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RELATED APPLICATION INFORMATION
[0001] This patent claims benefit of the filing date of the following provisional patent applications: Application No. 61/084,207, entitled High Speed Memory Module, filed Jul. 28, 2008; and Application No. 61/090,178, entitled High Speed Memory Module with Low Impedance Traces, filed Aug. 19, 2008.
[0002] A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever.
BACKGROUND
[0003] 1. Field
[0004] This disclosure relates to memory modules for use in computers and other applications.
[0005] 2. Description of the Related Art
[0006] Computers commonly use random access memory (RAM) for temporary storage of instructions and data. The RAM is commonly packaged in Dual In-line Memory Modules (DIMMs). Current state-of-the-art RAM chips, such as Dual Data Rate 3 (DDR3) Synchronous Dynamic RAM (SDRAM) chips, allow data to be transferred between the RAM chips and an associated memory controller at speeds up to 1600 million transfers per second. However, physical limitations of transmission lines that conduct the data and address signals between the memory controller and the RAM chips may degrade the quality of the signals and thus necessitate operating the RAM chips at less than their maximum speed.
DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a block diagram of a computer.
[0008] FIG. 2 is a schematic diagram of a read signal path from a memory chip to a memory controller.
[0009] FIG. 3 is a schematic diagram of a write signal path from a memory controller to a memory chip.
[0010] FIG. 4A is a schematic plan view of a dual in-line memory module.
[0011] FIG. 4B is a schematic plan view of a fully-buffered dual in-line memory module.
[0012] FIG. 5 is a graph showing results from a simulation of memory write cycles.
[0013] FIG. 6 is a graph showing results from a simulation of memory read cycles.
[0014] FIG. 7A is an eye diagram for a simulated signal received at a memory controller.
[0015] FIG. 7B is an eye diagram for a simulated signal received at a memory controller.
[0016] FIG. 8 is a graph plotting eye opening voltage of a simulated signal received at a memory controller versus the length and impedance of DIMM I/O signal traces.
[0017] FIG. 9A is a schematic diagram illustrating a primary signal path between a memory controller and a memory chip.
[0018] FIG. 9B is a schematic diagram illustrating a reflected signal component propagating between a memory controller and a memory chip.
[0019] FIG. 9C is a schematic diagram illustrating another reflected signal component propagating between a memory controller and a memory chip.
[0020] FIG. 10 is a chart plotting signal waveforms versus time.
[0021] FIG. 11 is a chart plotting signal waveforms versus time.
[0022] FIG. 12A is an eye diagram for a signal received at a memory chip.
[0023] FIG. 12B is an eye diagram for a signal received at a memory chip.
DETAILED DESCRIPTION
[0024] Description of Apparatus
[0025] Referring to FIG. 1 , a computer 100 may include a central processing unit (CPU) 120 and a memory controller 130 which may be mounted on a mother board 110 . The memory controller 130 and the CPU 120 may be combined on a single integrated circuit chip or may be all or portions of separate integrated circuit chips. The memory controller 130 may be a portion of a so-called “bridge” chip or chipset. The mother board 110 may include connectors to mate with one or more memory modules such as a dual in-line memory module (DIMM) 140 . Although a single memory controller 130 is shown in FIG. 1 , computers such as servers may have more than one central processing unit and more than one memory controller. Each memory controller may typically be coupled to four connectors which may, in turn, mate with one to four memory modules.
[0026] Each DIMM 140 may include a circuit board and a plurality of dynamic random access memory (RAM) chips 160 mounted on the circuit board. The DIMM 140 may include a multiple of 8 RAM chips (as shown in FIG. 1 ) if the computing device does not use error correction. Each DIMM 140 may include a multiple of 9 dynamic random access memory (RAM) chips 160 if the computing device does use error correction, the extra bit per “byte” providing redundancy in the data signals exchanged between the memory controller 130 and the one or more DIMM 140 . Each set of 8 or 9 RAM chips 160 is commonly termed a “rank”. Currently, the capacity of each DIMM must be equal to a power of 2. Thus the number of ranks per DIMM may also be a power of 2. Each DIMM 140 may contain 1, 2, 4 or even 8 ranks, and thus may contain 8, 16, 32, or 64 RAM chips (9, 18, 36, or 72 if error correction is used).
[0027] Each memory controller 130 may provide address and control signals to the associated DIMMs 140 . The memory controller 130 and the one or more DIMMs 140 may exchange bidirectional data signals, traditionally referred to as D/Q signals. A total of more than 200 different address, control, and D/Q signals may be routed between the memory controller 130 and the one or more DIMMs 140 using a corresponding number of electrical connections. The electrical connections may be controlled impedance transmission line or traces on the mother board 120 . These signals are represented in FIG. 1 by a single trace 150 .
[0028] FIG. 2 is a schematic diagram of an exemplary D/Q signal connection between a memory controller 230 and a device 260 , which may be a portion of a memory module 240 , during a memory read operation. The device 260 may be a memory chip or a buffer chip that isolates the memory controller 230 from one or more memory chips included in the memory module 240 . A driver 262 within the device 260 provides a D/Q signal representative of a data bit being read from the memory module 240 . The D/Q signal may be coupled from the driver 262 to the memory controller 230 by a first transmission line 255 and a second transmission line 250 . To read the data stored within the memory module 260 , each D/Q signal must be recognized by a receiver 234 within the memory controller 230 . The first transmission line 255 may be a trace on a circuit board within the memory module 240 and a portion of a connector mated with the memory module. The first transmission line 255 may have a length L 1 . The second transmission line 250 may be a trace on a mother board 210 . The second transmission line 250 may have a length L 2 . L 2 may typically be about 75 mm to 175 mm (3 to 7 inches). The D/Q transmission lines may be bidirectional, and the memory controller may also include a driver (not shown in FIG. 2 ) connected to the second transmission line 250 .
[0029] The first transmission line 255 , the second transmission line 250 , and an extension of the second transmission line (shown as a dashed line) leading to additional memory module sockets may meet at a “T” junction 252 . Since three transmission lines meet at the T junction 252 , there may be a discontinuity in the impedance of each line at the junction. This impedance discontinuity may result in reflection of a portion of the signal energy from the T junction 252 .
[0030] Reflections may also occur at the input to the memory controller 230 and the output of the device 260 . Reflections will not occur at the input of the memory controller if the input impedance, represented by the terminating resistor Rt, is equal to the characteristic impedance of the second transmission line 250 . However, to minimize power consumption within the memory controller, the input impedance Rt may be substantially higher than the impedance of the second transmission line 250 such that a reflection may occur at the input to the memory controller. Similarly, reflections will not occur at the output of the memory chip if the output impedance of the driver 262 , represented by the resistor Rout, is equal to the characteristic impedance of the first transmission line 255 . However, to reduce the signal rise time and to increase the signal voltage swing at the memory controller, the output impedance Rout of the driver 262 may be substantially lower than the impedance of the transmission line 255 , such that a reflection may occur at the output of the memory chip.
[0031] FIG. 3 is a schematic diagram of an exemplary D/Q signal connection between a memory controller 330 and a device 360 , which may be a portion of a memory module 340 , during a memory write operation. A driver 332 within the memory controller 330 provides a signal representative of a data bit to be written into the memory chip. The signal may be coupled from the driver 332 to the device 360 by a first transmission line 355 and a second transmission line 350 .
[0032] The first transmission line 355 , the second transmission line 350 , and an extension of the second transmission line (shown as a dashed line) leading to additional memory module sockets may meet at a “T” junction 352 . Since three transmission lines meet at the T junction 352 , there may be a discontinuity in the impedance of each line at the junction. This impedance discontinuity may result in reflection of a portion of the signal energy from the T junction 352 .
[0033] Reflections may also occur at the input to the device 360 and the output of the memory controller 330 . Reflections will not occur at the input of the memory chip if the input impedance, represented by the terminating resistor Rt, is equal to the characteristic impedance of the first transmission line 355 . However, to minimize power consumption within the memory chip, the input impedance Rt may be substantially higher than the impedance of the first transmission line 355 . Similarly, reflections will not occur at the output of the memory controller if the output impedance of the driver 332 , represented by the resistor Rout, is equal to the characteristic impedance of the second transmission line 350 . However, to reduce the signal rise time and to increase the signal voltage swing at the memory chip, the output impedance Rout of the driver 332 may be substantially lower than the impedance of the second transmission line 350 .
[0034] FIG. 4A is a schematic plan view of a conventional DIMM 440 A which includes at least eight memory chips 460 A- 460 H mounted on a circuit board 442 A. The eight memory chips 460 A- 460 H constitute a first rank of memory chips. The DIMM 440 A may include one, two, four, or eight ranks of memory chips. A second rank of eight memory chips (not shown) may be mounted on the back side (not shown) of the circuit board 442 A. Third to eighth ranks of memory chips may be physically stacked on top of, or under, the first and second ranks of memory chips (not shown). The DIMM 440 A may include a register/buffer chip 466 A to buffer and temporarily store address and control signals for the memory chips.
[0035] A plurality of conductive contacts (not individually visible) may be disposed along an edge 444 A of the circuit board 442 A. These contacts may mate with a connector to establish electrical connections between the DIMM 440 A and a system memory bus which may be a portion of a motherboard (not shown). In a conventional DIMM, 64 D/Q signals may be routed from the edge 444 A of the circuit board 442 A directly to the appropriate memory chip or chips by controlled impedance traces such as trace 455 A. The contacts associated with the D/Q signals may be distributed along the edge 444 A such that each I/O signal connects to the circuit board 442 A proximate to the appropriate memory chip. Thus the length L 1 of the traces, such as trace 455 , carrying the 64 D/Q signals from the edge 444 A to the memory chips 460 A- 460 H may be relatively uniform. The length L 1 may be, for example, about 20 mm (0.8 inches).
[0036] Since a conventional DIMM module 440 A may contain 1, 2, 4, or 8 ranks for memory chips, each D/Q signal may connect to 1, 2, 4, or 8 memory chips. Thus the electrical load on each D/Q signal may change substantially depending on the number of ranks in a DIMM module. Since the load on each D/Q signal trace of a computer mother board may not be known until one or more DIMM module is connected to the motherboard, it may not be practical to optimize the memory controller and motherboard to allow operation of the memory chips at their maximum speed.
[0037] FIG. 4B is a block diagram of a fully-buffered DIMM 440 B which includes at least eight memory chips 460 A- 460 H mounted on a circuit board 442 B. The fully-buffered DIMM 440 B may include one, two, four, or eight ranks of memory chips. The fully-buffered DIMM 440 B may include a register/buffer chip 466 B to buffer and temporarily store address and control signals. The register chip 466 B may also buffer D/Q signals such that each D/Q signal may have only a single load (the register/buffer chip) independent of the number of ranks of memory chips on the DIMM 440 B. Since each fully-buffered DIMM 440 B places a known load on each D/Q signal, the design of the associated mother board and memory controller may be simplified and the operating speed of the memory chips within a computer may be increased.
[0038] To maintain compatibility, the physical locations of the electrical connections to the fully-buffered DIMM 440 B may be the same as for the conventional DIMM 440 A. Thus the conductive fingers associated with the 64 D/Q signals may be distributed along an edge 444 B of the circuit board 442 B. However, each of the 64 D/Q signals may be routed from the card edge 444 B to the register/buffer chip 466 B. Thus the length L 1 of some of the D/Q traces, such as trace 455 B, carrying D/Q signals from the card edge to the register/buffer chip 466 B may be substantially longer that the traces (such as trace 455 A) in the conventional DIMM 440 A. The length L 1 of the D/Q traces in a fully-buffered DIMM may vary, for example, from about 20 mm (0.8 inches) to about 75 mm (3.0 inches).
[0039] FIG. 5 is a graph showing results from a numerical simulation of an exemplary D/Q signal during memory write operations. The simulation assumes that three DIMMs are connected to a common memory controller. The three DIMMs are disposed in a first, second, and third slot, or connector, on a mother board. The simulation further assumes that the transmission line on the mother board from a memory controller to the first DIMM slot has a length L 2 of 175 millimeters (7 inches) and a characteristic impedance of 40 ohms. The first DIMM slot is the closest to the memory controller and the first, second, and third DIMM slots are spaced on 10 mm (0.4 inch) centers. The simulation further assumes that the output impedance of the memory controller is 27.5 ohms and that the DIMM modules have switchable on-die termination (ODT) such that the input impedance of the first DIMM (the target DIMM being written) is 120 ohms and the input impedances of the second and third DIMMs are 60 ohms.
[0040] The memory operation was simulated for the D/Q traces (such as trace 455 A or 455 B in FIG. 4 ) within each DIMM having a length L 1 of 20, 38, 50, 62, and 75 millimeters (0.8, 1.5, 2, 2.5, and 3 inches) and for characteristic impedances of 40 ohms and 60 ohms.
[0041] In FIG. 5 , the solid line 510 and the dashed line 515 are graphs of the “eye opening” voltage at a D/Q input to a memory chip on a DIMM module in the first DIMM slot while random data is written into the memory chip at a rate of 1333 million writes per second. The eye opening voltage is plotted as a function of the D/Q trace length within the DIMM. An eye diagram is a graph or an oscilloscope display in which numerous repetitive samples of a digital data signal are superimposed. The term “eye diagram” is commonly used since the pattern may look like a series of eyes between a pair of rails. The eye diagram is useful for visualizing digital signal quality, since the eye diagram encompasses the effects of signal rise and fall times, amplitude noise, and timing errors or phase noise. For a digital signal to be correctly received, the “eye” must be “open”, which is to say that there must be a usable margin or “eye opening” between the one and zero voltage levels for a sufficient period of time to correctly sample the signal. For reliable operation of a memory system, the minimum usable eye opening may be about 200 millivolts.
[0042] The solid line 510 plots the eye opening voltage at a memory chip assuming the D/Q trace within the DIMM has an impedance of 40 ohms. The dashed line 515 plots the eye opening voltage at the memory chip assuming the D/Q trace within the DIMM has an impedance of 60 ohms. 60-ohm traces are typically employed in current conventional DIMMs.
[0043] The solid line 520 and the dashed line 525 are similar graphs of the eye opening at a memory chip on a DIM M in the second DIM M slot. The solid line 530 and the dashed line 535 are similar graphs of the eye opening at a memory chip on a DIMM in the third DIMM slot.
[0044] The data plotted in FIG. 5 shows that, with conventional 60-ohm D/Q signal traces (dashed lines 515 , 525 , 535 ), the eye opening voltage varies between the three DIMM slots. Further, the eye opening voltage varies with the D/Q signal trace length within the DIMMs, particularly for the DIMM in the first DIMM slot. In particular, when the DIMM installed in the first DIMM slot is a fully buffered DIMM as shown in FIG. 4B , the eye opening voltage at the inputs to some of the memory chips (those inputs connected to traces longer than 2.5 inches) will be less than the minimum useable value of about 200 millivolts.
[0045] However, when the DIMM D/Q signal traces have 40-ohm impedance, the eye opening voltages (solid lines 510 , 520 , 530 ) are more consistent between the DIMM slots and nearly independent of the D/Q signal trace length. The simulated eye opening voltage is greater than 250 millivolts at each of the three DIMM slots for any signal trace length from 0.8 inches to 3 inches. Thus all three DIMM slots can be populated by fully buffered DIMMs, as shown in FIG. 4B , having 40-ohm I/O signal traces.
[0046] FIG. 6 is a graph showing results from a numerical simulation of an exemplary D/Q signal during memory read operations. The input impedance of the memory controller is assumed to be 120 ohms, the output impedance of the memory chip is 20 ohms, and the input impedances of the inactive DIMMS are 60 ohms. Other assumptions used for the simulation were the same as used to generate the data shown in FIG. 5 .
[0047] In FIG. 6 , the solid line 610 and the dashed line 615 are graphs of the “eye opening” voltage at a D/Q input to a memory controller chip on a mother board while random data is read from a DIMM module in the first DIMM slot at a rate of 1333 million writes per second. The eye opening voltage is plotted as a function of the D/Q trace length within the DIMM. The solid line 610 plots the eye opening voltage assuming the D/Q trace within the DIMM has an impedance of 40 ohms. The dashed line 615 plots the eye opening voltage assuming the D/Q trace within the DIMM has a conventional impedance of 60 ohms.
[0048] The solid line 620 and the dashed line 625 are similar graphs of the eye opening at the memory controller when data is read from a DIMM in the second DIMM slot. The solid line 630 and the dashed line 635 are similar graphs of the eye opening at a memory controller when data is read from a DIMM in the third DIMM slot.
[0049] The data plotted in FIG. 6 shows that, with conventional 60-ohm I/O signal traces, the eye opening voltage (dashed line 615 , 625 , 635 ) varies when reading from the three DIMM slots. In particular, the eye opening voltage (dashed line 615 ) when reading from the DIMM in the first DIMM slot is significantly less than the desired minimum value of 200 millivolts. Memory systems with three DIMM slots populated with convention DIMMs may not be operable at 1333 million transfers per second and may be restricted to a lower speed such as 800 million transfers per second.
[0050] In contrast, when the DIMM I D/Q traces have 40-ohm impedance, the eye opening voltages (solid line 610 , 620 , 630 ) are more consistent between the DIMM slots and nearly independent of the D/Q trace length. In particular, the eye opening voltage (solid line 610 ) when reading from the DIMM in the first DIMM slot is above the desired minimum value of 200 millivolts.
[0051] FIG. 7A is an eye diagram showing results from a numerical simulation of an exemplary D/Q line during a memory read operation. The eye diagram shows the input voltage at a memory controller when reading data from a DIMM assumed to be in the first DIMM slot. The D/Q trace on the DIMM is assumed to be 75 mm in length and to have an impedance of 60 ohms. The other assumptions used in the simulation are the same as the assumptions used to generate the data shown in FIG. 6 . In the example of FIG. 7A , the eye opening at time=500 picoseconds is 132 millivolts. 132 millivolts is substantially less than the 200 millivolt eye opening desired for reliable memory operation.
[0052] FIG. 7B is an eye diagram showing results from another numerical simulation of an exemplary signal line during a memory read operation. The eye diagram shows the input voltage at a memory controller when reading data from a DIMM assumed to be in the first DIMM slot. The other assumptions used in the simulation are the same as the assumptions used to generate the data shown in FIG. 7A , except the D/Q trace on the DIMM has an assumed impedance of 40 ohms. In the example of FIG. 7B , the eye opening at time=500 picoseconds is 230 millivolts. 230 millivolts may be sufficient for reliable memory operation.
[0053] FIG. 8 is graph showing results from another numerical simulation of an exemplary signal line when reading from a DIMM in a first DIMM slot. FIG. 8 graphs the eye opening voltage of a signal received at a memory controller versus DIMM D/Q trace length, with the impedance of the DIMM D/Q traces as a parameter. The assumptions used in the simulation are the same as the assumptions used to generate the data shown in FIGS. 6 and 7 , except that the input impedance of the memory controller is 60 ohms and the terminating impedance of the idle second and third DIMM modules is 40 ohms.
[0054] Compared to the data shown in FIG. 6 , the eye opening voltages plotted in FIG. 8 are lower for equivalent DIMM D/Q trace length and impedance. The reduction in eye opening voltage in the data of FIG. 8 may be due to generally lower signal levels resulting from the assumed lower input impedances for the memory controller and idle second and third DIMM modules. In agreement with FIG. 5 and FIG. 6 , FIG. 8 also demonstrates that lower DIMM D/Q trace impedance results in lower dependence of eye opening voltage on DIMM D/Q trace length. Specifically, the variation of eye opening voltage, for DIMM D/Q trace lengths from 0.8 to 3.0 inches, is less than ±10% when the DIMM D/Q trace impedances is from 37 to 46 ohm. In contrast, the variation of eye opening voltage, for the same range of DIMM D/Q trace length, is about ±28% for 60 ohm DIMM D/Q traces. Similarly. FIG. 5 and FIG. 6 , which are based on different assumptions from the assumption used to generate the data for FIG. 8 , show that the variation of eye opening voltage (for the first DIMM slot and DIMM D/Q trace lengths from 0.8 to 3.0 inches) is about ±6% for both read and write for 40 ohm DIMM D/Q traces. In contrast, the variation of eye opening voltage (for the first DIMM slot and DIMM D/Q trace lengths from 0.8 to 3.0 inches) is about ±28% for write and ±17% read with 60 ohm DIMM D/Q traces.
[0055] As expected, an effect of lowering the DIMM D/Q trace impedance from 60 ohms, as used on conventional DIMMs, to a lower value, such as 40 ohms, may be to incrementally increase I/O signal amplitude and thus incrementally increase D/Q signal eye opening. However, the simulation results shown in FIGS. 4 to 8 demonstrate that lower DIMM D/Q trace impedances have the unexpected effect of substantially reducing the dependence of eye opening voltage on DIMM I/O signal trace length. Thus lowering the impedance of the D/Q traces within the DIMM may be particularly significant for DIMMs, such as fully-buffered DIMMs, having at least some long D/Q traces. Additionally, lower DIMM D/Q trace impedances also provide the unexpected benefit of substantially reducing the dependence of eye opening voltage on DIMM slot position. Thus lowering the impedance of each D/Q trace between the DIMM card edge connector from 60 ohms to a lower value such as 40 ohms may enable fast (transfer rates equal to, or more than, 1333 million transfers per second) memory systems which include multiple fully-buffered or un-buffered DIMMs.
[0056] An additional technique that may be used in combination with lowered DIMM D/Q trace impedance is to configure a computer, such as the computer 100 , such that spurious signals, which result from reflection of the data signals, effectively cancel each other. FIG. 9A is a schematic diagram of a first signal path PI between a device 960 and a memory controller 930 , which may be the memory controller 130 . The device 960 may be a memory chip, such as the memory chip 160 , or buffer chip such as the buffer chip 466 B. A signal launched from the device 960 may propagate along a first transmission line segment 955 which has a length L 1 and an associated propagation time t 1 . The first transmission line 955 may intersect with a second transmission line segment 950 at a T junction 1052 . The second transmission line segment may have a length L 2 and an associated propagation delay t 2 . Thus a signal may travel from the device 960 to the memory controller along the signal path P 1 which has a total propagation time of t 1 +t 2 . However some of the signal energy might not travel along the path P 1 .
[0057] As shown in FIG. 9B , a first reflection R 1 may occur at the T junction 952 such that a portion of the signal energy is reflected back towards the device 960 . The un-reflected majority of the signal energy may propagate along the second transmission line segment 950 to the memory controller 930 . A second reflection R 2 may occur at the input to the device 960 such that a portion of the energy reflected at R 1 is reflected back towards the memory controller 930 . Thus a twice-reflected portion of the signal may travel from the device 960 to the memory controller 930 along a path P 2 which has a total propagation time of 3(t 1 )+t 2 .
[0058] The signal reflected at the T junction may have the opposite polarity to the signal launched from the device 960 , since the reflection R 1 is caused by a transition from a higher impedance (the characteristic impedance of the first transmission line segment 955 ) to a lower impedance (the characteristic impedances of the second transmission line segment 950 and the dashed extension 954 of the second transmission line segment in parallel). The reflected signal (R 2 ) at the output of the device 960 may have the opposite polarity to the reflected signal R 1 , since the reflection R 2 is caused by a transition from a higher impedance (the characteristic impedance of the first transmission line segment 955 ) to a lower impedance (the output impedance of a driver within the device 960 ). Thus the twice-reflected that follows the signal path P 2 may have the same polarity as the signal originally launched from the device 960 .
[0059] As shown in FIG. 9C , a third reflection R 3 may occur at the input to the memory controller 930 such that a portion of the signal energy is reflected back towards the device 960 . A fourth reflection R 4 may occur at the T junction 952 such that a portion of the energy reflected at R 3 is reflected back towards the memory controller 930 . Thus another twice-reflected portion of the signal may travel from the device 960 to the memory controller 930 along a path P 3 which has a total propagation time of t 1 +3(t 2 ).
[0060] The signal R 3 reflected at the input to the memory controller 930 may have the same polarity to the signal launched from the device 960 , since the reflection R 3 is caused by a transition from a lower impedance (the characteristic impedance of the second transmission line segment 950 ) to a higher impedance (the input impedance of the memory controller 930 ). The signal R 4 reflected at the T junction 952 may have the opposite polarity to the reflected signal energy R 3 , since the reflection R 4 is caused by a transition from a higher impedance (the characteristic impedance of the second transmission line segment 950 ) to a lower impedance (the characteristic impedance of the first transmission line segment 955 and the extension of the second transmission line segment in parallel). Thus the twice-reflected signal that follows path P 3 will have the opposite polarity as the signal originally launched from the device 960 .
[0061] Thus a primary component of a signal output from the device 960 (roughly equivalent to the launched signal energy less the portions reflected at the first and third reflections) may travel from the device 960 to the memory controller 930 along the first signal path PI having a total propagation time of t 1 +t 2 . A twice-reflected signal component having the same polarity as the primary signal component may travel from the device 960 to the memory controller 930 along the second signal path P 2 having a total propagation time of 3(t 1 )+t 2 . Another twice-reflected signal component having the opposite polarity as the primary signal component may travel from the device 960 to the memory controller 930 along the third signal path P 3 having a total propagation time of t 1 +3(t 2 ).
[0062] FIG. 10 is a graph showing results from a numerical simulation of an exemplary signal line, such as the signal line of FIGS. 9A-9C during a memory read operation. In the simulated example, the first transmission line segment ( 955 in FIGS. 9A-6C ) is assumed to have a length L 1 of 20 millimeters (0.8 inch) and a characteristic impedance of 60 ohms. The second transmission line segment ( 950 in FIGS. 9A-9C ) has a length L 2 of 178 millimeters (7 inches) and a characteristic impedance of 40 ohms. Assuming 178 millimeters for the length L 2 of the second transmission line segment may be representative of the longest distance anticipated between a memory controller and a DIMM in a computer.
[0063] In FIG. 10 , the solid line is a graph of the voltage at an input to a memory controller in response to a voltage step output from a memory chip. The voltage at the input to the memory controller has three major components. A primary component travels along a path P 1 having a propagation time of t 1 +t 2 , as shown in FIG. 9A . A first twice-reflected component travels along Path P 2 having a propagation time of 3(t 1 )+t 2 , as shown in FIG. 9B . A second twice-reflected component travels along a path P 3 having a propagation time of t 1 +3(t 2 ), as shown in FIG. 9C . Since t 1 is short compared to t 2 , the second twice-reflected component that travels along path P 3 arrives at the memory controller long after (2 nanoseconds after) the first twice-reflected along path P 2 .
[0064] In FIG. 10 , the dashed line is a graph of the voltage at the input to the memory controller in response to a 750 picosecond voltage pulse launched by the memory chip. A 750 picosecond pulse is representative of a single bit being read from the memory chip at a data rate of 1300 transfers per microsecond. The first and second twice-reflected components of the pulse continue to propagate in the transmission lines after the original voltage pulse has ended. These reflected components are essentially noise, or inter-symbol interference, that may degrade the quality of signals subsequently launched from either the memory chip or the memory controller.
[0065] FIG. 11 is a graph showing results from another numerical simulation of an exemplary signal line, such as the signal line of FIGS. 9A-9C , during a memory read operation. In this example, the lengths L 1 , L 2 of the first and second transmission line segments ( 955 , 950 in FIGS. 9A-9B ) are both assumed to be 178 millimeters (7 inches) and the propagation times t 1 , t 2 of the first and second transmission line segments are assumed to be equal. Both of the first and second transmission line segments have a characteristic impedance of 40 ohms. Setting t 1 =t 2 results in 3(t 1 )+t 2 =t 1 +3(t 2 ), such that the propagation times along the P 2 and P 3 of the twice-reflected signal components are the same.
[0066] In FIG. 11 , the solid line is a graph of the voltage at an input to a memory controller in response to a voltage step output from a memory chip. As previously shown in FIG. 10 , the voltage at the input to the memory controller has three major components. A primary component travels along a path PI having propagation time t 1 +t 2 , as shown in FIG. 9A . A first twice-reflected component travels along a path P 2 having a propagation time of 3(t 1 )+t 2 , as shown in FIG. 9B . A second twice-reflected component travels along a path P 3 having a propagation time of t 1 +3(t 2 ), as shown in FIG. 9C . However, since 3(t 1 )+t 2 =t 1 +3(t 2 ), the first twice-reflected component and second twice reflected component arrive at the memory controller essentially simultaneously. Since the first and second twice-reflected components have opposite polarity and nearly the same amplitude, they effectively cancel each other at the input to the memory controller ( 930 in FIGS. 9A-9C ).
[0067] In FIG. 11 , the dashed line plots the voltage at the input to the memory controller in response to a 750 picosecond voltage pulse launched by the memory chip. The first and second twice-reflected components of the pulse continue to propagate in the transmission lines after the original voltage pulse has ended. However, the propagation times of the first and second twice-reflected components are equal, the twice-reflected components effectively cancel each other at the input to the memory controller ( 930 in FIGS. 9A-9C ), resulting in a significant reduction (compared, for example, to the data shown in FIG. 10 ) in inter-symbol interference that may degrade the quality of signals subsequently launched from either the memory chip or the memory controller.
[0068] FIG. 12A is an eye diagram of the input voltage at the memory controller, simulated using the same assumptions used to generated the data shown in FIG. 10 . In the simulated example of FIG. 12A , the maximum eye opening voltage is 182 millivolts. FIG. 12B is an eye diagram of the input voltage at the memory controller, simulated using the same assumptions used to generated the data shown in FIG. 11 . In the simulated example of FIG. 12B , the maximum eye opening voltage is 368 millivolts. Thus equalizing the propagation times t 1 , t 2 of the first transmission line segment and the second transmission line segment causes the “eye” to further “open” and doubles the eye opening voltage compared to the previously presented results. Further, the improvement in the signal quality may allow computers to operate one DIMM or multiple DIMMs at the full speed capability of the memory chips.
[0069] The substantial improvement in signal quality, as evidenced by the eye opening voltage charts of FIG. 12A and FIG. 12B may be realized if two conditions are met. First, the two primary reflected components of the signal must have opposite polarity and approximately the same amplitude. The two primary reflected components may be considered to have “approximately the same amplitude” if the difference in the amplitudes of the two components is small compared to the eye opening voltage. This condition may be met by appropriate selection of the impedances of the first and second transmission line segments ( 955 , 950 in the example of FIGS. 9A-9C ) and/or appropriate selection of the output impedance at the signal source and the input impedance at the signal receiver. Second, the propagation delays of the signal paths (P 2 , P 3 in the example of FIGS. 9A-9C ) of the two primary reflected signal components must be approximately equal. The two primary reflected components may be considered to have approximately the same propagation delay if the difference in the propagation delays of the two components is small compared to the inverse of the memory transfer rate. Note that the propagation delay of a transmission line segment depends on the length of the line and the permittivity of the material adjacent to the transmission line segment. Thus equalizing the propagation delay of two transmission line segments is not necessarily the same as equalizing the lengths of the transmission lines.
[0070] Closing Comments
[0071] Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. With regard to flowcharts, additional and fewer steps may be taken, and the steps as shown may be combined or further refined to achieve the methods described herein. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments.
[0072] As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of”, respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.
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A memory module may include a circuit board connectable to a system memory bus through a plurality of contacts disposed along one edge of the circuit board, the system memory bus having three positions for connecting memory modules. A plurality of memory chips may be mounted on the circuit board. The circuit board may include a plurality of D/Q traces to couple a corresponding plurality of D/Q signals from respective contacts to the plurality of memory chips or to one or more buffer chips that isolate the system memory bus from the memory chips. Each of the plurality of D/Q traces may have a predetermined trace impedance selected to provide a predetermined D/Q signal quality level when the memory module is installed in any of the three positions on the system memory bus and equivalent memory modules are installed in the other two positions.
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This application is a continuation of of now abandoned application Ser. No. 07/210,183 filed on Jun. 22, 1988 which, in turn, is a continuation-in-part of Ser. No. 07/068,158 filed on Jun. 30, 1987 and now abandoned.
FIELD OF THE INVENTION
The present invention generally relates to a toner used for developing a magnetic latent image in magnetography and an electrostatic latent image in electrostatic printing and electrophotography and the like; and more particularly to a toner having magnetic shell.
BACKGROUND OF THE INVENTION
Conventionally, two types of methods have been known for developing an electrostatic latent image in electrophotography and electrostatic printing. One method is a two-component-type system wherein colored resin powder called "toner", and a carrier composed of iron powder, glass beads and the like are rubbed together to make the toner charged; then the charged toner is electrostatically attracted on an electrostatic latent image of a photosensitive member so as to develop the image. The other method is a one-component-type system wherein a carrier is not used; instead, a toner obtained by means of melting and kneading the following materials, such as binder resin, coloring agent, and magnetic powder, is used for developing a image. In both methods, a fixing process whereby a toner is transferred and fixed on a copy paper, is indispensable. There are two types of fixing methods; one is a heat-roller-fixing method wherein an image is melted and fixed by a heat roller; the other is a pressure-fixing method wherein an image is fixed by pressure.
In recent years, energy saving in both fixing methods is strongly demanded, i.e., improvement in low-temperature performance for the heat-roller-fixing method, and improvement in low-pressure performance for the pressure-fixing method are required. To cope with the above-described demands from the aspect of a toner design, a glass-transition temperature of the binder resin can be lowered in order to achieve low-temperature fixability; however, on the other hand, the use of the resin having a low glass-transition temperature causes the agglomeration of the toner. Consequently, the toner forms an agglomerate during storage, or electric charge quantity decreases due to the lowered flowability in the developing machine.
As for the pressure-fixing method, various methods have been proposed, such as Japanese Patent Publication Open to Public (hereinafter referred to as Japanese Patent O.P.I Publication), No. 14260/1982, No. 146261/1982, No. 41648/1982, and No. 44155/1982. According to the proposed methods, a toner is obtained by melting and dispersing magnetic powder in wax followed by grinding and classifying into fine particles, and then dispersing the fine particles in a liquid solution which has dissolved a resin, such as polystyrene, followed by spray-drying. According to this method, however, the particles stick together because of softening the surface resin thereof when spray-dried. Even if the size of the core material may be made the same, the particle-size distribution becomes large because of the sticking and the charge quantity fluctuates, thus causing deteriorated image quality.
Also, as described in Japanese Patent O.P.I. Publication No. 25156/1986, a capsule toner can be obtained through the following procedures; First, porous polymer particles are dispersed in an aqueous medium containing metal salt mainly composed of iron salt to precipitate metal hydroxides or oxides on the polymer particles (core particles) and then the precipitated polymer particles are used as seed particles to polymerize in an aqueous solution containing a polymerizable monomer to form the capsule toner. According to this method, however, the metal oxide layer formed on the core particles is formed only by precipitation. Therefore, the layer thickness of the metal oxide is limited, and the quantity of the magnetic material present on the surface of polymer particles depends on the surface area of the particles. Accordingly, in order to increase the surface area, the polymer particles have to be made porous. However, to make the polymer particles porous, extremely large amount of a crosslinking agent must be used. Consequently, it is impossible to provide the heat-roller fixability or pressure fixability to the polymer particles. Therefore, in order to provide fixability to the toner, it is required to further form a resin layer on the surface of the polymer particles (core particles). However, in order to ensure low-temperature fixability or low-pressure fixability, glass-transition temperature of the further formed resin layer on the surface of the particles have to be lowered, whereby blocking resistance is deteriorated.
SUMMARY OF THE INVENTION
The inventors of the present invention have found that the cohesiveness and stickiness of a toner can be prevented by means of forming magnetic shell having a thickness of 0.001 to 1 micron, preferably 0.005 to 0.5 micron on the surface of colored particles mainly composed of a coloring agent and a binder resin.
In short, the object of the present invention is to provide a magnetic-shell-coated toner used for heat-roller fixing. The toner is fixable at low temperatures, and the surface of the particles are uniformly magnetized and stably charged.
Also, another object of the present invention is to provide a magnetic-shell-coated toner for pressure fixing. The toner is fixable at low pressure, and the surface of the particles are uniformly magnetized and stably charged.
Furthermore, another object of the present invention is to provide a thermally and mechanically stable toner which does not agglomerate in a long storage or long-period operation.
The magnetic-shell-coated toner of the present invention is preferably obtained by an electroless ferrite plating method.
DETAILED DESCRIPTION OF THE INVENTION
Colored particles used in the present invention which are mainly composed of a binder resin and a coloring agent, are usually obtained by a melt-kneading method or a particulated polymerization method (such as, an emulsion polymerization method and a suspension polymerization method). The particle diameter of the colored particles is usually 2 to 30 micron, preferably 5 to 20 micron. When the particle diameter is under 2 micron, the flowability of the obtained colored particles becomes too low. When the particle diameter is over 30 micron, the image quality is deteriorated.
In the melt-kneading method, a coloring agent or other additives such as wax and the like, if necessary, are melted and dispersed in the binder resin, and then they are ground so as to obtain colored particles. Example of the binder resin is a polymer or copolymer of styrene or styrene derivatives, such as polystyrene, polyvinyltoluene, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-maleic anhydride copolymer; acrylic resin; polyester resin; epoxy resin; xylene resin; ionomer resin; ketone resin; terpene resin; phenol-modified terpene resin; rosin, rosin-modified resin; maleic-acid-modified phenol resin; petroleum resin; polyvinyl alcohol; polyvinyl pyrolidone and a mixture thereof.
Examples of the coloring agents are Carbon Black, Nigrosine, Lamp Black, Aniline Blue, Calcoil Blue, Ultramarine Blue, Phthalocyanine Blue, Chrome Yellow, Quinorine Yellow, Du Pont Oil Red, Rose Bengal, Methylene Blue Chroride and the like.
In the emulsion polymerization method, colored particles are obtained through the following procedures: Usually, a part of a polymerizable monomer and a polymerization initiator are added in ion-exchanged water which may contain an emulsifying agent, and the mixture is agitated and emulsified; then, the rest of the polymerizable monomer is gradually added dropwise to obtain polymer particles having a particle diameter of 0.2 to 1 micron. The polymer particles obtained in this manner are used as seeds for seed polymerization wherein another polymerizable monomer mixture in which dye pigment is dissolved or dispersed is used. Also, the polymer particles are used for seed polymerization wherein another polymererizable monomer mixture does not contain a coloring agent and then the polymer particles are colored by means of a dye solution or a dye-dispersed solution to obtain colored particles.
Any type of polymerizable monomers may be used for emulsion polymerization, examples of which are ethylene, propylene, styrene, alpha-chlorostyrene, alpha-methylstyrene, 4-fluorostyrene, acrylic acid, methacrylic acid, acrylonitrile, acrylamide, methyl acrylate, methyl methacrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, trifluoroethyl methacrylate, vinyl acetate, maleic anhydride and a mixture thereof.
In addition, other additives include a polymerization initiator, emulsifying agent and the like. The polymerization initiator includes two types of polymerization initiator; a free radical initiator, such as hydrogen peroxide, peracetic acid, azobisisobutyronitrile, t-butylhydroperoxide, ammonium persulfate, potassium persulfate; a redox initiator, such as sodium persulfate-sodium formaldehydesulfoxilate, and hydrogen peroxide-ascorbic acid. The emulsifying agent includes an anion surfactant, for example, potassium stearate, potassium oleate, sodium dodecylsulfonate, and sodium laurate and the like; a cation surfactant, for example, a long-chain quaternary amine salt and the like; and a nonion surfactant, for example, an ethylene oxide condensate of linoleinic acid and lauric acid and the like.
According to the present invention, magnetic shell composed of iron oxide is formed on the surface of the colored particles. In other words, colored particles are protected by encapsulating with a magnetic shell. Accordingly, those materials which are considered difficult to be used for a toner due to low glass transition temperature can be also employed for a binder resin of the colored particles. The binder resin conventionally used for a toner has a glass transition temperature of 40° to 80° C. According to the present invention, the glass transition temperature can be extend to a range of 20° to 80° C., preferably 35° to 70° C. The magnetic material formed on the colored particles is, in general, ferrite or magnetite.
The method of forming magnetic material is preferably a electroless ferrite plating method described in Japanese Patent O.P.I. Publication No. 111929/1984 (P39-48 "FUNCTIONAL MATERIAL" September 1984).
In this patent publication, it is only exemplified that the ferrite wet plating method is applicable to a plate-like material. Until now, it had been believed that it was difficult to apply the electroless ferrite plating method to particulate materials, because the ferrite forming reaction was carried out in a place other than on the particle surface to form mere ferrite particles. However, it has been found that, when it is applied to particles, the ferrite layer is mainly formed on the surface of the particles based on the activity of the surface of individual particles. It, also, has been found that, if nitrite is employed as an oxidizing agent in the method, the formation of the ferrite layer on the particles is accelerated.
According to the electroless ferrite plating method, the colored particles are uniformly dispersed in an aqueous solution containing some metal ions, at least ferrous ions, so that ferrous hydroxide ions (FeOH + ) or other metal hydroxide ions are uniformly absorbed onto the surface of the colored particles by means of the reaction occurring at the interface of the colored particles and the aqueous solution. Absorption FeOH + obtained through the procedures described above is, then, oxidized to FeOH 2+ so that crystallization reaction of ferrite or magnetite takes place between the above-described FeOH 2+ and other metal hydroxide ions in the aqueous solution, thereby generating crystalline layer on the surface of the colored particles. In the process of this method, ferrous ion hydroxide ions or other metal hydroxide ions are further adsorbed onto the crystalline layer thus generated. The thickness of the crystalline layer can be controlled by regulating the quantity of metal ion in the bath. Also, the electric conductivity of the generated magnetic crystalline layer is controlled by regulating the concentration of the ferrous ion hydroxide and the other metal ions in the bath.
In executing the electroless ferrite plating process, the dispersion solution containing the colored particles obtained by the particulated polymerization can be utilized without treating it thereafter; if colored particles are to be obtained by the melt-kneading method, the particles should be, in general, preferably dispersed uniformly in the ion-exchanged water in which a surfactant is dissolved, or the particles should be preferably impregnated by alcohol before uniformly dispersing the particles in the ion-exchanged water.
According to this plating method, an oxygen atom on the surface of the colored particles and ferrous ion or other transitional metals, such as Zn 2+ , Co 2+ , Co 3+ , Ni 2+ , Mn 2+ , Mn 3+ , Fe 3+ , Cu 2+ , V 3+ , V 4+ , V 5+ , Sb 5+ , Li + , Li + , Mo 4+ , Mo 5+ , Ti 4+ , Pd 3+ , Mg 2+ , Al 3+ , Si 4+ , Cr 3+ , Sn 2+ , Sn 4+ , etc. are combined to form chemical bond, thus forming consecutively ferrite cyrstal. The thickness of the magnetic shell to be formed should range from 0.001 to 1 micron, preferably from 0.005 to 0.5 micron. If the thickness exceeds over 1 micron, a thick layer is formed between paper and colored particles to deteriorate the fixability. If the thickness of the magnetic shell to be formed is under 0.001 micron, the mechanical strength of the magnetic shell becomes weak, causing blocking and the like due to destruction of the shell. It should be noted that the thickness of the magnetic-shell is calculated using the true specific gravity of the colored particles, magnetic-shell-coated toner and magnetic material.
The magnetic-shell-coated toner of the present invention has a crystal layer composed of iron-oxide type magnetic material; therefore, the toner is free from any damages caused by the mechanical shocks like agitation movement in the developing machine or thermal influence during storage or in the developing machine; thus the glass-transition temperature of the binder resin can be lowered when forming a toner. Accordingly, the low-temperature fixability as well as low-pressure fixability is improved. Also, when employing the electroless ferrite plating method for forming magnetic shell, the thickness of the shell can be easily controlled. Moreover, in the case of two-component-type toner, if the magnetic-shell-coated toner of the present invention is used, the dispersion of the toner is effectively prevented because of the effect of the magnetic material.
The present invention is illustrated by the following examples, which, however, are not construed as limiting the scope of the present invention to their details.
EXAMPLE 1
Production of Colored Particles
First, 150 parts of ion-exchanged water was poured into a polymerization-reaction container equipped with an agitator, a thermometer, a monomer-dropping funnel, a reflux condenser, a heater, and a nitrogen-introduction pipe. At the temperature of 80° C., one part by weight of a monomer mixture (A) containing styrene and 2-ethylhexyl acrylate in a weight ratio of 75:25 of styrene and 2-ethylhexyl acrylate, and 10 parts by weight of 10% ammonium persulfate water solution were added. Then, 99 parts of the above-described monomer mixture (A) was added dropwise for three hours, thereby obtaining a seed latex. The particles thus obtained were observed using an electron microscope. The diameter of the particles was uniform and had 0.6 micron.
Using the same system, 0.2 parts of the seed latex were first added to 250 parts of ion-exchanged water, then at the temperature of 80° C., 10 parts of a 10% ammonium-persulfate water solution and 100 parts of the monomer mixture (A) were added dropwise for 8 hours; thus, large-diameter latex particles were produced through a seed polymerization. Observation through an electron microscope showed that diameters of the particles ranged from 6 to 8 microns, and their shape was near to true sherical. By adding 50 parts of a 5% water solution of black dye, Sumi Acryl Black B (basic dye manufactured by Sumitomo Chemical Co., Ltd.) to the latex described above, and agitating the mixture for one hour, colored particles were obtained wherein the surface of the latex particles had absorbed dye.
The glass-transition temperature of the colored particles (I) was measured by DSC (differential scanning calorimeter: Daini Seikosha Co., Ltd. SSC/560), the result was 37° C.
Formation of a Magnetic Crystalline Layer
The amount of 180 g of the above-described colored particle emulsion (solid portion: 30%) was poured into a device equipped with an agitator, a thermometer, a metal-ion-dropping funnel, an heater, and a nitrogen-introduction pipe; then, nitrogen gas was introduced so as to removed oxygen contained in the emulsion. On the other hand, a ferrous-ion solution was obtained by means of dissolving 62 g of ferrous chloride into 62 ml of ion-exchanged water which previously removed oxygen by nitrogen gas. Also, a sodium-nitrite solution was prepared by dissolving 13 g of sodium nitrite into 330 g of ion-exchanged water which previously removed oxygen by nitrogen gas. Furthermore, an ammonium-acetate solution was obtained by dissolving 124 g of ammonium acetate into 430 g of ion-exchanged water which previously removed oxygen by nitrogen gas.
Next, the above-described ammonium acetate was added to the emulsion of the colored particles (I) and mixed sufficiently. Then, the total amount of the above-described ferrous ion solution was poured and heated to 70° C. at a pH of 6.5 to 7 under mixing in a nitrogen blanket, with maintaining at this condition, the total amount of the sodium-nitrite solution described above was then added dropwise at the rate of 10 to 20 ml/min to generate a magnetite crystalline layer on the surface of the colored particles. The obtained particles were dried by a spray-dryer to obtain a magnetic-shell-coated toner (I).
The obtained magnetic-shell-coated toner (I) was observed by an electron microscope, and it was found that magnetite crystal layer was uniformly formed on the surface of the particles. Also, the thickness of the magnetite crystal layer of the colored particles was calculated to evaluate 0.1 micron.
EXAMPLE 2
Using the colored particles (I) obtained in Example 1, a magnetic-shell-coated toner (I) was prepared as generally described in Example 1 with the exception that the dissolved amount of ferrous chloride was changed to 0.62 g, the dissolved amount of sodium-nitrite was changed to 0.13 g, and the dissolved amount of ammonium acetate was changed to 1.2 g. The obtained toner was observed by an electron microscope, and it was found that a magnetite crystal layer was almost formed. Also, the thickness of the magnetite crystal layer of the toner was calculated to find less than 0.0008 micron.
EXAMPLE 3
Using the colored particles (I) obtained in the Example 1, a magnetic-shell-coated toner (III) was prepared as generally described in Example 1 with the exception the amount of colored-particle emulsion (solid portion: 30%) was changed to 30 g, the dissolved amount of ferrous chloride was changed to 130 g, the dissolved amount of sodium-nitrite was changed to 27 g, and the dissolved amount of sodium acetate was changed to 260 g. The obtained toner was observed by an electron microscope, and it was found that magnetite crystal layer was uniformly formed on the surface of the colored particles. Also, the thickness of the magnetite crystal layer of the toner was calculated to find 1.2 micron.
EXAMPLE 4
Production of Colored Particles
Using the same type of reaction system employed in Example 1, colored particles having a particle diameter of 6 to 8 micron were prepared as generally described in Example 1 with the exception that the composition of the mixed monomer was changed to 60:40 of styrene and n-butyl acrylate. The glass-transition temperature of the obtained particles was measured using a D.S.C.; the result was 20° C.
Formation of a Magnetic Crystal Layer
Using the same system under the same conditions of Example 1, a magnetic-shell-coated toner (IV) was prepared as generally describe in Example 1, wherein a magnetite crystal layer was generated on the surface of the above-described colored particles, then the layer was dried by a spray dryer. The thickness of the crystal layer formed on the surface of the toner was 0.1 micron.
EXAMPLE 5
Production of Colored Particles
The colored particles (I) obtained in Example 1 was used.
Formation of a Magnetic Crystal Layer
Using the same system employed in Example 1, a magnetic-shell-coated toner (V) was prepared as generally described in Example 1 with the exception that the composition of the metal-ion solution was changed to the following equation, Fe 2+ :Mn 2+ :Zn 2+ =2:0.5:0.5 (ferrous chloride, magnanese chloride, and zinc chloride, respectively), a ferrite crystal layer was generated on the surface of the colored particles and dried by a spray dryer. The thickness of the crystal layer formed on the surface of the obtained toner was 0.15 micron. Furthermore, as a result of atomic analysis, the composition of the ferrite layer was found to be Mn 0 .1.Zn 0 .3.Fe 2 .6.O 4 .
EXAMPLE 6
Production of Colored Particles
______________________________________Component Weight______________________________________Styrene resin 85 (Weight ratio)(Trade name "Piccolastic D-125"Hercules Co., Ltd.)Carbon black 8 (Weight ratio)(Trade name "Monarch 880" Cabot Corp.)Polypropylene wax 7 (Weight ratio)(Trade name "Biscole 550P"Sanyo Chemical Industry Co.,Ltd.)Oil black 2 (Weight ratio)(Trade name "Bontron S-34"Orient Chemical Co., Ltd.)______________________________________
After carrying out a dry blending of the components described above for 12 hours using a ball mill, the mixture of the components was heated and kneaded by means of a biaxial extruding machine, wherein barrel temperature was set to 125° C. degrees. Then, the mixture of the components was finely ground using a pin mill and a jet mill, and an air classifier classified the particles into a specified ratio, i.e., the amount of particles having a diameter exceeding 20 micron was under 1% of the weight ratio, the amount of particles having a diameter less than 5 micron was under 1%, making the average diameter of the particles 10 micron, thus classified colored particles (III) were obtained.
Formation of a Magnetic Crystal Layer
The amount of 3.6 g of nonionic surfactant (Nonipole 100: Sanyo Chemical Industry Co., Ltd.) was dissolved into 180 ml of ion-exchanged water, then 60 g of the colored particles (III) was gradually added and uniformly dispersed while the mixture was agitated at a rotation velocity of 1000 to 1500 r.p.m. Then, removal of oxygen was carried out simultaneously with the defoaming process performed by a vacuum deaerator, and the mixture was poured into the magnetic-material-generating system employed in Example 1, wherein crystallization was accomplished under the same conditions of Example 1 to obtain a magnetic-shell-coated toner (VI).
The obtained toner (VI) was observed by an electron microscope, and it was found that magnetite crystal layer was uniformly formed on the surface of the colored particles; the thickness of the magnetite crystal layer of the toner was 0.1 micron.
COMPARATIVE EXAMPLE 1
The colored particles (I) obtained in Example 1 were subjected to a conventional silica treatment to obtain a toner (VII).
COMPARATIVE EXAMPLE 2
______________________________________Component Weight______________________________________Styrene resin 85 (Weight ratio)(Trade name "Piccolastic D-125"Hercules Co., Ltd.)Carbon black 8 (Weight ratio)(Trade name "Monarch 880" Cabot Corp.)Polypropylene wax 7 (Weight ratio)(Trade name "Biscole 550P"Sanyo Chemical Industry Co.,Ltd.)Oil black 2 (Weight ratio)(Trade name "Bontron S-34"Orient Chemical Co., Ltd.)______________________________________
After carrying out a dry blending of the components described above for 12 hours using a ball mill; the mixture of the components was heated and kneaded by means of a biaxial extruding machine, wherein barrel temperature was set to 125° C. Then, the mixture of the components was finely ground using a pin mill and a jet mill, and an air classifier classified the particles into a specified ratio, i.e., the amount of particles having a diameter exceeding 20 micron was under 1% of the weight ratio, the amount of particles having a diameter less than 5 micron was under 1%, making the average diameter of the particles 9.5 micron; furthermore, the particles was subjected to a conventional silica treatment to form colored particles (VIII).
Table 1 shows the results of the performance evaluation as for eight kinds of toners obtained in Examples 1 to 6, and Comparative Examples 1 to 2.
In evaluating fixability and image quality, resin-coated iron powder was used as a carrier for toners (I) to (IV), and toners (VI) to (VIII), wherein the weight ratio of a toner and a carrier was set to 4:96. In this way, developers (I), (II), (III), (IV), (V), (VI), (VII), and (VIII) were prepared and provided. As for toner (V), however, the evaluation was made as an one-component toner.
TABLE 1__________________________________________________________________________Performance of toners Example Example Example Example Example Example Comparative Comparative 1 2 3 4 5 6 Example 1 Example__________________________________________________________________________ 2Type of toner I II III IV V VI VII VIIIType of developer I II III IV -- VI VII VIIIAverage particle 7.2 7.1 7.8 6.8 7.3 10 7.0 9.5diameter (micron)Thickness of magnetic 0.1 0.0008 1.2 0.1 0.15 0.1 -- --layerGlass-transition 37 37 37 20 37 46 37 52temperature of coloredparticles (°C.)Fixable temperature 120 120 160 15 120 150 120 180(°C.)Blocking resitance Normal Partial Normal Normal Normal Normal Agglomeration Normal agglomerationInitial Resolution 5 5 5 5 5 5 5 5performance Fog Not Not Not Not Not Not Not Not detected detected detected detected detected detected detected detectedAfter Resolution 5 -- 5 5 5 5 3.5 4accomplishing Fog Not -- Not Not Not Not -- Fog in total arealife-time test detected detected detected detected detected Toner con- Normal Agglomeration Normal Normal Normal Normal Agglomeration Soft dition in agglomeration developing machineFixation method Heat Heat roller Heat Pressume Heat Heat Heat roller Heat roller roller fixation roller fixation roller roller fixation fixation fixation fixation fixation fixation__________________________________________________________________________
NOTE
Evaluation Method
(1) Average particle diameter: Colter counter (Toshiba Chemical Co., Ltd.)
(2) Glass-transition temperature of colored particles: DSC method (SSC/560 Daini Seikoosha DCol, Ltd.)
(3) Fixable temperature:
A non-fixed image was prepared by using U-Bix V (Konishiroku Photo Industry Co., Ltd.), then fixation was carried out by a temperature-variable fixation-testing machine (pressure 2 Kg/cm 2 ) comprising a teflon upper roller and a silicon lower roller. Then, rubbing the fixed image with a load of 2 Kg ten times using a plastic rubber, and image density of the rubbed portion and non-rubbed portion was compared. In this way, a fixable temperature was set to a temperature at which no difference in image density was recognized.
As for toner (IV), after obtaining a non-fixed image, fixation was carried out under the condition of 20 Kg/cm loaded by a pair of metal rollers.
As for toner (V), after obtaining a non-fixed image using U-Bix T (Konishiroku Photo Industry Co., Ltd.), fixation was carried out by a fixation-testing machine.
(4) Blocking resistance:
After slightly tapping a 50 ml sample tube containing 30 g of a toner, the tube was left in an incubator for 24 hours which was maintained at a temperature of 50° C. Then, the toner was taken out from the sample tube and was spreaded on a sheet of paper for observation.
(5) Life-time test:
Consecutive copying operation, 10,000 times, was carried out.
(6) Toner condition in developing machine: Visual inspection.
(7) Development degree, fog: Visual inspection.
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Disclosured is a toner comprising colored particles and a magnetic shell coated thereon, wherein said colored particles are composed of a binder resin and a coloring agent, and said magnetic shell is formed from an iron-oxide type magnetic material. The toner can be fixable at a low temperature or a low pressure, but the toner particles do not agglomerate with each other during long-term storage.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed to U.S. provisional application Serial No. 60/095,329 filed Aug. 4, 1998.
BACKGROUND OF THE INVENTION
[0002] This is generally in the field of production of polyhydroxyalkanoates by genetic engineering of bacterial enzymes.
[0003] Numerous microorganisms have the ability to accumulate intracellular reserves of poly [(R)-3-hydroxyalkanoate] (PHA) polymers. PHAs are biodegradable and biocompatible thermoplastic materials with a broad range of industrial and biomedical applications (Williams and Peoples, 1996, CHEMTECH 26: 38-44). PHAs can be produced using a number of different fermentation process and recovered using a range of extraction techniques (reviewed by Braunegg et al. 1998, J. Biotechnol. 65: 127-161; Choi and Lee, 1999). Plant crops are also being genetically engineered to produce these polymers offering a cost structure in line with the vegetable oils and direct price competitiveness with petroleum-based polymers (Williams and Peoples 1996, CHEMTECH 26:38-44; Poirier, Y. 1999, Plant Biotechnology pp. 181-185). PHAs are formed by the action of a PHA synthase enzyme. As the polymer chains grow, they form insoluble granules. The PHAs can then be recovered and then converted into chemicals or converted into chemicals during the recovery process (Martin et al. PCT WO 97/15681). Therefore, in addition to their utility as polymers, the PHAs represent a unique mechanism for storing new chemistries in both microbial and plant crop systems.
[0004] PHA copolymers containing 3-hydroxyvalerate (3HV), especially PHBV, have been described extensively. Many wild type microorganisms are capable of producing 3HV-containing PHAs. PHBV has been produced commercially using Ralstonia eutropha (formerly Alcaligenes eutrophus ) from glucose and propionate and from glucose and isobutyrate (U.S. Pat. No. 4,477,654 to Holmes et al.). A number of other microorganisms and processes are known to those skilled in the art (Braunegg et al. 1998, Journal of Biotechnology 65: 127-161). Poly(3HV) homopolymer has been produced using Chromobacterium violaceum from valerate (Steinbüchel et al., 1993, Appl. Microbiol. Biotechnol. 39:443-449). PHAs containing 3HV units have also been synthesized using recombinant microorganisms. Escherichia coli harboring the R. eutropha PHA biosynthesis genes has been used to produce PHBV from glucose and either propionate or valerate (Slater et al., 1992, Appl. Environ. Microbiol. 58:1089-1094) and from glucose and either valine o: threonine (Eschenlauer et al., 1996, Int. J. Biol. Macromol. 19:121-130). Klebsiella oxytoca harboring the R. eutropha PHA biosynthesis genes has been used to produce PHBV from glucose and propionate (Zhang et al., 1994, Appl. Environ. Microbiol. 60:1198-1205). R. eutropha harboring the PHA synthase gene of Aeromonas caviae was used to produce poly(3HV-co-3HB-co-3HHp) from alkanoic acids of odd carbon numbers (Fukui et al., 1997, Biotechnol. Lett. 19:1093-1097).
[0005] PHA copolymers containing 3-hydroxypropionate units have also been described. Holmes et al. (U.S. Pat. No. 4,477,654) used R. eutropha to synthesize poly(3HP-co-3HB-co-3HV) from glucose and either 3-chloropropionate or acrylate. Doi et al. (1990, in E. A. Dawes (ed.), Novel Biodegradable Microbial Polymers, Kluwer Academic Publishers, the Netherlands, pp. 37-48) used R. eutropha tri synthesize poly(3HP-co-3HB) from 3-hydroxypropionate, 1,5-pentanediol, 1,7-heptanediol, or 1,9-nonanediol. Hiramitsu and Doi (1993, Polymer 34:4782-4786) used Alcaligenes latus to synthesize poly(3HP-co-3HB) from sucrose and 3-hydroxypropionate. Shimamura et al. (1994, Macromolecules 27: 4429-4435) used A. latus to synthesize poly(3HP-co-3HB) from 3-hydroxypropionate and either 3-hydroxybutyrate or sucrose. The highest level of 3-hydroxypropionate incorporated into these copolymers was 88 mol % (Shimamura et al., 1994, ibid.). No recombinant 3HP containing PHA producers have been described in the art.
[0006] It is economically desirable to be able to produce these polymers in transgenic crop species. Methods for production of plants have been described in U.S. Pat. No. 5,245,023 and U.S. Pat. No. 5,250,430; U.S. Pat. No. 5,502,273; U.S. Pat. No. 5,534,432; U.S. Pat, No. 5,602,321; U.S. Pat, No. 5,610,041; U.S. Pat, No. 5,650,555: U.S. Pat, No. 5,663,063; WO 9100917, WO 9219747, WO 9302187, WO 9302194 and WO 9412014, Poirier et. al., 1992, Science 256; 520-523, Williams and Peoples, 1996. Chemtech 26, 38-44. the teachings of which are incorporated by reference herein). In order to achieve this goal, it is necessary to transfer a gene, or genes in the case of a PHA polymerase with more than one subunit, encoding a PHA polymerase from a microorganism into plant cells and obtain the appropriate level of production of the PHA polymerase enzyme. In addition it may be necessary to provide additional PHA biosynthetic genes, e.g. a ketoacyl-CoA thiolase, an acetoacetyl-CoA reductase gene, a 4-hydroxybutyryl-CoA transferase gene or other genes encoding enzymes required to synthesize the substrates for the PHA polymerase enzymes. In many cases, it is desirable to control the expression in different plant tissues or organelles. Methods for controlling expression in plant tissues or organelles are known to those skilled in the art (Gasser and Fraley, 1989, Science 244; 1293-1299; Gene Transfer to Plants, 1995, Potrykus, I. and Spangenberg, G. eds. Springer-Verlag Berlin Heidelberg N.Y. and “Transgenic Plants: A Production System for Industrial and Pharmaceutical Proteins”, 1996, Owen, M. R. L. and Pen, J. Eds. John Wiley & Sons Ltd. England, incorporated herein by reference).
[0007] Although methods for production of a variety of different copolymers in bacterial fermentation systems are known, and production of PHAs in plants has been achieved, the range of copolymers possible in bacterial has not been achieved in plants. It would be advantageous to be able to produce different copolymers in transgenic plants, and to have more options with regard to the substrates to be utilized by the transgenic plants.
[0008] It is therefore an object of the present invention to provide methods and reagents for production of PHAs in plants.
[0009] It is a further object of the present invention to provide methods and reagents for production of PHAs using simple sugars and alcohols as substrates.
[0010] It is still another object of the present invention to provide methods and reagents for production of copolymers other than PHB and PHVB.
SUMMARY OF THE INVENTION
[0011] Organisms are provided which express enzymes such as glycerol dehydratase, diol dehydratase, acyl-CoA transferase, acyl-CoA synthetase B-ketothiolase, acetoacetyl-CoA reductase, PHA synthase, glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase, which are useful for the production of PHAs. In some cases one or more of these genes are native to the host organism and the remainder are provided from transgenes. These organisms produce poly (3-hydroxyalkanoate) homopolymers or copolymers incorporating 3-hydroxypropionate or 3-hydroxyvalerate monomers wherein the 3-hydroxypropionate and 3-hydroxyvalreate units are derived from the enzyme catalysed conversion of diols. Suitable diol.; that can be used include 1,2-propanediol, 1,3 propanediol and glycerol. Biochemical pathways for obtaining the glycerol from normal cellular metabolites are also described. The PHA polymers are readily recovered and industrially useful as polymers or as starting materials for a range of chemical intermediates including 1,3-propanediol, 3-hydroxypropionaldehyde, acrylics, malonic acid, esters and amines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a flow chart of the production of 3-hydroxyvaleryl-CoA from glycerol3-P.
[0013] [0013]FIG. 2 is a schematic of the plasmid construct pFS44C encoding glycerol dehydratase (dhaB) and 4-hydroxybutyryl-CoA transferase (hbcT).
[0014] [0014]FIG. 3 is a schematic of the plasmid construct pFS45 encoding dhaB, hbcT and phaC.
[0015] [0015]FIG. 4 is a schematic of the plasmid construct pFS47A, encoding dhaT, dhaB, and hbcT.
[0016] [0016]FIG. 5 is a schematic of the plasmid construct pFS48B, encoding dhaT, dhaB, hbcT, and phaC.
[0017] [0017]FIG. 6 is a schematic of the plasmid construct pMS 15, encoding dhaT, DAR1-GPP2 (DAR1, dihydroxyacetone phosphate dehydrogenase; and GPP2, sn-glycerol-3-phosphate phosphatase), dhaB, hbcT, and phaC.
[0018] [0018]FIG. 7 is a schematic of the plasmid construct pFS51, encoding GPP2 and DAR1.
DETAILED DESCRIPTION OF THE INVENTION
[0019] New metabolic pathways have been developed for the production of PHAs containing 3-hydroxyvalerate units from 1,2-propanediol and of PHAs containing 3-hydroxypropionate units from 1,3 propanediol or glycerol. In the case of glycerol, the glycerol can either be fed to the microorganism or can be produced from central metabolic intermediates. The key enzymes components of these novel metabolic pathways leading to these monomers and their polymerization are illustrated in FIG. 1. 1,2-propanediol and glycerol are inexpensive substrates that are non toxic to many microorganisms even at high concentrations. 1,3-propanediol can be produced from renewable resources (Anton, D. “Biological production of 1,3-propanediol”, presented at United Engineering Foundation Metabolic Engineering II conference, Elmau, Germany, Oct. 27, 1998). 1,2-propanediol is present in industrial waste streams from production of propylene glycol. Glycerol can also be obtained from metabolism in a number of microbes and plant crops. In many cases, these are superior feedstocks for fermentation as compared to organic acids, which generally become toxic at low concentrations to many microorganisms. 3-Hydroxypropionic acid is not chemically stable and therefore is not commercially available.
[0020] Organisms to be Engineered
[0021] In one embodiment, genes for the entire pathway illustrated in FIG. 1 are introduced into the production organism. An organism that does not naturally produce PHAs, such as Escherichia coli , may be used. A number of recombinant E. coli PHB production systems have been described (Madison and Huisman, 1999, Microbiology and Molecular Biology Reviews, 63: 21-53). The genes encoding a vicinal diol dehydratase, from an organism that naturally can convert glycerol to 3-hydroxypropionaldehyde ( Klebsiella pneumoniae , e.g.), are introduced into this host. In the case of 1,2-propanediol, the vicinal diol dehydratase converts the substrate to propionaldehyde, which can be converted to propionyl-CoA by the endogenous metabolism of the microorganism, optionally with the aid of an exogenous acyl-CoA transferase or acyl-CoA synthetase. It may be useful to mutagenize and select strains with increased resistance to propionaldehyde. Propionyl-CoA can then be accepted by the ketoacyl-CoA thiolase in a condensation with acetyl-CoA, thus forming 3-hydroxyvaleryl-CoA. The ketoacyl-CoA thiolase will also condense acetyl-CoA with acetyl-CoA, thus forming 3-hydroxybutyryl-CoA. Both 3-hydroxyvaleryl-CoA and 3-hydroxybutyryl-CoA can be accepted by various PHA synthases such as the one expressed in the recombinant host, and therefore PHBV is synthesized by the recombinant host.
[0022] The host described above can also be fed 1,3 propanediol or glycerol either during growth or after a separate growth phase, and a 3HP polymer is accumulated within the cells. E. coli does not synthesize coenzyme B-12 de novo, and therefore coenzyme B-12 or a precursor that E. coli can convert to coenzyme B-12, such as vitamin B-12, must also be fed. In the case of glycerol, the vicinal diol dehydratase converts the substrate to 3-hydroxypropionaldehyde, which can be converted to 3-hydroxypropionyl-CoA by the endogenous metabolism of the microorganism, optionally with the aid of an exogenous acyl-CoA transferase or acyl-CoA synthetase. 3-Hydroxypropionyl-CoA may then be polymerized by PHA synthase to P3HP. Hydroxyacyl-CoA monomer units in addition to 3HP may also be incorporated into the polymer. If ketoacyl-CoA thiolase and reductase are expressed, for example, then a copolymer of 3-hydroxybutyrate and 3-hydroxypropionate can be formed.
[0023] In order to produce the 3HP polymers directly from carbohydrate feedstocks, the E. coli is further engineered to express glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase. Such recombinant E. coli strains and methods for their construction are known in the art (Anton, D. “Biological production of 1,3-propanediol”, presented at United Engineering Foundation Metabolic Engineering II conference, Elmau, Germany, Oct. 27, 1998; PCT WO 98/21339).
[0024] In another embodiment, a recombinant organism that naturally contains a vicinal diol dehydratase can be used. One example of such an organism is Klebsiella oxytoca , although several others exist, as discussed above. In this embodiment no exogenous vicinal diol dehydratase need be imported from another organism. However it may be useful to mutagenise this organism and select mutants that express the dehydratase during aerobic growth or it can be genetically engineered to express the gene under aerobic conditions. It is generally the case that organisms which contain one or more coenzyme B-12-dependent vicinal diol dehydratases can synthesize coenzyme B-12 de novo, and in those cases it is not necessary to add coenzyme B-12 or closely related precursors thereof to any part of the cultivation. In this case, a PHA synthase or an entire PHB biosynthetic pathway and optionally an exogenous acyl-CoA transferase or acyl-CoA synthetase is introduced into this organism. Techniques for doing this are well known in the art (for example, Dennis et al., 1998, Journal of Biotechnology 64: 177-186). In order to produce the 3HP polymers directly from carbohydrate feedstocks, the strain is further engeneered to express glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase as described above.
[0025] In another embodiment, an organism that naturally produces PHAs can be used. Examples of such organisms include Ralstonia eutropha, Alcaligenes latus and Azotobacter but many others are well-known to those skilled in the art (Braunegg et al. 1998, Journal of Biotechnology 65: 127-161). The introduction of the diol dehydratase is accomplished using standard techniques as described by Peoples and Sinskey (1989, J. Biol. Chem. 164, 15298-15303). In these cases it may be useful to mutate the organism and select for increased resistance to 3-hydroxypropionaldehyde. PHA-producing organisms vary in their ability to synthesize coenzyme B-12 de novo, and therefore coenzyme B-12 or a precursor which the organism can convert to coenzyme B-12 would be added as appropriate. PHBV is then produced by feeding 1,2 propanediol and at least one other feedstock. PHBP is produced by feeding 1,3 propanediol or glycerol and one other feedstock, for example, glucose. In order to produce the 3HP polymers directly from carbohydrate feedstocks, the strain is further engineered to express glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase as described above. It may be useful to utilize mutations that are beneficial for the production of the P3HP homopolymers in these organisms. Specific mutations include inactivating the β-ketothiolase and/or acetoacetyl-CoA reductase genes. As these genes are generally well known and available or isolatable, gene disruptions can be readily carried out as described for example by Slater et. al., 1998 (J. Bacteriol.) 180(8):1979-87.
[0026] The implementation of the production of poly(3-hydroxypropionate) and its copolymers is also not limited to bacteria as described in the examples. The same genes may be introduced into eukaryotic cells, including but not restricted to, yeast and plants, which, like bacteria, also produce glycolytic intermediates such as dihydroxyacetone phosphate, from which glycerol and ultimately poly(3-hydroxypropionate) may be derived.
[0027] Genes for Utilization of Substrates
[0028] Genes and techniques for developing recombinant PHA producers suitable for use as described herein are generally known to those skilled in the art (Madison and Huisman, 1999, Microbiology and Molecular Biology Reviews, 63: 21-53; PCT WO 99/14313, which are incorporated herein by reference). Because all of the genes necessary to implement the production of poly(3-hydroxypropionate) from central metabolic intermediates via glycerol have been cloned and are available in genetically manipulatable form, any combination of plasmid-borne and integrated genes may be used, and the implementation of this pathway is therefore not restricted to the schemes outlined herein. Many different implementations will be apparent to those skilled in the art.
[0029] Glycerol dehydratase (EC 4.2.1.30) and diol dehydratase (EC 4.2.1.28) are distinct coenzyme B-12-requiring enzymes found in several species of bacteria. Often glycerol dehydratase is induced during anaerobic growth on glycerol and diol dehydratase is induced during anaerobic growth on either glycerol or 1,2-propanediol (Forage and Foster, 1979, Biochim. Biophys. Acta 569:249-258). These dehydratases catalyze the formation of 3-hydroxypropionaldehyde from glycerol and propionaldehyde from 1,2-propanediol. These aldehydes are usually converted to the corresponding alcohols by a dehydrogenase. Organisms that contain one or both dehydratases typically are able to convert glycerol to 3-hydroxypropionaldehyde or 1,3-propanediol. Bacterial species noted for this ability include Klebsiella pneumoniae (Streekstra et al., 1987, Arch. Microbiol. 147: 268-275), Klebsiella oxytoca (Homann et al., 1990, Appl. Microbiol. Biotechnol. 33: 121-126), Klebsiella planticola (Homann et al., 1990, ibid.) and Citrobacter freundii (Boenigk et al., 1993, Appl. Microbiol. Biotechnol. 38: 453-457) although many other examples are generally known. Both dehydratases are formed of three subunits, each of which is homologous to its counterpart in the other enzyme.
[0030] The substrate range of the glycerol and diol dehydratases (which will also be referred to generically from this point on as “vicinal diol dehydratases”) is not limited to glycerol and 1,2-propanediol. Bachovchin et al. (1977, Biochemistry 16:1082-1092), for example, demonstrated that the substrates accepted by the K. pneumoniae enzyme include glycerol, (R)-1,2-propanediol, (S)-1,2-propanediol, ethylene glycol, thioglycerol, 3-chloro-1,2-propanediol, 1,2-butanediol, 2,3-butanediol, isobutylene glycol, and 3,3,3-trifluoro-1,2-propanediol. In all cases, the product of the reaction is the aldehyde or ketone formed by the effective removal of a water molecule from the substrate.
[0031] Organisms that naturally produce glycerol from sugars through phosphoglycerate include Bacillus licheniformis (Neish et al., 1945, Can. J. Res. 23B: 290-296), Lactobacillus sp. (Nelson and Werkman, 1935, J. Bacteriol. 30: 547-557), Halobacterium cutirubrum (Wassef et al., 1970, Can. J. Biochem. 48: 63-67), Microcoleus chthonoplastes (Moezelaar et al., 1996, Appl. Environ. Microbiol. 62: 1752-1758), Zymomonas mobilis (Viikari, 1988, CRC Crit. Rev. Biotechnol. 7:237-261), Phycomyces blakesleeanus (Van Schaftiger. and Van Laere, 1985, Eur. J. Biochem. 148: 399-405), Saccharomyces cerevisiae (Tsuboi and Hudson, 1956, Arch. Biochem. Biophys. 61: 197-210), Saccharomyces carlsbergensis (Tonino and Steyn-Parve, 1963, Biochim. Biophys. Acta 67: 453-469), Rhizopus javanicus (Lu et al., 1995, Appl. Biochem. Biotechnol. 51/52: 83-95), Candida magnoliae (Sahoo, D. K., 1991, Ph. D. Thesis, Indian Institute of Technology, Delhi), Candida utilis (Gancedo et al., 1968, Eur. J. Biochem. 5: 165-172), Aspergillus niger (Legisa and Mattey, 1986, Enzyme Microb. Technol. 8: 607-609), Trichomonas vaginalis (Steinbüchel and Muller, 1986, Molec. Biochem. Parasitol. 20: 45-55), Dunaliella salina (Sussman and Avron, 1981, Biochim. Biophys. Acta 661: 199-204; Ben-Amotz et al., 1982, Experientia 38: 49-52), Asteromonas gracilis (Ben-Amotz et al., ibid.), Leishmania mexicana (Cazzulo et al., 1988, FEMS Microbiol. Lett. 51: 187-192), and Crithidia fasciculata (Cazzulo et al., ibid.). In many of these organisms, glycerol is known to be derived from dihydroxyacetone phosphate, an intermediate of the glycolytic pathway. Escherichia coli does not normally synthesize glycerol in significant amounts when grown on most sugars (Baldomà and Aguilar, J. Bacteriol. 170:416, 1988). However, transgenic E. coli strains that can form glycerol from common sugars such as glucose have been described, for example, in PCT WO 97/20292.
[0032] Genetically engineered systems for the production of glycerol from sugars (WO 98/21339), the production of 1,3-propanediol from glycerol (WO 96/35796, WO 98/21339) and the production of 1,3-propanediol from sugars have been described. E. coli expressing the DAR1 (dihydroxyacetone phosphate dehydrogenase) and GPP2 (sn-glycerol-3-phosphate phosphatase) genes of Saccharomyces cerevisiae were shown to accumulate high concentrations of glycerol in the medium when grown on glucose (Anton, D. “Biological production of 1,3-propanediol”, presented at United Engineering Foundation Metabolic Engineering II conference, Elmau, Germany, Oct. 27, 1998).
[0033] Regulation of Expression
[0034] In any of the aforementioned embodiments, it is possible to control the composition of the polymer produced by controlling the expression of the vicinal diol dehydratase or by controlling the availability of coenzyme B-12. The higher the dehydratase activity, the more activated mc nomer will be derived as a result of its activity, up to the point where another factor such as substrate availability or an enzyme activity downstream of the dehydratase becomes limiting. Methods for modulation of gene expression (and thus enzyme activity) in various organisms are well-known to those skilled in the art. An additional method for the control of vicinal diol dehydratase activity is the modulation of the availability of coenzyme B-12 to the microorganism. Many strains of Escherichia coli , for example, are unable to synthesize coenzyme B-12 de novo, and therefore recombinant vicinal diol dehydratase, which depends upon coenzyme B-12 for activity, is not active in these strains unless coenzyme B-12 or a suitable precursor such as vitamin B-12 is added to the medium. In Escherichia coli strains which harbor PHA synthesis genes and a vicinal diol dehydratase, it has been found that with no coenzyme B-12 addition, only PHB is synthesized even though 1,2-propanediol is present in the medium. The addition of 1 μM coenzyme B-12 to a cultivation of the same strain in the same medium leads to PHBV formation as discussed in the examples. Skraly et al. (1998, Appl. Environ. Microbiol. 64:98-105) found that transgenic Escherichia coli synthesized increasing levels of 1,3-propanediol from glycerol as increasing concentrations of coenzyme B-12 were provided in the medium, up to a concentration of about 20 nM, after which the 1,3-propanediol yield did not increase. Therefore, coenzyme B-12 concentrations from 0 to 20 nM can be used to control the PHBV composition in Escherichia coli harboring PHA synthesis genes and a vicinal diol dehydratase gene cultivated in a medium containing 1,2-propanediol. The same basic premise is true for deriving poly(3-hydroxypropionate) from glycerol. The cells are able to make a PHA (such as PHB) in the presence of comonomer when no vicinal diol dehydratase is present. The use of coenzyme B-12 to control polymer composition can be accomplished with any microorganism that is unable to synthesize coenzyme B-12 de novo. Such organisms include those that naturally lack this ability (such as Escherichia coli ) and those that naturally possess this ability (such as Klebsiella pneumoniae ) but have been mutated by the use of chemical mutagenesis or by genetic methods such as transposon mutagenesis to lose this ability.
[0035] In the case of some microorganisms, some of the genes can be integrated into the host chromosome and others provided on a plasmid. In some cases, compatible plasmid systems can be used, for example, with several steps on the pathway encoded on one plasmid and the other steps encoded by a second plasmid. A combination of the two approaches may also be used.
[0036] Substrates
[0037] As discussed above, substrates that can be used to make PHAs include glycerol and glucose. A number of other substrates, in addition to glycerol or glucose, can be used successfully. Examples of other substrates include starch, sucrose, lactose, fructose, xylose, galactose, corn oil, soybean oil, tallow, tall oil, fatty acids or combinations thereof.
[0038] The present invention will be further understood by reference to the following non-limiting examples.
EXAMPLE 1
PHBV Production from Glucose and 1,2-propanediol
[0039] [0039] Escherichia coli strain MBX769 (Huisman et. al. PCT WO 99/14313), which expresses the PHA synthesis genes from Zoogloea ramigera (acetoacetyl-CoA thiolase, acetoacetyl-CoA reductase, and PHA synthase) containing plasmid pFS44C was used to synthesize PHBV from glucose and 1,2-propanediol. Plasmid pFS44C (shown schematically in FIG. 2) contains the genes encoding Klebsiella pneumoniae glycerol dehydratase (dhaB), isolated from pTC53 (Skraly et al., 1998, Appl. Environ. Microbiol. 64:98-105), and the Clostridium kluyveri 4-hydroxybutyryl-CoA transferase (hbcT), isolated from pCK3 (Söhling and Gottschalk, 1996, J. Bacteriol. 178:871-880), both in one operon under control of the trc promoter. pFS44C also contains the lac repressor gene (lacI), an ampicillin resistance gene (ampR), and an origin of replication (OR1), all derived from the vector pSE380 (Invitrogen; La Jolla, Calif.).
[0040] The cells were precultured in 100 mL of a medium containing 25 g/L of LB broth powder (Difco; Detroit, Mich.) and 100 mg/L ampicillin. They were removed from this medium by centrifugation (2000×g, 10 minutes) and resuspended in 100 mL of a medium containing, per liter: 5 g LB broth powder; 50 mmol potassium phosphate, pH 7; 10 g 1,2-propanediol; 2 g glucose; 1 μmol coenzyme B-12; 100 μg ampicillin; and 0.1 mmol isopropyl-β-D-thiogalactopyranoside (IPTG). The cells were incubated in this medium with shaking at 225 rpm at 30° C. for 48 hours. They were then removed by centrifugation as above, washed once with water, and lyophilized.
[0041] The same experiment was done in parallel, except that no coenzyme B-12 was added. About 25 mg of lyophilized cell mass from each flask was subjected to simultaneous extraction and butanolysis at 110° C. for 3 hours in 2 mL of a mixture containing (by volume) 90% 1-butanol and 10% concentrated hydrochloric acid, with 2 mg/mL benzoic acid added as an internal standard. The water-soluble components of the resulting mixture were removed by extraction with 3 mL water. The organic phase (1 μL at a split ratio of 1:50 at an overall flow rate of 2 mL/min) was analyzed on an SPB-1 fused silica capillary GC column (30 m; 0.32 mm ID; 0.25 μm film; Supelco; Bellefonte, Pa.) with the following temperature profile: 80° C., 2 min; 10 C° per min to 250° C.; 250° C., 2 min. The standard used to test for the presence of 3-hydroxybutyrate and 3-hydroxyvalerate units in the polymer was PHBV (Aldrich Chemical Co.; Milwaukee, Wis.). The polymer in the experiment with coenzyme B-12 added accounted for 60.9% of the dry cell weight, and it was composed of 97.4% 3-hydroxybutyrate units and 2.6% 3-hydroxyvalerate units.
[0042] The supernatant at the conclusion of this experiment was found by high-performance liquid chromatographic (HPLC) analysis to contain 0.41 g/L propanol, indicating that the glycerol dehydratase was functional. The polymer in the experiment with no coenzyme B-12 added accounted for 56.7% of the dry cell weight, and it was PHB homopolymer. The supernatant at the conclusion of this experiment did not contain propanol. HPLC analysis was done with an Aminex HPX-87H column with sulfuric acid (pH 2) as the mobile phase at a flow rate of 0.6 mL/min and a column temperature of 50° C. Detection was by both refractive index and ultraviolet absorption.
EXAMPLE 2
PHBV and Growth from 1,2-propanediol as Sole Carbon Source
[0043] MBX 184 was selected for growth on 1,2-PD, to yield E. coli strain MBX 1327. MBXI327 was transduced with the PHB genes ABC5KAN from MBXI 164 to yield E. coli strain MBX 1329. MBX1164 is MBX247::ABC5KAN (encoding the thiolase, reductase and PHB synthase from Z ramigera ). MBX247 is LJ5218 (Spratt, et al. 1981 J. Bacteriol. 146:1166-1169) E. coli genetic stock center CGSC 6966) mutagenized with 1-methyl-3-nitro-1-nitrosoguanidine (NTG) by a standard procedure (Miller, J., A short course in bacterial genetics, 1992, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y.), and screened for the ability to grow with 1,2-propanediol as sole carbon source. Strains of E. coli with this ability and methods for generation of such strains have been described previously (Sridhara et al., 1969, J. Bacteriol. 93:87). E. coli strain MBX1329 has both the capability to grow with 1,2-propanediol as the sole carbon source and to synthesize PHB from carbon sources that generate acetyl-CoA.
[0044] MBX1329 harboring plasmid pFS44C (shown in FIG. 2) was grown in a medium containing, per liter: 6.25 g LB broth powder; 3.5 g sodium ammonium phosphate; 7.5 g dibasic potassium phosphate trihydrate; 3.7 g monobasic potassium phosphate; 0.12 g magnesium sulfate; 2.78 mg iron (II) sulfate heptahydrate; 1.98 mg manganese (II) chloride tetrahydrate; 2.81 mg cobalt (II) sulfate heptahydrate; 1.47 mg calcium chloride dihydrate; 0.17 mg copper (11) chloride dihydrate; 0.29 mg zinc (11) chloride heptahydrate; 10 mg thiamine; 10 g 1,2-propanediol; 50 nmol coenzyme B-12; 100 μg ampicillin; and 0.05 mmol isopropyl-β-D-thiogalactopyranoside (IPTG). The total volume was 50 mL in a 250-mL Erlenmeyer flask; the inoculum was 0.5 mL of an overnight culture in 25 g/L LB broth powder and 100 μg/mL ampicillin. The cells were incubated in this medium for 3 days at 37° C. with shaking at 200 rpm. They were removed from this medium by centrifugation (2000×g, 10 minutes), washed once with water, centrifuged again, and lyophilized.
[0045] Intracellular polymer content was analyzed by butanolysis as in Example 1. The cells grew to an optical density (at 600 nm) of 9.8 and contained PHBV to 6% of the dry cell weight. The polymer itself was composed of 2.5% 3-hydroxyvalerate units and 97.5% 3-hydroxybutyrate units.
EXAMPLE 3
Poly(3-hydroxypropionate) from 1,3-propanediol and 1,3-propanediol from Glycerol.
[0046] [0046] Escherichia coli strain MBX184, which is deficient in the fadR gene and expresses the atoC gene constitutively, was used to synthesize 1,3-propanediol from glycerol and poly(3-hydroxypropionate) from 1,3-propanediol. In both instances the cells harbored plasmid pFS45 (shown schematically in FIG. 3) which contains genes encoding Klebsiella pneumoniae glycerol dehydratase, Clostridium kluyveri 4-hydroxybutyryl-CoA transferase, and Ralstonia eutropha PHA synthase, all in one operon under the control of the trc promoter. The cells were cultivated as described in Example 1, except that glycerol was present instead of 1,2-propanediol.
[0047] HPLC analysis showed that the cells in the coenzyme-B 12-containing medium synthesized 1.3 g/L of 1,3-propanediol while the cells in the medium free of coenzyme B-12 did not synthesize any 1,3-propanediol. The same strain was also cultivated using the method of Example 1 except that 1,3-propanediol was present instead of 1,2-propanediol, and no coenzyme B-12 was added.
[0048] Lyophilized cell mass was analyzed by GC as in Example 1, with an additional standard of beta-propiolactone to quantify poly(3-hydroxypropionate). These cells were shown by GC analysis to contain poly(3-hydroxypropionate) homopolymer at 7.8% of the dry cell weight. The synthesis of poly(3-hydroxypropionate) from glycerol likely did not occur because of the accumulation of 3-hydroxypropionaldehyde, which is very toxic to many microorganisms (Dobrogosz et al., 1989, Wenner-Gren Int. Symp. Ser. 52:283-292). This toxicity may be addressed by discouraging the accumulation of 3-hydroxypropionaldehyde in at least two ways: 1) a 1,3-propanediol oxidoreductase from a 1,3-propanediol-producing organism such as those mentioned above can also be expressed, and 2) the activity of the unidentified endogenous dehydrogenase from Escherichia coli that is responsible for the observed formation of 1,3-propanediol when glycerol dehydratase is present can be increased by screening for Escherichia coli cells expressing glycerol dehydratase that grow well in the presence of both glycerol and coenzyme B-12. The second approach can be accomplished, for example, by transforming mutagenized Escherichia coli with a plasmid such as pFS45, so that the mutagenesis does not affect the glycerol dehydratase gene, followed by enrichment in a medium containing glycerol and coenzyme B-12.
EXAMPLE 4
Poly(3-hydroxypropionate) from Glycerol
[0049] The two pathways in Example 3 (glycerol to 1,3-propanediol and 1,3-propanediol to poly(3-hydroxypropionate) were activated in the same recombinant Escherichia coli. E. coli strain MBX820, which stably expresses the PHA biosynthetic genes phaA, phaB, and phaC from Zoogloea romigera, was transformed with the plasmid pFS47A (shown schematically in FIG. 4), which contains, under control of the trc promoter, the genes encoding 4-hydroxybutyryl-CoA transferase from Clostridium kluyveri and glycerol dehydratase and 1,3-propanediol oxidoreductase from Klebsiella pneumoniae . PFS47A was constructed from the plasmid pFS16, a predecessor of pFS47A, as follows: The Clostridium kluyveri orfZ gene was amplified by PCR from plasmid pCK3 (Söhling and Gottschalk, 1996, J. Bacteriol. 178: 871-880) using the following oligonucleotide primers:
5′-TCCCCTAGGATTCAGGAGGTTTTTATGGAGTGGGAAGAGATATATAAAG-3′ (orƒZ 5′ AvrII) 5′-CCTTAAGTCGACAAATTCTAAAATCTCTTTTTAAATTC-3′ (orƒZ 3′ SalI)
[0050] The orfZ PCR product was ligated to pTrcN, which had been digested with XbaI (which is compatible with AvrII) and SalI.
[0051] The cells were precultured in 100 mL of a medium containing 25 g/L of LB broth powder (Difco; Detroit, Mich.) and 100 mg/L ampicillin. They were removed from this medium by centrifugation (2000×g, 10 minutes) and resuspended in 100 mL of a medium containing, per liter: 2.5 g LB broth powder; 50 mmol potassium phosphate, pH 7; 5 g substrate (glycerol; 1,2-propanediol; or 1,3-propanediol); 2 g glucose; 5 nmol coenzyme B-12; 100 μg ampicillin; and 0.1 mmol isopropyl-β-D-thiogalactopyranoside (IPTG). The cells were incubated in this medium with shaking at 225 rpm at 30° C. for 48 hours. They were then removed by centrifugation as above, washed once with water, and lyophilized.
[0052] The lyophilized cell mass was analyzed by GC analysis as in Example 1, with an additional standard of beta-propiolactone to quantify poly(3-hydroxypropionate). The cells cultivated in glycerol and 1,3-propanediol both contained a copolymer of 3-hydroxybutyrate and 3-hydroxypropionate units, and the cells cultivated in 1,2-propanediol contained a copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate units. Polymer compositions and quantities as a percentage of dry cell weight are given in Table 1. The glycerol-cultivated cells synthesized more polymer than the 1,3-propanediol-cultivated cells, but the percentage of 3-hydroxypropionate units was smaller in the glycerol-cultivated cells. These differences may be explained by the fact that 3-hydroxypropionaldehyde is toxic and that it is probably generated more quickly by 1,3-propanediol oxidoreductase from 1,3-propanediol than it is by glycerol dehydratase from glycerol. The toxicity of 3-hydroxypropionaldehyde can negatively impact cell health and therefore overall polymer content, but its formation from glycerol is necessary for 3-hydroxypropionyl-CoA formation whether the necessary intermediate is 3-hydroxypropionaldehyde or 1,3-propanediol.
TABLE 1 Polymers produced by MBX820/pFS47A cultivated in various substrates. Total polymer 3HB units 3HP units 3HV units Substrate (% of dcw a ) (% of polymer) (% of polymer) (% of polymer) glycerol 55.8 98.2 1.8 0.0 1,2-propanediol 41.3 97.1 0.0 2.9 1,3-propanediol 26.7 95.1 4.9 0.0
EXAMPLE 5
Control of Polymer Composition by Variation of Coenzyme B-12 Concentration.
[0053] Because the vicinal diol dehydratases depend upon coenzyme B-12 for activity, and because the formation of 3-hydroxypropionyl-CoA from glycerol or of propionyl-CoA from 1,2-propanediol depends upon dehydratase activity, the composition of the copolymer in either case can be controlled by variation of the availability of coenzyme B-12 to the dehydratase. In this example, this was accomplished by variation of coenzyme B-12 concentration added to the medium in which E. coli strain MBX820 carrying the plasmid pFS47A was producing PHA.
[0054] The cells were precultured in 100 mL of a medium containing 25 g/L of LB broth powder (Difco; Detroit, Mich.) and 100 mg/L ampicillin. They were removed from this medium by centrifugation (2000×g, 10 minutes) and resuspended in 100 mL of a medium containing, per liter: 2.5 g LB broth powder; 50 mmol potassium phosphate, pH 7; 10 g substrate (glycerol or 1,2-propanediol); 2 g glucose; 100 μg ampicillin; 0.1 mmol isopropyl-β-D-thiogalactopyranoside (IPTG); and 0, 5, 20, or 50-nmol coenzyme B-12. The cells were incubated in this medium with shaking at 225 rpm at 30° C. for 72 hours. They were then removed by centrifugation as above, washed once with water, and lyophilized. The lyophilized cell mass was analyzed by GC analysis as in Example 4.
[0055] Table 2 shows the amounts and compositions of the PHAs produced in this way. The absence of coenzyme B-12, whether the substrate was glycerol or 1,2-propanediol, resulted in synthesis of only PHB. Glycerol was more conducive to PHA formation in the absence of dehydratase activity, as shown by the final optical density and polymer content, presumably because E. coli can utilize glycerol as a carbon and energy source under aerobic conditions (Lin, Ann. Rev. Microbiol. 30:535, 1976), while generally this is not true of 1,2-propanediol (Baldomà and Aguilar, ibid.). When coenzyme B-12 is added in increasing amounts to cells cultivated with glycerol, the percentage of 3-hydroxypropionate units in the polymer increases, while the overall polymer content decreases. This decrease is probably due to the toxicity of 3-hydroxypropionaldehyde, which results in decreased health of the cells. When coenzyme B-12 is added in increasing amounts to cells cultivated with 1,2-propanediol, 3-hydroxyvalerate units are incorporated into the polymer, but the percentage of 3-hydroxyvalerate in the polymer does not increase to the same extent as the percentage of 3-hydroxypropionate units did in the glycerol experiment. This indicates that the concentration of coenzyme B-12 is not limiting to 3-hydroxyvaleryl-CoA synthesis when its concentration reaches even a few nanomolar, and that some other factor becomes limiting.
[0056] This example demonstrates that the composition of PHAs derived from the use of coenzyme B-12-dependent dehydratases can be controlled by varying the concentration of coenzyme B-12 made available to the dehydratase. The extent to which the control can be executed is dependent on the diol substrate used. This can be due to the preference of the vicinal diol for certain substrates over others and on the rest of the host metabolism leading from the aldehyde derived from the diol to the acyl-CoA which serves as the activated monomer for PHA formation.
TABLE 2 Composition of polymers produced by MBX820/pFS47A from glycerol and 1,2-propanediol in media with various coenzyme B-12 concentrations. [CoB12] OD a 3HB b , 3HV c , 3HP d , polymer, Substrate nM (600 nm) % of PHA % of PHA % of PHA % of dcw e glycerol 0 19.3 100 0 0 65.4 5 17.7 81.4 0 18.6 56.6 20 10.0 79.6 0 20.4 45.9 50 3.9 54.4 0 45.6 12.0 1,2-propanediol 0 4.4 100 0 0 34.1 5 4.8 98.6 1.4 0 32.4 20 3.9 97.6 2.4 0 19.5 50 4.2 98.5 1.5 0 21.2
EXAMPLE 6
Production of Poly(3-hydroxypropionate) from Central Matabolic Intermediates.
[0057] Examples 1-5 demonstrate that it is possible to obtain poly(3-hydroxypropionate) from glycerol, and as discussed above, it is possible in both transgenic and nontransgenic organisms to produce glycerol from central metabolic intermediates. Therefore, a combination of the two pathways will allow the synthesis of poly(3-hydroxypropionate) from central metabolic intermediates. These pathways can be combined either by introducing the poly(3-hydroxypropionate synthesis genes into a glycerol-producing host or by introducing glycerol synthesis genes into a host already capable of poly(3-hydroxypropionate) synthesis from glycerol, such as described in the above examples.
[0058] In the former case, genes encoding a vicinal diol dehydratase, a PHA synthase, and optionally an aldehyde dehydrogenase, 1,3-propanediol oxidoreductase, and hydroxyacyl-CoA transferase are expressed in a host capable of producing glycerol from central metabolic intermediates. An example of such a host is an Escherichia coli that expresses the Saccharomyces cerevisiae DAR1 (dihydroxyacetone phosphate dehydrogenase) and GPP2 (sn-glycerol-3-phosphate phosphatase) genes (Anton, D. “Biological production of 1,3-propanediol”, presented at United Engineering Foundation Metabolic Engineering II conference, Elmau, Germany, Oct. 27, 1998; PCT WO 98/21339), as described above. Many strains of E. coli naturally express 1,3-propanediol oxidoreductase and aldehyde dehydrogenase enzymatic activities, but their levels may optionally be augmented by mutagenesis or purposeful overexpression of enzymes that carry out these functions. The additional genes necessary can be introduced on a plasmid such as pFS48B, which contains, under the control of the trc promoter, 4-hydroxybutyryl-CoA transferase from Clostridium kluyveri; PHA synthase from Zoogloea ramigera and glycerol dehydratase and 1,3-propanediol oxidoreductase from Klebsiella pneumoniae. Any or all of these genes may also be introduced by integration into the chromosome using standard techniques well-known to those skilled in the art.
[0059] Similarly, the DAR1 and GPP2 genes can be introduced into a host already capable of poly(3-hydroxypropionate) synthesis, such as MBX820/pFS47A, described above. The DAR1 and GPP2 genes may be introduced on a plasmid compatible with pFS47A (a plasmid that can be maintained simultaneously with pFS47A), or they may be integrated into the chromosome. MBX820 stably expresses acetoacetyl-CoA thiolase, 3-hydroxybutyryl-CoA reductase, and PHA synthase, and therefore it is capable of synthesizing poly(3-hydroxybutyrate-co-3-hydroxypropionate). If the homopolymer poly(3-hydroxypropionate) is desired, a strain expressing only PHA synthase rather than all three PHB biosynthetic genes may be used.
[0060] In order to demonstrate the pathway for the biosynthesis of PHP form glucose, plasmid pMS 15 (shown schematically in FIG. 6) was constructed to express the following genes as an operon from the trc promoter: PHB synthase from A eutrophus, the 4-hydroxybutyryl-CoA transferase from C. kluyveri, the glycerol dehydratase from Klebsiella, the DAR1 gene from S. cerevisae, the GPP2 gene from S. cerevisae and the 1,3-propanediol oxidoreductase from K. pneumoniae.
[0061] The plasmid pFS51 was constructed by ligating DAR1 and GPP2 PCR products one at a time to pTrcN. The DAR1 gene was amplified by PCR from S. cerevisiae genomic DNA using the following oligonucleotide primers:
The DAR1 gene was amplified by PCR from S. cerevisae genomic DNA using the following oligonucleotide primers: 5′-CTTCCGGATCCATTCAGGAGGTTTTTATGTCTGCTGCTGCTGATAGA-3′ ( S. cer. DAR1 5′ Bam HI) 5′-CTTCCGCGGCCGCCTAATCTTCATGTAGATCTAATTC-3′ ( S. cer. DAR1 3′ Not I) The GPP2 gene was amplified in the same way using the following oligonucleotide primers: 5′-CTTCCGCGGCCGCATTCAGGAGGTTTTTATGGGATTGACTACTAAACCTC-3′ ( S. cer. GPP2 5′ Not I) 5′-CCTTCTCGAGTTACCATTTCAACAGATCGTCC-3′ ( S. cer. GPP2 3′ Xho I)
[0062] PCR for each gene was carried out with Pfu DNA polymerase (Stratagene; La Jolla, Calif.) in a reaction volume of 50 μL, which contained: 10 units Pfu polymerase, 1× reaction buffer provided by the manufacturer, 50 pmol of each primer, about 200 ng S. cerevisiae genomic DNA, and 200 μM of each dNTP. The thermal profile of the reactions was as follows: 27 cycles of (94° C., 1 min; 55° C., 2 min; 72° C., 3 min), then 7 min at 72° C. The Pfu polymerase was not added until the reaction mixture had reached 94° C.
[0063] The PCR products were purified from a 1% low-melt agarose gel and digested with the restriction enzymes whose corresponding sites had been included at the 5′ ends of the primers (BamHI and NotI for DAR1, NotI and XhoI, for GPP2). The vector pTrcN is a version of pTrc99a (Pharmacia; Uppsala, Sweden) modified such that it lacks an NcoI site. pTrcN was cut with BamHI, NotI, and calf intestinal alkaline phosphatase (CIAP; Promega; Madison, Wis.) for insertion of DAR1 and with NctI, XhoI, and CIAP for insertion of GPP2. The ligations were carried out with T4 DNA ligase (New England Biolabs; Beverly, Mass.) according to the instructions provided by the manufacturer. The products of the ligations were pFS49 (DAR1) and pFS50 (GPP2). To assemble both genes on one plasmid, pFS49 was cut with Mul and NotI, and the 2.3-kb fragment containing the trc promoter and DAR1 was ligated to pFS50 that had been digested with the same two enzymes and CIAP. The resulting plasmid, which contained the operon DAR1-GPP2 under control of the trc promoter, was denoted pFS51.
[0064] [0064] E. coli strain MBX 184 containing the plasmid pMS 15 (shown schematically in FIG. 6) was grown overnight in a 200-mL square bottle at 37° C. in 50 mL of LB medium which also contained 100 μg/mL ampicillin. The cells were removed from this culture by centrifugation for 10 minutes at 2000×g, and the cells were resuspended in 50 mL of a glucose medium and incubated for 72 hours at 30° C. with shaking at 200 rpm. The glucose medium contained, per liter: 6.25 g LB powder; 100 μg ampicillin; 20 g glucose; 50 mmol potassium phosphate, pH 7; 10 μmol isopropyl-β-D-thiogalactopyranoside (IPTG); and 0, 10, or 100 nmol coenzyme B-12. After the incubation, the cells were removed from the medium by centrifugation for 10 minutes at 2000×g, washed once with water and centrifuged again, then lyophilized. Gas chromatographic (GC) analysis of the lyophilized cell mass showed that, in the experiment with 10 nM coenzyme B-12, poly(3HP) made up 0.11% of the dry cell weight; in the experiment with 100 nM coenzyme B-12, poly(3HP) made up 0.13% of the dry cell weight; and in the experiment with no coenzyme B-12, poly(3HP) was not detected. No polymer constituents other than 3HP were found in any case. GC analysis was conducted as follows: 15 to 20 mg of lyophilized cell mass was subjected to simultaneous extraction and propanolysis at 100° C. for 3 hours in 2 mL of a mixture containing (by volume) 50% 1,2-dichloroethane, 40% 1-propanol, and 10% concentrated hydrochloric acid, with 2 mg/mL benzoic acid added as an internal standard. The water-soluble components of the resulting mixture were removed by extraction with 3 mL water. The organic phase (1 μL at a split ratio of 1:50 at an overall flow rate of 2 mL/min) was analyzed on an SPB-1 fused silica capillary GC column (30 m; 0.32 mm ID; 0.25 μm film; Supelco; Bellefonte, Pa.) with the following temperature profile: 80° C. for 2 min; 10 C.° per min to 250° C.; 250° C. for 2 min. The standard used to test for the presence of 3HP residues was β-propiolactone. Both poly(3HP) and β-propiolactone yield the 1-propyl ester of 3-hydroxypropionate when subjected to propanolysis.
EXAMPLE 7
[0065] PHBV from Central Metabolic Intermediates
[0066] As demonstrated above, it is possible to obtain PHBV from 1,2-propanediol with the optional addition of other carbon sources such as glucose, and it is possible in both transgenic and nontransgenic organisms to produce 1,2-propanediol from central metabolic intermediates (Cameron et. al., 1998, Biotechnol. Prog. 14 116-125). Therefore, a combination of the two pathways will allow the synthesis of PHBV from central metabolic intermediates. These pathways can be combined either by introducing the PHBV synthesis genes into a 1,2-propanediol-producing host or by introducing 1,2-propanediol synthesis genes into a host already capable of PHBV synthesis from 1,2-propanediol, such as described in the above examples.
[0067] In the former case, genes encoding a vicinal diol dehydratase, a PHA synthase, a 3-ketoacyl-CoA thiolase and reductase, and optionally an aldehyde dehydrogenase, 1-propanol oxidoreductase, and hydroxyacyl-CoA transferase are expressed in a host capable of producing 1,2-propanediol from central metabolic intermediates. An example of such a host is an Escherichia coli that expresses rat lens aldose reductase or overexpresses E. coli glycerol dehydrogenase, as described above. Many strains of E. coli naturally express 1-propanol oxidoreductase, aldehyde dehydrogenase, and propionyl-CoA transferase enzymatic activities, but their levels may optionally be augmented by mutagenesis or purposeful overexpression of enzymes that carry out these functions. The additional genes necessary can be introduced as plasmid-borne genes or may be integrated into the chromosome, or a combination of the two approaches may be used. For example, a plasmid such as pFS48B, which contains, under the control of the trc promoter, 4-hydroxybutyryl-CoA transferase from Clostridium kluyveri; PHA synthase from Zoogloea ramigera and glycerol dehydratase and 11,3-propanediol oxidoreductase from Klebsiella pneumoniae, may be used in combination with integration of the PHB synthesis genes into the chromosome using standard techniques well-known to those skilled in the art.
[0068] Similarly, the rat lens aldose reductase or E. coli glycerol dehydrogenase genes can be introduced into a host already capable of PIIBV synthesis, such as MBX769/pFS44C, described above. An additional improvement may result from the overexpression of a methylglyoxal synthase gene, as suggested by Cameron et al., 1998 (Biotechnol. Prog. 14 116-125). The rat lens aldose reductase or E. coli glycerol dehydrogenase gene may be introduced on a plasmid compatible with pFS44C (a plasmid that can be maintained simultaneously with pFS44C), or they may be integrated into the chromosome.
EXAMPLE 8
Identification of 3-bydroxypropionaldehyde Dehydrogenase Activity.
[0069] The aldH gene sequence from E. coli is available from GENBANK. This gene was cloned into the Acc65I and NotI sites of the cloning vector pSE380 following PCR amplification using the approach described in Example 6 and the following primers:
ald-Acc65I 5′-ggtggtaccttaagaggaggtttttatgaattttcatcacctggctt ald-NotI 5′-ggtgcggccgctcaggcctccaggcttatcca
[0070] The resulting recombinant plasmid pALDH was intoduced into E. coli DH5 alpha and grown in 5 ml LB medium with 100 μg/ml ampicillin 37° C. The next day a 100 ml containing 100 μg/ml ampicillin was innoculated with 100 μl of the overnight culture and grown until the absorbance at 600 nm reached 0.5 at which time the trc promoter was induced with 1 mM IPTG and incubated a further 3 hours at 37° C. The cells were harvested, washed and resuspended in 0.1M Tris.HCl pH 8.0 and lysed by sonication. The cell lysate was assayed for aldehyde dehydrogenase activity using 3-hydroxypropionaldehyde with both NAD and NADP as cofactor. Assays were performed using an Hewlett Packard diode array spectrophotometer. Enzyme reactions were carried out in 1.5 ml UV cuvettes in a solution containing the following: 0.1 M Tris .Hcl, pH 8.0, 1 mM NAD or NADP, 6 mM dithiothreitol and crude cell extract to a final volume of 1 ml. The mixture was incubated for 20 seconds before initiating the reaction by adding 1 mM 3-hydroxypropionaldehyde and monitoring the reaction at 340 nm. The lysate showed significant 3-hydroxypropionaldehyde dehydrogenase activity when NAD was the cofactor (1.35 μmoles/min/mg protein) which was not present in the control sample prepared using the vector alone. Therefore the aldH gene can be used to increase the 3-hydroxyproionaldehyde dehydrogenase activity in the strains described in the previous examples.
[0071] Modifications and variations of the methods and materials described herein will be obvious to those skilled in the art and are intended to come within the scope of the following claims:
1
8
1
49
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
1
tcccctagga ttcaggaggt ttttatggag tgggaagaga tatataaag 49
2
38
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
2
ccttaagtcg acaaattcta aaatctcttt ttaaattc 38
3
47
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
3
cttccggatc cattcaggag gtttttatgt ctgctgctgc tgataga 47
4
37
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
4
cttccgcggc cgcctaatct tcatgtagat ctaattc 37
5
50
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
5
cttccgcggc cgcattcagg aggtttttat gggattgact actaaacctc 50
6
32
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
6
ccttctcgag ttaccatttc aacagatcgt cc 32
7
47
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
7
ggtggtacct taagaggagg tttttatgaa ttttcatcac ctggctt 47
8
32
DNA
Artificial Sequence
Description of Artificial Sequence
Oligonucleotide primer
8
ggtgcggccg ctcaggcctc caggcttatc ca 32
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Organisms are provided which express enzymes such as glycerol dehydratase, diol dehydratase, acyl-CoA transferase, acyl-CoA synthetase β-ketothiolase, acetoacetyl-CoA reductase, PHA synthase, glycerol-3-phosphate dehydrogenase and glycerol-3-phosphatase, which are useful for the production of PHAs. In some cases one or more of these genes are native to the host organism and the remainder are provided from transgenes. These organisms produce poly (3-hydroxyalkanoate) homopolymers or co-polymers incorporating 3-hydroxypropionate or 3-hydroxyvalerate monomers wherein the 3-hydroxypropionate and 3-hydroxyvalreate units are derived from the enzyme catalysed conversion of diols. Suitable diols that can be used include 1,2-propanediol, 1,3 propanediol and glycerol. Biochemical pathways for obtaining the glycerol from normal cellular metabolites are also described. The PHA polymers are readily recovered and industrially useful as polymers or as starting materials for a range of chemical intermediates including 1,3-propanediol, 3-hydroxypropionaldehyde, acrylics, malonic acid, esters and amines.
| 2
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FIELD OF THE INVENTION
[0001] The present invention relates to a novel crystalline form of atorvastatin calcium, to processes for preparing it and to pharmaceutical compositions and dosages containing it.
BACKGROUND OF THE INVENTION
[0002] Atorvastatin is a member of the class of drugs called statins. Statin drugs are currently the most therapeutically effective drugs available for reducing low density lipoprotein (LDL) particle concentration in the blood stream of patients at risk for cardiovascular disease. A high level of LDL in the bloodstream has been linked to the formation of coronary lesions which obstruct the flow of blood and can rupture and promote thrombosis. Goodman and Gilman, The Pharmacological Basis of Therapeutics 879 (9th ed. 1996). Reducing plasma LDL levels has been shown to reduce the risk of clinical events in patients with cardiovascular disease and patients who are free of cardiovascular disease but who have hypercholesterolemia. Scandinavian Simvastatin Survival Study Group, 1994; Lipid Research Clinics Program, 1984a, 1984b.
[0003] The mechanism of action of statin drugs has been elucidated in some detail. They interfere with the synthesis of cholesterol and other sterols in the liver by competitively inhibiting the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase enzyme (“HMG-CoA reductase”). HMG-CoA reductase catalyzes the conversion HMG to mevalonate, which is the rate determining step in the biosynthesis of cholesterol, and so, its inhibition leads to a reduction in the concentration of cholesterol in the liver. Very low density lipoprotein (VLDL) is the biological vehicle for transporting cholesterol and triglycerides from the liver to peripheral cells. VLDL is catabolized in the peripheral cells which releases fatty acids which may be stored in adipocytes or oxidized by muscle. The VLDL is converted to intermediate density lipoprotein (IDL), which is either removed by an LDL receptor, or is converted to LDL. Decreased production of cholesterol leads to an increase in the number of LDL receptors and corresponding reduction in the production of LDL particles by metabolism of IDL.
[0004] Atorvastatin is the common chemical name of [R—(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid. The free acid is prone to lactonization. The molecular structure of the lactone is represented by formula (I).
[0000]
[0005] Atorvastatin is marketed as the hemi calcium salt-trihydrate under the name LIPITOR by Warner-Lambert Co.
[0000]
[0006] Atorvastatin was first disclosed to the public and claimed in U.S. Pat. No. 4,681,893. The hemi calcium salt depicted in formula (II) (hereafter “atorvastatin calcium”) is disclosed in U.S. Pat. No. 5,273,995. This patent teaches that the calcium salt is obtained by crystallization from a brine solution resulting from the transposition of the sodium salt with CaCl 2 and further purified by recrystallization from a 5:3 mixture of ethyl acetate and hexane. Both of these U.S. patents are hereby incorporated by reference.
[0007] The present invention includes a new crystal form of atorvastatin calcium in both hydrate and anhydrate states. Polymorphism is the property of some molecules and molecular complexes to assume more than one crystalline or amorphous form in the solid state. A single molecule, like the atorvastatin in formula (I) or the salt complex of formula (II), may give rise to a variety of solids having distinct physical properties like solubility, X-ray diffraction pattern and solid state 13 C NMR spectrum. The differences in the physical properties of polymorphs result from the orientation and intermolecular interactions of adjacent molecules (complexes) in the bulk solid. Accordingly, polymorphs are distinct solids sharing the same molecular formula, which may be thought of as analogous to a unit cell in metallurgy, yet having distinct advantageous and/or disadvantageous physical properties compared to other forms in the polymorph family. One of the most important physical properties of pharmaceutical polymorphs is their solubility in aqueous solution, particularly their solubility in the gastric juices of a patient. For example, where absorption through the gastrointestinal tract is slow, it is often desirable for a drug that is unstable to conditions in the patient's stomach or intestine to dissolve slowly so that it does not accumulate in a deleterious environment. On the other hand, where the effectiveness of a drug correlates with peak bloodstream levels of the drug, a property shared by statin drugs, and provided the drug is rapidly absorbed by the GI system, then a more rapidly dissolving form is likely to exhibit increased effectiveness over a comparable amount of a more slowly dissolving form.
[0008] U.S. Pat. No. 5,969,156 discloses three polymorphs of atorvastatin designated Forms I, II, and IV by the inventors of those forms. While the inventors of U.S. Pat. No. 5,969,156 claim certain processing and therapeutic advantages of their forms over amorphous atorvastatin calcium, advantages may yet be realized by other heretofore undiscovered forms of atorvastatin calcium.
SUMMARY OF THE INVENTION
[0009] The present invention provides new Form V of atorvastatin calcium in both anhydrate and hydrate states, which possesses the advantage of higher solubility in water than atorvastatin Form I. The present invention further provides a process for preparing new Form V as well as pharmaceutical compositions and dosages containing the new form.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an X-ray powder diffractogram of atorvastatin calcium Form V.
[0011] FIG. 2 is a solid state 13 C NMR spectrum of atorvastatin calcium Form V.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The new crystalline form of atorvastatin calcium Form V is well distinguished from the crystal modifications obtained by carrying out the procedures described in U.S. Pat. Nos. 5,273,995 and 5,969,156 using X-ray powder diffraction and solid-state 13 C nuclear magnetic resonance techniques.
[0013] The X-ray powder diffractogram of Form V ( FIG. 1 ) has two medium peaks at 5.3±0.2 and 8.3±0.2 degrees 2θ and one large peak in the range 18-23 degrees 2θ with a maximum at about 18.3±0.2 degrees two-theta. This X-Ray pattern is well distinguished from that of known Forms I, II, III and IV and also is well distinguished from the X-Ray pattern of amorphous atorvastatin calcium which is characterized by two broad humps in the ranges 8-14 degrees 2θ and 15-26 degrees 2θ. The X-ray powder diffractogram of FIG. 1 was obtained by methods known in the art using a Philips X-ray powder diffractometer with a curved graphite monochromator using goniometer model 1050/70. Copper radiation of λ=1.5418 Å was used. Measurement range: 3-30 degrees 2θ.
[0014] The solid-state 13 C NMR spectrum of Form V is characterized by the following chemical shifts:
[0000]
δ (ppm)
21.9
25.9
40.4
41.8
42.3
63-73
(two broad peaks)
115.6
118.9
122.5
128.7
(strong)
135.1
161.0
167.1
176-186
(broad peak)
[0015] This solid-state 13 C NMR spectrum ( FIG. 2 ) is well distinguished from those of known Forms I, II, III and IV, and also is distinguished from that of the amorphous form which displays a different pattern with shifts significantly different from that of Form V at 21.0 ppm, 26.4 ppm, one broad peak in the range 60-75 ppm with a maximum at 69.7 ppm and 138.8 ppm. The spectrum of FIG. 2 was obtained on a Bruker DMX-500 digital F NMR spectrometer operating at 125.76 MHz. The instrument was equipped with a BL-4 cpmas probehead and a high resolution/high performance (HPHP) 1 H for solids. The magic angle and proton decoupling efficiency were optimized before acquisition. The sample was spun at 5.0 kHz spin rate on 4 mm zirconia rotors.
[0016] Atorvastatin calcium Form V may contain up to 12% water, which corresponds to the stoichiometric value of 9 water molecules per molecule of atorvastatin calcium. Thus, atorvastatin calcium Form V can be in various states of hydration, between 0 and 9 moles of water.
[0017] The present invention further provides a process for the preparation of atorvastatin calcium Form V. The process comprises the steps of dissolving a salt of atorvastatin in a solvent to form an atorvastatin salt solution, optionally removing impurities from the atorvastatin salt solution, contacting the atorvastatin salt solution with a calcium salt and isolating atorvastatin calcium in new Form V.
[0018] The atorvastatin salt of the present invention includes alkali metal salts, e.g. lithium, sodium, and potassium salts; alkaline-earth metal salts such as magnesium salts; as well as ammonium and alkyl, aryl or alkaryl ammonium salts. The preferred atorvastatin salts are alkali metal salts; most preferred is the sodium salt.
[0019] Any solvent capable of dissolving the atorvastatin salt and from which atorvastatin calcium Form V may be isolated is a suitable solvent of the invention. The choice of solvent will therefore depend upon the selection of the atorvastatin salt and the calcium salt. The solvent should be selected from those in which the atorvastatin salt and calcium salt are at least sparingly soluble. By sparingly soluble is meant not substantially less soluble than 0.02 g/ml at 50-60° C. for the atorvastatin salt and not substantially less soluble than 0.0002 M at 10-15° C. for the calcium salt.
[0020] Suitable solvents include but are not limited to hydroxylic solvents like water, alcohols and mixtures thereof, including hydroxylic solvents and hydroxylic solvent mixtures which have been made either acidic or basic by addition of a mineral acid or base. Preferred solvents are water, methanol, ethanol and mixtures thereof.
[0021] The calcium salt of the present invention includes organic and inorganic salts of calcium which are capable of dissociating into Ca 2+ and an anionic component when added to the atorvastatin salt solution. Among the organic salts that may be used are carboxylates and sulfonates. Among the carboxylates are lower alkyl carboxylates like acetate, proprionate, butyrate and tartrate and aryl carboxylates like benzoate and phthalate as well as higher alkyl carboxylates like stearate, dodecanoate and the like. Also included are calcium ascorbate and succinate. Among the sulfonates that may be used are lower alkyl and aryl sulfonates like calcium methane sulfonate, calcium benzene sulfonate and calcium p-toluene sulfonate. The preferred organic calcium salts are lower carboxylate salts, the most preferred organic calcium salt is calcium acetate.
[0022] Depending upon solubility, inorganic salts which may be used include halide salts such as CaCl 2 , CaF 2 , CaBr 2 and CaI 2 , as well as calcium borate (B 4 CaO 7 ), calcium tetrafluoroborate (CaBF 4 ), calcium carbonate (CaCO 3 ), monobasic calcium phosphate (Ca(H 2 PO 4 ) 2 ), dibasic calcium phosphate (CaHPO 4 ) and tribasic calcium phosphate (Ca(PO 4 ) 2 ), calcium sulfate (CaSO 4 ) and calcium hydroxide (Ca(OH) 2 ), and hydrates thereof.
[0023] Whether organic or inorganic, the calcium salt is preferably added in an amount that provides one half mole of Ca 2+ per mole of atorvastatin in the atorvastatin salt solution. For example, if the atorvastatin salt is atorvastatin sodium (atorvastatin − Na + ), then about one half mole of calcium salt per mole of the atorvastatin salt is appropriate. If the atorvastatin salt is atorvastatin magnesium ([atorvastatin − ] 2 Mg 2+ ), then about one mole of calcium salt per mole of atorvastatin salt is appropriate. Otherwise, mixed salts containing atorvastatin may form.
[0024] The calcium salt may be contacted with the atorvastatin salt solution by adding the calcium salt in substantially pure form, i.e. either as a solid or, if liquid, as a neat liquid, to the atorvastatin salt solution or, preferably, by first forming a calcium salt solution and then contacting the atorvastatin salt solution and calcium salt solution. It is most preferred to contact the calcium salt and the atorvastatin salt solution by first dissolving the calcium salt in a solvent and then adding the calcium salt solution to the atorvastatin salt solution slowly. Suitable calcium salt solvents are solvents previously mentioned as being suitable solvents for the atorvastatin salt, provided the calcium salt is at least sparingly soluble in the particular solvent.
[0025] In a particularly preferred embodiment, wherein the atorvastatin salt is an atorvastatin alkali metal salt and the atorvastatin salt solvent is a 1:2 methanol:water mixture, the preferred calcium salt is calcium acetate and the preferred calcium salt solvent is water. When the calcium salt solvent is water, it is preferably used in an amount that provides about a 20 to 30 millimolar solution of the calcium salt, more preferably about a 25 millimolar solution.
[0026] In addition, the atorvastatin and calcium salts are preferably combined at elevated temperature and at concentrations disclosed above and in the examples, which follow, in order that crystallization of Form V may be induced by cooling of the so-formed atorvastatin calcium solution. The elevated temperature is preferably above 40° C. and below 80° C., more preferably above 50° C. and below 70° C. and most preferably about 60° C. One skilled in the art will appreciate that by adjusting temperature and concentration, the yield of atorvastatin calcium Form V may be optimized. Crystallization of atorvastatin calcium Form V may also be induced by addition of a seed crystal of atorvastatin calcium, preferably Form V although other forms also may be used.
[0027] Once crystals of atorvastatin Form V have crystallized, either spontaneously, upon cooling, upon seeding or by another inducement, the crystals may be isolated by filtration or other conventional means known to the art. The isolated crystals may also be dried by conventional means.
[0028] It has also been found that atorvastatin calcium can be crystallized in Form V by dissolving atorvastatin calcium in THF or alcohols like methanol or ethanol, and subsequently adding water as an antisolvent.
[0029] A further aspect of the present invention is a pharmaceutical composition and dosage form containing the novel form of atorvastatin calcium.
[0030] The compositions of the invention include powders, granulates, aggregates and other solid compositions comprising novel Form V of atorvastatin calcium. In addition, Form V solid compositions that are contemplated by the present invention may further included diluents, such as cellulose-derived materials like powdered cellulose, microcrystalline cellulose, microfine cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose salts and other substituted and unsubstituted celluloses; starch; pregelatinized starch; inorganic diluents like calcium carbonate and calcium diphosphate and other diluents known to the pharmaceutical industry. Yet other suitable diluents include waxes, sugars and sugar alcohols like mannitol and sorbitol, acrylate polymers and copolymers, as well as pectin, dextrin and gelatin.
[0031] Further excipients that are within the contemplation of the present invention include binders, such as acacia gum, pregelatinized starch, sodium alginate, glucose and other binders used in wet and dry granulation and direct compression tableting processes. Excipients that may also be present in a solid composition of Form V atorvastatin calcium further include disintegrants like sodium starch glycolate, crospovidone, low-substituted hydroxypropyl cellulose and others. In addition, excipients may include tableting lubricants like magnesium and calcium stearate and sodium stearyl fumarate; flavorings; sweeteners; preservatives; pharmaceutically acceptable dyes and glidants such as silicon dioxide.
[0032] The dosages include dosages suitable for oral, buccal, rectal, parenteral (including subcutaneous, intramuscular, and intravenous), inhalant and ophthalmic administration. Although the most suitable route in any given case will depend on the nature and severity of the condition being treated, the most preferred route of the present invention is oral. The Dosages may be conveniently presented in unit dosage form and prepared by any of the methods well-known in the art of pharmacy.
[0033] Dosage forms include solid dosage forms, like tablets, powders, capsules, suppositories, sachets, troches and losenges as well as liquid suspensions and elixirs. While the description is not intended to be limiting, the invention is also not intended to pertain to true solutions of atorvastatin calcium whereupon the properties that distinguish the solid forms of atorvastatin calcium are lost. However, the use of the novel forms to prepare such solutions (e.g. so as to deliver, in addition to atorvastatin, a solvate to said solution in a certain ratio with a solvate) is considered to be within the contemplated invention.
[0034] Capsule dosages, of course, will contain the solid composition within a capsule which may be made of gelatin or other conventional encapsulating material. Tablets and powders may be coated. Tablets and powders may be coated with an enteric coating. The enteric coated powder forms may have coatings comprising phthalic acid cellulose acetate, hydroxypropylmethyl-cellulose phthalate, polyvinyl alcohol phthalate, carboxymethylethylcellulose, a copolymer of styrene and maleic acid, a copolymer of methacrylic acid and methyl methacrylate, and like materials, and if desired, they may be employed with suitable plasticizers and/or extending agents. A coated tablet may have a coating on the surface of the tablet or may be a tablet comprising a powder or granules with an enteric-coating.
[0035] Preferred unit dosages of the pharmaceutical compositions of this invention typically contain from 0.5 to 100 mg of the novel atorvastatin calcium Form V, or mixtures thereof with other forms of atorvastatin calcium. More usually, the combined weight of the atorvastatin calcium forms of a unit dosage are from 2.5 mg. to 80 mg.
[0036] Having thus described the various aspects of the present invention, the following examples are provided to illustrate specific embodiments of the present invention. They are not intended to be limiting in any way.
EXAMPLES
Example 1
[0037] The sodium salt of atorvastatin (52.2 g) was dissolved in methanol (510 ml) and then diluted with water (1 L). The resulting solution was transferred to a separatory funnel containing 1:1 ethyl acetate/hexane (1 L). The phases were mixed by bubbling nitrogen gas through the separatory funnel. Upon cessation of nitrogen flow, the phases separated and the upper, organic, phase was removed. The lower, aqueous, phase was washed with 1:1 ethyl acetate/hexane (1 L) and then transferred to a round bottom flask. Active charcoal (10.2 g) was added. The flask was heated to 50° C. and the solution was stirred for two hours. The activated charcoal was then removed by filtration through celite, the charcoal and celite being rinsed with methanol (1540 ml), and the rinsate and filtrate then being combined into one atorvastatin sodium salt solution.
[0038] The quantity of atorvastatin obtained by purification was determined by calibrated HPLC analysis of the purified atorvastatin sodium salt solution. Based on this analysis, a quantity of calcium acetate (8.38 g, 0.5 eq.) was dissolved in water (1.9 L) and heated to 60° C. The atorvastatin sodium salt solution was heated to 63° C. and the solutions were combined by slow addition of the calcium acetate solution to the atorvastatin sodium salt solution. Upon completing the addition, the mixture was cooled. Crystallization of Form V began to occur at a temperature of 43° C. and cooling was continued until the flask temperature reached 13° C.
[0039] The crystals were isolated by slow vacuum filtration and then dried over anhydrous silica for 5 days to yield atorvastatin calcium salt Form V.
Example 2
[0040] Atorvastatin calcium (10 g) was dissolved in methanol (400 ml) at room temperature. Water (300 ml) was added slowly to the methanolic solution with stirring and the resulting solution was heated to 60° C. The solution was then cooled to between 10 and 15° C. within 3 h. Precipitation started at about 40° C. The thick slurry was then dried at 50° C. under reduced pressure for 48 h to yield atorvastatin calcium Form V.
Example 3
[0041] Atorvastatin calcium (5 g) was dissolved in methanol (100 ml) at room temperature. To this methanolic solution, water (100 ml) was added while stirring. Precipitation occurred instantly and after cooling the slurry to 15° C. the precipitate was filtered and dried at 50° C. under reduced pressure for 48 h to yield atorvastatin calcium Form V.
Example 4
[0042] Atorvastatin calcium (5 g) was dissolved in methanol (200 ml). The methanolic solution was placed into a stirred reactor containing water (150 ml) at 45° C. The obtained slurry was cooled to 10° C., filtered and dried at 50° C. under reduced pressure for 48 h to yield atorvastatin calcium Form V.
Example 5
[0043] Atorvastatin calcium (1 g) was dissolved in ethanol (15 ml) after heating. To this ethanolic solution, water (10 ml) was added while stirring. Precipitation occurred instantly. The gel-like precipitate was filtered without vacuum and dried at 50° C. under reduced pressure for 24 h to yield atorvastatin calcium Form V.
Example 6
[0044] Atorvastatin calcium (1 g) was dissolved in THF (25 ml) at room temperature. To this solution, water (60 ml) was added while stirring. The reaction mixture was stirred for 18 hours at room temperature and the precipitate (gel) was filtered without vacuum and dried at 50° C. under reduced pressure for 24 h to yield atorvastatin calcium Form V.
[0045] The invention has been described with reference to its preferred embodiments. From this description, those skilled in the art may appreciate changes that could be made in the invention which do not depart from the scope and spirit of the invention as described above and claimed hereafter.
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The present invention relates to atorvastatin calcium, a useful agent for lowering serum cholesterol levels. New atorvastatin calcium Form V, processes for preparing the new form, and pharmaceutical compositions and dosage forms containing the new form are disclosed.
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BACKGROUND OF THE INVENTION
The present invention relates to a heat generator that generates heat by shearing viscous fluid.
A typical heat generator used as an auxiliary heat source for a vehicle has a housing and a rotor. The rotor, which has a specially designed shape, is rotated to shear silicone oil filling the housing, to generate heat. For example, Japanese Unexamined Patent Publication No. 2-246823 discloses a rotor having labyrinthine grooves. Japanese Unexamined Utility Model Publication No. 3-98107 discloses a rotor having multiple fins. The applicant company has also proposed a heat generator having a disk-shaped rotor.
A conventional disk-shaped rotor is made by machining carbon steel, such as S45C, and has a hole in the center. The diameter of the hole is slightly smaller than that of a drive shaft to which the rotor is to be fitted. The rotor is secured to one end of the drive shaft by press fitting the drive shaft into the hole of the rotor. When machining the rotor, a boss is formed about the hole. The boss is axially longer than the rest of the rotor. The boss increases the contact area between the rotor and the shaft thereby securely fixing the rotor on the shaft. The greater the force acting on the contact area, due to the press fit, the less the connection between the rotor and the drive shaft is affected by temperature changes in the heat generator.
However, machining the rotor from steel is difficult and burdensome, thus increasing costs. Heat generators having rotors as described above are therefore not suitable for mass production. Thus, a relatively thin steel plate made of SPCC or SPHC has been tested as a material for a rotor. That is, a plate made of SPCC or SPHC was deep-drawn into a rotor. However, steel plates that are used in presswork have a relatively weak tensile strength. The rotor is therefore hardened immediately after being pressed for improving the tensile strength of parts in the rotor (especially, the boss). The hardening improves the tensile strength of the rotor. The rotor is therefore securely fixed to the drive shaft.
However, hardening is very costly. Further, rotors are often deformed by hardening. Therefore hardened plate often needs to be processed to correct its deformation. Approximately half of the manufacturing cost of a heat generator can be spent on hardening of the rotor and the process thereafter. Thus, as far as cost saving is concerned, there is no reason to manufacture the rotor by pressing instead of by machining.
SUMMARY OF THE INVENTION
Accordingly, it is an objective of the present invention to provide an inexpensive heat generator having a rotor that is securely fixed to a drive shaft.
To achieve the above objective, the present invention provides a heat generator having a housing, a heating chamber defined in the housing for containing a viscous fluid, a rotor located in the heating chamber. The rotor rotates to shear the viscous fluid to heat the viscous fluid. The heat generator includes a drive shaft, a coupler and a fastener. The drive shaft is rotatably supported in the housing. The coupler is formed on the rotor and couples the rotor to the drive shaft. The fastener tightens the coupler against the drive shaft.
The present invention is also embodied in a method for manufacturing a heat generator having a housing for containing a viscous fluid, a heating chamber defined in the housing and a rotor located in the heating chamber. The rotor rotates to shear the viscous fluid to heat the viscous fluid. The method includes forming a coupler for coupling the rotor to the drive shaft, on the rotor. The coupler is formed by pressing the center of a plate to form a projection that conforms to the shape of the drive shaft. The method includes bending a distal section of the coupler by 180 degrees to form a double-ringed cylindrical structure. The method also includes fixing the coupler to the drive shaft by inserting the drive shaft into the coupler.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
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.
FIG. 1 is a cross-sectional view illustrating a heat generator according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view illustrating a part of the drive shaft and the rotor illustrated in FIG. 1;
FIG. 4(A) is a cross-sectional view illustrating a heat generator according to a second embodiment of the present invention;
FIG. 4(B) is a cross-sectional view illustrating a heat generator according to a third embodiment of the present invention; and
FIG. 5 is a schematic cross-sectional view showing steps in a process for producing the rotors illustrated in FIGS. 4(A) and 4(B).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An on-vehicle heat generator according to a first embodiment of the present invention will now be described with reference to FIGS. 1-3. The heat generator is used in a vehicle air conditioner.
In FIG. 1, the left side is defined as the front side of the heat generator and the right side is defined as the rear side of the heat generator. As shown in FIG. 1, the heat generator includes a front housing body 1 and a rear housing body 2. The front housing body 1 has a hollow cylindrical boss 1a, which protrudes forward, and a cylinder 1b, which has a larger diameter than that of the boss 1a and extends backward from the proximal end of the boss 1a. The cylinder 1b has a wide opening opposite to the boss 1a. The rear housing body 2 covers the opening of the cylinder 1b. The front housing body 1 and the rear housing body 2 are fastened to each other by four bolts 3 (see FIG. 2). The fastened housing bodies 1, 2 accommodate a front plate 5 and rear plate 6. The housings 1, 2 and the plates 5, 6 are made of aluminum alloy.
The plates 5, 6 have peripheral rims 5a, 6a. When the housing bodies 1, 2 are fastened to each other, the rims 5a, 6a are pressed against the walls of the housing bodies 1, 2. This fixes the plates 5, 6 relative to the housing bodies 1, 2. A heating chamber 7 is defined between the plates 5, 6.
As shown in FIGS. 1 and 2, the rear plate 6 includes a boss 6b extending rearward from the central portion of its rear face and fins 6c extending arcuately and concentrically about the boss 6b. The fins 6c have the same axial dimension as the rim 6a. A cylindrical wall 2a extends forward from the central portion of the front face of the rear housing body 2. The cylindrical wall 2a is press fitted in the boss 6b. The inner wall of the rear housing 2 and the fins 6c define a rear water jacket 9. The cylindrical wall 2a of the rear housing 2 and the boss 6b define a reservoir 10. The reservoir 10 is located inside the boss 6b. In the rear water jacket 9, the rim 6a, the boss 6b and the fins 6c define water passages and guide the flow of water. The rear water jacket 9 is located behind the heating chamber 7 and functions as a heat exchange chamber.
Like the rear plate 6, the front plate 5 includes a boss 5b and fins 5c. The boss 5b extends forward and is fitted to the inner wall of the front housing 1. The circumference of the boss 5b is sealed, for example, by an O ring. The fins 5c extend concentrically and arcuately about the boss 4b. The axial dimension of the fins 5c is the same as that of the rim 5a. The inner wall of the front housing 1 and the fins 5c define a front water jacket 8. In the water jacket 8, the rim 5a, the boss 5b and the fins 5c define water passages and guide the flow of water. The front water jacket 8 is located in front of the heating chamber 7 and functions as a heat exchange chamber.
As shown in FIG. 2, an inlet port IP and an outlet port OP are formed on the side wall of the front housing 1. The inlet port IP leads circulation water from a vehicle heating circuit 19 into the water jackets 8, 9, and the outlet port OP leads the water from the water jackets 8, 9 to the heating circuit 19. The circulation of the water transmits the heat of the heat generator to the heating circuit 19.
As shown in FIG. 1, a drive shaft 13 is rotatably supported by bearings 11, 12 in the front housing body 1 and the front plate 5. The bearing 12 is located between and seals the boss 5b of the front plate 5 and the circumference of the shaft 13.
A substantially disk-shaped rotor 20 is press fitted about the drive shaft 13. The rotor 20 is placed in the heating chamber 7 during assembly of the heat generator. A predetermined clearance exists between the rotor 20 and the heating chamber 7. The structure of the rotor 20 and installation of the rotor 20 to the shaft 13 will be described later.
The rear plate 6 includes upper and lower bores 6d and 6e, which communicate the heating chamber 7 with the reservoir 10. The cross-sectional area of the lower bore 6e is larger than that of the upper bore 6d. A radial groove 6f is formed on the front face of the rear plate 6.
The heating chamber 7, the reservoir 10 and the bores 6d, 6e constitute an inner space, which is filled with a predetermined amount of silicone oil (not shown). The amount of the silicone oil is determined such that the fill factor of the oil is fifty to eighty percent of the volume of the inner space at room temperature. The level of the silicone oil is lower than the upper bore 6d and higher than the lower bore 6e, which functions as a supply passage. When the rotor 20 is rotated, the viscosity of the silicone oil draws the silicone oil out of the reservoir 10 through the lower bore 6e. The drawn silicone oil then flows along the groove 6f and is evenly distributed in the space between the heating chamber 7 and the rotor 20.
A pulley 16 is secured to the front end of the drive shaft 13 by a bolt 15. A V-belt 17 is engaged with the circumference of the pulley 16. The belt 17 couples the pulley 16 with an engine 18. The engine 18 rotates the drive shaft 13. The rotor 20 is rotated integrally with the drive shaft 13. When rotated, the rotor 20 shears the silicone oil in the space between the inner wall of the heating chamber 7 and the rotor 20, which generates heat. Heat generated in the chamber 7 is transmitted to circulating water in the water jackets 8, 9 through the plates 5, 6. The heated water is then used by the heating circuit 19 for heating the passenger compartment.
Rotation of the rotor 20 causes the silicone oil in the heating chamber 7 to flow toward the drive shaft 13 due to the Weissenberg effect. The upper bore 6d is located substantially in the central area of the heating chamber 7. Thus, the silicone oil in the heating chamber 7 is returned to the reservoir 10 through the upper bore 6d. On the other hand, due to its high viscosity and its own weight, the silicone oil in the reservoir 10 is drawn to the heating chamber 7 by rotation of the rotor 20. In this manner, rotation of the rotor 20 causes silicone oil to circulate between the heating chamber 7 and the reservoir 10. Since the lower bore 6e has a larger diameter than that of the upper bore 6d, the amount of oil supplied to the heating chamber 7 exceeds the amount of oil recovered to the reservoir 10. Therefore, silicone oil stored in the reservoir 10 is quickly supplied to the heating chamber 7 through the lower bore 6e and flows to the peripheral portion of the heating chamber 7 along the groove 6f. The Weissenberg effect quickly moves the silicone oil from the peripheral portion to the center portion of the heating chamber 7. The silicone oil is therefore evenly distributed in the space between the rotor 20 and the wall of the heating chamber 7. Thereafter, the silicone oil is drawn back to the reservoir 10 from the heating chamber 7 through the upper bore 6d.
After returning from the heating chamber 7 to the reservoir 10, silicone oil stays in the reservoir 10 for a certain period. Immediately after silicone oil enters the reservoir 10 from the heating chamber 7, the temperature of the oil is high. Some of the heat, however, is transmitted to the rear plate 6 and the housing 2. This lowers the temperature of the silicone oil. Accordingly, the silicone oil is prevented from being heated to high temperatures over a prolonged period and thus damaged.
When the engine 18 is not running, in other words, when the drive shaft 13 is not rotating, the level of silicone oil in the heating chamber 7 is equal to the level of the silicone oil in the reservoir 10. Therefore, when the engine 18 starts rotating the drive shaft 13, the contact area between the rotor 20 and the silicone oil is relatively small. This allows the pulley 16, the drive shaft 13 and the rotor 20 to be driven with relatively little torque.
The structure and installation of the rotor 20 will now be described.
As illustrated in FIG. 1, the rotor 20 includes a disk 21 and a boss 22, which are integrated. The disk 21 shears the silicone oil. The boss 22 includes an inner circumferential surface 22a (shown in FIG. 3), for contacting the drive shaft 13. A ring 23 is located about the boss 22. The ring 23 presses the boss 22 against the drive shaft 13, which forms a double structure for securely coupling the rotor 20 to the drive shaft 13.
As illustrated in FIG. 3, the disk 21 and the boss 22 are integrally formed by pressing a steel plate having a thickness of two to four millimeters. The inner diameter d1 of the boss 22 is slightly smaller than the outer diameter d2 of the drive shaft 13. The boss 22 is formed in the center of the disk 21 by performing deep-drawing. Thus, the thickness of the boss 22 is substantially equal to the thickness of the disk 21, that is, the thickness of the steel plate.
The ring 23 is also formed by pressing a metal plate. The inner diameter d3 of the ring 23 is equal to or slightly smaller than the outer diameter d4 of the boss 22. The axial thickness t1 of the ring 23 is substantially equal to the thickness of the steel plate from which the ring 23 is formed. The radial thickness, or the width t2, of the ring 23 is arbitrarily determined by selecting the press die. The ring width t2 is preferably greater than the radial thickness ((d4-d1)/2) of the boss 22.
Assembly of the rotor 20 to the drive shaft 13 will now be described.
Initially, the drive shaft 13 is press fitted in the boss 22 using a jig. Then, the position of the rotor 20 on the drive shaft 13 is determined. Accordingly, the clearance between the disk 21 and the wall of the heating chamber 7 is determined. Thereafter, the ring 23 is engaged with the drive shaft 13 and fitted about the boss 22. The ring 23 tightly presses the inner circumferential surface 22a of the boss 22 against the drive shaft 13. Consequently, the rotor 20 is tightly fixed at the predetermined position on the drive shaft 13.
The disk 21 includes through holes 24. The holes 24 are located at the same distance from the axis X of the drive shaft and are angularly spaced apart at equal intervals. Each hole 24 communicates the clearance at the front side of the rotor 20 and the clearance at the rear side of the rotor 20. The holes 24 promote the circulation of silicone oil thereby equalizing the pressure and the temperature of the silicone oil at the front and rear side of the rotor 20.
The heat generator of FIGS. 1 to 3 has the following advantages.
The ring 23 is used to fix the rotor 20 to the shaft 13. Therefore, although the disk 21 and boss 22 are integral, the rotor 20 does not need to be hardened or subjected to a process for correcting its deformation, which lowers the cost of the heat generator.
The assumed minimum temperature at which the heat generator will be used is minus forty degrees centigrade, and the maximum possible temperature of the silicone oil is two hundred degrees centigrade. Therefore, the temperature of the heating chamber 7 will repeatedly change between minus forty degrees centigrade and two hundred degrees centigrade, if the heat generator is used in the coldest climate. However, the ring 23, which reinforces the attachment of the rotor 20 to the drive shaft 13, prevents the rotor 20 from sliding relative to the drive shaft 13 and allows the rotor 20 to rotate integrally with the drive shaft 13 despite the extreme temperature changes.
The above advantages are unique to the heat generator of FIGS. 1 to 3 in comparison to an exemplary prior art heat generator. The prior art heat generator does not have the ring 23. Instead, the boss 22 is welded to the drive shaft 13. The prior art heat generator was intermittently started and stopped several times in an extremely cold environment. That is, the heat generator was repeatedly subjected to temperature changes between minus forty degrees centigrade and two hundred degrees centigrade. A disassembly of the heat generator thereafter revealed formation of cracks at the welded part between the boss 22 and the drive shaft 13 and that the boss 22 was about to break from the shaft 13. It was apparent that a few more intermittent operations of the heat generator would cause the rotor 22 to slide relative to the drive shaft 13. The heat generator of FIGS. 1 to 3 was subjected to the same experiment. However, there was no abnormality between the boss 22 and the drive shaft 13. That is, the firm attachment between the boss 22 and the shaft 13 was maintained.
Since the ring 23 is separately formed from the rotor 20, the thickness t2 of the ring 23 may be arbitrarily determined. In other words, the pressing force of the boss 22 acting on the drive shaft 13 may be easily changed by varying the thickness t2 of the ring 23.
The rotor 20 is firmly fixed to the drive shaft 13 and does not slide relative to the drive shaft 13. This maintains the clearance between the rotor 20 and the heating chamber 7. Therefore, the heat generator of FIGS. 1 to 3 has a stable heating performance.
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. Particularly, it should be understood that the invention may be embodied in the following forms.
FIG. 4(A) shows a rotor 30 according to a second embodiment. The rotor 30 does not have the separately formed ring 23. The rotor 30 includes a disk 31 and a cylindrical portion 32. The rotor 30, or the disk 31 and the cylindrical portion 32, is integrally formed by pressing a single metal plate. The front end of the cylindrical portion 32 is bent outward. The bent portion 33 contacts the circumferential surface of the cylindrical portion 32. In this manner, the rotor 30 is fixed to the drive shaft 13 by the double-ringed structure of the cylindrical portion 32 and the bent portion 33. In other words, the cylindrical portion 32 and the bent portion 33 form the boss of the rotor 30.
FIG. 4(B) shows a rotor 30' according to a third embodiment. Like the rotor 30, the rotor 30' does not have the separate ring 23. The rotor 30' includes a disk 31 and a cylindrical portion 32. The rotor 30, or the disk 31 and the cylindrical portion 32, is integrally formed by pressing a single metal plate. The front end of the cylindrical portion 32 is bent inward. The bent portion 33 contacts the inner circumferential surface of the cylindrical portion 32. In other words, the cylindrical portion 32 and the bent portion 33 form the boss of the rotor 30.
The manufacturing process of the rotors 30, 30' according to the second and third embodiments will now be described with reference to FIG. 5.
Step 1: a disk-shaped steel plate 35 is prepared. Step 2: a cylindrical press die 36 (shown by a dashed line) is pressed against the plate 35 and forms a recess 37. Step 3: the bottom of the recess 37 is cut off to form the cylindrical portion 32. The front end of the cylindrical portion 32 is bent either (A) outward or (B) inward. Step 4: the outwardly bent portion 33 contacts the cylindrical portion 32 to form the double-ringed boss structure of FIG. 4(A). The inwardly bent portion 33 contacts the cylindrical portion 32 to form the double-ringed boss structure of FIG. 4(B).
The rotors 30, 30' shown in FIGS. 4(A) and 4(B) each have an outer ring of the boss pressing an inner ring against the drive shaft 13. This firmly fixes the rotors 30, 30' to the drive shaft 13. Like the rotor 20 of FIGS. 1 to 3, the rotors 30, 30' do not need to hardened or subjected to a process for correcting their deformation. The manufacturing cost of the heat generator is lowered, accordingly.
In the rotors 30, 30' of FIGS. 4(A), 4(B), the outer ring 33, 32 of the boss may be crimped inwardly. This further enforces the attachment of the rotors 30, 30' to the drive shaft 13.
The separate ring 23 may be employed in the rotors 30, 30' of FIGS. 4(A), 4(B). That is, the ring 23 may be fitted about the boss of the rotors 30, 30' of FIGS. 4(A) and 4(B).
The boss of the rotors 30, 30' may be bent two or more times to form a multiple-ringed boss.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims.
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A viscous fluid type heat generator, which shears viscous fluid for generating heat. The heater includes a rotor located in a heating chamber and viscous fluid accommodated in the heating chamber. The rotor is rotated integrally with a drive shaft by a vehicle engine. The rotor includes a boss for attaching the rotor to the drive shaft. The boss has a double-ringed structure for reinforcing the attachment of the boss to the drive shaft.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image formation system configured by connecting two or more image formation devices comprising a fixing device for fixing an unfixed development image to a record medium.
2. Description of the Related Art
In an image formation device using an electrophotographic method, a development image made of coloring particles formed on a photoconductor is transferred to a record medium such as paper and an unfixed development image adhering to the record medium is fixed to the record medium by a fixing device and thereby an image is obtained.
As a method for fixing an unfixed development image on a record medium, a fixing device called a thermal roller fixing method in which a heat source is had in the inside and a toner image is brought into direct contact with a heating roller made of metal material heated to a temperature enough to melt toner and simultaneously a pressure is applied by a pressurizing roller and fixing is performed by inserting a record medium between both the rollers is used.
In such an image formation device, a tandem type image formation system for disposing a joint path for transporting a record medium between plural image formation devices and forming an image is proposed.
In the tandem type image formation system, using coloring particles of different colors every each image formation device, images of plural colors can be formed, or an image of one side of the record medium can be formed by the first image formation device and an image of the back side of the record medium can be formed by the next image formation device.
In the tandem type image formation system, in a fixing process by image formation of only one side of the record medium, the record medium passes between both the rollers in a state in which the side to which a toner image is transferred makes contact with a heating roller in the first image formation device and the second image formation device and at this time, a slight amount of toner electrostatically adheres to a surface of the heating roller. Generally, in the heating roller, a cleaning web impregnated with silicone oil etc. is arranged so as to make sliding contact with the surface of the heating roller in order to ensure release characteristics of the heating roller and the toner on the record medium.
This cleaning web is non-woven fabric and makes sliding contact with the surface of the heating roller and thereby, silicone oil gradually seeps from the inside and the oil is applied to the heating roller and simultaneously by rubbing action, a slight amount of toner adhering to the surface of the heating roller is captured by the non-woven fabric and the cleaning web has action of cleaning the surface of the heating roller.
SUMMARY OF THE INVENTION
Many pressurizing rollers may have a fluorine resin layer such as PFA on a surface of the pressurizing roller in order to ensure release characteristics of the pressurizing roller and toner. Since an electrification series of the PFA is negative, the surface of the pressurizing roller is at a negative potential in many cases.
For example, after a toner image is formed on one side of a record medium by the first image formation device, paper is reversed and passes through a joint path and is introduced into the second image formation device. In the record medium transported to a transfer process of the second image formation device, the toner image formed on a surface of a photoconductor is transferred to the record medium. In the case of an image formation device using a reversal development method, toner is negatively charged. When the negatively charged toner is transferred to the record medium, a positive charge is injected into the back side of the record medium and a toner image is transferred. At this time, the toner image formed by the first image formation device is present on the back side of the record medium. The toner image on the back side of the record medium has a high probability of occurrence of toner having the positive charge because of the positive charge provided in the transfer process of the second image formation device.
The toner image present on the back side of the record medium is fixed by the first image formation device, but a situation in which the toner image is 100% fastened to the record medium does not occur generally. About several percent of toner of the toner image is in a state capable of adhering to the peripheral members in the case of applying slight force. When the record medium of such a state makes contact with a pressurizing roller of a fixing device of the second record medium, toner having small force of fastening to the record medium and having a positive charge of the back side of the record medium shifts to a surface of the pressurizing roller having a negative charge by electrostatic force.
Thus, slightly unfixed toner on a print surface among the toner image after fixing generated on one side of the record medium by at least the first image formation device makes direct contact with the pressurizing roller and as a result, the toner electrostatically shifts to the surface of the pressurizing roller and toner accumulation on a similar pressurizing roller may be caused. When the heating roller makes contact with the pressurizing roller and the rollers run idle at the time of restarting the image formation device, etc. and a temperature of the pressurizing roller exceeds the softening point of toner and its toner accumulation melts, its toner adheres to the side of contact between the transported record medium and the pressurizing roller, that is, the back side and the toner stains the record medium and serious error printing may be caused.
Particularly, in the case of a tandem type image formation system, it was proved that in an image formation device located in the downstream portion of an image formation device for forming an image upstream, the toner image creation side of a record medium in which the image is formed upstream makes contact with a surface of a pressurizing roller and the toner adheres to a surface of a pressurizing roller of the downstream image formation device in a manner similar to the principle described above. Also, when the toner adhering to the pressurizing roller is remarkably large at this time, the melting toner acts as an adhesive and a jam in which the record medium is wound on the side of the pressurizing roller may be caused.
In order to clean the toner adhering to the surface of the pressurizing roller, it is also considered that the toner is prevented from adhering by heating the surface of the pressurizing roller and setting a surface temperature of the pressurizing roller at the softening point or more of toner always, but adding a device for heating the surface of the pressurizing roller increases power consumption and also causes upsizing of the fixing device and it becomes a problem in design of the image formation device.
In order to recover the toner adhering to the surface of the pressurizing roller, it is also considered that extra toner is prevented from adhering to the record medium from the pressurizing roller by arranging a cleaner in the surface of the pressurizing roller and cleaning the pressurizing roller, but arranging the cleaner in the surface of the pressurizing roller causes upsizing of the device and also a temperature of the surface of the pressurizing roller is lower than a temperature of the heating roller, so that a problem that the toner of the surface of the pressurizing roller is fastened and all the toner cannot be recovered even in the case of attempting to recover the toner by the cleaner arises.
Therefore, it becomes necessary that the toner be not shifted from the record medium to the surface of the pressurizing roller wherever possible. A problem is to achieve a charge balance in which a toner image formed on a surface of a record medium does not shift to a pressurizing roller even in the case of making contact with the pressurizing roller.
According to one aspect of the invention, there is provided an image formation system configured by connecting two or more image formation devices, including: a fixing device fixing an unfixed development image to a record medium, and a charge elimination device eliminating a charge of the record medium in an inlet of the fixing device of the second or later image formation device.
By thus configuration, an image formation system in which a development image on a record medium does not adhere to a fixing roller and a good image without extra printing is obtained can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic configuration diagram of a fixing device.
FIG. 2 is a schematic configuration diagram of an image formation system.
FIG. 3 exemplarily shows an alternate configuration having a corotron 73 at the inlet of the second engine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a fixing device, and numeral 61 is a heating roller, and numeral 62 is a pressurizing roller, and numeral 63 is a charge elimination brush, and numeral 64 is an inlet paper guide plate, and numeral 66 is a heater lamp, and numeral 67 is a cleaning web, and numeral 68 is a pressure contact roller, and numeral 69 is a paper peel claw, and numeral 9 is toner, and numeral 91 is a development image, and numeral 4 is a record medium.
FIG. 2 is one example of an image formation system, and numeral 1 is a photoconductor drum, and numeral 2 is an electrification device, and numeral 3 is a developing device, and numeral 31 is a developing roller, and numeral 4 is a record medium, and numeral 5 is a transfer device, and numeral 6 is a fixing device, and numeral 7 is a cleaner, and numeral 8 is an exposure device, and numeral 9 is toner, and numeral 10 is a carrier, and numeral 21 is a paper reversal device, and numeral 51 is a first image formation device (hereinafter also called “a first engine”), and numeral 52 is a second image formation device (hereinafter also called “a second engine”), and numeral 53 is a joint path.
A tandem type image formation system shown in the present embodiment has a structure of joining the first engine 51 to the second engine 52 by the joint path 53 , and devices used in an electrophotographic method of a similar structure are arranged in both of the first engine 51 and the second engine 52 .
FIG. 2 also shows exemplarily the charge elimination brush 63 at the inlet of the fixing device 6 of the second engine 52 . A corresponding charge provisioning device, such as a corotron 73 , is shown in the inlet of the fixing device 6 of the second engine 52 in FIG. 3 .
First, an electrostatic latent image by disappearance of a charge through the exposure device 8 according to image information is formed on a surface of the photoconductor drum 1 electrified to a negative potential uniformly by the electrification device 2 inside the first engine 51 shown in FIG. 2 . Thereafter, the toner 9 electrified to a negative charge is supplied from the developing roller 31 of the developing device 3 and a toner image 91 which is a visualized image is formed according to the electrostatic latent image. The toner 9 having the negative charge on the surface of the photoconductor drum 1 developed thus is transferred on the record medium 4 by a positive charge supplied from the transfer device 5 .
The transferred toner 9 is inserted into a portion of contact between the pressurizing roller 62 and the heating roller 61 in which a surface of the roller is controlled at a predetermined temperature by the heater lamp 66 inside the fixing device 6 , and penetrates to the front side of the record medium 4 by pressure as well as heating melting by heat energy and thereafter, is fastened and fixed on the record medium 4 . However, a situation in which the toner 9 on the record medium 4 is 100% fixed does not occur, and several percent of the toner 9 is in a state movable by external force or electrostatic force of the periphery.
The record medium 4 passing through the fixing device 6 is reversed by the reversal device 21 and passes through the joint path 53 . After passing through the joint path 53 , the record medium 4 is introduced into the second engine 52 . In the record medium 4 introduced into the second engine 52 , an electrostatic latent image by disappearance of a charge through the exposure device 8 according to image information is formed on a surface of the photoconductor drum 1 electrified to a negative potential uniformly by the electrification device 2 inside the second engine 52 . Thereafter, the toner 9 electrified to a negative charge is supplied from the developing roller 31 of the developing device 3 and a toner image 91 which is a visualized image is formed according to the electrostatic latent image.
The toner 9 having the negative charge on the surface of the photoconductor drum 1 developed thus is transferred on the record medium 4 by a positive charge supplied from the transfer device 5 . In the case of the transfer, the quantity of positive charge best suitable to transfer the toner image 91 developed on the photoconductor drum 1 to the record medium 4 is supplied to the transfer device 5 . In that case, the toner image 91 formed by the first engine is present on the back side of the record medium 4 and an excessive positive charge is injected into the toner image 91 of the back side of the record medium 4 . Because of the influence, the toner image 91 present on the back side of the record medium 4 results in the toner image 91 electrified to the positive charge.
The record medium 4 passing through the transfer device 5 makes contact with the charge elimination brush 63 arranged in the front of the inlet paper guide plate 64 of the fixing device 6 . As a result of this, the charge of the toner image 91 present on the back side of the record medium 4 is eliminated and each of the particles of the toner 9 changes to a zero potential. Thereafter, the record medium 4 is introduced into the inlet paper guide plate 64 and reaches a portion of contact between the pressurizing roller 62 and the heating roller 61 heated. A fluorine resin layer is arranged on surfaces of the pressurizing roller 62 and the heating roller 61 in order to ensure release characteristics to the toner. The heating roller 61 and the pressurizing roller 62 contact and rotate with the rollers mutually pressed and contacted. An electrification series of the resin layer is negative and the resin layer is maintained at a negative potential of several kV always.
Therefore, adsorption is performed when there is an object having a positive charge in the periphery. The toner image 91 on the back side of the record medium 4 reaching the portion of contact between the heating roller 61 and the pressurizing roller 62 is at a zero potential at this time and in the case of making contact with the pressurizing roller 62 , the toner image 91 does not shift to a surface of the pressurizing roller 62 and stays on the back side of the record medium 4 . In the portion of contact between the heating roller 61 and the pressurizing roller 62 , in a manner similar to the first engine 51 , the toner 9 on the front side of the record medium 4 penetrates to the front side of the record medium 4 by pressure as well as heating melting by heat energy and thereafter, is fastened and fixed on the record medium 4 . The image formation is completed in the process described above.
According to the embodiment described above, a positive charge of the toner 9 adhering to the back side of the record medium 4 is eliminated and the toner 9 having the positive charge can be prevented from being adsorbed to a surface of the pressurizing roller 62 having a negative charge, and there is an effect of preventing unnecessary toner 9 from adhering to the surface of the pressurizing roller 62 .
