6-8) that respectively apply heat to the surfaces of upper heated pressure roller 16 and lower heated pressure roller 18 . Pressure is applied to upper heated pressure roller 16 and lower heated pressure roller 18 in a known manner by, for example, eccentrics, levers, etc. that are not shown. Lower heated pressure roller 18 can be driven such that when upper heated pressure roller 16 and lower heated pressure roller 18 are pressed together they both rotate. A lead edge 34 (FIG. 2) of lamination sandwich 100 is fed into nip portion 32 formed by moving upper heated pressure roller 16 and lower heated pressure roller 18 . Lamination sandwich 100 is heated and thermal print media 24 positioned on paper receiving stock 26 are pressed together (FIG. 3) as they pass through nip portion 32 formed by upper heated pressure roller 16 and lower heated pressure roller 18 . As lamination sandwich 100 emerges from nip portion 32 formed by upper heated pressure roller 16 and lower heated pressure roller 18 being pressed together (FIG. 4 ), until it exits nip portion 32 and on to the exit table 14 as shown in FIG. 1 . After lamination sandwich 100 cools sufficiently a support layer of thermal print media 75 is peeled from the laminated sandwich leaving behind a prepress proof 76 as shown in FIG. 5 and described in U.S. Pat. No. 5,203,942.
FIGS. 6-8 are schematic side elevation views showing details as well as alternate details of heated pressure rollers 16 , 18 according to the present invention of FIG. 2 . In FIG. 6 upper heated pressure roller 16 and lower heated pressure roller 18 are shown. Both upper heated pressure roller 16 and lower heated pressure roller 18 are of the same construction. That is, both upper heated pressure roller 16 and lower heated pressure roller 18 include a metal or substantially solid hollow core or layer 42 which is adapted to accept heating element 30 . A deformable sleeve or layer 48 is formed around layer 42 in a known manner so as to surround and be bonded to layer 42 . Deformable layer 48 can be a low durometer rubber, a compressible rubber, a solid rubber silicone, a foam silicone rubber or other materials such as urethane which exhibit deformable or compressible properties. A roller sleeve or layer 46 which makes up a second deformable layer is shown around layer 48 . Layer 46 can be in the form of a metal or plastic belt or tube.
Typically in the industry a fluorine resin is coated onto the silicone or a fluorine tube is made and shrunk fit onto the silicone layer using a bonding agent. This has been the practiced since early 1992 While this works somewhat for light pressure and low temperature applications. In the case of lamination this is impractical, tubes made of a fluorine material have a low and limited temperature range. They typically continue to shrink with higher temperatures this causes the tube to split or delaminate from and walk off the silicone layer destroying the roller. While coated fluorine rollers cannot achieve sufficient integrity for high temperature or high pressure applications. For this application the preferred embodiment is the use of a polyimade and better yet a polimade with silicone. While metal can be used it is subject to damage dents which can render it non-useable. Although the outer deformable layer 46 can be made as a tube fashioned by a dip-coated skived or extruded methods, because the tube must be placed in a mold to cast the first deformable layer 42 the tolerances required make it impractical. The preferred method is form the outer deformable layer 46 by a spin-cast method in the same tool used to cast the first deformable layer 42 without removing the outer deformable layer 46 . After the outer deformable layer 46 is spin-cast the tool with the outer deformable layer 46 is removed. A substantially solid hollow core or layer 42 is added. Then the first deformable layer 42 is cast or foamed between the substantially solid hollow core or layer 42 and the outer deformable layer 46 . The thickness of the outer layer 46 is greater than 50 mm.
As shown in FIG. 6, as lamination sandwich 100 passes nip portion 32 , deformable layers 48 and 46 deform to increase a width of nip portion 32 and form an enlarged nip portion 32 . The arrangement of the present invention permits the width of nip portion 32 to be decreased or increased as needed. Nip portion 32 is also substantially uniform as it extends along a rotational axis of heated pressure rollers 16 , 18 . This configuration overcomes or minimizes lateral shear stresses and overdrive as lamination sandwich 100 passes nip portion 32 . In the embodiment of FIG. 6, since both rollers are of the same construction, the increased width nip portion 32 is formed on both sides of media passage 200 .
In the embodiment of FIG. 7 a , the upper roller 16 has the same construction as the heated pressure roller 16 shown in FIG. 6 . In FIG. 7 a heated pressure roller 18 is made of a solid or substantially solid material such that only heated pressure roller 16 deforms to form nip portion 32 .
FIG. 7 b shows a further embodiment in which heated pressure roller 16 has the same construction as heated pressure roller 16 of FIG. 7 a . In FIG. 7 b a movable platen 500 having media 100 retained thereon is axially moved passed heated pressure roller 16 to cause rotation of heated pressure roller 16 . In the embodiment of FIG. 7 b , heated pressure roller 16 deforms as shown in FIG. 7 a.
In the embodiment of FIG. 8, heated pressure roller 16 has the same construction as heated pressure roller 16 of FIGS. 6 and 7 a , 7 b . Heated pressure roller 18 of FIG. 8 includes heater core 30 and metal or substantially solid core or layer 42 which surrounds heater core 30 . In the embodiment of FIG. 8, the outer circumference of heated pressure roller 18 is formed by layer 48 . Therefore, as shown in FIG. 8, heated pressure roller 16 deforms to form nip portion 32 .
Although the illustrated embodiments show both pressure rollers as heated pressure rollers, it is recognized that only one pressure roller can be heated. It is further recognized that both pressure rollers do not have to be heated for cold lamination applications.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention. | A laminating assembly and method bonds a lamination sheet to receiver stock. The laminating assembly includes a pressure roller arrangement which comprises upper and lower pressure rollers ( 16, 18). At least one of the upper and lower pressure rollers includes at least one deformable layer. The roller arrangement including the at least one deformable layer permits an increase in a width of a nip portion ( 32) between the upper and lower rollers to overcome lateral shear stresses and overdrive. |
FIELD OF THE INVENTION
The present invention is directed to a bicycle locking system. More particularly, the invention relates to a bicycle frame which is generally and easily lockable to a vertical structural or material element such as a metal or wooden post or tree trunk.
BACKGROUND OF THE INVENTION
Approximately one-half million bicycles are stolen each year, and many are stolen because they are inadequately locked. Bicycling magazine (August, 1994) reports test results in which most portable bicycle locks were violated in less than one minute. To combat theft, two general systems of portable bicycle locks have been developed in prior art. Each kind of lock has a different weakness, which may allow the bicycle to be stolen with relative ease.
A first kind of lock includes one or more elements such as a lock, shackle, or cable) that is external to or carried by the bicycle frame. This kind of lock attempts to secure the bicycle to a stationary external object. Because these locks have at least one component that is external to the bicycle frame, the locks can be broken using simple hand tools, such as bolt cutters to cut a cable, an automobile jack to pry a lock open,or a hammer to shatter a lock that a thief made brittle by subjecting it to extreme cooling with dry ice or liquid nitrogen. With this class of devices, the external components of the lock can be broken or compromised without damaging the bicycle or disturbing its operation. The stolen bike is usable and sellable.
A second kind of bicycle lock eliminates the weakness of an external element by keeping the locking system essentially entirely within the bicycle frame. This kind of lock makes the bicycle non-functional, but the bicycle can nevertheless be stolen merely by picking it up and carrying it to another location where the internal lock can be broken or removed using more sophisticated tools. An example of this is U.S. Pat. No. 3,774,421 (Stephens) where the horizontal top tube of a bicycle frame includes a lock and a chain is stored within the top tube. In use, however, the chain in the locking mode can be easily cut by a thief.
To effectively prevent theft, a locking system must have two characteristics: (a) every piece of the locking system must be protected within the bicycle, so that breaking the lock causes damage to the bicycle, and (b) the lock must secure the bicycle to a fixed external object. In order to meet these geometric requirements, the bicycle frame itself should function as a lock.
The art of folding bicycles broadly suggests the use of articulating bicycle frame parts so as to make the bicycle smaller and more easily transported or stored. U.S. Pat. No. 4,417,745 (Shomo) discloses a bicycle which hinges inter alia about a vertical hinge located in the bicycle frame. This bicycle along with most or all other folding bicycles, serves no anti-theft purpose. Folding bicycles with their myriad of folding parts requires manufacturing considerably different from a standard bicycle. Components to separate a bicycle for packing in a wheel-sized carrying case have been sold by S and S Machine, Roseville, Calif. Torque couplings are provided to separate one end of the bicycle top tube, one end of the down tube and the front fork from the seat tube, the pedal crank housing and the rear fork. Italian Patent No. 360,530 (Ascaralli) shows separation of a head tube from a top tube, seat tube and a bottom tube leading to the pedal crank housing. French Patent No. 883,836 also shows a folding bicycle having a series of pivoting joints in each of the bicycle frame tubes with one end of a top tube being demountable from the seat tube. None of the above collapsible or folding bicycles serve any anti-theft purpose. U.S. Pat. No. 3,814,462 (Kelly) shows an anti-theft bicycle frame where one end of a top tube is split and lockable to a stub end of the top tube attached to the seat tube and where the forwardly extending diagonal frame members i.e. most of the fixed top tube, the head tube and the down tube are pivotably connected to the pedal crank housing. This necessitates the whole bicycle or at least a pivoted half to be lifted to open the bicycle as seen in FIG. 5 of Kelley and the need for a special pivoting joint at the crank housing or otherwise, where the bicycle is lifted off the ground in order to open the frame.
From the above it is seen that there has been a need for a simple but effective locking system contained in the structure of the bicycle 1) where damaging the lock or top tube damages and immobilizes the bicycle, 2) where the bike can be simply and easily leaned against a pole or tree or other immovable structural member, so that the bicycle can be relocked and then cannot be carried away by a thief and 3) where these needs can be accomplish with a standard bicycle frame slightly modified and enabling manufacture using standard processes.
SUMMARY OF THE INVENTION
The above needs may be realized by providing a self-locking bicycle where the top tube only of the normally closed polygonal portion of the frame, i.e. the top tube, the down tube and seat tube, is unlocked and removed, or unlocked and pivoted, so as to open the bicycle at a top tube removed position so that the then open top bicycle merely can be leaned into a tree trunk or immovable vertical high pole and the top tube replaced or repivoted between the down tube and seat tube and then relocked. An unauthorized user of the bicycle would have to destroy the frame in order to remove the bicycle from the immovable fixed external object (tree, pole or other fixed bar post structure).
The invention provides a self-locking bicycle including a head tube rotatively mounting a wheel-containing front fork; a down tube rigidly connected to and extending from the head tube to a fixed bicycle drive pedal crank housing; a seat tube rigidly extending from a bicycle seat assembly to the crank housing and rigidly connected thereto, the seat tube rigidly mounting a wheel-containing rear fork; and an essentially horizontal top tube extending from the head tube to the seat tube; the top tube being lockingly affixed between the head tube and the seat tube and demountable from at least one of the head tube and the seat tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a self-locking bicycle of the invention locked to a vertical pole and the top tube and, in phantom, the top tube in a pivoted opened position prior to leaning the bicycle into a pole.
FIG. 2 is a side view of a second embodiment thereof showing the top tube entirely removed.
FIG. 3 is a cross-sectional view of a top tube locking torque connector.
FIG. 4 is a perspective exploded view thereof.
FIG. 5 is a perspective view of a top tube on a pivot cylinder on a bicycle head tube.
FIG. 6 is a perspective view of an unclamping device for the pivot cylinder permitting pivoting of the top tube.
FIG. 7 is an exploded perspective view of a second embodiment of the top tube and locking connector thereof in a disconnected mode.
FIG. 8 is an exploded schematic cross-sectional view of the locking mechanism taken on the line 8--8 of FIG. 7.
FIG. 9 is an exploded schematic perspective view of the combination lock embodiment of the locking mechanism.
DETAILED DESCRIPTION
Referring to FIG. 1 of the drawing, a bicycle 10 of conventional construction having a triangular polygonal frame 11 including an essentially horizontal top tube 12, a head tube 13 supporting a front fork 14 and front wheel 15, a down tube 16 rigidly affixed to and extending from the head tube 13 to a lower end rigidly affixed to a pedal crank housing 17, and a seat tube 18 rigidly affixed to the crank housing and supporting a rear fork 19 and rear wheel 20. A saddle assembly 21 is adjustably mounted on or in the top end 18a of the seat tube 18. The forward end 12a of top tube 12 is hinged (pivotable) on a cylinder 22 which is rotatable on head tube 13 below handle bars 23. The other seat end 12b of top tube 12 is lockingly affixed to a connector 24 having a bolt head part 24a which is rigidly fixed to the seat tube 18 and a locking and torque transmitting connector end 25. Rigid affixation of the above parts is normally done by welding.
Unlocking of the top tube 12 and removal of a nut part 36 of the connector end 25 and the top tube 12 from bolt head 24a, along with loosening of cylinder 22 on the head tube 13, permits the top tube to be pivoted into the dashed lined position 27 opening up frame 11. The bicycle then can be leaned into a high post or tree trunk 30 with the opening 26 between the head tube 13 and seat tube 18 passing past the post or tree. The pivoted top tube 12 is then repivoted and reconnected by the tube captured nut 36 (FIG. 3) to the bolt head 24a, and by retightening cylinder 22 on the head tube 13, to return structural integrity to the bicycle. A locking mechanism FIGS. 3 and 4 in the bolt head 24a is then turned or otherwise actuated to lock the top tube and a tube captured nut 36 to the connector end 25 and the bolt head 24a. The nut 36 is captured on the tube end 12b by a fixed peripheral ring 12c extending cylindrically therearound, preventing removal of the bicycle from the pole 30, except by one having a key accessing a key slot 29 or a combination, if a combination lock is incorporated, or when another mechanical or electronic lock actuator is employed. Any other attempt to remove the bicycle would result in such damage to the bicycle that it would no longer have structural integrity. The pole 30 must be high enough e.g. a flag or light pole or the like, so that one could not lift the bike over the pole top.
FIG. 2 shows a second embodiment of the invention in which the top tube includes a captured nut 36 at each tube end, and the top tube and nuts are entirely removed from respective bolt heads 24a and connector ends 25 on the head tube 13 and seat tube 18. The bicycle can then be leaned into a tree or pole as seen in FIG. 1. The nuts are each shifted back toward the middle of top tube 12 and are repositioned and rethreaded on the bolt heads 24a reconstituting the structural integrity of the bicycle and then locked preventing unauthorized access to the bicycle locked around the tree trunk or pole.
FIGS. 3 and 4 illustrate a first embodiment of the tube connector 24. The connector 24 includes a bolt head 24a rigidly affixed as by welding typically to the seat tube in FIG. 1. In the FIG. 2 embodiment separate bolt heads are rigidly affixed to both the seat tube and head tube. The bolt heads include a key-lock cylinder 31 and cylinder bore 31a. For illustration purposes only, the bore 31a and cylinder are shown as being gapped. Normally, the cylinder will slide into the bore with a close sliding fit. The cylinder includes a fixed cantilevered arm which is rotatable over about 15° to 20° of arc to move (arrows 32a) a cylinder bolt 33 attached to the arm, slidingly through an aperture 34 in an intermediate portion of connector end 25 outboard of a threaded part 38 of the intermediate portion. In a locked position, bolt 33 coacts and abuts against an interior flange surface 35 of nut 36 to lock the top tube. A facing opposite nut end interior flange surface 39 abuts a peripheral side surface of fixed ring 12c on tube 12, when the nut threads 37 fully cinch up the nut on the threads 38 of the intermediate portion. The peripheral end of the connector end 25 includes an anti-rotation surface, for example, a series or plurality of parallel ridges 40 which interfit in friction contact in the fully cinched-up assembled condition of the threaded nut and threaded bolt portion, with a corresponding anti-rotation surface, such as a second series or plurality of parallel ridges 41 on the end of the top tube. The ridges may be provided on an end of a plug 41a which is insertable into the end 12b of tube 12. Arrows 42 illustrate the sliding action of bolt 33 to be in a position less than the diameter of threads 37 at an inner position and to lock against flange surface 35 in an outer position. The gaps between the threaded members, and around the bolt 33 and between ridges 40 and 41 are likewise made large for illustration purposes only. In actuality, in the connected mode of operation, these are all within sliding or abutting surface tolerances. For manufacturing assembly purposes, the ring 12c is welded to tube 12 after nut 36 has been inserted over the tube end 12b and slid rearwardly past the position at which ring 12c is to be welded.
FIGS. 5 and 6 illustrate the pivot cylinder 22 which is initially loosely mounted around head tube 13 between cylindrical ridges 13a and 13b to confine the cylinder longitudinally. The cylinder 22 is rigidly affixed to top tube 12 and contains an opposed longitudinal slot 44, the edges of which may be tightened together by the clamping of integral spaced tabs 45 extending outwardly from the slot edges, which tabs and edges can be brought together by a hand-operated lever 47 and integral bicycle clamp bolt 46 threaded into nut 48. When the tabs and slot edges are brought together, the cylinder is firmly clamped to head tube 13 affording sufficient structural integrity to the connection between the top tube and head tube. Loosening of bolt 47 allows the top tube to be pivoted, after the other end 12b of the top tube has been unlocked from connector end 25, allowing the bike frame to be positioned about a pole.
FIGS. 7 and 8 show a second embodiment of a locking connector in which a top tube 50 is modified to have half-round ends 50a and 50b which include depending locking pins 51 and 52. Top tube stubs 54 and 56 are welded to the head tube and seat tube respectively and each contain apertures 53 and 55. Pins 51 slidingly fit into apertures 53 and pins 52, each of which having a lock notch 62, fit into apertures 55 at the tube end 50a. A key-operated locking cylinder 57 is provided in the end of stub 56, including a rotatable lock operator 60 having a locking tongue 61 which is rotatable into locking engagement with notches 62 of inserted pins 52. The half round end 50b of the top tube 50 is long enough so that key 58 can be inserted into lock cylinder 57. The stubs 54 or 56, the connector ends 25 and bolt heads 24a (FIG. 2) and the cylindrical sleeve 22 (FIG. 5) each variously shown connected to the head tube or seat tube, are included in the generic term "connection piece" used herein, to which ends of the top tube 12 or 50 are connected.
FIG. 9 schematically shows a combination lock embodiment of the locking mechanism. A half-round end 50b of the top tube 50 includes a depending pin 52 (not shown) which is inserted with aperture 55 as in FIG. 7, and a depending cylindrical combination lock pin 52a having aligned spaced projections 92 thereon, as conventionally employed on a bicycle chain combination lock. A series of rotatable dials 91 each with an internal notch (not shown) which notches when aligned, allow the projections 92 on lock pin 52a to pass into top tube stub 56 through aperture 55a and into the notches (not shown) of the dials. When the dials are rotated, in the usual manner as in the bicycle chain combination lock, so that the given lock combination is not aligned with an indicia mark 93, the lock pin 52a is then locked in stub 56. The rotating dials 91 have numbers 0, 1, 2, 3, etc. inscribed on their peripheries to indicate the combination of numbers which must be dialed and aligned with mark 93 to unlock the combination lock.
The above description of embodiments of this invention is intended to be illustrative and not limiting. Other embodiments of this invention will be obvious to those skilled in the art in view of the above disclosure. | A polygonal frame self-locking bicycle includes a head tube mounting a wheel-containing front fork, a down tube rigidly connected between the head tube and a pedal crank housing, a seat tube mounting a rear fork and wheel and rigidly connected to the crank housing and a top tube locking with and demountable from at least one of the head and seat tubes. Preferably, a top tube end is key-locked to the seat tube and the other end affixed to a clamping cylinder around the head tube. Loosening of the clamping cylinder permits pivoting an unlocked top tube to open a space between the seat and head tubes. The demounted top tube forms a frame opening that can be leaned past a vertical pole and the top tube remounted and relocked locking the frame about the pole. |
BACKGROUND OF THE INVENTION
The present invention relates to a new and improved construction of an explosive practice hand grenade and to a new and improved method of manufacturing such explosive practice hand grenade.
In its more particular aspects, the present invention relates specifically to a new and improved construction of an explosive practice hand grenade of high explosive pressure power and which comprises a shell, a body made of a high-explosive charge enclosed by the shell and defining an axis. A detonator including a delayed-action fuze is provided and arranged substantially in the axis defined by the body made of the high-explosive charge.
Explosive practice hand grenades for training purposes are known. Such hand grenades only approximately correspond to the conditions of combat practice with respect to their size, shape and the sound of the explosion. Particularly, the explosive practice hand grenades do not possess the properties or characteristics known for combat-duty fragmentation hand grenades. The weight, the position of the center of mass and the impact behavior after the throwing of the explosive practice hand grenade as well as the explosion pressure power, i.e. the explosive sound effect during the explosion, do not satisfy combat requirements. The known fragmentation hand grenades are also unsuited for training purposes due to the extraordinary danger caused by their fragments.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved construction of an explosive practice hand grenade which meets the handling requirements and corresponds in function to a combat-duty fragmentation hand grenade without exposing the personnel to the danger caused by its fragments.
Now, in order to implement these and still further objects of the invention which will become more readily apparent as the description proceeds, the explosive practice hand grenade of the present development is manifested by the features that a ring or ring member is embedded in the explosive charge and is substantially completely enclosed by such explosive charge.
On detonating the inventive explosive practice hand grenade a large portion of the released energy is used for pulverizing and accelerating the particles of the aforementioned ring. The remaining energy firstly destroys the shell which is preferably formed by two interconnected hemispherical shells and then is released in the form of harmless clouds of smoke. Since the particles have a small size, such particles are very rapidly aerodynamically decelerated. The ring simultaneously serves as a balancing body.
Preferably the ring is composed of inorganic particles.
The particles, for example, may be compacted to form a compressed body which is decomposed into its components by the explosion. In this manner no effective fragments can occur at a distance of 5 m. Non-effective fragments are understood to represent fragments which are unable to pierce an aluminum sheet having a thickness of 2 mm and a tensile strength of 400 N/mm 2 .
This effect is advantageously achieved due to the fact that the explosive charge approximately has a spherical shape define an explosive body having a body axis and the detonator is arranged approximately at the center of the spherical shape and along the body axis of the body of the explosive charge. A substantial portion of the explosive is thereby also arranged at the center of the ring and thus can uniformly act in a concentrated manner upon the ring due to the central detonation.
This effect is enhanced if the ring has preferably, and at least approximately, the shape of a hollow cylinder.
Advantageously, the height of the ring is selected such as to be substantially twice as great as its maximum wall thickness. A value of about 2:1 for the ratio of the height to the wall thickness results in manufacturing advantages, for example, during production of the molds required therefor.
In order to concentrate the largest possible proportion of the explosive charge in the interior of the ring, it is recommended to select the maximum spacing of the ring from the shell such that the spacing is substantially equal to the wall thickness of the ring.
When the outer substantially cylindrical shell of the ring is stepped, the attachment of a holding ring at approximately medium height of the ring is facilitated, which is of advantage for the assembly of the inventive explosive practice hand grenade.
The manufacture and assembly of the ring or ring member is additionally facilitated by providing the ring with bevelled peripheral edges.
Preferably, the powderous particles of the ring are selected from a particle size in the range of about 20 to 200 μm. For this purpose, a particle size distribution has been found favorable which contains a maximum of 35 percent of particles smaller than 63 μm and a maximum of 15 percent of particles which are greater than 160 μm.
It is particularly advantageous to produce the particles from sintering iron or steel. The sintering iron powder or steel can be economically manufactured and can be readily compacted when subjected to pressure. However, other metal powders or metal oxide powders can also be used for this purpose.
Preferably, the shell is formed by an upper substantially hemispherical shell and a lower substantially hemispherical shell. These hemispherical shells can be interconnected by welding as well as by bending-over or flanging or the like. Other known manners of interconnection can also be employed. It is recommendable therefore to select aluminum or an aluminum alloy as the material for the hemispherical shells. The sheet thickness of the substantially hemispherical shells is dimensioned such that no effective fragments are formed as a result of the explosion and amounts to values in the range of about 0.2 to about 2.0 mm, preferably about 0.5 to about 1 mm.
Advantageously, the holding ring is mounted on the inside between the connecting edges of the two substantially hemispherical shells. The holding ring primarily serves to essentially center the ring until such ring is fixed in its desired position by the explosive as it solidifies after casting.
Preferably, the holding ring is made of the same material as the substantially hemispherical shells which form the shell, i.e. of aluminum or of an aluminum alloy.
At its inner margin the holding ring preferably comprises recesses. These recesses serve as discharge openings for the air which escapes during the casting of the explosive as well as for enabling the explosive to continue to flow thereinto during casting.
As alluded to above, the invention is not only concerned with the aforementioned construction aspects, but also relates to a novel method of manufacturing the explosive practice hand grenade. Generally speaking, the inventive method is directed to manufacturing an explosive practice hand grenade containing a body of an high-explosive charge and a ring embedded in and substantially completely enclosed by said high-explosive charge.
To achieve the aforementioned measures, the inventive method, in its more specific aspects, comprises:
compressing powderous sintering iron or steel of a particle size in the range of, for example, about 20 μm to about 300 μm.
After a heat treatment by annealing with the addition of high molecular weight waxes in order to facilitate the compressing operation, the powderous sintering iron is compressed in a displaceable die at a pressure in the range of about 4,000 to about 8,000 bar, preferably at about 6,000 bar.
Preferably, the ring is phosphatized after the compressing operation.
Advantageously, the phosphatized ring is covered by a lacquer layer having a thickness in the range of about 20 to about 300 micrometers (μm); such lacquer layer is made of an explosive-compatible lacquer on the basis of acrylates.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings there have been generally used the same reference characters to denote the same or analogous components and wherein:
FIG. 1 is a longitudinal sectional view along an axis I--I of an exemplary embodiment of the inventive explosive practice hand grenade;
FIG. 2 is a cross-section through the explosive portion of the explosive practice hand grenade shown in FIG. 1 in the region of a holding ring of the explosive practice hand grenade;
FIG. 3 is a cross-sectional view of a detail in the region of the mounting of the holding ring shown in FIG. 2; and
FIG. 4 is a cross-sectional view of a detail showing a variant of the mounting of the holding ring illustrated in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the explosive practice hand grenade has been shown as needed for those skilled in the art to readily understand the underlying principles and concepts of the present development, while simplifying the showing of the drawings. Turning attention now specifically to FIG. 1 of the drawings, there has been shown a longitudinal section of an exemplary embodiment of the inventive explosive practice hand grenade. The shell of the inventive explosive practice hand grenade possesses a central axis A and comprises an upper substantially hemispherical shell 1 and a lower substantially hemispherical shell 2 which are made of, for example, aluminum or an aluminum alloy. A threaded adapter 3 for receiving a fuze or detonator is provided in the upper substantially hemispherical shell 1. A ring or ring member 4 which is also called a disintegrating body, comprises a compressed body of powderous sintering iron or steel and is provided with a step or stepped portion 4'. As shown in FIG. 1 of the drawings the ring 4 is located about the central axis A of the practice hand grenade.
A holding ring 5 made of aluminum or an aluminum alloy engages the step or stepped portion 4'. This holding ring 5 is secured with its periphery between connecting edges 1' and 2' of the substantially hemispherical shells 1 and 2. The holding ring 5 is held at its inside against the inside of the lower hemispherical shell 2 by means of a clamp 6 and against the ring 4 by means of a further clamp 6'. It is the task of the holding ring 5 to insure the mounting and positioning of the ring 4 within the substantially hemispherical shells 1 and 2 prior to, and during, the casting of an explosive charge 8. The ring 4 which has an outer surface, an inner surface, a top surface and a bottom surface, is embedded in, and completely enclosed by, the explosive charge 8 which constitutes an active charge and each of these surfaces of the ring 4 is in contact with the explosive charge 8 as will be clearly evident by inspecting FIG. 1. Due to this arrangement, the application of the explosive is substantially concentrated at the inside of the ring 4. The region occupied by the explosive between the outside of the ring 4 and the inside of the substantially hemispherical shells 1 and 2 is dimensioned such that the shell can be disintegrated during the detonation only into ineffective fragments. A fuze or detonator head 9 is threaded into the threaded adapter 3. The left-hand side of a fuze or detonator element 10 is illustrated in a front-elevational view. A fuze or detonator cap 11, a fuze or detonator cap carrier 12 and a delay set 13 in a delay tube 14 are incorporated in an upper portion of the fuze or detonator element 10. In a lower portion of the fuze or detonator element 10, a sleeve 18 is inserted into an axial cut-out in the explosive charge 8 and accommodates a detonator or primer cap 15, an initiating explosive or primary charge 16 and an augmenting or secondary charge 17. A safety bracket 19 is attached to the fuze or detonator head 9 and carries by means of a pivot shaft or axle 20 a tension spring 21 which is secured by means of a safety split pin or splint 22. An impact device 23 carries an impact hammer 24.
FIG. 2 shows a cross-section in the region of the holding ring 5 through the explosive portion of the exemplary embodiment of the inventive explosive practice hand grenade illustrated in FIG. 1. In FIG. 2, a number of recesses 7 are shown in the holding ring 5 which ensure the escape of air from the lower substantially hemispherical shell 2 during the casting operation of the explosive charge 8 as well as during the follow-up flow of the explosive. For better clarity, the explosive between the ring 4 and the sleeve 18 as well as in the recesses 7 has not been illustrated by hatching as in FIG. 1. The holding ring 5 comprises protrusions on its inside which assume the shape of the clamp 6 and of the further clamp 6'. The clamps 6 serve to substantially center the holding ring 5 on the inside of the substantially hemispherical shells 1 and 2. The further clamps 6' on the inside of the holding ring 5 have a bending angle of more than 90° and are intended to readily yield due to their elasticity during assembly with the ring 4 such that they exert a clamping force. These further clamps 6' engage the substantially cylindrical surface of the holding ring 5 in such a manner that a return displacement of the holding ring 5 is prevented. The inner protrusions of the holding ring 5 are of such a length that they bear upon the step or stepped portion 4' of the ring or member 4.
FIG. 3 is a detailed cross-sectional view of the region between the upper substantially hemispherical shell 1 and the lower substantially hemispherical shell 2. The holding ring 5 is mounted within a groove of a weld seam 5'. As shown, a protrusion on the inside of the holding ring 5 engages the step or stepped portion 4' of the ring 4.
A variant of the interconnection of the substantially hemispherical shells 1 and 2 is shown in FIG. 4 and assumes the shape of a bending-over or flanged or bordered interconnection 5" at the rims of the two hemispherical shells 1 and 2. In this case, the holding ring 5 is secured within such bending-over or flanged interconnection.
The exemplary embodiment of the inventive explosive practice hand grenade fulfills the same function as a fragmentation hand grenade with respect to the outer shape, the size, the position of the center of mass, the nature of the outer surface, the weight as well as the impact behavior after throwing and the same explosive sound effect during explosion. However, the inventive explosive practice hand grenade has the decisive advantage that it generates only a minimum fragmenting power during explosion. This minimum fragmenting power is achieved due to the ring or ring member 4 which disintegrates into powder during the explosion.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. | In an explosive practice hand grenade a ring containing inorganic particles is encased in a shell and substantially completely enclosed by an explosive charge. The ring is practically pulverized during detonation so that no effective fragments are formed. The ring is manufactured by compressing a metal or metal oxide powder. The inventive explosive practice hand grenade has substantially the same properties or characteristics as a combat-duty fragmentation hand grenade, however, has the advantage that the inventive explosive practice hand grenade, during its explosion, generates only a minimum fragment action and thus ensures the safety of personnel to be trained. |
This invention was made with Government support under Contract No.: H98230-04-3-0001 awarded by the U.S. Department of Defense. The Government has certain rights in this invention.
FIELD OF THE INVENTION
The present invention relates to privacy preserving data mining techniques and, more particularly, to distributed privacy preserving data mining techniques.
BACKGROUND OF THE INVENTION
Privacy preserving data mining has become an important issue in recent years due to the large amount of consumer data tracked by automated systems on the Internet. The proliferation of electronic commerce on the World Wide Web has resulted in the storage of large amounts of transactional and personal information about users. In addition, advances in hardware technology have also made it feasible to track information about individuals from transactions in everyday life.
For example, a simple transaction such as using a credit card results in automated storage of information about user buying behavior. In many cases, users are not willing to supply such personal data unless its privacy is guaranteed. Therefore, in order to ensure effective data collection, it is important to design methods which can mine the data with a guarantee of privacy. This has resulted in a considerable amount of focus on privacy preserving data collection and mining methods in recent years.
Privacy preserving data mining approaches may essentially be considered one of two types: (1) privacy determination using a single server; and (2) distributed privacy preserving data mining.
(1) Privacy Determination Using a Single Server.
In this approach, users are not willing to share their data with the server which stores their data. A recent approach to privacy preserving data mining of this kind of data has been a perturbation-based technique. Users are not equally protective of all values in the records. Thus, users may be willing to provide modified values of certain fields by the use of a (publicly known) perturbing random distribution. This modified value may be generated using custom code or a browser plug-in. Data mining problems do not necessarily require the individual records, but only distributions. Since the perturbing distribution is known, it can be used to reconstruct aggregate distributions. This aggregate information may be used for the purpose of data mining algorithms.
It is to be noted that the perturbation approach results in some amount of information loss. The greater the level of perturbation, the less likely it is that the data distributions are estimated effectively. On the other hand, larger perturbations also lead to a greater amount of privacy. Thus, there is a natural trade-off between greater accuracy and loss of privacy.
(2) Distributed Privacy Preserving Data Mining.
In this kind of privacy preservation, the users are willing to share the records with their individual servers, but not with other servers. In many cases, it may be desirable to find a way to mine the aggregate data across the different servers. An example of such a case is the situation in which different competing businesses do not wish to share their competitive data, but they do wish to cooperate to the extent that aggregate data across different servers is shared. This situation can often arise in a retail environment in which different competing entities may desire to find aggregate information about market basket transactions. Unfortunately, existing techniques do not provide suitable ways to mine the aggregate data across the different servers.
Accordingly, it would be highly desirable to provide techniques for use in accordance with a distributed privacy preserving data mining approach.
SUMMARY OF THE INVENTION
The present invention provides techniques for use in accordance with a distributed privacy preserving data mining approach.
For example, in one aspect of the present invention, a technique for data mining in a privacy-preserving manner in a distributed computing environment including a plurality of entities, comprises the following steps/operations. A first entity of the plurality of entities exchanges summary information with a second entity of the plurality of entities via a privacy-preserving data sharing protocol such that the privacy of the summary information is preserved, the summary information associated with an entity relating to data stored at the entity. The first entity may then mine data based on at least the summary information obtained from the second entity via the privacy-preserving data sharing protocol.
The first entity may obtain, from the second entity via the privacy-preserving data sharing protocol, information relating to the number of transactions in which a particular itemset occurs. The first entity may obtain, from the second entity via the privacy-preserving data sharing protocol, information relating to the number of transactions in which a particular rule is satisfied.
Further, the summary information exchanging step/operation may further comprise the first entity adding a random number to a global count and transmitting the global count to the second entity. The first entity may subtract a random number from a global count and transmit the global count to the second entity.
Still further, the summary information exchanging step/operation may further comprise: the first entity transmitting a first random number to the second entity; the first entity receiving from the second entity a first result, the first result representing a summation of the first random number and a second random number associated with the second entity; the first entity transmitting a second result to the second entity, the second result representing a summation of the first result and summary information relating to data stored at the first entity; the first entity receiving a third result from the second entity, the third result representing a summation of the second result and summary information relating to data stored at the second entity; the first entity transmitting a fourth result to the second entity, the fourth result representing a subtraction of the first random number from the third result; and the first entity receiving a fifth result from the second entity, the fifth result representing a subtraction of the second random number from the fourth result.
In addition, the summary information exchanging step/operation may further comprise the first entity exchanging summary information with two or more of the plurality of entities and the first entity mining data based on the summary information obtained from the two or more entities. The summary information may relate to a limited subset of items. The first entity may define the limited subset of items for which summary information is to be exchanged. The first entity may determine participating entities for each itemset for which summary information is to be exchanged. The first entity may transmit summary information only to a participating entity for a particular itemset.
The inventive technique may further comprise the step/operation of the first entity discarding itemsets having a number of potential participants below a particular threshold value. Also, the first entity may generate one or more association rules from one or more itemsets.
Thus, in accordance with embodiments of the present invention, techniques are provided for distributed privacy preserving mining of data from multiple entities. Advantageously, data may be mined without revealing either individual or summary information among the different entities. The invention also provides techniques in which entities can selectively contribute information about different items.
These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a distributed environment wherein various entities interact with one another for the purpose of privacy preserving data mining, according to one embodiment of the present invention;
FIG. 2 is a block diagram illustrating an architecture for each of the interacting entities illustrated in FIG. 1 , according to an embodiment of the present invention;
FIG. 3 is a flow diagram illustrating an overall data mining process with a protocol for performing information exchange during the data mining process, according to an embodiment of the present invention;
FIG. 4 is a flow diagram illustrating a procedure for computing counts of itemsets, according to an embodiment of the present invention; and
FIG. 5 is a flow diagram illustrating a procedure when a limited set of items is utilized for itemset mining process, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The following description will illustrate the invention using an exemplary distributed data processing system architecture. It should be understood, however, that the invention is not limited to use with any particular distributed system architecture. The invention is instead more generally applicable to any distributed data processing system in which it is desirable to provide improved techniques for use in accordance with a distributed privacy preserving data mining approach. As used herein, the term “entity” generally refers to one or more computing devices or systems such as, for example, may be associated with a data repository or server. However, the term is not intended to be limited to any particular computing device or system.
As will be illustratively described herein, the invention provides techniques for distributed privacy preserving data mining. Examples of data that may be mined include, but are not limited to, itemsets and association rules. This includes methods for situations in which different servers may have different numbers of transactions or items. The invention provides a protocol for passing information among the different servers in such a way that the privacy of the data in individual servers is maintained. At the same time, the aggregate itemsets can be mined for use by any of the servers.
Referring initially to FIG. 1 , a block diagram illustrates a distributed environment wherein various entities interact with one another for the purpose of privacy preserving data mining, according to one embodiment of the present invention. More particularly, FIG. 1 illustrates an overall setup for the invention. In the overall setup, a distributed procedure is used for the privacy preserving data mining technique. In this setup, a number of different data repositories are maintained which can share data among each other. The blocks 20 , 40 , 60 , 80 , and 100 represent the different data repositories. These data repositories may correspond to different businesses which may not wish to share their entire set of business information. At the same time, they may wish to collaborate to the extent that essential business information can be shared across multiple customers.
Referring now to FIG. 2 , a block diagram illustrates an architecture for each of the interacting entities (i.e., data repositories) illustrated in FIG. 1 , according to an embodiment of the present invention. That is, FIG. 1 illustrates an architecture at each customer end. Each of the entities contains a computing system in the form of a server 150 which is used for storing the data at its end. Each computing system may also include more than one server. This stored data is utilized for the purpose of data mining.
The server 150 contains a central processing unit (CPU) 110 , main memory 120 , and disk 130 . Disk 130 contains the private information belonging to each entity. CPU 110 performs the methodologies of the invention, i.e., processing related to the data mining. Main memory 120 is used by CPU 110 to perform the methodologies.
Each entity (server 150 ) also contains a connection to other clients (e.g., other data repositories), as is depicted in FIG. 2 . This connection to the other clients is used in order for the entities to exchange information with one another during the data mining process. It is to be appreciated that each entity in the distributed system may be coupled via a network (e.g., Internet, private network, a local area network, or some other suitable network).
Accordingly, in this illustrative embodiment, all or portions of the data mining operations of the present invention are executed in association with server 150 . All or a portion of the results generated in association with the computer system may be presented on a display (not shown) to a system user, if so desired. Further, in one embodiment, software components including program instructions or code for performing the methodologies of the invention, as described herein, may be stored in one or more memory devices described above and, when ready to be utilized, loaded in part or in whole and executed by the CPU.
Referring now to FIG. 3 , a flow diagram illustrates an overall data mining process with a protocol for performing information exchange (data sharing) during the data mining process, according to an embodiment of the present invention. It is to be understood that any one or more of the interacting entities (e.g., servers 150 ) in the distributed environment may perform the data mining process in accordance with the information exchange protocol of the invention. Alternatively, a computing system separate from any of the servers may perform the inventive process.
In accordance with an illustrative embodiment, we discuss the problem of itemset generation from transactional data belonging to different customers. However, the inventive technique can be easily extended to a host of other problems.
As an example, we will use the case of transactional data bought by customers in a superstore. The transactional data includes groups of items bought by different customers in a superstore. The problem illustrated here is that of finding large itemsets from these groups of customers. An itemset is defined to be a group of items which are bought together. For example, the set of items {Bread, Butter, Milk} could correspond to an itemset.
We define a k-itemset as a set which has at least k items therein. Typically, an itemset corresponds to a group of closely related items. For an itemset to be considered relevant by the data mining process (i.e., also referred to as a large itemset), it should be present in at least a certain fraction of the overall number of customers. This fraction is defined as the minimum support. We note that the data sets are divided over the different entities illustrated in FIG. 1 . This makes the problem of computing the overall support values especially difficult. This is because each entity is not privy to the data available to other entities. Therefore, it is desirable to share the data in such a way that only aggregate statistics are shared among the different entities. At each stage, we do not wish to share the actual records, but only aggregate summary statistics about the supports of particular itemsets local to each group.
Even the aggregate summary statistics need to be masked appropriately, since in many cases entities may not be willing to provide such statistics for competitive reasons. Thus, the invention provides a protocol which is able to share the information among different entities while also maintaining the privacy of the summary characteristics of this group. In order to achieve this goal, a levelwise algorithm as illustrated in FIG. 3 is applied.
In the levelwise algorithm, the (k+1)-candidates are generated sequentially by utilizing successive joins on the k-itemsets. The process begins at block 300 and starts off by setting k to 1 in step 310 . The set of candidate 1-itemsets is simply all possible 1-items.
In step 320 , the supports of the k-itemsets are counted. This is a key step which requires careful data sharing among the different entities. The details of this step are described below in the context of FIG. 4 . Once the counts for the various itemsets have been determined, these counts are transmitted across the different entities (e.g., servers 150 ). These counts are utilized for the purpose of determining the frequent k-itemsets.
In step 330 , a join is performed on the set of k-itemsets in order to generate the set of (k+1)-candidates. In step 340 , k is incremented by one. If the set of (k+1)-candidates is empty, as checked in step 350 , then the process terminates (block 360 ). Otherwise, the process returns to step 320 in order to generate the next set of k-itemsets. We now describe how to count the support of k-itemsets.
Referring now to FIG. 4 , a flow diagram illustrates a procedure for computing counts of itemsets, according to an embodiment of the present invention. It is to be understood that FIG. 4 illustrates one embodiment of step 320 ( FIG. 3 ).
In order to illustrate this step, we will describe the process of counting the support of a single k-itemset. Since entities are not even willing to provide the counts for the individual itemsets, it requires an ordering protocol among the different entities. In order to illustrate our point, we will use the example of FIG. 1 . As shown in FIG. 4 , after start block 400 , the first step is to create an ordering among the different entities. This is achieved in step 410 . This ordering is utilized for the purpose of transmitting the itemset counts among the different entities. Consider, for example, the case when the counts at entities 1 , 2 , 3 , 4 and 5 ( FIG. 1 ) are 3 , 7 , 5 , 8 and 11 , respectively. The first step from each entity is to generate a random number independently.
The value that each entity passes to another entity may be considered a “global count.” That is, each entity adds to or subtracts from the global count, as will be illustrated in the example below.
Let us say that the random numbers generated are 2, 5, 11, 3 and 6, respectively. In the first round, the entities pass around the random numbers additively. Thus, entity 1 passes the number 2 to entity 2 (e.g., the global count is initially zero to which entity 1 adds the number 2), then entity 2 passes the number 2+5 to entity 3 , then entity 3 passes the number 2+5+11 to entity 4 , entity 4 passes the number 2+5+11+3 to entity 5 , and entity 5 passes the number 2+5+11+3+6=27 back to entity 1 . Thus, in step 420 , the random numbers are additively passed around without divulging the exact perturbations.
In the next round, each entity adds his own true itemset count to the overall count of 27 (step 430 ). Thus, entity 1 passes the number 27+3 to entity 2 , entity 2 passes 27+3+7 to entity 3 , entity 3 passes 27+3+7+5 to entity 4 , entity 4 passes 27+3+5+entity 5 , and entity 5 passes 27+3+7+5+8+11 (27+34) to entity 1 . Thus, entity 1 now has both the random number count (27) as well as aggregate count (27+34). From this, the entity can deduce that the true itemset count is 34, and propagate this to the rest of the group.
However, for reasons that will soon become apparent, the process uses a third step in order to calculate the actual counts. In the third step, each entity subtracts his random number before transmitting to the next member in the group. Thus, entity 1 transmits 27+34−2 to entity 2 , entity 2 transmits 27+34−2−5 to entity 3 , and so on until entity 5 transmits 27+34−27 to entity 1 . This is accomplished in step 440 . Final counts are shared in step 450 . The process ends at block 460 .
One reason for performing this 3-layered approach is that the entities now need not necessarily use any particular ordering among the three layers. Thus, for example, an entity may choose to add his true count in the first round, subtract the random number in the second round and add in the third. The overall result is still the same irrespective of what ordering an entity chooses. However, this results in a greater level of privacy for all the remaining entities since partial counts are not known at intermediate stages. This also provides a greater level of privacy in the event of a leak of one or more of the transmissions among different entities.
In many cases, it is also possible to share the information among the different entities when different entities carry information about different sets of items. This is quite likely in most real situations. For example, in a superstore, not all items may be stored by all customers. This situation can be effectively handled by using an approach in which each entity only sends the count for the itemset to the next entity which subscribes to all such items. This is illustrated in FIG. 5 .
Referring now to FIG. 5 , a flow diagram illustrates a procedure when a limited set of items is utilized for itemset mining process, according to one embodiment of the present invention. The process starts at block 500 . In step 510 , each entity specifies the set of items that they are providing data about. The entities share this information freely among one another. Once this information is shared, it is easy for the entities to determine the relevant entities for each itemset.
An entity is considered relevant for an itemset if and only if it shares information pertaining to all possible items in it. This is referred to as potential participation in step 520 . The basic algorithm for sharing summary statistics remains the same among different entities. The only difference is that an entity only transmits the count for an itemset to the next potential participant in the designated ordering. In addition, the global counts for those itemsets with too few potential participants are not determined and the itemsets may be discarded (what comprises too few potential participants, e.g., 0, 1, 2, . . . , etc., may be decided based on the user support threshold and, in any case, such number is application-dependent). This is necessary in order to provide a greater level of robustness during the information sharing process. This step ensures that each entity receives global information about those items that it participates in.
In step 530 , summary information is shared among items based on potential participation. The process ends at block 540 .
We note that the method can be easily extended to the case in which it is desirable to find association rules instead of itemsets. That is, in a customer transaction database, a typical goal is to find correlations among items. For example, in a supermarket, it is often the case that people who buy milk also buy butter. Therefore, an example of an association rule is: Milk→Butter. Thus, an association rule may be defined as a set relationship of the form: S 1 →S 2 , where S 1 and S 2 are two sets of items. The strength of the association rule is defined by measures such as support, as described above.
In this case, the process shares data about the strength of the potential rules instead of itemsets. Once the itemsets have been generated, the process determines all possible potential rules. As in the previous case, the process exchanges information about the counts of transactions satisfying each rule. The same data exchange procedure with randomization (as discussed in FIG. 4 ) is used.
This procedure also ensures that the data about individual entities is not known on a global basis.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made by one skilled in the art without departing from the scope or spirit of the invention. | Distributed privacy preserving data mining techniques are provided. A first entity of a plurality of entities in a distributed computing environment exchanges summary information with a second entity of the plurality of entities via a privacy-preserving data sharing protocol such that the privacy of the summary information is preserved, the summary information associated with an entity relating to data stored at the entity. The first entity may then mine data based on at least the summary information obtained from the second entity via the privacy-preserving data sharing protocol. The first entity may obtain, from the second entity via the privacy-preserving data sharing protocol, information relating to the number of transactions in which a particular itemset occurs and/or information relating to the number of transactions in which a particular rule is satisfied. |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of our co-pending application Ser. No. 07/589,729 filed Sep. 28, 1990 now U.S. Pat. No. 5,091,418.
BACKGROUND OF THE INVENTION
The present invention relates to a benzo[a]naphthacene compound having α-glucosidase inhibiting activity. The compound of the present invention is therefore useful as human and animal medicament for the treatment of conditions in which it is desirable to suppress α-glucosidase action, or to inhibit the increase of blood glucose level; such conditions include, for example diabetes, prediabetes, obesity, and adiposity.
Recently, Japanese Kokai 2-83351, published Mar. 23, 1990, reported the isolation of a novel α-glucosidase inhibitor from fermentation broth of Actinomycetes Strain MH193-16F4. The inhibitor, benanomicin C, has the following structure formula ##STR2##
Although benanomicin C also possesses a benzo[a]naphthacene ring nucleus, its substituents differ substantially from those of the compound of the present invention. Furthermore, the compound of the present invention exhibits unexpectedly high α-glucosidase inhibitory activity compared to benanomicin C.
SUMMARY OF THE INVENTION
The present invention provides a novel α-glucosidase inhibitor designated pradimicin Q having the formula (I) ##STR3## and its pharmaceutically acceptable base salts.
Another aspect of the present invention provides a process for producing pradimicin Q which comprises cultivating a strain of pradimicin Q producing Actinomadura verrucosospora subsp. neohibisca under submerged and aerobic conditions in a medium containing assimilable sources of carbon and nitrogen, and recovering from said medium pradimicin Q.
A further aspect of the present invention provides a pharmaceutical composition comprising pradimicin Q and a pharmaceutically acceptable vehicle.
Yet a further aspect of the present invention provides a method for inhibiting an increase in blood glucose level in an animal, including humans, which comprises administering to said animal in need of such treatment a therapeutically effective amount of pradimicin Q.
DETAILED DESCRIPTION OF THE INVENTION
One aspect of the present invention provides the compound pradimicin Q and its pharmaceutically acceptable base salts. "Pharmaceutically acceptable base salts" includes, but is not limited to, salts formed with inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, calcium carbonate, magnesium hydroxide, and the like, or with organic bases such as diethylamine, ethylenediamine, triethylamine, ethanolamine, and the like.
Pradimicin Q is produced by cultivating pradimicin Q producing strain of Actinomadura verrucosospora subsp. neohibisca, or a variant thereof, or a mutant thereof, in a medium containing sources of assimilable carbon and nitrogen.
A strain capable of producing pradimicin Q is Actinomadura verrucosospora subsp. neohibisca strain R103-3. Another pradimicin Q producing strain is a mutant strain, herein designated as strain A10102, derived from strain R103-3. The characterizing properties of both strains are provided hereinbelow.
Producing Organism
(i) Strain R103-3 was isolated from a soil sample collected in Puerto Viejo Costa, Peru. A biologically pure culture of strain R103-3 was deposited with the American Type Culture Collection, Rockville, Md. under accession number ATCC 53930. This culture has been accepted for deposit under the BUDAPEST TREATY ON THE INTERNATIONAL RECOGNITION OF THE DEPOSIT OF MICROORGANISMS FOR THE PURPOSES OF PATENT PROCEDURE.
The morphological, cultural, physiological, and chemotaxonomical characteristics of strain R103-3 are similar to those of Actinomadura verrucosospora, but strain R103-3 is differentiated from Actinomadura verrucosospora in the formation of red diffusible pigments and other physiological characteristics. Therefore, strain R103-3 was designated Actinomadura verrucosospora subsp. neohibisca subsp. nov.
(a) Morphology
Strain R103-3 forms short or rudimental aerial mycelium and well-branched non-fragmentary substrate mycelium. Loop or spiral short spore-chains (5-12 spores per chain) are formed on the aerial hyphae. The spores are oval (0.8×1.2-1.5 μm), non-motile, and have a warty surface.
(b) Cultural and Physiological Characteristics
The cultural and physiological characteristics were examined by the methods of Shirling and Gottlieb (Int. J. Syst. Bacteriol., 1966, 16:313-340), and Gordon, et al. (J. Gen. Microbiol., 1978, 109:69-78).
Strain R103-3 forms aerial mycelium and spore-chain in ISP media Nos. 3, 4, 5, and 7 and produces abundantly reddish diffusible pigments (pradimicins) in Czapek's agar and natural organic media, such as ISP medium No. 2. Cultural and physiological characteristics are shown in Tables 1 and 2, respectively.
TABLE 1______________________________________Cultural Characteristics of Strain R103-3 Aerial Substrate DiffusibleMedium Growth Mycelium Mycelium Pigment______________________________________Sucrose-nitrate Moderate None Very deep Very deepagar (Czapek- red (14) purplishDox agar) red (257)Tryptone-yeast Poor, not None Deep red Moderateextract broth turbid (13) red (15)(ISP No. 1)Yeast extract- Good None Very deep Very darkmalt extract red (14) red (17)agar(ISP No. 2)Oatmeal agar Moderate Moderate; Moderate Grayish(ISP No. 3) pale pink pink (5) pink (8) (7) to light grayish red (18)Inorganic salts- Moderate Poor; white Moderate Lightstarch agar pink (5) grayish(ISP No. 4) red (18)Glycerol- Poor Poor; white Colorless Noneasparagineagar(ISP No. 5)Peptone-yeast Good Scant; Grayish Very deepextract-iron white pink (8) red (14)agar to deep(ISP No. 6) red (13)Tyrosine agar Moderate Poor; white Moderate Light(ISP No. 7) red (15) yellowish pink (28)Glucose- Poor None Colorless Lightasparagine agar pink (4)Nutrient agar Moderate Poor; white Dark pink Dark red (6) (16)Bennett's agar Good None Blackish Blackish red (21) red (21)______________________________________ Observation after incubation at 28° for 3 weeks. Color Name: ISCCNBS colorname charts.
TABLE 2______________________________________Physiological Characteristics of Strain R103-3______________________________________ Decomposition of: Adenine - Casein + Hippuric acid + Hypoxanthine - Tyrosine + Xanthine - Decarboxylation of: Benzoate - Citrate - Mucate - Succinate + Tartrate - Production of: Amylase - Esculinase + Gelatinase + Nitrate reductase + Tyrosinase - Urease - Growth in: Lysozyme, 0.001% - NaCl, 1%-7% + 8% - pH, 5.8-11.0 + 25° C.-39° C. + 22° C. and 42° C. Acid Production from*: Adonitol - D-Arabinose - L-Arabinose + Cellobiose + Dulcitol - Erythritol - D-Fructose + D-Galactose - D-Glucose + Glycerol - Inositol - Lactose - D-Mannitol + D-Mannose - D-Melezitose - Melibiose - Methyl-α-glucoside - Raffinose - L-Rhamnose + D-Ribose + Salicine + Soluble starch + D-Sorbitol - L-Sorbose - Sucrose + Trehalose - D-Xylose +______________________________________ *Basal Medium: PridhamGottlieb medium (ISP No. 9), omitted CuSO.sub.4.7H.sub.2 O
(c) Chemotaxonomy
The whole cell hydrolyzate of strain R103-3 contains meso-diaminopimelic acid, glucose, and madurose. Hence, the strain belongs to cell wall type III and sugar pattern B. The phospholipids contain phosphatidylglycerol and phosphatidylinositol without nitrogenous phospholipids and, hence, is placed in type P-I.
(d) Taxonomic Position
Based on the morphology and chemotaxonomy of strain R103-3, the strain is placed in the genus Actinomadura. Among hitherto described known species of Actinomadura, strain R103-3 is physiologically most similar to Actinomadura verrucosospora, but it is differentiated from the latter in its production of red diffusible pigment, resistance to NaCl, and negative acid formation from glycerol, lactose, and trehalose. Thus, strain R103-3 was designated Actinomadura verrucosospora subsp. neohibisca subsp. nov.
Strain R103-3 is also distinct from Actinomadura hibisca known producer of pradimicins. Table 3 shows the differential characteristics of Actinomadura hibisca strain P157-2 (ATCC No. 53557) and strain R103-3 ATCC No. 53930.
TABLE 3______________________________________Differential Characteristics of Actinomaduraverrucosospora Subsp. neohibisca Strain R103-3 fromActinomadura hibisca Strain P157-2 Strain R103-3 Strain P157-2______________________________________Morphology:Spore-chain Short, hook Long, straightSpore surface Warty SmoothCultural and physiologicalcharacteristics:Tyrosine agar: Not Formed FormedBrownish pigmentGlucose-asparagine agar:Growth Poor AbundantReddish pigment Scant AbundantUtilization of:L-Arabinose + -D-Mannitol + -L-Rhamnose + -D-Xylose + -______________________________________
(ii) Strain A10102 is derived from strain R103-3 by mutation using N'-methyl-N'-nitro-N-nitrosoguanidine (NTG). A biologically pure culture of A10102 was deposited with the American Type Culture Collection under accession number ATCC 55092. This culture has been accepted for deposit under the BUDAPEST TREATY ON THE INTERNATIONAL RECOGNITION OF THE DEPOSIT OF MICROORGANISMS FOR THE PURPOSES OF PATENT PROCEDURE. The procedure for mutation of strain R103-3 and for the screening of the mutant strains is described below.
Strain R103-3 was grown at 28° C. for 14 days on a modified Bennett's agar consisting of soluble starch 0.5%, glucose 0.5%, fish meat extract 0.1%, yeast extract 0.1%, NZ-case 0.2%, NaCl 0.2%, CaCO 3 0.1%, and agar 1.6%; pH 7.0. Spores of the strain were suspended in saline, dispersed by sonication for 20 seconds in ice-bath, harvested by centrifugation at 3,500 rpm for 10 minutes at 25° C., and resuspended in 10 mM Tris-HCl, pH 9.0. The spore suspension (3 ml) was mixed with 3 ml of NTG solution (5,000 μg/ml in a mixture of water-dimethyl sulfoxide 9:1 (v/v)). The mixture was gently shaken at 28° C. for 1 hour. The NTG-treated spores were harvested by centrifugation, resuspended in saline, spread on a new agar plate, and incubated at 28° C. for 7 days. Each colony was picked up, inoculated to a fresh agar plate, and incubated at 28° C. for 7 days to be used as a mother culture plate. Each culture was transferred to 10 ml of the vegetative medium (Medium A) consisting of Na L-glutamate 0.1%, L-methionine 0 05%, L-arginine 0.05%, soluble starch 1.0%, glucose 1.0%, (NH 4 ) 2 SO 4 0.01%, K 2 HPO 4 0.6%, MgSO 4 .7H 2 O 0.05%, NaCl 0.05%, CaCO 3 0.3%, salt solution (FeSO 4 .7H 2 O 0.1 g, ZnSO 4 .7H 2 O 0.1 g, MnCl 2 .4H 2 O 0.1 g, in 1 liter of water) 1% v/v, pH 7.0. The culture was incubated at 28° C. for 14 days on a shaker operating at 200 rpm. Pradimicin Q was identified by silica gel TLC (Merck) using a solvent system of methyl acetate/n-propanol/28% ammonium hydroxide (45:105:60), Rf for pradimicin Q was 0.2-0.25. As a result of the screening, a mutant strain designated as A10102 was found to produce pradimicin Q as its major fermentation product.
(a) Morphology
Both parent and its mutant strains form tufts of loop or spiral short spore-chains (5 to 10 spores per chain) on the short aerial mycelium. The spores are oval (0.8×1.3 μm), non-motile, and have a warty surface.
(b) Cultural Characteristics
Unlike parental strain R103-3, mutant strain A10102 produces reddish-purple pigments in ISP Media Nos. 2, 3, and 7 and brownish-black pigment in ISP Medium No. 6 (Table 4).
TABLE 4______________________________________Characterization of Cultural DifferencesAmong R103-3 and A10102CulturalCharacteristics Strain R103-3 No. A10102______________________________________Malt extract- G +++; Very dark red ++; Blackish redyeast extract (17) (21)agar A None None(ISP No. 2) D Very deep red (14) Very dark purplish red (260)Oatmeal agar G ++; Pinkish white (9) ++; Reddish(ISP No. 3) purple (241) A Scant; white Scant; white D Pinkish white (9) Light reddish purple (240)Inorganic salts- G +; Pale yellowish- +; Light reddishstarch agar pink (31) puple (240)(ISP No. 4) A Scant; white Scant; white D Pale yellowish Light reddish pink (31) purple (240)Peptone-yeast G ++; Grayish red (19) +++; Brownishextract-iron black (65)agar A None None(ISP No. 6) D None Brownish black (65)Tyrosine agar G ++; Moderate ++; Pale reddish(ISP No. 7) yellowish pink (28) purple (244) A Poor; white Poor; white D Pale yellowish Pale reddish pink (31) purple (244)Glucose- G ±; Colorless ±; Colorlessasparagine agar A None None D None None______________________________________ Observation after incubation at 28° C. for 2 weeks. Color Name: ISCCNBS colorname charts. Abbreviations: G, growth (+++ good, ++ moderate, + poor, ± scant) and reverse color; A, aerial mycelium; and D, diffusible pigment.
(c) Physiological Characteristics
Mutant strain A10102 shows almost the same physiological reactions as the parental strain (Table 5).
TABLE 5______________________________________Physiological Characteristics ofStrains R103-3 and A10102 Strain R103-3 Strain A10102______________________________________Hydrolysis of:Gelatin + +Soluble starch - -Potato starch - -Production of: -/+ -/+Nitrate reductase*Utilization of**:Glycerol +(w) -D-Arabinose - -L-Arabinose + +D-Xylose + +D-Ribose + +L-Rhamnose + +D-Glucose + +D-Galactose +(w) +(w)D-Fructose + +D-Mannose - -L-Sorbose - -Sucrose - -Lactose - -Cellobiose + +Melibiose - -Trehalose + +(w)Raffinose - -D-Melezitose - -Soluble starch + +(w)Cellulose - -Dulcitol - -Inositol - -D-Mannitol + +D-Sorbitol - -Salicin + +______________________________________ *Czapek's sucrosenitrate broth/Peptonenitrate broth. **Basal Medium: PridhamGottlieb medium. +(w): Weakly Positive; -/+: Marginal Utilization
B. Antibiotic Production
Strains R103-3 and A10102 produce the novel compound pradimicin Q, along with other pradimicins A, B, C, D, E and L, when cultivated in a conventional medium. The producing organism is grown in a nutrient medium containing known nutritional sources for actinomycetes, i.e., assimilable sources of carbon and nitrogen added with optional inorganic salts and other known growth factors. Submerged aerobic conditions are preferably employed for the production of large quantities of antibiotic, although surface cultures and bottles may also be used for production of limited amounts. The general procedures used for the cultivation of other actinomycetes are applicable to the present invention.
The nutrient medium should contain an appropriate assimilable carbon source, such as ribose, glucose, sucrose, and cellobiose. As a nitrogen source, ammonium chloride, ammonium sulfate, urea, ammonium nitrate, sodium nitrate, etc., may be used either alone or in combination with organic nitrogen sources, such as peptone, meat extract, yeast extract, corn steep liquor, soybean meal, cotton seed meal, etc. There may also be added, if necessary, nutrient inorganic salts to provide sources of sodium, potassium, calcium, ammonium, phosphate, sulfate, chloride, bromide, carbonate, zinc, magnesium, manganese, cobalt, iron, and the like.
Production of the antibiotic complex comprising pradimicin components may be effected at any temperature suitable for satisfactory growth of the producing organism, e.g., 25°-40° C., and is most conveniently carried out at a temperature of around 27°-32° C. Ordinarily, optimum antibiotic production is obtained by flask fermentation after shaking with incubation periods of 5 to 12 days. If fermentation is to be carried out in tank fermentors, it is desirable to use a vegetative inoculum in a nutrient broth from a slant culture or a lyophilized culture. After obtaining an active inoculum in this manner, it is aseptically transferred to the fermentation medium in a tank fermentor. Antibiotic production in tank fermentors usually reached a maximum after 3-6 days of incubation. Agitation in the tank fermentor is provided by stirring, and aeration may be achieved by injection of air or oxygen into the agitated mixture. Antibiotic production was monitored by HPLC followed with spectroscopic techniques, or by a conventional biological assay.
Pradimicin complex thus produced may be recovered from the fermentation broth, and pradimicin Q of the present invention separated, by any suitable methods for such recovery and separations; examples of these methods include extraction, precipitation, chromatography, and other art recognized conventional techniques. A preferred isolation and purification sequence for pradimicin Q is given in Examples 2 and 3.
It is to be understood that, for the production of pradimicin Q, the present invention is not limited to the particular organisms mentioned above but includes the use of variants and mutants thereof that retain the antibiotic-producing capability. Such variants and mutants can be produced from parent strains by various means, such as X-ray radiation, UV-radiation, and chemical mutagens, such as N-methyl-N'-nitro-N-nitrosoguanidine.
Thus, another aspect of the present invention provides a method for producing pradimicin Q which comprises cultivating an antibiotic-producing strain of Actinomadura verrucosospora subsp. neohibisca under submerged and aerobic conditions in a medium containing assimilable carbon and nitrogen sources. Preferably, the antibiotic-producing strains are strain R103-3, ATCC No. 53930, and strain A10102, ATCC No. 55092.
α-Glucosidase Inhibitory Activity
Forty μl of α-glucosidase (Sigma G-5003, #11 U/mg protein) (0.1 mg/ml in 100 mM phosphate buffer, pH 6.8=0.44 U/assay) for tests (or the buffer for the control), 950 μl of 0.7 mM p-nitrophenyl-α-D-glucopyranoside (Sigma N1377), and 10 μl of the assay compound (various concentrations dissolved in DMSO) were mixed and incubated at 37° C. for 15 minutes. To the reaction mixture, 1.0 ml of 0.2N NaOH and then 1.0 ml of n-butanol were added and voltex-mixed. Absorbance of n-butanol layer at 415 nm was measured by spectrophotometer. α-Glucosidase inhibitory activity was expressed as the IC 50 (μg/ml), the concentration at which the test compound inhibits 50% of the enzyme activity. IC 50 was determined from a standard curve of p-nitrophenol released when the assay was run without the test compound (0% inhibition) and when the assay was run without the enzyme (100% inhibition).
Results
Pradimicin Q showed the strongest α-D-glucosidase activity with an IC 50 value of 3 μg/ml. This value is significantly higher than that for benanomicin C which showed an IC 50 value of 62 μg/ml. In contrast, pradimicins A and L and N,N-dimethylpradimicin FA-2, all active as antifungal compounds, have no α-glucosidase inhibitory activity.
TABLE 6______________________________________Compound IC.sub.50 (μg/ml)______________________________________Pradimicin A >100N,N-dimethylpradimicin FA-2 >100Pradimicin L >100Benanomicin C 62Pradimicin Q 3______________________________________
It is apparent that the compound of the present invention exhibit high α-glucosidase inhibitory action. Pradimicin Q is, therefore, useful for inhibiting an increase in blood glucose in animals, including humans, and for treating animals, including humans suffering from conditions such as prediabetes, diabetes, obesity and adiposity.
Pradimicin Q is administered to the animal in need of such treatment in a therapeutically effective amount by any accepted routes, including intravenous, intramuscular, oral, intranasal, and for superficial infections, topical administration. Preferably, the compound of the invention is administered parenterally or orally. Preparations for parenteral administration include sterile aqueous or non-aqueous solutions, suspensions, or emulsions. They may also be manufactured in the form of sterile solid compositions which can be dissolved in sterile water, physiological saline, or some other sterile injectable medium immediately before use. Oral formulation may be in the form of tablets, gelatin capsules, powders, lozenges, syrups, and the like. For topical administration, the compound may be incorporated into lotions, ointments, gels, creams, salves, tinctures, and the like. Unit dosage forms may be prepared using methods generally known to those skilled in the art of pharmaceutical formulations.
It will be appreciated that, when treating a host according to the method of this invention, the actual preferred route of administration and dosage used will be at the sound professional discretion of the attending physician and will vary according to the severity of the condition to be treated, route of administration, and patient characteristics, such as age, body weight, rate of excretion, concurrent medications, and general physical condition.
EXAMPLE 1
Production of Pradimicin Q by Fermentation of Actinomadura verrucosospora subsp. neohibisca
A. Agar Slant
Actinomadura verrucosospora subsp. neohibisca strain R103-3 (ATCC No. 53930) was propagated on an agar slant of modified Bennett's medium at 28° C. for 14 days. The composition of the medium is soluble starch (Nichiden Kagaku) 0.5%, glucose 0.5%, fish meat extract (Mikuni Kagaku Sangyo) 0.1%, yeast extract (Oriental Yeast) 0.1%, NZ-case (Sheffield) 0.2%, NaCl 0.2%, CaCO 3 0.1%, and agar 1.6%.
B. Seed Culture
A small portion of the microbial growth from the slant culture was inoculated to a 500-ml Erlenmeyer flask containing 100 ml of the vegetative medium consisting of soluble starch (Nichiden Kagaku) 1%, glycerol 1%, yeast extract (Oriental Yeast) 1%, peptone (Daigo Eiyo) 0.5%, NaCl 0.3%, and CaCO 3 0.2%. The pH of the medium was adjusted to 7.0 before autoclaving. The seed culture was incubated at 28° C. for 7 days on a rotary shaker at 200 rpm.
C. Flask Fermentation
A 5 ml portion of the seed culture was transferred to a 500-ml Erlenmeyer flask containing 100 ml of the production medium (FR-17) consisting of soluble starch (Nichiden Kagaku) 1%, glucose 1%, sodium L-glutamate 0.1%, L-methionine 0.05%, L-arginine 0.05%, (NH 4 ) 2 SO 4 0.1%, MgSO 4 .7 H 2 O 0.05%, NaCl 0.05%, CaCO 3 0.3%, K 2 HPO 4 0.6%, and salt solution 1% (v/v) (FeSO 4 .7 H 2 O 0.1 g, ZnSO 4 .7H 2 O 0.1 g, and MnCl 2 .4H 2 O 0.1 g in 1 liter of water). The pH of the medium was adjusted to 7.0 before autoclaving. The fermentation was carried out at 28° C. for 14 days on a rotary shaker (200 rpm). Antibiotic production in the fermentation broth was determined spectrophotometrically. The production of total pradimicin reached a maximum at 290 μg/ml on day 11.
EXAMPLE 2
Isolation of Pradimicin Q - Method 1
The fermentation broth pooled from fifty 500-ml Erlenmeyer flasks containing 100 ml broth in each flask was centrifuged at 5,000 rpm for 10 minutes at room temperature. The supernatant (4.5 L) was adjusted to pH 2.0 with 6N HCl and mixed with ethyl acetate (2 L). Ethyl acetate layer was washed twice with H 2 O (200 ml each) and concentrated to dryness to give a crude solid (453 mg). The crude solid was dissolved in CH 3 CN-0.15% KH 2 PO 4 , pH 3.5 (1:1), and applied on a column of ODS-A60 (200 ml, Yamamura Chemical Lab.) which had been equilibrated with the same solvent mixture. Elution was carried out with the same solvent mixture. Fractions containing the pradimicin Q monitored by HPLC were pooled and concentrated to give a purple-red solid (190 mg). This solid (50 mg) was dissolved in 2 ml of MeOH-H 2 O (3:2) and subjected to a column of Sephadex LH-20 eluting with the same solvent mixture. A yellow-red powder (27 mg) was obtained as a free form. Purity of the compounds was determined by HPLC and was over 98%. The physico-chemical properties of pradimicin Q are given in Table 7.
TABLE 7______________________________________Physico-Chemical Properties of Pradimicin Q______________________________________Nature: Purple-Red PowderM.P. (dec.): >200° C.HR FAB(+)-MS m/z (M + H): Found 465.0811 (Calcd: 465.0800)Molecular Formula: C.sub.24 H.sub.16 O.sub.10UV λmax nm (ε)in MeOH: 229 (25,600), 288 (19,500), 514 (13,200)in 0.01 N HCl-50% MeOH: 232 (25,800), 289 (20,600), 512 (14,000)in 0.01 N NaOH-50% MeOH: 242 (20,000), 305 (19,600), 549 (15,900)IR (KBr) cm.sup.-1 : 3197, 1712, 1600, 1488, 1399, 1245, 1187.sup.1 H NMR (400 MHz, DMSO-d.sub.6) δ: 2.50(s), 6.97(s), 4.55(dd, J=9.8&4.3), 2.66(dd, J= 15.8&9.8), 3.10(dd, J= 15.8&4.3), 6.63(d, J= 2.4), 7.24(d, J=2.4).sup.13 C NMR (100 MHz, DMSO-d.sub.6) δ: 187.5(s), 185.7(s), 171.5 (s), 165.5(s), 164.5(s), 156.0(s), 155.0(s), 153.9 (s), 146.1(s), 140.2(s), 137.0(s), 134.9(s), 131.6 (s), 119.2(s), 118.4(s), 118.3(d), 115.3(s), 110.6 (s), 109.1(s), 108.5(d, 108.2(d), 66.2(d), 30.7 (t), 21.6(q)______________________________________
EXAMPLE 3
Isolation of Pradimicin Q - Method 2
The fermentation broth (600 ml) was centrifuged at 5,000 rpm, and the supernate was applied on a column of HP-20 (200 ml). The resin was washed with water followed with acetone-H 2 O (3:2). Fractions containing compound Q were pooled and concentrated to dryness (1.4 g crude powder). The solid (170 mg) was dissolved in CH 3 CN-H 2 O (1:4) and applied on a column of ODS-A60 (200 ml). The resin was washed with CH 3 CN-H 2 O (1:1). Fractions containing pradimicin Q were concentrated to dryness (27 mg powder). This solid (25 mg) was applied on a column of Sephadex LH-20 (70 ml) eluting with a mixture of MeOH-H 2 O (1:1, pH 8.5). A yellow-red powder (6.3 mg) was obtained as a sodium salt form. Compound Q showed weak antibacterial activity against Bacillus subtilis PCI-219 (125 μg/ml) and cytotoxic activity against mouse melanoma B16 cells with IC 50 at 75 μg/ml.
EXAMPLE 4
Production of Pradimicin Q by Fermentation of Strain A10102 (ATCC No. 55092)
Strain A10102 was grown in a 500-ml Erlenmeyer flask containing 100 ml of the vegetative medium consisting of soluble starch (Nichiden Kagaku) 1%, glycerol 1%, yeast extract (Oriental Yeast) 1%, peptone (Daigo Eiyo) 0.5%, NaCl 0.3%, and CaCO 3 0.2%. The pH of the medium was adjusted to 7.0 before autoclaving. The seed culture was incubated at 28° C. for 7 days on a rotary shaker at 200 rpm.
A 5 ml portion of the seed culture was transferred to a 500-ml Erlenmeyer flask containing 100 ml of the production medium consisting of glucose 3%, Protein S (soybean flour, Ajinomoto) 3%, yeast extract 0.1%, CaCO 3 0.3%, pH 7.0. The fermentation was carried out at 28° C. for 11 days on a rotary shaker at 200 rpm. Identification of pardimicin Q was done employing silica gel TLC (Merck) using a solvent system of MeOAc-n-PrOH-28% NH 4 OH (45:105:60). Rf for pradimicin Q: 0.2-0.25 (cf pradimicin L: 0.35-0.4). From the TLC pattern, pradimicin Q was seen as the major product in the fermentation broth of strain A10102. | The present invention relates to a novel a-glucosidase inhibitor, pradimicin Q, having the following formula ##STR1## and its pharmaceutically acceptable base salts. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatuses for controlling negative pressure in internal combustion engines. More particularly, the present invention pertains to apparatuses for controlling negative pressure in internal combustion engines that are provided with brake boosters, which use negative pressure to improve braking force.
2. Description of the Related Art
Brake boosters have become widely used in vehicles to decrease the required pressing force of the brake pedal. A typical brake booster uses negative pressure, which is produced in an intake passage downstream of a throttle valve, as a drive source. In other words, negative pressure is communicated to the brake booster through a communicating pipe connected to the downstream side of the throttle valve. Negative pressure corresponding to the pressed amount of the brake pedal acts on a diaphragm, which is incorporated in the brake booster, and increases the braking force.
However, internal combustion engines such as diesel engines do not control the amount of air intake during operation. Thus, it is difficult to produce negative pressure at the downstream side of the throttle valve. In such cases, vacuum pumps are provided to produce negative pressure for the brake booster.
Japanese Unexamined Patent Publication No. 61-21831 describes an apparatus that produces negative pressure for the brake booster when the vacuum pump malfunctions. The apparatus slightly closes the throttle valve to produce negative pressure at the downstream side of the throttle valve. The negative pressure is communicated to the brake booster.
However, the employment of a vacuum pump increases the engine load and degrades the fuel efficiency.
Furthermore, in engines that perform stratified charge combustion, stoichiometric air-fuel mixture is supplied to the vicinity or an ignition plug in a cylinder. The other portions of the cylinder are provided with only air. Hence, the throttle valve is substantially completely opened during normal running conditions. As a result, practically no negative pressure is produced at the downstream side of the throttle valve. This causes the negative pressure communicated to the brake booster to be insufficient.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide an apparatus for communicating sufficient pressure to the brake booster without increasing the engine load in an engine that completely opens the throttle valve under normal running conditions.
To achieve the above objective, the present invention provides an apparatus for controlling negative pressure in a combustion engine. The apparatus has a brake booster capable of increasing braking force of a vehicle based on the negative pressure supplied to an interior of the brake booster. The apparatus includes a means for generating the negative pressure that is supplied to the brake booster. The apparatus also includes means for controlling the generating means. The controlling means actuates the generating means when pressure in the brake booster is in excess of a predetermined magnitude.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a diagrammatic drawing showing an apparatus for controlling negative pressure in an engine according to a first embodiment of the present invention;
FIG. 2 is an enlarged cross-sectional view showing the engine cylinder;
FIG. 3 is a schematic drawing showing the brake booster;
FIG. 4 is a flowchart illustrating a flowchart of a program executed by an electronic control unit (ECU) in the first embodiment;
FIG. 5 shows a map for obtaining the throttle valve compensation angle of the throttle valve in the program of FIG. 4;
FIG. 6 is a flowchart showing a program executed by the ECU in a second embodiment according to the present invention;
FIG. 7 shows a map for obtaining the opening angle compensation of the throttle valve in the program of FIG. 4;
FIG. 8 is a diagrammatic view showing the mechanical structure of a third embodiment according to the present invention;
FIG. 9 is an explanatory drawing showing the fuel injection mode in the third embodiment;
FIG. 10 is a flowchart showing a program executed by the ECU in the third embodiment;
FIG. 11 is a flowchart showing the fuel injection routine executed by the ECU in the first, second, and third embodiments;
FIG. 12 is a flowchart showing a program executed by the ECU in a fourth embodiment according to the present invention;
FIG. 13 is a flowchart showing a program that derives from the program shown in FIG. 12;
FIG. 14 is a flowchart showing a program that continues from FIG. 12;
FIG. 15 is a table (map) showing the relationship between the closing compensation angle and the value obtained by subtracting the brake booster pressure value from the negative pressure value when terminating stratified charge brake control;
FIG. 16 is a flowchart showing a main routine executed by the ECU;
FIG. 17 is table (map) showing the relationship between the throttle closing angle and the fuel injection timing compensation angle;
FIG. 18 is a graph illustrating the relationship of the brake booster pressure at low and high altitudes;
FIG. 19 is a graph showing the relationship between time and the throttle closing angle;
FIG. 20 is a timing chart showing the relationship between time and air-fuel ratio and between time and the fuel injection signal.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of an apparatus for controlling negative pressure in an internal combustion engine according to the present invention will now be described with reference to the drawings.
As shown in FIG. 1, an engine 1 is provided with, for example, four cylinders 1a. The structure of the combustion chamber of each cylinder 1a is shown in FIG. 2. As shown in these drawings, the engine 1 has a cylinder block 2 that accommodates pistons. The pistons are reciprocated in the cylinder block 2. A cylinder head 4 is arranged on top of the cylinder block 2. A combustion chamber 5 is defined between each piston and the cylinder head 4. In this embodiment, four valves (first intake valve 6a, second intake valve 6b, and two exhaust valves 8) are provided for each cylinder 1a. The first intake valve 6a is provided with a first intake port 7a while the second intake valve 6b is provided with a second intake port 7b. Each exhaust valve 8 is provided with an exhaust port 9.
As shown in FIG. 2, the first intake port 7a is a helical port that extends in a helical manner. The second port 7b extends in a straight manner. Ignition plugs 10 are arranged at the middle of the cylinder head 4. High voltage is applied to each ignition plug 10 by an ignitor 12 though a distributor (not shown). The ignition timing of the ignition plugs 10 is determined by the output timing of the high voltage sent from the ignitor 12. A fuel injection valve 11 is arranged near the inner wall of the cylinder head at the vicinity of each set of first and second intake valves 6a, 6b. The fuel injection valve 11 is used to inject fuel directly into the associated cylinder 1a and enables both stratified charge combustion and uniform charge combustion.
As shown in FIG. 1, the first and second intake ports 7a, 7b of each cylinder 1a are connected to a surge tank 16 by a first intake passage 1a and a second intake passage 15b, which are defined in an intake manifold 15. A swirl control valve 17 is arranged in each second intake passage 15b. The swirl control valves 17 are connected to, for example, a step motor 19 by a common shaft 18. The step motor 19 In controlled by signals sent from an electronic control unit (ECU) 30. The step motor 19 may be replaced by an actuating member controlled by the negative pressure in the intake ports 7a, 7b.
The surge tank 16 is connected to an air cleaner 21 through an intake duct 20. An electrically controlled throttle valve 23, which is opened and closed by a step motor 22, is arranged in the intake duct 20. The ECU 30 sends signals to drive the step motor 22 and open and close the throttle valve 23. The throttle valve 23 adjusts the amount of intake air that passes through the intake duct 20 and enters the combustion chambers 5. The throttle valve 23 also adjusts the negative pressure produced in the intake duct 20.
A throttle sensor 25 is arranged in the vicinity of the throttle valve 23 to detect the opening angle (throttle angle TA) of the valve 23; The exhaust ports 9 of each cylinder 1a are connected to an exhaust manifold 14. After combustion, the exhaust gas is sent to an exhaust pipe (not shown) through the exhaust manifold 14.
A conventional exhaust gas recirculation (EGR) mechanism 51 recirculates some of the exhaust gas through an EGR passage 52. An EGR valve 53 is arranged in the EGR passage 52. The EGR passage 52 connects the downstream side of the throttle valve 23 in the intake duct 20 to an exhaust duct. The EGR valve 53 includes a valve seat, a valve body, and a step motor (all of which are not shown). The opening area of the EGR valve 53 is altered by causing the step. motor to intermittently displace the valve body with respect to the valve seat. When the EGR valve 53 opens, some of the exhaust gas sent into the exhaust duct enters the EGR passage 52. The gas is then drawn into the intake duct 20 via the EGR valve 53. In other words, some of the exhaust gas is recirculated by the EGR mechanism 51 and returned to the air-fuel mixture. The recirculation amount of the exhaust gas is adjusted by the opening amount of the EGR valve 53.
As shown in FIGS. 1 and 3, a brake booster 71 is provided to enhance the braking force of the vehicle. The brake booster 71 increases the pressing force of the brake pedal 72. The pressing force is converted to hydraulic pressure and used to actuate brake actuators (not shown) provided for each wheel. The brake booster 71 In connected is to the downstream side of the throttle valve 23 in the intake duct 20 by a connecting pipe 73 and actuated by the negative pressure produced in the duct 20. A check valve 74, which is opened by the negative pressure produced in the intake duct 20, is provided in the connecting pipe 73 (FIG. 3). The brake booster 71 includes a diaphragm, which serves as an actuating portion. One side of the diaphragm communicates with the atmosphere. The negative pressure produced in the intake duct 20 and communicated through the connecting pipe 73 act; on the other side of the diaphragm. A pressure sensor 63 is arranged in the connecting pipe 73 to detect the pressure in the brake booster 71, or the brake booster pressure PBK.
The ECU 30 is a digital computer provided with a random access memory (RAM) 32, a read only memory (ROM) 33, a central processing unit (CPU) 34, which is a microprocessor, an input port 35, and an output port 36. A bidirectional bus 31 connects the RAM 32, the ROM 33, the CPU 34, the input port 35, and the output port 36 to one another.
An acceleration pedal 24 is connected to an acceleration sensor 26A. The acceleration sensor 26A generates voltage proportional to the degree of depression of the acceleration pedal 24. This enables the degree of acceleration pedal depression ACCP to be detected. The voltage output by the acceleration sensor 26A is input into the input port 35 by way of an analog to digital (A/D) converter 37. The acceleration pedal 24 is also provided with a complete closure switch 26B, which detects whether the acceleration pedal 24 is not pressed at all. The closure switch 26B outputs a complete closure signal XIDL set at one when the acceleration pedal 24 in not pressed at all and outputs a complete closure signal XIDL set at zero when the acceleration pedal 24 is pressed. The output voltage of the closure switch 26B is also input into the input port 35.
A top dead center position sensor 27 generates an output pulse when, for example, the piston in the first cylinder 1a reaches the top dead center position. The output pulse in input into the input port 35. A crank angle sensor 28 generates an output pulse each time a crankshaft of the engine 1 is rotated by a crank angle CA of 30 degrees. The output pulse sent from the crank angle sensor 27 is input into the input port 35. The CPU 34 reads the output pulses of the top dead center position sensor 27 and the crank angle sensor 28 to compute the engine speed NE.
The rotational angle of the shaft 18 is detected by a swirl control valve sensor 29 to measure the opening area of the swirl control valves 17. The signal output of the swirl control valve sensor 29 is input into the input port 35 by way of an A/D converter 37.
The throttle sensor 25 detects the throttle angle TA. The signal output of the throttle sensor 25 is input into the input port 35 by way of an A/D converter 37.
An intake pressure sensor 61 is provided to detect the pressure in the surge tank 16 (intake pressure PiM). The intake pressure PiM detected by the intake pressure sensor 61 when the engine 1 is started is substantially equal to the atmospheric pressure PA. Thus, the intake pressure sensor 61 also detects atmospheric pressure.
A coolant temperature sensor 62 is provided to detect the temperature of the engine coolant (coolant temperature THW). A vehicle speed sensor 64 is provided to detect the speed of the vehicle (vehicle speed SPD). The signal outputs of the sensors 61, 62, 64 are input into the input port 35 by way of A/D converters 37. The signal output of the pressure sensor 63 is also input into the input port 35 by way of an A/D converter 37.
The running condition of the engine 1 is detected by the throttle sensor 25, the acceleration sensor 26A, the complete closure switch 26B, the top dead center position sensor 27, the crank angle sensor 28, the swirl control valve sensor 29, the intake pressure sensor 61, the coolant temperature sensor 62, the pressure sensor 63, and the vehicle speed sensor 64.
The output port 36 is connected to the fuel injection valves 11 the step motors 19, 22, the ignitor 12, and the ECR valve 53 (step motor) by way of drive circuits 38. The ECU 30 optimally controls the fuel injection valves 11, the step motors 19, 22, the ignitor 12 (ignition plugs 10), and the EGR valve 53 with control programs stored in the ROM 33 based on signals sent from the sensors 25-29, 61-64.
A control program stored In the apparatus for controlling negative pressure in the engine 1 by controlling the throttle valve 23 will now be described with reference to a flowchart shown in FIG. 4.
In step 101, the ECU 30 computes the reference throttle angle THRB based on the present detecting signals (such as the degree or acceleration pedal depression ACCP and the engine speed NE) read by the ECU 30. The ECU 30 refers to a map (not shown) when obtaining the reference throttle angle THRB. In step 102, the ECU 30 computes the time period t during which the injection valve is opened based on the intake pressure PiM and the engine speed NE. In step 103, the ECU 30 determines whether the time period t is greater than a predetermined reference time period tM. The time period tM is a fixed value and indicates the time required for the throttle valve 23, which is completely opened, to close and produce negative pressure.
If it is determined that the time period t is greater than the reference time period tM in step 103, the ECU 30 determines that stable combustion is possible even if the throttle valve 23 is closed to produce negative pressure and proceeds to atop 104. At atop 104, the ECU 30 reads the pressure PBX that is applied to the brake booster 71.
In step 105, the ECU 30 determines whether the flag XFLAG, which indicates the closing of the throttle valve 23, is set at one. If the flag XFLAG is not set at one, this indicates that closing of the throttle valve 23 is not being performed. In this case, the ECU 30 proceeds to step 106 and determines whether the brake booster pressure PBX is higher than the first reference pressure PH. The first reference pressure PH is the highest negative pressure that will actuate the brake booster 71. That is, it represents the minimum level of vacuum required to actuate the booster 71.
When it is determined that the booster pressure PBX is greater than the first reference pressure PH in step 106, that is, the booster vacuum Is insufficient, the ECU 30 proceeds to step 107 and sets the flag XFLAG at one. At stop 108, the ECU 30 uses the engine speed NE and the injection valve opening time period t as a function to compute the throttle valve opening compensation angle DTHR. The compensation angle DTHR is determined from the following equation:
DTHR=DTHR(NE, t)
FIG. 5 shows a map for determining the throttle valve opening compensation angle DTHR. The horizontal axis represents the engine speed NE while the vertical axis represents the compensation angle DTHR. The parameters obtained indicate the injection valve opening time period t.
In step 109, the ECU 30 computes the command value THR related to the throttle valve opening angle by subtracting the compensation angle DTHR from the reference throttle angle THRB.
When it is determined that the closing of the throttle valve has been carried out in step 105, the ECU 30 proceeds to stop 110 and determines whether the brake booster pressure PBX is lower than the second reference pressure PL. The second reference pressure PL corresponds to the pressure value at which the negative pressure in the brake booster 71 is satisfactory. Thus, closing the throttle valve 23 is no longer necessary when the second reference pressure PL is reached. The second reference pressure PL is lower than the first reference pressure PH.
When it is been determined that the brake booster pressure PBK is lower than the second reference pressure PL in step 110, the ECU 30 proceeds to stop 111 and resets the flag XFLAG at zero. In step 112, the ECU 30 sets the reference throttle angle THRB as the throttle valve angle command value THR.
When it has been determined that the negative pressure is sufficient for actuating the brake booster 72 (i.e., the ECU 30 determines that it is not necessary to close the throttle valve 23) in step 106, the ECU 30 proceeds to step 112.
If it is determined that the negative pressure in the brake booster 71 is insufficient for actuating the booster 71, the ECU 30 proceeds to step 108 and closes the throttle valve 23. From either step 109 or step 112, the ECU 30 proceeds to step 113 and outputs the throttle valve angle command value THR. The ECU 30 then terminates the routine.
In this embodiment, the negative pressure control apparatus forcibly closes the throttle valve and produces negative pressure regardless of the running state of the vehicle when the negative pressure that acts on the brake booster 71 is insufficient. However, the closing of the throttle valve 23 decreases the amount of the air intake supplied to the engine 1. This effects the combustion of the air-fuel mixture. Thus, it is undesirable that the throttle valve 23 be closed, so it should be done as little as possible. The second embodiment copes with this requirement.
In a second embodiment according to the present invention, a brake switch 72a is added to the mechanical structure of the first embodiment. When the brake pedal 24 is pressed, the brake switch 72a outputs an ON signal. This causes the ECU 30 to set the brake actuation flag XBRG in the RAM 32. When the brake pedal 24 is released, the brake switch 72a outputs an OFF signal. This causes the ECU 30 to reset the brake actuation flag XBRG in the RAM 32.
The second embodiment will now be described with reference to the flowchart shown in FIG. 6. In step 201, the ECU 30 computes the reference throttle angle THRB based on the running condition of the engine 1. In step 202, the ECU 30 determines whether a predetermined time α has elapsed since the starting of the engine 1. If it is determined that the predetermined time a has elapsed, the ECU 30 proceeds to step 203. In step 203, the ECU 30 determines whether the flag XFLAG, which indicates the execution of the valve closing control, is set at zero. If the flag XFLAG is set at zero, the ECU 30 proceeds to step 204 and determines whether the brake actuation flag XBRK is set at one.
When it is determined that the actuation flag XBRK is sat at one in step 204, the ECU 30 proceeds to step 205 and adds one to the brake count CBK, which is a count of brake actuation time, in an incremental manner. In step 206, the ECU 30 determines whether the brake count CBK has exceeded a predetermined count value CBKO. If the brake count CBK exceeds the count value CBKO, the ECU 30 determines that the brake pedal 24 has been pressed continuously for longer than a predetermined time. In this case, the ECU 30 proceeds to step 207 and sets the flag XFLAG at one.
In step 208, the ECU 30 uses the engine speed NE as a function to obtain the throttle valve compensation angle DTHR from the equation of DTHR=DTHR(NE). A map used to obtain the compensation angle DTHR is shown in FIG. 7. The horizontal axis represents the engine speed NE while the vertical axis represents the compensation angle DTHR. In step 209, the ECU 30 computes the throttle valve angle command value THR by subtracting the compensation angle DTHR from the reference throttle angle THRW. The ECU 30 then proceeds to step 215 to output a signal corresponding to the command value THR.
When it is determined that the brake pedal 24 is not being pressed in step 204, the ECU 30 proceeds to step 210 and resets the brake count CBK at zero. Since the brake pedal 24 is not pressed, it is not necessary to produce negative pressure by closing the throttle valve 23. Thus, in step 211, the ECU 30 sets the reference throttle angle THRB as the command value THR. The ECU 30 then proceeds to step 215 and outputs a signal corresponding to the command value THR.
When it is determined that the value of the brake count CBK has not reached the predetermined count value CBKO in step 206, the brake pedal 24 has not been pressed continuously for longer than a predetermined time period. Thus, it is not necessary to close the throttle valve 23 and produce negative pressure. In this case, the ECU 30 proceeds to step 211. If the predetermined time a has not elapsed since starting the engine 1, the ECU 30 proceeds to step 212 to guarantee the initial negative pressure regardless of the state of the brake pedal 24.
If the flag XFLAG is set at one in step 203, the ECU determines that the closing control of the throttle valve 23 is being carried out and proceeds to step 212. In step 212, the ECU 30 determines whether the brake booster pressure PBK is lower than the reference pressure PH, which is the higher negative pressure required to actuate the brake booster 71. If the brake booster pressure PBK is higher than the reference pressure PH, the ECU 30 proceeds to step 207 to produce the necessary negative pressure for actuating the brake booster 71. The throttle valve 23 is closed by carrying out step 207.
If the booster pressure PBK is equal to or lower than the reference pressure PH in step 212, the ECU 30 determines that the negative pressure is sufficient for actuating the brake booster 71. In this case, the ECU 30 sets the throttle valve closing flag XFLAG at zero in step 213 and then proceeds to step 214. At step 214, the reference throttle angle THRB is set as the throttle valve angle command value THR. At atop 215, the ECU 30 outputs a signal corresponding to the command value THR.
In this embodiment, negative pressure need not be produced unless the brake pedal 72 is pressed longer than the predetermined time. Accordingly, the throttle valve 23 is not closed as often as in the prior art. This drastically reduces the combustion disturbance caused when performing throttle valve control.
A third embodiment according to the present invention will now be described with reference to FIGS. 8 to 10.
As shown in FIG. 8, a negative pressure reserve tank 90 is provided in the connecting pipe 73 of the negative pressure control apparatus. A pressure sensor 91 is connected to the reserve tank 90. Negative pressure is accumulated in the reserve tank 90. The reserve tank 90 lengthens the time period during which the brake booster vacuum is adequate. Thus, the number of times the throttle valve is closed is reduced.
In a stratified combustion engine, to which the present invention is mainly applied, the throttle valve 23 is completely opened most of the time. Thus, the closing of the throttle valve 23 effectively produces negative pressure. However, closing of the throttle valve 23, especially when performing stratified charge combustion, hinders stable combustion. The fuel injection mode of a typical stratified combustion engine is illustrated in FIG. 9. In this drawing, the horizontal axis represents the engine load (corresponding to the flow rate of the intake air as an example) while the vertical axis represents the injected amount of fuel (corresponding to the time period during which the injection valve is opened).
When the engine load is within the range of L0 to L1, fuel is injected from a stratified charge injection valve 11a toward the vicinity of the ignition plug 10 in the compression stroke to perform strong stratified charge combustion. If the engine load is within the range of L1 to L2, the injection is divided into two parts. During time period t, fuel is injected from the stratified charge injection valve 11a in the compression stroke until time t1 elapses. During the remaining time period (t-t1), fuel is injected from a uniform charge injection valve 11b in the intake stroke. This causes the air-fuel mixture in the cylinder to be in a weak stratified state.
If the engine load becomes higher than L2, fuel is injected through the uniform charge injection valve 11b during the entire fuel injection period in the intake stroke. If the throttle valve 23 is closed when fuel is injected through the uniform charge injection valve 11b, the air-fuel mixture at the vicinity of the ignition plug may be excessively rich. This hinders ignition.
In addition, it is more beneficial if fuel to injected using only the stratified charge injection valve during the intake stroke when uniform charge combustion is required. To cope with these matters, the following fifth embodiment has been proposed.
A routine executed in the third embodiment will now be described with reference to the flowchart of FIG. 10. In step 301, the ECU 30 determines whether a predetermined time α has elapsed since the starting of the engine 1. When it is determined that the predetermined time α has elapsed, the ECU 30 proceeds to step 302. In step 302, the ECU 30 determines whether the throttle valve closing flag XFLAG, which indicated performance of throttle valve closing control, is set at zero. If the flag XFLAG is set at zero, indicating that the valve closing control is not being executed, the ECU 30 proceeds to step 303 and determines whether the brake actuation flag XBRK is set at one.
When it is determined that the actuation flag XBRK is set at one in step 303, the ECU 30 proceeds to step 304 and adds on to the brake count CBK, which indicates the occurrence of brake actuation, in an incremental manner. In step 305, the ECU 30 determines whether the brake count CBK has exceeded a predetermined count value CBKO. If the brake count CBK exceeds the count value CBKO, the ECU 30 determines that the brake pedal 24 has been promised continuously for longer than a predetermined time. In this case, the ECU 30 proceeds to stop 306 and determines whether the brake booster pressure PBK is equal to or lower than the predetermined pressure PH, which is required to actuate the brake booster.
If it is determined that the brake booster pressure PBX is equal to or lower than the predetermined pressure PH in step 306, the ECU 30 proceeds to stop 307 and sets the throttle valve closing flag XFLAG at zero. In step 308, the ECU 30 sets the reference throttle angle THRB as the throttle valve angle command value THR. The ECU 30 then outputs a signal corresponding to the command value THR in step 313.
When the brake booster pressure PBK is higher than the predetermined pressure PH in step 306, the ECU 30 determines that the negative pressure for actuating the brake booster 71 is insufficient. In this case, the ECU 30 proceeds to step 309 and mete the throttle valve closing flag XFLAG at one. In step 310, the ECU 30 uses the engine speed NE as a function to obtain the throttle valve compensation angle DTHR. In step 311, the ECU 30 computes the throttle valve angle command value THR by subtracting the compensation angle DTHR from the reference throttle angle THRB. The ECU 30 then proceeds to step 313 to output a signal corresponding to the command value THR.
If it is determined that the brake actuation flag XBRK is set at zero in step 303, this indicates that the brake pedal 24 is not being pressed. In this case, the ECU 30 proceeds to step 312 and resets the brake count CBK at zero. The ECU 30 then proceeds to step 308. If it is determined that the brake count CBK is equal to or smaller than the count value CBKO in stop 305, the ECU 30 proceeds to step 308.
FIG. 11 shows a flowchart of the fuel injection mode control that is executed by the ECU 30. This control routine is executed as part of the main routine.
In step 401, the ECU 30 reads the engine speed NE and the degree of acceleration pedal depression ACCP. In step 402, the ECU 30 uses the engine speed NE and the degree of pedal depression ACCP to compute the injection valve opening time period t. In step 403, the ECU 30 determines whether the opening time period t is longer than the first reference time period tr1. The first reference time period tr1 indicates the period of time during which the amount of fuel injection is small and the load applied to the engine 1 is small. If it is determined that the opening time period t is equal to or shorter than the reference time period tr1 in step 403, the ECu 30 proceeds to step 404 and sets the fuel injection mode flag XINJ at zero. This indicates that the strong stratified injection mode is being carried out.
When the opening time period t is longer than the reference time period tr1, the ECU 30 proceeds from stop 403 to step 405. In step 405, the ECU 30 determines whether the opening time period t is shorter than the second reference time period tr2. The second time period tr2 indicates the period of time during which a medium level of load is applied to the engine when the injection valve is opened. The values of the first and second reference time periods tr1, tr2 may be fixed. As another option, the values may be a function of the engine speed NE.
If it is determined that the opening time period t is shorter than the second reference time period tr2, the ECU 30 proceeds to step 406 and sets the fuel injection mode flag XINJ at one. This indicates that the two-part injection mode is being carried out. If the opening time period t is equal to or longer than the second reference time period tr2 in step 405, a high level of load is applied to the engine 1. In thin case, the ECU 30 proceeds to step 407 and sat& the fuel injection mode flag XINJ at two. This indicates that the uniform charge injection mode is being carried out.
After performing step 404, 406, or 407, the ECU 30 proceeds to step 408 and determines whether the throttle valve closing flag XFLAG is set at one. That is, the ECU 30 judges whether the throttle valve 23 is closed to produce negative pressure.
If the flag XFLAG is set at one in step 408, the ECU 30 proceeds to step 409 and forcibly changes the fuel injection mode flag XINJ to two, which indicates the uniform charge injection mode. By forcibly switching to the uniform charge injection mode, ignition is guaranteed when the throttle valve is closed to produce negative pressure in the medium and high level load range during which the injected amount of fuel is relatively small. The ECU 30 then proceeds to stop 410.
If the flag XFLAG is not set at one in step 408, this indicates that the throttle valve 23 is not closed. In this case, the ECU 30 proceeds directly to step 410. When proceeding to step 410 from either step 408 or step 409, the ECU 30 determines whether the fuel injection mode flag XINJ is set at zero. If set at zero, the ECU 30 proceeds to step 411 and computes the parameters for the stratified charge injection mode. The routine is terminated afterward.
If the flag XINJ is not set at zero in step 410, the ECU 30 proceeds to step 412 and determines whether the flag XINJ is set at one. When set at one, the ECU 30 proceeds to step 413 and computes the parameters for the two-part injection mode. The routine is terminated afterward. If the flag XINJ is not set at one in step 412, the ECU 30 proceeds to step 414 and computes the parameters for the uniform charge injection mode. The routine is terminated afterward.
The ECU 30 stores the fuel injection parameters in the form of maps for each mode.
This preferred embodiment guarantees the negative pressure that is required to actuate the brake booster 71 without degrading the ignitability of the air-fuel mixture regardless of the running state of the engine 1.
A fourth embodiment according to the present invention will now be described with reference to the flowchart shown in FIGS. 12 to 14. In the routine illustrated in the flowchart, the throttle valve 23 (step motor) 22 is controlled to control the negative pressure communicated to the brake booster 71.
When entering the routine, the ECU 30 first determines whether the engine 1 is presently performing stratified charge combustion in step 500. If stratified charge combustion is not being performed, the ECU 30 determines that the engine 1 is presently performing uniform charge combustion. This indicates that problems related with negative pressure are unlikely to occur. In this case, the ECU 30 proceeds to step 512.
In step 512, the ECU 30 computes the basic throttle angle TRTB from the present detecting signals (the degree of acceleration pedal depression ACCP, the engine speed NE, and other parameters). The ECU 30 refers to a map (not shown) to compute the basic throttle angle TRTB. The ECU 30 proceeds to step 513 and sets the final target throttle angle, or throttle opening area TRT, by subtracting the present throttle closing angle TRTCBK from the basic throttle angle TRTB. The ECU 30 then temporarily terminates subsequent processing. When the ECU 30 jumps from step 500 to step 512, the value of the throttle closing angle TRTCBK is set at zero. Thus, the basic throttle angle TRTB is set equal to the final target throttle opening area TRT.
In step 500, if it is determined that the engine 1 is performing stratified charge combustion, the ECU 30 proceeds to step 501. At step 501, the ECU 30 subtracts the most recent brake booster pressure PBX, which is detected by the pressure sensor 63, from the atmospheric pressure PA to obtain the pressure difference DPBK.
In step 502, the ECU 30 determines whether the present vehicle speed SPD is equal to or higher than a predetermined speed (e.g., 20 km/h). If the vehicle speed SPD is lower than the predetermined speed, the ECU 30 continues the stratified charge combustion mode and proceeds to step 503 to execute the throttle angle control (stratified charge brake control).
In step 503, the ECU 30 determines whether the flag XBKIDL that indicates the execution of the stratified charge brake control is set at one. The execution flag XBKIDL is set at one when producing negative pressure while performing the stratified charge combustion mode. If the execution flag XBKIDL is set at zero, that is, if the stratified charge control is not in process, the ECU 30 proceeds to step 504.
In step 504, the ECU 30 determines whether the present pressure difference DPBK is smaller than a predetermined negative pressure value tKPBLK (e.g., 300 mmHg), which initiates the stratified charge brake control. It the pressure difference DPBK is smaller than the negative pressure value tKPBLK, the ECU 30 proceeds to step 505.
In step 505, the ECU 30 sets the execution flag XBKIDL to one to enter the stratified charge brake control mode. The ECU 30 then proceeds to step 506 and computes the closing compensation angle a. To obtain the closing compensation value a, the ECU 30 refers to a map such as that shown in FIG. 15. In the map, the closing compensation angles a are Indicated in correspondence with values that are obtained by subtracting the value of the pressure difference DPBK from the target negative pressure value tKPBKO (e.g., 350 mmHg). If the pressure difference DPBK is much smaller than the predetermined negative pressure value tKPBKO (i.e., if the subtracted value is large), the closing compensation angle a is set at a large value to increase the closing speed of the throttle valve 23. On the contrary, the closing compensation angle a is set at a small value to decrease the closing speed of the throttle valve 23 when the pressure difference DPBK approaches the predetermined negative pressure value tKPBKO (i.e., when the subtracted value is small).
In step 507, the ECU 30 renews the throttle closing angle TRTCBK to a value obtained by adding the present closing angle compensation value a to the throttle closing angle TRTCBK of the previous cycle and then proceeds to step 512. In step 512, the ECU 30 computes the basic throttle angle TRTB. Then, in step 513, the ECU 30 sets the final target throttle opening area TRT by subtracting the present throttle closing angle TRTCBK from the basic throttle angle TRTB. Afterward, the ECU 30 temporarily terminates subsequent processing. Accordingly, if the ECU 30 carries out steps 503 to 507, the increasing value obtained by subtracting the throttle closing angle TRTCBK is set as the final target throttle opening area TRT.
In step 504, if the pressure difference DPBK is equal to or greater than the negative pressure value tRPBLK that initiates the stratified charge brake control, the ECU 30 jumps to step 512. In this case, stratified charge brake control is not executed.
If the execution flag XBKIDL is set at one in step 503, the ECU 30 proceeds to step 508 and determines whether the pressure difference DPBK exceeds the negative pressure value tKPBKO that terminates the stratified charge brake control. If it is determined that the pressure difference DPBK does not exceed the negative pressure value tKPBKO, the ECU 30 proceeds to step 506. The ECU 30 carries out steps 506, 507 and then proceeds to step 512 to compute the basic throttle angle TRTB. Subsequently, in step 513, the ECU 30 vets the final target throttle opening area TRT to a value obtained by subtracting the present throttle closing angle TRTCBK from the basic throttle angle TRTB. Afterward, the ECU 30. temporarily terminates subsequent processing. Accordingly, in this case, the value obtained by subtracting the presently increasing throttle closing angle TRTCBK is set as the final target throttle opening area TRT.
If it is determined that the pressure difference DPBK exceeds the negative pressure value tKPBKO in step 508, the ECU 30 proceeds to step 509 to decrease the throttle closing angle TRTCBK (and increase the target throttle opening area TRT). At step 509, the ECU 30 renews the throttle closing angle TRTCBK to a value obtained by subtracting a predetermined closing angle compensation value b (b is a constant value) from the throttle closing angle TRTCBK of the previous cycle.
In step 510, the ECU 30 determines whether the throttle closing angle TRTCBK corresponds to a value of zero. If it in determined that the throttle closing angle TRTCBK does not correspond to a value of zero, the ECU 30 proceeds to step 512 to compute the basic throttle angle TRTB. Subsequently, in step 513, the ECU 30 sets the final target throttle opening area TRT to a value obtained by subtracting the present throttle closing angle TRTCBK from the basic throttle angle TRTB. Afterward, the ECU 30 temporarily terminate subsequent processing. Accordingly, in this case, the value obtained by subtracting the presently decreasing value of the difference between the throttle closing angle TRTCBK and the basic throttle angle TRTB is set as the final target throttle opening area TRT.
If the throttle closing angle TRTCBK corresponds to a value of zero in atop 510, the ECU 30 proceeds to step 511. At step 511, the ECU 30 sets the execution flag XBKIDL to zero to terminate the stratified charge brake control mode. The ECU 30 then carries out steps 512, 513 and temporarily terminates subsequent processing. When the ECU 30 proceeds from step 511 to step 512, the value of the throttle closing angle TRTCBK is set at zero. Thus, the basic throttle angle TRTB is set equal to the final target throttle opening area TRT.
In step 502, if the present vehicle speed SPD is equal to or higher than the predetermined speed, the ECU 30 proceeds to step 514 to temporarily perform uniform charge combustion while executing throttle angle control (uniform charge combustion brake control).
In step 514, the ECU 30 determines whether the flag XBKDJ that indicates execution of the uniform charge combustion brake control is set at one. The execution flag XBKDJ is set at one when negative pressure is guaranteed by the performance of the uniform charge combustion. If determined that the execution flag XBKDJ is not set at one but set at zero, the ECU 30 proceeds to step 515.
In step 515, the ECU 30 determines whether the present pressure difference DPBK is smaller than the negative pressure value tKPBKLS at which the uniform charge brake control is initiated,(e.g., 300 mmHg). If determined that the pressure difference DPBK is equal to or greater than the negative pressure value tKPBKLS, the ECU 30 jumps to step 512. In this case, the uniform charge combustion brake control is not carried out.
If the pressure difference DPBK is smaller than the negative pressure value tKPBKLS, the ECU 30 determines that negative pressure is insufficient and proceeds to step 516. At step 516, the ECU 30 sets the execution flag XBKDJ at one to execute uniform charge combustion control. The ECU 30 then proceeds to step 517 and temporarily switches to the uniform charge combustion mode. During stratified charge combustion, either the stratified charge combustion mode or the uniform charge combustion mode is performed. The stratified charge combustion control is usually performed. However, uniform charge combustion control is performed when necessary. In this mode, the throttle valve 23 is opened and closed in accordance with the load applied to the engine 1 by supplying the necessary amount of air-fuel mixture to produce the power required by the engine 1.
In step 518, the ECU 30 determines whether the present pressure difference DPBK is greater than the negative pressure value tKPBKSO at which the uniform charge combustion brake control is terminated (e.g., 350 mmHg). In most cases, the pressure difference DPBK is still equal to or smaller than the negative pressure value tKPBKSO. In such cases, the ECU 30 proceeds to steps 512, 513. This causes the engine 1 to completely enter uniform charge combustion. Thus, the throttle valve 23 is closed to communicate negative pressure to the brake booster 71.