Incidentally, in the embodiment, the charge elimination brush 63 has been used in an inlet of the fixing device 6 , but an effect similar to that obtained in this embodiment is obtained when the charge of the toner image 91 on the back side of the record medium 4 can be eliminated in the front of the heating roller 61 and the pressurizing roller 62 . Therefore, a similar effect can naturally be obtained when an inlet guide of the fixing device 6 of the second engine 52 is installed at a ground level, using, for example, a charge elimination brush 63 , and time and length of contact with the toner image 91 on the back side of the record medium 4 are sufficiently ensured and charge elimination of the toner image 91 on the back side of the record medium 4 is achieved.
Also, an effect becomes larger when the toner 9 on the back side of the record medium 4 has a negative charge so that the toner 9 on the back side of the record medium 4 is not adsorbed to the pressurizing roller 62 having a negative charge on the surface. Therefore, a larger effect can be obtained when an inlet of the fixing device 6 is provided with a corotron capable of providing a charge for the back side of the record medium 4 and a negative charge is provided for the toner 9 on the back side of the record medium 4 , similar to corotron 73 exemplarily shown in the inlet of the fixing device 6 of the second engine 52 , as shown in FIG. 3 .
Further, in order that the toner 9 is not adsorbed to a surface of the pressurizing roller 62 , the surface of the pressurizing roller 62 could be set at a zero potential or be controlled to polarity opposite to polarity of the charge which the toner 9 has, so that an effect similar to that of the embodiment can also be obtained by controlling a potential of the surface of the pressurizing roller 62 by the corotron or the charge elimination brush, etc.
In the embodiment, a phenomenon in the second engine 52 of the tandem type image formation system has been described, but when image formation devices such as a third engine or a fourth engine are further connected, action and effect similar to those of the embodiment can also be obtained in fixing devices of each of the image formation devices.
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An image formation system is configured by connecting two or more image formation devices. The system includes a fixing device fixing an unfixed development image to a record medium and a charge elimination device eliminating a charge of the record medium in an inlet of the fixing device of the second or later image formation device.
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FIELD OF THE INVENTION
The present invention relates to the field of protective apparel, and more particularly, to helmets for outdoor sporting activities.
BACKGROUND OF THE INVENTION
Helmets and other forms of protective headgear have become increasingly popular in recent years as users have become more aware and concerned about preventing head injuries while participating in individual and team sporting events. Numerous forms of special helmets have been developed for wear in a wide range of indoor and outdoor sporting activities.
While the helmets developed for some activities are compact and intended to protect the more vulnerable areas of the head and neck, others cover a more substantial portion of a user's head. For example, helmets for motorcyclists tend to be expansive and cover not only the head, but often comprise a faceshield to protect the wearer from debris and flying objects that may be encountered at driving speeds. Because these helmets cover substantially the entire head and neck of the wearer, the interiors of these helmets tend to become uncomfortably warm, especially in warm weather. This often leads to fogging of the faceshield as condensation builds inside the helmet. To combat this problem, vents have been incorporated into some helmet constructions to intake, circulate, and discharge air. This, of course, is possible since forced ventilation is ensured by the velocity of incoming air due to the speed of driving. As such, these vents often are located on the front facial portions of the helmets. Although such a configuration is somewhat effective in ventilating the facial area, it does not provide ventilation to the crown of the wearer's head.
In sports such as snowboarding and skiing, ventilation measures for the head heretofore have not been highly effective. One known helmet construction incorporates small apertures around the headband region for some air exchange and evaporation of perspiration, but lacks any effective ventilation provision for the top of the head. As is well known, the top, or crown, of the head is where the average person radiates the greatest amount of body heat.
What is needed is a helmet for outdoor sports such as snowboarding and skiing that provides an effective ventilation construction and that allows a wearer to maximize, limit, or eliminate air flow to the top of the head. Further, a helmet construction is desired that will allow a user to regulate easily the degree of ventilation for the range of anticipated conditions; e.g., restricting or eliminating ventilation in extremely cold weather or when snow or rain are likely to get into the top of the helmet, or maximizing ventilation in warmer weather.
SUMMARY OF THE INVENTION
The present invention is directed to a simple, yet versatile, helmet construction that not only provides protection to the head, but that also permits the wearer to maximize, limit, or shut off ventilation to the crown, or dome, of the helmet.
In one embodiment, the helmet comprises a protective outer ventilating shell, a liner, a ventilating shutter plate, a shutter plate positioning mechanism and an adjustable strap arrangement. The protective outer ventilating shell is a relatively thin, lightweight, impact-dispersing and puncture-resistant plastic. The shell is contoured upwardly around the facial area and downwardly adjacent the neck area. A shock-absorbing liner is disposed within the inner surface area of the outer protective shell. The liner is formed of an injection molded expanded plastic or styrene material.
A plurality of spaced-apart vents are formed through the outer protective shell and the shock-absorbing liner. The vents, which are elliptically-shaped in one embodiment, are located at spaced intervals in both the front and rear portions of the shell and liner construction. This orientation of vents, often in conjunction with interior channels, facilitates air flow from the front to the rear of the helmet.
The ventilating shutter plate is rotably mounted within a recess in the shock-absorbing liner. In one preferred embodiment, the ventilating shutter is a relatively thin, circular, durable plastic construction. It may be either dome-shaped to correspond to the contour of the helmet, or may be planar. The ventilating shutter plate also has a pattern of spaced-apart apertures formed therethrough. These apertures conform in dimension and position to the vents in the outer protective shell and liner so that they are in substantial registration with one another when the shutter plate is rotated to a first position. The shutter plate is selectively moveable between at least two positions, i.e., a first position where the apertures register with the vents so that the vents are completely open, and a second position wherein the apertures are completely misaligned with the vent openings and the vent openings are completely closed, or blocked, by the shutter plate.
To hold the shutter plate in position within the liner, a liner plate is provided. The liner plate, which is formed of the same material as the liner, is dimensioned to fit within the recess in the liner so that the smooth contour of the total liner is maintained. The liner plate also has slots that correspond in dimension and placement to the vents in outer shell, liner, and shutter plate.
So that a wearer may manually select the position of the shutter plate, the shutter plate positioning mechanism includes a positioning lever connected to the shutter plate for selectively rotating the shutter plate to open and close the vent openings. In its simplest form, the lever that has a fixed end connected to the edge of the shutter plate and a free end that extends through an elongate slot in either the front or rear of the helmet.
In operation, the wearer may selectively move the lever to a plurality of positions within the elongate slot, without having to remove the helmet. Each position of the lever corresponds to a selected position of the apertures in the shutter plate with respect to the vents in the shell and liner. In one embodiment, the lever, and therefore the shutter plate, may have a fully open position, a half-open position, and a fully closed position. The lever is positioned at a low angle relative to the wearer's skull to avoid transferring external impact energy through the helmet to the wearer's skull.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments when considered in conjunction with the drawings. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right front perspective view of the vented helmet of the present invention;
FIG. 2 is a view of the helmet of FIG. 1 , with the protective shell partially cut-away;
FIG. 3 is a left rear perspective view of the helmet of the present invention;
FIG. 4 is a bottom view of the helmet of the present invention showing the plurality of vents in the fully open position;
FIG. 5 is an enlarged view of FIG. 4 with the liner plate removed, showing the alignment of the shutter plate with the plurality of vents in the fully open position;
FIG. 6 is a top rear perspective view of the liner plate of the present invention;
FIG. 7 is a rear perspective view of the helmet of the present invention showing the plurality of vents in the partially-open position;
FIG. 8 is an enlarged bottom view of FIG. 7 with the liner plate removed, showing the alignment of the shutter plate with the plurality of vents in the half-open position; and
FIG. 9 is enlarged bottom view of FIG. 1 with the liner plate removed, showing the alignment of the shutter plate with the plurality of vents in the fully closed position;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 through 3 , the present invention is directed to a helmet for protecting a wearer's head during sporting activities, such as skiing or snowboarding. More specifically, the helmet readily permits a wearer to maximize, restrict, or shutoff ventilation to the dome, or crown portion of the helmet. Shown generally as 10 , the protective helmet comprises a protective outer ventilating shell 12 , a liner 22 , an adjustable strap arrangement 32 , a ventilation controlling shutter plate 42 , and a positioning mechanism 52 .
The protective outer ventilating shell 12 is a hard-shell, impact-dispersing plastic that can withstand significant blows and temperature extremes without fracture. It is also puncture-resistant, and lightweight. As will be appreciated by those skilled in the materials arts, an outer ventilating shell 12 with these properties may be molded from polycarbonate or ABS plastic, or other durable composite material. As is conventional in protective helmets, the shell, and thus the helmet, has an upwardly contoured open portion 12 a adjacent the face of the wearer, and a downwardly contoured portion 12 b adjacent the back of the neck of the wearer.
A plurality of spaced-apart vents 14 are formed through the outer ventilating shell. It has been found that vents 14 having generally elliptical shapes provide the most desirable, and streamlined, airflow; however the present invention is not limited thereto. The vents 14 are further recessed in the ventilating shell within generally parabolic recesses 13 that facilitate a streamlined flow of air into and out of the upper interior of the helmet 10 . As best shown in FIGS. 3 and 7 , the vents 14 are formed at spaced intervals in both the front and rear portions of the shell. FIGS. 4 and 5 provide a view of the general orientation of the vents 14 as they appear from the bottom of the helmet 10 . While the embodiment illustrated herein has an equal number (3) of front and rear vents, the invention is not limited thereto; rather, for effective ventilation, at least one front vent and one rear vent, or only front or rear vents, may well be sufficient. Further, the sizes of the vents may be varied so that the desired number of vents 14 is either increased or decreased. To facilitate air flow during use, the elliptically-shaped vents 14 are generally oriented with their major axes running from the front to the rear of the helmet 10 . Additionally, but not important to the utility of the invention, one or more faux vents 16 may be formed in the shell for ornamental purposes.
Turning now to FIGS. 2 and 4 , a lightweight, shock-absorbing liner 22 is disposed within and adhered to substantially the entire inner surface of the shell 12 . The liner 22 is made of molded styrene, polystyrene, expanded plastic, or the similar shock-absorbing material. As best seen in FIG. 4 , the vents 14 are also formed through the liner 22 .
As shown in FIG. 2 , a ventilating control shutter plate 42 is disposed within the liner 22 ; i.e., the shutter plate is positioned within a substantially cylindrical recess that is formed in the liner. The shutter plate 42 may be dome-shaped, spherical, or toroidal/near-spherical, to correspond to the interior contour of the helmet 10 , or may be substantially planner. The shutter plate 42 , which is desirably formed of a flexible, lightweight, durable plastic, is relatively thin. When made of a flexible material, the shutter plate 42 can accommodate the change in shape required to rotate within the non-spherical or near-spherical recess in the liner 22 . The thickness of the shutter plate 42 is not critical, but is related to the economy of space within the liner 22 of the helmet 10 . Apertures 44 are formed through the shutter plate 42 . The apertures 44 correspond in dimension and relative position to the vents 14 formed through the protective shell 12 and liner 22 .
To maintain the shutter plate 42 in position within the liner 22 , a liner plate 24 is provided. The liner plate 24 is dimensioned to fit within the recess in the liner so that the smooth contour of the inner liner of the helmet is maintained. The liner plate 24 is formed of the same material as the liner 22 and is adhered to the liner 22 along its peripheral edges. Best shown in FIG. 6 , the liner plate has slots 26 that also correspond in dimension and placement to the vents 14 in shell 12 and liner 22 , and the apertures 44 in the shutter plate 42 . To hold the shutter plate in its desired orientation, and to provide a central hub for rotational movement of for the shutter plate 42 , projections 27 and 28 are provided on the innermost side of the liner plate 24 . Projection 27 extends through slot 48 in the shutter plate 42 and into recess 27 a of liner 22 to provide the hub for rotational movement of the shutter plate 42 . Optionally, projections 28 , which are generally actuate in shape, extend through opposed slots 46 and into recesses 28 a of the liner 22 to facilitate rotation of the shutter plate 42 , without undue lateral shifting or sliding, and provide additional structural support through the shutter plate to maintain the shutter plate recess in the foam liner.
The positioning mechanism 52 of the present invention comprises a lever, or detent, 54 that is either connected to, or integrally formed with the shutter plate 42 . The lever 54 is desirably formed of the same durable material as the shutter plate so that it is not easily damaged or broken due to anticipated, repeated use. The lever 54 extends from its fixed end through a slot 56 formed therethrough the liner 22 and the protective shell 12 . The lever 54 may have an enlarged end, or more desirably, a knob 58 is affixed to its free end so that the wearer can easily grasp it to manipulate the lever 54 . The lever 54 may also be so formed and positioned that it is slightly spring biased either upward or downward against the slot 56 . This is possible since the durable plastic is resilient. The bias assists in preventing the lever 54 and the connected shutter plate 42 form shifting or sliding during use. Optionally, indentations 59 may be formed along one edge of the slot 56 to engage the lever, or detent, 54 at some point along the length of the lever 54 to hold the lever 54 in a desired position along the slot 56 . This enables the wearer to know which position the lever, or detent, 54 , and thus the shutter plate 42 , are in and to selectively change their positions by touch, without having to remove the helmet 10 . By exerting a small amount of force in the lateral direction the wearer can overcome the spring bias and move the lever, or detent, 54 laterally within the slot 56 . The positioning lever, or detent, 54 is also positioned at a low angle relative to the wearer's skull to avoid transferring external impact energy through the helmet to the wearer's skull.
In use, the wearer may manipulate the lever 54 and connected shutter plate 42 to open or close the vents 14 to achieve the desired degree of ventilation into and out of the crown of the helmet 10 . For example, referring to FIGS. 2 , 3 , and 5 , when the lever 54 is in position ‘A’ along slot 56 , the apertures 44 of the shutter plate are in complete alignment and registration with the vents 14 so that the vents 14 are completely opened, or unblocked. By sliding the lever 54 to position ‘B’ along slot 56 , the shutter plate is rotated counterclockwise to the position shown in FIGS. 7 and 8 . The apertures 44 are then in partial alignment with the vents 14 , thereby limiting, or restricting, the air flow. Since the vents 14 and apertures 44 are not geometrically radial about the pivot point of the shutter plate 42 , the air flow through the apertures 14 when the lever 54 is in position ‘B’ is less than half of the air flow potential of position ‘A’.
Referring to FIGS. 1 and 9 , by moving the lever 54 to position ‘C’ along slot 56 , the shutter plate is rotated further counterclockwise. In this position, the opening to each of the vents 14 are completely blocked and no ventilation is permitted. This position may also be desirable when the wearer wishes to keep rain or snow from entering the top of the helmet.
To ensure the comfort of the helmet 10 and to ensure that the helmet does not fall off during use, a conventional type of strap arrangement 32 is provided. The strap arrangement may be attached to the shell 12 or liner 22 in a number of conventional ways. The straps arrangement 32 comprises left and right ear covers 34 a , 34 b , an adjustable chin strap pair 36 a , 36 b , and an interlocking buckle assembly 38 a , 38 b.
Although the present invention has been described with exemplary constructions, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.
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A helmet for protecting the head of a wearer during sporting activities, comprising a protective shell, vents formed in the protective shell, and a shutter plate positioned within the protective shell. The shutter plate has apertures conforming in dimension and position to the vent openings so that that the apertures are in substantial alignment with the vents when the shutter plate is in a first position. The shutter plate is selectively moveable so that the vents are opened or closed.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Application Ser. No. 60/582,113, entitled “Using POD/mLSE algorithms to provide measurement input from surface measurements for driving actuators in active feedback flow control,” filed on Jun. 23, 2004.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to airfoil actuator feedback controls and, more specifically, to the use of proper orthogonal decomposition (POD) and modified linear stochastic estimation (mLSE) for the determining the flow velocities over an airfoil and correspondingly controlling the actuators of the airfoil.
2. Description of Prior Art
The present invention is based on a foundation laid by Taylor, J. A. and Glauser, M. N., 2002, Towards Practical Flow Sensing and Control via POD and LSE Base Low - Dimensional Tools, 2002 ASME Fluids Engineering Division, Summer Meeting, Montreal, ASME Paper FEDSM 2002-31416, To appear, J. Fluids Eng., March 2004, hereby incorporated by reference, that demonstrates in the “ActiveWing” facility that such methods could be used for state estimation from wall pressure alone. The background of the present invention is also premised on Glauser, M., Young, M., Higuchi, H., Tinney, C. and Carlson, 2004, H. POD Based Experimental Flow Control on a NACA -4412 Airfoil ( Invited ), 42nd AIAA Aerospace Sciences Meeting and Exhibit—AIAA 2004-0575, hereby incorporated by reference.
The ActiveWing facility consists of a backward ramp and a variable geometry flap mounted above the ramp. The adverse pressure gradient can be altered by varying the position of the flap. As the flap angle is raised from a position parallel to the ramp to fully raised, the flow transitions from a channel flow, through a point of incipient separation, and finally to a separated flow. The ActiveWing flow study was performed to investigate the benefits of developing low-dimensional descriptions using a general basis set which includes information from all flow states, as opposed to a basis set optimized for a particular flap angle. Taylor and Glauser found that a 5 mode POD model predicts incipient separation effectively. In addition a 5 mode POD/mLSE model for the system state estimate (from wall pressure alone) captures the general features of the velocity field/POD expansion coefficients, which is key for implementation of closed-loop control. While the ActiveWing facility is essentially an internal flow, the present invention encompasses methods that are applicable to the external flow over the NACA 4412 airfoil.
Siegel, S., Cohen, K. and McLaughlin, T., 2003, Feedback Control of a Circular Cylinder Wake in Experiment and Simulation ( Invited ), 33rd AIAA Fluid Dynamics Conference and Exhibit—AIAA 2003-3569, hereby incorporated by reference, demonstrated POD based feedback control for the external flow over a circular cylinder wake with excellent results indicating that such methods indeed work for external flows as well. This report, however, used inflow measurements and not the practical surface measurements of the present invention. The recent applications of POD/mLSE by Schmit, R. and Glauser, M., 2003, Low Dimensional Tools for Flow - Structure Interaction Problems: Application to Micro Air Vehicles, 41st AIAA Aerospace Sciences Meeting and Exhibit—AIAA 2003-0626, and Schmit, R. and Glauser, M., 2004, Improvements in Low Dimensional Tools for Flow - Structure Interaction Problems: Using Global POD, 42nd AIAA Aerospace Sciences Meeting and Exhibit—AIAA 2004-0889, hereby incorporated by reference, to a Micro Air Vehicle wing wake flow demonstrate the utility of using the mLSE method for external flows as well. These trials were able to estimate with reasonable fidelity the velocity field in the wake just from dynamic strain gages mounted on the flexible wing structure.
Glauser, M, Young, M, Higuchi, H., Tinney, C. and Carlson, H.POD Based Experimental Flow Control on a NACA -4412 Airfoil ( Invited ), 42nd AIAA Aerospace Sciences Meeting and Exhibit—AIAA 2004-0575, hereby incorporated by reference, showed that an estimation method works well for the NACA 4412 foil, and thus provide a key foundation for the present invention.
In 1967, Lumley, J. L., The structure of inhomogeneous turbulent flows , Atm. Turb. and Radio Wave Prop., Nauka, Moscow and Toulouse, France, Yaglom and Tatarsky eds., pp. 166-178 (1967), hereby incorporated by reference, proposed POD as an unbiased technique for studying coherent structures in turbulent flows. POD is a logical way to build basis functions which emphasize the energetic features of the flow (Holmes, P. J., Lumley, J. L., Berkooz, G., Mattingly, J. C. & Wittenberg, R. W., Low - Dimensional Models of Coherent Structures in Turbulence , Physics Reports, v. 287, pp. 337-384 (1997), hereby incorporated by reference). This results in a small number of the structures containing a large percentage of the system dynamics.
POD is a straightforward mathematical approach based on the Karhunen-Loeve expansion. It is used to decompose the velocity field 1 of 9 into a finite number of empirical functions, which can be used to ascertain a subspace where a model can be constructed by projecting the governing equations on it (Holmes, P. J., Lumley, J. L. & Berkooz, G., Turbulence, Coherent Structures, Dynamical Systems and Symmetry , Cambridge University Press (1996), hereby incorporated by reference). These functions, φ, are linearly independent and form a basis set chosen to maximize the mean square projection of the velocity field. The eigenfunctions are obtained from the following integral eigenvalue problem:
∫ R ij ( {right arrow over (x)},{right arrow over (x)}′ )φ j (n) ( {right arrow over (x)}′ ), d{right arrow over (x)}′=λ (n) φ 0 ( {right arrow over (x)} ). (1)
The kernel of equation 1 is the ensemble averaged two-point spatial velocity correlation tensor, R ij ( {right arrow over (x)},{right arrow over (x)}′ ), which is defined as
R ij ( {right arrow over (x)},{right arrow over (x)}′ )= ū i ( {right arrow over (x)},t o ) u j ( {right arrow over (x)}′,t o ) (2)
where to is a given time snapshot. The eigenfunctions of equation (1) give the optimal basis, and are termed empirical eigenfunctions since they are derived from the ensemble of the observations. The Hilbert-Schmidt theory ensures that if the random field occurs over a finite domain, an infinite number of orthonormal solutions can be used to express the original random velocity field, ui,
u
i
(
x
→
,
t
)
=
∑
n
=
1
∞
a
n
(
t
)
ϕ
i
(
n
)
(
x
→
)
(
3
)
where the coefficients are defined as,
α n ( t )=∫ D u i ( {right arrow over (x)},t )φ i (n)− ( {right arrow over (x)} ) d{right arrow over (x)} (4)
In 1977, Adrian, R. j., On the role of conditional average in turbulence theory , Turbulence in Liquids: Proceedings of the Fourth Biennial Symposium on Turbulence in Liquids, Science Press, Zakin, J. & Patterson, G., eds., pp. 323-332 (1977), hereby incorporated by reference, proposed the application of stochastic estimation to instantaneous data. Adrian recognized that the statistical information contained within the two-point correlation tensor, R i j, could be combined with instantaneous information to form a technique for estimating the flow field. Cole, D. R., Glauser, M. N. & Guezennec, Y. G., An Application of Stochastic Estimation to the Jet Mixing , Layer. Phys. Fluids, 4(1), pp. 192-194 (1991), hereby incorporated by reference, demonstrated this in the axisymmetric jet shear layer where they successfully estimated the velocity radially across the jet shear layer using information from only a few radial locations. Bonnet, J. P., Cole, D. R., Delville, J., Glauser, M. N. & Ukeiley, L. S., Stochastic estimation and proper orthogonal decomposition: Complementary techniques for identifying structure , Experiments in Fluids. 17 pp. 307-314 (1994), hereby incorporated by reference, expanded on the work of Adrian (1977) and Cole et al. (1991) to form the complementary technique which combines the POD and LSE to obtain the time dependent POD expansion coefficients from instantaneous velocity data on course hot wire grids.
Taylor and Glauser (2002, 2004) further expanded these methods and demonstrated how instantaneous wall pressure measurements could be used to construct an accurate representation of the instantaneous velocity field from wall pressure alone (i.e., the modified complementary technique or modified linear stochastic estimation (mLSE)). This approach can be applied to the POD using either the “conditional” or “global” POD eigenfunctions described above. Boree, J., Extended proper orthogonal decomposition: A tool to analyze correlated events in turbulent flows , Experiments in Fluids 35, pp. 188-192 (2003) and Fogleman, M., Lumley, J. L., Rempfer, D. and Haworth, D., Analysis of tumble breakdown in ic engine flows , To appear Physics of Fluids (2004), hereby incorporated by reference, apply a similar approach to engine cylinder flow, but the approach has not been used to determine the flow velocity over an airfoil, nor has it been used to control airfoil actuators.
3. Objects and Advantages
It is a principal object and advantage of the present invention to provide a method for using Proper Orthogonal Decomposition and Modified Linear Stochastic Estimation to determine the flow velocity over an airfoil.
It is an additional object and advantage of the present invention to provide a method for feedback control over airfoil actuator using Proper Orthogonal Decomposition and Modified Linear Stochastic Estimation to determine the flow velocity and a feedback loop.
Other objects and advantages of the present invention will in part be obvious, and in part appear hereinafter.
SUMMARY OF THE INVENTION
By using a combination of Particle Image Velocimetry PIV and multiple surface pressure measurements, processed through a POD/mLSE algorithm, estimates of the velocity field from wall pressure alone are extracted. From such estimates knowledge of the state of the flow above the airfoil can be obtained (i.e., attached, fully separated or incipiently separated). Integral to the POD/mLSE algorithm is the estimation of the global POD coefficients. The utility of these time dependent coefficients, which are estimated from surface pressure only, are demonstrated in a simple proportional feedback loop (as the time series to drive the actuators) to keep the flow attached. This methodology of the present invention is critical for implementation of realistic feedback flow control since surface measurements and not inflow measurements are required for practical applications. The methodology of the present invention also works well in connection with dynamic strain on flexible bodies, so the approach is not limited to estimation from pressure only.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic view of a low speed wind tunnel test according to the present invention.
FIG. 2 is an exploded view of a NACA 4412 Airfoil.
FIG. 3 is a side and a top view of a NACA 4412 Airfoil.
FIG. 4 is a schematic illustrating movement of the PIV window.
FIG. 5 is a profile of the mean velocities at a 16° angle of attack, N=840.
FIG. 6 is a profile of the mean velocities at a 15° angle of attack, N=840.
FIG. 7 is a profile of the mean velocities at a 14° angle of attack, N=840.
FIG. 8 is a profile of the mean velocities at a 13° angle of attack, N=840.
FIG. 9 is a time snap shot of the u and v components of the fluctuating velocity field at a 16° angle of attack.
FIG. 10 is a time snap shot of the u and v components of the fluctuating velocity field at a 15° angle of attack.
FIG. 11 is a graph of the convergence of POD eigenvalues for both conditional and global POD.
FIG. 12 is a graph of a reconstruction using 50 conditional POD modes for the fluctuating velocity snapshop at a 15° angle of attack.
FIG. 13 is a graph of a reconstruction using 50 global POD modes for the fluctuating velocity snapshop at a 15° angle of attack.
FIG. 14 is a graph of a reconstruction using 50 global POD modes with the mLSE method for the fluctuating velocity snapshop at a 15° angle of attack.
FIG. 15 is a graph of the airfoil surface pressure spectra at a 15° angle of attack.
FIG. 16 is a graph of the time resolved estimates of 4 global POD coeffiecients from airfoil surface pressure, measurements at a 15° angle of attack.
FIG. 17 is a graph of the first POD coefficient estimated from wall pressure (no control) modulating 2000 Hz wave for angle of attack from 12-15 degrees (used to drive actuators).
FIG. 18 is a graph of the first POD coefficient estimated from wall pressure (with control) modulating 2000 Hz wave for angle of attack from 12-15 degrees (used to drive actuators).
DETAILED DESCRIPTION
The present invention uses the mLSE method to compute the POD velocity coefficients above the airfoil using discrete pressure measurements taken on the airfoil surface, i. e., the conditional structure is the random POD coefficient, a n (t) and the conditions are the wall pressure. The present invention uses the time dependent information provided by equation (3) of the POD to develop the low-dimensional descriptions of the flow. It is essential to have knowledge of the flow field at all points in space simultaneously so that the required projection can be executed to obtain the time dependent expansion coefficients from the POD. Through the POD method, most of the flow's kinetic energy can be captured in a small number of modes, enabling accurate characterization of the physics in a low-dimensional model.
The POD method is applied to the flow in two distinct ways. First, POD is used to solve each flow state (angle of attack) separately. The kernel that is used to solve equation 1 of the POD is:
R i j ( {right arrow over (x)},{right arrow over (x)}′,t o ,α)= u i ( {right arrow over (x)},t o ,α) u j ( {right arrow over (x)}′,t o ,α) . (5)
This can be thought of as a conditional (at a given angle of attack, Reynolds number) application of the POD. The second approach to the problem is to average over the individual flow states. This method uses a kernel of the form:
R i j ( {right arrow over (x)},{right arrow over (x)}′,t o )= u i ( {right arrow over (x)},t o ) u j ( {right arrow over (x)}′,t o ) . (6)
The advantage to this method is that the eigenfunctions obtained are richer in the sense that that know about multiple states of the flow, which, for example may include flow states at different angles of attack, different Reynolds numbers and with/without control inputs. This approach has been termed the global POD. Substituting either the conditional or global kernel into equation (1) provides the desired basis functions.
Since both the fluctuating pressure and the random POD coefficients are integrated quantities, the correlation between them is strong and the method makes sense from a physical standpoint. The instantaneous wall pressure is used in equation (7), shown below, to obtain ã n the estimate of the random POD coefficient that describes the velocity field over {right arrow over (x)} given the instantaneous surface pressures, p i (t).:
ã n ( t )= a n ( t )| p ( t ) (7)
The estimated random coefficients for each POD mode can be described as a series expansion using the instantaneous surface pressures available at i positions on the airfoil surface:
ã n ( t )= B n1 p 1 ( t )+ B n2 p 2 ( t )+ . . . + B nq p q ( t ). (8)
Truncating this expression to include only the linear term (plus the error associated with neglecting the higher order terms) results in:
ã n ( t )= B ni p i ( t )+ O[p i 2 ( t )]. (9)
The coefficients are considered to be the conditional structures of the flow, and they effectively describe a certain percentage of the energy contained in a certain spatial POD mode. The elements of B ni are chosen to minimize the mean square error,
e ã n =[ ã n ( t )− a n ( t )] 2 ã n ( t )− a n ( t )] 2
by requiring that
∂
ɛ
a
~
n
∂
B
ni
=
∂
[
B
ni
p
i
(
t
)
-
a
n
(
t
)
]
2
_
∂
B
ni
=
0
The solution to the minimization problem of equation (9) is a linear system of equations, which can be written in matrix form as:
[
〈
p
1
2
〉
〈
p
1
p
2
〉
⋯
〈
p
1
p
q
〉
〈
p
2
p
1
〉
〈
p
2
2
〉
⋯
〈
p
2
p
q
〉
⋮
⋮
⋱
⋮
〈
p
q
p
1
〉
〈
p
q
p
2
〉
⋯
〈
p
q
2
〉
]
[
B
n
1
B
n
2
⋮
B
nq
]
=
[
〈
a
n
p
1
〉
〈
a
n
p
2
〉
⋮
〈
a
n
p
q
〉
]
The elements B ni are then substituted into equation (9) to estimate the random POD coefficient for each instantaneous pressure measurement. These coefficients when combined with the POD eigenfunctions provide an estimate of the instantaneous velocity field, u i from application of equation 3.
For flow control studies, the present invention uses the mLSE method to provide the state of the flow from wall pressure only. This provides one method for monitoring the system state with physically realizable input from practical wall sensors. The estimated coefficients obtained from equation (9) may then be used as a time series to drive airfoil actuators via a simple proportional feedback loop.
EXAMPLE
The present invention was tested in the subsonic wind tunnel facility at Syracuse University, which consists of a Gottingen-type, closed, recirculating design with the flow loop arranged in a horizontal configuration. The test section, 24 in (w)×24 in (h)×96 in (1), was made of optical plexiglass panels and is illustrated with the full experimental test section 10 in FIG. 1 . The speed in test section 10 is continuously variable from less than 10 ft/s to greater than 230 ft/s.
A NACA 4412 airfoil 12 with an 8 inch chord was selected for the experiments. The test model was designed to meet several requirements. It had two-dimensional with a constant chord length and included an airfoil section geometry along the span. The model size was chosen to avoid significant blockage in the 2 ft.×2 ft. wind tunnel test section. Actuator sections 14 and pressure transducers 16 were configured in a modular fashion to enable rearrangement when required. Three-dimensional effects from tip vortices and the tunnel walls are reduced to a negligible level by locating the measurement window far enough from the ends of airfoil 12 and wall of test section 10 . The wing span was 2 ft., thus covering the entire width of the test section 10 . Pressure and PIV measurements were taken at a mid-span plane where the flow is assumed to be two dimensional.
Results were obtained at a free-stream velocity of 40 ft/s, corresponding to a Reynolds number of 170,000, based on chord length. Measurements were obtained at four angles of attack: 13°; 14°; 15° and 16° which corresponds to a fully attached (13° & 14°), incipiently separated (15°) and fully separated flow state (16°). For each angle of attack, 840 statistically independent samples 3 of 9 were obtained. Each sample included a measurement of all three components of velocity using a DANTEC FLOWMAP Stereo PIV System setup to capture data in an x-y (streamwise-spanwise) plane above airfoil 12 . Concurrently, the dynamic pressure was measured at eleven locations along the chord.
The output signals of pressure transducers 16 were sampled at a rate of 4 kHz using a NATIONAL INSTRUMENTS PXI-based 800 MHz signal conditioner with dedicated 24 bit high-resolution AID converters and anti-aliasing filter. The PXI A/D system has an internal trigger for simultaneous sampling between channels, ensuring that all the pressure measurements acquired are synchronized. It also has an external trigger to temporally link pressure measurements and PIV velocity measurements. With each laser pulse, corresponding to one snapshot of the flow, a signal is sent from the PIV processing unit to the PXI and a marker is inserted in the continuous stream of pressure data. The phase-aligned information (velocity field and pressure at the surface of the wing) is input to the POD/mLSE algorithms. The PIV system is composed of two CCD cameras 18 (1280×1024 pixels) and an associated mount 20 , a pair of pulsed NEWWAVE RESEARCH 200 mJ Nd:YAG lasers 22 , a laser sheet 24 , and a post-processing unit (not shown). A TSI olive oil based seeder (not shown) was used to produce spherical liquid particles with diameters between 1 and 51 μm, which would follow the fluctuations in the flow. The seeding was introduced directly downstream of airfoil 12 and was allowed to circulate through test section 10 before measurements began.
Laser sheet 24 lit a plane in the flow 26 through test section 10 , and cameras 18 photograph the illuminated particles from two different angles. The post processing unit combines the 2D information from the snapshots and extracted the three components of velocity in the plane. From two successive measurements, the displacement of the particles was calculated, and the velocity was computed using the elapsed time between the two snapshots.
Given the thickness distribution of airfoil 12 , the most accessible location for actuators sections 14 were in the first 10 to 30 percent of the chord. This is a good choice of location for actuation based on the boundary layer location as well. The wing was machined from aluminum and divided along the span into three sections, a center section of 9 in. sandwiched between two 7.5 in. outer sections. These three main pieces are held in position with pins 28 and fastened together by a threaded rod 30 , as shown in FIG. 2 . The angle of attack must be continuously variable, covering a range from attached to separated flow. Therefore, airfoil 12 was hinged on the sides of test section 10 using a hollow tube as an exit guide for the wires and tubing. Each of the two outer sections contained a 5.6 in. long modular segment that housed three actuators 14 . The center section was comprised of a similar segment that is 8.75 in. long, in addition to a 5 in. wide segment for the dynamic pressure transducers and static pressure ports. FIG. 3 illustrates a top view of airfoil 12 .
A pressure sensor insert section 32 contained eleven dynamic pressure transducers 16 with accompanying static pressure manifolds, distributed at equidistant locations along the chord. The eleven dynamic pressure transducers 16 were spaced evenly from x/c=0:29 to x/c=0:78 with a δx/c spacing between each transducer 16 of 0.049. This leaves the remaining space for actuator insert sections 14 (see FIG. 3 ). Pressure transducers 16 embedded in the wing measure the fluctuating surface pressure on the model, providing data for the system state estimate via POD/mLSE. Transducers 16 were ICP pressure sensors from PCB Piezotronics. They have a 2 psig measurement range, a 0.02 mpsig resolution, 4 of 9 and a bandwidth of 5 Hz-13 kHz. The sensors are miniature air turbulence sensors (0.375 in. diameter, 0.22 in. height) and were chosen because of their response characteristics. Due to space constraints in the airfoil, the small size was necessary.
The control input consisted of eleven small oscillatory jets near the leading edge of the airfoil, produced by vibrating speakers on the surface. To avoid three dimensional effects, actuator output should be invariant in the spanwise direction. This is achieved with a small 1/32 in. wide slot in the actuator section 14 for the airfoil. The speakers chosen are ICC FNTERVOX shielded low leakage speakers. The selected speakers are 1.12×1.57 in, with depth of 0.44 in and rated power is 1.0/2.0 W (Nom/Max). These speakers have the advantage of covering a wide range of frequencies (250 200 kHz) while maintaining a significant velocity at the exit of the slot.
The full setup of the system was designed to allow for future experiments where airfoil 12 will pitch dynamically. In determining feasible options, much consideration was taken in deciding how to keep cameras 18 in line with airfoil 12 at all times. Since the area of focus of cameras 18 correspond to the computational domain used for POD/mLSE computations, the camera domain was fixed in the airfoil coordinate so that cameras 18 followed the movement of airfoil 12 ( FIG. 4 ). Camera mount 20 was linked to the hinge of airfoil 12 , to allow airfoil 12 and cameras 18 to rotate in unison about the same axis. Laser 22 was fixed in space and positioned on a tripod 34 in front of test section 10 , as shown in FIG. 1 .
FIGS. 5 , 6 , 7 and 8 present the mean velocities at α=16°; 15°; 14° and 13°, respectively, of the {tilde over ( )}u and {tilde over ( )}v components of the velocity field. These profiles have been created from an ensemble average of 840 stereo PIV vector measurements. From these figures, it is clear that the flow is attached for α=13° and 14°, incipient for α=15° and fully separated for α=16°.
FIGS. 9 and 10 are instantaneous snap shots at α=16° and 15°, respectively, of the fluctuating u and v components of the velocity field. The α=15° snapshot is rebuilt using both the conditional and global POD to get a sense of the low dimensionality of the flow. The mLSE is used to demonstrate the ability of the present invention to reconstruct the flow in the incipient state from airfoil surface pressure. Applications of conditional and global POD FIG. 11 shows the convergence of the POD eigenvalues from application of both the conditional POD for angles α=15°; 14° and 13° as well as the global POD which include knowledge of all 3 angles. α=16° is not included since it is desirable to utilize feedback control before the flow reaches the fully separated state. Only the fluctuating u and v components of the velocity in the tensor are used.
The plots on the upper portion of the graph are the cumulative sum of the eigenvalues and those on the lower part are the individual contributions of the eigenvalues to the total energy, both relative to the total energy. Note that the conditional POD applications converge slightly more rapidly than the global for all conditions, however the global are a richer set of eigenfunctions and can be used for all 3 angles.
FIG. 12 shows a 50 POD mode reconstruction of the snapshot shown in FIG. 10 (the incipient condition) using the conditional POD. A 50 mode reconstruction (out of a total of 1820 POD modes) provides a nice representation of the actual snapshot indicating that the flow is low-dimensional. FIG. 13 shows a 50 POD mode reconstruction of the snapshot shown in FIG. 10 using the global POD. One can see that fifty global POD modes provides a nice representation of the actual snapshot. This result is also quite similar to that from the conditional application shown in FIG. 12 .
From these results we conclude that this flow is low dimensional and that the global POD modes provide a suitable basis which can be used for all 3 angles of attack. These global POD eigenfunctions are next used in the mLSE method.
FIG. 14 shows a 50 POD mode reconstruction of the snapshot shown in FIG. 10 using the global POD with the mLSE method which uses airfoil surface pressure only. The general features of the snapshot are captured with this estimate. This is consistent with the results of Taylor and Glauser (2002, 2004), who demonstrated in the ActiveWing facility that such methods could be used for state estimation from wall pressure alone (airfoil surface pressure for the NACA 4412).
As seen above, the mLSE method provides a reasonable estimate of the velocity field above the airfoil. The next step is to close the feedback loop using these low dimensional estimates based on the global POD eigenfunctions. As a first step, the POD coefficients obtained from equation 9 are used as a time series to drive actuator sections 12 via a simple proportional feedback loop. Estimates of these coefficients are obtained from the time dependent airfoil surface pressure only, processed through the POD/mLSE algorithm. Thus, an error is defined between the estimated time dependent global POD coefficients at the incipient condition (15°), and the RMS of these coefficients at the fully attached condition (13°): the desired state. This can be written as
ε( t )= a (n) ( t ) 15 −RMS( a (n) ( t ) 13 )
Actuators 16 will then be driven according to:
Act input =A ε( t )sin(2 πf o t ) (10)
where the amplitude A can be selected based on open loop results. The time series from the estimated global POD coefficients are thus being used to amplitude modulate, since actuators 14 are driven continuously at a value of f o , which is selected based on the optimal operating characteristics of actuators 14 . The speakers are best operated at frequencies above 200 Hz but typical flow separation events are at a much lower bandwidth (20-40 Hz range) as can be seen in the surface pressure spectra shown in FIG. 15 . Hence, amplitude modulation provides the necessary lower frequency flow excitation for the current experiment.
Equation 10 is written for a given POD mode n. A decision must be made as to which particular n to select in the formula
ε( t )= a (n) ( t ) 15 −RMS( a (n) ( t ) 13 )
FIG. 16 shows the time series for the first 4 estimated POD coefficients at the incipient condition (α=15°). As can be seen from these time series, it appears that global POD mode 1 is the best candidate since it has the largest amplitude and the lowest frequency information. The experiments described below relate to an airfoil where feedback is applied using the results from equation 10 with n=1. The POD coefficients are estimated from surface measurements, which alone are necessary for practical feedback flow control.
FIG. 17 shows the first POD coefficient estimated from surface pressure only(with no actuation), low pass filtered at 100 Hz, modulating the 2000 Hz wave (which we drive the actuators at in this case) for AoA from 12-15 degrees. FIG. 17 illustrates several key points.
First, the RMS amplitude of the estimated POD coefficients increases with the AoA, as it senses the incipient separation and the growing structures in the boundary layer. The dated is gleaned from surface pressure, a practical variable to measure, and then processed through the POD/mLSE algorithm. The growing amplitude with the angle is a necessary criteria for the control method to be possible. The control will be robust, since the separated flow at 16 degrees has a significantly larger amplitude than that at the lower angels of attack, showing the onset of separation signature. Even if the flow separates, the control will grow larger and will be able to reattach the flow.
Second, the modulation frequency estimated from the POD/mLSE method is within the proper frequency band for the boundary layer scales (compare for example to the pressure spectra shown in FIG. 15 , in particular the band between 50-100 Hz).
Hence, from the estimated POD coefficient the relevant amplitude and frequency information for driving the actuators in a feedback flow control loop are being provided.
This information may next be utilized in a proportional feedback control loop. FIG. 18 shows the first POD coefficient estimated from wall pressure, low pass filtered at 100 Hz modulating 2000 Hz wave with the actuators on being driven by this POD coefficient. At 12, 13, 14 degree AoA, the actuation has little effect on the flow if the RMS in this Figure is compared to FIG. 17 . This results stems from the fact that the amplitude is being properly tracked and, since the flow is not in the incipient condition, the amplitude is low. At 15 degrees, the actuation does decrease the amplitude of the coefficients, a necessary criteria for the control to be stable. Incipient conditions up to 17 deg AoA are maintainable (see RMS still lower than that of FIG. 16 , separated as shown in FIG. 17 , without optimizing the actuation and with a rather low RMS output from the speakers.
|
A method of measuring the state of flow above an airfoil using an estimation of the velocity field based on a combination of Particle Image Velocimetry PIV and multiple surface pressure measurements processed through a POD/mLSE algorithm. Integral to the POD/mLSE algorithm is the estimation of the global POD coefficients. The utility of these time dependent coefficients, which are estimated from surface pressure only, are demonstrated in a simple proportional feedback loop (as the time series to drive the actuators) to keep the flow attached. This method requires realistic feedback flow control since surface measurements and not inflow measurements are required for practical applications. The estimation method works well with dynamic strain on flexible bodies and is not limited to estimation from pressure only.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to surface cleaning vehicles, and more particularly to a combined single and twin power system for independently driving sweeping machinery of a surface cleaning vehicle.
2. Description of the Related Art
Street cleaning vehicles are well known in the art having mechanical conveying systems, either in the form of a conveyor elevator that drags collected debris up an inclined ramp or via an inclined conveyor belt. The discharge from the conveyor is deposited into a hopper that is provided with a tipping mechanism for discharge.
Street cleaning vehicles employing pneumatic conveying systems are also well known in the art, and fall into two categories, vacuum and regenerative. Both categories of machine employ an exhauster fan to induce high velocity airflow for conveying the debris through a conduit. Regenerative machines additionally utilize the exhauster fan to aid the collection system, whereas vacuum machines do not.
In general, pneumatic conveying systems have a much greater power requirement, as compared to mechanical conveyors, as a result of using the exhauster fan to perform the debris collection and conveying functions. The power requirement for driving the brooms is similar for both types of machines.
The conveying system may be driven either by the prim mover engine used to propel the vehicle—referred to herein as ‘Single’, or by utilizing a separate engine—referred to herein as ‘Twin’.
Single mechanical machines utilize the vehicle's prime moving engine to drive the sweeping mechanisms. More particularly, the sweeping and conveying equipment is hydraulically driven by a pump or pumps coupled to the prime mover engine via a disconnectable power-take-off. The engine and transmission forming part of the carrier vehicle, require little or no change to the driveline and produce sufficient power for the sweeping mechanisms when running at low engine speeds that occur when driving the vehicle slowly, for example at less than 5 MPH (8 km/h). The single machine design enjoys the perception of simplicity in terms of construction and operation. The only criterion of the single design is that, at low speeds, the prime mover engine provides sufficient power to drive the sweeping equipment and perform effectively (i.e. when the vehicle is being driven slowly. Machines of the ‘single’ type have been to be best suited to municipal operations associated with lighter duty street cleaning operations where the machine provides adequate performance (e.g. 40 to 50 Horsepower (30 to 40 kilowatts)) at low operating costs.
Pneumatic machines often incorporate the aforenoted second engine, or ‘twin’ configuration, to drive the sweeping equipment. More particularly, the sweeping and conveying equipment is driven by a mechanical transmission or by a fluid power mechanism powered by a pump or pumps coupled to the second engine. Although there are examples of single engine pneumatic machines, these machines employ auxiliary driveline systems using hydrostatics and/or mechanical gearboxes to enable power to be extracted from the engine at higher speeds whilst maintaining slow sweeping speeds. These modifications greatly increase the cost and complexity of the machine. Moreover, a prime-mover engine of higher than usual power is often required, which tends to further increase the initial cost.
In general, the driveline configuration requirements of the carrier vehicle for a ‘mechanical’ machine are similar to those of a normal commercial transport vehicle with automatic transmission. The vehicle specifications are similar for both the single and twin designs.
The twin design offers more flexibility than the single design in terms of operating modes, since there are no requirements of the prime-mover engine in terms of power or speeds. The sweeping and conveying functions operate independently of how the vehicle is driven, which vary according to the conditions of work (i.e. stop, start, forward, reverse, slow, fast, etc.). By using a second engine, it is possible to design a twin machine with higher sweeping and conveying performance on a given type of vehicle than would be possible with a similar power rating of prime mover engine of single machine design. The flexibility in operation and corresponding sweeping performance are the major advantages of the twin design. These advantages make the twin design best suited to duties associated with industrial activities, road construction and where heavier duty sweeping conditions prevail. The disadvantages are that the machine incurs additional operational costs for fuel and maintenance and there is a perception of increased complexity over single machine design, as a result of using two engines.
SUMMARY OF THE INVENTION
It is an aspect of the present invention to provide a combined single and twin power system for independently driving sweeping machinery of a surface cleaning vehicle. According to the invention, both the single and twin designs are combined into one machine with a selectable mode of operation. The benefit to the operator is the ability to work in the lower cost single mode for most of the time, with the option to switch to twin mode for heavy-duty sweeping tasks (e.g. seasonal tasks such as spring cleanup following winter gritting, or in emergency situations).
Preferably, an hour and distance counter is provided to record the operation when working in either single or twin mode. This allows a contractor to use a variable scale of charges according to the type of work and conditions contracted to.
These together with other aspects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of a surface cleaning vehicle having a mechanical sweeping apparatus operable in single and twin operating modes, according to a preferred embodiment of the invention.
FIG. 2 is a schematic block diagram of the drivelines from the prime mover engine and from the second engine and the fluid-power link to the sweeping equipment system, for the vehicle of FIG. 1 .
FIG. 3 is a schematic diagram of the electrical control system for discrete operation of either single or twin modes, for the vehicle of FIG. 1 .
FIG. 4 is an elevation view of a surface cleaning vehicle having a pneumatic vacuum sweeping apparatus operable in combined single and twin operating modes, according to a first alternative embodiment of the invention.
FIG. 5 is an elevation view of a surface cleaning vehicle having a pneumatic regenerative sweeping apparatus operable in combined single and twin operating modes, according to a second alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 , a base vehicle is provided with a commercially available truck chassis 1 with prime-mover engine. According to the preferred embodiment, a truck is provided having a gross vehicle mass of nominally 15000 kilograms, a prime mover engine of greater than 175 Horsepower (130 kilowatts) at 2200 rpm, and a torque converter coupling between the engine and transmission. Automatic transmission is provided which, when coupled with the rear axle ratio, allows the vehicle to be driven at slow speed (e.g. 2 MPH (3 km/h)).
A second, ‘twin’ engine 2 is provided, having sufficient power (typically 60 Horsepower (45 kilowatts)), to drive sweeping equipment including scarifying brooms 3 and 4 , and conveyor elevator 5 . The debris is deposited from conveyor 5 into a hopper 6 , in a well known manner.
Referring to FIG. 2 , the vehicle driveline is shown comprising a prime mover engine 20 , torque converter 21 and automatic transmission 22 connected to a propeller shaft 23 . The propeller shaft is connected to a rear axle for driving the rear wheels of the truck. The driveline components are connected to the main functional components of the mechanical sweeping equipment and fluid power systems 24 , which are common for the single and twin operating modes. The only variance is that power to the systems 24 is provided either by the single or twin fluid power pump/s 25 via shuttle or check valves 26 . The control system of FIG. 3 operates the pump/s 25 , ensuring that only one pump 25 can be in operation at any particular time. As illustrated, power-take-off (PTO 27 ) is included, with engagement and disengagement of the PTO 27 under dynamic conditions, to power the sweeping equipment fluid power pump/s 25 .
The pumps 25 in both systems can be variable displacement units with control mechanisms to deliver a uniform flow once a minimum operating speed has been met. Alternatively, the pump/s 25 coupled to the second engine can be of fixed displacement design.
The ‘single’ operation component has an additional control to the prime mover engine, to increase its low idle speed to nominally 900 rpm when the PTO 27 is engaged. At this speed, the engine 20 has sufficient power to drive the pump 25 and not be prone to stalling once the accelerator foot pedal is fully relaxed. The pump is configured to deliver a predetermined flow of fluid, so that any increase in speed above this setting does not increase the fluid flow. The above-described additional control to the prime mover engine for increasing the speed function is a feature of the carrier vehicle and is offered in the supplier's specification when auxiliary equipment is to be driven. Typically an electrical connection from the sweeper control (in this case by the master stop/start switch via the mode select switch, discussed in greater detail below with reference to FIG. 3 ) is made to the engine's ECU (Electronic Control Unit) to effect the operation. Similarly, a parallel connection is made to engage the PTO function to drive the pump/s 25 as indicated in FIG. 3 .
At the low engine speed of 900 rpm the torque converter 21 only delivers a portion of its normal torque capability. The application of the vehicle's braking system can be administered to arrest it in order to achieve very low vehicle creeping speeds or static condition when the transmission is in its lowest gear by stalling the converter 21 .
In this working condition, the vehicle's speed is controlled in a similar fashion to that of a regular transport vehicle by means of an ‘accelerator’ foot pedal that can vary the engine speed throughout the normal speed range, or by the application of the brakes. Increasing the engine speed not only delivers more engine power but also increases the torque capacity of the converter 21 and allows the vehicle to be propelled up inclines. By employing the variable displacement pump with a control that maintains a constant flow, increasing the engine speed does not increase the fluid flow or the power requirement to drive it. Therefore, the pump 25 is capable of operating throughout the engine's entire speed range.
For the twin mode of operation, the second engine 2 and fluid power pump/s 25 are matched in terms of speed and power etc. to deliver a similar or preferably a greater fluid flow when compared to the single mode of operation. In the twin operating mode, the second engine 2 is set to run at a set speed and the vehicle may be driven in the normal fashion at any speed.
As discussed above, a feature of the present invention is that it is only possible to operate the vehicle in either the single or twin mode but not in both modes simultaneously.
FIG. 3 shows the electrical control system for operating the PTO 27 or the second engine 2 . Two switches are employed: a master switch and a two position mode selector for switching between single and twin modes of operation.
The master switch has three positions ( 0 ) Off, ( 1 ) Run and ( 2 ) Second-Engine-Start or PTO engagement. For position ( 2 ) the switch is ‘Hold to Run’ and once released springs back to position ( 1 ). Switching from position ( 0 ) to position ( 1 ) provides power to either the engine 2 or the PTO 27 depending on the position of the selector switch. Switching to position ( 2 ) either starts the engine 2 by-way of its starter motor or engages the PTO 27 and increases the engine idle speed. A latching relay is provided to hold the PTO 27 in engagement with increased engine speed once energized. When the mode selector switch is returned to position ( 0 ), the power is severed to whichever of the engine 2 or PTO 27 is in operation at the time, and the engine 2 either shuts-down or the PTO disengages 27 accordingly.
Power to the master start/stop switch is received from the carrier vehicle power supply, once its ‘ignition key’ or isolation switch has been activated.
Operating the mode selector switch when one of the systems is in operation also has the same effect as shutting-down. To start-up in a new selected mode, it is necessary to reactivate the master switch to position ( 2 ).
This control feature is also extended to the condition when the carrier vehicle's ignition key is switched-off, in which case it is necessary to activate the master switch to initiate machine operation once the ignition key switch has again been switched to the ‘on’ position.
This re-start feature has been implemented in the design to avoid the condition of an unexpected start-up in the event that the mode selector is inadvertently disturbed, or following a situation where the vehicle's ignition key switch is turned-on and the prime mover engine started with master switch set in the run ( 1 ) position.
Whilst it may be inferred from the foregoing that application of the present invention may not be practical in pneumatic machine, there is no technical impediment to such application, although cost may be a disincentive in some circumstances. The invention is, nonetheless, equally applicable to both mechanical surface cleaning machines, as shown in FIG. 1 , or pneumatic surface cleaning machines as shown in FIGS. 4 and 5 .
FIG. 4 depicts a surface cleaning machine with vacuum-operated sweeping apparatus, according to a first alternative embodiment. A tipping hopper 41 is mounted to the truck chassis for collecting and, upon tipping, discarding collected trash. The sweeping arrangement includes a gutter broom 42 and main broom 43 for directing debris toward a pick-up nozzle 45 of a suction conveyor duct 44 . A vacuum wander hose 46 is also provided, as is known in the art. A vacuum suction fan is selectively operated either in single mode, or via an auxiliary engine power unit 47 for twin mode, as discussed above in connection with FIGS. 2 and 3 .
FIG. 5 depicts a surface cleaning machine with regenerative air sweeping apparatus, according to a second alternative embodiment. The sweeping arrangement includes gutter brooms and pick-up head 51 selectively operated either in single mode, or via an auxiliary engine power unit 52 for twin mode, as discussed above in connection with FIGS. 2 and 3 . Debris directed by the brooms and pick-up head 51 is drawn into hopper 55 via a combination blower/suction fan and air blast discharge duct 54 . A vacuum wander hose 53 is also provided, as is known in the art. The tipping hopper 55 is mounted to the truck chassis for collecting and, upon tipping, discarding collected trash.
The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the invention that fall within the true spirit and scope 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 illustrated and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
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A surface cleaning vehicle is provided with hydraulically driven sweeping machinery. The vehicle comprises a truck chassis for carrying the sweeping machinery and a prime mover engine for propelling the vehicle. A second engine is connected to said chassis, and first and second pumps and associated check valves are connected to respective ones of the prime mover and second engines for driving said sweeping machinery. A control mechanism is provided for selectively connecting only one of the prime mover engine or second engine to drive the sweeping machinery.
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BACKGROUND OF THE INVENTION
The present invention is directed to a temporary supporting device for plate-like workpieces, such as sheets of paper or cardboard, within a delivery station of machine that is processing these workpieces.
A machine for processing sheet-like workpieces usually includes an infeed station in which a pile of sheets is arranged. Each sheet is successively taken from the top of the pile in order to be carried onto a feeding table. Once on the feeding table, every sheet is positioned against from lays and side-marks prior to being seized on its front edge by a series of grippers mounted on a crosswise bar, whose ends are attached to a pair of lateral continuous chains which are arranged for transferring the bar and sheet in succession through the processing stations. The processing stations can consist of a die-cutting press, which is then followed by a waste stripping station. These processing stations are followed by a delivery station in which every sheet is released by the grippers end is aligned when dropping on top of a stack or pile being formed on an outlet pallet. This pallet is carded by a plate-like elevator which is lowered as the pile grows in order to keep the top of the pile at a constant level with regard to the machine or device.
When the outlet pile has a predetermined number of sheets, a temporary supporting device is inserted in the path of the dropping sheets in order to support the next sheets as the pile on the pallet is removed. In the meantime, the elevator is brought back to ground level and the full pallet is removed prior to being replaced by an empty pallet. The plate is then raised again until the empty pallet takes over supporting the weight of the new pile which is being built up, at which time the temporary supporting device is retracted to deposit the temporary pile on the pallet.
A known semi-automatic supporting device includes a horizontal track or cradle, for example a frame which carries a pair of lateral grooves, one on both sides of the pile. This device includes a so-called non-stop grid or grate which is made of a plurality of parallel and horizontal forks which are held together with crossbars connected to two lateral lengthwise beams. These lengthwise beams have, moreover, a plurality of outer rollers engaged in the grooves of the track or cradle. This arrangement allows for a manual movement of the grid in the tracks of the cradle in order to place it in direct alignment with the passage of the sheets or to move it to a retracted position to withdraw it from the path of the sheets being delivered. The cradle can be moved in translation by a vertical jack slowly downward in the course of the building up of the temporary pile on the engaged grid and quickly upward with the grid in a disengaged position for coming back to a starting position for the cradle.
It has appeared, however, that the grid in its disengaged or retracted position, although functioning satisfactorily, will protrude from the delivery station and could become an almost permanent danger for inattentive operators who could hurt themselves on it. This danger is also present if the grid is not completely engaged when being used, as in the case for the delivery of small-sized sheets and, therefore, partially protrudes from the delivery station.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a supporting device which is more discreet for the full security of the operator and remains, at the same time, efficient and easy to handle.
These objects are achieved in a device which includes a non-stop grid or grate which is able to be moved horizontally forward and backward in a cradle between s position for receiving workpieces being delivered at the delivery station and a retracted position allowing passage of the workpieces onto a pallet disposed on the delivery elevator. The improvements are that, when moved to a retracted position, a portion of the grid can be partially separated from the cradle in order to allow for a complementary rotary movement that will bring the grid into a vertical position for storage. Preferably, the grid is rotated around a front edge and it takes up a position extending parallel to a side face or wall of the station. If the grid is lowered around one of its lateral lengthwise beams, it then makes up a conventional barrier very visible and, hence, less dangerous.
According to a preferred way of constructing the device, the lateral lengthwise beams supporting the grid have two pairs of outer rollers, with a front pair and a rear pair, which are engaged in two groove-like tracks arranged in the cradle on either side of the pile. More specifically, the inlet end of the grooves has an upwardly opening aperture designed to allow removal of the rear pair of rollers so that the grid can then be able to be rotated and lowered around a point or axis of rotation defined by the front rollers.
When it is foreseen that the upstream adjustable aligning member or square is also provided with a stop for the positioning of the front part of the grid, the grooves of the cradle have a length greater than the length of the grid by 20% to 30%. Thus, for small-sized sheets, the grid or grate will remain entirely within the delivery station in such a way that the grid will always remain harmlessly protected in the cradle.
In an advantageous embodiment, the downstream edge or end of a lateral wall of the cradle has a dampening device for the positioning of the lengthwise beams of the grid when in the stored or completely retracted position.
Other advantages and features of the invention will be readily apparent from the following description of the preferred embodiments, the drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view with portions broken away of the temporary supporting device of the present invention disposed in a delivery station of a device;
FIG. 2 is a partial cross sectional view taken along the line 11--11 of FIG. 1 with portions in elevation for purposes of illustration;
FIG. 3 is a top plan view of an inlet end of the groove; and
FIG. 4 is a perspective view of the downstream end of a delivery station with the grid in the disengaged or stored position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The principles of the present invention are particularly useful when incorporated in a delivery station, generally indicated at 100 in FIG. 4. The delivery station 100 forms a pile 2 (see FIGS. 1 and 4) of plate-like workpieces that rest on a transport pallet 6, which is usually made out of wood. The pallet 6 is carried by an elevating plate 8 of an elevator which is raised and lowered by conventional means such as a chain 101 of FIG. 4.
The delivery station 100 includes a movable cradle 30, which supports a non-stop grid or grate 10 that receives a temporary pile 4 (see FIG. 1) of plate-like workpieces which will accumulate on the grid or grate after an ultimate recentering by means of a downstream guide 3, an upstream guide 3' and lateral or side guides 3". These guides are adjustable based on the size of the sheet. When describing items as "downstream" and "upstream", it should be noted that the workpieces forming the pile are entering the station in FIG. 1 in the direction of arrow 102.
More precisely, the movable cradle 30 is a frame made out of two lateral vertical walls 32 with each wall having a horizontal section with a vertical section at an upstream end of the horizontal section. The two walls are joined together on an upstream side by a horizontal reinforcing plate 33 and by a crosswise vertical wall 34. This cradle 30 is movable vertically along two guides 40 which are part of the frame of the station and are located opposite the upstream vertical section or part of the lateral wall 32. This guiding is principally obtained in the vertical direction by spaced pairs of rollers 44 belonging to the cradle 30 engaging on the guides 40, and the guide 40 has rollers 42 engaging on the lateral walls 32. The cradle 30 is moved along the vertical guides by a jack 20 which acts between a floor or base and a fastening point mounted on an offset portion 34' of the upstream wall 34.
As best illustrated in FIGS. 1 and 4, the non-stop grid 10 consists of a plurality of parallel forks 11 which are oriented in a sheet travelling direction 102. These forks 11 are linked or interconnected at their downstream end by a first crossbar 13 and on their other end by one or several complementary crossbars 16. The ends of these crossbars are secured on two lateral lengthwise beams 12 to form a rectangular grid. A handlebar 15 is mounted in the middle of the first crossbar 13.
Each of the lengthwise beams 12 has a pair of rollers 14. As best illustrated in FIG. 2, each roller 14 is formed by a roller bearing 70 which is received on an axle formed by a boll 72 and centered between the head of the boll and the lengthwise beam by distance pieces or spacers 76. The bolt 72 is secured on the lengthwise beam 12 by a nut 74. Moreover, these rollers 14 are engaged on either side of the pile 2 in a horizontal groove arranged along the upper edge of each of the two lateral walls 32 of the cradle 30.
In the way of realizing without limiting, each groove is shaped as a horizontal border or flange 36 which ends the lateral wall 32 and consists, on its lower part, of a roller track 50 mounted on the wall by means of a plurality of bolts 52, which plurality is illustrated in FIG. 1. As best illustrated in FIGS. 1 and 3, the downstream end of the groove formed by the flanges 36 and 50, which is on the left-hand side in FIG. 1, has an upwardly opening aperture 37. In other words, a groove inlet formed by this aperture is made by an extension 39 of the lateral wall 32 which ends in a horizontal corner flange forming a stop 38. The roller track 50 protrudes from the wall 32 in order to almost reach the stop 38. As illustrated in FIG. 3, this aperture 37 is much larger than the diameter of the roller 14.
In addition, a downstream lower edge of the wall 34 has an elastomer block 60 which serves as a dampening device mounted thereon. This block 60 is located in the path of the lengthwise beam 12 of the non-stop grid 10, as best illustrated in FIG. 4, so that when the grid is in the stowed position, the block engages the beams 12.
The above-described temporary supporting device is used in the following way. During the setting of the delivery station according to the size of the plate-like workpieces, the position of the downstream guide 3 and upstream guide 3' is adjusted. The upstream guide 3' has a lower stop 1 which defines the final working position for the grid 10.
Thus, when a built-up pile 2 is in the process of being carded out of the machine, the non-stop grid 10 is engaged in the movable cradle 30 and moved to a supporting position for supporting a temporary pile 4, which position is defined by the stop 1. As can be seen, the length of the lateral walls 32 and, hence, the groove formed by the flange 36 and the track 50 is slightly longer (approximately 20% to 30%) than the length of the grid 10 so that, even with reduced sizes, the grid remains within the delivery station and, hence, inoffensive to the operator.
When the new empty pallet is raised by the plate 8 of the elevator and has taken over the weight of the temporary pile 4, the now free non-stop grid 10 can be pulled back toward the retracted position by being shifted toward the left, as illustrated in FIG. 1. When the first or rear pair of rollers 14' reach the stop 38, the end crossbar 13 of the grid can be raised by lifting on the handle 15 in order to raise the first pair of rollers 14' through the vertical aperture 37 and out of the groove.
With the rollers 14' freed from the track or groove of the cradle 30, a continuation of the motion in the backward horizontal direction can be coupled with the rotation of the grid around the front rollers 14, which action allows a simultaneously lowering of the end having the first pair of rollers 14' to a new vertical resting position 10' illustrated in FIG. 1. As illustrated in FIGS. 1 and 4, this downward position extend parallel to one of the walls of the delivery station, such as the end wall. In this position, the front rollers 14 will rest on the stop 38, whereas the lengthwise beams 12 rest on the dampening devices or pads 60 in this position, the grid which is not in use is no danger to the operator who has to move around the machine.
Although various minor modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent granted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
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A temporary supporting device for plate-like workpieces within a delivery station of a machine that processes the workpieces includes a grid which is movable within a cradle between a position for receiving the workpieces being released at the delivery station and a disengaged position. The cradle has a pair of grooves forming tracks for rollers on the sides of the grid to enable the movement, and the tracks enable the removal of a pair of rollers at one end so that the grid can be pivoted around an axis formed by the other pair of rollers from a horizontal orientation into a vertical position extending parallel and along one side of the delivery station.
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BACKGROUND OF THE INVENTION
The present invention is directed to a shock-absorbing unit for vehicle barriers and, more particularly, to a shock-absorbing unit for cushioning the impact of a vehicle that hits a safety barrier or a guard rail.
Vehicle barriers such as highway guard rails are designed to stop or to return a misdirected vehicle into a direction approximately parallel to the guard rail with a deceleration acceptable to the occupants of the vehicle. Their primary function is to increase the length of time of the entire event of stopping or redirecting the vehicle, to increase the distance through which the impact energy is alleviated, and to reduce correspondingly the forces of deceleration on the passengers of the car.
Highway guard rails are adapted to intercept an impacting vehicle at a low angle of incidence and are placed in generally parallel alignment with the direction of traffic flow along shoulders of a roadway, along median strips of a divided highway and elsewhere wherever movement off the highway would be hazardous to the vehicle and its passengers. Thus, the guard rail should not only be a mechanical guide but should also function as a shock absorber that dissipates the kinetic energy of the vehicle tending to leave the road and causing immobilization along the guard rail without violently rebounding the vehicle onto the traveled lanes. However, a problem has existed in designing highway guard rails in such a manner that they have both the strength to retain the vehicle and the ability to absorb the force of impact. For example, a conventional highway guard rail structure in common usage comprises lengths of a heavy corrugated or profiled sheet metal strip spanning a plurality of inflexible posts, usually of wood or concrete, arranged in spaced apart relationship along the side of a road, the lengths of sheet metal strip overlapping at their ends. Such a guard rail possesses high elasticity so that vehicles colliding with the rail are often rebounded into the path of moving traffic. Guard rail structures of lower resiliency featuring hollow or foam-reinforced sheet metal profiles and flexible posts are known but suffer the disadvantage of high cost.
Vehicle barriers such as safety barriers are designed to receive the impacting vehicle at a high angle of incidence and are located at the gore noses of highway exit ramps, at the ends of parallel bridges or highway rails, or in front of pilings of overhead crossing bridges, massive posts, signs, buildings or other unyielding obstacles with which an out of control vehicle might collide. Conventional safety barriers have been formed from crushable metals and plastics, but they are permanently deformed by an impacting vehicle and must be replaced after each incident as they are incapable of self restoration to usefulness. Safety barriers featuring metal springs as the means of absorbing the impact elastically store too much of the energy and consequently tend to rebound the vehicle after the impact.
The present invention provides a reusable vehicle barrier having sufficient elasticity to absorb the force of impact while, at the same time, it is not so elastic as to rebound the vehicle into the path of moving traffic.
SUMMARY OF THE INVENTION
The present invention is directed to a shock-absorbing unit for vehicle barriers comprising, in combination, a post provided with upper and lower generally coparallel passages therethrough for the reception of individual push rods, the inboard ends of said push rods supporting a rail, an oriented elastomer member connecting the outboard end of said push rods, and said post, and means for pretensioning the elastomer member a predetermined amount thereby affording an energy absorber responsive to displacement of the push rods under impact. Means for supporting the oriented elastomeric member is fixed to the outboard ends of said push rods. Preferably, the elastomeric member is in the form of a belt encircling said support means and said post between said passages. Conveniently, the oriented elastomeric member is pretensioned by employing at least one spacer located between the post and the belt support means. Generally, means for supporting the elastomeric member is a plate or rod spanning the push rods. The oriented elastomer preferably is a copolyetherester.
DESCRIPTION OF THE DRAWING
The above features and advantages of the present invention become more readily apparent from the following description, reference being made to the accompanying drawing in which:
FIG. 1 is a plan view of the device of the invention in the form of a highway guard rail;
FIG. 2 is a side elevation of the device; and
FIG. 3 is a perspective view of the device in the form of a safety barrier shown in the position reached at full impact.
DETAILED DESCRIPTION OF THE INVENTION
While it is recognized that the shock-absorbing unit of this invention for vehicle barriers such as safety barriers and guard rails can be used in different environments, for example, parking lots, alongside buildings, in docks, etc., it is particularly applicable to use along highways, and it will be hereinafter described primarily in relation to that principal field of application.
Referring to FIG. 1 and FIG. 2 of the drawing depicting a highway guard rail, post 1 is provided with generally coparallel passages 7 normally aligned with respect to the border of the highway for passage of push rods 3. Post 1 can be of any shape, e.g., rectangular or square, and it is generally made of wood or cement. The push rods are usually made of metal, e.g., steel. Rail 2 is mounted on the inboard end of push rods 3 by any suitable means, e.g., bolted or riveted. The rail can be the usual steel rail used on most guard rails or various modifications thereof, such as rubber or foam plastic reinforced guard rails. An oriented elastomeric belt 6, preferably a copolyetherester elastomer, is wrapped around post 1 between coaligned passages 7 and support means plate 4 for holding belt 6. The belt is pretensioned to a predetermined amount and this can be accomplished by any convenient means, for example, inserting a spacer 5 that functions as a pretensioner lock. Conveniently, the spacer can be a "U" shaped wedge located between post 1 and plate 4, the depth of the spacer determining the degree of pretensioning of belt 6. If desired, a skid support can be mounted anywhere along lower push rod 3 to better hold the rail in proper position upon impact by a vehicle.
FIG. 3 illustrates a safety barrier for vehicles that is a modification of the highway guard rail shown in FIGS. 1 and 2 and is designed to receive the impacting vehicle at a high angle of incidence. Again support post 1' is provided with generally coparallel passages 7' for passage of push rods 3'. Rail 2' is mounted on the inboard end of said push rods. The elastomeric member 6' encircles post 1' between coaligned passages 7' and support means bar 4', spanning both push rods. The primary difference between the illustrations is that in FIG. 3 spacer 5' comprises a clamp fixed to push rods 3' to prevent its movement along said rods and to maintain a fixed minimum space between bar support means 4' and post 1' necessary to pretension belt 6' a predetermined amount. Thus, belt 6' can be pretensioned a predetermined amount by appropriate placement of the spacer clamp on rod 3'. When the device is in position ready for operation spacer 5' rests against post 1', thus maintaining tension on oriented elastomer belt 6'.
The elastomeric member of the device, represented in the drawings as belt 6, is an oriented elastomer and preferably an oriented copolyetherester elastomer. A copolyetherester elastomer used to form the belt consists essentially of multiplicity of recurring long-chain and short-chain ester units joined head-to-tail through ester linkages, said long-chain ester units being represented by the structure: ##STR1## and said short-chain ester units being represented by the structure: ##STR2## wherein:
G is a divalent radical remaining after removal of terminal hydroxyl groups from poly(alkylene oxide) glycols having a molecular weight between about 400-6000, e.g., poly(tetramethylene oxide) glycol;
R is a divalent radical remaining after removal of carboxyl groups from a dicarboxylic acid having a molecular weight less than about 300, e.g., phthalic, terephthalic or isophthalic acids; and
D is a divalent radical remaining after removal of hydroxyl groups from a low molecular weight diol having a molecular weight less than about 250; said short-chain ester units constitute about 15-95% by weight of the copolyetherester and said long-chain ester units constitute the balance.
The copolyetheresters can be made conveniently by a conventional ester interchange reaction. A preferred procedure involves heating the dicarboxylic acid, e.g., dimethyl ester of terephthalic acid, phthalic or isophthalic acid, with a long-chain glycol, e.g., poly(tetramethylene oxide) glycol having a molecular weight of about 600-2000 and a molar excess of diol, e.g., 1,4-butanediol, in the presence of a catalyst at about 150°-260° C and a pressure of 0.5 to 5 atmospheres, preferably ambient pressure, while distilling off methanol formed by the ester interchange. Thus, preferably, in the above formula G is the group remaining after removal of hydroxyl groups from poly(tetramethylene oxide) glycol having a molecular weight of about 600-2000; R is the group remaining after removal of carboxyl groups from phthalic, terephthalic or isophthalic acids or mixtures thereof, and D is the group remaining after removal of hydroxyl groups from 1,4-butanediol. At least about 1.1 mole of diol should be present for each mole of acid, preferably at least about 1.25 mole of diol for each mole of acid. The long-chain glycol should be present in the amount of about 0.0025 to 0.85 mole per mole of dicarboxylic acid, preferably 0.01 to 0.6 mole per mole of acid.
Preferred copolyesters are those prepared from dimethyl terephthalate, 1,4-butanediol, and poly(tetramethylene oxide) glycol having a molecular weight of about 600-2000 or poly(ethylene oxide) glycol having a molecular weight of about 600-1500. Optionally, up to about 30 mole percent and preferably 5-20 mole percent of the dimethyl terephthalate in these polymers can be replaced by dimethyl phthalate or dimethyl isophthalate. Other preferred copolyesters are those prepared from dimethyl terephthalate, 1,4-butanediol, and poly(propylene oxide) glycol having a molecular weight of about 600-1600. Up to 30 mole percent and preferably 10-25 mole percent of the dimethyl terephthalate can be replaced with dimethyl isophthalate or butanediol can be replaced with neopentyl glycol until up to about 30% and preferably 10-25% of the short-chain ester units are derived from neopentyl glycol in these poly(propylene oxide) glycol polymers.
The copolyetherester compositions comprising belt 6 may also contain up to about 5 weight percent of an antioxidant, e.g., between about 0.2 and 5 weight percent, preferably between about 0.5 and 3 weight percent. The most preferred antioxidants are diaryl amines such as 4,4'-bis(α,α-dimethylbenzyl) diphenylamine.
The most preferred copolyetherester compositions comprising belt 6 may also contain up to about 5 weight percent of an antioxidant, e.g., between about 0.2 and 5 weight percent, preferably between about 0.5 and 3 weight percent. The most preferred antioxidants are diaryl amines such as 4,4'-bis(α,α-dimethylbenzyl) diphenylamine.
Belts of the oriented copolyetherester can be formed in a number of ways. For example, a billet can be molded from the polymer in a conventional manner and the billet oriented by stretching, heat setting, and cooling. The copolyetherester belt is oriented by stretching the copolyetherester by conventional means at least 300% of its original length and preferably at least 400% at a temperature below its melting point by at least 20° F. It is maintained at that length and brought to or maintained at a heat setting temperature between 150° and 20° F below its melting point. It is then cooled to a temperature below the heat setting temperature by at least 100° F.
The copolyetheresters used to make the elastomeric member are further described in Witsiepe, U.S. Pat. No. 3,766,146, and the oriented copolyetheresters are also described in Brown and McCormack, Ser. No. 542,257, filed Jan. 20, 1975, the disclosures of which are incorporated herein by reference.
The oriented copolyetherester is, preferably, in the form of a belt encircling post 1 and plate 4 and most preferably is a lapped belt having multiple windings. A lapped belt can be fabricated conveniently by making multiple windings of a tape or belt of oriented elastomer around said post and support means, e.g., plate or bar, as the case may be, and securing the belt from unwinding by suitable means, e.g., heat or solvent welding the free ends to the adjacent strip of belt, or clamps or other fasteners. The number of windings of the belt will depend upon the weight of the belt needed for a particular energy absorbing capacity as described below.
To prepare the shock-absorbing mechanism shown in FIGS. 1 and 2 for operation, belt 6 is prestressed by inserting spacer 5, for example, a "U"-shaped metal wedge, between post 1 and plate 4. Thus, the displacement of plate 4 stretches belt 6 and places it under tensile stress, as shown in FIG. 1. The belt is of such length that such displacement causes the desired degree of prestressing and provides high initial impact force for greater energy absorption. Impact upon rail 2 causes push rods 3 to move in a direction toward their outboard end relative to post 1. The distance between the support means for the belt and the post that is maintained by spacer 5 determines the degree of tensioning and stretching of belt 6 whereby the energy of impact is absorbed and the movement of rail 2 is cushioned. As can be seen from FIG. 3, the safety barrier device illustrated therein operates in the same manner. Spacer 5 is a clamp that is so positioned on push rods 3' that the elastomeric belt 6' in the operating condition is pretensioned. Some of the energy absorbed is reversibly stored in the belt and is used to return the shock-absorbing device to its original position and the remainder of the energy is dissipated. Thus, after the impact is so dissipated, push rods 3 and rail 2 return to their original positions as a consequence of the elastic nature of belt 6 with spacer 5 again resting against post 1 and plate 4 and the shock-absorbing unit is ready to function again, when needed, in the manner described above.
Dimensions of belt 6 of oriented elastomer and the depth of spacer 5 will depend upon the amount of energy required to be absorbed by the shock absorbing mechanism and the desired rate of absorption. Factors which increase the energy absorbing capacity are: (1) enlarging the cross-sectional area of the belt, (2) increasing the potential displacement of the rail by lengthening the push rods and the belt, and hence, increasing the ultimate stretch and stress level of the extended belt, and (3) increasing the degree of prestressing of the belt by increasing the depth of spacer 5. Selecting a higher modulus elastomer for fabrication of belt 6 is another factor that can be used to increase energy absorbing capacity of the shock-absorbing unit. For highway guard rails and dock guards the above specifications will vary because of varying energy absorption requirements and varying limitations on maximum force and maximum deflection. A typical belt for a guard rail, as represented in FIGS. 1 and 2, when made of the preferred oriented copolyetherester elastomer, as referred to above, has a cross-sectional area of about 2.6 sq. cm. and a circumference of about 102 cm, weighs about 0.67 kg., and the depth of spacer 5 will be sufficient to permit the belt to be prestrained by stretching to about 10% of its original length. This belt when struck by a vehicle at an angle of incidence of about 10° and stretched to a maximum strain of 40% will exert a maximum total restoring force of 2380 pounds. A safety barrier because of its exposure to impacts of high angle incidence must have a greater energy absorbing capacity than a guard rail and consequently will have a larger belt. The stopping distance for the impacting vehicle and the maximum force developed will be directly and inversely proportional, respectively, to the original length and cross-sectional area of the belt. Typically, a belt capable of absorbing the full energy of a 3000 pound vehicle in impact at an angle of 90° at an initial speed of 50 miles per hour weighs 11.3 kg. (25 lbs.), has a cross-sectional area of 4.3 sq. cm. and a circumference of 2030 cm., is installed with a 10% prestrain, and stretched in impact to 40% strain. The vehicle is stopped within about 10 feet after impact with a maximum total force of about 40,000 pounds and a maximum deceleration of about 13.2 G.
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A shock-absorbing unit comprising a post with upper and lower generally coparallel passages therethrough, e.g., bores, for the reception of individual push rods, the inboard ends of the push rods supporting a rail, an oriented elastomer, e.g., a copolyetherester, connecting the outboard end of the push rods and the post, and means for pretensioning the elastomer, e.g., a wedge, a predetermined amount.
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention generally relates to processing compressed digital images. More particularly, this invention relates to methods and apparatus which accomplish rotation in conjunction with variable-length compression/decompression operations.
2. Description of Related Art
Data compression is required in data handling processes, where too much data is present for practical applications using the data. Commonly, compression is used in communication links to reduce the transmission time or required bandwidth. Similarly, compression is preferred in image storage systems, including digital printers and copiers, where “pages” of a document to be printed are stored temporarily in precollation memory. The amount of media space on which the image data is stored can be substantially reduced with compression. Generally speaking, scanned images, i.e., electronic representations of hard copy documents, are often large, and thus make desirable candidates for compression.
The image compression standard disseminated by the Joint Photographic Experts Group (JPEG) committee is a compression technique which reduces data redundancies based on pixel-to-pixel correlations. Generally, a photographic image does not change very much on a pixel-to-pixel basis and therefore has what is known as “natural spatial correlation.” In natural scenes, correlation is generalized, but not exact. Noise makes each pixel somewhat different from its neighbors.
SUMMARY OF THE INVENTION
The methods and apparatus of this invention seek to enhance the conventional methods for rotating digital images. In a conventional method for rotating digital images, an image source provides the compressed image data to the system. The image source can be an input device such as a camera or scanner, a transmission channel or a storage device. The compressed image data is input to a decompression unit that reconstructs the image. The uncompressed image is fed into the image rotation unit. The image output is sent to an output image sink, which can be a storage device, a transmission line, or a display device such as a printer or monitor. The disadvantage of this conventional method is that the rotation operations are performed on the decompressed image. Color documents typically contain tens of millions of pixels, such that even simple operations on those image can be computationally and economically expensive and time consuming.
This invention provides a method and apparatus for rotating a compressed digital image as it is decompressed.
This invention separately provides a method and apparatus that generates additional information as the digital image is compressed, where the additional information is used during decompression to rotate the digital image.
This invention separately provides a method and apparatus that generates, as additional information, the DC values of each scanline and pointers to the start position of each initial block of the current scanline.
This invention separately provides a method and apparatus that generate additional information to rotate a digital image that can be stored using a small amount of memory space.
The methods and apparatus of this invention provide an improved image rotation process by reducing its complexity. The methods and apparatus of this invention reduce the computational effort spent in decompressing and rotating a decompressed image. In the methods and apparatus of this invention, rotation is assumed to be an operation which rotates the image by +90° or −90° or may even represent image transposition. The rotation operations can also be combined with image mirroring in the vertical or horizontal direction.
The methods and apparatus of this invention expand on a variable-length compression operation by adding an image rotation operation, where the M×M blocks within the image are orthogonally rotated to rotate the entire image using the compressed image blocks, to avoid the need for buffering the entire image or large sections of it.
More particularly, the methods and apparatus of this invention reduce the memory necessary to orthogonally rotate a digital image in conjunction with a variable-length compression technique, such as Huffman encoding A small amount of auxiliary information, including pointers to the start of the scanlines and the DC coefficients, are stored. A significantly reduced, small-sized block of working memory can be used to save this information. In particular, the space required to store this additional information is proportional to the square root of the space required by the compressed image.
One aspect of this invention deals with a basic problem in digital image processing systems regarding the memory-intensive and computationally-intensive image rotation operation. This aspect is further based on the discovery of a technique that alleviates this problem. This technique associates the rotation of a small image segment or block with decompressing that small image segment or block, and managing the rotated-decompressed blocks to enable rotation using minimal buffer memory.
By avoiding the very expensive process of rotating the decompressed image, the method and apparatus of this invention reduces the computation necessary to rotate a digital image. Using the method and apparatus of this invention, the rotated image has excellent quality without requiring a full buffer's worth of memory.
The method and apparatus of this invention can be implemented, for example, by modifying basic JPEG compression and decompression methods, where image rotation is performed on the compressed image data (compressed units). Accordingly, the method and apparatus of this invention can be applied to any number of devices, including digital printers and copiers, that need to provide a rotated image. The apparatus according to this invention includes data or image processing systems capable of compressing images.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The preferred embodiments of this invention will be described in detail, with reference to the following figures, wherein:
FIG. 1 is a generalized functional block diagram of a compression and decompression system according to this invention;
FIG. 2 depicts the segmentation of an exemplary image into blocks for compression as applied in the compression and decompression system of FIG. 1;
FIG. 3 shows a generalized functional block diagram of a compressor according to this invention;
FIG. 4 shows a generalized functional block diagram of a decompressor according to this invention;
FIG. 5 is a flowchart outlining an image compression and decompression method in accordance with this invention;
FIG. 6 is a flowchart outlining in greater detail the compression step of FIG. 5; and
FIG. 7 is a flow chart outlining in greater detail the decompression and rotation step of FIG. 5 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a generalized functional block diagram of a compression and decompression system 100 according to this invention. The compression and decompression system 100 includes an image source 110 that may be any one of a number of different sources, such as a scanner, a digital copier or a facsimile device suitable for generating electronic image data, or a device suitable for storing and/or transmitting the electronic image data, such as a client or a server of a network. The electronic image data from the image source 110 is provided to an encoder 400 of the compression and decompression system 100 .
In particular, the encoder 400 includes an image blocking portion 410 that divides the electronic image data into a plurality of M×M block or segments. In one embodiment, the blocking operation may be accomplished by windowing or cropping that enables the transfer of data comprising one or more M×M blocks of data from the input document to a block memory to be stored in the encoder 400 . Once stored, the data is input by a compressor 430 . In the compressor 430 , the M×M blocks of image data are compressed to form a compressed image. Preferably, the compressor 430 compresses the image using various compression operations associated with the JPEG compression standard to compress the image data within a block, although any known or later developed compression technique that compresses the image on a block-by-block basis is equally usable. In the compressor 430 , the data may be operated on in any of a number of well-known bit- or byte-wise operations to accomplish the compression of the image data, wherein additional information are generated as the image is compressed.
Once compressed, the compressed image data then is preferably transferred to the channel or storage device 300 . The channel or storage device 300 can be either or both of a channel device for transmitting the compressed image data to the decoder 500 or a storage device for indefinitely storing the compressed image data until there arises a need to decompress the compressed image data. The channel device can be any known structure or apparatus for transmitting the compressed image data from a first apparatus implementing the encoder 400 according to this invention to a physically remote decoder 500 according to this invention. Thus, the channel device can be a public switched telephone network, a local or wide area network, an intranet, the Internet, a wireless transmission channel, any other distributed network, or the like.
Similarly, the storage device can be any known structure or apparatus for indefinitely storing compressed image data, such as a RAM, a hard drive and disk, a floppy drive and disk, an optical drive and disk, flash memory or the like. Moreover, the storage device can be physically remote from the encoder 400 and/or the decoder 500 , and reachable over the channel device described above.
The compressed image data is then preferably processed by the decoder 500 , where rotation using the additional information or the like is accomplished. In particular, the decoder 500 includes a decompressor 530 that receives compressed image data from the channel or storage device 300 and an output controller 510 that pastes the blocks of decompressed image data from the decompressor 530 in their corresponding position. Though the decoder 500 is shown in FIG. 1 as physically separate from the encoder 400 , it should be understood that the decoder 500 and the encoder 400 may be different aspects of a single physical device.
The output controller 510 sends the reconstructed image to the output device 200 . It should be understood that the output device 200 can be any device that is capable of processing the decompressed image data generated according to the invention, for example, a rotated image. For example, the output device 200 can be a printer, such as a laser printer, an ink jet printer, a thermal printer, a dot matrix printer, a digital photocopier or the like, a display device, such as a CRT, flat panel LCD or LED display, or the like. Moreover, the decompressor 500 can be physically incorporated into the printer or the display device.
FIG. 2 depicts the segmentation of an exemplary image into blocks for compression, preferably in accordance with the JPEG standard, and subsequent rotation. Blocks A 1 -A N represent the top-most blocks of scanlines or rasters of data in the input image, while blocks A 1 -Z 1 represent the left-most blocks of scanlines in the image. Each block is an M×M segment of the image. In a rotated image, each block is intra-block rotated and the relative position of each block within the image is also inter-block rotated to completely rotate the image, so that blocks Z 1 ′-A 1 ′ are the top-most blocks and Z 1 ′-Z N ′ are the left-most blocks in a +90° rotated image. It should be appreciated that the intra-block rotation of a single M×M block can be accomplished in a rapid fashion using an equivalently-sized memory region so that the value associated with any pixel position is simply copied or moved to the corresponding rotated position. On the other hand, a more processing intensive approach may be to simply use a single register to temporarily store the data associated with only a single pixel position and to move successive pixels through that single register to rotate the pixels of that block.
FIG. 3 shows a generalized functional block diagram of the compressor 430 , when implementing the JPEG compression standard. It will be apparent to those of ordinary skill in the art, from the following description of the compressor 430 , how to modify the compressor 430 to implement other compression techniques to generate the additional information according to this invention. Thus, because such modifications are readily apparent and predictable from the following discussion of the JPEG and Huffman implementation of the compressor 430 , additional descriptions of other compression techniques' implementations are not necessary and are thus omitted.
In the compressor 430 , a DCT compressor 432 inputs the M×M blocks of image data and outputs compressed data. A first compressed data buffer 434 inputs and stores the compressed data. The DCT compressor 432 also outputs additional information related to the implemented JPEG compression technique. Thus, for JPEG compressed data, the additional information is the DC coefficients of the blocks. An additional information register 433 inputs and stores the additional data. Because the compressor 430 uses the JPEG standard to compress the image data, the additional information register 433 includes a DC coefficient buffer 437 . The compressed image data from the first compressed data buffer 434 is then input to an encoder 438 to further compress this data. However, it should be appreciated that this additional compression is optional.
In a preferred embodiment of the compressor 430 , additional encoding, such as Huffman encoding, is performed. In such instances, additional information, for example, scanline pointers, are output from the encoder 438 . The additional information register 433 inputs and stores the scanline pointers. Thus, the additional information register also includes a scanline pointer buffer 435 .
It should be appreciated that though the encoding method of the encoder 438 discussed above is Huffman encoding, any other variable length encoding method, or any other second level encoding method, which does not use image blocking, can be used. In such instances, such as run-length encoding, the image is compressed without blocking the image prior to compression.
In the preferred embodiment of the compressor 430 described above, the image data is compressed using the JPEG standard with subsequent Huffman encoding. It should be appreciated that in instances in which the additional encoding, such as Huffman encoding, is not performed, the scanline pointer buffer 435 and the encoder 438 are not needed. It will also be understood by those skilled in the art that the particular components of the additional information register 433 will depend on the particular compression technique or techniques used to compress the M×M blocks.
For the system described above that implements JPEG block compression, the DC coefficient of only the left-most block of the set of scanlines forming the blocks, assuming left-to-right analysis of the blocks, is needed as the additional information sufficient to decompress and rotate the compressed image data. This is because the JPEG decompression process of each block will inherently generate the value of the DC coefficient for the next block in the current scanline of the unrotated image. Similarly, only the start position or address of the left-most block is needed as additional information sufficient to decompress the Huffman encoded compressed image data. This is because the Huffman decompression process of each block will inherently generate the start position or address of the next block in the current scanline of the unrotated image.
Upon decompression, a rotated readout processor reads the scanline pointers from a scanline pointer buffer and the DC coefficients from a DC coefficient buffer, and processes compressed data based on the read scanline pointers and DC coefficients. Accordingly, a significantly smaller block of working memory is used instead to store the scanline pointers and the DC coefficients obtained from the compressor 430 .
FIG. 4 shows a generalize functional block diagram of the decompressor 530 , which decompresses image blocks compressed using Huffman encoding and the JPEG compression standard. It will be apparent to those of ordinary skill in the art, how to modify the decompressor 530 from the following description of the decompressor 530 to implement other decompression techniques to use the additional information generated according to this invention. Thus, because such modifications are readily apparent and predictable from the following discussion of the JPEG and Huffman implementation of the decompressor 530 , additional descriptions of other compression techniques' implementations are not necessary and are thus omitted.
The decompressor 530 includes a rotated read out processor 532 , a second compressed data buffer 531 and an additional information register 533 . The rotated read out processor includes a decoder 534 , a DCT intra-block rotator 536 and an inverse DCT processor 538 . Because the decompressor 530 is using the JPEG standard and Huffman decoding to decompress the image data, the additional information included with the compressed image data includes the JPEG DC coefficients and the scanline pointers of selected ones of the compressed blocks of image data. Thus, the additional information register 533 includes a scanline pointer buffer 535 and a DCT coefficient buffer 537 .
In operation, the decompressor 530 separates the additional information from the compressed image data and stores the additional information in the additional information register 533 and the compressed image data in the second compressed data buffer 531 . It will be understood by those skilled in the art that the particular additional information supplied with the compressed image data will depend upon the particular compression techniques used to compress the M×M blocks. Thus, the particular components of the additional information register 533 will depend on those particular compression techniques.
In the preferred embodiment of the compressor 430 described above, the image data is compressed using the JPEG standard with subsequent Huffman encoding. Accordingly, the additional information supplied with the compressed image data includes scanline pointer data and DC coefficient data. Accordingly, the additional information register 533 includes the scanline pointer buffer 535 and the DC coefficient buffer 537 . In particular, the scanline pointer data is stored in the scanline pointer buffer 535 while the DC coefficient data is stored in the DC coefficient buffer 537 . As each compressed and encoded block is output by the second compressed data buffer 531 to the rotated read out processor 532 , the appropriate scanline pointer data and DC coefficient data for that particular block are output by the scanline pointer buffer 535 and the DC coefficient buffer 537 to the rotated reader processor 532 .
In particular, the scanline pointer data is output by the scanline pointer buffer 535 to the decoder 534 while the DC coefficient data for that block is provided to the inverse DCT processor 538 from the DC coefficient register buffer 537 . The decoder 534 uses the scanline pointer data to extract the appropriate Huffman encoded data for that block and decodes that Huffman encoded block to form a decoded block. The decoded block is then output by the decoder 534 to the DCT intra-block rotator 536 . The DCT intra-block rotator 536 intra-block rotates the compressed image data, as set forth in copending U.S. patent application Ser. No. 08/721,130, herein incorporated by reference in its entirety. The intra-block rotated block is then output by the DCT intra-block rotator 536 to the inverse DCT processor 538 .
The inverse DCT processor 538 inverse DCT transforms the current block to decompress it using the DC coefficient for the current block supplied by the DCT coefficient buffer 537 . The inverse DCT processor 538 then outputs the decompressed intra-block rotated block to the output controller 510 , where it is placed into the image at the appropriate inter-block rotated location.
It should be appreciated that in instances in which Huffman encoding is not performed, the decoder 534 and the scanline pointer buffer 535 are not needed.
In operation, the +90° rotated image is formed left-to-right and top-to-bottom. Thus, the compressed and Huffman encoded blocks of image data are decoded and then decompressed and simultaneously rotated by selecting the compressed and encoded data corresponding to the Z 1 through A 1 blocks to form the top scanline of the +90° rotated image. The next scanline is formed by selecting the compressed and encoded data corresponding to the Z 2 through A 2 blocks, and so on.
Thus, for each of the Z 1 through A 1 blocks, the decoder 534 inputs the scanline pointers for the Z th through A th blocks in order from the scanline pointer buffer 535 .
Based on each of the Z th through A th scanline pointers read from the scanline pointer buffer 535 , the decoder 534 selects the set of encoded data that it will decode to form each of the Z 1 through A 1 blocks of compressed image data. This also identifies the start position or address of each of the sets of encoded data that will decode to form each of the Z 2 through A 2 blocks of compressed image data. These Z 2 -A 2 new start positions or addresses are then re-stored in the scanline pointer buffer 535 as the Z th -A th scanline pointers, respectively, and will be used to point to the start positions or addresses to be used when decoding the rotated second scanline data.
Similarly, for each of the Z 1 through A 1 blocks of compressed image data, the inverse DCT processor 538 inputs, in order, the DC coefficient for the Z th through A th blocks from the DC coefficient buffer 537 . The inverse DCT processor 538 , based on each of the Z th through A th DC coefficients read from the DC coefficient buffer 537 , inverse DCTs, or decompresses, the intra-block rotated Z 1 through A 1 blocks of image data, respectively. This also generates the DC coefficient values needed to decompress the Z 2 through A 2 blocks of image data, respectively. The Z th through A th new DC coefficient values are then re-stored in the DC coefficient buffer 537 as the Z th through A th DC coefficients, respectively, and will be used to decompress the rotated second scanline of compressed image data.
FIG. 5 is a flowchart outlining one embodiment of an image compression and decompression method in accordance with this invention. Beginning in step S 1000 , control continues to step S 1100 , where electronic image data is generated from an original image. Then, in step S 1200 , the electronic image data is input from the image source.
It should be appreciated that, while the flowchart of FIG. 5 shows generating the electronic image data as part of the process, this step is not necessarily needed. That is, while the electronic image data can be generated by scanning an original image, or the like, the electronic image data could have been generated at any time in the past. Moreover, the electronic image data need not have been generated from an original physical image, but could have been created from scratch electronically. Accordingly, if the electronic image data is already available to the image source, step S 1100 can be skipped, with control continuing directly from step S 1000 to step S 1200 .
In step S 1300 , the M×M image blocks are generated from the electronic image data. Then, in step S 1400 , the compressed image data and the additional information are generated from the M×M image blocks. Next, in step S 1500 , the compressed image data and the additional information are transmitted to an alternate image source or to storage.
It should also be appreciated that the compressed image data could have been previously stored and/or previously transmitted to the location where the compressed image data is to be decompressed, and that steps S 100 -S 1500 can be omitted from the process. That is, the decompression method according to this invention is unconcerned with how and/or when the original image was converted into electronic image data, and how and/or when the electronic image data was generated, converted to compressed image data, and/or transmitted to and/or stored at the location where the compressed image data is to be decompressed. Accordingly, if the compressed image data is already available, steps S 1100 -S 1500 can be skipped, with control continuing directly from step S 1000 to step S 1600 .
In step S 1600 , the compressed image data is decompressed and rotated using the additional information. Subsequently, in step S 1700 , the rotated blocks are pasted into their corresponding inter-block rotated positions. Next, in step S 1800 , the image data is output. Then, in step S 1900 the control routine ends.
According to the method and apparatus of this invention, rotation of the compressed image data occurs in the decompressor at step S 1600 . This rotation step can be done by intra-block rotating each image block separately, and pasting the consecutive image blocks in their respective inter-block rotated positions.
FIG. 6 outlines in greater detail the compression process of step S 1400 . Beginning in step S 1400 , control continues to step S 1405 , where the control routine determines the number of block scanlines N in the image. Then, in step S 1410 , the number of blocks M in each block scanline is determined.
In step S 1415 , the scanline counter n is set to 1. Then, in step S 1420 , the block counter m is set to 1. Control then continues to step S 1425 .
In step S 1425 , the block (n,m) is compressed. In step S 1430 , the DC component is extracted. In step S 1435 , block (n,m) is encoded. Control then continues to step S 1440 .
In step S 1440 , the control routine determines if m equals 1. If so, control continues to step S 1445 . Otherwise, control jumps to step S 1455 .
In step S 1445 , the control routine determines a pointer to the beginning memory location for the scanline based on the stored block. Then, in step S 1450 , the DC coefficient and the pointer for the stored block are stored.
In step S 1455 , the control routine determines if m equals M. If not, control continues to step S 1460 . Otherwise, if the last block M has been compressed and encoded, control jumps to step S 1465 .
In step S 1460 , m is incremented by one. Control then returns to step S 1425 .
In step S 1465 , the compressed block (n,m) is stored to memory. In step S 1470 , the control routine determines if n equals N. If not, control continues to step S 1475 . Otherwise, if the last scanline is reached, control jumps to step S 1480 .
In step S 1475 , n is incremented by one. Control then returns to step S 1420 .
In step S 1480 , the control routine returns to step S 1500 .
FIG. 7 outlines in greater detail the decompression process of step S 1600 . Beginning in step S 1600 , control continues to step S 1605 , where the compressed image data and additional information are input and stored to memory. Then, in step S 1610 , the number of blocks M in each block scanline and the number of block scanlines N in the image are determined.
In step S 1615 , the block counter m is set to 1. Then, in step S 1620 , the scanline counter n is set to N. Control then continues to step S 1625 .
In step S 1625 , the DC coefficient and the pointer for the scanline n are input from memory. Then, in step S 1630 , the compressed and encoded image data for block (n,m) at the memory location indicated by the pointer is input. Control then continues to step S 1635 .
In step S 1635 , the encoded and compressed block (n,m), is decoded to obtain the compressed image data for the block (n,m) and thus the new DC coefficient and scanline pointer for the current scanline n. Then, in step S 1640 , the new DC coefficient and the new scanline pointer for the current scanline n are stored in the memory in place of the present DC coefficient and scanline pointer for the current scanline n. Next, in step S 1645 , the decoded compressed block (n,m) is intra-block rotated. Control then continues to step S 1650 .
In step S 1650 , the rotated compressed block (n,m) is inverse transformed using the input DC coefficient. Then in step S 1655 , the decompressed block (n,m) is output. Control then continues to step S 1660 .
In step S 1660 , the control routine determines if n equals 1. If not, control continues to step S 1665 . Otherwise, control jumps to step S 1670 .
In step S 1665 , n is decremented by one. Control then returns to step S 1625 .
In step S 1670 , the control routine determines if m equals M. If not, control continues to step S 1675 . Otherwise, the last block M of each of the scanlines has been decoded and decompressed and control jumps to step S 1680 .
In step S 1675 , m is incremented by one. Control then returns to step S 1620 .
In step S 1680 , the control routine returns to step S 1700 .
According to the methods and apparatus of this invention, when implementing the JPEG compression/decompression standard, the DC coefficient employed is based upon the current block or an initial condition. For a +90° clockwise rotation, each block Z 1 -A 1 is treated as the first block in a sequence of blocks, and the DC coefficients for each block A 1 -Z 1 are stored in the DC coefficient buffer 437 so that the DC coefficients will be available during the processing of blocks that will immediately follow each of the Z 1 -A 1 blocks in the rotated image. Accordingly, the output of the variable length encoding operation stores the DC coefficients in the DC coefficient buffer 37 so that they are available when needed as an initial condition. Also, the scanline pointers for the first blocks A 1 -Z 1 , of the scanline are stored in scanline pointer buffer 435 . It will be appreciated that the size of the buffers 435 , 437 , 535 and 537 are dependent upon the size, or more particularly the length, of the initial image, requiring memory of sufficient size to store offsets of each block A 1 -Z 1 .
In the decompression process, using InScan as the index value of the current scanline of blocks, ranging from 1 to N, and InBlock as the index value of the current block, ranging from 1 to M, the following steps are followed:
1. For In Block=1 to M
2. For InScan=N downto 1 by 1
3. DC=DCVals[InScan]
4. PTr=ScanPtrs[InScan]
5. Huffman decode( )
6. Intra-block Rotate( )
7. Decompress( )
8. DCVals[InScan]=DC
9. ScanPtrs[InScan]=Ptr
If another rotated copy is to be made, the values of DCVals and ScanPtrs may be recovered as:
For InScan 1 to N−1 by 1
DCVals[InScan+1]=DCVals[InScan]
ScanPtrs[InScan+1]=ScanPtrs[InScan]
DCVals[ 1 ]=128
ScanPtrs[ 1 ]=(address of start of image).
For 8-bit image data, a value of “128” is the assumed value of the DC term of the block before the first block of the first scanline.
For a tiny image of 12 blocks, wherein M=3 and N=4, the blocks 1 through 12 are numbered as:
1
2
3
4
5
6
7
8
9
10
11
12
There are 4 scan pointers and 4 DC values initialized for the scanlines. The pointers and DC values are initialized as if the decompressor were about to decode blocks 1 , 4 , 7 and 10 . For each block, the DC term for that block and the memory address of that block are, for example:
128
0
50
10
45
18
33
27
67
38
78
47
35
56
35
63
35
69
40
68
41
79
43
96
First, the following values are assigned or obtained from memory: InBlock=1, which is less than N (3); InScan=4, which is greater than 1; DC=40; and PTr=68. That is in steps 1 - 4 , m is set to 1, n is set to 4, the value of the DC coefficient read from memory for the fourth scanline is 40 and the value for the scanline pointer for the fourth scanline is 68 .
Then, block 10 of the encoded compressed image data is read from memory beginning at the memory location 68 . Then, decoding, such as Huffman decoding, is performed in step 5 . This effectively sets the value of the DC coefficient (DC) to 41 and the value of the scanline pointer (PTr) to 79 for the next block, block 11 , in the fourth scanline. Then, block 10 is intra-block rotated in the transformed domain and decompressed in steps 6 and 7 . Then, DCVals[ 4 ] is set to 41 in step 8 and ScanPtrs[ 4 ] is set to 79 in step 9 and stored in memory as the DC coefficient and the scanline pointer for the fourth scanline to enable decoding and decompressing block 11 .
Then, for InScan=3, which is greater than 1, the following values are obtained from memory for the third scanline: DC=35 and PTr=56 in steps 3 and step 4 .
next, block 7 of the compressed image is read from the memory beginning at the memory location 56 and Huffinan decoded in step 5 . This effectively sets the value of the DC coefficient (DC) to 35 and the value of the scanline pointer (PTr) to 63 for the next block 8 , in the third scanline. Then, block 7 is intra-block rotated and decompressed in steps 6 and 7 as before. Then, DCVals[ 3 ] is set to 35 in step 8 and ScanPtrs[ 3 ] is set to 63 in step 9 and stored in memory as the DC coefficient and the scanline pointer for the third scanline to enable decoding and decompression block 8 .
The process continues in like fashion, Huffman decoding blocks 4 and then 1 in step 5 , which are read from the memory beginning at memory locations 27 and 0 , respectively, rotating blocks 4 and 1 in step 6 and decompressing blocks 4 and 1 in step 7 , as above. At this point InScan reaches 0 . In response, the value of InBlock is increased by 1 to 2 in step 1 , and the entire process of steps 2 - 9 is repeated for blocks 11 , 8 , 5 and 2 . This process of steps 1 - 9 is repeated a third time for blocks 12 , 9 , 6 and 3 , after which InBlock reaches the value 3.
In this fashion, intra-block rotated versions of blocks 10 , 7 , 4 and 1 are formed first and pasted into the appropriate inter-block rotated position in the output image. This is then followed by forming and inter-block pasting the intra-block rotated versions of blocks 11 , 8 , 5 and 2 , and so forth, giving a rotated final version of the image as:
10R
7R
4R
1R
11R
8R
5R
2R
12R
9R
6R
3R
It should be appreciated that, although the method and apparatus described above provides for a clockwise rotation, counterclockwise rotations may be obtained. For a counterclockwise rotation, readout is from top-to-bottom, but from right to left. That is, in step 2 , InScan increases from 1 to N while in step 1 , InBlock decreases from M to 1. However, right to left decoding of Huffman encoded data is not possible. Thus, direct counterclockwise rotations can only be used without subsequent variable length encoders. Thus, steps 4 , 5 and 9 will be omitted.
Thus, for a counterclockwise rotation of data of −90° (or a clockwise rotation of data of +270°) where Huffman encoding is used, the blocks of the image data are first mirror-transformed about a vertical axis before it is compressed, and then the decoding is modified to effectively transpose the image about a diagonal axis to provide a clockwise rotated image of +270°. It should be appreciated that in order to provide a mirror-transformed image before compression, the image creator is required to know that a counterclockwise-rotated image is to be formed upon decompression before the compression is performed.
Thus, for a counterclockwise rotation, the image is first mirror-transformed about a vertical axis:
3
2
1
6
5
4
9
8
7
12
11
10
Also, the following steps are followed:
1. For InBlock=1 to M
2. Foe InScan 1 to N
3. DC=DCVals[InScan]
4. PTr ScanPtrs[InScan]
5. Huffman decode( )
6. Intra-block Rotate( )
7. Decompress( )
8. DCVals[InScan]=DC
9. ScanPtrs[lnScan]=Ptr
In this instance, the scanlines are read from top-to-bottom instead of the bottom-to-top process of the clockwise rotation. Thus, instead of N down to 1, [InScan] ranges from 1 to N for a counterclockwise rotation. That is, step 2 is modified to increase InScan from 1 to N. This effectively transposes the mirror-transformed image about a diagonal axis and thus provides an image rotated by +270°, or counterclockwise rotated image of −90°. In this fashion, intra-block rotated versions of blocks 3 , 6 , 9 and 12 are formed first and pasted into the appropriate inter-block rotated position in the output image. This is then followed by forming and inter-block pasting the intra-block rotated versions of blocks 2 , 5 , 8 and 11 , and so forth, giving a rotated final version of the image as:
3R
6R
9R
12R
2R
5R
8R
11R
1R
4R
7R
10R
It should be appreciated that the counterclockwise rotation of data of −90° (or a clockwise rotation of data of +270°) where Huffman encoding is used can alternatively be done by first mirror-transforming about a vertical axis and additionally mirror-transforming about a horizontal axis before compression and then performing the +90° clockwise rotation discussed above.
It should be appreciated that if rotation is not necessary, the additional information can be ignored and that decompression is performed normally. In particular, it should be appreciated that if a counterclockwise-rotated image is to be provided by rotating the decompressed image after the image is decompressed normally, the counterclockwise rotation process described above is not required and storing the additional information can be avoided.
For an 8½×11 page, this invention requires a significantly smaller sized buffer to store the pointers and coefficients than that needed for an uncompressed rotation buffer. Thus, using the method and apparatus of this invention, the rotated image has excellent quality without requiring a full buffer's worth of memory.
As shown in FIG. 1, the encoder 400 may be implemented on a programmed general purpose computer. However, the encoder 400 can also be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmable logic device such as a PLD, PLA, FPGA or PAL, or the like. In general, any device, capable of implementing steps S 1400 -S 1500 of FIGS. 5 and 6 can be used to implement the encoder 400 .
As shown in FIG. 1, the decoder 500 is preferably implemented on a programmed general purpose computer. However, the decoder 500 can also be implemented on a special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmable logic device such as a PLD, PLA, FPGA or PAL, or the like. Furthermore, as set forth above, both of the encoder 400 and decoder 500 can be implemented in a single general purpose computer, a single special purpose computer, a single programmed microprocessor or microcontroller and peripheral integrated circuit elements, a single ASIC or other integrated circuit, a single digital signal processor, a single hardwired electronic or logic circuit such as a discrete element circuit, a single programmable logic device such a PLD, PLA, FPGA or PAL, or the like.
As shown in FIGS. 3 and 4, the additional information register 433 and 533 , and the scanline pointer buffers 435 and 535 and the DC coefficient buffers 437 and 537 can be implemented using any known or later developed memory devices and structures including RAM, video RAM, flash memory, cache memory, registers, buffer memory, a hard disk and drive, a floppy disk and drive, an optical disk and drive, a magneto-optical disk and drive, and the like. That is, the operation and structure of the memory device is not critical to the operation of the system and method of this invention.
This invention has been described in connection with the preferred embodiments. However it should be understood that there is no intent to limit the invention to the embodiments described above. On the contrary, the intent to cover all alternatives, modification, and equivalents as may be included within the spirit and scope of the invention.
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This invention is a method and apparatus for processing compressed digital images. More particularly, this invention relates to methods and apparatus which accomplish rotation in conjunction with a variable-length decompression operation. A small amount of auxiliary information consisting of pointers to the starts of the scanlines is stored along with the DC coefficients in the decompressor, instead of the compressed image, to reduce the memory requirements for orthogonally rotating an image.
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BACKGROUND OF THE INVENTION
The present invention relates broadly to hospital fixtures and, more particularly, to a headwall fixture which defines a station for neonatal infant care and provides a cluster of necessary services, equipment and accessories.
Neonatal infant care facilities are areas in hospitals which care for premature babies and other infants who are in some form of medical distress. They may be placed in cribs or incubators and, as is common in modern hospitals, typically require a plethora of equipment to support and sustain life.
As is also common, neonatal infant care is provided in large rooms with a plurality of individual stations that provide all the necessary equipment to care for one infant thereat. The equipment typically includes air, vacuum, oxygen and electrical services. Further, blood pressure monitors, heart monitors, and other analyzers are common. Additionally, tools and hand-held instrumentation need to be close at hand.
Currently, neonatal headwall fixtures are typically rectangular cabinets having flat walls. A crib or incubator on wheels is rolled into a position adjacent the cabinet and positioned at whatever orientation provides the best access to the necessary services, instrumentation and accessories. Such an arrangement remains unfocused in that the infant support device, be it crib or incubator, may be positioned in virtually any orientation with respect to the headwall fixture. This is likely a sufficient arrangement, yet it is less than ideal for attending to neonatal infant care.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a neonatal infant care headwall fixture with a focused array of equipment.
It is another object of the present invention to provide such a headwall fixture which provides a positive location for the infant support device and convenient access to the necessary services and equipment.
To that end, a neonatal infant care headwall fixture defining an infant care station for concentrating infant care equipment in a neonatal infant care facility includes a body formed from a plurality of wall members including at least one vertically extending wall member defining a front surface and at least one horizontally extending wall member defining a top surface, the front surface and the top surface cooperating to define a recess for receiving therein at least a portion of an infant support structure to locate infant care equipment associated with the headwall fixture in juxtaposition with an infant support structure at least partially disposed within the recess.
Preferably, the front surface defining the recess includes three vertically oriented wall members disposed in a predetermined angular relationship with one another to define the recess in the vertically extending wall member. Preferably, the top surface includes three angularly oriented edge portions disposed in juxtaposition with the three vertically oriented wall members to define the recess in the horizontally extending wall surface.
It is preferred that the headwall fixture include at least one tower projecting upwardly from the horizontally oriented wall member for supporting infant care equipment associated with the headwall fixture. Preferably, the tower includes an electrical power supply accessible from outside the tower. It is further preferred that the tower include an arrangement for mounting infant care equipment thereto with the mounting arrangement including an assembly for releasably retaining the mounting arrangement at a predetermined vertical spacing from the top surface. It is further preferred that the mounting arrangement include an equipment support arm extending from the tower in a cantilevered manner.
It is additionally preferred that the assembly for releasably retaining the mounting arrangement at a predetermined vertical spacing from the top surface includes a vertically oriented slider rack mounted to the tower, a slider movably disposed within the slider rack and having a support arm mounted thereto and an assembly for releasably locking the slider in a predetermined position along the slider rack for supported vertical positioning of infant care equipment along the tower. The equipment support arm preferably includes at least one downwardly projecting support member mounted thereto for supporting infant care equipment suspended therefrom. Further, a second cantilevered support arm is mounted to the tower and the at least one downwardly projecting member to stabilize the downwardly projecting member.
Preferably, the body includes a plurality of selectively accessible storage compartments disposed therein with access to the storage compartments being available from the front surface. Further, at least one of the three vertically oriented wall members includes an assembly for accessing electrical power formed therein. Preferably, the assembly for accessing electrical power includes at least one electrical socket mounted to one of the vertically oriented wall members.
By the above, the present invention provides an efficient neonatal infant care headwall fixture which positively locates the infant support structure and gathers the necessary equipment for infant care in an efficient arrangement to enhance the ability of caregivers to sustain and support neonatal infant life.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a neonatal infant care headwall fixture according to the preferred embodiment of the present invention;
FIG. 2 is an elevational view of the tower structures associated with the neonatal infant care headwall fixture illustrated in FIG. 1;
FIG. 3 is a top plan view of the neonatal infant care headwall fixture illustrated in FIG. 1 with an infant support structure located thereat; and
FIG. 4 is a perspective view of the neonatal infant care headwall fixture with another infant support structure located thereat.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings and, more particularly, to FIG. 1, a neonatal infant care headwall fixture defining an infant care station for concentrating infant care equipment in a neonatal infant care facility is illustrated generally at 10 and includes a generally elongate floor-standing body 12 mounted against a hospital room wall 18. The fixture 10 includes a front surface 14, a top surface 16 mounted at right angles thereto, and a side wall surface 15 mounted at right angles to both the front surface 14 and the top surface 16. The top surface 16 is formed as a generally planar countertop with the front surface 14 projecting downwardly therefrom with a baseboard 19 intermediate the lower portion of the front surface 14, side surface 15 and the floor. It should be noted that several fixtures according to the present invention may be used in abutment with one another, thereby concealing the side wall 15.
In order to properly locate an infant care support structure such as a crib 74 as seen in FIG. 3 or an incubator 76 as seen in FIG. 4, a recess 20 is formed in the body to include the top surface 16 and the front surface 14. The recess 20 is centrally located between either end of the headwall fixture 10 and creates an indentation in the front surface 14 and the top surface 16 which extends almost halfway across the top surface 16 toward the hospital wall 18. The recess 20 is best seen in FIGS. 1 and 3. It is preferred that the recess be formed from three vertically oriented wall members 22,24,26 which extend inwardly toward the hospital wall 18 from the outermost extent of the front surface 14. As best seen in FIG. 1, the recess 20 is also formed from three edge portions 22a, 24a, 26a, which are cut into the top surface 16 and which have an angular relationship and orientation that correspond generally to the angular relationship and orientation between wall members 22, 24, 26, as described hereafter. These vertically oriented wall members 22,24,26 are disposed at a predetermined angular relationship with one another with the center wall 24 of the three walls 22,24,26 being generally parallel with the outermost extent of the front surface 14. The width of the central wall 24 is slightly wider than the width of the infant support structure, such as the crib 74 and the incubator 76, seen in FIGS. 3 and 4, respectively. The recess 20 acts as the focal point for the entire headwall fixture 10 and allows the personnel associated with positioning the infant support structure to readily locate the infant support structure in its optimum position for neonatal infant care. As may be expected, the optimum position is associated with the optimum placement of equipment.
To enhance equipment placement, a pair of towers 44,50 are mounted to the top surface 16 and are formed as generally square rectangular members projecting vertically upwardly. They are mounted to the top surface 16 using a flange-like base 48,68 and conventional screws or bolts 49. Each tower 44,50 is placed on either side of the recess 20 for easy access by hospital personnel. It should be understood that the following descriptions of the towers offer specific structural features and these structural features, while illustrated on one tower or the other, are interchangeable and no one tower should be considered as the only configuration available.
A first tower 44 includes electrical sockets 46 for attachment of electrical power equipment. A pressure gauge 84 is mounted thereto in a cantilevered manner to illustrate the ability of the tower to accommodate various equipment.
A second tower 50 is somewhat more complex. As seen in FIG. 2, the second tower 50 is formed similarly to the first tower 44 and includes similar electrical outlets 54. A slider rack 60 is mounted to the side of the tower facing outwardly from the wall 18 and includes a slider 58 slidably mounted thereto. A locking nut 62 is provided to lock the slider in place. A pivotal arm 56 is mounted in a cantilevered manner to project outwardly from the slider 58 and supports some form of infant care equipment, shown as a monitor 52 connected to the electrical outlet 54 in FIG. 2. As may be expected, the lock nut 62 may be loosened and the slider 58 moved along the track 60 to position the monitor 52 at any predetermined vertical spacing from the top surface 16.
Optionally, two spaced parallelly oriented arms 64,70 are pivotally mounted to another side of the tower 50 and are tightened in place using hand wheel 72. Two downwardly projecting members 69 extend therebetween. These downwardly projecting members accommodate further equipment, such as the analyzer illustrated in FIG. 2. A plurality of hooks project upwardly from the downwardly projecting member 69 with the hooks 67 configured to hold scissors, hemostats, tape or other items off the top surface 16.
The lower portion, i.e., the portion of the body 12 disposed below the top surface 16, includes a variety of fittings and attachments. Initially, a plurality of drawers 28 are arrayed about the body in a conventional, cabinet-like manner and are accessible using drawer pulls 29. Additionally, fixtures to supply vacuum 82, as well as fixtures to supply air 78, are mounted to the front surface 14. As is typical, the air and oxygen are mixed in a mixer 36 which is likewise mounted to the front surface 14. Mounting members 32 are provided to mount such items on the front surface 14 in a slidable manner such that they may be interchanged with other necessary equipment. A vacuum service 82 is provided and is attached to an evacuator 34. As may be expected, these accessories and fixtures are interchangeable with other fixtures and accessories using the mounting members 32. A plurality of electrical outlets 30 are provided on one of the three vertical walls 22. The power service to the headwall fixture is electrically isolated and access to a power panel is provided through an opening 38 in the central vertical wall 24. An isolation monitor 42 is likewise provided adjacent the access panel 38. Control of power is provided through a central switch 40 mounted to a vertically oriented wall 26. Further, while not specifically illustrated, the lighting associated with the present invention is equally versatile and several different lighting combinations can be accessed by a plurality of switches to provide lighting of different intensities as is generally known.
Variable bedside lighting is essential for promoting developmental gains in critically ill infants. Offering a range of lighting from 20 through 60 footcandles allows for accurate clinical assessment while minimizing the effects of bright direct light exposure to the infant.
In operation, and as is best seen in FIGS. 3 and 4, the hospital personnel can easily locate an infant support structure 74,76 by aligning it with the central wall 24 associated with the recess 20. This places all the necessary life support and caregiving equipment in easy reach of the hospital personnel with the equipment being configured and disposed for easy application to the infant for which care is to be given.
By the above, the present invention provides a neonatal infant care headwall fixture which improves over the prior art by providing a positive location for the infant support structure which adds to its ease of use and locates necessary life giving equipment closely adjacent the infant under care to enhance the ability of the hospital personnel to provide the necessary care in a neonatal infant care facility.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
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A neonatal infant care headwall fixture defining an infant care station for concentrating infant care equipment in a neonatal health care facility includes a body formed from a plurality of wall members with at least one vertically extending wall member defining a front surface and at least one horizontally extending wall member defining a top surface with the front surface and top surface cooperating to define a recess for receiving therein at least a portion of an infant support structure to positively locate the infant support structure and to locate infant care equipment associated with the headwall fixture in juxtaposition with an infant support structure at least partially disposed with the recess.
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BACKGROUND
1. Field of the Invention
The present invention is related to the dynamic routing of mobile agents.
2. Related Art
A mobile agent can be written as a program that executes on a set of network hosts. The agent visits the network hosts to execute parts of its program. The agent may need, for example, to access information located on a given network host or there may be some preference to execute parts of its program on various network hosts.
In the prior art, the sequence of hosts that the agent visits is statically pre-configured when an agent program is written. For example, U.S. Pat. No. 5,603,031, Feb. 11, 1997, issued entitled "System and Method for Distributed Computation Based Upon the Movement, Execution, and Interaction of Processes in a Network," by White et al., describes a method for statically pre-configuring an agent's itinerary in a destination list composed of destination objects. Each destination object has a telename and a teleaddress preassigned to specific regions of the network. A static pre-configuration of an agent's itinerary introduces a number of weaknesses. First, a pre-configured program is not robust because it can fail if the location of the information or destination objects changes or if the network host becomes unavailable after the mobile agent is configured. Second, the pre-configured program is not amenable to a dynamic environment where network hosts can become unsuitable due to an increasing load. Third, the system can be difficult to manage because information or destination objects cannot be freely relocated without causing the programs that use them to fail. In "IBM Aglets WorkBench--Programming Mobile Agents in Java," by Lange et al., available on the World Wide Web at URL=http://www.trl.ibm.co.jp/aglets/whitepaper.html, Lange et al., suggest statically configuring multiple alternate network hosts. Although statically configuring multiple alternate network hosts may lessen some of the above weaknesses, it does not eliminate them.
SUMMARY
In accordance with the aforementioned needs, the present invention is directed to an improved method and apparatus for dynamic execution of mobile agents. In a preferred embodiment, a mobile agent is written using symbolic names for its constituent components. A symbolic name can be one of a physical address of a machine, a logical address of a machine, and a logical name of a component.
The present invention has features wherein a symbolic name for a component to be executed can be dynamically resolved using a component directory to determine an appropriate network host that the agent needs to visit. Preferably, the component directory can be queried by client or host machines, and updated by component hosts.
The present invention has other features which enable more robust agents. For example, changes in a component's location and/or availability can be captured at runtime and the agents dynamically routed to alternate component hosts.
The present invention has still other features which enable agents to flexibly accommodate the dynamics of the system. For example, if the attributes of a component are modified, or a component host becomes heavily loaded, agents can adapt to such changes by looking up an alternate host for the same component.
The present invention has yet other features which allow for improved system manageability. For example, component hosts can freely update a component's location and/or attributes at any time. Changes to code for agents that use components residing at an updated component location are not required.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will become apparent from the accompanying detailed description and drawings, wherein:
FIG. 1 shows an example of a loosely-coupled system having features of the present invention;
FIG. 2A shows an example of the Component Directory of FIG. 1;
FIG. 2B shows an example of a record in the Component Directory;
FIG. 2C shows an example of logic for the Query Subsystem of FIG. 1;
FIG. 2D shows an example of logic for the Update Subsystem of FIG. 1;
FIG. 3 shows an example of logic for the Agent Personal Assistant of FIG. 1;
FIG. 4 shows an example of logic for the Agent Execution Shell of FIG. 1; and
FIG. 5 shows an example of logic for the composition, routing, and execution of an agent.
DETAILED DESCRIPTION
FIG. 1 depicts an example of a system having features of the present invention. Here, a loosely-coupled system connects computers that have distinct roles in the system. The computers 102-106, which can be running conventional operating systems such as OS2, UNIX, AIX, or Windows NT, are interconnected by way of a communication network 108 and communication protocol. The communication protocols can be, e.g., Sun Microsystems RPC, which can run either on UDP/IP or TCP/IP. The network 108 can be a LAN, Internet, or intranet. The client 102 and Component Host 104 can be embodied as conventional personal computers (PC) such as IBM PCs. The Directory Server 106 can be embodied by conventional servers such as an IBM RISC System/6000 machine. Note that the distinction between a Client 102 and a Component Host 104 is logical only.
Although a single Client 102 is shown, there can be many client machines in the system. Agents are invoked on the Client machines. The execution of an agent is coordinated on the Client by a software subsystem called the Agent Personal Assistant (APA) 110 (details in FIG. 3) which is invoked each time an agent is launched on a client machine.
On each computer there is a conventional Communication System 112, such as the TCP/IP stack in the operating system, that is used to communicate over the network. The system also includes a Component Host 104. Although only one is shown, there can be a plurality of Component Hosts in the system. The Component Host 104 stores a number of Components 124 that can be accessed by agent programs running on this machine. Components can be considered as one or more object classes including applets and servlets. Those skilled in the art will appreciate however, that a component can be generalized to any executable unit of code. According to the present invention, each Component Host includes a software subsystem called an Agent Execution Shell 120 (details in FIG. 4) that acts as the single coordinator for component execution by any agent.
The Component Host also has a Component Manager 122 subsystem that manages the local components 124. An example of a conventional Component Manager is an object store for serving and locally managing Components 124. such as is sold under the trademark OBJECTSTORE by Object Design (see e.g., http://www.odi.com). The Component Manager 122 serves components to the Agent Execution Shell 120. According to the present invention, the Component Manager 122 is adapted to communicate with the Directory Server 106 to query or update component 124 properties. The Component Manager 122 may also add new components, delete components, or modify component names, locations, and attributes. The Component Manager 122 may update component properties in an explicit fashion under the control of a system administrator. The Component Manager 122 can also periodically update dynamic component attributes such as availability and the load on the Component Host.
The system also includes a Directory Server 106. An example of a Directory Server can be any LDAP compliant server such as Netscape's DIRECTORY SERVER. One skilled in the art can realize the same function using a standard database management server (DBMS) such as is sold by IBM under the trademark DB2. The Directory Server can also be embodied by a plurality of computers cooperating together and appearing as a single directory server. Although it is shown separately, the Directory Server 106 could alternately reside on a Component Host 104, or even a client (having sufficient performance and storage).
As will be discussed in more detail with reference to FIGS. 2-5, the Directory Server and Component Directory 134 provide important features of the present invention. For example, a symbolic name for a named component to be executed can be dynamically resolved using the Component Directory to determine an appropriate Component Host 104 that the agent needs to visit. Preferably, the Component Directory can be queried by Clients 102 or Component Hosts 104 and updated by Component Hosts. As will be discussed with reference to FIG. 2A and 2B, the Component Directory 134 can be implemented as a conventional relational table that includes a plurality of directory entries 202 (also called records). Each directory entry stores component properties such as the name, location, and attributes of the component. Those skilled in the art will appreciate that although the preferred embodiment implements the function of the Directory Server 106 as a conventional DBMS, that the present invention could be implemented using a non-relational table or other structure, such as a tree.
Referring again to FIG. 1, the Directory Server includes a Query Subsystem 130 and an Update Subsystem 132. The Query Subsystem 130, which will be discussed in more detail with reference to FIG. 2C, allows the client 102 or Component Host 104 to query the contents of the Component Directory 134. The Update Subsystem 132, which will be discussed in more detail with reference to FIG. 2D, allows component hosts to add, modify, or delete components in the component directory.
FIG. 2A shows a more detailed example of the Component Directory 134. As will be described with reference to FIG. 2B, the Component Directory 134 includes a plurality of Directory Entries 202.
FIG. 2B shows a more detailed example of a Directory Entry 202. As depicted, each Directory Entry 202 stores properties and a set of attributes for a single Component 124. The component attributes are attribute name and value pairs describing supported features. In this example, each entry 202 stores a plurality of attribute values for component properties 203a . . . 203n such as the name 203b, location 203a, and/or other attributes 203c . . . 203n of the component such as a machine architecture type or a load indicator.
FIG. 2C shows an example of logic for the Query Subsystem 130. As depicted, in step 204, a query request message from a Client 102 or Component Host 104 arrives at the Query Subsystem 130 of the Directory Server 106. The query request message contains the name and attributes of a desired component and preferably the number of desired locations to be returned that match the specified name and attributes. In step 206, the Query Subsystem 130 retrieves the requested number of component locations 203a from the Component Directory 134 that match the name 203b and attributes 203c . . . 203n in the query request message. In step 208, the Directory Server 106, communicates a query result message containing the retrieved component locations to the requesting Client 102 or Component Host 104.
FIG. 2D shows an example of logic for the Update Subsystem 132. As depicted, in step 220, an update message arrives from a Component Host 104 to the Update Subsystem 132 of the Directory Server 106. In step 222, the Update Subsystem 132 updates (adds, modifies, or deletes) one or more Directory Entries 202 specified in the update message. In step 224, the Directory Server 106 then communicates an acknowledgment to the requesting Component Host 104.
FIG. 3 shows an example of logic for the Agent Personal Assistant 11O. The Agent Personal Assistant (APA) 110 is preferably invoked each time an agent is launched by a client. In step 302, the APA inspects the agent to determine the name and attributes of the first component that the agent needs to execute. In step 304, the APA queries the Directory Server 106 with the name and attributes of the first component and obtains a location 203a of a Component Host 104 for the first component. In step 306, the APA tests if the location is satisfactory, for example by determining if the Component Host is unreachable due to a failure or a network partition. A failure could be indicated, for example, by a time-out when querying the Component Host. If the location is not satisfactory, the process returns to step 304 and the APA can query the Component Directory 134 for another location. Thus, the present invention enables agents to flexibly accommodate the dynamics of the system. If the attributes of a component are modified, or a Component Host becomes overloaded, agents can adapt to such changes by looking up an alternate host for the same component. If the location is satisfactory, in step 308, the APA dispatches the agent to that location. Alternately, the component could be downloaded from the Component Host for execution on the client. In this alternative the process would return to step 302 (and repeat) until the client executed all the components. In step 310, the APA waits until it receives a completion notification from the Component Host that executed the last component of the agent. The process ends in step 312, upon receipt of the completion notification.
FIG. 4 shows an example of logic for the Agent Execution Shell (AES) 120. Unlike the APA 110, which is invoked each time an agent is launched on the client, the AES logic preferably runs, for example, as a daemon on the Component Host 104 and coordinates the execution of all agents on the Component Host 104. In step 402, the AES 120 waits for an agent to arrive. In step 404, upon the arrival of an agent, the AES executes the first component of the agent and removes it from the agent. In step 406, the AES determines if there are any more components that this agent needs to execute. If not, in step 408, the AES sends a completion notification to the originating client and the process repeats, at step 402. If there are more components to be executed, in step 410, the AES determines the name and attributes of the next component associated with the agent. In step 412, the Component Manager 122, queries the Directory Server 106 with the additional name and attributes and obtains a corresponding component location. In step 414, the AES 120 tests, for example, if the location is satisfactory by determining if the location is unreachable, for example, due to a failure. If the location is not satisfactory, the process iterates step 412 and step 414, i.e., the AES repeatedly queries the Component Directory and tests new locations until a satisfactory location is obtained. In step 416, when a satisfactory location is obtained, the AES forwards the agent to that location. The process then returns to step 402 and the AES waits for another agent to arrive. Note that in an alternative embodiment, the AES 120 can create a delegate to coordinate actual component execution and agent forwarding while it simply waits for the arrival of the next agent.
FIG. 5 shows an example of logic for the composition, routing, and execution of a dynamic mobile agent in the system. By way of example only, the system depicted includes a client 102, four Component Hosts 104a-104d, and a single Directory Server 106. The agent initially includes a list 512 of four component names A, B, C, and D that are to be executed in order. In step 522, the client 102 queries the Directory server 106 for component A and obtains the value of the corresponding location 203a, in step 524. Next, the client 102 forwards the agent including the list 512 to the Component Host 104a for component A. The Host 104a then executes component A and removes it from the agent's list 514 of components. In step 526, the Component Host 104a queries the Directory Server 106 for the location of component B. In step 528, the Component Host 104a obtains the value, here Host 104b, of the corresponding location 203a for component B. Next, the Component Host 104a dispatches the updated agent 514 to the Host 104b for component B. In steps 530-536, the remaining components of the agent are similarly located and executed on component hosts 104b and 104c. Finally, Component Host 104d executes the last component of the updated agent 518 and sends a completion notification 520 to the client 102.
Now that the invention has been described by way of a preferred embodiment, various modifications and improvements will occur to those of skill in the art. Thus, it should be understood that the preferred embodiment is provided as an example and not as a limitation. The scope of the invention is defined by the appended claims.
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An improved method and apparatus for dynamic execution of mobile agents. For example, a symbolic name for a component to be executed can be dynamically resolved using a component directory to determine an appropriate network host that the agent needs to visit. Preferably, the component directory can be queried by client or host machines, and updated by component hosts. Changes in a component's location and/or availability can also be captured at runtime and the agents dynamically routed to alternate component hosts. Still other features enable agents to flexibly accommodate the dynamics of the system. For example, if the attributes of a component are modified, or a component host becomes heavily loaded, agents can adapt to such changes by looking up an alternate host for the same component. Yet other features provide improved system manageability. For example, component hosts can freely update a component's location and/or attributes at any time. Changes to code for agents that use components residing at an updated component location are not required.
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FIELD OF THE INVENTION
[0001] The present invention relates to a textile component, and more particularly to a textile component with collagen.
BACKGROUND OF THE INVENTION
[0002] Textile clothes is one of article in necessity for human beings. The textile clothes and textile article, such as garment, pants, and sock, helps people to adapt the change of temperature when is used for covering the body, and also prevents us from dusts or germs as well. Textile is an element of the textile article. Textile article is formed by spinning textile.
[0003] The material of textile directly decides its functionality and effective application of the textile article. For example, the artificial fiber is advantage in that it is not so expensive, easy washed, and not easy to shrink. However, it is not environmental-friendly, bad water absorption, and bad contact feel. On the other hand, the vegetal fiber is overwhelming in that it is good in absorption and its softness. However it is wrinkly and poor heat resistance. In another aspect, the animal fiber is good in elasticity, heat preservation, shrink resistance, and easy for dyeing, and in the contrary it is too expensive to be used to form a textile.
SUMMARY OF THE INVENTION
[0004] Although the technologists constantly investigate the material of the textile. The focus is rare to the field of textile to improve the effect for the skin of human beings. It should be deeply concerned that some textiles even cause the skin allergy. Further to the effect of textile such as cold resistance, easy washed, water absorption, the invention is effect to improve the health of skin in regard with the textile.
[0005] Accordingly, an aspect of the present invention is to provide a textile component with collagen that improves the health of skin.
[0006] The textile component with collagen comprises a plurality of textile members, wherein the textile member includes a first fiber component and a second fiber component. The first fiber component is composed of a fiber with collagen. The second fiber component is without any fiber with collagen. The outer surface of the first fiber component and the outer surface of the second fiber component contact each other along the length direction of the first fiber component by textile spinning
[0007] According to an embodiment of the present invention, the second fiber component includes an elastic fiber.
[0008] According to an embodiment of the present invention, the first fiber component and the second fiber component combine with each other by textile spinning, wherein the proportion between the first fiber component and the second fiber component is 1:1.
[0009] According to an embodiment of the present invention, the fiber with collagen includes a collagen and a fiber, the collagen bonds with the fiber at the bonding part of the fiber.
[0010] According to an embodiment of the present invention, the collagen bonds with the fiber by dipping the fiber in a collagen solution of which the temperature is 60-70 degrees Celsius and then stirring the collagen solution.
[0011] According to an embodiment of the present invention, the first fiber component has 8%-10% collagen thereof.
[0012] According to an embodiment of the present invention, the textile member has less than 3% collagen thereof.
[0013] According to an embodiment of the present invention, the fiber is a rayon fiber.
[0014] By means of technical means of the present invention, the collagen can be in contact with the skin so as to contribute to the efficacies for, as example, anti-aging, skin-whitening, and wrinkles-eliminating when people wear the textile article of the invention. Since the collagen has hydrophilic natural moisturizing factor (NMF) that has good water retentivity for keeping the skin moist, supple, and glossy. And the skin pores can be narrowed and the skin wrinkles can be smoothed out to let skin looks tensely and elastically. Also it can improve the metabolism of skin and provide the skin cell with a more healthy ambience.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings.
[0016] FIG. 1 is a diagrammatic drawing illustrating the textile component of the first embodiment according to the present invention;
[0017] FIG. 2 is a diagrammatic drawing illustrating the textile component of the second embodiment according to the present invention;
[0018] FIG. 3 is a diagrammatic drawing illustrating the textile component of the third embodiment according to the present invention;
[0019] FIG. 4 is a process flow chart illustrating the textile component of the third embodiment according to the present invention;
[0020] FIG. 5A is a diagrammatic drawing illustrating the collagen solution;
[0021] FIG. 5B is a diagrammatic drawing illustrating the fiber dipping in the collagen solution;
[0022] FIG. 5C is a diagrammatic drawing illustrating stirring the collagen solution;
[0023] FIG. 5D is a diagrammatic drawing illustrating the first fiber component of the third embodiment according to the present invention;
[0024] FIG. 5E is a diagrammatic drawing illustrating the textile member of the third embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The First Embodiment
[0025] A textile component with collagen 100 of the present invention is shown in FIG. 1 . FIG. 1 is a diagrammatic drawing illustrating the textile component of the first embodiment according to the present invention. The textile component with collagen 100 of the present invention comprises a plurality of textile members 1 . The textile member 1 comprises: a first fiber component 11 composed of a fiber with collagen 110 ; and a second fiber component 12 without any fiber with collagen. The outer surface of the first fiber component 11 and the outer surface of the second fiber component 12 contacting each other along the length direction of the first fiber component 11 by textile spinning. The fiber with collagen 110 includes a fiber 111 and a collagen 112 . The collagen 112 is a polymeric substance constituting the interstitial matrix between cells and plays a role as a connective tissue in the animal. It can supplement nutrition to the skin and enhance the collagen activity in skin.
[0026] In this embodiment, the textile component 100 is a pants, and the textile member 1 is the cloth of the textile component 100 . The first fiber component 11 and the second fiber component 12 are the fibers of the textile member 1 . Because the first fiber component 11 of the textile component 100 has the collagen 112 , the collagen 112 of the first fiber component 11 is in contact with the skin when the users wears the textile component 100 , thereby the skin can be moisten by the collagen 112 and thus be good in maintenance.
The Second Embodiment
[0027] Refer to FIG. 2 . FIG. 2 is a diagrammatic drawing illustrating the textile component of the second embodiment according to the present invention. The textile component 100 a of the second embodiment is different from the textile component 100 of the first embodiment as follows. In this embodiment, the textile component 100 a is an upper garment. And the second fiber component 12 of the textile component 100 a includes an elastic fiber, such as Lycra fiber. Thereby, the textile component 100 a is not easy to be deformed and is fitted and comfortable. And the textile component 100 a can easily return to be smooth after being wrinkled. Also the collagen 112 is in contact with the skin more closely so that the maintenance efficacy to the skin is more obvious. In this embodiment, the textile member la is formed by twining the first fiber component 11 and the second fiber component 12 together, wherein the proportion between the first fiber component 11 and the second fiber component 12 is 1:1.
The Third Embodiment
[0028] Refer to FIG. 3 . FIG. 3 is a diagrammatic drawing illustrating the textile component of the third embodiment according to the present invention. In this embodiment, the textile component 100 b is a tights. The textile member lb of the textile component 100 b includes the first fiber component 11 , the second fiber component 12 , and a third fiber component 13 . The second fiber component 12 and the third fiber component 13 combine with the first fiber component 11 by textile spinning, wherein the second fiber component 12 and the third fiber component 13 are fiber components without any fiber with collagen.
[0029] Because too much collagen will also cause skin allergy, the proportion of the collagen in the clothes is preferably less than 3%. In this embodiment, the proportion (surface area proportion) between the first fiber component 11 , the second fiber component 12 , and the third fiber component 13 is 20:40:40 in the textile member 1 b of the textile component 100 b. The first fiber component 11 has 8%-10% collagen 112 thereof, so the textile member 1 b has less than 3% collagen 112 thereof. However, the present invention is not limited to that proportion, the proportion between the first fiber component 11 , the second fiber component 12 , and a third fiber component 13 can be adjusted according to user's requirement.
[0030] The fiber 111 and the collagen 112 can be combined with each other by drying, resin molding, or any other methods. In order to make a better combination between the fiber 111 and the collagen 112 , the combination method in this embodiment is as follows.
[0031] Refer to FIG. 4 . First, provide a collagen solution S of which the temperature is 60-70 degrees Celsius (step S 1 ). The collagen solution S is a solution containing the collagen 112 dissolved therein as shown in FIG. 5A . Next, as show in FIG. 5B , dip the fiber 111 in the collagen solution S (step S 2 ). In this embodiment, the fiber 111 is a rayon fiber. The fiber 111 also can be other fiber, such as cotton fiber, linen fiber, nylon fiber, or wool fiber. As show in FIG. 5C , stir the collagen solution S (step S 3 ) to generate a bond 114 between the collagen 112 and a bonding part 113 of the fiber 111 that makes the fiber 111 and the collagen 112 bond with each other, and so that the fiber with collagen 110 is formed and then forming a first fiber component 11 b, as show in FIG. 5D .
[0032] After forming the first fiber component 11 b, dry the first fiber component 11 b (step S 4 ) for following textile process. This step is not necessary and can be omitted in some conditions. And then combine the first fiber component 11 b, the second fiber component 12 , and the third fiber component 13 by textile spinning to form the textile member 1 b (step S 5 ), as show in FIG. 5E . In this embodiment, the second fiber component 12 is an elastic Lycra fiber and the third fiber component 13 is a nylon fiber, thereby the elasticity of the textile member 1 b and the pull resistance of the textile member 1 b both increase. Of courses, this step is not necessary and also can be omitted.
[0033] And then combine a plurality of textile members 1 b to form the textile component 100 b (as show in FIG. 3 ) (step S 6 ). By means of the steps mentioned above, the textile component 100 b which functions as collagen can be formed. The textile component 100 b is elastic and tensile so it can contact the skin closer with the more obvious efficacy of collagen. Note in the steps mentioned above, the ambient temperature and the temperature for ironing the textile component can't be larger than 110 degrees Celsius in order to prevent the collagen within the textile component from being damaged.
[0034] The garment, pants, and tights are taken as the example as the textile component in above embodiments. However, the present invention is not limited to those examples. The sleeve, hat, mouth mask, eyeshield, face shield, hoods, personal clothing, and all kinds of socks also can be made of the textile component.
[0035] As can be appreciated from the above embodiments, the textile component with collagen of the present invention has industry worth which meets the requirement for a patent. The above description should be considered as only the discussion of the preferred embodiments of the present invention. However, a person skilled in the art may make various modifications to the present invention. Those modifications still fall within the spirit and scope defined by the appended claims.
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A textile component with collagen includes a plurality of textile members, wherein the textile member includes a first fiber component and a second fiber component. The first fiber component is composed of a fiber with collagen. The second fiber component has no fiber with collagen. The outer surface of the first fiber component and the outer surface of the second fiber component contact each other along the length direction of the first fiber component by textile spinning. The collagen can be in contact with the skin so as to contribute to the efficacies for, as example, anti-aging, skin-whitening, and wrinkles-eliminating when people wear the textile component.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to motor vehicle clutches and more particularly to mechanical clutch actuating linkages for engaging and disengaging a clutch of a motor vehicle.
[0002] In the past some inexperienced or poorly coordinated operators of manual transmissions of motor vehicles have experienced problems when removing foot pressure from the clutch pedal or when releasing manual pressure from the handle on a handle bar too quickly or too slowly causing unwanted jerking of the motor vehicle or causing damage to the clutch. In particular, excessively rapid engagement of a clutch in a motor vehicle can shock the drive train of the motor vehicle. By preventing drive train shock, satisfactory balance of the vehicle and handling characteristics are enhanced. It is well known that clutch engagement needs to occur at a certain rate to be efficient. Engaging a clutch too quickly can damage the drive train components of the motor vehicle including the transmission, differential, half shafts, axles, and CV joints. Engaging the drive train too slowly can damage the clutch friction disc by causing clutch slippage.
[0003] Heretofore to achieve such a result a number of complicated designs have been employed.
[0004] An object of this invention is to ameliorate or eliminate problems of jerking of the vehicle caused by operation of the clutch by an inexperienced or physically challenged operator with a minimal complication and with few additional parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a partially schematic diagram showing a clutch pedal operated hydraulic clutch system in accordance with this invention for a motor vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position.
[0006] FIG. 2 is a partially schematic diagram showing a modification of FIG. 1 which is a clutch pedal operated embodiment of this invention comprising a mechanical clutch system for a motor vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position.
[0007] FIG. 3 is a schematic perspective drawing of a clutch pedal operated embodiment of this invention comprising a hydraulic clutch system for a motor vehicle incorporating dampers with a clutch housing and a transmission.
[0008] FIG. 4 is a schematic perspective drawing of a clutch pedal operated embodiment of this invention comprising a mechanical clutch system for a motor vehicle with a clutch housing and a transmission comprising a modification of FIGS. 2 and 3 also incorporating dampers with the orientation of the clutch housing and a transmission reversed for convenience of illustration.
[0009] FIG. 5A is a schematic diagram showing a manually operated embodiment of this invention employing a control lever mounted by a perch on a handlebar for operation of the clutch throw-out fork of a motor vehicle. FIG. 5A is a modification of FIG. 4 comprising a mechanical clutch system for a motorcycle type of vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position.
[0010] FIG. 5B is an enlarged schematic perspective drawing of a modification of FIG. 5A with the control lever rotated to expose the shaft of a damper. FIG. 5C is a modification of FIG. 5B with a damper in the perch in contact with the control lever.
[0011] FIG. 6 is a sectional view of a spring operated damper with a hollow damper cylinder containing a piston with a piston rod on the sealed end thereof extending through a cap bearing sealed by a bearing seal at the sealed end of the damper cylinder.
[0012] FIG. 7A is a perspective view of a spring operated damper including a damper cylinder and a piston rod extending through a cap bearing on the right end thereof. FIG. 7B is a side view of the damper of FIG. 7A with the piston rod extending from a cap bearing on the right end thereof. FIG. 7C is a left end view of the damper of FIG. 7A with a hole to access the needle valve adjustment screw for the (pressure or return) stroke of the damper (depending on manufacturer's design). FIG. 7D is a right end view of the damper of FIG. 7A with the piston rod 41 in the center of the cap bearing on the right end.
[0013] FIG. 8A is a perspective sectional view of a spring operated damper including a damper cylinder housing a damper piston from which the piston rod extends on the right through the center of a sealed cap bearing on the right end. A vent hole in the left end is formed in an orifice block. FIG. 8B is a sectional side view of the damper of FIG. 8A . FIG. 8C is a sectional left end view of the damper of FIG. 8A . FIG. 8D is a sectional right end view of the damper of FIG. 8A .
[0014] FIGS. 9A and 9B are partially sectional views of a slow compression, faster expansion hydraulic damper in accordance with this invention comprising a hydraulic cylinder which houses a damper piston with a piston rod and a return coil spring.
[0015] FIG. 9A shows the slow return damper with the piston rod in its normally extended position awaiting compression thereof by deactivation of the clutch pedal to drive the piston rod and the piston into the retracted position shown in FIG. 9B .
[0016] FIG. 9B shows the slow return damper with the piston rod and the damper piston in the fully shaft retracted position and with the damper spring fully compressed under external pressure previously exerted upon the piston rod.
[0017] FIG. 10A is a schematic drawing of a MagnetoRheological (MR) damper for use with a clutch actuating linkage. FIG. 10B is a schematic drawing of an electrical wiring circuit for increasing the viscosity of the MR fluid in the cylindrical housing in FIG. 10A by closing a normally open switch after a predetermined time delay.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIG. 1 is a partially schematic diagram of an embodiment of the present invention showing a hydraulic clutch system for a motor vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position. In FIG. 1 , the hydraulic clutch system 7 includes a clutch housing 42 , a transmission 43 and a drive shaft 44 from the engine to the clutch (not shown) which is located within the clutch housing 42 . The hydraulic clutch system 7 has been modified in accordance with the present invention to overcome the problem of jerking of the vehicle during rapid clutch engagement in a low gear by incorporation of dampers 40 A- 40 C for the purpose of retarding the return of the clutch to the fully engaged position. The hydraulic clutch system 7 has been converted to operate with smooth clutch engagement by installation in accordance with the present invention of one or more hydraulic or spring operated dampers 40 A, 40 B and 40 C with each having a piston rod 41 to ameliorate or eliminate problems of jerking of the vehicle caused by operation of the clutch by an inexperienced or physically challenged operator starting out from an at rest or stopped condition. Only one damper may be needed to perform with the improved operation provided by the present invention.
[0019] However to show alternative locations for a damper, FIG. 1 shows three dampers 40 A- 40 C with shafts 41 pressing upon parts of the linkage to a clutch system to ameliorate or eliminate problems of jerking of the vehicle caused by clutch operation by an inexperienced or physically challenged operator starting out from an at rest or stopped condition.
[0020] The pre-existing clutch system of FIG. 1 includes a clutch pedal 8 mounted on the proximal end of a pedal arm 11 which is mounted extending radially from the distal end of a rotatable cross shaft 10 so that when the clutch pedal 8 a vehicle operator depresses pedal 8 , in the direction indicated by the arrow above the clutch pedal 8 , the rotatable cross shaft 10 turns clockwise. A metal bearing 32 (shown in phantom) is provided to support the cross shaft 10 for rotation. The metal bearing 32 is integral with a support 33 (also shown in phantom) which is secured to the frame of the motor vehicle, as will be understood by those skilled in the art. A first weld 21 bonds the proximal end of the rotatable cross shaft 10 to a downwardly depending pedal return lever 12 (depending downwardly from the cross shaft 10 .) The pedal return lever 12 is secured to the proximal end of a return spring 13 that returns the clutch pedal 8 to its normally disengaged position. To perform that function, the return spring 13 is secured at its distal end to a mounting bracket 9 secured to the body of the motor vehicle. The pedal return lever 12 supports an actuating rod 14 that is comparatively short which, when pedal 8 is depressed, drives a piston (not shown) into the master cylinder 15 the hydraulic clutch system 7 . The hydraulic fluid tube 16 from a hydraulic master cylinder 15 in turn energizes a smaller hydraulic slave cylinder 17 . When the slave cylinder 17 is energized a master cylinder piston therein (not shown) extends a slave cylinder piston rod 18 which is outwardly projecting with its free end seated in a cup-like abutment 19 formed on a clutch disengaging lever referred to hereinafter as a throw-out fork 20 of a clutch system in the clutch housing 44 . When the piston rod 18 is extended, it presses upon the throw-out fork 20 thereby disengaging the clutch in the clutch housing 42 .
[0021] In accordance with this embodiment of the present invention, the three dampers 40 A- 40 C are shown for slowing reengagement of the clutch to ameliorate or eliminate problems of jerking of the vehicle caused by operation of the clutch by an inexperienced or physically challenged operator starting out from an at rest or stopped condition. A first damper 40 A is installed behind pedal arm 11 . A piston rod 41 actuated by the first damper 40 A pushes against the pedal arm 11 in the direction indicated by the arrow above the pedal 8 to slow down the return of the pedal 8 to its initial position prior to actuation, as shown in FIG. 1 , thereby slowing down reengagement of the clutch. The piston rod 41 of the first damper 40 A pushes in the same direction as the arrow next to the pedal 8 which is opposite direction from the force exerted by the return spring 13 , to retard the return of the pedal 8 to its initial position, slowing clutch engagement. The piston rod 41 of a second damper 40 B pushes the pedal return lever 12 clockwise against the force exerted by the return spring 13 and the shaft of a third damper 40 C presses against the throw-out fork 20 , both working to slow clutch reengagement.
[0022] In summary, with regard to the embodiment of the invention shown in FIG. 1 , when the clutch pedal 8 is depressed in the direction indicated by the arrow adjacent thereto, the clockwise rotation of the cross shaft 10 against the force of the return spring 13 causes the actuating rod 14 to actuate the hydraulic master cylinder 15 by pushing its piston into it, thereby forcing hydraulic fluid out of line 16 from the hydraulic master cylinder 15 through the hydraulic fluid tube 16 into the input of the hydraulic slave cylinder 17 causing the slave cylinder piston therein to extend its slave cylinder piston drive rod 18 therefrom so that it presses the clutch throw-out fork 20 to disengage the clutch (not shown) located in the clutch housing 42 . Later, when the force on the clutch pedal 8 is removed by withdrawing the foot of the operator therefrom, the cross shaft 10 tends to return to its original position, thereby causing the actuating rod 14 to pull the piston in the master cylinder 15 towards its original position, returning hydraulic fluid from the slave cylinder 17 through hydraulic fluid tube 16 into the master cylinder 15 . As the hydraulic fluid returns from the slave cylinder 17 to the master cylinder 15 the piston therein withdraws the drive rod 18 to the right. As the drive rod 18 withdraws, it relaxes the force on the throw-out fork 20 . As the throw-out fork returns to its original position, a conventional clutch return spring (not shown) within the clutch housing 44 causes the clutch to re-engage. The operation of the clutch throw-out fork, and the actual structural configuration of the elements employed to achieve disengagement of the clutch are well known to those skilled in the art and has been illustrated and described here in a general fashion to facilitate an understanding of the use of the damper(s) of the present invention.
[0023] FIG. 2 is a partially schematic diagram showing of an embodiment of the present invention which comprises a modification of FIG. 1 in the form of a clutch pedal operated mechanical clutch system for a motor vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position. In FIG. 2 , a metal tube 34 is inserted onto the proximal end of the cross shaft 10 which is longer than in FIG. 1 and which is secured thereto by a conventional set screw that is not visible at the angle shown in the drawing. A weld 35 secures the pedal return lever 12 to the metal tube 34 and thus to the cross shaft 10 . A weld 23 secures the proximal end of the metal tube 34 to a hole in the upper end of a crank 24 . The crank 24 comprises an elongated, rectangular metal plate. The weld 23 the tube 34 and the cross shaft 10 fill the hole in the crank 24 . As explained above, the crank 24 and the tube 34 are fixedly secured to cross shaft 10 for rotation therewith.
[0024] The crank 24 depends downwardly from cross shaft 10 and is oriented in a plane transverse to the axis of rotation of both the cross shaft 10 and the tube 34 . Pivotal attachment holes 25 through the crank 24 are spaced respectively at different distances from the common rotational axis of tube 34 and the cross shaft 10 . A clevis 26 is provided with a clevis pin 27 that is shown passing through one of the attachment holes 25 and adapted to be retained in the selected hole for pivotal motion therein by means of a cotter pin (not shown) on the remote side of plate 24 . An elongated actuating rod 28 includes a threaded section 29 at one end thereof for thread engagement with the clevis 26 . Rod 28 is adapted to be screwed a selected distance into clevis 26 to adjust the effective length of rod 28 , and a jam nut 30 is provided for locking the rod 28 to clevis 26 at the selected adjusted length. Adjacent to the free end of rod 28 , a comparatively short length thereof is bent through an angle to the main direction of elongation of the rod to facilitate engagement of the free end of rod 28 with abutment 19 on the throw-out fork 20 . Thus it is assured that the free end of the rod 28 extends into the cup-like abutment 19 at substantially right angles to the plane of the throw-out fork 20 to disengage the clutch by pressing upon the throw-out fork 20 .
[0025] In FIG. 2 , in accordance with the present invention, as in FIG. 1 , a first damper 40 A is shown installed behind pedal arm 11 with piston rod 41 of first damper 40 A pushing pedal arm 11 in the direction indicated by the arrow above the pedal 8 to slow down the return of the clutch pedal 8 to its initial position prior to actuation, as shown in FIG. 1 . The pedal return lever 12 is secured to the proximal end of a return spring 13 that returns the clutch pedal 8 to its normally disengaged position. The piston rod 41 pushes in the same direction as the arrow next to the pedal 8 . That is the opposite direction from the force exerted by the return spring 13 , thereby retarding the return of the clutch pedal 8 to its initial position. As in FIG. 1 , the shaft of a third damper 40 C presses against the throw-out fork 20 . In FIG. 2 , a modification comprises using a fourth damper 40 D with its piston rod 41 pushing the plate 24 and the pedal return lever 12 clockwise against the force exerted by the return spring 13 .
[0026] Thus return motion of clutch pedal 8 to its initial position slows as in FIG. 1 . Also as in FIG. 1 , piston rod 41 pushes in the same direction as the arrow next to pedal 8 which is opposite direction from the force exerted by return spring 13 , thereby retarding the return of the pedal 8 to its initial position. As in FIG. 1 , piston rod 41 of second damper 40 B pushes pedal return lever 12 clockwise against the force exerted by return spring 13 . As in FIG. 1 , the shaft of the third damper 40 C presses against the throw-out fork 20 .
[0027] FIG. 3 is a schematic perspective drawing of a clutch pedal operated embodiment of this invention comprising a hydraulic clutch system 7 for a motor vehicle with a clutch housing 42 and a transmission 43 . As with FIG. 1 , the hydraulic clutch system 7 has been converted to operate with smooth clutch engagement by installation in accordance with the present invention by incorporation of two hydraulic or spring operated dampers 40 A and 40 C, each of which has a piston rod 41 . As with FIG. 1 , the pre-existing clutch system includes a clutch pedal 8 mounted on the proximal end of a pedal arm 11 which is mounted extending radially from the distal end of a rotatable cross shaft 10 so that when the clutch pedal 8 is depressed by the operator of the vehicle (in the direction indicated by the arrow above the clutch pedal 8 ,) the rotatable cross shaft 10 turns clockwise. A metal bearing 10 B secured to the vehicle body supports the cross shaft 10 for rotation. The pedal arm 11 is secured to the proximal end of a return spring 13 that returns the clutch pedal 8 to its normally disengaged position. The return spring 13 is fastened at its distal end to a mounting bracket 9 is secured to the body of the motor vehicle. In FIG. 3 , an actuating rod 14 is connected to pedal arm 11 by a clevis 26 so that when clutch pedal 8 is depressed, actuating rod 14 drives a piston (not shown) into the hydraulic master cylinder 15 of the clutch system, and the hydraulic fluid tube 16 from the hydraulic master cylinder 15 in turn energizes a smaller hydraulic slave cylinder 17 . When the slave cylinder 17 is energized a master cylinder piston therein (not shown) drives a slave cylinder piston rod 18 which projects outwardly. Its free end presses directly on the clutch throw-out fork 20 of a clutch system in the clutch housing 44 to disengage the clutch or to reengage it as the clutch pedal 8 is released. The dampers 40 A and 40 C and the piston rods 41 thereof perform as described above on the pedal arm 11 and the clutch throw-out fork 20 .