In step 514, if the execution flag XBKDJ is set at one indicating execution of uniform charge brake control (and indicating that uniform charge combustion is in progress), the ECU 30 proceeds to step 519. At step 519, the ECU 30 determines whether the present pressure difference DPBK is greater than the negative pressure value tKPBKSO at which the uniform charge combustion brake control is terminated (e.g., 350 mmHg). If the pressure difference DPBK is still not greater than the negative pressure, the ECU 30 repeats steps 517, 512, 513 and continues uniform charge combustion.
When sufficient negative pressure is communicated to the brake booster 71 as a result of the uniform charge combustion mode causes the pressure difference DPBK to becomes greater than the negative pressure value tKPBKSO, at which the uniform charge brake control is terminated, the ECU 30 proceeds to step 520. The ECU 30 proceeds to step 520 from either step 519 or step 518 (in most cases from step 519). At step 520, the ECU 30 determines that there is no need to further produce negative pressure and sets the execution flag XBKDJ to zero. In atop 521, the ECU 30 discontinues the uniform charge combustion mode and enters the stratified charge combustion mode. The ECU 30 then carries out steps 512, 513 and terminates subsequent processing.
In the negative pressure control routine, the pressure difference DPBK is computed from the atmospheric pressure PA and the brake booster pressure PBK. The closing control of the throttle valve 23 (negative pressure guaranteeing control) in executed when the pressure difference DPBK is smaller than the negative pressure value tKPBKL, which initiates stratified charge brake control, or smaller than the negative pressure value tKPBKLS, which initiates uniform charge combustion control. If the vehicle speed SPD is lower than the predetermined speed, a negative pressure that guarantees control for stratified charge combustion is provided. If the vehicle speed SPD is equal to or higher than the predetermined speed, a negative pressure guaranteeing control for uniform charge combustion is provided.
In addition, it is determined whether the negative pressure that actuates the brake booster 71 is sufficient (steps 504, 515, etc.). When it is determined that the negative pressure is insufficient, the angle closing control of the throttle valve 23 is carried out. The closing of the throttle valve 23 increases the negative pressure (reduces the pressure) and guarantees the operation of the brake booster 71.
To determine whether it is necessary to produce negative pressure for the actuation of the brake booster 71, the difference between the atmospheric pressure PA and the brake booster pressure PBK, which is detected by the pressure sensor 63, is computed to obtain the pressure difference DPBK. If the pressure difference DPBK is smaller than either the negative pressure value tKPBKL, at which stratified charge brake control is initiated, or the negative pressure value tKPBKLS, at which the uniform charge brake control is initiated, the closing control of the throttle valve 23 (negative pressure ensuring control) is carried out.
Thus, as shown in FIG. 18, when traveling at a high altitude, the decrease in the atmospheric pressure PA causes the brake booster pressure PBK to be lower than when traveling at a low altitude. Accordingly, the brake booster pressure PBK may be low while the actual negative pressure for actuating the brake booster 71 is insufficient. However, in this embodiment, the closing control of the throttle valve 23 is executed to produce negative pressure when tho pressure difference DPBK, and not the brake booster pressure PBK, is smaller than the reference value (negative pressure value tKPBKL for initiating stratified charge brake control or the negative pressure value tKPBKLS for initiating uniform charge brake control). This always guarantees sufficient negative pressure for the actuation or the brake booster 71 even when the atmospheric pressure PA fluctuates such an when traveling at high altitudes.
Furthermore, the closing control of the throttle valve 23 is executed if the pressure difference DPBK is smaller than the reference value (negative pressure value tKPBKL for initiating stratified charge brake control or negative pressure value tKPBKLS for initiating uniform charge broke control), and the closing control is terminated if the pressure difference DPBK becomes greater than a larger reference value (negative pressure value tKPBKO for terminating stratified charge brake control or negative pressure value tKPBKSO for terminating uniform charge brake control). In other words, the reference value has a hysteresis. This prevents hunting caused by the pressure difference DPBK becoming smaller than the reference value and then equal to or greater than the reference value in a repetitive manner. Repetitive execution and non-execution of the closing control does not take place.
Although the opening area of the intake passage is narrowed to produce negative pressure, an electronically controlled throttling mechanism that includes the throttle valve 23 and the step motor 22 is employed as a means to guarantee negative pressure. Thus, conventional devices are used to produce negative pressure. This lowers costs.
In this embodiment, when increasing the throttle closing angle TRTCBK, the throttle closing angle TRTCBK is renewed by adding the presently set closing angle compensation value b to the throttle closing angle TRTCBK of the previous cycle. The closing angle compensation value a is set at a large value if the pressure difference DPBK is much smaller than the negative pressure value tKPBKO for terminating stratified charge brake control. Therefore, as shown in FIG. 19, the closing speed is high immediately after the initiation of the closing control. This readily guarantees negative pressure.
If the pressure difference DPBK approaches the negative pressure value tKPBKO for terminating stratified charge brake control, the closing angle compensation value a is set at a small value. Thus, when a certain time elapses after starting the closing control, the closing speed decreases. This suppresses overshooting of the closing action and the negative pressure.
The injection timing control executed during stratified charge combustion negative pressure control (stratified charge combustion brake control) will now be described. The fuel injection control is executed to prevent the air-fuel ratio from becoming rich when performing stratified brake control. FIG. 16 shows a flowchart of a main routine of the fuel injection control executed by the ECU 30.
When entering the main routine, the ECU 30 first reads various detecting signals such as the degree of acceleration pedal depression ACCP and the engine speed NE in step 601.
In step 602, the ECU 30 determines whether stratified charge combustion is being performed. If the stratified charge combustion is not being performed, the ECU 30 temporarily terminates subsequent processing. If the stratified charge combustion is being performed, the ECU 30 proceeds to step 603 and computes the target fuel injection amount TAU.
In step 604, the ECU 30 computes the basic fuel injection timing AINJ (in relation with when the piston is located at the top dead center position). In step 605, the ECU 30 computes the target ignition timing SA. In step 606, the ECU 30 computes the basic throttle opening area TRT. In step 607, the ECU 30 computes the target EGR opening area EGRT.
After obtaining the parameters, the ECU 30 determines whether the flag XBKIDL indicating the execution of the stratified charge brake control is set at one. If the execution flag XBKIDL is get at one, the ECU 30 proceeds to step 609 and computes the fuel injection timing compensation angle KAINJ based on the present throttle closing angle TRTCBK. The ECU 30 refers to a map shown in FIG. 17 to compute the injection timing compensation angle KAINJ. In other words, if the throttle closing angle TRTCBK indicates a value of zero, the injection timing compensation angle KAINJ is set at zero. As the value of the throttle closing angle TRTCBK becomes greater, the fuel injection compensation value KAINJ is set at a larger value (toward advancement).
If the execution flag XBKIDL is not set at one but set at zero, the ECU 30 proceeds to step 610 since there is no need to compensate the injection timing. At step 610, the ECU 30 sets the injection timing compensation angle KAINJ to zero.
The ECU 30 proceeds to step 611 from either step 609 or step 610 and advances the basic injection timing AINJ by adding the injection timing compensation angle KAINJ. The obtained value is set as the final target injection timing AINJE. At atop 612, the parameters are reflected in the stratified charge combustion. Subsequent processing is then temporarily terminated.
In the main routine, the closing control of the throttle valve 23 is carried out while performing stratified charge combustion If the stratified charge brake control in executed. In this case, the target injection timing AINJE is advanced from the basic injection timing AINJ by the injection timing compensation angle KAINJ. This prevents the air-fuel ratio from becoming rich.
In the main routine, the closing control of the throttle valve 23 is carried out while performing stratified charge combustion during the stratified charge brake control. In this state, the closing of the throttle valve 23 causes the air-fuel ratio to become rich since the intake air amount decreases, as shown by the dotted line in FIG. 20. If normal fuel Injection and ignition is performed with the air-fuel ratio in a rich state, this may result in an undesirable combustion state. However, in this embodiment, the target injection timing AINJE is advanced from the basic injection timing AINJ by the injection timing compensation angle KAINJ, as shown by the double-dotted line in FIG. 20. This guarantees the normal air-fuel ratio during ignition. As a result, the air-fuel ratio is prevented from becoming rich. This prevents an undesirable combustion state.
Although only one embodiment of the present invention has been described so far, it should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. More particularly, the present invention may be modified as described below.
(1) In the illustrated embodiment, an electronically controlled throttle mechanism is used as the negative pressure producing means. The throttle mechanism includes the throttle valve 23 arranged in the intake duct 20, and the step motor 22 serving as an actuator for opening and closing the throttle valve 23. However, an idle speed control (ISC) mechanism may be used am the negative pressure producing means. Such an ISC mechanism includes an idle speed control valve arranged in an intake passage that bypasses the throttle valve 23 and an actuator for opening and closing the control valve.
The EGR mechanism 51 provided with the EGR valve 53 and other parts may also be employed as the negative pressure producing means.
Negative pressure producing mechanisms other than those shown in the drawings may also be employed. For example, a mechanical throttle valve that is linked to the acceleration pedal may be used in lieu of the electronically controlled throttle valve.
(2) In the illustrated embodiment, the computation of the closing compensation angle a enables the closing speed of the throttle valve 23 to be variable. However, the closing speed may be constant. Furthermore, in the preferred and illustrated embodiment, the fuel injection timing is altered when executing the closing control while performing stratified charge combustion. However, the closing control may be eliminated.
(3) The present invention is applied to the cylinder injection type engine 1 in the illustrated embodiment. The present invention may also be applied to an engine that performs stratified charge combustion and weak stratified charge combustion. For example, the present invention may be applied to an engine that insects fuel beneath the intake valves 6a, 6b provided in the associated intake ports 7a, 7b. The present invention may also be applied to an engine that injects fuel directly into the cylinder bores (combustion chambers 5) from injection valves arranged near the intake valves 6a, 6b. As another option, the present invention may be applied to an engine that does not perform stratified charge combustion.
(4) In the illustrated embodiment, helical type intake ports are employed to produce swirls. However, the swirls do not necessarily have to be produced. In such case, parts such as the swirl control valve 17 and the step motor 19 may be eliminated.
(5) The present invention is applied to a gasoline engine in the illustrated embodiment. However, the present invention may also be applied to other types of engines such as diesel engines.
(6) In the illustrated embodiment, the atmospheric pressure PA is detected by the intake pressure sensor 61. However, an atmospheric pressure sensor may be provided to detect the atmospheric pressure.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention in not to be limited to the details given herein, but may be modified within the scope of the appended claims. | An improved apparatus controls negative pressure in a combustion engine. The apparatus has a brake booster that is capable of increasing braking force of a vehicle by means of the negative pressure in the brake booster. A valve disposed in an air intake pressure generates the negative pressure that is supplied to the brake booster. An electric control unit controls the valve when pressure in the brake booster is in excess of a predetermined magnitude. |
BACKGROUND OF THE INVENTION
1. Field Of The Invention
This invention relates generally to a polishing tool for contact lenses and an associated method and more specifically, to a product and method that polishes the central optical section, the edges and the outside and peripheral bevels of a contact lens to very precise tolerances.
2. Description Of The Prior Art
Polishing a contact lens is necessary in order to achieve a proper fit between the contact lens and the eye. The more precisely and smoothly polished a contact lens is the sharper the image the wearer can obtain and the more comfortably the contact lens will fit the wearer.
The prior art contains polishing tools that have polishing heads mounted on a rigid base (usually brass) of an exact curve. It is important to have a rigid tool in order to implant its curve to the central optical portion of the contact lens in order to achieve good optical clarity.
Another aspect of contact lens fitting involves polishing the outside and peripheral bevels and the edges of a contact lens. In the periphery of the cornea, where the outer part of the contact lens fits, there is a flatenning of the corneal curve. This must be imitated by the inside periphery of the contact lens to provide for complementary configurations. It has been known in the art to employ a series of curved grinding balls to make these bevels, this variable surface then being polished with the same type rigid tools described above as were used in polishing central curves. This method, however, produced an uneven contact lens surface having a series of ridges in the junction or shoulder regions where the peripheral bevels and the central optical curves met.
U.S. Pat. No. 3,583,111, while not related to contact lenses, discloses a lens grinding apparatus comprising an abrasive disc fastened to a resilient cushion and a holder. The lens is placed on a rotating table and is brought in contact with the abrasive disc in order to polish the lens. The metal portion determines the shape of the polishing tool.
U.S. Pat. No. 3,517,466, which also does not relate to contact lenses, discloses a polishing wheel for contoured surfaces. Abrasive-faced studs are mounted on a stud carrying disc that is in turn mounted on a sponge rubber material. These layers are then mounted on a steel plate that engages a steel shaft.
U.S. Pat. No. 2,990,664 shows a method of finishing the edges of a contact lens. The lens is held on a lens holder, and the method involves twelve steps including beveling, touch polishing of the bevel, and creating the secondary curve.
U.S. Pat. No. 3,238,676 discloses various means for polishing the exterior of a contact lens by means of an enlarged concave surface.
Several patents disclose different types of grinding pads that can be used in association with a lens grinding tool. See, e.g., U.S. Pat. Nos. 3,144,737 and 3,578,850.
There remains a need for a contact lens polishing apparatus that polishes the interior surface, or central optical zone, the edges and the outside and peripheral bevels of a contact lens to a smooth blended predetermined curved shape. There also remains a need for a resilient polishing tool that can be easily manufactured into many different specific and exact curves so as to facilitate different central optical section curvatures and different edge and outside and peripheral bevel shapes.
SUMMARY OF THE INVENTION
The present invention has produced a solution to the above-described needs by providing a polishing tool for contact lenses and an associated method. The polishing tool has a base, an exteriorly convex resilient polishing head of predetermined spheric or aspheric curved shape, and a polishing member, which may be a cloth, in overlying contact with the polishing head. The base may be secured to a rotatable shaft, such as a motor shaft, by means of a shaft opening in the base or by other means. The polishing head may be made of any suitable resilient material, said material enabling the polishing head to better conform to the various surfaces on a contact lens. The polishing member is preferably secured to the resilient polishing head by suitable means.
The method of the present invention involves connecting the polishing tool to a rotatable shaft and contacting the rotating polishing head to the central optical section of the contact lens. Another embodiment of the polishing tool can be used to polish the outside and peripheral bevels and the edges of a contact lens.
It is an object of the invention to provide a contact lens polishing tool and associated method that precisely contours the central optical section, the edges and the peripheral and outside bevels of a contact lens.
It is an object of the invention to provide a polishing tool that will not distort the optics of a contact lens if a polishing tool of a somewhat too steep a curvature is used.
It is an object of the invention to provide a polishing tool that more quickly polishes a contact lens than conventional brass tools.
It is an object of the invention to provide a polishing tool with a resilient polishing head that allows the polishing head and polishing cloth to smoothly contour uneven surfaces present in contact lenses.
It is an object of the invention to provide a contact lens polishing tool that is easy to mount and use.
It is an object of the invention to provide a contact lens polishing tool that can be used with different types of polishing cloths with different mounting mechanisms.
It is an object of the invention to provide easy manufacture of polishing tools of different sizes and curvatures.
It is an object of the invention to provide an alternate embodiment of the polishing head to facilitate polishing the edges and the peripheral and outside bevels of a contact lens.
It is an object of the invention to use materials such as silk on the polishing tool to polish specified small areas instead of using thick fuzzy pads associated with prior art rigid tools.
It is a further object of the invention to provide a soft tool that polishes the outside bevels of a contact lens to cut down on spherical aberration.
These and other objects of the invention will be fully understood from the following description of the invention with reference to the illustrations appended hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged cross-sectional view of a contact lens upon which the polishing tool of the present invention operates.
FIG. 2 is a perspective view of the polishing tool of the present invention.
FIG. 3 is an elevational view of the polishing tool of FIG. 2.
FIG. 4 is a right side elevational view of the polishing tool of FIG. 3.
FIG. 5 is a left side elevational view of the polishing tool of FIG. 3.
FIG. 6 is an elevational view of another embodiment of the polishing tool.
FIG. 7 is a right side elevational view of the embodiment of the polishing tool shown in FIG. 6.
FIG. 8 is a partial elevational view of the operation of the polishing tool shown in FIG. 6 on a contact lens.
FIG. 9 is a partial cross-section showing the embodiment of the polishing tool shown in FIG. 6 with the polishing cloth fixedly secured to the polishing head with an O-ring.
FIG. 10 is an elevational view of the polishing tool of FIG. 2 with an alternate mounting mechanism.
FIG. 11 is a left side elevational view of the polishing tool of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an enlarged illustration of a contact lens upon which the polishing tool operates. The contact lens 1 has an interior portion 2 which contacts the eyeball of the wearer and an exterior portion 3 which does not contact the eyeball of the wearer. The exterior portion 3 is further comprised of an outside curve 4 and two outside bevels 5. The interior portion 2 is comprised of a base curve or central optical section 6 and two peripheral bevels 7. The junction or shoulder 8 is the point where the optical section 6 and the peripheral bevels 7 meet. Two edges 9 are formed at where the exterior portion 3 and the interior portion 2 meet. The contact lens 1 can be hard or soft.
FIG. 2 shows one of the preferred embodiments of the polishing tool. The polishing tool 10 consists of a base 11, an exteriorly convex resilient polishing head 12 and a polishing member 14. It is preferred that the polishing tool 10 have a generally cylindrical shape with a convex end. It may, for example, have an overall length of about 3/4 to 3 inches and be approximately 3/8 to 1 inch in diameter in the cylindrical region. It will be appreciated that different lengths and widths can be used depending on particular needs.
Referring to FIG. 3, the polishing tool shown is preferably symmetrical about axis a--a. The polishing tool 10 consists of a base 11, an externally convex resilient polishing head 12, and a polishing member 14, which is preferably a cloth, secured in intimate overlying relationship with respect to the domed portion 15 of the polishing head 12. If desired, the base 11 and polishing head 12 may be formed of a unitary body rather than being two components joined by any suitable means such as adhesive or welding, for example. The base 11 is preferably made of materials selected from the group consisting of synthetic rubber, tetrafluoroethylene (sold under the trade designation, "Teflon"), nylon, acetal resins (sold under the trade designation, ""Delrin"), or other stable machinable material. The polishing head 12, which may be 7/16" to 5/8" in diameter, for example, can be made of synthetic rubber or any other material that can be machined or formed to a specific aspheric or spheric curve and that is resilient and strong enough to maintain the desired curvature. The hardness of <the polishing head 12 preferably ranges from about 30 to 90 durometer hardness (shoe points method). The base 11 and polishing head 12 can be made of the same material to facilitate molding a single unit comprising of a base 11 and a polishing head 12.
The polishing head 12 is resilient in order to facilitate better conformance to the interior portion 2 of a contact lens. This resiliency resists undesired distortion of the optics of the contact lens if a polishing tool of a little too steep curvature is used and, also quickens polishing of the contact lens because the polishing head 12 has more contact with the interior portion 2 of the contact lens as compared to a brass tool.
The polishing cloth 14, which may be made of cotton, silk, or other suitable materials such as those products sold under the trade designations "Pellon" or "Velveteen" is preferably fixedly secured to the polishing head 12 by adhesive means such as a pressure sensitive adhesive or the like.
The polishing tool 10 is mounted on a rotation creating power source (not shown) by a rotary shaft engaging means 16 which in this embodiment is a shaft opening 20 formed into the center 24 of the bottom portion of the base 26 which can best be seen in FIG. 5. The shaft opening 20 is preferably tapered towards closed end 28 to facilitate more intimate engagement between the shaft opening 20 and the rotation power source. The power source is preferably equipped with a speed control to provide different rotational speeds for the polishing tool 10.
Another embodiment of the polishing tool is shown in FIGS. 6 and 7. This embodiment shows a base 30 which may be similar to base 11 and shaft opening 32 and polishing cloth 14', as was shown above, however the polishing head 36 has a central dome 40, and an annular ridge 44 with an annular recess 48 therebetween. This configuration can best be seen in FIGS. 6-9.
This embodiment of the polishing tool is not only used to polish the interior portion 2 of a contact lens, but also used to polish the outside bevels 5, the peripheral bevels 7 and edges 9 of the contact lens 1. As seen in FIG. 8, a contact lens 1 is placed in the annular recess 48 which is shaped to correspond to the edges 9 and bevels 5,7 of a contact lens 1 such that the edges 9 and the bevels 5,7 of the contact lens can be polished. Polishing of the edges 9 and bevels 5,7 is necessary to insure proper fit of the contact lens on the wearer's eye.
FIG. 9 shows an alternate method of mounting a polishing cloth 14' on the polishing head 36 of the polishing tool embodiment shown in FIG. 6. The polishing cloth 14' is placed in overlying contact with the polishing head 36. The polishing cloth is held in place in a preferred form by elastic band means 64 such as an O-ring that engages C of the polishing cloth 14' providing tension to hold the polishing cloth 14' in the desired portion of the polishing head 36. The elastic means 64 is preferably a rubber band. In lieu thereof other means such as a pressure sensitive adhesive means may be employed. It will be appreciated that the above polishing cloth mounting means can be used with all embodiments of the polishing tool and the means disclosed for retention of the polishing cloth in the embodiment of FIGS. 2-5 may be employed with this embodiment.
FIG. 10 shows an alternate embodiment of the polishing tool 10' with polishing cloth 14" with an alternate mounting structure 78. The mounting structure 78 includes a cylindrical shaft 79 protruding from the base 80. This can best be seen by viewing FIGS. 10 and 11. The shaft 79 can be constructed of materials selected from the group consisting of synthetic rubber, tetrafluoroethylene (sold under the trade designation, "Teflon"), nylon, acetal resins (sold under the trade designation, "Delrin"), or other stable machinable material, or can be molded into a single unit with the base 80 and polishing head 82.
It will be appreciated that the method of the invention involves providing the polishing tool as described above, mounting the tool on a motor or other power driven shaft, rotating the polishing tool, and contacting the resilient externally convex area of the polishing head of the polishing tool with the interior portion of the contact lens. Polishing the edges and the outside and peripheral bevels of the contact lens involves mounting the alternate embodiment of the polishing tool, rotating the tool, and contacting the edges and the outside and peripheral bevels of the contact lens with the polishing tool to polish these areas. An operator can contact different parts of the edges or the outside and peripheral bevels by canting or tilting the contact lens with respect to the tool to obtain desired polishing and curvature of a contact lens.
It will be appreciated that the polishing head, due to its resiliency, will better conform to the interior portion of the contact lens, thus providing a polishing tool that can better smooth the interior portion which, in turn, increases the quality of the contact lens. The polishing head can be formed to an exact curve and the polishing cloth, which can be silk as opposed to bulkier fuzzy pads, can be used to polish specific areas of the contact lens without disturbing other areas of the contact lens. The polishing tool is simple to manufacture and can be made into several polishing head sizes and curvatures. By way of example, a set of twenty seperate polishing tools of different curvatures and sizes will adequately serve a majority of a contact lens maker's requirements.
It can also be appreciated that the outside edges and peripheral and outside bevels of the contact lens can also be polished effectively with the polishing tool. The use of the polishing tool smooths the junction or shoulder, thus creating a smooth blended curve that greatly enhances the comfort of wearing the contact lens. Polishing the bevels with the alternate embodiment of the polishing tool resists spherical aberration of the contact lens, while at the same time not disturbing the central optical section of the contact lens.
Whereas particular embodiments of the invention have been described above, for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details may be made without departing from the invention as defined in the appended claims. | A polishing tool for contact lenses and an associated method is provided. The polishing tool is comprised of a base, an exteriorly convex resilient polishing head, and a polishing cloth. The polishing head is made of a suitable resilient material, said material allowing the polishing head to better conform to the interior portion of the contact lens. The method of the present invention involves connecting the polishing tool to a rotatable shaft and exposing the rotating polishing head to the interior of the contact lens. The polishing head can be adapted, in another embodiment, to polish the edges and the outside and peripheral bevels of a contact lens. |
This application is a division of U.S. Ser. No. 08/902,808, filed on Jul. 30, 1997, now U.S. Pat. No. 5,823,147 issued Oct. 20, 1998.
FIELD OF THE INVENTION
The present invention relates in general to fabricating semiconductor devices, and particularly to fabricating well-formed gate stacks.
BACKGROUND OF THE INVENTION
A gate in a semiconductor device acts as a capacitor, separating source/drain terminals. Controlling the charge on the gate controls the current flow between the source/drain regions. The conventional method of constructing a gate follows the general steps of: defining active device regions on a silicon substrate, growing a gate oxide on the substrate, depositing a layer of doped polysilicon on the gate oxide, and then depositing a conductive layer (generally a refractory metal or metal silicide) on the polysilicon. Gates are then defined using a photolithographic mask and etch. In conventional processing the gate oxide layer acts as an etch stop in the unexposed portions of the mask. Etching creates gate stacks by selectively removing the material in the unexposed areas. This process exposes a cross section of the device layers on the side walls of each gate stack. Source/drain regions are then implanted into the active regions on either side of the gate stack which are covered by the remaining thin gate oxide. A reoxidation step, referred to as poly reoxidation, follows to replace the screen oxide which is stripped off after source/drain implant. During poly reoxidation a new oxide is grown over the source/drain regions and on the sidewalls of the gate. During the reoxidation step the quality of the conductive layer and the profile of the gate stack may, however, be compromised. This results from sidewall oxidation forming a bird's beak under the polysilicon edge.
One method of preventing gate stack degradation is to form a protective oxidation barrier on the side walls of the gate stack. While this method of preventing gate stack degradation protects the metal layers of the gate stack, in conventional processing the gate oxide left over from the gate etch is relied upon to serve as an etch stop for the nitride spacer dry etch. Overetching of the gate oxide layer is therefore a potential problem. It increases the risk, especially for a thin gate oxide process, of compromising the quality of the silicon surface in underlying active regions, such as source/drain regions. Another disability of this method is that, because the nitride spacers overlie the entire sidewall surface of the gate, the source/drain reoxidation has to depend upon the oxidant to diffuse through the gate oxide layer beneath the gate and nitride spacers. As a result the desired oxidation of the polysilicon gate corner may be retarded. One partial solution was to use H 2 SO 4 boiling to undercut the TiN (see D. H. Lee, K. H. Yeom, M. H. Cho, N. S. Kang and T. E. Shim, Gate Oxide Integrity (GOI) of MOS transistore with W/TiN stacked gate, pages 208-209, 1996 Symposium on VLSI Technology Digest of Technical Papers). Lee's approach was to prevent direct contact between the gate electrode with the patterned edge by undercutting the TiN.
Device dimensions continue to shrink for reasons such as improved device performance and increased circuit density. Smaller dimensions require thinner layers. As one example, current 4-megabit dynamic random access memories (DRAMs) typically use gate oxide layers having a thickness within a range of 200 to 250 Å for both memory array and peripheral transistors. For 16-megabit DRAMs, this figure is expected to fall to 150 to 200 Å; and for 64-megabit and 256-megabit DRAMs, the thickness is expected to fall still further. For electrically-programmable memories such as electrically-erasable programmable read-only memories EEPROMs) and flash memories, even thinner gate oxide layers are required to facilitate Fowler-Nordheim tunneling (universally used as the erase mechanism and often as the write mechanism). For the current generation of 4-megabit flash memories, 110 Å-thick gate oxide layers are the norm. For future generations of more dense flash memories, gate oxide layers are expected to drop to the 80 to 90 Å range. As gate oxide layers become thinner, it becomes increasingly important that such layers be defect free in order to eliminate leakage. Conventional gate etching uses the gate oxide layer as an etch stop. The increasingly thin gate oxide layer requires increased selectivity in the gate etch step in order to minimize the risk of compromising the quality of the gate oxide. A defect-free, very thin, high-quality oxide without contamination is essential for proper device operation. As a result, conventional processes experience, for example, higher production costs due to higher device failures and smaller process volumes.
SUMMARY OF THE INVENTION
The present invention teaches a process of fabricating a semiconductor device which preserves the integrity of the gate stack materials. According to one embodiment, a method of fabricating a gate on a semiconductor device is described. The method comprises forming a plurality of gates having sidewalls, using a polysilicon layer as the etch stop. A first oxidation barrier is formed on the exposed sidewalls of the plurality of gates. The sidewalls are extended by performing a dry etch, using the gate oxide layer as the etch stop. Source/drain regions are formed on either side of the gates and oxide is grown over the source/drain regions and the sidewalls of the plurality of gates. Optionally, a second oxidation barrier is formed on the sidewalls of the plurality of gates.
According to another embodiment, the step of forming a first oxidation barrier comprises forming nitride spacers, while in another embodiment the step of forming a first oxidation barrier comprises forming oxide spacers. In a further embodiment step of forming a second oxidation barrier comprises forming nitride spacers.
In another embodiment, a semiconductor device is provided. The semiconductor device comprises a plurality of gates on a gate oxide layer which has been grown on a silicon substrate. Each of the plurality of gates comprises a polysilicon layer adjacent to the gate oxide layer, a conductive layer adjacent to the polysilicon layer, and a first oxidation barrier on each of the gates' sidewalls, wherein the oxidation barrier covers the exposed sidewall of the conductive layer and a portion of the exposed sidewall of the polysilicon.
In a further embodiment the first oxidation barrier comprises nitride. Yet another embodiment describes a second oxidation barrier covering the entire surface of the gates' sidewalls. In one embodiment the second oxidation barrier comprises nitride.
Still another embodiment describes a method of forming a structure for controlling current flow between source and drain regions. The method comprises the steps of forming active regions in a semiconductor substrate, forming a gate oxide layer over the semiconductor substrate, forming an insulating layer over the gate oxide layer, forming a conductive layer over the insulating layer, forming sidewalls on a plurality of gates by etching, using the insulating layer as the etch stop, forming a first oxidation barrier on the sidewalls, and extending the sidewalls of the plurality of gates by etching, using the gate oxide layer as the final etch stop.
In another embodiment the method further comprises the step of forming a second oxidation barrier on the sidewalls of the plurality of gates. In yet another embodiment the first oxidation barrier is nitride. According to another embodiment the second oxidation barrier is nitride.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a portion of an in-process semiconductor wafer following a conventional nitride spacer etch of the thin nitride layer, using the gate oxide layer as the etch stop.
FIG. 2 is a cross-sectional view of a portion of an in-process semiconductor wafer prior to any etching.
FIG. 3 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 2 following gate line masking and a subsequent dry etch of the exposed silicon nitride, using the polysilicon layer as the etch stop.
FIG. 4 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 3 following deposition of a thin nitride layer over the surface of the device.
FIG. 5 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 4, wherein a gate line is formed following a two-step dry etch, the first step comprising a nitride dry etch to clear the thin nitride layer and the second step comprising a polysilicon dry etch to remove the exposed polysilicon.
FIG. 6 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 5, showing a second oxide barrier as fabricated according one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
A semiconductor device comprises layers of materials with different conductive properties. The term "gate stack" refers to the layers of materials which comprise a gate on a semiconductor device. Device features are then formed through a series of etchings and depositions or different materials.
FIG. 1 is a cross-sectional view of a portion of an in-process semiconductor wafer following conventional processing. In the conventional process, the oxide 110 remaining from the gate etch is used as the etch stop for the dry etch which forms the nitride spacers 120. In conventional processing a nitride dry etch is performed on the oxidation barrier using gate oxide layer 110 as the etch stop. The relatively low selectivity of a nitride dry etch increases the risk of overetching, reducing oxide layer 110 and compromising silicon surface quality.
FIGS. 2-5 show a portion of a semi-conductor device in various stages of processing according to one embodiment of the present invention. FIG. 2 shows a cross-section of a portion of a semiconductor wafer 200 after the initial layers are manufactured in the following, or a similar, manner. First, a thin gate oxide 220 is grown on a semiconductor wafer substrate 210. Next a layer of doped polysilicon 230 is deposited on the gate oxide 220. A film 250 containing at least a layer of conductive material is then deposited on the polysilicon layer 230. In the example shown in the figures the film 250 comprises layers of titanium nitride, tungsten, and nitride. Those skilled in the art will recognize that the materials mentioned are illustrative and not intended to limit the scope of the invention to a particular composition.
The next step is to mask the device 200 to form a gate line, and then dry etch the device, using the polysilicon layer 230 as the etch stop. FIG. 3 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 2 following gate line masking and a subsequent dry etch of the exposed silicon nitride, using the polysilicon layer 230 as the etch stop. Stopping in the polysilicon layer 230 provides two primary benefits over conventional processing. First, it avoids any potential degradation of the underlying gate oxide layer 220. Second, it preserves a portion of the polysilicon layer 230 for later exposure during poly reoxidation, allowing for a more efficient oxidation of the polysilicon gate corner.
Once the gates have been constructed source/drain regions are formed on either side of the gates. Those skilled in the art will recognize that the step of forming source/drain regions may be performed before or after forming an oxidation barrier or further etching.
FIG. 4 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 3. After removing the mask material 310, an oxidation barrier is formed. In one embodiment, a thin layer of nitride 410 is deposited on the entire surface of the wafer 200, including the sidewalls of the gate stack 420. Those skilled in the art will recognize that other materials, such as oxynitride, can be used as the oxidation barrier without exceeding the scope and spirit of the present invention. The oxidation barrier protects the conductive layer from re-oxidizing, which could otherwise create problems for the gate profile.
Next, the gate line is formed by a two-step etch. First, a nitride dry etch clears the nitride 410, and then a polysilicon dry etch removes the polysilicon 230. This two-step etch is more effective than conventional procedures.
The result of the two-step etch, according to one embodiment of the present invention as shown in FIG. 5, is a gate stack 500 with nitride spacers 510 protecting the conductive layer 150. FIG. 5 is a cross-sectional view of the portion of an in-process semiconductor wafer depicted in FIG. 4, wherein a gate line is formed following a two-step dry etch, the first step comprising a nitride dry etch to clear the thin nitride layer and the second step comprising a polysilicon dry etch to remove the exposed polysilicon. After completion of the two-step etch a poly reoxidation step is performed. The nitride spacers 510 protect the conductive layer 150 from oxidation. Otherwise the gate profile may be adversely affected by defects which result from sidewall oxidation during the poly reoxidation step. One such defect is the oxidation of the conductive layer, the barrier layer, or both. Reoxidation is important because it improves the lifetime of the device. Thus it is important that this step be included in this type of device processing. By performing the two-step dry-etch process, the nitride dry etch can stop in the polysilicon layer 230. The secondary polysilicon dry etch, which is generally more selective to oxide than a nitride dry etch, completes the gate line etch and stops at the gate oxide layer 220. An additional benefit of employing a polysilicon dry etch is that, because it has a better selectivity in oxide than a nitride dry etch, the integrity of the gate oxide layer 220 is more likely to be preserved.
As shown in FIG. 6, in one embodiment a second spacer 610 is formed to isolate the entire gate stack 500 from other conductive layers. The second spacer 610 can be an oxide or a nitride. When oxide is used, the second spacer 610 can be formed before or after sidewall oxidation. When nitride is used, the second spacer 610 will be formed after sidewall oxidation.
Note that, by stopping the initial gate etch in the polysilicon layer 230, the nitride spacers 510 extend only to the top of the polysilicon 230. The reoxidation step is therefore able to more effectively oxidize the polysilicon gate corner 230. Conventional processing, represented in FIG. 1, creates nitride spacers the full length of the gate stack 400. As a result the reoxidation step in conventional processing must rely on the oxidant diffusing through the remaining gate oxide 110 beneath the nitride spacers 120. This can retard the desired oxidation of the polysilicon gate corner 130.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. | A process of manufacturing a gate stack whereby the integrity of both the gate sidewalls and the substrate surface is maintained. Nitride spacers are constructed on the sidewalls of a gate which has been etched only to the top of the polysilicon layer. This allows more of the polysilicon sidewall to be exposed during subsequent reoxidation while at the same time minimizing effects such as bird's beak resulting during reoxidation. After the nitride spacers are constructed the subsequent etch is performed in two steps in order to minimize degradation of the substrate surface in underlying active regions. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of condensate drain equipment for steam header/piping systems and, more particularly, to a system and method for automatically draining condensate from steam sootblower header/piping systems for fossil-fueled steam generators used in electric power generation.
A fossil-fueled steam generator utilizes the stored chemical energy contained within the remains of fossil vegetation as the source of heat. Combustion of the fossil fuel releases this stored chemical energy which, in turn, is used to heat water and generate steam. By expanding the steam through a turbine connected to a generator, the energy in the steam is converted to electricity.
The combustion process generates hot combustion gases and, in most instances, residues known as "ash". The transfer of heat to the water/steam is accomplished by passing the hot combustion gases across banks of tubes known as heating surface, and through which the water/steam flows. The heating surface can be water cooled, superheater or reheater surface, depending on the fluid flowing therethrough. Continuous operation of the steam generator causes ash deposits or soot to build up on the tubes, decreasing the heat transfer efficiency. The deposits must be removed to restore the thermal efficiency and this removal is accomplished through the use of sootblowers. A sootblower directs a jet of high pressure media against the tube surface to dislodge the accumulated ash deposits and clean the heating surface. The sootblowers generally employ saturated or superheated steam as the blowing media. The sootblower steam source is generally the steam generator itself, and thus the operation of the heat transfer process in the steam generator has a direct effect upon the temperature and pressure of the steam for the sootblowers.
As would be expected, various areas of the steam generator's heat transfer surfaces have different cleaning requirements. The type of deposit and heating surface being cleaned determines the frequency and duration of a sootblower cleaning cycle, as well as the performance requirements of the sootblowing steam. Due to the nature and size of the steam generators themselves, and their arrangement of heat transfer surfaces located in the path of the combustion gases, elaborate steam header/piping systems are required to transport the steam from a given source in the steam generator (for example, a header connected to a bank of superheater or reheater heat transfer surface) to a given sootblower, while still providing the proper steam temperature and pressure to the sootblower to adequately clean the tubes during a cleaning cycle.
2. Description of the Related Art
The aforementioned steam header/piping systems require some means of warm-up to ensure that the proper degree of superheat is maintained and to rid the system of condensate before initiating a sootblowing cycle. This is usually accomplished by blowdown, using steam to purge and heat the sootblower piping. In the past, various methods and apparatus have been used to accomplish blowdown. Very early approaches were simple, manually operated, orificed drain valves. Later approaches incorporated automatic float and thermally operated traps. The present state of the art also includes thermally controlled, air operated drain valves; i.e., the thermal drain. FIGS. 1A, 1B and 1C show the aforementioned methods in their simplest form. FIG. 1A shows the use of the manual orifice, while FIG. 1B shows the use of a steam trap. Both of these approaches can be used where the sootblowing media is either saturated steam or superheated steam. FIG. 1C shows the use of the thermal drain to eliminate condensate from a piping system. Generally the thermal drain has a HI and LO temperature setpoint, at which the valve closes or opens, respectively, with a 50° F. temperature differential therebetween. The thermal drain is thus generally used only with superheated, and not saturated steam, because the difference in temperature between hot condensate and saturated steam at a given pressure is practically nil. All of these blowdown methods are still in common use today. The thermal drain and trap have both evolved into sophisticated complex units in an attempt to improve operating reliability.
As used herein, the terms "saturated steam" and "superheated steam" are used in their ordinary thermodynamic context as known to those skilled in the art. The term "saturation temperature" designates the temperature at which vaporization takes place at a given pressure, and this pressure is called the "saturation pressure" for the given temperature. Thus, for water at 212° F., the saturation pressure is 14.7 psia, and for water at 14.7 psia the saturation temperature is 212° F. If a substance exists as a liquid at the saturation temperature and pressure, it is called saturated liquid. If a substance exists as a vapor at the saturation temperature, it is called saturated vapor, and if water is the substance, it is called "saturated steam". Similarly, when the vapor is at a temperature greater than the saturation temperature, it is said to exist as superheated vapor, and if water is the substance, it is called "superheated steam". For further details, the reader is referred to Fundamentals of Classical Thermodynamics, Second Edition, Van Wylen and Sonntag, John Wiley and Sons, Inc., 1973.
There are problems with the use of traps and thermal drains. While the steam generators have a full load maximum steaming capacity in pounds per hour of steam at a required temperature and pressure, the steam generator often operates at lower loads. The rate of heat transfer between the combustion gases and the water/steam flowing through the heat transfer surfaces changes with boiler load. A point which produced steam at a certain temperature and pressure at maximum load will produce steam at a different temperature and pressure at lower loads, and yet the sootblowing steam media requirements to clean a bank of heating surface remain the same. Variations in fuel quality can also change the combustion process and heat transfer distribution that results, as well as affecting the cleanliness of individual banks of heat transfer surface within the steam generator. Further, seasonal ambient variations in temperature can also affect the steam generator's performance. As mentioned earlier, thermal drains will not work with saturated steam. Steam traps can easily stick open and/or closed due to the low actuating force derived from the controlled media.
FIG. 2 is a schematic of a typical prior art system. As shown, this system uses a single thermal sensor located near the drain, such as a thermal well or thermostatic trap, to provide a signal that is compared to a manually adjustable setpoint for drain valve control. In such systems, the drain valve is opened to drain condensate when the steam temperature (T1) is less than the setpoint temperature (T MIN ). The drain valve is closed when T1 is greater than or equal to the minimum allowable normal operating temperature (T NORM ). T NORM is defined as:
T.sub.NORM =T.sub.MIN +T.sub.DIFF
where T DIFF is a margin or setpoint differential added to the setpoint temperature, T MIN . Between T NORM and T MIN is a "deadband" where the drain valve will retain its position (open or closed) until T NORM or T MIN is reached.
In some cases, however, the source steam temperature (T SOURCE ) varies more than the setpoint differential, T DIFF . This condition renders the thermal controller useless until it is readjusted, leaving the drain valve continually open (dumping steam) or continuously closed (resulting in loss of superheat and/or condensate buildup). Changes in ambient temperature can also cause thermal sensor response errors greater than T DIFF , leading to the same problem.
Accordingly, it has become desirable to develop an improved condensate drain controller which overcomes the problems of the prior art.
SUMMARY OF THE INVENTION
The present invention utilizes two temperature sensors, one located near the steam source and the other located near the drain. Signals provided by each of these sensors are provided to a summing amplifier unit which calculates the difference in steam temperature between the temperatures measured by these two sensors. This difference is then compared to a temperature setpoint signal which is selected to provide the minimum allowable difference in steam temperature between the steam temperature at the source and the steam temperature at the drain valve (i.e., the degree of superheat) for the worst case steam source conditions. A drain valve control signal is produced, based upon a comparison of this difference in steam temperature with the temperature setpoint signal. When this difference in steam temperature is greater than or equal to the temperature setpoint signal, the drain valve control signal causes the drain valve to open, warming the header while removing any condensate. When this difference in steam temperature is less than the temperature setpoint signal, the header has been sufficiently warmed and the drain valve control signal causes the drain valve to close.
A plurality of temperature sensors can be used on large complex header/piping systems (i.e., one sensor for measuring the source steam temperature supplying several sootblowers, and several sensors, each located near a plurality of drains to measure the temperature at each drain). If desired, modulating type drain valves can be employed, and the drain valve control signal can be used as an analog input to proportionally control the drain valves' position, and thus the flow of condensate through the drain valves.
The various features of novelty which characterize the invention are pointed out with particularly in the claims annexed to and forming a part of this disclosure. For a better understanding of the present invention and the advantages attained by its use, 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
FIGS. 1A, 1B and 1C are schematics showing, respectively, the manual orifice, steam trap and thermal drain arrangements of the prior art;
FIG. 2 is a schematic of a typical single thermal sensor/thermal well system of the prior art;
FIG. 3 is a simplified schematic of the present invention, as applied to a sootblower steam piping system, utilizing two temperature sensors;
FIGS. 4 and 5 are block diagram schematics of the invention; and
FIG. 6 is a diagram comparing the operation of the prior art thermal well/drain with the condensate drain controller of the invention at various operating conditions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings generally, wherein like numerals designate the same element throughout the several drawings, and to FIG. 3 in particular, there is shown a portion of a sootblower steam piping system, generally referred to as 10, of a type typically employed on a fossil-fueled steam generator (not shown) which will supply the steam for the sootblowers. The pressure part design of the sootblower steam piping system 10 would be performed according to known applicable boiler and piping codes and, as such, is beyond the scope of the present invention. The steam for the sootblower steam piping system 10 is conveyed from a steam source in the steam generator, typically a header connected to a bank of superheater or reheater surface, by means of piping 12 to a pressure reducing valve (PRV) 14. The PRV 14 is required because the sootblower steam pressure requirements are generally much lower than the available pressure at the steam source. The PRV 14 is used to reduce the steam pressure to the level required by the sootblowers. The steam is conveyed from the PRV 14 by means of piping 16 to various sootblower branch lines that supply steam to the individual sootblowers. Only two such sootblower branch lines 18, 20 have been shown; it is understood that more branch lines could be supplied by a given steam source. Drain piping 22 is provided after the last or lowest sootblower branch line (shown here as branch line 20), to a drain valve 24 the outlet of which is connected to drain valve outlet piping 26.
First temperature sensing means 28 are provided on the piping 16, just downstream of the PRV 14 and as close as is practical to the steam source, to produce a first signal representative of the steam temperature at the source. Second temperature sensing means 30 are provided on the drain piping 22 as close as practical to the drain valve 24, to produce a second signal representative of the steam temperature at the drain valve 24. Advantageously, each of the temperature sensing means 28, 30 is a resistance temperature detector (RTD) selected so that its range will encompass the normally expected steam temperature range within its associated piping. The main feature required of the first and second temperature sensing means 28, 30 is that each must be capable of producing a signal representative of the steam temperature that varies in substantially linear fashion with the actual steam temperature.
The first and second temperature sensing means 28, 30 provide their signals along lines 32, 34, respectively, to a microprocessor based control unit 36. A first summing amplifier unit 38 receives at the positive input thereof the first signal representative of the steam temperature at the source; the second signal representative of the steam temperature at the drain valve 24 is provided to the negative input of the first summing amplifier unit 38. First summing amplifier unit 38 produces a signal representative of the difference in steam temperature between the source and drain, ΔT=T1-T2, at the output thereof which is transmitted along line 40 to a positive input of a second summing amplifier unit 42. Potentiometer (P) 44 is used to provide a variable setpoint temperature T SP at the negative input of the second summing amplifier unit 42. This second summing amplifier unit 42 produces a signal based upon a comparison of the setpoint temperature T SP and ΔT as shown. This signal is transmitted along line 46 to an arrangement of microprocessors and associated electronic circuitry, generally referred to as 48, which produces a drain valve control signal that is outputted along line 50 to open or close the drain valve 24. The drain valve control signal is operative to close the drain valve 24 when ΔT is less than T SP and to open the drain valve 24 when ΔT is greater than or equal to T SP . The drain valve control signal is used to operate means for controlling the drain valve 24, advantageously an air operated pilot solenoid valve 52, connected to an external pneumatic air supply, and to control the drain valve 24 via line 54.
The power supply for the microprocessor based control unit 36 is conventional single phase, 120 volt AC 50/60 Hz, provided over a power supply line 56. Additionally, the microprocessor based control unit 36 can be interconnected with existing sootblower control panel(s) (not shown), provided for the sootblowers on a given steam generator, via line or lines 58. Thus, the entire operation of sootblower initiation, and the preheating and draining of condensate can be automatically controlled. This is not a necessity, however, and the system of the present invention can be used to control draining of condensate and/or preheating of the steam piping independently of the sootblower controls.
Referring now to FIG. 4, there is shown a block diagram schematic of a portion of the microprocessor based control unit 36. The first temperature sensing means 28 produces a first signal representative of the steam temperature at the source which is supplied along line 32 to the positive input of the first summing amplifier unit 38. Line 60, connected to line 32, also provides the first signal representative of the steam temperature at the source to dipswitch 62 connected to the positive input of a third summing amplifier unit 64. Potentiometer 66 is used to provide a variable setpoint temperature T HDR at the negative input of the third summing amplifier unit 64. Connector terminal 68 is provided on a line connecting potentiometer 66 with the third summing amplifier unit 64 to allow for calibration and setting of the setpoint temperature T HDR . The setpoint temperature T HDR is indicative of whether or not the steam piping connected to the source is energized, i.e., carrying steam. If the temperature sensed by the first temperature sensing means 28 is greater than or equal to the setpoint temperature T HDR as represented by the setting of potentiometer 66, the output signal of the third summing amplifier unit 64 will be a logical 1 value. However, if the temperature sensed by the first temperature sensing means 28 is less than the setpoint header temperature T HDR , the output signal of the third summing amplifier unit 64 will be a logical 0 valve. These logical 1 and logical 0 signals are output along a line 70 and utilized by specific elements of the system as disclosed later in this detailed description.
The second temperature sensing means 30 produces a second signal representative of the steam temperature at the drain valve 24 along line 34 to the negative input of the first summing amplifier unit 38. At the output of the first summing amplifier 38, there is produced the signal representative of the difference in steam temperature between the source and drain, ΔT=T1-T2, which is transmitted along line 40 through a dipswitch 72 to the positive input of the second summing amplifier unit 42. The potentiometer 44 is used to provide a variable setpoint temperature T SP to the negative input of the second summing amplifier unit 42. Connector terminal 74 is provided on a line connecting potentiometer 44 with the second summing amplifier unit 42 to allow for calibration and setting of the setpoint temperature T SP . The output signal of the second summing amplifier unit 42 is provided over line 46 and has a logical 1 valve when the ΔT is greater than or equal to the setpoint temperature T SP or a logical 0 valve when the ΔT is less than the setpoint temperature T SP . These logical 1 and logical 0 signals from the second summing amplifier unit 42 are utilized by specific elements of the system as disclosed later in this detailed description.
The system of the present invention can be used to proportionally control the position of a modulating type of drain valve 24. For this purpose, line 76 is connected to line 40 for providing the signal representative of the difference in steam temperature between the source and drain, ΔT, through a dipswitch 78 to buffer amplifier unit 80. The output of the buffer amplifier unit 80 is provided along a line 82 and is an analog output proportional to the ΔT, and which would be used to proportionally control the position of a modulating type of drain valve 24.
Referring now to FIG. 5, there is shown a continuation of the block diagram set forth in FIG. 4. Lines 70 and 46 are connected to the input side of an input/output (I/O) port, Random Access Memory (RAM) and timer unit 84, advantageously an INTEL 81C55 integrated circuit. Unit 84 interfaces along address, data, and control bus 86 with address decoding modules 88, advantageously a MOTOROLA 74HCT138 and 74HC373 integrated circuits, EPROM, PROM or ROM program module 90, advantageously a NATIONAL 2764 EPROM, and microprocessor unit 92, advantageously a OKI 80C85 integrated circuit. Bus 86 allows the aforementioned unit 84 to communicate and transfer data between itself and units 88, 90 and 92. Additionally, by means of lines 94 and 96, the address decoding modules 88 can select the appropriate device to be controlled. Lines 98 and 100 are connected to the output side of the unit 84 and to relay drivers 102, 104, respectively. The relay drivers 102, 104 are advantageously a SPRAGUE 2803 integrated circuit. The outputs of these relay drivers 102, 104 are transmitted along lines 106, 108, respectively to relay coils 110 and 112. These relay coils 110, 112 are connected to a 14 volt power source by means of line(s) 114 and are used to activate their associated relay contacts K1, K2 in the following manner.
The timer portion of unit 84 is set by means of line 116 connected to the input side of unit 84 and to a series of dipswitches 118, 120, 122 and 124. The timer setting can be varied from 15 seconds to a period of 15 minutes, as shown in TABLE 126 schematically indicated in FIG. 5. Appropriate settings of the various dip switches 118-124 allows for these various timer settings and, together with the timer portion of unit 84, are used to open and close the relay contacts K1, K2 as desired. In particular, relay contact K2 closes and relay contact K1 opens when the first signal representative of the steam temperature at the source is less than the header setpoint temperature T HDR , or when the difference in steam temperature between the source and drain, ΔT, is greater than or equal to the setpoint steam temperature, T SP . In particular, if the timer has timed out, and the temperature representative of the steam temperature at the source is greater than the header setpoint temperature T HDR , or if the difference in temperature between the steam temperature at the source and steam temperature at the drain is less than the steam setpoint temperature, T SP , relay contact K2 is opened and relay contact K1 is closed. | A system for automatically controlling a drain valve connected to a sootblower steam piping system utilizes two temperature measurements, one near the steam source and the other near the drain valve. Comparison of the difference in steam temperature between these two locations with an adjustable temperature setpoint allows the drain valve to be opened to drain condensate and maintain minimum allowable superheat over a wide range of conditions. The system allows the temperature sensing to "float" with steam source conditions, since it is continuously adjusted to compensate for steam source temperature and ambient temperature changes. |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates generally to the field of blinds for use in windows and more particularly to collapsible blinds for use in arch-shaped windows.
[0003] 2. Description of the Prior Art
[0004] Many buildings have windows that are arch shaped. Often it is desirable to prevent sunlight from directly entering the building through these arch windows. For these reasons, a number of blinds suitable for arch windows have been developed. Some designs such as are shown in U.S. Pat. No. 4,776,380 to Lester use venetian blinds. Venetian blinds have many slats making them relatively difficult to assemble, opaque and of distinctive appearance.
[0005] Simpler designs employ pleated material rather than venetian blind slats. Some pleated material designs use curved round rods such as shown in U.S. Pat. No. 1,609,877 to Kendall. Other designs require that supports be affixed into the window structure. These supports can be a plurality of hooks as shown in U.S. Pat. No. 4,825,611 to Basset or a mounting block as shown in U.S. Pat. No. 4,934,436 to Schnebly.
[0006] Accordingly, there are a large variety of blinds or shades for windows in the marketplace, including both vertical and horizontal types. Their most common characteristic is that they are foldable and that they have a rectangular shape, when they are in an unfolded position.
[0007] Since also most conventional windows are rectangular in shape, no problem is encountered for this class of windows. There is, however, a better class of windows of higher finesse and elegance, which have at least one arched portion. This class of windows is generally referred to as arched windows. It becomes evident then, that the conventional blinds, having a rectangular shape, may not be used in conjunction with arched windows.
[0008] Although it might sound as a simple problem to solve, it certainly is not. Mere proof of this is the fact that the applicant has not been able to find such a blind available in the marketplace.
[0009] A number of attempts have been made, but apparently they have all failed to provide an effective solution, since none of these approaches has been accepted by the public, as the absence of commercially available blinds for arched windows evidences.
[0010] Representative references describing blinds for arched windows may be found in the patent literature as early as 1891, but after the first quarter of the 20th century, no substantial progress seems to have been made.
[0011] U.S. Pat. No. 451,068 to Lark, issued Apr. 28, 1891; U.S. Pat. No. 602,967 to Wells, issued Apr. 26, 1893; and U.S. Pat. No. 1,609,877 to Kendall, issued Dec. 7, 1926, disclose blinds for arched windows, which, however, are driven by cumbersome cord mechanisms acting o the outside circumference of the blind, and having serious disadvantages, such as for example the need for hiding these mechanisms within an extended portion of the blind, thus sacrificing useful window area, as well as decorative window aspects. Other serious disadvantages include, but are not limited to, the fact that the complicated cord mechanisms are liable to malfunction, to the fact that no effective way of maintaining the opening of the blind at any desired level is provided, and to the fact that blinds structured to be driven by cord mechanisms at their circumference are not easily controllable, and therefore flimsy in their operation.
[0012] There is a need for a simplified blind for arch windows that uses pleated blind material and does not have many visible support rods, support hooks, cords or other readily noticeable support structure. Preferably, the blind should have no support rods or support hooks. The blind should be low cost, reliable, easy to assemble and easy to operate. Preferably, the blind should be capable of remote operation such as through use of a pull cord.
SUMMARY OF THE INVENTION
[0013] It is an object of the present invention to provide an arch shaped window treatment to solve the problems which currently exist in the prior art. More specifically, it is an object of the present invention to provide a window treatment for an arch-shaped window including a frame having an arch portion and a horizontal portion; at least one shade panel pivotally connected to a central portion of the horizontal portion of the frame; at least one channel formed on an inner surface of the arch portion, wherein the at least one channel forms a longitudinal slot on an inner surface thereof; and a chain at least partially housed within the at least one channel and moveable therein for effectuating arcuate movement of the at least one shade panel between an open and a closed position, wherein the chain is configured and dimensioned to move within the at least one channel without falling out of the longitudinal slot. The at least one shade panel may include a first and a second shade panel formed in a pleated or honeycomb configuration. The window treatment further includes a U-shaped removably secured to a central portion of the horizontal portion. A valence may be mounted on the arch portion and the horizontal portion to prevent the intrusion of sunlight around the perimeter of the window treatment.