[0028] FIG. 4 is a schematic perspective drawing of a clutch pedal operated embodiment of this invention comprising a mechanical clutch system 7 for a motor vehicle with a clutch housing 42 and a transmission 43 comprising a modification of FIGS. 2 and 3 , with the orientation of the clutch housing 42 and a transmission 43 reversed for convenience of illustration. The cross shaft 10 located below the clevis 26 so that the disengagement rod 28 is pushed to actuate the throw-out fork 20 to disengage the clutch. The pedal arm 11 is secured to the proximal end of a return spring 13 that returns the clutch pedal 8 to its normally disengaged position; and the return spring 13 that is fastened at its distal end to a mounting bracket 9 is secured to the body of the motor vehicle. The dampers 40 A and 40 C and the piston rods 41 thereof perform as described above on the pedal arm 11 and the clutch throw-out fork 20 .
[0029] FIG. 5A is a schematic perspective diagram showing a manually operated embodiment of this invention employing a lever mounted by a perch on a handlebar for operated which is a modification of FIG. 4 comprising a mechanical clutch system for a motorcycle type of vehicle incorporating dampers for retarding the return of the clutch to the fully engaged position. A hand-operated control lever 22 is mounted by a perch 36 on a cylindrical handlebar 35 of a vehicle (not shown) such as a motorcycle, etc. The handlebar 35 is provided with a manually operated control lever 22 with a linkage, such as a cable linkage 37 or a rigid mechanical linkage (not shown) operated by reciprocation or in another manner well-known to those skilled in the art when the control lever 22 is actuated. Control lever 22 is secured to the handlebar 35 by a perch 36 , i.e. a handlebar mounting bracket. The perch 36 is clamped to the handlebar 35 in the conventional manner. The control lever 22 is pivotally secured to the perch 36 by a pivot axis screw/nut 22 N so that the control lever 22 pivots about the pivot axis screw/nut 22 N. A damper 40 A is inserted into the control lever with its piston rod 41 in contact with the perch 36 . The dampers 40 A and 40 C and the piston rods 41 thereof perform as described above on the pedal arm 11 and the clutch throw-out fork 20 .
[0030] FIG. 5B is an enlarged schematic perspective drawing of a modification of FIG. 5A with the control lever 22 rotated to expose the piston rod 41 of damper 40 A. FIG. 5C is a modification of FIG. 5B with a damper 40 E in the perch with the piston rod 41 of damper 40 E in contact with the control lever 22 .
[0031] FIG. 6 is a sectional view of a spring operated hydraulic damper 40 with a hollow damper cylinder 45 containing a piston 50 with a piston rod 41 on the sealed end thereof extending through a cap bearing 48 sealed by a bearing seal 48 S at the sealed end of cylinder 45 . The damper 40 includes a damper return coil spring 46 tending to drive the piston rod 41 out of the cylinder 45 . An orifice block 71 is provided at the other end of the hollow damper cylinder 45 . The orifice block 71 is adjusted by an orifice adjustment screw 72 . Inside of the hollow damper cylinder 45 is a piston/spring liner 73 . The liner 73 may contain grooves or holes to regulate the flow of hydraulic fluid during the compression stroke.
[0032] FIG. 7A is a perspective view of a spring operated damper 40 with a damper cylinder 45 , a left end 39 , and a piston rod 41 extending through a cap bearing 48 on the right end. FIG. 7B is a side view of damper 40 of FIG. 7A with piston rod 41 extending from the right end of damper 40 . FIG. 7C is a left end view of damper 40 with an access hole 38 in the left end 39 for access to a needle screw valve (not shown, but see FIG. 8B ) for adjustment of the (pressure or return) stroke of the damper (depending on manufacturer's design). FIG. 7D is a right end view of the damper 40 of FIG. 7A with piston rod 41 in the center of cap bearing 48 on the right end.
[0033] FIG. 8A is a perspective sectional view of a spring operated damper 40 including a damper cylinder 45 housing a damper piston 50 from which the piston rod 41 extends on the right through the center of sealed cap bearing 48 on the right end. The vent hole 38 in the left end 39 is formed in an orifice block 71 . FIG. 8B is a sectional side view of the damper 40 of FIG. 8A showing a needle valve adjustment screw 72 . FIG. 8C is a sectional left end view of the damper 40 of FIG. 8A . FIG. 8D is a sectional right end view of the damper 40 of FIG. 8A .
[0034] FIGS. 9A and 9B are partially sectional views of a hydraulic damper 65 in accordance with this invention. During a fast compression phase of operation, the damper 65 moves from the position shown in FIG. 9A to the position shown in FIG. 9B . During a slow expansion phase of operation, the damper 65 moves from the position shown in FIG. 9B to the position shown in FIG. 9A . The damper 65 includes a hydraulic cylinder 55 which houses a damper piston 70 with a piston rod 41 and a return coil spring 66 . Coil spring 66 is shown in the expanded position in FIG. 9A and compressed in FIG. 9B . Hydraulic cylinder 55 has a closed end 49 on the left. On the right hydraulic cylinder 55 is closed by a cap bearing 48 which includes a sealed shaft hole 48 S through which the piston rod 41 extends for reciprocal motion therethrough. The return coil spring 66 presses on the left against the proximal, closed end 49 of the hydraulic cylinder 55 and on the right against the left surface of piston 70 . The piston rod 41 is affixed to the distal, right end of the piston 70 . A feature of the damper piston 70 is that it includes two check valves 51 / 61 extending therethrough between the spring end 53 on the left and the shaft end 54 on the right. Those check valves 51 / 61 comprise a fast compression check valve 61 and a slow expansion check valve 51 . The fast compression check valve 61 includes a large diameter compression orifice 62 through the piston 70 operated by a compression orifice ball 57 . The slow expansion check valve 51 includes a small diameter orifice 52 operated by the expansion orifice ball 56 .
[0035] Piston 70 of FIGS. 9A / 9 B moves within the damper cylinder 55 in the presence of hydraulic fluid contained by cylinder 55 on both sides of the piston 70 . The slower flow orifice 52 of the slower flow expansion check valve 51 is somewhat smaller than faster flow orifice 62 of the faster flow compression check valve 61 . Slower flow orifice 52 is designed to assure a slow rate of expansion of coil spring 66 that causes extension of piston rod 41 . As a result, when clutch pedal 8 is released, piston rod 41 moves relatively slowly towards the position shown in FIG. 9A from the retracted position shown in FIG. 9B . On the other hand the faster flow compression orifice 62 is designed to provide a fast rate of retraction of the piston rod 41 when the clutch pedal 8 is depressed thereby pressing the piston rod 41 against the force of the compression spring 66 from the position shown in FIG. 9A into the position shown in FIG. 9B .
[0036] Referring to FIG. 9A , in operation of the hydraulic damper 65 , when spring 48 is forced to compress under pressure applied to the piston rod 41 by depression of the clutch pedal 8 , the hydraulic fluid flows rapidly through the faster flow compression check valve 61 from the left side to the right side of piston 70 . On the other hand, when the coil spring 66 is enabled to expand, as the pressure on the clutch pedal 8 is removed by the operator of the motor vehicle, the hydraulic fluid flows slowly through slower expansion check valve 51 to the left side from the right side of piston 70 In other words, because the orifice 62 of the faster flow compression check valve 61 is larger than the orifice 52 of the slower flow expansion check valve 51 , when foot pressure is applied to clutch pedal 8 thereby pressing the piston rod 41 to the left, the coil spring 66 contracts at a faster rate than it can expand since the hydraulic fluid is freely passing through the larger, faster flow compression orifice 62 of the fast compression check valve 61 .
[0037] Referring to FIG. 9B , the slow expansion phase of operation of the damper 65 follows the fast compression phase of operation of the damper 65 as described above. During the expansion phase, the damper coil spring 66 pushes on the piston 70 which restores the damper 40 to the uncompressed state over a period of time in preparation for providing slow engagement of the clutch after the pedal 8 is released. The damper piston rod 41 pushes directly on the pedal 8 (or indirectly on the linkage thereto) thereby slowing engagement of the clutch while slowing movement of the pedal 8 towards the released position thereof. Fluid within the damper cylinder 55 on the left side of the piston 70 is driven through expansion check valve 51 while applying considerable resistance to the action of the spring and tending to counteract the forces which would otherwise rapidly restore the pedal 8 to the released position. Assuming that the damper cylinder 55 contains a medium weight hydraulic oil then both orifices 52 and 62 would have to be nearly the same size with the compression orifice 62 being larger than the expansion orifice 52 so that the recovery under low pressure is as slow or slower as the compression speed is under high pressure forcing oil from left to right through compression orifice 62 .
[0038] FIG. 9A shows the slow return damper 65 with the piston rod 41 in its normally extended position awaiting withdrawal thereof by activation of the clutch pedal 8 which will drive the piston rod 41 and the piston 70 into the retracted position shown in FIG. 9B . The slow return damper 60 is shown with the piston rod 41 fully extended because the coil spring 66 has pressed the piston 70 against the cap bearing 48 and little or no force is pressing upon the distal end 47 of the damper piston rod 41 . In other words, the piston 70 has been driven to the right end of the cylinder 32 by the force of the coil spring 66 so that the piston rod 41 is fully extended by the force of the coil spring 66 exerted upon the piston 70 which is also in its fully extended position. Thus piston rod 41 is fully extending the out through the cap bearing 48 of cylinder 45 in position to limit the rate of motion of an object, such as the mechanism linked to the clutch pedal 8 contacted by the distal end 47 of the piston rod 41 . The damper 65 can be employed with an embodiment with a clutch pedal 8 , as described in connection with FIGS. 1-4 and a hand-operated control lever 22 on a handlebar as in FIGS. 5A-5C .
[0039] FIG. 9B shows the slow return damper 65 with the piston rod 41 and the damper piston 70 in the fully shaft retracted position and with the damper spring 46 fully compressed under external pressure exerted upon the piston rod 41 in the direction of the arrow proximate to the piston rod 41 by a force such as that exerted upon a clutch pedal 8 , as described in connection with FIGS. 1-4 and a hand-operated control lever 22 on a handlebar as in FIGS. 5A-5C .
[0040] FIG. 10A is a schematic drawing of MagnetoRheological (MR) damper 116 which comprises a cylindrical housing 120 and a piston 130 with an attached hollow piston rod 132 . Housing 120 contains MR fluid 118 . The proximal end 122 of cylindrical housing 120 is closed, and it has an attachment eye 124 secured to proximal end 122 . At the distal end of cylindrical housing 120 a seal 128 retains MR fluid in the cylindrical housing 120 . The seal 128 has an opening for reciprocation of the piston shaft 132 therethrough. The piston rod 132 is secured to the wall 134 of the motor vehicle by mounting elements and a threaded nut 138 screwed onto the distal end of the piston shaft 132 . Wires 146 and 156 are connected through the distal end of the piston rod 132 to the piston 130 to energize an electromagnet 140 formed on the piston 130 . The electromagnet 140 is energized to raise the viscosity of the MR fluid, as will be well understood by those skilled in the MR damper art, to slow the movement of the piston 130 in the cylindrical housing 120 when the circuit 142 in FIG. 10B has been in the ON condition for a predetermined time delay of about two seconds.
[0041] FIG. 10B is a schematic electrical wiring diagram of a circuit 142 for increasing the viscosity of the MR fluid in the cylindrical housing 120 in FIG. 10A by closing a Normally Open (NO) switch 152 with a button 151 when the clutch is disengaged turning ON the output of circuit 142 to the electromagnet 140 . The negative terminal of a DC voltage source 145 connects to electrical conductor 146 and to ground 147 . Electrical conductor 146 is one of the lead lines to a terminal of the electromagnet 140 in the cylindrical housing 120 . The positive terminal of the DC voltage source 145 is connects by line 146 to on terminal of NO switch 152 which is adapted to be energized manually by operating button 151 . When NO switch 152 is closed, it connects voltage to node 153 . Node 153 connects both to one terminal of NO switch 154 and one terminal of time delay relay (TDS) 155 . TDS 155 is connected at its other terminal to ground. TDS 155 closes NO switch 154 after the predetermined time delay of about two seconds to energize the electromagnet 140 by current passing through line 156 to the other terminal of the electromagnet 140 . When electromagnet 140 is energized it increases the viscosity of the MR fluid in the cylindrical housing 120 to slow engagement of the clutch when the pedal 8 or the control lever 22 is released by the operator of the motor vehicle. The circuit of FIG. 10B enables the MR damper 116 after the time delay provided by the time delay switch actuator TDS 1 155 and later disables the MR damper 116 after the vehicle is in motion.
[0042] In summary, referring to FIG. 10B , when the time delay switch 151 is closed turning the circuit 142 ON, (with pedal/lever IN) the time delay relay TDS 155 waits for a predetermined time before closing switch 154 to power the electromagnet 140 . The activated electromagnet 140 thickens the fluid in the MR damper 116 and slows the engagement of the clutch. When the linkage reaches it's “rest” position (OUT/engaged), the switches 151 and 154 both open, allowing the system to function again without delay until switches 151 and 154 are both closed once more. The time delay of the relay TDS 155 prevents the damper 116 from working during normal operation because it does not turn on the damper 116 unless the pedal or lever is disengaged for a longer time period than it takes to perform a normal shift. All embodiments of dampers 40 described above should move slowly. The pistons 50 / 70 in the dampers 40 / 65 move slowly at a “slow in” rate when the clutch engages under the high pressure force of the clutch drive train return mechanism (pressure plate). Similarly the pistons 50 / 70 in the dampers 40 / 65 also move slowly in the low pressure state when the piston is under the influence of the internal return springs 46 / 66 in the dampers 40 / 65 . This is done with the proper sized valving (during extension) and/or channels in the piston sleeve (during compression). The MR type of damper 116 of FIG. 10A operates with a fixed delay controlled by the TDS relay 155 , as described above.
[0043] The “slow out” damper movement is a principal feature of the present invention. After the vehicle is in motion, the damper does not have time to recover to the extended position and will not work. The advantage of this invention is that the device will not work to delay clutch reengagement in any normal driving situation other than starting out from a standing position.
[0044] Therefore, all models except MR should be “slow in” as the clutch engages under the high pressure force of the clutch drive train return mechanism (pressure plate), and “slow out” in it's low pressure state as the piston is under the influence of it's internal return spring. This can be done with the proper sized valving (during extension) and/or channels in the piston sleeve (during compression).
[0045] The “slow out” is the part that makes this invention useful. After the vehicle is in motion, the damper does not have time to recover to the extended position and will not work. The beauty of this device is that it will not work in any normal driving situation other than starting out.
[0046] The foregoing description discloses only exemplary embodiments of the invention. Modifications of the above disclosed apparatus and methods which fall within the scope of the invention will be readily apparent to those of ordinary skill in the art. While this invention is described in terms of the above specific exemplary embodiment(s), those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims, i.e. changes can be made in form and detail, without departing from the spirit and scope of the invention. Accordingly, while the present invention is disclosed in connection with exemplary embodiments thereof, it should be understood that changes can be made to provide other embodiments which may fall within the spirit and scope of the invention and all such changes come within the purview of the present invention and the invention encompasses the subject matter defined by the following claims.
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A motor vehicle includes a clutch linkage connected to a throw out lever which is operated by a clutch pedal or said control lever biased by a return spring to a clutch engaged position. A damper with a cylinder housing a piston and a piston rod delays excessively rapid engagement of the clutch by engaging the clutch linkage to provide a force opposed to pressure from the return spring. The damper functions to prevent mechanical damage to the motor vehicle and to avoid discomfort to passengers.
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RELATED APPLICATIONS
[0001] This application is a continuation in part of application Ser. No. 09/507,174, filed Feb. 18, 2000, which claimed priority from U.S. provisional patent application No. 60/120,842, filed Feb. 19, 1999. This application also claims priority from U.S. provisional patent application No. 60/239,536, filed Oct. 10, 2000.
TECHNICAL FIELD
[0002] This invention relates to the formation of an electrically conductive, freestanding microporous polymer sheet and, in particular, to such a sheet for use in the manufacture of energy storage and other suitable devices including supercapacitors, pseudocapacitors, electrochemical capacitors, double layer capacitors, electrochemical double layer capacitors, hybrid capacitors, asymmetric capacitors, and ultracapacitors.
BACKGROUND OF THE INVENTION
[0003] The following background information is presented by way of example with reference to the manufacture of electrodes used in energy storage devices. Descriptions of the construction details of energy storage devices relevant to the present invention are set forth in A. Burke, Ultracapacitors: why, how, and where is the technology, J. Power Sources 91, (2000) pp. 37-50.
[0004] Ultracapacitors differ from batteries in that they provide higher power density, excellent reversibility, and very long cycle life. Exemplary charge-storage mechanisms of ultracapacitors include double layer capacitance and charge transfer pseudocapacitance. Double layer capacitance arises from the separation of charge at a solid-electrolyte interface, whereas pseudocapacitance involves reversible faradaic reactions occurring at a solid surface over a defined potential range.
[0005] Significant effort has been devoted to research focusing on the use of high surface area carbon powders as the electrochemically active material in ultracapacitors. While some of these powders have specific capacitance values in excess of 100 Farads/gram, their low densities provide a much lower volumetric capacitance values, which are of importance in ultracapacitor fabrication.
[0006] Furthermore, the micropores (<2 nm diameter) of activated carbons are often not accessible to the electrolyte in an ultracapacitor, resulting in no double layer formation and lower than expected capacitance. Carbon aerogels are a unique form of carbon derived from the sol-gel polymerization of organic monomers, such as resorcinol and formaldehyde, followed by pyrolysis at elevated temperature (>800° C.). As discussed in Pekala et al., Structure and Performance of Carbon Aerogel Electrodes, Materials Research Society Symposium Proceedings 349, (1994) pp. 79-85, carbon aerogels can be synthesized over a wide range of densities with high surface areas (600-800 m 2 /g), a predominance of mesopores (2-50 nm), and low electrical resistivity. This microstructure provides high volumetric capacitance values for carbon aerogel monoliths and powders. As such, the incorporation of carbon aerogels into a free-standing, microporous polymer sheet is of great interest as a new method for the fabrication of ultracapacitor electrodes.
[0007] Many transition metal oxides and mixed metal oxides have also been investigated as electrochemically active materials for ultracapacitors where the principal charge-storage mechanism is pseudocapacitance. Certain forms of ruthenium oxide have specific capacitance values as high as 750 Farads/gram. Other metal oxides such as tantalum oxide, manganese dioxide, lead oxide, and nickel oxide are under investigation. In each case, the incorporation of these materials into a freestanding, microporous polymer sheet has not been contemplated for the fabrication of ultracapacitor electrodes.
[0008] Ultracapacitors can also be fabricated with one electrode being of a double layer material (e.g., activated carbon) while the other electrode is made from a pseudocapacitance material (e.g., ruthenium oxide). Such energy storage devices are referred to as hybrid or asymmetric capacitors.
[0009] Electrode preparation for many energy storage devices begins with the formation of a slurry containing an electrochemically active material in powder form, a fluoropolymer, and solvent. The slurry is coated onto a metal foil that acts as a current collector. The metal foil coated with the electrochemically active material is then passed through a drying oven to remove the solvent. The fluoropolymer acts as a binder that holds together the electrochemically active material and forms a porous electrode. Often the electrode is calendered to densify the electrochemically active material coated on the current collector by increasing the volume or packing fraction of the electrochemically active material and thereby reducing the porosity of the electrode. The current collector functions also as a carrier for the electrochemically active material and the binder because the combination of the two of them is of insufficient mechanical integrity to stand on its own as a freestanding, microporous polymer sheet. The electrode is then cut into ribbons for winding or stacking into a packaged energy storage device.
[0010] Fluoropolymers, such as polyvinylidene fluoride, have historically been used as polymer binders because of their electrochemical and chemical inactivity in relation to most polymer, gel, or liquid electrolytes. However, it is difficult, if not impossible, to produce freestanding porous electrodes utilizing fluoropolymers at traditional binder contents (2 -10 wt. %) because their low molecular weights provide inadequate chain entanglement. Other binders such as EPDM rubber and various types of polyethylene can be used, but they also do not provide microporous sheets with freestanding properties. “Freestanding” refers to a sheet having sufficient mechanical properties that permit manipulation such as winding and unwinding in sheet form for use in an energy storage device assembly.
[0011] A special type of polyethylene, ultrahigh molecular weight polyethylene (UHMWPE), can be used to make a microporous sheet with freestanding properties at the binder contents specified above. The repeat unit of polyethylene is shown below:
[0012] (—CH 2 CH 2 —) x ,
[0013] where x represents the average number of repeat units in an individual polymer chain. In the case of polyethylene used in many film and molded part applications, x equals about 10 3 -10 4 whereas for UHMWPE x equals about 10 5 . This difference in the number of repeat units is responsible for the higher degree of chain entanglement and the unique properties of UHMWPE.
[0014] One such property is the ability of UHMWPE to resist material flow under its own weight when the UHMWPE is heated above its crystalline melting point. This phenomenon is a result of the long relaxation times required for individual chains to slip past one another. UHMWPE exhibits excellent chemical and abrasion resistance, and the hydrocarbon composition of UHMWPE has a much lower skeletal density (0.93 g/cc) than many of the fluoropolymers commonly used in electrode preparation. Such commonly used fluoropolymers include polyvinylidene fluoride (1.77 g/cc) and polytetrafluoroethylene (2.2 g/cc).
[0015] UHMWPE is commonly used as the polymer matrix or binder for separators used in lead-acid batteries. Such separators result from the extrusion, calendering, and extraction of mixtures containing UHMWPE, precipitated silica, and processing oil. The resultant separators have many advantages: high porosity (50-60%), a dentritic growth-inhibiting ultrafine pore size, low electrical resistance, good oxidation resistance, and sealability into a pocket configuration. These separators usually contain a silica to UHMWPE weight ratio from about 2.5 to about 3.5 or a corresponding volume fraction ratio in the range of 1.0 to 1.5. Such separators are designed to prevent electronic conduction (i.e., short circuits) between the anode and cathode while permitting ionic conduction via the electrolyte that fills the pores.
[0016] While UHMWPE is an integral part of separator technology, its use in the extrusion and extraction of free-standing, electrically conductive porous film electrodes has never been achieved. This invention addresses the desire to fabricate such film electrodes for use in energy storage and other electronic device applications.
SUMMARY OF THE INVENTION
[0017] An object of the present invention is, therefore, to provide an electrically conductive, freestanding microporous polymer sheet formed with a relatively high volume fraction of the electrically conductive matrix (composed of an electrochemically active powder and an electrically conductive agent, if required) to the polymer matrix and having sufficient mechanical properties for use as ultracapacitor electrodes. An electrochemically active powder is one that exhibits sufficient double-layer capacitance or pseudocapacitance for the purpose of this invention.
[0018] The present invention is a freestanding, microporous polymer sheet that is composed of a polymer matrix binding a material composition (i.e., the electrically conductive matrix) having electrical conductivity properties. The polymer matrix preferably includes UHMWPE, and the material composition preferably contains one of a carbonaceous material and a metal oxide, or a combination thereof. Exemplary carbonaceous materials include high surface area carbon (>250 m 2 /g), activated carbon, and carbon aerogel. Exemplary metal oxides include ruthenium oxide, tantalum oxide, manganese dioxide, nickel oxide, and lead oxide. The UHMWPE is of a molecular weight that provides sufficient molecular chain entanglement to form a sheet with freestanding characteristics, and the material composition powders have relatively high surface areas. Preferably, the polymer matrix of the microporous sheet does not exceed a volume fraction of about 0.20.
[0019] Multiple microporous sheets can be wound or stacked in a package filled with an electrolyte to function as electrodes in an energy storage device, such as a battery or an ultracapacitor. Metallic layers can be applied to the microporous sheets to function as current collectors in such devices.
[0020] In a first preferred embodiment of the invention, the freestanding, microporous polymer sheet is manufactured by combining UHMWPE, a material composition in powder form and having electrical conductivity properties, and a plasticizer (e.g., mineral oil). A mixture of UHMWPE and the material composition powder is blended with the plasticizer in sufficient quantity and extruded to form a homogeneous, cohesive mass. A blown film process or another traditional calendering method is used to shape the oil-filled sheets to their final thicknesses. In an extraction operation similar to that used for the production of lead acid battery separators, the oil is removed from the sheets. Metallic layers are then applied to the extracted sheets to form current collectors. A metallic layer can be one of a metal film formed by sputter deposition on, electroless deposition on, electrodeposition on, plasma spraying on, or roll coating of a metal slurry on the microporous sheet; or a porous or nonporous metal foil laminated to the microporous sheet. In some cases, sufficient metal powder can be incorporated in the polymer sheet such that a metallic layer as described above is not required.
[0021] In a second preferred embodiment of the invention, a polymer matrix, containing an UHMWPE in an amount and of a molecular weight sufficient to provide the necessary molecular chain entanglement to form a freestanding microporous sheet, binds a material composition having electrical conductivity properties. The resulting electrically conductive sheet is wound or stacked in a package, and the pores of the sheet are filled with an electrolyte and used as one of many electrodes in an energy storage device, for example, a battery, capacitor, supercapacitor, or fuel cell. One of the benefits of this polymer matrix is that it can be used to form, and potentially provide intimate contact between adjacent electrode and separator layers.
[0022] In a third preferred embodiment of the invention, multiple electrode and separator layers are coherently bonded to one another to form an ultracapacitor. One preferred method of coherently bonding the multiple layers involves simultaneously coextruding the layers through multiple extruders. A second preferred method involves laminating individual layers together. These processes promote an integral, coherent bond between adjacent electrode and separator layers and reduce the risk of delamination during extraction. These processes also provide intimate contact between the porous electrodes and the separator without collapsing porosity at adjacent layer interfaces. The resultant multiple layer ribbon with one or more current collectors is cut to size, and the pores are filled with electrolyte to produce an energy storage device.
[0023] Additional objects and advantages of this invention will be apparent from the following detailed description of preferred embodiments thereof which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a fragmentary cross-sectional side view of a capacitor cell of the present invention.
[0025] [0025]FIG. 2 is a schematic diagram showing a continuous process for forming the cell assemblies of this invention.
[0026] [0026]FIG. 3 is a fragmentary cross-sectional view of the electrode assembly of this invention.
[0027] [0027]FIG. 4 is a fragmentary cross-sectional view of an electrochemical cell incorporating the electrode assembly of this invention.
[0028] [0028]FIG. 5 is a schematic diagram of a hybrid capacitor.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] As used herein, the term ultracapacitor includes supercapacitors, pseudocapacitors, electrochemical capacitors, double layer capacitors, electrochemical double layer capacitors, hybrid capacitors, and asymmetric capacitors.
[0030] The polymeric material preferably used in this invention is an ultrahigh molecular weight polyolefin. The polyolefin most preferably used is an ultrahigh molecular weight polyethylene (UHMWPE) having an intrinsic viscosity of at least 10 deciliter/gram, and preferably greater than about 14-18 deciliters/gram. It is not believed that there is an upper limit on intrinsic viscosity for the UHMWPEs usable in this invention. Current commercially available UHMWPEs have an upper limit of intrinsic viscosity of about 29 deciliters/gram.
[0031] The plasticizer employed in the present invention is a nonevaporative solvent for the polymer, and is preferably a liquid at room temperature. The plasticizer has little or no solvating effect on the polymer at room temperature; it performs its solvating action at temperatures at or above the softening temperature of the polymer. For UHMWPE, the solvating temperature would be above about 160° C., and preferably in the range of between about 160° C. and about 220° C. It is preferred to use a processing oil, such as a paraffinic oil, naphthenic oil, aromatic oil, or a mixture of two or more such oils. Examples of suitable processing oils include: oils sold by Shell Oil Company, such as ShellFlex™ 3681, Gravex™ 41, Catnex™ 945; and oils sold by Chevron, such as Chevron 500R; and oils sold by Lyondell, such as Tufflo™ 6056.
[0032] Any solvent for extracting the processing oil from the individual films or multiple layer film may be used in the extraction process, so long as the solvent is not deleterious to the electrode active ingredients contained in the polymer matrix and has a boiling point that makes it practical to separate the solvent from the plasticizer by distillation. Such solvents include 1,1,2 trichloroethylene, perchloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, 1, 1, 2-trichloroethane, methylene chloride, chloroform, 1,1,2-trichloro-1,2,2-trifluoroethane, isopropyl alcohol, diethyl ether, acetone, hexane, heptane, and toluene.
[0033] In some cases, it is desirable to select the processing oil such that any residual oil in the polymer sheet after extraction is electrochemically inactive.
[0034] A first preferred embodiment of the present invention is use of the freestanding microporous film as a composition. The terms “film” and “sheet” are used interchangeably throughout this patent application to describe products made in accordance with the invention, and the term “web” is used to encompass films and sheets. The practice of the invention is not limited to a specific web thickness. The present invention forms a freestanding microporous polymer sheet, which is manufactured by combining an UHMWPE, an electrochemically active powder and an electrically conductive agent (e.g., carbon black), if required, with sufficient plasticizer at an appropriate temperature to allow formation of a homogeneous, cohesive sheet. The electrochemically active powders used to form these sheets vary widely. Some examples are as follows:
EXAMPLE 1
Production of a Granulated Carbon-Containing Sheet
[0035] UHMWPE (1900 HCM; Basel Polyolefins, 1.0 g) was added to granulated carbon powder (ENSACO 350; MMM Carbon, 10.0 g having a surface area of about 800 m 2 /g) in a 250 ml plastic beaker. The powders were blended with a spatula until a homogeneous mixture formed, at which time ShellFlex™ 3681 process oil (Shell Oil Co., 25.0 g) was added. The oil-containing mixture was stirred until a free-flowing state was achieved, and then the mixture was placed into a HAAKE Rheomix 600 miniature intensive mixer fitted with roller blades and driven by a HAAKE Rheocord 90 torque Rheometer, turning at 80 RPM and set at 180° C. Additional oil (13.4 g) was added to the mixing chamber. The resultant mixture was compounded for five minutes, resulting in a homogeneous, cohesive mass. This mass was transferred to a C.W. Brabender Prep-Mill Model PM-300, two-roll mill, turning at 15 rpm and set at 150° C. The roll gap was adjusted to about 0.3 mm, and the resulting polymer sheet was removed from the rolls with a take-off knife.
[0036] The sheet was allowed to cool to room temperature, and then a razor blade was used to cut 40 mm×60 mm specimens from the sheet. The specimens were next placed in a 500 ml trichloroethylene bath in which a magnetic stir bar was used to circulate the solvent, thereby promoting extraction of the ShellFlex™ 3681 oil. This procedure was repeated three times with fresh trichloroethylene to ensure that the oil was fully extracted from the specimens. The trichloroethylene-laden specimens were dried in a fume hood for five minutes at 20° C., followed by 15 minutes at 90° C. in a forced air oven.
[0037] The resultant porous sheet having a 0.29 mm thickness was weighed and measured to determine its density, which was recorded as 0.41 g/cc.
EXAMPLE 2
Production of an Activated Carbon-Containing Sheet
[0038] UHMWPE (1900 HCM; Basel Polyolefins, 1.0 g) was added to activated carbon powder (Norit SX Ultra; NORIT Americas Inc., 10.0 g having a surface area of about 1150 m 2 /g) in a 250 ml plastic beaker. The powders were blended with a spatula until a homogeneous mixture formed, at which time ShellFlex™ 3681 process oil (Shell Oil Co., 12.0 g) was added. The oil-containing mixture was stirred until a free-flowing state was achieved, and then the mixture was placed into a HAAKE Rheomix 600 miniature intensive mixer fitted with roller blades and driven by a HAAKE Rheocord 90 torque Rheometer, turning at 80 RPM and set at 180° C. Additional oil (6.9 g) was added to the mixing chamber. The resultant mixture was compounded for five minutes, resulting in a homogeneous, cohesive mass. This mass was transferred to a C.W. Brabender Prep-Mill Model PM-300, two-roll mill, turning at 15 rpm and set at 150° C. The roll gap was adjusted to about 0.3 mm, and the resulting polymer sheet was removed from the rolls with a take-off knife.
[0039] The oil-filled sheet was extracted as outlined in Example 1.
[0040] The resultant porous sheet having a 0.30 mm thickness was weighed and measured to determine its density, which was recorded as 0.43 g/cc.
EXAMPLE 3
Production of a Manganese Dioxide-Containing Sheet
[0041] UHMWPE (1900 HCM; Basel Polyolefins, 2.6 g) and graphite powder (BG-35, Superior Graphite Co., 4.0 g) were added to manganese dioxide powder (alkaline battery grade; Kerr-McGee Chemical LLC., 32.0 g) in a 250 ml plastic beaker. The powders were blended with a spatula until a homogeneous mixture formed, at which time ShellFlex™ 3681 process oil (Shell Oil Co., 8.0 g) was added. The oil-containing mixture was stirred until a free-flowing state was achieved, and then the mixture was placed into a HAAKE Rheomix 600 miniature intensive mixer fitted with roller blades and driven by a HAAKE Rheocord 90 torque Rheometer, turning at 80 RPM and set at 180° C. Additional oil (12.0 g) was added to the mixing chamber. The resultant mixture was compounded for five minutes, resulting in a homogeneous, cohesive mass. This mass was transferred to a C.W. Brabender Prep-Mill Model PM-300, two-roll mill, turning at 15 rpm and set at 150° C. The roll gap was adjusted to about 0.4 mm, and the resulting polymer sheet was removed from the rolls with a take-off knife.
[0042] The oil-filled sheet was extracted as outlined in Example 1
[0043] The resultant porous sheet having a 0.39 mm thickness was weighed and measured to determine its density, which was recorded as 1.27 g/cc.
EXAMPLE 4
Production of Carbon Aerogel-Containing Sheet
[0044] Carbon aerogel powder (<20 μm particle size; Ocellus Technologies Inc., 18.0 g) was added to ultrahigh molecular weight polyethylene [UHMWPE](1900 H; Basel Polyolefins, 1.08 g) in a 250 ml plastic beaker. The powders were blended with a spatula to form a homogeneous mixture, at which time ShellFlex™ 3681 process oil (Shell Oil Co., 12.0 g) was added. The oil-containing mixture was stirred until a free-flowing state was achieved, and then the mixture was placed in a HAAKE Rheomix 600 miniature intensive mixer fitted with roller blades and driven by a HAAKE Rheocord 90 torque Rheometer, turning at 80 RPM and set at 180° C. Additional oil (8.0 g) was added to the mixing chamber. The resultant mixture was compounded for 5 minutes, resulting in a homogeneous, cohesive mass. This mass was transferred to a C.W. Brabender Prep-Mill Model PM-300, two-roll mill, turning at 15 rpm and set at 160° C. The roll gap was adjusted to about 0.25 mm, and a sheet was removed from the rolls with the take-off knife after lowering the roll temperature to 140° C.
[0045] The oil-filled sheet was allowed to cool to room temperature, and then a razor blade was used to cut 50 mm×250 mm specimens from the sheet. The specimens were next placed in a 500 ml trichloroethylene bath in which a magnetic stir bar was used to circulate the solvent, thereby promoting extraction of the Shellflex™ 3681 oil. This procedure was repeated three times with fresh trichloroethylene to ensure that the oil was fully extracted from the specimen. The trichloroethylene-laden specimens were dried in a fume hood for five minutes at 20° C., followed by 15 minutes at 90° C. in a forced air oven.
[0046] After extraction, the resultant porous sheet had a density of 0.62 g/cc.
EXAMPLE 5
Production of Carbon Aerogel-Containing Sheet
[0047] Using the same procedure as outlined in Example 4, porous sheet was formed from a mixture containing carbon aerogel powder (<20 μm particle size; Ocellus Technology Inc., 17.28 g), UHMWPE (1900 H; Basel Polyolefins, 1.08 g), conductive black (Super P™; MMM Carbon, 0.72 g), and Shellflex™ 3681 oil (Shell Oil Co., 20.0 g.)
[0048] After extraction, the resultant porous sheet had a density of 0.67 g/cc.
EXAMPLE 6
Production of Carbon Aerogel-Containing Sheet
[0049] Using the same procedure as outlined in Example 4, a porous sheet was formed from a mixture containing carbon aerogel powder (Ocellus Technology Inc., 14.7 g), UHMWPE (1900 H; Basel Polyolefins, 1.64 g), and Shellflex 3681 oil (Shell Oil Co., 20.0 g.)
[0050] After extraction, the resultant porous sheet had a density of 0.45 g/cc.
EXAMPLE 7
Production of Carbon Aerogel-Containing Sheet
[0051] Using the same procedure as outlined in Example 4, a porous sheet was formed from a mixture containing carbon aerogel powder (Ocellus Technology Inc., 21.56 g), UHMWPE (1900 H; Basel Polyolefins, 2.4 g), and Shellflex™ 3681 oil (Shell Oil Co., 20.0 g.)
[0052] After extraction, the resultant porous sheet had a density of 0.68 g/cc.
[0053] A second preferred embodiment of the invention is directed to use of the freestanding microporous polymer sheet in an energy storage device. The polymer sheet is especially useful in such devices because it is freestanding, porous, electrically conductive, and electrochemically active. Energy storage devices in which the invention can be used include, but are not limited to ultracapacitors, batteries, and fuel cells.
[0054] A preferred implementation of this second preferred embodiment is the use of the freestanding microporous polymer film in an ultracapacitor. Capacitors are electrical energy storage devices that store electrical energy on an electrode surface. Many traditional capacitors cannot store sufficient energy in the volume and weight available to provide significant energy. In contrast, ultracapacitors are able to store more energy per weight and to deliver energy at a higher power rating than traditional capacitors. Ultracapacitors create and store energy by microscopic charge separation at an electrode-electrolyte interface or through charge-storage based on fast, reversible faradaic reactions occurring at an electrode surface. Specifically, an ultracapacitor includes two porous electrodes isolated from each other by a porous separator. The separator and electrodes are impregnated with an electrolyte that allows ionic current to flow between the electrodes. The capacitors of the present invention have a high volume fraction of the electrode active material in the microporous polymer matrix and thereby maintain low electronic resistivity. Potential ultracapacitor applications include pulse power delivery and load leveling in portable electronic devices and electric vehicles.
[0055] As shown in FIG. 1, ultracapacitor cell 100 includes a pair of electrodes 102 and 104 , a separator 106 , and a pair of current collector plates 108 and 110 . Ultracapacitor 100 includes an ultrahigh molecular weight polyolefin, preferably UHMWPE, as a binder for the electrode active material. Preferably, the UHMWPE is present in an amount that does not exceed 20% by volume of the electrode. The active materials used in ultracapacitor 100 can be any particulate or fibrous material; however, preferred active materials include high surface area carbon, (>250 m 2 /g), activated carbon, carbon aerogel, ruthenium oxides (either hydrous or anhydrous), tantalum oxides, manganese dioxide, nickel oxide, or lead dioxide.
[0056] The following examples are illustrative of use of the present invention in ultracapacitors.
EXAMPLE 8
Carbon Black, Ensaco 350 GR Capacitor
[0057] [0057] TABLE 1 Electrode Separator Carbon Black 1 , g 11.0 Silica 2 , g 7.0 Colorant 3 , g 0.2 Lubricant 4 , g 0.03 Antioxidant 5 , g 0.03 UHMWPE 6 , g 1.0 2.4 Oil 7 , 9 42.0 18.0
[0058] The components of a carbon black, Ensaco 350 GR capacitor are set out in Table 1. The dry electrode ingredients in Table 1 were combined in a 600 ml tall form beaker and blended with a spatula. Oil (28 g) was then added to the beaker while blending with a spatula. Once thoroughly blended, this mixture formed a free flowing powder.
[0059] This free flowing powder was added to a HAAKE Rheomix 600 miniature intensive mixer fitted with roller blades and driven by a HAAKE Rheocord 90 torque Rheometer, turning at 80 RPM and set at 180° C. The remaining oil (14 g) was added to the miniature intensive mixer. This mixture was compounded for approximately five minutes, resulting in a homogeneous, cohesive mass. This mass was transferred to a C.W. Brabender Prep-Mill, Model PM-300, two-roll mill, turning at 15 rpm and set at 175° C. The roll gap was adjusted to about 0.4 mm, and a sheet was removed from the rolls with the take-off knife.
[0060] The procedure above was repeated for the separator formula with the following exceptions: oil (12 g) was blended with the dry ingredients in a 600 ml tall form beaker, additional oil (6 g) was added to the miniature intensive mixer, the temperature of the two-roll mill was approximately 173° C., and the gap on the two-roll mill was set to about 0.3 mm. An 8 cm×8 cm square was cut from this separator sheet, placed between aluminum foil cover sheets, transferred to a Carver Laboratory Press, at 143° C., and pressed to a thickness of 0.10 mm at a pressure of approximately 2,500 kPa. The film was allowed to cool to room temperature, and the aluminum foil cover sheets were removed.
[0061] Two 4 cm×6 cm rectangles were cut from the electrode sheet. One 6 cm×8 cm rectangle was cut from the separator film. Two 4 cm×6 cm current collectors with 2 cm×10 cm take-off tabs were cut from expanded titanium foil, 2Ti3.5-4/OA made by Exmet Corporation. This foil was 0.05 mm thick and had a strand thickness of 0.09 mm. The collectors, oil-filled sheets, and separator film were stacked in the following order: collector, electrode sheet, separator film, electrode sheet, and collector. This stack was then laminated in a Model C Carver Laboratory Press, at about 143° C. and at a pressure not greater than 100 kPa. This laminated capacitor assembly was extracted in a tall form 600 ml beaker of trichloroethylene with a magnetic stir bar turning at 100 rpm. This procedure was repeated three times with fresh trichloroethylene to ensure that the oil was fully extracted. The trichloroethylene-laden capacitor was dried in a fume hood for five minutes at 20° C., followed by 15 minutes at 90° C. in a forced air oven.
[0062] The resultant porous capacitor assembly was immersed in a 250 ml specimen jar containing 1.28 sp. gr. H 2 SO 4 electrolyte. The capacitor assembly and jar were placed in a vacuum desiccator, which was evacuated to a pressure of 125 mm of Hg for one minute, after which the vacuum was released. This evacuation release cycle was repeated five times. The saturated capacitor was placed in a 75 mm×125 mm polyethylene bag so that the current collectors protruded from the bag.
[0063] The capacitor collector tabs were connected to the terminals of a Hewlett Packard Model 6611C DC power supply. The power supply voltage limit was set to 1.2 volts, and the current limit was set to 1 ampere. The initial current was 71 milliamperes, decaying exponentially to 19 milliamperes after 10 minutes. After 10 minutes, the power supply was disconnected and the open circuit voltage of the capacitor was recorded. The initial open circuit voltage was 0.98 volt, decreasing to 0.65 volt 10 minutes after power supply disconnection. Although equipment necessary to quantify capacity in farads was unavailable, the behavior above is consistent with that of a functioning capacitor.
EXAMPLE 9
Aerogel Carbon, Ultracapacitor
[0064] An oil-filled sheet as described in Example 6 was laminated to a nickel expanded metal grid at approximately 140° C. using a Carver Press and subsequently extracted in trichloroethylene to form a porous electrode. The electrode/grid assembly was soaked in isopropanol and then placed in an excess of 5M KOH solution overnight so that 5M KOH would fill the pores, rather than isopropanol. A glass fiber separator filled with 5M KOH was then sandwiched between two electrode/grid assemblies to form a supercapacitor that was held under compression in a stainless steel fixture. The resultant ultracapacitor was charged at 0.1 A/g to 1.2 V and then held at this voltage for 1 hour.
EXAMPLE 10
Aerogel Carbon, Ultracapacitor
[0065] Using the same procedure as outlined in Example 9, a ultracapacitor was formed using two of the oil-filled sheets described in Example 7.
[0066] The ultracapacitors of Examples 9 and 10 were discharged at the rates shown in Table 2, and capacitance values were calculated from the discharge curves.
TABLE 2 Capacitance Capacitance Capacitance Capacitance Z(real) Electrodes (F/g) @ 0.1 A/g (F/g) @ 0.05 A/g (F/cc) @ 0.1 A/g (F/cc) @ 0.05 A/g milliohm Example 9 12.7 21.0 5.2 8.5 116.9 Example 10 13.3 14.1 8.1 8.7 67.3
[0067] A third preferred embodiment of the invention is a process of forming a multiple layer film composed of individual electrode and separator layers. The resultant multiple layer film with current collectors is cut to size and filled with electrolyte to produce an ultracapacitor.
[0068] [0068]FIG. 2 illustrates one preferred process of coherently bonding the multiple layers, which involves a simultaneous coextrusion of the layers through multiple extruders. The process illustrated in FIG. 2 employs three extruders and a coextrusion die.
[0069] An extruder 10 has a metering section containing a feed port 11 by means of which a suspension of a polymer in a non-evaporative plasticizer is fed into the extruder. Extruder 10 has a second metering section containing second feed port 111 by means of which an active material is fed into the second (down stream) metering section. Extruder 10 extrudes first porous electrode layer 102 .
[0070] An extruder 12 has a metering section containing a feed port 13 by means of which a suspension of polymer and filler in a nonevaporative plasticizer is fed into the extruder. Extruder 12 extrudes separator layer 106 . An extruder 14 has a metering section containing a feed port 15 by means of which a suspension of a polymer in a nonevaporative plasticizer is fed into the extruder. Extruder 14 has a second metering section containing second feed port 115 by means of which an active material is fed into the second (down stream) metering section. Extruder 14 extrudes second porous electrode layer 104 .
[0071] Extruders 10 , 12 , and 14 are, preferably, twin screw extruders having mixing and conveying sections. The twin screw extruders may have screws that are either co-rotating or counter-rotating. The temperatures employed in the extruders are such as to ensure that the polymer is solvated by the plasticizer, but not so high as to cause degradation of any component of the slurry composition during its residence time in the extruder. Although twin screw extruders are preferred, other means for applying heat and shear to the various slurries may be used, such as, for example, a Farrel continuous mixer.
[0072] The first porous electrode layer extrudate is conveyed from extruder 10 to a coextrusion die 20 via a heated pipe 16 ; the separator extrudate is conveyed from extruder 12 to coextrusion die 20 via a heated pipe 17 ; and the second porous electrode layer extrudate is conveyed from extruder 14 to coextrusion die 20 via a heated pipe 18 . Melt pumps may be used to feed the extrudates from extruders 10 , 12 , and/or 14 to coextrusion die 20 .
[0073] Coextrusion die 20 may be either a sheet die or a blown film die. If a blown film is formed, its tubular construction may be slit into a wider, single thickness web before extraction of the plasticizer.
[0074] Although not illustrated, if a sheet die is used, it may be desirable to pass a resultant three-layer precursor film 30 through the nip of two or more calender rolls to aid in controlling film thickness and other properties. Alternatively, the hot precursor film 30 may be cast onto a quench roll and a series of draw down rolls used to control film thickness and other properties.
[0075] In addition, three-layer precursor film 30 , whether formed in a blown film die, as a calendered film from a sheet die and calender stack, or as a melt cast film from a sheet die and quench roll, can be drawn in the machine and/or cross machine direction by means of a tentering frame to modify film thickness and other properties.
[0076] The three-layer film 30 formed by coextrusion die 20 , with or without modification by various intermediate processes, is fed along with a first porous electrode layer current collector 81 and a second porous electrode layer current collector 83 into the nip of laminating rolls 84 and 85 to form a complete cell structure. The current collectors in roll stock form are supplied from unwind stations 80 and 82 to the laminating rolls.
[0077] A five-layer cell structure 86 , which includes three-layer precursor film 30 , is fed around roll 40 and into an extraction bath 42 contained in tank 44 . The five-layer cell structure then passes around a roll 46 and exits tank 44 . The portion of the five-layer cell structure 86 comprised of three-layer precursor film 30 has substantially all of the contained plasticizer removed by the solvent in extraction bath 42 . The extracted five-layer cell structure passes around roll 60 and enters a drying section 88 where the solvent is volatilized.
[0078] The extracted solvent-free five-layer cell structure 89 passes into a controlled moisture environment 90 where the cell structure is cut to length, cut lengths are assembled into individual ultracapacitors, electrolyte is introduced, and other final assembly operations are carried out. When the cell structure is cut to length, the continuous portion of the ultracapacitor production ends.
[0079] The extraction process has been illustrated as being carried out in tank 44 for ease of illustration. However, the extraction is preferably carried out in an extractor similar to that described in U.S. Pat. No. 4,648,417. After extrusion, the resultant multiple layer cell structure can be further calendered to control porosity and layer thickness.
[0080] The continuously produced multiple (three)-layer cell assembly 30 (before extraction) and multiple (five)-layer electrochemical cell structure 89 are illustrated in FIGS. 3 and 4, respectively. As can be seen, cell structure 89 is comprised of a first porous electrode current collector 81 , a first porous electrode layer 52 , a separator layer 54 , a second porous electrode layer 56 , and a second porous electrode current collector 83 .
[0081] Although the process of forming the multiple layer cell structure of this invention is preferably accomplished by coextruding the electrode layers and the separator; laminating current collectors; extracting the plasticizer; and removing the extraction solvent in a continuous series of operations, the operations can be performed separately or in various combinations. If the electrode and separator layers are formed separately, they are preferably laminated to each other and to their respective current collectors before solvent extraction of the plasticizer to promote coherent bonding between the adjacent layers. However, it may be desirable to extract the plasticizer from one or more of these layers in a separate operation and subsequently laminate the extracted layers. If the electrode and separator layers are formed separately, it may be desirable to pass the respective extrudate from each extruder through a calender roll stack to aid in controlling film thickness and other parameters. A suitable such calender roll stack is disclosed in U.S. Pat. No. 4,734,229. After solvent extraction of the plasticizer, the cell assembly is passed into a controlled moisture environment, as is well known in the art.
[0082] Whether the electrode and separator films are formed separately or as a multiple layer film, the film or films may be oriented (stretched) in the machine direction, cross-machine direction, or both, before or after solvent extraction of the plasticizer from the film but prior to lamination to current collectors.
[0083] After the electrochemical cell assembly is formed, the web is cut to size, packaged, and grouped into ultracapacitors. The packaged cell assemblies are then filled with electrolyte and sealed, all in a manner known in the art.
[0084] Ultracapacitors can be fabricated with one electrode being of a double-layer (carbon) material and the other electrode being of a pseudocapacitance material. Such devices are often referred to as hybrid capacitors. Most of the hybrid capacitors developed to date have used nickel oxide as the pseudocapacitance material in the positive electrode. The energy density of these devices can be significantly higher than for double-layer capacitors. Hybrid capacitors can also be assembled using two non-similar mixed metal oxide or doped conducting polymer materials.
[0085] [0085]FIG. 5 shows a schematic diagram of an exemplary hybrid ultracapacitor 500 in which separator 106 is positioned between a battery-like electrode 502 and a double-layer electrode 104 . Current collectors 108 and 110 are positioned adjacent to electrodes 502 and 104 , respectively.
[0086] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments of this invention without departing from the underlying principles thereof. The scope of the present invention should, therefore, be determined only by the following claims.
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A freestanding, microporous polymer sheet is composed of a polymer matrix binding an electrically conductive matrix. The polymer matrix preferably includes UHMWPE, and the electrically conductive matrix preferably contains one of a carbonaceous material and a metal oxide, or a combination thereof. The UHMWPE is of a molecular weight that provides sufficient molecular chain entanglement to form a sheet with freestanding characteristics. Multiple microporous sheets can be wound or stacked in a package filled with an electrolyte to function as electrodes in an energy storage device, such as a battery or an ultracapacitor.
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FIELD OF THE INVENTION
The present invention relates to transmission control protocol performance problems that arise because of bandwidth asymmetry effects and, in particular, relates to a method for selective discarding of ACK packets from the lowest bandwidth channel queue.
BACKGROUND OF THE INVENTION
Data Over Cable Service Interface Specification (DOCSIS) cable modem devices allow fast, and usually bandwidth asymmetrical, access to the Internet, where the available downstream (DS) bandwidth tends to be larger than the upstream (US) bandwidth. This bandwidth asymmetry is reasonable for most applications, since the bulk of transferred bytes tends to be carried in the DS direction rather than the US direction. This is particularly the case for popular applications using the Transmission Control Protocol (TCP), such as file downloads via the File Transfer Protocol (FTP) and web browsing through the Hypertext Transport Protocol (HTTP). In these applications, an Internet server sends more and larger TCP packets to a client (in the DS direction) than the client sends to the server (in the US direction).
While it is true that the bulk of data is carried in the DS direction, the performance (speed) of the DS channel is nevertheless constricted by the performance of the US channel. In order to guarantee that each data packet sent by a source reaches its destination, TCP applications utilize a reliability mechanism in which the destination client explicitly acknowledges successful reception of data packets from a source by sending ACK packets back to the source. Typically, a server sends several data packets at a time to a client and then waits to receive ACK packets from the client acknowledging receipt of the data packets. If the server does not receive ACK packets from the client within a certain time, the server determines that the data packets were not successfully delivered to the client, stalls the transmission of further new data packets, and retransmits the unacknowledged packets until it receives ACK packets from the client acknowledging their receipt.
An ACK indicates to the server that all previous packets have been properly received by the client. This is accomplished by the use of sequence numbers. Each byte the source sends to the destination is individually numbered according to the sequence in which those bytes are to be delivered. A forward packet (sent in the DS direction from source to destination) includes in its TCP header the position (sequence number) that the first byte in the packet payload (data) occupies in the overall data stream. An ACK packet (sent in the US direction from destination to source) includes in an ACK number field the sequence number of next byte expected, the last byte in the sequence that was correctly received plus one.
Hence, in a very simplified scenario for purposes of illustration, where one six-byte packet is sent at a time and each packet is ACK'd by the destination, a forward packet including bytes numbered 1 - 6 would include the sequence number 1 in is header to indicate the position that the first byte in the packet occupies in the data stream. Upon receiving this forward packet, the destination would transmit an ACK in the US direction including the number 7 in its ACK number field to indicate the last byte in the sequence that was correctly received and the next byte expected. Upon receiving this ACK, the source is able to confirm that the destination has received all bytes up to byte number 6 and is ready to receive new bytes beginning with byte number 7 . Hence, it may send a forward packet with the sequence number 7 in its header and containing bytes 7 - 12 , and then wait for reception of an ACK with sequence number 13.
As one might imagine, actual implementation is significantly more complex than this simplified scenario. A source typically sends several packets at a time, and ACKs sent by the destination may cover more than one packet. As successive ACK packets arrive at the source, the source may increase the number of packets that are sent at a time. TCP uses a window flow control mechanism in which the source and destination entities maintain a valid range, or window, of sequence numbers that can be exchanged at a certain point of time. The width of the sequence number range determines the window size and the number of data and ACK packets that can be in transit between the source and destination at a given time.
Hence, in actual implementations, multiple packets will typically be in transit in the DS direction from source to destination. Since these packets may take different paths in the source-destination path, they may arrive at the destination out-of-order. Some packets may also be lost. A TCP receiver issues a duplicate ACK whenever an out-of-order segment arrives. Hence, all packets received after a lost packet will trigger duplicate ACKs. If packets are not lost, but are simply received out-of-order, some duplicate ACKs will result. The destination saves these out of order packets, which gives rise to gaps in the stream of sequence numbers received. When eventually an in-order packet fills a gap, the destination will send a new ACK (containing the sequence number that indicates receipt of all the in-order packets received, with no gaps till that sequence number).
When the US channel becomes clogged with traffic, ACKs begin to accumulate in a queue at the cable modem. Many of the ACKs may be duplicate ACKs, as described above. Some of these duplicate ACKs may be important, for instance, to indicate to the source that a packet with a higher sequence number has not yet been received. Conversely, some of the duplicate ACKs may not be important. When a packet with the next sequence number has arrived, for instance, and an ACK indicating such has been generated but is in the queue behind duplicate ACKs that were generated before the next packet's arrival, the duplicate ACKs no longer convey important information to the source since the next data packet has actually arrived.
Additionally, some of the ACKs may be redundant relative to other ACKs in the queue. For a byte sequence having sequence numbers 1-20, for example, an ACK containing sequence number 12 is rendered redundant by a subsequent ACK containing sequence number 18. The ACK with sequence number 18 indicates that all bytes up to number 17 have been received; hence, the ACK with sequence number 12 indicating that all bytes up to number 11 have been received is no longer necessary in view of the subsequent ACK.
As previously described, when the DS channel carries much more data than the US channel, and much more bandwidth is available to the DS channel than is available to the US channel, the US channel queue may become clogged and transmission of ACKs from destination to source is delayed. Since the source must wait for arrival of the appropriate ACKs before sending out new data packets, delays in the US channel are tied to and negatively impact DS channel speed performance.
ACK “filtering” has been proposed to remove excess ACKs from the US queue and thereby improve US and overall TCP performance. However, not all duplicate ACKs can simply be dropped; some convey important information to the source. Additionally, while some redundant ACKs may be safely dropped, excessive dropping of redundant ACKs can lead to excessive burstiness at the source. That is, if too many redundant ACKs are removed from the queue, a “stretch ACK” may result indicating receipt of a large number of packets at once, and leading to a “bursty” transmission of a large number of new packets at once by the source. The loss of these “stretch ACKs” can also adversely affect performance. Finally, some ACKs contain important control information and possibly even data, and these ACKs cannot safely be dropped either.
While the prior art has recognized the desirability of ACK filtering, there has been no proposal to date on how or when to carefully discard duplicate ACKs from the US channel, on how to handle those ACKs containing SACK and ECN information, and how to track the number of ACKs discarded or to what level should the ACK discarding be limited in order not to cause excessive burstiness at the source.
SUMMARY OF THE INVENTION
One embodiment of the invention is a method for transmission control protocol (TCP) acceleration. The method comprises the steps of receiving an incoming acknowledgement packet belonging to a TCP session, and searching an upstream queue for queued acknowledgment packets belonging to the same TCP session. If the incoming acknowledgment packet is not a duplicate of the queued acknowledgment packet, one of the queued acknowledgment packets is replaced with the incoming acknowledgment packet in the position in the upstream queue occupied by the oldest of the queued acknowledgment packets.
Another embodiment of the invention is a system for TCP acceleration. The system includes an upstream queue for queuing packets, including TCP acknowledgment packets, and a means for receiving incoming acknowledgement packets belonging to a TCP session. The system also includes means for searching an upstream queue for queued acknowledgment packets belonging to the same TCP session, and means for replacing one of the queued acknowledgment packets with the incoming acknowledgment packet in the position in the upstream queue occupied by the oldest of the queued acknowledgment packets if the incoming acknowledgment packet is not a duplicate of the queued acknowledgment packet.
Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
FIG. 1 is a diagram of an exemplary network system in which the present invention may be implemented as part of the cable modem (CM) device.
FIG. 2 is a diagram of a simplified queue and a new packet arriving at the queue for upstream transmission.
FIG. 3 is a flow chart illustrating a method for ACK discarding according to the present invention.
FIG. 4 is a flow chart illustrating the method of FIG. 3 in greater detail.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts an example network system 100 in which the present invention may be implemented as part of the cable modem (CM) device. System 100 includes, on the client side, a computer (the client) 102 attached to a cable modem device 104 coupled to the Internet 108 via a Cable Modem Termination System (CMTS) device using the DOCSIS interface 106 . On the source or server side, the server 112 is coupled to the Internet 108 via any of a number of possible high-speed (HS) interfaces 110 (e.g., 100 MB Ethernet, T3 or OC-3 leased lines, etc.) immaterial to the invention. The communications path from source-to-destination is referred to as the downstream (DS) path 114 , and the reverse communications path from destination-to-source is referred to as the upstream (US) path 116 . It should be understood that the scenario presented in FIG. 1 is just one example of a system in which the present invention may be implemented, and that the present invention has utility in any TCP communication over a path where improved performance and efficiency to compensate for bandwidth asymmetry in the path is desired. In these cases the invention can be implemented as part of the device with a bandwidth asymmetric interface.
In the case of a cable modem 104 that provides fast, and usually asymmetrical, access to Internet 108 utilizing the Internet Protocol (IP) suit of protocols such as the Transmission Control Protocol (TCP), the downstream (DS) bandwidth is typically much greater than the upstream (US) bandwidth. This bandwidth asymmetry leads the DS performance for TCP transfers to be constricted by US performance. A significant factor in US performance is the US transmission of ACK packets to acknowledge receipt of data packets. The present invention extends on a Performance Enhancing Proxy (PEP) technique known as ACK-filtering that improves the DS performance of bandwidth asymmetric devices such as a cable modem 104 for TCP DS data traffic by carefully discarding ACK packets congesting the US channel. ACK packets queued for US transmission are inspected and chosen for discarding in a manner so as not to stall the sender (starve the sender of ACKs) or delete ACKs that convey important data or control information or are used for special functions.
FIG. 3 is a flow chart setting forth a method 200 for ACK discarding according to the present invention. FIG. 4 is a flow chart illustrating method 200 in greater detail. Preferably, method 200 is implemented as software or hardware in a device with bandwidth asymmetric interface such as cable modem 104 in FIG. 1 . In one implementation, the cable modem 104 is a DOCSIS cable modem and the present invention is implemented as part of the DOCSIS software on a chip in cable modem 104 .
The description of ACK-filtering method 200 assumes a simplified queue, such as queue 150 illustrated in FIG. 2 . Queue 150 , as depicted, is a buffer or other suitable memory construct having a particular number of slots for storing packets awaiting for upstream transmission. Queue 150 , as depicted, has eight spaces or slots 151 - 158 for storing packets; it should be understood, of course, that the particular number of slots in the queue may vary and has no bearing on the present invention. Slot 151 is the “head” of the queue and the packet stored there is the next packet to be transmitted upstream. Slot 158 is the “tail” of the queue and is the slot where a new packet 159 to be added to the queue will be placed (assuming that packet 159 does not replace a packet elsewhere in the queue, per method 200 ). Queue 150 preferably operates as a FIFO (first in, first out) buffer, with the newest packets being placed at the tail and gradually making their way to the head for upstream transmission.
Referring to FIG. 3 , each new packet received for US transmission (e.g., a packet 159 as shown in FIG. 2 ) is examined to determine whether it is an ACK packet, and whether it is a candidate for replacing another ACK packet that is currently queued for US transmission (step 202 ). As will be described in more detail with reference to FIG. 4 , this depends on whether the packet is a TCP ACK packet and, if so, the control information, options settings and any data carried with the ACK (some ACK packets can replace another ACK packet but may not be dropped themselves). If the new packet is not a potential replacement ACK, it is added to the tail of the queue (step 220 ).
If the new packet is a potential replacement ACK, in step 204 , the packets already queued for US transmission are inspected, from the head of the queue (oldest queued packet) to the tail of the queue (newest queued packet). With reference to queue 150 of FIG. 2 , if packet 159 has been determined to be a potential replacement ACK, the packets held in queue 150 are inspected beginning with the packet in the head position 151 and ending with the packet in the tail position 158 .
In step 206 , a determination is made as to whether the queued packet is a potentially replaceable ACK. Again, this determination depends on the control setting, options data and data carried by the packet and will be described in more detail with respect to FIG. 4 . If the packet is not a potentially replaceable ACK, the method moves on to inspect the next queued packet (step 222 ). Hence, in FIG. 2 , the “NEXT” arrow would move from packet 151 to packet 152 , and packet 152 would then be inspected.
If the queued packet is a potentially replaceable ACK, in step 208 , a determination is made as to whether the ACK in that position has been dropped (replaced) too many times. It is desirable to maintain some minimum flow of ACKs in the US channel to the source in order to avoid a “stretch ACK” and burstiness at the source. That is, if few ACKs acknowledging large numbers of packets are sent to the source, the source ends up sending large amounts of packets in the DS direction at once rather than sending a more even flow of packets in the DS direction. As will be described with reference to FIG. 4 , step 208 is carried out by maintaining a “drop count” for each queued packet. If the ACK currently under inspection has been dropped too many times, it is retained in the queue, and the method moves on to inspect the next packet in the queue (step 222 ).
If the queued packet is a potentially replaceable ACK and has not been dropped too many times, in step 210 , it is determined whether the queued ACK is in the same session as the new ACK. A new ACK may only replace a queued ACK for the same TCP session. FIG. 4 sets forth the details for making this determination. If the queued ACK is in a different TCP session, it is left in the queue and the next packet in the queue is inspected (step 222 ).
Moving to step 212 , it has now been determined that the ACK packet currently being inspected is potentially replaceable, has not already been dropped too many times and is in the same TCP session as the new ACK packet. Step 212 asks whether the new ACK has a higher ACK number than the queued ACK. That is, it asks whether the sequence number in the ACK field of the new ACK is higher than the sequence number in the ACK field of the queued ACK. If the new ACK has a higher ACK number than the queued ACK, it renders the queued ACK redundant and the queued ACK can be safely replaced by the new ACK or dropped altogether. A new ACK with an ACK number of “13”, for example, would indicate that all bytes in the sequence up to and including byte “12” have been received. Hence, if the ACK under inspection had an ACK number of “7”, that ACK is rendered redundant by the new ACK and can be replaced or dropped.
If the new ACK does not have a higher ACK number than the queued ACK, then it is a duplicate ACK and cannot be dropped or replaced yet. In this event, the new ACK is added to the tail of the queue (step 220 ). As previously discussed, when data packets arrive out-of-order, the receiver issues a duplicate ACK. After the source receives a particular number of duplicate ACKs, it will assume that the data packet indicated in the ACK was lost and retransmits it. Thus, until the next packet is received and a new ACK with a higher ACK number is generated by the receiver, the duplicate ACKs must be left in the queue because they convey important information (the next packet has not yet arrived) to the source.
Moving to step 214 , we have now determined that a queued packet is in fact a replaceable ACK packet because it has not been dropped or replaced too many times already, it is in the same TCP session as the new ACK packet, and it has a lower ACK number than the new ACK packet. Step 214 asks whether an ACK has already been replaced during the current inspection or sweep of the queue with the new ACK. If there has not yet been a replacement, then the queued ACK is replaced with the new ACK (step 214 ), and the method moves on to inspect the next queued packet (step 222 ). If the new ACK has already been used to replace a queued ACK, then the current ACK under inspection no longer serves a purpose and may be removed from the queue altogether (step 218 ).
Referring now to FIG. 4 , a specific implementation of method 200 will now be described. Steps 250 - 261 correspond to step 202 of FIG. 3 : new packets arriving for US transmission are evaluated and characterized to determine whether they are potential replacement ACKs. In step 250 , a new frame arrives for US transmission. If the frame carries an IP packet (step 251 ), it is evaluated further. If it does not, the packet cannot be a TCP ACK packet. In accordance with the present invention, each packet is linked to a variable PcktTy indicating its packet type. PcktTy may be “Ack”, indicating that it can be replaced with another ACK packet or even dropped from the queue at some point; or “Other”, indicating that the packet cannot be replaced or dropped from the queue. If, in step 251 , we determine that the frame does not even carry an IP packet, PcktTy for that frame is designated “Other” (step 261 ) and it is placed in the queue (step 295 ). When the queued packet is later inspected in accordance with method 200 , the designation “Other” will serve to indicate that the packet must be left in the queue for US transmission and not dropped or replaced.
Step 252 asks whether the new packet is a TCP packet, and is carried out by looking at the IP protocol field in the IP header. If the packet is not a TCP packet, the packet type is designated “Other” (step 261 ) and the packet is queued (step 295 ). If the packet is a TCP packet, step 253 asks whether it is a “simple” IP packet. A simple IP packet is one that has no options and, in one implementation, is identified by an IHL field having a value of 5 in the IP header. If the packet is not a simple IP packet (i.e., the IHL field in the IP header has a value greater than 5), the packet type is designated “Other” (step 261 ) and the packet is queued (step 295 ). If the packet is a simple IP packet, step 254 asks whether it is a TCP control packet. In one implementation, a bitwise AND operation performed on the TCP header “Data Offset”, “Reserved”, and “Flags” fields where 0x0007 evaluates to true indicates that the packet is a TCP control packet (TCP DataOff+Reserv+Flags &&0x0007=True). In this regard, it should be noted that the designation TCP DataOff refers to the “Data Offset” field of the TCP header. Hence, the designation TCP Reserv refers to the “Reserved” field of the TCP header, and so on. If the packet is a TCP control packet, it cannot be dropped from the queue and is designated “Other” and queued.
If the packet is not a TCP control packet, step 255 asks the crucial question: whether it is a TCP ACK packet. In accordance with the present invention, only TCP ACK packets may be dropped from or replaced in the queue. In one implementation, a bitwise AND operation performed on the TCP header “Data Offset”, “Reserved”, and “Flags” fields where 0x0010 evaluates to true indicates that the packet is a TCP ACK packet (TCP DataOff+Reserv+Flags &&0x0010=True). If the packet is not a TCP ACK packet, it is designated as type “Other” (step 261 ) and queued (step 295 ). If the packet is a TCP ACK packet, we now know that it is at least a candidate for replacing other TCP ACK packets and it is not added to the queue for now. It should be noted that, in some implementations, steps 251 - 255 may be carried out as a single step that asks whether the packet is a TCP ACK packet.
Some TCP ACK packets may be used to replace other ACK packets, but cannot be dropped themselves. In other words, such packets are suitable replacement ACKs, but are not replaceable ACKs. In particular, ACK packets carrying data in the reverse direction, having certain option settings, with explicit congestion notification (ECN) or with control flags set in the TCP header must not be dropped. Steps 256 - 260 perform this evaluation and characterization.
Step 256 asks whether the packet is a “plain” TCP ACK packet. A plain ACK packet is one that contains no data to be carried in the reverse (US) direction. In one implementation, if [IP TotLength −4XIP IHL −4XTCP DataOffSet ]=0, the packet is a plain ACK packet. If the packet is not a plain ACK packet (i.e., it carries data), it can be used to replace another ACK packet but it can not be dropped itself, so its packet type is designated “Other”.
Step 257 looks at the “Options” field of the ACK packet TCP header. Certain options carry important information and must be included in the US transmission. Packets containing these options must be designated “Other” so they are not dropped. Other option settings may be safely dropped. The inventor has determined, in particular, that packets having the timestamp option (kind=8) and/or selective ACK (SACK) option (kind=5) may be safely discarded without appreciably diminishing system performance. That is, the virtual increase in US capacity and consequent increase in DS capacity utilization offsets any negative impact from the loss of the information contained in dropped ACKs having timestamp and/or SACK options.
The timestamp option (kind=8) gives the sender an accurate RTT measurement for every ACK packet, which in a sensible receiver corresponds to every other data packet. Therefore, the dropping of ACK packets in general clearly reduces the sampling frequency for the path-RTT estimation when the timestamp option is used. In addition, when dropping ACK packets that carry a timestamp option, the RTT computation yields shorter estimations because ACK packets echoing earlier timestamp values, and that waited longer to be transmitted, are dropped. The inventor has determined that the reduction in the sampling frequency for the RTT estimation is a more negative side effect of ACK-filtering than the impact on the variance in the RTT estimation. Accordingly, the present invention simply allows ACKs having timestamp options to be dropped. While special processing could be provided for handling timestamp options, such as keeping the oldest timestamp across ACK-drops, this is not preferred since it would increase complexity and add processing delay.
The SACK option (kind=5) provides the TCP source with more qualified acknowledgement information, allowing the receiver to indicate to the sender the successful receipt of non-contiguous (out-of-order) packets, hence SACK is present on duplicate ACKs. The method of the present invention drops duplicate ACKs only when the ACK number of a new ACK is higher than the ACK number of older packets in the queue. Thus, the new ACK may be closing some of the holes (sequence number gaps) reported in the SACK blocks of previous ACK packets. Therefore, a new ACK packet with an ACK number bigger than the ACK number on the queued ACK packet can always replace the older queued ACK packets. Since the new ACK advances the sender window and possibly closes holes in SACK blocks, there is little loss of information when the dropped ACK packets carried a SACK option.
In addition to the timestamp (kind=8) and SACK (kind=5) options, the “End of Options List” (kind=0) and the “No Operation” (kind=1) options can also be safely discarded if present on a TCP ACK packet. So, in step 257 , the TCP options are “OK” (i.e. the packet may be dropped) if TCP DataOffSet =5 (no options) or if TCP DataOffSet >5 and only option kinds 0, 1, 5 or 8 are present. If other option kinds are present, the packet may be used as a replacement packet for other ACKs, but it must not be dropped itself and is designated as type “Other” (step 259 ).
Finally, step 258 asks whether the packet is marked with explicit congestion notification (ECN). In one implementation, a bitwise AND operation performed on the TCP header “Data Offset”, “Reserved”, and “Flags” fields where 0x00C0 evaluates to true indicates that the packet is a ECN-marked packet (TCP DataOff+Reserv+Flags &&0x00C0=True). If the packet is ECN-marked it must not be dropped and is designated “Other”. If an ACK packet is plain (step 256 ), has OK options (step 257 ) and is not ECN-marked, it is designated as type “Ack” in step 260 . Such an ACK packet may both replace other ACK packets and be dropped or replaced itself.
Now that a new packet has been identified as a TCP ACK packet, and has been characterized as “Other” (do not drop) or “Ack” (droppable), the packets currently in the queue may be inspected and compared to the new packet to determine whether they may be replaced by the new packet or dropped. Steps 265 - 268 begin the process of inspecting the queue. First, in step 265 , the “Replaced” flag is set to false to indicate that no packets in the queue have been replaced. As the method proceeds, when a packet in the queue is replaced, the “Replaced” flag will be changed to true. FIG. 2 illustrates a replace flag 160 associated with queue 150 that may be set to N or Y to signal whether any of packets 151 - 158 in queue 150 have yet been replaced by the new packet 159 under consideration.
Step 266 begins the inspection process at the head of the queue (step 266 ). Step 267 obtains the next packet in the queue for inspection. As shown in FIG. 2 , step 267 may be thought of as sequentially moving a pointer “NEXT” through queue 150 from head 151 to tail 158 to obtain the next queued packet for inspection. Hence, the queued packet currently being inspected is designated “Next”; the new packet currently being considered (i.e. packet 159 of FIG. 2 ) is designated “Pckt”.
Step 268 asks whether there is no next packet (i.e. NEXT=NULL). This occurs when the inspection process has moved through the entire queue and no packets remain to be inspected. So long as packets remain to be inspected, the method moves on to step 270 . When the entire queue has been inspected, however, if any packets were replaced during the just-finished inspection of the queue (step 290 ), the method simply terminates (step 299 ) and awaits the arrival of the next US frame when it will begin anew. If no packets were replaced, the new packet is assigned a drop count (“DropCnt”) set to zero (step 292 ), the new packet is queued (step 295 ) and the method terminates (step 299 ) and await arrival of a new frame for US transmission.
Step 270 considers the packet type (PcktTy) of the “Next” packet, or the queued packet currently under inspection. A packet type is “Ack” indicates that the Next packet is an ACK packet and may also be dropped. In this case, the method moves on to step 272 for further analysis of the Next packet. If the packet type is not “Ack” (i.e., if it is “Other”), the Next packet may not be dropped so the inspection process skips over it and moves on to step 267 to inspect the next packet in the queue. Step 270 corresponds to step 206 of FIG. 3 , which asks whether the next queued packet is a potentially replaceable packet.
Step 272 , corresponding to step 208 of FIG. 3 , determines whether the queued packet currently being inspected has been dropped too many times by considering its drop count (DropCnt). As previously discussed, the method is careful not to drop a packet to many times in order to avoid stretch ACKs and burstiness at the source. Accordingly, step 272 compares the drop count of the currently queued (next) packet to a predetermined maximum drop count (a drop threshold) D. If Next.DropCnt>=D, then the packet has been dropped its maximum number of times and should be left in the queue for US transmission. In this event, the packet is skipped over (left in the queue) and the method proceeds to step 267 to consider the next queued packet.
Steps 275 - 277 correspond to step 210 of FIG. 3 and determine whether the queued ACK is part of the same TCP session as the new ACK. Step 275 compares the IP destination address field of the new packet with the IP destination address field of the currently queued packet, or asks whether Pckt(IP DstAdd )=Next(IP DstAdd ). Step 276 compares the TCP source and destination ports of the new packet with the TCP source and destination ports of the currently queued packet, or asks whether Pckt(TCP SDPort )=Next(TCP SDPort ). Step 277 compares the IP source address field of the new packet with the IP source address field of the currently queued packet, or asks whether Pckt(IP SrcAdd )=Next(IP SrcAdd ). If any of these tests fail, the new and queued ACKs are not part of the same session and the method moves on to the next queued ACK in step 267 . Otherwise, it is confirmed that the new and queued ACKs are part of the same session and the method moves onto step 280 .
In step 280 , it has now been determined that the queued ACK packet currently being inspected is replaceable (Next.PcktTy=Ack), has not been dropped too many times (Next.DropCnt<D) and is in the same TCP session as the new ACK packet. Step 280 asks whether the new ACK has a higher ACK number than the next ACK, or Pckt(TCP Ack )>Next(TCP Ack )?. That is, it asks whether the sequence number of the new ACK is higher than the sequence number of the queued ACK. If the new ACK has a higher ACK or sequence number than the queued ACK, it renders the queued ACK redundant and the queued ACK can be safely replaced by the new ACK or dropped altogether.
If the new ACK does not have a higher ACK number than the queued ACK, then it is a duplicate ACK and cannot be dropped or replaced yet. In this event, the method proceeds to step 290 , the new packet is assigned a drop count set to zero (step 292 ) and the new packet is added to the tail of the queue (step 295 ). As previously discussed, when data packets arrive out-of-order, the receiver issues a duplicate ACK. After the source receives a particular number of duplicate ACKs, it will assume that the next data packet in the sequence was lost and retransmits it. Thus, until the next packet is received and a new ACK with a higher ACK number is generated by the receiver, the duplicate ACKs must be left in the queue because they convey important information (the next packet has not yet arrived) to the source.
If the queued ACK does have a lower ACK number than the new ACK packet, it can safely be replaced or discarded. Step 282 asks whether an ACK has already been replaced during the current inspection of the queue with the new ACK by looking at the status of the “Replace” flag. If the “Replace” flag is false, indicating that there has not yet been a replacement, then the queued ACK is replaced with the new ACK (step 283 ), and the packet type is set to match the packet type of the new ACK (step 284 ). The drop count of the packet is increased by one (step 285 ) and the “Replace” flag is set to true (step 286 ) to reflect the replacement that has just occurred. The method moves on to step 267 to inspect the next queued packet.
If step 282 reveals that the new ACK has already been used to replace a queued ACK (“Replace”=True), then the current ACK under inspection is a duplicate ACK with dated loss information and it no longer serves a purpose since the new ACK information (higher ACK number) has already been inserted into the queue. In this case, the queued ACK is removed from the queue altogether (step 287 ). The method then moves on to step 267 to inspect the next queued packet.
The ACK discarding described in this invention is intended to improve performance for DS TCP transfers. However, performance degradation is also possible due to congestion state in source-destination path. For this reason, the drop threshold D in 272 of FIG. 4 is a configurable parameter that the manager of the device implementing this invention can set. A recommended value of two (2) for the configurable drop threshold D represents a balance between performance gains and capping the source burstness. Larger values can possibly yield higher performance improvements at increased source burstness and the risk of data packet losses over congested paths. Setting this parameter to one only yield modest performance gains but could be used during peak usage times.
While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention.
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A system and method for transmission control protocol (TCP) acceleration. Incoming acknowledgement (ACK) packets belonging to a TCP session are received, and an upstream queue is searched for queued acknowledgment packets belonging to the same TCP session. If the incoming acknowledgment packet is not a duplicate of the queued acknowledgment packet, one of the queued acknowledgment packets is replaced with the incoming acknowledgment packet in the position in the upstream queue occupied by the oldest of the queued acknowledgment packets. After the oldest queued acknowledgement packet is replaced, remaining acknowledgement packets in the queue are dropped.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a liquid injection type screw compressor comprising a pair of male and female screw rotors that are installed in a space surrounded by a bore face within a casing of the compressor, while a liquid such as oil or water is injected to the bore face; whereby, a lip part is provided so as to prevent the liquid from flowing-back to a working gas inlet side, being placed on the bore face, within a range from a suction seal line (a suction closure line or a suction containment boundary locus) to a line parallel thereto apart from the suction seal line, by a distance equal to one screw pitch (a tooth groove distance in the rotor axis direction) of the rotors.
[0003] In hitherto known liquid injection type screw compressors, a pair of a male screw rotor and a female screw rotor within a casing of the compressor are engaged in each other, so as to form a working/operation space inside which a liquid such as oil or water is injected whereby a working substance of a gas-liquid mixing phase is pressurized. The liquid injection brings the screw compressor a cooling function, a sealing function, and a lubricating function; thus, the compressor of the type obtains high efficiency even during a low speed operation, becoming widespread in the industry.
[0004] The bore faces forming the working space within the casing of the compressor are important elements so as to secure gas/liquid tightness, when the working space is under a compression process where a gas seal across adjacent tooth spaces is required; consequently, it is a prerequisite to keep the clearance between the addendum circles of the rotors (tooth tip surfaces of the rotors) and the bore faces as small as possible. In this specification, the bore faces in the part as mentioned are called main bore faces.
[0005] On the other hand, a gas leakage between adjacent tooth spaces does not effect on the performance of the compressor when working spaces are under gas suction process; therefore, the bore faces in the associated part as mentioned are expanded toward outside in comparison with the main bore faces so that a power consumption is reduced by evading useless possible friction between the bore faces and the tooth tips; thus, the bore faces in the part as mentioned are called expanded bore faces.
[0006] In conventional liquid injection type screw compressors as described above, a weir (a lip part) is provided therein so as to prevent oil from scattering through a suction side end face of the rotor casing toward a gas inlet side; thus, it is intended to preserve the compressor volumetric efficiency and reduce the compressor power loss.
[0007] Conventional screw compressors with such a weir as mentioned are disclosed, for instance, in a patent literature 1 (JP patent: 1967-10027), a patent literature 2 (JP: 1991-194183) and a patent literature 3 (JP: 1999-13661).
[0008] The FIGS. 1 and 2 in the patent literature 1 disclose that a lip (weir) 44 is provided between a gas inlet 24 and an expanded bore part 40 so as to lessen a heat exchange between a hot back-flow gas from a compression space formed in a rotor tooth space, and a flow-in gas from the gas inlet 24 .
[0009] On the other hand, the FIG. 1 in the patent literature 2 discloses a lip (weir) 39 that is provided at a suction side end-face of a casing 3 so that the lip 39 prevents a back-flow oil from flowing from expanded bore parts 7 and 8 back to a gas inlet side, from warming-up an inhaled gas, and also from deteriorating a charging efficiency of the inhaled gas to be charged into a rotor teeth space.
[0010] Moreover, the patent literature 3 discloses that the oil injected into a working space flows back to a gas inhaling space; thereby, an oil mist generated from the back-flow oil suspends in the gas inhaling space, while the oil mist heats up the inhaled gas under a suction process; namely, a phenomenon, what is called inhaled gas heating, occurs; thus, the phenomenon increases a temperature of the gas to be compressed as well as expands a volume thereof; as a result, in a displacement type compressor that needs to inhale a gas of a constant specific volume, not only a reduction of mass-throughput but also a deterioration of volumetric efficiency are brought.
[0011] In order to evade the above-mentioned difficulties, according to the patent literature 3 , as shown in FIG. 2 of the patent literature 3 a lip part 5 is provided at a suction side end-face of a casing 3 that accommodates the rotors, so that the lip part 5 protrudes inside, i.e. toward screw rotors; further, a heat-up prevention wall (a baffle plate) 8 to close a gap between the screw rotors and the lip part 5 is provided so as to prevent an inhaled gas from leaking toward a gas inlet side.
[0012] FIGS. 9 a and 9 b that are attached to this application shows a casing for conventional screw rotors; for explanatory convenience, FIG. 9 a shows a divided upper half and FIG. 9 b shows a divided lower half. In FIGS. 9 a and 9 b , a space that accommodates a male rotor and a female rotor is formed inside the casing 01 ; thereby, the boundary of the space comprises:
a male rotor side main-bore-face 02 a that faces a male rotor tooth tip with a slight clearance A 1 , a female rotor side main-bore-face 02 b that faces a female rotor tooth tip with a slight clearance A 2 , a male rotor side expanded-bore-face 03 a that faces a male rotor tooth space during a gas suction process, and a male rotor tooth tip with a clearance B 1 greater than the mentioned clearance A 1 , and a female rotor side expanded-bore-face 03 b that faces a female rotor tooth space during a gas suction process, and a female rotor tooth tip with a clearance B 2 greater than the mentioned clearance A 2 .
[0017] Further, a lip part 04 is provided along a suction side end-face of a casing 01 so that the lip part 04 of the casing 01 protrudes inside, toward screw rotors; on the other hand, a suction seal line (a suction containment boundary locus) 05 is formed on a boundary between the male rotor side main-bore-face 02 a and the male rotor side expanded-bore-face 03 a as well as between the female rotor side main-bore-face 02 b and the female rotor side expanded-bore-face 03 b.
[0018] In the configuration as stated above, a working space is formed with a tooth space of the male rotor and another working space is formed with a tooth space of the female rotor, the pair of tooth spaces being independent; whereby, the tooth spaces are engraved on an outer periphery of rotors along a screw tooth spiral. While the working spaces are communicated with the expanded-bore-faces 03 a or 03 b , the working spaces are gradually expanded to a maximum volume, inhaling a gas through a gas inlet; then, the working spaces pass through the suction seal line (the suction containment boundary locus) 05 , and the working spaces form a closed space the boundary of which includes a male rotor side main-bore-face 02 a and a female rotor side main-bore-face 02 b . Thus, after the working space becomes a closed space, the volume of the working spaces is gradually reduced and a confined gas within the space is compressed; at a last stage of compression, the gas inside the spaces is discharged through a discharge opening.
[0019] During the mentioned compression process, a liquid such as oil or water is injected into the working space, for the purpose of cooling, sealing, and lubricating.
[0020] FIGS. 10 a and 10 b schematically depicts bore faces of a conventional screw rotor casing. FIG. 10 a shows a transparently perspective view seen from the top, depicting a suction seal line and a lip part. FIG. 10 b is a development of FIG. 10 a.
[0021] In FIGS. 10 a and 10 b , the reference numeral 01 a denotes a male rotor side casing, and the numeral 01 b does a femamale rotor side casing 01 b ; a suction seal line 05 is formed on a boundary between a male rotor side main-bore-face 02 a and the male rotor side expanded-bore-face 03 a as well as between the female rotor side main-bore-face 02 b and the female rotor side expanded-bore-face 03 b ; a lip part 04 of the casing 01 protrudes inside, toward screw rotors.
[0022] The working (operation) spaces formed with the male rotor and the female rotor face the male rotor side expanded-bore-face 03 a and the female rotor side expanded-bore-face 03 b , while the working spaces gradually increase during a suction process, inhaling a gas through a gas inlet. After the volume of the working spaces reaches a maximum volume and the working spaces cross the suction seal line 05 , the spaces form a sealed space, being surrounded by the main-bore-faces 02 a and 02 b . Subsequently, as the volume of the working spaces is reduced, the gas confined in the spaces is compressed. And the compressed gas is discharged through a discharge opening at a discharge side end face 07 of the rotor casing.
[0023] In the above situation, the liquid such as oil or water injected into the working spaces leaks toward a lower pressure suction side and accumulates in the concaved expanded bore faces 03 a / 03 b . The lip part 04 prevents the liquid from leaking and scattering toward the gas suction end face 06 of the rotor casing.
[0024] Patent literatures:
Patent literature 1, JP 1967-10027; Patent literature 2, JP 1991-194183; Patent literature 3, JP 1999-13661.
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0028] In spite of the disclosure according to the configuration such as in the patent literature 3, the conventional technologies are insufficient in sealing a liquid within the working spaces as well as in preventing deterioration as to volumetric efficiency; the insufficiency is caused on the ground that great distances remain between rotor tooth tips and the lip part 04 ( 04 a and 04 b in FIGS. 10 a and 10 b ) placed at the suction side end face of the rotor casings.
[0029] As just mentioned above, the lip part is provided at the suction side end face of the rotor casings in conventional liquid injection screw compressors; thus, a gas inlet has to be placed outside across the suction side end face; moreover, the lip part lessens a gas inlet passage area (opening area) around the suction side end face of the rotor casings; therefore, in case of manufacturing a mono-block casting of the rotor casings and the gas inlet casing, it becomes difficult to allocate a casting core for rotor casing bores.
[0030] Further, in conventional ways, only by means of lengthening rotor space in the axial direction, it is possible to secure a sufficient gas inlet passage for inhaling a gas into the working space; in addition, insufficient inlet passage area enhances suction resistance during a high-speed operation.
[0031] Because of the above-mentioned situations, it is conventionally difficult to obtain a mono-block casting of the rotor casings and the gas inlet casing. That is, in casting, it is necessary to manufacture the rotor casing and the gas inlet casing separately; further, it becomes necessary to provide each casing with an essentially useless part such as an additional flange that is needed for assembling the parts. Thus, an increased whole weight and an intricate production process are brought; further, as mentioned above, in a high speed operation, there arise difficulties such as an increased gas suction resistance as well as a lessened volumetric efficiency.
[0032] In view of the mentioned subjects in conventional liquid injection type screw compressors, the goals of the present invention are:
preventing a liquid such as oil or water from leaking outside the working spaces of high compression, which are formed by screw rotors, toward the gas inlet side during a compression process, more effectively than conventional ways; lessening a gas suction resistance of a gas flow into the rotor casings from an outside gas inlet so as to improve volumetric efficiency of the inhaled gas, as a result; and realizing an liquid injection type screw compressors of a simplified structure so as to bring manufacturing cost reduction.
[0036] Further, the invention aims at realizing a liquid injection type screw compressor provided with a variable compression ratio mechanism, that is, an internal volume ratio adjusting valve; wherein, the compressor has a compact structure so as to not prolong a manipulation mechanism of the internal volume ratio adjusting valve, making manufacturing cost be further reduced.
Means to Solve the Problem
[0037] In order to attain the mentioned goals, the present invention proposes a liquid injection type screw compressor comprising of:
a pair of a male rotor and a female rotor, a rotor casing comprising a pair of bores that accommodate the pair of the male rotor and the female rotor, a gas inlet and a gas outlet that are connected to the pair of the bores, the gas inlet being provided at a first end part of the rotor casing, while the gas outlet being provided at a second end part of the rotor casing, and a lip part that is provided on a surface of the bores and protrudes inside so as to prevent the liquid on the surfaces of bores from back-flowing toward the gas inlet, the lip part being located at a gas upstream side of a suction seal line of the rotor casing; wherein the lip part is placed within a range between the suction seal line and a line that is apart from the suction seal line, by one screw pitch distance of the screw rotors, toward the expanded-bore-face side of the male rotor side casing and/or the female rotor side casing (namely, toward the gas inlet side).
[0043] In a screw compressor according to the present invention, a lip part for preventing liquid from back-flowing toward a gas inlet is provided on a casing bores, within a range between a suction seal line and a line that is apart from the suction seal line, by one screw pitch distance of the screw rotors, toward the expanded-bore-face side of the male rotor side casing and/or the female rotor side casing; hence, the lip part is placed nearer to the suction seal line in comparison with conventional ways; as a result, a liquid leakage from the compressed working spaces toward the gas inlet side is effectively prevented; further, the lip part placed nearer to the suction seal line makes it possible to eliminate a part of bore faces that is located at the gas inlet side from the lip part. So can be realized a simplified configuration of rotor casings with a reduced bore surface as well as a reduced suction resistance and a reduced manufacturing cost which are attributable to the simplification.
[0044] A preferable configuration of the present invention may comprise:
a straight development-line portion of the suction seal line in a development view, lying at right angles to a bore intersection line that is defined as a common generating line of a male rotor bore and a female rotor bore, a lip-entering-edge of the lip part that is placed apart from the suction seal line toward the gas inlet side in a rotor axis direction, whereby the lip-entering-edge in response to the above-mentioned straight-line portion is bent so as to protrudes toward the suction seal line, and a lip ending (trailing) edge of the lip part whereby the lip ending edge in response to the straight-line portion is placed parallel thereto so as to form a straight line portion of the lip ending edge in a development view, and a thickened (wide in the rotor axis direction) lip part in response to the straight-line portion.
[0049] The above preferable configuration can surely prevent a liquid leakage around a neighborhood along the bore intersection line.
[0050] According to a further preferable aspect of the above configuration,
the straight line portion of the suction seal line in a development view lies at right angles to the bore intersection line, and starts from a cross-point of the bore intersection and the suction seal line on the male bore surface as far as a point on the suction seal line on the female bore surface, the lip-entering-edge of the lip part is placed apart from the suction seal line toward the gas inlet side in the rotor axis direction, and the lip-entering-edge in response to the above-mentioned straight-line portion is bent so as to protrudes toward the suction seal line; wherein, a part of the lip-entering-edge in response to the straight line portion starts from a cross-point of the bore intersection line and the lip-entering-edge on the male bore surface, as far as a point on the lip-entering-edge on the female bore surface, the lip ending (trailing) edge of the lip part in response to the straight-line portion is placed parallel thereto so as to form the straight line portion of the lip ending edge in a development view, and the thickened (wide in the rotor axis direction) lip part is provided in response to the straight-line portion, whereby a straight line portion of the ending edge starts from a cross-point of the bore intersection and the lip-ending-edge on the male bore surface, as far as a point on the lip-ending-edge on the female bore surface.
[0055] The above configuration can surely prevent a liquid leakage around the bore intersection line.
[0056] Another preferable aspect of the invention according to the mentioned configuration is the liquid injection type screw compressor, wherein the rotor casing with the gas inlet casing is formed in one piece or a plurality of divided-pieces from the lip ending edge toward a gas downstream side. Thus, the gas inlet side bore surface of the rotor casing can be omitted in a way that the lip part is located nearer to the suction seal line; as a result, it becomes possible to form a gas inlet casing and a rotor casing in one body.
[0057] Consequently, the invention realizes a smaller rotor casing, saving an installation space; in addition, the invention greatly relieves restrictions concerning a position where a gas inlet casing is disposed in a rotor casing; in this regard, the degree of freedom as to the gas inlet casing design can be greatly expanded.
[0058] According to a further preferable aspect of the invention, a labyrinth structure is embodied on the inner surface which faces rotor tooth tips in the lip part. For example, a pertinent roughness of the surface (e. g. a pertinent casting surface roughness) or an intended uneven surface can realize lesser liquid leakage.
[0059] According to another preferable aspect of the invention, different outer diameters are applied to a pair of the male rotor and the female rotor so that the outer diameter of the male rotor is greater than that of the female rotor, and the number of the male rotor teeth is fewer than that of the male rotor teeth in a case when the same outer diameter is applied to a pair of the male rotor and the female rotor.
[0060] In this way, a screw pitch distance of the male rotor can be shortened and the lip part can be located nearer to the suction seal line; thus, the liquid leakage can be further surely prevented; in addition, the geometry of the casings can be simplified.
[0061] According to another preferable aspect of the invention, the lip part is provided at the lower side of the casing bore surfaces. In this configuration, the liquid accumulated by gravity at the bottom of the bore surfaces can be easily prevented from scattering toward the gas inlet side; thus, a simple structure can be realized.
[0062] Another preferable aspect of the invention according to the mentioned configuration is a liquid injection type screw compressor comprising:
a slide valve (capacity control valve), and an internal volume ratio (U i ) adjusting valve; whereby, the slide valve has a cut-out part, at a discharge end thereof, which regulates a gas discharge throat between a discharge end part (of gas discharge side) of the slide valve and an end face (of gas discharge side) of the rotor casing, and a valve driving rod (a pushrod) that is prolonged toward the gas inlet casing on a rotor end face so that the valve driving rod protrudes across the gas inlet casing, through a storage space of the internal volume ratio adjusting valve that is provided on a side of the gas inlet casing which comes in contact with the rotor end face, the valve driving rod being connected to a drive source i.e. a hydraulic cylinder in order that the slide valve can move forward and backward along an axis of the driving rod by means of the drive source and the driving rod, while the internal volume ratio (U i ) adjusting valve in the storage space is placed adjacent to a gas inlet side end face of the capacity control valve (a slide valve), with a positioning means that adjusts variably the position of the internal volume ratio (U i ) adjusting valve, along a direction to/from a gas discharge side, wherein an internal volume ratio (U i ) is adjusted such that the positioning means shifts the internal volume ratio (U i ) adjusting valve to a predetermined position, while an internal gas capacity (that is equivalent to a gas density at a compression commencement) is adjusted by by-passing an inhaled gas back to the gas inlet side through a gap between the internal volume ratio (U i ) adjusting valve, and the capacity control valve (a slide valve) that slides to and fro along the driving rod direction by means of the drive source, through the driving rod.
[0069] The installation of an internal volume ratio (U i ) adjusting valve makes a whole compressor compact, realizing a compressor of three kinds of compression ratios, namely, of lower/medium/higher compression ratios, without changing a gas inlet casing, only by replacing a rotor casing. Thus, a gas inlet casing can be applied to these kinds of compressors in common.
[0070] On the other hand, conventional compressors are apt to be of a large size, as a positioning means to position the internal volume ratio (U i ) adjusting valve is prolonged toward a gas discharge side, penetrating a gas discharging casing so as to be used for setting (positioning) the valve.
[0071] In order to solve the difficulty, according to a further preferable aspect of the present invention, the positioning means comprises:
a hollow shaft which is placed concentric to the driving rod, having a screw part on an outer surface of the hollow shaft so that the screw part is engaged into a corresponding screw part inside the internal volume ratio adjusting valve, and a rotation rod that is placed so as to intersect with the hollow shaft in order that the rod can transmit a rotational driving movement of the rod to the hollow shaft, via a connection part; whereby, the rotational movement transmitted to the hollow shaft is transformed into a to-and-fro movement of the internal volume ratio adjusting valve, through the mentioned screw engagement, so that the internal volume ratio adjusting valve is positioned to a predetermined position.
[0074] According to the above aspect, there is no need to prolong a positioning means as in conventional approaches; a driving mechanism to position the internal volume ratio-adjusting valve can be formed as a compact one. The mentioned connection part between the hollow shaft and the rotation rod may be a bevel gear pair or a crossed helical gear pair.
Effect of the Invention
[0075] In a screw compressor according to the disclosed invention, a lip part for preventing liquid from back-flowing toward a suction inlet is provided on a casing bores, within a range between a suction seal line and a line that is apart from the suction seal line, by one screw pitch distance of the screw rotors, toward the expanded-bore-face side of the male rotor side casing and/or the female rotor side casing.
[0076] Therefore, a liquid leakage scattering during a compression process from the compressed working space formed by the screw rotors toward the gas inlet side can be effectively prevented.
[0077] Moreover, the lip part placed nearer to the suction seal line makes it possible to eliminate a part of the rotor casing at the gas inlet side from the lip part. So can be realized a simplified configuration of rotor casings with a reduced bore surface as well as a reduced suction resistance of an inhaled gas and an enhanced volumetric efficiency of the compressor.
[0078] Further, the lip part placed nearer to the suction seal line makes it possible to eliminate a part of the rotor bore faces at the gas inlet side from the lip part. Hence, the rotor casing can be formed in one body with a gas inlet casing. As a result, manufacturing processes can be simplified and a manufacturing cost can be reduced. Consequently, the disclosed invention greatly relieves restrictions regarding installation position of a gas inlet casing in a rotor casing. Further, the degree of freedom as to the gas inlet casing design can be greatly expanded; in addition, a compact casing can be realized and a compressor installation space can be reduced.
[0079] Also as already explained, in a screw compressor according to the disclosed invention, the compressor comprises:
a straight development-line portion of the suction seal line in a development view, lying at right angles to a bore intersection line that is defined as a common generating line of a male rotor bore and a female rotor bore, a lip-entering-edge of the lip part that is placed apart from the suction seal line toward the gas inlet side in a rotor axis direction, whereby the lip-entering-edge in response to the above-mentioned straight-line portion is bent so as to protrudes toward the suction seal line, and a lip ending (trailing) edge of the lip part whereby the lip ending edge in response to the straight-line portion is placed parallel thereto so as to form a straight line portion of the lip ending edge in a development view, and a thickened (wide in the rotor axis direction) lip part in response to the straight-line portion.
[0084] Thus, the above configuration can surely prevent a liquid leakage around a neighborhood along the bore intersection line.
[0085] Further, in a screw compressor according to the disclosed invention, the compressor comprises:
the straight line portion of the suction seal line in a development view lies at right angles to the bore intersection line, and starts from a cross-point of the bore intersection and the suction seal line on the male bore surface, as far as a point on the suction seal line on the female bore surface, the lip-entering-edge of the lip part is placed apart from the suction seal line toward the gas inlet side in the rotor axis direction, and the lip-entering-edge in response to the above-mentioned straight-line portion is bent so as to protrudes toward the suction seal line; wherein, a part of the lip-entering-edge in response to the straight line portion starts from a cross-point of the bore intersection and the lip-entering-edge on the male bore surface, as far as a point on the lip-entering-edge on the female bore surface, the lip ending (trailing) edge of the lip part in response to the straight-line portion is placed parallel thereto so as to form the straight line portion of the lip ending edge in a development, and the thickened (wide in the rotor axis direction) lip part is provided in response to the straight-line portion, whereby a straight line portion of the ending edge starts from a cross-point of the bore intersection and the lip-ending-edge on the male bore surface, as far as a point on the lip-ending-edge on the female bore surface.
[0090] Thus, the above configuration can surely prevent a liquid leakage around a neighborhood along the bore intersection line.
[0091] Further, in a screw compressor according to the disclosed invention, different outer diameters are applied to a pair of the male rotor and the female rotor so that the outer diameter of the male rotor is greater than that of the female rotor, and the number of the male rotor teeth is fewer than that of the male rotor teeth in a case when the same outer diameter is applied to a pair of the male rotor and the female rotor.
[0092] In this manner, a screw pitch distance of the male rotor can be shortened and the lip part can be located nearer to the suction seal line; thus, the liquid leakage can be further surely prevented; in addition, the geometry of the casings can be simplified.
[0093] Further, in a screw compressor according to the disclosed invention, the compressor comprises:
a slide valve (capacity control valve), and an internal volume ratio (U i ) adjusting valve; whereby, the slide valve has a slide valve (capacity control valve), and an internal volume ratio (U i ) adjusting valve; whereby, the slide valve has a cut-out part, at a discharge end thereof, which regulates a gas discharge throat between a discharge end part (of gas discharge side) of the slide valve and an end face (of gas discharge side) of the rotor casing, and a valve driving rod (a pushrod) that is prolonged toward the gas inlet casing on a rotor end face so that the valve driving rod protrudes across the gas inlet casing, through a storage space of the internal volume ratio adjusting valve that is provided on a side of the gas inlet casing which comes in contact with the rotor end face, the valve driving rod being connected to a drive source in order that the slide valve can move forward and backward along an axis of the driving rod by means of the drive source and the driving rod, whereas the internal volume ratio adjusting valve in the storage space is placed adjacent to a gas inlet side end face of the capacity control valve (a slide valve), with a positioning means that adjusts variably the position of the internal volume ratio adjusting valve, along a direction to/from a gas discharge side, wherein an internal volume ratio is adjusted such that the positioning means shifts the internal volume ratio adjusting valve to a predetermined position, while an internal gas capacity is adjusted by by-passing an inhaled gas back to the gas inlet side through a gap between the internal volume ratio adjusting valve, and the capacity control valve (a slide valve) that slides to and fro along the driving rod direction by means of the drive source, through the driving rod.
[0101] According to the above disclosure, the installation of an internal volume ratio (U i ) adjusting valve can make a whole compressor compact, realizing a compressor of three kinds of compression ratios, namely, of lower/medium/higher compression ratios, without changing a gas inlet casing, only by replacing a rotor casing. Thus, a gas inlet casing can be applied to these kinds of compressors in common.
[0102] Still further, in a screw compressor according to the disclosed invention, the compressor comprises a positioning means for positioning the internal volume ratio-adjusting valve, the positioning means comprising:
a hollow shaft which is placed concentric to the driving rod, having a screw part on an outer surface of the hollow shaft so that the screw part is engaged into a corresponding screw part inside the internal volume ratio adjusting valve, and a rotation rod that is placed so as to intersect with the hollow shaft in order that the rod can transmit a rotational driving movement of the rod to the hollow shaft, via a connection part; whereby, the rotational movement transmitted to the hollow shaft is transformed into a to-and-fro movement of the internal volume ratio adjusting valve, through the mentioned screw engagement, so that the internal volume ratio adjusting valve is positioned to a predetermined position.
[0105] According to the above aspect, there is no need to prolong a positioning means as in conventional approaches; a driving mechanism to position the internal volume ratio-adjusting valve can be formed as a compact one.
BRIEF DESCRIPTION OF THE DRAWINGS
[0106] The present invention will now be described in greater detail with reference to the preferred embodiments of the invention and the accompanying drawings, wherein:
[0107] FIG. 1 a shows a transparently perspective view seen from a top as to a first embodiment of the present invention;
[0108] FIG. 1 b is a development view of FIG. 1 a;
[0109] FIG. 2 a shows a perspective view of an upper side rotor-casing seen from the inside thereof, as to a first embodiment;
[0110] FIG. 2 b shows a perspective view of a lower side rotor-casing seen from the inside thereof, as to the first embodiment;
[0111] FIG. 3 shows a perspective view of apart of a rotor casing as to the first embodiment;
[0112] FIG. 4 shows a longitudinal plan view of a second embodiment of the present invention;
[0113] FIG. 5 shows a longitudinal section view concerning the second embodiment;
[0114] FIG. 6 explains a development view showing a suction seal line (a suction containment boundary locus) as to each of the male/female rotors that have different tip diameters;
[0115] FIG. 7 gives an explanation about the male/female rotors that have different tip diameters;
[0116] FIG. 8 shows a perspective view as to a variation of the second embodiment;
[0117] FIG. 9 a shows a perspective view of an upper side rotor-casing seen from the inside thereof, as to a conventional compressor;
[0118] FIG. 9 b shows a perspective view of a lower side rotor-casing seen from the inside thereof, as to a conventional compressor;
[0119] FIG. 10 a shows a transparently perspective view seen from the top as to a conventional compressor in consideration of a schematic explanation for bore faces thereof; and
[0120] FIG. 10 b is a development view of FIG. 10 a.
REFERENCE NUMERALS
[0000]
01 a , 1 a , and 11 a a male rotor side casing;
01 b , 1 b , and 11 b a female rotor side casing;
02 a and 2 a a male rotor side main-bore-face;
02 b and 2 b a female rotor side main-bore-face;
03 a and 3 a a male rotor side expanded-bore-face;
03 b and 3 b a female rotor side expanded-bore-face;
04 , 4 , and 33 a lip part;
4 c and 33 c a thickened lip part;
4 d and 33 d a lip entering edge;
4 e and 33 e a lip ending (trailing) edge
05 , 5 , and 32 a suction seal line (a suction containment boundary locus)
5 c and 32 c a straight line portion of a suction seal line in a development view
06 and 6 a suction side end face
07 and 7 a discharge side end face
08 , 8 , and 34 a bore intersection line (that is defined
as a common generating line of a male rotor bore and a female rotor bore)
9 and 12 a gas inlet (a suction inlet)
11 a rotor casing
13 a gas inlet casing
14 a male rotor shaft
15 a female rotor shaft
16 and 19 a thrust bearing
17 , 18 , 20 , and 21 a radial bearing (a journal bearing)
22 a male rotor
23 a female rotor
24 a mechanical seal
25 a discharge outlet (a gas outlet)
26 a gas outlet casing
27 and 36 a tightening bolt
28 a slide valve (a capacity control valve)
28 a a cut-out part
29 a pushrod (a valve driving rod for manipulating a capacity control valve)
30 an oil-hydraulic cylinder (for driving a capacity /displacement-volume control valve)
31 an internal volume ratio (U i ) control device of a manual operation type
35 a casing
37 an internal volume ratio (U i ) adjusting valve for adjusting compression ratio U i
38 a hollow shaft
39 a and 39 b a bevel gear (a movement communicating part)
40 a rotation-rod
41 a discharge opening
“a” in FIG. 4 an intersection point of a suction seal line and a bore intersection line
“b” in FIG. 4 an intersection point of a lip entering edge and a bore intersection line
“c” in FIG. 4 an intersection point of a lip ending (trailing) edge and a bore intersection line
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0164] Hereafter, the present invention will be described in detail with reference to the embodiments shown in the figures. However, the dimensions, materials, shape, the relative placement and so on of a component described in these embodiments shall not be construed as limiting the scope of the invention thereto, unless especially specific mention is placed.
[0165] FIG. 1 a shows a transparently perspective view seen from the top as to a first embodiment of the present invention; FIG. 1 b is a development view of FIG. 1 a ; FIG. 2 a shows a perspective view of an upper side rotor-casing seen from the inside thereof, as to the first embodiment; FIG. 2 b shows a perspective view of a lower side rotor-casing seen from the inside thereof, as to the first embodiment; FIG. 3 shows a perspective view of a part of a rotor casing as to the first embodiment; FIG. 4 shows a longitudinal plan view of a second embodiment of the present invention; FIG. 5 shows a longitudinal section view concerning the second embodiment; FIG. 6 explains a suction seal line (a suction containment boundary locus) as to each of the male/female rotors that have different tip diameters; FIG. 7 gives an explanation about the male/female rotors that have different tip diameters; FIG. 8 shows a perspective view as to a variation of the second embodiment;
FIRST EMBODIMENT
[0166] FIGS. 1 a and 1 b schematically depict a bore face in a rotor casing of a screw compressor according to the present invention; FIG. 1 a shows a perspective view as to a suction seal line (a suction containment boundary locus) and a lip part on the bore face seen transparently from a top; and, FIG. 1 b is a development view of FIG. 1 a ; in FIGS. 2 a and 2 b , the rotor-casing is divided into an upper side part and a lower side part so that the bore face of the casing is easily explained.
[0167] In a male rotor side casing la and a female rotor side casing 1 b of FIGS. 1 a , 1 b , 2 a , 2 b , and 3 , a suction seal line (a suction containment boundary locus) 5 is formed on a boundary between main bore faces 2 a / 2 b and expanded bore faces 3 a / 3 b , whereby the main bore faces 2 a / 2 b are located opposite to addendum circles of the a male rotor and a female rotor, with a slight clearance, while a lip part 4 as a protruding part is provided apart from the suction seal line 5 , by a screw pitch distance to a suction side end face 6 . Here, an example of dimension data is such that a clearance between the main bore faces 2 a / 2 b and the addendum circles of the a male rotor and a female rotor is substantially 0.05 mm to 0.125 mm (a clearance to a diameter c/D=0.8 to 1.0/1000), while a distance between the expanded bore faces 3 a / 3 b and the addendum circles of the rotors is substantially 5 mm (a clearance to a diameter c/D=0.05 to 0.06). It is noted hereby that c and d denote a clearance and a diameter respectively.
[0168] The suction seal line 5 includes a curved part 5 a that is on a main bore face of the male rotor side casing 1 a , a curved part 5 b that is on a main bore face of the female rotor side casing 1 b , and a curved part 5 c that is also on the main bore face of the female rotor side casing 1 b ; whereby, in the development figures of FIGS. 1 a and 1 b , the curved part 5 c is seen as a straight line which starts from a point “a” that is a cross point of the curved part 5 a and a bore intersection line 8 ; further, in FIGS. 1 a and 1 b , the straight line lies at right angles to the bore intersection line 8 , while the straight line ends a point where the line intersects with the curved part 5 b.
[0169] On the other hand, in response to the suction seal line 5 , the geometry of the lip part 4 comprises:
a lip-entering-edge 4 d of the lip part 4 c that is placed apart from the suction seal line, within one screw pitch distance, toward the gas inlet side along a rotor axis direction, whereby the lip-entering-edge in response to the above-mentioned straight-line 5 c is bent so as to protrudes toward the suction seal line; wherein, a part of the lip-entering-edge in response to the straight line portion starts from a cross-point “b” of the bore intersection line 8 and the lip-entering-edge on the male bore surface, as far as a point on the lip-entering-edge on the female bore surface, a lip ending (trailing) edge 4 e of the lip part 4 c whereby the lip ending edge in response to the straight-line 5 c is placed parallel thereto so as to form a straight line portion of the lip ending edge in a development view; wherein, a straight line portion of the ending edge starts from a cross-point “c” of the bore intersection line 8 and the lip-ending-edge on the male bore surface, as far as a point on the lip-ending-edge on the female bore surface, and a thickened (wide in the rotor axis direction) lip part 4 c in response to the straight-line portion 5 c.
[0173] Liquid such as oil or water injected into a compression working space is apt to leak toward a lower pressure suction side and accumulates in concaved expanded bore faces 3 a / 3 b . The lip part 4 prevents the liquid from leaking and scattering toward a gas inlet side.
[0174] According to the first embodiment as described above, the distance between the suction seal line 5 and the lip part 4 is substantially within one screw pitch distance; thus, the lip part 4 is provided at a location closer to the suction seal line 5 in comparison with conventional ways. Therefore, in comparison with conventional ways, is effectively prevented a liquid leakage that scatters, during a compression process, from the compressed working space which is formed by the screw rotors toward the gas inlet side. Moreover, the lip part placed nearer to the suction seal line makes it possible to eliminate a part of the rotor casing, located at the gas inlet side from the lip part. So can be realized a simplified configuration of rotor casings with a reduced bore surface as well as a reduced suction resistance of an inhaled gas and an enhanced volumetric efficiency of the compressor.
[0175] Further, in the above embodiment, a straight line portion 5 c of the suction seal line 5 is provided in the neighborhood of the bore intersection line, the line lying at right angles with the bore intersection line in a development view. In addition, a thickened lip part 4 c is provided, comprising:
a lip-entering-edge 4 d of the lip part 4 c that is placed apart from the suction seal line, within one screw pitch distance, toward the gas inlet side in a rotor axis direction, wherein the lip-entering-edge in response to the above-mentioned straight-line portion 5 c is bent so as to protrudes toward the suction seal line; and a lip ending (trailing) edge 4 e of the lip part 4 c , being placed parallel to the straight line portion 5 c so as to form a straight line portion of the lip ending edge in a development view; wherein, the straight line portion of the ending edge is vertical to the bore intersection line 8 in a development.
[0178] In this manner, can be surely prevented a liquid leakage around the neighborhood along the bore intersection line, toward a gas inlet side, from the working (compression) spaces which are formed by the male female rotors.
[0179] Moreover, it becomes possible to eliminate a part from the lip part 4 toward a side of the gas inlet 9 in the rotor casing; in addition, a simplified configuration of rotor casings can be realized. Further, since the gas inlet casing can be placed nearer to the rotor casing, the rotor casing can be formed in one body together with the gas inlet casing. As a result, manufacturing processes can be simplified and a manufacturing cost can be reduced.
SECOND EMBODIMENT
[0180] A second embodiment of the present invention is now detailed with reference to FIGS. 4 to 8 . As shown in FIG. 7 , in the second embodiment a male rotor and a female rotor of different rotor sizes, namely different outer diameters, are used; where the outer diameter of the male rotor is larger than that of the female rotor, and the number of teeth as to the male rotor is 5 , while that as to the female rotor is 6 .
[0181] In FIGS. 4 and 5 , the reference numeral 11 denotes the rotor casing that accommodates both the male rotor and the female rotor, and the rotor casing 11 together with a gas inlet casing 13 that forms a gas inlet 12 is made of mono casting. The rotor casing 11 accommodates the male rotor 22 and the female rotor 23 shown in FIG. 7 , here the detail of the rotors is omitted. The reference numeral 14 denotes a male rotor shaft that is supported by a thrust bearing 16 and radial bearings 17 / 18 , while the numeral 15 denotes a female rotor shaft that is supported by a thrust bearing 19 and radial bearings 20 / 21 .
[0182] A mechanical seal 24 is provided near a shaft end part 14 a of the male rotor shaft 14 , the shaft end part 14 a being connected to an output shaft of a drive motor (not shown) as a power source.
[0183] A gas outlet casing 26 that forms a gas outlet 25 is made of casting; however, the casing 26 is made of different casting from the rotor casing 11 , and the casing 26 is fastened thereto with tightening bolts 27 . At a lower part of the rotor casing 11 , is provided a slide valve (a capacity control valve) 28 that makes it possible to regulate a compressor capacity (an inhaled gas capacity) by means of sliding-manipulation along an axis direction of the rotors; thereby, a pushrod (a driving rod) 29 regulates a length as to the sliding-manipulation of the slide valve 28 . In addition, the pushrod 29 is operated through an oil pressure that is supplied to a left cylinder room 30 a and a right cylinder room 30 b in an oil-hydraulic cylinder 30 .
[0184] At the middle part of the pushrod 29 , is installed a U i -control device (an internal volume ratio control device) 31 of a manual operation type; hereupon, the device 31 makes it possible to optimize the internal volume ratio U i . A casing 35 that contains the U i -control device 31 is fastened to the gas inlet casing 13 with tightening bolts 36 , while the oil-hydraulic cylinder 30 is fitted to the casing 35 . The reference numeral 37 denotes an internal volume ratio (U i ) adjusting valve; thereby, the U i -adjusting valve 37 is engaged into a screw part 38 a that is provided on an outer face of a hollow shaft 38 . Here, the hollow shaft 38 is installed around the pushrod 29 having a round cross-section, so that a round hollow cylinder of the hollow shaft 38 and the round cross-section of the pushrod 29 are concentric, and the hollow shaft 38 can rotate freely around the pushrod 29 . Further, the U i -adjusting valve 37 moves along the rotor axes with a rotational movement of the hollow shaft 38 .
[0185] On the other hand, the reference numeral 39 a denotes a bevel gear that is fitted to a suction-side end part of the hollow shaft 38 , while the bevel gear 39 a is engaged in a corresponding bevel gear 39 b that is fitted to an end part of a rotation-rod 40 ; hereupon, it is noted that the axes of the hollow shaft 38 and the rotation-rod 40 lie at right angles to each other.
[0186] According to the above-mentioned configuration, when the rotation-rod 40 is rotated, either clockwise or counterclockwise, a rotational movement is transmitted to the hollow shaft 38 ; as a result, the U i -adjusting valve 37 moves back and forth along an rotor axis, through an engagement of the screw part 38 a and the U i -adjusting valve 37 . A steering wheel (not shown) or the like may be fitted to the rotation-rod 40 so as to enable an operator to turn the wheel by hand in case of manual control.
[0187] When the internal volume ratio (U i ) is adjusted, the following sequence of manipulations is performed: rotating the rotation-rod 40 under a stop condition of the compressor; making the U i -adjusting valve 37 move along an rotor axis; as a result, thrusting the slide valve 28 toward the gas outlet 25 ; adjusting an opening level of a discharge opening 41 that is formed between a cut-out part 28 a provided at a discharge-front end side of the slide valve 28 , and the gas outlet casing 26 ; thus, initializing the internal volume ratio (U i ).
[0188] In addition, when a capacity of the compressor needs to be adjusted, the slide valve 28 is shifted along the axes of the rotors through a movement of the pushrod 29 ; thereby, a by-passed gas flow toward the gas inlet side from a gap between the slide valve 28 and the pushrod 29 controls the capacity (the inhaled gas flow quantity).
[0189] FIG. 6 shows the male rotor 22 , the female rotor 23 , and the suction seal line 32 in the second embodiment, in which the male rotor 22 and the female rotor 23 of different rotor sizes, namely, different outer diameters, are used, where the outer diameter of the male rotor is larger than that of the female rotor; in addition, the number of teeth as to the male rotor is 5 , while the number of teeth spaces as to the female rotor is 6 .
[0190] Incidentally, in FIG. 4 , are shown the suction seal line 32 and the lip part 33 , for explanation use. Similar to FIG. 1 as to the first embodiment, the lip part 33 is provided apart from the suction seal line 5 , by a screw pitch distance, toward the gas inlet side.
[0191] As shown in FIGS. 4 and 6 , the suction seal line 32 comprises:
a curved part 32 a on the bore in the male rotor casing 11 a, a curved part 32 b on the bore in the female rotor casing 11 b , and a straight line portion 32 c in a development view whereby the straight part lies at right angles to the bore intersection line 34 ; wherein, the straight line starts from a cross-point “a” of the bore intersection line 34 and the curved part 32 a , as far as a point on the curved part 32 b on the bore in the female rotor casing 11 b.
[0195] Further, the lip part 33 comprises a male casing side lip part 33 a on the bore in the male rotor casing 11 a , and a female casing side lip part 33 b , while the boundary of the lip part 33 comprises a lip-entering-edge and a lip ending (trailing) edge; hereupon, the lip part 33 is away from the suction seal line, within a screw pitch distance.
[0196] Still further, the lip-ending-edge comprises:
a straight line portion 33 e , in response to the straight line 32 c of the suction seal line 32 , and lying at right angles to the bore intersection line 34 in a development view, while the line portion 33 e starts a cross-point “c” of the bore intersection line 8 and the lip-ending-edge on the bore in the male rotor casing 11 a , as far as a point of the lip-ending-edge on the bore in the female rotor casing 11 b ; in addition, the lip-entering-edge comprises: a bent curve portion 33 d , in response to the straight line portion 32 c of the suction seal line 32 , whereby the bent curve portion 33 d protrudes toward the straight line portion 32 c of the suction seal line 32 , while the bent curve portion 33 d starts a cross-point “b” of the bore intersection line 8 and the lip-entering-edge on the bore in the male rotor casing 11 a , as far as a point of the lip-entering-edge on the bore in the female rotor casing 11 b.
[0200] In the above-mentioned manner, a thickened lip part 33 c is formed with the bent curve portion 33 d and the line portion 33 e , in response to the straight line portion 32 c of the suction seal line 32 . So can be surely prevented a liquid leakage around the neighborhood along the bore intersection line, toward a gas inlet side, from the working (compression) spaces in the rotor casing 11 .
[0201] According to the second embodiment, in the same way as the first embodiment, the lip part 33 is provided apart from the suction seal line 5 , by a screw pitch distance, toward the gas inlet side; thus, can be surely prevented a liquid leakage around the neighborhood along the bore intersection line, toward a gas inlet side, from the working (compression) spaces. Further, since the lip part is provided around the neighborhood along the bore intersection line as mentioned above, a liquid leakage around the bore intersection line can be surely prevented.
[0202] Moreover, can be eliminated a part of the rotor casing on the gas inlet side of the lip part 33 . Thus, can be secured a satisfactory space that communicates the bore faces of the rotor casing to the gas inlet 12 , the space reducing a suction resistance of the gas inhaled from the gas inlet 12 . As a result, a volumetric efficiency of the compressor can be enhanced.
[0203] On the other hand, by means of eliminating a part of the rotor casing the part which is located on the gas inlet side of the lip part, the location of the gas inlet 12 can be shifted toward the rotor casing 11 . Thus, the rotor casing 11 together with a gas inlet casing 13 that forms a gas inlet 12 can be made of mono casting. In this way, a compact casing can be realized and a compressor installation space can be reduced. Consequently, a compact casing can be realized, a compressor installation space can be reduced, a compressor manufacturing cost can be greatly lowered, and the degree of freedom as to the gas inlet casing design about the rotor axis direction can be expanded.
[0204] Further, it becomes possible to design a compressor casing of the same kind compressors so that a distance L between an axis “i” of the gas inlet 12 and an axis “o” of the gas outlet 25 can be kept constant. Therefore, a manufacturing line of the compressor casings can be streamlined so as to mechanized and robotized.
[0205] The installation of an internal volume ratio (U i ) adjusting valve makes a whole compressor compact, realizing a compressor with three kinds of compression ratios , namely, of lower/medium/higher compression ratios, without changing sorts of a gas inlet casing, only by replacing a rotor casing. Thus, a gas inlet casing can be applied to these kinds of compressors in common. Namely, even if the rotor-casing is replaced by another one for constituting a different kind (capacity) of the compressor, it is not necessary to exchange the gas inlet casing.
[0206] Further, conventional compressors are apt to be of a large size, as a positioning means to position the internal volume ratio (U i ) adjusting valve is prolonged toward a gas discharge side, penetrating a gas outlet casing so as to be used for positioning the valve. Contrary to the above, the second embodiment comprises a positioning means for positioning the internal volume ratio-adjusting valve including:
[0207] a hollow shaft 38 , and
a rotation rod 40 that is placed so as to intersect with the hollow shaft with right angles in order that the rod can transmit a rotational driving movement of the rod to the hollow shaft, via a bevel gear pair 39 a / 39 b.
[0209] According to the above configuration, there is no need to prolong a positioning means as in conventional approaches; a driving mechanism to position the internal volume ratio-adjusting valve 37 can be formed as a compact one.
[0210] Incidentally, for the connection part between the rotation rod 40 and the hollow shaft 38 , a crossed helical gear pair may be applied instead of a bevel gear pair; a bevel gear pair tends to have a play to some extent between meeting gears, while a crossed helical gear has little play.
INDUSTRIAL APPLICABILITY
[0211] According to the present invention regarding a liquid injection type screw compressor, a liquid leakage, such as an oil leakage or a water leakage, that flows back to a gas inlet side from a compression room which is formed screw rotors is further effectively prevented in comparison with conventional compressors of the same kind. In addition, suction resistance of the gas inhaled from the gas inlet can be lowered, and volumetric efficiency as to the inhaled gas can be improved; further, cast modeling of a rotor casing can be simplified and a manufacturing cost can be reduced.
[0212] Thus, the invention greatly contributes to a practical compressor industry.
[0213] This is a continuation of International Application PCT/JP2005/0020041 (published as WO 2007-0542322) having an international filing date of Oct. 31, 2005. The disclosure of the priority application, in its entirety, including the drawings, claims, and the specification thereof, is incorporated herein by reference.
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A liquid injection type screw compressor in which, in a compression stroke of an working space formed by male and female rotors, liquids such as oil or water is prevented from leaking from the high pressure working space to a gas inlet side, suction resistance of gas sucked from the gas inlet to a rotor casing is reduced to improve volumetric efficiency, and shape forming of the casing is simplified.
The liquid injection screw compressor has the male and female rotor pair of screw rotors, the rotor casing ( 1 a , 1 b ) having a bore for receiving the rotors, a gas suction opening and a gas outlet that are provided in both end sections of the casing and communicate with the bore, and a lip section ( 4 ) projected from a bore surface ( 2 ) positioned more on the upstream side than a suction seal line ( 5 ) of the casing in order to prevent a back flow of the liquid from the bore surface toward the gas inlet side. The lip section ( 4 ) is positioned in a region surrounded by the suction seal line ( 5 ) and a line separated by a distance of one screw pitch of the rotors from the suction closure line ( 5 ) to the suction opening side.
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This application is a continuation of application Ser. No. 72,718 filed July 13, 1987 now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to construction panels for structural support systems having high strength to weight ratios and excellent insulating properties. The construction panels are primarily for use as exterior walls but may also be used for interior walls, partitions, ceilings and the like.
Currently, buildings are being constructed from a wide variety of materials. Among the more common are wood, cinder block, brick, concrete, metal and glass. Each has particular advantages and disadvantages. Wood, while relatively easy to work with, is flammable, requires the labor of skilled carpenters, and is becoming increasingly expensive. Cinder block and brick, although quite durable are quite heavy, thus requiring high transportation costs. In addition, working with brick and block requires the attention of skilled masons over long periods of time. Concrete is awkward to transport, comparatively expensive and requires the use of special construction techniques and building equipment. Metal panels are poor insulators and require the services of welders, riveters or other personnel to fasten the panels together and to the supporting structure by bolts, rivets or the like. Glass is breakable, hard to transport and is not a good insulator. Because of these disadvantages, new materials have been and are being developed to replace the traditional building materials.
Recently some states have passed new laws mandating that new structures must meet certain energy efficiency standards including high "R" value insulation standards. Additionally, the cost of lumber is escalating and natural resources are being depleted. Proper insulation of a building leads to conservation of both energy and natural resources while at the same time meeting the new energy efficiency standards being written into law.
Various prior art methods of insulating buildings have been proposed. The most common form of insulation is foil-backed fiberglass. Rolls of this material having various degrees of thicknesses are unrolled at a job site, cut to size and then mounted between adjacent wall studs. For pre-constructed structures, insulating material may be blown between the outer facing and the inner walls of a building to the desired density and R value.
Another technique of providing adequate insulation for buildings is to incorporate insulating material in prefabricated building panels. These panels offer the advantages of good insulating properties, mass production, and ease of on-site assembly of the panels, among other. These panels generally comprise a core of insulating material surrounded by structurally rigid panels. The core of insulating material may comprise balsa wood, glass wool, foamed or expanded polymeric materials such as polystyrene, polyvinyl chloride, polyurethane, etc. The core material may be surrounded by panel members comprising first and second major face members and side and end walls of such materials as plywood, metal, resin and resin reinforced with fibrous glass rovings, etc. Generally, these panels are strong, lightweight and provide proper insulating properties while using less wall space.
These modular panels also have some disadvantages. Since the foam used in forming the core is not elastic, once it is compressed, a space develops between the core and facing member. This results in weakened structural integrity and may be responsible for such conditions as warping, buckling and cracking of the face member or of the entire panel. An additional disadvantage is that the major face members generally cannot withstand a great amount of load-bearing pressure as may be encountered when the panels are used as load-bearing members. To make the panels stronger, various reinforcing means have been incorporated within them. U.S. Pat. No. 4,078,348 (Rothman) includes a discussion of patents that are representative of the way in which the prior art has attempted to overcome the problems and disadvantages associated with foamed core sandwich-type panels.
U.S. Pat. No. 4,163,349 (Smith) shows an insulating building panel including an insulating core and having an exterior skin on one side and an interior skin on the other side. The skins overlap the core about its periphery and, at the sides of the panel, extend from the core a distance to receive a portion of a bearing post to which adjacent panels are connected.
U.S. Pat. No. 4,567,699 (McClellan) relates to a prefabricated building system made up of a plurality of prefabricated panels. Each panel includes a formed body of insulating material having a top, a bottom, sides, a front face and a back face. At least one hollow tubular load-bearing member is embedded in the body intermediate the sides and faces thereof and extends vertically between the top and bottom. The tubular load-bearing member has a slot in the top and bottom. The slots have their axis generally parallel to the front and rear faces of the body. A bottom member is provided along the floor and has an upstanding flange extending into the slot of the bottom of the tubular member and a top member extends along the top of the panels and has a flange extending downwardly into the slots in the top of the tubular load-bearing members. The load-bearing members have a length greater than the length of the body so that vertical loads are not transmitted to the body.
Additional examples of modular wall sections employing foam insulation are shown in U.S. Pat. Nos. 3,828,502 (Carlsson); 3,791,912 (Allard); 3,562,985 (Nicosia) and 3,449,879 (Bloom).
Despite the several alternatives for providing prefabricated panels in building systems, there is still a need for a construction panel and building system which is less expensive to produce because of conservation of materials, requires less labor for erection at the work site, costs less to transport to the work site and minimizes energy losses. The present invention is directed toward filling that need.
SUMMARY OF THE INVENTION
The present invention relates to an integral energy-efficient load-bearing exterior wall fabricated of lightweight foam surrounding plastic load-bearing columns. The present invention includes both the prefabricated modular wall panels as individual elements and as part of an integrated building system.
In a preferred embodiment of the subject invention, a prefabricated modular wall panel is made from a foam material which is molded around a plurality of vertically oriented hollow support columns. Each of the columns contains a pair of vertically disposed T-shaped fastening supports extending along the full length of the support column. The fastening supports are arranged to form part of the interior and exterior surfaces of the foam wall. The hollow support columns, which are preferably made of a vinyl plastic, are set onto locking base plates that are mounted on a wood or concrete deck system. Locking top plates are also mounted on wood are then placed on top of the columns.
In alternative embodiments, the hollow support columns are shaped in cross-section in the form of a rectangle, a square, a diamond, an oval and a circle. The hollow columns are designed to be used as conduits for electrical wiring, water pipes and in certain cases can be fabricated to act as heat or air conditioning ducts.
It is thus a primary object of the present invention to provide a one-piece exterior wall construction which is fabricated from lightweight foam and includes plastic load-bearing columns.
It is another object of the present invention to provide an internally mounted stud for use in a prefabricated wall system.
It is still another object of the present invention to provide a prefabricated construction panel having a high strength to weight ratio.
It is yet another object of the present invention to provide a prefabricated insulated construction panel exhibiting excellent insulating properties.
It is a further object of the present invention to provide a prefabricated construction wall and building system capable of easy on-site assembly.
It is still a further object of the present invention to provide a modular wall system which is capable of easy mass production.
It is yet a further object of the present invention to provide a modular wall system resistant to rot, decay, termites, woodbores, etc.
It is another object of the invention to provide a modular wall system that is warp-resistant and free of knots.
These and other objects will become apparent from the following drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, partially cut away, of a portion of a building made up of pre-fabricated wall panels forming part of the inventive integrated building system.
FIG. 2 is a perspective view, partially cut away, showing the details of a vertically disposed hollow column incorporating the teachings of the present invention.
FIG. 3 is an exploded perspective view of the elements constituting the inventive integrated building system.
FIG. 4 is a view taken along lines 4--4 of FIG. 1.
FIG. 5 is a view taken along lines 5--5 of FIG. 4.
FIG. 6 is a view taken along lines 6--6 of FIG. 4.
FIG. 7 is a perspective view, partially cut away, showing the details of another embodiment of the hollow column of FIG. 2.
FIG. 8 is a perspective view, partially cut away, showing the details of yet another embodiment of the hollow column of FIG. 2.
FIG. 9 is a perspective view, partially cut away, showing the details of still another embodiment of the hollow column of FIG. 2.
FIG. 10 is a perspective view, partially cut away, showing an electrical box and wiring inserted into a vertically disposed hollow column.
FIG. 11 is a perspective view, partially cut away, showing the incorporation of an air duct into a vertically disposed hollow column having dovetail sides.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In describing the preferred embodiments of the subject invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
FIGS. 1 through 6 illustrate a portion of a building incorporating modular wall sections 10 embodying the teachings of the present invention. One modular wall panel 10 basically comprises a wall member 12 made from a foamed plastic material so that the member is principally designed for use as an exterior wall and thus has an exterior wall surface 14 and an interior wall surface 16 which are arranged parallel to each other. As oriented in FIGS. 1 and 3, each wall panel has a predetermined vertical height which approximates the height of an exterior wall normally found in industrial, commercial and residential buildings. Because the panels are made from foamed plastic, the panel size may be easily altered by workmen at the construction site.
Vertically disposed within the foamed wall panel 12 are a series of spaced, hollow studs or support columns 20. With reference to FIGS. 2 and 3, a hollow stud 20 is fabricated from a plastic vinyl such as PVC through an extrusion process. The stud basically comprises an elongated, hollow member. In a preferred embodiment as shown in FIGS. 2 and 3, the hollow member when viewed in cross-section is in the shape of a rectangle 22 that is defined as having a pair of opposed elongated walls 24 and 26 which are arranged to be generally parallel with the exterior and interior wall surfaces 14 and 16 when the column is in its position of intended use within wall panel 12. The cross-section is completed by a pair of opposed shorter walls 28 and 30 which are opposed from each other in a generally parallel relationship. Together the interior surfaces of the four walls 24, 26, 28 and 30 define an interior space or volume 32 that exists throughout the entire length of the column. Wall 24 contains an outside face 34 and wall 26 contains an outside face 36. Each of these faces contains the same structure which is described as follows. Using face 34 as exemplary, emanating from an area 38 defined vertically along the mid-point of face 24 are a pair of outwardly extending legs 40 and 42 which are arranged generally parallel to each other. These legs each define an elongated planar wall that is generally perpendicular to surface 24 and extends vertically along the entire length of the column. Each of legs 40 and 42 terminate a predetermined transverse distance from surface 24. Positioned at the termination of legs 40 and 42 is a planar strip 44 that is generally parallel to surface 24 along the full length of the column. Planar strip 44 terminates at its longitudinal side in two inwardly directed side fingers 46 and 48. An inside vertical strip 50 is positioned generally parallel and spaced from strip 44 and acts to join portions of fingers 46, 48 and legs 40 and 42 together. When viewed in cross-section as shown in FIG. 2, the structure just described resembles a T with the head 44 of the T defining a portion of the outer surface 14 of the wall panel and the base of the T being secured to the vertical surface 24 of the hollow column. A similar structural element is defined on face 26 in approximately the same place as the element defined on face 24 and thus contain the same reference numerals.
With reference to its orientation in FIGS. 1 and 3, the wall member 12 terminates at its top in a planar face 52 and at its bottom in planar face 54. The distance between planar face 52 and 54 as measured vertically along one of the columns 20 is approximately equal to the intended height of the finished wall. To complete the construction of the wall member 10, a plurality of locking base plates 56 are secured along a base stud 58 that is made of wood. In a preferred embodiment, the base stud 58 has a width that is substantially equal to the thickness of wall 12.
As shown in FIG. 3, each of the base plates is defined by four walls 61 through 64 that are joined together in a figure with an outer periphery that is slightly smaller and mating with the interior configuration of the hollow member 20 so that the hollow member may be placed on top of and receive the locking base plate 56 as shown in FIGS. 5 and 6. Surrounding the bottom periphery of each base plate is a flange 66. The flange contains a number of apertures 68 for a receiving fastening device such as nails 70 in order to secure the locking base plate at a predetermined position along the surface 72 of stud 58.
As can be seen with reference to FIGS. 3 and 5, locking base plates 56 are spaced along the surface of stud 58 so that surface 72 may be placed in intimate contact with surface 54 of wall section 12. The top of wall section 12 is completed through the use of spaced locking top plates 76 and wooden stud 78 in a manner similar to that described with reference to the locking base plate 56 and the bottom stud 58. The locking base and top plates 56 and 76 are secured within hollow column 20 through use of an appropriate adhesive such as that commonly used to secure PVC articles or with a mechanical fastener, such as a screw or nail.
With reference to FIGS. 3 and 4, the way in which the ends of two panels 10 are joined together is graphically illustrated. Each of the wall sections 12 terminate at its vertical edges in end columns 120 and 121. As shown in FIG. 4, each of the end columns when viewed in cross-section generally resembles one-half of the T member cross-section of column 20. When viewed in cross-section, end column 120 has a pair of opposed planar walls 122 and 124 which are arranged to be generally parallel with the exterior and interior wall surfaces 14 and 16 when the column is its position of intended use at the edge of wall panel 10. The cross-section is completed by planar wall 126 which joins the ends of walls 122 and 124 into a generally U-shaped member. Wall 122 contains an outside face 128 and wall 124 contains an outside face 130. Each of these faces contains the same structure which is described as follows. Using face 128 as exemplary, emanating from the free end of leg 122 of the U-shaped section is an outwardly extending leg 132. The leg defines and elongated planar wall that is generally perpendicular to surface 128 and extends vertically along the entire length of the column. Leg 132 terminates a predetermined transverse distance from surface 128. Positioned at the termination of leg 132 is a planar strip 134 that is generally parallel to surface 128 along the full length of the column. Planar strip 134 terminates along its free end in an inwardly directed finger 136. An inside vertical strip 138 is positioned generally parallel and spaced from strip 134 and acts to join leg 132 to finger 136. A similar complimentary structure is defined for edge column 121 and noted by the same reference numerals.
When the planar surfaces of legs 132 of edge columns 120 and 121 are placed into intimate contact with each other, the two edge columns define an interior space 140 that is of the same size and configuration at the interior space 32 of one-piece column 20.
In order to secure the edge columns 120 and 121 to each other, a U-shaped insert 142 is employed. The insert, which in a preferred embodiment, is extruded from a plastic such as PVC extends throughout the entire length of the edge columns with the exception of a predetermined space near the bottom and top of the column to leave room for insertion of the base and top plates 56 and 76. When viewed in cross-section, the generally U-shaped member 142 contains two elongated planar wall sections 144 and 145 which are arranged generally parallel and spaced from each other. The two walls are joined together to form the U-shape by a shorter wall 146 which is perpendicular to the other two walls.
The U-shaped insert 142 is sized to fit snugly within the interior area of the edge columns 120 and 121. As shown in FIG. 5, the U-shaped insert facilitates securing and joining of the two wall sections 12. The U-shaped wall member may either be glued within the edge columns or fastened through the use of screws 17 or nails 19.
FIGS. 3, 4 and 6 generally show the way that wall sections 10 are joined together at corners. A vertically oriented corner column is shown and designated as 152. In a preferred embodiment, the corner column 152 is extruded as a one-piece plastic unit incorporating three basic sections. At the heart of the corner column is a column defining area 154 which contains several vertically oriented walls 161 through 164 that are joined together in order to define an opening 156 that is the same size and shape as the opening 32 defined in vertical column 20. This is done so that the column 156 is able to receive the base and top plates 56 and 76 in a manner described hereinbefore with reference to space 32 of vertical column 20.
Spaced from wall 161 is an exterior corner wall 166 that is intended to lie in the same plane and define a portion of exterior wall 14. In a similar manner, spaced from wall 162 is another planar wall 168 that contributes to defining the other corner wall and lies in the same plane as exterior surface 14 for an adjacent wall member 12.
Corner column 152 terminates at each end in an edge column defining portion 168. The portion is constructed to define an interior area 170 that is of the same size and shape as the interior wall defined by edge members 120 and 121 so that when the corner column 152 is joined into operative contact with one of those members an interior space of proper size for receiving the bottom and top plates 56 and 76, as well as the U-shaped joining member 142, is provided.
FIGS. 1 and 3 show a number modular wall units 12 arrange in their position of intended use. As can be seen, the wall units 12 are erected in vertical fashion with the undersurface of base stud 58 in contact with the floor 55 or foundation of the building or dwelling. The wooden construction of the base and top studs 58 and 78 facilitate attachment of each wall member 10 to the building under construction. The wall is erected near the perimeter of the structure so that the wall 14 defines an exterior wall and the wall 16 defines and interior wall. The flat surfaces 44 of each of the columns 20 define an area along both surfaces 14 and 16 for receiving fastening devices such as nails or screws 57 to secure the appropriate type of wall covering 59 or skin to complete the construction of the modular wall member 10. The side surfaces 71 and 73 of top stud 78 and the side surfaces 75 and 77 of bottom stud 58 also occupy the same plane as faces 44 of columns 20 for facilitating attachment of the skin. The same relationship holds true for surface 134 of edge columns 120 and 121 and corner surfaces 166 and 168 of corner column 152. As shown in FIG. 4, the exterior surface 14 receives a sheet of plywood siding 15 which is fastened by chemical bond (adhesive) or by mechanical fastener such as screws 17 or nails 19 to the various faces 44, 134 and 168 of columns 20, 120, 121 and 152, respectively, and the side surfaces of the top and bottom studs 78 and 58. To complete the construction of the interior surface, drywall or paneling 21 is secured in a similar fashion.
FIGS. 7 through 9 show in cross-section alternative configurations for the hollow column 20. In an alternative preferred embodiment as shown in FIG. 7, the hollow member when viewed in cross-section is generally shaped like a square that is defined as having a pair of opposed walls 81 and 83 which are arranged to be generally parallel with the exterior and interior wall surfaces 14 and 16 when the column is in its position of intended use. The cross-section is completed by a pair of walls 82 and 84 which are opposed from each other in a generally parallel relationship. Together the interior surfaces of the four walls 81, 82, 83 and 84 define the interior space 32. Wall 81 contains an outside face 85 and wall 83 contains an outside face 87. Each of these faces contains the same structure which is described as follows. Using face 83 as exemplary, emanating from an area 38 defined vertically along the mid-point of face 83 is a vertically extending leg 86. The leg defines a planar wall that is generally perpendicular to surface 87. Leg 86 terminates a predetermined transverse distance from surface 87. Defined at the termination of leg 86 is a planar strip 88 that is generally parallel to surface 87. Planar wall 88 terminates at its sides in two inwardly directed side fingers 90. When viewed in cross-section as shown in FIG. 7, the structure just described resembles a T with the head 88 of the T defining a portion of the outer or inner surface 14 or 16 of the wall panel 12 and the base of the T being secured to the vertical surface 87 of the hollow column. A similarly configured element is defined on face 85 in approximately the same place as the element defined on surface 87. The outer face of walls 82 and 84 contain T structures 95 that are smaller than the T-structure emanating from surface 85. In the several T-structures, leg 92 resembles to leg 86, wall 94 resembles to wall 88 and fingers 96 resemble to fingers 90.
In still another preferred embodiment as shown in FIG. 8, the hollow member when viewed in cross-section is in the shape of a diamond that is defined as having a pair of opposed walls 181 and 183 which are arranged at about a 45° angle with the exterior and interior wall surfaces 14 and 16. The cross-section is completed by a pair of opposed walls 182 and 184 which are opposed from each other in a generally parallel relationship. Together the interior surfaces of the four walls 181, 182, 183 and 184 define the interior space 32. A side of wall 181 meets with a side of wall 184 at a corner 101 near surface 14 of wall 12. Similarly, a side of wall 182 meets with a side of wall 183 at a corner 103 near surface 16 of wall 12. Emanating from corner 101 as defined vertically along column 20 is leg 86. The leg defines a planar wall that is generally perpendicular to surface 14 of wall 12. Leg 86 terminates a predetermined transverse distance from corner 101. Defined at the termination of leg 86 is a structure similar to that shown in FIG. 7. Inner corners 105 and 107 of the column include structural elements 92 and 94 as previously described with reference to the embodiment in FIG. 7 without the fingers 96.
Finally, FIG. 9, shows another embodiment of the vertical columns which when viewed in cross-section resembles the square embodiment of FIG. 7 with rounded corners 181 through 184. For this reason, like elements contain like reference numerals. However, certain mirror differences are noted. In particular, the fastener strip 88 is much wider in the oval embodiment than in the square embodiment. Likewise, the inward fingers 96 are replaces by fingers 190 that extend both inwardly and outwardly.
As shown in FIGS. 10 and 11, the hollow interior of the vertical columns 20 provides usable space for use as a conduit for electrical wiring, plumbing and, in certain cases, heating or air-conditioning ducts.
FIG. 10 shows an electrical box 190 inserted within outside face 36 of column 20. A portion of box 190 is well within the open space 32 defined in the vertical column. Conventional household wiring 192 is shown passing through the volume 32 in the vertical column 20 and then into the interior of the electrical box for subsequent connection to conventional receptacles and switches. The box may be made of a PVC plastic and secured within the hollow column 20 so that it actually becomes part of the stud conduit. Alternatively, an opening may be cut on either side of the vertical column at any height and a box may be then introduced into the open space. The wire cables 192 may pass from location to location by entering and exiting holes (not shown) defined in the bottom and top plates 58 and 78.
FIG. 11 shows a vertical column 20 which has been cut on one of its faces to receive a box 200 in order to provide an exit point for air to pass through the vertical column. In this way, the volume 32 defined in the vertical column provides a duct work and the box 200 defines an air supply outlet. It is contemplated that the hollow conduits may be used in conjunction with equipment sold by Dunham Bush, Inc. under the trademark SPACE PACK. FIG. 11 also shows an alternate construction for the side walls 30 of the embodiment shown in FIG. 2. In particular, an elongated vertically extending mortis shape 202 is defined along the outer faces 28 and 30. The mortis indentation allows foam to form and act as a tenon, giving better bond of foam to the stud.
Thus it can be appreciated that a construction system employing the teachings of the present invention makes optimum use of an exterior wall construction module and assembly technique that includes a one-piece load-bearing exterior wall fabricated from light-weight foam surrounding load-bearing columns. The same construction technique may be used to produce walls for interior construction.
The modular panels 10 made in accordance with the teachings of the present invention enjoy several advantages. The individual wall panels may be pre-cast and molded in a factory setting away from the construction site. The wall units may be delivered as light-weight panels thus conserving both energy and transportation. Because of the way the panels are constructed, they are ready for easy erection using ordinary tools.
Each modular wall panel 10 includes a core 12 of expanded or foamed polymeric material which exhibits a high strength to weight ratio. The walls also exhibit super insulating properties especially because of the use of a continuous length and width of foamed material completely surrounding and touching the vertically oriented support columns 20. In addition, the hollow, vertical columns provide an excellent way to conceal wiring, plumbing and heating or cooling duct work. There is also a significant reduction in the number of wooden studs used in the construction.
From the above, it is apparent that 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.
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An integral energy efficient load-bearing exterior wall fabricated of light-weight foam surrounding plastic load-bearing columns. The invention relates to pre-fabricated modular wall panels as individual building elements and as part of an integrated building system. In a preferred embodiment, a prefabricated modular wall panel is made from a foamed material that is molded around a plurality of vertically disposed hollow support columns. Each of the columns contains a pair of opposed and vertically disposed T-shaped fastening supports which are arranged to form part of the interior and exterior surfaces of the foamed wall. The hollow columns are set onto locking base plates which are mounted on a wood or concrete deck system. Locking top plates are also mounted on wood and are then placed on top of the columns. The tubular columns are made of a plastic material and are shaped in cross-section in the form of a rectangle, square, diamond, oval or circle. The hollow columns may be used as conduits for electrical wiring, water pipes and in certain cases can be fabricated to act as heat or air-conditioning ducts.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for spinal column fixation. More particularly, but not by way of limitation, this invention relates to a mechanical device used to obtain a rigid posterior spinal column fixation in order to obtain a rigid posterior spinal column bony fusion for disabling back and leg pain.
In one embodiment, the apparatus includes a posterior fixation device which is attached to the involved vertebral bodies. The attachment is made by pedicle screws penetrating into the vertebral body with rigid attachment to ball-and-socket clamps and rods.
The invention also may include a pair of intervertebral metallic or radiolucent wedges inserted into the disc space of the involved vertebrae to increase the stability of the spinal column anteriorly and to avoid breakage of the pedicle screw. Additionally, the application also discloses a method of placing the fixation and wedge device in a posterior lateral approach.
Posterior spinal fusions have been performed on millions of people since at least the early 1900's. The principle of bony fusion has been and still is stabilization or prevention of motion between two adjacent vertebral bodies.
The most recent attempt to stop motion of the spinal column in order to obtain spinal fusion is internal fixation. One design consist of a series of hooks, rods, screws and wires attached to the lamina or spinous processes to correct deformity or to stabilize the spine.
Another design utilizes screws inserted posteriorly through the pedicle into the vertebral body connecting to plates, rods and clamps to stabilize the two adjacent segments.
The prior art pedicle screw devices have different functions. One function includes the correction of the degenerative curve of the lumbar spine between L3 and S1 or traumatic deformities. These devices have the internal purpose of this device is correction of a deformity through two vertebra such as seen in U.S. Pat. No. 4,987,892 to Martin H. Krag, and in U.S. Pat. No. 5,047,029 to Max Aebi and Robert Mathys, Jr.
Another function includes rigidly fixing the spinal column using a combination of intra-vertebral screws, plates, rods and clamps. In general, see U.S. Pat. Nos. 4,615,681, 4,648388, 4,655,199 to Steffie; 4,754,326, to Burton; 4,950,269 to Gaines; 4,653,481 to Howland; 4,913,134 to Luque; 4,836,196 to Parke and Weinstein; 4,946,458 to Harms; 5,030,220 to Howland; 4,887,595 to Heinig; and 5,042,982 to Harms.
Another function includes flexible or semi-rigid fixation shown in U.S. Pat. Nos. 4,913,134 to Luque; and, 4,743,260 to Buttem.
The present invention utilizes the rigid posterior fixation device which is attached to the involved vertebral bodies through pedicle screws connected with a series of operably associated ball-and-socket clamps and rods. One such device using a ball connector is seen in U.S. Pat. No. 4,946,458 to Harms. However, the prior art devices include several disadvantages. For instance, many devices were susceptible to breakage, and once breakage occurs, the devices are very difficult to retrieve. Also, the mechanism of clamps and rods is very complicated and difficult for the surgeon to install.
Furthermore, in both the rigid and flexible type of devices, the pedicle screw developed excessive motion and toggle. This in turn would cause the plate to become loose thereby allowing the plate to slide back and forth causing irritation, lack of fixation, and thus failure of fusion.
The rigid devices without inter-body fusion or rigid spacer will result in breakage in the screw because of mechanical factors. The greatest portion of the weight of the individual is taken through the vertebral body and disc. The center of motion of the vertebral segments is located in the posterior aspect of the disc. In the lower lumbar spine the greatest amount of motion is flexion and extension of the trunk, therefore, the intervertebral segment motion is mainly to the anterior frontal or posterior backward movement. Rigid posterior fixation is at a mechanical disadvantage because the forces of weight and motion are anterior to the rigid posterior fixation device. With repetitive motion the device either breaks or becomes loosened. With loosening or breakage, the motion will increase leading to more pain and failure.
Sciatica is pain which shoots down the posterior lateral aspect of the leg. Sciatica is caused by impingement or encroachment on the neural elements in the lumbar spine. Recent studies indicate that intervertebral body fusion is the most effective relief of sciatica. This is because the intervertebral disc is the mechanical center of motion between the intervertebral bodies, and the majority of the body weight of the individual is taken through the vertebral bodies.
Prior art devices are designed and placed in the intervertebral disc comprise several concepts. One is to replace the disc which has been removed with an artificial disc material which can function and behave biomechanically similar to the normal intervertebral disc when inserted in the space.
A second includes maintaining the disc height with no attempt at inter-body fusion. A spacer is placed in after removal of the intervertebral disc.
A third involves maintaining height and obtaining a fusion with a fenestrated spacer that will contain a bone graft. The fenestrated spacer is placed in directly posteriorly under the neural elements.
This invention solves these problem by combining the wedge insert anteriorly and the rigid posterior fixation device allowing the patient to obtain a solid, rigid fixation. The purpose of the wedge is to obtain anterior stabilization, restoration of intervertebral disc height, normal physiological lumbar lordosis, and intervertebral body bony fusion in the human spinal column. The posterior device stabilizes the mechanical dynamics associated with posterior forces, and the wedge compensates the forces associated with the anterior forces.
SUMMARY OF THE INVENTION
The invention includes both apparatus and method claims to a spinal column fixation device that includes multiple clamping means for clamping onto an implanted screw in the sacrum and involved vertebrae of a patient. The clamping means will also contain a stabilizing rod and a portion to receive a receptacle stabilizing rod from a complementary clamping means.
In one embodiment, the invention comprises a first sacrum clamping means for clamping to an implanted first sacrum screw in the pedicle of the person's sacrum, said first sacrum clamping means containing a stabilizing rod. The apparatus will also contain a second sacrum clamping means for clamping to an implanted second sacrum screw in the pedicle of the person's sacrum, the second sacrum clamping means containing a stabilizing rod.
The invention will contain a first vertebrae clamping means for clamping to an implanted first vertebrae screw in the pedicle of an involved vertebrae, with the first vertebrae clamping means receiving the stabilizing rod of said first sacrum clamping means. A second vertebrae clamping means for clamping to an implanted second vertebrae screw in the pedicle of an involved vertebrae is also provided, with the second vertebrae clamping means receiving the stabilizing rod of the second sacrum clamping means.
In one embodiment, the first vertebrae clamping means further contains a stabilizing rod, and wherein said second vertebrae clamping means contains a stabilizing rod, and the apparatus further comprises a third vertebrae clamping means for clamping to an implanted third vertebrae screw in the pedicle of an involved vertebrae, with the third vertebrae clamping means receiving said stabilizing rods of said third securing means. Also, a fourth vertebrae clamping means for clamping to an implanted fourth vertebrae screw in the pedicle of an involved vertebrae is furnished, with the fourth vertebrae clamping means receiving the stabilizing rods of said second vertebrae clamping means.
In one embodiment, the fourth vertebrae clamping means further contains a stabilizing rod, and the apparatus further comprises a first interconnecting means for interconnecting the stabilizing rod of the fourth and second clamping means. The third vertebrae clamping means contains a receiving portion, and the apparatus further contains a second interconnecting means for interconnecting the stabilizing rod of the first and third clamping means.
The implanted screws contain a first end and a second end, and wherein said first end contains external thread means for threading the implanted screws into the spinal column of the person, and more particularly into the pedicle of the involved vertebra, and sacrum. The second end contains a multi-sided, generally a hexagon, shaped nut member. Further, the hexagon shaped nut member has attached thereto a spherical handle end.
The first, second, third and fourth sacrum, as well as the first, second, and fifth vertebrae clamping means comprises a cap portion having an aperture therein, and wherein the cap portion has a first and second cavity formed therein, the first cavity being formed for receiving the spherical handle ends of the pedicle screws and the second cavity being formed for receiving the stabilizing rods. Also included is a base portion having an aperture therein, and wherein said base portion has a first and second cavity formed therein, the first cavity being formed for receiving the spherical handle ends of the pedicle screws and the second cavity being formed for receiving said stabilizing rod. Next, a bolting member fitted through the aperture of the base and the cap is included and cooperating with the base and the cap so that the spherical handle end and stabilizing rods are adapted to be received within the mating cavities.
The stabilizing rod may extend from the third and fourth sacrum clamping means and has a spherical handle end, and the third vertebrae and fourth vertebrae clamping means will comprise a cap portion having an aperture therein, and wherein the cap portion has a first and second cavity formed therein, the first cavity being to receive said spherical handle end of the pedicle screws and the second cavity being formed for receiving the spherical end of the stabilizing rod, a base portion having an aperture therein, and wherein the base portion has a first and second cavity formed therein, with the first cavity receiving the spherical handle end of the pedicle screws and the second cavity being formed for receiving the spherical end of the stabilizing rod. Also included will be a bolting member fitted through the aperture of the cap and base, and cooperating with said cap and base so that the spherical handle end of the implanted screw and stabilizing rod are adapted to be received within the mating cavities.
In the preferred embodiment, the apparatus may further comprise an intra-vertebral body wedge. The wedge will contain a first end having a tapered end increasing in size; a second end having a tapered end increasing in size; and wherein the first end taper and the second end taper converge at a point which forms the greatest width of the wedge. The wedge member will contain an opening therein for placement of a bone so that a bone graft may be performed. Further, the wedge may contain a threaded aperture for placement of bolting means for placement of an inserter to secure the wedge member for insertion into the discal space in a sagittal plane.
The application also discloses a method of stabilizing motion of involved spinal diseased vertebrae with a spinal fixation device, the spinal fixation device containing a plurality of implanted screws, the implanted screws containing a first and second end, the first end containing thread means and the second end containing a spherical handle end, the spinal fixation device further containing a plurality of spherical clamp means for securing onto the spherical handle ends. The device also contains a plurality of interconnecting rods for interconnecting the ball clamp means. Finally, a wedge member is provided for insertion into inter-discal space.
Generally, the method comprises the steps of performing two posterior lateral incisions or alternatively, one posterior incision on the back of the patient to the area of the involved spinal diseased segments.
Next, the method will expose the transverse process (FIG. 19, 224) of the involved spinal diseased segments; then, dissecting between and lateral to the transverse process of the involved spinal diseased vertebrae is performed so that the nerve roots (FIG. 19, 216) and the annulus fibrosis (FIG. 18, 210) are exposed. Subsequently, a cruciate incision is placed in the annulus fibrosis (FIG. 18, 210) posterior laterally near the intervertebral foramen; then, the surgeon removes the gelatinous disc material and cartilage end plate of the involved spinal diseased vertebrae.