[0014] The invention is not limited to the above-described embodiments, and various changes are possible without departing from the principles set forth herein. Furthermore, the embodiments include the invention at various stages, and various inventions can be extracted by properly combining multiple disclosed constructional requirements. There are many applications of this design.
[0015] The above is a brief description of some deficiencies in the prior art and advantages of the present invention. Other features, advantages and embodiments of the invention will be apparent to those skilled in the art from the following description, drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will become more clearly understood from the following detailed description in connection with the accompanying drawings, in which:
[0017] FIG. 1 is a front view illustrating a window treatment for an arch-shaped window in a closed position, in accordance with an embodiment of the present invention;
[0018] FIG. 2 is a front view illustrating a window treatment for an arch-shaped window in an open position, in accordance with an embodiment of the present invention;
[0019] FIG. 3 is a front view illustrating a valence associated with the window treatment for an arch-shaped window, in accordance with an embodiment of the present invention;
[0020] FIG. 4 is a cross-sectional front view illustrating a chain route for a window treatment for an arch-shaped window, in accordance with an embodiment of the present invention;
[0021] FIG. 5 is a cross-sectional front view illustrating a portion of a chain route for a window treatment for an arch-shaped window, in accordance with an embodiment of the present invention;
[0022] FIG. 6 is a cross-sectional view from the bottom looking up illustrating a portion of a chain route for a window treatment for an arch-shaped window, in accordance with an embodiment of the present invention;
[0023] FIG. 7 is a side view of a dolly for use with a window treatment for an arch-shaped window, in accordance with an embodiment of the present invention;
[0024] FIG. 8 is a cross-sectional end view illustrating a track for use with a window treatment for an arch shaped window, in accordance with an embodiment of the present invention;
[0025] FIG. 9 is a side view illustrating a roller for use with a window treatment for an arch-shaped window in accordance with an embodiment of the present invention;
[0026] FIG. 10 is a top view of a base in accordance with an embodiment of the present invention; and
[0027] FIG. 11 is a side view of the base illustrated in FIG. 10 in accordance with an embodiment of the present invention; and
[0028] FIG. 12 is a prospective view illustrating chain locks for use with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] 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 patent application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art and the generic principles 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 features described herein.
[0030] Referring now to the drawings in detail, and first to FIG. 1 , a window treatment for an arch-shaped window in a closed position is illustrated, in accordance with an embodiment of the present invention. The window treatment 10 comprises a frame built up of wood and including an outer frame arch or bow 12 and a horizontal base 14 . The horizontal base 14 has a downward-facing surface for resting the device on a window sill or similar horizontal surface 16 adjacent to a window to be shaded. The window treatment frame may also be constructed of a molded plastic or any other construction material known to one having ordinary skill in the art. The window treatment frame may be a monolithic unit and may be secured to the surrounding structure by any portion of the frame. For example, holes may be defined in the window treatment frame for receiving screws and/or nails to secure the window treatment frame to the surrounding structure.
[0031] The inner space defined by arch 12 and horizontal base 14 is filled with a first and second shade panel 20 and 22 . It is also contemplated that the shade panel for filling the inner space defined by arch 12 and horizontal base 14 may be formed of a single panel. The shade panel is preferably formed in a pleated or honeycomb configuration. Alternatively, the shade panel may be formed of a plurality of louvers configured and dimensioned to occupy at least a majority of the space defined by arch 12 and horizontal base 14 .
[0032] Referring now to FIG. 2 , the first and second shade panels are illustrated in the fully retracted position. In other words, the window treatment for an arch-shaped window is illustrated in an open position, in accordance with an embodiment of the present invention. The configuration of the shade panels according to the present invention advantageously provides for a low profile of approximately one inch, thereby maximizing the amount of light which is capable of entering the room through the window. A pivot bar 26 is positioned in the middle of horizontal base 14 and is configured in a U-shape. Pivot bar 26 permits first and second shade panels 20 and 22 to move between the open position illustrated in FIG. 2 to the closed position illustrated in FIG. 1 . Pivot bar 26 may be secured to horizontal base 14 by means of locking nuts 30 secured to a lower threaded portion of pivot bar 26 . Preferably, pivot bar 26 is removably secured in place by means of a pair of set screws and 32 . Alternatively, pivot bar 26 may be welded in place or secured by any other means known to one having ordinary skill in the art.
[0033] Locking clips 28 are positioned and configured to provide a means for securing a chain which is used for opening and closing first and second shade panels 20 and 22 , as will be discussed below. The first and second shade panels 20 and 22 are configured to be easily removed for cleaning and/or replacement. A plurality of shade clips and base clips are provided to maintain the first and second shade panels 20 and 22 within a predetermined position in window treatment 10 , as will be discussed in further detail below. To remove first and second shade panels 20 and 22 , begin by moving the shade panels 20 and 22 into their fully open position as illustrated in FIG. 2 . Next, loosen the set screws 32 and remove pivot bar 26 . Once pivot bar 26 is removed, loosen the base clips that hold the shades to the horizontal base 14 and remove the shade 20 and/or 22 from the clip.
[0034] Referring now to FIG. 3 , a valence 40 associated with the window treatment 10 for an arch-shaped window, in accordance with an embodiment of the present invention is illustrated. The valence 40 serves the function of hiding portions of the window treatment which detract from the aesthetic features thereof. The valance 40 comprises an arch-shaped portion 42 and a horizontal portion 44 . The valance 40 may be formed of the same material and texture as is used for the first and second shade panels 20 and 22 .
[0035] FIG. 4 is a front view illustrating a route for a chain 50 . Very often, the windows that are arch-shaped are positioned above existing windows and/or doors. Therefore, the length of chain 50 may be varied to permit easy access to a user. Chain 50 may be moved in the directions indicated by arrows A and B to cause movement of first and second shade panels 20 and 22 between an open and a closed position. Dollys 18 are configured and dimensioned for moving first and second shade panels 20 and 22 between an open and a closed position. A string 23 is connected to shade panels 22 and 23 to assist in maintaining shade panels 22 and 23 in a uniform configuration. A first end of dolly 18 is secured to chain 50 and a second end of dolly 18 is secured to a portion of the shade panel. Accordingly, as chain 50 is moved in a direction of either of arrows A and B, that motion will be translated through a dolly 18 to the shade panels 20 and 22 . Importantly, due to the configuration of the route of the chain 50 , each of first and second shade panels 20 and 22 will move in the same direction. Locking clips 28 are provided to lock chain 50 in a desired position to prevent further movement of the first and second shade panels 20 and 22 .
[0036] Rollers 34 and 36 are provided to guide chain 50 within a chain channel 52 . Roller 34 is centrally located at the top of arch-shaped portion 12 of the frame and roller 36 is located at the end of the chain 50 at an end of base 14 opposite to the end of base 14 wherein the chain 50 leaves and enters.
[0037] At least a portion of the route of chain 50 is shown more clearly in FIG. 5 . First, as shown in FIG. 5 , chain channel 50 is divided into two separate channels—a chain return channel 54 and a dolly channel 56 . Chain 50 travels in the chain return channel 54 until it hits roller 34 . At this point, as shown in FIGS. 5 and 6 , chain 50 crosses over and begins to travel within dolly channel 56 . In accordance with an embodiment of the present invention, chain 50 is prevented from falling out of the longitudinal slot 61 defined in the lower portion of dolly channel due to the size of the beads 58 on chain 50 .
[0038] As shown more clearly in FIG. 6 , the diameter of each of the beads 58 along the length of chain 50 is greater than the width of the slot 61 , thus allowing the dolly 18 to travel along the slot 61 while chain 50 is maintained within the dolly channel 56 as it is pulled through the arched frame. The width x of slot 61 is maintained relatively narrow to allow shade clip arm 62 ( FIG. 7 ) to be guided along the channel.
[0039] FIG. 7 is a cross-sectional side view of dolly 18 for use with a window treatment 10 for an arch-shaped window, in accordance with an embodiment of the present invention. FIG. 8 is a cross-sectional end view of the dolly 18 illustrated in FIG. 7 . Thus, with reference to FIGS. 7 and 8 , dolly 18 includes a shade clip 60 , a shade clip arm 62 , a set screw 64 and a dolly housing 68 . The shade clip 60 extends from a lower surface of dolly housing 68 via shade clip arm 62 . The shade clip 60 is configured to attach to the shade 20 , 22 . Preferably, shade clip 60 is connected to the top one-fifth portion of shade panels 20 , 22 . The shade clip 60 location assists in preventing light from shining through a gap between the first and second shade panels 20 , 22 when they are in a closed position. Set screw 64 is configured to secure housing 68 to the chain 50 by tightening the set screw 64 against a portion of the chain 50 , such as, for example, a chain bead 58 as illustrated in FIG. 7 . Wheels 66 are provided to assist movement of housing 68 along the dolly channel 54 .
[0040] As best illustrated in FIG. 8 , the dolly 18 travels in dolly channel 56 which is located adjacent to chain return channel 54 . A guide pin chamber 72 is positioned adjacent to each of dolly channel 56 and chain return channel 54 . Guide pin chamber 72 houses a plurality of guide pins 70 . Guide pins 70 are positioned to support the shade panel 20 , 22 from being blown out of the frame by a wind coming in through the window. The guide pins 70 are preferably attached to every third pleat of shade panel 20 , 22 and move within guide pin chamber 72 . Also shown in FIG. 8 is a clip 74 for attaching the valence (not shown) to the window treatment.
[0041] Referring now to FIG. 9 , a side view of roller 36 is illustrated. As illustrated, a bracket 38 is secured to base 14 . Roller 36 is rotationally attached to a portion of the bracket 38 to transfer the chain 50 from one of chambers 54 and 56 to the other of chambers 54 and 56 . Roller 36 defines a plurality of indentations which are configured and positioned to engage beads 58 on chain 50 . Roller 36 may also be connected to a motor for automatic operation of the window treatment.
[0042] FIGS. 10 and 11 are top and side views of a base 14 in accordance with an embodiment of the present invention. As shown in FIG. 10 , a plurality of base clips 24 are positioned on base 14 for providing support to shade panels 20 , 22 . Set screws 48 are provided for each of the base clips 24 . Set screws 48 may be loosened or removed to facilitate removal of the shade panels 20 , 22 from the frame.
[0043] FIG. 12 is a prospective view illustrating chain locks 28 for use with an embodiment of the present invention. Chain locks 28 are designed to engage the chain 50 between two chain beads 58 to secure the chain from moving from a desired position.
[0044] Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiment and these variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the invention. | A window treatment for an arch-shaped window including a frame having an arch portion and a horizontal portion; at least one shade panel pivotally connected to a central portion of the horizontal portion of the frame; at least one channel formed on an inner surface of the arch portion, wherein the at least one channel forms a longitudinal slot on an inner surface thereof; and a chain at least partially housed within the at least one channel and moveable therein for effectuating arcuate movement of the at least one shade panel between an open and a closed position, wherein the chain is configured and dimensioned to move within the at least one channel without falling out of the longitudinal slot. |
BACKGROUND OF THE INVENTION
This invention relates generally to liner bags for waste receptacles, and more particularly pertains to a fastener device and a method for its use in retaining a plastic liner bag in its waste-receiving disposition within a waste receptacle.
It is currently common practice at commercial and household locations to provide waste receptacles, often commonly referred to as wastebaskets, with plastic liners in the form of bags which are manually removable and replaceable as required. It is quite common to use a small waste receptacle formed of plastic and located in a bathroom and to use a larger size but similar receptacle in other desired household locations, the best example perhaps being the household kitchen area. Such a receptacle is commonly provided with a plastic bag or liner that is fitted substantially within the receptacle whereby an outer flap end of the bag extends outwardly and over the receptacle's rim. It is uncommon for such a bag to be of a size to fit firmly and tightly in its installed position in the receptacle; most often the bag is relatively large compared to the receptacle whereby a major portion of the bag fits loosely within the receptacle and there is a bag end flap that extends outwardly and downwardly relative to the peripheral rim of the receptacle. Depending on the nature of the waste or refuse deposited in the lined receptacle, it is not unusual and is quite objectionable for the bag to be dislodged from its original installed position such that the outer flap end shifts downwardly within the receptacle.
Dislodgement of the bag is a problem because additional trash deposited in the receptacle tends to cover over and conceal the bag flap within the receptacle and cause removal of the bag to be inconvenient. The person doing so must thrust his or her hands into the receptacle and into the trash contained therein in order to grasp the flap and withdraw the bag.
SUMMARY OF THE INVENTION
This invention comprehends a fastener device for temporarily fastening a plastic bag or liner in position on a trash receptacle. The fastener device is formed from a length of malleable wire of uniform diameter. The device is a one-piece clip having a curved intermediate loop portion and a pair of straight spaced-apart coextensive leg portions. The device is preferably of the size of a No. 2 paper clip. The leg portions are integral to and project from the curved loop portion equidistantly, in a common plane from the curved loop portion.
The fastener device is utilized in combination with a plastic bag and a trash receptacle. The receptacle is the type typically found in a home or commercial establishment, having a body portion with an upwardly-facing opening defined by a rim. The plastic bag is contained substantially within the trash receptacle as a liner and has a flap portion extending outside the rim and outwardly and downwardly therefrom, against the peripheral sidewall of the receptacle which is immediately subjacent the rim.
The method of utilizing the fastener or clip device in combination with the receptacle and its plastic bag liner involves a person manually grasping the device in a manner similar to holding an ignition key for an automobile and firmly thrusting the device against the outer flap such that the ends of the legs pierce the flap and contact the outer sidewall of the receptacle, and then manually twisting the device whereby the plastic bag bunches and gathers about the legs of the device, causing the flap to contract snugly against the outer wall of the receptacle. With the legs of the device engaged in the liner flap material, the outwardly-extending portion of the device is manually bent and deformed upwardly and over the receptacle rim whereby it conforms to the rim shape such that the loop portion of the device points downwardly into the receptacle and is firmly wedged against the inside receptacle surface and the overlying liner. A fastening action is thus completed, with the device being left in the position described until such time as it is desirable to remove the filled plastic liner from the receptacle. The removal action involves manually bending the clip back toward its original disposition whereby it can be withdrawn from its engagement with the bag flap portion and then, if desired, it can be used as a twist-tie about the end of the closed plastic bag prior to discarding the bag as refuse.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a trash receptacle containing a plastic bag liner, illustrating a first embodiment of a fastener device utilized in accordance with the present invention;
FIG. 2 is a perspective view of the receptacle and plastic liner first shown in FIG. 1 and illustrating the disposition of the fastener or clip device first shown in FIG. 1 as it is utilized in accordance with the present invention;
FIG. 3 is an elevational view of the fastener device first shown in FIG. 1 but shown in comparatively larger actual scale;
FIG. 4 is a perspective view of the fastener device shown in FIG. 3 ;
FIG. 5 is an alternate shape constituting a second embodiment of a fastener device in accordance with the present invention;
FIG. 6 is a perspective view of the device first shown in FIG. 5 ;
FIG. 7 is an elevational view of an enlarged segment of either the device shown in FIG. 3 or the device shown in FIG. 5 , as taken along lines VII—VII of either FIG. 3 or FIG. 5 ;
FIG. 8 is a perspective fragmentary view illustrating the final disposition of the fastener device relative to the receptacle and plastic bag first shown in FIGS. 1 and 2 ; and
FIG. 9 is an elevational view in reduced scale showing a plastic trash bag and showing a selective final disposition of the fastener device shown in FIGS. 1-4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a trash receptacle or wastebasket 10 containing substantially within it a liner or plastic bag 12 . The bag 12 has an outer flap or end 14 extending over the rim of the receptacle 10 , the rim being hidden beneath the flap 14 . A fastener device in the form of a clip 16 is shown in FIG. 1 being manually applied in a disposition transverse to the sidewall of the basket 10 .
FIGS. 3 and 4 illustrate one embodiment of the fastener device or clip 16 having a looped portion 17 and extending legs 18 and 20 . FIGS. 5 and 6 show a slightly different shape for a fastener device or clip in accordance with the present invention, the clip 22 having a loop portion 24 with integral leg portions 26 and 28 projecting from the loop portion 24 an equal distance and in parallel relationship to each other. The clips 16 and 22 are preferably formed from a malleable wire having the general characteristics of the wire in a jumbo or No. 2 paper clip. The clips 16 and 22 may be manually bent in accordance with the method of utilizing the invention and will hold the form to which each is manually bent until such time as manual force may be reapplied to alter the configuration. As shown in FIG. 7 , the outer or distal end of the legs 18 , 20 , 26 , and 28 may be provided with a sharpened end point 30 to facilitate the use of the clip as hereafter described.
Clip 16 is shown in an operative or functional position in FIGS. 1 , 2 , 8 , and 9 . The clip 16 is grasped in an individual's hand and placed substantially as shown in FIG. 1 whereby the ends of the legs 18 and 20 pierce and penetrate through the flap 14 and come to rest against the outer surface of the receptacle 10 just below the circular rim of the receptacle 10 . A twisting or rotative action is applied to the clip 16 whereby the adjacent flap material is caused to bunch and gather into a clump 32 encircling the legs of the clip 16 . The foregoing manual action pulls the flap tightly against the outer sidewall of the receptacle 10 so the bag is prevented from slipping downwardly into the receptacle as a result of trash being dropped into the receptacle. Then, the outwardly-extending loop portion 17 of the fastener device 16 is manually bent upwardly and over the flap 14 and rim 10 a of the receptacle 10 , as shown in FIG. 8 . The clip 16 is thus bendably formed over and against the receptacle rim whereby the loop 17 extends downwardly within the receptacle to hold the flap 14 in place as FIG. 8 illustrates.
Having heretofore described the utilization of the fastening device 16 in combination with the receptacle 10 and plastic bag 12 , it should be clearly understood that the simplified shape of the fastening device 22 shown in FIGS. 5 and 6 would be employed in the same manner as described with reference to the fastening device 16 to temporarily fasten a plastic bag in its installed position on the receptacle 10 .
The receptacle 10 shown in the drawings is only an example of one shape of a receptacle to which the present invention may be applied. Other common receptacles are rectilinear in cross-section and/or smaller or larger, depending upon location and intended use. There is no reason why the inventive concept herein disclosed would not be applicable to a substantially large heavy-duty plastic bag used in a garbage can or similar outdoor container or with other receptacle configurations used commercially and industrially.
FIG. 9 is an illustration of a plastic bag after it has been withdrawn from its support receptacle and having the fastening device 16 reshaped to close the bag, the illustration showing the device 16 twisted about the neck of the bag 12 to act as a twist-tie closure means on a trash-filled bag prior to its disposal.
While the foregoing description has shown and described the fundamental features as applied to the preferred embodiments of the present invention, it will be understood by those skilled in the art that modification embodied in various forms may be made without departing from the spirit and scope of the invention. | A fastener device in the form of a generally U-shaped wire clip for manual application to temporarily cause a plastic bag liner to be held in inserted position in a waste container and to also serve as a twist-tie closure for the plastic bag. |
TECHNICAL FIELD
[0001] The present specification generally relates to mounting structures for use in a motor compartment of a vehicle and, more specifically, to mounting structures for securing an electric motor within a vehicle.
BACKGROUND
[0002] Electric motors, like conventional engines, are secured by a motor mount to a vehicle frame, allowing the electric motor to apply torque to the drive train components. The motor mount reacts the motive torque applied to the drive train components, and prevents the electric motor from moving within the motor compartment. Known designs include attaching the electric motor to a single cross-member spanning the width of the motor compartment as is done with combustion engines. However, electric motors distribute forces in a manner different from combustion engines.
[0003] Accordingly, a need exists for alternative mounting structure for securing an electric motor within a vehicle.
SUMMARY
[0004] In one embodiment, an electric vehicle may include a right side member and a left side member with a motor compartment disposed therebetween. A motor compartment cross member may extend transversely across the motor compartment. The motor compartment cross member may be coupled to the left side member and the right side member. A front cross member may extend transversely across the motor compartment. The front cross member may be coupled to the left side member and the right side member and spaced apart from the motor compartment cross member in a vertical direction. A motor mount member may extend between the front cross member and the motor compartment cross member in a forward-aft direction of the electric vehicle. The motor mount member may be coupled to the front cross member and the motor compartment cross member and may include an attachment point for receiving a corresponding coupler of an electric motor.
[0005] In another embodiment, an electric vehicle drive train subassembly may include an electric motor, a front cross member, and a motor mount member. The front cross member generally extends between a first end and a second end of the front cross member and is oriented such that a long axis of the front cross member is substantially parallel with an axis of rotation of the electric motor. The motor mount member may include a hanger coupled to a top plate and a bottom plate. The bottom plate may be coupled to the front cross member. The hanger includes an attachment point and the motor is coupled to the attachment point.
[0006] In another embodiment, a method of assembling an electric vehicle drive train sub-assembly into a vehicle sub-assembly may include positioning an electric motor drive train subassembly below a vehicle body. The electric motor drive train subassembly may include an electric motor, a front cross member and a motor mount member. The front cross member extends between a first end and a second end of the front cross member and may be oriented such that a long axis of the front cross member is substantially parallel with an axis of rotation of the electric motor. The motor mount member may include a hanger coupled to a top plate and a bottom plate. The bottom plate may be coupled to the front cross member. The hanger may include an attachment point and the motor may be coupled to the attachment point. The electric motor drive train subassembly may be mated with a motor opening of the vehicle body and the front cross member may be secured to a left side member and a right side member of the vehicle body such that the front cross member extends transversely across the motor opening of the vehicle body. Thereafter, the motor mount member may be secured to a motor compartment cross member extending transversely across the motor opening of the vehicle body.
[0007] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
[0009] FIG. 1A schematically depicts a portion of an electric vehicle which includes a motor mounting assembly in accordance with one or more embodiments of the present invention;
[0010] FIG. 1B schematically depicts a portion of the motor compartment of the electric vehicle of FIG. 1A ;
[0011] FIG. 2 schematically depicts an exploded view of the motor mounting assembly of FIG. 1 ;
[0012] FIG. 3 schematically depicts a top view of the motor compartment of FIG. 1A and FIG. 1B ;
[0013] FIG. 4 schematically depicts the motor mount member of the motor mounting assembly of FIG. 2 ;
[0014] FIG. 5 schematically depicts an auxiliary side motor mount for use in conjunction with the motor mounting assembly;
[0015] FIG. 6 schematically depicts an auxiliary rear motor mount for use in conjunction with the motor mounting assembly; and
[0016] FIG. 7 is a partial cross-section of the motor mounting assembly of FIG. 3 .
DETAILED DESCRIPTION
[0017] FIG. 1A generally depicts an electric vehicle having an electric motor positioned in a motor compartment of the vehicle and secured with a motor mounting assembly. The motor mounting assembly generally includes a front cross member, a motor compartment cross member and a motor mount member. The front cross member extends transversely across the motor compartment and is coupled to the left and right side members of the electric vehicle. A motor compartment cross member extends transversely across the motor compartment and is coupled to the left and right side members of the electric vehicle. The motor compartment cross member is offset from the front cross member in a vertical direction. The motor mount member extends between the front cross member and the motor compartment cross member in a forward-aft direction of the electric vehicle and is coupled to the front cross member and the motor compartment cross member. Various embodiments of electric vehicles and motor mounting assemblies for electric vehicles will be described in more detail herein with specific reference to the appended drawings.
[0018] Electric motors, like gasoline combustion engines, generate motive forces to the drive train subassembly of the vehicle. However, electric motors generate and distribute those forces in a manner distinct from gasoline combustion engines. One such distinction is that electric motors produce greater torque at the armature of the motor. Further, the configuration of the electric motor and related components, such as the transmission and the like, may not be symmetrical with respect to the axes of the motor and, as such, the loads imparted by the motor to the surrounding motor compartment structure may not be equally distributed. Motor mount members designed to support gasoline combustion engines may not be configured to carry and distribute the increased torque of an electric motor as well as the unbalanced load of the electric motor. The motor mounting assemblies described herein overcome these efficiencies, particularly when the motor mounting assemblies are used to retrofit vehicles designed for conventional combustion engines with an electric motor drive train.
[0019] Referring now to FIGS. 1A and 1B , a front portion of an electric vehicle 110 is schematically depicted. The electric vehicle 110 generally includes a front left side member 114 and a front right side member 118 with a motor compartment 112 positioned between the front left side member 114 and the front right side member 118 . A motor mounting assembly 130 is coupled to the front left side member 114 and the front right side member 118 . An electric motor 200 is coupled to the motor mounting assembly 130 such that an axis of rotation 122 of the electric motor 200 is generally parallel to a transverse direction 124 of the electric vehicle 110 .
[0020] In the embodiments described herein, the motor compartment 112 is positioned in a front portion of the vehicle 110 and is generally defined by the front left side member 114 and the front right side member 118 . In the embodiments described herein, the front left side member includes a lower left side member 116 and an upper left side member 117 while the front right side member 118 includes a lower right side member 120 and an upper right side member 121 . The lower and upper left side members 116 , 117 and the lower and upper right side members 120 , 121 generally have a longitudinal orientation with respect to the vehicle 110 (i.e., the side members are generally parallel to a forward-aft direction 126 of the vehicle). In the embodiments described herein, the front left side member 114 and the front right side member 118 are secured to the front bumper beam (not shown) of the electric vehicle 110 at the front of the vehicle and are secured to the underbody structure of the vehicle aft of the motor compartment 112 .
[0021] The motor mounting assembly 130 is positioned within the motor compartment 112 and includes a transversely-oriented front cross member 140 , a transversely-oriented motor compartment cross member 150 , and a motor mount member 160 disposed between the front cross member 140 and the motor compartment cross member 150 . As used herein, the phrase “transversely oriented” means that the component is generally positioned in the transverse direction 124 of the electric vehicle 110 (as opposed to the forward-aft direction 126 of the electric vehicle 110 ). The motor compartment 112 further includes one or more auxiliary motor mounts 166 , 168 (FIGS. 2 and 5 - 6 ) which may be used to affix the electric motor 200 to an interior portion of the motor compartment 112 . The electric motor 200 is coupled to the motor mounting assembly 130 such that the axis of rotation 122 of the electric motor 200 is parallel to the transverse direction 124 of the electric vehicle 110 as noted above.
[0022] Referring now to FIGS. 1A-1B and 2 , the front cross member 140 is transversely oriented within the motor compartment 112 . The front cross member 140 extends between a first end 141 and a second end 142 . The first end 141 of the front cross member 140 mounts to the lower right side member 120 ( FIG. 1B ). The second end 142 of the front cross member 140 mounts to the lower left side member 116 ( FIG. 1B ). In the embodiments described herein, the front cross member 140 includes a plurality of apertures 143 located in the first end 141 and the second end 142 . The apertures facilitate securing the front cross member 140 to the lower right side member 120 and the lower left side member 116 with threaded fasteners, such as bolts. However, it should be understood that the front cross member may be secured to the lower right side member 120 and the lower left side member 116 using other joining techniques, including, without limitation, welding.
[0023] The front cross member 140 further includes a mounting platform 144 located between the first end 141 and the second end 142 . In the embodiment shown in FIG. 2 , the mounting platform 144 is integrally formed with the front cross member 140 , such as when the mounting platform 144 and the front cross member 140 are formed from a single piece of material. However, in other embodiments (not shown), the mounting platform 144 may be formed separately from the front cross member 140 and thereafter coupled to the front cross member 140 with by bolts, screws, rivets, welds or the like. In the embodiments described herein, the mounting platform 144 is adapted to support the lower plate 162 of the motor mount member 160 . For example, in the embodiment depicted in FIG. 2 , the mounting platform 144 includes a plurality of apertures 146 for receiving one or more bolts which secure the motor mount member 160 to the mounting platform 144 . In some embodiments, the apertures 146 may be threaded while, in other embodiments, each of the apertures may further include a weld nut welded to the underside of the mounting platform 144 in order to facilitate securing the motor mount member 160 to the mounting platform 144 of the front cross member 140 . To provide a greater surface area for supporting the motor mount member 160 , the mounting platform 144 protrudes from the front cross member 140 in the forward-aft direction 126 of the electric vehicle 110 .
[0024] In the embodiments described herein the front cross member 140 is formed from a metallic material such as, for example, galvanized steel. An exemplary steel material is SCGA 440 MPa galvanized or galvannealed steel. However, it should be understood that the cross members may be made from other metallic materials suitable for use in automotive structural applications. In the embodiments described herein, the front cross member 140 is formed by stamping the metallic material into the desired shaped. However, it should be understood that other forming techniques may be utilized to form the front cross member 140 .
[0025] Still referring to FIGS. 1A-1B and 2 , the motor compartment cross member 150 is transversely oriented within the motor compartment 112 . The motor compartment cross member 150 is offset from the front cross member 140 in the vertical direction 128 , as shown in FIGS. 1A-1B . In one or more embodiments, the motor compartment cross member 150 is also offset from the front cross member 140 in the forward-aft direction 126 of the electric vehicle 110 . The motor compartment cross member 150 extends between a first end 151 and a second end 152 . The first end 151 of the motor compartment cross member 150 mounts to the upper right side member 121 ( FIG. 1B ). The second end 152 of the motor compartment cross member 150 mounts to the upper left side member 117 ( FIG. 1B ). In the embodiments described herein, the motor compartment cross member 150 includes a plurality of apertures 153 located in the first end 151 and second end 152 . The apertures facilitate securing the motor compartment cross member 150 to the upper right side member 121 and the upper left side member 117 with threaded fasteners, such as bolts. However, it should be understood that the motor compartment cross member 150 may be secured to the upper right side member 121 and the upper left side member 117 using other joining techniques, including, without limitation, welding. In an alternative embodiment of the motor compartment cross member 150 , the first end 151 of the motor compartment cross member 150 is connected to the upper right side member 121 with a bracket.
[0026] It should be noted that, in some embodiments, the motor compartment cross member 150 is not planar. For example, as depicted in FIG. 2 , the first end 151 of the motor compartment cross member 150 is out of plane with respect to the remainder of the motor compartment cross member 150 .
[0027] The motor compartment cross member 150 further includes a mounting platform 154 located between the first end 151 and the second end 152 . In the embodiment shown in FIG. 2 , the mounting platform 154 is integrally formed with the motor compartment cross member 150 , such as when the mounting platform 154 and the motor compartment cross member 150 are formed from a single piece of material. However, in other embodiments (not shown), the mounting platform 154 may be formed separately from the motor compartment cross member 150 and thereafter coupled to the motor compartment cross member 150 such as by bolts, screws, rivets, welds or the like. In the embodiment described herein, the mounting platform 154 is adapted to support the upper plate 161 of the motor mount member 160 . For example, in the embodiment depicted in FIG. 2 , the mounting platform 154 includes a plurality of apertures 156 for receiving one or more bolts which secure the motor mount member 160 to the mounting platform 154 . In some embodiments, the apertures 156 may be threaded while, in other embodiments, each of the apertures 146 may further include a weld nut welded to the topside of the mounting platform 154 of the motor compartment cross member 150 .
[0028] In the embodiments described herein, the motor compartment cross member 150 is made of a metallic material such as, for example, galvanized steel. An exemplary steel material is SCGA 440 MPa galvanized or galvannealed steel. However, it should be understood that the motor compartment cross member may be made from other metallic materials suitable for use in automotive structural applications. In the embodiments described herein, the motor compartment cross member 150 is formed by stamping the metallic material into the desired shaped. However, it should be understood that other forming techniques may be utilized to form the motor compartment cross member 150 . In one embodiment, the motor compartment cross member 150 includes additional support structures 158 to support components mounted thereto. Such components may include drive system components and high voltage components.
[0029] Still referring to FIGS. 1A-1B and 2 , the motor mount member 160 generally extends between the front cross member 140 and the motor compartment cross member 150 and is connected to both the front cross member 140 and the motor compartment cross member 150 . The motor mount member 160 includes an upper plate 161 at a top portion thereof, a lower plate 162 at a bottom portion thereof, and a hanger 163 extending between the upper plate 161 and the lower plate 162 .
[0030] In the embodiments described herein, the upper plate 161 is integrally formed with the hanger 163 such as when the upper plate 161 and hanger 163 are stamped from a single piece of material. In alternative embodiments (not shown) the upper plate 161 and the hanger 163 may be separately formed. For example, the upper plate 161 and the hanger 163 may be separately formed and joined together such as by welding or the like. In the embodiments of the motor mount member 160 described herein, the upper plate 161 is trapezoidal in shape and includes a plurality of apertures 166 . The apertures 166 facilitate securing the upper plate 161 of the motor mount member 160 to the mounting platform 154 of the motor compartment cross member 150 with threaded fasteners, such as bolts. However, it should be understood that the motor mount member 160 may be secured to the motor compartment cross member 150 using other joining techniques, including, without limitation, welding.
[0031] In the embodiment of the motor mount member 160 depicted in FIGS. 2 and 4 , the lower plate 162 and the hanger 163 are separate components which are joined together such as by welding or the like. However, in other embodiments, the lower plate 162 and the hanger 163 may be integrally formed, such as when the lower plate 162 and the hanger 163 are formed from a single piece of material in a stamping operation.
[0032] In the embodiment of the motor mount member 160 described herein, a gusset plate is coupled to the hanger and at least one of the top plate and the bottom plate. In the embodiment shown in FIGS. 2 and 4 , the lower plate 162 and the hanger 163 are joined together with a gusset plate 168 . The gusset plate 168 may be a sheet of steel that can be fastened to the lower plate 162 and the hanger 163 using bolts, rivets, welding, or combinations thereof. The gusset plate 168 may be made from either cold rolled or galvanized steel. The gusset plate 168 generally reinforces the joint between the lower plate 162 and the hanger 163 thereby improving the load carrying capability of the motor mount member 160 .
[0033] In the embodiments of the motor mount member 160 described herein, the lower plate 162 includes a plurality of apertures 167 . The apertures 167 facilitate securing the lower plate 162 of the motor mount member 160 to the mounting platform 144 of the front cross member 140 with threaded fasteners, such as bolts. However, it should be understood that the motor mount member 160 may be secured to the front cross member 140 using other joining techniques, including, without limitations, welding. For example, in one embodiment, the lower plate 162 is attached with one or more bolts, such as when the mounting platform 144 of the front cross member 140 includes one or more weld nuts for threadably receiving the one or more bolts. In an alternative embodiment (not shown), the lower plate 162 may be welded to the mounting platform 144 .
[0034] As seen in FIGS. 2 and 4 , the hanger 163 of the motor mount member 160 is angled such that the upper plate 161 is horizontally offset from the lower plate 162 . The angled orientation of the hanger 163 allows the motor compartment cross member 150 to be both offset from the front cross member 140 in both the vertical direction 128 and in the forward-aft direction 126 of the electric vehicle 110 .
[0035] In the embodiments described herein, the hanger 163 of the motor mount member 160 includes an integrated attachment point 164 extending therefrom. When the motor mounting assembly 130 is positioned in the motor compartment 112 , the attachment point 164 extends toward the rear of the vehicle 110 . In one embodiment, the attachment point 164 is a clevis fastener which includes a U-shaped extension 169 . Each prong of the U-shaped extension 169 includes a circular opening 170 for receiving a mounting bolt 165 . The attachment point 164 is generally oriented such that, when the mounting bolt 165 is positioned in the attachment point 164 , the long axis of the mounting bolt 165 is oriented in the transverse direction 124 .
[0036] In the embodiments described herein, the motor mount member 160 is formed from a metallic material such as, for example, galvanized steel. An exemplary steel material is SCGA 440 MPa galvanized or galvannealed steel. However, it should be understood that the motor mount member 160 may be made from other metallic materials suitable for use in automotive structural applications. In the embodiments described herein, the motor mount member 160 is formed by stamping the metallic material into the desired shape of the various components of the motor mount member 160 (i.e., the lower plate 162 , gusset plate 168 , and hanger 163 ) and then welding the various components together. However, it should be understood that other forming techniques may be utilized to form the motor mount member 160 .
[0037] FIG. 3 is a top view of the motor compartment 112 . FIG. 3 shows the front cross member 140 oriented transverse to the motor compartment 112 . The motor mount member 160 is shown extending from the front cross member 140 . Although not shown in this figure, the motor compartment cross member 150 is attached to the upper plate 161 of the motor mount member 160 . The electric motor 200 is adjacent the motor mount member 160 , and although not shown in FIG. 3 , the electric motor 200 is attached to the motor mount member 160 at the attachment point of the hanger 163 . The electric motor 200 is positioned in the center of the motor compartment 112 .
[0038] Referring now to FIGS. 2 and 7 , FIG. 7 schematically depicts a partial cross-section of the motor mount member 160 and electric motor 200 showing the electric motor 200 mounted to the attachment point 164 of the motor mount member 160 . The mounting bolt 165 passes through the circular openings 170 of the U-shaped extension 169 of the attachment point 164 . The mounting bolt 165 also passes through a mounting point 210 coupled to the casing of the electric motor 200 . The front mounting bolt 165 is secured in place such as with a nut and/or retaining pin to attach the electric motor 200 to the motor mount member 160 .
[0039] FIG. 7 also includes a cross sectional view of an isolation member 190 . The isolation member 190 is positioned around the mounting bolt 165 . The isolation member 190 is made of vibration damping material, such as rubber or the like, which is inserted through the circular openings 170 in the U-shaped extension 169 and the mounting point 210 . The isolation member 190 fills the space between the mounting bolt 165 , the circular openings 170 and the mounting point 210 of the electric motor 200 to prevent unwanted vibration and/or movement of the electric motor 200 .
[0040] Referring now to FIGS. 2 and 4 - 6 , the electric motor 200 may generally include a housing 202 which encloses an inverter 204 . Additionally, the electric motor 200 may also include a transmission 206 which couples the armature of the electric motor to the drive train of the electric vehicle 110 . These components of the electric motor 200 increase the weight of the electric motor and, more importantly, cause the electric motor to be unbalanced. The effects of this imbalance are exacerbated by the transverse orientation of the motor with respect to the vehicle and the high torque generated by the motor during operation. Accordingly, in some embodiments, the electric vehicle may further include auxiliary motor mounts 172 , 180 which may be utilized in conjunction with the motor mounting assembly to further stabilize the electric motor in the motor compartment 112 of the electric vehicle, as noted above. As shown in FIG. 2 , the auxiliary motor mounts 172 , 180 may attach the electric motor 200 to one or more of the sides of the engine compartment and to structural components positioned aft of the electric motor 200 , such as, for example, the front suspension member of the vehicle.
[0041] FIG. 5 schematically depicts the right side auxiliary motor mount 172 . The right side auxiliary motor mount 172 includes an upper plate 173 which is generally oriented in the forward-aft direction 126 when the right side auxiliary motor mount 172 is installed in the engine compartment of the electric vehicle. In one embodiment, the upper plate 173 is mounted to the underside of the upper right side member 121 with a plurality of bolts. However, it should be understood that the upper plate 173 may be mounted at other locations on the frame of the electric vehicle 110 in order to secure the electric motor 200 to the vehicle. Further, it should be understood that the upper plate 173 may be attached using other joining techniques, such as welding. The right side auxiliary motor mount 172 further includes a first finger 175 and a second finger 176 integrally formed with the upper plate 173 . The first finger 175 and the second finger 176 generally extend downward in the vertical direction 128 from the bottom of the upper plate 173 . The first finger 175 and the second finger 176 each include a circular opening 177 at the distal end of each finger 175 , 176 . The first finger 175 and the second finger 176 are separated from each other in the forward-aft direction 126 . A mounting bolt 178 and, optionally, an isolation member such as a grommet formed from a vibration damping material, may be positioned in the circular openings 177 of both the first finger 175 and the second finger 176 to facilitate attaching the electric motor 200 to the right side auxiliary motor mount 172 . The mounting bolt 178 extends through a portion of the electric motor 200 to securely mount the electric motor 200 to the right side auxiliary motor mount 172 . While the side auxiliary motor mount 172 has been described herein as a “right side” auxiliary motor mount 172 , it should be understood that, a similar motor mount structure may be used, alternatively or additionally, on the left side of the electric motor.
[0042] Referring now to FIG. 6 , the rear auxiliary motor mount 180 includes a base 182 oriented in the transverse direction 124 when the rear auxiliary motor mount is installed in the motor compartment of the vehicle. The base 182 is mounted to structural components of the vehicle 110 aft of the electric motor 200 , such as the front suspension member. However, it should be understood that the base 182 may be mounted to other components in the engine compartment of the electric vehicle 110 in order to secure the electric motor 200 to the vehicle 110 . Further, it should be understood that the base 182 may be attached using other joining techniques, such as welding. The rear auxiliary motor mount 180 further includes a first support flange 186 and a second support flange 187 integrally formed with the base 182 . The first support flange 186 and the second support flange 187 are generally parallel with one another and extend from the top of the base 182 . The first support flange 186 and the second support flange 187 each include a circular opening 188 at a distal end of each support flange 186 , 187 . A mounting bolt 189 and, optionally, an isolation member such as a grommet formed from a vibration damping material, may be positioned in the circular openings 188 of both the first support flange 186 and the second support flange 187 to facilitate attaching the electric motor 200 to the rear auxiliary motor mount 180 . The mounting bolt 189 extends through a portion of the electric motor 200 to securely mount the electric motor 200 to the rear auxiliary motor mount 180 .
[0043] The side auxiliary motor mount 172 and the rear auxiliary motor mount 180 are may be initially attached to the electric motor (as shown in FIG. 2 ) and affixed to the vehicle during installation of the electric motor into the vehicle. Alternatively, the side auxiliary motor mount 172 and the rear auxiliary motor mount 180 may be attached to the vehicle and, thereafter, secured to the electric motor as the electric motor is installed in the motor compartment of the vehicle.
[0044] Referring again to FIGS. 1A-1B and 2 , in one embodiment, the front cross member 140 , motor mount member 160 and the electric motor 200 may be assembled prior to installation in the motor compartment to form an electric vehicle drive train sub-assembly. In the sub-assembly, the lower plate 162 of the motor mount member 160 is attached to the mounting platform 144 of the front cross member 140 and the electric motor 200 is secured to the attachment point 164 on the hanger 163 of the motor mount member 160 . When installed on the electric motor 200 , a long axis of the front cross member is substantially parallel with an axis of rotation of the electric motor. The sub-assembly may be installed into the motor compartment 112 of the electric vehicle 110 through the bottom of the motor compartment 112 . Once properly positioned within the motor compartment 112 , the sub-assembly is attached to the frame of the electric vehicle 110 . More specifically, the upper plate 161 of the motor mount member 160 is attached to the mounting platform 154 of the motor compartment cross member 150 , the front cross member 140 is secured to the lower right side member 120 and lower left side member 116 , and the electric motor 200 is attached to the right side auxiliary motor mount 172 and the rear auxiliary motor mount 180 .
[0045] It should now be understood that the motor mounting assemblies described herein may be utilized to support a transversely oriented electric motor in the motor compartment of a vehicle. The motor mounting assemblies described herein provide greater support to the electric motor and counter the torque developed by the electric motor. Specifically the extra torque generated by electric motor is transferred to the motor mount member and, because the motor mount member is attached at both the top and bottom to the motor compartment cross member and the front cross member which, in turn, are attached to the side members of the vehicle, the loads carried by the motor mount member are more equally distributed throughout the frame of the vehicle.
[0046] In particular, the transverse orientation of the motor compartment cross member and the front cross member forward of the electric motor facilitate positioning a mounting point for the electric motor forward of the motor where, in conventional vehicle configurations, there are no transverse structural support members with sufficient strength to carry the load and counteract the torque of the electric motor. More specifically, utilizing a motor compartment cross member and a front cross member which transversely span the motor compartment facilitates connecting the motor mount member between the motor compartment cross member and the front cross member such that the attachment point of the motor mount member is positioned in the motor compartment forward of the electric motor.
[0047] Further, auxiliary motor mounts may be utilized in conjunction with the motor mounting assemblies to provide additional support and stability to the electric motor. Specifically, the auxiliary motor mounts may be utilized at the transverse ends of the motor and/or aft of the motor to further support the electric motor and to counteract the torque exerted by the electric motor on the motor mounting assemblies.
[0048] It should also be understood that the motor mounting assemblies described herein may be utilized to retrofit vehicles designed for conventional internal combustion engines with electric motors.
[0049] It is noted that the terms “substantially” and “about” may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
[0050] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter. | An electric vehicle includes a right side member and a left side member with a motor compartment disposed therebetween, a motor compartment cross member extending transversely across the motor compartment, the motor compartment cross member coupled to the left side member and the right side member, a front cross member extending transversely across the motor compartment, wherein the front cross member is spaced apart from the motor compartment cross member in a vertical direction, and a motor mount member extending between the front cross member and the motor compartment cross member, wherein the motor mount member is coupled to the front cross member and the motor compartment cross member, the motor mount member comprising an attachment point for receiving a corresponding coupler of an electric motor. |
The present invention relates to the material rhenium (IV) sulphide in the polymorphic form of nanotubes and a method for preparation of this material.
BACKGROUND OF THE INVENTION
During the last years, new classes of materials termed nanotubes have attracted considerable attention. The most well known nanotubes are the so-called carbon nanotubes (Iijima, S. Nature 1991, 254, 56) that exist either as single-walled carbon nanotubes, SWCNT, or as multi-walled carbon nanotubes, MWCNT. Numerous preparative routes to these materials have been patented (e.g. Smalley, R. E., U.S. Pat. No. 5,591,312; Smalley, R. E. at al., WO 98/39250; Jang, J. and Chung, S.-J., EP 1 046 613 A2; Smalley, R. E. et al., WO 00/17102; Cheng, H. et al., EP 1 061 044 A1 and EP 1 061 041 A1; Resasco, D. E. et al., WO 00/73205 A1; Kambe, N. and Bi, X., U.S. Pat. No. 6,045,769).
Carbon nanotubes have been shown to posses a wide range of physical properties that suggest that these materials could find use in a variety of technological applications. Particularly, the possibility of using carbon nanotubes as the building blocks in nanotechnology has recently been a major driving force for detailed studies of such materials. Carbon nanotubes are composed of graphite layers rolled up as cylinders with a diameter determined by the number of carbon atoms in the perimeter of the tube as shown in FIG. 1 . The tubes can have closed ends. If there is only one cylindrical tube, the carbon nanotube material is termed single-walled (SWCNT). If more concentric cylindrical tubes are present (with a distance between the individual tubes of approximately 0.35 nm) the tubes are termed multi-walled (MWCNT). By high-resolution transmission electron microscopy (HRTEM) it is easily determined if a given sample contains either SWCNT or MWCNT. Obviously, to construct, for instance, electronic devices with the properties required for use in nanotechnological applications, it is desirable to have access also to nanotubes with a different chemical composition than carbon and thus with different physical and chemical properties. Consequently, much work has focused on the preparation of nanotubes of other materials. However, so far only a few materials have been isolated in the form of nanotubes, e.g., BN (Chopra, N. G. et al., Science 1995, 269, 966), B x C y N z (Stephan, O. et al., Science 1994, 266, 1683), WS 2 (Tenne, R. et al., Nature 1992, 360, 444), MOS 2 (Feldman, Y. et al., Science 1995, 267, 222 and Remskar, M. et al., Science 2001, 292, 479), NiCl 2 (Hacohen, Y. R. et al., Nature 1998, 395, 336), NbS 2 (Nath, M. and Rao, C. N. R., J. Am. Chem. Soc. 2001, 123, 4841 and Zhu, Y. et al., Chem. Commun. 2001, 2184), and Bi (Li, Y. et al., J. Am. Chem. Soc. 2001, 123, 9904).
A review article by R. Tenne ( Progress in Inorganic Chemistry 2001, 50, 269) gives an overview of the area. A vanadium oxide nanotube material, which contains α,ω-diamines intercalated between the metal oxide layers, has also been described (Spahr, M. E. et al., Angew. Chem., Int. Ed. Engl. 1998, 37, 1263. and Krumeich, F. et al., J. Am. Chem. Soc. 1999, 121, 8324) and patented (Nesper, R. et al., Wo 01/30690 A2).
WO 00/66485 describes the synthesis of long nanotubes of transition metal chalcogenides. The method is based on the synthesis of nanoparticles of a transition metal oxide. The oxide particles are annealed with for instance H 2 S to obtain nanotubes. This method was used to produce nanotubes of wolfram sulphide, WS 2 . One limitation of this method is that not all transition metal oxides can be easily handled under the conditions stated in the method. That makes this method unsuitable for the preparation of for instance rhenium sulphide nanotube materials.
All the nanotube materials have layer structures in their ordinary polymophic modifications. NbS 2 , MOS 2 and WS 2 have closely related structures. Each individual layer in these materials consists of a metal atom layer sandwiched between two layers of sulphur atoms. The transition metal atoms are trigonal prismatically coordinated with sulphur atoms. So far, there have been no reports of nanotubes containing elements from group 7 of the Periodic Table (i.e. Mn, Tc, and Re).
SUMMARY OF THE INVENTION
Rhenium (IV) sulphide, ReS 2 , has a layer structure similar to that of other transition metal disulphides such as e.g. NbS 2 , MoS 2 and WS 2 . Each ReS 2 layer consists of a rhenium atom layer sandwiched between two sulphur atom layers. ReS 2 contains a metal ion with an electron configuration not seen in the presently known metal sulphide nanotubes. Niobium (IV) sulphide has a d 1 electron configuration, molybdenum (IV) sulphide and tungsten (IV) sulphide have a d 2 electron configuration, whereas rhenium (IV) sulphide has a d 3 electron configuration. At the same time, rhenium (IV) sulphide also has a different coordination of rhenium. Rhenium is octahedrally coordinated by sulphur in ReS 2 contrary to the trigonal prismatic coordination of Nb, Mo and W in their sulphides. The rhenium (IV) sulphide material can therefore provide nanotubes with both an unprecedented electron structure and a new crystallographic structure.
Furthermore, the crystal structure of ReS 2 shows that the rhenium atoms form tetranuclear clusters due to metal—metal bonding interactions (Murray, H. H.; Kelty, S. P.; Chianelli, R. R.; Day, C. S. Inorg. Chem. 1994, 33, 4418). This structural characteristic is unique for ReS 2 .
It is therefore an object of the invention to provide a rhenium (IV) sulphide material in the form of nanotubes.
This object is achieved by providing a rhenium (IV) sulphide (ReS 2 ) nanotube material comprising hollow cylinders of concentric rhenium (IV) sulphide layers, the ReS 2 interlayer distance being 0.5-0.7 nm, each ReS 2 layer consisting of a layer of rhenium atoms sandwiched between two layers of sulphur atoms.
The rhenium (IV) sulphide nanotube material may have an inner nanotube diameter between 2 to 500 nm. The rhenium (IV) sulphide nanotube material may contain from 1-50 concentric layers.
A method for the preparation of the rhenium (IV) sulphide nanotube material is also provided. The method comprises the steps of:
(a) providing a nanotube template material (b) impregnating the template material with a rhenium-containing solution (c) drying the impregnated template material (d) treating the dried material from step (c) with a sulphiding agent.
In the above method, the nanotube template material may have an inner or outer diameter between 2 to 500 nm.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows a schematic drawing of a carbon nanotube and the positions of the carbon atoms.
FIG. 2 shows a High Resolution Transmission Electron Microscopy (HRTEM) image of a multi-walled carbon nanotube.
FIG. 3 shows a multi-walled carbon nanotube covered by 8-11 layers of rhenium (IV) sulphide.
FIG. 4 shows a multi-walled carbon nanotube covered by 4-7 layers of rhenium (IV) sulphide.
FIG. 5 shows a multi-walled carbon nanotube covered by 1-2 layers of rhenium (IV) sulphide.
DETAILED DESCRIPTION OF THE INVENTION
A wide range of different techniques has prepared Nanotubes of different materials. Particularly for carbon nanotubes and other carbon nanofilaments (carbon filaments with a diameter below 500 nm) several techniques are available that allow a detailed control of both the microstructure and the macrostructure of the nanotubes.
In the preparation of the rhenium (IV) sulphide nanotube material of the invention, carbon nanotubes were used as a templating material. Using this method, it was possible to rationally design rhenium (IV) sulphide nanotube material with respect to both nanotube diameter, which is determined by the diameter of the carbon nanotube starting materials and the number of ReS 2 layers determined by the amount of Re used relative to that of the carbon nanotube starting material. It was also possible to design the ReS 2 nanotubes with respect to their length, which is determined by the length of the carbon nanotubes.
Very long carbon nanotubes several centimeters in length are currently available and have been described by Zhu, H. W. et al. in Science 2002, 296, 884, but the method is not limited to using only these materials. Other nanotube materials not necessarily consisting of carbon could be used as templates. Such materials are further discussed by R. Tenne ( Progress in Inorganic Chemistry 2001, 50, 269).
Many different applications for nanotube materials have been suggested and are being explored. The use as super-strong fibres and their use as components for electronics (Collins, P. G.; Avouris, P. Scientific American December 2000, 38) are examples. Templating materials used for synthesis of nanotubes may be removed if this is necessary for the application.
The following examples illustrate the preparation of a ReS 2 nanotube material of the invention.
EXAMPLE 1
Multi-walled carbon nanotube material (MWCNT) containing approximately 8-10 carbon layers was used as template for the preparation of the ReS 2 nanotube materials of the invention. This was verified by the HRTEM image shown in FIG. 2 . The material had inner and outer diameters of 8-9 nm and 20 nm approximately. This material was impregnated with an aqueous solution of NH 4 ReO 4 containing a molar amount of Re which was 25% of the molar amount of carbon in the MWCNT material. The sample was dried and then treated with hydrogen sulphide at 1000° C. for 3 hours. The HRTEM image shown in FIG. 3 revealed that a new nanotube material had grown on the surface of the carbon nanotubes. In particular, FIG. 3 showed that ReS 2 covered the closed end of the carbon tube.
The interlayer distance was approximately 0.62 nm typical of the distance between layers of ReS 2 . Energy-dispersive X-Ray Analysis (EDX) of selected areas of the sample revealed the presence of only rhenium, sulphur and carbon. Chemical analysis, X-Ray Powder Diffraction and Raman Spectroscopy verified the formulation of the sample as ReS 2 . The ReS 2 tubes had typical inner and outer diameters of 25 and 40 nm, respectively. The number of ReS 2 layers was 811.
EXAMPLE 2
A sample of ReS 2 on MWCNT was prepared as described in Example 1, but with the difference that the molar amount of Re in the NH 4 ReO 4 impregnating solution was halved corresponding to a Re:C atomic ratio of 0.125 in the sample. The ReS 2 nanotube material obtained had the same characteristica as the material obtained in Example 1 with the exception that the typical number of ReS 2 layers on the MWCNT was 4-7. A HRTEM image of this sample is shown in FIG. 4 .
EXAMPLE 3
A sample of ReS 2 on MWCNT was prepared as described in Example 1, but with the difference that the molar amount of Re in the NH 4 ReO 4 impregnating solution is reduced to one tenth of the amount of Example 1 corresponding to a Re:C atomic ratio of 0.025 in the sample. The ReS 2 nanotube material obtained had the same characteristics as the material obtained in Example 1 with the exception that the typical number of ReS 2 layers on the MWCNT was 1-2. A HRTEM image of this sample is shown in FIG. 5 . | A rhenium (IV) sulphide (ReS 2) nanotube material and a method of preparation of the rhenium (IV) sulphide (ReS 2) nanotube material. The rhenium (IV) sulphide (ReS 2) nanotube material comprises hollow cylinders of concentric rhenium (IV) sulphide layers, the ReS 2 interlayer distance being between 0.5 to 0.7 nm. Each ReS 2 layer consists of a layer of rhenium atoms sandwiched between two layers of sulfur atoms. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a system managing method and apparatus and, more particularly, to a system managing method and apparatus using both a managed object interface and a non-managed object interface.