The surgeon then determines the proper size and length of the intra-pedicle screws and the drill point of the drill is placed on the vertebral body at the pedicle starting at the base of the transverse process. A bore hole is then drilled in the pedicle of the involved spinal diseased vertebrae or sacrum for placement of the pedicle screw. The pedicle screw is then rotated into the bored openings of the involved spinal diseased vertebrae with the wrench; and, the surgeon applies a spreader to the pedicle screws so that the disc is opened for placement of the wedge member.
The method may also include the steps of selecting the proper length, height, angle of the wedge member, and then placing a bone in small pieces into the inter-discal space of the involved spinal diseased segments, and in the fenestration of the wedge for intervertebral fusion prior to insertion of the wedge 180. In selecting the proper wedge member, a test wedge may be first employed on a trial basis in order to insure selection of the correct size, length and angle of the wedge.
Following this step, the wedge is inserted (FIGS. 16 and 17A-E) into the inter discal space of the involved spinal diseased vertebrae bilaterally, and the spreader is released which had been keeping the intra-pedicle screws separated thereby allowing the elasticity of the annulus fibrosis and adjacent tissue to lock the wedge in inter-discal space.
Subsequent to this step, the position of the intra-pedicle screws is examined with an image intensifier, and the ball clamp means is placed about the spherical handles of the implanted screws. The fastener member (nut) is tightened so that the ball clamp means will not slip off the spherical handle of the implanted screw. The surgeon will then determine the particular structural arrangement of the interconnecting stabilizing rods.
Next, the cutting of the interconnecting stabilizing rods is performed, with or without spherical balls on the end, to the proper length, and the interconnecting rods are placed into the ball clamp means so that the ball clamp means are linked; and tightening of the ball clamp means is executed so that the ball clamp means encases the spherical handle end and the interconnecting rods. Because of the curved contour of the spinal column, some bending and shaping of the rods may be necessary.
The application also includes a step wherein the process of placing the drill point on the involved spinal diseased vertebral bodies and drilling a bore hole in the involved spinal diseased vertebral bodies includes: placing the drill point on a first and second site of the pedicle of the sacrum; then, placing the drill point on a first and second site of the ala of the sacrum and drilling a bore hole to the first and second site on the ala of the sacrum; then, placing the drill point on a first and second site of the pedicle of the L5 involved spinal diseased vertebral body and drilling a bore hole to the first and second site of the L5 involved spinal diseased vertebral body; and, placing the drill point on a first and second site of the pedicle of the second involved spinal diseased vertebral body and drilling a bore hole to the first and second site of the L4 involved spinal diseased vertebral body.
At this point, completion of the application of the posterior intra-pedicle spinal fixation device is completed. The particular structure arrangement will vary on a case-by-case basis. Thus, the figures of this application show one possible sequence; however, other arrangements will depend on the particular circumstances so that the connections and cross connections can be many different arrangements.
A feature of the present invention includes the ability of using one or two screws on each side of the sacrum. Another feature includes use of triangular cross fixation rods to increase posterior stability. Yet another feature is that when combined with the wedge of the present invention, the device increases stability of the spinal column anteriorly and to avoid breakage of the implanted screws, the wedge creates support in the inter-discal space as well as creating the normal lordosis and increasing stability.
Another feature includes fewer moving parts which allows for the clamps to be mechanically cross connected. Another feature consist of the ball in the socket concept which allows for connecting two clamps at variable angles in both a horizontal and vertical plane, depending on the circumstances of each individual patient. The interconnecting stabilizing rods with a spherical handle end can rotate while in place in the clamping means up and down, as well as laterally relative to the implanted screw.
Still another feature includes the capability of measuring the length of the stabilizing rods during the procedure and cutting the rods to the appropriate length in order to conform to the particular circumstances of the patient. Still yet another feature consist of having less fiddle factor. Another feature consist of having the stem as the weakest point of the implanted screw member which allows for easy removal of the screw if breakage occurs. Put another way, the screw can easily be extracted because the nut and the penetrated portion of the screw is still intact.
An advantage of the present invention includes that the device is easy to insert. Another advantage is that the device allows for adjustable tightness of the various securing means. Yet another advantage includes avoiding breakage of screws.
Another advantage is that multiple clamps connecting to individually associated intra-pedicle screws allows for variations in the number of connecting rods and the variations in the pattern of interconnection. Still another advantage includes that the lamina and the spinous process are not disturbed which leaves a large area for bone grafting. Yet another advantage of the procedure allows for ease of facet joint fusion.
Still another advantage consist of the anterior and the posterior rigid fixation and the large bone grafting area achieved by this invention which leads to solid bony fusion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the spinal column bony elements viewed from the posterior of the human.
FIG. 2 is a cross-sectional view of the intra-pedicle screw.
FIG. 3A is a cross-sectional view of the wrench of the present invention.
FIG. 3B is a bottom view of the wrench seen in FIG. 3A.
FIG. 4A is an illustration of the main connector clamp of the invention secured to the ball of the intra-pedicle screw.
FIG. 4B is a cross-sectional view of the main connector clamp seen in FIG. 4A.
FIG. 5 is a front view of the main connector clamp.
FIG. 6 is a rear view of the main connector clamp.
FIG. 7 is a top view of the main connector clamp as seen from the posterior during application.
FIG. 8 is a bottom view of the main connector clamp.
FIG. 9 is an illustration of a modified main connector clamp secured to the ball of the intra-pedicle screw as well as the ball of the connecting rod.
FIG. 10 is an illustration of another modified main connector clamp when the invention requires three units connected to one clamp.
FIG. 11 is an illustration of a cross connecting clamp.
FIG. 12 is a cross-sectional view of the cross connecting clamp of FIG. 11.
FIG. 13 is an illustration of a modified cross connecting clamp.
FIG. 14 is an illustration of another modified cross connecting clamp.
FIG. 15 is a cross-sectional view of the modified cross connecting clamp of FIG. 14.
FIG. 16 is a three dimensional illustration of the intravertebral wedge.
FIG. 17A is an illustration of the top of the wedge seen in FIG. 16.
FIG. 17B is an illustration of one side of the wedge seen in FIG. 16.
FIG. 17C is an illustration of the lateral view of the wedge seen in FIG. 16.
FIG. 17D is an illustration of the second end of the wedge seen in FIG. 16.
FIG. 17E is a cross-sectional view of the wedge seen in FIG. 16.
FIG. 18 is a three dimensional illustration of the spinal column depicting two vertebra.
FIG. 19 a cross sectional view through the spinal column taken along line A--A.
FIG. 20 is an illustration of the wedge inserter device.
FIGS. 21A, 21B, and 21C illustrate the spreader device.
FIGS. 22A, 22B, and 21C illustrate the compressor device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Like numbers in the various figures refer to like components throughout the application. Referring to FIG. 1, the spinal column bony elements are depicted. Generally, the sacrum 2 is shown that will have the first sacrum clamping means 4 for clamping to an implanted first-arcum pedicle screw in the alae of the sacrum 2. The pedicle screw will be described in greater detail later in the application. It should also be noted that the sequence of interconnection of the various clamping means may be adjusted on a case-by-case basis, and as such, FIG. 1 depicts one possible arrangement. Other arrangements of the clamping means is possible.
A stabilizing rod 6 will extend from the clamping means 4. A pedicle clamping means 8 for clamping to an implanted pedicle screw to the opposite side, in the alae, of the sacrum may also be provided. The clamping means 8 will have second stabilizing rod 10 extending therefrom.
A first vertebrae clamping means 12 for clamping to an implanted first vertebrae screw to the involved vertebra, which in FIG. 1 is the fifth lumbar vertebra, may also be provided. The first vertebrae clamping means will have connected thereto first stabilizing rod 6, as well as having third stabilizing rod 14 extending therefrom.
A second vertebrae clamping means 16 will be attached to the involved vertebra by means of an implanted vertebrae screw, which in FIG. 1 is the fifth lumbar vertebra. The second vertebrae clamping means 16 will have connected thereto second stabilizing rod 10, as well as having fourth stabilizing rod 18 extending therefrom.
A third vertebrae clamping means 20 is used for clamping to an implanted third vertebrae screw in the pedicle of an involved vertebra, which in FIG. 1 is the fourth lumbar vertebra. The clamping means 20 will have connected thereto third stabilizing rod 14, as well as having first cross stabilizing rod 22 extending therefrom. It should be noted that other vertebrae clamping means (not shown) for clamping to other implanted vertebrae screws in the pedicle of other involved vertebrae may be provided as deemed necessary by the surgeon. The various clamping means will be interconnected by stabilizing rods.
A first interconnecting (or cross-connecting) means 24 for interconnecting the stabilizing rods from second clamping means 16 may also be provided. The first interconnecting means 24 will have connected thereto fourth stabilizing rod 18, as well as having fifth stabilizing rod 26 and second cross stabilizing rod 28 extending therefrom.
The invention will also contain a fourth vertebrae clamping means 30 for clamping to an implanted fourth pedicle screw (not shown). The clamping means 30 will be cross attached with the interconnecting means 24 by means of first stabilizing rod 26. This structural connection aids in balancing the distribution of stabilizing forces. Alternatively, fourth clamping means 30 may be connected directly to fifth stabilizing rod 26. A second interconnecting means could be used between first vertebrae clamping means 12 and third vertebrae clamping means 20.
A third and fourth sacrum clamping means 32, 34 for clamping to an implanted third and fourth sacrum alae screw to the sacrum 2 may also be included. The clamping means 32, 34 will first cross attached with the clamping means 20, 24 by means of first cross stabilizing rods 28 and second cross stabilizing rod 22. This cross structural connection aids in balancing the distribution of stabilizing forces.
Referring now to FIG. 2, the screw 36, used in the pedicle of the involved vertebra, sacrum as well as the ala of the sacrum, will now be described. It should be noted that through-out the application, the terms screw and intra-pedicle screw will be used interchangeably. The screw 36 will have a first end 38 that will have contained thereon external thread means 40 for boring into the involved sacrum and vertebra. The thread means will be of standard course thread for cancellus bone.
The thread means 40 extend to the smooth cylindrical surface 42, that in turn extends to the multi-sided (usually six) nut member 44, which may vary from 3 to 6 millimeters in width w. The nut member 44 will then conclude at the stem 46. In the preferred embodiment, the stem 46 will have the smallest outer diameter of the intra-pedicle screw 36 so that the stem will be the weakest point of the screw 36, and therefore, the stem will be the first to break. Also, the stem 46 increases the distance from the clamp to the bone for ease of bone grafting.
The stem 46 extends to the second end 48 which in the preferred embodiment will be excoriated on its surface and the actual size of the ball portion will vary between 6 and 12 millimeters.
Referring to FIG. 3A, the wrench 50 of the present invention is illustrated. The wrench 50 will generally comprise a receiving segment 52 that will reciprocally receive the hexagon nut member 44. The wrench 50 will also contain a cavity 54 that is a recess for receiving the spherical handle end 48. The actual wrench handle means 56 for allowing the surgeon to fastened the nut member 44 will be connected to the receiving segment 52. FIG. 3B depicts the bottom view of the wrench 50.
Turning now to FIG. 4A, a typical main connector clamp depicted as the vertebrae clamping means 16, which also is seen in the vertebrae clamping means 30, is shown and will be explained in greater detail. The main connector clamp will have cap member 62 that will have a first end 64 and a second end 66, and wherein the first end 64 has a generally spherical configuration that forms a cavity 68, as better seen in FIG. 4B, that receives the spherical handle end 48.
The second end 66 of the main connector clamp 16 will contain a second cavity 70 that is shaped so as to receive a stabilizing rod 72. The stabilizing rods of this invention can be round, as shown, square or some other configuration. The stabilizing rods may be manufactured out of stainless steel, titanium, or plastic. The cap member 62 will also contain an aperture 74, as better seen in FIG. 4B, that will receive a bolting member 76, that may have a hexagon nut head 78 and a threaded end portion 80.
The base member 82 will have a first end 84 and a second end 86, with the first end 84 having a cavity 88 that will have fitted therein a segment of the spherical handle end 48. The second end will also have a cavity 90 that will have a segment of the stabilizing rod 72 fitted therein, as well as an aperture 92 that will have the bolting member 76 fitted therein, as seen in FIG. 4B. The bolting member cap 76, cap 62 and base member 82 cooperate with one another so that the spherical handle end 48 and stabilizing rods are adapted to be received within the mating cavities 68, 88 and 70, 90 and secured together as the bolting member 76,80 threadedly attaches the cap member and base together (which can also be seen in FIG. 8). A lock washer, though not shown, may also be employed in order to lock the bolting member in place.
The main connector clamp 16 may have the cap member 62 and base member 82 manufactured generally from steel, but titanium, and/or plastic can also be used.
Referring now to FIG. 5, the front view of the main clamp 16 is depicted. This view depicts the first end 64 of the cap member 62 and the base member 82 engaged with the spherical handle end 48 of the pedicle screw 36, as well as the stabilizing rod 72 which exits from both sides of the main connector clamp 60.
Turning to FIG. 6, the rear view of the main connector clamp 16 is illustrated. This view shows the second end 66 of the cap member 62, as well as the second end 86 of the base member 82, with the threaded end 80 of the bolting member 76. It should be noted that the void (width) W2 is in place after securing the base 82 and cap member 62 together to ease placing the rod 72 in the cavities without difficulties.
Turning now to FIG. 7, the top view of the main connector clamp 16, as seen from posterior during application, is illustrated. This figure shows the stabilizing rods 72 operatively attached to the main connector clamp 60. Also, the first end of the cap member 64 is shown, as well as the second end of the cap member 66. Also, the hex nut head 78 is shown.
In FIG. 8, the bottom view of the main connector clamp 16 is illustrated. In this figure, the stabilizing rod 72 is shown, as well as the second end 86 of the base portion 82. A cross-section of the intra-pedicle screw stem 46.
The first end of the plate 84 surrounds half of the spherical handle 48 with a recess around the stem. Thus, because of the contour of the cavity 88 which surrounds the perimeter of the spherical handle 48, when the hex head nut 78 is tightened, the threaded portion 80 will lock the base member and cap portion together and beginning moving the base member 82 and cap member 62 together, which in turn effectively clamps the spherical handle end 48 and stabilizing rod 72 in the respective cavities of the base member 82 and cap member 62. The cavities can be excoriated in order to more easily obtain the proper amount of friction between the cavities and the stabilizing rod 72 and/or spherical handle 48.
Referring to FIG. 9, a modified main connecting clamp 4, which in FIG. 1 is the first sacrum clamping means, is illustrated. The modified clamp 4 will have a cap member 98 and a base member 100. The cap member 98 will have a first end 102 and a second end 104. The first end will be of general spherical construction and contain an inner cavity 106 (not shown) that is adapted to receive the spherical handle end 48 of the intra-pedicle screw 36. A second cavity 107 is also provided to receive the spherical end 108 of a stabilizing rod 109.
The base member 100 will also contain a first end 110 and a second end 111 that will have first cavity 112 that will receive the bottom portion of spherical handle end 48. A second cavity 114 is also formed thereon, which will receive the spherical end of a stabilizing rod. The modified clamp 4 connects the ball of the intra-pedicle screw to the connecting rod which in this case has a ball, or spherical handle end. The modified clamp 96 is best utilized in the sacrum as seen in FIG. 1, securing means 4 and 8, but also can be used on the upper vertebral connections if deemed appropriate by the surgeon.
The cap member 98 and base member 100 will be secured together by means of the bolting member 116, with the bolting member containing a hexagon head 118 similar to the hex head nut 78. The bolt member 116 will also contain thread means 120. The cap member 98 and base member 100 will contain apertures 122 and 124 respectfully, that will receive the bolt, and aperture 124 will contain internal thread means that will cooperate with the thread means 120 so that as the bolt 116 is threaded into the aperture 124, the base member 100 and cap member 98 will be joined together and will lock the spherical handles 48 and 108. When the hexagon head 118 is tightened, the two halves cover approximately two-thirds of the diameter of the ball 108 of the connecting rod 109 which in the preferred embodiment is excoriated and locks the ball 108 rigidly.
Referring now to FIG. 10, an interconnecting type of main connector 24, such as the first interconnecting means 24 of FIG. 1, is shown. This type of inter-connector may be utilized when the system of connectors chosen by the surgeon requires three clamp means connected at a particular location. The inter-connector 24 will have the stabilizing rods 18 and 26 connected thereto. Also, the cross-stabilizing rod 28 will be connected, with the spherical handle end 48 being disposed within the connector 24. The spherical handle 48 and stabilizing rods 18 and 26 will be disposed within the connector 24 by means of the cap portion 126 and the base portion (not shown) being fastened together by the bolting member 128, as previously described.
FIG. 11 depicts another cross connecting clamp 130 that is not necessarily shown in FIG. 1. The cross connecting clamp 130 is utilized to connect a connecting rod to a cross connecting rod. The cross connecting clamp 130 can be at 90 degrees from one cross connecting rod to the other. While only the 90 degree situation has been shown, other clamps can be at angles that range from 0 to 90 degrees, with the angles shown in FIG. 1 being 30 degrees and 45 degrees.
In FIG. 11, the stabilizing rod 132 is inserted between the cap member 134 and the base member 136. A bolting member 138, with lock washer 139 and thread means 140, is provided in order to fasten the cap 134 and base member 136 together as previously described.
A connecting, or stabilizing, rod 142 with the attached spherical end 144 having been encircled within a first cavity 144 located within the cap member 134, and a second cavity 146 located within the base member 136, as depicted in FIG. 12 which is a cross-sectional view of FIG. 11. It should be noted that other rods may have attached thereto, if desired, a spherical end similar to that shown in FIGS. 11, 12. The cap will also have a cavity 148 for placement of the stabilizing rod 132, as well as mating cavity 150.
In the embodiment shown in FIGS. 11 and 12, when the cap member 134 and base member 136 are tightened, the cap member 134 and base member 136 will generally cover two-thirds of the diameter of the ball, and with the tightening of the bolting member 138, the clamp becomes as rigid as preferred by the surgeon. Due to the posterior application of these devices, the bolting member 138 is tightened from the back of the patient (i.e. the spinal column) which makes for easy application.
FIG. 13 is another alternate cross-connecting clamp 152 which can be used to connect a connecting rod 154 to a second connecting rod 156. Like the other clamps previously discussed, the clamp 152 will have a cap member 156 and a base member 158, with the cap member 156 having a first cavity (not shown) for placement of the rod 154, and a second cavity 160 for placement of the rod 156. The base member will likewise contain a cavity (not shown) for placement of the rod 154, and a second cavity 162 for placement of the rod 156.
The bolting member 164 with lock washer (not shown) will be placed through apertures in the cap member 156 and base member 158, with the bolting member 164 having thread means 166. The bolting member 164 will have hexagon head 168, as seen in FIG. 14. The cap member 156 and base member 158 will be attached to one another by means of the bolting member 164 as previously described which will effectively lock the rods 154 and 156 in place.
Turning now to FIG. 15, a cross-sectional view of the alternate cross-connecting clamp 152 taken along line A--A is illustrated. As shown, the rod 154 is continuous therethrough; however, the rod 156 terminates at rod end 170. It should be noted that the embodiments depicted in FIGS. 13-15 can be made at 90 degrees as illustrated from one connecting rod to the other or it can be at 45 or 30 degrees, depending on the circumstances and the discretion of the surgeon.
With reference to FIG. 16, a three dimensional view of the intervertebral body wedge 180 is shown. The wedge 180 is generally a rectangular shaped device made from either stainless steel, titanium, fiberglass, or other suitable material. The height of the device can vary from 6 to 16 millimeters. The width of the device can vary from 8 to 16 millimeters. The device is wedged shaped with varying degrees of taper, from 4 to 20 degrees. All of these various measurements may vary, depending on the needs of the intra-vertebral space.
The wedge 180 will comprise a first side 182, second side 184, a top side 186, and a bottom side 188. The top side 186 contains a first angled surface 190 that concludes at second angled surface 192. The bottom side 188 will contain a first angled surface 194 that terminates at the second angled surface 196. The angled surfaces of the top 186 and bottom 188 sides provides for a wedged device. The wedge 180 also contains a first end 198 and a second end 200.
FIGS. 17A-17E depicts various views of the wedge 180 which will now be discussed. FIG. 17A is a top view of the wedge 180. As can be seen, the top side 186 contains an opening 202. The opening 202 (also known as the fenestration) is for application of bone grafting, as well as for locking purposes since the bone would sink into the opening 202.
FIG. 17B depicts the first end 198 of the wedge 180. The first end 198 will have contained thereon a threaded aperture 204. In the preferred embodiment, the first end 198 would be directed posterior in the patient or towards the back of the patient. The threaded aperture 204 is necessary for the application of the inserter means for inserting the device into the intra-vertebral space.
In FIG. 17C, the first side 182 is shown. This view depicts the angled surfaces 190 and 194 increasing the width of the device until the angled surfaces 192 and 196 are intersected thereby creating a tapered end which leads to second end 200. The point at which the sides 190, 192, 194 and 196 intersect represent the greatest thickness of wedge 180.
FIG. 17D is the second end 200 of the wedge. As seen, the angled surfaces 192 and 196 causes a tapered effect of the wedge at the second end 200. In FIG. 17E, a cross-sectional view taken along line A--A is illustrated. Thus, the first end 198 contains the threaded aperture 204, while the wedge 180 contains the opening 202. The second end is represented at 202.
Turning now to FIG. 18, a three dimensional view of the spinal column depicting two vertebra is illustrated. The FIG. 18 depicts the position of the intra-vertebral wedge 180 in position in the spinal column. The wedge 180 is in place between a first anterior vertebral body 206 and a second anterior vertebral body 208. Also depicted is the posterior longitudinal ligament and annulus fibrosis 210, the pars intra-articularis, part of the lamina, which is a bone extending from one vertebra and connects one vertebrae bone to the next 212, and the intra-vertebral foramen 214 which is the hole between each segment of the spine or vertebra that allows for the passage of the nerve roots and the presence of arteries, veins, and fat.
In FIG. 19, a horizontal view through the spinal column at the level of the intra-vertebral disc, generally at line B--B of FIG. 18, is shown. The purpose is to show the position of the wedges 180 (as seen here, two wedges have been employed) in the disc in a horizontal view of the intra-vertebral view. The wedges 180 converge anteriorly, but do not touch one another. The wedges 180 diverge posterior so that the wedges 180 can be inserted lateral to the nerve roots 216.
The lamina 218, the spinous process 220 which projects posterior of the vertebral column, the spinal cord 222, the transverse process 224, and the nerve root 216 passing out through the intra-vertebral foramen and it progresses anteriorly and inferiorly in front from the spinal column.
Referring to FIG. 20, wedge inserter 240 is shown. The inserter 240 has a generally cylindrical surface 242 that terminates at the radial collar surface 244, with the surface 244 extending to second cylindrical surface 246 that in turn will terminate at radial collar surface 248. The collar surface will have attached thereto the external thread means 250; the thread means 250 will mate and cooperate with the threaded aperture 204. The inserter 240 also has handle means 252 that extends from the cylindrical surface 242.
The spreader device 254 is shown in FIGS. 21A, 21B and 21C. The spreader device has a first prong 256 and second prong 258, with prongs 256 and 258 having generally curved surfaces that extend to aperture 260 that has fitted therein a connector pin 262. The prongs will have at one end jaw means 264 and 266, respectively, as seen in FIG. 21B. The jaw means will contain a notched groove 268 and 270 that will be sized so that the notched grooves 268 and 270 fit and cooperate with the stem 46 of the screw 36.
As seen in FIG. 21A, the spreader device has a threaded separating screw 272 that will have contained thereon an external thread. The separating screw 272 fits through a slotted opening 274 in the prong 256. A fastening nut 276 will be provided so that when the spreader device 254 is in use, the nut keeps a constant force applied to the jaw means 264 and 266. Thus, when the correct amount of spreading force has been applied, the fastening nut can be applied in order to fix the jaw means 266, 264 in a static position. Also, as seen in FIG. 21C, a lateral view of the prong 256 depicts the jaw means 264 along with pin 262 and the opening 274 for placement of the separating screw 272.
In FIG. 22A, a compressor device 278 is depicted. The compressor device 278 will contain a first prong 280 and a second prong 282 that will contain jaw means 284 and 286, with the jaw means 284 and 286 containing notched grooves 288 and 290, respectively, (as seen in FIG. 22B) that will engage and cooperate with the stem 46 of the screw 36 in a manner similar to the spreader device 254, except jaw means 284 and 286 will apply a compressive force relative to two implanted screws 36. The compressor device 278 will contain a torsion spring 292 that will have fitted therein a stem 294 that will be attached to the prong 280, and the stem will be fitted through the slotted opening 296. A fastening nut 298 will be provided such that the surgeon may set the desired force that jaw means 284 and 286 will be urged together by the torsion spring 292. FIG. 22C shows the lateral view of prong 280 which depicts the curved end 300 as well as the jaw means 284.
OPERATION
The surgical procedure is done bilaterally through two posterior lateral incisions or one posterior incision, exposure is carried out to the transverse process (FIG. 19, 224) of the spinal diseased segments. Gentle dissection between and lateral to the transverse process exposing the nerve roots (FIG. 19, 216) and the annulus fibrosis (FIG. 18, 210) is carried out in order to expose and visualize the nerve root, disc, vessels and intervertebral foramen.
The intervertebral foramen is enlarged, if necessary (FIG. 18, 214) by cutting away bone of the superior facet of the lower vertebra increasing the space and soft tissue around the nerve roots. A small cruciate incision is made in the annulus fibrosis (FIG. 18, 210) posterior laterally near the intervertebral foramen. The gelatinous disc material and cartilage end plate is removed (discectomy) to the vertebral bodies with a pituitary rongeur and a bone burr. This procedure is performed bilaterally down to firm bone but does not cut through the surface of the vertebral body.
At this point in the procedure the intra-pedicle screws are placed in posteriorly for posterior stabilization. The pedicle screws are applied under image intensifier control. The drill point is placed into the vertebral body through the pedicle starting at the base of the transverse process. Transverse processes are the bony extensions projecting outward from the side of a vertebrae. There are two transverse processes on each vertebrae, one on each side. The proper size and length of the intra-pedicle screws are then determined.
Next, the pedicle screw is rotated into the bored opening with the wrench. The pedicle screws are placed in the lumbar vertebral bodies bilaterally which needed fixation, which generally is either the pedicle of the fourth, fifth or first sacral vertebra. Two to four screws are placed into the sacrum at the discretion of the surgeon. A spreader is applied to the intra-pedicle screws and the disc is opened to the limits of strong annulus fibrous. 14. The wedge 180 is pre-measured for length, height, and angle of the wedge. Small pieces of bone are taken elsewhere from the patient and are placed into inter-discal space prior to insertion of the wedge 180. Small pieces of bone are also placed in the fenestration of the wedge for intervertebral fusion.
The pre-measured wedge 180 (FIGS. 16 and 17A-E) is inserted bilaterally as seen in FIGS. 18 and 19. As noted earlier, a temporary wedge may be placed within the discal space in order to aid in determining the exact size needed.
The distraction (spreader) on the intra-pedicle screws is released and the elasticity of the annulus fibrosis and adjacent tissue lock the wedge in solidly. The angled shape of the wedge 180 prevents retropulsion which is dangerous to the neural elements. Anterior extrusion of the wedge is prevented by the annulus fibrosis, anterior longitudinal ligament and the locking effect of the compression on the fenestrated wedge.
After the intra-pedicle screws are in place, the position is checked with the image intensifier and a direct visual check. Next, the ball clamp is placed about the spherical handles of the pedicle screw. The fastening member (nut) is tightened so that the ball clamp will not slip off the ball of the pedicle screw.
The particular structure arrangement will vary on a case-by-case basis. Thus, the figures of this application show one possible sequence; however, other arrangements will depend on the particular circumstances so that the connections and cross connections can be many different arrangements.
Once the plan is decided upon, the stabilizing rods, with or without spherical balls on the end, are cut to the proper length. Next, the rods are slipped into the clamps. Then, the compressor device 278 is applied to the intra-pedicle screws of two adjacent vertebra, and the screws are thereafter compressed with device 278. Next, the nuts of the clamping devices are tightened. At this point, completion of the application of the posterior intra-pedicle spinal fixation device is completed.
Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims.
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A spinal column fixation device and method is disclosed. Generally, the device contains a pedicle screw that has a first and second end. The first end of the screw has a threaded portion and the second end has a spherical handle. Also included will be a clamping apparatus that will clamp onto the spherical handle ends as well as having a receiving portion for placement of interconnecting rods. A novel intra-vertebral body wedge is also included. Further, a method of stabilizing motion of a plurality of involved spinal diseased vertebrae with the spinal column fixation device and wedge has been claimed.
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PRIORITY CLAIM
The present application claims priority under 35 U.S.C. Section 119 to Patent Application 201410429526.1, titled “Bitline Regulator for High Speed Flash Memory System” and filed in the People's Republic of China on Jul. 22, 2014, which is incorporated by reference herein.
TECHNICAL FIELD
A bitline regulator for use in a high speed flash memory system is disclosed.
BACKGROUND OF THE INVENTION
Flash memory systems are well-known. Flash memory systems typically comprise one or more arrays of flash memory cells. The cells are organized into rows and columns within the array. Each row is activated by a word line, and each column is activated by a bitline. Thus, a particular flash memory cell is accessed for either read or write operations by asserting a specific word line and a specific bitline.
In some prior art systems, during read operations, the bitline will be precharged by a bitline regulator to a bias voltage accurately in a very short period. This increases the speed and accuracy of the system.
As flash memory systems have become faster, the prior art bitline regulators have become limiting factors in how fast the system can run. For example, if a flash memory system operates at 100 MHz or faster, the bitline regulator must precharge the bitline in 1 ns or less. Prior art bitline regulators are unable to operate at this speed.
Some examples of prior art bitline regulators include those that utilize a Vt clamp, an operational amplifier, or an NMOS follower. These prior art systems are unable to operate accurately at higher speeds.
What is needed is an improved bitline regulator design that can operate at high speeds. What is further needed is a bitline regulator that can be automatically trimmed during operation of the memory system as operating conditions change and processes change.
SUMMARY OF THE INVENTION
An improved bitline regulator for use in flash memory systems is disclosed. The bitline regulator can be automatically trimmed so that it the bitline bias voltage is adjusted as operating conditions change.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an embodiment of a flash memory system comprising a bitline regulator.
FIG, 2 depicts an embodiment of a bitline regulator.
FIG. 3 depicts an embodiment of a sample and hold circuit and a comparator.
FIG. 4 depicts an exemplary timing diagram showing the trimming of a bitline regulator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1 , an embodiment of flash memory system 100 is depicted. Flash memory system 100 comprises flash memory array 180 , column multiplexor 170 , and sense amplifiers 160 a . . . 160 n (where n is an integer) as is known in the prior art. Each of the sense amplifiers 160 a . . . 160 n is used to read the voltage stored in a memory cell in a column corresponding to the bitline during a read operation.
Flash memory system 100 also comprises trimmable bitline regulator system 110 , which comprises bitline regulator 120 , sample and hold circuit 130 , comparator 140 , and arbiter 150 .
Bitline regulator 120 receives a reference voltage, VREF, and outputs a precharged bit line 195 , labeled VBL. An exemplary value for VREF is 1.0 volts. Precharged bitline 195 is provided to each of the sense amplifiers 160 a . . . 160 n and precharges the bit lines used during a read operation through sense amplifiers.
Sample and hold circuit 130 receives precharged bitline 195 as well as the control signal /ATD. Sample and hold circuit 130 will sample the precharged bitline 195 on an edge of control signal /ATD and will output the result to comparator 140 .
Comparator 140 also receives the reference voltage, VREF, and outputs a signal that indicates if VREF is greater than or less than the signal received from sample and hold circuit 130 .
Arbiter 150 receives the output of comparator 140 . If VREF is greater than the output of sample and hold circuit 130 , arbiter will adjust trim bits 190 to cause bitline regulator to increase the voltage of precharged bitline 195 . If VREF is equal to or less than the output of sample and hold circuit 130 , arbiter will adjust trim bits 190 to cause bitline regulator to decrease the voltage of precharged bitline 195 .
With reference to FIG. 2 , additional detail is depicted for an embodiment of bitline regulator 120 . Bitline regulator 120 comprises amplifier 201 . Amplifier 201 receives VREF on its positive input and outputs the voltage BIAS, where BIAS=VREF+the threshold voltage of NMOS transistor 202 . The negative input of amplifier 201 is node 250 , which will equal VREF. The output, VBL, will be equal to VREF−the threshold voltage of NMOS transistor 205 , which if NMOS transistor 205 and NMOS transistor 202 are well-matched, will be around VREF. The control signal ATD is received by inverter 204 to produce /ATD. When ATD is high, /ATD will be low, and as a result, PMOS transistors 208 , 221 , 231 . . . 241 will be turned on. When ATD is low, /ATD will be high, and as a result, PMOS transistors 208 , 221 , 231 . . . 241 will be turned off.
When ATD is high then VBL 195 will receive current from the boost circuit comprising NMOS transistor 205 and the boost circuit comprising PMOS transistor 209 and NMOS transistor 209 , which will supply a minimum current loading on VBL. This boost circuit will increase the output strength of bitline regulator 120 at VBL, which will prevent, for example, a voltage droop that might otherwise occur as the load changes. Thus, VBL will be held at a more constant level as the result of the automatic trimming process and will be able to withstand a wider range of load.
The values of trim bits 190 , which are set by arbiter 150 , also can add connect additional boost circuits to VBL 195 , which will further increase the output strength of bitline regulator 120 . Here, trim bits 190 comprise m+1 bits (where m is an integer, and generally will be equal to n, as there are n+1 sense amplifiers and n+1 columns in the array). Each of the trim bits 190 is connected to the gate of a PMOS transistor, here shown as PMOS transistor 222 , 232 . . . 242 . Although three boost circuits are shown for receiving trim bits 190 (one boost circuit comprising PMOS transistors 221 and 222 and NMOS transistor 223 ; another boost circuit comprising PMOS transistors 231 and 231 and NMOS transistor 233 ; and another boost circuit comprising PMOS transistors 241 , 242 and NMOS transistor 243 ), it is to be understood that there are m+1 boost circuits, each corresponding to one of trim bit 190 and each identical to any of the three boost circuits shown.
Thus, the bias voltage held by VBL 195 can be held constant by adjusting the values of trim bits 190 as conditions change. This avoids a droop in voltage.
With reference to FIG. 3 , additional detail is shown for an embodiment of sample and hold circuit 130 and comparator 140 . Sample and hold circuit 130 comprises inverter 301 , switch 302 (which comprises PMOS transistor 303 and NMOS transistor 304 ) and capacitor 305 . The control signal ATD, when low, turns on switch 302 , which in turn allows VBL 195 to be fed into comparator 140 . Comparator 140 then compares the voltages of the reference voltage VREF and the sampled voltage from VBL 195 , to generate an output COMPOUT, which is then provided to arbiter 150 .
Arbiter 150 optionally comprises a controller. In the alternative, arbiter 150 can comprise discrete logic.
With reference to FIG. 4 , exemplary timing diagram 400 is shown. The control signal ATD varies over time as shown. The values for trim bits 190 and the voltage of VBL 195 can be reassessed at every ATD pulse.
The output COMPOUT from comparator 140 is shown, and in this example, changes over time, which represents changes in the voltage of VBL 195 (perhaps due to changes in temperature, changes in load, etc.). Exemplary values for trim bits 190 are shown. For example, when the value of COMPOUT changes at the end of time period 1 , an adjustment can be made to trim bits 190 from 11110000 to 11100000 and then to 11000000, representing a change that will be made to VBL 195 by bitline regulator 120 . When the value of COMPOUT changes again at the end of period 3 , an adjustment is made to trim bits 190 from 11000000 to 11100000 and then to 11110000.
Thus, changes can be made to VBL 195 in real time by adjusting trim bits 195 .
References to the present invention herein are not intended to limit the scope of any claim or claim term, but instead merely make reference to one or more features that may be covered by one or more of the claims. Materials, processes and numerical examples described above are exemplary only, and should not be deemed to limit the claims. It should be noted that, as used herein, the terms “over” and “on” both inclusively include “directly on” (no intermediate materials, elements or space disposed there between) and “indirectly on” (intermediate materials, elements or space disposed there between). Likewise, the term “adjacent” includes “directly adjacent” (no intermediate materials, elements or space disposed there between) and “indirectly adjacent” (intermediate materials, elements or space disposed there between). For example, forming an element “over a substrate” can include forming the element directly on the substrate with no intermediate materials/elements there between, as well as forming the element indirectly on the substrate with one or more intermediate materials/elements there between.
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A bitline regulator for use in a high speed flash memory system is disclosed. The bitline regulator is responsive to a set of trim bits that are generated by comparing the bias voltage of a bitline to a reference voltage.
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to robotic parts handler system for removing containers filled with articles such as mail or packages from a high speed sorting, feeding and/or stacking apparatus and conveying the container, tray, or a cartridge for containing articles to be transported to another selected location at extremely high speeds.
2. Background Information
Articles of mail and packages are typically sorted, stacked, and conveyed by apparatus such as described in U.S. Pat. Nos. 5,634,562; 5,582,324; 5,562,195; 5,422,821; 5,201,397; all of which are incorporated by reference herein. A typical sorting and stacking apparatus is shown in FIGS. 2 and 3 consisting of a rectangular frame utilizing a plurality of receptacles and roller belt systems to convey, sort, and stack postal letters in accordance with a bar code or other indicia indicative of a particular destination. The articles are then fed into containers or boxes, whereby individuals detach the boxes upon filling, stack them on a cart, conveyor belt, or other means of moving, and transport the containers filled with mail articles to a distribution point.
The present mail distribution system is inherently inefficient in that the sorting, stacking, and conveying system is a highly automated high speed system capable of sorting and moving articles in a few seconds; however, the containers are manually carried by mail persons. Thus, the high speed equipment is frequently idle due to the inability of the mail persons to remove and replace the containers at a corresponding high rate of speed.
The present invention eliminates the necessary of mail persons to work in close proximity to the high speed operating equipment thereby eliminating the hazards associated therewith and the strenuous physical activities associated with moving the containers from the sorting apparatus to the distribution point manually. Moreover, conventional equipment utilizes a number of actuators, usually one for each mail slot or port requiring extensive maintenance and a large capital investment in equipment.
SUMMARY OF THE INVENTION
The present invention defines a robotic parts handling system having a platform forming a base including at least one linear servo magnetic motor affixed to and extending along the side beneath the platform. The platform is supported by a track including a first master rail and a second minor balancing rail. A plurality of supporting rollers supporting and hold the platform to the first master rail and the second minor balancing rail. A plurality of magnets mounted along the length of the first master rail are in cooperative magnetic engagement with the at least one linear servo magnetic motor. A plurality of positioning rollers mounted to the platform maintain a constant distance between the linear servo magnetic motor and the magnets mounted to the first master rail. A computer control unit controls and coordinates movement of the robot along the rails and the operation of the end effectors. A magnetic strip provides a means in close proximity to the rail for generating pulses readable by a reader in communication with the control unit for positioning the platform at selected positions upon the rail. A frame mounted upon the platform includes at least one pair of vertical rails spaced apart from and in alignment with one another. A pair of slide members, each one including a plurality of rollers cooperatively engage the vertical rails. A pair of timing belts provide means extending along the vertical rails in cooperative engagement with the slide members for moving the slide members up and down independently of one another along the Y-axis. A saddle having distal ends extending inbetween the vertical rails attaching to the slide members permit the saddle to be tiltable from side to side. A cylinder provides a means for tilting the saddle from front to back along the x-axis. At least one end effector mounted onto the saddle includes means for engaging and removing a container from a preselected position on one side of the platform and transferring the container to the opposite side of the platform and positioning and releasing the container in a selected location. One such means includes a conveyor having timing belts with protrusions for cooperative engagement with opposing depressions formed on the bottom of a cartridge container.
The present invention defines a high speed robotic container handling system having a digital magnetic positioning system, a platform frame having a linear servo motor thereon moveable along a pair of rails one of which includes magnets affixed thereto. The platform supports a pair of frame members supporting a tiltable saddle which supports one or more end effectors with actuators and conveyor capacity for interfacing with containers or cartridges filled with mail or the like held in multiple bins or slots on either side of the rails at selected sites up or down the track rails. In one preferred embodiment, the robotic container handling system removes containers filled with articles from the sorting apparatus, transfers and inserts them within a buffer and releasing them therein, moves to a position in alignment with the buffer containing an empty container(s) and extracts the container(s) therefrom, and inserts the container(s) into an empty location of the sorting machine; thereafter, repeating the cycle.
It is an object of the present invention to provide a robot to interface with a container, tray, or cartridge for receiving letter mail from an existing belt distribution system that guides the mail pieces into the tray at high speeds.
It is an object of the present invention to provide a robot to interface with a container, tray, or cartridge wherein the tray has an onboard lock-up means that retains the mail as the tray is used for off-system storage and/or transportation.
It is an object of the present invention to provide an end effector for manipulating the tray and interacting with the mail belt system and the tray at high speed.
It is an object of the present invention to provide a means for loading the tray containing mail onto the end effector, transport it to a position determined by an overall system controlling computer and unload the tray containing mail at a selected location at a selected time.
It is an object of the present invention to provide a conveyor module as a part of the end effector assembly which utilizes a belt having protrusions with interlock with opposing cavities and/or protrusions on the bottom surface of the tray allowing trays weighing in excess of twenty-five pounds to be handled at very high speeds and accelerations.
It is an object of the present invention to provide a robot having a platform base powered by linear servo magnetic motors providing a very high acceleration and deceleration and the ability to park the entire system consistently within at a preselected position.
It is an object of the present invention to provide a robot powered by a linear magnetic motor which is cooperatively magnetically engageable with a master rail having a plurality of permanent magnets affixed thereto together with guide rollers which maintain a necessary selected gap of about 0.020 of an inch between the motor and rail magnets in order to drive the unit back and forth in the X-axis with high speed and precision.
It is an object of the present invention for the linear motor and magnetic rail system to be adaptable with the platform of the robot for moving the robot over flat surfaces such as a floor with the aid of a second minor rail or balancing rail.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein:
FIG. 1 is a perspective view of the robotic container handling system of the present invention;
FIG. 2 is a top view showing the sorting and stacking apparatus having a platform base and end effector assembly movable upon a magnetic track rail system having a vertical lifting and stacking assembly including effector means for distributing and conveying articles;
FIG. 3 is a perspective view of a computer control center for the present invention together with a mail sorting apparatus on one side of the track and a storage unit on the opposite side of the track;
FIG. 4 is a sectional view along lines 4 — 4 of FIG. 2 showing the robotic handler system including effector head and platform base on a track with the effector head and conveyor assembly in the raised position in phantom lines, showing the effector head tilting and extending outwardly from the frame in phantom lines, showing support rail rollers on the top and inside of the track rail, and the linear servo motor and positioning roller on the outside of the opposing track rail;
FIG. 5 is a top partial cutaway view of the robot showing a pair of effector head assemblies supported by the saddle connected to the frame by slide members held within guide rails by rollers being moved in the Y-axis by a belt all being supported by the platform base setting on a master rail showing the positioning rollers resting on the vertical portion of the master rail for holding the linear motors a selected distance from the magnetic plates affixed to the outside surface of the master rail and showing support rollers mounted onto the minor balancing support rail;
FIG. 6 is a partial cutaway view showing the guide rollers of the platform base with the positioning guide rollers and support rollers in cooperative engagement with the master rail, showing the brake, magnets, linear servo motor, magnetic strip, and gap between the linear servo motor and positioning rollers;
FIG. 7 is a partial cutaway view of FIG. 19 showing the guide rollers, brake, and servo motor with respect to the master rail;
FIG. 8 is a side view showing the bank of permanent magnets attached to the master rail;
FIG. 9 is a side view showing a pair of effector head assemblies in (phantom lines) supported by the saddle connected to the frame by trunions and supported by the platform base mounted onto the magnetic rails wherein a saddle is shown in phantom lines in the raised and pivoted position;
FIG. 10 is a top sectional view showing the of a rail in cooperative engagement with the rail brake in the open unlocked position;
FIG. 11 is a top sectional view of the brake of FIG. 6 in cooperative engagement with the rail brake in the closed locked position;
FIG. 12 is a top view of the tiltable saddle supported by vertical support columns and movable up and down by rollers cooperatively engaging the vertical columns by trunions and powered by rotary servo motors;
FIG. 13 is a side view of the tiltable saddle of FIG. 12 and the vertical support columns showing the saddle connected to the columns by trunions and showing a pair of rotary servo motors for raising and lowering each side of the saddle independently;
FIG. 14 is a side view of the cylinder shown in FIGS. 12 and 13 used for tilting the saddle forward or rearward;
FIG. 15 shows a top view of the guide rollers mounted onto the saddle trunion supporting the end effector for sliding up and down the guide rails mounted to the vertical support rails of the frame having a pair of opposing fail safe brake pads extending against the interior surface of the support column to stop vertical motion of the assembly upon loss of power;
FIG. 16 is a perspective rear end view of a cross slide module of the present invention showing the cross slide saddle, base, rails, drive pulley, timing belt, pillow block, and drive motor;
FIG. 17 is a perspective front end view of the cross slide module of FIG. 16 showing the ball screw, ball screw cover, and ball screw support bearing housing;
FIG. 18 is a top view of FIG. 16 showing the cross slide module;
FIG. 19 is a sectional view of FIG. 18 showing the motor drive of the cross slide module;
FIG. 20 shows a sectional view of a the cross slide module of FIG. 18 showing a portion of the servo driven ball screw assembly;
FIG. 21 is a rear end view showing a saddle supporting a pair of cross slide modules having conveyor modules mounted thereon with a pair of container cartridge trays shown in phantom lines supported thereon;
FIG. 22 is a front end view of the cross slide module showing the ball screw and slide rods that move the cross slide saddle back and forth on the cross slide base;
FIG. 23 is a rear end view of the cross slide module showing the motor and drive train for moving the cross slide saddle back and forth over the slide rods mounted on the cross slide base;
FIG. 24 is a front end perspective view of a conveyor module of the effector head assembly;
FIG. 25 is a rear end perspective view of the conveyor module of FIG. 24;
FIG. 26 is a top view showing the conveyor module of FIG. 24 showing the motor and belt drive of the conveyor module;
FIG. 27 is a side view of FIG. 26 showing the conveyor module with the motor and belt drive whereby protrusions of the belt are engaging the indentations of the container cartridge shown in phantom lines;
FIG. 28 is a side view showing a cross slide module supporting the conveyor module including a container cartridge whereby protrusions of the belt are engaging the indentations of the container cartridge shown in phantom lines;
FIG. 29 is a rear perspective view of the drop gate actuator which mounts to the cross slide module of the effector end assembly showing the drop gate actuator in the down position;
FIG. 30 is a front perspective view of the drop gate actuator which mounts to the cross slide module of the effector end assembly showing the drop gate actuator in the extended “up” position;
FIG. 31 is a partial sectional view of the drop gate actuator assembly taken through FIG. 33 showing the curved slide cam and rollers and the drive motor;
FIG. 32 is sectional view taken through FIG. 33 showing the drive pulleys and belt for operating the drop gate assembly;
FIG. 33 is an front end view of the drop gate actuator assembly showing the drop gate top and bottom links in the raised position and also showing them in the lowered position with phantom lines wherein the engageable mail cartridge container or tray on the end effector conveyor are also shown in phantom lines and rotated 90 degrees for viewing clarity;
FIG. 34 is a top view showing the drop gate module, and showing the stack support actuator assembly in phantom lines of the end effector;
FIG. 35 is a side view of the drop gate actuator assembly mounted onto the end effector slide plate showing the arm in the raised position engaging the drop gate lever of the cartridge container in the raised position wherein the drop gate is lowered for receiving mail from a sorting apparatus;
FIG. 36 is a front perspective view showing a stack support actuator;
FIG. 37 is a rear perspective view showing the stack support actuator of FIG. 36;
FIG. 38 is a side view showing the stack support actuator with the cam track for lifting and engaging the fork rod with a receiver means extending through the bottom of a mail cartridge container;
FIG. 39 is a top view showing the stack support actuator assembly of FIG. 38 comprising a “rack and pinion” assembly wherein a fork extending from the distal end of a rod or “rack” is extendable back and forth by a pinion gear driven by a motor with a gear belt pulley and gear belt (shown in phantom lines) for driving another gear drive pulley attached to the pinion gear;
FIG. 40 is a front view of the effector head and stack support actuator of FIGS. 38 and 39, wherein a fork extending from the distal end of a rod or “rack” is extendable back and forth by a pinion gear driven by a motor. The mounting plate and drop gate assembly are shown in phantom lines;
FIG. 41 is a sectional view of the stack support actuator taken through FIG. 38 showing the drive mechanism and timing belt for the cam assembly and cam track;
FIG. 42 is a section along lines 43 — 43 taken through FIG. 40 showing the motor and drive belt (in phantom lines), and pulleys;
FIG. 43 is a sectional view taken through FIG. 42 showing the guide rollers on the cam track;
FIG. 44 is a top view of a pair of end effectors showing a pair of stack support actuators, a pair of drop gate actuators, and a pair of conveyor modules mounted on the cross slide module showing the saddle and trunions in phantom lines;
FIG. 45 is a perspective view of FIG. 44 showing details of the pair of end effectors with a pair of stack support actuators, a pair of drop gate actuators, and a pair of conveyor modules mounted on the cross slide module;
FIG. 46 is a front view of the cartridge showing the horizontal drop gate which is cooperatively engagable with the drop gate actuator of the end effector;
FIG. 47 is a rear end view of the cartridge which abuts and is cooperatively engageable with a mail sorter;
FIG. 48 is a top view of a cartridge showing the slot having a longitudinal notched member therein and showing a stack support in cooperative engagement therewith, and the peripheral drop gate pivot rod extending therearound;
FIG. 49 is a side view of the cartridge showing the drop gate rod pivot point;
FIG. 50 is a top view of a clearing gate actuator;
FIG. 51 is a side view of the clearing gate actuator of FIG. 50 ;
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Articles of mail and packages are typically sorted, stacked, and conveyed by apparatus such as described in U.S. Pat. Nos. 5,634,562; 5,582,324; 5,562,195; 5,422,821; 5,201,397; all of which are incorporated by reference herein. A typical mail sorting apparatus is shown in FIGS. 2 and 3. The present robotic container handling system 10 as best shown in FIG. 1, provides a means of handling the mail or other articles deposed in containers or cartridges. The present invention comprises a platform base movable upon a magnetic track or rail system having a vertical lifting and stacking assembly including effector end means for distributing and conveying articles. The distributing means consists of a effector head assembly 12 having a belt conveyor module 14 , clearing gate module 15 , drop gate module 17 , stack support module 90 , all mounted upon a cross slide module 23 to convey, sort, and stack postal letters in accordance with a bar code or other indicia indicative of a particular destinations These articles are then fed into containers, cartridges, or boxes 16 . The present invention robotic container handling system, (“robot”), 10 removes the containers 16 from the sorting apparatus 18 and conveys the containers 16 filled with articles, such as letters, to a selected distribution point defining a buffer or storage unit 20 having container receivers 21 or pockets therein which engages a container or cartridge 16 , such as shown best in FIGS. 27-28 and 46 - 49 , and returns in a matter of seconds to insert the container 16 into a preselected position of the sorting apparatus 18 selected by a computer control system 11 which may be mounted piggyback onto an end of the frame 40 or be contained in a control center station with a computer, monitor, keyboard and supporting control and electrical equipment as illustrated in FIG. 3 .
The robotic container handling system 18 of the present invention is manufactured from readily available materials and simple in design. The preferred embodiment is comprised of metal, more particularly stainless steel, steel, or brass; however, it is contemplated that plastic or other polymer composite materials, such as graphite fiber, nylon, or even fiberglass, could be molded and used in combination with or substituted for the steel components of the present invention.
With reference to FIG. 1, the present invention comprises a high speed robotic parts handling system 10 , whereby movement of the parts handling system 10 in the X-axis is accomplished by moving a platform or base 19 supported by rubber rollers 26 which roll on a pair of rails 28 . As best illustrated in FIGS. 1, 3 - 4 , and 54 , the pair of rails 28 include a first master rail 29 having a modified “I-beam configuration” including an “L-shaped member” 35 backed against a “C-shaped member” 37 . More particularly, the “L-shaped member” includes defining vertical body member connecting to a horizontal leg supported by a base defining the outside portion of the rail 29 . The interior portion of the master rail 29 includes a top arm extending inwardly connecting to a vertical body member supported by a horizontal leg mounted onto a base member thereby forming a channel. The minor rail 31 is a simple “I-beam” 31 provided only for stability. Of course, it is contemplated that the minor rail 31 could be replaced with another master rail 29 including magnets 30 for cooperatively engaging another linear servo motor 22 mounted to the opposing side of the platform 19 . A plurality of free wheeling rollers 26 hold the platform 19 to the rails 28 . In the preferred embodiment six rollers 26 are mounted along the sides of the platform 19 to roll on top of the rails 28 and two rollers 26 are mounted laterally to the platform providing lateral support thereto. The robot 10 and its payload are supported by anti-friction bearings. Furthermore, a plurality of positioning rollers are used to maintain a constant distance between the faces of the linear servo motors 22 mounted onto the moving platform 19 and continuous magnet panels or plates 30 mounted to the master guide rail 29 . In the preferred embodiment, twelve positioning rollers 24 are mounted onto a longitudinal support member 13 having a generally square cross-sectional shape and which extends along one side of the base 19 . The positioning rollers or guide wheels 24 are used to separate and hold the linear servo motors 22 away from the magnets 30 positioned alone the master rail 29 a selected distance. As best shown in FIGS. 1, 4 , 5 - 7 , the positioning rollers 24 contact the master rail 29 at points above and below the magnet plates 30 which are located thereinbetween. The positioning rollers 24 have the hub and inner wheel portion fabricated from aluminum and an outer periphery band is fabricated from stainless steel; however, it is contemplated that other materials such as graphite, other polymers, or even ceramic material could be used to fabricate the positioning rollers 24 . Using accurately sized positioning rollers 24 rolling upon the vertical sides of the master rail 29 provides a means for selecting and accurately maintaining a precise distance between the rail mounted magnets 30 and the linear servo motors 22 mounted to the platform 19 of the robot 10 .
The platform is powered by at least one and preferably a pair of brushless linear servo motors 22 and permanent magnets 30 mounted on edge to the side of the rail 28 whereby the faces of the motor(s) 22 and magnets 30 are perpendicular to the platform surface 19 and the supporting surface of the rails 28 . Thus, linear motor is mounted 22 vertically to the track rail 28 allowing for the use of a single master rail for both robot support and propulsion.
The linear motors 22 and magnets 30 provide a means to accelerate, propel, and stop the payload platform 19 at precise locations along the horizontal rail 28 .
The rails 28 having a magnet bank 30 of permanent magnet plates extending therealong as shown in the FIGS. 4-8 More particularly, the linear servo motors 22 are mounted in tandem for providing a magnetic positioning system whereby the platform 19 is suspended by a plurality of rail rollers 26 supported and guided upon rails 28 . A plurality of magnets 30 may be abutted together as longitudinal plates and affixed to the rail 28 depending upon the desired length of the track. In the preferred embodiment the magnets are attached to the outer vertical portion of the rail; however, it is contemplated that the magnets 30 could be affixed to the inside of the rail or a separate strip of longitudinal material in close proximity thereto. The thickness of the magnet plates is dependent upon the magnetic force required for the linear motor(s) selected, and the length and width of the magnetic plates 30 , but it is preferably less than one inch thick, more preferably less than one-half inch thick, and most preferably from about 0.35 to about 0.50 inches thick. As best shown in FIGS. 2 and 19, a gap 25 of approximately 0.020th of an inch gap exists between the motor 22 and the rail 28 . The strong attraction between the motor(s) 22 and magnets 30 allow the motors 22 (and platform 19 ) to follow a slightly irregular track path if required. Moreover, the unique arrangement allows clearing debris which could foul the running clearance necessary for motor efficiency.
A thin magnetic tape indicator strip 32 extends along the inner surface of at least one of the rails 28 includes magnetized graduations 36 which generate pulses readable by the a reader in communication with the control unit for the robot 10 as it moves along the rails 28 .
Movement is accomplished by interaction of the linear motors 22 with the magnets 30 based upon the Hall effect, whereby a transverse electric field is developed in a current-carrying conductor placed in a magnetic field. Ordinarily the conductor is positioned so that the magnetic field is perpendicular to the direction of current flow and the electric field is perpendicular to both. The high magnetic attraction between the coil assembly of the linear servo motors 22 and magnet plates is very effective for preloading heavy-duty bearings commonly used in high force applications such as the closed loop servo performance required for the instant invention.
As shown in FIGS. 10-11, at least one fail safety brake 29 is attached to the platform 19 having a brake shoe 27 held in the “on” position by springs to bear against the inside one of more of the rails 28 , wherein the brake shoe 27 is spaced apart from the rail 28 and held in the release “open” position by air pressure supplied to the actuators of the robot 10 , so that failure of the air pressure permits the shoes to contact the guide rail 28 stopping the motion of the platform 19 in case of an emergency.
Movement along the Y-axis is accomplished by having at least one end effector assembly 12 mounted on a cross slide module 23 attached to a support saddle 56 pivotally mounted between a pair of trunions 53 suspended by a pair of slide members 52 cooperatively engaging a timing belt 62 reciprocating up and down vertical rails 46 mounted to a vertical column 44 extending upward from the platform 19 and being supported by an “A-frame” 40 mounted upon the platform 19 . More particularly, as illustrated in FIGS. 1, 4 - 5 , 9 , 12 - 15 , and 44 - 45 , the “A-frame” or frame 40 includes a pair of spaced apart vertical support columns 44 extending upward from the base 19 . Three vertical guide rails 46 are attached to and extend along each support column 44 on the sides and outer surfaces thereof. The support columns 44 are connected together at the top end by a horizontal truss member 48 . A plurality of twelve guide rollers 50 move in cooperative engagement along the surface of the frame guide rails 46 in the Y-axis.
The support column 44 having three guide rails 46 includes guide rolls 50 in cooperative communication therewith extending from the interior side of a pair of aluminum slide members 52 . The slide members 52 consist of a back and sides plates attached forming a “U-shaped” slide member 52 . The guide rolls 50 positioned on each side of the rail 46 slidably hold the slide member 52 to the guide rails 46 . The slide members 52 have a pair of trunions 53 projecting inwardly therefrom connecting to the distal ends of an end effector support saddle 56 which support one or more end effectors assemblies 12 which pick up, convey, position, and release the containers or cartridges 16 . The saddle 56 defines a substantially flat base having upwardly extending arms in cooperative engagement with the trunions 53 providing for movement in tilting the saddle 56 along the X-axis in the Y direction “side to side”, so the saddle is 56 higher with respect to one side of the vertical support columns 44 than the other and utilizing hydraulic, air cylinders, or ball screw actuator (electric cylinder) 51 for tilting the saddle 56 pivoting around the X-axis providing a means to cooperatively engage the upper containers of the mail sorting apparatus and providing a means for engaging the receiver 21 of the buffer 20 which are formed having a downward angle of about 10 degrees in order to hold the containers 16 in position by gravity during transfer from the receiving point to the distribution point.
A means for attaching a steel and KEVLAR reinforced urethane timing belt 60 having a plurality of spaced apart projections extending therefrom is attached to an exterior side of each of the slide members 52 and extends around a pulley 62 mounted to the top of a column 44 and driven by a motor 63 mounted to the bottom of the column 44 for moving the slide member along the vertical guide rails 46 at a high rate of speed.
At least one and preferably more end effectors 12 are mounted onto the platform 19 providing a means of elevating and maneuvering a container or cartridge thereon. FIG. 15 shows a top view of the guide rollers 50 mounted onto the saddle trunion 53 supporting the end effector 12 for sliding up and down the guide rails 46 mounted to the vertical support 44 of the frame 40 having a pair of opposing fail safe brake pads 27 extending against the interior surface of the support column to stop vertical motion of the assembly upon loss of power.
A fail safety brake 29 is also attached to each slide member 52 having a brake shoe 27 in the “on” position to bear against the inside of the support column 44 , wherein the brake shoe 27 is spaced apart from the guide rail 46 and held in the release “open” position by air pressure supplied to the actuators of the robot 10 , so that failure of the air pressure permits the shoes 27 to contact the column 44 stopping motion of the slide member 52 in the vertical direction in case of an emergency.
As best illustrated in FIGS. 16-23, each end effector conveyor 14 is supported by a cross slide module 23 mounted onto the saddle 56 normal thereto. At least one end effector assembly 12 , and preferably more than one end effector assembly 12 is mounted onto the cross slide module 23 supported by a saddle 56 .
The cross slide module 23 includes a cross slide base 65 having a pair of rods or rails 61 mounted thereon slidably engaging corresponding linear ball bearings 69 within which support a cross slide mounting platform 64 . The mounting platform 64 is moved back and forth with respect to the cross slide 23 in the Z-axis with respect to the platform 19 by means of a servo driven ball screw 66 enclosed within a rubber bellows 67 ending in a ball screw support bearing housing 61 and powered by a drive pulley 62 connected to a servo motor 63 by a belt 60 .
Mounted onto the cross slide module 23 of the end effector head assembly 12 perpendicular to the end effector support saddle 56 is at least one and preferably two or more conveyor modules 14 as shown best in FIGS. 24-29 for interfacing with the container (cartridges) 16 . Each conveyor module 14 includes a frame 57 mounted onto the cross slide module 23 which supports a pair of conveyor rails 59 having a drive end pulley 47 and distal end pulley 54 . A belt guide projection 55 is located in front of the drive end pulley 47 and pass the distal end pulleys 54 . A spring 71 attached to the rail 59 biases against the conveyor take up end axle 73 of the distal end pulley 54 to maintain selected tension on the conveyor belt 68 . The conveyor belts 68 are driven by a servo motor 74 through a timing belt reduction drive 76 which engages a first set of drive pulleys 47 which are connected by the belt 68 to the set of idler pulleys 54 . A polyethylene slide plate 82 which rests upon an aluminum frame rails 59 supported by the frame 57 mounted to the cross slide saddle 64 . A pair of conveyor belts 68 fabricated of steel and KEVLAR reinforced urethane are driven by a timing belt 75 in communication with the drive end pulleys 47 and a servo motor 74 mounted to the frame 57 . It is contemplated a single belt fabricated from different material could be substituted for the belt 68 of the preferred embodiment. Moreover, the conveyor belt 68 of the preferred embodiment includes a plurality of spatial profiles or cleats 70 extending or projecting therefrom for positive cooperative communication with corresponding indentations 72 , molded into the bottom of the container (cartridge) 16 .
As best shown in FIGS. 29-34, a drop gate actuator assembly 90 comprises a support frame member 92 generally centrally mounted onto the cross slide module 23 inbetween the conveyor belts 68 and near the distal end of the conveyor belts 68 for engaging the drop gate of the container (cartridge) 16 held within the storage cart or slot of the sorting apparatus 18 . The entire drop gate actuator assembly 90 extends above the cross slide module 23 , but below the conveyor belts 68 and the pass line of the container 16 passing thereover.
A drop gate actuator motor 91 is mounted onto a support frame member 92 mounted onto the cross slide module 23 . Extending from the servo motor 91 is a shaft having a pulley 93 mounted thereon. The pulley drives a first timing belt 106 extending upward to a first drop gate pulley 102 attached to the a drive shaft 94 held by the inward end of the support frame member 92 in alignment with the drive shaft 94 . A second drop gate pulley 104 of a lesser diameter, preferably ½ the diameter of the first drop gate pulley 102 , is attached to the shaft 94 . A first drop gate link arm 96 is rigidly mounted to the shaft 94 extending at a selected angle therefrom. A second drop gate top link arm 98 is pivotally connected to the distal end of the first drop gate link arm 96 by a shaft 97 allowing rotation thereof from 0 to 180 degrees providing the second drop gate top link arm 98 to extend in a straight line or pivot back upon the first drop gate link arm 96 . The shaft 97 controlling the movement of drop gate arm 98 is rotatably held by a portion of the frame 92 in alignment with shaft 94 . An upper drop link control pulley 103 extending from the inward end of shaft 97 is in cooperative engagement with the pulley 104 and driven by timing belt 106 . Rotation of the upper control link pulley 103 by rotation of the timing belt 166 rotates the drop gate top link 98 effectively raising or lowering the distal end 100 of the drop gate top link arm 98 allowing movement in a vertical straight line and in vertical alignment with the drive shaft 94 . The ability for the distal 100 of the second drop link top arm 98 to move vertically develops the straight line motion required for alignment and engagement of the drop gate 132 of the container (cartridge) 16 . The means for engagement of the drop gate 132 , as shown in the preferred embodiment, is a socket 107 having a notch 108 therein extending normal from the front end of the distal end portion 100 of the second top link arm 98 . A tension means such as a spring 105 retains the socket 107 so that the notch 108 is in vertical alignment for engagement of the drop gate rod 132 of the container 16 .
Moreover, as best shown in FIGS. 29 and 33, a cartridge drop gate spring depressor 99 having a head 101 with a concave surface 160 for cooperatively engaging the socket 107 of the drop gate in the down position extends from the distal end of a curved push arm 95 . The push arm 95 is supported by frame 92 and guided by cam rod bearing 162 and a pair of vee guide wheels 107 . The push arm 95 slides over a spring retainer 164 biased by spring 168 for working simultaneously with the drop gate 90 . The cartridge drop gate spring depressor 164 raises in unison with the drop gate socket 107 and releases drop gate 132 holding/retaining members on the bottom of the cartridge 16 upon engagement of the drop gate socket 107 with the drop gate 132 .
As best illustrated in FIGS. 36-43, a stack support actuator assembly 112 supported by a stack support base 114 is mounted upon the cross slide module 23 of the effector end 12 . The actuator defines a rack “rod” 116 and pinion 118 assembly whereby the horizontal member or rack 116 extends through a block stack support 109 having a stop block 113 . The rear end of the rack includes a carriage pull finger 170 front end of the rack 116 defines a “two prong” or “fork” 120 shape tool for cooperative engagement with a stack support 130 of a container “cartridge” 16 . The fork 120 a release plunger 172 disposed inbetween the tines and a downwardly angled lifting surface 115 providing a means to engage a container (cartridge) 16 within a slot of the mail sorting apparatus 18 and lift a stack support 130 vertically disengaging the stack support 130 from a rod 121 forming a locking bar mechanism in the container 16 .
The stack support actuator assembly 112 is mounted to a support block 109 which is mounted by slide bars 111 in cooperative sliding engagement supported by a frame 110 . The frame 110 includes a roller plate 117 extending upwardly, spaced apart from, in alignment with, and opposite to, the support block 109 . At least one and preferably two sets of spaced apart vee guide rollers 119 extend inwardly in alignment with one another from the top and bottom of the roller plate 117 . A cam plate 123 having an “S-curve” track 121 is held between the vee guide rollers 119 of the roller plate 117 . The cam plate 123 is attached in the rear to a plunger 125 extending from a cylinder 127 mounted to a cylinder mount 129 . Extending from the support block 109 is a roller 131 which rolls along the cam plate track 121 providing forward lifting movement to the block 109 and stack support actuator assembly 112 mounted thereon upon actuation of the cylinder 127 . The cam mechanism provides good acceleration and declaration. For instance, a 2½ inch stroke lifts the fork 120 by about one inch.
The preferred embodiment of the container or cartridge 16 is formed of a plastic material; however, it is anticipated that metal or other material may utilized therefor. The container 16 of the preferred embodiment defines a mail cartridge formed having indentations 72 on the bottom thereof for positive cooperative engagement with the conveyor belts 68 of the belt conveyor module 14 of the end effector assembly 12 . A mail cartridge 16 is formed providing a generally rectangular box having a centrally located slot 122 extending at least a portion of the length thereof. A longitudinal member or rod 124 having notches 126 therealong defines a lock bar for cooperative engagement with an article “mail” stack support member 130 engageable from the bottom of the cartridge by fork 120 of the stack support actuator module 19 of the effector head assembly 12 . A constant force spring provides back pressure so that mail feeding into the cartridge does not collapse the stack support member 130 .
As shown in FIGS. 15-17, and 24 and best shown in FIGS. 39-42, the container 16 also utilizes a drop gate 132 which is formed from a peripheral rod 121 extending around the exterior sidewall of the container 16 attached thereto by a centrally located pivot point 134 . The rod 121 forms a rear engaging mechanism defining a pair of loops for cooperative engagement with a sorting apparatus 18 for retaining the mail articles therein and having a centrally positioned horizontal front section 128 for cooperative engagement with the drop gate actuator 90 . As shown in the drawings, while the drop gate 132 is up in the back of the cartridge 16 , mail from a sorter 18 is fed into the cartridge 16 abutting the stack support member 130 of the cartridge 16 and moving it forward to fill the cartridge 16 with a predetermined amount of mail.
As best shown in FIGS. 15, 22 , 26 and 27 , a clearing gate actuator 140 utilizes a cylinder 141 having a bumper 142 extending from a plunger to interface with a clearing gate of a mail sorter which sweeps the mail downward into the cartridge 16 compressing the mail slightly and moving it toward the stack support member 130 . As the drop gate actuator 90 engages and pulls the peripheral rod 121 of the drop gate 132 down in the front of the cartridge 16 , the loops 135 pivot upward between the mail and sorter 18 holding the mail securely for movement by the end effector assembly 12 to a desired position.
The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art based upon more recent disclosures and may be made without departing from the spirit of the invention and scope of the appended claims.
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A robotic parts handler system for removing containers filled with articles from a sorting, feeding and/or stacking apparatus such as a mail or package sorting apparatus, and moving the container to a selected location for insertion into another conveying system, transport device, carrier, or other apparatus at extremely high speeds.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. provisional patent application Ser. No. 60/861,686, filed on Nov. 29, 2006, which is herein incorporated by reference, and U.S. non-provisional patent application Ser. No. 11/619,092 filed on Jan. 2, 2007.
FIELD OF THE INVENTION
The present invention relates generally to the field of techniques for analyzing multimedia data and, in particular, methods and systems for searching a multimedia content for graphical objects of interest.
BACKGROUND OF THE INVENTION
Recognition of objects of interest (referred to herein as “targets”) in graphical contents of 2D images is used by military, law enforcement, commercial, and private entities, as well as individuals. Typically, the goal of target recognition is identification or monitoring of one or more targets depicted in images produced by surveillance apparatuses or in images stored in respective databases or archives. In some instances, portions of the images may be accompanied or substituted with respective annotating texts and, as such, represent a multimedia content (i.e., combination of graphics and text).
It has been recognized in the art that there are difficulties associated with computerized comparing of the graphical contents of images and, specifically, with searching multimedia contents. In particular, many challenges in the field of computerized target recognition relate to identification more than one target or targets that change their appearance due to orientation, lighting conditions, or partial occlusions.
Despite the considerable effort in the art devoted to techniques for computerized searching of multimedia contents, further improvements would be desirable.
SUMMARY OF THE INVENTION
One aspect of the invention provides a method for searching a multimedia content that includes pluralities of content images and text documents. The method is based on an assessment of a similarity score between the compared images and/or annotating texts and uses a multimedia user graphical interface (MGUI). The similarity score is defined as a complement to a pictorial edit distance (PED), which is asserted as a weighted sum of a 2D representation of Insertion, Deletion, and Substitution Error terms of the Levenshtein algorithm for matching or searching one-dimensional data strings.
In one embodiment, the method comprises the steps of indexing content images using similarity score metric, developing the MGUI, providing query data including query images and/or query texts, and searching the multimedia content using the MGUI for information relevant to the query data based on similarity scores between the query data and the content images.
Other aspects of the present invention provide an apparatus and system using the inventive method for searching a multimedia content.
Various other aspects and embodiments of the invention are described in further detail below.
The Summary is neither intended nor should it be construed as being representative of the full extent and scope of the present invention, which these and additional aspects will become more readily apparent from the detailed description, particularly when taken together with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram illustrating a method for searching a multimedia content in accordance with one embodiment of the present invention.
FIG. 2 is a schematic diagram depicting exemplary query and content images compared using the method of FIG. 1 .
FIG. 3 is a schematic diagram illustrating an image search engine used by the method of FIG. 1
FIG. 4 is a schematic diagram illustrating an embodiment of a multimedia user graphical interface used by the method of FIG. 1 .
FIG. 5 is a high-level, schematic diagram of an exemplary apparatus using the method of FIG. 1 .
To facilitate understanding, identical reference numerals have been used, where possible, to designate similar elements that are common to the figures, except that suffixes may be added, when appropriate, to differentiate such elements. The images in the drawings are simplified for illustrative purposes and have not necessarily been drawn to scale.
The appended drawings illustrate exemplary embodiments of the invention and, as such, should not be considered as limiting the scope of the invention that may admit to other equally effective embodiments. It is contemplated that features or steps of one embodiment may beneficially be incorporated in other embodiments without further recitation.
DETAILED DESCRIPTION
Referring to the figures, FIG. 1 depicts a flow diagram illustrating a method 100 for searching a multimedia content in accordance with one embodiment of the present invention, FIG. 2 depicts a schematic diagram 200 illustrating exemplary query and content images compared using the method 100 , and FIGS. 3-4 depict an image search engine (ISE) and a multimedia user graphical interface (MGUI), respectively, which are used in an embodiment of the method 100 . To best understand the invention, the reader should refer to FIGS. 1-4 simultaneously.
In various embodiments, method steps of the method 100 are performed in the depicted order or at least two of these steps or portions thereof may be performed contemporaneously, in parallel, or in a different order. For example, portions of steps 130 and 140 or steps 150 and 160 may be performed contemporaneously or in parallel. Those skilled in the art will readily appreciate that the order of executing at least a portion of other discussed below processes or routines may also be modified.
Aspects of the present invention are illustratively described below within the context of images depicting live objects such as humans or body parts thereof. The invention may also be utilized within context of images depicting material objects, such as missiles or their plumes, vehicles, objects floating in air, free space, or liquid, beams of light, and the like, as well as images depicting a combination of various live or material objects. It has been contemplated and is within the scope of the invention that the method 100 is utilized within the context of such images.
At step 110 , pictorial edit distance (PED) and similarity score metrics are provided for a multimedia content that may include a graphical content (referred hereafter to as “content images”), text documents, or a combination thereof. Some content images may selectively include textual annotations, which allow association of such images with particular key words.
The PED is asserted as a weighted sum of a 2D representation of Insertion, Deletion, and Substitution Error terms of the Levenshtein algorithm for matching or searching one-dimensional data strings, and the similarity score is defined as a complement to the PED. Techniques for determining the PEDs and similarity scores and comparing images using these properties are disclosed in commonly assigned U.S. patent application Ser. No. 11/619,133 filed on Jan. 2, 2007, Ser. No. 11/619,092, filed on Jan. 2, 2007 and Ser. No. 11/619,121, filed on Jan. 2, 2007, all of which are herein incorporated by reference. Techniques for determining PEDs and similarity scores and comparing images using these properties are further disclosed in the commonly assigned U.S. patent applications by C. Podilchuk entitled “Method and System for Comparing Images Using a Pictorial Edit Distance,” filed simultaneously herewith on this date, and “Method and System for Image Recognition Using a Similarity Inverse Matrix,” simultaneously filed herewith on this date, the contents all of which are incorporated herein by reference. Salient features of these techniques are briefly discussed below.
Referring to FIG. 2 , M exemplary content images 220 may be analyzed using a similarity matrix SM,
SM
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.
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Matrix elements S ij of the similarity matrix SM are defined as similarity scores between content images 220 i and 220 j , where i and j are integers and i+j=M. In the similarity matrix SM, each content image 220 forms a diagonal matrix element, and similarity scores of the content images 220 one versus another form non-diagonal matrix elements.
Diagonal matrix elements (i.e., matrix elements S ii or S jj ) relate to similarity scores of the respective content images versus themselves and, as such, are unity matrix elements (i.e., matrix elements which numerical value is equal to 1). Correspondingly, since similarity scores S ij and S ij for the respective content images 220 ij and 220 ji are equal to one another, the similarity matrix 300 is a symmetric matrix, and numerical values of the non-diagonal matrix elements are disposed in a range from 0 to 1.
To determine the similarity score between the content image 220 i and 220 j , an image disparity map is calculated for these images using a respective block matching algorithm. Using cost functions such as, for example, a mean absolute difference (or L 1 error) or a mean square error (or L 2 error), the image disparity map identifies disparity between pre-selected elementary blocks of pixels in the content images 220 i and 220 j as a weighted sum of the one-to-many, one-to-none, and matching error correspondences between the blocks of pixels.
These types of correspondences are expressed using terms of the Levenshtein algorithm as follows: (i) one-to-many correspondence between the elementary blocks is asserted as an equivalent of an Insertion term, (ii) one-to-none correspondence between the elementary blocks is asserted as an equivalent of a Deletion term, (iii) partial matching between the elementary blocks is asserted as an equivalent of a Substitution Error term, and (iv) a PED between the compared images is asserted as an equivalent of a Levenshtein's Edit Distance.
Herein, the term “one-to-many correspondence” relates to an elementary block matching, with a cost function smaller than a first pre-determined threshold Q 1 , two or more elementary blocks of the other image. Accordingly, the term “one-to-none correspondence” relates to an elementary block having no match among the elementary blocks of the other image (i.e., elementary block which cost function, with respect to the elementary blocks of the other image, is greater than a second pre-determined threshold Q 2 ). The term “partial matching” relates to the elementary blocks which cost functions, with respect to the elementary blocks of the other image, are disposed between Q 1 and Q 2 , i.e., Q 1 ≦Q≦Q 2 .
Referring back to FIG. 2 , the content images 220 may be compared to or searched for an exemplary query image 210 or one another, when the query image is selected from the content images. Illustratively, each of the content images 220 depicts a respective object 225 that is compared to a target 215 depicted in the query image 210 . Generally, the target 215 and objects 225 are depicted surrounded by live or material elements of their respective conventional habitats, conditions, or environments. For a purpose of graphical clarity, in the images 210 and 220 such elements are not shown.
Herein, the method 100 is discussed referring to the content and query images depicting a single object (content images 220 ) or a single target (query image 210 ). In alternate embodiments, content and query images depicting several such objects or targets may similarly be compared using processing steps of the method 100 .
In the depicted exemplary embodiment, the query and content images 210 , 220 are digitized 2D images having the same digital resolution (i.e., number of pixels per unit of area), and their graphical contents (i.e., target 215 and objects 225 ) have approximately the same physical dimensions, or scale factors.
Generally, at least a portion of these properties in available samples of the query and content images may differ from one another or at least one of the query and content images 210 , 220 may be a portion of a larger image plane. In operation, respective properties of such query and content images are normalized.
In particular, a normalization process may adjust scale factors or digital resolution of the query or content images, equalize or approximately equalize physical dimensions of particular elements in the images or the images themselves, produce copies of the query and content images having different digital resolutions, and the like. Such normalization of the images increases probability and reduces computational complexity of recognizing the target 215 in graphical contents of the content images 220 .
The query and content images 210 , 220 may be compared using a query vector V,
V = [ V q 1 V q 2 -- V qM ] ( Eq . 2 )
or an adjusted query vector V ADJ calculated as a product of the vector V and the inverse similarity matrix SIM, i.e.,
V ADJ =V ·( SIM ). (Eq. 3)
Herein the inverse similarity matrix SIM is a matrix that, when multiplied by the similarity matrix SM, forms a unitary diagonal identity matrix IM, i.e.,
( SIM )·( SM )= IM, (Eq. 4)
and elements S qk of the query vector V are selectively defined as similarity scores between the query image 210 and a respective content image 220 k , where k is an integer in a range from 1 to M.
In a further embodiment, the query image 210 may be compared to the content images 220 at least a portion of which is morphed, using respective graphics software, to examine how such variations relate to the similarity scores between the target 215 and the objects 225 . In particular, such graphics software may produce morphed content images 220 where lighting conditions, poses, or attributes (for example, clothing, hand-held or wearable objects, and the like) of the objects 225 are selectively modified.
In another embodiment, a plurality of the query images 210 n , where n is an integer and n>1, may similarly be compared to the content images 220 . In yet another embodiment, a plurality of thresholds T may be defined to identify particular groups of the content images (for example, groups which similarity scores with the respective query image(s) 210 correspond to pre-selected ranges of the similarity scores).
Referring to FIG. 3 , the content images 220 are indexed, or systemized, using an image search engine (ISE) 300 . The ISE 300 is generally a computer program that may be executed on a computer terminal 500 (discussed in reference to FIG. 5 below) such as, for example, a general purpose computer, a workstation, or a server. In one embodiment, the ISE 300 generally includes an object identifier module 310 , a generator 320 of matrices SMs and/or SIMs, an image indexing module 330 , and a database 340 of graphical information.
In the depicted embodiment, the object identifier module 310 is adapted to identify acquired content images 220 and text documents of the multimedia content. In further embodiments, the object identifier module 310 may also identify a particular graphical content, for example, images of humans, vehicles, and the like.
Using the generator 320 , the acquired content images 220 are normalized and the matrices SM and SIM are produced. In some embodiments, using certain pre-determined strategies, the content images 220 are optionally morphed and the matrices SM and SIM for such morphed images are also produced.
The image indexing module 330 generally performs docketing, analysis, and systemization of the matrices SM and SIM to define clusters, or classes, of particular types of images, such as, for example, people, cars, scenery, and the like.
The database 340 contains the content images 220 and data produced by the object identifier module 310 , generator 320 , and image indexing module 330 . In some embodiments, to accelerate efficiency of particular searches, portions of such data (for example, data corresponding to the multimedia content acquired within specific time interval, relating to specific geographical region, and the like) may form, temporarily or permanently, independently searchable sub-databases.
The database 340 and such sub-databases may be searched for particular query images 210 using, for example, techniques disclosed in commonly assigned U.S. patent application Ser. No. 11/619,104, and by the commonly assigned U.S. patent application by C. Podilchuk entitled “Method and System for Searching a Database of Graphical Data” simultaneously filed herewith on this date, the contents of which are herein incorporated by reference.
At step 120 , referring to FIG. 4 , the method 100 develops a multimedia user graphical interface (MGUI) 400 . The MGUI 400 is generally a computer program that, in operation, enables a user to utilize computational resources of the ISE 300 . Features of the MGUI 400 may be activated using a conventional pointing device, such as a computer mouse, touch pad, and the like.
Specifically, the MGUI 400 allows the user to search the multimedia content for the query data including (i) one or more query images or (ii) a combination of one or more query images and one or more query texts, such as key words or annotations to particular content or query images. In further embodiments, the MGUI 400 may also facilitate searching the multimedia content for particular image elements (for example, specific face or eye pattern, scenery, and the like), administering manipulating, resizing, or morphing of the images, or perform searches using Boolean operators, among other search strategies.
In the depicted exemplary embodiment, the MGUI 400 includes a query image field 410 , a key word search field, 420 , a search menu field 430 , a toolbar field 440 (N tools are shown), a working area field 450 , and a search results field 460 . Illustratively, the fields 450 and 460 are provided with scroll bars 452 and 462 facilitating viewing of large numbers of query and content images.
The query image field 410 includes query areas 412 for the selected query images 210 and logic areas 414 for Boolean operators establishing particular logical relationships between the query images 210 (two areas 412 and one area 414 are shown). The respective query images 210 may be placed in the query areas 412 (for example, dragged using a computer mouse) from the working area field 450 including a plurality of pre-selected query images.
In one embodiment, the pre-selected query images form a searchable library (i.e., database) of such images and may be retrieved from the library to populate the working area field 450 or the query areas 412 . Searches based on the query images 210 may further be supplemented with or replaced by key word searches. For example, at least some of query images 210 or content images 220 may be replaced with annotated texts describing the contents of these images.
The content images 220 , which similarity scores with the respective query data (i.e., query image(s) 210 , query text(s), or combinations thereof) exceeds a pre-selected threshold T, are shown in the search results field 460 (illustratively, in the depicted embodiment, the Boolean operator 414 is “AND”). In one embodiment, the search results field 460 includes areas 464 containing similarity scores of the respective content images and identifying a content image having a highest similarity score with the query data. Such and other specific features of the MGUI 400 may be initiated using the respective tools of the toolbar field 440 , commands listed in the search menu field 430 , a computer pointing device, or a combination thereof.
At step 130 , in operation, a multimedia content of interest is acquired by a user of the respective computer terminal 500 .
At step 140 , using the ISE 300 , a graphical content of the acquired multimedia content is processed, as discussed above in step 110 in reference to the content images 220 .
At step 150 , using the MGUI 400 , the user selectively provides search instructions from the search menu 430 , enables tools of the toolbar 440 , and defines the query data, i.e., selects one or more the key images (i.e., query images 210 ), places them in the query image field 410 , and, in some embodiments, enters in the key word search field 420 a query text including one or more user-defined key words.
At step 160 , following the user-selected instructions, the method 100 uses the ISE 300 to perform searching of the multimedia content for the query data of step 150 and, using the MGUI 400 , displays search results. Upon reviewing the search results, the user may modify the search instructions or the query data and repeat the search of the multimedia content using a new set of instructions or the query data.
In exemplary embodiments, the method 100 may be implemented in hardware, software, firmware, or any combination thereof in a form of a computer program product comprising computer-executable instructions. When implemented in software, the computer program product may be stored on or transmitted using a computer-readable medium adapted for storing the instructions or transferring the computer program product from one computer to another.
FIG. 5 is a high-level, schematic diagram of an exemplary apparatus 500 using the method 100 . The apparatus 500 is generally a computer terminal coupled to a network 550 (for example, the Internet, a wide area network (WAN), a local area network (LAN), and the like), which interconnects pluralities of users 560 and sources 560 of multimedia content.
Illustratively, the apparatus 500 is a computer (e.g., general purpose computer or a workstation) comprising a graphics-enabled display 510 , a processor 520 , and a memory unit 530 . In one embodiment, the memory unit 530 includes a MGUI computer program 532 , the ISE 300 , a text search engine 534 , a database 536 of query data, a database 538 of acquired multimedia content (for example, multimedia content acquired from the source(s) 570 ), and an image comparing program 540 .
When executed by the processor 520 , the program MGUI computer program 532 , the ISE 300 , and the text search engine 534 , together, facilitate processing steps of the method 100 . In particular, the MGUI computer program 532 enables the MGUI 400 , and a graphical portion of the acquired multimedia content is processed using the ISE 300 . In operation, the MGUI 400 allows a user to search the processed multimedia content as discussed above in reference to FIGS. 3-4 .
In alternate embodiments, at least some of the MGUI computer program 532 , ISE 300 , text search engine 534 , or image comparing program 540 , as well at least one of the databases 536 or 538 may reside on a removable magnetic or optical media (e.g., flash memory card or drive, compact disc (CD), DVD, Blu-Ray and/or HD optical disks and the like), a server (not shown) of the network 150 , or a remote computer (not shown) coupled to the network 150 or any other storage medium (not shown) coupled to the network 150 , including magnetic media such has hard disk drives, tapes, and the like. In other embodiments, some query images 210 may be selected from images contained in the database 538 (i.e., from content images 220 ).
Although the invention herein has been described with reference to particular illustrative embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. Therefore numerous modifications may be made to the illustrative embodiments and other arrangements may be devised without departing from the spirit and scope of the present invention, which is defined by the appended claims.
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A system for implementing a method for searching multimedia contents uses a pictorial edit distance to compare a search query consisting of an image to a database of images to determine the ranking of matches from closest match to least closest match between the search image and the images in the database or portions of the images in the database.
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BACKGROUND OF THE INVENTION
[0001] The invention is based on a seating apparatus, in particular, an aircraft seating apparatus, with at least one seat component and a fastening unit for fastening to the seat component.
[0002] A seating apparatus with a seat component formed by a seat base and with a fastening unit for fastening the seat component to supporting tubes is already known. The fastening unit has fastening means which are formed by hose clamps and by means of which the seat component is fastened to the supporting tubes.
SUMMARY OF THE INVENTION
[0003] The invention is based in particular on the problem of improving the fittability and removability.
[0004] The invention is based on a seating apparatus, in particular an aircraft seating apparatus, with at least one seat component and a fastening unit for fastening the seat component.
[0005] It is proposed that the fastening unit has at least one fastening means with at least one latching means which is provided for fastening the seat component, thus making it possible to achieve particularly simple fitting and removal which can be carried out rapidly and without tools. In this case, “provided” is to be understood in particular as meaning specially equipped and/or designed. A “latching means” is to be understood in particular as meaning a means which is provided in order to be deflected counter to an elastic tensioning force in order then subsequently, driven by the elastic tensioning force, to be moved into its latching position. In this case, the elastic tensioning force can be formed by an additional spring element, and/or can advantageously be implemented integrally with a latching arm and/or latching hook. Furthermore, a seat component is to be understood as meaning in particular a main component of a seat, such as a back rest, a leg rest and/or, particularly advantageously, a seat base.
[0006] In a further refinement of the invention, it is proposed that, in the fitted state, the fastening means is fastened to the seat component by means of the latching means, thus enabling the fastening means and the seat component to each be particularly advantageously coordinated with respect to their material with different requirements. Furthermore, a flexible arrangement of the fastening means on the seat component can be achieved. However, it is also conceivable for the fastening means together with the latching means to be at least partially integrally formed on the seat component, in particular in a multi-component process as well, thus enabling additional components, outlay on fitting and costs to be saved.
[0007] Furthermore, it is proposed that at least one latching means of the fastening means is provided in order to produce a latching connection between the fastening means and a corresponding component, as a result of which, in turn, the corresponding component and the fastening component can be configured, largely independently, in particular with regard to the choice of material, to different requirements. However, it would also be conceivable here for the fastening means to be at least partially integrally formed, such as in particular by a multi-component process, on a corresponding component which is formed in particular by a support component for absorbing supporting forces of the seat component.
[0008] The fastening means may be produced from various materials appearing expedient to a person skilled in the art, such as, in particular, from metal, a carbon fiber and/or, particularly advantageously, from a plastic, as a result of which said fastening means can be particularly light, cost-effective and also realized with a desired tensioning force in a structurally simple manner.
[0009] In a further refinement of the invention, it is proposed that the seating apparatus comprises a fastening unit for fastening an upholstery unit, the fastening unit of the seat component requiring a removal force in at least one main removal direction of the seat component which is at least 20%, preferably at least 40% and particularly preferably at least 50% greater than a required removal force in at least one main removal direction of the fastening unit of the upholstery unit, thus making it possible to reliably prevent the fastening unit for fastening the seat component to be undesirably detached during removal of the upholstery unit. In particular, the latching means is correspondingly designed for this purpose, to be precise in particular with regard to its shape, material thickness and/or type of material. In this case, a “main removal direction” is to be understood in particular to mean a predetermined removal direction, for example a removal direction predetermined by operating instructions, and/or a removal direction used primarily by an operator, with the main removal direction of the seat component in particular having a fixed orientation relative to the seat component.
[0010] Furthermore, an undesirable detachment can be advantageously avoided by the fastening unit having at least two fastening means which, in the fitted state, have differing main removal directions, i.e. in particular main removal directions which enclose an angle not equal to zero such that, in particular, a composite removal movement results, such as, in particular, a removal movement with a plurality of translatory movements in different directions and/or with at least one translatory movement and a pivoting movement and/or at least two pivoting movements about differing pivot axes.
[0011] If the fastening unit has at least two structurally identical fastening means, the multiplicity of parts and costs can be reduced, and erroneous fittings due to confusing differing fastening means can be prevented.
[0012] If the fastening means has at least two latching arms forming a C-shaped receiving region, an advantageous support, in particular on supporting tubes, can be achieved.
[0013] Furthermore, it is proposed that the fastening means has at least one barb-shaped latching arm, as a result of which a secure support can be achieved in a structurally simple manner.
[0014] If the seat component has at least one latching recess, the seat component can be realized in a structurally simple and cost-effective manner, in particular without latching arms. However, it is conceivable also to integrally form latching arms on the seat component and/or to fasten them thereto.
[0015] In a further refinement of the invention, it is proposed that the seating arrangement has at least one means which, at least in the fitted state, is arranged on the fastening means and has a higher coefficient of friction, in particular coefficient of static friction, than a basic body of the fastening means, as a result of which undesirable slipping and vibration noises can be avoided. In this case, the means with the higher coefficient of friction can be formed by a component which is to be additionally fitted, or it can be integrally formed on the fastening means, for example in a multi-component injection molding process. In addition, it is conceivable to provide a corresponding component, in particular a supporting tube, with a corresponding means.
[0016] Furthermore, it is proposed that the seating apparatus has at least one securing means which is provided in order to retain at least one latching means in its latching position. The securing means is preferably formed by a component which is separate from the latching means, but may also in turn be integrally formed on the latching means and/or on the seat component, and is connected to said latching means and/or said seat component, for example, via a film hinge, as a result of which said securing means could be retained captively on the fastening means or on the seat component. By means of a corresponding securing means, an undesirable detachment of a latching connection can be reliably avoided, to be precise in particular if the securing means itself has at least one latching means via which the securing means in turn can be secured in its securing position.
[0017] The solution according to the invention is suitable for all seats appearing expedient to a person skilled in the art, such as for seats for coaches, ferries, halls, convention halls, but advantageously for vehicle seats and particularly advantageously for aircraft seats.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Further advantages emerge from the description below of the drawing. The drawing illustrates an exemplary embodiment of the invention. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and put them together to form meaningful further combinations.
[0019] In the drawing:
[0020] FIG. 1 shows an aircraft seating apparatus according to the invention in a view obliquely from below,
[0021] FIG. 2 shows a cross section through the aircraft seating apparatus according to FIG. 1 in a state fitted on two supporting tubes,
[0022] FIG. 3 shows a seat component of the aircraft seating apparatus obliquely from above,
[0023] FIG. 4 shows a fastening means of a fastening unit of the aircraft seating apparatus from FIG. 1 obliquely from the side,
[0024] FIG. 5 shows the fastening means from FIG. 4 with a securing means in a side view, and
[0025] FIG. 6 shows an enlarged detail from FIG. 5 after the securing means is fitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] FIG. 1 shows an aircraft seating apparatus according to the invention in a view obliquely from below with a seat component 10 formed by a seat base and a fastening unit 12 for fastening the seat component 10 . The fastening unit 12 comprises four structurally identical fastening means 14 which each have four latching means 16 , 18 , 20 , 22 which are provided in order to fasten the seat component 10 .
[0027] In the fitted state, the fastening means 14 is fastened in latching recesses 36 and 38 of the seat component 10 by means of the latching means 16 , 18 , which are formed by barb-shaped latching arms, while the fastening means 14 , in the fitted state, is fastened by means of the latching means 20 , 22 to corresponding components 50 and 52 formed by a supporting tube ( FIGS. 1 , 2 and 4 to 6 ). The latching means 20 , 22 are formed by latching arms which form a C-shaped receiving region for the supporting tube.
[0028] The fastening means 14 is produced in a two-component injection molding process, to be precise the fastening means 14 has a basic body 42 composed of a first plastic and a means 40 , or friction device, which is integrally formed by the two-component injection molding process on an inner side of the latching arms forming the latching means 20 , 22 and is composed of a second, rubber-like plastic which has a higher coefficient of friction with respect to the supporting tubes than the basic body 42 of the fastening means 14 ( FIGS. 4 , 5 and 6 ). By means of the means 40 , a particularly secure support, in particular in the longitudinal direction of the supporting tubes, is advantageously achieved.
[0029] In principle, two fastening means 14 in the front region of the seat component 10 are latched into the front latching recesses 36 and two fastening means 14 in the rear region of the seat component 10 are latched into the rear latching recesses 38 . However, the seat component 10 has more than four latching recesses 36 , 38 , and therefore also more fastening means 14 can be provided and/or in particular the fastening means 14 can also be arranged at different positions depending on spatial boundary conditions.
[0030] In addition to the fastening unit 12 for fastening the seat component 10 to the supporting tubes, the seating apparatus has a further fastening unit 26 which is provided for fastening an upholstery unit 28 on the seat component 10 ( FIGS. 2 and 3 ). The fastening unit 26 comprises touch-and-close means 24 which are fastened on an upper side of the seat component 10 and interact in the fitted state with touch-and-close means (not illustrated specifically) fastened to the upholstery unit 28 . In the fitted state, the fastening unit 12 of the seat component 10 requires a removal force in the main removal directions 30 , 32 of the seat component 10 that is approx. 50% greater than a removal force required in a main removal direction 34 of the fastening unit 26 of the upholstery unit 28 , in which direction, as experience has shown, the upholstery unit 28 is generally removed from the seat component 10 . As a result, the main removal directions 30 , 32 of the seat component 10 arise in the direction in which the latching means 20 , 22 are substantially uniformly deflected during removal and therefore in the direction in which the fastening means 14 can be decoupled from the supporting tubes with as small a force as possible.
[0031] Furthermore, the invention is based on the finding that the upholstery unit 28 is basically pulled off in the front region of the seat component 10 . On the basis thereof, the seat component 10 is configured in the front region in such a manner that, in the fitted state, the front fastening means 14 have a main removal direction 32 which encloses an angle not equal to zero, preferably greater than 5° and particularly preferably greater than 10°, to the main removal direction 34 of the upholstery unit 28 ( FIG. 2 ).
[0032] In the fitted state, the front and the rear fastening means 14 have differing main removal directions 30 , 32 or main removal directions 30 , 32 which enclose an angle not equal to zero, thereby resulting in fitting and, in particular, in removal which are composed of a plurality of differing fitting and removal movements.
[0033] For the fitting, first of all the fastening means 14 are introduced with their latching means 16 , 18 into the latching recesses 36 , 38 , the latching means 16 , 18 being elastically deflected toward each other and subsequently latching behind edges of the latching recesses 36 and 38 . Between the latching means 16 , 18 , the fastening means 14 has an extension 58 which, in the fitted state, reaches between wall parts of the seat component 10 and serves to support bearing forces.
[0034] Subsequently, the latching means 16 , 18 are secured in their latching positions by means of a securing means 44 , or retainer, formed by a U-shaped clamp, as indicated in the rear region in FIG. 2 . For this purpose, the securing means 44 are introduced by their limbs from a side which faces away from the latching means 20 , 22 or from a top side of the seat component 10 between the latching means 16 , 18 ( FIGS. 5 and 6 ). In order to secure the securing means 44 captively between the latching means 16 , 18 , said securing means has, on outer sides of its limbs, latching means 46 , 48 which are formed by extensions and, when the securing means 44 is introduced between the latching means 16 , 18 , interact with latching means 54 , 56 , which are integrally formed on inner sides of the latching means 16 , 18 and are formed by extensions, and latch behind said latching means 54 , 56 .
[0035] Subsequently, the seat component 10 , substantially oriented horizontally such that the main removal direction 32 which has a fixed orientation relative to the seat component 10 is already substantially aligned vertically, is pressed by the front fastening means 14 substantially in the vertical direction onto the front supporting tube, with the latching means 20 , 22 being deflected elastically radially outward and subsequently latching by means of a respective subsection, starting from the seat component 10 in the direction of the front supporting tube, behind the same.
[0036] The seat component 10 is subsequently pivoted about the front supporting tube by the rear fastening means 14 in the direction of the rear supporting tube. The rear fastening means 14 are pressed onto the rear supporting tube, with the latching means 20 , 22 being deflected elastically radially outward and subsequently being latched, by means of a respective subsection, starting from the seat component 10 in the direction of the rear supporting tube, behind the same. Removal takes place in a reverse sequence. When the fastening means 14 are removed from the seat component 10 , the latching means 16 , 18 are deflected elastically toward each other by hand.
REFERENCE NUMBERS
[0000]
10 Seat component
12 Fastening unit
14 Fastening means
16 Latching means
18 Latching means
20 Latching means
22 Latching means
24 Touch-and-close means
26 Fastening unit
28 Upholstery unit
30 Main removal direction
32 Main removal direction
34 Main removal direction
36 Latching recess
38 Latching recess
40 Means
42 Basic body
44 Securing means
46 Latching means
48 Latching means
50 Corresponding component
52 Corresponding component
54 Latching means
56 Latching means
58 Extension
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A seating apparatus, in particular, an aircraft seating apparatus, includes a seating component ( 10 ) and at least one fastener ( 14 ). The fastener ( 14 ) has at least one latch ( 16, 18, 20, 22 ), which is adapted to fix the seating component ( 10 ) to a corresponding support component ( 50, 52 ).
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of patent application Ser. No. 07/550,339, filed Jul. 9, 1990, by Christopher B. Jackson, entitled "Marine Door Movement Control Apparatus" assigned to Condor Marine, Inc. and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains in general to the field of door control apparatus and in particular to the field of movement control of a sliding marine door which is affected by the rolling and pitching of a boat due to movement of the sea or other body of water within which the boat is in operation.
2. Description of the Prior Art
A number of boat designs include a sliding door between the outside deck of the boat and the inside of a cabin. Such sliding doors are frequently utilized on any type of boat or ship which includes a cabin on the deck thereof. In such applications, a sliding door is preferred over a hinged, swinging type of door because of space requirements and the negative aspects of a hinged door suddenly swinging in either direction due to rolling seas. Indeed, a swinging door could severely injure a person when he or she is trying to enter or exit through such door when the rolling of the boat due to rough seas suddenly swings the door toward the person.
While sliding doors are preferred, they are also subject to rapid opening or closing in an unrestrained condition due to rough seas. Thus, when a sliding door is unlatched, it will slide back and forth in its tracks depending upon the rolling or pitching motion of the boat and the location of the door. The result is that the door slams open or closed with a great deal of force. If a person is attempting to pass through the doorway associated with such a sliding door at the same time the boat is rocking, it is very probable that the person will be injured and the boat be damaged by the rapidly moving edge of the door.
In order to negate the force effects of an unrestrained sliding door, the usual practice is to latch the door either in an open or a closed position. Latching of a sliding door is not, however, a complete solution to the problem. For example, when a latched-shut door is unlatched preparatory to being open to allow a person or persons to pass therethrough, the rocking and/or rolling movement of the boat causes the door to move rapidly in either or both directions. To overcome this effect, the person must hold onto the edge of the door in an attempt to control the forceful motion of the door. Frequently, the person himself is trying to maintain his own balance and trying to control the movement of the door at the same time. Often, the result is a clumsy effort which is not successful and the door may slam against some part of the person causing him serious injury.
With the sliding door latched in an open position, passage therethrough in a safe and orderly manner is assured. But, the negative effects of the door always being open exist. The disadvantages of a latched open door during foul or rainy weather conditions is obvious.
The prior art door movement control apparatus is generally designed or intended to be used with a swinging type of door and whereby the door mechanism is biased in one direction and pressure activated in the other direction. For the most part, the door control apparatus intended for use with a swinging door is not adaptable to a sliding door particularly where the swinging door apparatus includes articulated lever arms. In the category of door control apparatus which is adaptable to a sliding door, that is, those door controls which utilize a piston and cylinder which move in an axial direction, such prior art apparatus do not satisfactorily control the motion of a sliding door on a boat. This is because such door apparatus will bias the door in either the open or closed direction while requiring force to move the door in the other direction. Therefore, with this type of door control apparatus, either a shut door or open door condition is imposed and the opposite condition is achieved by overcoming the biased spring force and the hydraulic pressure force. Accordingly, both an opened and a closed door position is not obtainable with the apparatus of the prior art, nor is a partially opened door condition obtainable.
Accordingly, a primary object of the present invention is to provide a sliding door on a boat or ship with control apparatus which renders the door stable in either an open or a closed condition, or any partially opened or partially closed condition therebetween.
Another object of the present invention is to provide a sliding door on a boat or ship with control apparatus whereby a constant force may be used to open or close the door from either position to the opposite position.
Another object of the present invention is to provide a sliding door on a boat or ship with control apparatus which prevents the door from slamming open or closed as a result of rolling or pitching motion of the boat or ship.
The above-stated objects as well as other objects which, although not specifically stated, but are intended to be included within the scope of the present invention, are accomplished by the present invention and will become apparent from the hereinafter set forth Detailed Description of the Invention, Drawings, and the claims appended herewith.
SUMMARY OF THE INVENTION
The present invention accomplishes the above-stated objectives as well as others, as may be readily determined by a fair reading and interpretation of the entire specification, the appended claims and drawings. Door control apparatus is provided by the present invention for use in conjunction with a sliding door and comprises a piston-cylinder combination having unique force-movement characteristics.
An elongated cylinder which is filled with atmospheric air includes a piston and a piston rod which moves axially within the cylinder in accordance with the direction of the force being applied to the door to which the apparatus is attached. The free end of the piston rod is attached either to the door or to the wall which contains the doorway while an opposite end of the cylinder apparatus is attached to the other of the door or the wall, or vice versa. The cylinder is filled with air, not under pressure, and is contained within the cylinder by means of a sealed end cap on one end of the cylinder and a piston rod seal arrangement in the other. The piston rod seal arrangement within the cylinder allows for motion of the piston rod in and out of the cylinder while maintaining the air within the cylinder. The piston includes a pair of seals oriented in opposite directions with a space therebetween. One each of the seals act in the direction which opposes the applied motion of the piston rod. An axial orifice through the piston allows for the transfer of air from one side of the piston to the other side and, therefore, provides for movement of the piston and rod in a direction opposite to the flow of air. A radial orifice is provided in the piston which communicates between the free end of the piston and the space between the pair of piston seals. The radial orifice compensates for the effect of the piston rod in moving the piston in one direction or the other. In this manner, the door control apparatus provides for an equal resistance in either opening or closing the door regardless of the orientation of the piston within the cylinder or the piston and cylinder combination in reference to the door or the wall. Moreover, the axially and radially orificed piston maintains the door in any partially opened or partially closed condition as is desired. The use of air within the cylinder, which is not under pressure and is therefore relatively compressible, imparts a cushioning effect when moving the door in either direction. These advantages are not achievable by the prior art door control mechanisms.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion taken in conjunction with the following drawings, in which:
FIG. 1 comprises an isometric view of a partial portion of a boat having a cabin which utilizes a sliding door for access through a passageway in the wall of the cabin with the inventive apparatus being attached;
FIG. 2 is a front plan view of one embodiment of the door control mechanism, as provided for by the present invention, attached to the door and wall of the cabin of FIG. 1;
FIG. 3 is a top plan view of the door control apparatus of FIG. 2;
FIG. 4 is a front plan view, partially in cross section, of the piston rod seal portion of the inventive door control apparatus of the embodiment of FIG. 2;
FIG. 5 is a front plan view, partially in cross section, of the piston and seal assembly of the inventive control door apparatus of the embodiment of FIG. 2;
FIG. 6 is a front plan view of another embodiment of the inventive movement control door apparatus attached to the door and wall of the cabin of FIG. 1; and,
FIG. 7 is a front plan view, partially in cross section, of the embodiment of FIG. 6 illustrating the piston and seal assembly at one end and the rod seal assembly at the other end.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Reference is now made to the drawings, wherein like characteristics and features of the present invention shown in the various figures are designated by the same reference numerals.
Reference is now made to FIGS. 1 through 3 of the drawings which, taken together, show the use of one embodiment of the inventive door control apparatus 10 as applied to a sliding door of a boat. In FIG. 1 a portion of a boat 11 is shown therein having a cabin 12 attached to the deck thereof. A back wall 16 of cabin 12 includes a doorway 15 which is covered by a sliding door 13 which slides open and closed on rails or tracks 14 at the upper and lower location of the door 13. In FIG. 1 door 13 is shown in the closed position. Door 13 may move sideways in either direction shown by arrows 17. The door control mechanism 10, as provided by the present invention, is seen in FIG. 1 to be attached at one end to the outside of door 13 and at its other end to the wall 16 of cabin 12. Door control apparatus 10 is oriented with the axial center line of piston rod 24 and cylinder 21 oriented in the same direction as the sideways motion of the door 13 in accordance with arrows 17. Door control apparatus 10 may be attached with cylinder 21 attached to door 13 and with piston rod 24 attached to wall 16 or vice-versa.
FIGS. 2 and 3 show an enlarged view of the door control mechanism 10 of FIG. 1. In FIGS. 2 and 3, door 13 and wall 16 are shown as broken portions with the door 13 being in a closed position. Accordingly, cylinder assembly 20 of the control door mechanism 10 is attached to door portion 13 while the free end of piston rod 24 is attached by a shoulder and a nut 28 to bracket 25, which is attached by screws 66, to block 27 which, in turn, is attached to wall 16. The cylinder assembly 20 of door control apparatus 10 is attached to door 13 by brackets 29 in conjunction with screws 26. Brackets 29 may be attached to cylinder 21 such as by welding or other appropriate means. Cylinder assembly 20 includes cylinder 21, a sealed end cap 22 and a rod end cap 23.
Reference is now made to FIGS. 4 and 5 of the drawings, which together show the details of the interior configuration of the door control apparatus 10. In FIG. 4 the details of the piston rod seal assembly 30 are shown in conjunction with one end of cylinder 21 and piston rod 24. End cap 23 is fitted onto the rod end of cylinder 21. Since the rod seal assembly 30 confines the air 31 within cylinder 21, there is no need for a seal between end cap 23 and cylinder 21. End cap 23 may be threadingly connected 32 to the exterior of cylinder 21. A hole 33 through the center of the plate portion of cap 23 allows for passage therethrough of piston rod 24.
Piston rod seal assembly 30 includes a support structure 34 having a threaded 35 outer diameter for threadingly connecting to the inside diameter 36 of cylinder 21. Blind holes 18 provide for screwingly attaching piston rod seal assembly 30 within cylinder 21. A through axial hole 37 in rod seal support structure 34 provides for clearance for the passage therethrough of piston rod 24. A first annular cutout 38 in support structure 34 provides space and a seating surface for seals 41 and 42. Seals 41 and 42 have a outer periphery cross-sectional shape which approximates that of a squared letter "C". Seals 41 and 42 face away from each other and may be in back-to-back contact with each other. Seal 41 comprises a pressure holding seal, while seal 42 comprises a vacuum holding seal.
A second annular cutout 43 axially removed from or spaced from cutout 38 provides for the space of and a seating surface for seal 44. Seal 44 has the same peripheral cross-sectional shape as seals 42 and 43 and is oriented in the same direction as seal 42. Seal 44 comprises a wiper seal to wipe any water or other foreign material from rod 24 as it moves into cylinder 21. Accordingly, rod seal assembly 30 maintains the air 31 within cylinder 21 during periods of operation or even non-operation of the sliding door control apparatus 10. It is to be noted that the air 31 within cylinder 21 is at atmospheric pressure. Thus, when the inventive mechanism 10 is at rest, there is no differential pressure across any of the seals.
FIG. 5 reveals the details of the piston assembly 45 includes piston 50 which is attached to the end of piston rod 24 which is contained within cylinder 21 while moving axially within cylinder 21 in accordance with the movement 17 of door 13. End cap 22 is seen to be required to maintain the air 31 within cylinder 21, hence, it comprises a sealed end cap assembly which is threadingly connected 47 to cylinder 21. In this regard, seal 46 becomes compressed forming a sealing barrier when end cap 22 is fully threaded onto the end of cylinder 21.
Still referring to FIG. 5, piston 50 includes a through hole 51 which may be internally threaded 52 for approximately one-half of its length. The end of piston rod 24 may also be threaded 53 to permit engagement to threads 52 within opening 51 of piston assembly 45. Piston 50 has an outer diameter 54 which is slightly smaller than the inner diameter of cylinder 21 so as to permit non-binding movement of piston assembly 45 within cylinder 21. Piston 50 includes a pair of spaced annular cutouts 55 and 56, each of which provides a location and seating surface for seals 57 and 58, respectively. The overall configuration of seals 57 and 58 is the same as that of seals 42 and 41, respectively, but with seals 57 and 58 being larger in diameter and spaced an axial distance between each of other. Accordingly, the open portion of seals 57 and 58 face away from each other with axial clearance space 59 therebetween. Seal 57 prevents air 31 from passing piston assembly 45 when the motion of piston assembly 45 is in the direction of arrow 61. Seal 58 prevents air 31 from passing piston assembly 45 when the direction of motion of piston assembly 45 is in the direction of arrow 62.
Orifice 63, comprising a relatively small hole provided longitudinally through piston 50, provides for the transfer of air 31 from the left side of the piston assembly 45 to the right side thereof and vice-versa in order to allow piston assembly 45 to move in a direction opposite to the direction of the transfer of air 31. Since cylinder 21 is fixedly attached to door 13 and rod 24 is fixedly attached to wall 16 or vice-versa, the movement of piston assembly 45, relative to cylinder 21, provides for opening, closing, or the partial movement of door 13 relative to doorway 15. Another orifice 64, which, in practice, has been shown to be slightly smaller than orifice 63, is provided radially in piston 50 and between seals 57 and 58. Orifice 64 functions only when piston assembly 45 moves in the direction of arrow 62. Orifice 64 compensates for the volume of air occupied by piston rod 24 within cylinder 21. Thus, a larger, effective orifice (orifice 63 and orifice 64) exists when piston 45 is moving in the direction of arrow 62 as compared to a smaller orifice (solely 63) which operates when piston assembly 45 is moved in the direction of arrow 61.
Still referring to FIG. 5, it is seen that orifice 64 communicates between the through hole 51 in piston 50 and the space 59 between seals 57 and 58. Air 31, which is transferred to within space 59 when piston 45 is moving in the direction of arrow 62, bypasses around the outer periphery of seal 57 and, therefore, no special opening is provided for transferring this flow of air to the left side of piston 45. The cross-sectional squared "c" shape and orientation of seal 57 facing away from air 31 allows the outer surface of seal 57, which is flexible, to relatively easily deflect away from the inner diameter of cylinder 21 when air 31 is flowing through orifice 64 so as to permit the flow of air 31 out of cavity 59.
FIG. 6 illustrates another embodiment of the inventive mechanism 110 being attached to the wall 16 and door 13 of the cabin 12 of boat 11. Cylinder assembly 120, comprising cylinder 121 and end caps 122 and 123, is attached by brackets 129 and screws 126 to door 13. Piton rod 124 is attached by nuts 128 to bracket 125, which, in turn, is attached by screws 166 to block 127 which is attached to wall 16.
FIG. 7 is an enlarged view of the embodiment of the inventive mechanism 110 of FIG. 6. The piston assembly 145 includes a piston 150 which is attached to the end of piston rod 124, and moves axially within cylinder 121 in accordance with the movement 17 of door 13. End cap 122 sealingly functions as in the embodiment of FIG. 5 but is configured differently. A chamfer 170 on the edge of cylinder 121 seals against a similar chamfer on end cap 122. A thread sealant compound may also be used to further assure a sealed joint. End cap 122 is threaded 147 to the inner diameter 136 of cylinder 121. Blind holes 165 allow end cap 122 to be assembled to cylinder 121. Blind holes 165 allow end cap 122 to be assembled to cylinder 121. End cap 123 functions similarly to end cap 23 but is also configured differently. End cap 123 is proportioned to have the same size outer diameter as cylinder 121 and is threadingly connected 135 to the exterior of rod seal assembly 30. Hole 133 through the center of end cap 123 allows for the passage of piston rod 124 therethrough. Holes 169 allow for the drainage of any water trapped between the end of rod seal assembly 130 and end cap 123.
In the embodiment of FIG. 6, a blind hole 151 with threads 152 is provided axially within piston 150 for approximately one-half of its length. A threaded end 153 of piston rod 124 may be threadingly fitted within hole 151 to firmly attach piston rod 124 to piston assembly 145. Annular cutouts 155 and 156 are provided for seals 57 and 58 which provide for a location and a seating surface for seals 57 and 58, respectively. Seals 57 and 58 function in accordance with the movement 61 and 62 of piston assembly 145 as in the embodiment of FIG. 5.
An orifice 163, also comprising a small hole which is provided at one end of a larger axial hole 167 through piston 150 provides for the transfer of air from the left side of piston assembly 145 to the right side thereof and vice versa in accordance with the direction of movement of piston assembly 145. The movement of piston assembly 145 provides for opening, closing, or partial movement of door 13 relative to doorway 15 as in the embodiment of FIG. 5.
Blind axial hole 168 is provided partially through the length of piston 150 beginning at the piston side of air space 31 and extending to approximately the middle of the length of piston 150 between cutouts 155 and 156. A radial orifice 164 is provided between hole 168 and the space 159 between seals 57 and 58. Radial orifice 164 functions in the same manner as orifice 64 in the embodiment of FIG. 5. Seals 57 and 58 in FIG. 7 also functions as seals 57 and 58 in FIG. 5. Thus, orifice 164 is smaller than orifice 163. Blind axial hole 168 may be larger than orifice 164 so that the size of orifice 164 controls the transfer of air from the right side of piston assembly 145 past seal 57 to the left side of piston assembly 145 when piston assembly 145 moves in the direction of arrow 62.
Thus, in all respects, the embodiment of FIG. 6 functions the same as the embodiment of FIG. 2 as regards the movement of and the force required to move door 13.
In accordance with the above, an equal, steady force, but in opposite directions, may be applied to door 13 in order to either open or close door 13. For example, in order to close door 13, (assuming that the boat is not rocking sideways) a person would apply a steady force to the door in a direction to the right (FIG. 5). This causes the cylinder 20 to move to the right (FIG. 5). The air 31 on the left side of piston assembly 45 must, therefore, in part, be displaced to the right side (FIG. 5) for the cylinder 20 to move to the right. This is accomplished by the air 31 being transferred from the left to the right through orifice 63 and continues to be so transferred as long as the person applies the steady force to the door 13 to the right. The amount of the steady force needed is proportional to the cross-sectional area of air to be transferred, i.e. the cross-sectional area of the piston 30 less the cross-sectional area of the rod 24. To move the door 13 to the left and to open the door 13, the person applies a steady force to the door 13 to the left (FIG. 5). The force applied in this instance is again proportional to the cross-sectional area of the air transferred; but, in this instance, includes the cross-sectional area of rod 24. This is accomplished by the extra air being transferred through orifice 64, into space 59 and past seal 57 as well as by the air being transferred through orifice 63. Because of the extra flow path of the air (through orifice 64) when moving the door to the left, the same steady force is applied to the door as required to move the door 13 to the right. While any rocking back and forth (sideways) of the boat might affect these forces, the effect would not be significant. Moreover, this equal force is applicable regardless of the initial location of door 13 within doorway 15. Also, since there is no biasing force (spring or otherwise) present within door control apparatus 10 or 110, door 13 will remain in any position in which it is placed unless acted upon by a substantial external force. Thus, for all intents and purposes, normal rolling or pitching of a boat within waters will not cause door 13 to materially open further or close further from the then position of door 13. During rough weather conditions, however, door 13 may open or close slowly of its own accord to some degree, but will not slam open or closed. The size of orifices 63 and 64 and 163 and 164 determine the amount of force necessary to either open or close door 13.
While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the scope of the breadth and scope of the claims here appended.
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Door control apparatus is provided for a sliding door for use with a boat or a ship. The door control apparatus is unbiased in either direction and will substantially maintain any position in which it is placed, except during extreme rolling or pitching of the boat or ship due to heavy weather conditions. The door control apparatus provides for equal but opposite force to open the door as to close the door. The door control apparatus includes piston and cylinder means with fixed orifices. Other than the piston its associated parts, there are no moving parts to the mechanism.
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This divisional application claims priority under 35 U.S.C. § 120 from U.S. patent application Ser. No. 10/873,798 filed on Jun. 22, 2004 now U.S. Pat. No. 7,261,173 by Robert D. Kurtz Jr., et al. with the same title, the full disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention generally relates to skid steer vehicles. More particularly, it relates to rear doors for skid steer vehicles.
BACKGROUND OF THE INVENTION
Skid steer vehicles such as skid steer loaders are a mainstay of construction work. In their most common configuration, they have two drive wheels on each side of a chassis that are driven in rotation by one or more hydraulic motors coupled to the wheels on one side and another one or more hydraulic motors coupled to the wheels on the other side.
The wheels on one side of the vehicle can be driven independently of the wheels on the other side of the vehicle This permits the wheels on opposing sides of the vehicle to be rotated at different speeds and in opposite directions. By rotating in opposite directions, the skid steer can rotate in place about a vertical axis that extends through the vehicle itself.
The vehicles have an overall size of about 10 by 12 feet, which, when combined with their ability to rotate in place, gives them considerable mobility at a worksite. It is this mobility that makes them a favorite.
Skid steer vehicles commonly have at least one loader (or lift) arm that is pivotally coupled to the chassis of the vehicle to raise and lower at the operator's command. This arm typically has a bucket, blade or other implement attached to the end of the arm that is lifted and lowered thereby. Most commonly, a bucket is attached, and the skid steer vehicle is used to carry supplies or particulate matter such as gravel, sand, or dirt around the worksite.
As a counterbalance to the loads provided at the front of the vehicle, skid steer vehicles typically have an engine that is located behind the operator. The radiator is also commonly disposed behind the operator, usually at the center rear of the vehicle.
A door or other access hatch is located at the very back of the vehicle to give the operator access to the engine and radiator from the very rear of the vehicle. Other doors and hatches may be disposed down the side of the vehicle or engine compartment instead of the rear to provide additional access.
One difficulty with rear engine access doors is their susceptibility to impact. Skid steer vehicles typically have a restricted view to the rear, preventing the operator from seeing behind the vehicle. Skid steer vehicles also spend a substantial amount of time traveling in reverse is close quarters. Skid steer vehicles are often operated in a rapid back-and-forth movement, making what are called “Y turns” as they move material from one pile to another perhaps several hundred times a day.
As a result, operators often misjudge the distance between the rear of the vehicles and obstacles and occasionally back skid steer vehicles into these obstacles, albeit at very slow speeds. Whenever a skid steer with a rear engine compartment door impacts an obstacle it is the door that suffers.
Even when the door is not damaged, however, the door hinges an the door latch may be damaged. The forces involved may not be great enough the actually damage the door itself, but it is often significant enough to tear or bend the hinges and latch, thereby either removing the door entirely, or jamming the door shut in its closed position
What is needed, therefore, is an improved skid steer vehicle having a door that is resistant to being damaged. What is also needed is a skid steer vehicle with a means for protecting the door hinges from upward rear impacts. What is also needed is a skid steer door that automatically protects the hinges without requiring additional operator input. What is also needed is a means for transmitting potentially damaging forces acting against the rear door directly to the frame or chassis. It is an object of this invention to provide these advantages. While not every claimed aspect of the invention provides all these advantages, each of these advantages is provided by at least one claimed aspect.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a rear door and chassis interlock for a skid steer vehicle is provided, including a first elongated and laterally-extending beam fixed to a door frame of the rear door of a skid steer vehicle, the first beam having a generally horizontal and upwardly-facing surface; and a second elongated and laterally-extending beam fixed to a rear chassis of the skid steer vehicle, the second beam having a generally horizontal and downwardly facing surface; wherein the upwardly-facing surface and the downwardly-facing surface interlock over substantially their entire lateral extent to reduce upward movement of the rear door with respect to the chassis.
The second beam may be fixed to and extend between two elongated chassis members disposed on either side of the engine. The first and second beams may extend substantially the entire width of a rear-facing opening of an engine compartment and may be interlocked over substantially the entire width of the opening, The first beam may have a box structure and may include an “L”-shaped angle bracket fixed to a forward surface thereof, and the angle bracket may extend laterally across the vehicle and may have the generally horizontal and upwardly-facing surface that is configured to interlock with generally horizontal and downwardly facing surface of the second beam The upper surface of the angle bracket may extend across substantially the entire width of the engine compartment. The first beam may include a generally vertical, forward-facing and laterally extending surface to which the angle bracket is fixed, the forward-facing surface may have a first surface portion that extends above the angle bracket that may be spaced closely enough to a rearward edge of the second beam to transmit the force of forward impacts to the second beam. The first and second beams may be spaced a distance apart sufficient that they engage one another when the door is lifted before hinges supporting the door on the vehicle and a latch holding the door closed are damaged.
In accordance with a second aspect of the invention, a rear engine compartment for a skid steer vehicle is provided, including a left sidewall, a right sidewall, and a top wall that are fixed to a chassis of the skid steer vehicle and are disposed to enclose the engine an define a rear opening to the engine compartment; a first elongated and laterally-extending beam fixed to the chassis, the first beam having a generally horizontal and downwardly facing surface extending from the rear opening; and a rear door pivotally coupled to a chassis of the vehicle, the door including a door frame and a second elongated and laterally-extending beam fixed to the door frame, the second beam having a generally horizontal and upwardly-facing surface, wherein the rear door is disposed to cover the rear opening and is supported by two hinges and a latch; wherein the upwardly-facing surface and the downwardly-facing surface interlock over substantially their entire lateral extent to reduce upward movement of the rear door with respect to the chassis.
The first beam may be fixed to and extend between two elongated chassis members disposed on either side of the engine. The first and second beams may extend substantially the entire width of the rear opening, and may be interlocked over substantially the entire width of the opening. The second beam may have a box structure and includes an “L”-shaped angle bracket fixed to a forward surface thereof, and the angle bracket may extend laterally across the vehicle and may have the generally horizontal and upwardly-facing surface that is configured to interlock with generally horizontal and downwardly facing surface of the first beam. The upper surface of the angle bracket may extend across substantially the entire width of the engine compartment. The second beam may include a generally vertical, forward-facing and laterally extending surface to which the angle bracket is fixed, and the forward-facing surface may have a first surface portion that extends above the angle bracket that is spaced closely enough to a rearward edge of the first beam to transmit the force of forward impacts to the first beam. The first and second beams may be spaced a distance apart sufficient that they engage one another when the door is lifted before hinges supporting the door on the vehicle and a latch holding the door closed are damaged.
In accordance with a third aspect of the invention, a rear chassis for a skid steer vehicle is provided, including a rear door including a door frame and a first elongated and laterally-extending energy-transmitting beam transversely fixed to the bottom of the door frame, the first beam having a generally horizontal and upwardly-facing surface; and a rear chassis including left and right longitudinally extending frame members, and a left side panel, right side panel and top panel fixed to the frame members to enclose the engine, the rear chassis also including a second elongated and laterally-extending beam, the second beam having a generally horizontal and downwardly facing surface; wherein the rear door is pivotally coupled to one side of the engine compartment with hinges, and further wherein the door is secured in a closed position by a latch; and wherein the upwardly-facing surface and the downwardly-facing surface interlock over substantially their entire lateral extent to reduce upward movement of the rear door with respect to the chassis.
The second beam may extend across a rear engine compartment opening that is defined between the left and right side panels and the top panel. The first and second beams may extend substantially the entire width of rear engine compartment opening and may be interlocked over substantially the entire width of the opening. The first beam may have a box structure and may include an angle bracket fixed to a forward surface thereof, and the angle bracket may extend laterally across the door frame and may define the generally horizontal and upwardly-facing surface. The upper surface of the angle bracket may extend across substantially the entire width of the opening. A portion of the first beam may be disposed slightly forward of a portion of the second beam to reduce door damage by transmitting the force of forward impacts from the door to the second beam. The first and second beams may be spaced a distance apart sufficient that they engage one another when the door is lifted before hinges supporting the door on the vehicle are damaged.
Numerous other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left side view of a skid steer vehicle in accordance with the present invention.
FIG. 2 is a fragmentary left side perspective rear view of the vehicle of FIG. 1 with the rear door closed.
FIG. 3 is a fragmentary left side perspective rear view of the vehicle of FIGS. 1 and 2 with the rear door open showing the chassis interlock and the inner door construction including the hinges, louvers and latches.
FIG. 4 is a fragmentary detailed perspective view of the upper hinge area of the vehicle shown in FIG. 3 .
FIG. 5 is a fragmentary cross-sectional view of the rear door and chassis of the vehicle of the foregoing FIGURES when the door is in the closed position as shown in FIGS. 1 and 2 taken along section line 5 in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the present invention is susceptible of being made in any of several different forms, the drawings show a particularly preferred form of the invention. One should understand, however, that this is just one of many ways the invention can be made. Nor should any particular feature of the illustrated embodiment be considered a part of the invention, unless that feature is explicitly mentioned in the claims. In the drawings, like reference numerals refer to like parts throughout the several views.
Referring now to the FIGURES, there is illustrated a skid steer vehicle 100 . The vehicle includes a chassis 102 on which are mounted four wheels (two shown) 104 . These wheels are disposed two on each side in a fore-and-aft relationship. All the wheels are drive wheels, driven by engine 106 that is disposed in a rear engine compartment 108 of vehicle 100 .
Engine compartment 108 encloses engine 106 , surrounding it on all four sides as well as its top. A rear engine compartment door 110 encloses the rear of the engine compartment and protects a transversely-mounted rear radiator 112 that is fixed to the chassis behind the engine.
The engine compartment 108 includes a top panel 114 , a left side panel 116 , and a right side panel 118 . These panels enclose not only the engine 106 , but the radiator 112 as well. The left panel is fixed to and supported by an elongated and longitudinally-extending left side chassis member 160 which can be seen best in FIG. 1 . The right panel is fixed to and supported by an elongated and longitudinally extending right side chassis member 136 that is configured identically to left side chassis member 160 , but is disposed along the right side of the chassis and is configured as a mirror image of member 160 . Chassis members 160 and 136 extend backward along both sides of engine 106 , which is fixed to both members.
Door 110 seals against top panel 114 as well as side panels 116 , and 118 to provide protection both from the elements and from rigid objects that might damage the engine and radiator if the operator backs vehicle 100 backs up into them.
Door 110 is in the form of a rectangular frame 120 having a central rectangular opening 122 . Opening 122 is covered with louvers 124 that are disposed vertically across the aperture formed by the opening. These louvers can be pivoted about their longitudinal axes to abut one another and close opening 122 , or alternatively to open and permit air to pass therethrough. In this manner, the operator can regulate the amount of cooling provided by the radiator, which is disposed right behind door 110 .
Door 110 is supported by two hinges, an upper hinge 126 and a lower hinge 128 . The upper hinge includes two hinge plates 130 , 132 ( FIG. 4 ), and a pin (not shown) pivotally coupling the two plates together. Hinge plate 130 is bolted to a vertical member 134 that in turn is bolted to right side chassis member 136 . Plate 132 is fixed to door frame 120 and pivots together with the frame of the door when the door is opened.
Referring now to FIGS. 3 and 4 , latch 138 is pivotally coupled to door frame 120 . It holds the door open in a first position, and permits the door to be closed in a second position. Latch 138 is pivotally mounted to door 110 by a bolt 140 . As the door is opened, hinge plate 132 , which is fixed to the door frame, pivots about hinge plate 130 , which is fixed with respect to the chassis. Latch 138 pivots together with plate 132 and the door as the door is opened, with its tang 141 sliding along the top outer edge 142 of plate 130 .
Latch 138 offers no resistance to this door opening, until the door is almost completely open (as shown in FIGS. 3 and 4 ), at which point a slot 144 in plate 130 moves underneath latch 138 . Slot 144 is just wide enough to receive the outwardly extending tang 141 . The weight of tang 141 unbalances latch 138 , causing it to fall of its own weight into slot 144 .
Latch 138 is shown in two positions in FIG. 4 : a first unlatched position “A” shown in phantom lines, and a second latched position “B” shown in solid lines. Position “B” illustrates how the latch would appear when it has rotated about 90 degrees clockwise under the force of gravity. The latch is configured such that it is not perfectly balanced when in position “A”, but is top heavy. The top heavy position is determined by the location of the hole in latch 138 through which bolt 140 passes. This hole is located such that latch 138 is not only top heavy, but tends to rotate in a clockwise direction (in FIG. 3 ), supported by top edge 142 of plate 130 .
Lower hinge 128 similarly includes two plates 146 , 148 and a pin 149 pivotally coupling the two plates together. These plates and pin are identically arranged to those of the upper hinge. Hinge plate 146 is bolted to vertical member 134 . Plate 148 is fixed to door frame 120 and pivots together with the door frame when the door is opened.
The door hinges are preferably arranged so that the entire door may be removed from the vehicle by lifting the door upward until the hinge pins of the upper and lower hinges are removed from their corresponding hinge plates. The operator can stop the vehicle, open the door, lift the door upward from the bottom, and remove the door from vehicle 100 .
A spring loaded door latch 150 is fixed to the opposite side of the door as hinges 126 , 128 . It has a catch 152 that grasps a rod 154 extending from striker plate 156 . Striker plate 156 is bolted to vertical member 158 that, in turn, is bolted to chassis member 160 . The engagement of catch 152 and rod 154 prevents the door both from being opened and from being lifted off its hinges. When an upward force is applied to the closed door the catch and rod interengage to prevent the door from moving upward.
While the catch and rod are sufficiently strong to resist the force of one or two people trying to lift the closed door upward off its hinges, they may not be sufficient to prevent a substantial upward blow to the bottom of the door from lifting the door upward and either damaging the catch and rod, or damaging both the catch and rod, and the hinges, too.
To resist these more forceful blows or impacts from lifting the door and damaging the various door components, additional support structures are provided. These support structures include mechanically interengaging (or interlocking) members that resist the relative upward movement of the door with respect to the rest of the vehicle. These members are located at the bottom of the engine compartment opening and extend across the entire width of the opening.
These additional support structures are provided on both door and the chassis. They are configured to interlock automatically whenever the door is closed and disengage automatically whenever the door is opened. No additional operator activity is required to interlock these structures.
FIGS. 3 and 5 show these structures in particular detail. In FIG. 3 , they are shown as they would appear when the door is open and the structures are not mutually interengaged. In the positions shown in FIG. 3 , the door can be lifted off the vehicle without damaging the door or the vehicle itself.
FIG. 5 shows the additional support structures as they are positioned when the door is closed. In FIG. 5 they are shown interlocked to resist the upward movement of the door.
Referring now to FIGS. 3 and 5 , the structures include a first beam member 162 that is fixed to an inner surface of door frame 120 just below door opening 122 . Member 162 may be permanently or removably fixed to door frame 120 , such as by welding or bolting the member thereto.
Member 162 extends laterally, side-to-side, across the entire width of the engine compartment opening. It has the form of an L-shaped beam comprised to two major planar portions: a first planar portion 164 extending horizontally that is fixed along its laterally extending leading edge 166 to a vertically and laterally extending planar beam portion 168 having a top edge portion 169 that is fixed to edge 166 .
Member 162 is fixed to a second beam member 170 that also extends laterally, side-to-side and is in turn fixed to the inner surface 172 of the lower portion of door frame 120 just below opening 122 . Beam member 170 includes a first planar portion 174 that extends generally horizontally and laterally within door frame 120 . It also includes a second planar beam portion 176 that extends generally laterally and vertically within door frame 120 . Planar beam portions 174 and 176 are fixed together along a rearward and laterally extending edge 178 of beam portion 174 and along a bottom and laterally extending edge 180 of beam portion 176 .
Beam portion 176 generally follows the contours of the inside rear surface 172 of door frame 120 just below door opening 122 . Beam portion 176 preferably abuts and is fixed to the inside surface of door frame 120 over substantially its entire width to provide a relatively large area of support for the lower portion of the door. Since the lower portion of the door typically impacts such things as piles of dirt, sand, or rock first, it is the most prone to damage. Locating the beam members along (and fixing the beam members to) this lower portion of the door, provides particularly good protection against door damage.
While we describe edges 178 and 180 above as being fixed together, they need not be formed separately and then fixed together, but may be formed integrally from a single sheet of metal that is bent to form a laterally extending bend 182 that defines the junction between beam portions 174 and 176 .
Similarly, beam member 162 may be formed from a single sheet of metal that is bent, thereby forming a laterally extending bend 184 at the junction of beam portion 164 and beam portion 168 .
Beam member 162 and beam member 170 together form a generally rectangular box beam, having an internal, laterally extending, and generally rectangular hollow 186 . This arrangement enhances the individual strength of beam members 162 and 170 .
Beam member 162 and beam member 170 are fixed together to provide additional strength for the lower portion of door frame 120 and additional resistance to deformation when the door is impacted. As shown in FIG. 5 , the two are fixed together by a weldment 187 that extends laterally, from side-to-side, inside door frame 120 . While a weldment is preferred, the two components may be removably fixed together with bolts, for example. This arrangement can be employed to permit each beam to be more easily mounted to the door or to permit each beam to be adjusted with respect to the other.
A third component of the additional support structures is an elongated and laterally extending edge member 188 that is fixed to a forward facing vertical surface 190 of beam member 162 . Edge member 188 includes a horizontally and laterally extending portion 192 , shown here as a planar and linearly extending flange, that is coupled to a vertically and laterally extending portion 193 , also shown as a planar and laterally extending flange.
Member 188 has a generally “L”-shaped form, commonly known as “angle iron” or “angle bracket” that is comprised of flanges 192 and 193 , the two flanges being joined at right angles to one another along an upper edge of flange 193 . Vertically extending flange 193 is fixed to vertical and forward facing surface 190 of member 162 , preferably by welding.
Portion 192 has an upper surface 194 that is surmounted by an elongated interlocking member 196 . Interlocking member 196 is shown in the FIGURES as a horizontally disposed planar sheet of steel that extends outward from the rear opening 198 ( FIG. 5 ) of the engine compartment. Member 196 extends laterally across the engine compartment from one side to the other. Member 196 is fixed to and between the two elongate chassis members
When door frame 120 is closed, member 196 is disposed immediately adjacent to and slightly above upper surface 194 of horizontally and laterally extending portion 192 of edge member 188 . In this position, member 196 cooperates with surface 194 to prevent the door from moving upward when an upward force is applied to the door and he door is closed.
Member 196 and portion 192 extend substantially the entire distance across the engine compartment opening 198 . This arrangement distributes the upward force of any door impact over substantially the entire width of the door, and over substantially the entire length of members 162 and 170 .
Just as the additional support structures reduce damage to the door from being forced upward, they also reduce damage to the door by being forced forward and inward toward the engine compartment opening 198 . When the door receives an impact that drives the door forward and generally into the engine compartment, vertically and laterally extending beam portion 168 of beam member 162 is forced forward against the rear edge 200 of member 196 . This transfers the load on the door to the member 196 which is fixed to the vehicle chassis. When this impact occurs, edge 200 engages surface 190 of beam member 162 over substantially the entire width of the engine compartment opening.
The door is positioned by adjusting the positions of the hinges and the latch. For this reason, a narrow gap 202 is provided between rear-facing edge 200 and the forward-facing surface 190 of beam member 162 . A similar narrow gap 204 is provided between upper surface 194 and the bottom surface of member 196 . These two gaps extend laterally across the width of the engine compartment opening. The width of each gap 202 , 204 is preferably the same across the entire width of the engine compartment.
From the foregoing, it will be observed that numerous modifications and variations can be effected without departing from the true spirit and scope of the novel concept of the present invention. It will be appreciated that the present disclosure is intended as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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An interlock for a skid steer vehicle with a rear engine compartment and a rear door to that compartment includes a beam that is mounted transversely to the bottom of the door and has an upward facing surface that, like the beam, extends across the entire rear engine compartment opening. An interlocking second member is fixed to the chassis and extends across the rear engine compartment opening. When the door is impacted and forced upward, the first beam engages the second interlocking member over its width and transfers the force from the door (and beam) to the chassis When the door is impacted with a forward-directed force, the first beam also contacts the second member and transfers the forward forces through the second member to the chassis. Injury to the door is reduced or eliminated by transferring door impact forces to the chassis since the first beam extends substantially the entire distance across the door and is fixed to an inner surface of the door's frame.
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FIELD OF THE INVENTION
The present invention relates to compositions of matter having utility in maintaining oral health. It also relates to methods of making such compositions, and the incorporation of same into pharmaceutically suitable vehicles for use in oral health care. More particularly, the invention relates to diacyl derivatives of arginine, optionally in combination with fluoride compounds, and their utility in maintaining oral health.
BACKGROUND OF THE INVENTION
It has been shown that tooth decay and dental disease can be attributed to bacteria forming plaque about the teeth. Growth and proliferation of bacteria is enhanced by the presence of entrapped food particles between the teeth. The removal of plaque and entrapped food particles reduces caries, reduces the tendency towards gingivitis, and reduces mouth odor as well as generally improving oral hygiene.
The prior art recognizes mechanical oral hygiene devices serving to clean the mouth of debris and remove plaque from teeth, such as toothbrushes, flosses, and toothpicks. It also recognizes compositions mostly used in conjunction with such devices but which impart a chemical action in cleaning teeth, such as dentifrices and rinses. In addition to these, various dental coatings and sealants have been applied to teeth as barriers against bacterial action and plaque formation. Another important approach in oral care includes the use of various fluoride-containing preparations which are able to deposit fluoride ions directly onto the surface of tooth enamel. While great advances were made in oral health care by the use of these various approaches, none seem to be completely effective.
A more recent approach to improved oral hygiene involves the recognition that bacteria present in the oral cavity metabolize dietary sugars, such as glucose and sucrose, to organic acids, such as acetic, propionic and lactic acids. The production of these acids results in a rapid drop in plaque pH. If the pH drops to a level of about 5.5 or below and remains there for more than a short period of time, the tooth enamel will begin to demineralize. This process, if repeated over a substantial period of time, will eventually lead to the development of caries. To correct for the pH drop, the saliva contains a pH-rise factor which moderates the extent and duration of the pH drop when glucose and sucrose are metabolized by oral bacteria. This factor was identified as an arginine-containing tetrapeptide. See, for example, Kleinberg, I., Kanapka, J. A., and Craw, D. "Effect of Saliva and Salivary Factors on the Metabolism of the Mixed Oral Flora" Microbial Aspects of Dental Caries, Vol. II, pp. 433-464 (1976). This pH-rise factor is believed to enter the bacterial cell and either neutralize the organic acids as they form or alter bacterial metabolism so that the acids are not produced.
DISCUSSION OF THE PRIOR ART
U.S. Pat. No. 2,689,170 to King, entitled "Oral Preparation for Inhibition of Dental Caries", discloses oral preparations for inhibition of dental caries having as the active ingredient a saturated higher series of alkyl acyl amide of a saturated aliphatic monoaminocarboxylic acid compound.
U.S. Pat. No. 4,154,813 to Kleinberg, entitled "Means and Method for Improving Natural Defenses Against Caries", discloses a method for supplementing the body's resistance to caries by providing a pH-rise factor which is a peptide of 2-4 amino acid units, one or more of which is arginine.
U.S. Pat. No. 4,225,579 to Kleinberg, entitled "Means and Method for Improving Defenses Against Caries", claims peptides of 2-4 amino acid units, one or more of which is arginine, for combatting caries. These arginine-containing peptides are disclosed to penetrate dental plaque and bacteria in the mouth and to counteract acid produced as a result of metabolism of carbohydrates.
British Pat. No. 1,352,420 to Yoshinaga et al, entitled "Novel Arginine Derivatives, Their Production and Their Use", discloses N.sup.α -acylarginines having antibacterial or germicidal properties for use in oral hygiene.
U.S. Pat. No. 3,809,759 to Bocher and Faure, entitled "Pharmaceutical Composition for Treating Mental Fatigue Containing Arginine-Potassium Phospho-citro-glutamate and Method of using the Same", discloses arginine-potassium phospho-citro-glutamate in pharmaceutical compositions, such as, granules, pills, tablets, and capsules for systemic treatment of mental fatigue.
U.S. Pat. No. 4,061,542 to Demny and Maehr, entitled "2-Methyl-L-Arginine produced by Cultivating Streptomyces Strain", discloses the title compound for use as an antibiotic and antibacterial agent.
U.S. Pat. No. 4,125,619 to Okamoto et al, entitled "N.sup.α -Naphthalenesulfonyl-L-Arginine Derivatives and the Pharmaceutically Acceptable Acid Addition Salts Thereof", discloses the title compounds for use as pharmaceutical agents for the inhibition and suppression of thrombosis.
Some long-chain N G -acyl derivatives of arginine are described in the chemical literature. See for example, Guttmann, St. and Pless, J. "On the Protection of the Guanidino Group of Arginine", Acta Chim Acad. Sci. Hung 44 (1-2), 23-30 (1965). The acyl groups are temporarily placed on the arginine molecule at the N G -position and serve as temporary blocking or protecting groups which are subsequently removed from the N G -position when the appropriate substituents are placed on the N.sup.α -position of arginine. These blocking groups thus serve to protect the N G -position from chemically reacting while the nitrogen atom at the N.sup.α -position participates in the chemical reaction.
The compounds of the present invention differ from the aforementioned prior art in that we use new and novel derivatives of arginine in which the polar character of the arginine molecule is modified by the presence of lipid-like substituents. This modification is believed to permit such arginine derivatives to more readily penetrate the phospholipid-containing cell wall of oral bacteria and to inhibit acid production of these bacteria.
Accordingly, one object of the present invention is to provide new and novel derivatives of arginine.
Another object of the present invention is to provide compositions containing an arginine derivative for use in oral applications.
Still another object of the present invention is to provide compositions containing an arginine derivative in combination with a fluoride compound for use in oral applications.
It is still a further object of the present invention to provide methods of preparing such compounds and compositions.
SUMMARY OF THE INVENTION
Oral compositions of the present invention comprise N.sup.α, N G -disubstituted acyl derivatives of arginine of the formula: ##STR1## where y is an integer from 0 to about 28, preferably from about 4 to about 18, and most preferably from 8 to 14.
The N.sup.α,N G -diacyl derivatives of arginine where y is not more than about 18 are preferred since these derivatives possess greater activity against oral bacteria than the higher members of the series.
In general N.sup.α,N G -diacylarginines may be prepared by dissolving L-(+)-arginine in a solution of 3 parts water and 2 parts acetone, and thereafter simultaneously adding sodium hydroxide and a solution of an aliphatic acid chloride and reacting the mixture at room temperature. The mole ratio of the L-(+)-arginine to the aliphatic acid chloride must be 1:2. The reaction is allowed to proceed at room temperature for about 24 hours whereafter the product is precipitated by adjusting the pH to 6 with glacial acetic acid. The precipitate is collected and recrystallized from an organic solvent such as methanol or ethanol.
The present invention also encompasses pharmaceutically acceptable salts of the N.sup.α,N G -diacyl derivatives of arginine such as those formed by reaction of an organic or inorganic base with the acidic (--COOH) portion of the diacylarginine molecule, and those formed by reaction of an organic or inorganic acid with the guanidino portion of the acylarginine molecule. Typical salts are those of the formula ##STR2## wherein y is an integer of from 0 to about 28; M is H, Na, K, Mg, Ca, Ag, Ce, Mn, Zn or the residue of a strong organic base; n is 0 or 1; and HX is HCl, HNO 3 , H 2 SO 4 , CH 3 COOH or gluconic acid ##STR3##
The present invention provides oral compositions of an N.sup.α,N G -diacyl derivative of arginine in the form of a mouthwash, spray, dentrifice, gel, powder, solution, lotion, varnish, lozenge, chewing gum, slow releasing device and the like for use in oral hygiene in combatting bacteria and to increase pH of the oral fluids.
The present invention further provides oral compositions of N.sup.α,N G -diacyl derivatives of arginine with a fluoride compound, such as, sodium fluoride, zinc fluoride, stannous fluoride, sodium monofluorophosphate, acidulated phosphate fluoride, ammonium fluoride, ammonium bifluoride and amine fluoride.
DETAILED DESCRIPTION OF THE INVENTION
The process for preparing compounds of this invention and oral compositions comprising such compounds are illustrated by the following specific examples, which are not intended to be limiting of the invention.
EXAMPLE 1
N.sup.α,N G -dilauroylarginine
Two grams (0.01148 mole) of L-(+) arginine were dissolved in a solution of 30 ml of water and 20 ml of acetone. To this solution were added, at room temperature, 10 ml of a 5M sodium hydroxide solution, followed immediately by the addition of one-half of a solution prepared by dissolving 5.02 gram (0.02296 mole) of lauroyl chloride in 10 ml of acetone. Fifteen minutes later, identical portions of the sodium hydroxide and lauroyl chloride solutions were added. The reaction mixture was allowed to stir overnight. The pH of the reaction mixture was then adjusted to 6 with glacial acetic acid which resulted in the precipitation of a white solid. The solid was collected by filtration and was washed with water. The washed solid then was air-dried and recrystallized from chloroform-acetone. The yield of N.sup.α,N G -dilauroylarginine having the formula below was 0.980 gram (24.4%). ##STR4## Exactly the same procedure was used to prepare the following N.sup.α,N G -diacyl derivatives of arginine:
N.sup.α,N G -dioctanoylarginine: (C 8 )
N.sup.α,N G -didecanoylarginine: (C 10 )
N.sup.α,N G -dimyristoylarginine: (C 14 )
N.sup.α,N G -dipalmitoylarginine: (C 16 ).
Representative compounds of the present invention were assayed to determine their effectiveness in reducing acid production from sugar by S. mutans as a measure of their efficacy in oral compositions.
ASSAY FOR INHIBITORS OF GLYCOLYSIS
This assay measures the rate of acid production from the metabolism of sucrose by Streptococcus mutans 6715. The assay solution consists of 10.00 ml of a phosphate buffer at pH 5.5 under nitrogen. To this solution are added 8×10 9 cells of S. mutans 6715, followed by 50 μl of 25×10 -3 M sucrose. A known volume of a 10 mg/ml solution of the test arginine derivative is then added, and the rate of acid production is monitored with the automatic addition of a 5×10 -3 N KOH solution by a pH-stat.
Table I illustrates acid inhibition activity of the indicated compounds in terms of the concentration of compound required to effect a 50% reduction in the rate of acid formation.
TABLE I______________________________________ ConcentrationArginine Derivative (W/V %)______________________________________N.sup.α,N.sup.G --didecanoylarginine 1.0N.sup.α,N.sup.G --dilauroylarginine 0.45N.sup.α,N.sup.G --dimyristoylarginine 1.0______________________________________
Oral compositions of the present invention include the combination of N.sup.α,N G -diacyl derivatives of arginine with a fluoride compound, e.g. sodium fluoride, zinc fluoride, stannous fluoride, sodium monofluorophosphate, acidulated phosphate fluoride, ammonium fluoride, ammonium bifluoride and amine fluoride. In general, the N.sup.α,N G -diacyl derivative of arginine should be present in an effective amount up to a saturated solution, while the fluoride ion should be present from as low as 0.0001% to 10%.
The preferred concentration of N.sup.α,N G -diacyl derivative of arginine is 0.05 to 10%, while that of the fluoride ion is 0.001 to 1.0%. The most preferred concentration of the arginine derivative is 0.5 to 5%, and the fluoride ion, 0.01 to 0.1%. While higher concentrations of both N.sup.α,N G -diacyl derivatives of arginine and fluoride ions could be used, no particular advantage is afforded thereby.
While it is presently preferred to have a polyol-containing aqueous vehicle as an acceptable carrier for the above composition, other nonaqueous compositions are not excluded from the list of suitable carriers, as for example various alcohols, polyols, and dimethylsulfoxide.
The composition of this invention may be in the form of a mouthwash, spray, dentifrice, gel, powder, solution, lotion, varnish, lozenge, chewing gum, slow releasing device or other forms suitable for oral application. Any pharmaceutically acceptable materials such as those ordinarily used in such oral compositions that are compatible with N.sup.α,N G -diacyl derivatives of arginine and fluoride ions may be employed in the compositions of this invention.
In accordance with the present invention, the compositions are supplied to teeth with an appliance, e.g., toothbrush, swab, impregnated dental floss and the like by gently brushing the teeth, both the buccal and linqual sides, at least once daily. The most preferred application of the above compositions to teeth is from lozenge and from chewing gum, whereby one slowly dissolves the lozenge in the mouth over 10 to 15 minutes, and by chewing the gum over 30 to 45 minutes after each meal.
The following examples will further serve to illustrate typical oral compositions of this invention.
EXAMPLE 2 (Mouthrinse)
______________________________________ w/w %______________________________________Glycerol, U.S.P. 10 to 40N.sup.α,.sup.G --diacylarginine 0.1 to 5NaF 0.2Flavors 1.0Preservatives 0.3Pluronic F-108 2.0Water, q.s. to 100 parts______________________________________
The N.sup.α,N G -diacyl derivative of arginine was dissolved in water with continuous stirring at 80° C. The remaining ingredients were dissolved in glycerol and mixed with the N.sup.α,N G -diacylarginine solution at room temperature.
EXAMPLE 3 (Gel Dentifrice)
______________________________________ w/w %______________________________________Pluronic F-127 20.0Flavors 0.8Preservatives 0.3N.sup.α,N.sup.G --diacylarginine 2.0Water, q.s. to 100 parts______________________________________
EXAMPLE 4 (Gel Dentifrice)
______________________________________ w/w %______________________________________N.sup.α,N.sup.G --diacylarginine 2.0NaF 0.2Pluronic F-127 20.0Flavors 0.8Preservatives 0.3Water, q.s. to 100 parts______________________________________
The gels of Examples 3 and 4 were prepared as follows:
The N.sup.α,N G -diacylarginine was dissolved in 50 ml water while continuously stirring at 80° C. After the arginine derivative had dissolved, the solution was cooled to room temperature and the NaF (if present) and preservatives were added. Separately, the Pluronic F-127 and flavors were dissolved at 4° C. The solution was allowed to warm up to room temperature and then blended into the arginine containing solution with continuous stirring. The mixture was homogenized and the pH of the gel adjusted to 5.5 by the addition of NaOH or HCl as required.
EXAMPLE 5 (Paste Dentifrice)
______________________________________ w/w %______________________________________N.sup.α,N.sup.G --diacylarginine 1 to 5NaF 0.2Glycerol 15.0Sorbitol 10.0Sodium lauryl sulfate 1.2Calcium pyrophosphate 40.0Propylene glycol 10.0Flavors 1.0Preservatives 0.3Pluronic F-127 10.0Water, q.s. to 100 parts______________________________________
The N.sup.α,N G -diacylarginine was dissolved in glycerol, sorbitol, propylene glycol, Pluronic F127 and water at 80° C. The pH was adjusted to 5.5 and the flavors, NaF, preservatives and sodium lauryl sulfate were added. The calcium pyrophosphate was blended into the mixture with continuous stirring at room temperature, and the mixture was homogenized with a roller mill. In this formulation, the sodium fluoride component is optional and may be omitted in the preparation of a nonfluoride dentifrice.
EXAMPLE 6 (Powder Dentifrice)
______________________________________ w/w %______________________________________N.sup.α,N.sup.G --diacylarginine 1 to 5Flavors 4.0Sodium lauryl sulfate 2.0Saccharin 0.4Abrasive, q.s. to 100 parts______________________________________
EXAMPLE 7 (Lozenge)
______________________________________ w/w %______________________________________N.sup.α,N.sup.G --diacylarginine 1 to 5Sorbitol 20.0Mannitol 20.0Starch 12.0Flavors 2.0Preservatives 0.4Saccharin 0.2Magnesium stearate 0.8Talc 0.5Corn syrup, q.s. to 100 parts______________________________________
The mixture of Example 7 was granulated into a homogeneous blend and pressed into a lozenge.
Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefore without departing from the principles and the true spirit of the invention.
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Oral hygiene formulations incorporating N.sup.α,N G -diacyl derivatives of arginine, or the pharmaceutically acceptable salts thereof, optionally in combination with fluoride compounds, are effective in combatting microorganisms, inhibiting acid production and reducing dental caries.
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FIELD OF THE INVENTION
This invention relates to cutting machines, particularly stump grinders and wood chippers.
BACKGROUND OF THE INVENTION
Stump grinding machines are used widely for removing tree stumps using a grinding wheel, a cutting chain or other cutting instrument. The grinding wheel, for instance, is swept back and forth across a tree stump. With each sweep, the grinding wheel is lowered incrementally until the stump is removed. The final sweeps of the grinding wheel may be below ground level to ensure that the entire stump has been eliminated.
Power to drive the grinding wheel is derived from an engine, usually a gasoline or diesel engine, installed on the grinding machine. The conventional grinding machine uses a power train that directly connects the engine to the grinding wheel to transfer the engine power to the grinding wheel. If the grinding wheel becomes jammed below ground level, for instance, while removing the tree stump, an overtorque situation can occur. Such a situation can transfer shear and overload forces to the engine, particularly its crankshaft, which can result in an engine failure that is costly to repair or may require replacement of the engine.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed in general to a cutting machine, which includes a drive assembly that connects an engine to a cutting apparatus. The drive assembly acts an operational interface or flexible coupling between the engine and the cutting apparatus to prevent damage to the engine if the cutting apparatus becomes overloaded. The component parts of the invention are simple and economical to manufacture, assemble and use, and other advantages of the invention will be apparent from the following description and the attached drawings, or can be learned through practice of the invention.
According to an aspect of the invention, a cutting machine includes a cutting apparatus for cutting a workpiece and an engine for powering the cutting apparatus. The workpiece can be a material such as wood, leaves, grasses and combinations of these materials. The cutting apparatus can chip, shred, grind or mulch the material.
In this aspect of the invention, a shaft assembly is provided to transfer energy from the engine to the cutting apparatus. The shaft assembly includes a shaft plate, a stub shaft and a coupling plate. The shaft plate is connected to the engine, and the coupling plate is positioned between the engine and the shaft plate. The shaft plate defines a shaft aperture through which the stub shaft extends. The stub shaft has a first end and an opposing second end defining a longitudinal axis. The first end extends from the shaft aperture and is connected to the cutting apparatus. Also in this aspect, the first end of the stub shaft defines at least one channel disposed parallel to the longitudinal axis. The coupling plate includes a coupling connected to the engine. The coupling plate includes a coupling chamber in which the second end of the stub shaft is connected such that a rotation of the coupling rotates the stub shaft to operate the cutting apparatus.
The cutting machine in this aspect of the invention further includes an engine sheave and a bushing. The engine sheave defines at least one annular race thereon for respective engagement with the endless belt. Additionally, the engine sheave defines a bushing aperture in which the bushing is located. A key extends from the bushing into the channel of the stub shaft to couple the engine sheave and the stub shaft together.
The cutting machine can include a jackshaft sheave defining at least one complementary annular race thereon for respective engagement with the endless belt, which is engaged with the annular race of the engine sheave noted above. The jackshaft sheave is rotatably connected to the cutting apparatus such that the rotation of the coupling rotates the stub shaft to rotate the engine and jackshaft sheaves to operate the cutting apparatus.
Also in this aspect of the invention, the second end of the stub shaft defines an outer surface having a plurality of splines depending radially therefrom. The splines are disposed parallel to the longitudinal axis of the stub shaft. The coupling chamber of the coupling defines an inner surface having a plurality of complementary splines depending inwardly therefrom and disposed parallel to the longitudinal axis, each of the complementary splines further disposed adjacent respective ones of the plurality of splines when the second end of the stub shaft is inserted in the coupling chamber of the coupling.
Further in this aspect of the invention, the flywheel is rotatably engaged with the coupling, and the splines and the complementary splines, which are engaged in the coupling chamber, are formed to fail prior to failure of an engine crankshaft of the engine. Additionally, the cutting machine in this aspect also includes a plurality of grommets, which are located about the coupling. The grommets are also formed to fail with or before the splines prior to failure of the engine crankshaft of the engine.
The cutting machine in this aspect of the invention can also include means for maneuvering the cutting machine, such as a locomotion apparatus selected from a wheel, an endless track and combinations of such devices. The means for maneuvering can further include a control system.
The cutting machine can include at least one lubrication or grease fitting in liquid communication with the shaft assembly. A first grease fitting, for instance, can be in liquid communication with the stub shaft to communicate a quantity of grease between the splines of the stub shaft and the coupling chamber to relieve friction when the stub shaft rotates. A second grease fitting, for instance, can be in liquid communication with the stub shaft to communicate a quantity of grease to a plurality of bearings located around the stub shaft in a housing chamber through which the stub shaft at least partially extends.
In another aspect of the invention, a shaft assembly for transferring energy from a power plant of a cutting machine to a cutting apparatus of the cutting machine is provided. In this aspect, the shaft assembly includes a shaft housing with a chamber therein, a stub shaft rotatably disposed in the chamber; and a coupling plate connected to the shaft housing. The coupling plate has a coupling with a coupling chamber therein. The stub shaft has a first end and an opposing second end defining a longitudinal axis. The first end extends from the chamber and is rotatably connected to the cutting apparatus. The second end extends from the chamber and is connected in the coupling chamber such that a rotation of the coupling rotates the stub shaft to operate the cutting apparatus. In this aspect, the flywheel is rotatably engaged with the coupling, and the stub shaft will fail before failure of a crankshaft in the engine.
This aspect of the invention also includes a plurality of bearings. Moreover, the shaft housing defines an inner race therein, and the bearings are rotationally disposed in the inner race and about an exterior surface of the stub shaft. The bearings rotate about the exterior surface of the stub shaft relative to the chamber. The shaft assembly in this aspect also includes at least one lubrication fitting in liquid communication with the shaft assembly to lubricate components in the chambers discussed above.
In yet another aspect of the invention, a cutting machine includes a cutting apparatus with a cutting device, an endless belt and an engine sheave. If the cutting machine is a stump grinder, it can also include a jackshaft sheave. The jackshaft sheave is rotatably connected to the cutting instrument with the endless belt disposed about the jackshaft and engine sheaves. Also included in this aspect is an engine with a flywheel having an interface for powering the cutting apparatus.
Additionally in this aspect of the invention, a shaft assembly is provided for transferring energy from the flywheel of the engine to the engine sheave. The shaft assembly includes a shaft plate, a stub shaft and a coupling plate. The shaft plate is connected to the coupling plate and defines a shaft aperture therethrough. The stub shaft in this aspect is located in the shaft aperture and has a first end with an opposing second end defining a longitudinal axis. The first end extends from the shaft aperture and is rotatably connected to the engine sheave. The coupling plate includes a coupling rotatably connected to the interface. The coupling has a coupling chamber therein, and the second end of the stub shaft extends from the shaft aperture and is connected in the coupling chamber such that a rotation of the coupling rotates the stub shaft to rotate the endless belt about the jackshaft and engine sheaves to operate the cutting apparatus.
The second end of the stub shaft in this aspect of the invention defines an outer surface having a plurality of splines depending radially therefrom. The splines are disposed parallel to the longitudinal axis. The coupling chamber of the coupling has an inner surface with a plurality of complementary splines depending inwardly therefrom. The complementary splines are disposed parallel to the longitudinal axis, each of the complementary splines further disposed adjacent respective ones of the plurality of splines when the second end of the stub shaft is inserted in the coupling chamber of the coupling. In this aspect, the stub shaft, when engaged in the coupling chamber, is designed to fail prior to failure of a crankshaft of the engine. Similarly, the coupling engaged with the stub shaft will fail if necessary prior to failure of crankshaft of the engine. Moreover, a plurality of bushings disposed about the coupling engaged with the stub shaft will fail prior to failure of the stub shaft and the crankshaft, flywheel or other engine components.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the invention will be apparent from the following description, or can be learned through practice of the invention, in combination with the drawings, which serve to explain the principles of the invention but by no means are intended to be exhaustive of all of possible manifestations of the invention. At least one embodiment of the invention is shown in the drawings in which:
FIG. 1 is a perspective side view of an embodiment of the present invention installed in an environment in which the invention is intended to be employed;
FIG. 2 is a front elevational view of a portion of a drive assembly taken along lines 2 — 2 in FIG. 1 ;
FIG. 3 is a detailed view of a portion of the drive assembly as in FIG. 2 with various components removed for clarity;
FIG. 4A is a front elevational view a detailed view of the portion of the drive assembly as in FIG. 3 with an engine sheave removed for further clarity;
FIG. 4B is a partial cross section of a shaft assembly taken along lines 4 B— 4 B in FIG. 4A ; and
FIG. 5 is an exploded perspective view of the shaft assembly as in FIG. 4B in relation to other components of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Detailed reference will now be made to the drawings in which examples embodying the present invention are shown. The detailed description uses numerical and letter designations to refer to features of the drawings. Like or similar designations of the drawings and description have been used to refer to like or similar parts of the invention.
The drawings and detailed description provide a full and written description of the invention, and of the manner and process of making and using it, so as to enable one skilled in the pertinent art to make and use it, as well as the best mode of carrying out the invention. However, the examples set forth in the drawings and detailed description are provided by way of explanation only and are not meant as limitations of the invention. The present invention thus includes any modifications and variations of the following examples as come within the scope of the appended claims and their equivalents.
The figures broadly embody a cutting machine, designated in general by the element number 10 . The cutting machine 10 generally includes a locomotion apparatus 12 for moving and maneuvering the cutting machine 10 , a power plant such as a gas or diesel engine 14 , and a cutting apparatus 16 such as a stump grinder or brush cutter to clear stumps, brush, and the like from an area of land. These and other components and characteristics of the cutting machine 10 are described in greater detail and by way of exemplary operation below.
With particular reference to FIG. 1 , the engine 14 of the cutting machine 10 provides power to the locomotion apparatus 12 to drive the cutting machine 10 . As shown in this example, the locomotion apparatus 12 is a tracked system, which includes a plurality of wheels 12 a and an endless tread or track 12 b for rotation about the wheels 12 a to maneuver the cutting machine 10 in various directions. Also shown, a control system 18 is provided to govern power transfer from the engine 14 to the cutting apparatus 16 such as by increasing rotation speed of components within a drive assembly 20 , as described below.
According to the embodiment shown in FIG. 1 , the cutting apparatus 16 is a stump grinder system, which includes a cutting device 19 for grinding and removing stumps. It will be appreciated that the cutting apparatus 16 is not limited to this exemplary stump removal arrangement. The skilled artisan will instantly appreciate that the cutting apparatus 16 can also be a brush cutter or a chipper. Therefore, as used herein, the phrase “cutting apparatus” is used to mean brush cutter, brush chipper, stump grinder and the like. It will be further appreciated that the cutting device 19 can utilize a cutting or grinding wheel, a chainsaw, a plurality of cutting teeth or similar cutting arrangements.
FIG. 1 further introduces a stub shaft assembly 22 , which is shown in phantom under a protective belt guard or cover 24 a . A portion of the stub shaft assembly 22 projects through an inner guard or wall 24 b of the drive assembly 20 from the engine 14 that, as will be described in further detail below, operably connects the engine 14 and the cutting apparatus 16 . In general, the stub shaft assembly 22 provides a failsafe mechanism to prevent damage to the engine 14 , more particularly, to an engine crankshaft 61 (see FIG. 5 ), should the cutting device 19 become wedged on a workpiece such as a tree stump. In other words, the stub shaft assembly 22 and its components as described in detail below are designed to fail at a predetermined shear modulus before an overtorque situation leads to failure of components of the engine 14 .
With reference to FIGS. 1 and 2 , the inner wall 24 b , one or more endless belts 26 such as V-belts, a jackshaft sheave assembly 28 , and an engine sheave assembly 30 are shown clearly with the belt guard 24 a removed. As shown, the jackshaft sheave assembly 28 is connected to the cutting device 19 . The skilled artisan will instantly appreciate that a jackshaft may not be necessary in some direct drive cutting machines such as a chipper and is provided here only by way of example.
The jackshaft sheave assembly 28 includes a jackshaft sheave 28 a with a plurality of annular races 28 b (alternatively, run or groove) formed about the jackshaft sheave 28 a . The belts 26 rotate about the annular races 28 b of the jackshaft sheave 28 a in concert with an engine sheave 32 of an engine sheave assembly 30 .
More particularly, with reference now to FIG. 3 , the engine sheave 32 includes a plurality of outer complementary annular races 32 a formed about the engine sheave 32 . The engine sheave assembly 30 is connected to the engine 14 to receive power from the engine 14 as noted above. As the engine 14 powers the engine sheave 32 , the belts 26 rotate about the complementary annular races 32 a of the engine sheave 32 , which also rotate about the annular races 28 b of the jackshaft sheave 28 a to power the cutting device 19 , also noted above. One skilled in the art will instantly recognize that a variety of endless belts, lines or chains made of metal, rubber or hardened plastic materials can be used for the belts 26 and further details are not necessary to appreciate and practice this aspect of the invention.
FIG. 3 further shows a bushing 34 in the engine sheave assembly 30 . As shown, the bushing 34 is located in a bushing aperture 32 b of the engine sheave 32 . The bushing 34 includes a plurality of first holes 34 a and a plurality of complementary bolts 34 b to mount the engine sheave 32 and the bushing 34 together. A plurality of second holes 34 c (alternatively, “push-off” or removal holes) is also provided in the bushing 34 to store respective bolts 34 b temporarily when the engine sheave assembly 30 is being disassembled for maintenance.
FIG. 3 also shows an inner shaft aperture 34 d in the bushing 34 for receipt of a stub shaft 42 . A key 34 e projects from the bushing 34 into a channel 44 b of the stub shaft 42 in this example to mate the bushing 34 and the stub shaft 42 together. The skilled artisan will instantly recognize that the key 34 e and the channel 44 b can be reversed on the bushing 34 and the stub shaft 42 , or additional keys and channels can be utilized to mate the bushing 34 and the stub shaft 42 together. Moreover, various combinations of keys and channels on each of the bushing 34 and the stub shaft 42 can be employed to ensure that the bushing 34 and the stub shaft 42 are aligned and secured together.
As further shown in FIG. 3 , a first grease fitting 46 and a second grease fitting 54 are provided to lubricate various components of the stub shaft assembly 22 . As shown, the first grease fitting 46 extends from a first end 44 of the stub shaft 42 for insertion of grease or other suitable lubricant to lubricate a plurality of splines 50 within the stub shaft assembly 22 (see FIG. 4B ). Similarly, the second grease fitting 54 is for insertion of grease or other suitable lubricant to lubricate a plurality of bearings 57 in the stub shaft assembly 22 (see FIG. 4B ). Moreover, the second grease fitting 54 includes a grease fitting extension 56 for convenient access to the grease fitting 54 when the drive assembly 20 is assembled with the belt guard 24 a in place as shown in FIG. 1 . Those skilled in the art will appreciate and understand operation of the grease fittings 46 , 54 without requiring additional details of this aspect of the invention.
Turning now to FIGS. 4A and 4B , the stub shaft plate assembly 22 is most clearly shown with the engine sheave assembly 30 and the grease fitting extension 56 removed. As shown, the stub shaft assembly 22 includes a shaft plate 36 with an external face 38 defining a number of attachment holes 38 a and a complementary number of attachment bolts 38 b . The shaft plate 36 is attached to the engine 14 via the attachment holes 38 a and the attachment bolts 38 b (see also FIG. 5 ). A plurality of service (“push-off” or removal holes) holes 38 c are also shown defined about the shaft plate 36 for use with one or more of the attachment bolts 38 b when the shaft plate 36 is being disassembled for service or repair. In use, some of the attachment bolts 38 b are removed from their attachment holes 38 a and inserted in the service holes 38 c to temporarily hold a weight of the shaft plate 36 as the shaft assembly 22 is being disassembled. The skilled artisan will instantly appreciate that any attachment device or mechanism other than bolts can be used to attach the shaft plate 36 to the engine 14 . For instance, screws, cotter keys and the like may be used in lieu of or in addition to the bolts 38 b.
As further shown in FIGS. 4A and 4B , the stub shaft 42 has a first distal end 44 defining a circumferential exterior surface 44 a in which the channel 44 b introduced above is formed. As shown, the stub shaft 42 extends from a shaft aperture 38 d of a shaft housing 52 . The housing 52 defines an outer annular surface 52 a and a shoulder 52 d . The second grease fitting 54 is located on the outer annular surface 52 a of the shaft housing 52 to lubricate the bearings 57 as noted above.
With more particular reference to FIG. 4B , the stub shaft 42 defines a longitudinal axis Z extending through the shaft plate 36 and from the shaft housing 52 . The shoulder 52 d of the shaft housing 52 is spaced apart from the external face 38 of the shaft plate 36 , which defines a predetermined depth D 1 of the shoulder 52 d relative to the shaft plate 36 . The depth D 1 of the shoulder 52 d and a predetermined length L of the stub shaft 42 position the engine sheave 32 at a desired distance from the external face 38 of the shaft plate 36 in order to accommodate components such as the grease fitting 54 and the grease fitting extension 56 .
Also shown in FIG. 4B , the exemplary shaft housing 52 includes a fixed run 52 a , an inner chamber 52 b , and a race 52 c . The bearings 57 rotate between the fixed run 52 a and the race 52 c within the inner chamber 52 b as a middle exterior surface 44 b of the stub shaft 42 rotates. As noted above, the second grease fitting 54 provides grease (not shown) to lubricate the bearings 57 as they rotate in the fixed run 52 a and the race 52 c . Those skilled in the art will understand that this arrangement of the fixed run 52 a , the race 52 c and the ball-shaped bearings 57 are provided by way of example only and any suitable race-bearing arrangement including tapered roller bearings can be used in lieu of or in addition to those shown and described.
FIG. 4B further shows a second end 48 of the stub shaft 42 , which defines a circumferential outer surface 48 a having a plurality of splines 50 radially extending from the outer surface 48 a . As shown, the splines 50 extend parallel to the longitudinal axis Z of the stub shaft 42 and are inserted into a coupling 60 positioned within the coupling plate 58 .
More particularly, with reference to FIGS. 4B and 5 , the stub shaft assembly 22 , the coupling plate 58 , the coupling 60 , and an engine flywheel 62 are shown respectively assembled and in a comparative exploded relationship. As shown, the shaft plate 36 of the stub shaft assembly 22 has an internal face 40 opposing its external face 38 . In this example, the internal face 40 is depressed or cupped inward such that the shaft plate 36 exhibits a concave shape for receiving the coupling 60 .
Also shown in FIGS. 4B and 5 , the coupling plate 58 includes a first cutter side 58 a and an opposing second flywheel side 58 b . The coupling plate 58 further includes a plurality of coupling holes 58 c with respective coupling bolts 58 d to attach the coupling plate 58 to the engine flywheel 62 . As noted above, any suitable attachment device or mechanism in lieu of or in addition to bolts can be used by the skilled artisan to couple the coupling plate 58 to the engine flywheel 62 .
FIG. 5 most clearly shows a coupling aperture 58 e through which the coupling 60 is inserted. A plurality of grommets or rubber bushings 64 is disposed about the coupling 60 and through the coupling plate 58 to provide absorb shock. A first reinforcement collar 68 according to this aspect of the invention is interposed between the grommets 64 and the coupling plate 58 to reinforce the area of the coupling plate 58 about the coupling 60 . As shown, the grommets 64 extend through the coupling plate 58 and the first reinforcement collar 68 continuing through the second flywheel side 58 b as well as a second reinforcement collar 70 in this aspect of the invention. A plurality of complementary bolts 66 secure the grommets 64 to the various components.
As further shown in FIG. 5 , the coupling 60 includes a shaft end 72 defining an annular surface 74 that when assembled with the shaft plate 36 is located within the internal face 40 of the shaft plate 36 . Also defined in the shaft end 72 of the coupling 60 is a coupling chamber 76 , which includes an inner annular surface 76 a with a plurality of teeth or complementary splines 76 b . The complementary splines 76 b are complementary to the splines 50 introduced above to achieve a sliding fit as shown in FIG. 4B .
FIGS. 4B and 5 further show a pilot end 78 of the coupling 60 , which extends from the second reinforcement collar 70 at a depth D 2 . The depth D 2 is sufficiently deep to extend past the bolts 66 in order for second end 48 of the stub shaft 42 to interact with the engine crankshaft 61 . More particularly, the engine flywheel 62 is arranged in the engine 14 , and the engine crankshaft 61 extends from the engine 14 for connection to the engine flywheel 62 in a known manner.
The engine flywheel 62 as shown in FIGS. 4B and 5 includes a plate-flywheel interface 80 having a predefined depth D 3 that is complementary to the depth D 2 of pilot end 78 of the coupling 60 . As shown, the coupling plate 58 is attached to the flywheel 62 via the coupling bolts 58 d and coupling plate attachment holes 82 in the flywheel 62 . Due to the interaction of the pilot end 78 with the plate-flywheel interface 80 , any shear or torquing forces are transmitted through the pilot end 78 of the coupling 60 rather than the coupling plate 58 , which as shown in this example is a thin metal plate to reduce weight and manufacturing costs and to ease assembly.
As best shown in FIG. 5 , the rubber grommets 64 extend through the coupling plate 58 in a manner that should one or more of the rubber grommets 64 fail, the stub shaft assembly 22 will generate noise and vibration indicating to a user that repair is needed. Should the noise and vibration of the failed grommets 64 go unheeded, the coupling plate 58 will fail due to a predetermined shear modulus of its thin metal construction. Finally, the splines 50 and/or the complementary splines 76 b of the coupling 60 will fail before damage occurs to the engine crankshaft 61 or other internal engine components (not shown). In other words, one or more of the above components external to the engine 14 will fail before the engine crankshaft 61 reaches its failure limit. Thus, costly damage to components of the engine 14 is avoided according to this exemplary aspect of the invention.
The invention may be better understood with reference the figures and to an operation and servicing of the cutting machine 10 .
Should the bearing supported stub shaft assembly 22 fail or require routine servicing, or if failure is suspected due to excessive noise and vibration during operation of the cutting machine 10 , the engine 14 and the control system 18 are powered off and secured to prevent inadvertent operation of the cutting system 16 and it cutting device 19 . Preferably, a battery supply (not shown) is also be disconnected from the engine 14 . Also, preferably, all components are allowed to cool prior to servicing to avoid burning the user.
According to a method of the invention, the stub shaft assembly 22 can be serviced by first removing the belt guard 24 a as shown in FIG. 1 . Next, the belts 26 (if more than one) are removed from the jackshaft sheave 28 a and the engine sheave 32 (see FIG. 2 ). The engine sheave assembly 30 is disassembled by removing the engine sheave 32 from the bushing 34 . The bushing 34 is removed from the belt drive assembly 20 by removing the bolts 34 b from their respective holes 34 a as shown in FIG. 2 . Preferably, the bolts 34 b are removed and temporarily stored in the holes 34 c in the bushing 34 to avoid losing the bolts 34 b during servicing. More particularly, the bolts 34 b are screwed into the holes 34 c to push the bushing 34 apart from the stub shaft assembly 22 . The holes 34 a , 34 c and the bolts 34 b have complementary helical threads that facilitate screwing the bolts 34 b out of the holes 34 a and into the holes 34 c in a known manner. As shown in FIG. 2 , the bushing 34 has a channel 34 e that fits or slides over the key 44 b of the stub shaft 42 . Therefore, the bushing 34 is slid from the key 34 e and away from the stub shaft 42 in a direction away from the belt drive assembly 20 . Finally, the inner guard wall 24 b is removed by removing bolts or the like.
With respect to FIG. 3 , the grease fitting extension 56 is removed from the second grease fitting 54 located on the outer annular surface 52 a of the shaft housing 52 . The bearing supported stub shaft plate 36 is next removed. Specifically, the attachment bolts 38 b are removed from the attachment holes 38 a and at least one of the attachment bolts 38 b attached in one of the service holes 38 c . As shown for example in FIG. 4A , there are twelve 10 mm bolts to remove. Also in this example, at least two of the bolts 38 b can be inserted into at least two of the services holes 38 c and rotated to push the stub shaft plate 36 apart from the flywheel 62 .
More specifically, the two bolts 38 b are screwed into the service holes 38 c until the shaft plate 36 breaks free from about the coupling plate 58 . By leaving at least two of the attachment bolts 38 b screwed at least slightly in the service holes 38 c , the bolts 38 b can assist in preventing the shaft plate 36 from dropping when separated from the engine 14 . When ready to remove the shaft plate 36 , the bolts 38 b can be completely removed from the service holes 38 c while holding the first end 44 of the stub shaft 42 as shown in FIG. 5 and sliding the shaft plate 36 away from the coupling plate 58 .
With reference to FIGS. 4B and 5 , the coupling plate 58 can be removed by loosening and removing its eight coupling bolts 58 d in this example. Once the coupling bolts 58 d have been removed from their respective coupling holes 58 c , the coupling plate 58 can be removed from the flywheel 62 . After all components have been removed as above and the flywheel 62 is exposed, the flywheel 62 can be cleaned with any suitable cleaning solvent and checked for burrs or other damage around the plate flywheel interface 80 as well as around its coupling plate attachment holes 82 .
If burrs or other minor damage are discovered, very fine sandpaper can be used to remove such burrs. If the damage has occurred to the bushings 64 or to the coupling plate 58 , then the grommets 64 can be removed by removing the holding bolts 66 and/or the entire coupling plate 58 can be replaced. If the damage is discovered too late, the stub shaft 42 may also have realized damage to the splines 50 and may require replacing. In one aspect of the invention, the stub shaft 42 may be made of a more brittle or fragile metal such as brass to allow the stub shaft 42 to fracture at a predetermined shear modulus prior to damage occurring to the engine 14 such as its crankshaft 61 . If the damage is determined to be beyond repair, then non-engine parts of the invention can be replaced quickly and conveniently at relatively lower cost than those of the engine 14 .
The steps described above are simply reversed to reassemble the component parts of the stub shaft assembly 22 . It has been found that some type of locking fluid such as Loc Tight® 242 brand should be placed on the bolts and all bolts lightly tightened to reassemble the components. Specifically, all bolts should be torqued to about 35 ft.-lbs. Further, an anti-seize coupling lubricant can be inserted in the coupling chamber 76 of the coupling 60 . Also, care should be taken to line up the splines 50 with the complementary splines 76 b before sliding the stub shaft 42 into the coupling chamber 76 to prevent any damage to the splines 50 , 76 b . Additionally, the grease fitting 54 should be placed substantially in the twelve o'clock position as shown in FIGS. 4A and 4B to ensure that the extension 56 can be reattached to the grease fitting 54 . Before starting the engine 14 , grease or other appropriate lubricant should be applied to the grease fittings 46 , 54 in a known manner. As shown in FIG. 4B , a grease relief fitting 55 is provided to release excess grease to prevent over-pressurizing the chamber 52 b.
Although the invention has been described in such a way as to provide an enabling disclosure for one skilled in the art to make and use the invention, it should be understood that the descriptive examples of the invention are not intended to limit the present invention to use only as shown in the Figures. For instance, an outer perimeter of the shaft plate 36 can be square, rectangular, oblong and various other shapes other than the illustrated round shape. Likewise, specific shapes of other components can be altered to suit particular applications. Additionally, positions of certain components can be reversed or alternated, such the key 34 e of the bushing 34 and the channel 44 b of the stub shaft 42 as previously noted. It is intended to claim all such changes and modifications as fall within the scope of the appended claims and their equivalents. Thus, while exemplary embodiments of the invention have been shown and described, those skilled in the art will recognize that changes and modifications may be made to the foregoing examples without departing from the scope and spirit of the invention.
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A cutting machine and a method of using the cutting machine includes a cutting apparatus having a cutting device, a jackshaft sheave, an endless belt and an engine sheave. The cutting machine may have a jackshaft sheave, which is rotatably connected to the cutting instrument with the endless belt disposed about the jackshaft and engine sheaves. An engine includes a flywheel with an interface, which are configured for powering the cutting apparatus. A shaft assembly transfers energy from the flywheel of the engine to the engine sheave. The shaft assembly includes a shaft plate, a stub shaft and a coupling plate. The shaft plate is connected to the coupling plate and defines a shaft aperture with the stub shaft disposed in the shaft aperture. The stub shaft depends from the shaft aperture and is rotatably connected to the engine sheave. The coupling plate includes a coupling rotatably connected to the interface. The coupling defines a coupling chamber in which another end of the stub shaft depends and is connected in the coupling chamber such that a rotation of the coupling rotates the stub shaft to rotate the endless belt about the jackshaft and engine sheaves to operate the cutting apparatus.
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FIELD OF THE INVENTION
[0001] The present invention relates to a coated substrate suitable for printing, said substrate being made of paper, cardboard, or the like.
[0002] The invention relates also to a method for making a coated substrate suitable form printing and to its use.
DESCRIPTION OF THE PRIOR ART
[0003] In the sector of paper for printing machines are known many types of coated paper having coatings of any composition and thickness for giving the substrate features for a better printing or for obtaining particular aesthetic effects, and many patents have been filed on the matter.
[0004] For instance, they are known printing substrates provided with coatings which gives the substrate a peculiar brightness and evenness which are desirable for obtaining specific decorative effects, for photographic printing, and in particular for products which would be metalized in a later time. For instance, patent documents U.S. Pat. No. 5,334,449, DE-B-1233248, U.S. Pat. No. 3,113,888 describe printing substrates having, among other features, the above cited features.
[0005] Another type of printing substrates have surface visual effects, such as a not uniform color. Such type of substrates, or their production processes, are described for instance in EP 1439263 and EP 1239077.
[0006] Among paper substrates with coatings for conferring peculiar visual effects there are products which are particularly suitable for the reproduction of paintings or murals as they have superficial effects which reproduce, for instance, the weft of a canvas, or the granulosity and mat aspect of a fresco.
[0007] Nevertheless, no known substrate suitable to be printed through the most common printing processes, such as the inkjet process or the offset process, is able to substantially reproduce all the visual and tactile sensations of paintings and/or murals so making it possible to print art pieces reproductions of great quality in a very simple and cost effective way.
SUMMARY OF THE INVENTION
[0008] The object of the present invention is to propose a coated printing substrate having visual and tactile surface features suitable for reproducing the visual and tactile features of paintings and/or frescos.
[0009] Further object of the present invention is to propose a low cost coated printing substrate for printing painting, frescos or photo reproductions.
[0010] Another object of the present invention is to propose a coated printing substrate which have a cost effective and easy to apply coating.
[0011] Another object of the present invention is to propose a method for making a coated printing substrate particularly suitable for printing paintings, frescos or photo reproductions.
[0012] Another object of the present invention is to propose a paper having a printable coating which can be hardly bent without breaking the coating and that at the same time has a consistency to touch similar to a mural.
[0013] The above objects are attained by a printing substrate having, on at least one surface, a coating having thickness from 40 to 400 micron and it is formed by a
[0014] mixture comprising: from 5 to 40 parts by weight of a water emulsifiable binder, from 10 to 60 parts by weight of calcium salts, from 1 to 40 parts by weight of granular material in an average particle size ranging from 20 micron to 150 micron, and from 20 to 50 parts by weight of water.
[0015] The consistency of the coating gives the printing substrate visual and tactile features which are peculiar in paintings or murals, and they can be made at industrial level at a low cost as it can be easily argued from the mixture composition.
[0016] In particular, the granular material gives the printing substrate a specific roughness and coarseness suitable to reproduce the consistency of paintings or murals.
[0017] The coating has a great mechanical strength and, mainly when the substrate is made of paper, canvas or other porous material, the coating permanently adheres to the substrate.
[0018] A printing substrate as above defined also grants a very good adhesion of the color and high print quality as concern color and resolution.
[0019] Advantageously the substrate is paper and, in the coating the calcium salts are calcium carbonate and/or calcium sulphate, the granular material is siliceous and/or calcareous material, preferably mainly composed of silicium dioxide and the binder is an acrylic resin.
[0020] The use of calcium carbonate and silicium dioxide allow a low cost of the printing substrate as they are substances of great diffusion and low cost.
[0021] In preferred embodiments of the substrate of the present invention the binder is in an amount from 20 to 50 parts by weight, the calcium salts is from 5 to 40 parts by weight, the granular material is from 5 to 40 parts by weight and the water is from 20 to 50 parts by weight.
[0022] The above ranges lead to the best features of the substrate ad concerns elasticity and mechanical strength of the coating and the ability of permanently fix the color.
[0023] The mixture which forms the coating preferably has a density from 1.1 to 2 gr/cm 3 .
[0024] Advantageously on the surface of the coating is obtained a texture having depth from 10 to 500 micron.
[0025] The above features is suitable for emphasizing the characteristics of the printing substrate in order to print paintings, frescos or photo reproduction which are as similar as possible to the originals. The above objects are also attained through a method for making a coated printing substrate comprising steps of:
applying on a surface of said substrate a layer having thickness from 25 to 1000 micron of a mixture comprising: from 5 to 70 parts by weight of a water emulsifiable binder, from 1 to 60 parts by weight of calcium salts, from 1 to 60 parts by weight of granular material in an average particle size ranging from 20 micron to 1000 micron, and from 10 to 60 parts by weight of water, passing said substrate with said layer of mixture through a soft unsmooth roller, drying said layer until a coating adhering to said substrate is obtained.
[0029] Preferably the above method is performed in a plant for applying thin films on a paper substrate comprising an unwinder of a paper web, a machine for applying a mixture on the paper web, one or more drying chambers and a rewinder, in which between a phase of applying the mixture on the paper web and a first drying phase there is a phase of pressing the mixture an the paper web by passing them through pairs of pressing rollers.
[0030] Advantageously between two subsequent pairs of pressing rollers the coated printing substrate is passed under air jets directed toward the surface of the mixture to accelerate the drying process.
[0031] Still advantageously the pressing rollers which are on the side of the mixture are made of polyurethane with open and/or closed cells.
BRIEF DESCRIPTION OF DRAWINGS
[0032] These and other characteristics of the invention will become more easily comprehensible from the following description of the preferred embodiments of the invention, given as not limiting examples, with reference to the enclosed drawings, in which:
[0033] FIG. 1 is a schematic side view of a plant for producing a coated printing substrate according to the present invention;
[0034] FIG. 2 is a schematic view of some components of the plant of FIG. 1 ;
[0035] FIG. 3 is a perspective view of a portion of a coated printing substrate according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0036] Preferred embodiments of the invention for obtaining coated substrates, in particular a coated paper suitable for printing with inkjet or offset printers, will be described in the followings.
[0037] According to a general way of producing a coated printing substrate according to the present invention it is made a mixture according to the invention having density of 1.5 gr/cm 3 , such that the granular particles that it contains remains in suspension for a time long enough to grant the homogeneity of the mixture when it is spread on the substrate.
[0038] In some cases, for a long conservation, the mixture can be stored with a low amount of water in it and it can be diluted just before the use.
[0039] On a printing substrate, which is preferably printing paper ranging from 80 to 450 gr/m 2 , but that in specific cases could also be cardboard, canvas, wood or other material, the mixture is applied so that an even thickness is obtained, for instance by machines using rollers, pads, blades or the like, or also by spraying devices.
[0040] Just after the mixture has been applied the substrate is passed through contact means suitable for improving the adhesion of the coating to the substrate and also useful to promote the creation of random patterns which are mainly due to the material of which said contact means are made, and to the composition and viscosity of the mixture. For instance, in a specific embodiment a soft unsmooth roller, preferably a sponge, is passed on the surface of the mixture for making the surface even and creating a texture whose depth and pattern are due to the pattern on the surface of the roller, to its elasticity and to the consistency of the mixture. Alternatively, if the mixture is sprayed on the substrate the sponge roller can be avoided as the mixture could already have the suitable roughness.
[0041] The substrate is then dried in a aired environment with humidity under control and after about 5 minutes it is obtained a coated substrate suitable for printing with inkjet or offset printers and for reproducing art pieces such as paintings, frescos or photos.
[0042] In fact, the consistency of the coating together with the pattern due to the soft roller give the coated substrate great similarity both on visual and tactile point of view, to a painted canvas or to a mural.
[0043] In order to obtain a specific smoothness of the coated surface the coated substrate can be subject to a smoothing process performed through specific rollers suitable for machining the crests of the surface, which are mainly composed of granular material, without creating a highly smooth surface.
[0044] In addiction, conventional transparent finishings can be applied to the coated substrate in order to improve brightness.
[0045] A different specific way of realizing a coated printing substrate according to the present invention will be now described with reference to FIGS. 1 and 2 and it is used for making a product that has good ability to keep the color, good printability (mainly by offset and inkjet printers) and good bendability with no risk of creeping or detachment of the coating from the paper, and it has consistency to touch and aesthetic appearance which are peculiar of whitewashed walls. Such a product is useful for printing images so that it seems, under both visual and tactile point of views, to be directly made on a whitewashed wall even if it is printed on a sheet paper that can be managed, stored and handled with the easiness of the paper. For instance, reproductions of frescos, photos or famous murals can be printed, both in real dimension and in scale, and it can also be used for making samples suitable to show which will be the visual and tactil aspect of an image the will be made on a whitewashed wall.
[0046] A product with the above features can be realized in a plant which has a layout very similar to plants for gluing plastic films or fabrics on substrate which are paper or other fabrics. In fact, a plant for producing a coated printing substrate according to the present invention comprises an unwinder, 10 , a blade type mixture applying machine, 20 , a set of pairs of pressing rollers, 30 , drying chambers, 40 , and a rewinder, 50 .
[0047] A web, B, of paper material, 101 (see FIG. 3 ), is loaded in the unwinder 10 and it is the substrate on a side of which a coating, 102 (see FIG. 3 ) is applied.
[0048] The paper material unwound from the web is fed to the mixture applying machine 20 where the web turns about a cylinder member, 21 and a mixture feeder, 22 , applies a fluid mixture according to the invention on the top surface of the paper substrate, 101 , then, at the point where the web leaves the periphery of the cylinder member, 21 , a blade, 23 , adjust the amount of fluid mixture that remains on the surface of the paper material 101 . The amount of fluid mixture remaining on the substrate is very high. In fact, while in the production of conventional coated paper the amount of product applied on the substrate is no more than 30 gr/m 2 , in the method of the present invention the amount of fluid mixture remaining on the paper substrate is variable in a range from 120 to 350 gr/m 2 . Then, the paper web with the fluid mixture on one side is passed through a set of pairs of pressing rollers 30 for pressing the fluid mixture on the substrate so that it promotes adhesion and the creation of random patterns. In fact, the viscosity of the mixture and the surface of the rollers generate adhesive forces between the two surfaces (forces which are variable as a function of the composition of the mixture, its viscosity, the material of the surface of the rollers, and the morphology of the surface of the rollers) such that surface movements take place in the coating which create random tridimensional patterns. The above effect is greater in the first pairs of pressing rollers, when the mixture is less viscous, while it decreases as long as the mixture solidifies. Each pair of pressing rollers 30 is made of a lower roller, 31 , substantially smooth, and a top roller, 32 , made of polyurethane or the like, with closed or open cells depending on the kind of desired surface effect (roughness of the surface). The use of polyurethane is very suitable as it has a proper paper adhesion coefficient and the elasticity of that material is such that it allows exerting the right pressure on the paper. Between a pair of rollers and the following pair are placed air inlet ducts, 33 , provided with air nozzles, 34 , suitable for emitting jets of compressed air towards the surface of the fluid mixture in order to promote drying. The pressure, the temperature and the humidity of the air emitted towards the surface of the mixture are properly controlled for obtaining the best drying conditions. Subsequently, the paper web is passed through a set of drying chambers 40 , where, at controlled humidity and temperature, it ends drying. Once come out of the drying chambers 40 the paper web is wound by a rewinder 50 .
[0049] With regard to conventional plants for applying coatings on a paper substrate, the plant for producing coated printing paper according to the invention has a much lower web feeding speed in order to allow the coating to correctly dry. In fact, while conventional paper coating plants has a web feeding speed ranging between 50 and 600 m/min, the plant of the present invention has a speed comprised between 4 and 20 m/min.
[0050] In FIG. 3 is shown a portion of a coated printing paper, 100 , according to the present invention which is composed of a sheet of paper material, 101 , and a layer of coating, 102 , made with a dried mixture according to the present invention. Usually, the side of the paper side of the product 100 is substantially smooth, while the coating side 102 has a greater roughness, could be characterized by a random pattern, and it has a visual and tactile aspect which are typical of whitewashed walls. Though it has the above aspect, the product 100 according to the invention keeps the advantages of a printing paper and, in particular, its thickness, the bendability without fractures in the coating and the ability to fix the inks.
[0051] In the followings will be described in detail to examples of coated substrates, which have to be intended are mere, not limiting examples of the invention.
Example 1
Printing Substrate for Inkjet Printers Using Water Inks or Resin Based Inks
[0052] On a paper substrate with a weight of 150 gr/m 2 is applied a layer of about 250 micron of a mixture composed of:
35% by weight of acrylic resin, 28% by weight of calcium carbonate, 6% by weight of quartz flour with an average grain size of 40 micron, 31% by weight of water, traces of titan dioxide as a pigment, traces of wetting and/or fluidizing additives.
[0059] Before drying the mixture is passed with a sponge roller for obtaining a pattern of about 100 micron of thickness.
Example 1
Printing Substrate for Inkjet Printers Using Solvent Inks
[0060] On a paper substrate with a weight of 250 gr/m 2 is applied a layer of about 300 micron of a mixture composed of:
40% by weight of acrylic resin, 20% by weight of calcium carbonate, 10% by weight of quartz flour with an average grain size of 100 micron, 30% by weight of water, traces of titan dioxide as a pigment, traces of wetting and/or fluidizing additives.
[0067] Before drying the mixture is passed with a sponge roller for obtaining a pattern of about 150 micron of thickness.
[0068] After drying a smoothing process is performed so that the coating is smooth to touch even if it appears irregular at sight.
[0069] As it would be obvious to the people skilled in the sector, mixture such as the above described are not used in the known art for producing coated paper but, they are similar as concern the composition to wall whitewashing substances or to wall paints. In fact, for instance, the binder used in the above examples is acrylic resin which is used in wall paints. Acrylic resins are also used for paper coatings but in paper products which have a very different destination of use with respect to the paper product of the present invention. Vinyl and/or versatic resins may also be used, and just like the acrylic resins they are not usually used for making coated paper for offset or inkjet printing. In addiction, calcium salts (mainly calcium carbonate), which in conventional coated papers are used in very low amount to avoid flouring and to prevent a problem in fixing the printing ink, in the above example are over 20% by weight and they may arrive to 40% which is a value typical of wall paints and wall whitewashing substances, and they give the final product the consistency of this last products. Even quartz flour is not usually used in coatings for offset or inkjet printing paper, while it is very common in exterior wall paints. The use of substances like calcium carbonate and quartz flour, which is common in paints, gives the product of the invention the consistency and the aesthetic aspect of whitewashed walls and, therefore, an image printed on the product of the invention seems directly made on a wall. Despite of the above similarities with wall paints, the other components of the coating of the present invention, and their percentages, are very important in order to obtain a good adhesion to the paper substrate, and good printing properties and they are therefore function of the kind of printings and inks for which the product is intended.
[0070] Certainly, with respect to the above described examples, many changes can be carried out both to the coated substrate production process and to the composition of the mixture which form the coating.
[0071] For instance, the water emulsifiable binder could be a vinyl, vinyl-versatic, silossanic resin, potassium silicate or other products having similar properties.
[0072] Though calcium carbonate is very cheap and it assures good performances, a different calcium salt can be used, such as a calcium sulphate, or a mixture of both.
[0073] The granular material is quartz flour in the examples, mainly composed of silicium dioxide with a grain size such that it gives the proper consistency to the coating, but any granular material could be used, both mineral and synthetic.
[0074] Further components can be added to the mixture in little amounts. In the above examples titanium dioxide is added for obtaining a with color of the coating, but, obviously, pigments of any other type can be added and additives for improving wetting or fluidity such as polysaccharides or tensioactives.
[0075] These and other changes or modifications could be applied to the coated printing substrate according to the invention or to the relating production method, still remaining within the protective scope defined by the following claims.
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A coated printing substrate, preferably for offset or inkjet printing, comprises a coating composed of a water eraulsifiable binder, calcium carbonate or sulphate, a granular material of the grain size of a flour or a fine sand, and water. BGy a proper production method can be obtained a product which can be produced at industrial level with low costs and it is particularly suitable for the reproduction of photos or art pieces such as paintings or frescos as it gives the visual and tactile sensations of such kinds of art pieces, allowing, at the same time, high quality printing.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
This application relates to U.S. Provisional Patent Application No. 61/280,109 filed on Oct. 29, 2009, entitled A METHOD FOR PRODUCING HIGH-CAPACITY CONCRETE BEAMS, which is hereby incorporated herein in its entirety by this reference.
FIELD OF THE INVENTION
The present invention relates generally to the prefabrication of structural building materials, and, more particularly, to the prefabrication of concrete beams or girders. Specifically, various embodiments of the present invention provide an apparatus and process to realize economic and quality benefits by producing concrete beams or girders of high structural capacity through practical steps that are easily implemented in most precast beam/girder production plants.
BACKGROUND OF THE INVENTION
Progress in the production of concrete beams (also known as “girders”) for construction of bridges and buildings was greatly stimulated in the 1950's when the technique of prestressing the concrete was proven to have advantages in the United States. There are two known techniques of prestressing: pre-tensioning and post-tensioning. Both techniques of prestressing employ steel cables or bars to apply and hold a concrete member in compression. Prestressing can be referred to as “active reinforcement” as compared to “passive reinforcement”, such as is obtained with mild reinforcing steel (rebar).
Pre-tensioning is the predominate form of prestressing employed in the precast concrete industry. This technique involves stretching steel cables with a high tensile force, with the cables held between fixed abutments that are situated at each end of a casting platform, or “bed”, and placing concrete in forms on the bed, which forms encase the cables to form a beam or girder. At a later time, after the concrete has gained sufficient strength and bonded well to the cables, the cables are released from the abutment anchors, the forms removed, and the completed beam or girder is lifted from the bed.
It is of great economic importance that this procedure be completed on a daily cycle. In order to do this, heating the newly cast concrete at a curing temperature as high as 180 degrees F. to accelerate concrete strength gain has been a common practice.
The post-tensioning technique is not generally practiced in precast concrete production. Post-tensioning is more expensive per pound than pre-tensioning, so it has been employed sparingly in the production of beams or girders other than in special cases to meet design requirements.
In recent years, there has been remarkable progress in making concrete that has much higher strength than ever before. Ultimate 56 day compressive strength is now possible in the 10,000 psi to 20,000 psi range, which is up to 10,000 psi higher than strengths attainable a short time ago.
However, there has not been an advantage taken of higher strength concrete by employing a proportionately higher prestressing force in the design of precast beams or girders. Beam or girder load carrying capacity is increased dramatically when, using the same beam or girder size and shape as those made with “standard” concrete, stronger high performance concrete (HPC) is employed with a substantially greater prestressing force. This fact was demonstrated on an experimental bridge project where HPC beams having a 56 day strength of 13,600 psi were constructed with approximately 60 percent more prestressing force than standard beams made with 6,000 psi concrete. Test results proved that four HPC beams had the same load carrying capacity as seven standard beams for “twin” bridges of an identical span and roadway width. Although the cost per beam was higher for the HPC beams, the cost of the bridge superstructure having four high structural capacity beams was approximately 15% lower than the bridge having seven standard beams. This project confirmed the economic viability of employing higher structural capacity beams made with superior concrete strength and constructed with a high prestressing force. However, industry has not reaped the benefits of these features to achieve an improved and more economic product. There are certain problems that must be solved.
In addition to the common precautions observed in the design of a concrete mix, there are two important factors that must be dealt with concerning concrete durability. Both of these factors pose potential problems in making durable concrete beams or girders, as well as other concrete members. The first is known as alkaline-silica reaction (ASR); the second is called delayed ettringite formation (DEF). ASR is caused in large part by high alkalinity in the concrete reacting over time with silica in the aggregate. In severe cases, which are not uncommon, this reaction results in cracking and destruction of the concrete.
On the other hand, it has been learned recently that DEF is promoted principally by curing the concrete at a very high temperature. DEF typically occurs over time in mature concrete. It has been mistakenly identified as ASR in some cases, because its apparent failure mode is similar to the failure mode attributable to ASR.
The solutions to both problems are now known. Damage due to ASR can be avoided by substituting another cementitious material such as fly ash or slag for a portion of the cement in the mix to reduce net alkalinity. The drawback to this approach is that early concrete strength gain is slowed. Although final strength is typically very high, the concrete strength required for transfer of stress (the “release strength”), is not reached in time for daily recycling on the prestressing bed. Daily recycling of the bed is critical to a beam or girder manufacturer's economics.
DEF can be avoided by restricting concrete curing temperature to a maximum of approximately 160 degrees F. Here again, because early concrete strength gain is dependent on curing temperature, the lower temperature requirement makes attaining release strength overnight less likely.
Thus, there are two factors that have constrained production of superior and more cost-effective beams or girders prefabricated with HPC. Since higher strength concrete beams or girders containing a high prestressing force have been shown to produce a significant lower cost for a completed structure, it is important to have a way of making prestressed HPC beams or girders on a daily production cycle.
Control of camber in concrete beams or girders can be yet another serious problem. Camber is the arching upward of a beam/girder or slab that is prestressed when the prestressing force is located below the centroid of the concrete. In almost all cases, the pre-tensioning force applied to a beam or girder on a pre-tensioning bed is well below the centroid of the concrete. When a prestressing force (which is a compressive force) is applied to concrete, the concrete immediately shortens elastically as the force is applied. Thereafter, there is an inelastic shortening due to a phenomenon known as “creep” of the concrete. The amount of creep is a function of time, the level of compressive stress, and the modulus of elasticity of the concrete. Camber takes place in a prestressed concrete beam or girder when the concrete fibers in the lower portion of the member are under a higher compressive stress than the fibers in the upper portion. Creep of the concrete continues to shorten the bottom of the member as time passes, causing camber to grow. There have been cases where camber growth has been so great that beams or girders became unfit for use in structures and were rejected. The economic implications of such a problem go well beyond loss of money by the precaster having to manufacture substitute beams or girders. The construction company, depending upon timely delivery of product for constructing the bridge or building, is impacted by delay that ensues while new beams or girders are manufactured to replace the rejected ones.
One objective of the present invention is to provide a process that can be readily implemented by beam or girder manufacturers to overcome these problems.
SUMMARY OF THE INVENTION
The various embodiments of the present invention provide a process for making precast beams or girders that have a greater load carrying capacity by employing a strategy that also provides additional control of quality. The process described makes it practical to use higher strength concrete that carries a high prestressing force. A substantial advantage is obtained by the following combination of steps to achieve superior load carrying capacity and quality and achieve advantageous economic results.
First, the full prestressing force required by the design requirements for a beam or girder is not introduced by pre-tensioning, as is now routinely done. Instead, only a portion of the full design force is applied by pre-tensioning while the beam or girder is on a prestressing bed. A pre-tensioning force is applied that is at least a magnitude that will allow the beam or girder to be removed from the bed and withstand stresses experienced in handling and storage. The pre-tensioning force needed is readily calculated as a part of production procedures as is well-known to persons skilled in the art.
The purpose of applying only a partial prestressing force is to allow earlier release of the pre-tensioning cables or rods, which release is made possible because the prestressing force that is applied to the concrete by pre-tensioning is reduced and thus permits the concrete strength to be lower before release of cables or rods from the abutments. Thus, the concrete beam or girder, although having an initial lower strength, can be removed from the bed earlier. Also, the effects of low early concrete strength that is caused by adjusting the concrete mix to diminish the prospect of ASR, and the lower curing temperature to combat DEF, as well as other factors that result in a concrete strength too low to carry the full prestressing force, are effectively managed, while daily cycling of the bed is achieved.
Second, after a beam or girder is removed from the bed, the beam or girder is stored on supports near its ends, so that gravity acting on the beam or girder counteracts most of the prestressing force and thus resists camber growth due to flexural stresses. The result is that little, if any, inelastic concrete creep and camber growth occurs over time.
Third, the remainder of the required prestressing force for the beam or girder is induced by post-tensioning. Post-tensioning can be accomplished at any time of the manufacturer's choosing, typically just several days before shipping the beam or girder to a customer's jobsite. By this timing strategy, unwanted camber growth can be eliminated.
An added operational advantage produced by this process is that post-tensioning is performed away from the casting area at a distance from the prestressing bed, and therefore it is not on a critical production path because it does not affect the high intensity core activity of the beam or girder manufacturer. Also, because a range of post-tensioning forces can be applied, the manufacturer can potentially build an inventory of partially constructed beams or girders and thus supply beams or girders to customers more quickly than if construction of the beams or girders had not yet begun.
The foregoing and other objects, features, and advantages of the present invention will become more readily apparent from the following detailed description of various embodiments of the present invention, which proceeds with reference to the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments of the present invention will be described in conjunction with the accompanying figures of the drawing to facilitate an understanding of the present invention. In the figures, like reference numerals refer to like elements. In the drawing:
FIG. 1 , comprising FIGS. 1A , 1 B, and 1 C, illustrates the basic process flow for beam or girder production in accordance with one embodiment of the present invention.
FIG. 2 , comprising FIGS. 2A and 2B , shows an embodiment of a beam or girder produced in accordance with the process of the invention illustrated in FIG. 1 .
FIG. 3 illustrates a cast-in-place concrete deck comprising the beam or girder shown in FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1A , 1 B, and 1 C illustrate a flowchart depicting a non-limiting example of the manufacturing process for a high strength concrete beam or girder, which synergistically allows for the use of high strength concrete combined with a rapid and economical cycling of the manufacturing bed, while providing a beam or girder strength that takes full advantage of the high strength concrete.
The example process of FIG. 1 begins in a step or operation 100 , as shown in FIG. 1A , and continues in an operation 102 in which the manufacturing bed is prepared for use. Then, in an operation 104 , reinforcement and pre-tensioning strands, for example, cables or rods, are installed in place on the bed, along with post-tensioning ducts, and anchorages. Next, in an operation 106 , tensile force is applied to the pre-tensioning strands that were deployed in operation 104 . In an operation 108 , the elongation of the pre-tensioning strands is measured and recorded. An operation 110 is then performed which assembles the forms in place on the bed to provide a structure that determines the beam or girder shape.
In an operation 112 , the high strength concrete is mixed. In certain example embodiments, a high cementitious content is used, along with water-reducing and plasticizing admixtures. The cementitious material in certain example embodiments comprises, for example, Portland Cement. In certain example embodiments a portion of the cementitious material comprises an alkalinity reducing material such as, for example, fly ash or slag to prevent the alkalinity of the mixture from being too high. Otherwise, alkalinity can cause a very serious reaction with silica in the aggregate, resulting in severe cracking of the concrete. While the introduction of the alkalinity reducing material does not materially affect the ultimate strength of the resultant concrete, the strength of the concrete is reduced in the short term, and other measures described herein are preferably taken to compensate for the short term lack of strength and its impact on the manufacturing process. The result is a synergistic combination that provides a beam or girder that takes full advantage of the strength of the highly cementitious mixture, avoids a silica reaction, and yet allows a rapid cycling of the manufacturing bed.
In an operation 114 the concrete mixture is poured into the form. A portion of the mixture is also poured into a number of cylindrical or cubical forms which allow the strength of the concrete to be sampled at various times. The curing apparatus is put in place in an operation 116 . Then, in an operation 118 the concrete is cured.
As shown in FIG. 1B , the strength of the concrete is measured in an operation 120 , typically using one or more of the concrete cylinders or blocks mentioned in the description of operation 114 . A decision operation 122 determines whether the concrete has achieved a strength that is at least adequate to endure pre-tensioning (the “release strength”), removal from the bed, and storage. If it is determined that the strength of the concrete is not adequate, then a wait operation 124 is performed to allow the concrete to gain more strength, and the process returns to operation 120 . If it is determined in operation 122 that the strength of the concrete has achieved a strength that is at least adequate to endure pre-tensioning, removal from the bed, and storage, then the process continues with operation 126 which releases the pre-tensioning strands from their abutment anchorages, thus placing the beam or girder under compression.
Next, in an operation 128 , the curing apparatus is removed to allow access to the beam or girder. Thereafter, in an operation 130 the forms are removed and cleaned for reuse. Then, in an operation 132 , the beam or girder is moved to storage. In certain example embodiments, the beam or girder is placed on supports proximate to the beam's or girder's respective ends, which allows the beam or girder to avoid camber growth, since the force applied in operation 106 is of less than full magnitude. The beam or girder, having gained sufficient strength to support its own weight and avoid deflection can be stored indefinitely. This removal of the beam or girder from the bed permits the bed to be re-used, and allows the beam or girder to gain strength over a period of time in storage. The timing of the removal from the bed is earlier than would otherwise be possible, and this early removal allows the bed to be used again for making another beam or girder. The removal of the beam or girder from the bed can be performed when the high strength concrete is relatively weak, because the pre-tensioning strands that were released in operation 126 have imparted only a portion of the total eventual prestressing force, yet a sufficient force for removing the beam or girder from the bed. The pre-tensioning in operation 126 , which imparts only a portion of the full prestressing force, thus synergistically allows high strength materials to be used even though those materials are relatively weak on the day after casting.
As described above, in the operation 132 the beam or girder is moved to storage and placed, for example, on supports proximate to the ends of the beam or girder in order to limit camber growth. An operation 134 shown in FIG. 1C is performed wherein the beam or girder is kept in storage while it gains strength sufficient for the full prestressing force. The amount of storage time can vary dependent on the formulation of the materials of the concrete, and also can vary with strength requirements for the beam or girder. The beam or girder can be allowed to gain strength over any desired amount of time in order to take advantage of the strength potential of the materials used, or meet time constraints that call for beams or girders of lesser strength in a relatively short amount of time. Next, in an operation 136 a post-tensioning force is applied. Then, in an operation 138 cement grout is injected into the tendon ducts employed in post-tensioning. Next, in an operation 140 the grout is allowed to cure over a period of time. Finally, the process is concluded in an operation 142 .
One example embodiment of the beam or girder that is the product of the process described in conjunction with FIG. 1 is shown in FIG. 2 . As shown in FIG. 2A , a beam or girder 200 comprises prestressed high strength concrete. The beam or girder is cast on a manufacturing bed (not shown) using a set of forms which determine the shape of the beam or girder. The example beam or girder shown in FIG. 2A has a resulting shape generally referred to as an “I-beam.”
As shown in FIG. 2A , the beam or girder 200 is prestressed during initial manufacture of the beam or girder on the bed using pre-tensioning strands 202 described earlier in conjunction with operations 104 and 106 illustrated in FIG. 1A . The strands 202 are preferably installed on the manufacturing bed prior to the erection of the forms used to contain the high strength concrete. Semi-flexible post-tensioning ducts 204 are also installed as described earlier in conjunction with operation 104 illustrated in FIG. 1A . The post-tensioning ducts 204 terminate at post-tensioning anchorages that may be installed employing reusable blockout forms 206 , as shown in FIG. 2B . As shown in FIG. 2B , there may be one or more post-tensioning ducts 204 which are placed into an approximate parabolic curve. Tensile force is then applied to post-tensioning strands inserted through the post-tensioning ducts 204 in operation 136 described earlier to provide the remainder of the required prestressing force for the beam or girder 200 .
In accordance with another aspect of the present invention, a beam or girder having sufficient area at the beam or girder ends for accommodating post-tensioning tendons that pass through more than one beam or girder is provided to connect with another beam or girder which is aligned with the first and is located in an adjacent span to form a continuous structural frame. A continuous frame, in which two or more spans are connected, reduces structure cost and makes longer spans possible. Precast beams and girders that are connected by post-tensioning tendons at support points such as piers or columns to make a continuous frame require an area at the beams' or girders' ends to permit “through” tendons to connect adjacent spans. If the area at beam or girder ends is not available due to the presence of post-tensioning anchorages previously placed at the ends of girders in “end blocks”, as is the present practice, there is insufficient room for the through tendons to pass through to make the connection. The described beam or girder shape permits locating previously placed tendon anchorages at a distance away from beam or girder ends, thus creating room for tendons to pass through to make a continuous frame.
In accordance with another aspect of the present invention, a plurality of beams or girders 200 can be deployed to construct a cast-in-place concrete deck 300 , as shown in FIG. 3 . The deck 300 comprises at least two beams or girders 200 . The spacing between adjacent beams or girders 200 varies according to loading and length of a span to a maximum spacing, for example, 15 feet. Additionally, the deck 300 comprises one or more deck panels 302 . For example, each deck panel 302 may be a four-inch thick prestressed concrete slab. Also, each deck panel 302 may further comprise a continuous neoprene strip 304 at each end of the deck panel in contact with the beams or girders 200 that support the deck panel. Additionally, the outside beam or girder 200 at each edge of the deck 300 is provided with a flange 210 that is preferably precast with the beam or girder. The flange 210 completes the concrete form for the deck 300 and thus retains concrete poured to construct the deck 300 , as well as supports a finishing machine (not shown) employed to smooth the surface of concrete poured to complete the deck. As shown in FIG. 3 , the flange 210 may also be subsequently employed to support an attached barrier rail or curb 306 of the deck 300 installed at the edge(s) of the deck. The modular elements shown in FIG. 3 enable a bridge superstructure to be built quickly with high quality at low cost. By fabricating beams or girders 200 of higher concrete strength than in the past and using a commensurately higher prestressing force to produce greater structural capacities, significant economy is achieved by requiring fewer beams or girders for a given span and by the elimination of overhang forms and most on-site superstructure formwork by employing the modular elements shown in FIG. 3 .
While the foregoing description has been with reference to particular embodiments and contemplated alternative embodiments of the present invention, it will be readily appreciated by those skilled in the art that changes in these embodiments may be made without departing from the principles and spirit of the invention.
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A prescribed prestressing process is employed to construct precast concrete beams and girders. The process is utilized where an early concrete strength is too low for transfer of the full pre-tensioning force on a daily schedule to avert an otherwise serious and costly production delay. The process described provides the producer a reliable way of making beams and girders that are prestressed to take advantage of the higher concrete strength characteristics. The consequent economic advantage of higher structural capacity beams and girders is thereby realized. Additionally, beam or girder camber is controlled by the process, fostering production of a superior quality product.
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BACKGROUND
[0001] The present invention relates to exit devices, and more particularly to exit devices that are visible in low light or dark conditions.
[0002] An exit device is a manual or electronic door operating mechanism operated from the inside of a door. A conventional exit device generally includes a frame or housing secured across a door face and substantially spanning the width of the door. A touch bar is movably mounted to the frame. The touch bar is mechanically linked to a latch mechanism, including a door latch which is movably mounted in the frame adjacent to a free edge of the door. Manually depressing the touch bar in the frame toward the door translates the mechanical linkage for actuating the latch mechanism in order to retract the door latch so that the door can be opened allowing egress.
[0003] During low light or dark conditions, such as during a power failure, or in an emergency, it is important to those within the building to quickly identify building exit doors. Commercial buildings are required to have signs identifying exits as well as directional or warning signage, which indicate to building occupants a path for leaving the building in low light or dark conditions. A pathway marking system may include passive lighting, which does not require a power source, to demarcate the outlines or sections of buildings structures such as stair risers, intersections of walls and floor, sloped ramps, doorways, hallways, or the location of handrails, and the like. Some passive pathway marking systems utilize photoluminescent materials which provide low level light as they discharge their stored energy. Photoluminescent materials contain inorganic phosphorus and pigments that absorb ambient light. In darkness, the photoluminescent material produces a sustained visible yellow-green, red or blue glow which provides sufficient illumination for guiding someone out of a darkened area. Examples of photoluminescent materials include zinc sulfide and alkaline metal oxide aluminates, such as calcium sulfide and strontium sulfide.
[0004] Unfortunately, passive marking systems have not been applied to exit devices. Electroluminescent exit devices are available. However, an electroluminescent exit device requires electricity with battery back-up power, and includes electrical wiring which extends through the exit device, the door and one of the door hinges for connection to a source of power.
[0005] For the foregoing reasons, there is a need for a photoluminescent exit device which is visible in low light or dark conditions for directing an occupant to a point of egress of a room or a building. The new exit device should ideally function effectively as a passive lighting device in a pathway marking
SUMMARY
[0006] According to the present invention, a photoluminescent member is provided for an exit device, the photoluminescent member comprising a housing member for mounting to the exterior surface of the exit device, the housing member including a photoluminescent portion for being energized by exposure to an ambient light source and operable to automatically emit visible light photoluminescently for a substantial period of time in low ambient light or dark conditions and without being energized by an electrical current so that the photoluminescent portion provides illumination to identify the exit device in the low ambient light or dark conditions for providing a visual cue directing a person to a location of the exit device.
[0007] Also according to the present invention, an exit device is provided comprising a frame for attachment to a surface of the door, a door latch mechanism mounted to the frame, the door latch mechanism including a latch bolt movable relative to the frame from an extended position to a retracted position. Means for actuating the exit device are movably mounted to the frame and operatively connected to the latch mechanism for moving the latch bolt from the extended position to the retracted position when pressure is applied to the actuating means for opening the door. A photoluminescent member is mounted to the frame, the photoluminescent member including a portion for being energized by exposure to an ambient light source and operable to automatically emit visible light photoluminescently for a substantial period of time in low ambient light or dark conditions and without being energized by an electrical current so that the photoluminescent member provides illumination to identify the exit device in the low ambient light or dark conditions for providing a visual cue directing a person to a location of the exit device.
[0008] Further according to the present invention, a combination including a door pivotally mounted along one edge to a door frame and an exit device is provided. The exit device comprises a housing adapted to be secured to the door surface and a latch bolt disposed at one end of the housing adjacent an edge of the door and movable relative to the housing between a projected position extending outwardly of the housing for securing the door relative to the frame in a closed position and a retracted position where the latch bolt is inside the housing for allowing the door to be opened. An actuator is movably supported on the housing for movement relative to the housing from a first position to a second position and operatively connected to the latch mechanism for moving the latch from the extended position to the retracted position when pressure is applied to the actuator for opening the door in response to movement of the actuator toward the second position of the actuator. A photoluminescent member is disposed on the housing, the photoluminescent member being energized by exposure to an ambient light source and operable to automatically emit visible light photoluminescently for a substantial period of time in low ambient light or dark conditions and without being energized by an electrical current. The photoluminescent member provides illumination to identify the exit device in the low ambient light or dark conditions for providing a visual cue directing a person to a location of the exit device and the door.
[0009] Still further according to the present invention, a system is provided for indicating the direction of an exit route for use in a building including a door through which a person will move in following the exit route. The system comprises a door pivotally mounted along one edge to a door frame and an exit device. The exit device comprises a housing adapted to be secured to the door surface and a latch bolt disposed at one end of the housing adjacent an edge of the door and movable relative to the housing between a projected position extending outwardly of the housing for securing the door relative to the frame in a closed position and a retracted position where the latch bolt is inside the housing for allowing the door to be opened. An actuator is movably supported on the housing for movement relative to the housing form a first position to a second position and operatively connected to the latch mechanism for moving the latch from the extended position to the retracted position when pressure is applied to the actuating means is pushed for opening the door in response to movement of the actuator member toward the second position of the actuator member. A photoluminescent member is disposed on the housing, the photoluminescent member being energized by exposure to an ambient light source and operable to automatically emit visible light photoluminescently for a substantial period of time in low ambient light or dark conditions and without being energized by an electrical current. The photoluminescent member provides illumination to identify the exit device in the low ambient light or dark conditions for providing a visual cue directing a person to a location of the exit device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention, reference should now be had to the embodiments shown in the accompanying drawings and described below. In the drawings:
[0011] FIG. 1 is a perspective view of an exit device according to the present invention mounted on a door;
[0012] FIG. 2 is an exploded perspective view of the exit device shown in FIG. 1 with a latch cover, end plate and touch bar removed;
[0013] FIG. 3 is a longitudinal cross section of the touch bar shown in FIG. 2 ; and
[0014] FIG. 4 is a front elevation view of a touch bar with the word “EXIT” for use with the exit device according to the present invention.
DESCRIPTION
[0015] The present invention provides a photoluminescent exit device that is visible in low light or dark conditions. The exit device according to the present invention is for use in commercial applications and the photoluminescent feature may be adapted for use with any conventional exit device such as, for example, the exit devices described by U.S. Pat. No. 4,796,931; U.S. Pat. No. 5,042,851; U.S. Pat. No. 5,605,362 and U.S. Pat. No. 5,816,017, the contents of all of which are hereby incorporated by reference. Accordingly, detailed explanations of the functioning of all of the exit device components are deemed unnecessary for understanding the present invention by one of ordinary skill in the art.
[0016] Certain terminology is used herein for convenience only and is not to be taken as a limitation on the invention. For example, words such as “upper,” “lower,” “left,” “right,” “horizontal,” “vertical,” “upward,” and “downward” merely describe the configuration shown in the FIGs. Indeed, the components may be oriented in any direction and the terminology, therefore, should be understood as encompassing such variations unless specified otherwise.
[0017] Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout several views, FIG. 1 shows an exit device according to the present invention mounted to a door to be secured and generally designated at 10 . The exit device 10 includes an elongated frame 12 that is mounted at a horizontal position across the interior surface of the door 14 . The housing 12 comprises a touch bar 16 , a latch housing 18 at one end and a cover plate 20 having an end cap 22 at the other end. The touch bar 16 longitudinally spans a substantial portion of the housing 12 and defines a surface 24 for receiving a manual pushing force exerted toward the door 14 by a person attempting to egress through the door.
[0018] According to the present invention, at least a portion of the exit device 10 includes photoluminescent material which provides a light source in low light or dark conditions. In one embodiment of the present invention, the portion of the exit device 10 that comprises photoluminescent material is the touch bar 16 .
[0019] Referring to FIG. 2 , the latch housing 18 , touch bar 16 , and a front end cap 26 are shown separate from the remaining components of the exit device 10 . A door latch mechanism 28 and an actuator 30 are visible. The latch mechanism 28 may be of the type illustrated, or it may be a concealed or visible vertical rod type, or any other type of latch mechanism known in the art. The actuator 30 is movably mounted in the frame 12 and operably connected to the latch mechanism 28 . When manual pushing force is applied to the actuator 30 through the touch bar 16 , the latch mechanism 28 is operated allowing opening of the door 14 . It is understood that the actuator 30 may be a pushbar, push rail, push plate or other type of exit device actuator known in the art.
[0020] Referring to FIG. 3 , the touch bar 16 comprises a solid, generally C-shaped body having a front surface 32 and a back surface 34 . The body of the touch bar 16 terminates in opposed in-turned flanges 36 which cooperate to define a receiving track. The cross-section of the touch bar 16 is designed to correspond to the cross-section of the actuator 30 and the receiving track is dimensioned for receiving the upper and lower edges of the actuator 30 . With this configuration, when the latch housing 18 and the front end cap 26 removed ( FIG. 2 ), the touch bar 16 may be slipped lengthwise over the actuator 30 for releasably coupling the touch bar 16 to the actuator 30 and the exit device 10 structure. It is understood that such removable attachment of the touch bar 16 to the exit device 10 simplifies repair and allows retrofit of the photoluminescent touch bar 16 to an exit device which has a conventional touch bar.
[0021] In the one embodiment of the present invention, the front surface 32 of the touch bar 16 includes a photoluminescent material. The photoluminescent material can be applied to the front surface 32 of the touch bar 16 using a coating composition which includes a photoluminescent pigment. A suitable photoluminescent material is available from Luna Technologies International, Inc., of Kent, Wash., sold under the trade name LUNAplast™, and comprises a strontium aluminate formulation. This strontium aluminate formulation is described in published international patent application number WO 99/27294, entitled “Photoluminescent Light Emitter with Enhanced Photometric Brightness Characteristics,” published Jun. 3, 1999, the contents of which are hereby incorporated by reference. In a preferred embodiment, a stainless steel touch bar 16 is first cleaned and coated with a white epoxy enamel paint. After curing, the touch bar 16 is then coated with a proprietary powder product. The powder product is a TGIC polyester specially blended powder material. The touch bar 16 is then cured.
[0022] It is understood that many alternatives are available for rendering photoluminescence to the touch bar 16 , or any other component of the exit device 10 . For example, photoluminescent material is commercially available as an acrylic water-based paint, a tape, and in vinyl strips for application on a substrate. In addition, commercially available phosphorescent powders can be mixed with a suitable carrier to produce a paste that can be applied to the substrate. The tape or a strip of photoluminescent material may be affixed to the front surface 32 of the touch bar 16 with an adhesive such that the photoluminescent material overlays the touch bar 16 . Moreover, although the strontium aluminate is described above as a preferred photoluminescent material, zinc sulfide or other alkaline metal oxide aluminate-based photoluminescent material can also be used. In addition, it is understood that many alternatives for rendering photoluminescence to the exit device 10 , or any component of the exit device. The touch bar 16 is preferred, but is only one example. The most important feature is that the photoluminescent component provides visibility to an occupant of a building.
[0023] Alternatively, a photoluminescent material may be mixed with a formable structural material for producing a unitary product used a component of an exit device 10 , such as the touch bar 16 . In this embodiment, the touch bar 16 can be manufactured by an extrusion or molding process from rubber, vinyl, and the like, to name a few suitable materials. A hard, durable plastic is another example, such as an acrylic plastic or a polyethylene plastic. The selected material should be impact resistant. Other selection criteria for the material include expected life, cost and suitability for use as a component of an exit device. Photoluminescent dyes or particles of a photoluminescent material may be dispensed in the structural material prior to forming. Because the composition has been formed together, the photoluminescent material is spread throughout the depth of the touch bar 16 and the glow is emitted by the photoluminescent dye or particles within the body of the touch bar.
[0024] An exit device 10 with a photoluminescent touch bar 16 according to the present invention is visible in low light or dark conditions. The photoluminescent exit device 10 emits light for an appreciable time allowing an occupant to locate the exit device 10 and door 14 . The building occupant is thus directed to the exit device 10 by the glow of the touch bar 16 . Moreover, the touch bar 16 also provides a visual directional cue, signaling the location of the door and exit device 10 and the location of the actuator 30 for the exit device 10 . When the building occupant room needs to exit the building, the occupant applies pressure to the illuminated touch bar 16 thereby opening the door 14 for egress. Further, the exit device 10 may function as a part of an emergency egress indication system including the exit device 10 , signage, directional indicator stripes, doorway markings, stairway and lighting indication and the like.
[0025] A graphic, such as a sign or display may be included on the front surface 32 of the touch bar 16 . As shown in FIG. 4 , the word “EXIT” is mounted directly on the touch bar 16 . Other words, such as “EMERGENCY” or “EMERGENCY EXIT”, or symbols may be employed, such as an arrow or other indicia (not shown). The sign can be applied using an opaque material laid over the photoluminescent material, such as an opaque film adhesively attached to the touch bar 16 thereby masking out the emitted light. An opaque paint or dye may also be applied to the touch bar. This leaves essentially dark marking portions for blocking illumination from the light emitting background. Alternatively, the touch bar or other background can be blacked out, letting the sign glow in the dark. The opaque portions may form the lettering of the sign or the area around the lettering. Alternatively, dyes, stains, and inks can be applied over the photoluminescent material. The dyes, stains, or inks glow in the dark with a different color than that of the photoluminescent layer. Thus, the both the background and the markings emit light. The sign and photoluminescent background form a sign assembly visibly mounted on the exit device.
[0026] Other alternatives are possible in keeping with the present invention. For example, a layer of reflective material may be provided on top of the photoluminescent portion of the exit device. The reflective material will also act as a light source and also reflect light. Preferably, the layer of reflective material is transparent in addition to being reflective. This will allow light emitted from the photoluminescent material to pass through the reflective layer.
[0027] Although the present invention has been shown and described in considerable detail with respect to only a few exemplary embodiments thereof, it should be understood by those skilled in the art that we do not intend to limit the invention to the embodiments since various modifications, omissions and additions may be made to the disclosed embodiments without materially departing from the novel teachings and advantages of the invention, particularly in light of the foregoing teachings. For example, any component of the exterior of the exit device could be rendered photoluminescent. Accordingly, we intend to cover all such modifications, omissions, additions and equivalents as may be included within the spirit and scope of the invention as defined by the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.
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A photoluminescent member is provided for an exit device. The photoluminescent member comprises a housing member for mounting to the exterior surface of the exit device. The housing member includes a photoluminescent portion for being energized by exposure to an ambient light source and operable to automatically emit visible light photoluminescently for a substantial period of time in low ambient light or dark conditions and without being energized by an electrical current so that the photoluminescent portion provides illumination to identify the exit device in the low ambient light or dark conditions for providing a visual cue directing a person to a location of the exit device.
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FIELD OF THE INVENTION
The present invention relates to shock sensors incorporating a reed switch in general, and to shock sensors incorporating self-testing in particular.
BACKGROUND OF THE INVENTION
A typical automobile manufactured today has a number of active safety systems that function to deploy air bags, and initiate seatbelt retractors and other devices. As the cost of air bags decreases, and the sophistication of air bags increases, the number of air bags provided in each vehicle is increasing. Systems now being installed or under development include multiple air bags to protect the passenger from front, rear, and side impacts, and to position the passenger's body to withstand acceleration. Deployment of safety systems requires sensors that can detect and characterize a crash as it occurs. The widespread use of safety systems results in ever increasing attention to producing systems that can be economically employed on a large number of vehicles.
Typically, the lowest cost sensors are those formed as micro devices on an integrated circuit chip used to form electronic circuitry. This technology is used to fabricate accelerometers that can detect accelerations indicative of a vehicle crash. These sensors are particularly cost effective when the sensor can be fabricated together with the deployment logic circuitry using the same technology which is used cost effectively for large scale integrated circuit chips. However, the very small size of these devices makes them sensitive to electromagnetic interference and the like, which can result in false indications that a crash is taking place.
Thus an important role remains for macro scale mechanical devices which are less prone to false readings. Such devices are used to verify the existence of an actual crash event. These macro scale devices employ a sensing mass mounted on a spring or pendulum. Motion of the mass is detected by actuation of a reed switch or a magnetic field sensor.
The typical reed switch shock sensor employs a magnet, a spring, and a reed switch mounted in a housing. The three components are arranged so that under an acceleration-induced load the magnet acting as an acceleration sensing mass compresses the spring and moves to a position where the magnetic field of the magnet causes the reeds of the reed switch to attract and thus close the reed switch.
The reed switch shock sensor is a highly reliable component. However, many electronic circuits today incorporate built-in test, and the reed switch is indistinguishable from an open circuit unless the circuit board is undergoing the proper acceleration. Thus, in some cases the shock sensor may incorporate some method of self-testing which can verify the presence of the reed switch and which may cause the reed switch to operate. Such self-testing functions typically require additional parts, including the addition of a self-test electrical coil to cause the reed switch to close.
What is needed is a shock sensor employing a reed switch that can be self-tested without the addition of a test coil.
SUMMARY OF THE INVENTION
The reed switch based shock sensor of this invention provides means for passing electrical current through the spring used to bias the shock sensing magnetic mass in the unactuated position. The spring extends between a first stop and a shock sensing magnetic mass that is biased against a second stop. So long as the magnetic mass is held against the second stop, the reed switch remains open. A path for electrical current is created which leads through the coil spring used to bias the sensing mass. The coil spring is wrapped around the reed switch, allowing the coil spring to act as an electrical coil. The electric coil generates a magnetic field of sufficient strength to cause the reed switch reeds to attract and so close the reed switch, thus allowing the reed switch to be tested, without the addition of an electrical test coil.
It is a feature of the present invention to provide a shock sensor that facilitates built-in test.
It is a further feature of the present invention to provide a shock sensor having a reed switch that can be electrically detected.
It is another feature of the present invention to provide a shock sensor that can be actuated electronically for a self-test, without the addition of a test coil.
Further features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the shock sensor of this invention.
FIG. 2 is a cross-sectional view of an alternative embodiment of the shock sensor of FIG. 1 .
FIG. 3 in an enlarged detail view of the electrical connection between the housing and the spring of FIG. 1 .
FIG. 4 in an enlarged detail view of the electrical connection between the housing and the spring of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
Referring more particularly to FIGS. 1-4 wherein like numbers refer to similar parts, a shock sensor 20 is shown in FIG. 1 . The shock sensor 20 has a housing 22 . A reed switch 24 is mounted on the housing 22 , and a shock sensing magnet 26 is positioned for movement on the housing. The shock sensing magnet 26 is in the shape of a ring which is positioned coaxially about the reed switch 24 . A spring 32 biases a shock sensing magnet 26 against a first stop 28 formed by portions 30 of the housing 22 . The spring 32 extends between the magnet 26 and a second stop 34 spaced from the first stop 28 and spaced axially along the reed switch 24 .
When the shock sensor 20 undergoes acceleration due to a crash event, the magnet 26 compresses the spring 32 until the magnet moves to a second position adjacent the overlapping portions 36 of the reed switch reeds 38 . Properly positioned, the magnet will cause the reeds to take on opposite magnetic polarities and so attract to close the switch formed by the reed switch 24 .
It is generally not practical or desirable to test a reed switch shock sensor by subjecting it to shock levels simulative of a crash event. It is known in the prior art to place an electrical coil around the reed switch so that when the coil is energized the reed switch closes. It is also known to use an electric coil to cause the shock sensing magnet 26 to move so as to close the reed switch 24 . Such prior art solutions require the addition of an electrical coil, resulting in some increase in cost, size and part count. The shock sensor of this invention 20 is arranged to pass a current through the spring 32 which is used to bias the shock sensing magnet against the first stop 28 . A typical coil used to actuate a reed switch will employ a coil having thousands to tens of thousands of turns, and operation of the reed switch by energizing the coil will typically require a power of a small fraction of one Watt.
Through experimentation it has been shown that coil springs having, for example, between 26 and 33 turns, can support sufficient current to cause actuation of a reed switch in a shock sensor configuration. Table 1 provides test results for two coil springs: part number 251-90-226-00 which has 26 coils and a resistance of 7.3 ohms; and part number 251-90-084-00 which has 27 coils and a resistance of 10.8 ohms. Each coil was positioned about a series of reed switches (Hamlin type MLRR-4) with different ampere turn requirements, as shown in column one of Table 1, the reed switch having ampere turn requirements of 14, 15, 16 and 23 ampere turns.
TABLE 1
251-90-
Theoretical
Theoretical
Coil Spring
226-00
AT
251-90-084-00
AT
Coil Turns
26
27
Resistance (Ω)
7.3
10.8
Switch AT
Volts
Volts
14
3.90
13.89
7.10
17.75
15
4.25
15.14
7.57
18.93
16
4.48
15.96
8.50
21.25
23
8.20
29.21
14.10
35.25
24
25
29
TABLE 2
251-90-
Theoretical
Theoretical
Coil Spring
018-00
AT
251-90-071-00
AT
Coil Turns
29
33
Resistance (Ω)
6.9
10.6
Switch AT
Volts
Volts
14
1.72
7.23
5.40
16.81
15
2.94
12.36
5.90
18.37
16
3.85
16.18
6.40
19.92
23
6.20
26.06
10.80
33.62
24
7.63
32.07
25
7.92
33.29
29
10.30
43.29
Voltage across the coil spring was increased until the switch closed and the voltage at which the switch closed was recorded. The number of ampere turns (Theoretical AT) required was calculated by taking the voltage value at switch pull in, dividing that value by the resistance of the spring to get a value for the current and finally multiplying the value of the current by the number of turns on the spring.
Similarly, in Table 2, coil spring part No. 251-90-018-00 having 29 coil turns and resistance of 6.9 ohms, and part number 251-90-071-00 having 33 coil turns and resistance of 10.6 ohms were tested with switches having ampere turn requirements between 14 and as high as 29. Again the number of ampere turns (Theoretical AT) required was calculated by taking the voltage value at switch pull in, dividing that value by the resistance of the spring to get a value for the current and finally multiplying the value of the current by the number of turns on the spring.
Voltage values for switches with higher ampere turn requirements are not entered in the tables where the high voltages caused warping of the springs. Generally, a burning smell was noticed around 5-6 volts when the voltage was left on for around 25 seconds. Therefore it is concluded that reed switches should be used which are sensitive enough to respond to the ampere turns which can be achieved with four volts.
Looking at the power dissipated, it is evident that 4 Volts corresponds to about two Watts of dissipated power. As evidenced by the Theoretical AT becoming substantially greater than the Switch AT at the higher voltages, the resistance of the coil is increasing due to the increased coil temperature. If greater ampere turn values are required in any shock sensor which utilizes the coil spring as a test coil, increasing the number of turns in the coil and/or decreasing the resistance of the coil will be necessary to avoid excessive power dissipation with the attendant undesirable heating of the coil spring.
Referring to FIGS. 1 and 3, it is illustrated how an electrical voltage source 40 can be connected across the spring 32 , which extends between the magnet 26 and a portion of the housing forming a second stop 34 . Referring particularly to FIG. 3, the magnet 26 is shown plated with a conductive material 42 such as copper or silver so that current can readily flow between a contact 44 attached to the portion of the housing 30 forming the first stop 28 and a first end 46 of the spring 32 . Similarly a contact 48 is formed on the second stop 34 completing the electrical circuit from the electrical voltage source 40 to the second end 49 of the spring 32 . Although movement of the magnet 26 breaks the electrical connection between the spring and the contact 44 , this occurs only during crash induced acceleration.
Referring to FIGS. 2 and 4, an alternative embodiment shock sensor 50 is shown in FIG. 2 . The shock sensor 50 employs a reed switch 52 mounted on a housing 54 . A magnet 56 is movable on the housing and is positioned coaxially about the reed switch 52 . This shock sensor 50 has the overall configuration of the shock sensor shown in U.S. Pat. No. 5,212,357 to Reneau which is incorporated herein by reference. The housing 54 has a first stop 58 and a second stop 60 spaced a fixed distance from the first stop 58 .
The activation magnet 56 , being slidably mounted on the housing 54 , has a first portion 62 engaged against the first stop 58 and a second portion 64 which engages against the second stop. The magnet first portion 62 has a greater magnetic flux than the second portion 64 . The reed switch 52 is responsive to the position of the activation magnet 56 such that the reed switch is activated when the magnet travels to a preselected activation position during movement of the magnet in response to acceleration applied to the sensor. A coil spring 66 biases the magnet 56 such that the first portion 62 engages against the first stop 58 , and the coil spring 66 extends between the magnet 56 and the second stop 60 .
FIG. 3 shows how a voltage source 68 is connected across the spring 66 by an electrically conducting portion 70 of the magnet, which abuts a contact 72 fixed to the portion of the housing 74 forming the first stop 58 . A first end 78 of the spring 66 is thus in electrical engagement with the magnet 56 . The electrical circuit is completed by a second contact 76 affixed to the second stop 60 which engages a second end 80 of the spring 66 .
It should be understood that the magnet could be conducting or other means for applying electrical current to the coil spring could be employed.
It should be understood that the coil spring through which the current passes must be positioned so as to result in a magnetic field that causes the reeds of the switch to attract, thus closing the reed switch.
It should be understood that the number of ampere turns required to activate a given reed switch is dependent on the detail configuration of the coil, and so the rated ampere turns is to some extent a relative measurement.
It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims.
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A reed switch based shock sensor provides for passing electrical current through the coil spring used to bias the shock sensing magnetic mass. The spring is wrapped around the reed switch, allowing the coil spring to act as an electrical coil. The coil generates a magnetic field of sufficient strength to cause the reed switch reeds to attract and so close the reed switch, thus allowing the reed switch to be tested without the addition of a test coil.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for the automatic sensing and positioning of a registration mark, indicia, or line target having finite contrast, either optically, magnetically, acoustically or electromagnetically relative to adjacent background utilizing a pseudo match of sensor width to registration mark width.
2. Description of the Prior Art
Mark sensing and scanning apparatus are disclosed in U.S. Pat. No. 3,335,281 to S. P. Willits. Such apparatus utilized a single sensor, having a particular physical width and length, in a cyclic scanning system. FIGS. 1, 4 and 5 in the prior patent show the waveform as generated by the photosensor scanning a given mark. The disclosure in this patent provides an insight into the capabilities of a system utilizing a sensing apparatus which automatically determines and adjusts the scan amplitude relative to the position error of the registration mark. Among these capabilities are a system for obtaining automatic scan amplitude change; higher positional accuracy due to higher loop gain with reduced scan amplitude of the scanning sensor; and demodulation of the sensor's output after amplification in a symmetrical, amplitude saturated amplifier.
While the apparatus suggested by this prior art patent solved many of the apparent problems present at that time, associated with "mark" positioning, and in most instances, provided excellent results for a wide variety of target width and target contrast ratios, it had definite limitations and restrictions in both loop gain characteristics and positional accuracy required by today's wide varieties of target and by the requirement to position to a very high degree of accuracy.
The concept of a "pitch match" sensor array for counting stacks of material having essentially the same thickness or pitch for each of the tightly packed sheets, is disclosed in: the Mohan & Willits U.S. Pat. No. Re. 27,869, where the concept of "pitch match" is described; the Mohan et al. U.S. Pat. No. 4,373,135, where the concept of a pseudo pitch match sensor array is described; and the Mohan et al. U.S. Pat. No. 3,663,803 where an apparatus for specific mark code decoding of a coded panel having relative linear velocity to a pitch matched sensor array is described.
The target sensor characteristics common to all of these pitch match devices are the cyclical repetitive nature of the data base presented to the sensing array and the signal enhancement gained by the technique of achieving the equivalent of spatial filtering by adapting either a single sensor into a pseudo pitch match sensor array or by physically matching a multiple sensor scanning array into a desired spatial pitch match array.
The positioning apparatus and method of the present invention are utilized in a device which automatically senses an indicia on a workpiece and positions the workpiece to bring the indicia into registration by diminishing registration error to near zero. More particularly, the device and method are adapted to sense preferably elongate indicia of varying widths utilizing a positioning apparatus with one or more sensing heads which automatically adapts its sensing modes utilizing comparisons of delayed time data with real time data to a variety of indicia widths and degrees of registration error to rapidly bring the indicia into accurate registration.
As explained above, automatic positioning devices for workpieces have been in existence almost since the beginning of the manufacture of controls. Their goal is to rapidly and accurately position a workpiece for some further operation. Typically, the workpiece to be positioned will bear one or more indicia which will allow the positioning device to accurately sense the indicia and then accurately position the workpiece or bring the workpiece into registration. Typically, the speed of positioning must be traded off against the accuracy of the final registration position for fixed control parameters and fixed inertia associated with the workpiece and movable elements of the positioning device.
The apparatus of the present invention senses an indicia and then moves the workpiece to bring the indicia into registration. The assignee of this application, Spartanics Ltd. of Rolling Meadows, Ill., owns a number of U.S. Patents disclosing apparatus for sensing an indicia or positioning a workpiece bearing an indicia or, in a somewhat unrelated field for sensing and counting sheets in a stack. Among these patents are the following, the disclosure of each of which is hereby incorporated by reference:
______________________________________U.S. Pat. No. Patentee______________________________________3,335,281 WillitsRe. 27,869 Willits et al.3,790,759 Mohan et al.3,813,523 Mohan et al.4,373,135 Mohan et al.4,542,470 Mohan et al.______________________________________
The significant teachings of these prior patents to the apparatus and method of the present invention are set forth below:
U.S. Pat. No. 3,335,281 to Willits is for a SYMMETRICALLY SATURATED POSITION SERVO CONTROL WITH DUAL AMPLITUDE OPTICAL OFFSET SCANNING. The control of this patent employs a single scanning head to sense each indicia. Further, by employing amplifiers in a saturated mode which does not affect the harmonic content and phase relationship of the sensing signal, the harmonic content and phase relationship being position dependent, exceptional stability over wide variances in loop gain is achieved. Until an indicia is sensed and moved near registration, the scan amplitude of the scanning head is large. Thereafter, the scan amplitude is reduced to provide for more accurate registration. While this control solved many problems in this field twenty-odd years ago, it is relatively intolerant of wide variations in indicia characteristics and is somewhat inaccurate in positioning by today's standards.
U.S. Pat. No. Re. 27,869 to Willits and the present inventor, William Mohan, is for a PITCH MATCHING DETECTING AND COUNTING SYSTEM utilized in counting sheets in a stack. While counting is a far different activity from positioning, this system does employ a sensing head which must distinguish between each of several objects to be counted by distinguishing each object from a near negligible interstitial boundary between the object and adjacent objects. Here the concept of matching a pair of sensors to the width of the object to be counted (pitch matching) was employed to spatially filter unwanted harmonics with their significant contribution to error. When a pair of PM sensors are employed, the phase shift between their respective signal combinations may be employed as an error signal, indicating the degree to which pitch match is achieved. A single sensor oscillating between two limits of oscillation may, if suitably manipulated, provide signals equivalent to that provided by a sensor pair.
U.S. Pat. No. 4,373,135 to Mohan, Willits and Kleemann is for a PITCH MATCH DETECTING AND COUNTING SYSTEM that is an improvement to the system disclosed in U.S. Pat. No. Re. 27,869. This patent discloses the employment of a tapped delay line to synthesized from a single sensor, the equivalent of one or more sensors whose signal outputs are the equivalent of those generated by a sensor array, pitch matched spatially or optically. A sensor signal generated in counting a stack of similar objects or elements is cyclic as the sensed area passes over a plurality of objects which are substantially identical. When a pair of sensors, or sensor arrays, are employed, the signals produced in each by a given, particular element is substantially identical to the other but displaced in time, or phase shifted, as a result of the spatial displacement of the sensors one from the other.
According to the teachings of the present invention, once a single sensor signal is generated (given known parameters) it may be electrically stored and employed to automatically produce a pseudo sensor whose signal is pitch matched to the equivalent of a pitch match system, although the real sensor effective width may be very narrow in comparison with the counted object width or pitch.
SUMMARY OF THE INVENTION
According to the invention there is provided a method for quickly and accurately positioning a workpiece, which is situated on a movable platform and which has at least one indicia mark thereon having a different sensitivity to a sensing means than an adjacent contrast area, to a position where the indicia mark is in registry with a registration axis, said method comprising the steps of:
effecting a scan of a sensing means transverse to the registration axis in the area on said workpiece through which said registration axis extends with sensing means that are capable of generating electrical signals related to what is sensed;
providing in said sensing means a sensor system;
processing the electrical signals generated by said sensor system in a manner whereby some of the signals are treated as the scan data of a first sensor and the other of the signals are treated as the scan data of a second sensor;
setting the effective width of the sensor system at rest to a value which is no greater than slightly greater than the width of said indicia mark;
setting the amplitude of the scan which is effected transversely of the indicia mark when the indicia mark is close to the registration axis to be equal substantially to one sensor width about a center axis of said sensing means;
setting the center axis of said sensing means in registration with said registration axis;
setting the PITCH, namely the area to be scanned by the sensor system to MATCH substantially the scan amplitude plus the effective width of one sensor;
combining the scan signals designated as being the signals of a first sensor with the scan signals designated as being the signals of a second sensor to generate an error correction signal;
supplying said error correction signal to means for controlling movement of said platform to move said platform an incremental amount; and
repeating the above steps until the error correction signal is at a null indicating registration of the indicia mark with said registration axis.
Further according to the invention there is provided an apparatus for quickly and accurately positioning a workpiece, which is situated on a movable platform and which has at least one indicia mark thereon having a different sensitivity to a sensing means than an adjacent contrast area, to a position where the indicia mark is in registry with a registration axis, said apparatus comprising:
sensing means;
means for effecting a scan of said sensing means transverse to the registration axis in the area on said workpiece through which said registration axis extends, said sensing means being capable of generating electrical signals related to what is sensed and including a sensor system;
means for processing the electrical signals generated by said sensor system in a manner whereby some of the signals are treated as the scan data of a first sensor and the other of the signals are treated as the scan data of a second sensor;
means a value which is for setting the effective width of the sensor system to a value which is no greater than slightly greater than the width of said indicia mark;
means for setting the amplitude of the scan which is effected transversely of the indicia mark when the indicia mark is close to the registration axis to be substantially equal to one sensor width and about a center axis of said sensing means;
the center axis of said sensing means being in registration with said registration axis;
means for setting the effective area to be scanned by a single sensor the PITCH, to MATCH substantially the scan amplitude plus one sensor width;
means for combining the scan signals designated as being the signals of the first sensor with the scan signals designated as being the signals of the second sensor to generate an error correction signal; and
means for supplying said error correction signal to means for controlling movement of said platform to move said platform an incremental amount.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged plan view of a registration mark and a sensor assembly used in one embodiment of the scanning system of the present invention.
FIG. 2 is a schematic circuit diagram, partly electrical and partly mechanical, of one scanning system constructed according to the teachings of the present invention wherein two sensors Sa and Sb are used as shown in FIG. 1.
FIGS. 3, 3A, 3B, 3C and 3D is a plan view of a sensor assembly comprising the sensors Sa and Sb and of the waveforms generated by moving sensors Sa and Sb over a mark where the sensors Sa and Sb (S') have a width of 4 units the mark line width LW=4, the scan peak-to-peak amplitude SA is 4 and there is a "pitch match" of (Sa+Sb)=(SA+S')=8.
FIGS. 4, 4A, 4B, 4C and 4D is a plan view of the sensor assembly comprising the two sensors Sa and Sb and of waveforms generated by the spatial (array) movement of the sensors Sa and Sb over the mark where there is no "pitch match" and where the pitch P=6 units each sensor has a width of 4 units and LW=4 units and SA=2 units.
FIGS. 5, 5A, 5B, 5C and 5D is a plan view of the sensor assembly comprising the two sensors Sa and Sb and of waveforms generated by movement of the sensors Sa and Sb over the mark where there is no "pitch match" and where the pitch P=12 units, each sensor has a width of 4 units and LW=4 units and SA=8 units.
FIG. 6 is a schematic circuit diagram, partly electrical and partly mechanical, of another scanning system constructed according to the teachings of the present invention wherein one sensor having a width matched to the width of the mark is used.
FIG. 7 illustrates five graphs A, B, C, E and G of the system positional error gain dependency characteristic as a function of five different scan amplitudes for a particular line width and sensor width utilizing delayed data comparison and plotting demodulated voltage vs "Mark" displacement for the five different scan amplitudes.
FIG. 8A is a set of waveforms comparing the waveform of scan real time null voltage with a 360° delayed image thereof.
FIG. 8B is a similar set of waveforms but showing a waveform for an error voltage for a mark displaced from a null by 0.001 inch.
FIGS. 8C and 8D are waveforms generated by forward and reverse spatial scans with FIG. 8C showing a waveform of real time scan data at null and with FIG. 8D showing a stored waveform at real time of past scan data at null.
FIG. 9 is a schematic circuit diagram, partly electrical and partly mechanical, of a further cyclic scanning system constructed according to the teachings of the present invention including a single very narrow width sensor for achieving a pitch match pseudo scanning system capable of optimizing the positional gain characteristic for all "Mark" indicia target widths.
FIG. 10A is a set of waveforms of the real time voltage and the delayed voltage (180° out of phase) at the null condition (registration) for a "pitch match" of 0.020 inch.
FIG. 10B is a set of waveforms of the real time voltage and the delayed voltage (180° out of phase) for a deviation from null of 0.0012 inch for a "pitch match" of 0.020 inch.
FIG. 10C is a set of waveforms of the real time voltage and the delayed voltage (180° out of phase) at the null condition (registration) for a "pitch match" of 0.010 inch.
FIG. 10D is a set of waveforms of the real time voltage and the delayed voltage (180° out of phase) for a deviation from null of 0.001 inch for a "pitch match" of 0.010 inch.
FIG. 11 illustrates seven graphs (j)-(m), (p) and (r) of the gain transfer characteristic for different pitch match and scan target mark with combinations plotting demodulating voltage versus "mark" displacement.
FIG. 12A is an enlarged plan view of a stationary sensor array used in still another embodiment of the scanning system of the present invention.
FIG. 12B is a schematic circuit diagram, partly electrical and partly mechanical, of still another scanning system constructed according to the teachings of the present invention wherein a stationary sensor array as shown in FIG. 12 is employed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail, there is illustrated in FIG. 1 an enlarged view of a scanning wand 10 having a single sensor Sa or Sb, here defined as S', mounted at the distal end thereof. This scanning wand 10 is caused to reciprocate a predetermined distance, transversely of the elongate axis 11 of the wand about a scan axis 12 (FIG. 2) over a target area 16 (FIG. 2). The target area 16 includes a registration axis 18 which is directly beneath the scan axis 12 and the objective is to position a workpiece 20 having a registration mark 21 on the registration axis 18 quickly and accurately so that an operation such as a cutting or stamping operation can be performed on the workpiece 20. The length, width or distance of reciprocation of the wand 10 is referred to as the scan amplitude SA. The width of the mark 21 is defined as LW.
It is to be understood that the reciprocation of the wand 10 is achieved by "waving" the wand about its proximal end with the motor 14 such that the sensor S' at the distal end of the wand actually moves through a slight arc which has a large radius relative to the distance of reciprocation or scan amplitude SA that for the purpose of the scanning systems of the present invention one can assume that the wand 10 is reciprocated side-to-side as illustrated in FIG. 1.
According to the teachings of the present invention to obtain quick and accurate registration of the mark 21 with the registration axis 18 and the scan axis 12, the scan peak-to-peak amplitude SA is so adjusted as to also match the effective width of a single sensor Sa or Sb, defined herein as S'.
"Pitch match" as used herein is defined as having a scanning sensor (pair Sa and Sb) effective width at rest (not scanning) equal to the effective width utilized by the single sensor (Sa or Sb) in its scanning mode.
Thus the pitch match condition is where Pitch, P, is the effective area scanned by a single sensor Sa or Sb; scan peak-to-peak amplitude is SA; and S' is either Sa or Sb:
Sa=Sb=SA=P/2=S' 1.
Sa+Sb=P 2.
SA+S'=P 3.
With these conditions of scan, each sensor Sa and Sb will generate an identical train of waveform data for the mark 21 centered on the scan axis 12. The waveform data generated for sensor (Sa and Sb) scan for various scan relationship conditions are shown in FIGS. 3-5.
In FIG. 2 one scanning system 30 constructed according to the teachings of the present invention is schematically illustrated. The system 30 includes a source of illumination 31 which is directed to the workpiece and utilizes a pair of matched sensors Sa and Sb which function in a scanning mode to sense reflected light from the workpiece to achieve the desired characteristic of a Pitch-Match scanning system. In particular, the system 30 is designed to have a desired positioning characteristic for a particular set of mark, width, scan amplitude and sensor pair width conditions.
In the embodiment the scanning wand 10 has a matched pair of sensors Sa and Sb mounted thereon and is driven by the motor 14 powered by an excitation voltage Ve to produce a peak-to-peak scan amplitude SA (FIG. 1).
The system 30 further includes signal processing circuitry 34, and drive circuitry 36 for operating the scan motor 14 for causing oscillation of the wand 10. Also, a lens 38 is provided below the sensor pair Sa and Sb to the width of the mark 21 image "pitch" area, P, located in a contrast area 40 on the workpiece 20 in a "mark continue window 41" upon the sensor pair.
System control logic 42 controls operation of the scan motor 14 for oscillating the wand 10 in wide scan and pitch match scan. A two phase servo motor 44 having windings 44a and 44b for positioning the workpiece is controlled by an error-voltage-responsive servo power amplifier 46.
The sensors Sa and Sb generate signal waveforms which are supplied to preamplifiers 48 and 50. The outputs from these preamplifiers 48 and 50 are supplied through coupling capacitor C1 and C2 to a summing amplifier 52. Likewise, the same outputs are supplied through coupling capacitors C1 and C2 to a subtracting amplifier 54. The waveform generated by sensor Sa is 180° from the waveform generated by sensor Sb and the two waveforms are summed in summing amplifier 52 after decoupling the d.c. with capacitors C1 and C2 from the preamplifiers 48 and 50 to obtain a null or error voltage.
The summation of the waveform generated by sensors Sa and Sb in the subtracting amplifier 54 results in a contrast signal whose magnitude is used to define a true null, i.e. when the output of amplifier 52 is a null--the output of amplifier 54 will state that the null is due to a positioned null not a zero target input. Any positional departure of the "mark" 21 from the true center of scan (axis 12 and 18) will generate a pair of displacement data signals in the preamplifiers 48 and 50, which will produce an error voltage in the summation amplifier 52 having a frequency of (f1), the scan frequency, and a phase relationship that is 180° apart for the mark displacement movement either "in" or "out" beyond the registration on center axis 18.
The error voltage on line 56 is further amplified in the A.C. power amplifier 44 and used to reposition a platform 58 which is driven by the servo (2 phase) motor 44 to reposition the mark 21 situated on the workpiece 20 to maintain the mark 21 at an exact centered position to the scan axis 12.
FIG. 3 shows a Pitch-Matched (PM) Scanning Condition, the width of Sa, Sb, and S' each equal 4 units, (Scan Amplitude, i.e. (P.P.)=SA equals 4 units, LW equals 4 units, and P=SA+S'=8; Sa+Sb=8; or (Sa+Sb)=(SA+S'S)=PM. Waveforms 3a and 3b, are generated at null wherein data generated from sensor Sa is 180° out of phase with data generated from sensor Sb.
Adding these two waveforms in amplifier 52 (FIG. 2) after decoupling the D.C. with capacitors C1 and C2 from preamplifiers 48 and 50, will produce a null positioned "mark" error voltage 60 shown as waveform 3C (FIG. 3).
FIGS. 4 and 5 show the waveforms which are generated from sensors Sa and Sb when amplitude SA is less than the width S'=Sa=Sb=LW (FIG. 4) or greater, than the width of S=Sa=Sb=Sb=LW (FIG. 5).
A unique feature of the present invention is the utilization of a method for setting the PITCH, which is defined as the effective area to be scanned by the sensor system, to MATCH substantially the scan amplitude plus the effective width of one sensor in order to quickly and effectively bring a mark into registry with a registration axis.
In another embodiment of the scanning system of the present invention a single sensor 68 is utilized in a unique manner in a cyclical scanning technique to provide a scanning system 70 (FIG. 6) which has some of the advantages of a "pitch match" cyclical scanning system. The system 70 is shown in FIG. 6 and includes a scan motor 72 and the two phase servo motor 44. The system 70 provides a positional, servo control voltage that is derived from the utilization of the single scanning sensor 68 whose real time output signal waveform 76 (FIGS. 8A and 8C) is differentially compared to a specific time delayed, stored image signal waveform 78 (FIGS. 8A and 8B) of its past opposite direction scan. Waveform 60 is the error voltage and waveform 80 is the logic control voltage which is a summation of waveforms 76, (a), and 78, (b). Here, the combining of the waveforms 76, (a), and 78, (b) is a subtracting of one from the other as opposed to the adding of the waveforms shown in FIGS. 3A and 3B in summing amplifier 52. In this embodiment, the width S' is equal to LW.
Since many of the components of the system 70 are identical to components of the system 30 like reference numerals are utilized to identify identical components.
In FIG. 6 the scanning sensor is positioned and centered relative to the mark 21, i.e., exactly on scan axis to the mark 21 and the sensor 68 is oscillating through the mark 21, first forward then backward as caused by the cyclical scan excitation voltage having a frequency f1. For this example, f1 is sixty cycles per second. This scan excitation voltage will generate a cyclic data rate of forward and reverse scans of f2 equal to 2f1 in scan sensor 68.
If one then provides a storage time delay T between the present scan data (output voltage 76 at frequency) f2 and the stored past scan data (output voltage 78) equal to the time of one cycle of f2, the data cyclic rate at null would, in essence, be comparing in real time: the forward scan data to the past historical backward scan data, and the real time backward scan data to the past historical forward scan data as shown in FIGS. 8A through 8D, where waveform 76 (φa) is the real time scan data and waveform 78 (φb) is the stored past scan data.
If the mark 21 registration axis 18 is perfectly centered on the scan axis 12 and there are no irregularities in the mark 21, the scan, the sensor's 68 uniformity, or the illumination, each direction of scan would look and generate data exactly the image of the others stored past data.
Taking the difference electrically, of these two signal waveform data trains, will produce a zero voltage at null, i.e, the mark 21 position is centered. Any deviation of the mark registration axis 18 from the reference scan axis 12 will produce an A.C. error signal 60 (FIGS, 8A and 8B), whose fundamental signal component will be at the basic scan reference frequency f1 and whose amplitude magnitude and phase polarity will depend on the direction and magnitude of the mark displacement from null reference position. The positional error voltage or null signal 60 will be essentially a harmonic free - zero voltage at null, having an abrupt 180° phase reversal as the mark 21 moves through the center of scan reference position or scan axis 12, thus presenting a uniquely clean, proportional, positioned control voltage for use in a material (workpiece 20) control positioning system 70.
Demodulation of the positional error control voltage 60 will provide the same characteristic for a D.C. control system.
Unlike the prior art, whose positional error voltage changes from a fundamental into a large second harmonic voltage near or at null position of scan, as shown by FIG. 8A by waveform 76 (φa), thereby placing limitations on the control characteristic. System 70, by comparing the scan real time null voltage, waveform 76 (φa) with its 360° delayed image, waveform 78 (φb), and taking the difference thereof, produces a true zero voltage control signal at null position, as shown by the error voltage waveform 60 (equal to 0 at null) shown in FIG. 8A and by the error voltage waveform 60 (greater than 0 for a mark displacement from null of 0.001") in FIG. 8B.
The system 30 shown in FIG. 2 for positional mark sensing lacks the ability to present a constant, positional loop gain for all index mark widths encountered for positioning.
Both system 30 and system 70 also lack the above ability. System 30 and 70 have these attributes only for a single unique relationship of the mark 21 width to the sensor 68 width to scan amplitude, where a pseudo pitch-match can be achieved.
In system 70, if the single sensor 68 width is 1/2 of the width of the mark sensing area P and the scan amplitude is also 1/2 of this width P as shown in FIG. 1, and the waveform data generated is combined in a specific manner, a "pseudo" pitch match scanning system is achieved. But again, this is only achieved for a single unique relationship of single sensor width to scan amplitude to mark P area, as disclosed below.
Referring again to the single sensor 68 and the system 70 shown in FIG. 6, if the clocking rate to delay line 84 is changed to a frequency fc of double the rate of that which generated the 360° delay of waveform data from the single sensor 68, or keeping the same clock rate but using the waveform data out of a tap (16) rather than tap (32), i.e. half way through the delay line 84 feeding a resistor R4 of the amplifier 54 and then adding this data into the summing amplifier 52 by moving the resistor R7 to the junction of resistors R5 and R6, one, in effect, generates data of a pseudo sensor 1/2 width of the mark area P provided that the single sensor 68 and the scan are each of the same effective width. In effect, a pair of matched sensors, one real time spatially and one temporal, are generated for feeding the output waveform data into the amplifier 52 to develop a positional control (error correction) output voltage 60.
FIG. 7 shows the system positional error gain dependency characteristic as a function of scan amplitude, for a particular line width and sensor width utilizing the delayed data comparison, as described above for the system shown in FIG. 6.
Inspection of FIG. 6, in light of the prior art, as described in Willits U.S. Pat. No. 3,335,281, and the system 70 described above, reveals the following observations for a particular set of scan parameters. With the single sensor 68 exactly matched in width to the mark target 21, relatively little scan amplitude will be required to develop full servo error control voltage for a minute displacement of the mark from the center of scan axis 27. This gain dependency on scan amplitude characteristic is shown in the graphs A, B, C, E and G shown in FIG. 7 where the "S" number is the curve slope ratio, and applies to the pseudo sensor system 70. For this system of mark positioning, the system positional servo loop gain is controlled by the change of phase of the sensor's output scan signal with a given change in mark displacement. Thus, the servo loop gain increases rapidly as the amplitude of scan is reduced. This is a highly undesirable condition of operation for a system which should be universally capable of operating on any width positioning mark. Thus the requirement of a Pitch-Match Cyclic Scanning System.
The graphs A, B, C, E and G in FIG. 7 are for a line width of 0.020 inch, a sensor width of 0.020 inch, and a time delay of T˜360° of a 60 Hz scan motor excitation voltage for differing scan amplitudes set forth below:
______________________________________Graph Scan Amplitude LW:SA Pitch Match______________________________________A 0.005 4:1 NoB 0.010 2:1 NoC 0.020 1:1 YesE 0.040 2:1 NoG 0.080 4:1 No______________________________________
The definition of "pitch-match" has been described in the various prior patents referred to above. It is a generic term applied to mean matching the effective width of a sensor or sensor array to the pitch of the particular target area in question. In counting, "pitch" has been defined to mean the width of a single element in a stack of sheet material being scanned. In reality it is the width of a single element, or sheet of material along with is minute interstitial contrasting space between the adjacent single sheet comprising the stack.
For the system 70 of the present invention, where a scan through a mark is carried out in a contrasting background for determining its position, the "pitch" is defined as the width of the area utilized by the single scanning sensor 68 as it traverses from one side of the contrasting background 40 through the mark to the other side of the background 40 in a single direction of scan, to generate a cycle or waveform of sensor data. FIG. 1 graphically shows this for both a cyclic scanning system, single sensor 68 (scanning wand 10) whose width is 1/2 of the pitch P and the linear scan system, as used in counting, and for a sensor pair of sensors Sa and Sb each one matched to 1/2 of the pitch P with a linear velocity Vt.
One preferred method of adapting a single, very narrow width, sensor 88 in a cyclic scanning system to achieve a "pitch-match" pseudo scanning system 110, capable of optimizing the positional gain characteristic for all mark indicia targets widths is shown in FIG. 9. The system 110 is one preferred system.
In operation of the system 110, a single, very narrow width sensor 88, as compared to a "mark" 121 indicia width situated in contrasting background 128 is cyclically scanned by a motor 130, excited by a controllable amplitude A.C. reference voltage 132. The scan motor 130 causes a sinusoidal velocity of scan by sensor 88 situated in wand 134 of the mark field 136 containing indicia mark 121 so imaged upon photosensor 88 by a lens system 138. The mark illumination has not been shown for convenience. It may be top illuminated for opaque material or bottom illuminated for transparent material.
The positional amplitude of scan about the mean scan reference axis 140 is determined by the magnitude of the scan excitation voltage 132. The magnitude of the phase relationship of scan is from -π/2 to +π/2 radians of scan excitation drive voltage 132. See FIGS. 1, 3, 4, and 5. The sinusoidal velocity vector 142 of the scan sensor 88 can be considered to be normal to the mark 121 and to have a near uniform linear velocity over the area of scan at or near the null reference position axis 140. The initial output of sensor 88 appearing at the output of signal amplifier 148 will have the same general appearance as in the prior art U.S. Pat. No. 3,335,281 except with added higher harmonic due to the narrow width of the sensor 88 profiling the target brightness characteristics. This signal is then processed through A.G.C. amplifier 150 to maintain its analog integrity and to prevent saturation of tapped analog delay line 152. It will be understood that the clocking rate of data through delay line 152 is established at sampling rate of 16 bits per cycle of data when a scanning voltage excitation 132 of 60 cycles per second f1 is utilized to produce a data rate of 2f1, i.e., data at null f2=2f1. The sampling or clocking rate of this 120 Hz input data will be such as to generate a pair of pseudo sensor waveform data trains, for each direction of scan within the 32 taps of the delay line 152. Therefore each pseudo sensor will consist of the sum of 16 output tap bits, requiring a clocking rate of f2×2×16=3840 cy/sec. This, multiplied by two, for a required two-phase input 154 of the delay line 152 require a clocking rate for an oscillator 156 of 7680 cycles per second. The oscillator clock 156 requires further synchronizing to scan excitation voltage frequency 132 and is locked into an f1 submultiple by a locking amplifier 158. This clocking rate is for this example only.
If we consider the sensor's effective width much smaller than the mark 121 width, the pitch of the scanned area P will be essentially that of the scan amplitude S.A.
With the above clocking criteria, the delay line 152 will automatically produce a pair of sensor signal waveforms, each one half the width of this pitch, by: summing output taps 1 through 16 of delay line 152 via a resistor bank 161, and by: summing output taps 17 through 32 via resistor bank 162. The output of resistor bank 161 is supplied to an input 164 of an operational amplifier 166 and the output of resistor bank 162 is supplied to an input 168 of an operational amplifier 170. The two waveform data trains from these amplifiers, 166 and 170, which are 180° out of phase at null mark position, are added through resistors 171 and 172 to provide a uniquely clean positional error control voltage 60 (FIGS. 10A-10D) out of summing amplifier 180.
For system 110, pitch (P) is defined as having the same effective physical dimensions as the peak-to-peak amplitude of scan, SA, assuming the scan sensor's width SW is very narrow as compared to the scan amplitude SA or the width LW of the mark. As such, the system 110 of FIG. 9 generates a pair of pseudo sensors having the effective width of the peak-to-peak scan amplitude SA. Further, if the system 110 of FIG. 9 is established or operated to first have a wide scan amplitude, i.e, ±0.05" greater than the mark width and centered about its reference axis 140, then a wide scan area can be utilized as a mark capture window 190 including registration axis 140. The system's servo positioning devices, comprising power amplifier 194 for converting the error voltage from null amplifier 180 then will properly drive a servo motor 196 to effect a "1st null" of the mark 121.
A system control logic unit 200 is provided, which receives an error control signal E,60 and which, in conjunction with the scan amplitude control logic 184 will automatically reduce the scan amplitude SA to the required pitch match width LW, once the mark is captured and positioned to the 1st null. The mark width is set in the system 110 by a dial 201.
The system 110 will then reposition the mark to a "fine-tuned" 2nd null, whose servo gain transfer characteristic will be essentially constant for all mark widths LW so dialed in and so matched to the final scan amplitude SA for final high gain closedloop servo positioning.
FIGS. 10A-10D are graphs of pseudo sensor signal waveforms wherein waveforms 202, φa, and 204, φb, are taken from output of amplifiers 166 and 170 respectively and the null error voltage E, (60) out of amplifier 180. The error signal BS 206 in FIGS. 10A-10C is the voltage at output 182 of amplifier 148 which is supplied to scan amplitude control logic 184.
It is to be noted that the graphs 10A-10D also represent the waveforms generated by the dual sensor system 30 shown in FIG. 2.
In this respect any positional departure of the "mark" 21 (FIG. 2) from the true center of scan 12 will generate a pair of displacement data signal waveforms identical to waveform 202, for pseudo sensor Sa, and 204, for pseudo sensor Sb, (180° out of phase with 202) in amplifiers 48 and 50 and as shown in FIG. 10B or FIG. 10D. The summation of these waveforms will produce the error control voltage 60 in the summation amplifier 52 having a frequency of f1, the scan frequency and a phase relationship that is 180° apart for mark displacement movement either "in" or "out" beyond the center axis 12.
In FIG. 11 are shown graphs of this characteristic where graphs j, k, l are for marks having a 4:1 ratio in width but enjoy an essentially constant displacement gain characteristic. Graphs m, n, p and r show the relative change of loop gain for non-pitch-match scan target combinations.
The parameters for graphs j, k, l, m, n, p and r are as follows:
______________________________________Graph SA LW PM______________________________________j 0.010 0.010 yesk 0.020 0.020 yesl 0.040 0.040 yesm 0.020 0.010 non 0.040 0.020 nop 0.060 0.040 nor 0.080 0.010 no______________________________________
Referring again to FIG. 9, tapped analog delay line 152 shows a system of 16 summed output taps per pitch-matched pseudo sensor. This number of taps is a convenience and in no means is the system 110 to be restricted to this number of taps--a lesser or greater number of taps can be utilized per pseudo sensor.
Further the scanning resistors comprising resistor banks 161 and 162 are of identical value, to give the equivalence of a rectangular weighted summation network. The Hamming values for each resistor comprising resistor banks 161 and 162 could also be incorporated to reduce some of the higher values of harmonic of the pseudo sensor's output--as utilized in the Mohan, et al. prior U.S. Pat. No. 4,373,135.
For the delay system of FIG. 6 the width of a single sensor 88 should be equal to or less than the width of a mark to be scanned, as in the system 70 where a delayed means of achieving a null voltage is used.
In the full pseudo system of FIG. 9, in order to ensure that an undesirable situation of exceedingly high positional servo gain is not inadvertently created by having the effective scan amplitude width exactly equal to the width of the effective mark width, to generate a pseudo pair of sensors 16, 16' or 116, 116', equivalent of a spatial pair of match sensors in PM mode wherein the Scan Amplitude is approaching zero, it is best to require the scan amplitude mark width dial 202 to be set to a definite amplitude value slightly greater than the "mark width" to give an effective known servo gain characteristic for each setting thereby to provide a finite gain characteristic for all width marks utilized for positioning or a secondary servo gain dial can be provided for selectable setting of one of a family of gain characteristics which are the same for any mark width so set in. Since, in the pseudo system 110, S' the sensor width and can be as little as 0.005". The effective scan amplitude SA should be no less than twice the sensor width plus the mark line width to ensure a finite gain characteristic.
Accordingly, to dial in a selectable servo gain, this dial could modify the scan amplitude by a selected additional width.
Multiple line pairs of pseudo sensors can be utilized on multiple mark targets, to gain further noise filtering, if required, as in multi-line pair arrays of the prior art systems for linear scanning.
A method of adapting a multiplicity or bank array of fixed very narrow width sensors, all situated in a linear, self-scanning array, such as a sensor array known as "The Reticon Series" into a Pitch-Matched Cyclic Scanning System, is shown schematically in FIGS. 12A and 12B.
The previous utilization of the Pitch-Match Cyclic Scanning techniques as disclosed herein were based upon a single sensor or dual sensor array situated within a wand whose axis of scan served as the mechanical reference null position of the indicia mark and whose effective mechanical optical scan of that indicia mark was at right angles or normal to that indicia long axis.
With the advent of modern technology and the development of self-scanning linear arrays, the cyclic mechanical scanning wand can be replaced by a fixed bi-directional self-scanning linear array 220 (FIG. 12A), having as few as 64 sensing elements 221 or as many as 4096 sensing elements 221 per direction of scan, all confined within a very small package.
FIG. 12B shows two linear arrays, 220a, 220b, fixed in space having its center or center axis 222 of active array utilized as the center of null reference axis 222, so imaged upon a mark indicia 224 by a lens 226 and at right angle to the indicia mark positional direction of correction as to detect and correct any misposition of the mark indicia 224 from the sensor array fixed axis 222 of reference by a bi-directional cyclic scanning of a linear array.
It is to be noted here that a source of illumination not shown is directed toward the mark indicia and reflected or scatter light (or the lack thereof) is sensed by the sensing elements 221.
The utilization of the dual or bi-directional self-scanning linear arrays 220a and 220b to generate the equivalent of the prior described mechanical cyclic optical scanner and whose output is directly application to the control of an A.C. servo system or D.C. system, function is described below:
First of all, FIG. 12A graphically depicts a pair of 64 element self-scanned arrays 220 centered over the mark 222 of having a width LW. The total array (N1 to N64) is so imaged on the mark scan area as to represent a capture window width of 0.10"(for this example).
A scanning system 230 utilizes the arrays 220a and 220b is shown in FIG. 12B. Since many components of the system 230 are identical to components in the system 110 shown in FIG. 9, the same reference numerals are used for the same components.
An oscillator 232 supplies scan logic control 234 with a synchronous single phase, hi-speed clock signal, to generate a scan. An internal counter in the logic control 234 will establish a 60 cycle scan of the array (both forward and backward) by setting the array clock frequency to the appropriate frequency of 2×60×64=7680 cycle per second. The start of the scan logic control 234 is supplied by the counter therein. The sequential analog 120 cy. output data of the two arrays 220a and 220b are serially outputted, to a signal conditioner 236, comprising low pass filter and amplitude control for proper operation of the storage delay line 152. The data bits are recombined in the delay line 152 to effect a pseudo pair of scanning sensors as described for FIG. 9.
Once first (or coarse) null is centered within the wide scan of 64 elements of the arrays 220a and 220b the mark width dial 210 having been set to match the mark width LW will effect a very high speed scan of elements #1 through N, then normal speed 60 cps scan through the (N+1) element of 221 through to (N+Pn) element of 221 and then very high speed scan of elements (N+Pn+1) through to element #64. The reverse scan of array 220b would be the reverse scanning of element by the array 220b. This would effect a narrow aperture scan amplitude equivalent to the match of the mark indicia (LW+2 element of the array).
A two phase clock of delay line 152 via a two phase generator 238 would have the same relationship to the scan data as in the system 110 shown in FIG. 9 and is so adapted to this by counting down the high speed common clock signal from oscillator 232 by dividing by N counter 240.
The above description of a bidirectional self-scanning linear array or dual array of FIGS. 12A and 12B involves construction of the system 230 to stimulate the identical type of scan data as generated by a mechanical, sinusoidal, spatial scanner.
Without sacrificing the inherent accuracy of this bidirectional system of dynamic scanning an area for mark positioning, the method shown in FIGS. 12A and 12B can be reduced to a single unidirectional self-scanning linear array.
If the second array 220b is eliminated and we just forward scan with the first array 220a as described for the complete forward scan system, then one will feed just this data into the delay line 152 to develop the pseudo pair of sensors and their output data. In this way,, one will develop a dual train of output data as illustrated in graphs 3A-3D in FIG. 3 for the mark centered. Any deviation of the mark from center will result in a phase sensitive sub-harmonic control signal by the addition of these waveforms as in FIG. 3C.
Rather than a reverse scan back through the array, the system would rapidly recycle for another forward scan. Thus, insuring a multiplicating of successive forward scans whose mark error displacement data will be derived from the differential summations of the two pseudo data train as graphically shown in FIG. 3C.
Although the systems 30, 70, 110 and 230 have been described utilizing the electromagnetic spectrum for positioning control systems, it is to be understood that other suitable means, such as magnetic, acoustic, etc., can be utilized.
From the foregoing description, it will be apparent that the systems 30, 70, 110 and 230 of the present invention have a number of advantages, some of which have been described above and others of which are inherent in the invention. Also, from the foregoing description, it will be apparent that modifications can be made to the system 30, 70, 110 or 230 of the present invention without departing from the teachings of the invention. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims.
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The method and apparatus are utilized for quickly and accurately positioning a workpiece, which is situated on a movable platform and which has at least one indicia mark thereon having a different sensitivity to a sensing means than an adjacent contrast area, to a position where the indicia mark is in registry with a registration axis. The method includes the steps of: effecting a scan of the sensing means transverse to the registration axis in the area on the workpiece through which the registration axis extends with sensing means that are capable of generating electrical signals related to what is sensed; providing in the sensing means a sensor system which can function as one or two sensors, real or pseudo; processing the electrical signals generated by the sensing systems in a manner whereby some of the signals are treated as the scan data of a first sensor, real or pseudo, and the other of the signals are treated as the scan data of a second sensor, real or pseudo; setting the effective width of the sensor system at rest to be no greater than slightly greater than the width of the indicia mark; setting the amplitude of the scan which is effected transversely of the indicia mark when the indicia mark is close to the registration axis to be substantially equal to a real or pseudo single sensor width and about a center axis of the sensing means; and setting the center axis of the sensing means in registration with the registration axis.
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BACKGROUND
This invention relates generally to swivel joints, and in particular to swivel bearings for use in swivel joints.
Swivel joints are commonly utilized in conduit systems in which conduits connected in end-to-end relationship require relative conduit movement, either in an angular or rotative manner, and where the integrity of the conduit system is to be preserved during such deformation. Conventional swivel joints have incorporated ball and socket arrangements, elastomeric seals, rotative seals and other mechanical devices which permit the interconnected conduits limited relative movement. Conventional swivel joints are commonly used in locations hundreds of feet below the surface of a body of water and the exteriors of the swivel joints are subjected to very high fluid pressure. Furthermore, the interiors of the swivel joints may also be subjected to very high fluid pressures.
Conventional swivel joints presently available for use under such adverse conditions have not proven as dependable and rugged as desired.
The present invention is directed to overcoming one or more of the limitations of existing swivel joints.
SUMMARY
According to one embodiment of the present invention, a swivel joint is provided that includes a body coupled to a first conduit, a sleeve coupled to a second conduit adapted to be received by the body, a retaining member coupled to the body, including a counterbore adapted to receive the sleeve, a chamber defined by the sleeve and retaining member, and a body of fluid contained within the chamber.
According to another embodiment of the present invention, a method of coupling a first rigid conduit to a second rigid conduit is provided that includes transmitting axial loads between the first and second conduits using a body of fluid.
The present embodiments of the invention provide a swivel joint that eliminates the creation and transmission of torsional and shear loads when one or more of the conduits are axially loaded. As a result, the operational life of the swivel joint, as well as the conduits coupled by the swivel joint, is greatly enhanced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating a first embodiment of a swivel joint.
FIG. 2 is a cross-sectional view illustrating a second embodiment of a swivel joint.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, the reference numeral 10 refers, in general, to a swivel joint according to an embodiment of the invention for coupling a conduit 12 to a conduit 14 . The swivel joint 10 includes a body member 16 defining a central through bore 16 a and having an annular flange 16 b formed at one end thereof and surrounding the bore for connecting to the corresponding end of the conduit 12 in any known manner, such as by welding. An enlarged counterbore 16 c is formed in the other end of the body member 16 for reasons to be described.
A sleeve 18 has an annular flange 18 a extending from one end thereof which extends in the counterbore 16 c of the body member 16 in a sliding fit. A threaded counterbore 18 b is formed in the other end of the sleeve 18 , and a central bore 18 c extends through the length of the sleeve 18 .
A retaining member 20 is provided for connecting the sleeve 18 to the body member 16 and includes a counterbore 20 a for receiving the sleeve 18 and a central bore 20 b . A pair of seal rings 22 a and 22 b are provided in two axially-spaced annular grooves, respectively, that are formed in the outer surface of the sleeve 18 . The seal rings 22 a and 22 b engage the corresponding inner wall of the retaining member 20 to seal the interface between the sleeve and the retaining member. An annular chamber 24 is defined between the bottom of the counterbore 20 a of the retaining member 20 and the corresponding end of the sleeve 18 . A seal ring 26 extends in an annular groove formed in the bottom face of the counterbore 20 a for reasons to be described. A lubricating fluid is disposed in the chamber 24 . A plurality of angularly spaced bolts 28 , two of which are shown in FIG. 1, extend through corresponding openings formed through the retaining member 20 and into corresponding internally threaded openings formed in the body member 16 to fasten the retaining member to the body member with the sleeve 16 captured there between.
A portion of a tubular member 30 extends in the bore 20 b of the retaining member 20 and has a central through bore 30 a . The tubular member 30 has an externally threaded end portion 30 b that extends in the internally threaded counterbore 18 c of the sleeve 18 in a threaded engagement. The other end of the tubular member 30 is connected to the corresponding end of the conduit 14 in a conventional manner, such as by welding. A pair of seal rings 34 a and 34 b extend in axially-spaced annular grooves formed in the inner surface of the retaining member 20 and engage the outer wall of the tubular member 30 to seal the interface between the retaining member and the tubular member.
The bores 16 a , 18 c and 30 a of the body member 16 , the sleeve 18 , and the tubular member 30 respectively, define a continuous bore that extends between, and in an aligned, coaxial relationship with the bores 12 a and 14 a of the conduits 12 and 14 . Thus, fluid can pass between the conduits 12 and 14 and through the swivel joint 10 .
During operation of the swivel joint 10 , axial loads applied to the second conduit 14 are transmitted to the lubricating fluid provided in the chamber 24 thus eliminating any significant torsional loads on the swivel joint 10 . Therefore, the operational life of the swivel joint 10 is significantly increased. In the event of leakage of any lubricating fluid from the chamber 24 , the O-ring seal 26 prevents metal to metal contact between the end walls 18 e and 20 c and any seizure of the swivel joint 10 .
Referring to FIG. 2 of the drawings, the reference numeral 100 refers, in general, to a swivel joint according to an alternate embodiment of the invention for coupling a conduit 112 to a conduit 114 . The swivel joint 100 includes a body member 116 defining a central through bore 116 a and having an annular flange 116 b formed at one end thereof and surrounding the bore for connecting to the corresponding end of the conduit 112 in any known manner, such as by welding. An enlarged counterbore 116 c is formed in the other end of the body member 116 for reasons to be described.
A tubular member 118 defining a central through bore 118 a has an annular flange 118 b extending from one end thereof which extends in the counterbore 116 c of the body member 16 in a sliding fit. The tubular member 118 further includes an annular flange 118 c extending from an intermediate portion thereof. The other end of the tubular member 118 is connected to the corresponding end of the conduit 14 in a conventional manner, such as by welding.
A retaining member 120 is provided for connecting the tubular member 118 to the body member 116 and includes a counterbore 120 a for receiving the annular flange 118 c of the tubular member 118 and a bore 120 b for receiving an end of the tubular member 118 . A pair of seal rings 122 and 124 are provided in two axially-spaced annular grooves, respectively, that are formed in the outer surface of the annular flange 118 c of the tubular member 118 . The seal rings 122 and 124 engage the corresponding inner wall of the retaining member 120 to seal the interface between the sleeve and the tubular member. A radially inclined annular chamber 125 is defined between the inclined bottom of the counterbore 120 a of the retaining member 120 and the corresponding inclined end of the annular flange 118 c of the tubular member 118 . A pair of seal rings 126 and 128 extend in two spaced annular grooves formed in the inclined end of the annular flange 118 c for reasons to be described. A lubricating fluid is disposed in the chamber 125 .
A pair of seal rings 130 and 132 are provided in two axially-spaced annular grooves, respectively, that are formed in the inner surface of the bore 120 b of the retaining member 120 . The seal rings 130 and 132 engage the corresponding outer surface of the end of the tubular member 118 to seal the interface between the retaining member 120 and the tubular member 118 .
A plurality of angularly spaced bolts 134 , two of which are shown in FIG. 2, extend through corresponding openings formed through the retaining member 120 and into corresponding internally threaded openings formed in the body member 116 to fasten the tubular member 118 to the retaining member 120 .
The bores 116 a and 118 a of the body member 116 and the tubular member 118 respectively, define a continuous bore that extends between, and in an aligned, coaxial relationship with the bores 112 a and 114 a of the conduits 112 and 114 . Thus, fluid can pass between the conduits 112 and 114 and through the swivel joint 100 .
During operation of the swivel joint 100 , axial loads applied to the second conduit 114 are transmitted to the lubricating fluid provided in the chamber 129 thus eliminating any significant shear or torsional loads on the swivel joint 100 . Therefore, the operational life of the swivel joint 10 is significantly increased. In the event of leakage of any lubricating fluid from the chamber 129 , the O-ring seals 126 and 128 prevent metal to metal contact between the end walls 18 e and 20 c and any seizure of the swivel joint 10 .
The swivel joints of the present disclosure provide several advantages. For example, the inclusion of a swivel bearing in the form of an annular body of lubricating fluid eliminates the generation of any torsional or shear loads. Furthermore, the addition of resilient members within the chambers housing the lubricating fluid of the swivel bearing prevents seizure of the swivel joints in the event of leakage of the lubricating fluid from the fluid chambers. Therefore, the swivel joints of the present disclosure maximize the useful operational life of conduits while also minimizing the generation of harmful torsional and shear loading conditions on the conduits.
It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, the chambers 24 and 129 may include a plurality of chambers that are axially and/or radially and/or angularly spaced apart in order to receive the lubricating fluid and provide additional axial load bearing capacity. Furthermore, the chambers 24 and 129 may be inclined at any angle relative to the axial direction in order to optimally accommodate axial and/or normal forces. In addition, the lubricating fluid provided in the chambers 24 and 129 may at least partially include gaseous and/or solid materials in order to minimize frictional forces. Although illustrative embodiments of the invention have been shown and described, a wide range of modification, changes and substitution is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.
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A swivel joint for coupling a first conduit to a second conduit includes a swivel bearing comprising a body of fluid. The swivel bearing eliminates the creation and transmission of torsional and shear loads when one or both of the conduits are axially loaded.
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CROSS REFERENCE TO THE RELATED PATENT APPLICATION
This application claims the priority right of the Chinese patent application No. 200510085875.7 filed on Jul. 18, 2005.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an electrical connection device, more particularly, relates to an electrical connection device with flexible wire.
2. Description of Prior Art
The electrical equipments in the prior art, such as TVs, refrigerators, washing machines, rice cookers, etc., are require wires to connect to peripheral devices or power source. Although there already has a few wireless connection devices, it is not broadly employed due to the high cost. As the length of wires in the prior art is unchangeable and can not be packed away, especially when they not in use, in this regard, plurality of wires is exposed in the working environment of the equipments, this will affects the appearance of the equipments as well as the working efficiency. Particularly with the situation of broad popularization of computers, more and more wires are needed, such as power supply wires, keyboard wires, mouse wires, printer wires, LAN wires etc, further more, various communication devices, such as mobile phones, digital devices (e.g., wires, data cables and charger wires of digital cameras etc.); with all these wires around the working platform, it will be very inconvenient if the wires be twisted. In fact, some of the wires are temporally unused but there's no place to store them; some of the wires are longer than they are required, but can not be shorted; moreover, some of the wires are shorter than it is required, but they are not extendable.
SUMMARY OF THE INVENTION
The object of the current invention is, to provide an electrical connection device with flexible wire, to solve the problems of the connection and storage of the wire.
The technical feature of the current invention for solving the problems is: provides an electrical connection device, which includes a position holding bar, a switching device sleeves outside of the position holding bar, and a wire twining device with position limiting button. The wire twining device comprises an active turnplate, an electrical connection wire enlaced on top surface of the turnplate, an active touching point fixed on the lower surface of the turnplate, and a reset spring fixed in a round ridge of the lower surface of the turnplate; the outer end of the enlaced wire is electrically connected with an active wire exit port, the inner end of the enlaced wire is connected with the active touching point of the turnplate; a fixed touching point that corresponding to the active touching point is set on the connection device, so that the active touching point keeps the electrical connection with the fixed touching point of the connecting device while the electrical connection wire is twined with the turnplate.
Advantageously, the fixed touching point is two or more concentric circle electric tracks that fixed on the switching device.
Advantageously, the active touching point is a lug boss made of bended tip of the inner end of the enlaced wire, the lug boss reveals outside of the ridge of the bottom of the turnplate, and electrically connected with the fixed touching point of the circle electric tracks of the switching device.
Advantageously, the turnplate is a 3-level-structure turnplate, where a disk with larger diameter is set in the middle level, and its centre is corresponds to the position holding bar; a hollow bar on the upper side of the turnplate extends upward for enlacing wire, and a pair of baffles is deposited inside the hollow bar, the bottom surface of the baffle is formed a first incline surface, and there's a thickness difference between two ends of the baffle of the first incline surface. A round ridge on the lower side of the turnplate is extends downwards, and a reset spring is deposited inside the ridge, two pairs of symmetrically distributed partial annular ridges are set on the outside of the round ridge, and there is a hole is cut on one end of each partial annular ridges, The inner side of the wire is pulled through the hole to wedge inside the partial annular ridges.
Advantageously, the active touching point can be electric track that wedged inside two or more annular ridges that on the underside of the turnplate. The fixed touching point is at least two metal protrudes fixed on the switching device, and electrically connected with the electric track.
Advantageously, the turnplate may also be a 3-level-structure turnplate. Where a disk with larger diameter is set in the middle level, the centre of the turnplate is a hole that corresponds to the position holding bar on the lower shell body, a hollow bar on the upper side of the turnplate that for enlacing wire is extends upwards, and a pair of baffles is deposited inside the hollow bar, the bottom surface of the baffle is formed a first incline, and there's a thickness difference between two ends of the first incline surface. A round ridge on the lower side of the turnplate is extends downwards, and a reset spring is deposited inside the ridge, symmetrically distributed partial annular ridges are fixed on the outside of the round ridge. A hole is cut on each of the annular ridges. The inner side of the wire is pulled through the hole and circle wise wedged inside the annular ridges.
Advantageously, the position limiting button comprises a non circular bar with its upper end inserted inside the button hole of the upper shell body, the shape of the non circular bar is corresponds with the shape of the hole, a bar with larger bottom diameter and a pair of position limiting pieces fixed on it; The upper surface of the position limiting piece is formed a second incline surface, which matches with the first incline surface of the baffle; and a spring hole is fixed on the bottom of the position limiting bottom, which support the position holding bar of the bottom shell body by a spring.
Advantageously, the inner end of the reset spring is bended to form a first hook and wedged on the position holding bar of the bottom shell body; and the outer end is bended to form a second hook and wedged on the round ridge of the turnplate.
Advantageously, the electrical connection device further comprises a shell body for fixing the switching device and the position holding bar, the shell body comprises a hole that separate the outer end of the wire from the active wire exit port.
Advantageously, the switching device comprises a printed circuit board (PCB) and a circuit unit that connected with the wire enter port, the element of the circuit unit is installed on the (PCB).
The benefits of implementing this invention are: in accordance with this invention, the wire can be stored inside the shell body, and installed on or inside the electrical equipments. The power supply ports of electrical equipments are connected to wire entrance. When in use, only needs to pull out a required length of wire, and when not in use, only needs to press the position limiting button to retract the wire back to the shell body. In this case, the wires are controlled conveniently. By implementing the flexible wires, the mass of wires are reduced, as well as saving spaces.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is the front view of the electrical connection device of the present invention.
FIG. 2 is the section view of the electrical connection device of FIG. 1 .
FIG. 3 is the exploded view of the electrical connection device from top to bottom, in accordance with an embodiment of the present invention.
FIG. 4 is the exploded view of the electrical connection device from bottom to top, in accordance with an embodiment the present invention.
FIG. 5 is the top view of the turnplate of the electrical connection device, in accordance with an embodiment the present invention.
FIG. 6 is three-dimensional view of the turnplate of the electrical connection device, in accordance with an embodiment the present invention.
FIG. 7 is three-dimensional view of the reset spring of the electrical connection device, in accordance with an embodiment the present invention.
FIG. 8 is three-dimensional view of the position limiting device of the electrical connection device, in accordance with an embodiment the present invention.
FIG. 9 is the top view of the electrical connection device without top shell body, in accordance with an embodiment the present invention.
FIG. 10 is the bottom view of the turnplate of the electrical connection device, in accordance with another embodiment of the present invention.
FIG. 11 is the bottom view of the switching device of the electrical connection device, in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in accordance with the drawings and the following embodiments.
As shown in FIG. 1 and FIG. 2 , according to one embodiment of the present invention, the main structure of the electrical connection device comprising a top shell body 13 , a bottom shell body 14 , elements contained in the inner space that formed by the top and bottom shell bodies, and a wire exit port 11 and a wire enter port 12 that extend outside of both sides of the shells. A tenon is set on the periphery of the top shell body 13 , and a hook is set on the tenon. Correspondingly, the periphery of bottom shell body 14 is fixed with an upward extending mortise having a slot that is engaged with the hook of the top shell body. The top shell body 13 and bottom shell body 14 forms an outer shell of the electrical connection device by the engagement of the tenon and mortise.
FIGS. 3 and 4 are exploded views of the electrical connection device from top to bottom and from bottom to top, in accordance with an embodiment the present invention. As shown, there are notches set on both sides of top shell body 13 and bottom shell body 14 respectively, when the top and bottom shell body closed together, it forms a relevant wire entrance 121 and wire exit 111 . An enlacing outer end 22 of the wire 2 is pulled out from the wire exit 111 and electrically connected with the wire exit port 11 . An enlacing inner end 21 of the wire is electrically connected to wire enter port 12 via switching device 3 .
A position limiting button hole 15 is set on the top surface of the top shell body 13 , and a position holding bar 16 which extends upwards is fixed on the bottom surface of the bottom shell body 14 . The position limiting button hole 15 is formed by the left and right cylindrical surfaces and the front and back surfaces. A position holding hole 161 is set on position holding bar 16 along the axis orientation, and two notches 162 are cut symmetrically on the side wall of the position holding bar 16 .
Elements contained in the inner space that formed by the top and bottom shell bodies comprises a switching device and a wire enlacing device with position limiting button that sleeve on the position holding bar 16 in sequence. The wire enlacing device includes a position limiting button 4 , a turnplate 6 , a wire 2 enlaced on the top surface of the turnplate 6 , a reset spring 7 located on the lower surface of the turnplate 6 . As shown in FIG. 5 and FIG. 6 , the turnplate 6 is a 3-level-structure turnplate, a disk with larger diameter and exact size to fit into the inner space of the shell body is in the middle, while a hole 61 is cutting in the centre of the disk and the disk is sleeved onto the position holding bar 16 through this hole. A hollow bar 62 extends upwards from the top surface of the turnplate and a certain length of wire 2 enlaces on the hollow bar 62 . A concentric hollow bar 66 with a smaller diameter is disposed on the inner side of the hollow bar 62 , an annular slot 67 is formed between the hollow bar 62 and 66 , as shown in FIG. 5 . A pair of baffles 661 is symmetrically fixed on the top portion of the inside wall of the hollow bar 66 , the top surface of the baffle 661 is on the same level with both hollow bars; and the bottom surface of the baffle is the first incline surface, there is thickness difference between two ends of the first incline face, and there also has a certain space between the bottom surface of the baffle 661 and the top surface of the turnplate. In addition, two notches are symmetrically cut on the side wall of the hollow bar 62 , and a narrow slot 65 is cut on the top disk surface and from inside to outside, multiple holes 641 at the end of the narrow slot 65 are set to drill through the disk. When enlacing the wire 2 , put the enlacing inner end of the wire 2 into the annular slot 67 , then pull out the wires through the two notches of the hollow bar 62 to separate the wires into two parts according to the types of the wires, and then insert the wires into the narrow slot 65 , meanwhile, pulling each part of the wires from holes 641 to the other side of disk. Therefore, the amount of holes 641 is depends on the amount of parts that formed wire 2 .
As shown in FIG. 6 , a round ridge 63 is downwards extends from the bottom side of the active disk 6 , a notch 631 is cut on the side wall of the round ridge 63 , and the reset spring 7 is deposited inside the ridge 63 . The reset spring 7 is made of an enlacing metal slice that has been entwined several circles. As FIG. 7 showing, the inner metal slice of the reset spring 7 is bended to form a first hook 71 and the outer metal slice is bended to form a second hook 72 . When in using, the first hook 71 buckles in the notch 162 of the position holding bar 16 , and the second hook 72 buckles in the notch 631 of the round ridge 63 . In this case, reset spring 7 can be frapped along with the turning of the turnplate 6 around the position holding bar 16 to create elastic deformation that has reset trend, therefore, leads the turning of the turnplate 6 when resetting. As shown in FIG. 6 , partial annular ridges 64 are symmetrically distributed on the outer side of the ridge 63 , the number of the partial annular ridges 64 are in accordance with the number of forming parts of wire 2 ; and one end of the partial annular ridges 64 is exactly begins from the hole 641 . The wire 2 is drawn from top to bottom of the disk through hole 641 and its each part of inner ends 21 is deposits into the partial annular ridges 64 separately, And a metal tie-in 211 is soldered on the end of each part of the enlacing inner ends 21 . The tie-in 211 of wire 2 can be a cooper wire, or other conductive metal wire with high rigidity. Both ends of each tie-in 211 are bended to form a “V” shaped lug boss 2111 and expose to outside of the partial annular ridges 64 to form the active touching point of the electrical connection device.
As shown in FIG. 3 , the switching device 3 of the electrical connection device of the present invention sleeves on the position holding bar 16 located inside the bottom shell body 14 through the centre hole, and is further fixed inside the bottom shell body 14 through the present mode of position holding hole. The wire enlacing device is above the switching device 3 . The switching device 3 comprises a PCB and a circuit unit 32 installed onto the PCB. The circuit unit 32 is connected with the wire enter port 12 , with LED light to indicate the working status of the electrical connection device. The Switching device 3 further includes two or more concentric circle electric tracks 31 which are centered at the position holding bar. The electric tracks 31 are working as fixed touching point, and correspond to the lug boss 2111 of the enlaced wire inner end 21 , and it further forms an electrical connection by tightly contacting with the lug boss 2111 . The electric tracks 31 could be a printed circuit set on the switching device 3 , which has electrical connection with circuit unit 32 . In this regard, when turnplate 6 is turning, lug boss 2111 may rotate along with the electric tracks 31 while keeping tight electrical connecting between them. Therefore, implement the electrical connection between the inner end of the enlaced wire 2 and wire enter port 12 via switching device 3 .
The upper end of the position limiting button 4 of the wire enlacing device is inserted into the position limiting hole 15 of the top shell body 13 , the lower end supports with the position holding hole 161 of the position holding bar 16 by spring 5 . As shown in FIG. 8 , position limiting button 4 is a non-cylinder that its top shape corresponds with the position limiting button hole 16 , a cylinder with larger bottom diameter, and a pair of position limiting piece 41 on the wall of the cylinder. The bottom of the position limiting piece 41 is on the same level with the bottom of the cylinder. The top surface of the position limiting piece 41 is the second incline surface, which matches with the first incline surface of the baffle 611 on the turnplate 6 , has a certain thickness difference on both ends along the direction of the second incline surface. Also a spring hole is fixed on the bottom of the position limiting button 4 , and one end of the spring is deposited into the spring hole, the other end is inserted into the position holding hole 161 of the position holding bar 16 .
According to another embodiment of the present invention, as shown in FIG. 10 , round ridge 63 is extends from the lower surface of the turnplate 6 , notch 631 is cut on the wall of the ridge 63 , and resetting spring 7 is contained inside the ridge 63 and wedged in the notch 631 by the second hook 72 . Two or more concentric annular ridges 64 ′ is distributed outside the round ridge 63 , the number of the ridges 64 ′ are accordance with the forming elements of the wire 2 , and hole 641 is exactly positioned into the round ridges 64 ′. Each part of the metal wire of the inner end 21 of enlaced wire pulled from upper disk to lower disk via holes 641 are contained in the annular ridges 64 ′ respectively, to form the annular electric track. Or, the metal tie-ins soldered on each end of the enlaced wire 21 , then clip inside ridge 64 ′ to form annular electric tracks. The tie-ins can be a certain length of copper wire, or other conductive metal wire with high rigidity. In this regard, the annular electric tracks form the active touching point of the electrical connection device.
Correspondingly, as shown in FIG. 11 , switching device 3 on the bottom of the active disk 6 sleeved on the position holding bar 16 , and fixed on the bottom shell body 14 via the mode of position holding hole. Two or more metal protrudes 31 ′ are fixed on the switching device 3 , their positions are corresponding with each annular ridge 64 ′ of the active disk 6 . The top of the metal 31 ′ extends into annular ridge 64 ′, and formed as fixing touching point tightly and electrically touching with the electric track 2111 ′ of the annular ridge 64 ′. Another end of the metal 31 ′ is connected to the circuit unit 32 . Thus the switching device 3 can be a piece of POB with metal protrude 31 ′ jointed thereon. In this regard, when active disk 6 is turning, electric track 2111 ′ rotating also, and the metal protrude 31 ′ keeps tight electrical connection between the electric track 2111 ′ and the active disk 6 while sliding relatively. Therefore, implement the electrical connection between the enlacing inner end of wire 2 and wire entrance 12 via switching device 3 .
The principle of how the wire can be extended and rolled by the electrical connection device will describe as following.
When the electrical connection device is not in use, as shown in FIG. 9 , wire 2 is deasil enlaced inside the electrical connection device, the exiting end of the active wire is situated at the wire exit port 11 ; Position limiting button 4 is extended outside the top shell body 13 , spring 5 and resetting spring 7 is in original status. The thicker end of the position limiting piece 41 and the thicker end of the baffle 661 supported to each other, and the thinner end of the position limiting piece 41 and the thinner end of the baffle 661 is in the status of back to back. The turnplate 6 can not turn anti-clockwise due to the upper end of the position limiting button is limited by the position limiting hole 15 , and it is further prevents the turnplate 6 from turning clockwise due to the elastic deformation effect of the resetting spring 7 .
If longer wire is needed while in use, the user may pull the wire exit port 11 to pull the wire 2 out of the wire exit 111 . In this regard, due to the pulling of wire 2 , active disk 6 may overcome the elasticity of resetting spring 7 to turn clockwise, forcing the baffle 661 disengage from the position limitation caused by the position limiting piece 41 . And, the baffle 661 pushes the position limiting piece 41 to the space under the baffle 661 by the force from the first incline surface to the second incline surface, to let the baffle 661 pass over the position limiting piece 41 smoothly, and the spring 5 is in compression status also. Active disk 6 rotates clockwise along with the pulling of wire 2 , while frapping the resetting spring 7 clockwise, and producing elastic deformation with resetting trend. During the pulling of wire, the active touching point on the active disk 6 remains tight contact with the fixed touching point on the switching device 3 .
After pulled out to required length, wire 2 is released, and the turnplate 6 rotates anti-clockwise due to the force of resetting spring 7 . In this regard, spring 5 ejects the position limiting button 4 , and the position limiting piece 41 returns to original status; the thicker end supports on the thicker end of baffle 661 , which forcing the active disk 6 can not rotate anti-clockwise, thus, keeping the wire 2 with required length.
When need to pull out the wire, the user can also press and hold the position limiting button 4 to compress the spring 5 , the position limiting piece 41 is located in the space that under the baffle 661 and can pass through the space smoothly, therefore the turnplate 6 can rotate clockwise along with the wire extending direction. In this regard, resetting spring 7 is frapped along with the rotation of turnplate 6 to produce elastic deformation with reset trend. During the pulling of the wire, the active touching point of turnplate 6 remains tight contact with the fixed touching point of switching device 3 . While wire 2 is pulled out for required length, releasing wire 2 and position limiting button 4 , and spring 5 will eject button 4 ; the position limiting piece 41 of the position limiting button 4 contacts and collaborates with the baffle 661 of the active disk 6 , thus keeps the active disk 6 can not rotate, and remains the required length of wire 2 .
When the out pulled wire need be retracted, the user only need to press position limiting button 4 , turnplate 6 will rotate anti-clockwise under the effect of the resetting spring, to enlace the wire 2 back to the active disk 6 and return to original status. Since one end of the resetting spring 7 is wedges on the notch 162 of the bar 16 , the resetting spring 7 fraps along with the rotation of active disk 6 , producing elastic deformation with resetting trend; While pressing down the position limiting button 4 , baffle 661 disengaged with the position limiting piece 41 , and turnplate 6 rotates anti-clockwise due to the resetting effect of the resetting spring 7 , the wire 2 enlaced back to active disk 6 and stored inside the shell body thus to reduce the mass caused by wires.
The electrical connection device of the present invention may be implemented on or inside the electrical equipments. The wire enter port 12 can be connected with the electrical equipments by insertion, soldering, screwing, rivet joint, etc., and the wire enter port can be fixed into or onto the shell body of the electrical equipment for convenient retraction and exceeding.
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The present invention provides an electrical connection device, which includes a position holding bar, a switching device sleeved outside of the position holding bar, and a wire twining device with position limiting button. The wire twining device comprises an active turnplate, an electrical connection wire enlaced on one surface of the turnplate, an activation point fixed on the other surface of the turnplate, and a reset spring fixed on the annular groove of the bottom of the turnplate; the outer end of the enlaced wire is electrically connected with an active wire port, the inner end of the enlaced wire is connected with the active touching point of the turnplate; a fixed touch point that corresponding to the active touching point is set on the connection device, so that the active touching point keeps the electrical connection with the fixed touching point of the connecting device while the electrical connection wire is twined with the turnplate. When implementing the electrical connection device, it is very convenience to control and use the wire, and makes the wire extending and retracting easily, thus reduces the mass caused by wires and saves the space.
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The present patent application is a Continuation of Application No. 12/745,227, filed Oct. 27, 2010, which is a National Stage Application of International Application No. PCT/AU2008/001749 filed Nov. 27, 2007.
FIELD OF THE INVENTION
The present invention relates to monitoring of vehicles and in particular, to a system for monitoring heavy vehicles and their compliance with specific network (e.g. road) access conditions using vehicle telematics solutions e.g. for regulatory purposes.
BACKGROUND TO THE INVENTION
Road transport is a popular method of transferring freight between cities, ports and distribution centres. Benefits of using the road network over other transport methods (e.g. rail, water and air) include that the cost is moderate and the fact that the road infrastructure is relatively well established. A network of roads provides efficient access to many destinations not accessible by rail, water or air.
Difficulties presented by use of the road network, particularly by heavy vehicles are that it is becoming increasingly difficult to monitor and control the road usage, and to plan for the growing infrastructure needs. Community interests are also at stake.
Jurisdictions such as councils, governments and road transport authorities develop schemes, permits, applications, notices, concessions, exemptions and gazettals which impose conditions on road usage. These conditions are intended to provide controlled access to the road network. Compliance with these conditions is important to road users and particularly heavy vehicle operators who are penalised with fines and/or licence suspensions if they are found to be non-compliant with certain conditions.
Monitoring compliance is difficult due to the number of heavy vehicles which use the road network and the number of roads which must be monitored. This is complicated further when there are different jurisdictions involved in long-distance haulage. Also, monitoring the conditions imposed typically requires monitoring a variety of different vehicle parameters such as vehicle location, vehicle speed, direction of travel, vehicle mass, time, date and so on. Driver logbooks typically focus on time, date, location by suburb and rest breaks but they do not usually record specific information relating to vehicle speed and location, mass and the like. Moreover, the logbook system is susceptible to misuse; it is not necessarily in the driver's interest to maintain evidence which substantiates a breach of a road use scheme or condition. Thus, it is rare that a vehicle logbook provides useful material for the purpose of monitoring compliance with road access conditions.
The discussion of the background to the invention included herein including reference to documents, acts, materials, devices, articles and the like is intended to explain the context of the present invention. This is not to be taken as an admission or a suggestion that any of the material referred to was published, known or part of the common general knowledge in Australia as at the priority date of any of the claims.
SUMMARY OF THE INVENTION
Unlike the domestic motor car, heavy transport vehicles do not usually have an automatic right of access to road infrastructure systems. In one of its embodiments, the present invention provides a system for remotely monitoring vehicles using in-vehicle systems that utilise sensors to monitor parameters of interest (such as position and time) and which uses wireless communications networks to transmit data from the sensors to Service Providers operating as part of the System. Service Providers transmit, automatically, non-compliance reports which are received by Jurisdictions responsible for administering the road access schemes and rules.
A Transport Operator, who is an operator of one or more vehicles eligible to apply to participate in the monitoring System, can apply to a Jurisdiction to be part of a “System Application”. The System Application includes a set of conditions selected by the Transport Operator from a set of available conditions of road use. Typically, the conditions are designed by the Jurisdiction (e.g. based on schemes, permits, applications, notices, concessions, exemptions and gazettals permitting or prohibiting road use and access under certain conditions). These may be referred to as “off the shelf” conditions. However, a Transport Operator may also nominate one or more “unique” conditions when applying to a Jurisdiction for access to a road network. Once a System Application is granted, the Transport Operator is granted access to the network in the form of a System Access Condition (SAC) which specifies the unique and off the shelf conditions agreed upon.
Jurisdictions include country, state, local and other road authorities that establish the schemes and rules for road use which are monitored using the System. Jurisdictions maintain control over the approval of Transport Operators applying to participate in the System, and monitor closely the details of proposed vehicles which accompany Transport Operator requests for access to the road network. This enables Jurisdictions to determine and control what effect, if any, the Transport Operator's proposal may have on safety, infrastructure and the environment. Based on that determination, a Jurisdiction can either approve a Transport Operator's request, or it can refuse access to the road network based on the conditions of use proposed.
Once a Transport Operator's request for a System Application has been approved, it seeks out a System Service Provider (System SP) to install in a vehicle the hardware required to monitor compliance with the conditions granted to that vehicle. System SPs also provide back-office computer processing and reporting of vehicle compliance according to the System. System SPs are typically private sector monitoring companies who provide telematics services (i.e. hardware, software and associated processes) and provide the primary monitoring service in accordance with the System.
The Applicant (Transport Operator) selects a System SP from a group of organisations which have been authorised by an Authorising Body via a certification process. The Authorising Body is responsible for overseeing operation of the System and the performance of each of the participants. Participants include Transport Operators and their drivers, System SPs, Jurisdictions, and Auditors of the System. Transport Operators are operators of one or more vehicles who are eligible to voluntarily enter a scheme that requires a compliance solution offered by the inventive System.
Eligibility is typically determined by the Jurisdiction. In addition to satisfying the criteria established by the Jurisdiction in a granted SAC, Transport Operators may also need to satisfy particular accreditation criteria to be eligible to participate in the System. In Australia for example, accreditation under the National Heavy Vehicle Accreditation Scheme (NHVAS) may be required.
The System SP engaged by the Transport Operator installs an In-Vehicle Unit (IVU) in the vehicle for which the System Application has been approved by the Jurisdiction. This enables the vehicle to be monitored by the System SP for compliance with the road access conditions granted to it. If applicable, the System SP is also responsible for installation of a trailer identification device (TID) on each trailer to be used with the vehicle, and any Self Declaration Input Device (SDID) approved by the Jurisdiction for use by the Transport Operator (and its vehicle drivers).
The System SP is also responsible for notifying the relevant Jurisdiction whenever a Transport Operator's vehicle fails to comply with one or more conditions defined in an applicable SAC. Notification of non-compliant activity occurs automatically via transmission of a non-compliance report (NCR) using an electronic communication protocol such as Business to Business (B2B). In addition, the System SP provides Jurisdictions with a periodic (e.g. monthly) Participants Report (PR) which aggregates the number of non-compliance reports issued to a vehicle. The Participant's Report may additionally/alternatively aggregate the number of participants being monitored. Importantly, data processing for the purpose of generating NCRs and PRs occurs entirely independently of both the Jurisdiction and of the Transport Operator and its drivers.
In the event that non-compliant vehicular activity within a Jurisdiction is identified and a non-compliance report is electronically transmitted to the relevant Jurisdiction, it is up to the Jurisdiction's discretion as to whether or not a contractual-based caution or a formal infringement notice is issued to the vehicle involved as a consequence of that non-compliant activity.
Data forming SACs. NCRs and PRs is securely transmitted electronically between the relevant System SPs and Jurisdictions using an electronic data interchange format (e.g. B2B) preferably using existing communications infrastructure such as the Internet, with transmissions electronically signed by the respective parties, as is known in the art.
Viewed from one aspect, the present invention provides a System for monitoring a vehicle's compliance with one or more vehicle-use conditions for accessing a transport network. The system includes an in-vehicle unit (IVU) associated with a vehicle being monitored, the IVU including; a receiver for receiving positioning signals; a processor for processing a time-marked log of vehicle data; a storage element for storing the time-marked log; and a first wireless communication element for communicating time marked data to a Service Provider (SP) processing apparatus. The System also includes one or more Service Providers operating Service Provider (SP) processing apparatus, the SP processing apparatus including: a SP wireless communication element for receiving time-marked data from one or more IVUs; a SP processor for processing received data, the SP processor adapted to compare received data from the time-marked log of a vehicle with one or more vehicle-use conditions that are specific to that vehicle, and to generate a non-compliance report where the comparison indicates that non-compliant activity has occurred; and a SP storage element for storing non-compliance reports and relevant time-marked data. The one or more vehicle-use conditions being monitored for compliance are specific to the vehicle being monitored have been defined electronically in a datafile unique to that vehicle.
Preferably, vehicle data and in particular position data used to generate a non-compliance report excludes data derived from low quality position signals. This ensures non-compliance reports are issued only when the supporting data exists at an evidentiary. level of accuracy.
Non-compliant activity may include one or more of spatial non-compliance; temporal non-compliance; speed non-compliance; self-declaration inputs; alarm status of the IVU, or other system hardware installed in the vehicle; and alarm data generated by the SP processing apparatus.
Viewed from another aspect, the present invention provides a method for granting permission for vehicle access to a network, including the steps of: (a) an applicant electing one or more desired conditions of vehicle use in an electronic datafile; (b) transmitting the electronic datafile via electronic transmission means to a third party for approval; (c) if the electronic datafile is approved, the third party appending approval data to the datafile, giving the applicant temporary permission to access the network in accordance with the elected conditions, conditional upon, in a prescribed time frame: (i) monitoring hardware being installed in the vehicle; and (ii) using a monitoring service to monitor use of the vehicle; and (d) when the third party is notified that the hardware has been installed and the monitoring service commenced, finalising the datafile for continued permission to access the network.
Viewed from yet another aspect, the present invention provides a method for assessing a vehicle's compliance with one or more conditions of vehicle use specific to a particular vehicle and defined in an electronic datafile; including the steps of: (a) a processor processing a time-marked log containing vehicle data for one or more parameters of vehicle use; (b) the processor comparing the vehicle data with one or more vehicle use conditions specific to that vehicle and defined in the datafile; and (c) where the comparison indicates that non-compliant activity has occurred, the processor generating an electronic non-compliance report.