In a system such as an exchange system supporting a plurality of kinds of interfaces including a managed object (MO) interface and a non-managed object (non-MO) interface, it is desired to simplify a process using the MO interface and the non-MO interface. The MO interface includes common management information protocol (CMIP). A TL 1 command and a graphical user interface (GUI) are included in the non-MO interface.
2. Description of the Related Art
FIG. 1 is an illustration for explaining a conventional system management model. The system management model shown in FIG. 1 is an open system interconnection (OSI) system which enables interconnection between different computer network systems. In the system management model shown in FIG. 1, communication between a managing system 41 (manager 43 ) and a managed system 42 is specified. The managed system 42 includes a plurality of managed objects (MOs) 45 and an agent 44 which operates the managed objects 45 .
The managing system 41 (manager 43 ) may correspond to a managing apparatus such as a maintenance terminal apparatus provided with processors and memories. The managed system 42 may correspond to a switching apparatus provided with processors and memories. In the system management model shown in FIG. 1, resources to be managed are abstracted so as to manage the resources as the managed objects. The managed objects include concepts of a managed object class (MO class) and a managed object instance (MO instance). The MO class defines a characteristic of a managed object. The MO class defines attributes, attribute groups, notifications, operations and behavior. The MO instance represents a specific object defined by the MO class.
For example, the above-mentioned CMIP is defined as a protocol for transmission and reception of management commands and notification information of the managed objects 45 between the managing system 41 (manager 43 ) and the agent 44 of the managed system 42 . The CMIP is a protocol for use on an individual managed object basis. A simple network management protocol (SNMP) is well-known as the CMIP. An interface between the manager 43 and the agent 44 is referred to as the MO interface. That is, the MO interface specifies communication between the managing system 41 and the managed objects 45 via the agent 44 such as transmission of managing operation commands from the managing system 41 (manager 43 ) to the managed objects 45 or transmission of notification from the managed objects 45 to the managing system 41 .
Such a specification of communication is known as a common management information service (CMIS). The managing operations according to the CMIS includes, for example, M-GET which is acquisition of an attribute value, M-SET which is setting of an attribute value, M-ACTION which is an operation on the managed object, M-CREATE which is creation of the managed object, M-DELETE which is deletion of a managed object and M-CANCEL-GET which is cancellation of the M-GET. Notification according to the CMIS includes M-ENENT-REPORT which is a notification sent from a managed object.
On the other hand, the TL 1 command or the GUI does not handle resources as the managed object. Such an interface is referred to as the non-MO interface. The non-MO interface is used in various systems including a switching system. In the TL 1 command, invoked process and parameters for the process are specified.
FIG. 2 is an illustration for explaining another conventional system management model in which both the MO interface and the non-MO interface are used. The management system model shown in FIG. 2 includes a managing system (manager) 51 for the MO interface, a managed system 52 , an agent 54 , a common processing unit 55 and a managing system (manager) 56 for the non-MO interface.
The managed system 52 is provided with the common processing unit 55 so that a managing operation for both the MO interface managing system 51 and the non-MO interface managing system 52 can be performed. The common processing unit 55 has a structure based on either the MO interface or the non-MO interface.
If the common processing unit 55 has a structure suitable for the MO interface in the above-mentioned system in which both the MO interface and the non-MO interface are supported, the unit of process requested of the common processing unit 55 is the MO class and a full distinguished name (FDN). The FDN is a symbol used for designating the MO instance which belongs to one of the MO classes in the MO interface. That is, the FDN is an identification number of the MO instance managed as a hierarchical structure according to a hierarchical relationship between a plurality of MO classes.
In this case, a function of the common processing unit 55 , which function is in accordance with the CMIP command including the MO class name and the FDN, can be correlated to a command sent from the MO interface. However, an appropriate function of the common processing unit 55 cannot be provided in response to a command sent from the non-MO interface since the command does not include the MO class name and the FDN. In such a case, a process is required for relating the non-MO command to a function of the common processing unit 55 that is based on the MO interface. Thus, the agent 54 performs such a process.
On the other hand, if the common processing unit 55 has a structure suitable for the non-MO interface, the function of the common processing unit 55 is constituted by the unit of command handled by the non-MO interface. Thereby, an appropriate function of the common processing unit 55 can be provided in response to a request from the non-MO interface. However, a command in the MO unit from the MO interface must be processed so as to be related to a command unit in the non-MO interface. In such a case, since the command unit of the non-MO interface has a course tendency as compared to that of the MO interface, there is a problem in that an appropriate function of the common processing unit 55 cannot be provided in response to the request from the MO interface.
Additionally, if a pointer attribute defined by the MO interface is handled in the common processing unit 55 , it is considered to set a definition of various pointers that indicates a relationship between the instances so as to perform processes according to the definition. However, in order to respond to the request, a large process load is applied to the common processing unit 55 . Additionally, there is a problem in that a long time and labor are required to develop a program performing such an operation.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful system managing method and apparatus in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a system managing method and apparatus in which a load applied to a common processing unit is decreased so as to improve a managing ability of the system.
In order to achieve the above-mentioned objects, there is provided according to the present invention a system managing method and apparatus for managing a system having a plurality of interfaces including a managed object interface and a non-managed object interface, the managed object interface handling resources as managed objects, the non-managed object interface handling resources as non-managed objects. A common processing unit performs operations common to the plurality of interfaces. A managed object interface agent is connected to the managed object interface so as to manage pointer attributes independently from the common processing unit. A non-managed object interface agent is connected to the non-managed object interface. The managed object interface agent includes a knowledge database and an agent database, the knowledge database storing information regarding a pointing instance and a pointed instance defined by each pointer attribute, the agent database holding the resources as instances of the managed object type so as to delete, add or update a value of each pointer attribute according to a process request.
According to the present invention, the pointer attributes can be processed solely by the managed object interface agent. That is, when a process request is transferred from the non-managed object interface agent to the common processing unit, the common processing unit determines whether or not the request is for the resources managed by the managed object interface. If the request is for the resources managed by the managed object interface, the common processing unit transfers the process request to the managed object interface agent so that the request is processed by the managed object interface agent. Thus, the common processing unit is not required to process the request for the resources managed by the managed object interface agent. That is, the common processing unit is required to perform only processes related to the non-managed object and basic processes common to the managed object and the non-managed object. This reduces a load to the common processing unit when a plurality of interfaces including the managed object interface and the non-managed object interface are present.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration for explaining a conventional system management model;
FIG. 2 is an illustration for explaining another conventional system management model in which both an MO interface and a non-MO interface are used;
FIG. 3 is a block diagram of a part of a switching apparatus according to a first embodiment of the present invention;
FIG. 4 is an illustration for explaining an operation of an MO interface agent shown in FIG. 3 when a request for deletion is issued by an MO interface manager; and
FIG. 5 is an illustration for explaining an operation of the switching apparatus shown in FIG. 3 when a request for deleting resources is issued by a non-MO interface manager.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A description will now be given of a system managing apparatus according to a first embodiment of the present invention. FIG. 3 is a block diagram of a part of a switching apparatus according to the first embodiment of the present invention.
The switching apparatus shown in FIG. 3 comprises a common processing unit 1 , an MO interface agent 2 and a non-MO interface agent 3 . The MO interface agent 2 comprises an agent database (agent DB) 4 and a knowledge database (knowledge DB) 5 . The agent database 4 includes instances a and b. A pointer attribute p is data defined in the instance a. It should be noted that an MO interface manager and a non-MO interface manager are not shown in the figure.
The common processing unit 1 performs basic operations of the switching apparatus such as call operations for controlling communication path switches (not shown in the figure). The common processing unit 1 also performs processes common to the MO interface and the non-MO interface. The MO interface agent 2 receives a process request from the MO interface, and sends the process request to the common processing unit 1 when a process requested by the process request is a basic process of the switching apparatus or a process common to the non-MO interface. The non-MO interface agent 3 receives a process request from the non-MO interface, and sends the process request to the common processing unit 1 when a process requested by the process request is a basic process of the switching apparatus or a process common to the MO interface.
The agent database 4 of the MO interface agent 2 stores resources of the switching apparatus as instances of a managed object type. In FIG. 3, the instances a and b correspond to resources of the switching apparatus having object classes A and B, respectively. The pointer attribute p holds information regarding a relationship between the instances a and b. In FIG. 3, the instance a designates the instance b. The knowledge database 5 holds the definition of a pointing instance and a pointed instance of the pointer attribute. The knowledge database 5 also holds information regarding correspondence between the resources when the resources are added or changed. Additionally, information regarding new correspondence can be added to the knowledge database 5 .
All pointer attributes used by the MO interface are managed by the MO interface agent 2 . An operation for reference, change or notification of change to the pointer attributes is basically performed within the MO interface agent 2 independently of the common processing unit 1 . However, when the substance of the pointer attribute is resources which can be managed by the common processing unit 1 , the MO interface agent 2 notifies the common processing unit 1 of the contents of operations by using an input interface format of the common processing unit 1 .
For example, when a request for deletion (M-DELETE) is made to the instance b, the MO interface agent 2 checks whether or not the pointer attribute referring to the object class B is present by referring to the pointing instances of the knowledge data base 5 by using the object class name (=B) of the instance b. In FIG. 3, it is assumed that the pointer attribute p of the object class A in the pointing instance designates the object class B as the pointed instance.
The MO interface agent 2 searches the agent database 4 so as to find an instance pointing to the instance b by using the “object class A” and the “pointer attribute p having a value corresponding to the instance be”. In the present case, since the instance a is found by the search, the identification number of the instance b is deleted from a value of the pointer attribute defined in the instance a. Additionally, the result of the change is sent to the MO interface manager as an attribute value change notification.
When a request for creating an instance (M-CREATE) is made by the MO interface, the request can be handled in the same manner as the above-mentioned case. In such a case, the MO interface agent 2 refers to the knowledge database 5 so as to add an instance to the agent database 4 , and sends the result of the addition to the MO interface manager.
Additionally, when a request for creating or deleting resources managed by the MO interface is issued by the non-MO interface, the non-MO interface agent 3 sends a process request to the common processing unit 1 . The common processing unit 1 performs a process requested by the process request. However, when the resources to be processed are managed by the MO interface, the common processing unit 1 notifies the MO interface agent 2 of the creation or deletion of the resources as creation or deletion of an instance.
The MO interface agent 2 searches the knowledge database 5 so as to determine whether or not a pointer attribute, which designates the instance to be created or deleted as a pointed instance, is present. If such a pointer attribute is present, the MO interface agent 2 extracts the pointing instance from the agent database 4 so as to delete a pointer attribute value of the extracted instance when the request is deletion or add a pointer attribute value when the request is creation. Then, the MO interface agent 2 sends a notification of the attribute change to the MO interface manager as the result of the process. That is, in this case, the MO interface agent 2 sends an attribute value change notification to the MO interface.
FIG. 4 is an illustration for explaining an operation of the MO interface agent 2 shown in FIG. 3 when a request of deletion is issued by the MO interface manager. In FIG. 4, parts that are the same as the parts shown in FIG. 3 are given the same reference numerals, and descriptions thereof will be omitted.
In FIG. 4, it is assumed that a request of deletion (M-DELETE) is issued by the MO interface manager. The contents of the request of deletion is (ds 3 LineTTPBid, FDN={A. 1 , B. 3 }). The MO interface agent 2 searches the knowledge database 5 with respect to the object class (ds 3 LineTTPBid) to be deleted and the identification number FDN={A. 1 , B. 3 } so as to check whether or not an object pointing to the object class (ds 3 LineTTBid) to be deleted is present.
As mentioned above, the knowledge database 5 stores information regarding a pointing instance and a pointed instance of the pointer attribute in relation to each other. In FIG. 4, the object class (=circuit Pack) as a pointing instance and the pointer attribute (=affected Object List) are stored with respect to the object class (=ds 3 LineTTPBid) as a pointed instance. Additionally, the object class (=uni) as a pointing instance and the pointer attribute (=underlyingTTP) are stored with respect to the object class (=tcAdapterTTP) as a pointing instance.
Accordingly, the object class (=circuit Pack) is obtained by searching the knowledge database 5 . Then, the agent database 4 is searched by using the obtained object class (=circuit Pack). As a result, a group of instances are extracted, and the agent database 4 is further searched based on a condition that the pointer attribute (=affected Object List) has {A. 1 , B. 3 }.
In this case, the instance of MO Class:(ds 3 LineTTPBid) corresponds to the instance b shown in FIG. 3; the instance of MO Class: (circuit Pack) corresponds to the instance a shown in FIG. 3; Naming Attribute D: 2 , affected Object List={A. 1 , B. 3 } corresponds to the pointer attribute p shown in FIG. 3 . It should be noted that “D: 2 ” is not shown in FIG. 3 .
Accordingly, the affected Object List of the instances extracted as the result of search of the agent database 4 is deleted. Then, the MO interface agent 2 sends an object deletion notification and an attribute value change notification to the MO interface manager. The object deletion notification indicates that (ds 3 LineTTPBid, FDN={A. 1 , B. 3 } is deleted, and the attribute value change notification indicates that (circuit Pack, affected object list) is changed.
That is, the agent database 4 is searched by referring to the knowledge database 5 in accordance with the request of deletion or creation, and the corresponding attribute value is deleted or created in response to the request of deletion or creation, and the notification of the result is sent to the MO interface manager.
FIG. 5 is an illustration for explaining an operation of the switching apparatus shown in FIG. 3 when a request for deleting resources is issued by the non-MO interface manager. In FIG. 5, parts that are the same as the parts shown in FIGS. 3 and 4 are given the same reference numerals. In FIG. 5, an identification number correspondence table 6 is shown which is referred to by the common processing unit 1 . The identification number correspondence table 6 stores the object class, storing position information OE and the identification number FDN.
When a request for deleting resources is issued by the non-MO interface manager, that is, when a TL 1 command such as (DLT-TER: OE=0201001021) is input to the non-MO interface agent 3 , the non-MO interface agent 3 transfers the request for deleting resources to the common processing unit 1 .
The common processing unit 1 processes the request of deletion so as to determine whether or not the resources to be deleted are resources managed by the MO interface. If the common processing unit 1 determines that the resources to be deleted are managed by the MO interface, the common processing unit 1 searches the identification number table 6 by using the object class (=ds 3 LineTTPBid) and the storing position OE (=0201001021) which are related by (TER: OE) of the object to be processed. In this case, the identification number FDN={A. 1 , B. 3 } in the MO interface is obtained. Accordingly, the common processing unit 1 sends to the MO interface agent 2 a resource deletion notification including the identification number FDN as indicated by (Deletion of ds 3 lineTTPBid) in FIG. 5 .
The MO interface agent 2 searches the agent database 4 according to the object class (=ds 3 LineTTPBid) and the identification number FDN (={A. 1 , B. 3 }) so as to extract MO class ds 3 LineTTPBid of the instance to be deleted and delete the extracted instance. Additionally, the MO interface agent 2 searches the knowledge database 5 so as to extract the pointer attribute pointing to the extracted instance.
Then, the MO interface agent 2 deletes the value {A. 1 , B. 3 } of the pointer attribute (affected object List) of the MO class (circuit Pack) of the agent database 4 in accordance with the extracted (circuit Pack+affected Object List). Thereafter, the MO interface agent 2 sends to the MO interface manager a change notification that is an object deletion notification (ds 3 LineTTPBid, FDN={A. 1 , B. 3 }), attribute Value Change (circuit Pack, affected Object List).
Although the operation for deleting an instance is described above, an operation for referring to, creating or changing can be performed in a similar manner by the MO interface agent 2 by referring to, creating or changing the pointer attribute value of the agent database 4 by referring to the knowledge database 5 . Additionally, the present invention is not limited to the combination of the MO interface using CMIP and the non-MO interface using the TL 1 command, and is applicable to a system including other interfaces.
The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.
The present application is based on Japanese priority application No.10-244725 filed on Aug. 31, 1998, the entire contents of which are hereby incorporated by reference. | In a system managing method and apparatus, a load applied to a common processing unit is decreased so as to improve a managing ability of the system. The system managing apparatus manages a system having a plurality of interfaces including a managed object interface and a non-managed object interface, the managed object interface handling resources as managed objects, the non-managed object interface handling resources as non-managed objects. A common processing unit performs operations common to the plurality of interfaces. A managed object interface agent is connected to the managed object interface so as to manage pointer attributes independently of the common processing unit. A non-managed object interface agent is connected to the non-managed object interface. The managed object interface agent includes a knowledge database and an agent database. The knowledge database stores information regarding a pointing instance and a pointed instance defined in each pointer attribute. The agent database holds the resources as instances of the managed object type so as to delete, add or update a value of each pointer attribute according to a process request. |
This is a divisional of application Ser. No. 08/263,305 filed Jun. 21, 1995, now U.S. Pat. No. 5,480,813.
BACKGROUND
1. Technical Field
The present invention relates to an accurate in-situ growth technique based upon reflection high energy electron diffraction dynamics for accurate lattice matching of dissimilar materials.
2. Discussion of Related Art
The invention of low loss optical fibers for use as a practical optical transmission medium has stimulated tremendous growth in other areas relating to optical communications. The term "optical" as used herein refers not only to visible light but to any electromagnetic radiation which can be transmitted within dielectric fibers. The term refers to electromagnetic radiation generally of wavelength between 0.1 and 50 microns. Recently, fiber to the home systems have been proposed which would utilize surface normal electroabsorption modulators to convert downstream light into upstream dam. One such system uses a single fiber to connect two locations and effects bidirectional data transmission over this fiber using a single laser. See, e.g., T. Wood et al., Elec. Lett., Vol. 22, pgs. 346-352 (1986) and T. Wood et al., J. Light Tech., Vol. 6, pages 527-528 (1988) the disclosures of which are incorporated herein by reference. This system uses a light modulator that imprints data on the fiber return and thus avoids the need for a second laser at the subscriber location. Particularly useful for modulation are electrooptic devices whose optical properties, such as absorption or index of refraction, may be varied by application of an appropriate electrical signal. Exemplary of such electrooptical devices is the multiple quantum well (MQW). The MQW includes a plurality of layers of different semiconductor materials such as gallium arsenide (GaAs) and aluminum gallium arsenide (AlGaAs). Other examples of suitable materials include such III-V systems a InAs/GaAs,(In,Ga)As/GaAs,(In,Ga)As/InP and (In,Ga)As/(In,Al)As. The layers alternate between wide bandgap material and narrow bandgap material. Appropriate selection of materials, compositions and layer thicknesses permits fabrication of unique electrooptic devices.
When used as a modulator, the MQW exhibits a significant shift in the absorption edge due to the change in the confinement energy associated with the applied electric field and consequent distortion of the well. This shift in absorption is the basis for the MQW as a modulator. Since the applied field can significantly alter the light absorption properties of a properly biased MQW, light passing through the MQW will be modulated.
In the fabrication of MQW's, thin films of the semiconductor materials are grown or deposited onto substrate material in a wide variety of reactors. One such reactor is a molecular beam epitaxy (MBE) reactor. See, e.g., U.S. Pat. No. 3,751,310 to Cho. Since 1983 it has become apparent that the period of oscillatory behavior observed in the intensity of the RHEED features on initiation of growth is directly related to the growth rate. See, e.g., J. H. Neave et at., Appl. Phep. A31,1 (1983) and J. M. VanHove et al., J. Vac. Sci. and Technol. B1,741, (1983) the disclosures of which are incorporated herein by reference. In fact, monitoring of the RHEED intensity oxillations has become an established technique for the in-situ calibration of beam fluxes and the control alloy compositions for the growth of lattice matched heterostructures. The accuracy of the analysis of the RHEED oscillatory data, for a thin layer GaAs/AIGaAs material system, is about 1%. See, e.g. Turner et al., J. Vac. Sci. Technol. B8, 283 (1990). Hence, there is a real need for a technique which allows accurate lattice matching conditions to be arrived at in a quick and reproducible manner for the realization of a variety of semiconductor optical devices such as, for example, modulators, lasers and detectors.
SUMMARY
An in-situ method is disclosed for highly accurate lattice matching using reflection high energy electron diffraction dynamics. The method includes the steps of providing a substrate of a first semiconductor material and initiating growth of a second semiconductor material thereon. The intensity I of a diffraction feature generated by using an electron beam (RHEED) is monitored versus time. A normalized figure of merit FM is calculated by using the relationship: ##EQU2##
By maximizing the value of FM, accurate lattice matching on the order of about two parts in ten thousand can be obtained.
A multiple quantum well light modulator is also provided including a semiconductor substrate of InP, a multiple quantum well region, disposed above the InP substrate, composed of InGaAs quantum well and InP barriers and having a thickness of about 4 μm. The modulator is characterized by a lattice mismatch of less than 2×10 -4 .
BRIEF DESCRIPTION OF THE DRAWINGS
Various methods are described hereinbelow with reference to the drawings, wherein:
FIG. 1 is a schematic illustration of a reflectivity measurement test set up for characterization of electroabsorption modular devices;
FIG. 2 is a plot of RHEED intensity oscillations for different In and Ga flux ratios;
FIG. 3 is a plot of the variation in oscillation amplitude for a systematic change in lattice mismatch;
FIG. 4 is a compilation of three plots, plot B showing RHEED Intensity Oscillations for InP growth on InP, Plot A showing RHEED Intensity Oscillations for InGaAs on InP and RHEED Intensity Oscillations for InGaAs on InGaAs with FIG. 4A showing a Fast Fourier Transform of the InP on InP RHEED oscillations;
FIG. 5 is a High Resolution X-ray Diffraction scan of a p-i-n modulator incorporating 225 InGaAs/InP MQW's in the intrinsic region;
FIG. 6 is a plot of reflectivity spectra at 300K of InGaAs/InP MQW.
FIG. 7 is a plot of contrast ratio at exciton at 300K of InGaAs/InP MQW;
FIG. 8 is a plot of contrast ratio below band edge at 300K of InGaAs/InP MQW;
FIG. 9 is a plot showing RHEED intensity oscillations for different InGaAs lattice mismatches on InP.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The invention will now be described in detail in connection with the drawings. FIG. 1 is a schematic drawing of a preferred embodiment of a measurement test set up, shown generally at 20 for use with the invention as applied to a modulator. Surface normal modulators are attractive candidates for fiber to the home applications where their amenability to processing in large two dimensional arrays would help keep unit costs down. In order to be useful, however, contrast and absorption values must be acceptable in the 1.3 to 1.55 μm regime corresponding to the low dispersion, low loss windows for optical fibers.
Surface normal In 0 .53 Ga 0 .47 As/InP MQW modulators operating at 1.55 μm are particularly attractive for this application. Such systems need modulators with on-off ratios of between 8:1 to 10:1 at 155 μm. However, the absorption coefficient exhibited by this material system is only about 40% of the value exhibited by the GaAs/AIGaAs material system. In order to overcome this drawback an intrinsic MQW region over 4 μm thick must be employed. At this thickness, lattice mismatches of several parts in 10 -4 can cause strain relief resulting in an inhomogeneously broadened exciton and thereby a reduced contrast ratio. Highly accurate lattice matching thus becomes very important.
To achieve this objective with a high yield, an in-situ growth approach based on RHEED dynamics is disclosed that allows InGaAs to be accurately lattice matched to an InP substrate. This approach is based on an analysis of the intensity amplitude as opposed to conventional approaches wherein growth rates are determined by an analysis of oscillation frequency. FIG. 1 is a schematic illustration of a reflectivity measurement test set up for characterization of electroabsorption modulator devices.
FIG. 2 shows a plot of the intensity oscillation of RHEED for different In and Ga flux ratios. Accurate lattice matching conditions are shown in FIG. 2 as clearly defined oscillations. But for slight mismatches, the RHEED oscillation amplitude is degraded both for Ga and In rich lattice mismatches. Even though the intensity oscillation amplitude has significantly changed (because of the mismatch) the oscillation frequency does not show a reproducible change. In fact, it is not possible to detect a change in oscillation frequency with reliability to better than 1%. FIG. 3 is a plot of the FM for a systematic change in lattice mismatch. Clearly the peak establishes perfect lattice matching conditions. The scale shows that mismatches as low as a few parts in 10 4 can be easily distinguished. This method has other application to many Group III-V systems such as, for example, InGaP/GaAs, GaAsSb/InP or ternaries, quaternaries under lattice matched conditions.
EXAMPLE 1
To exemplify the viability of this approach measurements were made on p-I(MQW)-n surface normal modulators incorporating thick intrinsic regions where the new process was used to obtain highly accurate lattice matching conditions. The data also shows that even mismatches of a few parts in 10 -4 result in an inhomogeneous broadening of the excitonic resonance and hence a degradation of performance. See Table 1.
The structures were grown by Gas Source MBE in a VG-80H M BE system modified to handle gas flow. Pure AsH 3 and PH 3 constituted the Group V fluxes, while elemental Ga and In were used as the Group III sources. A standard VG electron gun, operated at 15 KV with a filament current of 2.25 A is used to generate the RHEED pattern. The image generated on the phosphor screen is captured with a CCD camera which sends it to a TV monitor and also to a frame grabber card capable of 256 bit resolution located in a 486 desktop PC for display on the video monitor. The card is capable of sampling the image 30 times a second. Software written for this card allows the user to define boxes of different pixel sizes which function as a detector. By aligning the pixel box over a diffraction pattern, feature RHEED intensity oscillations can be recorded. The position of this aligned box pixel, once defined, remains fixed. Hence, once an aforesaid pixel box is defined and fixed any lateral drift in the diffraction geometries can be corrected for by realigning the diffraction spot within the confines of the pixel box A typical calibration run consists of recording the RHEED oscillations, and then transporting the data file to a program which allows us to perform both time and frequency domain analysis on the acquired data set. Using this setup a variance on the order of 1% in the growth rate between consecutive measurements can be achieved.
For our experiments RHEED intensity measurements were performed on a small (˜0.5 cm -2 )n+InP wafer positioned at the center of a molybdenum block with indium. Use of a small RHEED sample further minimizes any error. Further, the flux distribution over such a small piece can be assumed to be uniform. After thermal desorption of the oxide under a P flux, a layer of InP was first grown for an hour so as to allow the In cell to reach thermal equilibrium. At the same time, the Ga cell was also brought up to temperature and held with the shutter closed. All measurements were made at a growth temperature of 500° C. on a Group V stabilized ×2 reconstruction along the [110] azimuth. The Group V to Group III flux ratio was maintained at approximately 2.5:1.
All the measurements were made on a fresh, fully recovered InP surface. Prior to initiating growth of InGaAs, the Group V gases were switched and AsH 3 was allowed to flow into the chamber for 30 sec. RHEED intensity data was then acquired from the specular spot of the diffraction pattern with a 5×5 pixel sized box over 75 sec. (30 sec. of actual intensity oscillations plus 45 sec. to record the recovery characteristics) at a sampling rate of 30 Hz. Upon completion of the measurement the Group V gases were once again switched and InP grown for 3 minutes before repeating the measurement. The set point of the In cell was held constant throughout the measurement sequence, while the Ga cell temperature was stepped to lower values. A five minute layer of InP was inserted between each successive change in Ga set point.
As can be see in FIG. 2, qualitatively different forms of oscillations were encountered corresponding to situations where the composition was either Ga rich, In rich or lattice mismatched by small amounts. For In rich or lattice matched even by slight amounts under these conditions it was not possible to detect a reproducible change in the oscillation frequency as seen in FIG. 2.
Correlating lattice mismatch obtained from high resolution X-ray diffraction (HRXRD) measurements and measured linewidths from 77KPL measurements on p-i(MQW)-n devices containing thick MQW intrinsic layer shows that even small amounts of lattice mismatch leads to strain relief leading to an associated inhomogeneous broadening of the excitonic resonance.
Results
FIG. 4 shows RHEED Intensity oscillations for growth very close to lattice match conditions. In Plot B, the oscillations observed for InP growth on InP are the usual type expected for binary III-V growth. Here, InP exhibits sinusoidal oscillations at the periodicity of the monolayer growth rate. Initial cycles of the intensity oscillations are rapidly damped symmetrically about maximum and minimum surface disorder as time approaches a terminal configuration of equilibrium surface roughness. Oscillations eventually vanish when rate of formation of surface step density (i.e., spontaneous nucleation from growth) becomes comparable to the rate of 2-D ledge motion (i.e., steps on terraces coalescence to the step ledge). When this happens the state of surface roughness does not change with time (terminal roughness). The recovery dynamics, when measured with no In deposition, also exhibit typical behavior as evidenced by step coalescence dynamics which is single stage. This corresponding to an island size that grows in time. Final RHEED intensity after complete recovery equals initial intensity before deposition.
The inevitable damping of the oscillations is an important factor that limits lattice matching when based on conventional RHEED frequency analysis of the growth rate. A Fast Fourier Transform of the InP on InP RHEED oscillations is shown in FIG. 4A. The growth rate is Fourier Transform Limited 0.756 ML/s (center of the distribution) with a Full Width Half Maximum of 0.17 ML/s. In essence, by sampling the growth rate for an effective time of 6.0 s leads to an uncertainty in growth rate Δω/ω which is huge and impractical as a means to achieve lattice matching conditions. Alternatively, RHEED intensity oscillation observed in FIG. 9 for InGaAs growth on InP exhibit different characteristics that present a new and viable route to rapid lattice matching conditions. The differences show up in three ways and are dramatic when considering the fact that InGaAs growth in FIG. 4 is only slightly mismatched to InP (5×10 -4 ).
First, the initial state of InGaAs on InP growth oscillations that exhibit asymmetrical damping characteristics. They depict initial damping of growth oscillations from configurations of maximum and minimum surface disorder that clearly differ from the symmetrical case observed for InP growth. In addition, the recovery dynamics for InGaAs on InP show distinct differences from InP recovery in two ways. First, time evolution in recovery dynamics is complex with evidence of multiple components present. Secondly, terminal intensity after recovery is significantly lower than initial InP intensity. All three differences appear to associate with increased surface step disorder that is associated with mismatched growth. In essence, because of the difference in a real monolayer density of the mismatched flux with the substrate additional surface steps are created to conserve total surface area. The surface steps from mismatched growth are additive to those normally generated by spontaneous nucleation during growth. The first few cycles of asymmetrical damping show that the surface steps from the mismatch are rapidly formed within the first four monolayers deposited. Also, the multicomponent recovery characteristics and lower total surface reflectivity correspond to island coalescence to a new configuration of surface steps on InP because of the mismatched growth.
To quantify this approach as a route to accurate in-situ lattice matching a normalized figure of merit, FM, is defined for the initial oscillation quality to be the sum of (I + -I - )/ΔI over the first four consecutive ML cycles measured. I + (I - ) correspond to maximum (minimum) intensity of each waveform cycle whereas ΔI is the intensity drop from initial InP reflectivity to minimum reflectivity of the oscillation waveform during deposition. When the FM for the various growth cases in FIG. 4 is plotted, (plots A and B), the FM drops by a factor four from InP growth on InP to InGaAs growth in InP. The FM for InGaAs on InGaAs is 20% larger than InGaAs on InP because mismatched surface steps remain from the first sequence of InGaAs deposition on InP. For the latter case the asymmetry in oscillation damping has improved whereas InP intensity is 25% larger than recovered intensity after first InGaAs deposition. Recovered intensity after second InGaAs deposition equals recovered intensity after first InGaAs deposition.
FIG. 9 shows RHEED oscillations observed for different InGaAs mismatches on InP. This sequence was obtained by holding the In deposition rate fixed while varying the Ga growth rate from Ga rich to In rich conditions. Clearly, RHEED intensity during InGaAs deposition show systematic difference in the oscillation quality, recovery characteristics and intensity response. From the plot, a Ga cell temperature of 910.0° C. is very close to lattice matched conditions.
In FIG. 3, the FM is shown over the same range of mismatch at finer step size than the coarse display of FIG. 9. The FM is highly sensitive to mismatch and is strongly peaked at a lattice matching condition. The degradation in FM versus mismatch is symmetrical about Ga and In rich conditions with shape reminiscent of quality characteristics obtained by PL or X-ray diffraction measurements. Upon thick InGaAs layer deposition atop these sequences lattice matching on the basis of X-ray diffraction should be at the arrowed position.
A typical HRXD scan of a p-i-n modulator incorporating 225 InGaAs/InP MQW's in the intrinsic region is shown in FIG. 5. The average lattice mismatch is obtained by determining the angular separation between the zeroth order peak (which corresponds to the reflection from the layer with the average lattice parameter of the super lattice stack) and the reflection from the substrate peak. In Table-1 the values of linewidth as determined from 77K photoluminescence measurements are presented along with the mismatch values as determined from the HRXD measurement. As can be seen even small increases in the lattice mismatch result in a significant broadening (by a factor of almost two in going from a few parts in 10 -5 to a few parts in 10 -4 ) in the linewidth of the photo luminescence (PL) spectra. In device terms this broadening of the excitonic resonance means that to red shift the exciton from under the zero field E1-HH1 peak a higher electrical field is required, which further broadens the exciton due to associated polarization of the electron-hole pair, and hence the performance is degraded.
TABLE 1______________________________________PL FWHM(meV) Lattice mismatch, .increment.a/a______________________________________6.75 3.929 × 10.sup.-59.217 1.9647 × 10.sup.-411.472 2.59 × 10.sup.-4______________________________________
Referring to FIG. 6, the reflectivity spectrum over an applied reverse bias range of 0 to 50V is plotted. The half width half maximum (HWHM) of the zero applied bias exciton peak is 6.2 meV and the whole spectrum shows a good quantum confined stark effect (QCSE), with the peak shifting by more than 50 nm without significant broadening over the entire applied voltage range.
Referring now to FIGS. 7 and 8, the contrast ratios for the normally off and normally on states calculated from the reflection spectra are shown. A high contrast ratio of better than 8:1 is achieved by operating the exciton resonance at an applied reverse bias of 50V. Moreover, the bandwidth for greater than 3:1 contrast ratio, obtained at lower drive voltages is over 20 nm for both λ 0 and λ 1 modes of operation.
Thus, accurate in-situ lattice matching using RHEED dynamics has been presented. Use of this method has been applied to the growth of high contrast surface normal Multiple Quantum Well light modulators operating at 1.5 μm. What has been described is merely illustrative of the application of the principles of the present invention. Other arrangements and methods can be implemented by those skilled in the art without departing from the spirit and scope of the present invention. | An in-situ method is disclosed for highly accurate lattice matching using reflection high energy electron diffraction dynamics. The method includes the steps of providing a substrate of a first semiconductor material and initiating growth of a second semiconductor material thereon. The oscillation amplitude of intensity I of waveform cycles is monitored using reflection high energy electron diffraction. A maximum intensity I + and a minimum intensity I - is determined over a predetermined number of waveform cycles. The intensity drop DI from initial reflectivity to minimum reflectivity of the waveform cycles is determined and normalized figure of merit FM is calculated for the predetermined number of waveform cycles using the relationship: ##EQU1## The fluxes of the second semiconductor material are then adjusted to maximize FM and optimize matching. A multiple quantum well light modulator is also provided including a semiconductor substrate of InP, a multiple quantum well region, disposed above the InP substrate, composed of InGaAs and having a thickness of about 4 mm. The modulator is characterized by a lattice mismatch of less than 2x10 4. |
FIELD OF THE INVENTION
The invention involves a windshield wiper device for a vehicle windshield, having a wiper motor with a reversible rotational direction.
BACKGROUND OF THE INVENTION
From the patent DE 44 31 699 A1, a windshield wiper device with a wiper motor with a reversible rotational direction is known. This device uses a device to record the time that the wiper arm requires for a half wiper cycle, i.e., from an end position or park position until a reverse position. Furthermore, a time allowance device is provided, which specifies a maximum allowed time for a half wiper cycle. In a comparator, the maximum allowed time is compared with the time actually determined, and when this time is exceeded, a wiper operation is triggered in the opposite wiper direction. For this device, the wiped area that is covered is determined from the time allowance device and the correspondingly specified time values. Another wiped area, having another wiper angle, can only be adjusted in that the cycle time necessary for the new wiped area is determined in tests, and this time value is stored in the time allowance device. A simple modification of the wiped area or a subsequent compensation of the play that results within the wiper rod assembly during operation, which leads to a wiped area having a modified reversing situation that is modified to the new condition, is not possible.
From the patent WO 96/39740 a circuit arrangement for the control of a garage door drive is known. The circuit arrangement uses a switch with which a microprocessor can be set into a learning mode so that the maximum allowed force for the closing can be specified. It is further possible to determine and change the end positions of the garage door drive. This device is not suitable for use in vehicle wiper systems.
Finally, windshield wiper devices with gears are known, in which no reversal of the rotational direction of the electronic motor is performed. In these devices, the wiped area is a function of the gear mechanism, so that in order to change the wiped area, mechanical changes to the gear wheels or the allocated control arms are necessary.
SUMMARY OF THE INVENTION
The purpose of the invention presented here is thus to prepare a windshield wiper device having a motor with a reversible direction of rotation, in which any wiped area can be adjustably set in a simple and cost-effective manner. It is essential to the invention that it enables a single type of a windshield wiper device to apply to different application cases and for different types of automobiles. In other words, with one type of windshield wiper device, any possible application case should be covered without having to perform mechanical adjustments on the device itself. Furthermore, it should be possible to design the wiped area so that it can be adjusted after installation of the wiper system into an automobile for maintenance purposes.
The windshield wiper device has a processor which receives operating signals and sends control signals to the motor. The processor has an operating mode and a learning mode, where it can be switched into a learning mode by a switch signal so that a reversal position of the driven shaft and/or a reversal position of the wiper arm can be stored in a memory unit and can be called up as a wiper reversal position as often as desired in the operating mode. The invention thus involves the discovery that the reversal positions can be learned more or less in a testing operation, the learning mode, and can be reproduced in the operating mode. Mechanical changes for fitting the wiped area to the different circumstances or time measurements are not necessary as a result.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail using the drawing. The drawing shows:
FIG. 1 is a schematic block diagram of a windshield wiper device according to the invention; and
FIG. 2 is a schematic signal flow diagram to make clear the operating method of the windshield wiper device according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A windshield wiper device 1 includes a wiper motor 2 that can be reversed in its rotational direction and has a driven shaft 3 and a wiper arm 4 that is attached to it. A windshield wiper cleans a defined wiped area 5 of a vehicle windshield 6, removing dirt and contaminants. The wiped area is limited by a park position P and an outer reversal position U. The wiper motor 2 is equipped with a unit 7 for detecting the position of the driven shaft 3 and in addition or alternatively for detecting the position of the wiper arm 4. This unit 7 gives operating signals 8 to an electronic unit 9 in order to control the motor 2.
Two structural shapes of the position detection unit 7 can be distinguished. For a relative position sensing, a magnetic transmitting component is arranged on the driven shaft 3 and another magnetic transmitting component is arranged on a gear wheel of a reducing gear. To each transmitting component, a Hall sensor is allocated and the detection of rotational speed and rotational angle is done relative to the park position, which the transmitting component on the gear wheel side specifies. For absolute analog position sensing, only one transmitting component on the driven shaft side is planned for a sensor which signalizes the rotational angle of the driven shaft 3. From the rotational angle of the driven shaft and the rotational direction of the motor, the position of the wiper arm can then be calculated.
The wiper motor control is done as follows. An electronic unit 9 gives control signals 10 to the wiper motor 2, when an activation of a switch actuator has occurred beforehand in order to set the wiper motor 2 in motion. In FIG. 1, the activation that acts from the outside is indicated schematically by the arrow 11. As a result, the activation signals 11 as well as the operating signals 8 go over the system boundary 1 2 in the direction towards the electronic unit 9. On the other hand, the electronic unit 9 sends control signals 10 to the wiper motor 2. In the process, a constant comparison is made between the actual values determined by the position detection unit 7 and the target values calculated in the electronic unit 9 according to a certain control algorithm. According to the standard tolerance, an influence is made on the actuator wiper motor 2. It is understood that additional functions such as for example, interval switching, programmable interval switching, automatic reversing of the wiper motor 2 during total blocking, or similar special functions can also be implemented.
It is essential that the electronic unit 9 has a processor 13 which can be switched by a switching signal from an operating mode into a learning mode. The switch signal can for example, be supplied over an external, separate switch 14 as an activation 11 to the electronic unit 9. The learning mode allows the following: a defined, current position of the driven shaft 3 or the wiper arm 4 can be stored in a memory unit 15 and after being switched over into the operating mode, be called up as often as desired as a wiper reversal position. In other words, the end positions of the wiper arm are first determined after the windshield wiper device is completely assembled and possibly attached to the automobile. The wiped area is, in particular, not determined by an abstract time allowance device, but instead through a freely adjustable electronic unit 9. The adjustment of the desired wiper reversal position can be done simply and without specialized knowledge of electronics. In addition, a first and second switch signal can be provided, where by the first switch signal, the learning mode of the electronic unit 9 can be switched on, and by the second switch signal, a conversion can be made from the learning mode to the operating mode.
In an especially preferred embodiment form, the windshield wiper device can be switched over during learning mode more or less into a type of test operation, with which the wiped area can be completely fitted in an individual manner to the applied case that is present. This occurs as follows: On the vehicle windshield 6, at a certain distance from each other, stoppers 16, 17 are mounted, which define a desired wiped area. The stopper 16 symbolizes the desired outer reversal position of the wiper arm 4, and the stopper 17 symbolizes the park position.
It is fundamentally possible to not only adjust the reversal position but also to adjust the park position with the method described. However, the possibility does suggest itself of using a specific setting of the wiper motor 2 as a fixed reference point. Because in this way the park position is already determined, the stopper 17 could be left out and the programming of the park position would be obsolete.
In a next step, the electronic unit 9 is switched into the learning mode so that the wiper motor 2 goes into test operation and corresponding to the rotational direction of the transmitted control signal 10, proceeds with the wiper arm 4 starting from the park position in the direction towards the outer stopper 16. The position values of the driven shaft 3 or the wiper arm 4 are thus constantly transmitted to the electronic unit 9 via the unit in order to record the position 7. Within a certain time t, the electronic unit 9 thus obtains a certain number of operating signals 8. As soon as the wiper arm 4 hits against the stopper 16, the operating signals 8 are completely absent per unit of time, or they are greatly reduced. The last position of the wiper arm 4 reported to the electronic unit 9 is thus established as the reversal position and stored in a read-write memory unit (EE-PROM) 15.
As a result, the wiper motor 2 is reversed, thus reversed in its rotational direction, and the wiper arm 4 proceeds towards the other stopper 17. On this side, the routine described above repeats itself, if the park position is not specified by the machine-side reference point. After the conclusion of this procedure, the wiped area of the windshield wiper device is completely set and the electronic unit 9 is switched over to operating mode by a second switch signal. In the operating mode, the reversal position of the wiper arm 4 can be called up and reproduced as often as possible without being lost or automatically deleted.
It is possible, though, to switch the windshield wiper device again into learning mode, so that a new wiped area is programmable. As a result, the opportunity occurs, for windshield wiper devices 1 that are of an older operating age, to again determine the wiped area, so that the effect of mechanical play, which occurs in the course of time in linkages and mechanical transfer components, can be compensated.
The programming of the windshield wiper device 1 can also be integrated in an especially simple way into the manufacturing process. For example, to every vehicle model, a certain template is allocated, which has the stoppers 16, 17 and thus sets the boundaries of the desired wiped area. For programming, it is merely necessary to arrange the windshield wiper motor 2 in a receptacle so that the template is then arranged with the stoppers 16, 17 in relation to a rotational axis of the driven shaft 3, and then to start the learning mode. This makes it possible to provide every wiper motor 2 with an electronic unit 9, which has the wiped area data of a certain vehicle. Thus, no adjustment or programming work is necessary on the assembly line of the vehicle manufacturer. However, the possibility still arises for having an effect on the wiper end positions via the learning mode in this production stage or at a later operating stage.
Reference is made again to FIG. 1 for further explanation. From the FIGURE it can be gathered that the operating signals 8 supplied from the unit 7 for position detection are passed on to a position value counter 18. Two alternatives are conceivable corresponding to the operating signals 8. On the one hand, it is possible that too little or no signals are supplied over a specific time unit to the electronic unit 9. For this case, the blocking recognition 19 senses the blocking case and transmits a signal to the rotational direction reversal 20, which transmits a control signal 10 to the wiper motor 2 in order to reverse its rotational direction.
When the blocking case is not present, the current position value of the wiper arm 4 is constantly compared in a comparator 21 with the maximum possible position value of the wiper arm 4. For the case that the two values agree, the comparator 21 transmits a corresponding signal to the rotational direction reversal 20 in order to reverse the wiper motor 2. The individual structural units of the electronic unit 9 can be arranged both as separate processors or together on one processor. For example, the memory unit 15 is a component of the comparator 21.
In the following, FIG. 2 is described in greater detail. It starts from a condition in which the wiper arm 4 is located in the park position P. The park position is a reference point that is fixed on the machine, which is unambiguously defined by the position detection unit 7, for example, by a Hall sensor fixed on the housing and a magnetic transmitter component on the driven shaft 3. When the switch 14 has not transmitted a first signal, normal operation is in progress using the corresponding operating signals 10 for the wiper motor 2. By the activation of the switch 14, either a first or a second switch signal is transmitted to the electronic unit 9. By the second switch signal, the electronic unit 9 is set into operating mode so that the reversal position can be no longer be adjusted. If, though, a first switch signal is supplied to the electronic unit 9 as an activation 11, then the wiper motor 2 starts and the wiper arm 4 moves in the direction to the outer reversal position U. The current positions of the wiper arm 4 are constantly supplied to the position value counter 18 through the unit 7 as operating signals 8. This counter monitors the entrance of the position value signals within certain time intervals. When within the given time intervals, no position value signals enter, the motor is blocked and the rotational direction reversal 20 transmits a control signal 10 to brake to a stop and reverse the wiper motor 2. Provided a blocking is not in effect, a comparison of the current position values with the value of the outer reversal position occurs in the comparator 21. Provided the two values do not agree, a return guidance 22 occurs, so that the wiper motor 2 is operated further in the direction to the outer reversal position. If the position values agree, however, then the outer reversal position is reached and a corresponding control signal 10 occurs to brake to a stop, reverse and start the wiper motor 2.
It is understood that the procedure described can be performed multiple times one after the other when the intended result does not fulfill the requirements made of it. Furthermore, many embodiments and modifications of the invention can be made, without leaving the basic idea of the invention. | A windshield wiper device is described for a vehicle windshield, having a wiper motor that has a reversible direction of rotation. The wiper motor is controlled by an electronic unit with control signals. The electronic unit uses an operating mode and a learning mode, with which a reversal position of a wiper arm and/or a driven shaft can be stored in memory in the learning mode and called up as often as desired in the operating mode. In this way, a wiper motor is made that can be adapted to different operating cases with different wiped areas in a simple and cost-effective manner, without mechanical changes needing to be performed. |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application No. 60/204,290 filed May 15, 2000, U.S. Provisional Application No. 60/210,928 filed Jun. 12, 2000, U.S. Provisional Application No. 60/218,920 and U.S. Provisional Application No. 60/228,628 filed Aug. 29, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a latch assembly and more particularly to console latches where an actuation member is depressed to release the latch.
[0004] 2. Brief Description of the Prior Art
[0005] Console latches are generally used to secure the cover of a compartment such as, for example, a console in a vehicle. Often, a console consists of a container, which is swingably hinged between passenger seats to swing out of the way when the vehicle operator or passenger desires. Often, the consoles can store objects therein such as loose change, sunglasses, maps, pens, paper and other articles, which the driver and/or passengers may find it necessary to use.
[0006] It is desirable to maintain the console cover in a closed position to secure contents therein when the vehicle is being operated. It is also desirable to lift the console from a horizontal position to a vertical position in order to have access to the contents within the console, such that the console may be lifted from either the driver's side or the passenger's side, with the opening capable of facing both the driver's direction and the passenger's direction. It is known to provide a depressible latching device, which can secure a console lid to the console body and be opened as the vehicle operator or passenger desires by depression of a latch button.
[0007] There are, however, console latches, which employ more complex configurations than simply a cover or lid and console body. These console latches are often provided in intricate designs, with several individual parts, each of which must be separately manufactured and combined into one console lid unit. Thus, these intricate designs are often very expensive to manufacture and add to the overall cost of the vehicle. Moreover, in the event that the console lid is removed from the console body, reinstallation of the lid becomes very difficult as a result of trying to engage the several independent parts together and at the same time.
[0008] A need, therefore, exists for an improved latch, which can selectively regulate the opening and closing of a first console compartment, and which is constructed out of high strength material and of a simpler design than is currently available, and at a much lower manufacturing cost.
SUMMARY OF THE INVENTION
[0009] The present invention provides for a novel latch assembly, which can secure a closure cover to a compartment body. The latch of the present invention is a double hinge latch, whereby, the left side (or driver side) is the mirror image of the right side (or passenger side). The latch assembly has a lid substrate, which has molded elements for housing or securing various sub elements of the latch assembly. The latch assembly includes four slide pins, two mounted on the driver side, and two mounted on the passenger side. Each slide pin carries a pin member for engagement with a pair of keepers, which can be provided in the panel or bin of the console. An actuation member, such as a button, is connected to the slide member and is disposed for depression by an operator to actuate the latch. The actuation with the button moves the pins rearward with respect to the panel and out of engagement with the keepers. The actuation buttons are provided to be actuated on the front side of the console, with one button closer to the driver side, and one button closer to the passenger side. The latch assembly preferably includes an rotary link, which is actuates a lock link providing articulation between the driver's side components with the passenger's side components. The button includes a living spring component to facilitate returning of the button to its original position, once the console lid is returned to the closed position. The assembly is provided on both the driver's side and the passenger's side in order to allow the console lid to be opened in both directions. As such, when one assembly is used to open the lid from one side, the opposite mirror assembly acts as a hinge and allows for opening and closing of the console lid. The lock link allows the driver's side to be opened, while the passenger's side remains locked. Conversely, the lock link allows the passenger's side to be opened, while the driver's side remains locked.
[0010] It is an object of the present invention to provide a latch, which is useful for securing a console in a vehicle.
[0011] It is another object of the present invention to provide a latch, which includes a living spring member, which allows for the latch and button to return to their original position once it is released and the console lid is returned to the closed position.
[0012] It is another object of the present invention to provide a keeper member, which has a latching accommodating element for securing a pin
[0013] Still another object of the present invention is to provide for a mirrored pair of latch assemblies such that each side of the console comprises the same assembly as the other side.
[0014] It is another object of the present invention to provide a latch, which includes a rotary link and lock link, which allows one side of the console lid to be opened, while the other side stays locked.
[0015] Still another object of the present invention is to provide a latch, which is easily mounted in the console body and can easily accommodate the console lid.
[0016] Another object of the present invention is to provide a latch, which is designed relatively simply, yet can perform its function properly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a perspective view of the double-hinge console latch assembly in the neutral position according to the present invention.
[0018] [0018]FIG. 2 is a top plan view of the double-hinge console latch assembly of FIG. 1 in the neutral position.
[0019] [0019]FIG. 3 is an alternate top plan view of the double-hinge console latch assembly of FIG. 1 in the neutral position.
[0020] [0020]FIG. 4 is a left side elevation view of the double-hinge console latch assembly of FIG. 3 in the neutral position cut along line B-B of FIG. 3.
[0021] [0021]FIG. 5 is a magnified view of the double-hinge console latch assembly of FIG. 4.
[0022] [0022]FIG. 6 is a rear elevation view of the double-hinge console latch assembly of FIG. 1 in the neutral position.
[0023] [0023]FIG. 7 is a left side elevation view of the double-hinge console latch assembly of FIG. 1 in the neutral position.
[0024] [0024]FIG. 8 is a perspective view of the double-hinge console latch assembly in the driver semi-open position according to the present invention.
[0025] [0025]FIG. 9 is a top plan view of the double-hinge console latch assembly of FIG. 8 in the driver semi-open position.
[0026] [0026]FIG. 10 is an alternate top plan view of the double-hinge console latch assembly of FIG. 8 in the driver semi-open position.
[0027] [0027]FIG. 11 is a left side elevation view of the double-hinge console latch assembly of FIG. 10 in the driver semi-open position cut along line A-A of FIG. 10.
[0028] [0028]FIG. 12 is a magnified view of the double-hinge console latch assembly of FIG. 11.
[0029] [0029]FIG. 13 is a rear elevation view of the double-hinge console latch assembly of FIG. 8 in the driver semi-open position.
[0030] [0030]FIG. 14 is a left side elevation view of the double-hinge console latch assembly of FIG. 8 in the driver semi-open position.
[0031] [0031]FIG. 15 is a perspective view of the double-hinge console latch assembly in the driver open position according to the present invention.
[0032] [0032]FIG. 16 is a top plan view of the double-hinge console latch assembly of FIG. 15 in the driver open position.
[0033] [0033]FIG. 17 is an alternate top plan view of the double-hinge console latch assembly of FIG. 15 in the driver open position.
[0034] [0034]FIG. 18 is a left side elevation view of the double-hinge console latch assembly of FIG. 17 in the driver open position cut along line C-C of FIG. 17.
[0035] [0035]FIG. 19 is a magnified view of the double-hinge console latch assembly of FIG. 18.
[0036] [0036]FIG. 20 is a rear elevation view of the double-hinge console latch assembly of FIG. 15 in the driver open position.
[0037] [0037]FIG. 21 is a left side elevation view of the double-hinge console latch assembly of FIG. 15 in the driver open position.
[0038] [0038]FIG. 22 is a perspective view of the double-hinge console latch assembly in the passenger open position according to the present invention.
[0039] [0039]FIG. 23 is a top plan view of the double-hinge console latch assembly of FIG. 22 in the passenger open position.
[0040] [0040]FIG. 24 is a rear elevation view of the double-hinge console latch assembly of FIG. 22 in the passenger open position.
[0041] [0041]FIG. 25 is a left side elevation view of the double-hinge console latch assembly of FIG. 22 in the passenger open position.
[0042] [0042]FIG. 26 is a perspective view of the lid substrate according to the present invention.
[0043] [0043]FIG. 27 is a top plan view of the lid substrate of FIG. 26.
[0044] [0044]FIG. 28 is a rear elevation view of the lid substrate of FIG. 26.
[0045] [0045]FIG. 29 is a left side elevation view of the lid substrate of FIG. 26.
[0046] [0046]FIG. 30 is a perspective view of the slide pin according to the present invention.
[0047] [0047]FIG. 31 is a top plan view of the slide pin of FIG. 30.
[0048] [0048]FIG. 32 is a left side elevation view of the slide pin of FIG. 30.
[0049] [0049]FIG. 33 is a front elevation view of the slide pin of FIG. 30.
[0050] [0050]FIG. 34 is a right side elevation view of the slide pin of FIG. 30.
[0051] [0051]FIG. 35 is a bottom plan view of the slide pin of FIG. 30.
[0052] [0052]FIG. 36 is a rear elevation view of the slide pin of FIG. 30.
[0053] [0053]FIG. 37 is a perspective view of the rotary link according to the present invention.
[0054] [0054]FIG. 38 is a top plan view of the rotary link of FIG. 37.
[0055] [0055]FIG. 39 is a left side elevation view of the rotary link of FIG. 37.
[0056] [0056]FIG. 40 is a front elevation view of the rotary link of FIG. 37.
[0057] [0057]FIG. 41 is a right side elevation view of the rotary link of FIG. 37.
[0058] [0058]FIG. 42 is a rear elevation view of the rotary link of FIG. 37.
[0059] [0059]FIG. 43 is a bottom plan view of the rotary link of FIG. 37.
[0060] [0060]FIG. 44 is a perspective view of the button according to the present invention.