Viewed from another aspect still, the present invention provides a computer program product for assessing a vehicle's compliance with one or more predefined use conditions, the computer program product storing instructions for performing a method including the steps of: (a) accessing a time-marked log containing vehicle data for one or more parameters of vehicle use; (b) for each record in the time-marked log: (i) identifying, based on the one or more predefined use conditions, those conditions which are relevant to data in the record; (ii) arranging the relevant conditions into an order of precedence; and (iii) comparing the data in the record with the relevant conditions as ordered and assessing whether the vehicle is compliant.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in greater detail with reference to the specific embodiments illustrated in the accompanying drawings. It is to be understood that the particularity of the accompanying drawings does not supersede the generality of the preceding description of the invention.
FIG. 1 illustrates the participants in a monitoring and compliance system according to an embodiment of the present invention.
FIG. 2 is a schematic illustration of an in vehicle unit (IVU) according to an embodiment of the present invention.
FIG. 3 is a schematic illustration of a trailer identification device (TID) according to an embodiment of the present invention.
FIG. 4 is a schematic illustration of a self declaration input device (SDID) according to an embodiment of the present invention.
FIG. 5 illustrates steps involved and data exchanges that occur during issuance of a System Access Condition (SAC).
FIG. 6 is a schematic illustration representing features of a Service Provider.
FIG. 7 demonstrates schematically, spatial and temporal conditions included in an issued System Access Condition.
FIG. 8 is a schematic diagram illustrating speed data records considered when determining a speed event, according to an embodiment of the invention.
FIG. 9 illustrates examples of vehicle categories and numbers of vehicle axes.
FIG. 10 presents a summary of alarm codes that may be included in a NCR.
DETAILED DESCRIPTION
A specific embodiment of the present invention will now be described. It is to be understood that although aspects of the described embodiment are detailed and specific, this is not to be taken as limiting on the scope of the claims appended hereto. For instance, the specific embodiments refer to use of the System to monitor vehicle compliance, particularly heavy vehicle compliance, with conditions of access to a road network. However, it is to be understood that the invention has application beyond monitoring compliance with road access conditions and may be utilised for monitoring compliance by various land-based vehicles such as e.g. bicycles and mining vehicles and may be extended for monitoring compliance by aircraft, water-borne vessels, space craft and the like.
FIG. 1 illustrates generally, the participants of a System according to an embodiment of the invention. A Transport Operator 102 applies to a Jurisdiction 104 to become part of the compliance System. If approved, the Transport Operator selects a Service Provider 106 to provide the hardware required and also the monitoring service which involves monitoring vehicle position using positioning data obtained from e.g. global navigation satellites 108 . The System is overseen by an Authorising Body 109 who is also responsible for certification of System SPs. Performance of the participants (particularly the System SPs) may be periodically audited by approved System Auditors 110 .
An important part of the present system is the hardware installed in vehicles to facilitate their monitoring. This includes IVUs, TIDs and SDIDs.
In-Vehicle Unit (IVU)
An IVU, once certified by a certifying body or the Authorising Body is provided to a Transport Operator by a System SP that is also approved by the Authorising Body to participate in the System. SP participation includes installing IVUs and other hardware in Transport Operator vehicles and also providing a monitoring service.
The IVU collects, monitors and stores sensor data from a range of sensors on the vehicle. Sensor data includes positioning data (e.g. GPS or GNSS data), and e.g. alarm data and Self Declaration data. These data are monitored to assess a vehicle's compliance with access conditions defined in a SAC applicable to the vehicle. The IVU transfers data collected from these sensors to the relevant System SP, via a communications device. Preferably this is performed by wireless means.
In a preferred embodiment, if the volume of data collected and generated prior to transfer to the System SP exceeds the data storage capacity of the IVU, new data will not overwrite stored data already obtained. This approach is preferred as it supports evidentiary purposes for which the inventive System may be used, even though it is at the expense of the ability to collect more recent data.
Wireless data transmission permits data transfers from the vehicle. This may occur in real time or near real time (e.g. every 15 to 30 seconds), irrespective of the vehicle location (with the exception of delays occurring when the vehicle temporarily travels out of range). Some applications may require more frequent reporting, i.e. transmission of data, if stipulated in the conditions of vehicle use. However it is to be understood that real time transmission of data is not essential and data may be transmitted periodically, in batches. Thus, it is contemplated that periodical transfer of data could be by wired means.
Thus, transmission of sensor data from the IVU to the System SP may be by GPRS, radio transmission, GSM, satellites or other wired or wireless means capable of maintaining the data's integrity, authentication and encryption against access or tampering by third parties. Provision for wired data transfer enables a System SP to plug in and download data e.g. in the event of an IVU malfunction or wireless data transmission malfunction.
FIG. 2 is a schematic illustration of an IVU 200 according to an embodiment of the invention. The IVU is robustly connected to the vehicle, i.e. the primary vehicle being monitored. The IVU includes a processor 210 and memory 212 storing rules for execution by the processor as well as a storage element 214 for storing data collected by the IVU. The IVU includes a plurality of sensors 202 a to 202 n , one of which includes a GPS receiver connected to a GPS antenna via an antenna cable (not shown). Other suitable positioning sensors may be utilised, particularly other forms of Global Navigation Satellite System (GNSS) sensors. It is desirable that if positioning sensors other than GPS sensors are used, prior approval is obtained from the Authorising Body before such sensors are installed in or connected with an IVU.
A range of sensors may be included to monitor other vehicle-use parameters. For example, a vehicle ignition sensor may be included to monitor vehicle movement in the absence of GPS data. In certain embodiments, a second independent movement sensor (such as an accelerometer, external air flow sensor, torque sensor or the like) may be included which provides a signal to the IVU indicating that the vehicle is moving (or stationery). Additional sensors adapted for IVU tamper detection may also be provided e.g. if a GPS antenna becomes disconnected from the IVU.
Other sensor data which may be utilised by the IVU and monitoring system generally, may be derived from other systems deployed within the vehicle being monitored. For example, sensor data may be extracted from electronic braking systems (EBS) which provide electronic management and activation of vehicle brakes. EBS systems typically monitor on board vehicle mass and vehicle mass distribution (e.g. using air bag suspension systems) to control the application of brakes and these vehicle mass parameters may be provided as sensor inputs to the IVU. Data extracted from EBS systems which is indicative of on-board mass and mass distribution can be received as inputs by the IVU and utilised to check compliance with vehicle haulage mass ratings and mass limits applicable when accessing particular roads of a road network.
Other inputs to the IVU may be provided from ancillary devices used by the driver, such as fatigue monitoring devices. Fatigue monitoring devices may include fatigue monitoring eyewear detecting eyelid movement and blink rate, and devices used to detect sideways movement of the vehicle which is frequently associated with driver fatigue. Other data designed to monitor or anticipate driver fatigue may include Self Declaration inputs confirming the identity of the driver each time the vehicle is in motion. Biometric identification means could be incorporated to safeguard against false self-declaration of driver identity.
A range of other sensors may be incorporated to monitor compliance with network access conditions. These may facilitate monitoring of data including but not limited to: vehicle noise; vehicle emissions; tanker volume monitoring and refrigeration temperature monitoring. The IVU may also be adapted to exert different levels of control over the vehicle and/or implement Intelligent Speed Adaptation (ISA) e.g. to limit the speed of vehicle operation under certain conditions, or to alert the driver e.g. in the event of detected over-speed or fatigue. In addition or alternatively, the IVU may interface with security-sensitive devices adapted to make the vehicle inoperable in the event that a security event is detected (e.g. theft of the vehicle or terrorist activity), or to enable the vehicle to be controlled by another party, e.g. a Transport Operator manager, the road authorities, or police.
A communications device 204 connected to a communications antenna via a communications cable (not shown) is also provided, together with cabling and connectors for connecting the IVU with an external power supply 206 , and sensors 202 a to 202 n . The processor generates time marked data which is transmitted by the communications device from the IVU to the System SP via communications network 210 .
Each IVU issued for use in accordance with the System is preferably allocated a unique alphanumeric identifier (IVU ID). This is used to identify the particular IVU and data which originates from that IVU. Thus data received or processed by a System SP can be identified as having originated from a particular IVU. Preferably, the unique identifier is stored on non-volatile programmable read-only memory 208 within the IVU. The IVU ID may also include a portion which identifies the System SP responsible for issuing the IVU. For example, the IVU ID may include a unique three-character pre-fix which is associated with the issuing System SP. In addition, it is desirable that the IVU ID is physically marked onto the outside of the IVU apparatus in a manner which precludes removal or modification. Etching or engraving the IVU ID are examples of suitable forms of physical marking. It is preferred that, for security purposes, the IVU ID is not re-set or altered or otherwise tampered with. The IVU ID may only be altered by the IVU-issuing System SP.
In a preferred embodiment, the IVU is protected from physical tampering by use of an enclosure which is inaccessible by unauthorised parties. In one embodiment, the IVU physical enclosure includes physical seals which are tamper evident. Thus, the seals show signs of unauthorised attempts at removal or opening of the physical IVU, although it is desirable that the IVU apparatus and seals remain intact when exposed to the vibration and impact encountered during normal use of the vehicle.
Detection of unauthorised attempts to access an IVU may be provided in accordance with applicable known standards as may construction of the apparatus (see for example AS/NZ4255.1:1994 Security Category 10, Grade B). In one embodiment, removal or opening of the IVU can occur only by breaking the seals in such a way that once broken, they cannot be re-used or reinstated. Detected attempts to access or remove an IVU or to disconnect sensors from the IVU are preferably reported by the System SP to the relevant Jurisdiction. Preferably, this occurs by wireless transmission of a tamper detection alarm or the like.
Security and confidentiality of data stored within the IVU is paramount. Thus, with the exception of access by or with authorisation from the System SP, data stored within the IVU cannot be accessed by any other party or device (including a Self-Declaration Input Device). Data records stored within the IVU are deleted only after such data is transferred from the IVU to the System SP and successful receipt is confirmed using secure communications protocols and associated handshaking as would be known to a person skilled in the art. Any compression algorithms applied to data being transferred from the IVU to the System SP is preferably lossless. Data may be communicated in blocks.
An IVU may have additional functionality built in which is not related to features required according to the System. However, any such functionality must not affect the IVU's ability to collect data and perform as required by the Authorising Body.
In accordance with an embodiment of the present invention, an IVU is type approved before being installed into a vehicle for use with the System. Type-approval involves approving the IVU for use with particular vehicle types in accordance with specifications prescribed by the Authorising Body. For instance, a Level 1 type-approved IVU is suitable for use solely with a primary vehicle such as a prime mover or rigid truck. Thus, there is no requirement for a Level 1 type-approved IVU to have a trailer designation, i.e. additional inbuilt functionality adapted to identify automatically, trailers connected to the primary vehicle.
Alternatively, a Level 2 type-approved IVU is approved to monitor a primary vehicle which has been approved for use with one or more attached trailers. Trailers attached to the primary vehicle are automatically identified by the Level 2 type-approved IVU and trailer identification information from each trailer's Trailer Identification Device (TID) is recorded. Thus, there may be more than one trailer coupled to a primary vehicle, each of which is fitted with a TID. The TID includes a memory component identifying and recording identification information for the respective trailer. Thus, each trailer attached to a prime mover is thereby identified automatically by the IVU installed on the primary vehicle.
In a preferred embodiment, the IVU is configured to collect data, either directly or indirectly, the data including but not limited to one or more of: GPS quality data, date and time data, vehicle position data, vehicle direction of travel data, vehicle speed data, trailer identification data, alarm status data and self declaration data. The IVU produces data records in a time marked log which are stored for later transmission to the relevant System SP.
Preferably, the IVU is adapted to interface with additional sensors which may be fitted to the vehicle either before or after the Transport Operator has been issued a SAC for use with the System. Additional sensors may include e.g. cargo temperature, door open/closed, load mass, driver identification (e.g. biometric) sensors to name a few. Data from these sensors may be transmitted alongside position data (and time data) to the System SP for use in assessment of the vehicle's compliance with use conditions defined in a granted SAC. Performance specifications for additional sensors are preferably prescribed by the Authorising Body to ensure that the data they supply meets the standards of accuracy required for use as “evidentiary” data.
Thus, the system architecture is scaleable to accommodate other parameters for monitoring as may be deemed necessary or desirable. Preferably, the impetus for accommodating new parameters originates from the governing bodies (and jurisdictions) responsible for controlling access to and maintaining the road networks. Although, Transport Operators and other participants may elect to monitor additional parameters using the inventive system as a means for monitoring and improving vehicle and driver efficiency, cargo care and the like.
Once additional parameters are identified for monitoring using the system, technical solutions for their incorporation can be devised in a way which satisfies the evidentiary standards required and evaluated for compliance with these standards before ultimately being made available for inclusion in a SAC sought by an Applicant.
Additional parameters that may be of interest include vehicle parameters, trailer parameters, cargo parameters, and driver parameters to name a few.
Vehicle parameters may relate to engine performance (e.g. fuel consumption, engine revolutions, clutch activations, water temperature, oil pressure, gearbox speed/revolutions, acceleration). These may be monitored using proprietary sensor systems and/or may be derived or obtained directly from engine management systems and engine condition monitoring systems available from engine manufacturers. Additionally, for vehicles fitted with electronic braking systems, vehicle parameters may include brake activations, ABS/EBS interventions, brake air pressures, tilt, yaw, angle acceleration/g-forces, wheel speed, brake pad wear etc.
Trailer parameters may include e.g. distance travelled, door opening, tilt and other brake system data (if fitted with an electronic braking system (EBS)). Cargo parameters may include e.g. temperature, g-forces, humidity, movement, etc. Driver parameters may include e.g. driver identity, and eye movement data for the detection and prevention of driver fatigue.
Additionally, a monitored vehicle may be fitted with an electronic Dedicated Short Range Communication (DSRC) toll tag which can be interrogated by the system. Similarly, most vehicles when in use will contain another wireless communication device (e.g. the driver's mobile phone) which will also be GPS equipped. Thus, the telecommunications service provider has the ability to track the mobile handset which, in other embodiments, could be used to corroborate data obtained using the on-board GPS receiver installed for use with the inventive System. Data from DSRC tags and telecommunication devices in the vehicle do not originate from the vehicle itself, but from the tolling operator or network provider and so, have the potential to add further weight to the evidentiary quality of data obtained by the System.
Positioning Signal Quality Data
Positioning signal quality data, also referred to as GPS quality data may be measured using any suitable technique such as, for example, by monitoring the number of satellites whose signal is received by the IVU and taken into account in the determination of position data and the horizontal dilution of precision (HDOP).
The IVU should demonstrate positioning (GPS) signal quality to a level prescribed by the Authorising Body. This may be established using a reference system developed by the Authorising Body, where the IVU is tested by comparison with the reference system which has been configured to obtain GPS signals to a predefined quality level.
Alternatively/additionally, GPS quality data may be obtained during simulation testing of IVUs during for example, audits performed by System Auditors, as may be invoked by the Authorising Body or scheduled to occur from time to time. This ensures that hardware installed by System SPs is capable of monitoring vehicle use parameters to the level of certainty prescribed by the Authorising Body. Simulation testing may be performed in the field, in the office or workshop.
Date and Time Data
In a preferred embodiment, the IVU collects and stores date and time data in Coordinated Universal Time (UTC) format, and it is stored with a prescribed resolution, e.g. of one second. Ideally the IVU has an internal clock operating independently of the external power supply which is capable of operating for an extended period, e.g. of twenty-eight days, in the event of power shut-off from the external power supply. In accordance with the System, the Authorising Body may prescribe a level of accuracy which must be met by the internal clock. For example, it must not deviate by more than one second from the UTC date and time over a twenty-eight day period when using GPS signals; or, it must not deviate by more than ten seconds per day from the UTC date and time over any twenty-eight day period when not using GPS signals.
Vehicle Position Data
The IVU is adapted to generate position records utilising the data it collects. The position records identify the position of the vehicle being monitored at moments time. In one embodiment, the IVU determines the latitude/longitude of the vehicle in e.g. WGS84 or GDA94 or any other suitable format recognised by the System SP. The format and tolerances of the position data are typically prescribed by the Authorising Body to ensure high accuracy is maintained. For example, the Authorising Body may prescribe that the position data shall not deviate by more than 13 meters from the absolute horizontal position for 95% of the observations made when using at least 4 satellites and a HDOP of less than 4. The Authorising Body may also prescribe the resolution of stored latitude/longitude positions calculated by the IVU (e.g. 0.00001 degrees or better).
The Authorising Body may also prescribe how quickly a GPS signal must be reacquired where there has been an interruption to the received signal. If the prescribed requirements are not met, the data may not be considered to be of a sufficiently high quality to be utilised in a data record. This ensures the positioning data which is used to determine vehicle direction of travel and vehicle speed is of sufficient quality that its use can be evidentiary in nature, and is not vulnerable to challenges that the data is “inaccurate”.
In one embodiment, the position records are generated continuously while the vehicle is in operation, and stored at time intervals. The maximum time intervals at which vehicle position data is to be stored may be prescribed by the Authorising Body. For example, the Authorising Body may require vehicle position data to be stored which indicates the vehicle's position every 30 seconds during vehicle operation. A window of e.g. ±0.2 seconds may be permitted when calculating time intervals.
In an embodiment, vehicle position data includes the following: record number; date/time of position record generation; vehicle position (e.g. latitude and longitude); direction of travel; GPS quality (e.g. number of satellites used and HDOP); ignition status (on/off/disconnected); status of other independent movement sensor(s) (e.g. movement/no movement/disconnected); and trailer IDs for currently connected trailers (Level 2 type-approved vehicles only). In one embodiment, vehicle position data is blank or void where the IVU has used zero satellites or was unable to determine vehicle position.
Vehicle Direction of Travel Data
The IVU, or a positioning signal receiver associated with the IVU (e.g. a GPS receiver) is adapted to determine direction of vehicle travel. Preferably, this is in WGS84 or GDA94 format although other formats are also contemplated. The Authorising Body may prescribe tolerances for example, the direction of travel determined must not deviate from the actual direction of travel by more than 4 degrees for 95% of the observations made when using at lest 4 satellites and a HDOP of less than 4. The resolution of direction of travel may also be prescribed by the Authorising Body, e.g. the resolution may be required to be 0.1 degrees or better.
In one form of the invention, to more efficiently use the processing capabilities of the IVU and/or associated positioning signal receivers, the assessment of vehicle direction of travel is made only when the vehicle is travelling at speeds between e.g. 30 km/h and 150 km/h.
Vehicle Speed Data
In addition to determining position records, the IVU may also be configured to determine speed records indicative of a vehicle's speed at predetermined intervals or to receive speed records from a GPS receiver (e.g. GPS Doppler speed). Vehicle speed may be further validated by the System SP processor, e.g. by way of distance-time calculations. The duration of the predetermined intervals may be prescribed by the Authorising Body as e.g. 3 second intervals. A window of ±0.1 seconds may be permissible in calculating the interval.
In one embodiment, vehicle speed data is determined using a GPS Doppler derived method. The Authorising Body may prescribe that the determined vehicle speed must satisfy a predetermined degree of accuracy. For example, for vehicle speeds determined to be between 60 km/h and 150 km/h, the determined speed must be accurate to within 3.0 km/h when using at least 4 satellites and a HDOP of less than 4. Similarly, the Authorising Body may prescribe a resolution to be recorded, e.g. to 0.1 km/h or better.
In an embodiment, a speed record includes the following data: record number, date/time of speed record generation; vehicle position (e.g. latitude and longitude); vehicle speed; GPS quality (e.g. number of satellites used and HDOP); trailer IDS for currently connected trailers (Level 2 type-approved vehicles only). In one embodiment, vehicle speed data is blank or void where the IVU has used zero satellites or was unable to determine vehicle position.
Trailer Identification Device (TID) and Trailer Identification Data
A trailer identification device (TID) may be provided for each trailer couplable with a primary vehicle fitted with an IVU approved for use with the inventive system. The TID has a unique identifier (Trailer ID) that uniquely identifies the trailer and is included with data records transmitted from the IVU to the System SP for processing. It is also desirable that the Trailer ID is physically marked onto the outside of the TID apparatus in a manner which precludes removal or modification. Etching or engraving the trailer ID are examples of suitable forms of physical marking. For security purposes, the trailer ID may not be re-set or altered or otherwise tampered with. The System SP issuing the TID should be the only party able to access the trailer ID in a manner similar to the IVU identifier.
FIG. 3 is a schematic diagram of a TID 300 according to an embodiment of the invention. In a preferred embodiment, the TID is protected from physical tampering by use of an enclosure which is inaccessible by unauthorised parties. Preferably, the TID includes non-volatile programmable read-only memory 302 which stores the trailer ID in such a way that it cannot be altered without rendering the TID permanently inoperable. In this event, the Transport Operator (or its representative, e.g. driver) will be required to return to the System SP to obtain a replacement TID for the trailer involved.
A TID is robustly connected to the trailer it identifies. The TID unit itself includes hardware, software and connectors enabling it to communicate with the IVU associated with the primary vehicle with which the trailer is coupled. Alternatively/additionally, the TID may be configured to communicate directly with the System SP responsible for its installation, maintenance and monitoring. This enables the System SP to offer a “back-office” service for monitoring trailers independently of the prime mover to which the IVU is attached. Thus, it is conceivable that the System SP responsible for the IVU in the prime mover is a separate organisation from the System SP responsible for the TID on the trailer. The TID may communicate with the IVU or the relevant System SP(s) via any suitable means including wireless and wired connections.
The TID also includes a software component 304 and processor 306 which enable the TID to communicate with e.g. the IVU in such a way that the IVU can extract and record automatically, the TID unique identifier. Preferably, this occurs automatically when the trailer(s) are attached to the primary vehicle, without the need to make an additional electrical connection between the primary vehicle (or the IVU) and the TID(s). Similarly, when one or more trailers are de-coupled from the primary vehicle, the IVU processor adjusts automatically to record the identification details of the remaining attached trailers only.
Alarm Status Data and Alarm Records
Alarm records may be generated and stored by the IVU in respect of events including but not limited to one or more of the following: the external power supply is disconnected from or reconnected to the IVU; vehicle movement is detected by one or more vehicle movement sensors while the external power supply is disconnected from the IVU; ignition sensor or other vehicle movement sensor is disconnected from or reconnected to the IVU; detection of unauthorised access to IVU data or IVU software; disconnection or reconnection of a position-sensing (e.g. GPS) antenna.
Vehicle movement data is preferably obtained from two or more movement sensors which do not utilise data from positioning signals obtained from e.g. GPS satellites. The two or more vehicle movement sensors may therefore be selected from the group including but not limited to: an ignition status sensor; and independent accelerometer; an Engine Control Module (ECM); an odometer; and a tachograph.
Preferably, each alarm record generated by the IVU incudes the following data: alarm record number, date and time of alarm record generation; and the event that triggered the generation of the alarm record. When a System SP determines whether a non-compliance report is to be generated for transmission to the relevant Jurisdiction, it will refer to the alarm record triggering event to ascertain if inclusion of the alarm data/alarm status is necessary. An example of where it may not be necessary to include the alarm data/alarm status is where the battery has been disconnected from the IVU as this is common e.g. during servicing of the vehicle.
In an embodiment, alarm status data is also obtained during monitoring of a vehicle. Alarm status data may be generated for one or more of the following: the status of external power supply to the IVU; the status of one or more vehicle movement sensors; tamper detection status indicating unauthorised attempts to disconnect or remove the IVU (or a connected TID or SDID) from the vehicle, or access its contents, or its operating system; GPS antenna connections status; IVU data access status; and IVU software access status.
Self-Declaration Input Device (SDID) and Self Declaration (SD) Data
In one embodiment of the invention, an IVU is adapted to receive input from a user interactive device operable by e.g. a driver of a vehicle. Such a device is referred to as a self-declaration input device (SDID). Thus, the IVU is desirably configured to receive, confirm receipt of and store Self Declaration (SD) data from a SDID connected to it. The IVU also generates SD records from the SD data entered into the SDID.
An example of a SDID 400 is illustrated in FIG. 4 . The SDID includes data-input device 402 in the form of a touch screen, although this may be replaced with e.g. buttons or a stylus. A Display device (screen) 402 is provided so the user can read the self-declaration inputs entered. SD Entries may include vehicle category, number of axels, and total combination mass. FIG. 9 illustrates examples of vehicle categories and numbers of vehicle axes. SD Comments may also be entered. For example, where a Transport Operator is forced to make a detour onto a road which is part of an exclusion route or zone, a comment can be entered using the SDID under a comment name such as: “Road Closure”, “Redirection by authorised officer”, or “operating under special permit”. Other comment names may be used at the driver's discretion.
A SDID used with the system is installed by the responsible System SP to ensure that the necessary protocols and evidentiary standards for data collection by the IVU are complied with, notwithstanding any self-declaration inputs that may be supplied by the driver.
In a preferred embodiment, two distinct forms of SD record exist: SD (Vehicle Type/TCM) records and SD (Comments) records. A SD (Vehicle Type/TCM) record includes at least the following data: record number; date/time of SD data generation/input into the SDID; vehicle category; number of axles; and total combination mass. The SD record may also include a version number referring to applicable System specifications prescribed by the Authorising Body. In an embodiment, the System SP refers to the vehicle category data to ascertain if a relevant SAC applies for possible subsequent reporting to the Jurisdiction.
In an embodiment, a SD (Comments) record includes at least the following data: record number; date/time of SD data generation; comment name and the text of the comment entered by the vehicle operator using the SDID. For a SD (Comments) record, the Comment name is used by the System SP to determine whether it should refer to an applicable SAC for possible subsequent reporting to the Jurisdiction.
In an embodiment, position, alarm and SD records are assigned record numbers from a single record-numbering sequence with consecutive and increasing record numbers that are assigned in order of record generation. However, speed records are preferably assigned from a separate sequence of record numbers. This enables the system to maintain a sequence of speed records around non-compliant activity relating to a speed event, whereas position, alarm and SD records are monitored constantly during vehicle movement. In each case, the series of record numbers available should rotate through a sufficiently large cycle that the same record number is not issued more than once in close proximity. For example, the same record number is not used more than once every 12 months.
In a preferred embodiment, the System SP reports immediately any SDID malfunction which appears to be the result of tampering or an attempt at tampering with the SDID unit. This report is referred to the Jurisdiction who issued the SAC. Preferably, the Transport Operator is not informed of the detection or reporting of tamper events or suspected tampering with the SDID or other hardware devices installed in the Transport Operators vehicles or trailers.
In the event that any one SDID is subject to more than one instance of malfunction (of any type including tampering or otherwise), it is preferred that the System SP notifies the Authorising Body of each malfunction and the apparent cause of the malfunction and also the remedy applied or to be applied. This enables the Authorising Body to maintain a degree of control over the performance of participants in the System, ensuring that the high standards of monitoring are maintained.
It is to be understood that self declaration data may alternatively or additionally be entered directly to the System SP processing apparatus, e.g. by uploading information via a web-based application. Alternatively/additionally, SD inputs could be supplied to the System SP by telephone, or by batch processing by the Transport Operator. Such methods of supplying self-declaration information should be approved by the Authorising Body.
Joining the System
FIG. 5 illustrates steps involved when a Transport Operator seeks access to a road network by acquiring a SAC. A Transport Operator joins the System by initiating a System Access Application in a step 501 . This is achieved by the Transport Operator submitting to the Jurisdiction of interest, data identifying one or more vehicle-use conditions under which the Transport Operator seeks access to the Jurisdiction's road network, together with details identifying the applicant Transport Operator. Transport Operator details typically include information about the Transport Operator itself, the vehicle (e.g. vehicle identity, vehicle type, vehicle combination).
In a step 502 , the Jurisdiction assesses the Transport Operator's application. If the application is unsuccessful, it is terminated in a step 503 . If the assessment is successful, the Transport Operator's application is accepted and in a step 504 the Jurisdiction issues an Interim System Access Condition (Interim SAC) to the Transport Operator. An Interim SAC indicates the Jurisdiction's intention to grant the final SAC to the Transport Operator, contingent on the Transport Operator engaging a System SP and successful completion of the remainder of the System Application process.
An Interim SAC is a datafile including an Identifier for the SAC applied for, together with a lapse date and the conditions as approved by the Jurisdiction. It also includes the details of the Transport Operator and its vehicle combination (e.g. primary vehicle only, primary vehicle plus trailers). This preferably includes a Vehicle Identification Number (VIN) for the vehicle identified in the interim SAC, or another identifier such as the vehicle chassis number or engine number. This enables the System SP to verify that the vehicle being fitted with the monitoring hardware is the same vehicle for which the Jurisdiction issued the Interim SAC. An Interim SAC can be cancelled by the Jurisdiction at any time after it has been issued, but only prior to the lapsing date or the final SAC being issued by the Jurisdiction, at the completion of the application process.
Once the Interim SAC issues, the Transport Operator selects a System SP that has been certified by the Authorising Body (step 505 ) and in a step 506 takes the Interim SAC to the selected System SP who installs the necessary hardware in the Transport Operator's vehicle (step 506 ). This hardware includes an IVU and, where applicable, a SDID. Where the IVU installed in the vehicle is Level 2 type-approved, the System SP may also install TIDs in trailers to be used with the vehicle in which the Level 2 type-approved IVU has been installed. When hardware installation is complete the System SP adds to the Interim SAC data identifying itself (i.e. the System SP selected by the Transport Operator to monitor the vehicle), and data identifying the IVU and other devices it has installed on the vehicle (step 507 ). Then, in a step 508 , the updated Interim SAC is sent electronically, to the Jurisdiction. Preferably, this electronic transmission is via a Tier 1 data interchange, as defined below.
Upon receipt of the updated Interim SAC from the System SP, the Jurisdiction appends its assessment data, together with an Identifier to identify the final SAC which has ultimately been granted to the Transport Operator. The Transport Operator is finally issued the final SAC defining the constraints agreed upon and within which the Transport Operator can access the Jurisdiction's road network.
Conditions which are specified in the System Access Condition may be “off the shelf” or they may be “unique”. In one embodiment, “off the shelf” conditions are published by Jurisdictions and are assigned identifiers so they can be quickly and easily selected or identified by a Transport Operator seeking to submit an Application for a SAC. A Jurisdiction may update or revise the content of an “off the shelf” condition at any time. In the event, that an “off the shelf” condition selected by a Transport Operator is revised, the selected condition will automatically adopt the features of the most recent revision. Similarly, a Jurisdiction may offer a set of “off the shelf” conditions. In either case, if a Transport Operator has a SAC granted which refers to one or more “off the shelf” conditions these will be updated automatically to reflect any revisions to those conditions which are made by the Jurisdiction, without the need to cancel the original SAC and issue a replacement.
In contrast, a “unique” condition is a condition which is individually negotiated between the Transport Operator and the Jurisdiction. Once agreed upon, the features of the unique condition are embedded in a data file ultimately defining the granted SAC which includes the unique condition. Since the details of a unique condition are embedded in individually negotiated SACs, they typically cannot be changed or revised. Instead, if a change is required the Transport Operator must apply to the Jurisdiction for the issuance of an entirely new SAC. The original SAC will be cancelled.
Conditions which may be defined in a System Access Condition include, but are not limited to, spatial conditions, temporal conditions, speed conditions and self declaration conditions.
In one embodiment, the process by which a Transport Operator may apply to join the System may be referred to as a System Application. The Application is an electronic datafile that includes SAC identifying information, SAC conditions (Part 1 ), Transport Operator details (Part 2 ), System SP, IVU and TID installation details (Part 3 ) and Jurisdictional assessment (Part 4 ). Data for Part 1 and Part 2 is collected, entered into a datafile and held by the Jurisdiction. The Jurisdiction assesses the application and either issues an Interim SAC or terminates the application. If an Interim SAC issues, data for Part 3 is submitted by the System SP to the Jurisdiction via a Tier 1 communication (see below) and added to the datafile. Once the data in Part 4 is added to the datafile by the Jurisdiction, Parts 1 to 4 are issued, as the final SAC.
Spatial Access Conditions
Spatial conditions can include route conditions and zone conditions and these are used to specify where a vehicle is or is not allowed to travel. Thus, in a preferred embodiment of the invention a spatial condition is specified as one of an inclusion route/zone, absolute inclusion route/zone (both defining where access is allowed) and an exclusion zone (where access is not allowed), or Background. Route and zone spatial conditions exist and like other conditions, are specified by the issuing Jurisdiction responsible for approving the SAC.
Route conditions and zone conditions are defined using a contiguous set of links that are identified using persistent identifiers. In one embodiment, the persistent identifiers are sourced from an Intelligent Access Map (IAM). An IAM may be proprietary, e.g. to the Authorising Body. Alternatively, the persistent identifiers may correspond to global navigation coordinates, e.g. latitude and longitude indicators which can be used in respect of any global navigation-based map system approved by the Authorising Body. In any event, the persistent identifiers demonstrate geographically, the location (e.g. end points or boundaries) of a defined spatial condition.
A route condition describes a route where access is allowed or is not allowed, using a set of contiguous persistent identifiers or pre-defined links that identify the route from end to end. The first and/or last links in a spatial condition may be specified as partial links, rather than complete links. Thus, for a particular spatial condition a route start position may be specified by its latitude and longitude which limits the route to that position onward even though it is mid-way along the first link of the route. Similarly, a route end position may be specified by its latitude and longitude which limits the route to that location which is located part-way along the last link of the route.
A zone condition describes an area or region where access is allowed or is not allowed, using a set of contiguous persistent identifiers that describe a closed polygon. This closed polygon defines the boundary of the zone which may be an inclusion zone or an exclusion zone. Thus, an approved vehicle may travel freely anywhere within an inclusion zone, subject to any exclusion zones taking precedence.
In a preferred embodiment, a spatial condition specifying an inclusion/exclusion route, defines the route as including a window each side of a road or route centreline. Similarly, a spatial condition specifying an inclusion zone preferably includes a window extending outward from the inclusion zone boundary (and more preferably from an IAM road centreline by which a boundary may be defined). The window may be e.g. 50 meters, 100 meters or 150 meters from the boundary or centreline although these window values are examples only. Use of a window factors a degree of tolerance into the compliance system to eliminate spurious or inadvertent detection of non-compliant activity that is not a true breach of an agreed spatial condition.
One or many spatial conditions may be included within a SAC to define cumulative access granted to the vehicle. A spatial condition (i.e. route or zone condition) will apply 24 hours per day, 7 days per week while the SAC is active, unless the SAC is further qualified by a temporal access condition.
Within a SAC, any area of the Jurisdiction which is not specified in a spatial access condition is referred to as SAC Background and this can be denoted by the Jurisdiction as either inclusion or exclusion.
Where a SAC specifies more than one spatial condition, they are assigned an order of precedence as follows:
a. absolute-inclusion (takes precedence over all others); b. exclusion (takes precedence over inclusion); c. inclusion; and d. Background.
Temporal Conditions
Temporal conditions are typically used to qualify spatial conditions. Where a temporal condition is used to qualify a spatial inclusion condition, then the spatial condition will only permit access to the route/zone for those days/dates and/or times specified in the applicable temporal condition. Conversely, where a temporal condition is used to qualify a spatial exclusion condition, then the spatial condition will only restrict access to the specified route/zone for those days/dates and/or times specified in the applicable temporal condition.
Thus, in a particular SAC, a spatial condition is found to be “In Effect” at the days/dates and times specified in an applicable temporal condition also included in that SAC. FIG. 7 is an example of a cumulative set of spatial and temporal conditions specified in a single SAC. In this SAC, there are six spatial conditions defined. Spatial condition 1 is a zone condition which is qualified by a temporal condition in which access to zone 1 is permitted from 6 pm to 6 am only. Spatial condition 6 is also a zone condition but has no temporal condition qualifying it hence it applies twenty-four hours a day, seven days a week. Spatial conditions 2 , 3 , 4 and 5 are route conditions. Route condition 4 is also qualified by a temporal condition which permits access to route 4 from 8 am to 6 pm only. Spatial conditions 2 , 3 , 5 and 6 permit access twenty-four hours per day, seven days per week since they have no applicable temporal conditions.
Where a spatial condition specifies where access is not permitted and is qualified by a temporal condition, access is only restricted for the days/dates and/or times specified in the temporal condition.
In other embodiments, temporal conditions may be imposed e.g. where a licence restriction is placed on an individual who has been convicted of an offence for which the penalty is licence cancellation, but where the defendant has made a showing that the driving licence is required to travel to and from work. In such situations a temporal condition alone may be applied by a magistrate or judge, wherein the vehicle will be non-compliant if vehicle movement is detected outside of the permissible temporal limitations imposed.
Speed Conditions
Speed conditions specify the maximum speed usage (i.e. a speed threshold) of a vehicle. Preferably, a single speed condition (threshold) applies throughout a SAC-issuing Jurisdiction although conceivably more than one speed condition could apply in a Jurisdiction. Also, a speed condition could be specified in more than one SAC issued to a vehicle, e.g. when a vehicle is used in multiple Jurisdictions.
Where a vehicle operating under a speed condition is limited to only one speed threshold applicable throughout a Jurisdiction and across jurisdictional borders, it is the responsibility of the Jurisdictions affected to ensure that the threshold is consistent.
Where speed record processing (i.e. determination of speed records using e.g. position data obtained) is performed by the IVU processor, the IVU may store the speed threshold in memory. Alternatively, where speed record processing is performed by the System SP processor, it is not necessary for the IVU to retain the speed threshold in memory.
Preferably, a speed condition is not the only condition specified in a SAC. The SAC should also include at least one a spatial condition that describes the spatial access granted to the vehicle in the relevant Jurisdiction, and which is qualified by the speed condition granted for that access.
A Speed Event occurs where a vehicle is non-compliant with an applicable speed Condition, i.e. if speed records determined for a vehicle indicate that a speed threshold defined in an applicable SAC has been exceeded during vehicle use. In one embodiment, the speed threshold is determined to have been exceeded where an average value of a pre-determined number of speed records exceeds the speed threshold. Preferably, the average value is calculated using a rolling or “moving” average which more accurately indicates the longer term trend of the vehicle's speed than simply calculating the arithmetic mean. FIG. 8 is a schematic diagram illustrating speed data records considered when determining a speed event, according to one embodiment of the invention. The speed data records denoted SD may be determined by the IVU or the System SP using collected position and time data. Rolling average values are denoted RA.
A speed event SE is shown as including speed data records commencing at b 1 and ending at bn. This includes records shown at RA 1 used to calculate the first rolling average value, R 1 which exceeded the speed threshold, plus the determined speeds shown at RAn used to calculate the rolling average values which continue to exceed the speed threshold, ending at Rn. In a preferred embodiment the SE data further includes lead-in speed data for a time period ti (e.g. sixty seconds), and lead-out data for a time period t 2 (e.g. sixty seconds). The lead-in and lead-out data included in a Speed Event can be used by a Jurisdiction to determine whether or not to issue an infringement notice.
Preferably, the rolling average is calculated for ten consecutive speed records (e.g. a 1 to a 10 ). In a preferred embodiment where speed is determined using position signals received by the IVU, these records are only utilised when the position signal quality for each of those records meets the standards prescribed by the Authorising Body (e.g. at least four satellites with a HDOP of less than four) although this is not considered to be crucial for records in the lead in and lead out time periods t 1 , t 2 . If records available for the lead-in or lead-out periods are for less than t 1 or t 2 seconds, the speed event should include all available speed records in the lead-in and/or lead-out period.
While the illustrated embodiment illustrates the rolling average being calculated for a window of ten consecutive speed data records, it is to be understood that the Authorising Body may prescribe the use of more or less data records in the determination of the rolling average speed.
Preferably, the System SP processor executes the processing necessary to identify a speed event and the speed records comprising that event. However, it is to be understood that such functionality may alternatively/additionally be built into the IVU processor.
System Service Provider (System SP)
Each certified System SP is capable of receiving, implementing and assessing a vehicle's compliance with the conditions defined in an approved/issued SAC (including an Interim SAC). FIG. 6 is a schematic illustration of components of Service Provider processing apparatus 600 . The apparatus includes a SP wireless communication element 602 adapted to receive vehicle data records transmitted from IVUs using via communications network 210 . SP Processor 604 performs the processing necessary to generate non-compliance reports, according to instructions stored in software memory 608 . SP Storage element 606 stores non-compliance reports and non-compliance data for transmission to Jurisdictions via communications network 210 .
Where a vehicle is operating under multiple SACs, the System SP possess the hardware and processing attributes required to assess compliance against all of those conditions, as is required by the Authorising Body. In a preferred business model, a System SP commences monitoring of a vehicle for compliance within one working day after receiving the issued SAC from the issuing Jurisdiction, or on a SAC commencement date set by the Jurisdiction.
In a further preferred business model, a System SP notifies the Authorising Body automatically when it has in service a pre-defined percentage (e.g. 80%) of the number of IVUs for which it has been certified to operate. This will flag the System SP as one to watch as being close to its monitoring capacity, to ensure that it continues to monitor vehicles to the standards required by the Authorising Body. System SPs also provide programmed maintenance of hardware it installs replacing batteries, seals and connections where necessary. Where hardware malfunctions are recognised, the Jurisdiction is to be notified and informed of the remedial action to be taken and when. The same applies where there is evidence of tampering with hardware installed in vehicles by the System SP.
If a SAC includes a cessation date, the System SP deactivates the SAC on the stipulated date, if it has not been preceded by a request (e.g. from a Transport Operator or a Jurisdiction) for cancellation of the SAC. If a Transport Operator seeks to cancel an issued SAC, it can request the relevant Jurisdiction to take the necessary action. A System SP may apply to a Jurisdiction to cancel an issued SAC, by submitting a request over a Tier 1 data interchange (see below). In the event that a Jurisdiction cancels a SAC, it will communicate the SAC with a “cancelled” status to the System SP over a Tier 1 data interchange. In this event, in a preferred business model the System SP deactivates the SAC within a working day of receiving notice of the cancellation from the Jurisdiction.
As a participant in the system, each System SP supports electronic data interchanges with other participants in the system, including Jurisdictions and the Authorising Body. Two levels of data interchange should be supported at a minimum. A Tier 1 interchange involves a higher level of privacy and security for data transferred in transactions. A Tier 1 data interchange may be supported using, for example, an automated B2B interface employing web services, although other secure automated systems are also contemplated, particularly those which adopt SSL or other high-security protocols during transmission. Tier 1 data interchanges should be adopted for:
a. transmission of SACs between parties (e.g. from a Jurisdiction to a System SP); b. requests for cancellation or replacement of a SAC; and c. delivery of Non-Compliance Reports and Participation Reports (to a Jurisdiction or the Authorising Body).
Other communications between participants in the system may occur via a Tier 2 data interchange. Tier 2 data interchanges may be supported by other electronic transmission protocols including secure email and ftps or ftp with SSL. Alternatively, traditional communication processes such as registered mail may be used.
During use of a vehicle, the IVU periodically transfers the time-marked data obtained from the vehicle sensors to the System SP responsible for installation and monitoring of that IVU. Periodic transfer may be e.g. once every 24 hours or as soon as practicable thereafter when a communications network has not been available at the scheduled transfer time but has recently come back online. Transfers may occur more regularly where it is anticipated that the number of records in the time-marked log is almost due to exceed the storage capacity of the IVU.
The System SP assesses the IVU data records against all applicable SACs which have been issued (and updated from time to time where off the shelf conditions have been used) to determine whether any non-compliant activity has occurred. If non-compliant activity is identified, the System SP notifies the relevant Jurisdiction automatically, via transmission of a NCR using a Tier 1 electronic data interchange.
Non-Compliance Reports (NCRs)
A NCR may take a number of different forms, depending on the requirements of the participants and in particular the Jurisdiction to whom the NCR is communicated. Typically, the Authorising Body overseeing the System prescribes the form and content of NCRs. Minimum information to be included in a NCR is: the nature of the non-compliant activity for which the NCR has been issued (e.g. spatial, temporal, speed, alarm, self declaration); the duration of non-compliant activity including commencement time and position and end time and position and preferably, total duration of non-compliance. The NCR should also include the time and date on which the NCR was generated by the System SP (local SP time).
NCR reports contain, as applicable, NCR position records, NCR speed records, NCR alarm records—Type 1 ; NCR alarm records—Type 2 A, NCR alarm records—Type 2 B and NCR SD records. Preferably NCRs are transmitted from System SPs to the relevant Jurisdiction via a Tier 1 data interchange, after which time the Jurisdiction can take enforcement action if necessary.
When assessing a data record for spatial non-compliance, the System SP identifies applicable SACs as those which correspond to the vehicle combination, date/time and vehicle position as recorded in the data record received from the vehicle IVU. Thus, the assessment involves: identifying the set of spatial conditions which are relevant to the vehicle's position; select those conditions which are “in effect” at the time of data collection and separating the in effect conditions into a hierarchy. Thus, an absolute-inclusion spatial condition takes precedence over all other spatial conditions. If no absolute-inclusion condition exists, an exclusion condition takes precedence over inclusion conditions and the SAC Background which may be designated as “inclusion” or “exclusion”.
If a vehicle is assessed to be spatially non-compliant, the System SP should then also assess if the vehicle is additionally temporally non-compliant. Temporal non-compliance is found to occur where the vehicle is spatially non-compliant at the position under consideration and there is at least one temporal condition which applies to that position.
In one embodiment, a NCR includes all NCR position records for the full period of non-compliance. Contingencies are provided where the period of non-compliance is longer than 72 hours, and/or an event occurs which renders the System SP unable to continue assessing non-compliant activity, e.g. when the vehicle crosses a Jurisdiction's border.
Preferably, a spatial or temporal NCR is issued only where two or more consecutive position records in a time-marked log are found to be spatially or temporally non-compliant. The NCR includes all NCR position records for the full period of non-compliance, commencing with the first non-compliant position record and ending with the first collected of either: a) the last non-compliant position record preceding the first subsequent compliant position record; b) the last non-compliant position record collected within 72 hours of the first non-compliant position record; or c) the last position record collected prior to some event occurring which renders the System SP unable to continue assessing the non-compliant activity. A period of data records corresponding to compliant vehicular activity may be included either side of the non-compliant period to indicate the vehicle's behaviour around that time.
Where a data record indicates that, for a particular vehicle combination, date/time and vehicle position, there has been a period of non-compliance with an applicable speed condition, a Speed NCR will be issued, including speed data records collected during the period of speed non-compliant activity. This is known as a “Speed Event”. Where a Speed Event crosses a Jurisdiction's border, a Speed NCR will issue to each of the Jurisdictions affected.
For a Speed NCR, the applicable SACs over the period of a speed event are identified and where these include at least one speed condition, the System SP assesses and reports the entire speed event to the Jurisdiction. When assessing speed non-compliance, the applicable SACs are those pertaining to the particular vehicle combination, date/time and vehicle position as may be specified within the speed record being assessed. All speed records for the speed event are included in a Speed NCR. A Speed NCR will be issued, when necessary, irrespective of whether the vehicle is spatially or temporally compliant or non-compliant during the period of the Speed Event.
When assessing vehicle position for the purpose of determining speed and position non-compliance, where the vehicle is deemed to be outside of e.g. 13 meters of a boundary or road centreline defining a spatial condition, or where there are two or more possible roads on which the vehicle may be located, it is preferred that the location details are left blank. This avoids any potential adverse assessment where there is insufficient (or conflicting) evidence to substantiate an assessment of non-compliance.
For spatial, temporal and speed NCRs, if at least one of the SACs listed in the NCR includes at least one SD condition, the NCR shall also include all relevant NCR SD records. Preferably this includes records from the 24 hour period prior to the NCR beginning date/time for spatial and temporal NCRs and the first included speed record for a speed NR; and all NCR SD comments records for a 12 hour period following.
In one embodiment, in addition to all the data records for the time during which the vehicle was spatially or temporally non-compliant, an NCR also includes one or more records before the first non-compliant record. This may include records for a period of 1, 2, 3, 4, or 5 minutes, for example, prior to commencement of the period of non-compliant activity. Similarly, the NCR may also include one or more records immediately following the last non-compliant record for a period of, for example, 1, 2, 3, 4 or 5 minutes. This enables a Jurisdiction to consider a Transport Operator's behaviour either side of a period of non-compliant activity when deciding whether or not to issue an infringement notice.
Further, when issuing a NCR the System SP may also check the data records for the presence of alarm records transferred from the IVU. Alternatively/additionally, the System SP may generate alarm codes based on data tests conducted in respect of time-marked data received from an IVU. FIG. 10 sets out a summary of alarm codes which may be included in a NCR although this is not to be construed as a compulsory or an exhaustive set of codes.
For Alarm NCRs, the System SP checks for the presence of alarm records transferred from the IVU and alarms generated by the System SP as a result of data testing by the System SP intended to detect irregularities, inconsistencies or implausible data in records that have been transferred from the IVU. Preferably, the System SP uses alarm codes (e.g. of the kind set out in FIG, 10 ) when reporting alarm records and alarms to a Jurisdiction in an alarm NCR. In FIG. 10 , Alarm Codes 1 to 12 relate to IVU alarm records and alarm codes 51 to 59 relate to alarms generated by the System SP. Alarm records with alarm codes 3 to 12 may be designated alarm record type 1 . Alarm records with alarm codes 51 to 59 may be designated alarm record type 2 A. Alarm records with alarm codes 80 to 85 may be designated alarm record type 2 B. For type 1 alarm records, the Alarm NCR includes position records. For type 1 and type 2 A alarm NCRs, if there is an applicable SD condition, the Alarm NCR also includes SD condition type and all relevant SD NCR records for a period (e.g. 24 hours) leading up to the alarm event triggering the Alarm NCR and a period (e.g. 12 hours) after.
A System SP triggers a SD (Vehicle type/TCM) NCR when a self-declared TCM value exceeds the TCM threshold for the vehicle type. This NCR will issue irrespective of whether there is concurrent spatial, speed or temporal compliance. Position records may be included in the NCR.
Typically, any IVU will have only one applicable speed condition (e.g. a speed threshold applicable throughout a Jurisdiction). However, where there is more than one speed condition (i.e. speed threshold) defined in SACs applicable to an IVU, separate NCRs may be issued when the vehicle is non-compliant with each individual applicable speed condition. A separate NCR may be issued each time a spatial or a temporal condition is invoked, the report listing each individual SAC against which the non-compliant activity is detected. NCRs should be issued within one working day of the data records being transferred from the IVU to the System SP responsible for processing the data and assessing the vehicle's compliance.
It is desirable for NCR data to be retained by the System SP for a period of time as may be prescribed by the Authorising Body, for future use. Future use of retained NCR data may include use in proceedings in which, for example, an infringement notice is challenged by a Transport Operator or enforced by a Jurisdiction.
When a vehicle demonstrates non-compliant activity for an extended period (e.g. longer than 72 hours), the SP may issue more than one NCR and, for example, issue a NCR after each 72 hour period for which the vehicle has been continuously non-compliant. This applies to both temporal and spatial non-compliance as well as speed, alarm, self declaration and other non-compliant activity.
Where there is a conflict between conditions specified in a SAC which has been approved by a Jurisdiction, or where there are irregularities, the System SP should report these to the SAC issuing Jurisdiction. Instances of irregularities may include, for example, where any of the persistent identifiers used to specify a spatial access condition do not exist within an IAM or other map being used; where a spatial access condition intended to specify a zone is identified by a set of persistent identifiers that do not define a closed polygon; and where a SAC cessation date is after a “valid to” date stipulated in e.g. an “off the shelf” condition.
Participants Report (PR)
In an embodiment, System SPs issue to Jurisdictions specific periodic Participants Reports (PRs) which sets out the aggregated data that is provided by the System SP to the Jurisdiction over the reporting period (e.g. monthly). A PR is generated for every Jurisdiction which issued SACs that were applicable to any of the vehicles being monitored by the System SP during the reporting period. Preferably, a PR also includes details of SACs newly issued to Transport Operators during the reporting period.
The PR also reports on all vehicles monitored at some time during the reporting period. This enables Jurisdictions to establish NCR tallies for a reporting period and may enable Jurisdictions to plan future infrastructure development and road use schemes and permits. Preferably, PRs are delivered to Jurisdictions automatically by way of Tier 1 data interchange.
Since a NCR includes all the data points in the time-marked log during the period of non-compliant activity, Jurisdictions are able to ascertain the duration of the non-compliant activity, and may elect not to issue an infringement notice, e.g. if the period of non-compliance was very short. Additionally, for vehicles fitted with a SDID, the NCR will also include data corresponding to self-declaration inputs from the Transport Operator or its representative (e.g. the vehicle driver). The self declaration data may be utilised by a Jurisdiction to explain the non-compliant activity (e.g. road works forced a delay resulting in temporal non-compliance, or a detour due to road construction forced spatial non-compliance). This additional information could prevent the issuance of an infringement notice which would otherwise have likely been appealed or challenged by the Transport Operator improving efficiency in assessing compliance.
The present invention facilitates use of telematics solutions in a vehicle monitoring system which permits recordal of data pertaining to vehicle use which is of evidentiary nature. This is supported by the collection and recordal of data sets indicative of vehicle compliance or non-compliance over a period of time. This is a distinct improvement over prior art monitoring systems which record non-compliance at a moment in time only, that is by recording a single non-compliant data point. By including a series of points as evidence indicating non-compliance it is anticipated that in using the present system, Transport Operators will more willingly accept warnings and/or infringement notices issued by Jurisdictions and more importantly, take steps to improve practices to ensure compliance in the future.
Advantageously, embodiments also permit collection and recordal of vehicle use data for periods of time preceding and following non-compliant vehicular activity forming a vehicle use “history”. This arms Jurisdictions with further important information which may influence their decision to issue a notification to a Transport Operator. Moreover, collection and recordal of “self declaration” inputs can be utilised by Jurisdictions in their assessment of non-compliant vehicular activity.
In addition, the present system takes account of the quality of the signals which are used to determine vehicle position and hence direction of vehicle travel and speed. Where the signal quality does not meet prescribed levels, the data is not relied upon.
This multi-point and multi-parameter approach to determining non-compliance gives Transport Operators confidence in the System and potentially eliminates the opportunity for false NCRs being issued.
The system is also operable across jurisdictions due to the consistency of monitoring which is achieved by defining conditions of vehicle use in electronic SAC datafiles.
The present invention also permits use of a Business Model in which various private companies can be certified as Service Providers and negotiate contractual terms with Transport Operators utilising their services. The Transport Operator therefore has freedom of choice in determining who will provide the monitoring service, but can still have confidence that whichever System SP is selected, it will be required by the Authorising Body to perform the service to prescribed standards, or risk losing its certification. Periodic auditing by System Auditors enhances the business model.
Automating the SAC application process by applicants, Jurisdictions and System SPs updating an electronic application datafile also makes it easier and faster for Transport Operators to gain access to road networks according to the System. Where Transport Operators elect “off the shelf” conditions in an application, once the SAC finally issues, any updates are adopted automatically, without any extra effort required from the Transport Operator operating under the SAC. Similarly, in embodiments where a proprietary map (e.g. IAM) is used to define spatial conditions, map updates occur automatically when the Authorising Body controlling the map supplies the updates to the System SPs. This process is transparent to Transport Operators.
By assigning the monitoring task to certified System SPs, opportunities are presented for improved contract management, where the Authorising Body and e.g. governments can oversee and audit the performance of service contracts between Transport Operators and System SPs. This can facilitate improved structuring and targeting of concessions, and supports cooperative solutions to transport issues which are identified in the process.
Road authorities benefit from use of the System as they are able to provide better management of the road networks e.g. by monitoring PRs, and plan increased capacity to provide for growing freight transport needs. There are also flow on effects for improved safety and infrastructure, together with opportunities for improved environmental management, and management of community expectations.
It is to be understood that various modifications, additions and/or alterations may be made to the parts previously described without departing from the ambit of the present invention as defined in the claims appended hereto.
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A method for granting permission for a vehicle to access a transport network includes an applicant electing in an electronic datafile one or more desired conditions of vehicle use for accessing the network and transmitting the electronic datafile via electronic transmission means to a third party for approval. If the electronic datafile is approved, the third party appends approval data to the datafile, such that the applicant is granted temporary permission to access the network in accordance with the elected desired conditions conditional upon, in a prescribed time frame monitoring hardware being installed in the vehicle, and a monitoring service being engaged to monitor use of the vehicle when accessing the network. When the third party is notified that the hardware has been installed and the service has been engaged the datafile is finalized, granting continued permission to access the transport network.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent application Ser. No. 61/466329, filed Mar. 22, 2011 by the present inventor.
BACKGROUND
[0002] The impact of environmental and climate change, coupled with high oil prices, fossil fuel resources and energy regulations are driving the development of renewable energy. The present invention is based on thermal gradient energy conversion for the generation of hydroelectric power.
[0003] As the oceans cover a little more than 70 percent of the Earth's surface it makes the sea the largest solar energy collector on the planet and is ideally suited for the present invention. When the difference between the warm surface water and the cold deep water is above 18 degrees Centigrade, a thermal energy conversion system becomes viable as it utilizes this natural thermal gradient to drive a power plant. Typically around 3,000 mega watts of electrical power can be produced per 100 square miles of ocean surface.
[0004] Conventional ocean thermal energy conversion designs use a fluid, such as ammonia, (Closed cycle) or sea water (Open cycle) to rotate a turbine to generate electricity. The disadvantage of conventional designs is that a low pressure vapor turbine requires a much higher ocean temperature gradient to operate. Low pressure vapor turbines are inherently big, expensive and inefficient compared to high pressure hydraulic turbines of similar output. The system also requires a large floating platform to support the heat exchangers, pumps and turbine and the platform should also be designed to withstand severe storms and hurricanes.
[0005] As such it would be useful to have a thermal gradient hydroelectric power system and method.
SUMMARY
[0006] An object of the present disclosure is to provide an economical, reliable and environmentally friendly thermal gradient energy conversion system for generating electricity and providing the electricity to existing electrical power grids or other independent power consumers.
[0007] Specifically, the disclosure describes a power generation system, comprising a submersible evaporator, a vapor line, a condenser above the submersible evaporator, a liquid line, and a turbine system. The submersible evaporator can have a warm water inlet connectable to a natural warm water source, the warm water source having a first temperature; an evaporator shell connected to the warm water inlet; a warm water discharge connected to the evaporator shell; an evaporator working fluid inlet; a one or more evaporator coils connected to the working fluid inlet; and an evaporator working fluid discharge connected to the one or more evaporator coils. The vapor line can have a vapor line first end connected to the evaporator working fluid discharge and a vapor line second end. The condenser above the submersible evaporator can comprise a cold water inlet capable of receiving cold water from a natural cold water source; the cold water having a second temperature; a condenser shell connected to the cold water inlet; a cold water discharge connected to the condenser shell; a condenser working fluid inlet connected to the vapor line second end; a one or more evaporator coils connected to the working fluid inlet; a condenser working fluid discharge connected to the one or more evaporator coils. The liquid line can have a liquid line first end connected to the condenser working fluid discharge, and a liquid line second end. The turbine system can have a turbine system inlet connected to the liquid line second end; a turbine rotatable by a working fluid, the working fluid having a boiling temperature between the first temperature and the second temperature; and a turbine system outlet that connects to the evaporator working fluid inlet.
[0008] Specifically, the method can comprise cycling through a submersed evaporator warm from a natural warm water source, the warm water source having a first temperature. The method also can comprise evaporating a working fluid using the evaporator, and routing the working fluid from the evaporator through a vapor line to a condenser above the evaporator. Finally, the method can also comprise cycling through a condenser cold water from a natural cold water source, the cold water source having a second temperature, and condensing the working fluid, the working fluid having a boiling point between the first temperature and the second temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a schematic flow diagram of a thermal gradient hydroelectric power system.
[0010] FIG. 2 illustrates a general arrangement drawing, illustrating a submerged thermal gradient hydroelectric power system.
DETAILED DESCRIPTION
[0011] Described herein is a title system and method. The following description is presented to enable any person skilled in the art to make and use the invention as claimed and is provided in the context of the particular examples discussed below, variations of which will be readily apparent to those skilled in the art. In the interest of clarity, not all features of an actual implementation are described in this specification. It will be appreciated that in the development of any such actual implementation (as in any development project), design decisions must be made to achieve the designers' specific goals (e.g., compliance with system- and business-related constraints), and that these goals will vary from one implementation to another. It will also be appreciated that such development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the field of the appropriate art having the benefit of this disclosure. Accordingly, the claims appended hereto are not intended to be limited by the disclosed embodiments, but are to be accorded their widest scope consistent with the principles and features disclosed herein.
[0012] FIG. 1 illustrates a schematic flow diagram of a thermal gradient hydroelectric power system. One working, suitable fluid for the disclosed system and method is 1,1,1,2,3,3,3-Heptafluoropropane CF3-CHF-CF3 (R-227ea), as it has a good liquid to vapor density ratio and low latent heats of evaporation and condensation, thus giving the fluid a high energy conversion efficiency and available liquid head for the hydraulic turbine at low temperature gradients. Other refrigerant type of fluids can be used, but many give lower energy conversion efficiencies and liquid heads requiring a greater thermal gradient.
[0013] The working fluid can be in communication with one or more condenser tubes 8 , a liquid line 12 , a turbine 15 , a generator 17 , one or more vaporizer tubes 24 , and a vapor line 27 . In a no flow or static condition, the liquid level in pipe 12 and vaporizer tubes 24 can be equal.
[0014] A suction pipe 1 can feed relatively cold deep water to a pump 6 . In one embodiment, and inline de-aerator 2 and a cyclone 3 can remove debris, small marine organisms and dissolved gasses from the water. The gasses can be extracted by vacuum pump 5 and discharged. The debris and marine organisms removed by cyclone 3 can be returned as waste back to the body of water through a cyclone dip leg 4 . The cold water from pump 6 can be delivered to the shell of condensing heat exchanger 7 and can be external fluid communication with condenser tubes 8 providing the required quantity of water needed to condense vapor 13 inside condenser tubes 8 . The flow of the cold water can be, in one embodiment, regulated by a control valve 9 . Spent water can be exhausted through condenser outlet 14 back to the body of water at a temperature a few degrees higher than the condenser water inlet temperature. For example, saturated Heptafluoropropane (R-227ea) vapor at 2.67 Bar absolute and 8.3 degrees centigrade will condense when cold ocean water of between 2 and 3 deg Centigrade is pumped from approximately 1000 m below the surface and passed through a condensing heat exchanger. Within these conditions, 9.77 kg of water is required to pass through the heat exchanger to condense 1 kg of R-227ea vapor. Such example is exemplary and not limiting.
[0015] The difference in height between liquid level 10 in condenser tubes 8 and liquid level 23 in vaporizer tubes 24 depends on the physical properties of the working fluid, and the available thermal gradient. The optimum height (pressure head) of the liquid can be maintained by regulating the flow of liquid to a turbine or other engine by means of a second control valve 21 . For example, the optimum height for R-227ea with a 20 deg Centigrade thermal gradient is 430 meters. The height can decreases with a decrease in the thermal gradient. The height and flow of the fluid affects the turbine power output.
[0016] The condensed liquid 11 from condenser tubes 8 enters the high pressure side of turbine 15 through pipe 12 and is exhausted at a lower pressure into vaporizer tubes 24 . The transfer of energy of the flowing liquid causes turbine 15 to rotate providing the power to drive a generator 17 . The generator power output is regulated by the liquid flow control valve 21 . For example, liquid R-227ea at pressure head (height) of 430 meters at the turbine inlet and a flow rate of 180 kg/sec, can produce 1000 kw at a combined turbine and generator efficiency of 93%
[0017] A suction pipe 18 can feed warm surface water to pump 20 . Supply line 40 can deliver warm water from pump 20 to a shell side 25 of a vaporizing heat exchanger 16 and can be in external fluid communication with vaporizer tubes 24 providing the required quantity of water to boil the liquid 22 inside vaporizer tubes 24 . The flow of the warm water can be regulated by control valve 19 . The spent water is exhausted through vaporizer outlet 26 back to the body of water at a temperature a few degrees lower than the vaporizer water inlet temperature.
[0018] Vapor 27 , generated in vaporizer tubes 24 , can rise in vapor line 28 and can be delivered to condenser tubes 8 . As vapor 27 rises in vapor line 28 , the pressure and temperature of the vapor can decrease to slightly higher than that of condenser tubes 8 within which vapor 27 is again condensed, as previously described, thus completing a closed loop cycle of the working fluid. For example, liquid R-227ea at 3.6 Bar absolute and 17.6 deg Centigrade will boil when warm ocean surface water of between 22 and 23 deg Centigrade is pumped from the ocean surface and passed through a boiler and vaporizing heat exchanger. Within these conditions, 9.6 kg of water can boil and vaporize up to 1 kg of (R-227ea) liquid. As the vapor rises in the 430 meter high vapor line, the pressure drops to 2.67 Bar absolute and the temperature to 9.0 deg Centigrade at the condensing heat exchanger inlet. The cold ocean water of between 2 and 3 deg Centigrade passing through the condenser can once again condense the vapor. Such example is exemplary, and is not intended to be limiting.
[0019] The use of sodium hypochlorite at acceptable concentrations is effective in controlling bio-fouling on the surface of condenser tubes 8 and vaporizer tubes 24 . Salt water or seawater can be drawn through line 29 by pump 30 and delivered to an electro chlorinator 32 . The chlorine gas generated in the electro chlorinator 32 is delivered to the intake of pump 6 through line 33 and pump 20 through line 34 . The spent brine is discharged as waste from the electro chlorinator 32 through line 31 .
[0020] In one embodiment, as pumps 6 and 20 draw power from generator 17 , flow regulation of cold water from pump 6 and warm water from pump 20 is critical in achieving optimum heat exchanger performance. High flow rates may not improve heat exchanger efficiencies for a given temperature, thereby consuming unnecessary surplus power produced by the generator 17 .
[0021] FIG. 2 illustrates one exemplary arrangement of an equipment, pumps, piping and anchoring system. Cold water suction line 1 , de-aerator 2 , cyclone 3 and pump 6 are formed integrally with condensing heat exchange 7 and can be designed to be neutrally buoyant. In one embodiment, this can be accomplished using low density insulation. Liquid line 11 , turbine 15 and vaporizer 16 can be formed integrally with condensing heat exchanger 7 and also can be designed to be neutrally buoyant by means of low density insulation or other methods known in the art. Vapor line 28 is formed integrally with condensing heat exchanger 7 and vaporizing heat exchanger 16 and is designed to be near neutrally buoyant by means of high density concrete. Warm water suction 18 , pump 20 and warm water line 40 can also be formed integrally with vaporizing heat exchanger 16 and can be designed to be near neutrally buoyant by means of low density insulation. The low density insulation and high density concrete also serve as corrosion protection to the external wetted parts of the equipment and piping. Small equipment, pumps, instrumentation and switchgear are housed in compartment 39 . The power cable from the generator is fed up through vapor line 28 and is connected to the electrical bus bar in compartment 39 . The supply cable for pumps 6 and pump 20 is fed from the electrical bus bar. Surplus electrical power from the bus bar is transmitted via a subsea cable 41 to existing onshore electrical power grids or other independent power consumers.
[0022] The entire thermal gradient hydroelectric power system can be submerged and can be anchored by one or more cables 36 . In one embodiment, cables can connect one or more between condenser 7 and anchor block 35 . A floating warning buoy 37 can be attached to compartment 39 .
[0023] Various changes in the details of the illustrated operational methods are possible without departing from the scope of the following claims. Some embodiments may combine the activities described herein as being separate steps. Similarly, one or more of the described steps may be omitted, depending upon the specific operational environment the method is being implemented in. It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments may be used in combination with each other. 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. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.”
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A thermal gradient hydroelectric power system and method is disclosed herein. Specifically, the method can comprise cycling through a submersed evaporator warm from a natural warm water source, said warm water source having a first temperature. The method also can comprise evaporating a working fluid using said evaporator, and routing the working fluid from the evaporator through a vapor line to a condenser above said evaporator. Finally, the method can also comprise cycling through a condenser cold water from a natural cold water source, the cold water source having a second temperature, and condensing the working fluid, the working fluid having a boiling point between said first temperature and said second temperature.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent Application No. 60/847,237, filed Sep. 26, 2006.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for use with microphone headset systems, and, more specifically, to a shield which attaches to the microphone headset to prevent lip reading.
2. Description of the Background Art
In general, the use of headset microphone systems is known in the art. In particular, the use of headset microphone systems is very common in sporting events, such as football, to permit communication between coaches, managers and players. In other sporting events such as car racing, the use of headset microphone systems allows communication between the support staff and the participant (i.e., the pit crew and the driver).
However, in each of these sports, although the headset microphone systems provide a necessary and convenient means of communication, the systems are not without disadvantages. One of the main disadvantages is that as the user of the microphone system speaks into the microphone his or her adversary or opponent may be able to read the lips of the user and thereby gain valuable information that will give the opposing team an unfair advantage. For example, during a football game the coach will speak into the microphone to instruct his quarterback regarding the next play call. If the opposing team is able to read the lips of the coach, then the opposing team would be able to make the appropriate adjustments to defend against the play call, thereby creating an unfair advantage for the defensive team. Similarly, in car racing, if other drivers and pit crews knew of the intentions of their opponents, they would be able to plan accordingly.
Another disadvantage encountered with the use of microphone headset systems is the inability to overcome the noise on system created by either the surroundings or the wind. Many times the systems are used outside in windy environments and in stadiums with a lot of noisy fans.
Accordingly, there is a need in the art for a device that will provide the user with protection from external noise factors and provide the user with the protection from having his or her opponents from obtaining critical information.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a microphone shield device which is dimensioned and configured to shield the lips of the user so that the movement of the lips cannot be readily detected and/or read by another person. It is contemplated that the microphone shield device may be configured in any shape (e.g., a circle, an oval, a square, a rectangle, etc.) or size.
A microphone headset system typically includes a microphone, a speaker and a head strap. An arm connects the speaker and microphone. A first end of the arm is pivotally mounted about a point along the axis of speaker. Thus, the user is capable of pivoting the microphone in and out of position in front of the mouth of the user.
A microphone shield device includes a microphone shield plate, a shield plate arm and a microphone shield device attachment clip. The shield plate arm connects at a first end to shield plate and is pivotally connected at a second end to a pivot point on a first end of microphone shield device attachment clip. Accordingly, the user is able to pivot the microphone shield device in and out of position in front of microphone. Furthermore, the microphone shield device attachment clip may be configured to attach the microphone shield device at numerous positions along the arm of the microphone headset system. Thus, the user may position the microphone shield device in a plurality of positions on the microphone headset system to provide the maximum amount of benefit that may be achieved.
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.
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
The invention will become more clearly understood from the following detailed description in connection with the accompanying drawings, in which:
FIG. 1 is a front view illustrating a user wearing a microphone headset system having a microphone shield device mounted thereon, in accordance with an embodiment of the present invention;
FIG. 2 is a side view illustrating a user wearing a microphone headset system having a microphone shield device mounted thereon, in accordance with an embodiment of the present invention;
FIG. 3 is a top view illustrating a microphone headset system having a microphone shield device mounted thereon, in accordance with an embodiment of the present invention;
FIG. 4 is a top plan view illustrating one of the articulating features of a microphone shield device in accordance with an embodiment of the present invention;
FIG. 5 is a top plan view illustrating one of the articulating features of a microphone shield device in accordance with an embodiment of the present invention;
FIG. 6 is a front view of an embodiment of a microphone shield device in accordance with an embodiment of the present invention;
FIG. 7 is a rear view of an embodiment of a microphone shield device in accordance with an embodiment of the present invention;
FIG. 8 is a side view illustrating an embodiment a means for attaching a microphone shield device in accordance with an embodiment of the present invention;
FIG. 9 is a side view illustrating an embodiment a means for attaching a microphone shield device in accordance with an embodiment of the present invention;
FIG. 10 is a side view illustrating an embodiment a means for attaching a microphone shield device in accordance with an embodiment of the present invention; and
FIG. 11 is a side view illustrating an embodiment a means for attaching a microphone shield device in accordance with an embodiment of the present invention;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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.
Referring now to the drawings in detail, and first to FIG. 1 , a user 100 is illustrated wearing a microphone headset system 200 having a microphone shield device 300 mounted thereon, in accordance with an embodiment of the present invention. As illustrated in FIG. 1 , the microphone shield device 300 is dimensioned and configured to shield the lips of the user 100 so that the movement of the lips cannot be readily detected and/or read by another person. The microphone shield device 300 is illustrated in a particular shape. However, it is contemplated that the microphone shield device 300 may be configured in any shape (e.g., a circle, an oval, a square, a rectangle, etc.) or size.
FIG. 2 is a side view illustrating a user 100 wearing a microphone headset system 200 having a microphone shield device 300 mounted thereon, in accordance with an embodiment of the present invention. The microphone headset system typically includes a microphone 210 , a speaker 220 and a head strap 230 . An arm 240 connects the speaker 220 and microphone 210 . A first end 250 of arm 240 is pivotally mounted about a point along the axis of speaker 220 . Thus, the user 100 is capable of pivoting the microphone 210 in and out of position in front of the mouth 110 of the user 100 .
Another advantage of the present invention is illustrated in FIG. 2 . That is, the microphone is shielded from its surroundings by shield plate 310 , thereby minimizing noise that would otherwise be created by wind hitting the microphone.
Referring now to FIG. 3 , there is shown a top view illustrating a microphone headset system 200 having a microphone shield device 300 mounted thereon, in accordance with an embodiment of the present invention. As illustrated, the microphone shield device 300 includes a microphone shield plate 310 , a shield plate arm 320 and a microphone shield device attachment clip 340 . The shield plate arm 320 connects at a first end to shield plate 310 and is pivotally connected at a second end to a pivot point 330 on a first end of microphone shield device attachment clip 340 . Accordingly, the user is able to pivot the microphone shield device in and out of position in front of microphone 210 . Furthermore, microphone shield device attachment clip 340 may be configured to attach the microphone shield device 300 at numerous positions along arm 240 of the microphone headset system 200 . Thus, the user may position the microphone shield device in a plurality of positions on the microphone headset system to provide the maximum amount of benefit that may be achieved.
FIGS. 4 and 5 are top plan views illustrating the articulating features of the microphone shield device 300 in accordance with an embodiment of the present invention. As shown in FIGS. 4 and 5 , the shield plate arm 320 connects at a first end to shield plate 310 and is pivotally connected at a second end to a pivot point 330 on a first end of microphone shield device attachment clip 340 . Accordingly, the user is able to pivot the microphone shield device in and out of position in front of a microphone.
FIGS. 6 and 7 are front and rear views, respectively, of a microphone shield device 300 in accordance with an embodiment of the present invention. FIGS. 8 and 9 are side views illustrating an embodiment a means for attaching a microphone shield device in accordance with an embodiment of the present invention. As illustrated, this embodiment of a means for attaching a microphone shield device comprises a clip 340 having a pair of resilient legs 342 . The legs 342 are configured to deflect and return to their original position to attach to a tubular structure, for example.
FIGS. 10 and 11 illustrate two alternative means for attaching a microphone shield device in accordance with the present invention. More specifically, the attaching device in FIG. 10 includes a clamping device having a threaded rod 350 with a wing nut 360 connected thereto. At least one of the two clamp halves 370 is driven toward the opposing clamp half to secure the microphone shield device to a microphone headset system. The threaded rod 350 may be secured in place by tightening the wing nut 360 . FIG. 11 illustrates a spring loaded clamp device 380 for attaching a microphone shield device to a microphone headset system.
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.
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A microphone shield device includes a microphone shield plate, a shield plate arm connected at a first end thereof to the microphone shield plate, and means for attaching a second end of the shield plate arm to a microphone headset in a manner which at least partially obscures an ability to view a microphone headset user's mouth while the user is speaking into the microphone headset.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of U.S. Provisional Application Ser. No. 61/241,093 filed on Sep. 10, 2009, the disclosure of which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to a swellable elastomer element packer that may be placed around a tubular at any location and may be used in both conventional completions and intelligent well completions.
BACKGROUND OF THE INVENTION
[0003] Various types of swellable packers have been devised, including packers which are fixed to the OD of a tubular and the elastomer formed by wrapped layers, and designs wherein the swellable packer is slipped over the tubular and locked in place. If the operator desires to have control lines pass through the packer for intelligent well completions, the control line typically was axially aligned with a slot, generally in the exterior of the packer, since the packer was otherwise fixed to the casing or pipe. Manipulation of a control line to obtain proper alignment with a slot in the packer may be difficult, and may risk damage to the control line. An alternative solution is to cut the slot in the exterior of the elastomer cover at the rig site for alignment with the control line. This practice is complicated by the size variance in the cross-section of the control line and/or the encapsulation of the control line.
[0004] Swellable packers are disclosed in U.S. Pat. Nos. 7,472,757 and 7,552,768. U.S. Pat. No. 6,173,788 illustrates control lines on the exterior of a packer, and Publication 2007/0012436 discloses a control cable within the elastomeric body of the packer. Other patents of interest include U.S. Pat. Nos. 4,024,916, 5,137,970, and 6,431,282, 6,474,414, 6,828,531, 6,923,283, and 7,562,710.
[0005] The disadvantages of the prior art are overcome by the present invention, and an improved swellable packer and method of installing a packer is hereinafter disclosed.
SUMMARY OF THE INVENTION
[0006] In one embodiment, a swellable packer includes a two piece swellable element manufactured as a single unit and then split longitudinally into two halves. Each of the two halves includes swellable rubber between split end rings. Since the packer may be split in two halves, any control lines are visible from the bore of the respective packer half during installation of the packer on a tubular.
[0007] According to the method of the invention, a lower split end ring and an upper split end ring may be provided for surrounding the downhole tubular. The method includes providing two or more C-shaped elastomeric bodies each spaced longitudinally between the end rings to expand and seal the annulus about the downhole tubular. The end rings are fixedly connected to the downhole tubular, and a side face of one C-shaped elastomeric body is positioned adjacent a side face of another C-shaped elastomeric body to form an elastomeric seal when the elastomer is expanded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front view of one embodiment of the packer according to present invention.
[0009] FIG. 2 is a sectional side view of the packer shown in FIG. 1 .
[0010] FIG. 3 is an end view of the packer shown in FIG. 1 .
[0011] FIG. 4 is a cross sectional view of the packer shown in FIG. 1 .
[0012] FIG. 5 is a front view of an alternate embodiment of a packer.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] FIG. 1 depicts a swellable packer 10 with an elastomeric element formed as a unit and split into two halves 12 , 14 after manufacture. These two halves each include the swellable elastomer body 18 , and split end rings 20 , 22 . The swellable packer 10 may be fabricated conventionally from elastomer layers which are repeatedly wrapped around a mandrel, and then the elastomeric body is cured at an elevated temperature. The split elastomeric bodies and end rings may be slid off the mandrel, which may be reused for manufacturing another packer. Each end ring has wicker type grooves 24 , as shown in FIG. 2 , so that when the end rings are bolted together, the wickers are embedded into the tubular, thereby restraining the packer halves from moving circumferentially or axially. When the two packer halves are locked together on the tubular, there is no visible gap between the rubber halves, which are butted up against each other. The halves may have a straight cut axially separating the two halves, as shown in FIG. 1 , or a castellated type slot 32 , as shown in FIG. 5 . The tooth pattern of the slot may vary considerably, depending on the application. An advantage of the latter embodiment is that this provides a more tortuous path for any potential leak down the swelled joint at higher pressures and temperatures. Either or both of the halves 12 , 14 may include a slot 26 (see FIG. 2 ) for a suitable control line 28 . Alternatively, the control line may be encapsulated into the molded elastomer. The control line may be visible from the lower bore of the swellable packer, which allows the control line to be run in a normal manner on the outside of the tubular going down hole, then the split half swellable packer aligned with the control line, rather than aligning the control line with the slot in the packer. In this design, the control or encapsulated lines may be run along the outside of a downhole tubular, in a conventional fashion, and each swellable packer half aligned to a control line, not the other way around. Once the two packer halves are placed over the capsulated lines, the two halves are bolted together with the inner faces containing the wickers gripping the tubular. The inner face of each split end ring may be configured for reliable gripping engagement with the base tubular on which the packer is mounted. Various types of gripping teeth may be provided on the inner face of an end ring. In some applications, a C-shaped inlay may be provided, thereby effectively forming an inlay sleeve for gripping the base tubular without damaging the tubular. In other applications, one or more of the inner faces of a split end ring may be manufactured with a slight “wave” to the otherwise cylindrical inner surface of a split ring, thereby again concentrating forces to provide reliable gripping engagement without damaging the tubular.
[0014] FIG. 3 is the end view of the packer 10 shown in FIG. 1 , and illustrates the position of two control lines spaced circumferentially 180° apart. The lower end rings 22 and the mating faces of the two split end rings are also shown in FIG. 3 .
[0015] FIG. 4 is a cross sectional view through the elastomeric body 26 , and shows the circumferentially opposing control lines 28 and the tubular 40 on which the packer is mounted.
[0016] As the swellable packer is run into the well, the swelling fluid, whether an oil or a water based fluid, will act on the surface of the split elastomer sleeves. When the elastomer swells, it will touch the borehole, or the bore of the casing or other tubular in the hole, with continued swelling by absorption and adsorpotion of the fluid exposing the swelled areas between inner and outer diameters of the elastomeric element and the OD of the tubular and the ID of the outer tubular or borehole wall, and between the two mating side faces of adjacent split elastomeric elements, thereby continuing to have the swell fluid enter the swellable elastomer through those exposed areas. When the packer halves are fully swelled, the split faces will be swelled into one homogenous piece of elastomer and also swelled around the control lines. If pressure is applied from either or both ends of the packer at the same time, both ends of the swellable elastomeric element move simultaneously toward each other, thereby providing bi-directional sealing capability. For the FIG. 5 embodiment, the packer 10 need not include control lines. The packer may be fabricated as discussed above, then the two halves simply bolted or otherwise secured together on a tubular.
[0017] The packer as disclosed herein has significant advantages compared to the prior art. There is no need for well operations involving packer setting, and the packer has no moving parts and is thus simple and highly reliable. The packer may be shipped to the field and placed at any position on a tubular, as desired by the operator. As shown in FIG. 4 , the base tubular (pipe) may be wrapped with a thin layer 45 of swellable elastomer that adheres to the base tubular. The split halves of the elastomeric body abut during assembly, engage the thin elastomer layer 45 on the base tubular, and provide additional swell/seal around the control line.
[0018] Control line slots may be cut in the interior of the elastomeric body at a manufacturing facility, since in most cases the size, type and position of the control lines, e.g., control lines 180° apart, will be known as the packer is manufactured. In other situations, the control line gap may be cut in the field. Expansion of the elastomeric material fills any voids around the control line. The control lines may also be passed through apertures or slots in the upper and lower end rings.
[0019] The term “control line” as used herein includes any type of control line, encapsulated line, or other line comprising cable of any type, including fiber optic or electrical conductor, which conducts power or signals between the surface and downhole points.
[0020] A reliable swellable packer is obtained without having to ship the customer the tubular on which the swellable elastomer is molded and/or which there is a wrapping. This allows a substantially thicker rubber to be used compared to embodiments which slip an entire packer body over the end of the material, since the inner sleeve has size restrictions and overcoming the size of the tubular ends is not necessary. This allows for much higher flexibility to the operator, who may maintain a stock of packers of a selected size and promptly install and use the packer of this design on any proper size tubular.
[0021] Although specific embodiments of the invention have been described herein in some detail, this has been done solely for the purposes of explaining the various aspects of the invention, and is not intended to limit the scope of the invention as defined in the claims which follow. Those skilled in the art will understand that the embodiment shown and described is exemplary, and various other substitutions, alterations and modifications, including but not limited to those design alternatives specifically discussed herein, may be made in the practice of the invention without departing from its scope.
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A swellable packer ( 10 ) includes upper and lower end rings ( 20, 22 ) and elastomeric bodies ( 12, 14 ) spaced between the upper and lower end rings to expand and thereby close off an annulus about the downhole tubular. The elastomeric body may be positioned such that a slot ( 26 ) in the body receives a control line ( 28 ).
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BACKGROUND OF THE INVENTION
The invention relates to the system disclosed in the U.S. Pat. No. 3,872,451 issued to this inventor Mar. 18, 1975, and utilizes therein certain teachings set forth in U.S. Pat. No. 3,804,489 concerning induced stationary diffraction gratings. Such gratings are produced by an interdigital electrode structure which is deposited on an electro-optic material. The application of a voltage to the structure produces a spatial modulation of the electro-optic material's refractive index and thereupon allowing the material to act as a diffraction grating to light incident thereon.
SUMMARY OF THE INVENTION
An information bearing light beam is directed along a primary optical path, by means of a series of reflections, and made readily available for a redirecting thereof along secondary paths, selectively, utilizing electro-optic means at any of a number of controllable light reflecting positions in the system. The light beam, or information contained therein, in combination with its output position, may thereupon be utilized in communications or for data handling purposes.
It is an object of the invention to effect light beam positioning or distribution control independent of the control system stability of more conventional beam deflection methods. These and other objects, features, and advantages of the invention will best be understood from the description which follows when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 are first and second views of a light beam positioning system of the invention;
FIG. 3 is a diagramed detail of an electro-optic light beam control means of the invention; and
FIG. 4 is a view of a further embodiment of a light beam positioning system.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIGS. 1 and 2 a beam control unit 10 is illustrated which includes, for example, a four sided length of a light conducting material such as glass, plastic, crystaline material or the like, having a length L, and will be referred to as a light guide 12. Depending upon the light control requirements of the invention the guide 12 may be formed so as to present more, or less, than a four sided figure. Closely adjacent one side 21 thereof there is shown a prism 20, the material being somewhat like that of the guide 12 or of an exact material. Light, preferably from a laser source, is directed along a path 17 at an angle a, as indicated in FIG. 2. The angle indicated has been exaggerated, however, so as to simplify the discussion of the invention. Upon entering the light guide 12 the beam of light will be directed along, what will be referred to as, a primary optical path 16, spiralling its way to a point of exit 15 at the opposite end 14 of the guide 12.
Adjacent the side 23 of the guide 12 light conducting material having the form of a prism 25 is shown extending the length of the guide 12. Between the prism 25 and the side 23 there is an assembly of electro-optic light reflection control means 26, one of which is illustrated in FIG. 3, including a thin film of electro-optic material 29 deposited on the side 23 surface of the guide 12, and an interdigital electrode structure 28 comprised of electrodes 31 and 32, respectively. The material 29 may be that of a number of Kerr effect or Pockels effect materials in either a solid, liquid, gas or colloidal state. The electrodes can be of a light transparent electrically conductive material, tin oxide, for example. The dimensions of all Figures are of course exaggerated.
In spiralling its way through the light guide 12 the beam of light along the path 16 undergoes a series of reflections, one at each interface of the guide 12 material and media adjacent each of its sides 21, 22, 23 and 24, the media in each case presenting a lower index of refraction than that of the guide material. Upon closing a switch so as to extend the influence of an electrical potential to an individual one of the reflection control means of the assembly 26 a change in the electro-optic characteristics of the material 29 thereof will frustrate to a predetermined degree the reflection of light and allow a passing of light along a secondary path 50. Therefore, a beam of light entering the guide 12 will be reflected along a series of 360° side-by-side optical paths until reaching the point of exit 15, or, be permitted to pass along a secondary path 50, each leading from one of a plurality of light output positions 51, 52, 53, etc.
An interdigital electrode structure 28, intimately joined to the film of material 29, is positioned to coincide with each of the light output positions. When the influence of a potential is extended to an electrode structure 28, exemplified in FIG. 3 as being comprised of a potential source 40 under the control of a switch means 41, a potential difference is established between the fingers of the electrodes which results in a spatially varying change in the index of refraction in the film material 29 in the direction of light propagation. This change in the index of refraction acts as a diffraction grating for the light being directed along the path toward a given output position. Light is thereby diffracted through the material 29 and the electrode structure 28 and thereupon along an output path 50. In the absence of an induced grating the light will be deflected by the film material 29, which has a thickness, for example, of at least one wavelength, or, just thick enough so as to allow the light to be reflected without having to engage the grating of the electrode structure 28.
Although the use of a prism 25 is shown, depending upon light path 50 directional requirements, it may not be required. And in FIG. 4, instead of a prism, the use of another form of light guide means 42 is illustrated, being intimately joined to the electrodes 28 so as to establish a light output path 60. Also illustrated in this embodiment is the establishment of additional light output positions adjacent still another side 22 of the light guide 12, using a second assembly 26 of reflection control means. Similar assemblies may, of course, be supported adjacent the sides 21 and 24. Through the use of a light guide 12 comprised of an electro-optic material such as that of the film 29 the electrodes 31 and 32 may be intimately joined thereto and having an index matching material in the spacing therebetween, each such material having a lower index of refraction than that of the guide 12. When a potential difference is established between the fingers of the electrodes, this would result in a spatially varying change in the index of the guide 12 to the extent of providing the diffraction grating adjacent the surface 23 to a predetermined depth into the guide material. Light is thereby diffracted adjacent the interface of the light guide 12 and the electrode structure 28 and directed along an output path.
It should be understood by those skilled in the arts pertaining to the construction and application possibilities of the invention herein set forth that the embodiments included herein illustrate in a very limited sense the usefulness of the invention and that the invention includes such other modifications and equivalents as may be seen by those skilled in the arts, but still be within the scope of the appended claims.
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The system herein includes light optic means which functions as a light beam distributor in making available, almost instantly, an information bearing beam of light at a multiplicity of output positions in the system, as opposed to many well known line scan beam deflection systems.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to residential or commercial storage, or more particularly, to a platform lift apparatus for raising or lowering objects relative to an upper storage location such as an attic storage space located above a garage or living quarters.
[0003] 2. Description of Related Art
[0004] Many homes have attic spaces above garages and living quarters, and these attic spaces often provide a storage location for various items. While some attic spaces are finished and have access via a stairwell, most attic spaces remain unfinished and have more rudimentary access systems. The most basic access system is a simple opening or scuttle hole formed in the ceiling dividing the attic space from the room below. The scuttle hole is commonly located in a closet or main hallway, and may be covered by a hatch that comprises a removable portion of ceiling, such as formed from plywood or drywall. A user would position a ladder below the opening and access the storage space by carrying storage objects up and down the ladder. An improvement over this basic access system is a pull-down ladder that is built into a hingedly attached door covering the opening. The pull-down ladder may be folded into a plurality of sections to provide a compact structure when stowed. The user opens the door and unfolds the ladder to bring it into an operational position. This pull-down ladder has improved convenience since the user does not have to transport a ladder to and from the access location, and the ladder is anchored to the opening to thereby provide an increased degree of safety for the user.
[0005] Nevertheless, a drawback of each of these access systems is that it is difficult to transport objects up and down the ladder. The user cannot easily carry the object and grasp the ladder at the same time, thereby forcing a dangerous tradeoff between carrying capacity and safety. Moreover, the size and weight of the objects that may be transported is limited to that which could be manually carried and fit through the dimensions of the access opening. Users of such access systems have a substantial risk of injury due to falling and/or dropping objects, and the objects themselves can be damaged as well.
[0006] Thus, it would be advantageous to provide an improved way to transport objects to and from an attic storage space without the drawbacks and safety risks of the known access systems. Additionally, there are many other applications in which it would be desirable to transport objects to and from a raised position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] A more complete understanding of the platform lift system will be afforded to those skilled in the art, as well as a realization of additional advantages and objects thereof, by a consideration of the following detailed description of the preferred embodiment. Reference will be made to the appended sheets of drawings, which will first be described briefly.
[0008] FIG. 1 is an isometric view of a platform lift system in accordance with an embodiment of the invention;
[0009] FIG. 2 is a top view of the platform lift system and associated platform;
[0010] FIG. 3 is a sectional view of the platform lift system as taken through the section C-C of FIG. 2 ;
[0011] FIG. 4 is a sectional view of the platform lift system as taken through the section A-A of FIG. 2 ;
[0012] FIG. 5 is a sectional view of the platform lift system as taken through the section B-B of FIG. 2 ;
[0013] FIG. 6 is a side view of a lift pulley having a belt tensioner;
[0014] FIG. 7 is a front view of the lift pulley of FIG. 6 ;
[0015] FIG. 8 is a top view of an embodiment of a platform including an integrated basket;
[0016] FIG. 9 is a side view of the platform of FIG. 8 ;
[0017] FIG. 10 is a rear view of the platform of FIG. 8 ;
[0018] FIG. 11 is a side view of an alternative embodiment of a platform lift system that does not include a ceiling opening;
[0019] FIG. 12 is a front view of a drop down storage system in accordance with another embodiment of the invention;
[0020] FIG. 13 is a sectional view of the drop down storage system as taken through the section D-D of FIG. 12 ;
[0021] FIG. 14 is a top view of an alternative embodiment of the platform lift system that includes an integrated ladder;
[0022] FIG. 15 is a side view of the platform lift system of FIG. 14 ;
[0023] FIG. 16 is a front view of the platform lift system of FIG. 14 ;
[0024] FIG. 17 is a top view of another embodiment of the platform lift system that includes a pull-down ladder;
[0025] FIG. 18 is a side view of the platform lift system of FIG. 17 ;
[0026] FIG. 19 is an end view of the platform lift system of FIG. 17 ;
[0027] FIG. 20 is a cross-sectional side view of another embodiment of the platform lift system that includes a pull-down ladder;
[0028] FIG. 21 is a cross-sectional side view of the platform lift system of FIG. 20 ;
[0029] FIG. 22 is a top view of the platform lift system of FIG. 20 ;
[0030] FIG. 23 is a top view of the platform lift having traversed partly downward along the guide affixed to the ladder;
[0031] FIG. 24 is a side cutaway view of the platform pulley length adjust assembly;
[0032] FIG. 25 is an end view of the platform pulley length adjust assembly;
[0033] FIG. 26 is a sectional view of the reduction gears as taken through the section C-C of FIG. 22 ;
[0034] FIG. 27 is a side view of an embodiment of the platform lift having an impact detection system;
[0035] FIG. 28 is an enlarged side view of a portion of the impact detection system of FIG. 27 ;
[0036] FIGS. 29 a - c are side views of an alternative transition mechanism to permit the lift platform of FIG. 22 to transition to the ladder guide;
[0037] FIGS. 30 a - c are an alternative drive system for the platform lift system;
[0038] FIGS. 31 a - c are an another alternative drive system for the platform lift system;
[0039] FIG. 32 a - b are yet another alternative drive system for the platform lift system;
[0040] FIG. 33 is an alternative embodiment of a platform lift system adapted to move a load between interior and exterior structures;
[0041] FIG. 34 is another alternative embodiment of a platform lift system adapted to engage a window ledge;
[0042] FIG. 35 is a side view of another alternative embodiment of a platform lift system movable along a monorail;
[0043] FIG. 36 is a front view of the platform lift system of FIG. 35 ;
[0044] FIG. 37 is a perspective view of another alternative embodiment of a platform lift system having an expandable frame assembly;
[0045] FIG. 38 is a side view of another alternative embodiment of a platform lift system used in connection with an overhead rail;
[0046] FIG. 39 is a front view of another alternative embodiment of a lift system used to raise an enclosed compartment;
[0047] FIG. 40 is a top view of the lift system of FIG. 39 ; and
[0048] FIG. 41 is a side view of the lift system of FIG. 39 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0049] The present invention satisfies the need for an improved way to transport objects to and from an attic storage space without the drawbacks and safety risks of the known access systems. In the detailed description that follows, like element numerals are used to describe like elements illustrated in one or more figures.
[0050] More particularly, the invention provides a platform lift system that enables objects to be moved between an attic space and a room below. The platform lift system includes a frame that is mounted into a scuttle hole formed in an attic ceiling and a platform that is supported by the frame. The platform may be selectively raised or lowered in order to transport objects to/from the attic space. When in a raised position, the platform engages the frame and seals the attic space to provide a thermal barrier. The frame lies substantially flush with the ceiling floor, so as to maximize available storage space within the attic ceiling and minimize interference between the lift system and objects moved on and off the platform. The frame further includes a drive system that controls the movement of a plurality of belts that are coupled to the platform. The platform is raised by withdrawing the belts, and is lowered by paying out the belts.
[0051] Referring first to FIG. 1 , an isometric view of a platform lift system is illustrated in accordance with an embodiment of the invention. The platform lift system is installed in a ceiling structure that is supported by horizontally extending joists 21 . A rectangular scuttle hole is formed within the ceiling structure that is bounded on two sides by joists 21 and on the other sides by crosspieces that abut the joists. As shown in FIG. 1 , a section of an intermediary joist is removed for the length of the scuttle hole, such that the width of the scuttle hole corresponds to twice the separation between adjacent joists plus the width of one joist. As will be understood to persons skilled in the art, the platform lift system maintains the structural integrity of the ceiling notwithstanding the removal of a section of joist.
[0052] The platform lift system further comprises a vertically oriented frame 11 having a rectangular shape adapted to fit into the scuttle hole formed in the ceiling. The frame 11 may include mounting brackets 12 or integral flanges (not shown) that engage upper surfaces of the joists and crosspieces to facilitate attachment thereto. The frame 11 may be constructed of wood, metal, plastic, or other high strength, lightweight material capable of supporting a suitable load carried by the platform lift system.
[0053] A drive system coupled to the frame raises and lowers a platform (described below). In an embodiment of the invention, the drive system includes shafts 31 , 32 , shaft drive gear 34 , motor 41 , motor drive gear 46 , belt drive gears 51 , and drive belts 56 . The shafts 31 , 32 are rotatably mounted in parallel at opposite ends of the frame 11 . Each end of the shafts 31 , 32 includes a belt drive gear 51 mounted thereto in substantial alignment. This way, the respective belt drive gears on the left end of the shafts 31 , 32 are aligned and the respective belt drive gears on the right end of the shafts are similarly aligned. The left and right belt drive gears 51 carry respective right and left drive belts 56 . Shaft 31 further carries shaft drive gear 34 . Motor 41 is mounted to the frame 11 using suitable brackets and is adapted to drive motor drive gear 46 , which is in turn arranged in mesh with the shaft drive gear 34 . Accordingly, motor 41 drives shaft 31 to rotation by cooperation of the motor drive gear 46 and shaft drive gear 34 , and shaft 32 is driven to rotation in unison with shaft 31 by cooperation of the belt drive gears 51 and drive belts 56 . In a preferred embodiment of the invention, the shafts 31 , 32 are keyed to match associated keying of the belt drive gears 51 and shaft drive gear 34 so as to maintain synchronized movement of the shafts. Further, the drive belts 56 may include teeth that engage associated sprockets of the belt drive gears 51 to further maintain synchronized shaft movement. Motor 41 may further include speed reduction gearing 42 and bearings 44 to achieve a desired rotational rate of the shafts 31 , 32 .
[0054] The shafts 31 , 32 further carry a plurality of pulleys 52 for raising and lowering lift belts 55 . Each shaft has lift pulleys 52 disposed at both ends such that one pulley is located adjacent to each corner of the frame 11 . The lift pulleys 52 carry a respective lift belt 55 that winds onto the pulley. A first end of each lift belt 55 is fixedly attached to a respective lift pulley 52 , and a second end of the lift belt 55 hangs vertically from the pulley and is attached to the platform (described below). With respect to shaft 32 , the drive system further includes idler pulleys 57 that serve to move the respective lift belts toward the outer periphery adjacent to the frame 11 . It should therefore be understood that when motor 41 is driven to rotation in a clockwise direction, shaft drive gear 34 and shafts 31 will each be driven to rotation in a counter-clockwise direction to unwind the lift belts 55 and thereby lower the platform. Conversely, when motor 41 is driven to rotation in a counter-clockwise direction, shaft drive gear 34 and shafts 31 will each be driven to rotation in a clockwise direction to rewind the lift belts 55 and thereby raise the platform. It will be appreciated that the platform lift system will include suitable control circuitry for activating the motor 41 in forward and reverse directions.
[0055] FIG. 2 illustrates a top view of the platform lift system and associated platform 60 . Likewise, FIGS. 3, 4 and 5 illustrate sectional views of the platform lift system as taken through the section C-C, A-A, and B-B of FIG. 2 , respectively. As best shown in FIGS. 4 and 5 , the platform 60 includes a base 64 comprising a generally rectangular board having a shape corresponding to the scuttle hole. The platform 60 may further include vertically extending fences that define a carrying basket (described below). As shown in FIG. 4 , the base 64 may further include a seal 65 disposed on an upper surface therefore adjacent to an outer periphery of the base so as to form a thermal barrier and also to cushion the engagement of the platform 60 with the frame 11 when the platform is in the fully raised position. The frame 11 and the base 64 may further be provided with respective guide ramps 62 , 61 that facilitate the engagement of the platform 60 with the frame. FIG. 5 shows the engagement between the lift belts 55 and the platform 60 . In a preferred embodiment of the invention, the ends of the lift belts 55 are provided with a fastening device 66 , such as a quick release fastener, that engages a corresponding receptacle 63 coupled to the platform 60 . This permits the platform 60 to be disconnected from the lift belts 55 , such as to facilitate loading of objects onto the platform. It should be appreciated that a permanent connection between the platform 60 and the lift belts 55 could also be advantageously utilized.
[0056] Although the frame 11 is illustrated as a fixed rectangular shape, it should be appreciated that the frame may be adjustable to achieve different widths and/or lengths. The shafts 31 , 32 may be provided with adjustable length, such as using telescoping shaft segments that are fixed in position by tightening a set screw.
[0057] FIGS. 6 and 7 illustrate an embodiment of the lift pulleys 52 having a belt tensioner. More particularly, the belt tensioner includes a tension spring 71 mounted to a portion of the frame 11 . The tension spring 71 may be formed of a flexible band, such as a leaf spring. The tension spring 71 further includes a collar 70 that carries an axle 69 . A tension drum 68 is rotatably coupled onto the axle 69 . The tension drum 68 is biased into physical engagement with the lift belt 55 that has wound onto the lift pulley 52 , such that a constant pressure is applied to the lift belt 55 as it is either played out or re-wound onto the lift pulley 52 as the platform 60 is selectively lowered or raised. It should be appreciated that each of the four lift pulleys 52 would have a like belt tensioner.
[0058] FIGS. 8, 9 and 10 illustrate an embodiment of a platform 60 that includes an integrated basket. The platform 60 further includes a plurality of folded fences 75 , 76 , 77 and 78 . The fences are each hingedly attached to respective outer edges of a basket region, and are pivotable between horizontal and vertical positions. In the horizontal (or collapsed) position, fences 77 and 78 are nested below fences 75 , 76 . Each fence comprises a generally rectangular shape corresponding to roughly one-half of the area defined by the basket region. With the fences disposed in the horizontal or collapsed configuration, a flat surface is defined onto which objects may be carried. Alternatively, with the fences deployed to the vertical position, a generally rectangular basket is formed into which objects may be placed. A latching mechanism may be included that attaches the fences together in the vertical position in order to maintain the basket. It should be appreciated that the basket may be advantageous for transporting small objects that might otherwise fall off the platform while it is being raised or lowered. The platform 60 may also include a fixed position or fold-down ramp that facilitates loading of objects thereon.
[0059] FIG. 11 illustrates a side view of an alternative embodiment of a platform lift system. Unlike the preceding embodiments in which the platform carried objects through a scuttle hole formed in an attic ceiling, the embodiment of FIG. 11 carries objects to a storage location disposed below the ceiling. This embodiment might be advantageous in a garage or loft in which there is a high ceiling but no attic space above the ceiling. Objects could be carried up to this storage location, thereby clearing floor space below. The frame 11 of the platform lift system would be mounted to the ceiling, such as using angle brackets 80 . In the same manner as described above in any of the foregoing embodiments, lift belts 55 would carry a platform 83 . The platform 83 may have vertically extending alignment guides 81 that engage corresponding stops 82 , which serve the purpose of defining the vertical extent of travel of the platform and guiding the platform into an aligned position.
[0060] FIG. 11 also illustrates a retractable wheel assembly affixed to a bottom surface of the platform 83 . The wheel assembly includes a rotable wheel or caster 91 that rotates about an axle 90 . The wheel assembly is shown in a retracted (or horizontal) position. By pivoting the wheel assembly 90° about a pivot point 88 , the wheel assembly can be moved to an operational position with the wheel 91 oriented vertically. The retractable wheel assembly enables the platform 83 to serve as a dolly for the purpose of moving objects around the floor, after disengaging the lift belts 55 . It should be appreciated that all four corners of the platform 83 may include like retractable wheel assemblies. Moreover, the retractable wheel assemblies could also be used with any of the foregoing embodiments of the invention.
[0061] FIGS. 12 and 13 illustrate yet another embodiment of the invention providing a drop down storage system. Unlike the preceding embodiments, the drop down storage system provides a storage unit 100 , such as a pantry or cabinet, which can be lowered down from the ceiling to enable access. When not in use, the storage unit 100 can be raised back through the ceiling, with the bottom surface of the storage unit ending flush with the ceiling. The storage unit 100 may include a plurality of shelves or drawers or rolling pantry trays 102 (as shown in FIGS. 12 and 13 ). The storage unit 100 would be raised or lowered substantially as described above, except that the frame 11 is disposed above the ceiling rather than flush with the ceiling. In addition to the lift belts 55 described above, the drop down storage system may also include a scissor stabilizer assembly formed from a plurality of scissor linkages 111 coupled at pivot points 112 . An uppermost linkage 114 and lowermost linkage may have ends that travel in respective tracks 114 that permit the scissor stabilizer assembly to expand and retract. The scissor stabilizer assembly provides smooth, controlled motion of the storage unit 100 as it raises and lowers.
[0062] FIGS. 14-16 illustrate yet another embodiment of the invention providing a lift platform system that includes a pull-down ladder. The pull-down ladder may be folded into a plurality of sections to provide a compact structure when stowed, and may be hingedly attached to a door that seals a scuttle hole formed in the ceiling. When in the unfolded configuration, the rails of the ladder provide a track to guide the movement of a platform. The platform includes wheels extending from one edge thereof, with the wheels adapted to engage the track provided by the ladder. The platform would be raised and lowered substantially as described above, except that rather than traveling vertically between raised and lowered positions, the platform travels diagonally along the track provided by the ladder. This embodiment is advantageous since a user would only have to provide a single scuttle hole through the ceiling to provide for human access and movement of stored objects.
[0063] More particularly, FIG. 15 illustrates fold-down ladder 125 installed in a ceiling structure that is supported by horizontally extending joists 21 . The ladder 125 comprises a plurality of horizontal steps 126 and may be folded into a plurality of sections that permit the ladder to be stowed in the scuttle hole and enclosed in the ceiling when not in use. The ladder 125 is attached to an edge of the scuttle hole by a hinge 129 . When the ladder 125 is fully deployed, it extends downward at an angle of roughly 45-75° and comes into contact with the floor at the bottom of the ladder. The supporting frame (not shown) for a platform lift is installed above the scuttle hole, such as supported by rafters substantially above the floor of the attic space. The platform 64 may be raised above the scuttle hole to a height sufficient to permit users to climb the ladder 125 and access the attic space without being impeded by the platform.
[0064] As shown in FIGS. 14-16 , the platform 64 is suspended by lift belts 55 in the same manner as described above with respect to the preceding embodiments. The platform 64 of this embodiment further includes a pair of portal guide rollers 132 and a pair of ladder guide rollers 133 supported by roller support brackets 131 that extend substantially horizontally from an end of the platform. The portal guide rollers 132 are arranged to engage respective roller guides 130 disposed in a vertical orientation at opposite corners of an end of the scuttle hole. The ladder 125 further includes a roller guide 127 that extends the length of the ladder. Accordingly, when the platform 64 is lowered from the overhead stowed position, the portal guide rollers 132 engage the roller guides 130 , which guides the platform downward in a substantially vertical direction. Then, when the guide rollers 132 reach the bottom of the roller guides 130 , the ladder guide rollers 133 engage the roller guide 127 on the ladder 125 . As the platform 64 descends, its direction of travel transitions from substantially vertical to the angle defined by the position of the ladder 125 . The platform 64 will continue to descend along a track defined by the roller guide 127 until reaching the floor or selectively stopped by the user. A pair of guide rollers 144 may also be disposed at an end of the scuttle hole opposite the roller guides 130 . The guide rollers 144 engage an end of the platform 64 as it descends through the scuttle hole.
[0065] FIGS. 17-19 illustrate another embodiment of the invention providing a lift platform system that includes a pull-down ladder. In this embodiment, the platform system moves laterally along an overhead rail system. When it is desired to use the ladder to access the attic space, the platform is moved laterally to a position out of the way of the scuttle hole. But, when it is desired to use the platform lift system, the platform is moved laterally to a position aligned with the scuttle hole. From this position, the platform can be raised and lowered diagonally along the track provided by the ladder in the same manner as described above in the preceding embodiment. More particularly, a pair of platform frame tracks 135 are coupled to the floor of the attic space with corresponding mounting assemblies 138 . The platform assembly includes a plurality of sleeves 136 that engage the tracks 135 , permitting horizontal movement of the entire platform assembly. The platform assembly may thereby be moved horizontally between an operational position aligned with the scuttle hole and a non-operational position moved out of the way of the scuttle hole.
[0066] FIGS. 20-22 illustrate another embodiment of the invention providing a lift platform system that includes a pull-down ladder. In this embodiment, the platform system moves laterally along a rail disposed on the floor of the attic space. As in the preceding embodiment, when it is desired to use the ladder to access the attic space, the platform is moved laterally to a position out of the way of the scuttle hole. But, when it is desired to use the platform lift system, the platform is moved laterally to a position aligned with the scuttle hole. From this position, the platform can be raised and lowered diagonally along the track provided by the ladder in the same manner as described above in the preceding embodiment.
[0067] The lift platform system includes three main subsections: (a) a joist sleeve frame structure that engages a scuttle hole formed in a ceiling; (b) an unfoldable ladder and hatch door that is hingedly attached to the joist sleeve frame structure; and (c) a movable platform carriage assembly with platform lift. All three of these subsections are shown in FIG. 20 . A scuttle hole is bounded by joists 21 that form the ceiling. A joist sleeve frame 151 is inserted into and fixedly engaged with the scuttle hole so as to provide structural integrity for other subsections of the lift platform system. The sleeve frame 151 is coupled to track 159 using angle brackets 160 . The track 159 lies horizontally on the floor of the ceiling to provide a guide path for the movable platform carriage assembly. A roller guide 245 extends from a side of the sleeve frame 151 via bracket 243 to guide movement of the platform through the scuttle hole. Ladder 225 is shown in an unfolded configuration extending diagonally downward from the joist sleeve frame 151 . The ladder includes a roller guide 227 extending along the length thereof for engagement with a corresponding roller of the movable platform. The movable platform frame 211 is shown above the joist sleeve frame 151 . The moveable platform is shown in a fully raised position 264 a and partly lowered position 264 b. As in the foregoing embodiments, the platform 264 is supported by a plurality of lift belts 55 that unwind from respective lift pulleys 52 and idler pulleys 156 .
[0068] FIGS. 21 and 22 shown the moveable platform carriage assembly in greater detail. The drive mechanism for lifting the platform includes a motor 41 that drives an associated motor shaft 150 , and a plurality of helical gears driving a main shaft 270 with desired speed reduction. The platform frame 211 further includes a plurality of track roller wheels 271 that permit lateral movement of the platform carriage assembly along the track 159 (described above). The track roller wheels 271 are coupled to the platform frame 211 using axles 272 .
[0069] In an embodiment of the invention, the lift pulleys 52 further include torsional springs 269 that couple the pulleys to the main shaft 270 . The torsional springs 269 allow for differential stretch length of the lift belts 55 . Since two pulleys at one end of the platform lift the platform directly, while two others guide the lift belts laterally across the width of the platform to the pulleys at the other end before dropping down to lift the platform, differential stretching of the lift belts can result in the platform being moved unevenly. The amount of this differential stretching will also depend on the amount of loading of the platform. The torsional springs 269 are selected to have a spring constant k that matches the expected stretching, and will allow relative motion of the lift pulleys 52 with respect to the shaft 270 no matter what force is applied to the platform. FIG. 21 further shows a platform pulley length adjustment mechanism 152 that enables the connection between the lift belts 55 and the platform to be adjusted. Tightening the set screw of the platform adjustment mechanism 152 serves to change the length of the lift belts. The adjustment mechanism 152 is described in greater detail below with respect to FIGS. 24 and 25 .
[0070] FIG. 23 shows the platform of the preceding figures having traversed downward through the scuttle hole in the ceiling. In this embodiment, the platform includes a ladder guide bracket 154 that is coupled to the side of the platform 260 using a rotating joint 153 . The guide bracket 154 carries guide rollers 232 , 233 that engage the roller guide 227 affixed to the ladder.
[0071] FIGS. 24 and 25 show the pulley belt adjustment mechanism 152 in greater detail. An end of the belt 55 enters a slot 276 formed in an upper surface of the movable platform and enters an interior chamber. A threaded bolt 277 extends the length of the chamber and a slide block is threadingly coupled to the bolt. The belt 55 is affixed to the slide block. Turning the bolt 277 in a clockwise direction causes movement of the slide block within the chamber toward the head of the bolt, thereby loosening the belt 55 . Conversely, turning the bolt 277 in a counter-clockwise direction causes movement of the slide block within the chamber away from the head of the bolt, thereby tightening the belt 55 . It is anticipated that all four corners of the platform include a like mechanism for adjusting the belt length. The platform may also be equipped with a bubble level to enable the operator to accurately adjust the pulley belt adjustment mechanisms to level the platform. Instead of a manual adjustment, the same mechanism could be adapted to automatically level the platform each time it is operated.
[0072] FIG. 26 shows the gear train used to drive the main shaft, taken through the section C-C of FIG. 22 . The motor 41 drives a helical gear 290 , which is in mesh with helical gear 291 affixed to a worm shaft 292 oriented 90° to the motor shaft. The worm shaft 292 carries worm 293 , which drives worm gear 294 coupled to main shaft 270 . As discussed above, the main shaft 270 drives the pulleys 52 that raise and lower the lift belts 55 . It is anticipated that the gear train achieve a generally high gear reduction ratio (approximately 30:1).
[0073] FIG. 28 illustrates a side view of the lift platform having an impact detection system for the platform lift system. A contact plate 301 is coupled to the underside of the platform deck 360 using a plurality of pins 302 . The pins 302 are fixed to corresponding compression springs 304 , which are fixedly attached at an end to the platform deck 360 . The arrangement permits the contact plate 301 to be movable against the bias applied by the compression springs 304 . Electrical contacts disposed within the compression springs 304 make contact when the contact plate 301 causes one or more of the pins 302 to compress the associated compression springs 304 . Accordingly, if the platform deck 360 comes into contact with an object as the lift platform is descending, the signal electrical signal formed by the closed contacts could trigger a halt to the movement of the lift platform.
[0074] FIGS. 29 a - c illustrate a transition mechanism that enables the movable platform to transition from vertical movement to the diagonal movement along the ladder. FIG. 29 a shows the transition mechanism in a deployed configuration, with the ladder 225 extended downward from the pivot axle 247 that is fixed to the joist sleeve frame 151 . Roller guide 227 is coupled to the ladder 225 and provides a guide path for movement of the platform lift. A folding roller track mechanism 306 includes a track segment 309 that provides a continuous path with the roller guide 227 to enable transition from vertical to diagonal movement. The track segment 309 and roller guide 227 are oriented to engage the guide roller 233 coupled to the platform via bracket 154 . As shown in FIG. 29 a, the guide roller 233 first moves vertically in contact with the track segment 309 . Then, upon reaching an elbow defined by the intersection of track segment 309 and roller guide 227 , the guide roller 233 transitions to a diagonal path. Fence 311 keeps the guide roller 233 in contact with the track segment 309 . Spring 312 biases the folding roller track mechanism 306 into position when the ladder is deployed. It should be appreciated that the fence 311 contains the guide roller 233 on the outside as the guide roller moves vertically. Following the transition to diagonal movement, the ladder 225 provides an inner fence for the guide roller 233 . Accordingly, the guide roller 233 is controlled throughout its travel.
[0075] FIG. 29 b shows the transition mechanism in a stowed configuration, with the ladder 225 folded up and the attic hatch closed. The roller track mechanism 306 is moved out of the way to permit the ladder 225 to move upward as it is stowed. FIG. 29 c shows a sectional view of the roller track mechanism 306 as taken through the section A-A of FIG. 29 b. An advantage of using the folding roller track mechanism 306 of FIGS. 29 a - c is that it avoids the need for redundant sets of guide rollers on the platform.
[0076] FIGS. 30 a - c illustrate an alternative embodiment of the drive system for the platform lift system. Instead of a continuous loop, the drive belt 456 has a first end fixedly attached to the first belt drive gear 452 and a second end fixedly attached to the second belt drive gear. The drive belt 456 is wound onto the belt drive gears, such that when the platform is fully raised the drive belt is completely wound onto the first belt drive gear 452 and when the platform is fully lowered the drive belt is completely wound onto the second belt drive, gear. By fixedly attaching the ends of the drive belts 456 to the belt drive gears 452 , the belt provides a limit to the amount of vertical travel of the platform. Also, the shaft 432 is offset vertically with respect to shaft 431 , and the drive belt 456 is wound onto the belt drive gears in opposite directions. Thus, the first belt drive gear rotates counterclockwise while the second belt drive gear rotates clockwise, and vice versa. This arrangement has the advantage of paying out the lift belts from the outer periphery of the pulleys, thereby eliminating the need for separate idler pulleys (see FIG. 1 ) to manipulate the lift belt to the periphery. It should be appreciated that only the belt drive gears at one end of the shafts 431 , 432 are illustrated in FIGS. 30 a - c, and that the other ends would have a like construction.
[0077] FIGS. 31 a - c illustrate another alternative embodiment of the drive system for the platform lift system. In this embodiment, two of the lift pulleys are eliminated and the belt 556 provides both driving and lifting. Particularly, the drive belt 556 has a first end fixedly attached to the first belt drive gear 552 and a second end that is carried partly by the second belt drive gear and then extends vertically to provide a lift belt. Pulley 551 provides a second lift belt in the same manner described above with respect to FIG. 1 . When the platform is fully raised, the drive belt 556 is completely wound onto the first belt drive gear 552 and when the platform is fully lowered the drive belt is completely paid out. As in the preceding embodiment, the shaft 532 is offset vertically with respect to shaft 531 , and the drive belt 556 causes the belt drive gears to rotate in opposite directions. Thus, the first belt drive gear rotates counterclockwise while the second belt drive gear rotates clockwise, and vice versa. This arrangement has the advantage of reducing the number of lift pulleys and associated belts. It should be appreciated that only the belt drive gears at one end of the shafts 531 , 532 are illustrated in FIGS. 31 a - c, and that the other ends would have a like construction.
[0078] FIGS. 32 a - b illustrate yet another alternative embodiment of the drive system for the platform lift system. In this embodiment, all of the lift pulleys are eliminated and the belt 656 provides both driving and lifting. Particularly, the drive belt 656 has a first end fixedly attached to the first belt drive gear 652 and a second end that is carried partly by the second belt drive gear and then extends vertically to provide a lift belt. The first belt drive gear 652 also includes a separate lift belt 655 that is wound onto the drive gear along with the drive belt 656 . When the platform is fully raised, the drive belt 656 and lift belt 655 are completely wound onto the first belt drive gear 652 and when the platform is fully lowered the drive belt 656 and lift belt 655 are completely paid out. As in the preceding embodiment, the shaft 632 is offset vertically with respect to shaft 631 , and the drive belt 656 causes the belt drive gears to rotate in opposite directions. It should be appreciated that only the belt drive gears at one end of the shafts 631 , 632 are illustrated in FIGS. 32 a - b, and that the other ends would have a like construction.
[0079] FIG. 33 is an alternative embodiment of a platform lift system adapted to move items from outside a structure to an interior raised position. For example, the platform lift system could raise a load disposed on ground level outside a building and transport the load through an upper window into an interior of the building. As shown in FIG. 33 , the structure includes an exterior wall 703 and a raised room having floor 707 . A modular frame assembly 702 provides vertical support for a platform lift mechanism having wheels 771 that engage track 759 . The platform lift mechanism Includes platform 760 that is raised and lowered using belts that attach at lift points 766 . A load 704 may be strapped to the platform using restraints 705 . Pulleys 752 raise and lower the belts as substantially described above. With the load 704 and platform 760 in the raised position, the entire platform lift mechanism may be moved laterally along the track 759 to a position outside a window or balcony. The load 704 may then be lowered to the exterior floor by operation of the platform lift. The same process in reverse would be used to move a load into the structure.
[0080] FIG. 34 illustrates another alternative embodiment of a platform lift system adapted to move items from a window ledge. A frame assembly 802 is positioned in an interior space, and has foldable members that extend along an interior wall and out through a window. The frame assembly 802 supports a vertical rail 859 on which a platform lift mechanism travels. The platform lift mechanism includes wheels 871 that engage the vertical rail to permit the platform to be transferred between interior and exterior positions. As in the preceding embodiments, the platform lift mechanism includes a platform 860 that is lifted using belts coupled to pulleys 852 . It is anticipated that the frame assembly 802 not be permanently installed, but rather be merely secured in place ballast. This way, the platform lift mechanism can be deployed when it is need to move an object, and can otherwise be disassembled and put away.
[0081] FIGS. 35 and 36 illustrate another alternative embodiment of a platform lift system that is movable along a monorail 901 . The monorail 901 is coupled to the ceiling 958 using periodic mounting brackets 902 that are spaced along a travel path. A platform lift system includes a platform frame 911 having brackets 903 holding roller wheels 971 . The monorail 902 includes a track that engages the roller wheels 971 , enabling the platform frame 911 to be transported along the travel path. As in the foregoing embodiments, the platform frame 911 supports a platform that is lifted using belts. This way, an object could be picked up using the platform and transported anywhere along the travel path. Alternatively, the platform frame 911 may not include a platform, but rather the lift belts would directly engage an object to be transported, such as a wheelchair or gurney within a hospital.
[0082] FIG. 37 illustrates another alternative embodiment of a platform lift system having an expandable frame assembly. The expandable frame assembly enables the lift platform of the present invention to be modified to accommodate any size load. The frame assembly includes a frame formed from tubular sections 1068 , 1067 , 1069 , and 1070 . The tubular sections are telescoping such that end sections 1070 are movable within vertical sections 1068 to change the length dimension of the frame, and sections 1067 are movable over horizontal sections 1068 , 1069 to change the width dimension of the frame. Locking screws 1074 rigidly fix the sections in place after a desired frame shape is selected. The frame assembly carries a sling 1073 that is connected to the frame using quick-disconnect latches 1072 .. The entire frame assembly may be raised or lowered using a platform lift system as described in the previous embodiments.
[0083] FIG. 38 illustrates another alternative embodiment of a platform lift system used in connection with an overhead rail. Transverse frame tracks 1075 are suspended from a ceiling 1162 of an interior structure, such as a garage. A movable track segment 1059 extends between the transverse frame tracks 1075 and is movable along the transverse frame tracks using rollers. A platform lift system is movable on the movable track segment 1059 such that the platform lift system could be moved to any position within a space bounded by the transverse frame tracks 1075 . The platform lift system could lift any sized object, such as using the expandable frame assembly of FIG. 37 .
[0084] FIGS. 39 through 41 illustrate an alternative embodiment of the drop down storage system of FIGS. 12 and 13 used to lift a compartment 1060 .. The compartment 1060 may include a hingedly attached gate 1078 . The compartment 1060 may be suitable to transport a wheelchair.
[0085] Having thus described a preferred embodiment of a platform lift system, it should be apparent to those skilled in the art that certain advantages of the described system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention.
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A platform lift apparatus enables the safe movement of objects to and from an attic storage space. The platform lift apparatus includes a frame, a drive mechanism, and a platform. The frame includes internal and external mounting surfaces. The drive mechanism is substantially disposed within the frame and is coupled to the internal mounting surfaces. The drive mechanism includes a plurality of rotatable, parallel shafts with each shaft further including at least one lift drum having an associated lift tether at least partially wound thereon and having an end hanging therefrom. The platform is coupled to each lift tether end and is thereby suspended from the frame. The platform is selectively movable by operation of the drive mechanism within in a vertical dimension between raised and lowered positions. The drive mechanism further comprises an electric motor operatively coupled to the plurality of parallel shafts.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to provisional application No. 61/090,490 filed Aug. 20, 2008, entitled Vibratory Plow Assembly, which is incorporated by reference in its entirety herein.
FIELD OF THE INVENTION
[0002] This disclosure relates generally to a plow assembly for cutting a slit in the ground. More particularly, this disclosure relates to a plow assembly having a rotating mass for creating vibrations which are transmitted to the plow blade to provide increased efficiency.
BACKGROUND
[0003] Cables, conduits, and other services are often installed in relatively shallow underground trenches. For example, electrical lines (direct burial and/or conduit), telephone wiring/fiber optic, television cables, natural gas lines, and drainage lines are often buried in this manner. Additionally, drip irrigation lines and other types of conduits and lines can be installed underground. These lines, conduits, and pipes will be collectively referred to herein as “utility lines” for convenience.
[0004] These lines are often installed with a plow assembly, with such plows generally well-known in the art. Examples of such plows are described in U.S. Pat. No. 3,935,712; U.S. Pat. No. 4,102,403; and U.S. Pat. No. 4,337,712. These plows generally include a plow blade supported at the rear of the plow assembly. As used herein, the terms “front” and “rear” shall be with reference to the direction that the plow assembly moves during operation. As the plow blade is advanced through the ground, a narrow trench is created in which the utilities are laid. Initially, the act of creating the trench, installing the utility lines, and covering the trench were three separate acts. However, plow assemblies have advanced so that the utility lines are laid into the trench at the rear of the plow blade as the plow blade is advanced through the ground. Further, the plow assembly is designed such that any spoils from the trench are reintroduced into the trench and tamped by trailing tamping feet/wheels. In this manner, the utility lines are installed into the ground in a single pass over the ground by the plow assembly.
[0005] The energy needed to install utility lines depends on the desired depth, size of the utility lines, and the ground (soil) conditions (Clay, sand, loam, etc.). In hard conditions, the process may be slow and require a large amount of power from the tractor/plow assembly motor to pull the plow blade through the ground. To reduce this loading, various efforts have been made including injecting liquid to the plow blade and to the utility lines being installed to moisten and soften the ground. Other prior art plow assemblies have utilized rotating masses to impart a vibratory movement to the plow blade. However, even using these two methods, the rate at which the plow assembly can be advanced over the ground can still be relatively slow. Therefore, there is a need in the art for a method and apparatus for improving the efficiency in which the plow blade can be advanced through the earth. The present invention overcomes the shortcomings of the prior art.
SUMMARY
[0006] The present disclosure generally relates to a method and apparatus for installing utility lines underground by using a vibratory plow. One aspect of the invention relates to using a resilient member attached to a vibrator assembly, where the resilient member stores the kinetic energy of the vibrator assembly downward movement. The kinetic energy is then released during the upward movement. The energy is applied to a plow blade so as to improve the efficiency of the plow blade as it is drawn through the ground. Another aspect of the invention relates to connecting the resilient member to the ground via a set of wheels that do not appreciably deflect during the downward movement.
[0007] While the invention will be described with respect to preferred embodiment configurations and with respect to particular devices used therein, it will be understood that the invention is not to be construed as limited in any manner by either such configurations or components described herein. Also, while particular types of special links are described herein, it will be understood that such particular mechanisms are not to be construed in a limiting manner. Instead, the principles of this invention extend to any environment in which kinetic energy is stored during the downward movement of the rotating masses and then utilized during the upward movement. These and other variations of the invention will become apparent to those skilled in the art upon a more detailed description of the invention.
[0008] The advantages and features which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. For a better understanding of the invention, however, reference should be had to the drawings which form a part hereof, and to the accompanying descriptive matter in which there is illustrated and described a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 is a side view of a plow assembly according to an embodiment of the present disclosure with the plow blade in the retracted position;
[0010] FIG. 2 is a side view of the plow assembly of FIG. 1 with the plow blade in an extended position;
[0011] FIG. 3 is an enlarged view of a portion of FIG. 2 ;
[0012] FIG. 4 is a perspective view of a portion of the plow assembly of FIG. 1 ;
[0013] FIG. 5 is a side view of the portion of the plow assembly shown in FIG. 4 ;
[0014] FIG. 6 is a cross-sectional view of the plow assembly along line 6 - 6 of FIG. 5 ;
[0015] FIG. 7 is a rear view of the portion of the plow assembly shown in FIG. 4 ;
[0016] FIG. 8 is a cross-sectional view of the plow assembly along line 7 - 7 of FIG. 7 ;
[0017] FIG. 9 is a front view of the portion of the plow assembly shown in FIG. 4 ;
[0018] FIG. 10A is a side schematic view of the plow assembly in a first position;
[0019] FIG. 10B is a side schematic view of the plow assembly in a second position;
[0020] FIG. 11 is a side schematic view of a first alternative embodiment of the plow assembly of FIG. 1 ;
[0021] FIG. 12 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0022] FIG. 13 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0023] FIG. 14 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0024] FIG. 15 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0025] FIG. 16 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0026] FIG. 17 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0027] FIG. 18 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ;
[0028] FIG. 19 is a side schematic view of another alternative embodiment of the plow assembly of FIG. 1 ; and
[0029] FIG. 20 is an enlarged portion of an alternative embodiment showing a torsion axle;
[0030] FIG. 21 is a side view of the torsion axle embodiment in a retracted position;
[0031] FIG. 22 is a side view of the torsion axle embodiment in an extended position;
[0032] FIG. 23 is an enlarged view of a portion of FIG. 22 ;
[0033] FIG. 24 is a perspective view of the torsion axle connected to the vibratory mechanism;
[0034] FIG. 25 is a rear view of the torsion axle connected to the vibratory mechanism;
[0035] FIG. 26 is a side view of the torsion axle connected to the vibratory mechanism;
[0036] FIG. 27 is a cross-sectional view along line 27 - 27 of FIG. 26 ; and
[0037] FIG. 28 is a cross-sectional view along line 28 - 28 of FIG. 25 .
DETAILED DESCRIPTION
[0038] Referring to FIGS. 2 and 3 , an embodiment of the vibratory plow system according to the present disclosure is shown. The system 10 includes a vehicle 12 , a vibratory plow assembly 14 , and a connection linkage 16 that connects the vibratory plow assembly 14 to the rear of the vehicle 12 .
[0039] In the depicted embodiment the vehicle is a tracked machine, but it should be appreciated that in alternative embodiments many other types of vehicles may be used to drag the plow assembly. In the depicted embodiment the linkage 16 is a four bar type linkage that is actuated by a hydraulic cylinder 18 that extends and retracts the plow assembly 14 . FIG. 1 shows the linkage 16 in the retracted position (disengaged position), and FIG. 2 shows the linkage 16 in the extended position (engaged position). In the depicted embodiment the linkage 16 is configured to pivot horizontally about the vehicle at the connection location 20 between the linkage 16 and the vehicle 12 , and allow the plow assembly 14 to pivot about the linkage 16 about the connection location 22 . Hydraulic cylinders 24 and 26 are provided for actuation of the linkage 16 relative to the vehicle 12 and the linkage 16 relative to the plow assembly 14 . It should be appreciated that may other linkage configurations are also possible.
[0040] Referring to FIGS. 3-9 the plow assembly 14 is shown in greater detail. In the depicted embodiment the plow assembly 14 includes a vibration device 28 that is configured to be attached to the linkage 16 , a plow blade 30 , and two adjacent rollers 32 , 34 . The use of two adjacent rollers can be advantageous over a single roller in some embodiments as cables can be easily attached to the plow blade 30 via the gap between the rollers. However, it should be appreciated that any other number of rollers may be included in alternative embodiments of the present disclosure.
[0041] The rollers 32 , 34 of the depicted embodiment are connected to the vibration device in an identical manner, and can move independent from each other. For simplicity, the connection assembly for only one of the rollers 32 , 34 will be described herein. In the depicted embodiment, the roller 32 is connected to the lower portion of the vibration device 28 via a pair of pivot arms 36 , 38 . The distal ends of the pivot arms 36 , 38 are connected to the axel 40 and the proximal ends 42 , 44 of the pivot arms 36 , 38 are connected to the vibration device 28 . In the depicted embodiment the proximal ends are connected to a torsion bushing 46 . It should be appreciated that in alternative embodiment the torsion bushing could be replaced with a torsion axle.
[0042] In the depicted embodiment the torsion bushing 46 and pivot arms 36 , 38 are configured to accommodate a significant amount of vertical displacement, (also known as travel). In the depicted embodiment the travel is be between about 0 to 4 inches. More preferably, the travel is between about ½-1 inches. In the depicted embodiment the plow blade 30 is directly mounted to the vibration device 28 . It should be appreciated that in other embodiments the plow blade 30 is mounted to the vibration device in a manner that allows the blade 30 to move relative to vibration device 28 . In the depicted embodiment the vertical displacement of the vibration device 28 can be caused by the vibrations generated by the vibration device 28 in the vertical direction and/or caused by the plow blade 30 moving in the vertical direction as the plow blade 30 comes into contact with rocks and other materials in the ground.
[0043] Referring to FIGS. 10A and 10B , the movement of the pivot arms 36 , 38 are shown relative to the vibration device 28 and plow blade 30 . When the plow blade 30 and vibration device 28 are in the peak position (relative high position) as in FIG. 10A , the energy stored in the torsion bushing 46 is release. Conversely, when the plow blade 30 and the vibration device 28 move in valley (relative low position) as in FIG. 10B , the energy is loaded into the torsion bushing 46 . The vertical movement to plow blade 30 oscillates from peaks to valleys.
[0044] The configuration of the present disclosure results in a smoother, more efficient cut through the ground as it does not significantly dampen the vibration in the lateral direction and more efficiently uses the vibrations in the vertical direction. To provided a quantitative measure of some of the performance advantages associated with the present disclosure, a prior art vibratory plow system was compared to a comparably side by side with a powered system that incorporated features of the present disclosure.
[0045] In particular, the performance of a prior art vibratory plow with tamping feet and without a torsion bushing in the configuration described above was measured. Based on five trial runs the average feet per minute was 15.5 feet/min with a standard deviation of 9.5 feet/min. The performance of a comparably powered vibratory plow system with the above described rollers and torsion bushing was also measured. Based on five trial runs the average feet per minute was 115.4 feet/min with a standard deviation of 20.0 feet/minute. In view of the above test, it is evident that present disclosure provides a significantly faster system as compared to the prior art. It is believed that the improved performance is in part a result of the plow blade having more energy on the up stroke. It should be appreciated that the relative performance advantages associated with the plow system of the present disclosure over prior art systems is most evident in compressed soil conditions (i.e., difficult to plow soil). In compressed soil condition, the plow system according to the present disclosure imparts relatively less load on the pulling vehicle than system of the prior art.
[0046] Referring to FIGS. 11-19 , other alternative embodiments of the present disclosure are shown. FIG. 11 illustrates an embodiment that includes a cylinder 50 (e.g., air, hydraulic) that can be used in place of or in conjunction with the torsion bushing. FIG. 12 illustrates an embodiment that includes a cylinder and spring arrangement 52 that can be used in place of or in conjunction with the torsion bushing. FIG. 13 illustrates an embodiment that includes a leaf spring arrangement 54 that can be used in place of or in conjunction with the torsion bushing. FIG. 14 illustrates an embodiment that includes an air bag arrangement 56 that can be used in place of or in conjunction with the torsion bushing. FIG. 15 illustrates an embodiment that includes a spring arrangement 58 that can be used in place of or in conjunction with the torsion bushing. In the depicted embodiment the spring is located on the opposite side of the pivot point 60 between the roller 62 and the vibration device.
[0047] FIG. 16 illustrates an embodiment that includes a pair of cylinders 64 , 66 located on either side of the vibration device 28 that can be used in place of or in conjunction with the torsion bushing. FIG. 17 illustrates an embodiment that includes a pair of cylinders and spring arrangements 68 , 70 located on either side of the vibration device 28 that can be used in place of or in conjunction with the torsion bushing. FIG. 18 illustrates an embodiment that includes a pair of leaf springs 72 , 74 located on either side of the vibration device 28 that can be used in place of or in conjunction with the torsion bushing. FIG. 19 illustrates an embodiment that includes a pair of air bags 76 , 78 located on either side of the vibration device 28 that can be used in place of or in conjunction with the torsion bushing.
[0048] Referring to FIGS. 20-28 shows an embodiment of the plow system with a torsion axle 80 in place of the torsion bushing 46 . In the depicted embodiment the torsion axle 80 connects the wheels 82 , 84 to the vibratory device 86 . In the depicted embodiment the torsion axle is a resilient member that interfaces between the wheels and the vibratory device. In the depicted embodiment, the position between the wheels 82 , 84 and the torsion axis can be adjusted via adjustment nuts 90 on bolts 88 . Adjusting the adjustment nuts 90 pivots the wheels 82 , 84 about the adjustment pivot axis 94 . Once the adjustment nuts 90 are set the wheels 82 , 84 are arranged to pivot about the main pivot axis 96 in use. In the depicted embodiment the torsion axle 80 is mounted to the vibratory device 86 via a bracket assembly 98 . It should be appreciated that in alternative embodiments, the embodiments including torsion axles can be configured in many alternative arrangements.
[0049] Referring to FIGS. 21-28 , the above-described embodiment including a torsion axle is shown as part of a complete plow system. Many of the features are similar to the features of the above-described system; therefore, they are not described again herein.
[0050] The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.
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The present disclosure generally relates to a method and apparatus for installing utility lines underground by using a vibratory plow. One aspect of the invention relates to using a resilient member attached to a vibrator assembly, where the resilient member stores the kinetic energy of the vibrator assembly downward movement. The kinetic energy is then released during the upward movement. The energy is applied to a plow blade so as to improve the efficiency of the plow blade as it is drawn through the ground. Another aspect of the invention relates to connecting the resilient member to the ground via a set of wheels that do not appreciably deflect during the downward movement.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional application No. 60\391,356, filed Jun. 25, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus and method for visually combining an image with an object. More particularly, the present invention relates to a device and method for interposing a reflected image between an object and an individual or apparatus viewing the object for providing a physical collocation in real space of the object and image.
[0004] Visual perception is defined by both psychological (e.g. shading, perspective, obscuration, etc.) and physiological (convergence, accommodation, etc.) depth cues. Only the physiological depth cues are able to unambiguously discern the distance of points on an object from the viewer, since they arise from physiological changes in the vision system such as lens muscles contracting or expanding, or the movement of the eyes as they focus at different depths. If the vision system is to compare two objects, it is important they are perceived at the same depth, otherwise visual strain can result from differentially focusing between the objects. Strain arising from the visual system moving between the objects can be further reduced if the two objects are superimposed on each other. If one of these objects is a two-dimensional cross-section of a 3D object and is seen superimposed on the 3D object, it is important that the superimposed image is displayed at its correct distance within the object. Otherwise, the physiological depth cues will correctly inform the viewer that they are at different distances from the viewer, which can have serious consequences if the viewer is a surgeon.
[0005] 1. State of the Art
[0006] Current techniques in the field of neurosurgery for displaying three-dimensional scanned information require the viewer to look away from the direct field of view to look at either two-dimensional cross-sectional or three-dimensional alternative representations of the anatomy on two-dimensional display devices. Typically these alternative representations are three-dimensional scans of the anatomy derived from a CT, MRI, PET or other types of three-dimensional scanners, and are displayed to aid the healthcare professional in navigating through the real anatomy.
[0007] For example, U.S. Pat. No. 6,167,296 to Shahidi discloses a surgical navigation system including a surgical pointer and a tracking system interconnected to a computer having data from an MRI or CT volumetric scan. The surgical pointer may be positioned on a portion of the patient's body, wherein the position of the pointer may be tracked in real time and conveyed to the computer with the volumetric scans. The computer then provides the real time images from the viewpoint of the pointer in combination with the volumetric scans to be displayed on a display screen to, thereby, allowing a surgeon to positionally locate portions on the patient's body with respect to the volumetric scans. While the Shahidi reference provides a device for positionally locating portions of a patient's body with respect to a volumetric scan, such device requires the surgeon to look away from the patient to the display screen to make comparisons between the position of the surgical pointer and the volumetric scan.
[0008] U.S. Pat. No. 5,836,954 to Heilbrum et al. discloses a device for defining a location of a medical instrument relative to features of a patient's body. The device includes a pair of video cameras fixed with respect to the patient's body to provide a real-time image on a display. The real-time image is aligned with a previously scanned image, such as an MRI, CT or PET scan, so that the medical instrument can be localized and guided to a chosen feature in the scan. In this manner, a surgeon can positionally locate the medical instrument with respect to the scan and the real-time image. However, such device requires the surgeon to look away from the patient to the display screen to locate the position of the medical instrument.
[0009] In each of the references discussed above, the medical practitioner is not able to optimize physiological and psychological depth cues during an operational procedure. Such physiological and psychological depth cues are triggered by objects when seen in their true three-dimensional space. The human visual system uses both physiological and psychological depth cues to determine relative positions in a three-dimensional space. The physiological depth cues include convergence, accommodation, binocular disparity and motion parallax. These physiological depth cues are the most important to professionals making critical decisions, such as neurosurgeons, yet these depth cues are not available in their field of view, in typical stereo-tactic displays. Therefore, it would be advantageous to medical practitioners to conduct medical procedures without substantial hampering of physiological and psychological depth cues.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention relates to a method and apparatus for providing physical collocation of a real object and a projected image in real space. According to the present invention, the collocation of an object and a projected image may be accomplished by interposing a partially reflective device between an object and an individual viewing the object. An image to be collocated with the object may be projected to reflect from the partially reflective device such that an individual viewing the object through the partially reflected device also views the reflected image.
[0011] The ability of the present invention to visually create a collocated image with an object provides a tool and method for visually exploring the interior of an object without altering the physical characteristics of the object. For instance, the interior of an opaque object may be digitally represented as images produced by an electronic scan such as a CT scan, MRI scan, or the like. A series of scans may be combined to define a three-dimensional image of the object, including portions of the interior of the object. Cross-sections of the three-dimensional image may be projected onto the partially reflective device such that an individual viewing the object through the partially reflective device may see the cross-sectional image collocated within the object. This provides the viewer a unique look into the interior of the object.
[0012] The present invention may also be configured to accurately collocate an image of an interior portion of the object at a point in space corresponding with the actual portion of the object represented by the image. This provides an individual the ability to view a three-dimensional characterization of the object without altering the state of the object. Stated otherwise, the instant invention permits the user to “look” into the interior of an object without the need to cut into the object to reveal its interior. The invention provides a two-dimensional view of the interior of the object which can be transformed into a three-dimensional characterization through the viewing of multiple images over an extended period of time.
[0013] The partially reflected device for use with the various embodiments of the present invention may be part of an image projection device that also includes a display device, a computing system coupled to the display device, and a tracking system for tracking a position of the partially reflective device in a three-dimensional field about an object being viewed in accordance with the present invention. The display device may be used to project a desired image onto the partially reflective device and may include such things as computer displays, flat panel displays, liquid crystals displays, projection apparatuses, and the like. An image created by or stored in the computing system may be displayed on the display device and reflected off of the partially reflected device. The tracking system may be coupled with the computing system to track movement of the partially reflective device and to provide a reference point for determining the image to be displayed on the display device. Movement of the image projection device or the partially reflective device may be tracked by the tracking system and relayed to the computing system for updating the image displayed on the display device in accordance with the movement of the image projection device or partially reflective device.
[0014] In one embodiment of the present invention an image projection device includes a partially reflective device mounted a fixed distance from a display device. A computing system coupled with the display device includes one or more memories for storing data corresponding to images of an object. The computing system creates and displays images from the data stored in the memory of the computing system. A tracking system coupled to the computing system may be used to track the position of the partially reflective device within a three-dimensional space. The images created by the computing system and displayed on the display device may be altered by the movement of the partially reflected device as monitored by the tracking system. As the partially reflective device is moved, either manually or automatically, the display device also moves in a corresponding fashion such that the fixed distance and position between the partially reflected device and the display device remains constant. As the partially reflective device is moved within space around an object, the tracking system monitors the position of the partially reflective device and relays the position to the computing system. Based upon the position of the partially reflective device within space, the computing system creates a two-dimensional image of the object from the data stored in memory. The two-dimensional image is displayed on the display device and is reflected off of the partially reflective so that it may be viewed by a viewer. In this embodiment of the present invention, the image created by the computing system corresponds to the image that would appear a second fixed distance from the partially reflective device, the second fixed distance being the distance between the partially reflected device and a portion of the object being viewed. The second fixed distance is equal to the fixed distance between the partially reflective device and the display device. Thus, the image reflected off of the partially reflected device appears within the object a second fixed distance from the partially reflective device.
[0015] In another embodiment of the present invention, the partially reflective device and the display device may be operably coupled to a movement mechanism for controlling the movement of the partially reflective device and the display device. For instance, the movement mechanism may include a foot pedal control coupled to devices for moving the partially reflective device and display device as the foot pedal control is used. Alternatively, the movement mechanism may be controlled with a mouse-like control, a joystick, voice command system, or other device for receiving movement instructions and moving the partially reflective device and display device in accordance with the movement instructions. In this way preprogrammed view paths can be traced through the object.
[0016] In yet another embodiment of the present invention, the display device maybe moved relative to the partially reflective device such that the fixed distance between the display device and partially reflective device is altered. As the fixed distance between the display device and the partially reflective device is changed, the image reflected by the partially reflected device appears to move relative to the increase or decrease in distance between the partially reflective device and display device. The displayed images displayed by the display device may be altered in conjunction with the movement of the display device to reflect an image off of the partially reflective device corresponding to the distance between the partially reflective device and the display device.
[0017] In another embodiment of the present invention, the display device and computer system may be configured to change the display of an image without movement of the partially reflective device. An image displayed on the display device may include an image not associated with the object at the second fixed distance from the partially reflective device. The image displayed on the display device, and reflected from the partially reflective device, may instead be an image associated with a defined positive or negative distance from the second fixed distance. When displayed on the display device, the reflected image appears collocated with the object at a second fixed distance although the actual image being displayed is of that portion of the object a distance equal to the second distance plus or minus the defined distance. Using this embodiment of the present invention, a user may step forward or backward through reflected images to see portions of the object a further or shorter distance from the partially reflective device. In this way the viewer has a look-ahead capability without changing their focus from the current position. However, such disassociation of the reflected image position and the actual position within the object should be used with caution.
[0018] Other features and advantages of the present invention will become apparent to those of skill in the art through a consideration of the ensuing description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0019] While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the invention may be further understood from the following description of the invention when read in conjunction with the accompanying drawings, wherein:
[0020] [0020]FIG. 1 illustrates a side perspective view of an optical space combining device in communication with an electronic system and tracking system, according to a first embodiment of the present invention;
[0021] [0021]FIG. 2 illustrates a front perspective view of an optical space combining device in communication with the electronic system and tracking system, according to a first embodiment of the present invention;
[0022] [0022]FIG. 3 illustrates a perspective side view of the optical space combining device in communication with an electronic system and tracking system, according to a second embodiment of the present invention; and.
[0023] [0023]FIG. 4 illustrates a perspective side view of the optical space combining device in communication with the electronic system, according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The various embodiments of the present invention are hereinafter described with reference to the accompanying drawings. It is understood that the drawings and descriptions are not to be taken as actual views of any specific apparatus or method of the present invention, but are merely exemplary, idealized representations employed to more clearly and fully depict the present invention than might otherwise be possible. Additionally, elements and features common between the drawing figures retain the same numerical designation.
[0025] One embodiment of an image projection device 100 of the present invention that may be used to carry out the various methods embodied in the present invention is illustrated in FIG. 1. The image projection device 100 may include a partially reflective device 110 , a display device 120 , an imaging system 160 , and a tracking system 170 . The image projection device 100 may also include a carrier 130 to which the partially reflective device 110 and display device 120 may be moveably attached. Also illustrated in FIG. 1 are an object 150 and a view point 140 .
[0026] The partially reflective device 110 may include any device that is transparent and is also able to reflect light. For instance, the partially reflective device 110 may include a device commonly referred to as a half-silvered mirror. A half-silvered mirror allows light to pass through the mirror while reflecting a portion of the light impinging on one surface of the mirror. As illustrated, the partially reflective device 110 includes both a first surface 112 and a second surface 114 . If the partially reflective device 110 is a half-silvered mirror, light reflected off of object 150 passes from the object 150 through second surface 114 of the half-silvered mirror towards view point 140 . A portion of light directed from display device 120 towards first surface 112 of the half-silvered mirror is reflected off of the first surface 112 back to the view point 140 . Thus, light passes through the half-silvered mirror and is also reflected by the half-silvered mirror.
[0027] Additional devices capable of partially reflecting light and partially transmitting light through the device may be used as the partially reflective device 110 of the present invention. Like partial mirrors, such as a half-silvered mirror, polarized glass, glass plates, or plastic plates configured to both reflect and transmit light could be used. Furthermore, glass or plastic plates may be etched to alter the refractive qualities of the plate such that it could be used as a partially reflective device 110 . Other devices, such as a liquid crystal container filled with liquid crystals, may be used as the partially reflective device 110 such that the amount of reflectance and transmittance may be controlled by a user of the partially reflective device 110 . For example, variation of an electrical impulse to a liquid crystal container could alter the state of the liquid crystals in the container, thereby changing the amount of reflectance and transmittance realized by the liquid crystal container. The various embodiments of the present invention are not limited by the descriptions of the partially reflective devices 110 given herein.
[0028] The partially reflective device 110 may also include refraction altering films applied to one or more surfaces of the partially reflective device 110 . For instance, an antireflecting film 116 may be applied to a second surface 114 of the partially reflective device 110 to prevent the reflection of light reflecting off of object 150 . The use of an antireflective film 116 on a second surface 114 of the partially reflective device 110 helps to ensure that as much light as possible is transmitted through the partially reflective device 110 from object 150 to view point 140 . Other filtering films, polarization films, and the like may also be used with or applied to the partially reflective device 110 .
[0029] The display device 120 of the image projection device 100 may include any device capable of projecting or displaying an image. Any number of available display devices 120 may be used with the present invention, including such devices as a monitor screen, a flat panel display screen, a television tube, a liquid crystal display, an image projection device, and the like. The example display device 120 illustrated in FIG. 1 includes a display surface 122 recessed in a display housing 124 . An input port 126 in the display housing 124 may accept or transmit data, input power to the display device 120 , or provide other data communications. Data received at input port 126 may be converted to an image for display on display surface 122 .
[0030] The partially reflective device 110 and the display device 120 may be moveably attached to a carrier 130 such that the display device 120 may be positioned a distance d, from the partially reflective device 110 . Fastening devices such a bolts, screws, clamps, or other devices may be used to moveably attach the display device 120 and partially reflective device 110 to carrier 130 . Alternatively, the display device 120 and partially reflective device 110 may be moveably attached to or fitted into defined portions of carrier 130 for holding or supporting the display device 120 or partially reflective device 110 . In one embodiment, the carrier 130 may include two ends where one end terminates with the attachment to the partially reflective device 110 as illustrated in FIG. 1. In another embodiment, carrier 130 may include a track upon which a movable attachment device connected to display device 120 may be moved and fixed such that the display device 120 may easily move up and down carrier 130 to lengthen or shorten distance d 1 .
[0031] Imaging system 160 provides data to display device 120 for producing an image on a display surface 122 of display device 120 or otherwise projecting an image from display device 120 . As illustrated in FIG. 1, imaging system 160 may include a computer 162 with one or more memories 163 , one or more storage devices 164 , and coupled to one or more input devices 166 and displays 168 . Computer 162 may include any type of computing system capable of storing and transmitting data. For instance, computer 162 may include a standalone computing system, a networked computing system, or other data storage and processing device capable of storing and transmitting image data to a display device 120 . Storage devices 164 may include data storage devices and readers such as disk drives, optical drives, digital video disc drives, compact disc drives, tape drives, flash memory readers and the like. In an alternate embodiment of the present invention, the imaging system 160 may be incorporated with display device.
[0032] Image data corresponding to an object 150 may be stored in one or more memories 163 of the imaging system 160 or on media readable by storage devices 164 . Image data may include data for constructing three-dimensional representations of objects or for creating two-dimensional planar views of a three-dimensional image. For instance, image data may include data developed from a CT scan of a portion of a human being, such as a CT scan of a person's head. The image data may be utilized, i.e. integrated, to construct a three-dimensional image of the person's head. Alternatively, the image data from the CT scan may be used to compile two-dimensional “slices” of the larger three-dimensional image. Each two-dimensional slice image created from the data represents a particular portion of the person's head at a definite location about the person's head. Other types of image data may include data developed from MRI scans, ultrasound scans, PET scans, and the like. Methods for collecting and storing image data that can be used with the various embodiments of the present invention are known. Furthermore, software and hardware for integrating image data into two-dimensional slices or three-dimensional images as used by the present invention are also known. Such software or hardware may operate on or with computer 162 to create images for display on display device 120 from the image data accessible to the imaging system 160 .
[0033] The image projection device 100 of the present invention may also include a tracking system 170 for locating the position of the partially reflective device 110 or display device 120 within a three-dimensional space. The tracking system 170 may include any system capable of tracking the position of the partially reflective device 110 based upon coordinates along x, y, and z axes in a three-dimensional space. Furthermore, the tracking system 170 may also be configured to track the rotation of the partially reflective device 110 about the x, y, and z axes. The tracking system 170 may be operably coupled to the imaging system 160 to provide the location of the partially reflective device 110 such that the imaging system 160 may adjust the data sent to the display device 120 to alter the displayed image to correspond with the view of an object 150 from a view point 140 through the partially reflective device 110 .
[0034] The tracking system 170 of the present invention monitors the position of the partially reflective device 110 relative to the object 150 and communicates the position to the imaging system 160 . The imaging system 160 creates an image for display on display device 120 based upon the position of the partially reflective device 110 as monitored by the tracking system 170 . For instance, tracking system 170 may include a receiver 172 and a transmitter 174 . Transmitter 174 may transmit a magnetic field about object 150 and image projection device 100 . The receiver 172 may include a device that disrupts the magnetic field created by transmitter 174 . As the receiver 172 passes through the magnetic field created by transmitter 174 , the transmitter 174 detects the interruption in the magnetic field and determines the position of the disruption. Coordinates corresponding with the disruption in the magnetic field may be passed by the transmitter 174 to the imaging system 160 to relay the position of the partially reflective device 110 within the magnetic field. Images created by imaging system 160 and displayed on display device 120 are based upon the position of the partially reflective device 110 within the magnetic field. For example, the transmitter 174 may be placed next to an object 150 to create a magnetic field about the object 150 and the image projection device 100 . A receiver 172 mounted to the partially reflective device 110 creates disturbances in the magnetic field created by the transmitter 174 . The transmitter detects the disturbances and the tracking system 170 communicates the coordinates of the disturbances to the imaging system 160 . The imaging system 160 uses the coordinates received from the tracking system 170 to determine the data for creating an image on display device 120 and passing the data to the display device 120 . The tracking system 170 of the present invention is not limited to a magnetic field disturbance tracking system as described. Other tracking methods or systems capable of monitoring the position of the partially reflective device 110 about an object 150 may be used.
[0035] According to the various embodiments of the present invention, an image displayed by display device 120 may be reflected off of the partially reflective device 110 such that a viewer positioned at view point 140 views a collocation of the displayed image with an object 150 . The image projection device 100 may be positioned proximate an object 150 such that the object 150 may be viewed through the partially reflective device 110 from view point 140 . In particular, the partially reflective device 110 and display device 120 , preferably connected to carrier 130 , are positioned proximate to object 150 for viewing object 150 through the partially reflective device 110 from view point 140 . The position of the imaging system 160 is less important and the only requirement is that the imaging system 160 is capable of relaying data to display device 120 and receiving positioning coordinates from the tracking system 170 . For instance, the imaging system 160 may be located remote to the display device 120 and partially reflective device 110 while remaining in communication with the display device 120 and tracking system 170 through wired communications, wireless communications, or other data exchange communications. Alternatively, the imaging system 160 may be incorporated with display device 120 such that the display device 120 , partially reflective device 110 , and carrier 130 are moveable about object 150 without any hindrance. The tracking system 170 may be integrated with the carrier 130 or positioned about object 150 and partially reflective device 110 so that the position of the partially reflective device 110 with respect to the object 150 may be monitored and coordinates relayed to the imaging system 160 .
[0036] The positioning of the image projection device 100 about object 150 as monitored by the tracking system 170 dictates the image displayed by display device 120 . The imaging system 160 constructs an image from data based upon the position of the image projection device 100 about the object 150 and more particularly, based upon the position of the partially reflective device 110 with respect to object 150 . The image, or data representing the image constructed by the imaging system 160 , is communicated to the display device 120 and the image is displayed on the display surface 122 of the display device 120 . The displayed image is reflected off of the partially reflective device 110 in the viewing path 142 with the view of the object 150 from view point 140 . The reflection of the displayed image off of the partially reflective device 110 in the viewing path 142 , combined with the reflection of light off of the object 150 which passes through the partially reflective device 110 in viewing path 142 , creates a dual image at view point 140 for a person or camera viewing the object 150 from view point 140 . For instance, a person viewing object 150 through partially reflective device 110 from view point 140 would see both the object 150 and a reflection of the displayed image from display device 120 . The combination of the reflection of the displayed image and the image of the object 150 as viewed through the partially reflective device 110 creates a physical collocation of the object 150 with the reflected image displayed on display device 120 .
[0037] The various embodiments of the present invention provide methods for viewing imaged portions of an object 150 collocated, or superimposed, with the object 150 . For example, an object 150 may be scanned using a CT scan and the data from the CT scan stored in an imaging system 160 or made accessible to the imaging system 160 . The data from the CT scan may be constructed into images for display on display device 120 . When an image created from a CT scan of an object 150 is displayed by display device 120 , the image is also reflected off of partially reflective device 110 . A viewer viewing the object 150 through the partially reflective device 110 views both the object 150 and the reflected image. To the viewer, the reflected image appears to be superimposed on, or within, the object 150 . The apparent location of the image within the object 150 depends upon the distance between the display device 120 and the partially reflective device 110 . In certain embodiments of the present invention, the display device 120 is mounted a fixed distance d 1 from the partially reflective device 110 as illustrated in FIG. 1. A reflected image of the display of the display device 120 off of partially reflective device 110 will appear to be a distance d 1 ′ from the partially reflective device 110 where distance d 1 , and d 1 ′ are equal. If the distance between display device 120 and partially reflective device 110 is altered, the distance d 1 changes and the apparent location of an image reflected off of the partially reflective device 110 will also change to appear a distance d 1 ′ from the partially reflective device 110 where distance d 1 and d 1 ′ remain the same. Therefore, as the display device 120 is moved closer to the partially reflective device 110 the reflected image off of the partially reflective device 110 appears to move closer to the view point 140 . Similarly, as the display device 120 is moved away from the partially reflective device 110 the reflected image appears to move further away from view point 140 .
[0038] In certain embodiments of the present invention the distance between the display device 120 and the partially reflective device 110 is held at a constant distance d 1 . The images displayed by display device 120 and reflected off of partially reflective device 110 in viewing path 142 appear to a viewer at a view point 140 to be a distance d 1 ′ from the partially reflective device 110 . If a viewer is viewing an object through the partially reflective device 110 , the reflected image is superimposed in the object 150 at a distance d 1 ′ from the partially reflective device 110 . If the partially reflective device 110 and display device 120 are moved closer to the object 150 , the reflected image appears to move through the object 150 , maintaining a distance d 1 ′ from the partially reflective device 110 . Likewise, if the partially reflective device 110 and display device 120 are moved away from the object 150 the reflected image appears to move through object 150 towards view point 140 . At all times, the reflected image appears to be superimposed on the object 150 at a distance d 1 ′ from the partially reflective device 110 .
[0039] Imaging systems, such as the imaging system 160 used with the present invention, provide the ability to create two-dimensional or three-dimensional images of an object 150 based upon imaging data taken of the object 150 . For instance, data from a CT scan of an object may be constructed to create images of two-dimensional slices of the object 150 . One example of such a system is used for medical purposes. A CT scan of a human's head may be conducted and the data used to recreate images of the interior portions of the head. Typically, the images created are two-dimensional images representing slices through the head. Three-dimensional images may also be created from the data. The data may be combined such that the two-dimensional images may be created from any angle. In other words, the images may be constructed to represent slices appearing along multiple planes, from multiple angles. Thus, images may be constructed as if a person was looking at the head from the side of the head, from the top of the head, from the bottom of the head, or from any other angle. Based upon the desired viewing angle, the imaging system 160 is capable of constructing an image of the head.
[0040] Furthermore, imaging systems may be used to step through an object 150 and create images of the object 150 based upon the desired location within the object 150 . The ability of the imaging system 160 to create an image may depend upon the amount of data available to the imaging system 160 from the scan performed of the object 150 . For instance, with respect to a human's head, a CT scan may be performed wherein the equivalent of twenty scans at a distance of 5 millimeters are taken. Images created from the data are limited to the data available. Thus, if a person wished to step through the images of the scanned head they may be limited to twenty images corresponding to the twenty scans performed. However, if one hundred scans were performed at a distance of 1 millimeter, one hundred images could be stepped through using the imaging system 160 . In some instances, the imaging system 160 may be able to create a three-dimensional image from the scan data or be able to interpolate additional images based upon the overall three-dimensional structure of the object. An imaging system 160 capable of interpolating scan data into a three-dimensional image may be capable of creating as many images from the data as desired. Thus, a user could indicate that they wished to view two-dimensional images in one millimeter steps through the object 150 or in ⅕ millimeter steps through the object 150 .
[0041] The combination of the imaging system 160 capabilities with the partially reflective device 110 and display device 120 of the present invention provides methods for altering the displayed images on the display device 120 so that different portions of the object 150 may be viewed as reflections off of the partially reflective device 110 . Changing the displayed image changes the reflection so that a viewer viewing an object 150 through the partially reflective device 110 also sees the displayed portion of the object as it appears on the display device 120 superimposed on the object 150 at a distance d 1 ′ from the partially reflective device 110 . Thus, the imaging system 160 may be instructed to create two-dimensional images of the object 150 from scan data of the object 150 , and step through the data, creating and displaying images of each step through the object 150 on the display device. Thus, as a viewer views the object 150 through the partially reflective device 110 they may also see and step through the images created by the imaging system 160 . However, unless the partially reflective device 110 and display device 120 are moved as images corresponding to different portions of the object 150 are displayed by imaging system 160 , all of the images will appear superimposed on the object 150 at a distance d 1 ′ from the partially reflective device 110 .
[0042] The tracking system 170 of the present invention may be combined with the imaging system 160 , display device 120 , and partially reflective device 110 to provide a dynamic system that allows a user to alter the reflected images based upon the positioning of the partially reflective device 110 with respect to an object 150 . For instance, as the partially reflective device 110 is moved closer to the object 150 a reflected image created by the imaging system 160 and displayed on display device 120 appears to move through the object 150 , maintaining a distance d 1 ′ from the partially reflective device 110 . If the movement of the partially reflective device 110 with respect to the object 150 is tracked by tracking system 170 , the tracking system 170 may communicate the distance moved to the imaging system 160 so that the imaging system 160 may alter the displayed image to correspond with an image of the object 150 at the distance d 1 ′ from the partially reflective device 110 . Therefore, as the partially reflective device 110 is moved closer to the object 150 the displayed image changes to reflect that portion of the object 150 at the distance d 1 ′ from the partially reflective device 110 . A person using the present invention to view an object 150 through partially reflective device 110 along with a reflected image of an interior portion of the object 150 could therefore “step through” the object 150 and view superimposed scanned images of the object by moving the partially reflective device 110 closer to or away from the object 150 .
[0043] The collocation of a reflected image displayed by display device 120 with an object 150 such that a displayed image corresponds exactly with a portion of the object 150 a distance d 1 ′ from the partially reflective device 110 may be accomplished by coordinating the scanned images with the object 150 . Coordination of the images with the movement of the partially reflective device 110 may be accomplished by aligning registration points of the object 150 with registration points recorded with the scanned data and setting the tracking system 170 to monitor movement based upon the registration. The coordination of the images with the object 150 may be accomplished by aligning known common points, such as registration points 152 , appearing on the object 150 and in the displayed images. Two or more registration points 152 associated with object 150 may be aligned with registration points 152 appearing on images created from scanned data. Once aligned, the tracking system 170 may be set to monitor the movement of the partially reflective device 110 with respect to the object 150 based upon the registration. This provides a correlation between distance d 1 ′ from the partially reflective device 110 with the image displayed by imaging system 160 on display device 120 such that the displayed and reflected image viewed by a user is an image of the object 150 at the distance d 1 ′ from the partially reflective device 110 .
[0044] An example of a process that may be used to register the tracking system 170 involves the placement of registration points on an object before obtaining scan data. For instance, an object 150 , such as a human head, may be fixed with two or more registration points prior to a scan to obtain image data. The scanned data picks up and includes the positions of the registration points on the head. Viewing the head through the partially reflective device 110 , the registration points on the head may be seen. Images created from the scan data and displayed by imaging system 160 on the display device 120 may be adjusted to show images corresponding to the scanned data of the registration points. The partially reflective device 110 , with display device 120 fixed a distance d 1 from the partially reflective device 110 , may be moved with respect to the object 150 until the registration points 152 on the object align with and correspond to the registration point images reflected off of the partially reflective device 110 . Once the registration points 152 of the object 150 are aligned in space with the registration points on the images created by the imaging system 160 , the tracking system 170 may be configured to base movement instructions sent to the imaging system 160 based upon the registration alignment.
[0045] As the tracking system 170 monitors the movement of the partially reflective device 110 with respect to an object 150 , the tracking system 170 communicates the movement to the imaging system 160 which in turn alters the data sent to the display device 120 to alter the displayed image to correspond with the position within the object a distance d 1 ′ from the partially reflective device 110 . The images displayed and reflected in viewing path 142 create a collocated image within object 150 . This allows a user to explore the images of the interior of the object 150 from scan data collocated with the object 150 .
[0046] The various embodiments of the present invention may be used in numerous applications where it is desirable to view an object 150 while simultaneously viewing scanned data representing images of portions of the object 150 collocated with the object. As an example, use of the present invention in the medical field is explained, however, it is understood that the examples do not limit the scope of the invention or the claims.
[0047] Neurosurgery is a delicate procedure, often requiring precise movements and attention to detail. To facilitate neurosurgical procedures imaged data of a person's head is often viewed before and during the neurosurgical procedure. Scanned images of the head may be stepped through and viewed on a monitor as the neurosurgeon performs an operation. To view the scanned images, the neurosurgeon glances away from the head, or operating object, to view a monitor displaying the scanned images. Although alternating views of the operating object and the monitor allow the surgeon to view scanned images, it is difficult to correlate the images with the operating object because they are not in the same view path or superimposed on each other.
[0048] At least one embodiment of the present invention may be used to improve neurosurgical techniques. An image projection device 100 may be used during neurosurgery as illustrated in FIG. 2. The image projection device 100 may be used to display images of the scanned operating object 150 in the view path 142 of the surgeon 140 . This allows the surgeon to view both the operating object 150 and images of the interior of the operating object during the surgery.
[0049] In one embodiment of the present invention, the head of a patient may be scanned, such as by a CT scan, MRI scan, PET scan, or the like, and the data stored in an imaging system 160 for creating two-dimensional images of the head. Registration points 152 may be applied to the head 150 prior to scanning to provide images with registration point 142 for calibrating the image projection device 100 . In the operating room, the image projection device 100 may be located proximate to the head 150 of the patient such that a surgeon 140 may view the head 150 through the partially reflective device 110 of the image projection device 100 . Before use, registration or calibration of the tracking system 170 is performed. The surgeon 140 aligns the registration points 142 on the head 150 with registration point 142 images created by the imaging system 160 , displayed by display device 120 and reflected off of the partially reflective device 110 . The tracking system 170 may be set or configured once the registration points 142 on the head and the images are aligned.
[0050] During surgery, the image projection device 100 may be used to view scanned images of the portions of the head 150 that the surgeon wishes to view. For instance, if the surgeon is working within the head 150 and they wish to see what is coming up next, in other words a portion of the head 150 that is not yet exposed by surgery, the surgeon may move the partially reflective device 110 closer to the head 150 thereby causing a displayed image associated with a portion of the head 150 a distance d 1 ′ from the partially reflective device 110 to be collocated with the head 150 by reflection off of the partially reflective device 110 . The surgeon may move the partially reflective device 110 back, away from the head 150 to again view the portion of the head 150 where the surgery is taking place. Use of the partially reflective device 110 to perform such operations during surgery allows the surgeon to view, simultaneously, both the head 150 and a collocated image of a scan of the head 150 .
[0051] Movement of the partially reflective device 110 during surgery may be accomplished manually or mechanically. The image projection device 100 , and more importantly the partially reflective device 110 , may be equipped with handles or other devices so that the partially reflective device 110 may be moved along and about an x-axis, y-axis, and z-axis. Alternatively, the partially reflective device 110 may be controlled by a mechanical device also capable of moving the partially reflective device 110 along and about an x-axis, y-axis, and z-axis. The control system may include movement controls such as a foot pedal, mouse, joystick, control panel, voice operated system, or other control mechanism for initiating movement of the partially reflective device 110 . The amount of movement associated with a certain command issued to a mechanical control system may be altered and programmed as desired by the user. For instance, a surgeon may set the control system to provide one millimeter movements of the partially reflective device 110 upon each movement command issued to the control system. The movement distance could also be altered for another surgery or during a surgery if smaller or larger movement was desired. For example, once a surgeon reaches the portion of the head 150 where finer detail and more precision is required, the movement could be adjusted to one-half millimeter movement increments rather than one millimeter movement increments.
[0052] In another embodiment of the present invention, the surgeon may wish to advance the images produced by the imaging system 160 without moving the partially reflective device 110 . In other words, the surgeon may wish to maintain the position of the partially reflective device 110 while viewing the next image or series of images that can be created by the imaging system 160 . A control system, such as a foot operated control, hand operated control, voice operated control, or the like, may be integrated with the image projection device 100 to allow the surgeon to request movement through scanned images without movement of the partially reflective device 110 . Based upon the request to the control system, the imaging system 160 may be instructed to advance or step through the scanned images. The amount of movement through the images, in other words, the step distance or increment, may be set to a desired amount using the control system. Using this system, a surgeon could move forward through the scanned images of an object without moving the partially reflective device 110 . In instances where the images are altered without movement of the partially reflective device 110 , the reflected image will appear superimposed on the object 150 but they will not be collocated within the object because the distance d 1 ′ does not change as the images are displayed. This function, however, allows a surgeon to view images of the object that they will be seeing as they move deeper into the head during surgery. Also, a reset function may be incorporated with the control system for resetting the image corresponding to the distance d 1 ′ on the display device 120 thereby providing collocation of the reflected image with the head 150 .
[0053] In yet another embodiment of the present invention, the partially reflective device 110 of the image projection device 100 may be fixed to a neurosurgeons operating microscope or visual enhancement device. Images reflected off of the partially reflective device 110 are reflected into the microscope so that the surgeon views the images with the operating object, or head 150 , view. This allows the surgeon to view scanned images of the operating object superimposed on the operating object.
[0054] In each of the embodiments of the present invention, the display of the images produced by the imaging system 160 may be terminated and reinstated at will. In other words, a user may turn the display on and off in order to view a superimposed or collocated image or to remove the image from view path 142 . The display of the images may be turned on and off using manual or mechanical devices which may be integrated with control systems to allow voice control or manual control so the view of the object does not have to be disturbed to operate the display.
[0055] In an alternate embodiment of the present invention the image projection device 100 may be used in conjunction with real-time scanning equipment or an imaging system 160 conducting real-time scanning. Real-time scanning provides an image of an object in real-time. For instance, an ultrasound scan may be in progress while the image projection device 100 is being used. Images created from the ultrasound may be passed to the imaging system 160 and used with the image projection device 100 . In another embodiment, helical scanners may be used with an object to scan the object while viewing the object through the partially reflective device 110 . The integration of the image projection device 100 with real-time scanning is especially useful in surgical environments where a patient's body may be changing. For instance, during neurosurgery, portions of the brain may be altered by the surgery being performed or they may have changed since the time of the scan, such as with the growth of a tumor. Use of a real-time scanning device allows the imaging system 160 to produce images of the head or brain as the surgery is taking place. Thus, the image projection device 100 may be used to view real-time images collocated with the operating object during surgery.
[0056] [0056]FIG. 3 illustrates a perspective side view of the image projection device 100 in communication with an electronic system and a tracking system, according to a second embodiment of the present invention. The second embodiment is substantially the same as the first embodiment, except the second embodiment includes a stepper 292 and a foot pedal 294 . The stepper 292 may be an automated movable connector that is secured to the display device 120 and is movable by depressing the foot pedal 294 . The stepper 292 and foot pedal 294 combination provide a controlled, stepped movement of the display device 120 , wherein the receiver 172 should be in a fixed position with respect to said display device 120 . As such, the tracking system 170 tracks the movement and position of the display device 120 and changes the scanned image 180 with respect to such movement as described in the first embodiment herein.
[0057] In the second embodiment, the movability of the image projection device 100 in combination with the tracking device 170 may still be utilized to determine the optimal position or optimal directional viewing course to examine the patient and object 150 , by which the tracking system 170 provides the position of the image projection device 100 so that the computer 160 may generate a corresponding scanned image 180 . Once such optimal position is determined by the viewer 140 , the stepper 292 and foot pedal 294 combination provide the viewer 140 the ability to change the scanned image 180 along the optimal directional viewing course without having to manipulate the optical device manually, thereby, allowing the viewer to change the scanned image 180 with the viewer's hands free to continue performance of any medical procedures necessary.
[0058] Although the various embodiments are described where the partially reflective device 110 may sit suspended between the viewer and object, it is also contemplated that the partially reflective device 110 may be integrated on an ultrasound wand or other scanning device so that the partially reflective device 110 is reduced in size.
[0059] Having thus described certain preferred embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations thereof are possible without departing from the spirit or scope thereof as hereinafter claimed.
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An apparatus and method for visually enhancing the ability to perform a medical procedure. The apparatus and method relates to an optical device configured to superimpose a display image over an object, wherein the display image aligns and corresponds with a portion of the object. The optical device includes a partial reflective device and a display member having a display surface configured to display the display image. The display member is oriented with respect to the partial reflective device such that the display image appears superimposed to a viewer over the object. With this arrangement, the display member displays an image that reflects with the partial reflective device and into a viewer's optical viewing path so that the viewer can see the displayed image through the partial reflective device superimposed over the object. The viewer may change the displayed image to another displayed image representing a portion further in depth into the object to obtain additional information with respect to the object.
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FIELD OF THE INVENTION
This invention pertains generally to the field of molecular biology and particularly to the production of RNA in vitro.
BACKGROUND OF THE INVENTION
Through the development of recombinant DNA techniques, it has become fairly straightforward to clone DNA sequences from essentially any organism into plasmid or viral vectors for propagation and amplification in a foreign host. In this form the DNA can be studied with regard to its sequence, structure, coding capacity, or other properties. It can also be used for a variety of applications such as detection of complementary sequences in samples, generation of altered forms of a gene product, modulation of organismal function through insertion into new organisms, etc. Some vectors contain DNA sequences near the insertion site for foreign DNA which control the expression of the inserted DNA in the host cell. These vectors can be used to produce the product of a cloned gene in a host such as Escherichia coli.
More recently it has become possible to efficiently control the expression of cloned DNA sequences in vitro. The first system to be widely exploited for this purpose used a plasmid containing a late promoter from the Salmonella typhymurium bacteriophage SP6 and a purified DNA dependent RNA polymerase purified from the virus infected cells. Krieg, P. A. and Melton, D. A. (1984) Nucleic Acids Res. 12:7057-7070; Butler, E. T. and Chamberlin, M. J. (1982) J. Biol. Chem. 257:5772-5778. Using this system, an RNA copy of one strand of any DNA sequence inserted into the vector can be produced. The vector is constructed such that several unique restriction enzyme sites lie adjacent to the SP6 promoter to allow the insertion of a variety of DNA sequences into that region. The plasmid is then propagated in and purified from E. coli. Next, the purified plasmid is converted to a linear piece of DNA through the action of a restriction enzyme that cuts next to the inserted DNA on the side distal to the promoter. The purified RNA polymerase is added to the linearized DNA along with a substrate mixture and large amounts of the desired RNA can be produced. This RNA can be used as a hybridization probe, as a substrate for RNA processing enzymes, or as mRNA for synthesizing protein by in vitro translation. The relatively large amounts of RNA so produced are readily studied from a variety of structural and functional perspectives.
An analogous system has been configured using a different promoter and RNA polymerase from the E. coli bacteriophage T7. The T7 enzyme recognizes a specific DNA promoter sequence and has similar properties to the SP6 derived enzyme. Both the SP6 and T7 enzymes are extremely specific as they only recognize their own late phage promoters for in vitro transcription. The transcription reactions for either promoter system are very efficient and many copies of full length RNA may be produced from each template molecule. It is thus possible to synthesize milligram amounts of RNA from any cloned DNA sequence.
The above described in vitro transcription systems have the disadvantage that only one strand of the DNA molecule can be copied into RNA. For many applications an RNA copy of a specific strand of the DNA is needed, as for in vitro translation or RNA processing or synthesizing probes for RNA detection. At the time the DNA sequence is cloned into the vector, it often is not known which strand will be required and it often is not possible to control the orientation of the insertion. In such cases, the DNA must be inserted into two different vectors or a number of isolates must be generated and examined to obtain two plasmids which carry the same DNA sequence in opposite orientations with respect to the promoter. For other applications, such as processing double-stranded RNA, both strands of the DNA must be copied into RNA, again requiring much more effort since plasmids with the DNA in two orientations must be isolated.
SUMMARY OF THE INVENTION
In accordance with the present invention, it is possible to obtain RNA copies of one or both strands of a chosen DNA sequence which is inserted in a single cloning vector, for example, a plasmid. Since only one vector is required, the efficiency of the production of the desired RNA is significantly improved.
The vector utilized in the invention has two different promoter sequences separated by a series of unique restriction sites into which foreign DNA can be inserted. The promoters face each other such that transcription from either promoter proceeds toward the other. Each promoter sequence is associated with a unique RNA polymerase which recognizes only that promoter sequence in the vector. The cloning site which separates the promoters has at least one and preferably several distinct cleavage sites cleaved by distinct restriction enzymes which recognize no other sites in the vector.
Preferred plasmid vectors constructed in accordance with the invention, designated pGEM-1 and pGEM-2, are derived from suitably transformed isolates of plasmids from E. coli. The promoters contained in the vectors pGEM-1 and pGEM-2 originate from two bacteriophage, the Salmonella typhymurium virus SP6 and the E. coli virus T7. Each RNA polymerase for these two promoters is highly active in vitro and is specific to its own promoter. No known DNA sequences other than those from the respective viruses which are used as the promoters are recognized by these enzymes, providing extreme specificity to the RNA transcripts which are produced. The opposed promoters in the plasmids pGEM-1 and pGEM-2 are separated by a multiple cloning site containing eleven restriction sites which are unique within the vectors. The vectors pGEM-1 and pGEM-2 differ only in the orientation of the restriction sites in the multiple cloning site with respect to the two opposed promoter sequences.
The vector is utilized by applying a restriction enzyme specific to a selected restriction site in the multiple cloning site to cleave the vector at that site. A selected DNA sequence is then cloned into the vector and another restriction enzyme is applied to the vector which is specific to a restriction site between the inserted DNA and one of the promoters to cleave the vector at that site. If the orientation of the insert DNA is known, it can be cloned in a particular orientation by cleaving the vector and the insert DNA with two restriction enzymes that recognize unique sites in the multiple cloning site. An RNA polymerase specific to the promoter sequence remaining adjacent to the inserted DNA is then applied in a suitable RNA generating medium to generate mRNA copies of the DNA segment. The particular strand of the DNA segment which is transcribed is selected by cleaving on the side of the DNA segment away from the promoter from which the transcription is desired to take place followed by transcription using the appropriate RNA polymerase.
Double stranded RNA can also be readily produced by separating the vectors into two groups and cleaving one group with an endonuclease specific to a site between the DNA segment at one of the promoters and cleaving the second group with an endonuclease specific to a site between the DNA segment and the second promoter. The cleaved vectors may then be used to produce complementary RNA strands which can be hybridized to form double stranded RNA.
Further objects, features, and advantages of the invention will be apparent from the following detailed description of the invention and the illustrative drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a partial restriction site and functional map of the plasmid pGEM-1.
FIG. 2 is a partial restriction site and functional map of the plasmid pGEM-2.
FIG. 3 is a partial restriction site and functional map of the plasmid pGEM-0.
FIG. 4 is a partial restriction site and functional map of the parent plasmid pT7-1.
FIG. 5 is a partial restriction site and functional map of the parent plasmid pT7-2.
FIG. 6 is the promoter and multiple cloning site sequence for the plasmid pGEM-1 showing the coding strand for T7 RNA polymerase and the non-coding strand for SP6 RNA polymerase.
FIG. 7 is the promoter and multiple cloning site sequence for the plasmid pGEM-2 showing the coding strand for T7 RNA polymerase and the non-coding strand for SP6 RNA polymerase.
FIG. 8 is the promoter and multiple cloning site sequence for the plasmid pGEM-0 showing the coding strand for T7 RNA polymerase and the non-coding strand for SP6 RNA polymerase.
FIG. 9 is a partial restriction and functional map for the cloned plasmid pGEM-0 (lambda 1.37).
DETAILED DESCRIPTION OF THE INVENTION
The present invention allows selective transcription of RNA in vitro from either strand of a DNA sequence using a single vector regardless of the orientation of the DNA segment inserted in the vector. The vector constructed in accordance with the invention has two distinct promoter sequences capable of promoting transcription in vitro of a DNA segment inserted between them. The two promoters must face each other; that is, they must be oriented such that transcription from either promoter proceeds toward the other. Thus, RNA may be transcribed from either strand of the DNA segment depending upon the promoter at which the transcription begins. At least one restriction site must be present between the opposed promoters which can be cleaved to allow insertion of foreign DNA. However, as explained below, a number of additional restriction sites in the cloning site between the promoters is preferred to allow selection of a site that matches the cleaved ends of the DNA segment to be inserted. Multiple unique sites between the promoters are also preferred since, as explained further below, after insertion of the DNA segment, the vector is preferably cleaved at a position adjacent to the inserted segment and distal to the desired promoter at which transcription is to begin.
A variety of vectors can be constructed to contain a region having the two facing opposed promoters and the internal cloning site as described above. The rest of the vector can be designed as desired to have specific cloning or propagation advantages relating to a particular cloning application, and the construction of the remaining portion of the vector is not critical to the functioning of the transcription region. Vectors which may be used in conjunction with the invention include a variety of plasmids which contain genes facilitating selection, for example, genes contributing antibiotic resistance; bacteriophage vectors such as lambda or related phages; shuttle vectors designed to be propagated both in prokaryotes and eukaryotes, such as E. coli/yeast vectors; vectors which produce fusion proteins or which fuse the cloned DNA with regions of the vector which control expression; vectors capable of transforming mammalian cells and which might either integrate into the genome or be maintained or replicated extrachromosomally; and viral vectors for use with mammalian cells.
The two opposed promoters in the transcription segment must be capable of in vitro transcription and purified RNA polymerases which uniquely recognize only one of the two promoters are required. Two particularly suitable polymerases, both presently available commercially, are the SP6 polymerase derived from the S. typhymurium phage SP6, and the T7 polymerase derived from the E. coli phage T7. Suitable polymerases are also available for the T3 and N4 phage promoters and the ghl (Pseudomonas host) promoter. Many other polymerases and the promoters they recognize can be used in accordance with the invention. These include E. coli RNA polymerase with various promoters, Bacillus subtilis RNA polymerases with various sigma-like subunits and related promoters, other suitably specific bacteriophage polymerases and their promoters, and various plant and animal derived RNA polymerases and their promoters.
The following examples are provided as illustrative of the methods for generating vectors in accordance with the invention, the vectors generated, and the methods for in vitro production of RNA coded by the vectors.
EXAMPLE 1
Construction of plasmid pGEM-1
A plasmid designated pGEM-1 having the restriction and functional map shown in FIG. 1 was constructed from the parent plasmid pSP64 (Melton, D. A., et al. (1984) Nucleic Acids Research 12:7035-7056; Cox K. H., DeLeon D. V., Angerer L. M., and Angerer R. C. (1984) Dev. Biol. 101:485-502; Krainer A. R., Maniatis T., Ruskin B., and Green M. R. (1984) Cell 36:993-1005; Persson H., Hennighausen L., Taub R., DeGrado W., and Leder P. (1984) Science 225:687-693; Toole J. J. et al. (1984) Nature 312:342-347) and the parent plasmid pT7-1. The plasmid pT7-1 has the partial restriction and functional map shown in FIG. 4 and is available commercially from United States Biochemical Corporation, Cleveland, Ohio (Tabor, S. and Richardson, C. (1985) Proc. Nat. Acad. Sci. 82:1074-1078). The parent plasmids were codigested with the restriction enzymes Eco R1 and Pvu II. The fragments were then mixed and ligated using DNA ligase. The ligation mixture was used to transform competent E. coli, strain HB101. Isolates containing the ampicillin resistance gene (Amp R ) were selected on plates containing ampicillin. DNA was extracted from individual isolates and the size of the plasmid in each estimated on agarose gels. Isolates were selected which contained a plasmid of approximately 2.9 kilobases (kb) which is the size expected when the 0.18 kb Eco R1-Pvu II fragment of pSP64 is replaced by the 0.05 kb Eco R1-Pvu II fragment of pT7 -1 which contains the T7 promoter.
Specifically, one microgram of pT7-1 was digested with 20 units of Eco R1 restriction endonuclease (available from Promega Biotec, Madison, Wis.) and 20 units of Pvu II restriction endonuclease (Promega Biotec, Madison, Wis.) for 30 minutes at 37° C. in buffer consisting of 90 mM Tris-HCl pH 7.5, 0.1 mg/ml bovine serum albumin (BSA), 50 mM NaCl and 10 mM MgCl 2 in a volume of 50 microliters. One microgram of pSP64 was digested similarly. The digests were mixed together and to the resulting 0.1 ml reaction was added 0.01 ml of 10× ligase buffer (10× ligase buffer=0.1M MgCl 2 , 0.1M DTT, 4 mM ATP, 0.3M Tris-HCl pH 7.8) and 20 Weiss units of T4 DNA ligase (Promega Biotec, Madison, Wis.). Ligation was then allowed to proceed for 2 hours at 22° C. After this time the reaction was heated for 10 minutes at 65° C. 0.02 ml of the reaction was then used to transform 0.2 ml of competent E. coli HB101. Competent cells were prepared according to Maniatis T., Fritsch E. F., and Sambrook J. (1982) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., and the transformation protocol using Rb ++ /Ca ++ treated cells was essentially according to this reference. Transformed cells were plated on four 8 cm diameter Petri dishes containing Luria broth agar and 100 micrograms/ml ampicillin and then incubated for 16 hours at 37° C. to allow for the growth of ampicillin resistant transformants into small colonies. Colonies were screened for the presence of the appropriately sized plasmid using the "colony crack" method (Maniatis et al., 1982, id.). The resulting plasmid was checked for appropriate restriction sites and for promoter activity for both polymerases to verify the construction shown in FIG. 1. The plasmid pGEM-1 has the promoter and multiple cloning site sequence shown in FIG. 6. This vector within E. coli. HB101 has been deposited in the Agricultural Research Culture Collection, Peoria, Ill., U.S.A. under accession number NRRL B 15942.
EXAMPLE 2
Construction of plasmid pGEM-2
The construction of another plasmid, designated pGEM-2, followed the same procedures as in Example 1 except that the parent plasmids were pSP65 (Krieg and Melton, Nucleic Acids Res. 1984, id.) and pT7-2 (Tabor and Richardson, 1985, id.). pT7-2 has the partial restriction and functional map shown in FIG. 5 and is available from United States Biochemicals, Cleveland, Ohio. The plasmids were cut with the restriction enzymes Hind III and Pvu II and religated to insert the T7 promoter in the same manner as that described in Example 1. A partial restriction and functional map of the resulting plasmid pGEM-2 is shown in FIG. 2 and this plasmid has the promoter and multiple cloning site sequence shown in FIG. 7. This vector within E. coli. HB101 has been deposited in the Agricultural Research Culture Collection, Peoria, Ill., U.S.A. under accession number NRRL B 15943.
EXAMPLE 3
Construction of plasmid pGEM-0 and Insertion of foreign DNA into the plasmid and purification of the template
Cloning of DNA into a pGEM-type plasmid (i.e., a plasmid having opposed promoters separated by a multiple cloning site) and purification of the plasmid for use as a template is accomplished by standard cloning techniques. The pGEM plasmid is digested with one or (if a directional cloning strategy is to be employed) two different restriction endonucleases, and mixed together with a foreign DNA fragment having ends corresponding to those generated by digestion of the pGEM vector. Generally, the restriction enzyme(s) chosen will have a single recognition and cleavage site lying within the multiple cloning site of the vector and will recognize and cleave no other site on the vector. Following ligation with DNA ligase, the mixture is used to transform competent bacteria to ampicillin resistance as described in Example 1. pGEM vectors containing inserts of foreign DNA are distinguished from the parent plasmids based on their size as estimated by electrophoresis in agarose gels and staining with ethidium bromide following "colony cracks" to release the plasmid DNA from transformants (Maniatis et al., supra 1984). A specific example follows.
A plasmid designated pGEM-0 having the partial restriction and functional map shown in FIG. 3 and the promoter and cloning site sequence shown in FIG. 8 was constructed from the parent plasmid pSP64 (Krieg and Melton, supra 1984) which supplies the pUC-12 DNA replication origin, ampicillin resistance gene, M13 multiple cloning site (MCS) and the SP6 promoter, and the parent plasmid pAR2192 (Studier, supra, 1984) which supplies the T7 promoter. To construct the pGEM-0 plasmid, the Bam H1 site in pAR2192 was removed by cutting with Bam H1, filling the ends with the Klenow fragment of DNA Polymerase I, and rejoining by blunt-end ligation. Specifically, one microgram of pAR2192 was digested for 1 hour at 37° C. with 16 units of Bam H1 (Promega Biotec, Madison, Wis.) in a volume of 0.05 ml in buffer consisting of 20 mM Tris-HCl, pH 7.4, 7 mM MgCl 2 , 100 mM NaCl, 2 mM 2-mercaptoethanol and 0.1 mg/ml BSA. Following incubation, 0.5 microliters of 10% diethylpyrocarbonate (DEPC) (in ethanol) was added and the reaction then incubated for 10 minutes at 65° C. The reaction was then cooled to 20° C. and 2 microliters of 10× deoxyribonucleotide mix and 1 microliter of Klenow fragment (13 units/microliter, Promega Biotec, Madison, Wis.) was added (10× deoxyribo-nucleotide mix=4 mM each dATP, dGTP, dTTP and dCTP). Following a 15 minute, 20° C. incubation, 0.5 microliters of 10% DEPC was added and the reaction heated at 65° C. for 10 minutes. The reaction was then cooled to 25° C., 3 microliters of 10× ligase buffer and 20 units of T4 DNA ligase were added and the reaction was incubated for 16 hours at 25° C. The reaction was then heated for 10 minutes at 65° C. to inactivate the ligase and 1 microliter of 16 units/microliter Bam H1 was added and the reaction incubated for 30 minutes at 37° C. 5 microliters of the reaction was then used to transform 0.2 ml of competent E. coli HB101. Transformed cells were plated on plates containing Luria broth agar and 100 micrograms/ml ampicillin and incubated 16 hours at 37° C. Four of the resulting colonies were used to innoculate 50 ml Luria broth cultures (containing 100 micrograms/ml ampicillin) and the cultures grown at 37° C. for 16 hours. Plasmid DNA was then isolated from these cultures by procedures described below. Each of the plasmid DNAs was tested for the absence of the Bam H1 site by digestion with Bam H1 as described above and electrophoresis on gels containing 1% agarose and 1 microgram/ml ethidium bromide. Each of the four was found to be resistant to cutting by Bam H1. Digestion of the Bam H1 deleted plasmid with Eco R1 and Hinc II yields one large and two small (0.325 and 0.45 kb) fragments. The T7 RNA polymerase promoter is on the 0.325 kb fragment. This fragment was cloned into pSP64 by digesting Bam H1 deleted pAR2192 with Eco R1 and Hinc II, digesting pSP64 with Eco R1 and Pvu II, mixing the digests together and ligating. 0.5 micrograms pSP64 was digested with 20 units Eco R1 (Promega Biotec, Madison, Wis.), and 12 units Pvu II (Promega Biotec, Madison, Wis.) in a volume of 25 microliters containing 90 mM Tris-HCl, pH 7.5 50 mM NaCl, 10 mM MgCl 2 and 0.1 mg/ml BSA for 1 hour at 37° C. One microgram Bam H1 deleted pAR2192 was digested with 20 units Eco R1 and 18 units Hinc II in a volume of 25 microliters for 1 hour at 37° C. in the same buffer. Following the addition of 0.5 microliters 10% DEPC to each and heating at 65° C. for 10 minutes, the reactions were mixed together and 5 microliters of 10× ligase buffer and 20 units T4 DNA ligase added. Incubation was then allowed to proceed for 16 hours at 22° C. 24 units of Pvu II was then added and the reaction incubated for 30 minutes at 30° C. 0.010 ml was used to transform 0.2 ml of competent E. coli HB101. The desired pGEM-0 construction shown in FIG. 3 was selected by plasmid size screening on agarose gels following "colony cracks" and in vitro transcription with both T7 and SP6 RNA polymerases to demonstrate the presence of both promoters on the plasmid. The pGEM-1 and pGEM-2 plasmids differ from pGEM-0 by having fewer bases between the T7 promoter and the multiple cloning site (MCS).
A 1.37 kb Eco R1-Hind III lambda phage DNA fragment is commercially available in a control plasmid ("RIBOPROBE" control plasmid, Promega Biotec, Wisconsin, Wis.). This fragment was excised from the control plasmid and inserted into the pGEM-0 vector in the following manner. One microgram control plasmid was digested with 20 units Eco R1 and 18 units Hind III in a volume of 50 microliters containing 10 mM Tris-HCl, pH 7.5, 7 mM MgCl 2 , 60 mM NaCl and 0.1 mg/ml BSA for 1 hour at 37° C. One microgram of pGEM-0 was digested with the same enzymes under the same conditions. To each was then added 0.50 microliters 10% DEPC and the reactions heated for 10 minutes at 65° C. The reactions were then cooled to 22° C., mixed together, and following addition of 10 microliters 10× ligase buffer and 20 units T4 DNA ligase, were incubated for 2 hours at 22° C. The reaction was then heated for 10 minutes at 65° C. and 10 microliters were used to transform 0.2 ml competent E. coli HB101 to ampicillin resistance. Transformants were lysed and plasmid size estimated by electrophoresis on an agarose gel and staining with ethidium bromide. A 4.5 kb plasmid was identified in several of the lysates, corresponding to the size expected for the insertion of the 1.37 kb lambda DNA fragment from the control template into the pGEM-0 vector. The correct construction was confirmed by restriction endonuclease mapping and by transcription with both SP6 and T7 RNA polymerases. This cloned vector is referred to as PGEM-0 (lambda 1.37) vector and has the partial restriction and functional map shown in FIG. 9.
PURIFICATION OF RECOMBINANT PLASMIDS
Recombinant plasmids can be purified from large-scale bacterial cultures using standard procedures involving equilibrium density gradient centrifugation in cesium chloride gradients containing ethidium bromide (Maniatis et al., supra 1984) or by procedures not employing ultracentrifugation. These latter procedures involve cell lysis in alkaline sodium dodecyl sulfate, precipitation of the bulk of contaminating RNA with ammonium acetate, selective precipitation of plasmid DNA with polyethylene glycol, chloroform and phenol extraction to remove protein, and concentration of plasmid DNA by ethanol precipitation.
The pGEM type cloning vectors and recombinant plasmids derived from them by cloning procedures must be purified from bacterial extracts to enable them to be suitable for transcription in vitro. Minimally, the DNA preparations must be free from deoxyribonuclease, ribonuclease and nucleoside triphosphatase activities as well as free from inhibitors of RNA polymerase activity. The following procedure yields a highly purified and intact plasmid DNA product that is suitable not only for in vitro transcription reactions but also for other types of manipulations performed on DNA in the molecular biology laboratory. The product is free from the above mentioned contaminants as well as chromosomal DNA and low molecular weight nucleic acid contaminants. Other standard, published methods of purifying plasmid DNA may be substituted for this method provided that the DNA template is checked for its suitability in transcription reactions as discussed above. See, e.g., Maniatis, T., Fritsch, E. F., and Sambrook, J., Molecular Cloning--A Laboratory Manual, 1982, Cold Spring Harbor Laboratory.
Pure bacterial cultures for plasmid DNA purification are grown to saturation, without amplification with chloramphenol, in desired volumes of culture media such as L broth and in the presence of the antibiotic ampicillin at a concentration of 100 ug/ml. Many compatible bacterial hosts such as E. coli HB101 (ATCC #33694), C600, etc. can be used to propagate the plasmid DNA in culture. Cells are harvested by centrifugation and can be used immediately (fresh cells) or bacterial pellets can be stored frozen at -70° C. for at least one year with no apparent changes in yield or purity of the plasmid DNA product. The following steps are carried out:
(1) Thoroughly resuspend cells (fresh or frozen) in 10 volumes of room temperature 25 mM Tris-HCl, 50 mM EDTA (pH 8.0) in an Erlenmeyer flask of suitable size. (For 50 g of cells, a 4 liter flask is appropriate). (2) Add 2 volumes (based on the volume of buffer used in Step 1) of room temperature 0.20M NaOH, 1% SDS (freshly prepared), and mix thoroughly by vigorous swirling. Place on ice for 10 minutes. (3) Add 1.5 volumes (based on the volume of buffer used in Step 1) of ice-cold 5M potassium acetate pH 4.8.Mix thoroughly by vigorous swirling of the flask. Place on ice for 5 minutes. A heavy, flocculent precipitate will be seen. (4) Centrifuge the mixture for 15 minutes at 9000 g (4° C.). Decant the supernatant solution to a fresh flask through a Miracloth filter (Sigma Chemical Company, St. Louis, Mo.). (5) Add 0.6 volumes of 2-proponal (based on the volume of the supernatant solutions in Step 4). Mix well. Let sit at room temperature for 1 hour. (6) Centrifuge as in Step 4. Discard the supernatant solution. (7) Dissolve the precipitate in room temperature 10 mM Tris-HCl, 1 mM EDTA (pH 8.0), which will be herein referred to as TE buffer. (For 50 g of starting material, this can be done in 100 ml of buffer.) (8) Add 1 volume of room temperature 5M ammonium acetate solution (neutral pH, 7) to the solution from Step 7. (A heavy precipitate forms.) Place on ice for 20-30 min. (This mixture can be stored overnight in the refrigerator if time constraints arise). (9) Centrifuge as in Step 4. Save the supernatant solution and discard the pellet. (10) Add 2 volumes of 95% or absolute ethanol (room temperature or ice cold) to the supernatant solution from Step 9.Mix well and place on ice for 20-30 minutes. Centrifuge as in Step 4. Discard the supernatant solution. (11) Dissolve the pellet in a suitable volume of room temperature TE buffer (see Step 7 above). For 50 g of starting material, use minimally 5 ml of buffer. The solution should be as concentrated as possible but not have detectable viscosity. Increase the volume as needed with TE buffer. Add preheated (80° C. for 10 minutes, to destroy any trace DNase activity) RNase A to a final concentration of 10 ug/ml. Incubate at 37° C. for 15 minutes. (12) Add 5M NaCl (room temperature) to a final concentration of 1.5M to the solution. (13) Add 1/4 volume of room temperature 30% PEG 6000 or 8000 containing 1.5M NaCl and mix well. Incubate on ice for 30 minutes. (This solution may also be stored overnight at 0° C. if time constraints are present). (14) Centrifuge as in Step 4 (7500 rpm if using 30 ml Corex centrifuge tubes) at 4° C. Discard the supernatant solution. (15) Dissolve the precipitate by swirling in room temperature TE buffer. See Step 11 above for guidelines to selection of the appropriate volume. This precipitate may require over 30 minutes to dissolve completely. Extract the solution with 1 volume of chloroform/isoamyl alcohol (24:1) (Maniatis et al., id.) in Corex centrifuge tubes. Centrifuge at 7500 rpm for 15 minutes at room temperature. Collect the aqueous phase with a Pasteur pipette. (16) Add 5M NaCl to 0.5M and extract the solution with 1 volume of phenol/chloroform (1:1) saturated with TE buffer and 0.5M NaCl. Centrifuge as in Step 15 and collect the supernatant solution. (17) Precipitate the DNA from the solution by adding 2 volumes of ethanol. After mixing well, place on ice for 15 minutes. Centrifuge as in Step 15 and discard the supernatant solution. (18) Dissolve the precipitate in a small volume of water (See guidelines in Step 7 above for an appropriate volume.) Chill the solution on ice. Adjust to 0.075M NaCl (from a 5M stock solution) and 0.05M sodium acetate, pH 4.0 (from a 2M stock solution). (19) Extract the solution with 0.05M sodium acetate pH 4.0-buffered phenol by vortexing the mixture occasionally over a 5 minute period. Be certain to keep the solution as cold as possible (0° C.). Centrifuge at 7500 g at 4° C. Collect the aqueous (top) phase. (20) Precipitate the DNA with ethanol (see Step 17). Dissolve the pellet in a suitable volume (see guidelines in Step 7 above) of TE buffer containing a 0.1M NaCl. (21) Precipitate the DNA with ethanol again and collect by centrifugation. Discard the supernatant solution and drain the centrifuge tubes on absorbant paper. Dry the precipitates under vacuum and dissolve in a suitable volume of TE buffer.
The concentration and purity of the purified plasmid DNA may be determined by standard analytical spectrophotometric methods. The DNA solution can be stored at 0°-4° C. for short term needs. If desired, the solution can also be stored in aliquots at -70° C. if long-term storage is necessary.
EXAMPLE 4
In Vitro Production of RNA
Production of RNA from the template described in Example 3 may be accomplished by established procedures. Typically, recombinant plasmid DNA to be transcribed is first linearlized by digestion with a restriction endonuclease which cuts at the 3' (promoter distal) terminus of the insert. In this manner, only the insert sequences and not the vector sequences are transcribed. Note that the designation "promoter distal" refers to the promoter for that RNA polymerase (either SP6 or T7) which is to be used for transcription.
pGEM-0 (lambda 1.37) vector was linearized by digesting individually with Eco R1, Hind III and Hinc II and the digests mixed together in equimolar portions to form a control template. Specifically, 2.5 mg units of pGEM-0 (lambda 1.37) vector were digested with 1000 units Eco R1, Hind III, and Hinc II for 5 hours at 37° C. in volumes of 5 ml in the buffers recommended by the manufacturer. Reactions were monitored for completeness by electrophoresis on agarose gels and staining with ethidium bromide. Then to each reaction was added 0.05 ml 10% DEPC (in ethanol) and the reactions vortexed and then heated at 65° C. for 10 minutes. Each reaction was then extracted once with phenol:chloroform (1:1 in 50 mM Tris-HCl pH 7.9, 1 mM EDTA, 15 mM 2-mercaptoethanol, 0.5M NaCl, 0.1% 8-hydroxyquinoline), once with chloroform:isoamyl alcohol (24:1) and then precipitated twice with two volumes each time of 100% ethanol. The final ethanol pellets were vacuum-dried and dissolved in 1 ml 10 mM Tris-HCl pH 7.9, 0.1 mM EDTA. A 100 fold dilution of each digest was then scanned from 340 nm to 220 nm and the DNA concentration determined assuming a 1 mg/ml solution, giving an absorbance of 20 at 260 nm. Digestions were then diluted to 1 mg/ml with 10 mM Tris-HCl pH 7.9, 0.1 mM EDTA, and equal volumes of each of the three were mixed together to form the control template.
The control template was separately transcribed with SP6 and T7 RNA polymerases. Transcription reactions each contained (in a total volume of 20 microliters) an RNA generating medium composed of 40 mM Tris-HCl pH 7.9, 6 mM MgCl 2 , 2 mM spermidine, 10 mM NaCl, 10 mM dithiothreitol, 0.5 mM each of ATP, CTP, GTP and UTP, 2.5 micro Curies of alpha- 32 P-CTP, 1 microgram control template, and 7 units of SP6 or T7 RNA polymerase. The mixtures were incubated at 37° C. for 30 minutes, followed by the addition of 20 microliters of a solution of formamide containing 10% sucrose and tracking dyes. After heating at 65° C. for 5 minutes the reactions were quickly brought to room temperature and 10 microliter samples layered on a 5% polyacrylamide gel containing 7M urea. Following electrophoresis the gel was exposed to X-ray film to visualize labeled transcripts and additionally the transcripts were visualized by staining with ethidium bromide. Transcription with SP6 RNA polymerase generates run-off transcripts 11 bases, 172 bases and 1386 bases long while transcription with T7 RNA polymerase generates transcripts 43 bases, 679 bases and 1418 bases long.
It is understood that the invention is not limited to the particular embodiments specifically disclosed herein as exemplary, but embraces such modified forms thereof as come within the scope of the following claims.
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In vitro production of RNA copies of either strand of any cloned DNA sequence may be obtained utilizing a unique cloning vector having two different opposed promoter sequences which are separated by a multiple cloning site. RNA polymerases which recognize only one of the particular promoter sequences in the vector may be applied to obtain transcription which proceeds from the recognized promoter toward the other promoter. Transcription of a desired strand of any DNA sequence is obtained by cleaving a particular restriction site in the multiple cloning site between the two promoter sequences, cloning the desired DNA sequence into the cleaved site, then cleaving another site between the two promoters which is distal to the promoter from which transcription is desired. The RNA polymerase which recognizes the selected promoter may then be applied to the vector to obtain transcription of the selected DNA sequence in vitro. Double stranded RNA may also be formed utilizing the vector by providing multiple vectors cleaved on either side of the DNA segment and thereafter applying the two RNA polymerases to cause transcription of both strands of the selected DNA segment. Specific cloning vectors are novel plasmids designated pGEM-1 and pGEM-2 which are characterized by having the SP6 and T7 late phage promoters facing each other separated by a multiple cloning site.
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of wireless communications. In particular, the invention relates to the user interaction with a mobile terminal when switching between communication services.
[0003] 2. Discussion of the Related Art
[0004] In the development of wireless communications, there is a trend towards supporting various communication services in addition to a conventional voice call. Some communications services, such as short message service (SMS), multimedia message service (MMS), e-mail, network operator messages, push services, etc., are not continuous services and can be provided in secondary connections which are simultaneous with the primary connection and which do not require disconnection of the primary connection. Depending on the particular air interface, multiple simultaneous connections may be possible to/from a wireless communication terminal. For example, GSM wireless communication networks can provide a primary circuit switched (CS) connection for a voice/data call and a simultaneous secondary connection which can send and receive SMS messages during the call to a mobile terminal with a headset.
[0005] Some communications services, such as voice, instant messaging (such as chat), and video messaging, can only be provided through primary connections because the user interaction in the service is expected to be substantially continuous without any lengthy interruption. GSM and other conventional wireless communication networks can only provide one primary connection at a time to a mobile terminal. Thus, the primary connection for one communication service must be ended before the primary connection for another communication service is initiated. Furthermore, a communication service, such as a chat session, may be automatically terminated by an incoming phone call and cannot be resumed after the incoming phone call has ended.
[0006] A Wideband Code Division Multiplex Access (WCDMA) air interface has been proposed in the 3rd Generation Partnership Project (www.3gpp.org) which can provide several simultaneous primary connections to a single wireless communication terminal. However, even though multiple primary connections may be available over a WCDMA air interface, the user experience at the terminal when switching between primary connections may not be fluent or otherwise satisfactory, especially when a user wishes to continue communicating with the same person but through a different type of communication service. A person may desire to switch from a voice service to a chat service because they no longer wish to speak out loud. A person may desire to switch from a voice service to a video service so that they can see something, such a person's face, or to switch from a video service to a voice service so that something will not be seen.
[0007] Even if multiple primary connections are available in a wireless communication network, the user interaction necessary to switch between communication services consists of performing two separate methods, the first method consisting of those steps necessary to terminate the first communication service and the second method consisting of those steps necessary to activate the second communication service. Although the network allows different types of communication services, there is still a disadvantage that the user interaction is cumbersome at least because different methods and several steps are necessary to switch between the communication services. The lack of immediacy in switching is a concern because the user may believe that he has lost contact with the other person if there is a long period of time without contact while the switching occurs.
[0008] There are now numerous communication services which carry various forms and combinations of multimedia content such as video, web content, graphics and text. As used in this application, the term “multimedia” refers to any content having a visual element. The mobile terminals of wireless communication networks, particularly phones of cellular networks, are now capable of transporting data, including multimedia data in various communication services. Many types of mobile terminals are being used, such as cellular phones, cordless telephones, personal digital assistants (PDAs), palm-held computers and laptop computers. The strong push in current wireless technology development is to use mobile terminals for varied applications and to allow users of such devices to seamlessly integrate events and needs in their lives while maintaining adequate communications power to receive and transmit all of the data and information which has an impact on them.
[0009] An advanced mobile terminal supported by so-called third generation (3G) and fourth generation (4G) networks and using the latest innovations in computers, software, displays and other technologies may access and receive a variety of many different communication services. Unfortunately, the manner and duration (apparent to the user) of the procedure necessary for switching among the communication services may vary widely and unpredictably. These communication services may be provided by different information sources in other networks and may be based on and built upon a variety of data transfer techniques. This introduces more delay and uncertainty into mobile terminal switching among different communication services.
[0010] For at least these reasons, present methods of switching between different communication services at a mobile terminal have disadvantages. Accordingly, there is a need for effective solutions that allow for easy and substantially immediate mobile terminal switching between different communication services without it appearing to the user that the connection is broken at any time.
BRIEF SUMMARY OF THE PREFERRED EMBODIMENTS
[0011] To overcome limitations in the prior art described above, and to overcome other limitations that will be apparent upon reading and understanding the present specification, it is therefore an object of the following described preferred and exemplary embodiments to overcome the above mentioned disadvantages. In particular, an object of the preferred and exemplary embodiments is to provide a solution which facilitates mobile terminal switching among various communication services which appears, to the users of the mobile terminals, to be substantially immediate and the end-to-end connection unbroken.
[0012] In the preferred and exemplary embodiments, a method allows a user of a mobile terminal to switch from a communication service currently active between the mobile terminal and another mobile terminal to a different communication service in such a manner that the end to end connection between appears unbroken to the user. The user initiates the switch by inputting an appropriate command at the mobile terminal. The mobile terminal then transfers a request to the other mobile terminal. The request invokes a user interface on the other mobile terminal and prompts the user of the other mobile terminal to indicate whether or not they agree to switch from the currently active communication service to the other communication service. After receiving the user's response to the prompt, the other mobile terminal sends back a reply indicating the user's response. Signaling to perform the switch is initiated in response to the reply. The active communication service is terminated at the first and second mobile terminal at substantially the same time that the second communication service is initiated at the first and second mobile terminal.
[0013] A particular aspect of the preferred and exemplary embodiments involves a software application on the mobile terminal which carries out a method of switching between communication services in which the new communication service is substantially immediately presented to the users on the mobile terminals when the previous communication service is terminated without particular requests needing to be made by the user. Preferably, the user can make a simple selection on a displayed user interface to switch from a currently active communication service to one of a number of available communication services.
[0014] This and other features of the preferred and exemplary embodiments of the invention will become apparent and better understood from the following detailed description when considered in conjunction with the accompanying drawings. It is to be understood, however, that the detailed description and drawings are designed solely for the purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the drawings, wherein like reference numerals identify similar elements throughout the several views:
[0016] [0016]FIG. 1 is a block diagram of a network environment according to a 3GPP all IP reference model in which the preferred embodiments of the invention may be practiced.
[0017] [0017]FIG. 2 is an illustration of a possible user interface which may be deployed on the display of a mobile terminal during a voice call.
[0018] [0018]FIG. 3 is an illustration of a possible user interface which may be deployed on the display of a mobile phone in response to a request from another mobile terminal to switch from a voice call to a video call according to an embodiment of the present invention.
[0019] [0019]FIG. 4 is an illustration of a possible user interface which may be deployed on the display of the mobile terminal after the voice call has been switched to a video call.
[0020] [0020]FIG. 5 is a flowchart illustrating a method of switching the communication services between mobile terminals according to a preferred embodiment of the invention.
[0021] [0021]FIG. 6 is an illustration of the composition by a user of a request for a communication service at a first mobile terminal making the request according to a preferred embodiment of the invention.
[0022] [0022]FIG. 7 is an illustration of the request composed in FIG. 6 as it appears on the display of the first mobile terminal.
[0023] [0023]FIG. 8 is an illustration of the request composed in FIG. 6 as it appears on the display of a second mobile terminal receiving the request.
[0024] [0024]FIG. 9 is an illustration of the request for a second communication service made on the first mobile terminal during the communication service in FIG. 6.
[0025] [0025]FIG. 10 is an illustration of the display on the second mobile terminal at the time the request for the second communication service is made.
[0026] [0026]FIG. 11 is an illustration of the display on the first mobile terminal during the second communication service.
[0027] [0027]FIG. 12 is an illustration of the display on the second mobile terminal during the second communication service.
[0028] [0028]FIG. 13 is an illustration of the action taken at the first mobile terminal to end the second communication service and return to the first communication service.
[0029] [0029]FIG. 14 illustrates a method of switching the communication services between two mobile terminals from a video call service to an audio call service between two mobile terminals.
[0030] [0030]FIG. 15 is illustrating a method of switching the communication services between two mobile terminals from an audio call service to a video call service.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] In the following description of the various preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration various preferred embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.
[0032] Attention now is directed to FIG. 1, which shows a block diagram of a preferred and exemplary wireless communication network according to a 3GPP all IP reference model and in which a method of switching between communication services at mobile terminals may be carried out according to a preferred embodiment of the present invention. It will be appreciated that the present invention is applicable to a variety of different types of communications services, but is most advantageously applied to multimedia communication services requiring a primary connection on a wireless communication network.
[0033] According to FIG. 1, an Internet Protocol (IP) terminal device or terminal equipment 1 is connected to a third generation (3G) mobile terminal 2 which provides a bi-directional radio connection to an Universal Terrestrial Radio Access Network (UTRAN) 3 of the Universal Mobile Terrestrial Service, (UMTS) System. The mobile terminal is preferably capable of receiving any one or more of various communication services and providing corresponding received data to the user. The UTRAN 3 comprises at least one Radio Network Controller (RNC, not shown) for providing a switching function to e.g. a General Packet Radio Service (GPRS) network comprising a Serving GPRS Support Node (SGSN) 5 having a switching and mobility mangement function in the GPRS core network of the Universal Mobile Terrestrial Service (UMTS) system. Furthermore, the SGSN 5 is connected to a Gateway GPRS Support Node (GGSN) 6 which provides an access function to a multimedia IP-based network 12 , such as the Internet.
[0034] Additionally, the RNC of the UTRAN 3 may establish a connection to a circuit switched (CS) terminal equipment 11 via a fixed network or PSTN/ISDN network 10 and a Media Gateway (MGW) 4 arranged for adapting the PS multimedia connection of the UMTS network (including the SGSN 5 and the GGSN 6 ) to the CS connection of the PSTN/ISDN 10 . Similarly, the packet switched (PS) multimedia connection can be adapted to a CS connection of a CS mobile network such as the UMTS release 1999 CS domain or a GSM network. In particular, the MGW 4 may allow a PS H.323 or a Session Initiation Protocol, (SIP) system defined by 3GPP for use in the IP multimedia (IM) Core Network (CN) to interoperate with PSTN/ISDN terminals such as the CS terminal equipment 22 which may be a H.324 (H.324/I) compliant terminal. The gateway functionality of the MGW 4 is addressed e.g. in the ITU-T recommendation H.246 for the case of an interworking of H-series multimedia terminals with H-series multimedia terminals and voice/voice-band terminals on PSTN and ISDN.
[0035] The MGW 4 is connected to a Media Gateway Control Function (MGCF) 9 which is connected via a Transmission Signaling Gateway (T-SGW, not shown) to the PSTN/ISDN 10 . The MGCF 9 may be connected via a Call State Control Function (CSCF) 7 to a Home Subscriber Server (HSS) 8 comprising a subscriber multimedia profile database 80 .
[0036] The preferred embodiments of the invention are concerned with improving the switching between a variety of communication services. For example, users on a call may want to make silent comments in a chat session or drawings that are forwarded for display on the mobile terminal 2 of the other user. To accomplish this, a software application/user interface is preferably stored in mobile terminal 2 . Having the application resident on the mobile terminal 2 increases the speed of switching between the communication services, and allows the user interface to be well designed with suitable graphical elements for the characteristics of mobile terminal 2 .
[0037] [0037]FIG. 2 illustrates an exemplary display 200 of a mobile terminal 2 of a user (Eric Williams) having an active voice call to another person (Susan Adkins). The display 200 preferably includes a window 201 relating to the voice call. The window may contain, for example, the name of the other person, a preexisting picture of the other person (the picture is not a live picture), and an indication of the current duration of the call. The displayed text may be “Active Susan Adkins” as shown in FIG. 1, or “Audio call to Susan Atkins” or something similar. As will be explained more below, display 200 preferably includes tabs 202 - 205 corresponding to other available communication services (for example, a video call, a chat session, a whiteboard application and a shared view application as shown in FIG. 2). The other tabs 202 - 205 have closed connections and only the voice call tab with window 201 has an active connection. Alternatively, there may be a drop-down menu or some other method provided to allow easy selection and requesting of other available communication services. The variety of available communication services may vary greatly from one network environment to another. For example, a 2.5 G network may have only a chat service and whiteboard application service while a 3G network may also have a video call service and a shared view application service.
[0038] A example of the user interfaces on the mobile terminals in a preferred embodiment of the method of switching between communications services is shown in FIGS. 3 and 4. In the example, Eric having a voice call communication service with Susan wants to switch to a video call communication service with Susan. Eric enters a command on his mobile terminal 2 to send a request to Susan's terminal indicating his desire to switch from a voice call to a video call. In the example of a mobile terminal having a software application/user interface to provide display 200 as shown In FIG. 2, Eric makes the request by simply selecting the tab corresponding to the desired service.
[0039] Various information may be contained in the request message transmitted by the mobile terminal 2 , such as details of the mobile terminal related to carrying out the suggested service (video format type, etc). The request may be logged in the receiving mobile terminal. It is a design choice when to remove request entries; for example a request can be removed when that session is completed, plus some predetermined time.
[0040] [0040]FIG. 3 illustrates a simple example of a display 300 at Susan's terminal upon receipt of the request to switch to another communication service. The display 300 includes a window 301 which may contain, for example, the name and a preexisting picture of Eric. The window 301 preferably automatically includes a prompt such as “Change to video call” without the user of the receiving terminal having to take any action. Also, although the user interface is shown in FIG. 3 as being rather simple, the user interface may take a variety of forms and be in any number and combination of multimedia formats (video, audio, graphics, animation, etc.). The content may, for example, announce the identity or source of the other party or service provider with video programming, either with text, audio, video or graphics. There are several general methods in which either Eric or Susan, by accessing the multimedia subscriber profile 80 for Susan's terminal, is able to exert some control over the user interface and prompt on Susan's terminal, including window 301 . The prompt typically includes at least a display shown to the user on the display of the mobile terminal, but it may also consist of tactile notification, such as vibration of the mobile terminal, or a distinctive ringing tone.
[0041] It is particularly preferable that the user interface, including prompt, be available on Susan's terminal substantially immediately after the request is made at Eric's terminal. Susan can then respond to the prompt by simply pressing YES button 302 - 1 or NO button 302 - 2 or taking any other action appropriate for the user interface utilized on her terminal for the request to indicate whether or not she agrees to switch the communication service.
[0042] [0042]FIG. 4 shows an example of the resulting display 400 on Eric's mobile terminal immediately after the switch from the voice call communication service to the video call communication service has been completed. Unlike the preexisting pictures of the users in FIGS. 2 and 3, the pictures in FIG. 4 are “live” pictures according to the specification of the video call communication service. There may also be other information displayed or otherwise provided during the video call, such as, for example, the duration of the video call and/or the cumulative duration of the video call and the previous voice call. As explained below, at any time, the users may again switch to another communication service in the same manner as described above with respect to FIGS. 2 - 4 .
[0043] The method of switching communication service may utilize software application in a network element (e.g., MGCF a) to adapt the existing resources by releasing part of the used connection resources. Alternatively, the MGCF may reserve new resources and release earlier reserved resources. Another alternative is that the MGCF a reserves an additional portion of the required network connection resources in respect to an earlier used network connection in such a way that newly reserved and earlier provisional network connection resources are used together to satisfy the connection resource needs to support the newly switched service requirements.
[0044] The software application carrying out the above method of switching communication services may itself be able to perform one or more of the communication services or there may be one or more other software applications on mobile terminal 2 to perform one or more of the communication services. For example, there may be one software application to perform the video call service, another software application to perform the chat session, etc. Alternatively, a software application may perform more than one communication service. In any event, such software applications may interact with the software application carrying out the above method of switching communication services through application programming interfaces (APIs) or similar methods. Alternatively, each of such software applications may be revised or developed to include user interface commands for each one of the communication service change request. The mobile terminal 2 may have any one of a variety of different software application managers for managing the software applications resident on the mobile terminal 2 or downloaded to the mobile terminal 2 . Such a software manager may be terminal and implementation dependent.
[0045] Once stored in the mobile terminal 2 , the software application for carrying out the method of switching communications services can be launched at any time as long as a primary connection is active. The launch can be user activated or activated automatically whenever a primary connection is opened. However, it is preferred that some elements of user interface do not have to always be present. For example, as shown in FIGS. 2 and 4, a clock or timer in the upper right of the display, the function buttons on the left side (for printing, navigation, etc.) and the right side of the display (volume control, adding member, ending call, etc.) may be constant. The various windows 201 , 301 , and 401 are present and absent according to the state of communications. Furthermore, the tabs 202 - 205 , the Yes button 302 - 1 , the NO button 302 - 2 , and the function buttons for diverting a call are also present according to the state of communications. As indicated in FIG. 3, there may be a background, either fixed or at the user's preference, on the display when the elements are not present.
[0046] It is preferred that once the software application performing the method for switching communication services is launched, it remains in the background until the method is invoked, for example, a change in communication service is requested. Preferably, neither user has to provide complicated inputs. It is a particular feature of the preferred embodiments that the software application utilizes previously obtained information and requires only one single action by the appropriate user at the various steps in the method. This can be done as shown in FIGS. 2 - 4 , for example, by providing a plurality of tabs 202 - 205 each corresponding to an available communication service which may be requested and YES and NO buttons 302 - 1 and 302 - 2 for the reply to the request. In order to switch to a particular service according to a preferred embodiment of the invention, the user merely selects one of the tabs 202 - 205 , and in order to reply, the user selects one of the YES and NO buttons 302 - 1 and 302 - 2 . However, the implementation of FIGS. 2 - 4 is merely exemplary and others may be used instead.
[0047] [0047]FIG. 5 is a flowchart illustrating the general method of the preferred embodiments without specific reference to the implementation in FIGS. 2 - 4 . The first step in the method is the receipt of a user command at a first terminal to switch communication services (step 501 ). The second step is the transfer of the request to switch communication services from the first terminal to the second terminal (step 502 ). When the request is received at the second terminal, a prompt is provided to the user of the second terminal to obtain an indication from the user indicating whether or not the user agrees to switch communication services (step 503 ). If the user reply is NO (step 504 ), then the method reverts back to the initial state. If the user reply is YES (step 504 ), then the signaling is initiated to set up the change in communication services (step 505 ). The preferred embodiments for the signaling are addressed further below, but the signaling in step 505 is such that it enables the communication resources of the services to be modified in such a manner that the service switching appears to be substantially immediate on the displays of the mobile terminals (step 506 ).
[0048] Of course, FIG. 5 is a simple flowchart illustrating a single change of communication services according to a preferred embodiment of the invention. However, the communication service may be changed several times during a single end to end mobile terminal session. FIGS. 6 - 13 illustrate an example of a session in which the communication service is changed several times. service or vise versa between two mobile terminals in the communication network system.
[0049] [0049]FIG. 6 illustrates the composition of an original multimedia call at Eric's mobile terminal 2 . As indicated, the mobile terminal 2 includes a menu 610 that supports a variety of options for implementing calls. The options include the option to make a call accompanied by a message. Once this option is selected, a composition screen 601 appears which includes a message area 602 for adding a message to accompany the text. The message may be a simple text: “Next weeks meeting. Important!”.or it may be a selected picture or other content. Preferably, the content has a size small enough to allow it to be included in the payload of a Session Initiation Protocol (SIP) signaling message as an IP multimedia message supported in the core network. Once the message is composed, the request can be sent by selecting the call button 603 .
[0050] [0050]FIG. 7 shows the display, including the composed message, in window 701 at Eric's mobile terminal at the time that the call is made. FIG. 8 shows the display of Susan's terminal upon receipt of the request. The display includes the call request, including the individually composed message as well as pre-determined picture and name, in window 801 and answer button 802 for answering the call (other buttons available for diverting the call, silencing the call, or rejecting the call also available). After Susan's selection of answer button 802 , the display of Eric's terminal may be as set forth in FIG. 9, including window 901 , and the display of Susan's terminal may be as set forth in FIG. 10, including window 1001 .
[0051] As indicated by element 902 in FIG. 9, Eric may request a whiteboard service during the call by selecting tab 204 . After making a drawing, such as the map shown in FIG. 11, Eric may request a share view (step 1102 ) communication service. Assuming that the request for a change to the share view communication service is accepted by Susan, the display on her terminal may become as shown in FIG. 12, including the map shown in window 1201 . As indicated in FIG. 13, Eric may at the appropriate time activate the end share button 1302 to discontinue the shared view and return to the original call.
[0052] Some example implementations of steps 501 - 504 of FIG. 5 are provided above with respect to FIGS. 2 - 4 and to FIGS. 6 - 13 . As indicated therein, the software application carrying out the method of switching communication services preferably sends the request and reply upon a simple input by the user and without any further actions necessary by the user. Any one of several available signaling methods (such as GPRS, SMS, etc.) may be employed in the network and in the terminals to transfer the initial request to change communication services from the first terminal to the second terminal and to transfer the reply from the second terminal to the first terminal if the invention is implemented software in the mobile terminals only and no extra support is required in the network (e.g., MGCF a).
[0053] As indicated at step 505 of FIG. 5, the method includes signaling to set up a change in communication resources of the services applying the information received originally from user command therefore at step 501 and possibly, information available in the network (e.g., MGCF a or any other entity) and an affirmative reply at step 504 . As indicated at step 506 of FIG. 5, this signaling enables the switching of communication services on the displays of the terminals to appear to be substantially immediate. Exemplary, but non-limiting, implementations of steps 505 and 506 will now be discussed.
[0054] In a preferred embodiment, the request to change communication services is combined with a message or other information specific to the request and is synchronized with the request to be presented at substantially the same time that the prompt is provided to the receiving user. The presentation of this message or other information in a synchronized manner gives an impression of continuity to the receiving user.
[0055] The communication services may be established generally as described in published patent application W002052825, where there would be a circuit switched connection from the caller's terminal to the switch and the call leg from the switch to called party is a packet switched connection and the invention is implemented in the software of a mobile terminal. However, when a communication service is switched according to steps 501 - 504 , the software application at Eric's terminal provides a SETUP message including instructions to, for example, MGCF 9 in FIG. 1. In MGCF 9 , a SIP INVITE message is sent to Susan's mobile terminal. Feedback is signaled by sending a session progress message from Susan's mobile terminal to MGCF 9 to Eric's mobile terminal. Then, the physical call connection resources for the first communication service that are not required any more are released (disconnected) and the resources required for the second communication service are reserved. Next, alerting is signaled to Eric's mobile terminal and to Susan's mobile terminal. Preferably, the alert is not a ringing tone to be played, but instead some content (such as text or picture) drawn on the display of the mobile terminal. The presentation of this content is preferably synchronized with the availability of the second communication service in the manner described in pending U.S. patent application Ser. No. 10/026,912 filed on Dec. 27, 2001, and assigned to the same assignee (Nokia Corporation) as this application, the disclosure of which is hereby incorporated by reference into this application in its entirety. Preferably, the resources for the first communication service are disconnected only after a second CONNECT message is sent to the mobile terminals. Otherwise, during a very busy traffic hour, the connection from MGCF 9 to the mobile terminals may drop and the call connection may be released.
[0056] FIGS. 14 - 15 illustrate a method of switching the communication services from the video call service to audio call service or vise versa between two mobile terminals in the communication network system.
[0057] The method of switching communication services may require new software application in a network (e.g., MGCF a) to adapt the existing resources by releasing part of the used connection resources. Alternatively, (MGCF a) may reserve new resources and release earlier reserved resources. This is illustrated in detail in FIG. 14. The method starts with set up message sending (step 1401 ) from a first mobile terminal as result of its user wanting to establish a video call including audio a second mobile terminal. The MGCF 9 receives the originally sent set up message and it may retrieve the media profile of the calling mobile terminal (step 1402 ) that is applied for configuring the video call connection and is mapped from the Logical Link Control (LLC) Protocol from the Bearer Control Protocol H.324 to Session Description Protocol (SDP). The SDP is a session connection that may comprise one or more Radio Transfer Protocol (RTP) sessions and configured according to service requiring settings and consisting as many RTP sessions as required to satisfy the connection resource requirements. The MGCF a sends a SIP INVITE message to the called terminal (step 1403 ). The Session to be established, the second mobile terminal is signaled backwards to MGCF (step 1404 ) in a SESSION PROGRESS message and the MGCF a signals a CALL PROCEEDING message to the first mobile terminal (step 1405 ). When the first terminal has received the backward signaling from the second mobile terminal, it understands that the IP bearer is established from end to end between the first and second mobile terminals. The (first) (calling) mobile terminal is marked to include a user interface. UI 1 A receives an alerting signaling (such as an audio indication) from the network (step 1407 ) that is originally signaled from the second mobile terminal (marked to include user interface, UI 1 B) (step 1406 ). When the second mobile terminal (e.g., Eric) answers the initiated video call of the first mobile terminal owned by Susan, an OK SIP message is sent at step 1408 to MGCF and the network element MGCF sends CONNECT message of LLC to first mobile terminal (Susan). Now finally local channels from the first mobile terminal of Susan is established via MGCF 9 (step 1410 ) and MGCF 9 acknowledges the multimedia connection to be created to the second mobile terminal (the Eric's phone) by sending ACK SIP message (step 1411 ).
[0058] Now assume after a moment Susan wants to change from video call to audio for instance battery, because of power getting low or money being spent or for any other reason. She selects, from her user interface, a request to switch to an audio alternative. A setup message is sent from the first mobile terminal (step 1412 ), including audio e.g. G.723 request to the MGCF. Now the audio profile may be retrieved from Home Subscriber Server, (HSS) (step 1413 ) and used in configuring the mapping the Logical Link Control audio connection setup request to Service Description Protocol of an audio connection. The MGCF a sends a SIP INVITE message of audio IP bearer request (step 1414 ) to the second mobile terminal (Eric). The session going to be established to the second (called) mobile terminal is signaled backwards first to the network element MGCF (step 1415 ) in SESSION PROGRESS message and MGCF 9 signals CALL PROCEEDINGS message to the first mobile terminal (step 1416 ). When the first terminal has received the backward signaling from the second mobile terminal, it means that the audio IP bearer is established from end to end between mobile terminals first and second mobile terminals. The the first (calling) mobile terminal marked to include user interface, UI 1 A receives alerting signaling audio indication from the network (step 1418 ) that is originally signaled from the second mobile terminal (marked to include user interface, UI 1 B) (step 1417 ). When the called mobile terminal user (e.g., Eric) switches from the video call to the audio an OK SIP message is sent (step 1419 ) to MGCF 9 and the network element MGCF 9 sends CONNECT message of LLC to first mobile terminal (Susan) (step 1420 ). Now finally local channels from the first mobile terminal of Susan is established as H.245 type audio connection via network element MGCF 9 (step 1422 ) and MGCF 9 acknowledges an audio to be created to the second mobile terminal (the Eric's phone) by sending ACK SIP message (step 1424 ). The second mobile terminal may disconnect video connection (including the audio connection) immediately after having sent the SIP OK message of the audio connection (step 1419 ). Alternatively, an old audio part of the video connection is maintained concerning the RTP audio connections and only the moving picture part of the multimedia connection is disconnected (step 1421 ). The old video connection (including the audio as well) H.324 is disconnected (step 1423 ) between MGCF and first mobile terminal after the audio connection H.245 is established (step 1422 ). Alternatively, only the moving picture part of the bearer connection H.324 is disconnected in such a way that radio transfer protocol (RTP) connection used for audio is kept on and used for H.245. audio.
[0059] Another method of the invention is illustrated in FIG. 15. The MGCF 9 reserves new resources and release earlier reserved resources or the MGCF 9 reserves additional portion of the required network connection resources in respect to earlier used network connection in such a way that newly reserved and earlier provisional network connection resources are used together to satisfy the connection resource needs to support the newly switched service requirements. The method starts with set up message sending (step 1501 ) from first mobile terminal as result of its user wanting to establish an audio call to, the second mobile terminal. The MGCF 9 receives the originally sent set up message. The MGCF 9 may retrieve the medial profile of calling mobile terminal (step 1502 ) that is applied for configuring an audio call connection to be mapped from the Logical Link Control Protocol (LLC) and the Bearer Control Protocol H.245 to Session Description Protocol (SDP). The SDP is a session connection that may comprise one or more Radio Transfer Protocol (RTP) sessions and which are configured according to service required settings. The SDP connection consists as many RTP sessions as required to satisfy the connection resource requirements. The MSCF 9 sends an SIP INVITE message to be sent to the called terminal (step 1503 ). The Session going to be established to the (called) second mobile terminal is signaled backwards first to the network element MGCF (step 1504 ) in SESSION PROGRESS message and the MGCF signals CALL PROCEEDING message to the first mobile terminal (step 1505 ). When the first terminal has received the backward signaling from the second mobile terminal, it is understood that the IP bearer is established from end to end between mobile terminals first and second mobile terminals. The (calling) mobile terminal marked to include user interface, UI 1 C receives alerting signaling audio indication form the network (step 1507 ) that is originally signaled from the second mobile terminal (marked to include user interface UI 1 D) (step 1506 ). When the called mobile terminal user (e.g. Eric) answers the initiated audio call of the first mobile terminal owned by Susan, an OK SIP message is sent (step 1508 ) to MGCF 9 and the MGCF 9 sends CONNECT message of LLC to first mobile terminal (Susan). Now finally local channels from the first mobile terminal of Susan is established via MGCF 9 (step 1510 ) and MGCF 9 acknowledges the multimedia connection to be created to the second mobile terminal (the Eric's phone) by sending ACK SIP message (step 1511 ). Now assume that after a moment, Susan wants to change from audio call to video. She selects, from her user interface, a connection request to video alternative. A setup message is sent from the first mobile terminal including video (e.g. H.324) request to the MGCF 9 . Now the audio profile may be retrieved from Home Subscriber Server (HSS) (step 1513 ) and it is used in configuring the mapping the Logical Link Control audio connection setup request to Description Protocol of an audio connection. The MGCF sends a SIP INVITE message of audio IP bearer request (step 1514 ) to the second mobile terminal (of Eric's). The Session going to be established to the second (called) mobile terminal is signaled backwards first to MGCF 9 at step 1515 in SESSION PROGRESS message and the MGCF 9 signals CALL PROCEEDING message to the first mobile terminal (step 1516 ). When the first terminals has received the backward signaling from the second mobile terminals, it means that the video IP bearer is established from end to end between the mobile terminals first and second mobile terminals. The first (calling) mobile terminal marked to include user interface UI 2 C receives alerting signaling video indication from the network (step 1518 ) that is originally signaled from the second mobile terminal (marked to include user interface UI 2 D) (step 1517 ). When the called mobile terminal user (e.g. Eric) switches from the audio call to the video, an OK SIP message is sent (step 1519 ) to MGCF 9 and the network element MGCF 9 sends CONNECT message of LLC to first mobile terminal (Susan) (step 1520 ). Now finally local channels from the first mobile terminal of Susan is established as H.324 type video connection via network element MGCF 9 (step 1522 ) and MGCF 9 acknowledges a video connection to be created to the second mobile terminal (Eric's phone) by sending ACK SIP message (step 1524 ). The second mobile terminal may disconnect the audio connection immediately after having sent the SIP OK message of the video connection (step 1519 ). Alternatively the audio connection is kept on concerning the RTP connections and only the moving picture part of the multimedia connection is connected (step 1520 ). However if the established video connection H.324 is connected with totally new radio transfer resources, then the old audio connection H.245 is disconnected (step 1523 ) between MGCF 9 and the first mobile terminal after the video connection H.324 is established
[0060] While the invention has been described with reference to example embodiments, the description is illustrative and is not to be construed as limiting the invention. In particular, the various references to mobile terminals and Java refer merely to the terminology used in association with the preferred embodiments and is not meant to imply that the method according to the example embodiments must only be used with certain types of mobile terminals or implementing technologies.
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A method allows a user of a mobile terminal to switch from a communication service currently active between that mobile terminal and another mobile terminal to a different communication service in such a manner that the end to end connection between terminals appears unbroken to the user. The user initiates the switch by inputting an appropriate command at the mobile terminal. The mobile terminal then transfers a request to the other mobile terminal. The request invokes a user interface on the other mobile terminal and prompts the user of the other mobile terminal to indicate whether or not they agree to switch from the currently active communication service to the other communication service. After receiving the user's response to the prompt, the other mobile terminal sends back a reply indicating the user's response. Signaling to perform the switch is initiated in response to the reply. The active communication service is terminated at the first and second mobile terminal at substantially the same time that the second communication service is initiated at the first and second mobile terminal.
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CROSS REFERENCE TO RELATED APPLICATION
This is a Rule 60 Continuation of U.S. Ser. No. 447,509 filed May 23, 1995,now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to polyol ester-based turbo oils which exhibit rust inhibition by use of additives. More particularly it relates to turbo oils comprising esters of pentaerythritol with fatty acids as base stock, and containing a combination of additives to impart rust resistance.
2. Description of the Prior Art
Corrosion and rust are conditions which are extremely harmful to sophisticated, close tolerance gas turbine engines. They are especially harmful, over time, to engines operated under severe stress, atmosphere, duration and maneuver conditions. Exposure to the elements, chemicals, wide temperature swings, water and corrosive moisture environments put a strain on the engines which impact on their reliability, shorten the intervals between servicing and increase the likelihood of major overhaul and key parts replacement.
The principle weapon in fighting corrosion and rust in gas turbine engines is lubricating oil as sophisticated as the engines themselves. Turbo oils of complex formulation based on synthetic base stocks have been developed to defend the engines against wear, corrosion, rust and the other harmful effects of oxidizing atmosphere, severe temperature and a generally hostile environment.
U.S. Pat. No. 4,320,018 is directed to a synthetic turbo oil comprising a major portion of an aliphatic ester base containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxyanthraquinone, a hydrocarbylphosphate ester and a dialkyldisulfide compound. This oil is described as useful over a wide range of temperatures and as exhibiting good thermal and oxidative stability.
WO 94/10270 is directed to a corrosion inhibiting lubricant composition comprising a synthetic ester base stock, at least one aromatic amine antioxidant, a neutral organic phosphate, saturated or unsaturated dicarboxylic acids, a straight or branched chain saturated or unsaturated monocarboxylic acid which is optionally sulfurized or an ester of such an acid, and a triazole compound. This formulation is described as meeting the latest revision of Military Specification MIL-L-23699D of the United States Navy designated XAS-L-5724 (MIL-L-23699E) with respect to anti-corrosion properties.
Other references which teach synthetic ester based turbine oils containing various combinations of additives are U.S. Pat. No. 4,226,732, U.S. Pat. No. 4,216,100, U.S. Pat. No. 4,189,388, U.S. Pat. No. 4,188,298, U.S. Pat. No. 4,179,386, U.S. Pat. No. 4,157,971, U.S. Pat. No. 4,157,970, U.S. Pat. No. 4,141,845, U.S. Pat. No. 4,141,844, U.S. Pat. No. 4,124,514, U.S. Pat. No. 4,124,513, U.S. Pat. No. 4,119,551, U.S. Pat. No. 4,096,078, U.S. Pat. No. 4,064,059, U.S. Pat. No. 4,248,721, U.S. Pat. No. 4,049,563. An improved synthetic ester base stock per se is described and claimed in U.S. Pat. No. 4,826,633.
DESCRIPTION OF THE FIGURES
FIG. 1 presents a comparison of the MIL-L-23699E Ball Corrosion Test Performance of turbo oils containing amine phosphate and diacid alone and in combination at three different total additive concentration ranges. In all instances the combination exceeded each component's individual performance as well as what would have been expected from combining each component's individual contribution.
SUMMARY OF THE INVENTION
The present invention resides in a turbo oil composition exhibiting enhanced resistance to rust and corrosion and to a method for achieving that result in turbo oils.
The gas turbine lubricating oil of the present invention comprises a major proportion of a synthetic polyol ester based base stock and a minor proportion of an antirust/corrosion additive comprising an amine phosphate and a diacid. Other, conventional additives such as extreme pressure, pour point reduction, oxidative stability, anti-foaming, improved viscosity index performance, anti-wear, hydrolytic stability agents, corrosion inhibitor additives and others may also be employed.
Lubricating oil additives are described generally in "Lubricants and Related Products" by Dieter Klamann, Verlag Chemie, Deerfield Beach, Fla., 1984.
Such improved antirust/anticorrosion performance in turbo lube oils is achieved by adding to the synthetic polyol ester based lubricating oil an additive package containing a mixture of amine phosphate and dicarboxylic acid.
The amine phosphate is used in an amount in the range 25 to 500 ppm preferably 50 to 250 ppm, most preferably 75 to 150 ppm, while the diacid is used in an amount in the range 25 to 1000 ppm, preferably 50 to 400 ppm, most preferably 75 to 200 ppm, the combination of amine phosphate and diacid being used in a total amount in the range 50 to 1500 ppm, preferably 100 to 400 ppm, most preferably 100 to 300 ppm.
The use of amine phosphate-dicarboxylic acid additive mixture produced a turbo oil exhibiting markedly superior rust resistance and anticorrosion properties performance as compared to the performances exhibited if each additive component is employed alone, and compared to the performance results expected had one simply combined each component's individual contribution.
DETAILED DESCRIPTION
A turbo lube having unexpectedly superior rust resistance and anticorrosion performance properties is disclosed, said oil comprising a major portion of a synthetic polyol ester base oil and a minor portion of an antirust--anticorrosion additive package consisting essentially of a mixture of monobasic amine phosphate and dicarboxylic acid.
The synthetic polyol ester base oil is formed by the esterification of aliphatic polyols with carboxylic acids. The aliphatic polyol reactant contains from 4 to 15 carbon atoms and has from 2 to 8 esterifiable hydroxyl groups. Examples of polyols are trimethylolpropane, pentaerythritol, dipentaerythritol, neopentyl glycol, tripentaerythritol and mixtures thereof.
The carboxylic acid reactant used to produce the synthetic polyol ester base oil is selected from aliphatic monocarboxylic acids or a mixture of aliphatic monocarboxylic acids and aliphatic dicarboxylic acids. The carboxylic acid contains from 4 to 12 carbon atoms and includes the straight and branched chain aliphatic acids, and mixtures of monocarboxylic acids may be used.
The preferred polyol ester base oil is one prepared from technical pentaerythritol and a mixture of C 4 -C 12 carboxylic acids. Technical pentaerythritol is a mixture which includes about 85 to 92% monopentaerythritol and 8 to 15% dipentaerythritol. A typical commercial technical pentaerythritol contains about 88% monopentaerythritol having the formula ##STR1## and about 12% of dipentaerythritol having the formula ##STR2## The technical pentaerythritol may also contain some tri and tetra pentaerythritol that is normally formed as by-products during the manufacture of technical pentaerythritol.
The preparation of esters from alcohols and carboxylic acids can be accomplished using conventional methods and techniques known and familiar to those skilled in the art. In general, technical pentaerythritol is heated with the desired carboxylic acid mixture optionally in the presence of a catalyst. Generally, a slight excess of acid is employed to force the reaction to completion. Water is removed during the reaction and any excess acid is then stripped from the reaction mixture. The esters of technical pentaerythritol may be used without further purification or may be further purified using conventional techniques such as distillation.
For the purposes of this specification and the following claims the term "technical pentaerythritol ester" is understood as meaning the polyol ester base oil prepared from technical pentaerythritol and a mixture of C 4 -C 12 carboxylic acids.
As previously stated, to the polyol ester base stock is added a minor portion of an additive mixture comprising one or more amine phosphates and one or more dicarboxylic acids.
The monobasic amine phosphate(s) used include mono basic hydrocarbyl amine salts of acid phosphates and preferably are those of the formula: ##STR3## where R and R 1 are the same or different and are C 2 to C 24 linear or branched chain alkyl
R 1 is H or C 4 to C 20 linear or branched chain alkyl or R 4 -aryl-R 5 where R 4 and R 5 are the same or different and are H or C 1 -C 16 alkyl
R 2 is C 4 -C 20 linear or branched chain alkyl or R 4 -aryl-R 5 where R 4 and R 5 are the same or different and are H or C 1 -C 16 alkyl
R 3 is C 4 -C 20 linear or branched chain alkyl or R 4 -aryl-R 5 where R 4 and R 5 are the same or different and are H or C 1 -C 16 alkyl
The preferred monobasic amino phosphates are those wherein R is straight or branched chain C 6 -C 16 alkyl.
The monobasic amine phosphates are used in an amount in the range 25 to 500 ppm (based on polyol ester base stock) preferably 50 to 250 ppm, most preferably 75 to 150 ppm.
The dicarboxylic acid is a C 10 to C 40 total carbon numbers dicarboxylic acid, or mixture thereof, preferably a C 24 to C 40 dicarboxylic acid, or mixture thereof, most preferably a C 36 dicarboxylic acid or mixture thereof. The dicarboxylic acids can be any n-alkyl, branched alkyl, aryl, or alkyl substituted aryl dicarboxylic acid or mixture thereof having a total number of carbons falling within the above recited ranges. Preferred dicarboxylic acids are selected from the group consisting of the commercially available di-oleic acids known as "dimer acids", sebacic acid, azelaic acid and mixtures thereof.
The dicarboxylic acids are used in an amount in the range 25 to 1000 ppm (based on polyol ester base stock) preferably 50 to 400 ppm, most preferably 75 to 200 ppm.
The mixture of amine phosphate and dicarboxylic acid is used in an amount in the range 50 to 1500 ppm (based in polyol ester base stock), preferably 100 to 400 ppm, most preferably 100 to 300 ppm.
The amine phosphates and the decarboxylic acids are used in a ratio in the range 5:1 to 1:5, preferably 2:1 to 1:2.
The synthetic polyol ester--rust inhibiting additive containing turbo oil may also contain one or more of the following classes of additives: antioxidants, antiwear agents, extreme pressure additives, antifoamants, detergents, hydrolytic stabilizers and metal deactivators. Total amounts of such other additives can be in the range 0.5 to 15 wt %, preferably 2 to 10 wt %, most preferably 3 to 8 wt %.
Antioxidants which can be used include aryl amines, e.g. phenylnaphthylamines and dialkyl diphenyl amines and mixtures thereof, hindered phenols, phenothiazines, and their derivatives.
The antioxidants are typically used in an amount in the range 1 to 5 wt %.
Antiwear/extreme pressure additives include hydrocarbyl phosphate esters, particularly trihydrocarbyl phosphate esters in which the hydrocarbyl radical is an aryl or alkaryl radical or mixture thereof. Particular antiwear/extreme pressure additives include tricresyl phosphate, triaryl phosphate and mixtures thereof. Other or additional anti wear/extreme pressure additives may also be used.
The antiwear/extreme pressure additives are typically used in an amount in the range 0 to 4 wt. %, preferably 1 to 3 wt %.
Industry standard corrosive inhibitors may also be included into the turbo oil. Such known corrosion inhibitors include the various triazols.
For example, tolyltriazol, 1,2,4 benzene triazol, 1,2,3 benzene triazol, carboxy benzotriazole, alkylated benzotriazol.
The standard corrosion inhibitor additive can be used in an amount in the range 0.02 to 0.5 wt %, preferably 0.05 to 0.25 wt %.
As previously indicated, other additives can also be employed including hydrolytic stabilizers pour point depressants, anti foaming agents, viscosity and viscosity index improver, etc.
The turbo oils of the present invention meet or exceed the requirements set out by the United States Navy in MIL-L-23699E for corrosion inhibition type 5 cSt turbo oils. The MIL-L-23699E ball corrosion performance test is passed (75%=pass test) by polyol ester based, fully formulated, turbo oils to which have been added the antirust/corrosion inhibiting additive of the present invention consisting of a mixture of amine phosphate(s) and dicarboxylic acid(s).
The present invention is further described by reference to the following non-limiting examples.
EXPERIMENTAL
In the following examples a series of fully formulated aviation turbo oils were used which met all the specifications of MIL-L-23699. A polyol ester base stock prepared by reacting pentaerythritol with a mixture C 5 to C 10 acids was employed along with a standard additive package containing from 1.7-2.5% by weight aryl amine antioxidants, 1.5-2% tri-aryl phosphates, 0.1% benzo or alkyl-benzotriazole, and 0 to 0.04% ditridecyl amine. To this was added various corrosion inhibition packages which consisted of the following:
1) Phosphate alone: a monobasic phosphate amine where the alkyl substituents on the phosphate were primarily ethyl hexyl or octyl, but also contained some chains from C 6 to C 16 in length. (Ortholeum 535)
2) Diacid alone: Commercial dimerized oleic acids or Sebacic acid. The dimerized oleic acids contain many specific chemicals including cyclic and aromatic structures and which have a small amount (<3%) of undimerized acids and a small amount 2-10% of trimerized acids.
3) Combination (the present invention): the combination of the two materials described in (1) and (2) above.
These oils were testing in the MIL-L-23699E specification Ball Corrosion test for rust inhibition performance. This test simulates the ability of the oil to prevent the corrosion of stainless steel balls due to action by sea water and is fully described under the MIL-L-23699E specification. Typically, though not always, 10 balls are used in each experiment on a test oil along with 4 balls used to test a reference failing oil and 4 balls used to test a reference passing oil. An oil passes the Ball Corrosion test if at least 75% of the balls have no rust pits on them at the conclusion while the passing oil also shows at least 75% passing balls (at least 3 or 4) and the failing oil shows less than 75% passing balls (at most 2 of 4).
The results from a series of tests are shown in FIG. 1 over three concentration ranges. In all cases the concentration refers to the total corrosion additive concentration employed. For the combination cases, ratios between 1 part phosphate to 2 parts diacid and 2 parts phosphate to 1 part diacid by weight was used.
FIG. 1 shows the total percentage of balls passing over all experiments for the three corrosion inhibitor systems over the concentration ranges shown. In all three cases there was not a statistically significant trend over the three ranges shown at the 95% confidence level. Neither the phosphate or diacid ingredient used alone provided reliable protection from rust with fewer than half of the tests passing the minimum 75% specification. However, the combination of the two ingredients, used at the same total additive treat rate exhibited a synergistic effect, and increased the likelihood of a pass result greatly. The results are shown below in Table 1.
TABLE 1______________________________________ Total Balls/ Total Tests/ % of Balls % of Balls Passing Tests Passing Passing Tests Passing______________________________________Phosphate 149/99 66% 15/8 53%Amine AloneDiacid Alone 111/62 56% 12/4 33%Combination of Diacid 252/213 85% 25/21 84%& Phosphate Amine______________________________________
This table demonstrates that over a range of turbo oil formulations, the only case where consistent performance in the Ball Corrosion tests was demonstrated was for the combination of both ingredients. A passing result could not be obtained consistently from either ingredient when used alone, even if the concentration was increased to above 300 ppm, a concentration which would have caused other performance problems in the turbo oil (excessive Initial Acid number and poor hydrolytic stability for the diacid, excessive degradation of silicone seals for the phosphate amine).
EXAMPLE 2
In this example a series of turbo oils was used similar to those in Example 1, with the following differences. Here the use of a mixed mono-basic and dibasic phosphate amine as the corrosion inhibitor was investigated. The phosphate amines used were the commercial products Vanlube-692 and Vanlube-672 which are mixed methyl and butyl mono and di-basic phosphates. The Vanlube-692 is primarily butyl, while the Vanlube-672 has more methyl groups.
These materials were employed at 100-200 ppm along with 150 ppm of a commercial di-oleic acid, Empol 1022. In two experiments, 12 of 27 balls passed (44%) with 1 of the two tests having at least 75% passing balls (50% test pass).
In a second set of runs, 100 ppm of Vanlube-692 was added to a formulation containing 150 ppm of a commercial phosphate amine, Ortholeum 535 and 150 ppm of a commercial di-oleic acid, Empol 1022. From FIG. 1 it is seen that 85% of the balls using the combination of monobasic phosphate and diacid at a total of 300 ppm would be expected to pass in the absence of Vanlube-692, Table 1 indicating that this combination, should pass 84% of all tests. However, in results of 4 replicate runs at the U.S. Navy Testing Laboratory in which mixed mono and di-basic amine phosphates were added to the formulation containing mono-basic amine phosphate only 15 of 50 balls (30%) passed while none (0 of 4) of the tests produced 50% passing balls.
This example demonstrates the need for the use of mono-basic phosphate to achieve successful results as the di-basic phosphates were not effective in combination with the diacid, and degraded the performance of the mono-basic phosphate amine-dicarboxylic acid synergistic combination.
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A turbo oil possessing improved rust inhibiting properties is provided by adding to the turbo oil base stock minor amounts of monobasic aminophosphates and dicarboxylic acids. The use of the recited combination produces unexpected superior rust resistance performance as compared to use of the individual components. The turbo oil benefitted by the additive is preferably a polyol ester-based oil.
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BACKGROUND OF THE INVENTION
The present invention relates to door lights and more particularly to "integral door lights" wherein the door light frame is incorporated structurally into the door.
A door light is a window assembly especially adapted to be mounted within a door. Typically, the door light and door blank are manufactured separately from one another. The door light is subsequently mounted within the door blank by removing a portion of the door blank to form an opening and then mounting the door light within the opening. Typically, the door light includes inner and outer frames which engage the opposite sides of the door to sandwich the door blank therebetween.
Recently, "patio doors" have gained increasing popularity as an alternative to the traditional sliding door. The patio door is a hinged door supporting a door light extending the majority of the height and width of the door. Mounting traditional door lights in patio doors is undesirable for a number of reasons. First, the traditional manufacturing method is wasteful of material since the majority of the door blank must be removed and discarded to receive the door light. Second, the door light frame protrudes from both sides of the doors resulting in an undesirable bulky appearance.
As a consequence, "integral door lights" have been developed. "Integral door light" means any door light wherein the frame is specially adapted to structurally interfit with the remaining door components during manufacture to support the frame within the door.
Examples of integral door lights are illustrated in U.S. Pat. No. 4,546,585 issued Oct. 15, 1985 to Governale entitled DOOR PANEL AND METHOD OF MAKING and U.S. Pat. No. 4,327,535 issued May 4, 1982 to Governale entitled DOOR WITH GLASS PANEL. In both patents, the door light frame is assembled about the glass prior to manufacture of the door. The door light frame is then entrapped between the opposite steel jackets or skins of the door to maintain the door light in position. Specifically, a lip extends inwardly from both jackets to interfit with a groove in the door light frame. Following manufacture, the door light frame comprises an integral portion of the door construction and cannot be removed without substantially destroying the door. Therefore, the door light glass cannot be removed from the door subsequent to manufacture for replacement in case of breakage, scratching, or fogging.
SUMMARY OF THE INVENTION
The aforementioned problems are overcome in the present invention wherein an integral door light frame is provided enabling the glass to be easily removed for servicing subsequent to manufacture. More specifically, the door light includes a frame to be structurally incorporated within the door, a glass or other glazing panel mounted within the frame, and a plurality of glazing retainers or stops for securing the glass panel in the frame. The glazing stops are releasably secured to the frame enabling the stops to be relatively easily removed subsequent to assembly, permitting the glass panel to be removed for servicing or replacement as necessary.
In a first preferred embodiment of the invention, the removable glass retainers include a spring structure for biasing the glass retainers toward the glass panel in a direction generally perpendicular to the plane of the glass panel. This maintains the glass panel in firm contact with the frame and also permits the door light frame to accommodate glasses having slight thickness variations. In a second preferred embodiment of the invention, the frame includes an integral seal for sealing the exterior glass surface thereagainst. Most preferably, the seal is coextruded with the frame. The frame therefore provides an integral weather-proof seal to prevent the infiltration of water and/or air and to eliminate the need for separate glazing materials or compounds.
These and other objects, advantages, and features of the invention will be more readily understood and appreciated y reference to the detailed description of the preferred embodiment and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of the present door light mounted with a door;
FIG. 2 is a perspective exploded view of the door light;
FIG. 3 is a sectional view of the frame;
FIG. 4 is a sectional view of the glazing stop;
FIG. 5 is a sectional view taken along Plane V-V in FIG. 1;
FIG. 6 is an enlarged fragmentary sectional view of the glazing stop in one extreme position; and
FIG. 7 is a fragmentary sectional view of the glazing stop in its other extreme position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A door light constructed in accordance with a preferred embodiment of the invention is illustrated in the drawings and generally designated 10. The door light includes a frame 12, a glass panel or glazing panel 14, and a plurality of glazing stops or glass retainers 16. The door light lo is supported within a door 18; and more particularly, the steel skins 20a and 20b of the door extend into grooves in the frame 12 as will be described. The glass retainers 16 are removable from the frame 12 permitting the glass panel to be readily and easily removed from the door for servicing and/or replacement.
Turning specifically to the construction of the door light 10, the frame 12 (FIG. 2) is generally rectangular and is fabricated of four linear extrusions 12a, b, c, and d all generally identical in cross section. The cross sectional configuration of each of the extrusions is illustrated in FIG. 3. The extrusion 12 includes a body portion 22 and a glass support portion 24. The body portion 22 has a width essentially identical to the core of the door 18 between the skins 20. The body portion 22 includes a pair of lateral opposite surfaces 28a and 28b. Grooves 30a and 30b extend generally perpendicularly through the lateral surfaces 28a and 28b, respectively, to receive the steel door skins 20 as will be described. The spacing legs 60, 62, 64, and 66 all terminate in a common plane to abut the core 19 of the door.
The body portion 22 of the frame extrusion 12 (FIG. 3) also defines a glass-edge-facing surface 36 which is generally planar and parallel to the grooves 30 and perpendicular to the lateral faces 28. A snap-channel 38 extends through the surface 36 and has a cross section shape generally similar to the capital letter R. The channel has a straight side 40 and an opposite beveled entry surface 42 leading to a restricted portion 44. The channel 38 terminates in an enlarged area 46. A snap ridge 48 delineates the restricted area 44 from the enlarged area 46. The portion 5 of the channel 38 immediately adjacent the snap ridge 48 within the enlarged area 46 is radiused defining a quarter circle to provide a pivot surface for the glazing stop spring flange as will be described.
The glass support portion 24 of the frame extrusion 12 (FIG. 3) is integral with the body portion 22 and is located on the "exterior" side of the frame facing away from the building interior. The frame extrusion 12 is generally L-shaped in cross section with the body portion 22 comprising a first leg of the L; while the glass support portion 24 comprises the second leg of the L. The walls 70 and 72 extend from the body portion 22 and are connected at their remote ends by wall 74 to define a generally trapezoidal cross section. A leg 76 extends from the wall 70 to support a coextruded bulb seal 78. A curvilinear leg 80 extends from the junction of walls 70 and 74 to support a coextruded compression seal 82.
Preferably, the frame extrusion 12 is fabricated of a plastic resin to eliminate conductive heat transfer from the interior side to the exterior side of the frame. The materials selected as the rigid and flexible portions of the extrusion 12 are preferably easily hot-knife weldable enabling the formation of corners which reduce air and water infiltration. In the presently preferred embodiment, the frame extrusion 12 is fabricated of a rigid polyvinyl chloride (PVC) of weatherable grade and having a durometer of 50 Shore D. The coextruded bulb seal 78 and compression seal 82 are fabricated of a flexible PVC of weatherable grade having a durometer of 64 Shore A. For aesthetic reasons, the rigid PVC is preferably white; while the flexible PVC is preferably black.
The four extrusion segments 12a, 12b, 12c, and 12d (FIG. 2) are interconnected to form the rectangular frame 12. Preferably, the corners are formed by miter cutting both ends of the four extrusion segments 12a, b, c, and d by hot-knife welding to provide a rigid structure and to provide a continuous weather-tight interconnection of the seals 78 and 82 at the frame corners.
As illustrated in FIG. 5, the frame 12 is secured in position by the steel skins 20a and 20b. As is conventional in door constructions, the steel skins 20a and b form the interior and exterior surfaces of the door 18. During manufacture of the door, the edges of the skins 20 are roll formed to create lips 120a and 120b, respectively. The lips 120 extend about the entire periphery of the frame 12; and each extends inwardly approximately one-quarter inch from the planar portion of the skins 20. The lips 120 are received within the channels 30 and thereby lock the body portion 22 between the two skins 20. The construction of the door, including the core 19, is conventional as illustrated for example in the previously identified U.S. Pat. Nos. 4,546,585 and 4,327,535.
The glazing stops 16a, b, c, and d are all fabricated from a common extrusion and all have lengths slightly shorter than the corresponding extrusions 12a, 12b, 12c, and 12d to fit within the frame 12 and retain the glass panel 14 in position. The cross sectional configuration of the glazing stops or glass retainers 16 is illustrated in FIG. 4. The extrusion includes a base wall 90, a glass abutment wall 92, a trim wall 94, and a window grille wall 96. A notch or cut-out 98 is provided at the junction of the glass supporting wall 92 and the grille wall 96 permitting the tips of a window grille (not shown) to be inserted thereunder if desired.
A spring flange 100 extends from the base wall 90 of the glazing stop 16 at an acute angle of approximately 70 degrees. The spring flange 100 includes a body portion 102 terminating in a bulbous edge 104 generally circular in cross section. The diameter of the bulbous edge 104 is greater than the thickness of the spring flange 100. The width of the channel 38 is greater than the thickness of the spring flange body 102 permitting the body to pivot about the edge 104 to alter the position of the retainer 16.
The releasable intersecurement of the glazing stop 16 within the frame 12 is illustrated in FIGS. 5-7. The spring flange 100 is located within the channel 38 with the bulbous portion 104 located behind the snap ridge 48. The glazing stops are therefore located on the "interior" side of the frame facing the building interior. When the glazing stop 16 is fully inserted into the frame 12, the base wall 90 of the glazing stop lays against the surface 36 of the frame.
The glass panel 14 is of conventional construction and preferably is thermally insulated glass having an interior surface 110 and an exterior surface 112. The glass panel is positioned within the frame 12 such that the exterior surface 112 abuts and slightly compresses both the compression seal 82 and the bulb seal 78. The compression seal 82 is relatively narrow in a direction perpendicular to the glass panel 14 in comparison to the bulb seal 78. Consequently, the compression seal 82 bears the bulk of the pressure of the glass panel 14 against the glass support portion 24 to seal the exterior surface of the glass panel 14 against air and water infiltration. The glass panel 14 is retained in position by the glass support wall 92 cf the glazing stop 16 which bears against the interior surface 110 of the glass panel.
Assembly and Operation
Preferably, the door light 10 is fully assembled prior to manufacture of the door 18. The frame 12 is formed by interconnecting the four extrusion segments 12a, 12b, 12c, and 12d to define its rectangular shape. Preferably, the four corners are miter cut and hot-knife welded to provide rigid interconnections and continuity of seals at the corners. Other suitable corner fastening means can be used such as solvent or other adhesives.
The glass panel 14 is placed in the frame 12 with the exterior glass surface 112 (FIG. 5) abutting the compression seal 82 and the bulb seal 78. Both seals are continuous about the entire outer periphery of the frame 12 to form a continuous seal about the perimeter of the glass panel. Each glazing stop 16 is snap-pressed into the frame 12. Specifically, the spring flange 100 is guided into the channel 38. The beveled surface 42 facilitates guiding the spring flange into the channel. As the retainer is fully inserted, the bulbous edge 104 snaps behind the snap ridge 48 to provide a positive engagement of the retainer and to provide confirmation that the retainer has been properly installed. The spring flange 100 is flexed slightly during installation to bias the retainer 16 against the glass panel 14. The retainers 16 are mitered on their ends and meet one another in the corners of the frame 12. The retainers are not connected at their corners to facilitate assembly.
The spring flange 100, the compression seal 82, and the bulb seal 78 flex as necessary to accommodate glasses 14 having slightly varying thicknesses. FIGS. 6 and 7 illustrate the two extreme positions of the glazing retainer 16. FIG. 6 illustrates the position of the retainer 16 against a glass panel of relatively small thickness; while FIG. 7 illustrates the position of retainer 16 against a glass panel of greater thickness. In FIG. 6, the spring force of the spring flange 100 bearing against the snap ridge 48 forces the retainer 16 to the right extreme position as viewed in FIG. 6 and against the glass panel 14. Movement in the right direction is limited at the point wherein the spring flange 100 engages the frame 12. In FIG. 7, the greater thickness of the glass panel 14 forces the retainer to its left extreme position wherein the spring flange 100 is flattened against the surface 44 to be generally perpendicular to the base wall 90. Although the two extreme positions are illustrated in FIGS. 6 and 7, the glazing stop will normally assume a position therebetween for a given nominal glass panel thickness. This ability of the retainer 16 to accommodate glasses of different thicknesses permits minor variation in the thicknesses of the glass panel 14.
It is presently anticipated that the door will be fabricated with the door light 10 fully assembled. Alternatively, the door could be fabricated including the frame 12 alone with the glass panel 14 and retainers 16 being installed subsequently. In either case, a glazing compound (not shown) can be placed in the grooves 30 in the frame 12 to improve the seal between the skin lips 120 and the frame. The door can be fabricated as illustrated in the above cited patents.
The glazing retainers 16 can also be relatively easily removed from the frame 12 to permit the glass panel to be removed for servicing and/or replacement. To do so, the retainers 16 are moved in a direction parallel to the glass panel 14 so that the bulbous edge 104 rides over the snap ridge 48 enabling the spring flange 100 to be removed from the channel 38. With the described durometers, it is necessary to force a screwdriver between the frame 12 and the retainer 16 to provide leverage and the requisite force to remove the retainer from the frame. The same retainers can be reused over and over to retain the same glass panel 14 or a new replacement glass panel.
The above description is that of a preferred embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as set forth in the appended claims which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.
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The specification discloses a door light including a frame incorporated structurally into the door and a glass removable from the frame. The frame is fabricated of coextruded members each having a coextruded seal of lower durometer. Removable glass retainers or glazing stops are snap-fitted within the frame to retain the glass against the seal. Preferably, the glass retainers are biased against the glass to improve the seal and to accommodate glasses having slight thickness variations.
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BACKGROUND OF THE INVENTION
This invention relates generally to air conditioning systems and more particularly to an air conditioner base pan with drainage features that can be used with either single row or multiple row coil applications.
An inherent operating characteristic of a heat pump is the need to operate in a defrost mode for short periods of time to thereby remove the frost which has formed on the outdoor coil during operation in the heating mode. This is accomplished by reversing the system to operate in the cooling mode such that the outdoor coil gives off heat to thereby melt the formed ice. Upon melting the ice, the resulting water must be disposed of quickly before it freezes and plugs up the drainage system.
Traditionally, the melted ice has flowed from the coils to a base pan below, from which it drained through a plurality of holes or slots formed in the base pan for that purpose. The size of the drainage holes or slots was determined by the number of coil rows, with a multiple row coil requiring substantially larger openings than a single row coil for proper drainage.
For proper drainage, it should also be recognized that the base pan will be susceptible to the buildup of dirt and debris if the drainage openings are too small. Any accumulation of such material will not only impede the proper flow of liquid, but it will also tend to bridge the gap between the steel base pan and the aluminum coil to thereby cause electrolytic action between the two.
As a safeguard against the possibility of a fire being started from a spark or from molten metal that might be produced by the fan motor, the UL requirements for air conditioners have required that there be no openings in the bottom of an air conditioning structure which are directly below the electrical devices or wiring that may give off hot particles such as sparks or molten metal. Thus, it will be understood that the drainage holes must be located and sized in such a way as to avoid this exposure. If one is designing a base pan specifically for a single row coil or specifically for a multiple row coil, the drainage hole size and location can accordingly be chosen to accommodate that design. However, where one wishes to provide a single base pan design which can be used for either single or multiple coil use, then the above safeguard requirements, together with the requirements for proper drainage, become a problem.
lt is therefore an object of the present invention to provide an improved base pan drainage system for heat pumps.
Another object of the present invention is the provision for a single base pan design which can be used with either single row or multiple row coils.
Yet another object of the present invention is the provision for a base pan drainage structure which is not directly exposed to the fan motor and associated wiring but which provides adequate drainage for either single or multiple row coils.
Still another object of the present invention is the provision for a self-draining base pan which is economical to manufacture and effective in use.
These objects and other features and advantages become more readily apparent upon reference to the following description when taken in conjunction with the appended drawings.
SUMMARY OF THE INVENTION
Briefly, in accordance with one aspect of the invention, a base pan is formed with a plurality of drainage shelves disposed around its periphery just below where the coil(s) would be mounted. Also formed in the base pan, in direct drainage communication below, but radially offset from, the shelves, are openings through which water can be drained from the base pan. The size and location of the openings are such that either a single row coil or a multiple row coil can be mounted on the base pan without jeopardizing either the adequacy of the drainage system or the safeguard against exposure to hot particles emanating from the electrical apparatus mounted at a location within the coils. The location of the single row coil, or of the outer row coil in a multiple coil arrangement, is directly above the openings such that the water dripping therefrom can flow directly out through the opening, but the openings themselves are hidden from direct exposure to the electrical wiring and components by the coil. The inner row coils of a multiple coil arrangement is located over the shelf such that melted ice therefrom can drip onto the shelf and then flow to the opening where it is discharged.
In accordance with another aspect of the invention, the drainage shelves are integrally formed with the base pan and comprise both a vertically extending trough forming portion disposed directly below the location for the inner row coil, and an associated radially outwardly, and downwardly, extending portion which receives the defrosted liquid from the inner coil(s) and directs it to the discharge openings.
In the drawings as hereinafter described, a preferred embodiment is depicted; however, various other modifications and alternate constructions can be made thereto without departing from the true spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an air conditioning unit with a base pan in accordance with the present invention.
FIG. 2 is a top plan view of the base pan portion thereof.
FIG. 3 is a front elevational view of the base pan portion thereof.
FIG. 4 is a sectional view of the coil support portion thereof as seen along lines IV--IV. of FIG. 2.
FIG. 5 is a sectional view of the drainage opening portion thereof as seen along lines V--V of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the present invention is shown generally at 11 as incorporated in a base pan 12 of a typical condensing unit 13 of an air conditioning or heat pump system having an indoor coil connected thereto by way of refrigerant piping.
The condensing unit 13 includes an upstanding coil 14 which together with its outer protective grille 16 defines the shape of the unit. Although the particular unit shown is generally square in shape, the coil and supporting base pan can just as well be round, or any other desirable shape, while remaining within the scope of the present invention. The coil 14 functions as a condenser coil to give up heat to the surrounding air during the periods in which the heat pump is operating in the cooling or defrost modes, while it functions as an evaporator coil to extract heat from the surrounding air during periods when the system is operating in a heating mode.
In order to promote the flow of air through the coil 14, a fan 17 is axially mounted at the top of the cavity 18 formed by the coil 14. Mounted around the fan 17 is an orifice ring 19 which defines an outwardly expanding orifice 21 to conduct the outward flow of air. Thus, as the fan 17 is driven by an electric motor 22 it draws the air into the coil 14 and out through the orifice 21. A cover 23 with a louvered opening 24 is mounted on the top of the unit for purposes of protection and support.
Also mounted in the cavity 18 is a compressor 26 and the various valves and piping necessary to fluidly connect it to both the indoor and outdoor coils. The compressor 26 is mounted to and supported by the base pan 12 as shown.
Referring now to FIGS. 2 and 3, the base pan 12 is shown as formed from a single piece of sheet metal with portions being deformed or stamped therein. The principal surface of the base pan is indicated at 27 and is at a raised or intermediate elevational level, whereas a plurality of lowered or depressed surfaces are provided at 28, 29, 31, 32 and 33 for the purpose of strengthening the base pan structure. Provision is made for centrally mounting the compressor 26 with bolts secured in the openings 34. An upstanding skirt 36 extends upwardly from the principal surface 27 and forms the outer perimeter of the base pan 12. Located proximate the midpoint of each side of the base pan 12 are the coil support structures as indicated at 37, 38, 39 and 41, respectively. The details of those structures are more clearly seen by reference to FIG. 4.
Referring to FIG. 4, it will be seen that, as the base pan extends outwardly toward the upstanding skirt 36, the profile raises from the lowered surface 32 to the principal surface 27 and then to the coil support structure 41 which includes the gradually rising inner wall 42 and a substantially horizontal pedestal surface 43. In addition to the gradually rising inner wall 42, the coil support structure 41 also includes the gradually rising side walls 44 and 46 as shown in FIG. 2. The entire coil support structure 41 is therefore integrally formed as part of the base pan structure with the pedestal surface 43 being supported on three of its sides. On the outer side thereof, an opening 47 is formed between the shelf end 48 and the exposed end 49 of that portion of the principal surface 27 extending inwardly from the upstanding skirt 36. Mounted on the horizontal pedestal surface is a nonmetallic pad 51 which is preferably attached thereto by way of an adhesive or the like. The integral horizontal pedestal surface 43, and the nonmetallic pad 51 then form the support structure for the entire vertical load of the inner row coil 52 and outer row coil 53 on that side of the unit. The coil support structures 37, 38 and 39 are identical to the coil support structure 41 as just described.
As mentioned hereinabove, a protective grille 16 surrounds the coil 14 and forms the outer boundary of the unit. This grille 16 is normally disposed with its lower end inside the upstanding skirt 36 as shown and is secured within that skirt by way of a plurality of fasteners 54. If the outer row coil 53 were permitted to rest on the base pan at the level of the principal surface 27, it then would be susceptible to being damaged by the fasteners 54 when they are inserted inwardly. However, the raised horizontal pedestal surface 43 elevates the outer row coil 53 to a height which is above the level in which the fasteners 54 are installed and thus out of the zone in which damage could occur to them. With the outer coil 53 being raised, the fasteners may be installed at any location around the periphery of the skirt 36. However, since the coil 53 will have a tendency to sag between adjacent supports, and may well sag to the point where it could be punctured by a fastener 54, the fasteners 54 are preferably installed only at the locations corresponding to those of the supports (i.e. at the openings 47) such that they will always be below the coil 53.
As mentioned hereinabove, when the unit is operating in the defrost mode, the heated refrigerant in the coil 14 functions to melt the frost that is formed thereon. As this frost is melted, it is necessary to dispose of the resulting water. Thus, a plurality of drainage openings, indicated at 56-64 in FIG. 2, are provided. Although there are two such drainage openings on each side of the base pan as shown in FIG. 2, it should be understood that drainage openings of other shapes, locations, configurations and sizes may be employed while remaining within the scope of the present invention. The particular structure of the drainage opening 59 in accordance with the present invention, and as representative of the other openings, is shown in FIG. 5.
Referring now to FIG. 5, as the profile of the base pan 12 extends radially outwardly, the lowered surface 29 transitions to a rising surface 66 and then to the principal surface 27. That surface then transitions to a stepped down surface 67 which extends downwardly to a slanted shelf 68. The end 69 of the shelf 68, together with the end 71 of that portion of the principal surface 27 extending inwardly from the upstanding skirt 36, define an opening 72 for drainage of the water resulting from defrosting of the coils. Such a drainage opening can be used with either a single or a dual coil installation to obtain adequate drainage while at the same time preventing any sparks or hot metal from passing through the opening. For example, in a single coil installation, the single coil would be located in the position of the outer coil 53 as shown in FIG. 5. Since the coil is located directly over the opening 72, the water will drip directly from the coil to the opening 72. For purposes of protection against the downward movement of hot materials, the coil 53 and the slanted shelf 68 serve to provide a barrier against the hot materials that could fall directly through the opening 72. In a multiple coil application, the outer coil 53 is located in the same position and performs in the same manner as described hereinabove. The inner coil 52 is now located over the slanted shelf 68 such that the residue from defrost can drip directly onto the shelf 68 and then run down to the opening 72. Again, the coils 52 and 53, together with the slanted shelf 68 tend to act as a barrier against the downward movement of hot materials.
While the present invetnion has been described with particular reference to a preferred embodiment, the concepts of the invention are readily adaptable to other embodiments, and those skilled in the art may vary the structure thereof without departing from the essential spirit of the present invention.
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The base pan of a heat pump has a plurality of drainage openings formed near the periphery thereof such that either a single row coil or a multiple row coil heat exchanger may be used therewith to obtain adequate drainage of defrost liquid while at the same time preventing any downward movement of molten metal or hot particles through the drainage openings. The openings are located directly under the single or outside coil and a slanted shelf is placed directly under the location where the inner coil(s) would be placed, with the slanted shelf acting as a barrier for hot materials in a single coil apparatus and as a conduit for drainage to the opening when used with a multiple coil apparatus.
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BACKGROUND OF THE INVENTION
Owing to their numerous well-known advantages of lightness, strength and free running abrasion resistance qualities, double braided lines are widely used by many people such as yacht or boat owners, riggers, mountaineers and ranchers. Particularly in the nautical and marine arts, it often becomes necessary or desirable to splice an eye in the line.
The conventional method of forming an eye splice in a double braided line involves pulling the core of the line out of the sheath and feeding the end of the core back into the sheath in the opposite direction using a fid and a pusher. The end of the sheath is buried in the exposed portion of the core using the fid and pusher a second time and the exposed portion of the core and crossover are buried in the sheath by alternately pulling the various line components.
The fid which has been known heretofore is a rigid stick having one hollow end and one pointed end. The pointed end of the fid is tunneled through the center of the core or sheath and the end of the sheath or core, respectively, is pushed into the hollow end of the fid. The pusher is a rod which holds the end of the sheath or core in the hollow end of the fid and is used to push the fid and end of the sheath or core through the core or sheath, respectively.
This arrangement suffers from numerous disadvantages, one being that a different diameter fid must be provided for the different line diameters. It is necessary to provide a separate fid for each line carried on the vessel, and loss of one size fid can create a significant and annoying problem. Naturally, a set of fids is more expensive than one fid which would suffice for all line sizes. Another problem is that the end of the core or sheath in the hollow end of the fid tends to detach during passage through the sheath or core, respectively. Further, a fid of this design must be of the same diameter as the line since the end of the sheath must fit in the hollow end of the fid, and the fid is hard to push through the core. In summary, the conventional fid and pusher make eye splicing of doubled braided lines a difficult and often frustrating experience.
SUMMARY OF THE INVENTION
The present invention relates to an improved method of forming an eye splice in double braided line and a fid for practicing the method.
The conventional fid and pusher are replaced with a fid consisting of a flexible, elongated, small diameter handle having one pointed end. A hook extends from the other end of the handle. A knot is formed in the end of the core or sheath of the line and the hook is hooked therearound. The end is then whipped to the fid. The pointed end of the fid may then be readily inserted into the sheath or into the core, as required, and the fid and attached end of the core or sheath, respectively, worked therethrough with facility.
It is an object of the present invention to provide an improved method of forming an eye splice in double braided line.
It is another object of the present invention to provide a novel and unique fid for practicing the method.
It is another object of the present invention to provide a method of forming an eye splice which may be practiced using fewer and less expensive tools.
It is another object of the present invention to provide a method of forming an eye splice by which a single fid may be used for all sizes of line.
It is another object of the present invention to provide a method of forming an eye splice which makes it easier to push the fid through the line core or sheath, thus minimizing strain and abrasion of the core or sheath.
It is another object of the present invention to provide a generally improved method and apparatus for forming an eye splice in double braided line.
Other objects, together with the foregoing, are attained in the embodiment described in the following description and illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 are diagrams illustrating the state of art; and,
FIGS. 3 to 19 are diagrams illustrating the steps of the present method in generally sequential order.
DESCRIPTION OF THE PREFERRED EMBODIMENT
While the splicing apparatus of the invention is susceptible of numerous physical embodiments, and the method is capable of being practiced in a variety of ways, depending upon the environment and requirements of use, substantial numbers of the herein shown and described embodiment have been made, tested and used, in practicing the method disclosed, and have provided eminently satisfactory results.
FIG. 1 illustrates one step of a current widely used method of making an eye splice in the line being generally designated by the reference numeral 21 and comprising a braided core 22 and a braided sheath 23 with the core 22 shown as pulled out of an opening 24 in the sheath 23.
A prior art fid 26 is shown as buried in the core 22, the fid 26 having a pointed forward end 26a and a hollow after end 26b. The fid 26 is in the form of a rigid stick and has been pushed through the core 22 in the direction of the arrow 27, with the pointed end 26a leading. The end of the sheath 23 is taped as shown at 23a and inserted into the hollow end 26b of the fid 26. The pusher 28, or push rod, is then inserted into the taped end 23a of the sheath 23 and used to push the fid 26 and sheath end 23a through the core 22 so the fid 26 and the end 23a emerge from the core 22 at the position occupied by the end 26a of the fid 26 as illustrated in FIG. 1.
Since the end 23a of the sheath 23 must be inserted into the hollow end 26b of the fid 26, the diameter of the fid 26 must be equal to that of the line 21, and a separate fid 26 must be provided for each diameter of line. Furthermore, it is difficult to push the large diameter fid 26 through the core 22. As yet another drawback, an examination of FIG. 1 reveals how the taped end 23a of the sheath 23 can easily become dislodged from the hollow end 26b of the fid 26 during passage through the core 22.
FIG. 2 shows a subsequent step in the prior art method and illustrates still other rather difficult manipulations. Here, the fid 26 is pushed through the empty sheath 23 in the direction of the arrow 29. The end of the core 22 is taped, as indicated at 22a, and inserted into the hollow end 26b of the fid 26. The pusher 28 is then used as in FIG. 1 to push the fid 26 and the taped end 22a of the core 22 through the sheath 23 to emerge at the opening 24. However, the fid 26 is rigid and is not long enough to reach completely through the length of the empty sheath 23 and must be removed and reinserted at an opening 31 formed in the sheath 23. This makes the process generally difficult and makes it especially hard effectively to reunite the end 22a of the core 22 with the end 26b of the fid 26 after the fid 26 is reinserted.
The drawbacks of the prior art process are eliminated by the present method, illustrated in FIGS. 3 to 19. The present method utilizes a fid 32 which comprises an elongated flexible handle 32a formed with a leading pointed end 32b. A hook 32c extends aft from the other end of the handle 32a. Preferably, the handle 32a is hollow with the leading pointed end 32b closed.
The double braided line is here designated as 33 and as best illustrated in FIG. 8 comprises a core 34 and sheath 36. As a preliminary step in practicing the present process, a mark is made (see FIG. 3) with a ball point pen 37 or the like at a point B on the sheath 36 at a distance from the end 36a of the sheath 36 which depends on the diameter of the line 33. More specifically, the distance from the end 36a of the sheath 36 to the point B is determined as follows:
______________________________________Line Size Distance to B______________________________________1/4" 6"5/16" 7"3/8" 8"7/16" 9 1/2"1/2" 11"5/8" 13"______________________________________
The handle 32a of the fid 32 is then placed alongside the line 33, as shown in FIG. 3, so that the base of the hook 32c (i.e. where the hook joins the handle) indexes with the point B. A mark is then made on the sheath 36 at a point E which is spaced from the point B by the length of the hook 32c. The line 33 is then looped so that when a point A indexes with the point E the loop or eye thus formed has the desired size. A mark is then made at the point A. To control slack and allow the use of both hands while milking the sheath 36 over the core 34 in subsequent steps, an overhand knot 38 is tied in the line 33 about 3 feet from the point A (see FIG. 3).
The first step of the actual process is shown in FIG. 4 in which an opening 39 is formed through the sheath 36 at the point A and the core 34 is pried up pulled out of the sheath 26 using the pen 37 or other suitable tool. As the core 34 is just being pulled out, a mark is made on the core at a point F, as shown. The core 44 is then completely pulled out of the sheath 36 as shown in FIG. 8.
As the next step, the end 34a of the core 34 is unbraided as shown in FIG. 5 and a knot 34b is tied using two strands from opposite sides of the core 34. The hook 32c of the fid 32 is then hooked around the knot 34b.
Next, as illustrated in FIG. 6, the unbraided portion of the end 34a of the core 34 is whipped to the fid 32, using dental floss or thread as indicated at 41. The loose ends of the strands are then cut close using a knife 42. The whipping 41 is made as tight as possible to facilitate the subsequent steps.
As shown in FIG. 7, a tight wrap 43 of cellophane tape is then made around the ends of the whipping 41 so as to form a smooth, thin, tapered transitional ferrule between the handle 32a of the fid 32 and the whipped end of the core 34.
Next, the pointed end 32b of the fid 32 is inserted through the sheath wall into the tunnel defined by the empty sheath 36 at the point B and the fid 32 and end 34a of the core 34 are snaked or worked through the sheath 36 and brought out through the opening 39 at the point A. This is best seen in FIGS. 8 and 9. At this juncture, a significant length of the core 34 protrudes through the opening 39 and a significant length of empty sheath 36 is left between the point B and the end 36a of the sheath 36. The fid 32 is thereupon removed from the end 34a of the core 34 and attached to the end 36a of the sheath 36 in the manner illustrated in FIGS. 5 to 7.
The next step (see FIG. 10) involves pulling the core 34 farther out of the sheath 36 through the opening 39 so that a considerable amount of the core 34 is exposed between point F on the core and point A on the sheath.
The pointed end 32b of the fid 32 is then inserted into the exposed portion of the core 34 at a point C which is about 3 inches from the point F. The fid 32 is pushed through the core 34 until the whipped end 36a of the sheath 36 is buried in the center of the core 34, as appears in FIG. 11. The end 32b of the fid 32 is then caused to protrude at point D. Thereafter the fid 32 and end 36a of the sheath 36 are brought out of the core 34 at point D. The distance between the points C and D is substantially equal to the length of the handle 32a of the fid 32 and constitutes the length of the sheath 36 buried in the core 34. At this juncture, the end 36a of the sheath 36 protrudes through the outer side of the core 34.
As shown in FIGS. 12 and 13, the loose ends 34a and 36a of the core 34 and sheath 36, respectively, are alternately pulled to bring the points B and C together. The end result of this step is shown in FIG. 13. The union of the points B and C is referred to as the "crossover" point of the core 34 and sheath 36. The loose end 36a of the core 36 is then cut off at a long angle as indicated in FIG. 13 at 36b adjacent to the point D. The fid 32 is removed from the cut off portion (not shown) of the sheath 36 for reuse. Pulling on the exposed portion of the core 34 will cause the cut off end 36b to disappear in the core.
Next, the knot 38 is looped around a post 44, or the like, as shown in FIG. 14, and the portion of the sheath 36 below the point A is milked over the exposed portion of the core 34, using both hands. This process is continued until the crossover point B, C enters the sheath 36 of the main portion of the line 33 through the opening 39 and is buried therein. FIG. 15 shows the end result of this step by which the crossover point B, C is buried in the sheath 36 and the point E aligns with the point A. Thus, the crossover point B, C is buried in the sheath 36 by the distance between the points B and E which is equal to the length of the hook 32c of the fid 32.
FIG. 16 shows how the core 34 may be pulled out of the sheath 36 to facilitate milking the sheath 36 over the core 34 to align the points A and E. More specifically, an opening 46 is formed in the sheath 36 between the knot 38 and the opening 39 and the core 34 is partially pulled out of the sheath 36. A riding turn 47 is temporarily taken around a cleat 48 to secure the core 34. After the points A and E are aligned, the core 34 is allowed to return inside the sheath 36 and the line 33 is smoothed out. This procedure is helpful where it is necessary to overcome friction on an old or tight line.
FIGS. 17 to 19 show how the eye splice produced by the above described method is finished by whipping. Although a simple whipping can be made around the throat of the splice (just below the point A) using a small cord, in which case the protruding end portion of the core 34 would be cut off and allowed to disappear into the splice, the following method produces a whipping of superior strength and appearance.
As illustrated in FIG. 17 the eye is smoothed out as much as possible so that it feels equally hard to the touch at all points. Then, all but a few, preferably six strands of the end 34a of the core 34 are cut off to a length of about 3/8 inch. These cut strands will disappear into the splice when tension is applied to the line 33. The remaining strands are designated as 34c in FIG. 18 and are tied around the throat of the splice just below the point A in a clove hitch designated as 34d in FIG. 19. The end of the clove hitch 34d is cut off to a length of about 3/8 inch and heated with a match or butane lighter. This causes the strands of the clove hitch 34d to melt. Pressing down smoothly on the clove hitch 34d with a moistened finger causes the clove hitch 34d to fuse and be positively prevented from unraveling.
In summary, the present invention provides a substantially improved method and fid for making eye splices in double braided line. The small dameter, flexible fid is easy to snake through the line core or sheath and does not need to be detached and reinserted to make a long run. Furthermore, only one size of fid will serve for lines of all sizes.
It is to be noted, furthermore, that while the hook 32c of the fid 32 is disclosed herein as being in the form of a recurved or open loop, it can also be of a closed loop configuration, depending upon the personal preference of the user. One form is considered to be the equivalent of the other.
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A double braided line comprises a core covered by a sheath and a fid comprises an elongated flexible handle having a pointed end and a hooked end. After the size of the eye is established, a predetermined length of the core is pulled out of the sheath through an opening formed in the sheath and a knot is tied in the free end of the core. The hook of the fid is hooked around the knot and the end of the core is whipped to the fid. The fid and attached end of the core are snaked through the empty portion of the sheath back out the opening. The fid is removed from the end of the core and the hook attached to the end of the sheath with whipping, as before. The fid and attached end of the sheath are then pulled through the exposed portion of the core for a certain distance and the fid is removed from the end of the sheath. The core and sheath are thereafter alternately pulled to tighten the crossover of the core and sheath and bury the same in the sheath to complete the splice.
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BACKGROUND OF THE INVENTION
The infectious hypodermal and hematopoietic necrosis virus (IHHNV) is an economically significant pathogen of penaeid shrimp grown in mariculture. The virus has a broad host species range; it may kill up to 90% of the juveniles of certain penaeid shrimp species.
The penaeid shrimp virus IHHNV has been isolated from infected shrimps. ( Y. N. Lu, P. C. Loh, and J. A. Brock, "Isolation and Characterization of the Infectious Hypodermal and Hematopoietic Necrosis Virus of penaeid Shrimp," 89th Annual Meeting, American Society for Microbiology, New Orleans, La., May 14-18, 1989.) The virus has been found to have a buoyant density in CsCl of 1.33 g/cm 3 . Electron microscopical studies have shown the virus to exist as isometric particles with a size of 19±1 nm. Also, colorimetric analyses of the viral nucleic acid by the orcinol test have shown that the virus contains RNA. (Shatkin, A. J. in "Fundamental Techniques in Virology", Habel, K. and Salzman, N. P., eds. p. 23, Academic Press, N.Y. (1969)).
Previously, biological and biochemical studies of IHHNV have been limited because the virus could only be grown in young post-larval shrimps using an indicator shrimp bioassay. (Lightner et al., J. World Maric. Soc. 14:212-225, 1983). Consequently, the lack of an in vitro cell culture method for IHHNV made it difficult to develop serologically based methods useful for the rapid detection of the virus in shrimp stocks. Additionally, the only available method of IHHNV assay formerly available, the in vivo indicator shrimp bioassay procedure, is expensive, time consuming (on the order of days to weeks), and requires highly trained personnel.
The growth of crustacean virus according to the present invention provides a readily available source of cultured virus useful for development of immune sera for the rapid detection of virus in its habitat.
DESCRIPTION OF THE INVENTION
In brief, the present invention provides for an in vitro method of growth of crustacean virus in a fish cell line. In a preferred embodiment, the penaeid shrimp virus IHHNV is grown in an established culture of epithelioma papillosum cyprini (EPC), a cell line derived from proliferative skin lesions of carp, Cyprinus carpio. Initially, the host culture containing the fish cell line may be grown, typically at around 20° C., as a monolayer on a solid surface in a suitable nutrient medium, such as Eagle's minimal essential medium (MEM) supplemented with 10% fetal bovine serum (10FBS). If the IHHNV is used it is added to the culture and typically is adsorbed to host cells, such as EPC cells, at room temperature for one hour. A suitable growth medium will typically be added and the cells will be incubated at about 20° to 25°C. The culture may be monitored by light microscopy to assess cytopathology secondary to IHHNV infection. The virus will typically complete exponential growth within 48 hours. The virus is then harvested, preferably by suspension of the culture in phosphate-buffered saline (pH about 7.5), freezing-thawing, centrifugation; collection of the supernatant, extraction with trifluro-trichloroethane, and precipitation in the aqueous phase with PEG-NaCl. Upon purification, virus yields may be attained at 10 8 TCID 50 /ml or higher.
Virus which has been adapted as described above in EPC cells, may be further cultured in other fish cells lines such cells from grass carp (GC), using the culturing method described herein.
The culturing of IHHNV using EPC cells under a solid overlay also provides a plaque quantitative assay of the titer of IHHNV. By this method, a count of the foci of lesions caused by the virus can be quantitatively correlated with cultures of known quantities of virus.
It will be appreciated that various modifications of the above description may be made without departing from the scope of the invention. The following examples are provided by way of illustration and are not intended to limit the invention in any way.
EXAMPLE 1
The starting monolayer cultures of EPC are grown on Eagle's minimal essential medium (MEM) supplemented with 10% fetal bovine serum (10FBS), at 20° C., using plastic tissue containers of culture grade. The IHHNV used for inoculation of the EPC cells in the present invention was obtained from IHHNV-infected shrimp as described by Lu, supra. The IHHNV was then banded in cesium chloride (CsCl). The EPC monolayer was then infected with ten-fold dilutions of the CsCl-banded IHHNV. Viral adsorption to the cells is accomplished by retaining the cells together with the virus at room temperature for one hour. Thereafter, experimental medium, MEM10FBS, is added and the infected culture is re-incubated at 20°C.
During development the cell cultures were examined daily by light microscopy. Using light microscopy it was possible to detect focal areas of cytopathology, following application of undiluted virus, as early as two days following infection. The foci of cytopathology progressively increased in size. The counting of these foci may be used as a quantitative assay of viral concentration (or yield) when correlated to the number of such foci in known samples treated under identical conditions. By the fifth day post-infection almost the entire monolayer was destroyed. Where the cultures were infected with higher virus dilutions, cytopathology was not evident until later. Infectivity titres, as estimated by the 50% tissue culture infectious dose end point (TCID so ) were 10 6 TCID 50 /ml, using the method of Reed et al., Amer. J. Hyg. 27, 493-497 (1938).
Virus was harvested from the infected cultures and was serially passaged five times in EPC cells. As a general harvesting procedure, after collection of the virus-producing plaques, a 33% homogenized suspension in phosphate-buffered saline (PBS), pH 7.5, was prepared and the homogenate frozen and thawed three times. After slow speed centrifuge (1000 rpm, 10 min., 4°C.), the supernatant was collected and treated with trifluorotrichloroethane (Genetron 113) and the aqueous supernatant precipitated with polyethylene glycol-NaCl mixture (8% PEG in 0.125 M NaCl). The precipitate was recovered by slow speed centrifugation and resuspended in PBS. After centrifugation at 10,000 rpm, 20 minutes, 4° C., the recovered supernatant was centrifuged at 40,000 rpm., 1.5 hours at 4°C, and the pellet resuspended in PBS. For final purification the virus was isopycnically banded in CsCl and fractions were collected from the bottom of the tube and optical densities at 260 nm and 280 nm, respectively, read. Virus yields were as high as 10 8 TCID 50 /ml. Isopycnic ultracentrifugation in CsCl of such passaged virus preparations yielded particles with a buoyant density of 1.33g/cm 3 , similar to that of the original virus isolates. When the passaged virus preparations were negatively stained with 2% phosphotungstic acid and then examined by electron microscopy, only naked isometric particles of 19±1 nm diameter were seen. This particle size also corresponded to that of the original virus isolates.
The one-step growth cycle of the virus in EPC cells showed an eclipse period of about 3 hours, which was followed by an exponential growth phase which was completed by 48 hours post-infection. The virus yield at 48 hours post-infection was 10 8 .3 TCID 50 /ml.
EXAMPLE 2
Colorimetric analyses by the orcinol procedure of the starting IHHNV isolates revealed that the IHHNV contained RNA. That the virus contained RNA was reaffirmed using 5-bromo-2-deoxyuridine (BUDR), a DNA antagonist. At a concentration of 20ug/ml BUDR did not inhibit the replication of IHHNV in the EPC cells. In contrast, BUDR did interfere with the replication of DNA-containing vaccinia virus. Similarly, an inhibitory result was obtained when BUDR was used on the DNA-containing fish virus, channel catfish virus. An inhibitory result did not occur when BUDR was used to treat the RNA-containing fish virus, spring viremia of carp virus.
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A method is provided, whereby a crustacean virus is grown in fish cells. In particular, infectious hypodermal and hematopoietic necrosis virus (IHHNV) is grown in the established fish cell line, epithelioma papillosum cyprini (EPC).
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. §119(e) from earlier filed U.S. Provisional Application Ser. No. 61/810,638 filed on Apr. 10, 2013 and incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a sampling filter process for scalable video coding. More specifically, the present invention relates to re-sampling using video data obtained from an encoder or decoder process, where the encoder or decoder process can be MPEG-4 Advanced Video Coding (AVC) or High Efficiency Video Coding (HEVC). Further, the present invention specifically relates to Scalable HEVC (SHVC) that includes a two layer video coding system.
[0004] 2. Related Art
[0005] An example of a scalable video coding system using two layers is shown in FIG. 1 . In the system of FIG. 1 , one of the two layers is the Base Layer (BL) where a BL video is encoded in an Encoder E0, labeled 100 , and decoded in a decoder D0, labeled 102 , to produce a base layer video output BL out. The BL video is typically at a lower quality than the remaining layers, such as the Full Resolution (FR) layer that receives an input FR (y). The FR layer includes an encoder E1, labeled 104 , and a decoder D1, labeled 106 . In encoding in encoder E1 104 of the full resolution video, cross-layer (CL) information from the BL encoder 100 is used to produce enhancement layer (EL) information. The corresponding EL bitstream of the full resolution layer is then decoded in decoder D1 106 using the CL information from decoder D0 102 of the BL to output full resolution video, FR out. By using CL information in a scalable video coding system, the encoded information can be transmitted more efficiently in the EL than if the FR was encoded independently without the CL information. An example of coding that can use two layers shown in FIG. 1 includes video coding using AVC and the Scalable Video Coding (SVC) extension of AVC, respectively. Another example that can use two layer coding is HEVC.
[0006] FIG. 1 further shows block 108 with a down-arrow r illustrating a resolution reduction from the FR to the BL to illustrate that the BL can be created by a downsampling of the FR layer data. Although a downsampling is shown by the arrow r of block 108 FIG. 1 , the BL can be independently created without the downsampling process. Overall, the down arrow of block 108 illustrates that in spatial scalability, the base layer BL is typically at a lower spatial resolution than the full resolution FR layer. For example, when r=2 and the FR resolution is 3840×2160, the corresponding BL resolution is 1920×1080.
[0007] The cross-layer CL information provided from the BL to the FR layer shown in FIG. 1 illustrates that the CL information can be used in the coding of the FR video in the EL. In one example, the CL information includes pixel information derived from the encoding and decoding process of the BL. Examples of BL encoding and decoding are AVC and HEVC. Because the BL pictures are at a different spatial resolution than the FR pictures, a BL picture needs to be upsampled (or re-sampled) back to the FR picture resolution in order to generate a suitable prediction for the FR picture.
[0008] FIG. 2 illustrates an upsampling process in block 200 of data from the BL layer to the EL. The components of the upsampling block 200 can be included in either or both of the encoder E1 104 and the decoder D1 106 of the EL of the video coding system of FIG. 1 . The BL data at resolution x that is input into upsampling block 200 in FIG. 2 is derived from one or more of the encoding and decoding processes of the BL. A BL picture is upsampled using the up-arrow r process of block 200 to generate the EL resolution output y′ that can be used as a basis for prediction of the original FR input y.
[0009] The upsampling block 200 works by interpolating from the BL data to recreate what is modified from the FR data. For instance, if every other pixel is dropped from the FR in block 108 to create the lower resolution BL data, the dropped pixels can be recreated using the upsampling block 200 by interpolation or other techniques to generate the EL resolution output y′ from upsampling block 200 . The data y′ is then used to make encoding and decoding of the EL data more efficient.
SUMMARY
[0010] Embodiments of the present invention provide systems for the upsampling process from BL resolution to EL resolution to implement the upsampling of FIG. 2 . The upsampling process of embodiments of the present invention includes three separate modules, a first module to select input samples from the BL video signal, a second module to select a filter for filtering the samples, and a third module using phase filtering to filter the input samples to recreate video that approximates the EL resolution video. The filters of the third module can be selected from a set of fixed filters each with different phase, or one or more adaptive or variable filters with a selectable phase offset.
[0011] For embodiments of the present invention luma and chroma phase offset are separately accounted for in the filtering process. In one embodiment, the luma and chroma offset used in the downsampling are determined and used to modify the phase offset determined for upsampling and a filter chosen based on the combined offset.
[0012] The luma and chroma offsets can be separately accounted for in either horizontal or vertical dimensions or both using the filters. The filters can include separate row and column filters to enable parallel filter processing of samples along an entire row or column to accommodate a single dimension offset corrections for luma and chroma.
[0013] A flag in syntax can be used to signal deblocking and SAO processing. For the case of AVC and HEVC, the BL pixel data used for re-sampling can either be before or after the deblocking process. And for the case of HEVC, the BL pixel data used can either be with or without SAO processing. For AVC and HEVC BL, a first syntax flag can be signaled to indicate whether the upsampling is performed on data that has been previously deblocked. If the first flag is not set, then the upsampling is performed on data prior to deblocking. If the first flag indicates that upsampling is to be performed on data that has been previously deblocked, a second syntax flag is further signaled to indicate whether the upsampling is to be performed on data that has been further processed with SAO. If the second flag is set, then the upsampling is performed on data after SAO; otherwise, it is performed on data prior to SAO but after deblocking.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Further details of the present invention are explained with the help of the attached drawings in which:
[0015] FIG. 1 is a block diagram of components in a scalable video coding system with two layers;
[0016] FIG. 2 illustrates an upsampling process that can be used to convert the base layer data to the full resolution layer data for FIG. 1 ;
[0017] FIG. 3 shows a block diagram of components for implementing the upsampling process of FIG. 2 ;
[0018] FIG. 4 shows components of the select filter module and the filters, where the filters are selected from fixed or adaptive filters to apply a desired phase shift;
[0019] FIG. 5 shows a table including syntax for signaling of luma and chroma phase shift offset that is signaled to select from fixed filters;
[0020] FIG. 6 shows a flow chart of simplified method steps for selecting filters using luma and chroma phase offset in a first embodiment of the present invention;
[0021] FIG. 7 shows a table including syntax for signaling of luma and chroma adaptive filter parameters; and
[0022] FIGS. 8-9 show a flow chart of simplified method steps for signaling adaptive filters with luma and chroma phase offset in a second embodiment of the present invention.
DETAILED DESCRIPTION
I. Overview of Upsampling Circuitry for Adaptive Phase Correction
[0023] FIG. 3 shows a general block diagram for implementing an upsampling process of FIG. 2 for embodiments of the present invention. The upsampling or re-sampling process can be determined to minimize an error E (e.g. mean-squared error) between the upsampled data y′ and the full resolution data y. The system of FIG. 3 includes a select input samples module 300 that samples an input video signal. The system further includes a select filter module 302 to select a filter from the subsequent filter input samples module 304 to upsample the selected input samples from module 300 .
[0024] In module 300 , a set of input samples in a video signal x is first selected. In general, the samples can be a two-dimensional subset of samples in x, and a two-dimensional filter can be applied to the samples. The module 302 receives the data samples in x from module 300 and identifies the position of each sample from the data it receives, enabling module 302 to select an appropriate filter to direct the samples toward a subsequent filter module 304 . The filter in module 304 is selected to filter the input samples, where the selected filter is chosen or configured to have a phase corresponding to the particular output sample location desired.
[0025] The filter input samples module 304 can include separate row and column filters. The selection of filters is represented herein as filters h[n; p], where the filters can be separable along each row or column, and p denotes a phase index selection for the filter. The output of the filtering process using the selected filter h[n; p] on the selected input samples produces output value y′.
[0000] II. Circuitry with Filter Selection for Adaptive Phase Correction
[0026] FIG. 4 shows details of components for the select sample module 302 of FIG. 3 (labeled 302 a in FIG. 4 ) and the filters module 304 of FIG. 3 (labeled 304 a in FIG. 4 ) for a system with fixed filters. For separable filtering the input samples can be along a row or column of data. To supply a set of input samples from select input samples module 300 , the select filter module 302 a includes a select control 400 that identifies the input samples x[m] and provides a signal to a selector 402 that directs them through the selector 402 to a desired filter. The filter module 304 a then includes the different filters h[n; p] that can be applied to the input samples, where the filter phase can be chosen among P phases from each row or column element depending on the output sample m desired. As shown, the selector 402 of module 302 a directs the input samples to a desired column or row filter in 304 a based on the “Filter (n) SEL” signal from select control 400 . A separate select control 400 signal “Phase (p) SEL” selects the appropriate filter phase p for each of the row or column elements. The filter module 304 a output produces the output y′[n].
[0027] In FIG. 4 , the outputs from individual filter components h[n; p] are shown added “+” to produce the output y′[n]. This illustrates that each box, e.g. h[0; p], represents one coefficient or number in a filter with phase p. Therefore, the filter with phase p is represented by all n+1 numbers in h[0,p], . . . , h[n; p]. This is the filter that is applied to the selected input samples to produce an output value y′[n], for example, y′[0]=h[0,p]*x[0]+h[1,p]*x[1]+ . . . +h[n,p]*x[n], requiring the addition function “+” as illustrated. As an alternative to adding in FIG. 4 , the “+” could be replaced with a solid connection and the output y′[n] would be selected from one output of a bank of P filters representing the p phases, with the boxes h[n:p] in module 304 a relabeled, for example, as h[n; 0], h[n,1], . . . , h[n,p−1] and now each box would have all the filter coefficients needed to form y′ [n] without the addition element required.
[0028] In addition of how to configure the components of FIG. 4 to select input samples to add or combine coefficients to form y′ [n] other modifications to the circuitry of FIG. 4 can be made for additional embodiments of the present invention. Such modifications are described in the following sections A-C.
[0029] A. Filters with Adaptive Phase Control
[0030] Although the filters h[n:p] in module 304 a are shown as separate phase fixed devices, they can be implemented using a single filter with phase p selected and adaptively controlled. The adaptive phase filters can be reconfigured by software. The adaptive filters can thus be designed so that each filter h[n; p] corresponds to a desired phase p.
[0031] The filter coefficients h[n; p] can be signaled in the EL from the encoder so that the decoder can reconstruct a prediction to the FR data. Alternatively, a difference between the coefficients and a specified (or predicted) set of coefficients can be transmitted. The coefficient transmission can be made at some unit level (e.g. sequence parameter set (SPS), picture parameter set (PPS), slice, largest coding unit (LCU), coding unit (CU), prediction unit (PU), etc.) and per color component. Furthermore several sets of filters can be signaled per sequence, picture or slice and the selection of which set to be used for re-sampling can be signaled at finer levels, for example at picture, slice, LCU, CU or PU level.
[0032] B. Separable Column and Row Filtering
[0033] For the re-sampling process, in one embodiment the filters applied can be separable, and the coefficients for each horizontal (row) and vertical (column) dimension can be signaled or selected from a set of filters. This is illustrated by the filters h[n; p] in FIG. 4 that provide separate filters for either an individual row or column. The processing of row or columns separably allows for flexibility in filter characteristics (e.g. phase offset, frequency response, number of taps, etc.) in both dimensions while retaining the computational benefits of separable filtering.
[0034] The separable filtering in the re-sampling process can be specified as row filtering first or column filtering first, as the order may affect the memory or computational requirements. In the case of deriving filters based on only the BL and FR data as described previously, note that if row filtering and re-sampling is performed first, the estimation of the filters used for column filtering can be done based on the re-sampled row data (or vice-versa). The filter coefficients can be transmitted in the EL, or a difference between the coefficients and a specified (or predicted) set of coefficients can be transmitted.
[0035] C. Hardware and Software Modules for Circuitry
[0036] For the upsampling process components for FIG. 4 , embodiments of the present invention contemplate that the components can be formed using specific hardware components as well as software modules. For the software modules, the system can be composed of one or more processors with memory storing code that is executable by the processor to form the components identified and to cause the processor to perform the functions described.
III. Accounting for Luma and Chroma Offset
[0037] In SHM1.0, the upsampling process from the BL is performed using separable, fixed filters that are identical for each dimension. As a consequence, the phase offsets for the filters used for interpolation are fixed. However, since downsampling is a non-normative process, it is possible that upsampling with assumed, fixed phase offset filters may not properly compensate for a phase offset introduced from downsampling in each dimension. In particular, since luma and chroma components may have different color space resolutions, upsampling for the different color components may require different phase offsets for each dimension. To address this issue, embodiments of the present invention propose two possible solutions for SHVC.
[0038] A. Selecting a Filter Based on Normative Offset and Luma/Chroma Offset
[0039] The first embodiment provides for a selection of one of multiple filters in FIG. 4 to account for luma and chroma offset. In the current SHM1.0, a set of 16 fixed filters with different phase offsets in the unit interval can be specified. These filters are indexed where larger filter indices are used for larger phase offsets. In order to accommodate a phase offset introduced from downsampling required to maintain proper luma/chroma color space positions after upsampling, it is proposed that an offset parameter be signaled and used in computing the filter index separate from the normative offset. One example of this for the case of 16 filters is shown in Table 1 of FIG. 5 , where the signaling (highlighted) occurs at the PPS level. Note that the signaling can occur at other places within the PPS. Alternatively, signaling can be specified at other levels, e.g. VPS, SPS, slice, PU, etc. Further, although offset adjustment is being accounted for in luma/chroma phase positions, similar phase compensation can be made for color spaces, cropping, etc.
[0040] In Table 1, when cross-layer (CL) pixel prediction is allowed in an EL (e.g. nuh_layer_id>0 and a flag InterLayerTextureR1EnableFlag is set in SHVC Test Model 1), the four syntax elements listed below are signaled. Note that although specific logic syntax is shown in Table 1 to activate the following four syntax elements, the following four syntax elements, as also shown in Table 1, can be signaled whenever CL prediction is enabled.
[0041] luma_phase_offset[0] indicates that the filter index used for upsampling the rows of the luma component should be obtained by adding luma_phase_offset[0] to the offset in the scaled grid, before computing the final index. This is a signed value between −15 to +15 (given a scaled grid size of 16×).
[0042] luma_phase_offset[1] indicates that the filter index used for upsampling the columns of the luma component should be obtained by adding luma_phase_offset[1] to the offset in the scaled grid, before computing the final index. This is a signed value between −15 to +15 (given a scaled grid size of 16×).
[0043] chroma_phase_offset[0] indicates that the filter index used for upsampling the rows of the chroma component should be obtained by adding chroma_phase_offset[0] to the offset in the scaled grid, before computing the final index. This is a signed value between −15 to +15 (given a scaled grid size of 16×).
[0044] chroma_phase_offset[1] indicates that the filter index used for upsampling the columns of the chroma component should be obtained by adding chroma_phase_offset[1] to the offset in the scaled grid, before computing the final index. This is a signed value between −15 to +15 (given a scaled grid size of 16×).
[0045] The above syntax is proposed for the Joint Collaborative Team on Video Coding (JCT-VC), SHVC Test Model 1 (SHM 1) Section G.6.2 entitled “Derivation process for reference layer sample location used in resampling,” and in particular see J. Chen, J. Boyce, Y. Ye, M. Hannuksela, “Draft of SHVC Test Model Description,” JCTVC-L1007, January 2013. The proposed text for SHVC G.6.2 includes information helpful in understanding the syntax, so it is modified as follows:
[0046] For the SHVC text in G.6.2, the inputs to this process are:
a variable cIdx specifying the color component index, and a sample location (xP, yP) relative to the top-left sample of the color component of the current picture specified by cIdx.
[0049] The output of this process is a sample location (xRef16, yRef16) specifying the reference layer sample location in units of 1/16-th sample relative to the top-left sample of the reference layer picture.
[0050] If cIdx is equal to 0, the variables xRef16 and yRef16 are derived as follows:
[0000] x Ref16=( xP *PicWRL*16+Scaled W /2)/Scaled W +lumaphase_offset[0]
[0000] y Ref16=( yP *PicHRL*16+Scaled H /2)/Scaled H +luma_phase_offset[1]
[0051] Otherwise, the variables xRef16 and yRef16 are derived as follows:
[0000] x Ref16=( xP *PicWRL*16+Scaled W/ 2)/Scaled W +chromaphase_offset[0]
[0000] y Ref16=( yP *PicHRL*16+Scaled H/ 2)/Scaled H+ chroma_phase_offset[1]
[0052] Note that the syntax for this first embodiment concentrates on activity in FIG. 3 element 300 that selects samples to determine xRef16 and yRef16. The elements xRef16 and yRef16 are determined for downconverted reference pictures that are identified in the select samples element 300 . The PicWRL is the picture width reference layer and the PicHRL is the picture height reference layer, also identified in the select samples of element 300 . The references to ScaledW for scaled width and ScaledH for scaled height, however, are determined from the FR layer to enable a conversion back from the BL to calculate the EL picture elements with phases set by xRef16 and yRef16. Note that a rounding operation is used in the division operation by ScaledW and ScaledH in the calculation of xRef16 and yRef16. The phase offset determined by the operation for xRef16 and yRef16 first includes a portion divided by ScaledW and ScaledH that will provide a normative phase offset, and the luma and chroma offsets are added to create the final phase values.
[0053] FIG. 6 shows a simplified flow chart for the above method steps from Table 1 and syntax for determining xRef16 and yRef16 for selecting filters using luma and chroma phase offset in this first embodiment of the present invention. In step 600 , the cross layer (CL) prediction is examined to determine if luma and chroma offset steps are to be considered. If so, the steps after 600 are processed. In steps 601 and 602 the luma phase offset is determined for the rows and columns. In steps 603 and 604 , the chroma phase offset is determined for the rows and columns. Finally in step 605 the xRef16 and yRef16 values are determined for both luma and chroma from the syntax described above.
[0054] The syntax elements allow for different phase offset shifts for luma and chroma as well as for horizontal and vertical directions. However, drawbacks of this first filter selection approach are that only a shift in phase offsets is allowed, all 16 filters (or another fixed number in the system) need to be specified, and the 16 phase offsets are fixed. In addition, rounding operations still need to be performed from desired phase offsets to one the 16 fixed phase offsets. A proposed second embodiment to address these issues is described in the next section.
[0055] B. Adapting Filter Based on Luma/Chroma Offset
[0056] The second embodiment provides for adjusting the phase offset based upon signaling of adaptive filters. In order to allow for interpolation filters with more general phase offsets and characteristics, instead of re-indexing the filter index of existing fixed filters, this second embodiment signals the filters with the desired phase offsets. The filter coefficients can be differentially signaled using existing HEVC filters, such as the filters used for sub-pixel interpolation in HEVC. Other reference filters can also be used for differential coding of the coefficients.
[0057] The Table 2 of FIG. 7 shows syntax for a proposed example for signaling at the PPS level for an embodiment where adaptive filtering offset can be signaled. Note that the signaling can occur at other places within the PPS. As with the fixed filter embodiment of section A, for an alternative signaling can be specified at other levels, e.g. VPS, SPS, slice, PU, etc.
[0058] As with the fixed filters of Table 1, in Table 2 of FIG. 7 , when cross-layer (CL) pixel prediction is allowed in an EL (e.g. nuh_layer_id>0 and a flag InterLayerTextureR1EnableFlag is set in SHVC Test Model 1), the syntax elements for this embodiment are likewise signaled. Note that although specific logic syntax is shown in Table 2 to activate the following syntax elements, the following syntax elements can be signaled whenever CL prediction is enabled. The syntax elements for adaptive filtering are as follows:
[0059] num_phase_offsets_minus1[0] plus one indicates the number of filters with the desired phase offsets for the row upsampling process.
[0060] num_phase_offsets_minus1[1] plus one indicates the number of filters with the desired phase offsets for the column upsampling process.
[0061] luma_pixel_shift_flag[i][j] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]), whether the filter is to be applied to shifted input luma samples. When this flag is set to 1, the filter is applied to input samples that are shifted by one pixel; otherwise, input samples are not shifted.
[0062] ref_luma_filter_indx[i][j] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]), the filter index of one of the four HEVC reference filters used for sub-pixel luma interpolation at 0, ¼, ½ and ¾ phase offsets.
[0063] delta_luma_filter_coef[i][j][k] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]) and filter coefficient index k (k=0, . . . , num_luma_taps_minus1[i]), the incremental value which should be added to the corresponding coefficient of the reference filter with index ref_luma_filter_indx[i][j] to obtain the actual filter coefficients for the current filter phase index.
[0064] chroma_pixel_shift_flag[i][j] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]), whether the filter is to be applied to shifted input chroma samples. When this flag is set to 1, the filter is applied to input samples that are shifted by one pixel; otherwise, input samples are not shifted.
[0065] ref_chroma_filter_indx[i][j] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]), the filter index of one of the eight HEVC reference filters used for sub-pixel chroma interpolation at 0, ⅛, ¼, ⅜, ½, ⅝, ¾ and ⅞ phase offsets.
[0066] delta_chroma_filter_coef[i][j][k] indicates per dimension i (i=0, 1) and filter phase index j (j=0, . . . , num_phase_offsets_minus1[i]) and filter coefficient index k (k=0, . . . , num_chroma_taps_minus1[i]), the incremental value which should be added to the corresponding coefficient of the reference filter with index ref_chroma_filter_indx[i][j] to obtain the actual filter coefficients for the current filter phase index.
[0067] The values of num_luma_taps_minus1[i] and num_chroma_taps_minus1[i] per dimension i are set to 7 and 3, respectively. In general, these values can also be specified or signaled for each dimension.
[0068] To make operation more efficient, in some embodiments the luma_pixel_shift_flag[i][j] and a chroma_pixel_shift_flag[i][j] are implemented. If the flag is set to 1, then the corresponding j_th luma or chroma filter for dimension i is applied to input samples that are shifted by one pixel; otherwise, the input samples are not shifted.
[0069] The value of syntax elements ref_uma_filter_indx[i][j] or ref_chroma_filter_indx[i][j] indicates one of four HEVC sub-pixel luma or eight chroma interpolation filters that is used as a basis for prediction for the j_th luma or chroma adaptive phase offset filter along dimension i. The k_th coefficient of the j_th filter along dimension i for luma or chroma is modified by the adding the value of delta_luma_filter_coef[i][j][k] or delta_chromafilter_coef[i][j][k]. Together, these syntax elements specify the adaptive luma and chroma filters that are used to replace the fixed filters in Tables G-1 and G-2 in SHVC Test Model 1. Note that Tables G-1 and G-2 in SHVC Test Model 1 use 16 filters whereas in the proposed method the number of filters can be specified by numphase_offsets_minus1[i] in each dimension i.