[0061] [0061]FIG. 45 is a top plan view of the button of FIG. 44.
[0062] [0062]FIG. 46 is a front elevation view of the button of FIG. 44.
[0063] [0063]FIG. 47 is a left side elevation view of the button of FIG. 44.
[0064] [0064]FIG. 48 is a rear elevation view of the button of FIG. 44 .
[0065] [0065]FIG. 49 is a bottom plan view of the button of FIG. 44.
[0066] [0066]FIG. 50 is a right side elevation view of the button of FIG. 44.
[0067] [0067]FIG. 51 is a rotated top view of the double-hinge console latch assembly in the neutral position according to the present invention.
[0068] [0068]FIG. 52 is a magnified view of the double-hinge console latch assembly of FIG. 51.
[0069] [0069]FIG. 53 is a rotated top view of the double-hinge console latch assembly in the driver semi-open position according to the present invention.
[0070] [0070]FIG. 54 is a magnified view of the double-hinge console latch assembly of FIG. 53.
[0071] [0071]FIG. 55 is a perspective view of the angled trigger according to the present invention.
[0072] [0072]FIG. 56 is a top plan view of the angled trigger of FIG. 55.
[0073] [0073]FIG. 57 is a front elevation view of the angled trigger of FIG. 55.
[0074] [0074]FIG. 58 is a left side elevation view of the angled trigger of FIG. 55.
[0075] [0075]FIG. 59 is a rear elevation view of the angled trigger of FIG. 55.
[0076] [0076]FIG. 60 is a right side elevation view of the angled trigger of FIG. 55.
[0077] [0077]FIG. 61 is a bottom plan view of the angled trigger of FIG. 55.
[0078] [0078]FIG. 62 is a perspective view of the extension spring according to the present invention.
[0079] [0079]FIG. 63 is a top plan view of the extension spring of FIG. 62.
[0080] [0080]FIG. 64 is a left side elevation view of the extension spring of FIG. 62.
[0081] [0081]FIG. 65 is a front elevation view of the extension spring of FIG. 62.
[0082] [0082]FIG. 66 is a right side elevation view of the extension spring of FIG. 62.
[0083] [0083]FIG. 67 is a rear elevation view of the extension spring of FIG. 62.
[0084] [0084]FIG. 68 is a bottom plan view of the extension spring of FIG. 62.
[0085] [0085]FIG. 69 is a perspective view of the lock link according to the present invention.
[0086] [0086]FIG. 70 is a top plan view of the lock link of FIG. 69.
[0087] [0087]FIG. 71 is a rear elevation view of the lock link of FIG. 69.
[0088] [0088]FIG. 72 is a right side elevation view of the lock link of FIG. 69.
[0089] [0089]FIG. 73 is a front side elevation view of the lock link of FIG. 69.
[0090] [0090]FIG. 74 is a left side elevation view of the lock link of FIG. 69.
[0091] [0091]FIG. 75 is a bottom plan view of the lock link of FIG. 69.
[0092] [0092]FIG. 76 is a perspective view of the lock link compression spring according to the present invention.
[0093] [0093]FIG. 77 is a right side elevation view of the lock link compression spring of FIG. 76.
[0094] [0094]FIG. 78 is a rear elevation view of the lock link compression spring of FIG. 76.
[0095] [0095]FIG. 79 is a top plan view of the lock link compression spring of FIG. 76.
[0096] [0096]FIG. 80 is a left side elevation view of the lock link compression spring of FIG. 76.
[0097] [0097]FIG. 81 is a bottom plan view of the lock link compression spring of FIG. 76.
[0098] [0098]FIG. 82 is a front elevation view of the lock link compression spring of FIG. 76.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0099] Reference now being made to FIGS. 1 - 7 , where a double-hinge console latch 1 is shown in alternative views. In FIGS. 1 - 7 , the double-hinge console latch 1 is shown in a neutral position. The double-hinge console latch assembly 1 comprises a front end 107 ; a back end 106 ; a driver's side 108 ; a passenger's side 109 ; a lid substrate 2 ; a plurality of slide pins 4 , designated in the preferred embodiment as four slide pins shown as slide pin 4 a , 4 b , 4 c , 4 d ; a plurality of buttons 5 , designated in the preferred embodiment as two buttons shown as button 5 a , 5 b ; a lock link 6 , a plurality of rotary links 7 , designated in the preferred embodiment as two lock links shown as rotary link 7 a , 7 b ; a plurality of extension springs 8 , designated in the preferred embodiment as two extension springs shown as extension spring 8 a , 8 b ; and a plurality of angled triggers 9 , designated in the preferred embodiment as two angled triggers 9 a (shown) and 9 b (not shown). The double-hinge console latch is shown comprising a driver's side and a passenger's side, wherein the passenger's side mirrors the driver's side. The lid substrate 2 connects to the buttons 5 a , 5 b , which are connected to the slide pins 4 b , 4 d respectively. The slide pins 4 b , 4 d are connected to the rotary links 7 a , 7 b respectively, which are connected to the lid substrate 2 . The rotary links 7 a , 7 b are also connected to slide pins 4 a , 4 c respectively.
[0100] In the neutral position, as shown in FIGS. 1 - 7 , neither the driver's side button 5 a , nor the passenger's side button 5 b have been actuated, and in the neutral position a console lid (not shown) which would mount directly on top of the latch assembly would be in a closed position. FIG. 4 shows a left side view cut along line B-B of FIG. 3. In the magnified view shown in FIG. 5, the driver's side button 5 a is shown. In this neutral position, a living spring 78 a attached to the button 5 a is shown. The living spring 78 a terminates at a contact end 10 , wherein said living spring is capable of flexing. Also shown in FIG. 5 is the angled trigger 9 a , wherein said angled trigger 9 a is fixably attached to a console bin (not shown).
[0101] Next, reference is made to FIGS. 8 - 14 , which shows the driver's side button 5 a being actuated, thus the latch assembly is said to be in a driver semi-open position. In these views, the button 5 a is actuated, thereby causing lateral movement of button 5 a in a direction cc. This lateral movement causes lateral movement of slide pin 4 b also in the direction cc. This lateral movement further causes said rotary link 7 a to rotate counter-clockwise, thereby causing said lock link 6 to move in a direction bb towards the passenger's side, and also causing slide pin 4 a to move in a direction aa. An extension spring 8 , shown on the driver's side as 8 a , attaches said rotary link 7 a to the lid substrate 2 , whereby rotational movement of said rotary link 7 a causes said extension spring 8 to extend or expand. In FIG. 2, the extension springs 8 a , 8 b shown, are in the neutral position, thus there is no expansion or extension of said extension springs 8 a , 8 b . Furthermore, in this position, said extension springs 8 a , 8 b do not cross a center hole 60 in the rotary links 7 a , 7 b , and said extension springs 8 a , 8 b remain on a side closer to the driver's side and passenger's side respectively. However, in FIG. 9, extension spring 8 a is shown in a state of extension, such that said extension spring 8 a begins to articulate across the center hole 60 of the rotary link 7 a. FIG. 12 shows a magnified view of FIG. 11, which is a left side elevation view of the latch assembly in the semi-open position. In FIG. 12, it is seen that button 5 a is actuated in a direction cc. It can be seen that button 5 b remains in the neutral position. In the driver semi-open position, the living spring 78 a begins to flexibly bend such that contact end 10 is in full contact with the angled trigger 9 a. Thus, angled trigger 9 a creates a trigger force upon contact end 10 , thus causing the living spring 78 a to bend.
[0102] Referring now to FIGS. 15 - 21 , shows the driver's side button 5 a being fully actuated, thus the latch assembly is said to be in a driver open position. In these views, the button 5 a is fully actuated, thereby causing full lateral movement of slide pin 4 b in a direction cc, and full lateral movement of slide pin 4 a in a direction aa. This full lateral movement further causes said rotary link 7 a to further rotate counter-clockwise, thereby causing said lock link 6 to move further in a direction bb towards the passenger's side. An extension spring 8 , shown on the driver's side as 8 a , attaches said rotary link 7 a to the lid substrate 2 , whereby rotational movement of said rotary link 7 a causes said extension spring 8 to extend or expand. In FIG. 16, extension spring 8 a is shown in a state of full extension, such that said extension spring 8 a articulates across the center hole 60 of the rotary link 7 a. FIG. 19 shows a magnified view of FIG. 18, which is a left side elevation view of the latch assembly in the driver open position. In FIG. 19, it is seen that button 5 a is fully actuated in a direction cc. It can be seen that button 5 b remains in the neutral position. In the driver open position, the living spring 78 a is no longer in contact with the angled trigger 9 a. Thus, angled trigger 9 a has articulated in a direction dd, and the latch assembly remains in this driver open position, until the console lid, including the latch assembly, is closed by slam-action, which returns the button 5 a back into the neutral position.
[0103] Reference is now made to FIGS. 22 - 25 . In these figures, the passenger's side button 5 b being fully actuated, thus the latch assembly is said to be in a passenger open position. In these views, the button 5 b is fully actuated, thereby causing full lateral movement of slide pin 4 d in a direction cc, and full lateral movement of slide pin 4 c in a direction aa. This full lateral movement further causes the rotary link 7 b to rotate counter-clockwise, thereby causing said lock link 6 to move further in a direction ee towards the driver's side. The extension spring 8 , shown on the passenger's side as 8 b , attaches said rotary link 7 b to the lid substrate 2 , whereby rotational movement of said rotary link 7 b causes said extension spring 8 to extend or expand. In FIG. 23, extension spring 8 b is shown in a state of full extension, such that said extension spring 8 b articulates across the center hole 60 of the rotary link 7 b. It can be best seen in FIG. 25 that button 5 b is fully actuated in a direction cc, while button 5 a remains in the neutral position. Although not shown, in the passenger open position, the living spring 78 b is no longer in contact with the angled trigger 9 b. Thus, angled trigger 9 b has articulated in a direction dd, and the latch assembly remains in this passenger open position, until the console lid, including the latch assembly, is closed by slam-action, which returns the button 5 b back into the neutral position.
[0104] FIGS. 30 - 35 detail the slide pin 4 . Slide pin 4 further comprises a generally rectangular middle portion 18 , with an elongated tail portion 16 , and a protruding neck portion 14 . A curved mid section 19 connects the rectangular middle portion 18 to a generally sloped portion 12 , which terminates at a slightly tapered bottom portion 13 , which connects to the pin 11 . Pin 11 terminates with a pair of rounded ends 23 a , 23 b located on opposite sides. The generally rectangular middle portion 18 of the slide pin 4 further includes three generally elongated eyelet holes 20 , 21 , 22 . The tail portion 16 includes an eyelet hole 17 , and the protruding neck portion 14 includes an eyelet hole 15 .
[0105] FIGS. 26 - 29 show the lid substrate 2 . Said lid substrate 2 includes a base 3 , which has molded sub-elements fixably attached to it, which are detailed next. A lock link housing 24 is fixably attached on the base in the middle of the lid substrate 2 . Said lock link housing 24 comprises a rear straight wall 41 , a rear angled wall 42 , a front straight wall 43 , a front angled wall 44 , a driver's side end wall 46 , a middle catch wall 45 , and a passenger's side end wall 47 . Said passenger's side end wall 47 comprises two protruding guides 48 , 49 which are perpendicular to said passenger's side end wall 47 , and are contained within said lock link housing 24 . The lid substrate 2 further comprises a pair of living spring holes 25 a , 25 b , which allow the living springs 78 a , 78 b to protrude through the lid substrate and catch with the angled triggers 9 a , 9 b respectively. The lid substrate 2 further includes a plurality of slide pin housings 26 a , 26 b , 26 c , 26 d , which house the slide pins 4 a , 4 b , 4 c , 4 d respectively. Moreover, said slide pin housings 26 a , 26 b , 26 c , 26 d include a pin groove 52 a , 52 b , 52 c , 52 d to slidably guide said slide pins 4 a , 4 b , 4 c , 4 d respectively, and a plurality of slide pin holes 33 a , 33 b , 33 c , 33 d to slidably guide and catch slide pins 4 a , 4 b , 4 c , 4 d respectively. Said slide pin housings 26 a , 26 b further comprises a base 50 ; likewise, said slide pin housings 26 c , 26 d further comprises a base 51 .
[0106] A pair of rotary center posts 27 a , 27 b are also fixably mounted to said lid substrate 2 , wherein said rotary center posts comprise wings 53 , 54 attached to rotary center post 27 a , and wings 55 , 56 attached to rotary center post 27 b. The lid substrate 2 further comprises a pair of extension spring posts 28 a , 28 b ; button guide posts 29 a , 30 a used to guide button 5 a , and corresponding button guide posts 29 b , 30 b used to guide button 5 b ; rotary link post 31 ; rotary link stop post 32 a , 32 b , which terminate the rotational movement of rotary link 7 a , 7 b. The lid substrate also includes a plurality of slide pin housing guides 34 a , 34 b , 34 c , 34 d , which guide the slide pins 4 a , 4 b , 4 c , 4 d respectively. Said slide pin housing guide 34 a further comprises a plurality of slide pin guiding posts 35 a , 36 a , 37 a , which protrude through generally elongated eyelet holes 20 , 22 , 21 respectively of said slide pin 4 . Likewise, said slide pin housing guide 34 b further comprises a plurality of slide pin guiding posts 38 b , 39 b , 40 b , which protrude through generally elongated eyelet holes 21 , 22 , 20 respectively of said slide pin 4 . Moreover, said slide pin housing guide 34 c further comprises a plurality of slide pin guiding posts 38 c , 39 c , 40 c , which protrude through generally elongated eyelet holes 21 , 22 , 20 respectively of said slide pin 4 . Finally, said slide pin housing guide 34 d further comprises a plurality of slide pin guiding posts 35 d , 36 d , 37 d , which protrude through generally elongated eyelet holes 20 , 22 , 21 respectively of said slide pin 4 . Thus said slide pin 4 remains guided within said respective slide pin guiding posts described above.
[0107] FIGS. 37 - 43 fully illustrate the rotary link 7 . Said rotary link 7 , specifically rotary link 7 a , 7 b , comprises a center hole 60 for mounting on rotary center posts 27 a , 27 b of lid substrate 2 . Wherein said rotary link 7 a rests on top of wings 53 , 54 attached to rotary center post 27 a , and said rotary link 7 b rests on top of wings 55 , 56 attached to rotary center post 27 b. Said rotary link 7 further comprises a link 57 ; a notch 58 ; a catch 59 ; a generally circular cam portion 64 ; a plurality of snap posts 61 , 62 , 63 ; and a pair of legs 65 , 66 . Wherein, the underside of snap post 61 comprises a base 67 and a pair of semi-circular openings 67 a , 67 b. Likewise, the underside of snap post 62 comprises a base 68 and a pair of semi-circular openings 68 a , 68 b . Moreover, the underside of snap post 63 comprises a base 69 and a pair of semi-circular openings 69 a , 69 b . Furthermore, snap post 61 further comprises a pair of prongs 61 a , 61 b. Likewise, snap post 62 further comprises a pair of prongs 62 a , 62 b. Finally, snap post 63 further comprises a pair of prongs 63 a , 63 b. The semicircle openings 67 a , 67 b , 68 a , 68 b , 69 a , 69 b allow for support means to be inserted during construction of the rotary link 7 , thereby reinforcing the snap posts 61 , 62 , 63 . The enhanced durability of the prong members 61 a , 61 b , 62 a , 62 b , 63 a , 63 b is preferred due to the pinching and releasing during attachment of the slide pins 4 .
[0108] Upon actuation of button 5 a , said rotary link 7 a rotates counter-clockwise and continues to rotate until catch 59 comes into contact with rotary link stop post 32 a. Similarly, upon actuation of button 5 b , said rotary link 7 b rotates counter-clockwise and continues to rotate until catch 59 comes into contact with rotary link stop post 32 b. Snap post 63 protrudes through eyelet hole 15 of slide pin 4 , thus connecting said rotary link 7 a with slide pin 4 a , and said rotary link 7 b with slide pin 4 d.
[0109] [0109]FIGS. 44 through 50 illustrate the button 5 in further detail, wherein said button comprises an actuation portion 70 and a generally elongated link portion 81 . Said actuation portion 70 further comprises a front surface 71 and a rear surface 72 , wherein the user pushes the button 5 by pushing on the front surface 71 of the actuation portion 70 . Said generally elongated link portion 81 further comprises a front link portion 79 , a center link portion 76 , a rear link portion 80 , a protruding tail section 77 , a living spring eyelet 74 , a button guide eyelet 73 , a rear link eyelet 75 , and said living spring 78 , wherein said living spring 78 protrudes through said living spring eyelet 74 , and is attached to the front link portion 79 of said button 5 . The living spring 78 protrudes through living spring holes 25 a , 25 b of the lid substrate 2 . The button guide posts 29 a , 30 a protrude through said button guide eyelet 73 on button 5 a , wherein the button guide posts 29 b , 30 b protrude through said button guide eyelet 73 on button 5 b , thereby attaching said button 5 a , 5 b to lid substrate 2 . The legs 65 , 66 of the rotary link 7 protrude downward through said rear link eyelet 75 of the button 5 , thereby connecting said button 5 with said rotary link 7 .
[0110] [0110]FIGS. 51 through 54 show alternate views of the double hinge console latch 1 . Moreover, further magnified views of the lock link 6 are shown, as well as a view some of the external and internal components of said lock link 6 . These views show the sequence of the lock link 6 moving towards the passenger's side 109 in a direction bb.
[0111] [0111]FIGS. 55 through 61 illustrate the angled trigger 9 , which is connected to the bin (not shown), and whose function has been described above in relation to the living spring 78 upon actuation of the button 5 . The angled trigger 9 comprises a sloped portion 84 , which comes into and out of contact with the contact end 10 of the living spring 78 . Moreover, the angled trigger further comprises a top wall 85 , a back wall 86 , a front wall 87 , a left side surface 88 , a right side surface 92 , and a bottom wall 93 , wherein a curved portion 90 joins top wall 85 to back wall 86 ; a curved portion 91 joins top wall 85 with sloped portion 84 ; a curved portion 89 joins sloped portion 84 with front wall 87 .
[0112] [0112]FIGS. 62 through 68 illustrate the extension spring 8 , wherein the present invention comprises two extension springs 8 a , 8 b , wherein said extension spring 8 comprises a coiled central portion 94 terminating on each side by a hooks 95 a , 95 b , each connected to the coiled central portion 94 by a straight connecting portion 96 , 97 respectively. Hook 95 a attaches to extension spring post 28 a (and also 28 b for the second extension spring on the passenger's side). Hook 95 b attaches to snap post 62 of rotary link 7 a (and also 7 b for the second extension spring on the passenger's side).
[0113] [0113]FIGS. 69 through 75 further illustrate the lock link 6 . The lock link 6 comprises a push peg 83 , a push end 110 , a top surface 101 , a bottom surface 100 , a straight portion 99 , a generally angled portion 102 , and a stop 98 . Wherein said stop 98 further comprises two angled support legs 103 , 104 . Lock link 6 fits onto said lock link housing 24 of lid substrate 2 . The straight portion 99 of lock link 6 fits within rear straight wall 41 and front straight wall 43 of the lock link housing 24 . A compression spring 82 , comprising coils 105 , further shown in FIGS. 76 through 82, is housed within the protruding guides 48 , 49 located within lock link housing 24 . The compression spring 82 is sandwiched between the passenger's side end wall 47 of the lock link housing 24 and the stop 98 of the lock link 6 . The generally angled portion 102 of the lock link 6 fits within rear angled wall 42 and front angled wall 44 of the lock link housing 24 .
[0114] When the button 5 a is actuated, on the driver's side, causing rotary link 7 a to rotate, the link 57 of rotary link 7 a pushes against push end 110 of the lock link 6 thereby causing the lock link 6 to move in a direction bb towards the passenger's side. This movement allows the push peg 83 of the lock link 6 to move into notch 58 of rotary link 7 b on the passenger's side, thereby preventing rotary movement of rotary link 7 b , and causing the passenger's side of the latch assembly to remain in a neutral or locked position, and thus causing components of the passenger's side of the latch assembly to act merely as a hinge to allow the opening of the console lid. This is best seen in FIGS. 51 through 54.
[0115] These and other advantages of the present invention will be understood upon a reading of the Summary of the Invention, the Brief Description of the Drawing Figures and the Detailed Description of the Preferred Embodiment. Other modifications may be made consistent with the spirit and scope of the invention described herein. | The double hinged latch is an ambidextrous latch having corresponding activation means substantially parallel on either side of a lid substrate. During activation, a slide member drives a rotary linkage, which in turn disengage slide pins from the housing. Simultaneously, a lock link is driven by a rotary link, to secure the opposite rotary link, thereby locking the second side slide pins within the housing thereby being used as hinge. The slide members are biased by a living spring with aperture located therein. Engagement is biased by a compression spring attached to the rotary linkages. |
CLAIM OF PRIORITY
[0001] This application claims priority to U.S. Application No. 61/654,945, filed Jun. 3, 2012, of which is incorporated by reference in its entirety.
GOVERNMENT SPONSORSHIP
[0002] This invention was made with government support under Contract No. N00014-09-1-1000 awarded by the U.S. Navy. The government has certain rights in this invention.
TECHNICAL FIELD
[0003] The present invention relates to heterogeneous surfaces.
BACKGROUND
[0004] Superhydrophobic surfaces have received significant interest for dropwise condensation to increase the efficiency of energy applications such as heat exchangers, power plants, and solar thermal energy conversion systems. However, nucleation densities on regular superhydrophobic surfaces are difficult to achieve due to the high energy barrier for nuclei formation and hence enhancement of heat transfer can be limited.
SUMMARY
[0005] In general, heterogeneous surface structures can be made by infusing microstructured surfaces with low-surface tension oil, which lead to nucleation densities that were increased by over an order of magnitude while maintaining low droplet adhesion. The approach offers a simple and scalable approach to create surfaces that can be tailored for enhanced heat transfer.
[0006] In one aspect, a superhydrophobic surface can include a patterned substrate having a surface including a plurality of first regions distributed in a second hydrophobic region, the first regions including a surface modifying layer and the second hydrophobic region including a material infused into regions of the substrate. The first regions can have hydrophobic features and hydrophilic features.
[0007] In another aspect, a method of increasing nucleation density on a surface can include infusing a material into regions of a patterned substrate to form a surface including a plurality of first regions distributed in a second hydrophobic region, the first regions including a surface modifying layer and the second hydrophobic region including a material infused into regions of the substrate.
[0008] In certain embodiments, the patterned substrate can include a periodic structure on the surface of the substrate that form the regions of the substrate into which the material is infused. The first regions can be associated with the pattern of the patterned substrate. The periodic structure can be a micropillar or microcolumn.
[0009] In certain embodiments, the surface modifying layer can include a functionalized silane. In certain circumstances, the surface modifying layer can include a plurality of scattered hydrophilic sites while exhibiting overall hydrophobicity.
[0010] In other embodiments, the material can be an oil or wax. The oil can be a fluorinated oil.
[0011] Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A to 1D represent atomic force microscopy images of surfaces.
[0013] FIGS. 2A and 2B represent micrographs of a patterned surface and a patterned surface including an infused material.
[0014] FIGS. 3A to 3D represent a diagram and micrographs of surfaces showing condensation.
[0015] FIG. 4 represents a graph depicting condensation nucleation on surfaces.
[0016] FIG. 5 represents a graph depicting condensation nucleation rates.
[0017] FIGS. 6A and 6B represent micrographs depicting condensation on a patterned surface including an infused material.
[0018] FIGS. 7A to 7C represent a series of graphs and micrographs depicting parameters affecting condensation heat transfer coefficient on a flat surface.
[0019] FIGS. 8A to 8K represent diagrams, micrographs, and a graph depicting mechanism of immersion condensation.
[0020] FIGS. 9A to 9D are micrographs depicting scalable copper oxide surfaces for immersion condensation. FIGS. 9E and 9F are photographs depicting dropwise condensation on copper oxide surfaces.
[0021] FIG. 10 is a graph depicting experimental immersion condensation heat transfer measurement.
[0022] FIGS. 11A , 11 B and 11 C are schematics showing the relations between interfacial energies and contact angle using Young's equation.
[0023] FIG. 12A is AFM height images of flat silicon surfaces coated with DMCS. FIG. 12B is a graph depicting comparison of nucleation densities on surfaces with TFTS and DMCS coatings.
[0024] FIG. 13 is a schematic of experimental setup inside the chamber.
[0025] FIG. 14A is a series of photographs depicting droplet shedding radii on a dropwise hydrophobic surface. FIG. 14B is a series of photographs depicting droplet shedding radii on a Krytox oil-infused immersion condensation surface.
DETAILED DESCRIPTION
[0026] Condensation heat transfer has wide applications in various systems such as heat exchangers, heat pipes and power plants. The heat transfer coefficient of condensation is of great significance to the efficiency of such systems. Dropwise condensation, where the condensate forms discrete droplets rather than continuous films covering the substrate, is considered as one of the most promising approaches to enhance the heat transfer coefficient. Previous work has demonstrated the application of nanostructured superhydrophobic surfaces where condensate can be spontaneously removed via a surface-tension-driven mechanism. See, for example, J. B. Boreyko and C. -H. Chen, “Self-Propelled Dropwise Condensate on Superhydrophobic Surfaces”, PRL, 2009. 103(18): p. 184501, which is incorporated by reference in its entirety. However, the nucleation density on these surfaces is relatively low since the phase change process relies on high energy active sites to initiate nucleation at low supersaturations (low ΔT), limiting the overall heat transfer performance. Furthermore, air pockets trapped beneath the droplets during growth reduce the contact area between the condensing droplet and substrate, which increases the thermal resistance and reduces the heat transfer coefficient. See, for example, N. Miljkovic, R. Enright, and E. N. Wang, “Effect of Droplet Morphology on Growth Dynamics and Heat Transfer during Condensation on Superhydrophobic Nanostructured Surfaces”, ACS Nano, 2012 6(2): p. 1776-1785, which is incorporated by reference in its entirety.
[0027] Recently, Wong et al. demonstrated a liquid-solid composite surface created by infusing a porous fluoropolymer with water-immiscible, low-surface-tension Krytox oil. See, for example, T. -S. Wong, S. H. Kang, S. K. Y. Tang, E. J. Smythe, B. D. Hatton, A. Grinthal and J. Aizenberg, “Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity”, Nature, 2011. 477: p. 443-447, which is incorporated by reference in its entirety. On such a composite surface, the contact area between droplet and substrate can be large while contact line pinning remains very low allowing easy removal of droplets. These properties make the surfaces potentially suitable for enhanced condensation heat transfer. While such behavior is possible with the proper choice of silane, e.g., dichlorodimethylsilane on SiO 2 , the nucleation density is limited by the presence of high surface energy defects and contaminants at low supersaturations (low ΔT). The nucleation density on oil-infused, silane-coated structured surfaces can be significantly increased by the use of disordered long-chain silane coatings that result in nucleation sites limited only by the density of pillar structures comprising the surface. The increase in the nucleation density can be explained by heterogeneity in the surface energy of the silane coating and the reduced water-oil interfacial energy. This effect could potentially be used to significantly improve the heat transfer coefficient in condensation by controlling the nucleation density.
[0028] The surfaces described herein can increase the nucleation density during condensation process while maintaining the easy removal of condensate to enhance condensation rates. In order to achieve this, the surface can include three components. The first is a surface coating which is overall hydrophobic with local nanometer or micrometer scale hydrophilic sites, which create a heterogeneous surface structure. The purpose of the heterogeneity is to provide nucleation sites for condensation to happen while the overall hydrophobicity allows the easy removal of the condensate. The second is a filling fluid which is immiscible with the condensate and has low interfacial tension with the condensate. The filling serves for two purposes: providing a reduced interfacial tension between the condensate and the oil to reduce the energy cost of condensation; and help to remove the condensate from the substrate. The third component is micrometer or nanometer scale roughness to enhance the wetting of the filling fluid.
[0029] In particular, a superhydrophobic surface can be formed on a substrate from a pattern on the surface of a substrate. The pattern can be formed from a plurality of structures on the substrate. The structures can have nanometer sized or micrometer sized features. The features can be bumps, columns, pillars, channel, or trough. The features can be periodically spaced on the surface. For example, the features can be less than 10 micrometers, less than 5 micrometers, less than 2 micrometers, less than 1 micrometer, less than 0.5 micrometers, or less than 0.1 micrometers in width. The features can be spaced in intervals of about 0.5 micrometer, 1 micrometer, 2 micrometers, 5 micrometer, 10 micrometers or 20 micrometers, or more, from each other on the surface. The features can have a height of about 0.5 micrometer, 1 micrometer, 2 micrometers, 5 micrometer, 10 micrometers or 20 micrometers. In certain circumstances, the features are etched or machined from the substrate. In other circumstances, one or more feature can be grown or deposited on the surface of the substrate.
[0030] Once the patterned substrate has been formed, the surface can be coated with one or more coating layers. The coating layer can be selected to impart desired properties on the surface, such as, for example, mechanical robustness or increased hydrophobicity, or both. For example, the superhydrophobic surface can include a surface modifying layer on at least a portion of the nanostructures. The surface modifying layer can be a single layer or a multilayer. For example, an initial coating layer, e.g., a metallic layer can be deposited by (for example) electroless plating, chemical vapor deposition or atomic layer deposition. The initial coating layer can be a polymer or a metal. The surface modifying layer can be a hydrophobic material, such as a polymer or self-assembled monolayer, directly on the nanostructure or on the initial coating layer. For example, a silane or a thiol can be assembled on a surface. The hydrophobic material; e.g., a hydrophobic polymer, hydrophobic thiol, hydrophobic carboxylic acide or hydrophobic silane, can include hydrocarbon (e.g., a saturated hydrocarbon) groups, halohydrocarbon groups (e.g., a saturated fluorohydrocarbon), or halocarbon groups (e.g., a perfluorinated alkyl group). In certain examples, the hydrophobic material can be trichloro(1H,1H,2H,2H-perfluorooctyl) silane, (tridecafluoro-1,1,2,2-tetrahydrooctyl)-1-trichlorosilane, (1H,1H,2H,2H-perfluorodecyl acrylate), a Teflon amorphous fluoropolymer resin, or an alkyl or fluoroalkyl thiol deposited by appropriate techniques. The hydrophobic material can have C 2 -C 18 groups that can be fluorinated to varying degrees. The trifluoromethyl or difluoromethyl groups on the surface can allow the surface properties to be tailored, for example, to have advancing wetting angles of 105, 110, 115 or 120 degrees, depending on the choice of fluorinated alkyl group and base structure. The coatings can have a plurality of hydrophilic sites scattered in the overall hydrophobic background. The size of the hydrophilic sites can be 10 nanometer, 100 nanometer or 500 nanometer. The fraction of hydrophilic sites can be 1%, 5%, 10% or 40%. The local contact angles of the hydrophilic sites can be 50-70 degrees.
[0031] The surface modified patterned substrate can then be infused with a material. The infusion of the material can include drop coating, dip coating or roll coating the surface with the material. The material can be an oil, for example a fluorinated oil, or low melting point solid, such as a wax. The material can be a low surface tension material, which can allow it to infuse the pattern readily and completely.
[0032] For example, FIG. 1A represents an atomic force microscope (AFM) image of an example heterogeneous surface created by silane deposition on silicon surface. The bright spots in the image are hydrophilic sites. The local contact angle of water on the hydrophobic area is around 122° and the contact angle on the hydrophilic sites is around 60°. The overall advancing and receding contact angle on the whole surface is 122° and 78°, respectively.
[0033] Oil-impregnated surfaces have been recently reported as a promising approach to enhance condensation heat transfer surfaces due to the ultra-low droplet adhesion. However, easy droplet removal is not the only desired property for high heat transfer performance. Low contact angle and high nucleation densities are also essential to further enhance condensation heat transfer. By combining surface heterogeneity and oil-infusion, the nucleation density in condensation can be increased by over an order of magnitude via immersion condensation while maintaining low droplet adhesion. The increase in nucleation densities via the a combined effect of heterogeneity and the reduced oil-water interfacial tension was explained by this disclosure based on classical nucleation theory, which were also corroborated with control experiments using silane-coated silicon micropillar arrays. With improved understanding of the physics, oil-infused superhydrophobic copper oxide surfaces as a platform for condensation enhancement in practical systems were investigated. The condensation heat transfer coefficient on such oil-infused heterogeneous surfaces can be enhanced by approximately 100% compared to state-of-the-art dropwise surfaces in the presence of non-condensables gases. An order of magnitude increase in nucleation density could contribute to approximately 80% increase in the overall heat transfer coefficient. Meanwhile, the low departure radii and low contact angle also assisted in the total improvement. Achieving the three key aspects of condensation simultaneously can be important to realize heat transfer enhancement by as high as 100%. Further work is needed to tailor oil and coating properties, as well as surface geometry to minimize oil loss during operation and maximize condensing surface area. With continued development, immersion condensation promises to be an important condensation mode for a variety of heat transfer and resource conserving applications.
Fabrication
[0034] Well-defined silicon micro/nanopillar arrays with diameters, d, ranging from 0.4 μm to 5 μm, periods, l, ranging from 4 μm to 25 μm, and heights, h ranging from 10 μm to 25 μm were used in these experiments. The silicon surfaces were functionalized with three different chemicals: 1) (Tridecafluoro-1,1,2,2-tetrahydrooctyl)-1-trichlorosilane (TFTS) (UCT Specialties), which forms a self-assembled coating (SAC) by chemical vapor deposition (CVD) with a relatively long carbon chain (MW=481.54 g/mol), 2) Dimethyldicholorosilane (DMCS) (Sigma-Aldrich), which forms a self-assembled monolayer (SAM) by CVD with a short carbon chain (MW=129.06 g/mol), and 3) Poly(1H, 1H, 2H, 2H-perfluorodecyl acrylate) (PFDA) polymer, which was deposited using initiated chemical vapor deposition (iCVD) with a typical film thickness of 35 nm. Goniometric measurements on smooth functionalized silicon surfaces showed advancing and receding contact angles of: θ a /θ r =122°±1.3°/78°±1.3° (equilibrium contact angle θ e ≈102.1°±0.9°); θ a /θ r =103.8°±0.5°/102.7°±0.4° (θ e ≈103.2°±0.3°); and θ a /θ r =121.1°±2.2°/106.3°±2.4° (θ e ≈113.5°±1.6°) for deposited films of TFTS, DMCS, and PFDA respectively. A small droplet of Krytox GPL 100 oil (DuPont) was applied to the functionalized silicon pillar arrays. The surface tension of Krytox oil is ˜17-19 mN/m, allowing the oil to spread on the surface. A dry nitrogen stream was used to assist spreading and remove excess oil. Typical scanning electron micrographs (SEM) of the silicon pillar arrays without and with the oil are as shown in FIGS. 2A and 2B , which are scanning electron micrographs (SEM) of a pillar-structured silicon surface (d=5 μm, 1=25 μm, h=15 μm) (a) without and (b) with the oil infusion.
[0035] The nucleation behavior on the surfaces with and without the oil were investigated under white light optical microscopy (OM). The samples were horizontally mounted on a thermal stage (Instec Inc.) inside an enclosure and cooled to T w =283.1±0.1K in a dry nitrogen atmosphere. Following thermal equilibration (˜5 min), nucleation was initiated by flowing water-saturated nitrogen into the enclosure. The supersaturation, defined as the ratio of the vapor pressure to the saturation pressure at the stage temperature (p v /p w ), was controlled by the temperature of the water reservoir through which the nitrogen carrier gas was sparged and measured using a humidity probe (Hygroclip, Rotronic) located ˜1 cm above the sample. Typical values of the supersaturation were around S≈1.6. The nucleation density and subsequent growth behavior was recorded at a frame rate of 30 fps using a CMOS camera (Phantom V7.1, Vision Research) attached to the optical microscope.
[0036] Referring to FIG. 3A , a schematic drawing illustrates the nucleation on the oil-infused surface.
[0037] As shown in FIGS. 3B and 3C , the nucleation density on oil-infused surface with long-chain TFTS coating was significantly higher than that on the same surface without oil. Specifically, FIG. 3B represents a white-light microscopy image of condensation on a silicon pillar array without oil, with nucleation sites highlighted by circles. FIG. 3C represents white-light microscopy image of condensation on a composite surface with oil. Nucleation occurred on the tip of almost every pillar. Nucleation between pillars was not observed, which can be attributed to the large thickness of oil coverage between pillars that introduces a large diffusion resistance for water vapor. However, a droplet was formed on the tip of almost each pillar where the oil film was thin enough to allow sufficient mass to diffuse to the functionalized silicon surface. Referring to FIG. 3D , white-light microscopy image highlights the removal of the condensate. The condensate (water in this case) can be easily absorbed into the oil.
[0038] Meanwhile, on pillar arrays coated with DMCS and PFDA, similar increases in nucleation density were not observed, as shown in FIG. 4 . Specifically, FIG. 4 represents a comparison of the change in nucleation density with various surface coatings. The nucleation densities were normalized against pillar densities for a fair comparison.
AFM Imaging and Contact Angle Analysis
[0039] To investigate the mechanism for this drastic change in nucleation density, atomic force microscopy (AFM) was performed in tapping mode on a smooth TFTS-coated silicon surface and observed the presence of micelle structures, as shown in FIG. 1A . Such micelle structures have been observed in previous studies and considered as disordered agglomeration of excessive silane molecules. See, for example, B. C. Bunker, R. W. Carpick, R. A. Assink, M. L. Thomas, M. G. Hankins, J. A. Voigt, D. Sipola, M. P. de Boer, and G. L. Gulley, “The Impact of Solution Agglomeration on the Deposition of Self-Assembled Monolayers”, Langmuir, 2000, 16 (20), pp 7742-7751, which is incorporated by reference in its entirety. The phase image of the AFM measurement ( FIG. 1D ) showed significantly higher phase angle on the micelle structures, which suggests that the micelles were locally more hydrophilic compared to the background film. Such heterogeneity was also supported by the high contact angle hysteresis (θ a /θ r =122°±1.3°/78°±1.3°). However, such micelle structures were not observed on other kinds of surface coatings such as DMCS and PFDA, as shown in FIG. 1B and 1C . Specifically, FIG. 1 depicts atomic force microscopy (AFM) height images of smooth silicon surfaces coated with ( FIG. 1A ) TFTS, ( FIG. 1B ) DMCS, and ( FIG. 1C ) PFDA. Micelles structures were only observed on TFTS coated surfaces. FIG. 1D depicts AFM phase image of smooth silicon surface coated with TFTS. The local high phase angle indicates higher hydrophilicity of micelles.
[0040] The local contact angles on the hydrophobic substrate and the micelle structures can be determined based on a modified Cassie-Baxter model. Assuming the local contact angles on the hydrophobic substrate and the micelle structures to be θ 1 and θ 2 , respectively, the macroscopic advancing and receding contact angles are determined as
[0000] θ a =θ 1 , (1)
[0000] cos θ r =√{square root over (f)} cos θ 2 ÷(1 −√{square root over (f)} ) cos θ 1 , (2)
[0000] where f is the area fraction of the micelles.
[0041] Based on the macroscopically measured advancing and receding angles, θ a =122°±1.3° and θ r =78°±1.3°, and the fraction of the micelles determined as f≈0.4 from AFM, the local contact angles on the hydrophobic substrate and the hydrophilic micelles were found to be θ 1 =122°±1.3° and θ 2 =60°±1.5°.
Nucleation Theory
[0042] The nucleation rate, J, can be determined by classical nucleation theory (CNT) as (D. Kashchiev, Nucleation: Basic Theory with Applications. 1 ed. 2000, Oxford: Butterworth-Heinemann, which is incorporated by reference in its entirety)
[0000] I=zf *exp(− G *) (3)
[0043] In Eqn. (3), z is the Zeldovich factor and G* is the dimensionless energy barrier, given by
[0000] z =( kT In S ) 2 /aπv o √{square root over ( kTψ (θ) y 2 )} (4)
[0000] G* =16πψ(θ) v o 2 y 2 /3( kT ) 2 (In S ) 2 (5)
[0044] where S is the supersaturation and is the activity that accounts for the effect of contact angle. f* is the frequency of monomer attachment to the critical droplet nucleus dependent on the nature of the nucleus growth. The main modes of growth during heterogeneous nucleation are limited via surface diffusion or direct impingement of monomers to the nucleus. See, for example, G. M. Pound, M. T. Simnad, and L. Yang, “Heterogeneous nucleation of crystals from vapor” J. Chem. Phys., 1954. 22(1215) and R. A. Sigsbee, “Atom capture and growth rates of nuclei”, JAP, 1971. 42(10): p. 3904-3915, each of which is incorporated by reference in its entirety. Volumetric diffusion is a third growth limiting step, which is only considered important for nucleation taking place in liquid or solid solutions. See, for example, D. Kashchiev, Nucleation: Basic Theory with Applications. 1 ed. 2000, Oxford: Butterworth-Heinemann, which is incorporated by reference in its entirety. However, all three mechanisms were included when calculating the nucleation rates.
[0045] The frequency of monomer attachment due to direct vapor impingement is given by
[0000] f* l =y n [(1−cos(θ w ))/2ψ 2/3 (θ)](36 πv o 2 ) 1/3 In 2/3 (6)
[0000] where y n is the sticking coefficient (0<y n <1), I is the classical Hertz-Knudsen impingement rate I=P/√{square root over (2πm o kT)})), n is the number of molecules in the nucleated cluster, and v o is the volume of an individual water molecule (v o =3×10 −29 m 3 ). To determine an upper bound on the nucleation rate, a sticking coefficient of one was assumed (y n =1).
[0046] The frequency of monomer attachment due to surface diffusion is given by f* sd =v n c*λ s 2 I, where c* is the capture number due to surface diffusion (1<c*<5), and λ s is the mean surface diffusion distance of an adsorbed monomer on the substrate. The capture number c* is size independent and approximately equal to 1.9 for heterogeneous condensation of water vapor. See, for example, D. J. Pocker, and S. J. Hruska, “Detailed calculations of the number of distinct sites visited in random walk on several two-dimensional substrate lattices.” J. Vac. Sci. Tech., 1971. 8(6): p. 700-707, which is incorporated by reference in its entirety. The mean surface diffusion distance is dependent on the wettability of the substrate and is given by λ s =√{square root over (D ad τ d )} where D sd is the surface diffusion coefficient (D ad =d s 2 v s exp[−E sd /kT]), τ d is the desorption time (τ d =(1/v s )exp[−E dss /kT]), v s is the adsorbed molecule vibration frequency determined using the Debye approximation (v s =v D α/2), d s is the length of a molecular jump along the substrate surface approximated by the lattice constant of the substrate (d s =5.4 A) (J. P. Hirth, and G. M. Pound, Condensation and evaporation—nucleation and growth kinetics. 1963, England: Pergamon Press, which is incorporated by reference in its entirety) and V D is the speed of sound in the substrate (V D =8433 m/s). The desorption and surface diffusion energies are given by E des =E 1 ÷σ sv α o and E sd =0.5E des (P. A. Thiel, and T. E. Madey, “The interaction of water with solid surfaces: Fundamental aspects.” Surface Science Reports, 1987. 7(6-8): p. 211-385, which is incorporated by reference in its entirety), respectively, where E 1 is the binding energy of an n=1 sized cluster, σ sv is the solid vapour interfacial energy and α o is the water molecule surface area (α 0 =4.67×10 −19 m 2 ). The calculated energies of desorption show excellent agreement with that of experiment and molecular dynamics simulations (E des, SiO2 =0.9 eV). See, for example, J. N. Israelachvili, Intermolecular and surface forces. 2nd ed. 1991, Amsterdam: Academic Press and Y. Ma, A. S. Foster, and R. M. Nieminen, “Reactions and clustering of water with silica surface”. J. Chem. Phys., 2005. 122(144709), which is incorporated by reference in its entirety.
[0047] The frequency of monomer attachment due to volumetric diffusion is given by
[0000]
f
vd
*
=
γ
B
(
1
-
cos
θ
W
ϕ
1
/
2
)
(
6
π
2
v
o
)
1
/
2
DCn
1
/
2
(
7
)
[0000] where D is the self diffusion coefficient of water vapor (D=3/aπn o d o 2 )√{square root over (kT/πm o )}), C is the equilibrium concentration of monomers (c=(1/α o )exp(−w 1 /kT)), d o , m o and n o are the water molecule diameter (d o =3.0 Å) (J. N. Israelachvili, Intermolecular and surface forces. 2nd ed. 1991, Amsterdam: Academic Press, which is incorporated by reference in its entirety), mass (m o =3×10 −26 kg) (D. Kashchiev, Nucleation: Basic Theory with Applications. 1 ed. 2000, Oxford: Butterworth-Heinemann, which is incorporated by reference in its entirety) and number density (n o =N A /v M ), respectively.
[0048] By adding the nucleation rate from the three mechanisms together, the nucleation rate, J, can be determined as a function of the contact angle and surface tension of the condensate at given supersaturations, as shown in FIG. 5 . FIG. 5 depicts nucleation rate predicted by the classical nucleation theory as a function of contact angle and interfacial tension at S=1.6.
[0049] The surface tension of water in air is 72 mN/m and the interfacial tension between water and the Krytox oil was found to be 58 mN/m by measuring the contact angle of water droplet on oil film. From FIG. 5 it can be seen that for the hydrophilic micelles (θ≈60°), the reduced interfacial tension between water and oil leads to a significant increase in the nucleation rate. With the micelles acting as nucleation sites, nucleation was supposed to occur on almost every pillar tip where the oil film was thin enough for water vapor to diffuse through. On surfaces without the micelles, such as DMCS and PFDA-coated surfaces, the contact angles are over 100° and the nucleation rate was essentially zero even with reduced interfacial tension.
[0050] In order to validate this assumption, condensation experiments were carried out using silicon pillar arrays coated with 3-(trimethoxysilyl)propyl methacrylate (3-TMPM). The advancing and receding contact angle of water on a smooth silicon surface coated with 3-TMPM are 65°±1.5° and 53°±1.1°, respectively. The contact angle is in the range where the nucleation rate will be almost zero with a surface tension of 72 mN/m and nucleation should occur on every tip of pillars with an interfacial tension of 58 mN/m. Optical images of the condensation experiments are as shown in FIGS. 6A and 6B . Similar to the behavior of TFTS-coated surface, a significant increase in nucleation density was observed with the addition of Krytox oil as expected. This result supports well the hypothesis related to the role of the hydrophilic micelle structures in the droplet nucleation process. FIGS. 6A and 6B depict optical microscope images of the condensation experiments on 3-TMPM coated silicon pillar arrays ( FIG. 6A ) without (N=6.7×10 8 m −2 ) and ( FIG. 6B ) with Krytox oil (N=1.7×10 10 m −2 ). Nuclei are highlighted by circles in FIG. 6A and pillars without nucleation were highlighted by circles in FIG. 6B . The pillars have diameters of 2.5 μm, periods of 7.5 μm and heights of 25 μm (1 −2 =1.7×10 10 m −2 ).
Heat Transfer Coefficient
[0051] In practice, filmwise condensation, where a thin liquid film covers the surface, is the most prevalent condensation mode due to the high wettability of common heat transfer materials. In this condensation mode, the heat transfer coefficient is limited by the thermal resistance associated with the condensate film which insulates the surface. See Mills, A. F. Heat and Mass Transfer. 2 edn, (Prentice-Hall, 1999), which is incorporated by reference in its entirety. Accordingly, efforts spanning eight decades have been devoted to the realization of non-wetting surfaces for dropwise condensation where shedding droplets clear the surface for droplet re-nucleation/re-growth, leading to enhanced heat transfer rates. See Schmidt, E., Schurig, W. & Sellschopp, W. Versuche über die Kondensation von Wasserdampf in Film-und Tropfenform. Forschung im Ingenieurwesen 1, 53-63, (1930), Tanner, D. W., Potter, C. J., Pope, D. & West, D. Heat transfer in dropwise condensation—Part I The effects of heat flux, steam velocity and non-condensable gas concentration. International Journal of Heat and Mass Transfer 8, 419-426, (1965), O'Neill, G. A. & Westwater, J. W. Dropwise condensation of steam on electroplated silver surfaces. International Journal of Heat and Mass Transfer 27, 1539-1549, (1984), Boreyko, J. B. & Chen, C. -H. Self-Propelled Dropwise Condensate on Superhydrophobic Surfaces. Phys Rev Lett 103, 184501 (2009), Chen, C. -H. et al. Dropwise condensation on superhydrophobic surfaces with two-tier roughness. Appl Phys Lett 90, 173108-173103 (2007), and Le Fevre, E. J. & Rose, J. W. An experimental study of heat transfer by dropwise condensation. International Journal of Heat and Mass Transfer 8, 1117-1133, (1965), each of which is incorporated by reference in its entirety. One order of magnitude higher heat transfer coefficients compared to filmwise condensation have been reported using dropwise condensation in pure vapor environments. See Daniel, S., Chaudhury, M. K. & Chen, J. C. Fast Drop Movements Resulting from the Phase Change on a Gradient Surface. Science 291, 633-636, (2001), which is incorporated by reference in its entirety. In order to maximize the heat transfer coefficient, a high performance dropwise condensation surface should simultaneously achieve three properties: low contact angle hysteresis to minimize droplet departure radii, low contact angle to reduce the conduction resistance of the droplet, and high nucleation density (see Miljkovic, N., Enright, R. & Wang, E. N. Effect of Droplet Morphology on Growth Dynamics and Heat Transfer during Condensation on Superhydrophobic Nanostructured Surfaces. Acs Nano 6, 1776-1785, (2012), which is incorporated by reference in its entirety), as shown in FIG. 7 . Recently, investigations have focused on understanding how chemically modified micro/nanostructured surfaces can achieve superhydrophobicity to allow droplets in a stable Cassie wetting state (see Cassie, A. B. D. & Baxter, S. Wettability of porous surfaces. T Faraday Soc 40, 0546-0550, (1944), which is incorporated by reference in its entirety), which further improves droplet mobility and reduces the departure radii ( FIG. 7A ). See Enright, R., Miljkovic, N., Al-Obeidi, A., Thompson, C. V. & Wang, E. N. Condensation on Superhydrophobic Surfaces: The Role of Local Energy Barriers and Structure Length Scale. Langmuir 28, 14424-14432, (2012) and Rykaczewski, K. et al. How nanorough is rough enough to make a surface superhydrophobic during water condensation? Soft Matter 8, 8786-8794 (2012), each of which is incorporated by reference in its entirety. In certain cases, these surfaces enable surface-tension-driven droplet jumping at micron length scales. See Miljkovic, N. et al. Jumping-Droplet-Enhanced Condensation on Scalable Superhydrophobic Nanostructured Surfaces. Nano Lett 13, 179-187, (2012), which is incorporated by reference in its entirety. However, this focus on increasing the apparent hydrophobicity to reduce droplet departure radii does not necessarily address the other two aspects influencing condensation heat transfer rates. The high apparent contact angles of condensing droplets on superhydrophobic surfaces lead to an increase in the conduction resistance through the droplet (see Kim, S. & Kim, K. J. Dropwise Condensation Modeling Suitable for Superhydrophobic Surfaces. Journal of Heat Transfer 133, 081502 (2011), which is incorporated by reference in its entirety), hindering the overall heat transfer performance ( FIG. 7B ). Moreover, the Cassie wetting state introduces a vapor layer beneath the condensate droplet, which significantly increases the thermal resistance. In addition, hydrophobic surface chemistry increases the nucleation thermodynamic energy barrier, thus reducing the nucleation density and limiting the heat transfer coefficient ( FIG. 7C ). See Kashchiev, D. Nucleation: Basic Theory with Applications. 1 edn, (Oxford: Butterworth-Heinemann, 2000), which is incorporated by reference in its entirety. Hydrophobic structured surfaces with well-defined hydrophilic sites on the roughness features have also been explored to control the nucleation density (see Varanasi, K. K., Hsu, M., Bhate, N., Yang, W. & Deng, T. Spatial control in the heterogeneous nucleation of water. Appl Phys Lett 95, 094101-094101-094103 (2009), which is incorporated by reference in its entirety), but strong droplet adhesion on such surfaces is likely to limit their applicability for condensation heat transfer enhancement. More recently, composite surfaces have been proposed whereby hydrophobic structured surfaces were infused with oil to simultaneously achieve easy droplet removal and low contact angles. See Wong, T. -S. et al. Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity. Nature 477, 443-447 (2011) and Anand, S., Paxson, A. T., Dhiman, R., Smith, J. D. & Varanasi, K. K. Enhanced Condensation on Lubricant Impregnated Nanotextured Surfaces. Acs Nano, (2012), each of which is incorporated by reference in its entirety. During condensation, two-tier surface roughness was shown to enhance the removal of droplets suspended on top of the infused oil layer. While these works showed significant potential for enhanced condensation surfaces, achieving high nucleation densities has not previously been considered. Furthermore, experimentally obtained heat transfer enhancements with such surfaces have not been reported.
[0052] Immersion condensation, a new approach to enhance condensation heat transfer by introducing heterogeneous surface chemistry composed of discrete hydrophilic domains on a hydrophobic background in oil-infused micro and nanostructured surfaces is disclosed. This approach allows water droplets to nucleate immersed within the oil to achieve high nucleation densities while maintaining easy droplet removal and low contact angles ( FIGS. 8A and 8B ). In contrast to the same surface not infused with oil, nucleation densities were one order of magnitude larger due to the combined effect of the high-surface-energy sites and the reduced oil-water interfacial energy which, together, lower the thermodynamic energy barrier for stable nuclei formation. Meanwhile, the contact angle hysteresis was as low as 3° and the droplet apparent contact angle was ≈110°. The immersion of droplets in the presence of the heterogeneous coating is demonstrated to be essential to the high water nucleation densities and achieving significant heat transfer enhancements. The heterogeneous coating on flat silicon surfaces using AFM is characterized for the first time. The scans showed the presence of discrete high-surface-energy sites on a low-surface-energy background. Well-defined micropillar arrays were subsequently coated and then infused with oil to study the physics of condensation behavior. Finally, heat transfer enhancements of approximately 100% with oil-infused, heterogeneously coated copper oxide nanostructured surfaces in comparison with state-of-the-art dropwise condensing surfaces is demonstrated, which suggests the practicality of this invention. This work promises the development of a scalable strategy for highly efficient condensation heat transfer for industrial, building energy, electronics cooling, and water-harvesting applications.
Surface Heterogeneity by Self-Assembled Coatings
[0053] A self-assembled coating (SAC) of (tridecafluoro-1,1,2,2-tetrahydrooctyl)-1-trichlorosilane (TFTS) was deposited from the vapor phase (See Methods for the deposition process). The SAC coating method is capable of forming heterogeneity by agglomeration. See Bunker, B. C. et al. The Impact of Solution Agglomeration on the Deposition of Self-Assembled Monolayers. Langmuir 16, 7742-7751, (2000), which is incorporated by reference in its entirety. The SAC method was chosen due to its simplicity and scalability, but alternative methods are also available to generate heterogeneity at the appropriate length scale, e.g., block copolymer or nano-imprinting. See Park, M., Harrison, C., Chaikin, P. M., Register, R. A. & Adamson, D. H. Block Copolymer Lithography: Periodic Arrays of ˜1011 Holes in 1 Square Centimeter. Science 276, 1401-1404, (1997) and Guo, L. J., Cheng, X. & Chou, C. -F. Fabrication of Size-Controllable Nanofluidic Channels by Nanoimprinting and Its Application for DNA Stretching. Nano Lett 4, 69-73, (2003), each is which is incorporated by reference in its entirety. Height and phase atomic force microscope (AFM) images of the TFTS coating on a smooth silicon surface were obtained and are shown in FIGS. 8C and 8D , respectively, where the white spots are the nanoscale agglomerates of TFTS (≈200-500 nm in diameter). The phase angle of the agglomerates was significantly higher than that of the background, indicating that the agglomerates have higher surface energy. See James, P. J. et al. Interpretation of Contrast in Tapping Mode AFM and Shear Force Microscopy. A Study of Nafion. Langmuir 17, 349-360, (2000), which is incorporated by reference in its entirety. The local contact angle of water on the high-surface-energy agglomerates was determined to be 60°±1.5° by measuring the advancing and receding contact angle of a water droplet on the smooth, coated surface in air (θ a /θ r =122°±1.3°/78°±1.3°) and interpreting the data using a modified Cassie-Baxter model that incorporates the effect of local contact line deformation. See Raj, R., Enright, R., Zhu, Y., Adera, S. & Wang, E. N. A Unified Model for Contact Angle Hysteresis on Heterogeneous and Superhydrophobic Surfaces. Langmuir, (2012), which is incorporated by reference in its entirety.
Immersion Condensation on Silicon Micropillars
[0054] The SAC was deposited on silicon micropillar arrays to fundamentally investigate nucleation behavior on oil-infused surfaces. Silicon micropillar arrays were fabricated with diameters, d, ranging from 0.4-5 μm, periods, l, ranging from 4-25 μm, and heights, h, ranging from 10-25 μm using contact lithography and deep reactive ion etching (DRIE) processes. The geometries were chosen to satisfy the imbibition condition to enable oil spreading and to stabilize the oil film. See Bico, J., Thiele, U. & Quéré, D. Wetting of textured surfaces. Colloids and Surfaces A: Physicochemical and Engineering Aspects 206, 41-46, (2002), which is incorporated by reference in its entirety. The pillar surfaces were subsequently functionalized with the TFTS SAC, and infused with a fluorinated oil, Krytox GPL 100. The low surface tension of Krytox oil (≈17-19 mN/m) allowed it to spread on the surface and form a stable film via capillarity. A dry N 2 stream was used to assist spreading and remove excess oil. Typical scanning electron microscope (SEM) images of the coated pillar arrays without and with oil-infusion are shown in FIGS. 8E and 8F , respectively. On these TFTS-coated pillar arrays, the advancing and receding contact angles without oil-infusion were θ a /θ r =139°±3°/128°±3°, whereas those with oil-infusion were θ a /θ r =110°±2°/107°±2° ( FIGS. 8G and 8H ). Such low contact angle hysteresis is a key attribute for allowing droplets to be removed with a small departure radius under gravity during condensation. See Dimitrakopoulos, P. & Higdon, J. J. L. On the gravitational displacement of three-dimensional fluid droplets from inclined solid surfaces. Journal of Fluid Mechanics 395, 181-209, (1999), which is incorporated by reference in its entirety. FIGS. 8I and 8J show white light optical microscope images comparing the drastic difference in nucleation density during condensation without and with oil-infusion on the TFTS-coated micropillar arrays, respectively (see Methods for the experimental procedure). Under the prescribed supersaturation of S=1.6 (S=p v /p w where p v is the water vapor pressure and p w is the water saturation pressure associated with the surface temperature), nucleation was rarely observed on the surface without oil-infusion (nucleation density N≈(4±2)×10 8 m −2 ) ( FIG. 8I ), but was observed on every tip of the pillars after oil-infusion (nucleation density N≈(4.4±0.2)×10 9 m −2 ) ( FIG. 8J ). Nucleation in the space between the pillars was not observed due to the large thickness of oil coverage that limits water vapor diffusion to the SAC. Meanwhile, nucleation on the oil/vapor interface did not occur due to the low interfacial energy.
[0055] The increase in nucleation density on the oil-infused TFTS surfaces was achieved via the combination of the high-surface-energy sites and reduced water-oil interfacial energy. Based on classical nucleation theory, the nucleation rate can be determined as a function of the contact angle and the surface energy of the condensate at a given supersaturation, as shown in FIG. 8K ). See Blander, M. & Katz, J. L. Bubble Nucleation in Liquids. Aiche Journal 21, 833-848, (1975), J. P. Hirth & G. M. Pound. Condensation and evaporation—nucleation and growth kinetics (England: Pergamon Press, 1963), and Pound, G. M., Simnad, M. T. & Yang, L. Heterogeneous Nucleation of Crystals from Vapor. The Journal of Chemical Physics 22, 1215-1219 (1954), each of which is incorporated by reference in its entirety. On the oil-infused surface, the tips of the pillars were covered by oil due to its low surface tension. However, the tips were still visible in the SEM images ( FIG. 8F ) because of the small thickness of the oil film. In these regions, the water vapor is able to diffuse through the thin oil layer and form nuclei immersed in the oil layer on the high-surface-energy sites. The critical sizes of nuclei (<10 nm) were much smaller than the sizes of the high-surface-energy sites (2200-500 nm) so that the local contact angles of the nuclei are only determined by the high-surface-energy sites. With the introduction of oil, the local contact angle of nuclei on those high-surface-energy domains can be bounded in the range from 43° to 67° using Young's equation (see Supporting Information). As a result, the energy threshold for nucleation was significantly decreased due the low local contact angle, in combination with the reduced interfacial energy between water and oil (≈49 mJ/m 2 ) compared to that between water and vapor (≈72 mJ/m 2 ). See Anand, S., Paxson, A. T., Dhiman, R., Smith, J. D. & Varanasi, K. K. Enhanced Condensation on Lubricant Impregnated Nanotextured Surfaces. Acs Nano, (2012), which is incorporated by reference in its entirety. Accordingly, as shown in FIG. 8K , assuming a local contact angle lower than 67°, the predicted nucleation rate increases from 0.2 m −2 s −1 to greater than 10 14 m −2 s −1 due to the encapsulating oil phase in comparison with the same surface without oil-infusion. The oil encapsulation is essential in reducing the energy barrier for nuclei formation and enhancing nucleation density, which is distinct from previous work where the encapsulating oil phase was considered as unfavorable for condensation. The calculated nucleation rate allows the nucleation density to be orders of magnitude larger than the density of the high-surface energy domains. As a result, multiple nuclei could form on each tip of the pillars where the oil layer is thin enough for effective vapor diffusion. However, due to the resolution limits of the imaging experiments, only a single droplet was apparent on each pillar tip. Therefore, only an order of magnitude increase in the observed nucleation density was determined, which was equal to the density of the pillars ( FIG. 8J ). Control condensation experiments on oil-infused micropillar arrays with dimethyldicholorosilane (DMCS) were also performed, which is a homogeneous hydrophobic coating with advancing and receding contact angles of θ a /θ r =103.8°±0.5°/102.7°±0.4°. No observable change in nucleation density was found after oil-infusion on the DMCS coated surfaces, as predicted by theory ( FIG. 8K ). These results further support the idea that a high performance condensation surface can be achieved through the combination of local high-surface-energy sites and oil-infusion, which has not been demonstrated previously. However, the overall surface needs to be hydrophobic to prevent the spreading of the condensate beneath the oil film and maintain easy droplet removal. Otherwise, the condensate would wet the substrate, disrupting the oil film and resulting in droplet pinning.
Immersion Condensation on Scalable Copper Oxide Nanostructures
[0056] The overall heat transfer performance of an immersion condensation surface is disclosed. While studies on well-defined silicon micropillar arrays can provide physical insight into immersion condensation behavior, they are not practical due to cost and challenges in interfacing the silicon substrate and the heat transfer measurement apparatus with minimum uncertainties. Therefore, immersion condensation heat transfer measurements on oil-infused copper oxide (CuO) nanostructures functionalized with TFTS was performed, which promises a scalable, low cost platform for condensation surfaces. See Nam, Y. & Ju, Y. S. Comparative Study of Copper Oxidation Schemes and Their Effects on Surface Wettability. ASME Conference Proceedings 2008, 1833-1838 (2008), which is incorporated by reference in its entirety. SEM images of representative copper oxide nanostructures without and with Krytox oil-infusion are shown in FIGS. 9A and 9B , respectively. Condensation experiments were performed on the CuO surfaces without and with oil-infusion in an environmental SEM with 1<S<1.29 for visualization (see Methods for detailed imaging process). The FIGS. 9C and 9D show an order of magnitude increase in nucleation density on the oil-infused surface, as similarly observed on the silicon-based microstructures. To capture the condensation heat transfer behavior the oil-infused heterogeneous CuO surfaces were formed on copper tubes (see Methods for detailed fabrication process). FIGS. 9E and 9F show condensation on a typical dropwise hydrophobic surface and an oil-infused heterogeneous immersion condensation surface, respectively. Significantly higher droplet densities were observed on the oil-infused surface. Meanwhile, the average shedding radius of droplets was reduced from R DHP =1.83±0.31 mm on the typical dropwise hydrophobic surfaces to R IC =0.98±0.13 mm on the immersion condensation surfaces (see Supporting Information for details on determining the droplet shedding radii). Prior to droplet departure, the droplets grew orders of magnitude larger than the characteristic length scale of the nanostructures, thus high apparent contact angles of the droplet (≈110°) were observed, consistent with the low surface energy of the solid-oil composite surface.
[0057] Overall heat transfer coefficients were measured to evaluate the performance on three different CuO-based surfaces: a hydrophobic surface for typical dropwise condensation, a superhydrophobic TFTS-coated copper oxide surface, and a Krytox oil-infused, TFTS-coated CuO surface ( FIG. 10 ) (see Methods for detailed experimental process). The Krytox GPL 100 oil evaporates completely when the test chamber is evacuated to pressures lower than 1 Pa. Therefore, the initial chamber pressure was set as high as 30 Pa (primarily composed of non-condensable gases, NCG) to avoid the evaporation of oil with steam pressures ranging from 2 to 3 kPa (1<S<1.6) in the experiments. This is consistent with actual condenser systems where NCG partial pressures are typically found in the range of 30 Pa and significantly affect the condensation heat transfer performance. See Rose, J. W. Dropwise condensation theory and experiment: A review. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 216, 115-128, (2002), Denny, V. E. & Jusionis, V. J. Effects of noncondensable gas and forced flow on laminar film condensation. International Journal of Heat and Mass Transfer 15, 315-326, (1972), Sparrow, E. M., Minkowycz, W. J. & Saddy, M. Forced convection condensation in the presence of noncondensables and interfacial resistance. International Journal of Heat and Mass Transfer 10, 1829-1845, (1967), and Tanner, D. W., Pope, D., Potter, C. J. & West, D. Heat transfer in dropwise condensation at low steam pressures in the absence and presence of non-condensable gas. International Journal of Heat and Mass Transfer 11, 181-190, (1968), each of which is incorporated by reference in its entirety. Accordingly, with these experimental conditions, a more realistic condensation environment and demonstrate the practical significance of the immersion condensation mode was emulated. While the superhydrophobic surface is more hydrophobic than the typical dropwise hydrophobic surface, flooding and strong pinning of the condensate was observed due to the high supersaturation conditions (S as high as 1.6), leading to similar heat transfer coefficients with the typical dropwise hydropohobic surfaces. Note that these results are distinct from previous literature where jumping of droplets on superhydrophobic surfaces increased heat transfer coefficients at lower saturation conditions (S<1.12). See Miljkovic, N. et al. Jumping-Droplet-Enhanced Condensation on Scalable Superhydrophobic Nanostructured Surfaces. Nano Lett 13, 179-187, (2013), which is incorporated by reference in its entirety. In addition, the overall heat transfer coefficients on DHP surfaces in this work (h≈2-7 kW/m 2 K) are much lower compared to pure vapor conditions (h≈12-13 kW/m 2 K) due to the presence of NCGs acting as a diffusion barrier to the transport of water vapor towards the condensing surface. In comparison to the typical hydrophobic surfaces, the Krytox oil-infused TFTS-coated CuO surface demonstrated approximately a 100% improvement in heat transfer coefficient over the entire range of supersaturations tested (1<S<1.6) with the existence of NCGs. While the available condensation area was reduced due to the significant oil coverage, the significant improvement in the overall heat transfer coefficient highlights the collective role of enhanced nucleation density, more frequent droplet removal, and lower droplet contact angle ( FIG. 7 ).
Methods
Surface Fabrication
[0058] The silicon micropillar arrays were fabricated using contact lithography followed by deep reactive ion etching. For copper oxide surfaces, commercially available oxygen-free Cu tubes (99.9% purity) with outer diameters, D OD =6.35 mm, inner diameters, D ID =3.56 mm, and lengths L=131 mm as the test samples were used for the experiments. Each Cu tube was cleaned in an ultrasonic bath with acetone for 10 minutes and rinsed with ethanol, isopropyl alcohol and de-ionized (DI) water. The tubes were then dipped into a 2.0 M hydrochloric acid solution for 10 minutes to remove the native oxide film on the surface, then triple-rinsed with DI water, and dried with clean nitrogen gas.
[0059] Nanostructured CuO films were formed by immersing the cleaned tubes into a hot (96±3° C.) alkaline solution composed of NaClO 2 , NaOH, Na 3 PO 4 .12H 2 O, and DI water (3.75:5:10:100 wt. %). See Enright, R., Dou, N., Miljkovic, N., Nam, Y. & Wang, E. N. Condensation on Superhydrophobic Copper Oxide Nanostructures. 3 rd Micro/Nanoscale Heat & Mass Transfer International Conference (2012), which is incorporated by reference in its entirety. During the oxidation process, a thin (<200 nm) Cu 2 O layer was formed that then re-oxidized to form sharp, knife-like CuO structures with heights of h≈1 μm, solid fraction φ≈0.023 and roughness factor r≈10. To verify the independence of oxide thickness on chemical oxidation time (see Nam, Y. & Ju, Y. S. Comparative Study of Copper Oxidation Schemes and Their Effects on Surface Wettability. Imece 2008: Heat Transfer, Fluid Flows, and Thermal Systems, Vol 10, Pts a-C, 1833-1838 (2009), which is incorporated by reference in its entirety), four separate samples were made using oxidation times, τ=5, 10, 20, and 45 minutes. The sharp CuO structures were then coated with silane SAC to create SHP surfaces.
[0060] In addition to SHP surfaces, cleaned copper tubes were also immersed into hydrogen peroxide solutions at room temperature to form a thin smooth layer of Cu 2 O. The smooth surfaces were also coated with TFTS to achieve typical hydrophobic surfaces for dropwise condensation (DHP).
Surface Coating Deposition
[0061] The self-assembled coatings (SAC) were formed using a vapor deposition process. First, the silicon surfaces were cleaned using a Piranha solution (H 2 O 2 :H 2 SO 4 =1:3) to remove possible organic contamination and to create a large number of —OH bonds on the surface, which enables the bonding between silane molecules and the silicon surface. For the copper oxide surfaces, the surfaces were cleaned by intensive plasma (≈1 hr). The samples were then placed in a desiccator (Cole-Palmer) together with a small petri dish containing ≈1 mL of the silane liquid. The desiccator was pumped down to ≈10 kPa. The pump was then shut off and the valve was closed so that the silane liquid could evaporate in the low-pressure environment of the desiccator and attach to the surfaces to form the SAC via the following reaction,
[0000] Si—OH+R—Si—Cl→Si—O—Si—R+HCl.
[0062] During the self-assembly process, the silane molecule form nanoscale agglomerates with diameters of ≈200-500 nm shown in FIGS. 8C and 8D , as reported previously. See Bunker, B. C. et al. The Impact of Solution Agglomeration on the Deposition of Self-Assembled Monolayers. Langmuir 16, 7742-7751, (2000), which is incorporated by reference in its entirety. After 30 minutes of reaction, the desiccator was vented and the samples were rinsed using de-ionized (DI) water. Such vapor deposition process was used for both TFTS and Dimethyldicholorosilane (DMCS) coatings, but in dedicated desiccators to avoid cross-contamination of the different silane molecules.
Surface Characterization
[0063] Advancing and receding contact angles for all samples were measured and analyzed using a micro-goniometer (MCA-3, Kyowa Interface Science Co., Japan). Field emission electron microscopy was performed on a Zeiss Ultra Plus FESEM (Carl Zeiss GMBH) at an imaging voltage of 3 kV.
OM Imaging Procedure
[0064] The samples were horizontally mounted on a thermal stage inside an enclosure and cooled to T w =283.1±0.1 K in a dry nitrogen atmosphere. Following thermal equilibration (≈5 minutes), nucleation was initiated by flowing water-saturated nitrogen into the enclosure. The humidity of the gas flow was measured using a humidity probe located 1 cm above the sample to determine the supersaturation, S, defined as the ratio of the vapor pressure to the saturation pressure at the stage temperature (S=p v /p w ). Typical values of supersaturation were S≈1.6. The nucleation density and subsequent growth behavior was recorded at a frame rate of 10 frames per second using a high speed camera (Phantom V7.1, Vision Research) attached to the optical microscope. The observable nucleation density during each experiment was determined by counting the number of nuclei in the captured images and dividing the number of nuclei by the imaging area. Multiple experiments were performed to determine the average nucleation densities on the different surfaces.
ESEM Imaging Procedure
[0065] Condensation nucleation and growth were studied on these fabricated surfaces using an environmental scanning electron microscope (EVO 55 ESEM, Carl Zeiss GMBH). Backscatter detection mode was used with a high gain. The water vapor pressure in the ESEM chamber was 800±80 Pa. Typical image capture was obtained with a beam potential of 20 kV and variable probe current depending on the stage inclination angle. To limit droplet heating effects, probe currents were maintained below 2.0 nA and the view area was kept above 400 μm×300 μm. See Rykaczewski, K., Scott, J. H. J. & Fedorov, A. G. Electron beam heating effects during environmental scanning electron microscopy imaging of water condensation on superhydrophobic surfaces. Appl Phys Lett 98 (2011), which is incorporated by reference in its entirety. A 500 μm lower aperture was used in series with a 100 μm variable pressure upper aperture to obtain greater detail. The sample temperature was initially set to 4±1.5° C. and was allowed to equilibrate for 5 minutes. The surface temperature was subsequently decreased to 3±1.5° C., resulting in nucleation of water droplets on the sample surface. Accordingly, the supersaturation, S, during the imaging process was in the range of 1<S<1.29. Images and recordings were obtained at an inclination angle of 45° from the horizontal to observe droplet growth. Cu tape was used for mounting the sample to the cold stage to ensure good thermal contact.
Heat Transfer Measurements
[0066] The test samples, 6.35 mm diameter tubes with different surface treatments, were placed in an environmental chamber (Kurt J. Lesker) for the heat transfer measurements. A water reservoir, which was connected to the chamber via a vapor valve, was heated to >95° C. to produce steam. The vapor valve was opened to allow steam to flow into the chamber after the chamber was pumped down to the targeted non-condensable pressure (≈30 Pa). Chilled water flowed along the inside of the tube where the inlet temperature and outlet temperature were both measured by thermocouples so that the heat flux could be determined by the temperature rise. The temperature difference, ΔT was determined as the log-mean temperature difference (LMTD) between the vapor and the chilled water. Each data point in FIG. 10 was determined over 10 minutes of steady state operation. The vapor inflow valve was then adjusted to change the vapor pressure in the chamber.
Parameters Affecting the Condensation Heat Transfer Coefficient
[0067] Based on the model developed by Miljkovic et al. (Miljkovic, N.; Enright, R.; Wang, E. N., Effect of Droplet Morphology on Growth Dynamics and Heat Transfer during Condensation on Superhydrophobic Nanostructured Surfaces. Acs Nano 2012, 6 (2), 1776-1785, which is incorporated by reference in its entirety), on a dropwise condensation surface, the heat transfer rate through a single growing droplet can be determined as
[0000]
q
=
Δ
T
R
tot
=
π
R
2
(
Δ
T
-
2
T
sat
σ
Rh
fg
ρ
w
)
1
2
h
i
(
1
-
cos
θ
)
+
R
θ
4
k
w
sin
θ
+
1
k
HC
sin
2
θ
[
k
p
φ
δ
HC
k
p
+
hk
HC
+
k
w
(
1
-
φ
)
δ
HC
k
w
+
hk
HC
]
-
1
(
8
)
[0068] where R tot is the total thermal resistance through the droplet, R is the droplet radius, ρ w is the liquid water density, h fg is the latent heat of vaporization, T sat is the vapor saturation temperature, σ is the water surface tension, ΔT is the temperature difference between the saturated vapor and substrate (T sat -T s ), δ HC and h are the hydrophobic coating thickness (˜1 nm) and pillar height, respectively, k HC , k w , and k P are the hydrophobic coating, water, and pillar thermal conductivities, respectively, and h i is the interfacial condensation heat transfer coefficient. See Umur, A.; Griffith, P., Mechanism of Dropwise Condensation. J Heat Transf 1965, 87 (2), 275-&, which is incorporated by reference in its entirety. is the solid fraction of the micro/nanostructures. In the special case of a flat surface, φ=1 and h=0.
[0069] Droplet size distribution theory was considered to determine the fraction of droplets with a given radius, R, in the droplet heat transfer model. For small droplets, the droplet distribution is determined by
[0000]
n
(
R
)
=
1
3
π
R
e
3
R
^
(
R
e
R
^
)
-
2
/
3
R
(
R
e
-
R
*
)
A
2
R
+
A
3
A
2
R
e
+
A
3
exp
(
B
1
+
B
2
)
where
(
9
)
B
1
=
A
2
τ
A
1
[
R
e
2
-
R
2
2
+
R
*
(
R
e
-
R
)
-
R
*
2
ln
(
R
-
R
*
R
e
-
R
*
)
]
(
10
)
B
2
=
A
3
τ
A
1
[
R
e
-
R
-
R
*
ln
(
R
-
R
*
R
e
-
R
*
)
]
(
11
)
τ
=
3
R
e
2
(
A
2
2
R
e
+
A
3
)
2
A
1
(
11
A
2
R
e
2
-
14
A
2
R
e
R
*
+
8
A
3
R
e
-
11
A
3
R
*
)
(
12
)
A
1
=
Δ
T
h
fg
ρ
w
(
1
-
cos
θ
)
2
(
2
+
cos
θ
)
(
13
)
A
2
=
θ
4
k
w
sin
θ
(
14
)
A
3
=
1
2
h
i
(
1
-
cos
θ
)
+
1
k
HC
sin
2
θ
[
k
p
φ
δ
HC
k
p
+
hk
HC
+
k
w
(
1
-
φ
)
δ
HC
k
p
+
hk
HC
]
-
1
(
15
)
[0070] {circumflex over (R)} is the average departure radius, R* is the critical droplet size for nucleation, τ is the droplet sweeping period, and R s is the radius when droplets begin to merge and grow by droplet coalescence afterwards, R e =l C /2 with l C being the coalescence length determined by nucleation density, N
[0000] l C =(4 N ) −1 (16)
[0071] See Kim, S.; Kim, K. J., Dropwise Condensation Modeling Suitable for Superhydrophobic Surfaces. J Heat Trans - T Asme 2011, 133 (8), and Rose, J. W., On the mechanism of dropwise condensation. International Journal of Heat and Mass Transfer 1967, 10 (6), 755-762, each of which is incorporated by reference in its entirety.
[0072] For large droplets growing mainly due to coalescence, the droplet distribution can be determined as
[0000]
N
(
R
)
=
1
3
π
R
2
R
^
(
R
R
^
)
-
2
/
3
(
17
)
[0073] The total surface condensation heat flux, q″, can be obtained by incorporating the individual droplet heat transfer rate (Eqn. 8) with the droplet size distributions (Eqns. 9 and 17)
[0000]
q
″
=
∫
R
*
R
e
q
(
R
)
n
(
R
)
R
+
∫
R
e
R
^
q
(
R
)
N
(
R
)
R
(
18
)
[0074] The total condensation heat transfer coefficient is determined as
[0000] h C =q″/ΔT (19)
[0075] Therefore, the sensitivity of h c on the departure radius, advancing contact angle and nucleation density can be obtained as shown in FIG. 7 .
Estimation of Local Contact Angle on High-Surface-Energy Sites with the Existence of Oil
[0076] As shown in FIG. 11 , on a high-surface-energy domain of the TFTS coating without oil-infusion, the local contact angle of a water droplet on a surface, θ ws(v) , can be determined using Young's equation as
[0000]
cos
θ
ws
(
v
)
=
σ
vs
-
σ
ws
σ
ws
(
20
)
[0077] where σ vs is the interfacial energy between the surface and vapor, σ ws is the interfacial energy between water and the surface, and σ wv is the interfacial energy between water and vapor, which is 72 mJ/m 2 .
[0078] Similarly, with the introduction of oil which surrounds the water droplet on a surface, the local contact angle, θ ws(o) , can be determined as
[0000]
cos
θ
ws
(
o
)
=
σ
os
-
σ
ws
σ
wo
=
σ
os
-
σ
vs
+
σ
vs
-
σ
ws
σ
wo
(
21
)
[0079] where σ os is the interfacial energy between the surface and oil, σ ws is the interfacial energy between water and the surface, and σ wo is the interfacial energy between water and oil, which is 49 mJ/m 2 . See Anand, S.; Paxson, A. T.; Dhiman, R.; Smith, J. D.; Varanasi, K. K., Enhanced Condensation on Lubricant Impregnated Nanotextured Surfaces. Acs Nano 2012, which is incorporated by reference in its entirety.
[0080] Since σ os is experimentally difficult to obtain for the system, bounds for the local contact angle for the water-oil-substrate system, θ ws(o) , are provided as follows. The contact angle of oil on the high-surface-energy domain is considered using
[0000]
cos
θ
os
(
v
)
=
σ
vs
-
σ
os
σ
ov
(
22
)
[0081] where σ ov is the interfacial energy between vapor and oil, which is 17 mJ/m 2 . Since the oil wets the TFTS-coated surface, which means θ os(v) <90°. Therefore, it can be determined that 0<σ vs −σ os <17 mJ/m 2 .
[0082] As a result, the local contact angle of the water droplet on a surface surrounded by oil can be bounded as
[0000]
cos
θ
ws
(
o
)
=
σ
os
-
σ
vs
+
σ
vs
-
σ
ws
σ
wo
∈
(
-
17
+
36
49
,
0
+
36
49
)
∴
θ
we
(
o
)
∈
(
43
°
,
67
°
)
(
23
)
Derivation of Nucleation Rate as a Function of Contact Angle and Interfacial Energy
[0083] The nucleation rate, J, can be determined by classical nucleation theory (CNT) as
[0000] I=zf *exp(− G *) (24)
[0084] See, Kashchiev., D., Nucleation: Basic Theory with Applications. 1 ed.; Oxford: Butterworth-Heinemann: 2000, which is incorporated by reference in its entirety. In Eqn. (20), z is the Zeldovich factor and G* is the dimensionless energy barrier, given by
[0000] z =( kT In S ) 2 /8 λv o √{square root over ( kT ψ(θ) y 3 )} (25)
[0000] G* =16πψ(θ) v o 2 y 3 /3( kT ) 2 (In S ) 2 (26)
[0000] where S is the supersaturation and ψ(θ) is the activity that accounts for the effect of contact angle. f* is the frequency of monomer attachment to the critical droplet nucleus dependent on the nature of the nucleus growth. The main modes of growth during heterogeneous nucleation are limited via direct impingement of monomers to the nucleus or surface diffusion. See Pound, G. M.; Simnad, M. T.; Yang, L., Heterogeneous Nucleation of Crystals from Vapor. The Journal of Chemical Physics 1954, 22 (7), 1215-1219 and Sigsbee, R. A., Adatom Capture and Growth Rates of Nuclei. J Appl Phys 1971, 42 (10), 3904-3915, each of which is incorporated by reference in its entirety.
[0085] The frequency of monomer attachment due to direct vapor impingement is given by
[0000] f* i =y n [(1−cos(θ w ))/2ψ 2/3 (θ)](36 πv o 2 ) 1/3 In 2/3 (27)
[0000] where y n is the sticking coefficient (0<y n <1), I is the classical Hertz-Knudsen impingement rate (I=P/√{square root over (2πm o kT)})), n is the number of molecules in the nucleated cluster, and v o is the volume of an individual water molecule (v o =3×10 −29 m 3 ). To determine an upper bound on the nucleation rate, a sticking coefficient of one was assumed (y n =1).
[0086] The frequency of monomer attachment due to surface diffusion is given by
[0000] f* ad =y n c*λ s 2 I (28)
[0000] where c* is the capture number due to surface diffusion (1<c*<5), and 2, is the mean surface diffusion distance of an adsorbed monomer on the substrate. The capture number c* is size independent and approximately equal to 1.9 for heterogeneous condensation of water vapor. See Pocker, D. J.; Hruska, S. J., Detailed Calculations of the Number of Distinct Sites Visited in Random Walk on Several Two-Dimensional Substrate Lattices. Journal of Vacuum Science and Technology 1971, 8 (6), 700-707, which is incorporated by reference in its entirety. The mean surface diffusion distance is dependent on the wettability of the substrate and is given by λ s =√{square root over (D sd τ d )} where D sd is the surface diffusion coefficient (D sd =d s 2 v s exp[−E sd /kT]), τ d is the desorption time (τ d =(1/v s ) exp[−E des /kT]), v s is the adsorbed molecule vibration frequency determined using the Debye approximation (v s =v D α/2), d s is the length of a molecular jump along the substrate surface approximated by the lattice constant of the substrate (d s =5.4 Å) (see J. P. Hirth; G. M. Pound, Condensation and evaporation—nucleation and growth kinetics England: Pergamon Press: 1963, which is incorporated by reference in its entirety) and V D is the speed of sound in the substrate (V D =8433 m/s). The desorption and surface diffusion energies are given by E des =E 1 +σ sv α o and E sd =0.5E des (See Thiel, P. A.; Madey, T. E., The interaction of water with solid surfaces: Fundamental aspects. Surface Science Reports 1987, 7 (6-8), 211-385, which is incorporated by reference in its entirety), respectively, where E 1 is the binding energy of an n=1 sized cluster, σ sv is the solid-vapor interfacial energy and α o is the water molecule surface area (α 0 =4.67×10 −19 m 2 ). The calculated energies of desorption show excellent agreement with that of the experiments and molecular dynamics simulations (E des, SiO2 =0.9 eV). See Israelachvili, J. N., Intermolecular and surface forces. 2nd ed.; Academic Press: Amsterdam, 1991, and Ma, Y.; Foster, A. S.; Nieminen, R. M., Reactions and clustering of water with silica surface. The Journal of Chemical Physics 2005, 122 (14), 144709-9, each of which is incorporated by reference in its entirety.
[0087] By adding the nucleation rate from the two mechanisms together, the nucleation rate, J, can be determined as a function of the contact angle and interfacial energy of the condensate at given supersaturations, as shown in FIG. 8K .
Control Experiments on Homogeneous Hydrophobic Surfaces
[0088] Dimethyldicholorosilane (DMCS), which is a homogeneous hydrophobic coating, was used in the studies for control experiments. DMCS can be deposited on silicon surfaces using the vapor deposition process as described in the Methods section.
[0089] An atomic force microscope (AFM) image of a flat silicon surface coated by DMCS is shown in FIG. 12A . No high-surface-energy domains with the coatings were observed. The advancing and receding contact angles on the DMCS coated surface were measured to be θ a /θ r =103.8°±0.5°/102.7°±0.4°, respectively. The hysteresis was significantly lower compared to TFTS-coated surfaces, which also indicates the homogeneity of the DMCS coating.
[0090] Condensation experiments were performed on micropillar arrays coated by DMCS with and without oil-infusion using the same experimental setup for the condensation experiment on TFTS-coated micropillar arrays, as described in the Methods section. The results are summarized and compared to the TFTS-coated surfaces in FIG. 12B . The nucleation density was normalized against the density of pillars for a fair comparison between different geometries. The nucleation density increase was not observed on DMCS-coated surfaces even after oil-infusion, as predicted by classical nucleation theory. Note that classical theory predicted nucleation rates as low as 0.2 m −2 s −1 on TFTS-coated surfaces without oil-infusion. However, in experiments, some rare nucleation was observed as shown in FIG. 12B . Repeated condensation experiments showed that nuclei formation and droplet pinning occurred on identical spots for each subsequent test, indicating that the spots are defects in the silane coatings where the hydrophilic silicon oxide surface (contact angle θ=38°) was exposed. Such defects, while limited in number, act as nucleation sites for condensation.
Heat Transfer Measurement Apparatus and Experimental Procedure
[0091] A custom environmental chamber was built to test the heat transfer performance of each sample for the study. The vacuum chamber was made of stainless steel with two viewing windows. Resistive heater lines were wrapped around the exterior of the chamber walls to prevent condensation at the inside walls, and the chamber was wrapped with insulation on the exterior walls. Two insulated stainless steel water flow lines (Swagelok) were fed into the chamber via a KF flange port to supply cooling water to the chamber from a large capacity chiller (System III, Neslab). A flow meter (7 LPM MAX, Hedland) having an accuracy of ±2% was integrated along the water inflow line.
[0092] A secondary stainless steel tube line was fed into the chamber via a KF adapter port that served as the flow line for the incoming water vapor supplied from a heated steel water reservoir. The vapor line was wrapped with a rope heater (60 W, Omega) and controlled by a power supply (Agilent). The vapor reservoir was wrapped with another independently-controlled rope heater (120 W, Omega) and insulated to limit heat losses to the environment. The access tubes were welded to the vapor reservoir, each with independently-controlled valves. The first valve (Diaphragm Type, Swagelok), connecting the bottom of the reservoir to the ambient, was used to fill the reservoir with water. The second valve (BK-60, Swagelok), connecting the top of the reservoir to the inside of the chamber, was used to provide a path for vapor inflow. K-type thermocouples were located along the length of the water vapor reservoir to monitor temperature. To obtain the temperatures within the chamber, K-type thermocouple bundles were connected through the chamber apertures via a thermocouple feed through (Kurt J. Lesker). A pressure transducer (925 Micro Pirani, MKS) was attached to monitor pressure within the chamber. The thermocouple bundles and the pressure transducer were both connected to an analog input source (RAQ DAQ, National Instruments), which was interfaced to a computer to record and store data. A second bellows valve (Kurt J. Lesker) on the chamber was connected to a vacuum pump to bring the chamber down to vacuum conditions prior to vapor filling. A liquid nitrogen cold trap was placed between the chamber and vacuum pump which served to remove any moisture from the pump-down process.
[0093] To run the test samples inside the chamber, the stainless steel bellows tube lines (¼″, Swagelok) were connected to the external water flow lines. T-connection adapters (Swagelok) with bore through Ultra-Torr fittings (Swagelok) were used to adapt K-type thermocouple probes (Omega) at the water inlet and outlet. Prior to experimentation, the thermocouple probes were calibrated using a high precision temperature controlled bath (Lauda Brinkman) to an accuracy of ±0.2 K. The test samples, 6.35 mm diameter tubes with different surface treatments, were connected via a Swagelok compression fitting onto the T-connection. Chilled water flows through the inlet bellows tube, along the inside of the tube sample and through the outlet. Two supports were used to hold the sample and the entire configuration in place. Two separate pieces of insulation were embedded with K-type thermocouple leads and used for wet bulb temperature measurements during experimental runs. A third thermocouple was placed beside the sample to measure the reference temperature inside the chamber. As the experiment progressed, the wet-bulb insulating wick collected water from the bottom of the chamber to the embedded thermocouple. The temperature measured by this thermocouple was compared to the reference temperature calculated from the saturation pressure. This allowed for a high accuracy secondary measurement of saturation conditions inside the chamber. F Figure F3 shows the schematic of the test setup for the heat transfer performance measurement.
[0094] For each experimental trial, a set of strict procedures were used to ensure consistency throughout the experiments. The water vapor reservoir was filled with approximately 3.5 liters of DI water (99% full) using a syringe through the vapor release valve. After opening the vapor inflow valve and closing the vapor release valve, the rope heater around the water vapor reservoir was turned on and the heater controller set to maximum output. Then the rope heater connected to the vapor inflow valve was turned on. The temperature of the water reservoir was monitored with the installed thermocouples. Once boiling was achieved and all thermocouples on the reservoir reached >95° C. for at least 10 minutes, the vapor inflow valve was closed.
[0095] The next step was to begin the vacuum pump-down procedure. Valves connecting the chamber with the ambient, and valves connecting the chamber and the vacuum pump were both closed while the valve connected to the liquid nitrogen cold trap was opened. The vacuum pump was then turned on, initiating the pump-down process where the pressure inside the chamber was carefully monitored. This process took ≈30 minutes in order to achieve the target non-condensable gases pressure (≈30 Pa).
[0096] After pumping down, the vapor inflow valve was opened to allow steam flow into the chamber and condensation occurred on the surface of the tube. The heat flux was determined by the rise in the temperature of the chilled water from the inlet to the outlet. The temperature difference, ΔT was determined as the log-mean temperature difference (LMTD) between the vapor and the chilled water. See Mills, A. F., Heat and Mass Transfer. 2 ed.; Prentice-Hall: 1999, which is incorporated by reference in its entirety. Each data point in FIG. 10 was determined over 10 minutes of steady state operation. After that, the vapor inflow valve was adjusted to change the vapor pressure in the chamber. The error bars in FIG. 10 were determined based on the uncertainty in the thermocouple and flow rate measurement. The duration of each experimental run was around 45-60 minutes. The thermal conductivity of the Krytox GPL 100 oil was 0.08-0.09 W/mK. See Dupont KRYTOX Overview, which is incorporated by reference in its entirety. The associated conduction thermal resistance of the oil layer is very small due to the small thickness (≈1 μm). The oil-infusion was found to be very stable over days without significant change in heat transfer performance.
Droplet Shedding Radius
[0097] The experimentally-determined average droplet shedding radii ({circumflex over (R)}) for a typical dropwise hydrophobic surface ( FIG. 14A ) and a Krytox oil-infused immersion condensation surface ( FIG. 14B ) were determined via direct measurement through frame-by-frame analysis of high speed video. Videos (90 frames per second) of the condensation process taken at ≈2.4 kPa vapor pressure were analyzed to determine the radius of droplets that slide down from the top half of the surface and clean the surface for re-nucleation. Droplet size measurements were taken just prior to droplet sliding down the tube (to avoid coalescence effects). The shedding radius was averaged for 50 droplets for each tube sample and was determined to be {circumflex over (R)} DHP =1.83±0.31 mm and {circumflex over (R)} IC =0.98±0.13 mm on the typical dropwise hydrophobic and oil-infused surfaces, respectively. Reported error is due to droplet shedding variance from droplet to droplet.
Examples of Condensation Behavior
[0098] In case of TFTS-coated silicon micropillar array where the pillar diameters are 5 μm periods are 15 μm and the supersaturation in the experiment is S=1.6, almost no nucleation was observed except on sparse defects in the TFTS coating where hydrophilic silicon oxide substrate was exposed. In case of immersion condensation behavior on oil-infused TFTS-coated silicon micropillar array, where the pillar diameters are 5 μm, periods are 15 μm, and the supersaturation in the nexperiment is S=1.6, Nucleation occurred on every tip of the pillars, which yields over an order of magnitude higher nucleation density compared to TFTS-coated silicon micropillar array.
[0099] When a regular hydrophobic copper tube is horizontally placed with chilled water flowing inside with flow rate of 5 L/min and the vapor pressure in the experiment is ≈2.4 kPa, droplets grow and coalesce before removed by gravity at diameters around 2 mm. When an oil-infused TFTS-coated copper oxide tube is horizontally placed with chilled water flowing inside with flow rate of 5 L/min, and the vapor pressure in the experiment is ≈2.4 kPa, higher droplet density was observed compared to the regular hydrophobic copper tube while the departure diameter is reduced to approximately 0.98±0.13 mm.
[0100] In summary, over an order of magnitude increase in the nucleation density on hydrophobic silicon pillar arrays coated with a long-chain silane molecule was observed when hydrophobic oil was introduced on the surface. AFM imaging revealed the existence of locally hydrophilic micelles despite the overall hydrophobicity of the silane self-assembled coating (SAC). The increased nucleation density is explained in the context of classical nucleation theory as the combined effect of the hydrophilic micelles and the reduction in interfacial energy between water and oil. Control experiments on silicon pillar arrays with hydrophobic coatings without micelles and hydrophilic coatings were performed to support these findings. Such phenomena could potentially be used to create surfaces for enhanced condensation heat transfer for a variety of thermal and energy systems.
[0101] Other embodiments are within the scope of the following claims. | Condensation can be an important process in both emerging and traditional power generation and water desalination technologies. Superhydrophobic nanostructures can promise enhanced condensation heat transfer by reducing the characteristic size of departing droplets via a surface-tension-driven mechanism. A superhydrophobic surface can include a heterogeneous surface. |
BACKGROUND OF THE INVENTION
This invention relates to the recovery of metal values from superalloy scrap and more particularly to the separation of metal values from superalloy scrap in substantially pure form.
DESCRIPTION OF THE PRIOR ART
In recent years "superalloys" have found increased utility and great increases in volume of production due to the need for articles having the special properties afforded by these materials. Among these properties are high temperature strength, high temperature oxidation resistance, corrosion resistance and the like. As the use of these superalloys grows, so does the amount of scrap and other waste containing them. The form of the scrap includes off-quality products, turnings, grindings, pouring skulls, mold gates, flashings and waste products such as sludges and the like.
Typically, superalloys are based upon chromium, nickel, cobalt, molybdenum, small amounts of iron, aluminum, silicon, titanium, columbium, tantalum and the like. The superalloys are predominantly composed of chrome and nickel as major constituents, and in most instances cobalt.
In many instances, the scrap superalloy as hereinbefore described is discarded in landfills and similar disposal methods because the individual metal values cannot be isolated for reuse. More particularly, it is desirable to recover and reuse the cobalt, chrome and nickel values so that they can be reused in producing superalloys. While it is recognized that turnings and grindings can be recycled for use in heats having the same alloy composition, a large portion of the scrap is generally downgraded and in many instances discarded. Further, the turnings and grindings, if they are to be used in heats of the same alloy composition, must be isolated and classified so that the alloymakers place these turnings and grindings in the appropriate heat.
Metallurgical methods have been used to treat superalloy scrap, but it has generally only been possible to produce a metal of iron, cobalt, nickel and possibly chrome and molybdenum while the refractory metals such as tantalum, titanium and columbium are lost in the slag. Although these metal values are recovered, they are in a form which is unsuitable for use in superalloy production.
The skilled artisans have attempted many methods to recover metal values from superalloy scrap with varying degrees of success. Exemplary of such efforts are those processes disclosed in U.S. Pat. Nos. 4,138,249; 4,193,968; 3,083,085 and 3,544,309.
In accordance with the present invention, a method of separating metal values from superalloy scrap is provided wherein the major constituents of the superalloy, such as nickel, chromium, cobalt and molybdenum, are separated from each other and recovered. Such recovery allows for isolation of these values in substantially pure form so that they can be reused in the manufacture of superalloys, thus conserving valuable raw materials.
BRIEF DESCRIPTION OF THE INVENTION
A method for recovering superalloy scrap is provided. The method involves oxidizing superalloy scrap in an aqueous acidic medium. The aqueous acidic medium has an oxidation potential sufficient to oxidize nonferrous additive superalloy elements to insoluble oxides thereof and to oxidize major superalloy constituents to aqueously soluble ionic species. The insoluble solids from the aqueous solution are separated and the aqueous solution is extracted with an aqueously substantially insoluble tertiary amine to form an organic phase and an aqueous phase. The aqueous phase contains essentially nickel and chromium values. The organic phase is sequentially extracted with aqueous solutions which selectively solubilize individual metal value species to form individual aqueous solutions having substantially single metal value species therein. The metal value species solutions are processed to obtain substantially pure metal values.
DETAILED DESCRIPTION OF THE INVENTION
"Superalloys" as used herein means and refers to alloy compositions containing nickel and/or chromium and cobalt and at least one metal selected from the group consisting of molybdenum, aluminum, titanium, tantalum and columbium.
"Valve metals" as used herein means and refers to refractory metals such as titanium, tantalum, columbium and the like which form oxide films stable enough to serve as capacitors or electronic valves.
The superalloy scrap useful in the practice of the invention is in the form of high surface area per unit weight material, such as grindings and other particulate matter. Preferably, the material has a mesh size of 20 to 200, and more preferably a mesh size of 100 to 200. The high surface area is desired so that it will readily react in the aqueous acid medium. Although very large pieces of superalloy scrap, i.e. on the order of one-eighth to one-half inch in diameter may be used, it is preferred that they be reduced in size in order to allow for ready reactivity with the acid solution.
Preferably, the scrap is first degreased by an appropriate organic solvent and/or otherwise treated to remove particulate impurities such as dirt and the like from the scrap prior to treatment in the process in accordance with the invention.
The scrap is then contacted with the aqueous acidic medium. The aqueous acidic medium useful in the practice of the invention is one which is rich in chloride ion so that it readily reacts with the metal values in the scrap. The chloride concentration in the aqueous acidic medium should be in the range of 150 to 350 grams per liter corresponding to 4.2 to 10 molar HCl. The aqueous acidic solution can be provided by hydrochloric acid per se or with chlorine gas to provide the desired acidity and chlorine concentration to the media.
Further, a hydrochloric acid solution can be enriched by the addition of chlorine gas thereto.
The solution potential is preferably controlled in the range of above +500 millivolts in order to provide a rapid leaching, i.e. reaction of the metal values with the acidic medium. Further, the solution potential should be at least about 750, and more preferably at least about 800 millivolts prior to solvent extraction in order to have any iron present as Fe +3 and molybdenum as Mo +6 . Although these valence states for iron and molybdenum can be maintained at potentials less than 800 millivolts, it is desired to maintain the potential at or about 800 millivolts in order to ensure these valence states. In addition, the oxidation potential should be maintained at about 800 millivolts to ensure that the valve metals are converted from the metallic state to the oxide state. Typically, the valve metals in superalloys are aluminum, silicon, titanium, tantalum and columbium and, thus, are converted to aluminum oxide, silicon dioxide, titanium dioxide, tantalum oxide and columbium oxide. These valve metal oxides are believed to be insoluble in the aqueous acidic medium and are capable of being removed by filtration, and the aqueous acidic solution containing the metal values to be recovered can be further processed.
The solution potential is determined by placing a redox combination electrode in the solution and reading on the millivolt scale of a pH meter. The solution potential can be adjusted by addition of hydrogen gas or chlorine gas. If chlorine gas is bubbled into the solution, the oxidation potential will rise, while if hydrogen gas is bubbled in, the oxidation potential will decrease.
The initial reaction between the aqueous acidic medium and the superalloy scrap is conducted below about 105° C. at atmospheric pressure since it is limited by the boiling point of water and the ionic species present therein. However, higher temperatures may be utilized if the reaction is conducted under pressure. At a minimum, the initial reaction between the aqueous acidic medium and the superalloy scrap is about 80° C. Since the reaction is exothermic in nature, the reaction may be started at about 80° C. and the exotherm will cause a rise to near the boiling point, and will sustain the reaction at that temperature. It is recognized that these superalloys typically contain high amounts of cobalt and chromium and, in the case of most superalloys, a temperature of 70° to 80° C. is sufficient to provide reaction. However, due to the exothermic nature of the reaction, the solution typically rises to the 90° to 105° C. range.
The reaction between the aqueous acidic media and the superalloy scrap is allowed to proceed to apparent completion and the aqueous solution is filtered free of solids. The solids are the valve metal oxides and any other oxidized impurities that are present in particulate form. Typically, the resultant aqueous solution has 50 to 200 grams per liter of metal values in the form of iron, molybdenum, cobalt, chromium and nickel. The concentration of the various species is dependent, of course, upon the particular composition of the scrap. The soluble metal values are present in the form of Fe +3 , molybdenum as Mo +6 , cobalt as Co +2 , chrome as Cr +3 and nickel as Ni +2 .
The aqueous solution is first extracted with an aqueously substantially insoluble tertiary amine. The tertiary amines useful in the practice of the invention are those typical insoluble amines having an average of 5 or greater carbon atom chains pendent from the amino group. Exemplary of such aqueously insoluble amines are triphenylamine, triisobutylamine, trihexylamine and triisooctylamine. A typical commercially available amine which is useful in the practice of the invention is Alamine 336 which is triisooctylamine sold by Henkel Corporation. The tertiary amine is dissolved in a hydrophobic solvent, and more preferably in a hydrocarbon solvent. The hydrocarbon solvent is preferably one which boils at above 100° C. so as to avoid loss of the solvent during processing. Typically, hydrocarbon solvents or monoalcohols having an average of 9 or greater carbon atoms are useful. The upper limit of the carbon atom chain length is determined by whether or not the solvent is liquid at processing temperatures. From an economic point of view, it is desirable to use a hydrocarbon such as kerosene or the like. It has been found that a mixture of isodecanol and kerosene is particularly useful as a solvent for extraction of the metal values from the aqueous solution. Preferably, the amine concentration is at a level of 5 to 25 percent by volume.
The aqueous acidic media containing the metal values of iron, molybdenum, cobalt, chrome and nickel is maintained at a temperature of about 30° to 50° C. and intimately contacted by the amine solution. The amine solution extracts cobalt, iron and molybdenum into the organic phase, thus providing an aqueous solution containing nickel and chromium with an organic phase containing cobalt, iron and molybdenum at the oxidation states previously recited.
If the extraction is done by countercurrent method, a rate of 0.5 to 2.0, and more preferably 1.0 to 1.25 of organic phase to one of aqueous phase is preferable. The organic phase containing the metal values is then intimately contacted with a cobalt chloride solution having 30 to 100 grams chloride per liter, and preferably 40 to 75 grams per liter. The organic phase is extracted by the cobalt chloride solution, preferably in countercurrent fashion, at a ratio of 5 to 10 of organic phase to one of the cobalt solution. It is necessary to control the chloride content of the cobalt chloride solution in order to achieve a selective separation of cobalt from the remaining metal values, particularly iron, in the organic phase. Subsequent to the stripping of the organic phase with the cobalt chloride solution, the cobalt chloride solution containing the extracted cobalt is separated and the cobalt recovered by electrowinning or by other methods well known to those skilled in the art.
The organic phase from which the cobalt has been extracted is then intimately contacted with water slightly acidified to remove the ferric ion. The total chloride content in the water must be 30 grams per liter or less, otherwise the iron will be retained in the organic phase. Because iron is a particularly plentiful metal and sources of iron other than from recovery are much less expensive, the solution containing the ferric iron can be discarded. The organic phase, which is free of cobalt and iron, is then adjusted with an appropriate base such as sodium carbonate, sodium hydroxide or the like to a pH of 10 or greater. Upon adjustment of the pH to 10 or greater, the molybdenum is stripped from the organic and can then be recovered by methods known to those skilled in the art.
The aqueous solution which contains the chromium and nickel values can then be treated by deacidifying the solution with an appropriate base, such as sodium carbonate, to a pH above about 7. The precipitate is formed, which is theorized to be nickel carbonate in the case of sodium carbonate addition and chromium hydroxide. Other precipitation methods known to those skilled in the art may be used; however, the method specified herein has the advantage that a substantially pure nickel-chromium precipitate is formed without the inclusion of other metal values. The precipitate can then be converted by methods known to those skilled in the art to a substantially pure nickel-chromium alloy. In the alternative, the nickel and chromium can be separated into separate metal values. The nickel and chromium precipitate can be treated with a peroxide, such as hydrogen peroxide or the like, to convert chromium +3 to chromium +6 and put the chromium into solution. The nickel precipitate can then be separated from the chromate-containing solution.
The process of the invention can be more fully understood by reference to the following drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a process flow sheet illustrating the process in accordance with the invention.
DETAILED DESCRIPTION OF THE DRAWING
In FIG. 1, the scrap is charged to an appropriate vessel containing the aqueous acidic medium having an oxidation potential of about 800 millivolts and a concentration of chloride at a level of 150 to 350 grams per liter. Upon dissolution of the chromium and nickel in the aqueous acidic medium, the undissolved solids are separated by filtration or the like and discarded. The aqueous acidic medium containing the metal values to be recovered is charged to an appropriate vessel and extracted with the organic amine solution to produce the organic phase having iron, cobalt and molybdenum, and the aqueous phase containing chromium and nickel. The cobalt is then extracted using cobalt chloride in aqueous solution, thus providing the cobalt in an aqueous solution which is separated from the organic solution. The cobalt is then electrowon to form cobalt metal. The organic solution is again stripped with water to form a solution of iron chloride, which is subsequently disposed of with iron in the aqueous phase, and molybdenum in the organic phase. The molybdenum in the organic phase is then stripped with sodium carbonate and treated with ammonium chloride and nitric acid to form molybdenum oxide. The remaining organic phase is treated with concentrated hydrochloric acid to protonate the tertiary amine, and thus can again be used in the iron-cobalt-molybdenum extraction previously discussed. The aqueous phase containing the chromium and nickel is then treated by oxidizing the chrome +3 to chrome +6, precipitating the nickel (as an insoluble nickel carbonate) and separating the solid phase which contains the nickel from the liquid phase which contains the chromium +6 . The solid nickel is then calcined or electrowon to form nickel oxide or nickel metal, respectively, and the chromium solution is treated in order to crystallize the chromium to form Na 2 Cr 2 O 7 .
Thus, the process in accordance with the invention is applied in order to recover and separate the nickel and chromium which are present in scrap superalloy.
The following examples will more fully illustrate the process in accordance with the invention.
EXAMPLE I
Superalloy grindings having a composition of:
56 percent Ni
18 percent Cr
13 percent Co
5 percent Mo
1 percent Fe
Al, Ti, Ta and W
and having a particle size distribution of
______________________________________Mesh +20 -20 + 40 -48 + 100 -100 + 200 -200sizeWeight 2 20.6 49.30 20.50 7.60______________________________________
were used as a source of metal values.
To a 20 liter glass reactor fitted with a stirrer, thermometer and heating source was charged, at a nominal rate, 110 grams/hr of superalloy grinding and 16.6 ml/min of 29 percent HCl aqueous solution. The process was run for 21 hours at 85° to 105° C., thus treating 2090 grams of grindings with 19.9 liters of 29 percent HCl.
EXAMPLE II
Example I was repeated, except that the process was run for 19 hours and then for 3.4 hours at a grinding nominal feed rate of 110 grams/hr and 16 ml/min of 29 percent HCl aqueous solution. Finally, metal grindings were charged at a nominal feed rate of 220 grams/hr with an acid rate of 32 ml/min. The total grindings charged were 4050 grams, and the total acid charged was 14.5 liters. The run was conducted at 85° to 105° C.
EXAMPLE III
To the reactor of Example I was charged 300 grams of the metal grindings of Example I, along with 15 liters of 29 percent HCl. The reaction was run at 85° to 105° C. for 2 hours. After 2 hours, 1650 grams of grindings were charged at a nominal rate of 330 grams/hr along with 54 ml/min of 29 percent HCl for 4 hours. In Example III, 4650 grams of grindings were treated with 28 liters of 20 percent HCl.
EXAMPLE IV
Example III was repeated, except that after the initial 2 hour period grindings were charged at a nominal rate of 330 grams/hr, along with 54 ml/min of 29 percent HCl for 5.8 hours and, subsequently, 440 grams/hr of grindings along with 54 ml/min of 29 percent HCl for 8.1 hours.
In all of the examples there was an apparent dissolution of the metal grindings. However, there was about 5.6 percent of the initial grindings charged as a fine black metal powder.
EXAMPLE V
The acid solutions along with precipitated fractions were combined in a single vessel. The total solids were 19,400 grams with 151.7 liters of 29 percent HCl. The pH of the solution was well below zero. The reactor of Example I was charged with a portion of combined acid solution and the solution heated to 90° C. Grindings were fed into the reactor at a rate of 220 grams/hr and 29 percent HCl at a rate of 54 ml/min. The reaction was run for 5 hours.
In Examples I through V a total of 24,370 grams of metal grindings were utilized with only 930 grams remaining as undissolved metal.
Table I illustrates the material balance in grams for all of Examples I through V.
TABLE I__________________________________________________________________________ELEMENT Form/ Ni Cr Co Mo Fe Other Cl H O Total Compound__________________________________________________________________________Input Solid 13647.2 4874.0 3168.1 1218.5 243.7 1218.5 24370.0 Grinding All.sup.1 43009.0 1211.5 44220.5 HCl H.sub.2 O.sup.1 9124.9 72998.0 82123.8 H.sub.2 O Water.sup.2 4254.0 34032.2 38286.2 H.sub.2 O Total 13647.2 4874.0 3168.1 1218.5 243.7 1218.5 43009.0 14590.4 107030.2 189000.5 InputOutput Solution 12635.0 15204.8 27839.8 NiCl.sub.2 4693.0 9611.6 14304.6 CrCl.sub.3 2931.3 7055.0 99.4 10085.7 H.sub.2 CoCl.sub.4 2 960.3 1775.5 20.0 160.0 2915.8 H.sub.2 MoOCl.sub.5 3 231.0 585.9 8.3 825.2 H.sub.2 FeCl.sub.4 . 7725.2 217.6 7942.8 HCl 13358.9 106871.1 120230.0 H.sub.2 O Gas 886.2 886.2 H.sub.2 Crystals.sup.3 485.9 0.02 113.7 6.1 1051.0 1656.7 mixed crystals Undissolved 526.3 94.1 123.1 134.3 6.6 46.5 930.9 Grindings Solid Fine Black 86.88 123.9 1172 1382.8 Fine Black Material.sup.4 Material.sup.4 Total 13647.2 4874.0 3168.1 1218.5 243.7 1218.5 43009.0 14590.4 107031.1 189000.5 Output__________________________________________________________________________ .sup.1 Input is 35 percent HCl .sup.2 Water to make 29 percent HCl .sup.3 Mixed chloride crystals of Ni, Cr, and Fe .sup.4 Fine Black Material is valve metals and other impurities
The final solution properties of the combined reaction products were as follows:
87.50 grams/liter Ni
32.50 grams/liter Cr
20.30 grams/liter Co
6.65 grams/liter Fe
294.60 grams/liter Cl
2.00 molar HCl
Density: 1.280 grams/cm 3
Potential: +177 mv
It was noted during the running of Examples I through V that it was necessary to keep the chloride ion concentration at about 280 to 300 grams/liter for effective dissolution of grindings.
Although Examples I through V were conducted using HCl as an oxidant, other oxidants such as oxygen, ozone, chlorine, chromate ion or ferric ion can also be used in the practice of the invention.
The combined reaction products of Example I through V were raised to an oxidation potential of about +800 with H 2 O 2 and were filtered free of solids and used as the base material for the remaining examples.
EXAMPLE VI
To a 5 gallon glass reactor equipped with an agitator and a thermometer was charged 1 gallon of combined reaction product along with 1 gallon of 30 percent by weight Alamine 336 (triisooctylamine), 40 percent by weight isodecanol and 30 percent by weight kerosene. The organic phase and the aqueous phase were heated to 40° C. and agitated to ensure intimate contact of the two phases for 4 minutes. The organic phase was drawn off and 1 gallon of amine solution was charged to the reactor and contacted and separated as previously described. Again, 1 gallon of amine solution was charged, contacted and separated as previously described. Thus, 1 gallon of reaction product had the cobalt, molybdenum and iron extracted therefrom into 3 batches of organic phase.
The 3 batches of organic phase were combined and extracted by 4 successive extractors with 1 gallon of aqueous HCl solution having a pH of 2. The aqueous phase contained the cobalt and the organic phase contained Fe and Mo.
The organic phase, which has the Co removed therefrom, was extracted by contacting with 1 gallon of water to remove Fe in the aqueous phase. The organic phase, which now contained only Mo, was adjusted to a pH of 10 to 12 by the addition of a 22 percent by weight aqueous solution of sodium carbonate, and the molybdenum was stripped from the organic phase as Na 2 MoO 4 . The organic phase was protonated by the addition of HCl and used for subsequent extractions.
The process of Example VI was repeated several times in order to treat 10.5 gallons of combined reaction product.
In the process of Example VI, 95 percent of Co, 98 percent of Mo, 99 percent of Ni and 94 percent of Cr were recovered from the combined reaction product.
EXAMPLE VII
The cobalt solution recovered in accordance with Example VI was filtered and neutralized to a pH of 5.5 with sodium carbonate to remove nickel and iron. The cobalt was recovered by electrowinning the cobalt solution.
EXAMPLE VIII
The molybdenum solution formed in Example VI as Na 2 MoO 4 was converted to MoO 3 by reaction with ammonium chloride and then with nitric acid.
EXAMPLE IX
The aqueous solution containing Ni and Cr formed in Example VI was adjusted to a pH of 7 to 10 with sodium carbonate, thus precipitating NiCO 3 and Cr(OH) 3 .
The precipitate was slurried in water and reacted with H 2 O 2 to oxidize Cr +3 to Cr +6 , thus providing soluble sodium chromate and precipitated NiCO 3 . Once precipitated, the nickel can be electrowon. The chrome can be precipitated as CrO 3 or as Na 2 Cr 2 O 7 .
Thus, precipitate can also be calcined to remove CO 2 and aluminothermically reduced to an alloy of Ni and Cr.
In order to provide maximum recovery of metal values from the superalloy scrap, certain parameters must be observed during the process.
Thus, prior to extraction with the organic phase, the reaction product must be carefully oxidized so that iron is present as Fe +3 , Mo is present as Mo +6 , cobalt is present as Co +2 and chromium is present as Cr +3 . Further, to ensure the extraction of Co +2 , the Cl - content of the solution must be at about 250 grams/liter to ensure complete formation of the CoCl 4 -2 ion.
Although the specific examples herein are directed to a batch recovery process, the process of the invention is adaptable to performance of a continuous basis using known countercurrent methods.
Thus, the process of the invention provides a method of recovering a substantial amount of the valuable metal values in superalloy scrap.
Although the invention has been described with reference to specific processes and specific matrials, the invention is only to be limited so far as is set forth in the accompanying claims. | A method for recovering superalloy scrap is disclosed. The method involves oxidizing superalloy scrap in an aqueous acidic medium. The aqueous acidic medium has an oxidation potential sufficient to oxidize nonferrous additive superalloy elements to insoluble oxides thereof and to oxidize major superalloy constituents to aqueously soluble species. The insoluble solids from the aqueous solution are separated when the aqueous solution is extracted with an aqueously substantially insoluble tertiary amine to form an organic phase and an aqueous phase. The aqueous phase contains essentially nickel and chromium values. The organic phase is sequentially extracted with aqueous solutions which selectively solubilize individual metal value species to form individual aqueous solutions having substantially single metal value species therein. The metal value species solutions are processed to obtain substantially pure metals. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the design and operation of electrolysis cells for chemical production and more particularly to production scale electrolysis cells.
2. Description of the Related Art
High temperature electrolysis cells, such as are used for aluminum reduction are often operated using gravity stabilized liquid layers of molten metal, fused salt, etc. with the electrolysis electric current passing in a vertical direction through a shallow layer of electrolyte solution. For reactions in which gas is evolved in the form of, for example, oxygen bubbles or a deposit of a partially insulating film at an anode, the bubbles or film must be efficiently removed or the electrolyte will be displaced and cell resistance will rise.
For large industrial scale cells operating with currents of 10 5 amperes and above, the magnetic field developed at the periphery of a large cell is substantial and will induce a lateral force on the electrolyte which can exceed typical buoyant forces on bubbles or low density fluids. This force can be used to displace the electrolyte toward elevated channel regions where gas bubbles may be collected. Auxiliary systems to increase this magnetic field will permit more rapid flow of electrolyte and improve cell operation.
Unfortunately in the usual geometries of circular or rectangular cells, the self-magnetic field vanishes at the geometrical center. The present inventor has been specifically involved with investigating methods for producing oxygen from lunar soil. Operation of such electrolysis cells to produce oxygen on the moon by electrolyzing molten lunar soil or rock will encounter additional difficulties in bubble removal due to lowered buoyant forces with ambient gravity (1/6 earth value) and the higher viscosities of silicate fluids. It was during these investigations that the present inventor discovered the present invention, which, although is particularly adaptable for lunar applications, has broad based general applications.
As will be disclosed below, the present invention is designed to provide a minimum total or combined field of at least 70% of the edge field.
U. S. Pat. No. 4,713,161, issued to Chaffy et al., entitled "Device for Connection Between Very High Intensity Electrolysis Cells for the Production of Aluminum Comprising a Supply Circuit and Independent Circuit for Correcting the Magnetic Field", is based on using a separate predominantly horizontal electric circuit to compensate for the self-field of a line of rectangular cells in series and also to counteract the stray magnetic field due to adjacent lines of cells. The '161 device is intended to reduce the vertical part of the magnetic field in the cell as much as possible to minimize distortion in the molten cathode pool.
U.S. Pat. No. 4,469,759, issued to W. J. Newill, entitled "Magnetic Electrolyte Destratification" and U.S. Pat. 4,565,748, issued to E. A. Dahl, entitled "Magnetically Operated Electrolyte Circulation System" discloses pumping devices which are outside the working portion of the electrolysis cell or cell stack. The magnetic field of the pumping devices disclosed in these patents have negligible penetration into the working portion of the cell or cell stack. The '748 patent uses two-phase AC excitation of the magnetic coils and induced currents in the electrolyte. The '759 device uses DC or a permanent magnetic field and imposes current flow through the electrolyte to achieve a pumping effect. Both of these devices are primarily intended for use in multi-plate batteries rather than electrochemical production cells.
U.S. Pat. No. 3,969,214, issued to M. Harris, entitled "Permanent Magnet Hydrogen Oxygen Generating Cells" discloses the use of thermal energy, only, to produce hydrogen and oxygen from aqueous acids. It uses a combination of permanent magnets and coils to produce a magnetic field substantially at right angles to the electrode faces.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a principal object of the present invention to improve the current density and operation of electrolysis cells.
Another object is to promote the bubble removal of electrochemically generated gases on electrodes of these electrolysis cells.
Another object of the present invention is to lower the resistivity of the electrolyte and improve the energy efficiency of the cell.
These and other objects are achieved by the present invention which is a system for increasing laminar or turbulent lateral flow in an electrolysis cell. In its broadest aspects, the system includes at least one electrolysis cell having a principal direction of current flow. The electrolysis cell has two electrode surfaces whose mean surface planes are substantially parallel, separated by a fluid electrolyte layer.
One or both of the electrodes may have local regular or random structures (elevations or depressions above or below their mean surface planes) and in addition may consist of a plurality of smaller structures connected in parallel to the power sources. The electrolysis cell proper may be defined as comprising the electrolyte and container, electrodes and circuit elements essential to the electrochemical process involved.
Separate electric current conducting means, energized by an electric power source and independent of the electrolysis circuit elements are so arranged and constructed with respect to the cell to increase the average component of the magnetic field substantially parallel to the mean electrode surfaces within the fluid electrolyte layer. This increase in the magnetic field is relative to the magnetic field due solely to the electrolysis current. A flow return conduit is included for connecting at least one entrance port of the electrolysis cell to a least one exit port of the electrolysis cell. The ports are disposed substantially parallel to the pressure gradient formed by the magnetic forces present during operation.
The present invention can provide a smooth, shear flow parallel to the mean plane of the electrode surfaces. The shear flow can be adjusted over a considerable range of velocities for electrolysis cells of different sizes. Particularly, a large flow velocity can be achieved in small cell sizes which otherwise would have small magnetic self fields. Depending on the detailed geometry of the electrodes. It is possible to induce vortex flow which may aid in the removal of bubbles and partially insulating films.
In the preferred embodiment, annular electrolysis cells are divided into series connected groups and the current paths are minimized for assemblies within an even number of cell groups. These cell groups can be deployed in a manner which minimizes unwanted stray magnetic fields.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective illustration of two groups of interleaved, series connected annular electrolysis cells connected in accordance with the principles of the present invention.
FIG. 2 is an enlarged cross sectional view of two annular electrolysis cells connected in series, illustrating the wiring thereof and the arrangement for recirculant flow.
FIG. 3 illustrates an annular electrolysis cell with a toroidal coil used to enhance the magnetic field.
FIG. 4 illustrates a rectangular electrolysis cell with an enclosing rectangular solenoidal coil.
FIG. 5 is a plot of the normalized magnetic field strength versus radius for various annular electrolysis cells with different values of aperture current and radius ratios.
FIG. 6 illustrates a wiring schematic for three series connected cell groups which provide an aperture current equal to twice the cell current.
The same elements or parts throughout the figures are designated by the same reference characters.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings and the characters of reference marked thereon, FIG. 1 illustrates a preferred arrangement of electrolysis cells in accordance with the principles of the present invention, designated generally as 10. In a typical commercial plant system, a large number of electrolysis cells are operated in series. FIG. 1 illustrates the present novel connection of electrolysis cells to provide enhanced parallel magnetic fields.
FIG. 1 illustrates two groups of serially connected electrolysis cells, labelled a and b. Each group is preferably deployed in a straight line and the two lines are in close proximity to each other. All of the cells are substantially identical. Each electrolysis cell is annular in horizontal cross section and contains a central aperture. The current flow through the electrolysis cells is vertically downward. The electric current conducting means or conductor 12 contacts the anode 14 of the last cell a N of the a group of serially connected electrolysis cells. It exits through the bottom electrode or cathode 16 of cell a N . The exiting current is brought up along the electric current conducting means, as shown at location 18, and passes down through the aperture 20 of the adjacent cell of the b group, b N-1 . Electric current conductor 18 is then directed to the anode 22 of the preceding a-group cell, a N-1 . This interleaved conducting pattern is continued between each preceding successive cell. The current finally passes through the cathode 24 of the first cell, a 1 and passes along conductor 26 to an external power source 27.
The serially connected b-group of electrolysis cells are connected in the same manner as the a-group of cells. Prior to the point where the current enters or leaves its respective chain it must pass through an aperture of the adjacent chain. Thus. for example, prior to the current entering the a N anode or upper electrode 14 the conductor is first introduced through the aperture in cell b N . In the case of the b chain, the current exiting the cathode or bottom electrode b 1 will be brought up and passed downward through the aperture of a 1 before being connected to the external power source 27.
The magnetic force between the current carrying electrolyte and the magnetic field is directed radially inward on the fluid and produces a pressure gradient increasing in the radial inward direction. The electrolyte is allowed to recirculate by passing through an exit port 28 on the inner surface of the annulus and flowing through a conduit 30 to an entrance port 32 on the outer periphery of each annular cell. Although for simplicity in the drawing, FIG. 1 shows only one conduit 30 for each cell these conduits might normally be arranged in a series of radial conduits disposed about the circumference of each annular cell.
The current flow arrangement shown in FIG. 1 has the electric current in the cell groups a and b running essentially parallel in the end-to-end flow of the cell groups. An alternative arrangement produced by a slight modification of the wiring diagram would be to arrange for the series flow in cell group b to flow from left to right rather than right to left as shown in the figure. This may be of advantage in a further option where the cell string a and cell string b are connected in series. In that case the current exiting cell string a, for example, on the left hand edge, could be connected to the cell b 1 and the current could progress then from b 1 to b n . Both the entrance and the exit current from the combined cell stacks would thus be at the right hand edge of the figure.
In conventional static electrolysis the current density is often limited by heating effects. The current density may be limited by chemical diffusion in the electrolyte or by evolution of gaseous bubbles at one or both electrodes and deposition of partially insulating films on the electrodes. The effects of depletion of charge carrying species in vicinity of the electrodes and accumulation of gas bubbles can be reduced or eliminated by accelerating the stirring action in the electrolytic fluid. Insulating films such as those deposited during anodization of metal surfaces may also be favorably influenced by increased stirring action.
The magnetic fields due to the current flowing vertically downward through the electrolytic cells and their apertures produce a circulating circumferential field in the clockwise direction viewing along the direction of current flow. By adjusting the current ratio through the apertures and the cells and the ratio of inside to outside radii or diameters of the annular electrodes, one can produce nearly uniform and elevated levels of magnetic field strength through the volume of the electrolyte (see FIG. 5). The magnetic pressure gradient due to current carrying fluids in a magnetic field is given by the vector product of the current density and magnetic induction. By developing a higher average magnetic field or induction higher pressure drops are developed across the electrolysis cell and increased recirculant flow is produced.
Referring now to FIG. 2, an alternate embodiment is illustrated showing two electrolysis cells 34, 36 connected in series. The input current lead 38 for the electrolysis cell 36 first passes through the aperture 40 of cell 34. It is then brought up and enters the anode 42 of cell 36. The cathode 44 from cell 36 is connected to the anode 46 of cell 34 via conductor 48. The current emerges from the cathode 50 of cell 34 and is then brought up and directed through the aperture 52 of cell 36. The current is then passed via path 54 to the power source (not shown).
Alternately, path 54 can be deployed in the manner of path 38 on an additional pair of electrolysis cells and the current pattern repeated for any even number of cells. The apparatus for allowing the recirculant flow of the electrolyte is shown in the figure as conduit 56. The electrolyte fluid flows out exit port 58 through the conduit 56 and enters the entrance port 60 at the outer periphery of the electrolysis cell. The fluid in the conduit does not experience any sizable pressure gradient since it is carrying a negligible current level, even though the magnetic field may be appreciable at that point.
The conduit may be located within the insulated space for high temperature cells to avoid congealing or freezing the electrolyte (not shown). The electrolysis cell is shown with an electrolyte area or volume larger than that between the electrodes. This can allow for additional fluid inventory or permit temperature differentials to allow the electrolyte to freeze up in certain zones to protect the cell walls 62 against corrosion.
In the arrangement shown, in which current passing through aperture is the same value as the current passing through the cell, there is a unique ratio of outside radius to inside radius of the electrode zones which will provide more nearly uniform magnetic fields across the electrolyte between the electrodes. This radius ratio would be 2 to 1, that is the outside radius of the electrode r max would be twice that of the inside radius r o of the electrode in the cell.
In the above mentioned embodiments, the electric current conducting means are energized by the same electrical power source, providing current to the electrolysis cells. In a second class of embodiments which incorporate the principles of the present invention, an electric power source is utilized which is independent from the source which provides the electrolysis current for the electrolysis cells. In this class of systems it is usually advantageous to use multi-turn coils to reduce the current values and conductor sizes.
Referring now to FIG. 3, an annular electrolysis cell 64 is illustrated surrounded by a multi-turn radial toroidal coil 66. The direction of current flow is selected to provide a magnetic field in the same direction as the field due to the electrolysis current. With this arrangement it is possible to elevate the magnetic field to a value many times that of the field of the cell electrolysis current. This is particularly useful with small electrolysis cells. Coils 66 may be thermally insulated and constructed of superconducting materials to provide high magnetic fields without power consumption.
Referring now to FIG. 4 an embodiment is illustrated for a rectangular cell profile in which, as in FIG. 3, the electrical source is independent of the source which provides the electrolysis current for the electrolysis cell. An electrolysis cell 68 having a substantially rectangular cross section is enclosed by a multi-turn rectangular solenoidal coil 70. This, like the FIG. 3 embodiment allows generation of magnetic fields much higher than the field due to cell electrolysis current. The embodiments of this class, which uses multi-turn coils for the electric current conducting means can be energized in series for a large group of cells to reduce the current requirements and improve the engineering advantages of high voltage and low current supplies. In cases where the coils are made of superconducting material it is preferable to energize the persistent current separately for each cell so that in the event of over temperature occurring someplace in the circuits, this would not terminate the stirring system for all the cells at once. The coils could then be separately energized and separately turned on or off during cell operation. For rectangular cell geometry, it is also possible to have a single solenoid coil enclose two or more electrolysis cells either axially or laterally, or conversely, to use several smaller solenoids to enclose a single electrolysis cell.
Referring now to FIG. 5, a plot of normalized magnetic field strength versus radius is shown for several of the above-described annular electrolysis cells. The ordinate axis (y) shows the normalized magnetic field strength as a function of the radius from the center of symmetry for circular annular cells displayed on the abscissa or x-axis.
Curve 72 shows how the magnetic field decays from the right hand edge where the outer radius of the electrode down toward the center for the case where the inner aperture drops to zero, that is the case of a solid circular cylinder conductor. The field vanishes where the radius equals zero and reaches a maximum of 2 on the normalized scale. If that same circular conductor is modified by introducing an aperture to form a hollow conductor where the inside radius of the electrode is half the outside radius and operated at the same current density as the original conductor, the maximum field at the outside or right hand edge drops to 75% of the maximum value of curve 72 (i.e. 1.5), as illustrated by curve 74. Note that curve 74 refers to the case where there is no extra current flowing through the aperture and the magnetic field drops to zero at the inside radius. For the same annular cell with the inside to outside electrode radius ratio of 1 to 2 the magnetic field is shown in curve 76 where the extra electric current passing through the aperture is equal to the current passing through the cell, characteristic of the embodiments which use the same cell current source for the electric current conducting means. Note that the magnetic field is increased from curve 74 to 76 and furthermore that the magnetic field is very nearly uniform within 5% across the electrolyte within the electrode areas. Inside the aperture, the magnetic field, as shown in the dotted line, increases to a minimum radius depending on the radius of the central conductor, but this is of no consequence in the operation of the cell.
Curve 78 shows the corresponding case where the current passing through the internal aperture is twice the current passing through the cell as one might obtain from using three groups of cells which are interleaved. In this case, if one selects the inner radius of electrode area to be 2/3 of the outer radius one will obtain a nearly uniform magnetic field across the cell. Again, the magnetic field within the annulus that is not in the electrolyte area is shown increasing as the distance from the central axis is decreased.
For the earlier case shown in curve 76, the average magnetic field and average pressure gradient across the cell from the outside to inside edge is approximately 4 times higher than that shown in curve 74, which is the annulus without the central aperture current. This indicates that the total pressure drop from the inside to the outside edge is 4 times as large as for the case where no aperture current is used. This translates into about 4 times as high a recirculant flow rate through a given conduit system.
Referring now to FIG. 6, a wiring schematic is illustrated which corresponds to the curve 78 in FIG. 5. For this case the aperture current is equal to twice the current through an individual cell provided by using 3 groups of cells in series and interleaving the conductors. For example the groups b and c conductors pass through the a cell aperture and conductors for the a and c group cells pass through the b cell apertures and the a and b group cell conductors pass through the apertures of the c cells.
It is understood that the magnetic fields, due to the portions of the circuit which do not pass through the aperture, can be deployed in such a fashion to minimize the stray vertical magnetic fields or the non-uniformity of the horizontal fields by making such current carriers more nearly symmetrical with respect to the axis of the cells. This can minimize adverse effects due to the uneven or unwanted magnetic fields of the system.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | The system includes at least one electrolysis cell having a principal direction of current flow. The electrolysis cell has two electrode surfaces whose mean surface planes are substantially parallel, separated by a fluid electrolyte layer. Separate electric current conducting means, energized by an electric power source and independent of the electrolysis circuit elements are so arranged and constructed with respect to the cell to increase the average component of the magnetic field substantially parallel to the mean electrode surfaces within the fluid electrolyte layer. This increase in the magnetic field is relative to the magnetic field due solely to the electrolysis current. A flow return conduit is included for connecting at least one entrance port of the electrolysis cell to a least one exit port of the electrolysis cell. The ports are disposed substantially parallel to the pressure gradient formed by the magnetic forces present during operation. |
BACKGROUND OF THE INVENTION
The present invention is directed generally to an improved parts container and more particularly to such a container having a rack member receiving opening through the parts chamber therein for space efficient packing and display of the containers.
Small containers are used in connection with the packaging and sales of many different types of parts, such as fishing tackle, including leaders, swivels, weights, bobbers and the like and hardware, including nuts, bolts, washers, electrical fittings and the like. The container of these parts is generally blister wrapped or shrink wrapped onto a header card which extends above the container and has a hole for supporting the card on a rack wire of a typical retail store rack.
Whereas the containers provide convenient storage for selling a plurality or assortment of parts as a unit, they have several disadvantages. First, since parts containers are generally not supportable on the rack wires of a retail display or user's workbench, a header card is generally required which, after it is removed, destroys the capability of supporting the containers to be supported on the rack wires. Certain containers are provided with an integral external flange having the rack wire receiving opening therein but that flange extends the dimensions of the container in at least one direction with no corresponding increase in storage capacity for the container. The flange interferes with efficient packing of the containers for storage and transport and requires sufficient separation between containers on display racks to provide room for the flanges.
Accordingly, a primary object of the present invention is to provide an improved parts container having a rack member receiving opening through the parts receiving chamber within the container.
Another object is to provide an improved parts container adapted for space efficient packing in boxes for storage and transport.
Another object of the invention is to provide an improved parts container which eliminates the need for a separate header card for retail display on rack wires and the like.
Another object is to provide an improved parts container which may be opened, closed and reracked on a rack wire.
Another object is to provide an improved parts container which enables the racked containers to be arranged in closely spaced relation for space efficient display.
Another object is to provide an improved method for storing and displaying parts.
Finally, another object of the invention is to provide an improved parts container which is simple and rugged in construction, economical to manufacture and efficient in operation.
SUMMARY OF THE INVENTION
The parts container of the invention is adapted for support on a rack member and includes a top wall, bottom wall and a peripheral sidewall defining a parts containing chamber. A container lid is moveable between closed and opened positions of providing access to parts in the container. The top and bottom walls have generally aligned openings therethrough and a generally tubular sleeve is connected to at least one of the top and bottom walls around the opening therein. The sleeve extends toward the other wall in general alignment with the opening therein so that the container may be supported on a rack member directed through both openings and the sleeve. The sleeve prevents parts from being lost through the top wall and bottom wall openings when the container is closed. It also facilitates guiding the containers onto a rack member without interference.
The top wall preferably serves as the lid and is pivotally connected to a base formed by the bottom wall and peripheral sidewall. A divider wall may be connected to and extended between the sleeve and peripheral sidewall both to structurally reinforce the sleeve and divide the chamber into a plurality of compartments. Additional subdivider walls may be added to divide the chamber into as many compartments as are desired.
The containers are thus self-supporting on a display rack wire and may be reracked any number of times during the long useful life of the containers. Since the rack member receiving opening is arranged within the confines of the peripheral sidewall of the container, there are no protrusions from the containers which would interfere with efficient packing of container into boxes for space efficient storage and transport.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the improved parts container of the invention;
FIG. 2 is a perspective view of the parts container with the top wall pivoted to an open position;
FIG. 3 is a top plan view of the parts container;
FIG. 4 is a top plan view of the base portion of the parts container;
FIG. 5 is an end view of the parts container;
FIG. 6 is a side elevation view of the parts container;
FIG. 7 is a diagrammatic view of prior art containers displayed on a retail rack; and
FIG. 8 is a diagrammatic view of the parts containers of the invention supported on a display rack.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The parts container 10 of the invention is illustrated in the drawings as including a base 12 adapted to be closed by a pivotal lid 14. Base 12 includes a bottom wall 16 and a peripheral sidewall 18 which is connected to and extended upwardly from the bottom wall so that the base defines a parts receiving chamber 20.
The lid 14 includes top wall 22 which is of a size and shape for closing the open top of base 12. To connect the lid to the base for movement between closed and open positions, top wall 22 has a peripheral flange 24 with depending hinge arms 26 having holes for receiving pivot pins 28 on the end walls 30 and 32 of base 12. Lid 14 is thus pivotally moveable between the closed position of FIG. 1 wherein access to the chamber 20 is substantially blocked and the open position of FIG. 2 providing access to chamber 20 and any parts therein. Whereas a hinged connection between the top wall and base is illustrated, it is understood that the top wall could alternately be provided as a slide panel with connecting structure providing for sliding movement in either in a straight or pivotal path relative to the open top of base 12. Alternately, access to the container could be provided by an access opening through any of the walls thereof with a closure cap being provided for the access opening. The illustrated embodiment is preferred for providing maximum access to parts in the container.
In the illustrated embodiment, lid 14 is releasably secured in its closed position by a tab 34 on flange 24, which tab has a recess for engaging a shoulder 36 on one sidewall 38 of base 12.
Bottom wall 16 has a rack member receiving opening 40 adjacent one end, which opening is preferably aligned with a similarly shaped opening 42 through top wall 22 in the closed position of the top wall. A generally tubular wall or sleeve 44 is secured to bottom wall 16 around the periphery of opening 40, which sleeve extends upwardly for engaging top wall 22 in the closed position thereof to prevent the loss of parts through the openings 40 and 42. Sleeve 44 is preferably a continuous peripheral wall, but may include openings, slots, or other interruptions for reducing the weight or material of the container, or for venting chamber 20 if desired. Whereas sleeve 44 may be arranged in spaced relation from end wall 30, as illustrated in the preferred embodiment, it could alternately be formed as a U-shaped member which is closed by one end wall 30.
Chamber 30 may be subdivided by a divider wall 46 connected to and extended between sleeve 44 and peripheral sidewall 18. The compartments defined by divider wall 46 may be further subdivided by subdivider walls 48 extended between divider wall 46 and peripheral sidewall 18 thereby to define multiple compartments within base 12. The height of the peripheral sidewall 18, sleeve 44, divider wall 46 and subdivider walls 48 is preferably uniform so as to be closed and sealed by the top wall 22 upon movement of the lid to its closed position.
An important advantage of the parts container of the invention is that it enables space efficient packing and display. In comparison, FIG. 7 illustrates typical prior art parts containers 50 which are blister wrapped or shrink wrapped onto header cards 52, each having a hole 54 for support on a typical retail store rack member or wire 56. Since the header cards 52 necessarily protrude outwardly from the containers 50 in at least in one direction, the containers are necessarily separated by at least the protruding dimension of the header card when the containers are stored on vertically spaced apart rack wires as illustrated in FIG. 7. Furthermore, the prior art containers 50 lose the capability of being reracked once the header cards are removed and discarded.
These problems are resolved by the improved parts container of the invention. Referring to FIG. 8, a plurality of parts containers 10 may be racked in very closely spaced vertical relation since no protrusions from the containers are necessary for racking. Furthermore, when a container 10 is removed from the rack and opened and closed, it can be reracked since the rack receiving openings and sleeve are integral parts of the container itself. It is often advantageous for the purchaser to display the containers of fishing lures, hardware, or the like on a pegboard equipped with racking wires for ready access to the parts. The containers are preferably formed of a translucent or transparent plastic so that the parts therein are visible through the container.
For sealing, the containers prior to sale, a transparent film may be shrunk wrapped or otherwise adhesively secured around the container to prevent opening of the container prior to destruction of the film.
The invention is, therefore, furthermore, directed to a method of packing and displaying parts container for retail sale or storage, including providing a plurality of the containers, providing a display including a series of vertically spaced apart rack members, placing parts in the containers and supporting the containers on the rack members by directing a rack member through the rack member receiving opening of each container. Such method further envisions reracking containers after they have been opened and closed.
Whereas the invention has been shown and described herein in connection with a preferred embodiment thereof, it is understood that many modifications, additions, and substitutions may be made which are within the intended broad scope of the appended claims. | A small parts container includes a top wall, bottom wall and peripheral sidewall connected to define a parts containing chamber. A moveable lid affords access to parts in the container. Aligned openings are provided through the top wall and bottom wall and an internal generally tubular wall surrounds those openings for defining a rack member receiving slot through the container. |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a special-purpose suit, in particular for pilots or vehicle drivers or other individuals whose bodies need to be protected, having an outer protective layer which protects against undesirable external influences, and a moisture-permeable and/or vapor-permeable inner layer.
2. Description of the Prior Art
Known protective suits provide insulation against heat and cold, but, when used for a prolonged period of time under extreme conditions or in emergency situations--e.g. a worker on an oil rig in bad weather conditions, a fire fighter in direct contact with the flames or a pilot in water--lead to rapid cooling or heating-up, this hindering or limiting the endurance of the person wearing the special-purpose suit, the period over which he or she can remain physically active, or his or her chances of survival.
It is, furthermore, known to use special protective suits to insulate and shield a person from the exterior surroundings, as this person carries out special tasks, by the provision of foils or sheets, non-flammable fibers, armoring, etc. However, the disadvantage with these known protective suits is that they hinder the natural regulation of the body heat and metabolic functions, because the foils or sheets, non-flammable fibers, armoring, etc. do not have the normal climatic properties of conventional clothing. The impaired heat exchange, in particular the lower evaporative transmission of heat, thus results in an increase in the average body temperature and sweating (dehydration). Accordingly, this reduces the endurance of the person wearing the special-purpose suit and the period for which he or she can remain physically active and prejudices his or her safety, in particular due to the lack of concentration and endurance.
The object of the present invention is thus to provide an improved special-purpose suit, in particular for pilots, which is insulated against undesirable external influences, while simultaneously maintaining normal climatic properties in the interior of the special-purpose suit, and provides a space-maintaining, elastic and heat-insulating function, in particular in high-acceleration phases or high-deceleration phases or in different pressure conditions.
SUMMARY OF THE INVENTION
According to the invention, a special-purpose suit or protective suit, in particular for pilots or vehicle drivers or other individuals whose bodies need to be protected, comprises an outer protective layer which protects against undesirable external influences, a moisture-permeable and/or vapor-permeable inner layer, and a space-maintaining, fluid-permeable spacer layer which is arranged between the outer protective layer and the inner layer and can be climatically conditioned with the introduction of a fluid, the protective layer, the inner layer and the spacer layer being designed such that they essentially cover the torso and/or the leg and/or the arm areas of the special-purpose suit.
The invention provides body-enclosing, enforced spacing in a special-purpose suit or special-purpose clothing in order to ensure the formation of an interspace between the body and the protective layer, by way of which interspace the basic insulation is increased and through which interspace a fluid or medium can flow without resistance. Climatic conditioning (in particular in terms of temperature, moisture and/or pressure) close to the body can be achieved, in particular, by conditioning of the fluid.
This thus provides a microclimate which is close to the body and ensures the dissipation of the heat and moisture which the body releases. The climatic conditioning close to the body thus provides relief for the body of the wearer, in particular by the direct heat and moisture exchange adapted to the body, and increases the capacity for physical activity and endurance of the wearer.
Furthermore, according to the invention, the body-enclosing spacer layer improves the basic insulation, in particular by minimizing the heat bridges and by the lower heat conduction of the medium or fluid itself.
According to the invention, the spacer layer comprises an elastic lattice with a flexible and compression-resistant, space-maintaining knitted fabric and/or woven fabric of interlinked plastic yarns.
Furthermore, providing a slight overpressure in the spacer layer hinders contamination by the penetration of contaminants. It is, furthermore, possible to provide in particular in the outer protective layer, layers which bind penetrating contaminants, this reducing the risk of contamination. In a preferred embodiment, fluid can pass through the spacer layer in an essentially coplanar manner.
The knitted fabric is, in particular, a knitted space-maintaining, textile fabric which permits free selection of the spacer-layer thickness and ensures a permanent restoring elasticity and stretchability of the spacer layer.
Furthermore, the knitted fabric and/or woven fabric makes it possible for the special-purpose suit to be designed with a low weight, this ensuring large freedom of movement and reduced strain to the wearer.
The spacer layer is particularly preferably divided up into at least two separate fluid regions, preferably different microclimates being produced in the at least two fluid regions, and sealing means preferably being arranged between the fluid regions.
Furthermore, the spacer layer preferably extends along the leg areas and/or the arm areas and/or the hand areas and/or the pelvic area and/or the abdominal area and/or the chest area and/or the area of the back.
According to a further preferred embodiment, the spacer layer is subdivided at least partially into fluid-connected sublayers which enclose annularly predetermined areas of the body.
The structure is preferably an elastic lattice structure of interconnected yarns, the spacer layer preferably comprising yarns, in particular of plastic, which are interlinked in the manner of cells.
In addition, furthermore at least one fluid connection or inlet is preferably provided for the connection of the special-purpose suit to a climate-conditioning device, in order to permit enforced climatic conditioning of the spacer layer, the fluid contained or present or arising in the spacer layer preferably being isolated fluidically from the exterior surroundings.
Furthermore, an additional space-maintaining, fluid-permeable spacer layer is preferably provided in the area of the head, in particular between the outer protective layer and the head.
According to a further embodiment of the present invention, the spacer layer is of a different thickness, preferably thicker, in certain areas.
The spacer layer is preferably thicker in the area of the back and/or in the area of the bottom and/or the pelvic area and/or the shoulder area than in the other areas, the spacer layer preferably being as thick to twice as thick in the area of the back and/or the area of the bottom and/or the pelvic area and/or the shoulder area as in the other areas.
According to a preferred embodiment, the spacer layer has a thickness of from approximately 3 to approximately 20 mm, preferably from approximately 5 to approximately 15 mm and particularly preferably from approximately 6 to approximately 13 mm in the area of the back and/or the area of the bottom and/or the pelvic area and/or the shoulder area.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention are described by way of example hereinbelow with reference to the drawing, in which
FIG. 1 shows a schematic sectional view of the layers of a preferred embodiment of the special-purpose suit according to the invention;
FIG. 2 shows a schematic view of a first embodiment of the special-purpose suit according to the invention; and
FIG. 3 shows a diagrammatic view of a second embodiment of the special-purpose suit according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the special-purpose suit according to the invention comprises a multi-layered woven fabric 100 shown in FIG. 1.
The multi-layered woven fabric 100 comprises an outer protective layer 110 which protects against undesirable external influences, e.g. against a naked flame, extreme cold and/or against toxic surroundings. The outer protective layer 110 may be formed, in particular, from a plurality of layers which are insulated against individual external influences, i.e., for example, from a heat-deflecting layer, a liquid-impermeable layer, a cold-insulating layer, a gas-impermeable layer, a radiation-impermeable layer and/or a layer which ensures ballistic protection, in particular against bullets and material fragments.
The multi-layered woven fabric 100 further comprises an inner layer 120 which lies, in particular, next to the skin H of the person wearing the special-purpose suit, it also being possible for the inner layer 120 to comprise, in particular, textile undergarments. The inner layer 120 is moisture-permeable, in particular permeable to water vapor, in order to permit perspiration or sweat of the person wearing the suit to penetrate into the multi-layered woven fabric 100 from the inside (in a direction W in FIG. 1), it being possible for the inner layer 120 to be preferably of the type which transports moisture or sweat away from the skin H of the person wearing the suit, stores it for an interim period and discharges it to the fluid in the spacer layer 130 for climatic conditioning.
The multi-layered woven fabric 100 further comprises, between the outer protective layer 110 and the inner layer 120, a spacer layer 130. The spacer layer 130 may comprise a knitted space-maintaining textile fabric of natural and/or synthetic fibers which has yarns which are interlinked or interconnected in the manner of cells. The knitted space-maintaining fabric has, in particular, interconnected, fluid-permeable channels which are arranged in a coplanar manner (in a direction C in FIG. 1) with respect to the spacer layer 130 and ensure that a fluid flows through the spacer layer 130 in a coplanar manner, in particular. The fluid can thus pick up, and lead to the outside, moisture which the body releases. The recovery and space-maintaining properties and compressive strength of the spacer layer 130 further ensure that the fluid-permeable channels are not interrupted, even if the spacer layer 130 is subjected to loading by the weight of the person wearing the special-purpose suit 10 and/or by external forces. The spacer 130 may be adhesively bonded to the inner layer 120 and/or the outer layer 110 and/or may be attached thereto, in particular, by means of a touch-and-close fastener or attachment.
Depending on the area of the body in which it is arranged, the spacer layer 130 may be of different thicknesses. In particular in the case of protective suits for pilots, it is advantageous for the spacer layer to be thicker in the area of the back and/or the rear pelvic area than in the other areas of the body, the spacer layer 130 preferably being from approximately 5 to approximately 15 mm, preferably approximately 6 to 13 mm in the area of the back and/or the rear pelvic area, whereas it has a thickness of approximately 6 mm in the other areas. The transitions between areas of increased spacer-layer thickness and the areas with normal spacer-layer thickness preferably take place continuously, so that the person wearing the special-purpose suit 10 cannot feel any edges or "steps".
The special-purpose suit 10 shown in FIG. 2 preferably comprises the multi-layered woven fabric 100 in FIG. 1. The special-purpose suit 10 has an inlet E and an outlet A, which are connected fluidically to the fluid-permeable spacer layer 130, which essentially covers the entire body, respectively for the purpose of admitting a fluid into the spacer layer 130 and for discharging a fluid out of the spacer layer 130. The fluid, in particular air and/or helium, is climatically conditioned by a climate-conditioning device 20, it being possible, in particular, for its temperature, moisture, pressure and/or chemical composition to be regulated or controlled or set, and is introduced into the spacer layer 130 through the inlet E. The fluid preferably flows around various areas of the body and is discharged out of the spacer layer 130 through the outlet A. It is possible, in particular, to provide various outlets A and/or various inlets E and the spacer layer 130 may be divided up into fluidically separate subregions, it being possible for these various subregions to be sealed off or separated from one another by sealing means. By providing various, separate fluid subregions, different microclimates can be produced by one or more climate-conditioning devices 20, and these microclimates permit, in particular, adaptation to external conditions. It is thus possible, in particular, to provide protective suits which are suitable for increased-acceleration applications (e.g. for fighter pilots) and/or reduced-acceleration applications (μg-applications, for example for astronauts), since these suits make it possible, by locally increasing or reducing pressure, to achieve vasoconstriction or a constriction of blood vessels, which prevents blood draining, for example, into the leg area in the event of increased acceleration.
The fluid supplied to the climate-conditioning device 20 may be contained in a receiving vessel or device 30 and/or may be taken from the surroundings.
In the special-purpose suit 10 shown in FIG. 3, the outlet A is re-connected to the receiving vessel 30 via a conditioning device 40. The fluid flowing out of the spacer layer 130 through the outlet A is supplied, via lines, to a conditioning device 40 which conditions the fluid, in particular by removing moisture, filtering substances and/or particles and adding further substances, etc.
The special-purpose suit 10 shown in FIG. 3 thus has a separate, independent circuit which can be separated in its entirety from the surroundings, this vastly reducing, in particular, the risk of contamination.
Furthermore, the special-purpose suit 10 shown in FIG. 3 comprises an additional spacer layer in the area of the head K. This additional spacer layer is arranged, in particular between an outer protective layer, in particular an outer plastic shell, and the head or the surface of the head or the scalp and permits additional climatic conditioning of the area of the head and/or the supply of respiratory air or gas. The fluid supplied to the area of the head K may be climatically conditioned in a climate-conditioning device 20 identical to that used for the other areas of the body, or it may be conditioned by a separate system. Preferably, the fluid which flows into the area of the head K is resupplied to the climate-conditioning device 20 via a conditioning device 40.
The climate-conditioning device 20, the receiving vessel 30 and/or the conditioning device 40 may be arranged within and/or outside the special-purpose suit 10. Furthermore, the spacer layer 130 may be completely self-contained and serve merely for insulation, specifically without enforced climatic conditioning having to take place. This can be achieved, in particular, by providing a self-closing inlet E and a self-closing outlet A, said inlet and outlet closing of their own accord when they are separated from the corresponding lines, so that the spacer layer 130 is "closed off" and separated from the surroundings. This is advantageous, in particular, for protective suits for pilots, which are separated from the climate-conditioning device 20, in particular, in emergency situations (e.g. when the ejector seat is actuated), so that "passive" insulation or basic insulation is, advantageously, made possible by providing an insulating air or fluid layer within the spacer layer. Accordingly, the special-purpose suit 10 provides increased insulation, e.g. against cooling, if a pilot lands in the water following an emergency evacuation. Furthermore, penetration of, for example, air or water into the spacer layer 130 is prevented.
In addition, the spacer layer 130 may be thicker in certain areas in order that a person who is wearing the special-purpose suit 10 and is in the water can be brought into a stable floating position, even if, in particular, he or she is unconscious. The increased thickness of the spacer layer, e.g. in the chest and shoulder areas, results in a larger overall volume per unit area of the spacer layer 130 in said chest and shoulder areas, so that, if air or a fluid with a lower density than the water density is introduced into the spacer layer 130, said chest and shoulder areas are subject to pronounced buoyancy and thus bring the person into a stable and secure floating position.
Accordingly, the special-purpose suit or protective suit is particularly suitable for use by divers, firefighters, oil-rig workers, in particular also for the protection of the latter en route to the oil rig (e.g. in a helicopter), motorcyclists, surfers, police or members of a special task force etc., the special-purpose suit protecting the wearer against external influences and ensuring the climatic conditioning, in particular basic insulation, of the wearer. | A special-purpose suit is provided, in particular for pilots or vehicle drivers or other individuals whose bodies need to be protected, having an outer protective layer which protects against undesirable external influences, a moisture-permeable and/or vapor-permeable inner layer, and a space-maintaining, fluid-permeable spacer layer which is arranged between the outer protective layer and the inner layer and can be climatically conditioned with the introduction of a fluid, the protective layer, the inner layer and the spacer layer being designed such that they essentially cover the torso and/or the leg and/or the arm areas of the special-purpose suit. |
FIELD
The subject matter herein generally relates to a motherboard, and particularly to a computer control system including the motherboard.
BACKGROUND
Typically, a user must remember to manually turn off a workstation before leaving the desk in order to save energy.
BRIEF DESCRIPTION OF THE DRAWINGS
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
FIG. 1 is a block diagram of an embodiment of a computer control system.
FIG. 2 is a circuit diagram of the controlling module coupled to a video graphics array (VGA) connector and a north bridge chipset of FIG. 1 .
FIG. 3 is a diagrammatic view of a VGA connector of a motherboard coupled to a VGA connector of a display of FIG. 1 .
DETAILED DESCRIPTION
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrates details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
A definition that applies throughout this disclosure will now be presented.
The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like.
FIG. 1 illustrates an embodiment of a computer control system. The computer control system can comprise a motherboard 10 and a display 20 . The motherboard 10 can comprise a north bridge chipset 104 , a basic input output system (BIOS) 108 , a VGA connector 102 , and a controlling module 106 . The controlling module 106 is electrically coupled to a VGA connector 202 of the display 20 through the VGA connector 102 .
In at least one the embodiment, the VGA connector 102 obtains a switch signal from the VGA connector 202 , and transmits the switch signal to the controlling module 106 .
In at least one the embodiment, the BIOS 108 can set three work modes of the computer, such as sleep mode, dormant mode, and shutdown mode. When the computer is placed in the sleep mode, the BIOS 108 sets the north bridge chipset 104 to output a sleep signal to the controlling module 106 . When the computer is placed in the dormant mode, the BIOS 108 sets the north bridge chipset 104 to output a dormant signal to the controlling module 106 . When the computer is placed in the shutdown mode, the BIOS 108 sets the north bridge chipset 104 to output a shutdown signal to the controlling module 106 . In at least one the embodiment, the controlling module 106 can comprise a sleep control circuit 1062 , a dormant control circuit 1064 , and a shutdown control circuit 1066 .
The sleep control circuit 1062 can obtain the switch signal from the VGA connector 102 and the sleep control signal from the north bridge chipset 104 . The sleep control circuit 1062 outputs a first mode signal to the north bridge chipset 104 according to the switch signal and the sleep control signal, the BIOS sets the north bridge chipset 104 to control the computer to be in a state of sleep when the north bridge chipset 104 obtains the first mode signal.
The dormant control circuit 1064 can obtain the switch signal from the VGA connector 102 and the dormant control signal from the north bridge chipset 104 . The dormant control circuit 1064 outputs a second mode signal to the north bridge chipset 104 according to the switch signal and the dormant control signal, the BIOS sets the north bridge chipset 104 to control the computer to be dormant when the north bridge chipset 104 obtains the second mode signal.
The shutdown control circuit 1066 can obtain the switch signal from the VGA connector 102 and the shutdown control signal from the north bridge chipset 104 . The sleep control circuit 1066 outputs a third mode signal to the north bridge chipset 104 according to the switch signal and the shutdown control signal, the BIOS sets the north bridge chipset 104 to control the computer to be shutdown when the north bridge chipset 104 obtains the third mode signal.
When the computer is sleeping, dormant, or shutdown, significant electrical consumption is saved compared to leaving the computer fully on.
FIG. 2 illustrates that the north bridge chipset 104 can comprise a sleep terminal S_SLP_S 3 #, a dormant terminal S_SLP_S 4 #, a shutdown terminal S_SLP_S 5 #, a boot terminal PWRBTN#IN, a general purpose input output (GPIO) terminal GPIO 1 -GPIO 3 . The VGA connector 102 can comprise an idle pin P 9 .
The sleep control circuit 1062 can comprise three field effect transistors (FETs) Q 1 -Q 3 . The gate G of the FET Q 1 is coupled to the sleep terminal S_SLP_S 3 # to obtain the sleep control signal from the north bridge chipset 104 , and the drain D of the FET Q 1 is coupled to the GPIO 1 terminal. The gate G of the FET Q 2 is coupled to the sleep terminal S_SLP_S 3 # to obtain the sleep control signal from the north bridge chipset 104 , the source S of the FET Q 2 is coupled to a dual power source+3VDUAL, and the drain D of the FET Q 2 is coupled to the gate G of the FET Q 3 . The source S of the FET Q 3 is coupled to the boot terminal PWRBTN#IN, and both the source S of the FET Q 1 and the drain D of the FET Q 3 are coupled to the idle pin P 9 of the VGA connector 102 .
The dormant control circuit 1064 can comprise three field effect transistors (FETs) Q 4 -Q 6 . The gate G of the FET Q 4 is coupled to the dormant terminal S_SLP_S 4 # to obtain the dormant control signal from the north bridge chipset 104 , and the drain D of the FET Q 4 is coupled to the GPIO 2 terminal. The gate G of the FET Q 5 is coupled to the dormant terminal S_SLP_S 4 # to obtain the dormant control signal from the north bridge chipset 104 , the source S of the FET Q 5 is coupled to the dual power source+3VDUAL, and the drain D of the FET Q 5 is coupled to the gate G of the FET Q 6 . The source S of the FET Q 6 is coupled to the boot terminal PWRBTN#IN, and both the source S of the FET Q 4 and the drain D of the FET Q 6 are coupled to the idle pin P 9 of the VGA connector 102 .
The shutdown control circuit 1066 can comprise three field effect transistors (FETs) Q 7 -Q 9 . The gate G of the FET Q 7 is coupled to the shutdown terminal S_SLP_S 5 # to obtain the shutdown control signal from the north bridge chipset 104 , and the drain D of the FET Q 7 is coupled to the GPIO 3 terminal. The gate G of the FET Q 8 is coupled to the shutdown terminal S_SLP_S 5 # to obtain the shutdown control signal from the north bridge chipset 104 , the source S of the FET Q 8 is coupled to the dual power source+3VDUAL, and the drain D of the FET Q 8 is coupled to the gate G of the FET Q 9 . The source S of the FET Q 9 is coupled to the boot terminal PWRBTN#IN, and both the source S of the FET Q 7 and the drain D of the FET Q 9 are coupled to the idle pin P 9 of the VGA connector 102 .
FIG. 3 illustrates that the VGA connector 202 can comprise an idle pin P 9 . The VGA connector 102 is electrically coupled to the VGA connector 202 . The idle pin P 9 of the VGA connector 102 is electrically coupled to the idle pin P 9 of the VGA connector 202 .
When the button of the display 20 is pressed, the VGA connector 102 obtains the switch signal with low level from the idle pin P 9 of the VGA connector 202 , and the VGA connector 102 transmits the switch signal to the controlling module 106 .
When the BIOS 108 sets the computer in the sleep mode, the sleep terminal S_SLP_S 3 # of the north bridge chipset outputs the sleep control signal to the sleep control circuit 1062 , the sleep control circuit 1062 starts working. When the computer is fully running, the sleep control signal output by the north bridge chipset 104 is at a high level state, and the FET Q 1 is turned on, both the FET Q 2 and the FET Q 3 are turned off. When the user leaves the computer, and the button of the display 20 is pressed, the VGA connector 102 obtains a switch signal with low level from the idle pin P 9 of the VGA connector 202 , and the source S of the FET Q 1 obtains the switch signal with the low level, as the FET Q 1 is turned on, the GPIO 1 terminal of the north bridge chipset 104 obtains the first mode signal with low level from the sleep control circuit 1062 , and the north bridge chipset 104 controls the computer to sleep. When the computer is sleeping, both the gate G of the FET Q 1 and the gate G of the FET Q 2 obtain a low level sleep control signal, the FET Q 1 is turned off, the FET Q 2 is turned on, and the FET Q 3 is turned on. When the user comes back to the computer, and the button of the display 20 is pressed, the idle pin P 9 of the VGA connector 102 transmits the switch signal with low level to the drain D of the FET Q 3 , and the FET Q 3 is turned on, the boot terminal PWRBTN#IN of the north bridge chipset 104 obtains the switch signal with low level, at the same time, the computer is woken up.
When the BIOS 108 sets the computer in the dormant mode, the dormant terminal S_SLP_S 4 # of the north bridge chipset outputs the dormant control signal to the dormant control circuit 1064 , the dormant control circuit 1064 starts working. When the computer is fully running, the dormant control signal output by the north bridge chipset 104 is at a high level, and the FET Q 4 is turned on, both the FET Q 5 and the FET Q 6 are turned off. When the user leaves the computer, and the button of the display 20 is pressed, the VGA connector 102 obtains a switch signal with low level from the idle pin P 9 of the VGA connector 202 , and the source S of the FET Q 5 obtains the switch signal with the low level, as the FET Q 4 is turned on, the GPIO 2 terminal of the north bridge chipset 104 obtains the second mode signal with low level from the dormant control circuit 1064 , and the north bridge chipset 104 controls the computer to be dormant. When the computer is dormant, both the gate G of the FET Q 4 and the gate G of the FET Q 5 obtain a low level dormant control signal, the FET Q 4 is turned off, the FET Q 5 is turned on, and the FET Q 6 is turned on. When the user comes back to the computer, and the button of the display 20 is pressed, the idle pin P 9 of the VGA connector 102 transmits the switch signal with low level to the drain D of the FET Q 6 , and the FET Q 6 is turned on, the boot terminal PWRBTN#IN of the north bridge chipset 104 obtains the switch signal with low level, at the same time, the computer is woken up.
When the BIOS 108 sets the computer in the shutdown mode, the shutdown terminal S_SLP_S 5 # of the north bridge chipset outputs the shutdown control signal to the shutdown control circuit 1066 , the shutdown control circuit 1066 starts working. When the computer is fully running, the shutdown control signal output by the north bridge chipset 104 is at a high level, and the FET Q 7 is turned on, both the FET Q 8 and the FET Q 9 are turned off. When the user leaves the computer host, and the button of the display 20 is pressed, the VGA connector 102 obtains a switch signal with low level from the idle pin P 9 of the VGA connector 202 , and the source S of the FET Q 8 obtains the switch signal with the low level, as the FET Q 7 is turned on, the GPIO 3 terminal of the north bridge chipset 104 obtains the third mode signal with low level from the shutdown control circuit 1066 , and the north bridge chipset 104 controls the computer to be turned off. When the computer is turned off, both the gate G of the FET Q 7 and the gate G of the FET Q 8 obtain a shutdown control signal with low level, the FET Q 7 is turned off, and the FET Q 8 is turned on, the FET Q 9 is turned on. When the user comes back to the computer, and the button of the display 20 is pressed, the idle pin P 9 of the VGA connector 102 transmits the switch signal with low level to the drain D of the FET Q 9 , and the FET Q 9 is turned on, the boot terminal PWRBTN#IN of the north bridge chipset 104 obtains the switch signal with low level, at the same time, the computer is woken up.
While the disclosure has been described by way of example and in terms of a preferred embodiment, it is to be understood that the disclosure is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the range of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | The disclosure provides a motherboard including a north bridge chipset, a basic input output system (BIOS), a first video graphics array (VGA) connector, and a controlling module. The north bridge chipset outputs a sleep signal to the controlling module, the controlling module obtains a switch signal from the first VGA connector, the controlling module outputs a first mode signal to the north bridge chipset according to the sleep signal and the switch signal, the north bridge chipset controls the computer host to be asleep according to the sleep mode. The disclosure also provides a computer control system including the motherboard. The motherboard and the computer control system control the computer to be asleep via a display. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.