[0070] In one embodiment, a set of default filters for upsampling can be agreed upon for the encoder and decoder. In the case that the default filters are used, a flag can be set and signaled to indicate this. If the flag is not set, then the method described above can be used to signal the filter parameters, and signaling of the filter coefficients can be based on differential coding of the coefficients relative to the default filters.
[0071] The semantics corresponding to the above syntax of Table 2 can be changed in the draft Sections G.6.2, G.8.1.4.1.3 and G.8.1.4.1.4 (for Luma and Chroma sample interpolation process) of SHVC Test Model 1 (SHM 1). It should be noted that the proposed derivation process no longer requires rounding operations. The proposed text to help in understanding the syntax, is as follows:
[0072] Inputs to this process are
a variable cIdx specifying the color component index, a sample location (xP, yP) relative to the top-left sample of the color component of the current picture specified by cIdx,
[0075] Output of this process is a sample location (xRef, yRef) specifying the reference layer sample location relative to the top-left sample of the reference layer picture, and phases (xPhase, yPhase).
[0076] 1. The variables xRefphase and yRefphase are derived as follows:
[0000] x Refphase=( xP *PicWRL*(num_phase_offsets_minus1[0]+1))/Scaled W
[0000] y Refphase=( yP *PicHRL*(num_phase_offsets_minus1[1]+1))/Scaled H
[0077] 2. The variables xRef and xPhase are derived by
[0000] x Ref=( x Refphase/(num_phase_offsets_minus1[0]+1))
[0000] x Phase=( x Refphase− x Ref*(num_phase_offsets_minus1[0]+1))
[0078] 3. The variables yRef and yPhase are derived by
[0000] y Ref=( y Refphase/(num_phase_offsets_minus1[1]+1))
[0000] y Phase=( y Refphase− y Ref*(num_phase_offsets_minus1[1]+1))
[0079] Note that for certain values of num_phase_offsets_minus1[0] and num_phase_offsets_minus1[1], the operations for computing xRef, xPhase, yRef, and yPhase may be performed by simpler operations (e.g. shift, &0x0F). Also, if the number of filters is restricted to be 2̂g, the index g (instead of the value 2̂g) can be signaled to indicate 2̂g filters. Also, in order to account for negative phase offsets, the luma or chroma values of xRef or yRef are decreased by one if the corresponding luma_pixel_shift_flag or chroma_pixel_shift_flag flags are set; otherwise the values of xRef or yRef are not modified.
[0080] As with the embodiment of Table 1, for the above syntax a concentration is made on the select samples element 300 of FIG. 3 , but also with this embodiment calculations performed using syntax in filter selection element 302 is illustrated. The xRef and yRef are position locations based on downconverted reference pictures that are identified in the select samples element 300 . The xRef and yRef values are determined using xRefphase and yRefphase that are calculated in a similar matter to the syntax shown previously relative to Table 1. The xRefphase and yRefphase values in this current embodiment will produce a remainder that will be used to calculate the phase offsets xPhase and yPhase. The xPhase and yPhase values are the phase offset values used to select a filter element in selection module 302 of FIG. 3 . Because the filters in this embodiment are adaptive, a rounding operation is not necessarily required after calculations unlike with the previously described embodiment.
[0081] FIGS. 8-9 shows a simplified flow chart for the above method steps from Table 2 and syntax for determining xRef, yRef, xPhase and yPhase for signaling adaptive filters with luma and chroma phase offset in this second embodiment of the present invention. In step 800 , the cross layer (CL) prediction is examined to determine if luma and chroma offset steps are to be considered. If so, the steps after 800 are processed. In steps 801 and 802 the number of filters to be evaluated for phase offset adjustment is determined along rows and columns. Next in a loop through steps 803 - 806 to consider the luma offset for each filter, a flag indicating if a pixel shift should be made is evaluated in step 804 , a reference luma filter is determined in step 805 , and the delta_luma_filter_coef values are used to modify the reference luma filter in step 806 . Further in steps 807 - 810 , a similar loop is performed to determine the chroma filters. Finally in steps 811 - 812 the xRef, yRef, xPhase and yPhase values are determined.
[0082] Benefits of this second embodiment include the following: (1) Arbitrary phase offsets are allowed in each dimension. (2) Better matching of filters and phases to scalability ratios other than 2×, 1.5×. (3) Less computation needed since rounding operations to map a desired phase to one of the current fixed phases are eliminated. (4) Only the filters and phases necessary for performing the upsampling need to be signaled and indexed; there is no need to design and implement 16 luma and 16 chroma filters.
[0083] C. Deblocking and SAO Processing
[0084] Either of the embodiments illustrated with Table 1 or Table 2 can be implemented whether deblocking or SAO processing is used. In the upsampling process, pixel data from the encode/decode process from the BL is used to generate a prediction for the FR pixel data. The BL pixel data can be extracted, for example, at various points in the decoding process. For the case of AVC and HEVC, the BL pixel data used for re-sampling can either be before or after the deblocking process. And for the case of HEVC, the BL pixel data used can either be with or without SAO processing. In one embodiment for an AVC and HEVC BL, a first syntax flag can be signaled to indicate whether the upsampling is performed on data that has been previously deblocked. If the first flag is not set, then the upsampling is performed on data prior to deblocking. In addition, for the case of an HEVC BL, if the first flag indicates that upsampling is to be performed on data that has been previously deblocked, a second syntax flag is further signaled to indicate whether the upsampling is to be performed on data that has been further processed with SAO. If the second flag is set, then the upsampling is performed on data after SAO; otherwise, it is performed on data prior to SAO but after deblocking. The signaling of the flags can be made at some unit level (e.g. SPS, PPS, slice, LCU, CU, PU, etc.) and per color component, or it can be derived or predicted from other previously decoded data.
[0085] Although the present invention has been described above with particularity, this was merely to teach one of ordinary skill in the art how to make and use the invention. Many additional modifications will fall within the scope of the invention as that scope is defined by the following claims.
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A sampling filter process is provided for scalable video coding. The process provides for re-sampling using video data obtained from an encoder or decoder process of a base layer (BL) in a multi-layer system using adaptive phase shifting to improve quality in Scalable High efficiency Video Coding (SHVC). In order to compensate for phase offsets introduced by downsampling an appropriate phase offset adjustment is made for upsampling in SHVC with an appropriate offset included for proper luma/chroma color space positions. In one approach the luma/chroma phase offset is specified and a filter is selected to apply the appropriate phase change.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/935,938, filed Sep. 8, 2004 now U.S. Pat. No. 7,861,373, which claims priority of provisional application No. 60/501,289, filed Sep. 8, 2003, the disclosures of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to jerk handles for lanyards of manual inflators or the manual portion of automatic inflators.
2. Description of the Background Art
As the term is commonly employed, a “jerk handle” is a handle connected to the trailing end of a lanyard composed of a cord. The standing end of the lanyard cord is then operatively connected to a device that requires manual actuation upon pulling of the jerk handle. A common application for jerk handles is in the inflation art. In the inflation art, a manual inflator (or the manual portion of an automatic inflator) is connected to an inflation valve of a cartridge of compressed gas. The assembly is then sealingly connected to an article to be inflated. Typical articles may include an inflatable life vest or life raft. To inflate, the user simply grasps the jerk handle and gives it a jerk to manually actuate the inflator causing inflation of the inflatable article.
Heretofore, the trailing end of a length of lanyard cord is molded in situ with the jerk handle to form the lanyard. U.S. Pat. No. 5,099,546, the disclosure of which is hereby incorporated by reference herein, discloses a mold-in-situ jerk handle for inflators. In this form, the lanyard is typically shipped to the manufacturer of the inflator who then assembles it by operatively coupling the standing end of the lanyard cord to the inflator in a manner dictated by the particular design of the inflator itself.
It is often desirous to have a supply of lanyards with different lengths of cords and therefore there exists a need in the industry for the ability for the inflator manufacturer to assemble the jerk handle to the trailing end of the cord as needed instead of having to purchase the assembly molded in situ. U.S. Pat. No. 5,347,685, the disclosure of which is hereby incorporated by reference herein, discloses an assemblable jerk handle comprising a channel in which the lanyard cord is positioned and then secured by means of a strip with spikes that snap-fit into the channel to “spike” the lanyard cord and hold it in position. However, a more durable assemblable jerk handle is needed that more securely retains the lanyard cord and that is not disassemblable once assembled.
Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the inflation art.
Another object of this invention is to provide a jerk handle that may be permanently affixed about the trailing end of a lanyard cord by a simple coupling of two components together to securely and permanently grasp the cord therebetween.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
For the purpose of summarizing this invention, the first embodiment of this invention comprises an assemblable jerk handle composed of two pieces that snap together to securely retain a lanyard cord therebetween. More particularly, the jerk handle of the invention comprises a base portion having interior progressive teeth forming a channel for receiving the lanyard cord and a cap portion for permanently snap-fitting to the base portion whereupon the lanyard cord is forcibly entrained by the teeth to securely and permanently grasp the lanyard cord.
The second embodiment of this invention comprises an assemblable jerk handle including a base portion having a center channel positioned therethrough for receiving a bifurcated plug. During assembly, the trailing end of the lanyard cord is positioned within the bifurcated plug and then inserted as a combination into the center channel of the base portion. Upon further inward movement of the bifurcated plug, the plug forcibly closes about the lanyard cord to securely grip and therefore retain the trailing end of the lanyard cord within the center channel of the base portion. Importantly, once the bifurcated plug is forced into the center channel, the bifurcated plug cannot be removed therefrom and therefore permanently grips the lanyard cord.
The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a front view of the first embodiment of the jerk handle of the invention;
FIG. 2 is a rear view thereof showing the cap;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a top exploded view thereof;
FIG. 6 is a bottom exploded view thereof;
FIG. 7 is a rear view thereof showing the inside portion of the base portion with the cap removed;
FIG. 8 is a view showing the inside of the rear of the jerk handle illustrating the matched opposing teeth which grip the lanyard cord to be positioned therebetween;
FIG. 9 is a perspective view of the second embodiment of the jerk handle of the invention;
FIG. 10 is a front view thereof partially cut-away to show the bifurcated plug inserted into the center bore;
FIG. 11 is a top view thereof;
FIG. 12 is a bottom view thereof;
FIG. 13 is a front view of the bifurcated plug that is configured and dimensioned to be inserted into the center bore of the jerk handle;
FIG. 14 is a bottom view thereof;
FIG. 15 is a right and left side view thereof; and
FIG. 16 is a cross-sectional view of FIG. 11 along lines 16 - 16 showing the insertion of the bifurcated plug within the center bore of the jerk handle.
Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2 , the first embodiment of the jerk handle 10 of the invention comprises a base portion 12 with opposing handles 12 A for easy grasping by a person's hand. Base portion 12 further comprises a neck portion 12 B extending between the handle portions 12 A.
As best shown in FIG. 2 , the handle 10 further includes a cap 14 which is permanently snap-fitted to the base portion 12 by means of feet 14 F that fit into corresponding slots in the neck 12 B of the base portion, whereupon the cap 14 is then pivoted until four tabs 14 T snap into similar slots formed in the handle portions 12 A of the base portion 12 . Alternatively, a living hinge may be employed in lieu of the two feet 14 F.
Referring now to FIGS. 3-7 , the inside of the rear of the base portion 12 comprises a center channel 16 for receiving a lanyard cord 17 . The channel 16 is flanked by opposing slanted teeth 18 of upstanding ridges 19 . The teeth 18 are preferably configured in the manner disclosed in U.S. Pat. No. 3,574,900, the disclosure of which is hereby incorporated by reference herein.
Toward the bottom of the channel 16 , a circular upstanding protrusion 20 redirects the channel 16 about somewhat of a circular path 16 C to exit the bottom 16 B of the base portion 12 . The teeth 18 coupled with the protrusion 20 form a circuitous path for receiving the lanyard cord 17 such that the lanyard cod 17 is firmly grasped between the teeth 18 . Indeed, preferably the distance between the opposing teeth 18 gradually decreases from the protrusion 20 to the uppermost end of the channel such that the lanyard cord 17 is progressively grasped tighter and tighter along the length of the channel 16 .
As shown in FIG. 8 , the lanyard cord 17 is forced into the channel 16 by means of the cap 14 having a longitudinal ridge 22 aligned with the channel 16 and dimensioned at a height to force the lanyard cord 17 to the bottommost portion of the channel 16 between the opposing teeth 18 . Similarly, the inside of the cap 14 further includes an L-shaped ridge 24 of a configuration similar to that of the circuitous portion of the channel 16 C such that the lanyard cord 17 is firmly forced therein when the cap 14 is assembled to the base portion. The cap 14 includes a protruding stay 21 with a V cut-out that forces the end of the cord 17 into a recess 21 F. This assures that the cord 1 is firmly engaged by the teeth 18 .
As shown in FIGS. 9-16 , a second embodiment of the jerk handle 110 of the invention comprises a base portion 112 with opposing handles 112 A for easy gripping by a person's hand. Base portion 112 further comprises a neck portion 112 B extending between the handle portions 112 A.
The jerk handle 110 of the invention further includes a bifurcated plug 114 which is inserted into a center bore 116 formed within the neck portion 112 B. As best shown in FIGS. 10 and 16 , the center bore 116 preferably comprises a frustro cross-sectional configuration having a large diameter opening at its top and a smaller diameter opening at its bottom. Correspondingly, as best shown in FIGS. 13 and 16 , the bifurcated plug 114 preferably comprises a mating frustro configuration having an enlarged top and a reduced bottom for slidable fitting into the center channel 116 . The frustro configurations of the center channel 116 and the bifurcated plug 114 assure that the bifurcated plug 114 is compressed inwardly as it is forced into the center bore 116 from the top to the bottom thereof.
In its preferred embodiment, the bifurcated plug 114 comprises a bifurcated configuration similar to that of a conventional hair pin with cooperating left and right side portions 114 S having inwardly disposed teeth 118 that are preferably slanted toward the top and staggered relative to one another. The side portions are preferably connected together by a loop portion 114 L that essentially serves as a living hinge to allow the side portions 114 S to move inwardly as the bifurcated plug 114 is forced into the center bore 116 .
As best shown in FIGS. 11 and 12 , the center bore 116 preferably comprises a roughly rectangular cross-sectional configuration having frustro lateral sides 120 F that taper closer together from the top to the bottom of the bore 116 to slidably mate with the outermost surfaces of the side portions 114 S of the bifurcated plug 14 as the plug 114 is forced therein. Without departing from the spirit of this invention, the center bore 116 and the bifurcated plug 114 may alternatively comprise other tapered configurations such as frustro-conical configurations.
As best shown in FIG. 16 , during assembly, the trailing end of the lanyard cord 117 is positioned between the side portions 114 S of the bifurcated plug 114 to be grasped by the inwardly protruding teeth 118 thereof. With the lanyard cord 117 being threaded through the center channel 116 , the bifurcated plug 114 is then aligned therewith and forced inwardly. As noted above, as the bifurcated plug 114 is forced inwardly within the center channel 116 , the frustro sides 114 F of the plug 114 slide along the frustro lateral sides 120 F of the slot 120 forming the center bore 116 whereupon the sides 114 S progressively squeeze the lanyard cord 117 therebetween tighter and tighter. As shown in FIG. 16 , the dimensions of the bifurcated plug 114 relative to the center channel 16 and the lanyard cord 117 , are such that the bifurcated plug 114 will be recessed in position within the center bore 116 once the lanyard cord 117 is permanently grasped. In this manner, since the bifurcated plug 114 does not protrude from the top of the jerk handle 10 , it is virtually impossible to remove and can be considered to be permanently installed.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.
Now that the invention has been described,
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An assemblable jerk handle for a lanyard cord including in one embodiment a base portion having a center channel with interior progressive teeth for receiving the lanyard cord and a cap portion for permanently snap-fitting to the base portion to securely grip and therefore retain the lanyard cord within the base portion. In another embodiment, the assemblable jerk handle comprises a base portion having a center channel positioned therethrough for receiving a bifurcated plug that receives the lanyard cord therein and forcibly closes about the lanyard cord to securely grip and therefore retain the lanyard cord within the base portion.
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TECHNICAL FIELD
[0001] This patent disclosure relates generally to continuously variable transmissions and, more particularly to continuously variable transmission having a clutchless input that does not require a torque converter.
BACKGROUND
[0002] When a powered machine is accelerated, i.e., “launched,” from a standstill to a forward or reverse speed, the primary mover, e.g., the engine, of the machine transitions from a disengaged state to an engaged state. Whenever the engine is in the engaged state, its speed is generally related to the speed of the machine by a transmission ratio. However, this relationship is approximate in that a clutch or torque converter is generally employed to smooth the transition from the disengaged to the engaged state. Without the clutch or torque converter, the engine could stall or, at best, lug severely.
[0003] Although a number of types of transmissions are usable in such machines, a continuously variable transmission (“CVT”) is often used for its ability to provide a wide range of ratios and to smoothly vary the transmission ratio. One traditional CVT type is a split path transmission which includes an input for the primary mover as well as for two motors. The two motors, working in cooperation, set the ratio of the transmission. However, while providing smooth operation and a wide range of transmission ratios, the motors also contribute size, weight, and expense to the final transmission assembly.
[0004] Although single motor CVTs have been attempted, none has been of a design and configuration sufficient to substantially ameliorate the foregoing problems.
SUMMARY
[0005] In one aspect, the disclosed principles pertain to a single motor drive train system for propelling a host machine, the drive train system comprising an engine, a motor, and a lossless buffer receiving the engine output and the motor output, and having a buffer output, such that the lossless buffer provides a range of transmission ratios between the rotational engine output and the rotational buffer output, wherein the range of transmission ratios includes a zero transmission ratio. It should be noted that in the context of this disclosure, the term “lossless” does not mean that the entity in question experiences, or has imposed upon it, no loss of energy whatsoever. Rather, the term “lossless” denotes the absence of intentional frictional losses/slippage such as may be present in clutches and torque converters.
[0006] Continuing with this aspect of the disclosure, the transmission input is linked directly to the rotational buffer output, and has a rotational transmission output linked to a propulsion means to propel the host machine. Thus, rotation of the transmission input rotates the transmission output, causing the propulsion means to propel the host machine.
[0007] In another aspect, a machine is provided for rendering clutchless engagement of a transmission without the use of a torque converter. The machine comprises an engine for propelling the machine, a transmission having a transmission input and a transmission output, and a lossless buffer between the engine and the transmission, wherein the lossless buffer employs a single electric motor to provide ratios in a range including zero between the engine output and the transmission input.
[0008] In yet another aspect of the disclosure, a buffer system is provided for managing the transmission of power between an engine and a transmission in the absence of a torque converter or clutch between the engine and the transmission. The buffer system comprises a mechanical buffer receiving as input an output of the engine and providing as output an input to the transmission, and a single electric motor controlling the input-to-output transmission ratio of the mechanical buffer to allow the mechanical buffer to provide such ratios in a range including zero. The system also includes a controller for controlling the single electric motor to modify the transmission ratio of the mechanical buffer.
[0009] Other aspects and features will be apparent from the detailed description, taken in conjunction with the drawings, of which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic illustration showing a power train system and an associated environment within which embodiments of the disclosed principles may be employed;
[0011] FIG. 2 is a schematic illustration of a lossless buffer system according to an embodiment of the disclosed principles;
[0012] FIG. 3 is a power flow diagram illustrating power flow during an idle mode from an engine to a motor via a lossless buffer according to an embodiment of the disclosed principles;
[0013] FIG. 4 is a power flow diagram illustrating power flow from an engine and motor to machine propulsion via a lossless buffer during propelled motion of the host machine according to an embodiment of the disclosed principles;
[0014] FIG. 5 is a power flow diagram illustrating power flow from the host machine to the motor via the lossless buffer during braking of the host machine according to an embodiment of the disclosed principles; and
[0015] FIG. 6 is a flow chart illustrating a process of regulating and coordinating a lossless buffer, engine and motor according to an embodiment of the disclosed principles.
DETAILED DESCRIPTION
[0016] This disclosure relates to machines requiring a transmission to link a power source to a final ground-engaging mechanism, e.g., wheels, tracts, etc. Examples of such machines include machines used for mining, construction, farming, transportation, and other industries and endeavors known in the art. For example, the machine may be an earth-moving machine, such as a wheel loader, excavator, dump truck, backhoe, motor grader, material handler or the like. Moreover, an implement may be connected to the machine. Such implements may be utilized for a variety of tasks, including, for example, loading, compacting, lifting, brushing, and may include, for example, buckets, compactors, forked lifting devices, brushes, grapples, cutters, shears, blades, breakers/hammers, augers, and others.
[0017] FIG. 1 is a diagrammatic illustration showing a power train system 100 and the associated environment within which embodiments of the disclosed principles may be used. The illustrated power train system 100 includes an engine 101 , which is an example of a primary mover, having an engine output 106 . It will be appreciated that the operation of the engine 101 is executed based on one or more inputs, including, for example, an input from a user interface (not shown), e.g., a pedal or lever, as well as an input from a controller 105 , e.g., for purposes of torque control, traction control, etc.
[0018] A motor 103 , e.g., an electric motor is provided having a motor output 107 . It will be appreciated that the motor 103 may consume electrical energy to provide a torque or may be driven while providing a reactive force, thus generating electricity for storage in a battery (not shown) or other storage element. A lossless buffer 109 is interposed between the motor 103 and engine 101 , and a transmission 111 . For driving a load, the lossless buffer 109 provides at a buffer output 113 to the transmission 111 a weighted combination of the rotation of the engine 101 and the rotation of the motor 103 .
[0019] The details of the lossless buffer 109 will be discussed in detail below with reference to FIG. 2 , however, before proceeding, the characteristics and operation of the power train system 100 will be described in overview via continued reference to FIG. 1 . As can be seen, the power train system 100 operates to provide rotational power to the remainder of the machine drive train 115 , which may comprise one or both of wheels, tracks, or other propulsion means. The power required to propel the drive train 115 originates in the primary mover, e.g., the engine 101 . Additional power may be supplied via a battery which may be charged by one or both of an off-board system and the motor 103 .
[0020] The power train system 100 exhibits three primary states. The first occurs when the engine 101 is running, but the machine is not moving. In this state, the torque provided to the transmission 111 by the engine 101 via the engine output 106 is essentially reflected to the motor 103 via the motor output 107 , whereupon the energy is either stored, e.g., via a battery, or dissipated, e.g., via a resistive grid. In the second state, usually occurring when the machine is being launched from the first state, the engine 101 provides torque to the lossless buffer 109 via the engine output 106 , the machine is moving at least slightly, and the motor 103 is being driven by the lossless buffer 109 via the motor output 107 , but is providing a reactive torque to accelerate or move the machine.
[0021] In other words, in this second stage, the motor 103 resists movement, and as such, the buffer output 113 of the lossless buffer 109 moves or accelerates under the force of the engine 101 . In the third stage, the engine 101 provides torque to the lossless buffer 109 via the engine output 106 and the motor 103 provides proactive torque to the lossless buffer 109 via the motor output 107 . In this state, the rotational speed of the buffer output 113 is a weighted average of the rotational speed of the engine 101 and the motor 103 . The effective transmission ratio of the lossless buffer 109 relative to the engine output 106 is controlled by the rotational speed of the motor output 107 , i.e., the rotational speed of the motor 103 . Thus, for example, if the engine speed and motor speed are of equal magnitudes but opposite directions, the transmission ratio of the lossless buffer 109 is zero. Moreover, fractional or overdrive ratios between the engine output 106 and the buffer output 113 can be provided by varying the speed of rotation of the motor output shaft 107 .
[0022] The illustrated configuration thus allows the machine to be launched from a stationary state to a moving state without clutches or torque converters between the engine 101 and the split torque transmission 103 , while also allowing a wide range of effective transmission ratios. This provides the benefits of allowing a compact and simple installation, while avoiding excess expenditures on equipment and maintenance.
[0023] FIG. 2 illustrates in detail an example of a lossless buffer 109 according to the disclosed principles. In particular, FIG. 2 is a schematic view of the lossless buffer 109 , showing exemplary configurations and internal connections and gearings of the lossless buffer 109 . As discussed above, the lossless buffer 109 links an engine output 106 , a motor output 107 , and a buffer output 113 . In the illustrated embodiment, the lossless buffer 109 includes a planetary gear set 200 including at least one sun gear 201 , at least one ring gear 203 , and at least one planet gear/planet gear carrier assembly 205 .
[0024] As can be seen, the engine output 106 is connected to the at least one sun gear 201 , such that rotation of the engine 101 serves to rotate the at least one sun gear 201 at a like speed and in a like direction. Also shown, the motor output 107 is linked to the at least one ring gear 203 . In this way, the torque of the at least one ring gear 203 is transferred to second input 107 and hence to the motor 103 . Likewise, the torque of the motor 103 is transferred via the motor output 107 to the at least one ring gear 203 . Finally, in the illustrated embodiment, the at least one planet gear/planet gear carrier assembly 205 is linked to the buffer output 113 . In this way, the engine output 106 , motor output 107 , and buffer output 113 are interconnected and their rotational speeds are interrelated.
[0025] It will be appreciated that the tooth counts used to reach these ratios are not critical, and that the ratios used in any particular implementation need not match the example given above to fall within the disclosed principles of operation.
[0026] FIGS. 3-5 illustrate the power flow in the lossless buffer 109 according to the disclosed principles in various modes of operation including an idle state, a moving state, and a braking state. Referring specifically to FIG. 3 , the power flow during the idle mode is from the engine 101 via the engine output 106 to the motor 103 via the motor output 107 . In this mode, the buffer output 113 is static because the host machine is stationary.
[0027] Referring to FIG. 4 , this power flow diagram illustrates the power flow through the lossless buffer 109 during propelled motion of the host machine. As can be seen, the power flow in this instance is from the engine 101 via the engine output 106 , and from the motor 103 via the motor output 107 , to the buffer output 113 . It will be appreciated that within this mode, the engine 101 provides a rotational torque in a given direction and the lossless buffer 109 imposes a rotational torque on the buffer output 113 in a given direction. However, the motor 103 may provide either active or reactive torque and thus will rotate in a direction that is dependent upon the desired speed of the machine in motion.
[0028] Thus, for example, at the time of transition from the idle mode to forward or reverse motion of the machine, the motor 103 transitions from being a strictly driven element to providing an active or reactive torque at the second input 107 . The active or reactive torque can be generated by supplying a voltage input to the motor 103 in a direction the same as or opposite to (for reactive torque) the induced current, with the polarity of voltage determining the direction of the applied torque and the magnitude of the voltage determining the extent of the torque on the motor output 107 .
[0029] It is also expected to use the illustrated configuration to provide a braking force to the buffer output 113 , e.g., to decelerate the host machine. FIG. 5 illustrates the power flow in the split torque transmission 103 during braking. In particular, the engine 101 , which is no longer needed for acceleration, provides a resistive or reactive torque to the engine output 106 . At the same time, the motor 103 is switched from a powering mode to a generating mode, such that any electrical power is dissipated, e.g., via a resistive grid, or stored, e.g., via one or more batteries. Ordinary service brakes, e.g., friction brakes, may also be employed at this time. Moreover, it will be appreciated that, depending upon the degree of braking required, powered reactive braking through the motor 103 may also be employed.
[0030] As shown in the example environment of FIG. 1 , the operation of the lossless buffer 109 as well as the engine 101 and the motor 103 are monitored and controlled via a controller 105 . The controller 105 may be any computing device capable of sensing one or more conditions of the lossless buffer 109 , engine 101 and/or motor 103 and providing control outputs to one or more of the lossless buffer 109 , engine 101 and motor 103 . By way of example, the controller 105 may be integrated with an engine or machine control module, or may be a separate device. The controller 105 operates by reading computer-readable instructions from a computer-readable medium and executing the read instructions. The computer-readable medium may be a tangible medium such as a hard drive, optical disc, jump drive, thumb drive, flash memory, ROM, PROM, RAM, etc., or may be an intangible medium such as an electrical or optical wave form traveling in air, vacuum, or wire.
[0031] The process executed by the controller 105 in regulating and coordinating the lossless buffer 109 , engine 101 and motor 103 is shown via the process 600 of FIG. 6 . Although the process 600 proceeds from a stationary state, through a moving state, returning to a stationary state, it will be appreciated that the initial state may be other than stationary and that the control process in such a case would be executed from the appropriate step onward.
[0032] The initial state of the host machine prior to execution of process 600 is idle, i.e., the engine 101 is running but the host machine is not moving. At stage 601 of the process 600 , the controller 105 receives an acceleration command, e.g., from a physical or electrical user interface element. Pursuant to the command received at stage 601 , the controller 105 first optionally connects the motor 103 to a motor controller at stage 603 if the motor 103 had been providing electrical power to a battery or the like during idling. At stage 605 , the controller 105 increases fuel flow to the engine 101 to increase its output power, while also increasing the reactive torque provided by the motor 103 via the motor controller. These actions have the net effect of increasing torque at the buffer output 113 to accelerate the host machine.
[0033] Once a desired speed is attained, e.g., further acceleration is not requested, the controller 105 may continue to increase the speed of the motor 103 while decreasing the speed of the engine 101 at stage 607 . This increases the effective transmission ratio of the split torque transmission 103 to conserve fuel and allow the engine 101 to operate within an optimal operating range.
[0034] At stage 609 , the controller 105 receives a retarding command, again optionally resulting from interaction of the user with a user interface element. At stage 611 , in response to the retarding command, the controller 105 idles the engine 101 and shunts the motor inputs so that the motor now supplies electrical energy to a battery or dissipater. This action tends to reduce the speed of the machine. If need be, the controller 105 may optionally apply the service brakes of the machine at stage 613 .
INDUSTRIAL APPLICABILITY
[0035] The present disclosure is applicable to driven machines having transmissions for imparting motion to the machine. In particular, the disclosed principles provide a mechanism for omitting a clutch and torque converter from the machine drive train while maintaining the ability to start and stop the host machine without lugging or stalling the engine 101 . This system may be implemented in on-highway or off-highway machines, construction machines, industrial machines, etc. Although many machines that may benefit from the disclosed principles will be machines used at least occasionally for transport of goods, materials, or personnel, it will be appreciated that such transmissions are used in other contexts as well, and the disclosed teachings are likewise broadly applicable.
[0036] Using the disclosed principles, a lossless buffer 109 is disposed in the machine drive train system 100 between driving elements, e.g., engine 101 and motor 103 , and a transmission. The buffer provides zero, fractional, and overdrive ratios between the engine 101 and the transmission to allow start up from full stop with the engine 101 running and to allow stopping from forward motion without stalling the engine 101 . It will be appreciated that this description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. Moreover, the references to examples herein are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to various features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. Although the motor 103 has been referred to herein as an electric motor, it will be appreciated that the motor 103 may instead be a hydraulic motor or other non-electric motor without departing from the scope of the disclosed principles.
[0037] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order and from any suitable step unless otherwise indicated herein or otherwise clearly contradicted by context.
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A single motor clutchless, torque converter-less buffer system is provided for linking an engine ( 101 ) to a transmission ( 111 ). Within this context of this system, the drive train comprises an engine ( 101 ), an electric motor ( 103 ), and a lossless buffer ( 109 )receiving the engine output ( 106 ) and the motor output ( 107 ), and having a buffer output ( 113 ), such that the lossless buffer ( 109 ) provides a range of transmission ratios including a zero transmission ratio. The term “lossless” denotes the absence of intentional frictional losses/slippage such as may be present in clutches and torque converters. In an embodiment, the lossless buffer ( 109 ) includes a planetary system between the engine ( 101 ) and the transmission ( 111 ), wherein the single electric motor ( 103 ) functions to vary the transmission ratio of the buffer ( 109 ).
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[0001] This application claims priority to French patent application No.FR 02 09 683 filed on Jul. 30, 2002.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to a window lifter geared motor assembly including a sensor that detects the separation between an axis of a drive shaft and an axis of a reduction gearset to detect the presence of a trapped object.
[0003] Numerous motor vehicle equipment items are operated using geared motor assembly electric motors. For example, window lifter windows are increasingly driven by electric motors. It is possible for an object or a person's hand to accidentally lie in the closure path of the window and become trapped between the top edge of the window and the surround in the door, possibly resulting in damage or injury. Various devices for forcing the window to be lowered are known.
[0004] Thus, document U.S. Pat. No. 5,296,658 uses window seals containing capacitances or optical fibers. The characteristics of these seals are modified when an object is trapped, providing a trapping signal that acts on the window drive. However, these seals are expensive and detrimental to the aesthetics of the vehicle because they are bulky and visible.
[0005] Document DE-A-3 034 114 proposes to measure the rotational speed of the electric motor. Document DE-A-4 442 171 proposes measuring the electric current of the electric motor. However, these methods have disadvantages. Because of the characteristics of the electric motor, particularly its inertia, its resistance, or its flux, there is a relatively long response time between the trapping of an object and the detection of this trapping. The force driving the window may, in the meantime, increase appreciably and cause injury. The trapping force may also exceed the levels defined in the standards, making vehicle homologation difficult.
[0006] There is therefore a need for a geared motor assembly able to solve the problem of detecting an object trapped in a window lifter.
SUMMARY OF THE INVENTION
[0007] The invention provides a window lifter geared motor assembly including a drive shaft, a reduction gearset rotationally driven by the drive shaft, and a sensor. The state of the sensor is a function of the separation between an axis of the reduction gearset and an axis of the drive shaft.
[0008] According to one embodiment, the reduction gearset can be rotationally driven about a reduction shaft that is guided with respect to a casing by a bearing on which the sensor is located. According to another embodiment, the drive shaft can be guided with respect to the casing by a bearing on which the sensor is located.
[0009] Preferably, the driving of the drive shaft is a function of the state of the sensor. In one example, the sensor is a piezoresistive sensor.
[0010] According to another embodiment, the geared motor assembly further includes an electric motor in the casing that rotationally drives the drive shaft and a damper that dampens the movements of the electric motor in the casing.
[0011] In one example, the damper is a spring positioned between the casing and the electric motor. The invention also relates to a window lifter including the geared motor assembly as described hereinabove.
[0012] Other features and advantages of the invention will become apparent from reading the detailed description that follows of some embodiments of the invention given solely by way of example and with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a cross-sectional view of the geared motor assembly of the present invention;
[0014] FIG. 2 shows a top view of the geared motor; and
[0015] FIG. 3 shows a front view of the geared motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The invention relates to a window lifter geared motor assembly 1 including a drive shaft 5 that drives a reduction gearset 7 and a sensor 8 . The state of the sensor 8 is a function of the separation between the drive shaft 5 and the reduction gearset 7 . When the reduction gearset 7 is blocked in its rotation because of the presence of an object across the path of the window, the force developed by the geared motor assembly 1 to overcome the presence of the obstacle is proportional to the force that causes an increase in separation 23 of an axis 20 of the drive shaft 5 and an axis 6 of the reduction gearset 7 . By detecting the increase in separation 23 , the sensor 8 is able to unambiguously detect the trapping of an object in the path of the window.
[0017] FIG. 1 shows a cross-sectional view of the geared motor assembly 1 of the present invention. The geared motor assembly 1 includes an electric motor 3 in a casing 2 that rotationally drives the drive shaft 5 via a rotor 11 and a stator 10 . The drive shaft 5 is rotationally driven about the axis 6 to rotationally drive the reduction gearset 7 .
[0018] In one example, the connection between the drive shaft 5 and the reduction gearset 7 is a worm and wheel connection. The reduction gearset 7 is a toothed wheel rotationally driven by a screw thread on the drive shaft 5 . The reduction gearset 7 is rotationally driven about the axis 20 (shown in FIG. 2 ). The axis 20 of the reduction gearset 7 and the axis 6 of the drive shaft 5 are orthogonal. In the worm and wheel connection, the tooth separation force is one of the components of the forces involved in the driving of the wheel by the worm. It is proportional to the torque developed by the geared motor assembly 1 . The tooth separation force is in a direction orthogonal to the axis 6 and to the axis 20 . It is manifested in an increase in separation 23 between the two axes 6 and 20 .
[0019] The sensor 8 detects the tooth separation force, making it possible to detect the forces applied at the output to the reduction gearset 7 . As long as the separation 23 between the axes 6 and 20 remains within a predetermined threshold, the corresponding tooth separation force will be due to the development of a torque representative of normal operation of the geared motor assembly 1 . This corresponds to unimpeded operation of the window lifter. By contrast, when the sensor 8 is in a state that indicates an increase in the separation 23 and, in particular, when the state of the sensor 8 indicates that the separation 23 is exceeding the predetermined threshold, the corresponding tooth separation caused by the development of an operating torque that is abnormal for the geared motor assembly 1 . The geared motor assembly 1 develops a higher torque to overcome an obstacle impeding the path of the window. The increase in the developed torque increases the separation 23 and is detected by the sensor 8 .
[0020] Preferably, the driving of the drive shaft 5 is a function of the state of the sensor 8 . When the sensor 8 detects an increase in the separation 23 , and therefore the crossing of the predetermined threshold of separation of a tooth on the drive shaft 5 and the reduction gearset 7 , operation of the geared motor assembly 1 is allowed to be interrupted. A circuit (not illustrated) processes the state of the sensor 8 and is able to stop the operation of the electric motor 3 . This prevents an object impeding the path of the window from being trapped. This is particularly advantageous when a finger is in the path of the window, avoiding any injury. Additionally, when an object impedes the path of the window, the reduction gearset 7 driving the window lifter cable winding drum is blocked in its rotation. The blockage of the reduction gearset 7 may damage the worm and wheel connection. By interrupting the operation of the electric motor 3 , the link and the geared motor assembly 1 can be protected. Another advantage is that the window closure force can be monitored and thus spare the mechanical stops of the window lifter.
[0021] Advantageously, the circuit for processing the state of the sensor 8 reverses operation of the geared motor assembly 1 . This allows the window to be lowered and the object impeding the path of the window to be disentangled.
[0022] FIGS. 2 and 3 show various possible locations for the sensor 8 on the geared motor assembly 1 . Preferably, the sensor 8 is arranged on elements of the geared motor assembly 1 that are not in motion when the geared motor assembly 1 is in operation. The advantage is that the sensor 8 can be connected more easily to the circuit for processing the state of the sensor 8 than it could be if the sensor 8 were driven back and forth.
[0023] FIG. 2 shows a top view of the geared motor assembly 1 of FIG. 1 . In this embodiment, the drive shaft 5 is guided with respect to the casing 2 by bearings 18 and 19 . The sensor 8 is arranged on the bearing 19 that guides the drive shaft 5 . The sensor 8 can also be arranged on both the bearings 18 and 19 , thus improving detection of the increase in separation 23 . The increase in the separation 23 between the axes 6 and 20 gives rise to a load in the bearings 18 and 19 . This load corresponds to the tooth separation force and is detected by the sensor 8 .
[0024] FIG. 3 shows a front view of the geared motor assembly 1 of FIG. 1 . The reduction gearset 7 is rotationally driven about a reduction shaft 24 guided with respect to the casing 2 by a bearing 21 on which the sensor 8 is located. The increase in the separation 23 between the axes 6 and 20 gives rise to a load in the bearing 21 that guides the reduction shaft 24 in the casing 2 . This load corresponds to the tooth separation force and is detected by the sensor 8 . The sensor 8 is also depicted in FIG. 1 as being located on the bearing 18 .
[0025] The variation in the state of the sensor 8 as a function of the separation 23 makes it possible to detect the trapping of an object without having to measure an intermediate parameter, such as the rotational speed of the electric motor 3 or the electric current in the electric motor 3 .
[0026] It is possible, for example, to use a piezoresistive sensor 8 known per se and commercially available. The electrical impedance of the sensor 8 increases in proportion to the load applied to its two faces. It is also possible to use a sensor 8 exhibiting a capacitance, an inductance, or more generally an impedance. The value of the sensor 8 varies as a function of the load applied to it. Such a sensor 8 is compact and may have terminals ready for connection. The response time of the sensors 8 is preferably shorter than 25 ms.
[0027] Preferably, the geared motor assembly 1 includes a damper 4 , as depicted in FIG. 1 . The damper 4 dampens the movements of the electric motor 3 in the casing 2 and prevents damage to the geared motor assembly 1 when it becomes blocked by an object in the path of the window. In particular, the damper 4 makes it possible to avoid breakage of part of the reduction gearset 7 , such as the meshing teeth. The damper 4 is able to dampen movement of the drive shaft 5 when the reduction gearset 7 is rotationally blocked by the presence of an obstacle. The damper 4 can be positioned on either side of the electric motor 3 , depending on the desired direction of damping. Preferably, the damper 4 is positioned on both sides of the electric motor 3 .
[0028] For unambiguous detection by the sensor 8 of the blocking of a window, it is preferable for the driveline between the obstacle on the window and the sensor 8 to be “rigid.” The term “driveline” is to be understood in a window lifter to mean the sequence including the window, the slider on the window, the cable, the drum, the reduction gearset 7 , the drive shaft 5 and the electric motor 3 . Instead of the drum and the cable, the window lifter can comprise a pinion and a sector arm.
[0029] Preferably, the damper 4 is a spring positioned between the casing 2 and the electric motor 3 . More specifically, the spring 4 is positioned between the casing 2 and the envelope 9 of the electric motor 3 . The advantage is that the rigidity of the driveline is not interrupted. Thus, the presence of the sensor 8 on a bearing that guides the drive shaft 5 or the reduction shaft 24 of the reduction gearset 7 is able to quickly and unambiguously detect the presence of an obstacle in the path of the window.
[0030] The invention also relates to a window lifter comprising such a geared motor assembly 1 . All the advantages described hereinabove are repeated in the case of the window lifter. Such a window lifter allows unambiguous detection of the trapping. This allows the window lifter to meet the standards in force.
[0031] Of course, the present invention is not limited to the embodiments described by way of example; thus, the geared motor assembly described may be the one used to operate a sunroof. It may also be used to move a car seat. The invention is particularly advantageous when the leg of a rear-seat passenger impedes the sliding of the seat.
[0032] The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.
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A window lifter geared motor assembly includes a drive shaft driven about an axis, a reduction gearset driven about an axis rotationally driven by the drive shaft, and a sensor. The output of the sensor is dependent upon a distance between the axis of the reduction gearset and the axis of the drive shaft. When the sensor detects an increased in the distance that exceeds a threshold value, operation of the geared motor assembly is interrupted. The assembly detects trapping that is likely to occur when an object, and particularly a hand, impedes the operation of the window.
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[0001] In normal bowels, the immune reaction is regulated to maintain homeostasis of the gut. Inflammatory bowel disease (IBD) is a phrase used to describe an inappropriate immune response that occurs in the bowels of affected individuals. Two major types of IBD have been described: Crohn's disease (CD) and ulcerative colitis (UC). Both forms of IBD show abnormal profiles of T cell mediated immunity. In the gut of CD, a strong Th1 reaction is induced, while the Th2 response is upregulated in the colon of UC.
[0002] A variety of inflammatory cytokines have been implicated in IBD. For example, in UC increased proinflammatory cytokine production is observed. IL-13 was identified as an important effector cytokine in UC that impairs epithelial barrier function by affecting epithelial apoptosis, tight junctions, and restitution velocity (Heller, et al., Gastroenterology 129(2): 550-64, 2005). TNF-α has been implicated in the pathology of CD and antibodies directed against TNF-α have been used to treat CD (see Nakamura, et al. World J Gastroenterol 2006 Aug. 7; 12(29): 4628-4635).
[0003] The barrier function of the intestines is impaired in IBD. For example, Crohn's disease is associated with increased permeability of the intestinal barrier even in quiescent patients (Oshitani, et al., Int J Mol Med 15(3):407-10, 2005). A TNF-α-induced increase in intestinal epithelial tight junction (TJ) permeability has been proposed to be an important proinflammatory mechanism contributing to intestinal inflammation in Crohn's disease and other inflammatory conditions (see Ye et al., American Journal of Physiology-Gastrointestinal and Liver Physiology, 290(3):496-504, 2006). Increased intestinal permeability during episodes of active disease correlates with destruction or rearrangement of the tight junction protein complex (Willemsen, et al. Clin. Exp. Immunol. 142(2): 275-284, 2005).
[0004] Zonula occludens toxin (ZOT), which is produced by Vibrio cholerae , has been characterized by Fasano et al., ( Proc. Natl. Acad. Sci., USA, 8:5242-5246 (1991)) and the sequence has been determined (GenBank accession no. A43864). ZOT increases the intestinal permeability of rabbit ileal mucosa by modulating the structure of intercellular tight junctions.
[0005] Peptide antagonists of tight junction opening were described in U.S. Pat. No. 6,458,925, which is incorporated by reference herein in its entirety, which corresponds to WO 00/07609. Peptide antagonists of tight junction opening may bind to the receptor utilized by the zonnula occludens toxin expressed by Vibrio cholerae , yet not function to physiologically modulate the opening of mammalian tight junctions. The peptide antagonists competitively inhibit the binding of ZOT and zonulin to the ZOT receptor, thereby inhibiting the ability of ZOT and zonulin to physiologically modulate the opening of mammalian tight junctions.
[0006] The main treatments available for IBD are steroids and immunosuppressive agents which non-specifically reduce immunity and inflammation. These therapies are prone to undesired side effects. There remains a need in the art for treatments of IBD. This need and others are met by the present invention.
SUMMARY OF THE INVENTION
[0007] The present invention provides methods and materials for treating inflammatory bowel disease. In some embodiments, the invention provides methods of treating inflammatory bowel disease comprising administering to a subject in need thereof a composition comprising a tight junction antagonist. As used herein, a “subject” may be any mammal, for example, a human, dog, cat, horse, cow, etc. In some embodiments, a subject may be a human. In other embodiments, a subject may be a dog. Any tight junction antagonist may be used, for example, a tight junction antagonist of the invention may be a peptide. When a tight junction antagonist for use in the invention is a peptide, the peptide may comprise one or more of SEQ ID NOs: 1-24, which may be on the same or different molecules. In some embodiments, a peptide tight junction antagonist may comprise the sequence GGVLVQPG (SEQ ID NO:15). In some embodiments, the peptide tight junction antagonist may consist essentially of the sequence GGVLVQPG (SEQ ID NO:15). Compositions suitable for use in treating IBD may be formulated in any manner known to those skilled in the art. In some embodiments, a composition suitable for treating IBD may comprise a tight junction antagonist and may be a delayed release composition. Compositions for use in treating IBD, delayed release or otherwise, may comprise one or more tight junction antagonists and one or more therapeutic agents. Suitable therapeutic agents include, but are not limited to, aminosalicylates, corticosteroids, immunomodulators, antibiotics, and biologic therapeutics. In some embodiments, a composition suitable for treating IBD may comprise a peptide tight junction antagonist (e.g., a peptide comprising SEQ ID NO: 15) and a therapeutic agent, e.g., a steroid.
[0008] The present invention provides methods and materials for treating Crohn's disease. In some embodiments, the invention provides methods of treating Crohn's disease comprising administering to a subject in need thereof a composition comprising a tight junction antagonist. Any tight junction antagonist may be used, for example, a tight junction antagonist of the invention may be a peptide. When a tight junction antagonist for use in the invention is a peptide, the peptide may comprise one or more of SEQ ID NOs: 1-24, which may be on the same or different molecules. In some embodiments, a peptide tight junction antagonist may comprise the sequence GGVLVQPG (SEQ ID NO:15). In some embodiments, the peptide tight junction antagonist may consist essentially of the sequence GGVLVQPG (SEQ ID NO:15). Compositions suitable for use in treating Crohn's disease may be formulated in any manner known to those skilled in the art. In some embodiments, a composition suitable for treating Crohn's disease may comprise a tight junction antagonist and may be a delayed release composition. Compositions for use in treating Crohn's disease, delayed release or otherwise, may comprise one or more tight junction antagonists and one or more therapeutic agents. Suitable therapeutic agents include, but are not limited to, aminosalicylates, corticosteroids, immunomodulators, antibiotics, and biologic therapeutics. In some embodiments, a composition suitable for treating Crohn's disease may comprise a peptide tight junction antagonist (e.g., a peptide comprising SEQ ID NO: 15) and a therapeutic agent, e.g., a steroid.
[0009] The present invention provides methods and materials for treating ulcerative colitis. In some embodiments, the invention provides methods of treating ulcerative colitis comprising administering to a subject in need thereof a composition comprising a tight junction antagonist. Any tight junction antagonist may be used, for example, a tight junction antagonist of the invention may be a peptide. When a tight junction antagonist for use in the invention is a peptide, the peptide may comprise one or more of SEQ ID NOs: 1-24, which may be on the same or different molecules. In some embodiments, a peptide tight junction antagonist may comprise the sequence GGVLVQPG (SEQ ID NO:15). In some embodiments, the peptide tight junction antagonist may consist essentially of the sequence GGVLVQPG (SEQ ID NO:15). Compositions suitable for use in treating ulcerative colitis may be formulated in any manner known to those skilled in the art. In some embodiments, a composition suitable for treating ulcerative colitis may comprise a tight junction antagonist and may be a delayed release composition. Compositions for use in treating ulcerative colitis, delayed release or otherwise, may comprise one or more tight junction antagonists and one or more therapeutic agents. Suitable therapeutic agents include, but are not limited to, aminosalicylates, corticosteroids, immunomodulators, antibiotics, and biologic therapeutics. In some embodiments, a composition suitable for treating ulcerative colitis may comprise a peptide tight junction antagonist (e.g., a peptide comprising SEQ ID NO: 15) and a therapeutic agent, e.g., a steroid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows Body Weight area under the curve from 4-17 weeks of age.
[0011] FIG. 2 shows a measurement of Gastric Permeability measured as sucrose excretion.
[0012] FIG. 3 shows Small Intestinal Permeability measured by lactulose mannitol test.
[0013] FIG. 4 shows Small Intestinal Permeability measured by lactulose mannitol test.
[0014] FIG. 5 shows in vitro measurement of colonic permeability at 8 weeks of age.
[0015] FIG. 6 shows in vitro colonic electrical resistance at 8 weeks of age.
[0016] FIG. 7 shows colonic inflammation (neutrophil infiltration) at 17 weeks.
[0017] FIG. 8 shows colonic inflammation at 17 weeks (TNF secretion over 24 hours).
[0018] FIG. 9 shows colonic inflammation at 17 weeks (IFN secretion over 24 hours).
[0019] FIG. 10 shows Colonic Permeability as measured by sucralose excretion.
DETAILED DESCRIPTION OF THE INVENTION
Antagonists of Tight Junction Opening
[0020] Any antagonist of tight junction opening may be used in the practice of the present invention. As used herein, tight junction antagonists prevent, inhibit or reduce the opening of tight junctions. A tight junction antagonist may bind to the zonulin receptor and prevent, inhibit, reduce or reverse the tight junction opening triggered by zonulin. For example, antagonists of the invention may comprise peptide antagonists. Examples of peptide antagonists include, but are not limited to, peptides that comprise an amino acid sequence selected from the group consisting of
[0000]
Gly Arg Val Cys Val Gln Pro Gly,
(SEQ ID NO: 1)
Gly Arg Val Cys Val Gln Asp Gly,
(SEQ ID NO: 2)
Gly Arg Val Leu Val Gln Pro Gly,
(SEQ ID NO: 3)
Gly Arg Val Leu Val Gln Asp Gly,
(SEQ ID NO: 4)
Gly Arg Leu Cys Val Gln Pro Gly,
(SEQ ID NO: 5)
Gly Arg Leu Cys Val Gln Asp Gly,
(SEQ ID NO: 6)
Gly Arg Leu Leu Val Gln Pro Gly,
(SEQ ID NO: 7)
Gly Arg Leu Leu Val Gln Asp Gly,
(SEQ ID NO: 8)
Gly Arg Gly Cys Val Gln Pro Gly,
(SEQ ID NO: 9)
Gly Arg Gly Cys Val Gln Asp Gly,
(SEQ ID NO: 10)
Gly Arg Gly Leu Val Gln Pro Gly,
(SEQ ID NO: 11)
Gly Arg Gly Leu Val Gln Asp Gly,
(SEQ ID NO: 12)
Gly Gly Val Cys Val Gln Pro Gly,
(SEQ ID NO: 13)
Gly Gly Val Cys Val Gln Asp Gly,
(SEQ ID NO: 14)
Gly Gly Val Leu Val Gln Pro Gly,
(SEQ ID NO: 15)
Gly Gly Val Leu Val Gln Asp Gly,
(SEQ ID NO: 16)
Gly Gly Leu Cys Val Gln Pro Gly,
(SEQ ID NO: 17)
Gly Gly Leu Cys Val Gln Asp Gly,
(SEQ ID NO: 18)
Gly Gly Leu Leu Val Gln Pro Gly,
(SEQ ID NO: 19)
Gly Gly Leu Leu Val Gln Asp Gly,
(SEQ ID NO: 20)
Gly Gly Gly Cys Val Gln Pro Gly,
(SEQ ID NO: 21)
Gly Gly Gly Cys Val Gln Asp Gly,
(SEQ ID NO: 22)
Gly Gly Gly Leu Val Gln Pro Gly,
(SEQ ID NO: 23)
and
Gly Gly Gly Leu Val Gln Asp Gly
(SEQ ID NO: 24)
[0021] When the antagonist is a peptide, any length of peptide may be used. Generally, the size of the peptide antagonist will range from about 6 to about 100, from about 6 to about 90, from about 6 to about 80, from about 6 to about 70, from about 6 to about 60, from about 6 to about 50, from about 6 to about 40, from about 6 to about 30, from about 6 to about 25, from about 6 to about 20, from about 6 to about 15, from about 6 to about 14, from about 6 to about 13, from about 6 to about 12, from about 6 to about 11, from about 6 to about 10, from about 6 to about 9, or from about 6 to about 8 amino acids in length. Peptide antagonists of the invention may be from about 8 to about 100, from about 8 to about 90, from about 8 to about 80, from about 8 to about 70, from about 8 to about 60, from about 8 to about 50, from about 8 to about 40, from about 8 to about 30, from about 8 to about 25, from about 8 to about 20, from about 8 to about 15, from about 8 to about 14, from about 8 to about 13, from about 8 to about 12, from about 8 to about 11, or from about 8 to about 10 amino acids in length. Peptide antagonists of the invention may be from about 10 to about 100, from about 10 to about 90, from about 10 to about 80, from about 10 to about 70, from about 10 to about 60, from about 10 to about 50, from about 10 to about 40, from about 10 to about 30, from about 10 to about 25, from about 10 to about 20, from about 10 to about 15, from about 10 to about 14, from about 10 to about 13, or from about 10 to about 12 amino acids in length. Peptide antagonists of the invention may be from about 12 to about 100, from about 12 to about 90, from about 12 to about 80, from about 12 to about 70, from about 12 to about 60, from about 12 to about 50, from about 12 to about 40, from about 12 to about 30, from about 12 to about 25, from about 12 to about 20, from about 12 to about 15, or from about 12 to about 14 amino acids in length. Peptide antagonists of the invention may be from about 15 to about 100, from about 15 to about 90, from about 15 to about 80, from about 15 to about 70, from about 15 to about 60, from about 15 to about 50, from about 15 to about 40, from about 15 to about 30, from about 15 to about 25, from about 15 to about 20, from about 19 to about 15, from about 15 to about 18, or from about 17 to about 15 amino acids in length.
[0022] The peptide antagonists can be chemically synthesized and purified using well-known techniques, such as described in High Performance Liquid Chromatography of Peptides and Proteins: Separation Analysis and Conformation , Eds. Mant et al., C.R.C. Press (1991), and a peptide synthesizer, such as Symphony (Protein Technologies, Inc); or by using recombinant DNA techniques, i.e., where the nucleotide sequence encoding the peptide is inserted in an appropriate expression vector, e.g., an E. coli or yeast expression vector, expressed in the respective host cell, and purified therefrom using well-known techniques.
[0023] Formulations
[0024] The compositions of the invention may be formulated for enteric delivery, for example, may comprise one or more coatings, for example, delayed release coating containing one or more enteric agents. A delayed release coating is typically substantially stable in gastric fluid and substantially unstable (e.g., dissolves rapidly or is physically unstable) in intestinal fluid, thus providing for substantial release of the tight junction antagonist from the composition in the duodenum or the jejunum. Typically, compositions comprising a tight junction antagonist (e.g., peptide antagonist) comprise a pharmaceutically effective amount of the antagonist. The pharmaceutically effective amount of antagonist (e.g., peptide antagonist) employed may vary according to factors such as the disease state, age, sex, and weight of the individual. Dosage regimens may be adjusted to provide the optimum therapeutic response. For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation.
[0025] Compositions of the invention may comprise one or more tight junction antagonists at a level of from about 0.1 wt % to about 20 wt %, from about 0.1 wt % to about 18 wt %, from about 0.1 wt % to about 16 wt %, from about 0.1 wt % to about 14 wt %, from about 0.1 wt % to about 12 wt %, from about 0.1 wt % to about 10 wt %, from about 0.1 wt % to about 8 wt %, from about 0.1 wt % to about 6 wt %, from about 0.1 wt % to about 4 wt %, from about 0.1 wt % to about 2 wt %, from about 0.1 wt % to about 1 wt %, from about 0.1 wt % to about 0.9 wt %, from about 0.1 wt % to about 0.8 wt %, from about 0.1 wt % to about 0.7 wt %, from about 0.1 wt % to about 0.6 wt %, from about 0.1 wt % to about 0.5 wt %, from about 0.1 wt % to about 0.4 wt %, from about 0.1 wt % to about 0.3 wt %, or from about 0.1 wt % to about 0.2 wt % of the total weight of the composition. Compositions of the invention may comprise one or more tight junction antagonists at a level of about 0.1 wt %, about 0.2 wt %, about 0.3 wt %, about 0.4 wt %, about 0.5 wt %, about 0.6 wt %, about 0.7 wt %, about 0.8 wt %, or about 0.9 wt % based on the total weight of the composition.
[0026] Compositions of the invention may comprise one or more tight junction antagonists at a level of from about 1 wt % to about 20 wt %, from about 1 wt % to about 18 wt %, from about 1 wt % to about 16 wt %, from about 1 wt % to about 14 wt %, from about 1 wt % to about 12 wt %, from about 1 wt % to about 10 wt %, from about 1 wt % to about 9 wt %, from about 1 wt % to about 8 wt %, from about 1 wt % to about 7 wt %, from about 1 wt % to about 6 wt %, from about 1 wt % to about 5 wt %, from about 1 wt % to about 4 wt %, from about 1 wt % to about 3 wt %, or from about 1 wt % to about 2 wt % of the total weight of the composition. Compositions of the invention may comprise one or more tight junction effectors at a level of about 1 wt %, about 2 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, or about 9 wt % based on the total weight of the composition.
[0027] The terms “stable in gastric fluid” or “stable in acidic environments” refers to a composition that releases 30% or less by weight of the total tight junction antagonist in the composition in gastric fluid with a pH of 5 or less, or simulated gastric fluid with a pH of 5 or less, in approximately sixty minutes. Compositions of the of the invention may release from about 0% to about 30%, from about 0% to about 25%, from about 0% to about 20%, from about 0% to about 15%, from about 0% to about 10%, 5% to about 30%, from about 5% to about 25%, from about 5% to about 20%, from about 5% to about 15%, from about 5% to about 10% by weight of the total tight junction antagonist in the composition in gastric fluid with a pH of 5, or less or simulated gastric fluid with a pH of or less, in approximately sixty minutes. As use herein, “about” used to modify a numerical value means within 10% of the value. Compositions of the invention may release about 1%, about 2%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, about 9%, or about 10% by weight of the total tight junction antagonist in the composition in gastric fluid with a pH of 5 or less, or simulated gastric fluid with a pH of 5 or less, in approximately sixty minutes.
[0028] The term “unstable in intestinal fluid” refers to a composition that releases 70% or more by weight of the total tight junction antagonist in the composition in intestinal fluid or simulated intestinal fluid in approximately sixty minutes. The term “unstable in near neutral to alkaline environments” refers to a composition that releases 70% or more by weight of the total amount of tight junction antagonist in the composition in intestinal fluid with a pH of 5 or greater, or simulated intestinal fluid with a pH of 5 or greater, in approximately ninety minutes. For example, a composition that is unstable in near neutral or alkaline environments may release 70% or more by weight of a tight junction antagonist peptide in a fluid having a pH greater than about 5 (e.g., a fluid having a pH of from about 5 to about 14, from about 6 to about 14, from about 7 to about 14, from about 8 to about 14, from about 9 to about 14, from about 10 to about 14, or from about 11 to about 14) in from about 5 minutes to about 90 minutes, or from about 10 minutes to about 90 minutes, or from about 15 minutes to about 90 minutes, or from about 20 minutes to about 90 minutes, or from about 25 minutes to about 90 minutes, or from about 30 minutes to about 90 minutes, or from about 5 minutes to about 60 minutes, or from about 10 minutes to about 60 minutes, or from about 15 minutes to about 60 minutes, or from about 20 minutes to about 60 minutes, or from about 25 minutes to about 90 minutes, or from about 30 minutes to about 60 minutes.
[0029] In addition to a tight junction antagonist, compositions of the invention may further comprise one or more therapeutic agents. Therapeutic agents include, but are not limited to, steroids and other anti-inflammatory compounds. Suitable therapeutic agents may include one or more of aminosalicylates, corticosteroids, immunomodulators, antibiotics, and biologic therapies. Examples of suitable therapeutic agents that may be included in the compositions of the invention to treat IBD (e.g., Crohn's disease and/or ulcerative colitis) include, but are not limited to:
[0030] 5-ASA agents (e.g., Sulfasalazine), Azulfidine®, Asacol,® Dipentum,® Pentasa,® and Rowasa®;
[0031] Antibiotics, for example, metronidazole (Flagyl®) and ciprofloxacin (Cipro®), although there are many others that may be effective in certain individuals;
[0032] Steroids, e.g., corticosteroids. Suitable steroids include, but are not limited to, prednisone, hydrocortisone, Medrol®, and budesonide multiple-release capsule MRC (EntocortREC®).
[0033] 6-mercaptopurine (6-MP, Purinethol®) and azathioprine (Imuran®); and
[0034] antibodies against inflammatory cytokines, e.g., Infliximab (Remicade™).
[0035] Compositions of the invention may also comprise one or more pharmaceutically acceptable excipients. Suitable excipients include, but are not limited to, buffers, buffer salts, bulking agents, salts, surface active agents, acids, bases, and binders.
[0036] Methods of Use
[0037] The compositions of the invention can be used for preventing, slowing the onset of, ameliorating and/or treating IBD (e.g., Crohn's disease and/or ulcerative colitis). In one embodiment, the present invention provides a method of treating Crohn's disease by administering a composition comprising one or more tight junction antagonists. In one embodiment, the present invention provides a method of treating ulcerative colitis by administering a composition comprising one or more tight junction antagonists.
[0038] In some embodiments, compositions of the invention may be given repeatedly over a protracted period, i.e., may be chronically administered. Typically, compositions may be administered one or more times each day in an amount suitable to prevent or reduce the likelihood of an attack of IBD (e.g., Crohn's disease and/or ulcerative colitis). Such compositions may be administered chronically, for example, one or more times daily over a plurality of days.
[0039] In some embodiments, compositions of the invention may be use to treat acute IBD (e.g., Crohn's disease and/or ulcerative colitis) attacks. Typically, embodiments of this type will require administration of the compositions of the invention to a subject undergoing an attack in an amount suitable to reduce the severity of the attack. One or more administration may be used.
EXAMPLES
[0040] Effect of AT-1001 on intestinal permeability and colitis in the IL-10 KO mouse (129/Sve/IL-10KO)
[0041] The purpose of this study is to determine the ability of AT-1001, administered daily in drinking water to alter intestinal permeability (measured by absorption/excretion of lactulose and mannitol) and to inhibit the development of colitis in the 129/Svev/IL-10 KO mouse.
[0000]
Anticipated*
Suc/lac/Man/
#
Content
Dose,
Sucralose
Animals
Animal
AT-1001
(weight/
AT-1001
Dose (0.2 ml sugar
per
Group
ID's
Treatment
Formulation
vehicle)
mg/day
probe gavage)
Group
1
129/Svev/
Control
—
—
0
Sucrose 500 mg/ml
12
IL-10KO
Lactulose 60 mg/ml
1M001-1M012
Mannitol 40 mg/ml
Sucralose 30 mg/ml
2
129/Svev/
Gavage of
—
—
0
Sucrose 500 mg/ml
12
IL-10KO
probiotic
Lactulose 60 mg/ml
2M001-2M012
conditioned
Mannitol 40 mg/ml
media
Sucralose 30 mg/ml
3
129/Svev/
Low dose of
Neat
AT-1001
0.2
Sucrose 500 mg/ml
12
IL-10KO
AT-1001
Chemical in
0.1 mg/ml
Lactulose 60 mg/ml
3M001-3M012
autoclaved,
H 2 O
Mannitol 40 mg/ml
H 2 O
Sucralose 30 mg/ml
4
129/Svev/
High dose of
Neat
AT-1001
2
Sucrose 500 mg/ml
12
IL-10KO
AT-1001
Chemical in
1 mg/ml
Lactulose 60 mg/ml
4M001-4M012
autoclaved,
H 2 O
Mannitol 40 mg/ml
H 2 O
Sucralose 30 mg/ml
5
129/Svev/
Control for
—
—
0
—
4
IL-10KO
baseline
zonulin level
measurement
*assumes 2 ml/day water consumption
[0042] Dose Administration
[0000]
Method and
AT-1001 neat chemical in drinking water, and
Routes
Suc/lac/man/sucralose given by gavage
Dosing
Suc/lac/man/suralose: (Groups 1-4)
Timepoints
1.
Weeks 1-2
Suc/lac/man/suralose solution on days 3, 6, and 9
2.
Weeks 3-15
Suc/lac/man/suralose solution first day of every week
Probiotic conditioned media: (Group 2)
Daily in the mornings (Start Day 1 of study)
AT-1001 Neat Chemical 0.1 mg/ml: (Group 3)
Ad libidum (Start Day 1 of study)
AT-1001 Neat Chemical 1 mg/ml: (Group 4)
Ad libidum (Start Day 1 of study)
Duration
Eighty days
Frequency
AT-1001: continuously. Suc/lac/man/sucralose: Days
3, 6, 9, 14, 21, 28, 35, 41, 49, 56, 63, 70, 77, 84
Volume
Suc/lac/man/sucralose 0.2 mL gavage per animal
[0043] Dose Administration Details
[0044] AT-1001 neat chemical will be administered ad libidum every day starting at day 1 to Group 3 at 0.1 mg/ml and Group 4 at 1 mg/ml in sterile water via the drinking water supply. Dosing of AT-1001 will be continued when the animals are in the metabolic cages for 22 hours. Probiotic conditioned medium will be given every morning to Group 2. The solution is prepared by dissolving 0.01 g in 10 ml of MRS medium and incubating it at 37° C. for 24 h. After incubation, the tube will be centrifuged 10 minutes at 10,000 rpm. The supernatant will be filtered through a 0.22 micron filter and diluted 1:10 with MRS medium. Animals will receive 30 μl of this dilution every morning. The conditioned media must be prepared fresh every morning. Sucrose/lactulose/mannitol/sucralose solution is prepared by dissolving Sucrose (50 mg), lactulose (6 mg), mannitol (4 mg), and sucralose (3 mg) in water (100 mL).
[0045] Each week, food and water will be removed 4 hours prior to gavage. All the collection vials will have 100 μl of paraffin oil to avoid urine evaporation and 100 μl of thymol (10% m/w in propanol). Each animal will be gavaged with 0.2 ml of sugar solution, and placed in metabolic cages with access to H 2 O only for 22 hours. For the duration of the 22 hours, urine will be collected into previously weighed vials. At the end of the collection, the funnel of the cages will be washed off with 2 ml of water to collect any sugar that may have dried out before reaching the collection tube. After the collection of urine is complete, the animals will be placed in their respective cages, and provided with food and water. Each tube will be weighed to determine volume of urine collected. For the first 2 weeks, the animals will be handled, administered Suc/lac/man/suralose solution, and introduced to the cages 3 times during 10 days. After this it will be done once a week.
[0046] Test Articles
Test Articles
[0047]
[0000]
Identification
Suc/lac/man/sucralose (Cat. # 84097, L7877,
#M9647, 7106A respectively)
Lot/Batch Number
New sucrose has not arrived yet, 1085532,
036935, 011B99, respectively
Purity, Composition,
Maintained by manufacturer
and Expiry
Storage Conditions
Room temperature
Source and Manufacturer
Sigma Chemical Corporation, St. Louis, MO
Special Handling
Appropriate PPE required (Lab coat, safety
Precautions
glasses, gloves).
Prepared
Immediately prior to dosing
[0000]
Identification
AT1001 (neat chemical, Groups 3, and 4)
Lot/Batch Number
AT1001; Lot E050082
Purity and
>95%; neat AT1001
Composition
Storage Conditions
Frozen
Source and
Solvay/Peptisyntha Inc
Manufacturer
Special Handling
Appropriate PPE required (Lab coat,
Precautions
safety glasses, and gloves)
Prepared
Freshly prepared each day prior to dosing
[0000]
Identification
Probiotic conditioned media
Lot/Batch Number
5160D5
Storage conditions
Room temperature
Source and manufacturer
Sigma-Tau Pharmaceuticals
Special Handling
Use aseptic technique and appropriate PPE
Precautions
required (Lab coat, safety glasses, gloves).
Prepared
Dissolve 0.1 g in 10 ml of MRS media,
incubate at 37 C. for 24 hours. Filter through
0.22 μm membrane and dilute filtrate 1/10 in
MRS media. Gavage animals with 30 μl.
[0048] Preparation of Test Articles
[0000]
Suc/lac/man/suralose
AT1001
AT1001
solution
(neat chemical)
(neat chemical)
Test Article
(Groups 1, 2, 3, and 4)
(Group 3)
(Group 4)
Type of
Solution in water
Oral solution in
Oral solution in
Formulation
drinking water
drinking water
Method of
Weigh 50 g of sucrose, 6 g
Weigh 10 mg of neat
Weigh 100 mg of
Preparation
of lactulose, 4 g of
AT1001. Dissolve in
neat AT1001.
mannitol and 3 g of
100 mL sterile water.
Dissolve in 100 mL
sucralose and dissolve in
sterile water.
100 ml of sterile water.
Frequency of
Every week
Every day
Every day
Preparation
Dose
Sucrose 500 mg/ml
0.1 mg/ml
1 mg/ml
Concentration
Lactulose 60 mg/ml
Mannitol 40 mg/ml
Sucralose 30 mg/ml
Dose Volume
0.2 ml
N/A
N/A
Storage
Refrigerated
Refrigerated
Refrigerated
Conditions
[0049] Test System
[0000]
Species/Strain or Breed
129/Svev/IL-10 KO mouse
Age at Study Initiation
Approximately 28 days
Weight
Approximately 10 grams at study initiation
and 20 grams at study termination
Acclimation
At least 3 days
Selection Criteria/
Randomized assignment of group and
Randomization
animal number prior to study start
Identification
Ear markings and cage cards
Animal Use Protocol Number
138
[0050] Animals to be used on this study will be selected on the basis of acceptable findings from physical examination and body weights. The animals will then be assigned to treatment groups prior to dosing.
[0051] Environmental Conditions
[0000]
Caging
Individually housed cages and in metabolism cages during
urine collection
Bedding
Direct bedding - wood chips prior to study start
Temperature
Approximate range 72 +/− 4° F.
Humidity
Range 30% to 70%
Lighting
Approximate 12-hour light, 12-hour dark cycle. The
lighting cycle may be interrupted for performance
of protocol-defined activities.
Water
Sterile filtered (0.22 micron filter) water
Diet
Certified Purina Rodent Meal 5001.
[0052] Clinical And Physical Examinations
[0000]
Survival and Moribundity
Throughout treatment periods of study
Observations
Clinical Signs
Once daily
Unscheduled Observations
To be performed at the discretion of the
study director/principal investigator
Physical Examinations
To be conducted once prior to the initiation
of dosing
Routine Body Weights
Prior to randomization and the first day of
every week thereafter
Food Consumption
Two times a week. Mice will be fasted 4
hours prior to each sugar gavage
Water Consumption
Every day.
Stool Collection
First day of every week and screened for
the presence of blood
[0053] Clinical Pathology
[0054] Urine Collection
[0055] During each intestinal permeability trial, all subjects will be gavaged with suc/lac/man/sucralose solution and placed in metabolic cages immediately after to enable urine collection. Urine from each animal will be collected for 22 hours in chilled collection tubes, treated with 100 μL of a 10% Thymol solution (1.0 g/10 mL isopropanol) and paraffin oil (100 μL, to prevent urine evaporation) from the following interval post dosing 24 hours. Samples will be frozen at −80° C. until analysis. All sugars will be quantified by ion exchange HPLC. LAMA ratio, total sucrose and total sucralose will be obtained per measurement.
[0056] Stool Sample Collection
[0057] On the first day of every week stool sample will be collected from every animal and screened for the presence of blood. Stool samples will also be collected at the termination of the study.
[0058] Sample Storage Conditions
[0059] 50-100 μl serum from animals in Group 5 will be frozen until zonulin measurements made. 100 μl serum from animals from Groups 1-4 at Day 57 and at day 77 will be frozen at −20° C. until zonulin measurements made.
[0060] Sacrifice Schedule
[0061] Animals found dead will be refrigerated and necropsied at the earliest possible time (within working hours). Terminal body weight organ weights will not be taken from animals found dead. Protocol defined tissues will be collected.
[0062] Moribund/unscheduled animals that are sacrificed during normal working hours will be taken immediately to necropsy. A terminal body weight will be taken and the animal will be necropsied. Protocol defined tissues for histology will be taken. Moribund/unscheduled sacrifice animals that are sacrificed outside of normal working hours will be refrigerated after a terminal body weight and necropsied at the earliest possible time (within working hours). Organ weights will not be collected unless the entire study is sacrificed early and control organ weights can be collected at the same time or the study is taken down at the scheduled sacrifice.
[0000]
Animals Found
Animals found dead will be refrigerated and
Dead
necropsied at the earliest possible time (within
working hours). Gross findings will be noted.
Moribund/
Moribund/unscheduled sacrifice animals that are
Unscheduled
sacrificed outside of normal working hours will be
Sacrifice
refrigerated and necropsied at the earliest possible
time (within working hours). Gross findings will be
noted. Protocol-defined tissues will be collected.
Sacrifice
1. At time 0, all 4 animals of group 5 will be
Schedule
sacrificed. 50-100 μl serum will also be collected to
measure zonulin levels.
2. After 8 weeks, on day 57, 4 animals from the
Groups 1-4 will be sacrificed and their intestinal
permeability (small bowel and colon) will be
measured using Ussing chambers and samples from
both sites will be assessed for histology, MPO
and cytokine secretion. 100 μl of serum will be
collected from these animals and sent to Alba
Therapeutics for zonulin levels determination.
3. On day 77, after final urine collection, all animals
will be sacrificed for measurements as above.
Number of Animals
All
(survival permitting)
Method of
Cervical dislocation
Euthanasia
Fasting
Animals will be fasted overnight prior to necropsy
Requirements
Terminal Body
Will be taken at necropsy
Weight
Macroscopic
Will be performed by the study pathologist at
Examination
necropsy
[0063] Immediately upon expiration, stomachs, small intestines, and colons will be collected and weighed. Each tissue will be scored for macroscopic lesions to assess intestinal damage by the Study Pathologist. ELISAs will be performed on each tissue to measure the levels of MPO, IL-8, TNFα, and IFNγ. A section of the tissues will be fixed in formalin for HE histology. The day after the final intestinal permeability measures on day 77, all surviving animals will be euthanized and intestinal tissues collected and processed.
[0064] Clinical observations, physical examinations, and body weights will be recorded on appropriate paper forms. Sucrose, lactulose, mannitol, and sucralose and lactulose:mannitol ratios will be determined according to the published procedures.
[0065] Data Acquisition
[0066] The following data will be acquired
[0000]
Data Type
Schedule
Weights
1.
Weigh all animals on the first day of every week
2.
Weigh all animals at sacrifice
3.
Week 8
Sacrifice 4 animals from each group to dissect out stomachs, small
intestines, and colons and weigh them
4.
Week 11
Sacrifice the remaining 8 animals from each group to dissect out
stomachs, and intestines, and colons and weigh them
Suc/lac/manLAMA
1.
Weeks 1-2
in urine
Administer Suc/lac/man/suralose and collect urine for 22 hours on
days 3, 6, 9
2.
Weeks 3-11
Administer Suc/lac/man/suralose and collect urine urine for 22 hours
on days 14, 21, 28, 35, 41, 49, 56, 63, 70, 77
Intestinal
1.
Week 8 - Day 57 of study
permeability with
Sacrifice 4 animals from each group to dissect out stomachs, small
Ussing chambers
intestines and colons and measure intestinal permeability
2.
Week 11 - termination of study at day 77
Sacrifice the remaining 8 animals from each group to dissect out
stomachs, small intestines and colons and measure intestinal
permeability
Scoring lesions
1.
Day 1
histologically
Dissect out stomachs, small intestines and colons of 4 animals in Group
5 for scoring macroscopic lesions as control, fix sections for histology.
2.
Week 8 - Day 57 of study
Dissect out stomachs, small intestines and colons of 4 animals from
Groups 1-4 for scoring macroscopic lesions, fix sections for histology
3.
Week 11- Day 77 of study
Dissect out stomachs, small intestines and colons of remaining 8
animals from Groups 1-4 for scoring macroscopic lesions, fix sections
for histology
Zonulin levels
1.
Sacrifice all 4 animals from Group 5 to measure zonulin levels day 1
2.
Week 8 - Day 57 of study
Measure zonulin levels in the animals from Groups 1-4 sacrificed
on this day
2.
Week 11- Day 77 of study
Measure zonulin levels in the animals from Groups 1-4 sacrificed on
this day
Levels of MPO,
1.
Measure levels of these proteins in animals from Group 5
IL-8, TNF-α, IFNγ
2.
Measure levels of these proteins in animals from Groups 1-4 at the
beginning of Week 8 - Day 57 of study
3.
Measure levels of these proteins in animals from Groups 1-4 when
study is terminated at Week 11- Day 77 of study
Water consumption
1.
Measure water consumption daily for dose measurement
[0067] FIGS. 1-4 show that development of disease is associated with an increase in small intestinal permeability. This increase can be abrogated by high dose AT-1001.
[0068] FIG. 5-10 show the results of analysis of disease in the colon. Disease in the colon was evaluated at both 8 and 17 week time points. The former with Using chamber measurements and the latter with histology, mucosal cytokine secretion, MPO and sucralose permeability. At 8 weeks of age AT-1001 reduced colonic permeability to mannitol and prevented the reduction in electrical resistance observed in the untreated animals. At 17 weeks AT-1001 reduced all tissue markers of colonic inflammation that were measured
[0069] All publications, patents and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains, and are herein incorporated by reference to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference.
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The present invention provides materials and methods for the treatment of inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis). Materials of the invention may include compositions comprising one or more tight junction antagonists and optionally one or more therapeutic agents. Methods of the invention may comprise treating a subject in need thereof with a composition comprising one or more tight junction antagonists and, optionally one or more therapeutic agents.
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BACKGROUND OF THE INVENTION
[0001] This is a Continuation-in-Part of U.S. patent application Ser. No. 10/871,089, filed by the present applicant on 18 Jun. 2004. The invention disclosed in that application relates to a bubble-squeezing toy. The present relates to the development of the hand-held soft toys disclosed in the above application and comprising a body that when squeezed deforms to transfer internally captured air into one or more expanding hemispherical bubble shapes that extend from the body exterior. The invention might also have a mechanical sounding device formed internally therein to sound when the body is squeezed.
OBJECTS OF THE INVENTION
[0002] It is an object of the present invention to provide an interesting and amusing toy that can be squeezed to form expanding generally hemispherical bubble shapes at its exterior.
DISCLOSURE OF THE INVENTION
[0003] There is disclosed herein a bubble-squeezing toy, comprising a body formed of resilient, stretchable plastics material having two internal chambers, one of which has an area that can stretch to form an external bubble upon squeezing of the body.
[0004] Preferably said area that can stretch is of reduced thickness.
[0005] Preferably the toy further comprises a partition between the internal chambers and an aperture in the partition via which the chambers communicate with one another.
[0006] Probably, the toy further comprises an air-driven squeaker attached to the partition at the aperture.
[0007] Probably, the body has a plug sealing an opening from one of the chambers to atmosphere.
[0008] Preferably, the body is formed of a material selected from the group consisting of: Polyvinyl Chloride (PVC); Thermoplastic Elastomer (TPE); Thermoplastic Rubber (TPR); and Polyethylene (PE).
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein:
[0010] FIG. 1 (A) is a schematic cross-sectional elevation of a bubble-squeezing toy in an unsqueezed configuration,
[0011] FIG. 1 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 1 (A) in a squeezed configuration,
[0012] FIG. 2 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0013] FIG. 2 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 2 (A) in a squeezed configuration,
[0014] FIG. 3 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0015] FIG. 3 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 3 (A) in a squeezed configuration,
[0016] FIG. 4 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0017] FIG. 4 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 4 (A) in a squeezed configuration,
[0018] FIG. 5 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0019] FIG. 5 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 5 (A) in a squeezed configuration,
[0020] FIG. 6 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0021] FIG. 6 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 6 (A) in a squeezed configuration,
[0022] FIG. 7 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0023] FIG. 7 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 7 (A) in a squeezed configuration,
[0024] FIG. 8 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0025] FIG. 8 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 8 (A) in a squeezed configuration,
[0026] FIG. 9 (A) is a schematic cross-sectional elevation of another bubble-squeezing toy in an unsqueezed configuration,
[0027] FIG. 9 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 9 (A) in a squeezed configuration,
[0028] FIG. 10 (A) is a schematic elevation of another bubble-squeezing toy in the form of a frog,
[0029] FIG. 10 (B) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIG. 10 (A) in an unsqueezed configuration,
[0030] FIG. 10 (C) is a schematic cross-sectional elevation of the bubble-squeezing toy of FIGS. 10 (A) and 10 (B) in a squeezed configuration,
[0031] FIG. 11 (A) is a schematic elevation of a further bubble-squeezing toy in the form of a frog,
[0032] FIG. 11 (B) is a schematic cross-sectional elevation of the toy of FIG 11 (A) in a relaxed configuration, and
[0033] FIG. 11 (C) is a schematic cross-sectional elevation of the toy of FIGS. 11 (A) and 11 (B) in a squeezed configuration in which its throat bubble is expanded.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] In FIG 1 (A) and 1 (B) of the accompanying drawings there is depicted schematically a bubble-squeezing toy 10 comprising an inner liner 11 surrounded substantially by a body 12 . The inner liner 11 is typically formed of a material selected from the group consisting of: gelatinous compositions of Styrene Block Copolymers (SBC); Thermoplastic Elastomer (TPE) compounds and alloys; Thermoplastic Polyurethane (TPU) compounds and alloys; Thermoplastic Vulcanisates (TPV) compounds and alloys; Thermoplastic Olefins (TPO) compounds and alloys; and Thermoplastic Rubber (TPR) compounds and alloys. However, the inner liner could be made of any other flexible plastics material having a high elongation of preferably not less than 300 percent up to about 1600 percent. The material must also have good retraction properties so as to return to the configuration of FIG. 1 (A) after squeezing. The thickness of the inner liner is typically between 1 and 3 mm.
[0035] The body 12 is typically formed of a material selected from the group consisting of: Polyvinyl Chloride (PVC); Thermoplastic Elastomer (TPE); Thermoplastic Rubber (TPR); and Polyethylene (PE). However, the body could be made of any flexible plastics material which can be squeezed or compressed. The elongation properties of the body should be low, and preferably be less than 2 - 5 percent.
[0036] There is an aperture 15 in the body 12 having a diameter typically between 5 mm and 15 mm. The thickness of the body would typically be from 1 mm to 5 mm.
[0037] When the body 12 is squeezed, the inner liner stands through the aperture 15 to form a substantially hemispherical bubble 16 as shown in FIG. 1 (B).
[0038] Upon alternately squeezing and releasing compression quickly, a popping sound will be created from the protruding and retracting bubble.
[0039] There are sealing plugs 13 and 14 within respective apertures of the inner liner 11 and body 12 . The size of sealing plug 14 is larger than sealing plug 13 , but the plugs are aligned so that access to the sealing plug 13 is gained upon removal of the sealing plug 14 .
[0040] FIGS. 2 (A) and 2 (B) depict an embodiment 20 which is similar to that of the proceeding figures, but includes a pair of apertures 15 A and 15 B through which a pair of bubbles 16 A and 16 B protrude simultaneously upon squeezing of the body 12 .
[0041] FIGS. 3 (A) and 3 (B) depict an embodiment 30 having a body similar to that of FIGS. 1 (A) and 1 (B), but also including within the body 12 a pouch 16 adjacent to a smaller version of the inner liner 11 and communicating therewith via a squeaker 17 . In this embodiment, the sealing plug 13 is in the pouch, rather than in the inner liner 11 . The pouch would typically be made of the same material from which the inner liner is made. Upon squeezing the body 12 , air will pass back and forth through the squeaker 17 as the bubble 16 expands and contracts. The squeaker will produce repeated squeaking sounds. The squeaker 17 comprises a mechanical assembly mounted upon a partition comprising adjacent portions of the liner 11 and pouch 16 . The squeaker 17 can be inserted into the body through the sealing plug apertures. Air is then injected into the toy and the plugs are sealed.
[0042] FIGS. 4 (A) and 4 (B) depict a further embodiment 40 in which the body does not house a separate inner liner. Instead, the body whose overall thickness is typically from 3 to 6 mm is provided with a thin area 19 that expands to form a bubble when the body is squeezed. The thin area 19 would typically be 1 to 2 mm thick in the relaxed state as depicted in FIG. 4 (A). The material from which the body 18 is formed would typically be chosen from the same group from which the liners of FIGS. 1 to 3 are made. These are all elastomeric materials with high elongation and good retraction properties. By alternately squeezing and releasing the body rapidly, a popping sound will be created from the protruding and retracting bubble.
[0043] FIGS. 5 (A) and 5 (B) depict an embodiment 50 in which the body is the same as that depicted in FIGS. 4 (A) and 4 (B), but comprising the internal components the same as those depicted in the embodiment of FIGS. 3 (A) and 3 (B). The bubble formed by this embodiment is double-linered comprising and inner bubble liner 16 and an outer liner 19 . The body 12 as well as the inner liner 11 and pouch 16 would all be formed of the same highly elastic material.
[0044] The embodiment 60 depicted in FIGS. 6 (A) and 6 (B) comprises two liners of material. The body or outer liner 12 is of high elastic material with high elongation and good retraction properties and has a thinner bubble-forming portion 19 . The inner liner 11 is made of a plastic material - not necessarily having a high elongation, but is nevertheless flexible so as to return to its original shape once handed compression is released.
[0045] For example, the inner liner might be chosen from a material having low elongation of preferably less than 2 percent. There is a squeaker 17 positioned directly behind the bubble-forming portion 19 . When squeezed, air passes from the interior of the inner liner through the squeaker into the bubble-forming volume to expand portion 19 as shown.
[0046] The construction 70 depicted in FIGS. 7 (A) and 7 (B) is similar to that of FIG. 2 (A) and 2 (B), except that there are two separate inner liners 11 A and 11 B that do not share air. This construction allows a bubble to protrude from each respective aperture independently of one another when the body is squeezed.
[0047] FIGS. 8 (A) and 8 (B) depict an embodiment 80 the same as that depicted in FIGS. 7 (A) and 7 (B), except there is a squeaker situated between the two inner liners 11 A and 11 B.
[0048] FIGS. 9 (A) and 9 (B) depict an embodiment 90 somewhat similar to that of FIGS. 6 (A) and 6 (B), but having an inner liner of reduced volume.
[0049] A practical example of the invention is depicted in FIGS. 10 (A), 10 (B) and 10 (C). This practical example is a bubbled belly-popping frog 100 . This frog is made in accordance with the construction principles of FIGS. 5 (A) and 5 (B). Similarly, by applying the constructions as described here into different applications, a wide range of toys such as balls, dolls, animals, birds, insects etc can be made with expanding bubble characteristics with or without additional squeaking sounds as the case may be.
[0050] In Figs. 11 (A) to 11 (C) of the accompanying drawings, there is depicted schematically a further embodiment taking the visual form of a frog similar to that depicted in FIGS. 10 (A) to 10 (C). Instead of being provided with separate internal liners however, the frog's body 12 comprises a unitary moulding including a small chamber 23 and a large chamber 24 . There is a partition 21 between the two chambers having an aperture 22 into which a squeaker 17 is fitted. A connection band or ring 25 (perhaps of plastics material that might be stretchable) might be provided to secure the elastic material of the toy about the squeaker. The squeaker can be provided with a peripheral annular groove 26 about which the band 25 is fitted. There is a plug 13 in the base of the frog closing an aperture of the large chamber 24 which communicates with atmosphere. This aperture is needed to construct the toy and particularly for the purpose of installing the squeaker therein. There is an area of reduced thickness 16 under the frog's chin. This defines a thin, expandable portion of a wall of the small chamber 23 .
[0051] When the body of the frog around the large chamber 24 is squeezed, air from within that chamber passes through the squeaker into the small chamber 23 so that the bubble 16 expands with a sound made by the squeaker. Released hand pressure from the body will allow the resilience of the material to return the toy to the configuration depicted in FIGS. 11 (A) and 11 (B) and the squeaker 17 might sound again depending upon it's design (one-way or two-way sounding).
[0052] It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example, two or more small chambers 23 might be provided in addition to the large chamber, each having an area of reduced thickness. For example the frog's eyes might have individual small chambers and areas of reduced thickness. Of course shapes other than frogs are envisaged.
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A bubble-squeezing toy has a body formed of resilient, stretchable plastics material having two internal chambers, one of which has an area of reduced thickness that can stretch to form an external bubble upon squeezing of the body. A partition exists between the internal chambers and an aperture is provided in the partition via which the chambers communicate with one another. An air-driven squeaker is attached to the partition at the aperture.
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BACKGROUND OF THE INVENTION
The present invention relates to recombinant DNA that encodes the RsaI restriction endonuclease, as well as the RsaI methylase, and to the production of the RsaI restriction endonuclease from the recombinant DNA.
Type II restriction endonucleases are a class of enzymes that occur naturally in bacteria. When they are purified away from other bacterial components, restriction endonucleases can be used in the laboratory to cleave DNA molecules into fragments for molecular cloning and gene characterization.
Restriction endonucleases act by binding to particular sequences of nucleotides (the ‘recognition sequence’) along the DNA molecule. Once bound, they cleave the DNA molecule within, to one side of, or to both sides of the recognition sequence. Different restriction endonucleases recognize and cleave different nucleotide sequences. Over two hundred restriction endonucleases with unique specificities have been identified among thousands of bacterial species that have been examined (Roberts and Macelis, Nucl. Acids Res. 24:223-235, (1996)).
Restriction endonucleases are named according to the bacteria from which they derive. Thus, the bacterium Deinococcus radiophilus for example, produces three different restriction endonucleases, named DraI, DraII and DraIII. These enzymes recognize and cleave the sequences 5′-TTTAAA-3′, 5′-PuGGNCCPy-3′ and 5′-CACNNNGTG-3′ respectively. Escherichia coli RY13, on the other hand, produces only one restriction enzyme, EcoRI, which recognizes the sequence 5′ GAATTC 3′.
Restriction endonucleases usually occur together with one or more companion enzymes termed methyltransferase, the whole forming a restriction-modification (R-M) system. Methyltransferases are complementary to the restriction endonuclease they accompany and they provide the means by which bacteria are able to protect their own DNA and distinguish it from foreign, infecting DNA. Modification methylases recognize and bind to the same recognition sequence as the corresponding restriction endonuclease, but instead of cleaving the DNA, they chemically modify one of the nucleotides within the sequence by the addition of a methyl group to form 5-methylcytosine, N4-methylcytosine, or N6-methyladenine. Following methylation, the recognition sequence is no longer cleaved by the cognate restriction endonuclease. The DNA of a bacterial cell is always fully modified by virtue of the activity of its modification methylase(s), and therefore it is completely insensitive to the presence of the restriction endonuclease. It is only unmodified, and therefore identifiably foreign DNA, that is sensitive to restriction endonuclease recognition and cleavage.
With the advent of recombinant DNA technology, it is possible to clone genes and overproduce the enzymes they encode in large quantities. The key to isolating clones of restriction endonuclease genes is to develop a simple and reliable method to identify such clones within complex ‘libraries’, i.e. populations of clones derived by ‘shotgun’ procedures, when they occur at frequencies as low as 10 −3 to 10 −4 . Preferably, the method should be selective, such that the unwanted majority of clones are destroyed while the desirable rare clones survive.
Type II restriction-modification systems are being cloned with increasing frequency. The first cloned systems used resistance to bacteriophage infection as a means of identifying or selecting restriction endonuclease clones (EcoRII: Kosykh et al., Mol. Gen. Genet. 178:717-719, (1980); HhaII: Mann et al., Gene 3:97-112, (1978); PstI: Walder et al., Proc. Nat. Acad. Sci. 78:1503-1507, (1981)). Since the presence of restriction-modification systems in bacteria enable them to resist infection by bacteriophages, cells that carry cloned restriction-modification genes can, in principle, be selectively isolated as survivors from libraries that have been exposed to phages. This method has been found, however, to have only limited value. Specifically, it has been found that cloned restriction-modification genes do not always manifest sufficient phage resistance to confer selective survival.
Another cloning approach involves transferring systems initially characterized as plasmid-borne into E. coli cloning plasmids (EcoRV: Bougueleret et al., Nucl. Acids. Res. 12:3659-3676, (1984); PaeR7: Gingeras and Brooks, Proc. Natl. Acad. Sci. USA 80:402-406, (1983); Theriault and Roy, Gene 19:355-359 (1982); PvuII: Blumenthal et al., J. Bacteriol. 164:501-509, (1985)).
A third approach to clone R-M systems is by selection for an active methylase gene (U.S. Pat. No. 5,200,333 and BsuRI: Kiss et al., Nucl. Acids. Res. 13:6403-6421, (1985)). Since R and M genes are usually closely linked, both genes can often be cloned simultaneously by selecting for only one. Selection for the M gene does not always yield a complete restriction system however, but often instead yields only the methylase gene (BspRI: Szomolanyi et al., Gene 10:219-225, (1980); BcnI: Janulaitis et al., Gene 20:197-204 (1982); BsuRI: Kiss and Baldauf, Gene 21:111-119, (1983); and MspI: Walder et al., J. Biol. Chem. 258:1235-1241, (1983)).
Another approach is to clone R-M Systems in E.coli by making use of the fact that certain modification genes, when cloned into a new host and adequately expressed, enable the host to tolerate the presence of a different restriction gene (Wilson et al; U.S. Pat. No. 5,246,845).
A more recent method, the “endo-blue method”, has been described for direct cloning of restriction endonuclease genes in E. coli based on the indicator strain of E. coli containing the dinD::lacZ fusion (Fomenkov et al., U.S. Pat. No. 5,498,535; Fomenkov et al., Nucl. Acids Res. 22:2399-2403, (1994)). This method utilizes the E. coli SOS response following DNA damages caused by restriction endonucleases or non-specific nucleases. A number of thermostable nuclease genes (Tth111I, BsoBI, Tf nuclease) have been cloned by this method (U.S. Pat. No. 5,498,535).
Because purified restriction endonucleases, and to a lesser extent modification methylases, are useful tools for manipulating DNA molecules in the laboratory, there is a commercial incentive to create bacterial strains through recombinant DNA techniques that produce these enzymes in large quantities. Such overexpression strains also simplify the task of enzyme purification.
SUMMARY OF THE INVENTION
The methylase selection method was used to clone the RsaI methylase gene (rsaIM) from Rhodopseudomonas sphaeroides (NEB (New England Biolabs, Beverly, Mass.) Culture Collection #233, (Lynn, et al., J. Bacteriol. 142:380-383 (1980)) into the E.coli plasmid vector pBR322. Subcloning, deletion mapping, and DNA sequencing verified the location of the inserted RsaI methylase gene (ORF1) and revealed the presence of a second incomplete converging open reading frame (ORF2).
Because methylase endonuclease genes usually occur next to each other in bacterial DNA, ORF2 was assumed to be the rsaIR gene and efforts were made to clone the missing portion of ORF2. Southern blots revealed that Bc/I-, BstYI-, and PstI-fragments could potentially contain rsaIM as well as enough adjacent DNA to include the whole ORF2. Methylase selection on de novo libraries made with Bc/I and BstYI, as well as with size-fractionated, gel-purified, PstI-digested, chromosomal DNA failed to yield any RsaI methylase clones whatsoever, suggesting that these fragments were perhaps toxic in E.coli.
Native RsaI restriction endonuclease was purified to near homogeneity from a Rhodopseudomonas sphaeroides cell extract. Two proteins of approximately 18 kDa and 22 kDa were found to be present in the prep by SDS-PAGE gel analysis. The N-terminal amino acid sequences of both of these proteins were determined, and they were used to synthesize primers for PCR of a fragment containing rsaIM and the converging ORF2. These PCR attempts also failed to yield the desired clone.
Finally, inverse PCR, was used to isolate the adjacent chromosomal DNA and this fragment was cloned into both pCAB16 and pUC19 and sequenced. Two complete open reading frames (ORFs) were found downstream of the rsaIM gene (ORF1) including the above mentioned second converging ORF (ORF2) and an additional ORF (ORF3). The derived amino acid sequences of the proteins encoded by ORF2 and ORF3 did not match any of the known proteins in the Genbank data base which is indicative of a potential restriction endonuclease. However, amino acid sequence encoded by the beginning of the third ORF (ORF3) matched exactly the N-terminal amino acid sequence of the 18 kDa endonuclease candidate protein. The amino acid sequence encoded by the beginning ORF2 did not match the N-terminal sequence of either the 18 kDa or the 22 kDa protein. This indicated that ORF3 was probably the rsaIR gene, and not ORF2, and that the RsaI endonuclease protein was 18 kDa in size.
In most R-M systems, the restriction and modification genes occur side-by-side with no other genes between them. The RsaI R-M system appears to be unusual in that a gene of unknown function, ORF2, separates the R and M genes. Intervening genes have been found in a few R-M systems, but in all cases the functions of these intervening genes are known. For example, in the BsuRI R-M system, a vsr-type mismatch repair (V) gene separates the bsuRI R and M genes (J. Barsomian and G. Wilson, unpublished). In the AhdI R-M system, a DNA sequence-specificity (S) gene separates the ahdI R and M genes (K. Lunnen, T. Cui and G. Wilson, unpublished). And in the BamHI R-M system, a regulatory, or C, gene separates the bamHI R and M genes (Ives, et al., J. Bacteriol., 174:7194-7201 (1992); Sohail, et al., Gene 157:227-228 (1995)). The intervening gene in the RsaI R-M system is different from these other intervening genes, and it is unique. The protein encoded by the gene resembles neither V, C, or S, proteins, nor any other protein in the GenBank database.
Methanococcus jannascii encodes an isoschizomer of RsaI designated MjaV. The R and M genes of the MjaV R-M system occur in a different, opposing, orientation to the genes of the RsaI R-M system, but they too are separated by a unique gene. The protein encoded by this gene does not resemble the corresponding intervening protein of the RsaI system, and it is also unique in that it resembles neither V, C, or S, proteins, nor any other protein in the GenBank database. (Bult, et al. Science 273:1058-1073, (1996); Morgan, R., Posfai, J., Patti, J., Roberts, R.J, unpublished, New England Biolabs; R. Morgan, K. Lunnen, and G. Wilson, unpublished, New England Biolabs)).
Attempts to clone an active RsaI restriction gene (ORF3) directly into pRRS (Skoglund et al, Gene, 88:1-5 (1990)) by transforming into a pre-modified E.coli host containing the RsaI methylase gene failed. Only two pRRS-rsaIR clones, #13 and #14 with reduced RsaI endonuclease activity were isolated from a RsaI methylase pre-modified E.coli host. The same ligation transformed into a MjaV methylase pre-modified E. coli host also failed to yield any clones. DNA sequencing of reduced activity clone #14 revealed a deletion mutation of T at the start codon (ATG) which most likely truncated the RsaI endonuclease at the N-terminal end due to a delayed GTG start codon downstream. The truncated RsaI endonuclease clones revealed low or no activity when grown at 30° C. verses a sustained RsaI partial endonuclease activity for cultures grown at 37° C.
An rsaIR PCR fragment from Rhodopseudomonas sphaeroides chromosomal DNA was then cloned and sequenced after ligation into pCAB16 at a BsaAI site. pCAB16 is a pUC18 derivative containing the active mspIR gene cloned into the polylinker of pUC18 with mspIR in line with the Plac promoter. pCAB16 was linearize at a BsaAI site in mspIR, interrupting mspIR expression (which would otherwise be lethal) and thereby selecting for inserts by ligating into the BsaAI site (FIG. 7 ). The rsaIR PCR fragment was ligated into pCAB16, transformed into a RsaI methylase pre-modified Ecoli host. Colony PCR was performed on ten colonies; one isolate #9 contained the PCR rsaIR fragment. Sequencing showed correct DNA sequence for rsaIR matching the predicted N-terminal amino acid sequence of the 18 kDa protein. The pCAB16-rsaIR #9 was in the opposite orientation to Plac and mspIR, and when assayed showed detectable, but partial, RsaI restriction endonuclease activity.
The RsaI endonuclease gene (rsaIR) fragment from pCAB16-rsaIR #9 was gel purified following digestion with PstI and BamHI, and then ligated into pRRS. Transforming this ligation into separate E.coli hosts pre-modified with either the RsaI or the MjaV methylase failed to produce transformants carrying of an active RsaI restriction clone in pRRS.
Attempts to directly clone the RsaI restriction-modification system on a PCR fragment containing all three ORFs, rsaIM (ORF1), convergent unknown ORF rsaIU (ORF2), and rsaIR (ORF3) from Rhodopseudomonas sphaeroides chromosomal DNA into pUC19, also failed to yield an intact RsaI endonuclease. Only 3 pUC19 clones, #1, #6, and #12 were isolated that proved resistant to RsaI endonuclease digestion, and these contained a smaller deleted DNA fragment. DNA sequencing of #1 revealed an intact rsaIM gene with only part of the unknown gene rsaIU (ORF2) and all of rsaIR (ORF3) completely deleted.
Another attempt to establish an RsaI endonuclease clone involved the use of a plasmid pLT7K (NEB#1285, New England Biolabs, Inc., Beverly, Mass.) containing a highly regulated T7 promoter. pLT7K has the colE1 origin of replication compatible with both pSX20 and pIH919. The plasmid contains the PR promoter from phage lambda orientated against the IPTG regulated T7 promoter, and it also contains ampicillin and kanamycin resistance genes. The P R promoter is repressed at 30° C. by the lambda cI repressor. This repressor, the product of the phage lambda cI857 gene, is temperature sensitive and fails to repress P R above 37° C., allowing P R promoter expression. The Tn903-derived kanamycin gene is located in line with P R promoter with cloning sites on either side allowing for direct selection for inserts on plasmids which become Kan sensitive. At the other end is the opposing T7 promoter regulated by the lacI repressor which is induced by the addition of IPTG. The method for endonuclease gene overexpression using pLT7K is as follows: Plasmids containing an endonuclease gene in line with T7 promoter are grown at 37° C. to an OD590 0.8 to 1.0, allowing antisense expression from P R promoter which interferes with any expression of the endonuclease gene from the opposing T7 promoter. The culture temperature is lowered to 30° C., PR becomes repressed, then IPTG is added to induce the T7 promoter and the endonuclease gene. (ie.rsaIR)
Using Vent® DNA polymerase, the RsaI endonuclease gene (rsaIR) was PCR-amplified from pCAB16-rsaIR #9, and cloned following digestion with XbaI and XhoI, and ligation into pLT7K. The ligation reaction was tranformed into E.coli DH5α, which lacks the T7 RNA polymerase, and plated on LB+Amp plates containing 20 mM glucose at 37° C. Plasmid DNA was isolated from 18 kanamycin-sensitive colonies. Twelve contained the correct size rsaIR fragment as indicted by XbaI+XhoI double digestion. Four of these pLT7K-rsaIR clones were transformed into an RsaI methylase pre-modified E.coli ER2566 host containing T7 RNA polymerase. When assayed, the pLT7K-rsaIR clones showed varying amounts of detectable RsaI restriction endonuclease activity. The clone with the most RsaI endonuclease activity, #5-3 pLT7K-rsaIR showed the most RsaI endonuclease activity. Four individual colonies from #5-3 pLT7K-rsaIR plate were again grown and then IPTG-induced and assayed for RsaI endonuclease activity but this time, no RsaI endonuclease activity was detected, suggesting that the clone was unstable.
To create a stable over-expressing RsaI endonuclease clone one more step was found to be necessary, namely the use of an E.coli host pre-modified with both methylases, M.RsaI and M.MjaV. Using compatible vector plasmids containing these two methylases, a highly expressing RsaI endonuclease clone was established in E.coli. In order to do this, the RsaI methylase gene (rsaIM) was cloned onto pIH919, a derivative of pACYC184 containing the Plac promoter and polylinker from pUC18. The MjaV methylase gene (mjaVM) was cloned into pSX20, a derivative of pSC101 compatible with both pBR322 and pACYC-based plasmids. The pSX20-mjaVM methylase plasmid was then transformed into competent E.coli host ER2744 containing the pIH919-rsaIM plasmid. This E.coli host ER2744 strain, containing both methylases was made competent and was tranformed with the original miniprep DNA from pLT7K-rsaIR #5, described above. The host, E.coli ER2744, contains the T7 polymerase necessary for expression of the rsaIR from Thr T7 promoter.(Note: An attempt to clone an active RsaI restriction gene rsaIR directly into pRRS by transforming into this dual pre-modified E.coli host containing the M.RsaI and M.MjaV failed. Plasmid DNAs of twelve colonies from this transformation were isolated and no clones appeared to contain the correct size rsaIR insert or show detectable RsaI endonuclease activity.
Five colonies, from this transformation, were then grown at 37° C. to OD590 0.8 to 1.0, culture temperature was then lowered to 30° C., followed by IPTG induction. When asssayed for RsaI endonuclease activity, all five clones #51, #52, #53, #54 and #55 showed varying amounts of RsaI endonuclease activity, the highest being #51 at over 10 6 u/g (FIG. 8 ). A glycerol stock of pLT7K-rsaIR #51 clone was stored at −70° C. #51 glycerol stock was later thawed, restreaked on LB ampicillin, chloramphenicol and kanamycin plates at 37° C. and again individual colonies were grown and induced at 30° C. and assayed for RsaI endonuclease activity. All four individual clones, including one such clone pKL167-51 expressed R.RsaI at more than 5×10 6 units of RsaI endonuclease produced per gram of wet E.coli cells. The recombinant RsaI endonuclease from pKL167-51 can be purified by chromatography to near homogeneity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 . Gene organization of RsaI restriction-modification system
FIG. 2 . RsaI methylase gene (SEQ ID NO:1) and its encoded amino acid sequence (SEQ ID NO:2).
FIG. 3 . RsaI endonuclease gene (SEQ ID NO:3) and its encoded amino acid sequence (SEQ ID NO:4).
FIG. 4 . RsaI unknown gene (SEQ ID NO:5) and its encoded amino acid sequence (SEQ ID NO:6).
FIG. 5. A plasmid map of pIH919-rsaIM methylase clone.
FIG. 6. A plasmid map of pSX20-mjaVM methylase clone.
FIG. 7 A plasmid map of pCAB16.
FIG. 8. A plasmid map of pLT7K-rsaIR endonuclease clone #5.
FIG. 9 . Photogragh illustrating RsaI restriction enzyme activity from E.coli cell extract of pKL167-51.
DETAILED DESCRIPTION OF THE INVENTION
In order to successfully overproduce the RsaI endonuclease from a clone, further steps beyond methylase selection were required including the use of a specially-repressed plasmid vector pLT7K, in an E.coli host pre-modified with two methylases, M.MjaV and M.RsaI. Two MTases were needed to completely protect E.coli DNA from RsaI digestion, and they were introduced into the host using two compatible plasmids, one containing rsaIM and the other mjaVM. These plasmids were transformed into an E. coli host containing T7 RNA polymerase, and this strain was then transformed with a third compatible plasmid pLT7K-rsaIR containing the rsaIR gene, followed by selection for colonies containing all three recombinant plasmids on antibiotic Luria-Broth plates.
The method described herein by which the RsaI methylase gene and the RsaI restriction endonuclease genes are preferably cloned and expressed in E.coli employs the following steps:
1. Construction of an ApoI Partial Genomic DNA Library
Rhodopseudomonas sphaeroides genomic DNA was digested with ApoI to achieve the desired partial digestion. The ApoI complete and partially digested genomic DNA in the range of 0.5-20 kb was ligated into EcoRI-cut and CIP-treated vector pBR322 at 17° C. overnight. Transformation was carried out using ER2418 E.coli competent cells and ligated DNA. The transformants were pooled and amplified. Plasmid DNA was prepared from the overnight cell cultures.
2. Challenge the ApoI Partial Library DNA with RsaI Digestion and Isolate of the RsaI Methylase Gene
The ApoI partial library DNA was digested with RsaI at 37° C. for 2 hr. The digested DNA was transformed into ER2418 competent cells. Plasmid DNA was isolated from cell cultures of individual transformants. The individual plasmid DNAs were digested with RsaI to detect any resistance to digestion. Two plasmids, isolate #1 and #2, displayed complete resistance to RsaI digestion. These clones carried the cloned RsaI M gene.
3. Sequencing of the Insert Carrying the RsaI Methylase Gene
DNA sequencing verified the location of the inserted RsaI methylase gene (ORF1) within the insert and revealed a partial, converging, open reading frame (ORF2). When the complete ORF1 was compared to the known gene products in GenBank using BLAST, it showed homology to N4-methyl cytosine methylases. The complete ORF1 of 1230 bp encodes the RsaI methylase (409 amino acid molecular mass=45.4 kDa). The partial ORF2 showed no match to any of the known proteins in the Genbank data base.
4. N-Terminal Amino Acid Sequencing of Purified RsaI Restriction Endonuclease
The non-recombinant RsaI endonuclease was purified to near-homogeneity and subjected to SDS-PAGE. Two protein bands were detected with molecular masses of approximately 18 kDa and 22 kDa. The N-terminal amino acid sequence of the 18 kDa protein was determined to be (M)ERRFPLRW DEEELARAFKVTTK (SEQ ID NO:7). The N-terminal amino acid sequence of the 22 kDa protein was determined to be (M)AREIPDLQAVVRTGTGKGAARQARX (SEQ ID NO:8). (The 18 kDa protein sequence matches exactly with the predicted N-terminal amino acid sequence encoded by ORF3 as described in section 5. The 22 kDa sequence did not match any of the cloned ORFs. It was concluded that RsaI restriction endonuclease would most likely be the 18 kDa protein.)
5. Inverse PCR to Clone ORF2 and ORF3
Rhodopseudomonas sphaeroides genomic DNA was amplified by inverse PCR of self-ligated, HpaII- and NciI-cleaved DNA. The inverse PCR product was cloned following digestion with ApoI and PstI and ligation into pUC19. The ligation was transformed into a M.RsaI pre-modified strain. Plasmid DNAs were isolated from eight colonies and digested with ApoI and PstI. NciI #7, HpaII #2, #3, #4, and #7 contained an inverse PCR fragment. DNA sequencing of NciI #7 and HpaII #7 revealed 493 bp of new DNA sequence. The sequence confirmed the location of the ApoI site on the chromosome of Rhodopseudomonas sphaeroides, and completed the sequence of the converging open reading frame ORF2. The inverse PCR fragments included the ApoI site, thus containing new DNA from this ApoI site out to the HpaII/NciI site on the Rhodopseudomonas sphaeroides chromosome. (The HpaII site (CC/GG) overlaps the NciI site (CC/GGG)). The inverse-PCR fragment sequence also contained an ATG start codon and 102 bp of a new ORF running in the same direction as rsaIM. The derived amino acid sequence of the product of this new ORF (ORF3) included experimentally determined sequence of the 18 kDa candidate protein and 14 additional amino acids. When this new partial ORF (ORF3) was compared to known gene products in GenBank using BLAST, it did not match with known proteins in the Genbank data base. This is a typical feature of restriction endonuclease.
In the direction of the ApoI site, back towards rsaIM, a GTG start codon, proposed to be the beginning of the convergent unknown ORF2, was located 31 bp away from the beginning of ORF3 (rsaIR). This unknown ORF2 termed rsaIU, was originally assumed to be rsaIR; however, as described above, N-terminal R.RsaI endonuclease (18 kDa) protein sequence proved that this assumption was wrong, since the N-terminal 18 kDA protein sequence matched the beginning of ORF3 and not the beginning of ORF2. To identify the C-terminal end of R.RsaI, PCR primers were designed to PCR the 3′ end of rsaIR excluding the ATG start of the gene to minimize any potential toxic expression of an intact rsaIR. Genomic DNA was amplified by inverse PCR of self-ligated, MfeI-cleaved DNA. The Vent® polymerase PCR product was digested with PstI, and cloned into pUC19 cut with SmaI and PstI, and then sequenced. The newly-derived sequence extended the total DNA sequenced to 2714 bp, including the sequence from the original ApoI fragment isolate #1, and the inverse PCR of the HpaII/NciI chromosomal fragment. Translation of this complete DNA sequence in all six reading frames indicated that there were two complete open reading frames downstream of the RsaI methylase gene: the unknown converging rsaIU (ORF2) and rsaIR (ORF3)(FIG. 1 ). The sequences of products of ORF2 and ORF3 did not match any of the known proteins in the Genbank data base.
6. Expression of the RsaI Methylase Gene in E.Coli
The entire RsaI methylase gene (1230 bp) was PCR amplified from genomic DNA using Vent® polymerase and two oligonucleotide primers to rsaIM. The PCR product was digested with KpnI and BamHI, ligated into pIH919 digested with KpnI and BamHI, and transformed into E.coli ER2502, and ER2566. The transformants were pooled and amplified. Plasmid DNA was prepared from an overnight culture and then digested with RsaI at 37° C. for 1 hour. The digested pool was re-transformed into ER2502 and ER2566. Individual plasmid DNAs were purified and digested with RsaI to detect resistance to RsaI digestion; four isolates, #1, #2, #4 and #6 contained the rsaIM PCR fragment and all appeared to be completely modified against RsaI digestion. #1 was then transformed into E.coli strains ER2566 and ER2744, and the transformants were made competent using standard CaCl 2 method.
7. Expression of the MjaV Methylase Gene in E. Coli
A 0.9 kb PCR fragment from Methanococcus jannaschii containing the mjaVM methylase gene was gel-purified, digested with BamHI and SalI, ligated into the BamHI- and Sa/I-cleaved pSX20, and then transformed into E.coli. The resulting pSX20-mjaVM plasmid DNA was purified and was shown to be completely modified against RsaI digestion. The pSX20-mjaVM plasmid was then transformed into E.coli strain ER2566 and made competent using standard CaCl 2 method. The pSX20-mjaVM plasmid was also transformed into competent E.coli ER2744 containing the pIH919-rsaIM plasmid (section 11).
8. Cloning of the Complete RsaI Restriction Endonuclease Gene
Two primers were synthesized for PCR-amplification of the rsaIR gene (ORF3) from Rhodopseudomonas sphaeroides chromosomal DNA. The PCR product was digested with PstI and BamHI, ligated into PstI- and BamHI-digested pRRS, and then transformed into E.coli strains ER2566 [pSX20-rsaIM] and ER2566 [pSX20-mjaVM]. The pSX20-rsaIM plasmid contained a subcloned DNA fragment from the original methylase clone, ApoI #1 (section 2).
Although both E.coli strains appeared to fully protected against RsaI digestion, only ER2566 [pSX20-rsaIM] cells yielded clones with RsaI endonuclease activity. Two clones out of twenty, isolates #13 and #14, contained the correct rsaIR fragment as detected by colony PCR, and showed some endonuclease activity. ER2566 [pSX20-mjaVM] yielded no RsaI endonuclease clones from the same ligation. Minipreps of #13 and #14 were also transformed into ER2566 [pSX20-mjaVM] and re-assayed for RsaI endonuclease activity again. Several isolates of #14 showed varying amounts of RsaI activity with the highest amount of RsaI activity from cultures grown at 37° C. verses 30° C. DNA sequence of the reduced activity clone #14 revealed a deletion mutation of T at the start codon (ATG) which most likely truncated the RsaI endonuclease at the N-terminus leading to initiation at a later, downstream GTG codon. These truncated RsaI endonuclease clones exhibited little or no RsaI endonuclease activity when grown at 30° C., and partial activity when grown at 37° C.
The above mentioned undigested PCR of rsaIR (ORF3) was then blunt-end ligated into pCAB16 at the BsaAI site followed by transformation into ER2566 [pSX20-rsaIM] cells. One out of ten isolates, #9, contained the correct rsaIR fragment as detected by colony PCR. Sequencing showed correct DNA sequence for rsaIR, matching the predicted N-terminal amino acid sequence of the 18 kDa protein. The rsaIR gene in clone #9 was in the opposite orientation to Plac and mspIR, and when assayed the clone showed partial RsaI restriction endonuclease activity.
9. Expression of the RsaI Endonuclease Gene in E.Coli ER2566 [pIH919-rsaIM]
Since the pCAB16-rsaIR #9 clone contained the correct DNA sequence for rsaIR, an attempt was made to subclone the RsaI endonuclease gene from this plasmid into pRRS. Using flanking PstI and BamHI sites designed within the PCR primers, pCAB16-rsaIR #9 was digested with PstI and BamHI, and the resulting rsaIR gene fragment was gel-purified and ligated into PstI- and BamHI-digested pRRS. This ligation reaction was transformed into ER2566 [pIH919-rsaIM], and plasmid DNA was individually purified from 16 colonies. The plasmid DNAs were digested with PstI and BamHI to identify the rsaIR insert. None of the clones contained the rsaIR DNA fragment.
10. Expression of the RsaI Endonuclease in E. Coli Gene ER2566 [pIH919-rsaIM] using pLT7K
Using Vent® DNA polymerase, the RsaI endonuclease gene (rsaIR) in pCAB16-rsaIR #9 was PCR-amplified digested with XbaI and XhoI, and ligated into pLT7K. The ligation reaction was transformed into E.coli DH5α. Plasmid DNAs were isolated from 18 colonies. Twelve contained the correct size rsaIR fragment as indicted by XbaI and XhoI double-digestion. Clones,#1, #4, #5, and #14 were transformed into a RsaI methylase pre-modified E.coli ER2566 host containing T7 RNA polymerase. The number of transformants varied between the four individual transformations of pLT7K-rsaIR clones: one for #14, three for #5, 1000 for #4, and 250 for #1. All the transformants from #5 and #14, and two for each #1 and #4 were inoculated, re-streaked and grown at 37° C. followed by induction with IPTG. When assayed, #1, #4, #5 and #14 rsaIR-pLT7K clones showed varying amounts of detectable RsaI restriction endonuclease activity. #5-3 pLT7K-rsaIR showed the most RsaI endonuclease activity. Four individual colonies from #5-3 pLT7K-rsaIR plate were again grown at 37° C., IPTG-induced and assayed for RsaI endonuclease activity. No RsaI endonuclease activity was detected, suggesting that the clone was extremely unstable.
11. Over-Expression of RsaI Endonuclease Gene in E. Coli Strain ER2744 [pIH919-rsaIM] and [pSX20-mjaVM]
Our failure to isolate and maintain clones overexpressing the RsaI endonuclease was judged to be a consequence of inadequate protection by the M.RsaI MTase. This problem was solved by the addition of a third plasmid containing an isoschizomer methylase M.MjaV MTase.
First, the RsaI methylase gene (rsaIM) was PCR-amplified and cloned onto pIH919, a derivative of pACYC184 containing the Plac promoter and polylinker from pUC18. The MjaV methylase gene (mjaVM) was cloned into pSX20, a derivative of pSC101 compatible with both pBR322 and pACYC-based plasmids. It has the pBR322 tetracycline resistance gene, pSC101 origin of replication, and a kanamycin resistance gene. The pSX20-mjaVM methylase plasmid was then transformed into competent E.coli ER2744 containing the pIH919-rsaIM plasmid. The resulting strain, containing both above mentioned methylases, was made competent. Note: An attempt to clone an active RsaI restriction gene (rsaIR) (ORF3) directly into pRRS by transforming into this dual pre-modified E.coli host containing the M.RsaI and M.MjaV failed. Twelve colonies from this transformation were isolated and no clones appeared to contain the correct size insert. Attempts to clone rsaIR using pLT7K into an E.coli strain containing the RsaI methylase alone failed to establish a stable RsaI endonuclease clone.
To finally establish an over-expressing RsaI endonuclease clone, the original miniprep DNA from pLT7K-rsaIR #5 (described above) was transformed into a T7 RNA polymerase containing E.coli host ER2744 pre-modified with two methylases, M.RsaI and M.MjaV. Five colonies were grown at 37° C. to OD590 0.8 to 1.0, culture temperature was then lowered to 30° C., followed by IPTG induction. When asssayed for RsaI endonuclease activity, all five clones #51, #52, #53, #54 and #55 showed various amounts of RsaI endonuclease activity, the highest amount of activity came from #51 at over 10 6 u/g (FIG. 8 ). A glycerol stock of pLT7K-rsaIR #51 clone was stored at −70° C. #51 glycerol stock was later thawed, re-streaked on LB ampicillin, chloramphenicol and kanamycin plates at 37° C. and again individual colonies were grown and induced at 30° C. and assayed for RsaI endonuclease activity. All four individual clones, including one such clone pKL167-51 expressed R.RsaI at more than 5×10 6 units of RsaI endonuclease produced per gram of wet E.coli cells. The recombinant RsaI endonuclease from pKL167-51 is purified by chromatography to near homogeneity.
12. Purification of RsaI Restriction Endonuclease
The recombinant RsaI endonuclease was purified by standard protein purification techniques such as affinity chromatography, or ion-exchange chromatography.
The present invention is further illustrated by the following Examples. These Examples are provided to aid in the understanding of the invention and are not construed as a limitation thereof.
The references cited above and below are herein incorporated by reference.
EXAMPLE I
Cloning of RsaI Restriction-Modification System In E.Coli
1. Construction of an ApoI Partial Genomic DNA Library
Genomic DNA was prepared from Rhodopseudomonas sphaeroides , NEB Culture Collection #233, (Lynn el, J. Bacteriol. 142:380-383 (1980)). 7.5 μg of this genomic DNA was digested with 3, 1.5, 0.75, 0.375, 0.18, 0.09, 0.045, and 0.025 units/μg of ApoI at 50° C. for 1 hour to give a range of complete and partial digestion products. The tubes were incubated at 68° C. for 10 minutes to heat-kill the enzyme, then the digests were pooled. The pooled ApoI digested genomic DNA was ligated into EcoRI cut and CIP-treated vector pBR322 at 17° C. overnight followed by transformation into E.coli ER2418 and plated on LB+Amp (100 μg/ml). About 1000 colonies were obtained from transformation. To increase the number of colonies, a 3×transformation was again carried out using ER2418 cells and ligated DNA. About 5,000 transformants were obtained. All the transformants were pooled and inoculated into 500 ml of LB+Amp and incubated at 37° C. overnight. Plasmid DNA was prepared from the overnight cells by CsCl centrifugation.
2. Challenge the ApoI Partial Library DNA with RsaI Digestion and Cloning of the RsaI Methylase Gene
1 μg of the ApoI partial library DNA was digested with 30 units of RsaI at 37° C. for 2 hours. The digested DNA was transformed into ER2418 and plated on LB+Amp plates. Two transformants were obtained and plasmid DNAs were isolated from each individual transformant and digested with 10 units/μg of RsaI at 37° C. for 2 hours to detect any resistance to digestion. Both plasmids, #1 and #2 appeared to have complete resistance to RsaI digestion. Both contained two ApoI fragments of approximately 5.3 kb and 6.3 kb DNA.
3. Sequencing of the Insert Carrying the RsaI Methylase Gene
Deletion mapping and subcloning of the pBR322 ApoI #1 methylase clone showed that rsaIM was located on the 5.3 kb ApoI fragment. The deleted insert of #1 plasmid DNA was sequenced by primer walking by the dideoxy termination method using Ampli Taq DNA polymerase dye deoxy terminator sequencing kit and ABI373A automated DNA sequencer. DNA sequencing verified the location of the rsaIM gene (ORF1) and identified a partial converging open reading frame (ORF2). ORF1 of 1230 bp encoded the RsaI methylase (409 aa. molecular mass=45.4 kDa)(FIG. 2 ). The partial ORF2 did not match with known proteins in the GenBank data base.
4. N-Terminal Amino Acid Sequencing of the Purified RsaI Restriction Endonuclease
The non-recombinant RsaI endonuclease was purified to near homogeneity and the purified protein was subjected to SDS-PAGE. Two protein bands (approximately 18 kDa and 22 kDa) were detected. The N-terminal amino acid sequence of the 18 kDa protein was determined as (M)ERRFQLRWDEEE LARAFKVTWK (SEQ ID NO:7). The N-terminal amino acid sequence of the 22 kDa protein was determined as (M)AREI PDLQAVVRTGTGKGAARQARX (SEQ ID NO:8). The 18 kDa protein sequence matches exactly with the predicted N-terminal amino acid sequence of ORF3 described in section 5. The 22 kDa sequence did not match any of the cloned ORF's. It was later concluded that RsaI restriction endonuclease would most likely be the 18 kDa protein.
5. Inverse PCR to Clone ORF2 and ORF3
To clone the missing portion of the ORF2, Rhodopseudomonas sphaeroides genomic DNA was amplified by inverse PCR. 10 μg of genomic DNA was cleaved with HpaII and 10 μg more was cleaved with NciI. Both digestions were performed at 37° C. for 1 hour, heat killed at 65° C. for 10 minutes, and, then placed on ice. Each of the two cleaved DNA samples was self-ligated at a low concentration (2 μg/ml) at 17° C. overnight, and used as templates for inverse PCR with the following two primers:
5′ AGGTCCGGATCCATCGGATTGWITlFGTTGCAGCGGC 3′ (C.rsaIM) (SEQ ID NO:9)
5′ AGGTCCCTGCAGTTGGTGCCTTTGGAGCCGTTATCC 3′ (c.rsaIM) (SEQ ID NO:10)
PCR conditions of 95° C. 1′, 55° C. 1′, 72° C. 3′, 25 cycles, were employed. Using Vent® (Exo-) polymerase an inverse PCR product of approximately 850 bp was generated in both cases. 1 μg of 850 bp PCR fragment was gel-purified from both reactions and digested with ApoI to verify the ApoI site within ORF2 of the original methylase clone #1. The ApoI site within ORF2 downstream of rsaIM dropped out an approximately 350 bp fragment generated by the C.rsaIM PCR primer. From this ApoI site outward, approximately 500 bp of new DNA was generated by the other inverse pcr primer c.rsaIM. Another 1 μg of gel-purified 850 bp PCR fragment from each reaction was then digested with ApoI and PstI (c.rsaIM PstI site) and ligated to ApoI- and PstI-cleaved pUC19 followed by transformation into E.coli ER2566 containing pSX20-rsaIM and plated on LB+Amp+Kan (100/50 μg/ml) and incubated at 37° C. overnight. Plasmid DNAs were isolated from 16 colonies, 8 from the HpaII reaction, and 8 from the NciI reaction. 1 μg of each plasmid was digested with ApoI and PstI and analyzed by gel electrophoresis. NciI #7, HpaII #2,3,4, and #7 contained an inverse pcr fragment. DNA sequencing of NciI #7 and HpaII #7 revealed 493 bp of new DNA sequence, and that the HpaII (CCGG) and NciI (CCGGG) sites coincided. This new sequence completed ORF2, and contained an ATG start codon and 102 bp of a new DNA open reading frame from (ORF3) running in the same direction as rsaIM. The first 20 amino acids of the protein encoded by this new ORF was identical to the observed N-terminal protein sequence of the 18 kDa candidate R.RsaI protein (section 4) indicating that this was the true start of the rsaIR gene.
To identify the C-terminal end of ORF3, another inverse PCR primer (R.Rsa.c) was designed to PCR the 3′ end of rsaIR excluding the ATG start of the gene to minimize the potential toxicity of an intact rsaIR.
10 μg of genomic DNA was cleaved with MfeI at 37° C. for 1 hour, heat killed at 65° C. for 10 minutes, and then placed on ice. The MfeI-cleaved DNA was self-ligated at a low concentration (2 μg/ml) at 17° C. overnight and then used as the template in an inverse PCR reaction using a newly designed primer (R.Rsa.c) with (c.rsaIM) primer heading toward an MfeI site within rsaIM (ORF1):
5′ AGGTCCCTGCAGTTGGTGCCTTTGGAGCCGTTATCC 3′ (c.rsaIM) (SEQ ID NO:11)
5′ TGCGCGCGCCTTCAAGGTCACGAC 3′ (R.Rsa.c) (SEQ ID NO:12)
The same inverse PCR conditions were employed as before. 1 μg of gel-purified PCR product was digested with PstI, ligated into SmaI- and PstI-cleaved pUC19 and then transformed separately into E.coli ER2683 and E.coli ER2566 [pSX20-rsaIM] and plated on LB+Amp or LB+Amp+Kan plates respectively. Plasmid DNAs were isolated from both ER2683 and ER2566 [pSX20-rsaIM] transformants. Two such clones, ER2683 #2-2, and ER2566 [pSX20-rsaIM] #5-4 were CsCl-purified and then sequenced. The newly-derived sequence from #2-2 and #5-4 extended the total DNA sequenced to 2714 bp and completed ORF3. Within this DNA were three large ORFs: the RsaI methylase gene, rsaIM, (ORF1); an unknown converging gene, rsaIU, (ORF2); and the gene finally identified as rsaIR, (ORF3) (FIG. 1 ). The rsaIR gene (ORF3) is 483 bp in length. It codes for a 160-aa protein of predicted MW of 18.7 kDa (FIG. 3 ), in agreement with the observed size of 18 kDa seen by PAGE.
6. Cloning of the RsaI Methylase Gene
In order to clone the entire complete RsaI endonuclease gene (rsaIR), an E.coli strain modified against RsaI endonuclease digestion was made by cloning rsaIM into a compatible pACYC184 derivative, pIH919. The entire methylase gene (1230 bp) was amplified from genomic DNA using Vent® polymerase with PCR conditions 95° C. 1′ 54° C. 1′, 72° C. 1′, 30 cycles and two primers (5mRsaI) and (3mRsaI):
5′ CGGGGTACCGCATGCAAGGAGGTTTAAAATATGAACCAGCTCTCCA TGTTTGACCGAGTC 3′ (5mRsaI) (SEQ ID NO:13)
5′TGGCGGCCGGGATCCTCACTAGTGCCGCTGCAACAAAACAATCCG 3′ (3mRsaI) (SEQ ID NO: 14)
The PCR fragment was digested at 37° C. for 1 hour with KpnI, extracted with phenol/CHCl 3 and precipitated with isopropanol. The rsaIM PCR fragment was then resuspended and digested with BamHI at 37° C. for 2 hours and phenol/CHCl 3 -extracted, and precipitated again, then ligated at 17° C. overnight into KpnI- and BamHI-cleaved pIH919. The ligation was transformed into E.coli ER2502 and ER2566 plated on LB+chloramphenicol (25 μg/ml) at 37° C. for overnight. The transformants were pooled and amplified. Plasmid DNA was prepared from a 10 ml overnight culture and then each pool was digested with RsaI at 37° C. for 1 hour. The digested pool was transformed into ER2502 and ER2566 and individual plasmid DNAs from 8 colonies from each transformation and all appeared to be the correct size plasmid. Four isolates from each transformation, #1, #2, #4, and #6, were analyzed futher and found to contain the rsaIM PCR fragment, and all appeared to be completely modified against RsaI digestion. #1 was then transformed into E.coli strains ER2566 and ER2744 were made competent using standard CaCl 2 method.
7. Cloning of the MjaV Methylase Gene
Two primers were synthesized for PCR amplification of mjaVM. The entire MjaV methylase gene (879 bp) was amplified from genomic DNA using Vent® polymerase with PCR conditions 95° C. 1′ 54° C. 1′, 72° C. 1′, 25 cycles and two primers (mj1498 Foward) and (mj1498 Reverse):
5′ GTTGGATCCGTMTTMGGAGGTAATTCATATGGAGATAAATAA AATCTAC 3′ (mj1498 Forward) (SEQ ID NO:15)
5′GTTGAATCCGTCGACTATTTAAATAAATGCATC 3′ (mj1498 Reverse) (SEQ ID NO: 16)
An approximately 0.9 kb PCR fragment from Methanococcus jannaschii containing the mjaVM methylase gene was gel purified, digested with BamHI and SalI and then ligated into the BamHI- and SalI-cleaved pSX20 at 17° C. overnight. This reaction was transformed into E.coli and plated on LB+Kan (50 μg/ml) and incubated at 37° C. overnight. The pSX20-mjaVM plasmid DNA was purified and appeared to be completely modified against RsaI digestion. The pSX20-mjaVM plasmid was transformed into ER2744 [pIH919-rsaIM] and plated on LB+Kan+Cam Kan (50/25 μg/ml) plates at 37° C. ER2744 containing [pIH919-rsaIM] and [pSX20-mjaVM] plasmids was made competent using standard CaCl 2 method for overexpression (section 11).
8. Cloning of the Complete RsaI Restriction Endonuclease Gene
Two primers were synthesized for PCR amplification of the entire rsaIR gene (ORF3). The gene was amplified from genomic DNA using Vent® polymerase with PCR conditions 95° C. 1′ 54° C. 1′, 72° C. 3′, 25 cycles and two primers (rsa.r5) and (rsa.3r-2):
5′TTGTTCTGCAGTMGGAGGTTTAAAATATGGAAAGACGlTTTCAACTT CGGTGG 3′ (rsa.r5) (SEQ ID NO:17)
5′TTGGGATCCTCAGTGCCGAATGTCCCGGACCATGTC 3′ (rsa.3r-2) (SEQ ID NO:18)
The PCR product was gel purified, digested with PstI and BamHI, ligated into PstI- and BamHI-cleaved pRRS, transformed into E.coli strains ER2566 [pSX20-rsaIM] and ER2566 [pSX20-mjaVM], and then plated on LB+Amp+Kan (100/50 μg/ml) plates at 37° C. overnight.
Even though both E.coli strains appear to completely protect against RsaI digestion, only ER2566 [pSX20-rsaIM] cells yielded clones with RsaI endonuclease activity. Two clones out of twenty isolates, #13 and #14 from ER2566 [pSX20-rsaIM] cells, contained the correct size rsaIR fragment. This was verified by colony PCR of twenty colonies using pUC19 universal primers #1233 and #1224 (New England Biolabs) as follows: Individual colonies were picked from the LB agar plates, placed in 100 μl of dH 2 O, boiled 5 minutes and then each allowed to cool to room temperature. Direct or colony PCR conditions of 95° C. 10 sec, 62° C. 1′, 72° C. 1′, 30 cycles were employed using 2.5 μl of boiled DNA in a 50 μl reaction with Vent® (Exo-) polymerase. Only #13 and #14 from ER2566 [pSX20-rsaIM], contained the rsaIR fragment and when assayed showed low levels of RsaI endonuclease activity. When sequenced, #14 revealed a deletion mutation of T at the start codon (ATG).
The rsaIR PCR fragment from primers, rsa.r5 and rsa.3r-2, was then blunt-end ligated into pCAB16 at the BsaAI site followed by transformation into ER2566 [pSX20-rsaIM] and plated on LB+Amp+Kan plates at 37° C. overnight. Colony PCR of ten colonies identified one clone, #9, which contained the correct rsaIR fragment as detected by colony PCR. Sequencing of pCAB16-rsaIR #9 showed correct DNA sequence for rsaIR matching the amino acid sequence of the 18.7 kDa protein.
9. Expression of the RsaI Endonuclease Gene in E.Coli Strain ER2566 [pIH919-rsaIM] using pRRS
The pCAB16-rsaIR #9 clone contained correct DNA sequence for rsaIR, so an attempt was made to subclone the RsaI endonuclease gene from this vector into pRRS, and to transform it into an RsaI-methylase pre-modified E.coli host. Using the flanking PstI and BamHI sites designed within the PCR primers, 10 μg of pCAB16-rsaIR #9 plasmid (section 8) was digested with PstI and BamHI at 37° C. for 2 hours, and the rsaIR insert was gel purified and ligated into PstI- and BamHI-cleaved pRRS. This ligation reaction was transformed into ER2566 [pIH919-rsaIM] and plated on LB+Amp+Cam plates at 37° C. Plasmid DNA's were purified from 16 colonies, and then digested with PstI and BamHI. None of the clones contained the desired rsaIR gene insert. The same ligation was transformed into ER2566 [pSX20-mjaVM], plated on LB+Amp+Kan plates at 37° C. 20 colonies were picked and analyzed by colony PCR using pUC19 universal primers, #1233, and #1224. Again, none of the isolates were found to contain the rsaIR gene insert.
10. Expression of the RsaI Endonuclease Gene in E.Coli Strain ER2566 [pIH919-rsaIM] using pLT7K
Two primers were synthesized for PCR amplification of rsaIR for cloning into pLT7K. The entire RsaI restriction endonuclease gene (483 bp) was amplified from template pCAB16-rsaIR #9 using Vent® polymerase with PCR conditions 95° C. 1′ 54° C. 1′, 72° C. 1′, 25 cycles and two primers (Xba5RT7) and (Xho3RT7):
5′TGGGGTCTAGAGGAGGTAACATATGGGMAGACGTTTTCAACTTCGGT GGGATGAGGAGGAGC 3′ (Xba5RT7) (SEQ ID NO:19)
5′TTGGGTCTCGAGTCAGTGCCGAATGTCCCGGACCATGTCACG 3′ (Xho3RT7) (SEQ ID NO:20)
The rsaIR PCR product generated from pCAB16-rsaIR #9, was gel-purified, digested with XbaI and XhoI and then ligated into XbaI- and XhoI-cleaved pLT7K at 17° C. overnight. The ligation reaction was transformed into E.coli DH5α and plated on (pre-warmed 37° C.) LB+amp plates containing 20 mM glucose at 37° C. overnight. Plasmid DNAs were isolated from eighteen ampicillin resistant, kanamycin sensitive colonies. Twelve contained the correct size rsaIR fragment as indicted by XbaI and XhoI digestion. One clone, pLT7K-rsaIR #5 was transformed into an ER2566 [pIH919-rsaIM] and plated on LB+Amp/Cam (100/25 μg/ml) plates (pre-warmed to 37° C.) and incubated overnight at 37° C. Only 3 transformants were obtained. All three colonies, #5-1, #5-2, and #5-3, were re-streaked on pre-warmed LB+Amp/Cam plates and also inoculated into pre-warmed 10 ml cultures containing LB+Amp/Cam and grown at 37° C. overnight. 0.5 ml of the overnight cultures were diluted in pre-warmed 50 ml cultures containing LB+Amp/Cam grown at 37° C. and grown to an OD590 of between 0.8 and 1.0, IPTG was to added to 85 mg/L and induced at 30° C. for approximately 2 hours. When assayed, all three rsaIR-pLT7K clones showed detectable, but varying amounts of RsaI restriction endonuclease activity. pLT7K-rsaIR #5-3 showed the most RsaI endonuclease activity. Four individual colonies from pLT7K-rsaIR #5-3 plate (stored at 4° C.) were again grown at 37° C. and IPTG induced at 30° C. and re-assayed for RsaI endonuclease activity. No RsaI endonuclease activity was detected.
11. Over-Expression of RsaI Endonuclease Gene in E. Coli Strain ER2744 [pIH919-rsaIM]; [pSX20-mjaVM]
Our failure to isolate and maintain expressing clones of the RsaI endonuclease in E.coli hosts carrying either the rsaIM gene or the mjaVM gene was judged to be a consequence of inadequate Mtase protection. Consequently, a new E.coli host was prepared that contained both Mtases, and when this host was transformed with rsaIR gene, a stable R.RsaI overexpressing clone was finally obtained. To finally establish this over-expressing RsaI endonuclease clone, the original miniprep DNA from pLT7K-rsaIR #5 (section 10) was transformed into a T7 RNA polymerase containing E.coli host ER2744 pre-modified with two methylases, M.RsaI and M.MjaV, plated on (37° C. pre-warmed) LB+Amp+Cam+Kan plates (100/25/50 μg/ml) and placed at 37° C. overnight. Five colonies, #51, #52, #53, #54 and #55, were inoculated into 10 ml (37° C. pre-warmed) LB+Amp+Cam+Kan and grown at 37° C. overnight. 1 ml of each overnight culture was inoculated into 50 ml of (37° C. pre-warmed) LB+Amp+Cam+Kan and grown to OD590 0.8 to 1.0, then the culture temperature was then lowered to 30° C., followed by IPTG (85 mg/L) induction at 30° C. overnight. When asssayed for RsaI endonuclease activity, all five clones, showed various amounts of RsaI endonuclease activity, the highest amount of activity came from #51 at over 10 6 u/g (FIG. 8 ). A glycerol stock of pLT7K-rsaIR #51 clone was stored at −70° C. #51 glycerol stock was later thawed, re-streaked, on pre-warmed LB+Amp+Cam+Kan plates at 37° C. overnight. Four individual colonies were inoculated into 10 ml (37° C. pre-warmed) LB+Amp+Cam+Kan and grown at 37° C. overnight. 1 ml of each overnight culture was inoculated into 50 ml of (37° C. pre-warmed) LB+Amp+Cam+Kan and grown to OD590 0.8 to 1.0, then the culture temperature was then lowered to 30° C., followed by IPTG (85 mg/L) induction at 30° C. overnight. All four individual clones expressed R.RsaI at more 106 u/g. One such clone, pKL167-51, expressed R.RsaI at approximately 5×10 6 units of RsaI endonuclease produced per gram of wet E.coli cells. This assay was performed as follows: IPTG-induced cells were harvested, resuspended in 5 ml of sonication buffer, then lysozyme was added to 25 μg/ml, and the suspension was incubated on ice for 1 hour. 1 ml was sonicated for three, 10 second pulses and then clarified by centrifugation for 10 minutes at 4° C. The clarified cell extract was then assayed for RsaI endonuclease activity by mixing 1 μg λ DNA in 50 μl of reaction buffer with 1 μl of extract; 25 μl is removed and then diluted 2-fold each time though a series of 9 tubes and then incubated at 37° C. for 1 hour.(FIG. 9 ). The recombinant RsaI endonuclease from pKL167-51 is purified by chromatography to near homogeneity.
A sample of the E. coli ER2744 containing [pIH919-rsaIM, pSX20-mjaVM, pLT7K-rsaIR], (NEB#1242) has been deposited under the terms and conditions of the Budapest Treaty with the American Type Culture Collection on May 26, 2000 and received ATCC Accession Number PTA-1926.
10. Purification of RsaI Restriction Endonuclease
The recombinant RsaI restriction endonuclease is purified by standard protein purification techniques such as affinity chromatography, or ion-exchange chromatography.
20
1
1230
DNA
rhodopseudomonas sphaeroides
CDS
(1)..(1230)
1
atg aac cag ctc tcc atg ttt gac cga gtc caa ttc gca gac tcc tcc 48
Met Asn Gln Leu Ser Met Phe Asp Arg Val Gln Phe Ala Asp Ser Ser
1 5 10 15
gcg acg ttc att gct gag gta gaa gcc ttc tgc gag ttc ggt caa cgg 96
Ala Thr Phe Ile Ala Glu Val Glu Ala Phe Cys Glu Phe Gly Gln Arg
20 25 30
acc atc gtg gac agc cgg gat ggc atc ccc tac ttc atc aac gag ttc 144
Thr Ile Val Asp Ser Arg Asp Gly Ile Pro Tyr Phe Ile Asn Glu Phe
35 40 45
tgg act gct ggg cag cgt cag gcc cat tcc atc cac gag gta tcc tac 192
Trp Thr Ala Gly Gln Arg Gln Ala His Ser Ile His Glu Val Ser Tyr
50 55 60
cgc gcc tgc ttc aag gct cag ttg ccg gag ttc ttc atc ggg aga ctg 240
Arg Ala Cys Phe Lys Ala Gln Leu Pro Glu Phe Phe Ile Gly Arg Leu
65 70 75 80
aca aag ccc gga gac gtg gtg ttt gat cca ttc atg ggg cgc ggc acg 288
Thr Lys Pro Gly Asp Val Val Phe Asp Pro Phe Met Gly Arg Gly Thr
85 90 95
acc ccg gtt cag gct gcg ctg atg gag cgg cag gcc ttc gga aat gac 336
Thr Pro Val Gln Ala Ala Leu Met Glu Arg Gln Ala Phe Gly Asn Asp
100 105 110
gtg aac cca ctg tca gtc ctt ctg tcg cgc cca cgg ctg cgg cca atc 384
Val Asn Pro Leu Ser Val Leu Leu Ser Arg Pro Arg Leu Arg Pro Ile
115 120 125
acc att gat gcc gtt gct gcg gcg ctt cgg tcg gtg gac tgg tcg gct 432
Thr Ile Asp Ala Val Ala Ala Ala Leu Arg Ser Val Asp Trp Ser Ala
130 135 140
ggt gag gtc agg cgt gag gac ctc ttg gcg ttc tac cat ccg gcc act 480
Gly Glu Val Arg Arg Glu Asp Leu Leu Ala Phe Tyr His Pro Ala Thr
145 150 155 160
tta aag aaa ctg gaa gcc ctg cgc ctt tgg att gag gag cgc gcg cca 528
Leu Lys Lys Leu Glu Ala Leu Arg Leu Trp Ile Glu Glu Arg Ala Pro
165 170 175
ctt ggt tca act gat gtt gat ccg gtt gca gac tgg att cgc atg gtc 576
Leu Gly Ser Thr Asp Val Asp Pro Val Ala Asp Trp Ile Arg Met Val
180 185 190
gca atc aat cgt tta tcg ggc cat tca ccc ggt ttc ttc tct ggt cgg 624
Ala Ile Asn Arg Leu Ser Gly His Ser Pro Gly Phe Phe Ser Gly Arg
195 200 205
tcc atg ccg cca aac caa gcc gtg tcc gta aag gcg caa ctc aag atc 672
Ser Met Pro Pro Asn Gln Ala Val Ser Val Lys Ala Gln Leu Lys Ile
210 215 220
aat gaa aag ctc ggt gta tcg ccg ccg gag cgt gac gtt gcg ggc gtc 720
Asn Glu Lys Leu Gly Val Ser Pro Pro Glu Arg Asp Val Ala Gly Val
225 230 235 240
atc atc aaa aag tca aag act ctg ttg aag gac ggc tgt gcc cca agt 768
Ile Ile Lys Lys Ser Lys Thr Leu Leu Lys Asp Gly Cys Ala Pro Ser
245 250 255
cag gtt cag tcc agc ctg cat acg ggt gct gct tgg gcc gtt ccc ggc 816
Gln Val Gln Ser Ser Leu His Thr Gly Ala Ala Trp Ala Val Pro Gly
260 265 270
atc cca gac gcc tct gtt gac ctg aca gtc aca tcc ccg ccg ttt ttg 864
Ile Pro Asp Ala Ser Val Asp Leu Thr Val Thr Ser Pro Pro Phe Leu
275 280 285
gac att gtc cag tat gcc gct gac aac tgg ctg cgt tgc tgg ttc gct 912
Asp Ile Val Gln Tyr Ala Ala Asp Asn Trp Leu Arg Cys Trp Phe Ala
290 295 300
gga att gag ccg gag gcc gtc gca atc gac atg cac aag acc gaa gaa 960
Gly Ile Glu Pro Glu Ala Val Ala Ile Asp Met His Lys Thr Glu Glu
305 310 315 320
gcg tgg act ttg atg gtc aac cgg gtc ctg cgg gaa cag gcc aga ata 1008
Ala Trp Thr Leu Met Val Asn Arg Val Leu Arg Glu Gln Ala Arg Ile
325 330 335
ctg cgc ccg ggc ggc tat gtc gcc ttt gag gtg ggc gaa gtc cga aat 1056
Leu Arg Pro Gly Gly Tyr Val Ala Phe Glu Val Gly Glu Val Arg Asn
340 345 350
ggc aag gtg ttg ctt gag aag cta gtc tgg cgg gca gcg gag ggt cta 1104
Gly Lys Val Leu Leu Glu Lys Leu Val Trp Arg Ala Ala Glu Gly Leu
355 360 365
cct ttt gag cgg ctg ggt gtg atg gtg aac gac caa gag ttc acc aaa 1152
Pro Phe Glu Arg Leu Gly Val Met Val Asn Asp Gln Glu Phe Thr Lys
370 375 380
aca gcc aat tgc tgg ggc gtg gat aac ggc tcc aaa ggc acc aac aca 1200
Thr Ala Asn Cys Trp Gly Val Asp Asn Gly Ser Lys Gly Thr Asn Thr
385 390 395 400
aat cgg att gtt ttg ttg cag cgg cac tag 1230
Asn Arg Ile Val Leu Leu Gln Arg His
405 410
2
409
PRT
rhodopseudomonas sphaeroides
2
Met Asn Gln Leu Ser Met Phe Asp Arg Val Gln Phe Ala Asp Ser Ser
1 5 10 15
Ala Thr Phe Ile Ala Glu Val Glu Ala Phe Cys Glu Phe Gly Gln Arg
20 25 30
Thr Ile Val Asp Ser Arg Asp Gly Ile Pro Tyr Phe Ile Asn Glu Phe
35 40 45
Trp Thr Ala Gly Gln Arg Gln Ala His Ser Ile His Glu Val Ser Tyr
50 55 60
Arg Ala Cys Phe Lys Ala Gln Leu Pro Glu Phe Phe Ile Gly Arg Leu
65 70 75 80
Thr Lys Pro Gly Asp Val Val Phe Asp Pro Phe Met Gly Arg Gly Thr
85 90 95
Thr Pro Val Gln Ala Ala Leu Met Glu Arg Gln Ala Phe Gly Asn Asp
100 105 110
Val Asn Pro Leu Ser Val Leu Leu Ser Arg Pro Arg Leu Arg Pro Ile
115 120 125
Thr Ile Asp Ala Val Ala Ala Ala Leu Arg Ser Val Asp Trp Ser Ala
130 135 140
Gly Glu Val Arg Arg Glu Asp Leu Leu Ala Phe Tyr His Pro Ala Thr
145 150 155 160
Leu Lys Lys Leu Glu Ala Leu Arg Leu Trp Ile Glu Glu Arg Ala Pro
165 170 175
Leu Gly Ser Thr Asp Val Asp Pro Val Ala Asp Trp Ile Arg Met Val
180 185 190
Ala Ile Asn Arg Leu Ser Gly His Ser Pro Gly Phe Phe Ser Gly Arg
195 200 205
Ser Met Pro Pro Asn Gln Ala Val Ser Val Lys Ala Gln Leu Lys Ile
210 215 220
Asn Glu Lys Leu Gly Val Ser Pro Pro Glu Arg Asp Val Ala Gly Val
225 230 235 240
Ile Ile Lys Lys Ser Lys Thr Leu Leu Lys Asp Gly Cys Ala Pro Ser
245 250 255
Gln Val Gln Ser Ser Leu His Thr Gly Ala Ala Trp Ala Val Pro Gly
260 265 270
Ile Pro Asp Ala Ser Val Asp Leu Thr Val Thr Ser Pro Pro Phe Leu
275 280 285
Asp Ile Val Gln Tyr Ala Ala Asp Asn Trp Leu Arg Cys Trp Phe Ala
290 295 300
Gly Ile Glu Pro Glu Ala Val Ala Ile Asp Met His Lys Thr Glu Glu
305 310 315 320
Ala Trp Thr Leu Met Val Asn Arg Val Leu Arg Glu Gln Ala Arg Ile
325 330 335
Leu Arg Pro Gly Gly Tyr Val Ala Phe Glu Val Gly Glu Val Arg Asn
340 345 350
Gly Lys Val Leu Leu Glu Lys Leu Val Trp Arg Ala Ala Glu Gly Leu
355 360 365
Pro Phe Glu Arg Leu Gly Val Met Val Asn Asp Gln Glu Phe Thr Lys
370 375 380
Thr Ala Asn Cys Trp Gly Val Asp Asn Gly Ser Lys Gly Thr Asn Thr
385 390 395 400
Asn Arg Ile Val Leu Leu Gln Arg His
405
3
483
DNA
rhodopseudomonas sphaeroides
CDS
(1)..(483)
3
atg gaa aga cgt ttt caa ctt cgg tgg gat gag gag gag ctt gcg cgc 48
Met Glu Arg Arg Phe Gln Leu Arg Trp Asp Glu Glu Glu Leu Ala Arg
1 5 10 15
gcc ttc aag gtc acg aca aag gat gtg cgg gag tat ttg act gac ggt 96
Ala Phe Lys Val Thr Thr Lys Asp Val Arg Glu Tyr Leu Thr Asp Gly
20 25 30
cgc cgg gtc tca ttc atc att gag cgc cgt ctc atg tgg gaa aac ccc 144
Arg Arg Val Ser Phe Ile Ile Glu Arg Arg Leu Met Trp Glu Asn Pro
35 40 45
ggc tgg aag ctc gct cca tcc gaa ggg gca ggc tat gac ctt ctg gac 192
Gly Trp Lys Leu Ala Pro Ser Glu Gly Ala Gly Tyr Asp Leu Leu Asp
50 55 60
ccc gaa ggc ggc atg tgg gaa gtc cgg tcc atc acc cgg cag ggc gtc 240
Pro Glu Gly Gly Met Trp Glu Val Arg Ser Ile Thr Arg Gln Gly Val
65 70 75 80
tat ttc aac cca agc aat cag gtt ggg tct ggc cgc aag ttc aac gag 288
Tyr Phe Asn Pro Ser Asn Gln Val Gly Ser Gly Arg Lys Phe Asn Glu
85 90 95
gat ggc ttc cag ttg aaa atg agt ggc atc aag ggg ttc atc ttg tcc 336
Asp Gly Phe Gln Leu Lys Met Ser Gly Ile Lys Gly Phe Ile Leu Ser
100 105 110
gac att gtg ggc ttc ccg ctc gtg gac gtt tac gtt gtc ccc gtt gag 384
Asp Ile Val Gly Phe Pro Leu Val Asp Val Tyr Val Val Pro Val Glu
115 120 125
aac gtg ctg cgc tgg cac caa gcc cgg gcg ctg ggt gcg aat gcg aag 432
Asn Val Leu Arg Trp His Gln Ala Arg Ala Leu Gly Ala Asn Ala Lys
130 135 140
gtg tcc cgc gag aag ttc ctg cgt gac atg gtc cgg gac att cgg cac 480
Val Ser Arg Glu Lys Phe Leu Arg Asp Met Val Arg Asp Ile Arg His
145 150 155 160
tga 483
4
160
PRT
rhodopseudomonas sphaeroides
4
Met Glu Arg Arg Phe Gln Leu Arg Trp Asp Glu Glu Glu Leu Ala Arg
1 5 10 15
Ala Phe Lys Val Thr Thr Lys Asp Val Arg Glu Tyr Leu Thr Asp Gly
20 25 30
Arg Arg Val Ser Phe Ile Ile Glu Arg Arg Leu Met Trp Glu Asn Pro
35 40 45
Gly Trp Lys Leu Ala Pro Ser Glu Gly Ala Gly Tyr Asp Leu Leu Asp
50 55 60
Pro Glu Gly Gly Met Trp Glu Val Arg Ser Ile Thr Arg Gln Gly Val
65 70 75 80
Tyr Phe Asn Pro Ser Asn Gln Val Gly Ser Gly Arg Lys Phe Asn Glu
85 90 95
Asp Gly Phe Gln Leu Lys Met Ser Gly Ile Lys Gly Phe Ile Leu Ser
100 105 110
Asp Ile Val Gly Phe Pro Leu Val Asp Val Tyr Val Val Pro Val Glu
115 120 125
Asn Val Leu Arg Trp His Gln Ala Arg Ala Leu Gly Ala Asn Ala Lys
130 135 140
Val Ser Arg Glu Lys Phe Leu Arg Asp Met Val Arg Asp Ile Arg His
145 150 155 160
5
645
DNA
rhodopseudomonas sphaeroides
CDS
(1)..(645)
5
gtg cca cgg caa cag gat cgg atc aag gag gct gtt ttg tcg cgt ttt 48
Val Pro Arg Gln Gln Asp Arg Ile Lys Glu Ala Val Leu Ser Arg Phe
1 5 10 15
gac gac tat ctg aca gaa gtg cag cag cga atg ggc ctt gtg ccc atc 96
Asp Asp Tyr Leu Thr Glu Val Gln Gln Arg Met Gly Leu Val Pro Ile
20 25 30
aac tta atc agg acg tgg act gct gct gaa atc act tcg gtt gaa ttg 144
Asn Leu Ile Arg Thr Trp Thr Ala Ala Glu Ile Thr Ser Val Glu Leu
35 40 45
gca atc cga act gcc gtg gca gca agt caa att gtg gga atg gtg atc 192
Ala Ile Arg Thr Ala Val Ala Ala Ser Gln Ile Val Gly Met Val Ile
50 55 60
cct aat ttt gtt ggc acc aat cag gca aaa ggg aac aaa gcc gca gac 240
Pro Asn Phe Val Gly Thr Asn Gln Ala Lys Gly Asn Lys Ala Ala Asp
65 70 75 80
ttc ttt att gcg aca atc ccg cct cat ctt cct gca aac aac agc ata 288
Phe Phe Ile Ala Thr Ile Pro Pro His Leu Pro Ala Asn Asn Ser Ile
85 90 95
gtt gcc gcc cga ggt gca ggc tat cca gac cgc ctt ttc gtg tct ggg 336
Val Ala Ala Arg Gly Ala Gly Tyr Pro Asp Arg Leu Phe Val Ser Gly
100 105 110
gcc aca agg cat tgc atg gaa ttc aag gcg acc tca aat tgg caa gat 384
Ala Thr Arg His Cys Met Glu Phe Lys Ala Thr Ser Asn Trp Gln Asp
115 120 125
ggt gat cca aac aga agg gtc ctg acc agc gcc ccg acc aaa atg atc 432
Gly Asp Pro Asn Arg Arg Val Leu Thr Ser Ala Pro Thr Lys Met Ile
130 135 140
cgt ctg gta aac tca cgt caa gtt ggg gtt gcg ccg aac cat gtc cca 480
Arg Leu Val Asn Ser Arg Gln Val Gly Val Ala Pro Asn His Val Pro
145 150 155 160
gca cac ctg atc tgc act gtc ctt tac agt gaa cag caa tca tct gtg 528
Ala His Leu Ile Cys Thr Val Leu Tyr Ser Glu Gln Gln Ser Ser Val
165 170 175
caa ggc gtc cgt cta gat ttt ctt gag cca gac tct gag gta aac att 576
Gln Gly Val Arg Leu Asp Phe Leu Glu Pro Asp Ser Glu Val Asn Ile
180 185 190
cga ttg gag gcc tca acc tct caa cgg cta ctt gcg atg ggc act cag 624
Arg Leu Glu Ala Ser Thr Ser Gln Arg Leu Leu Ala Met Gly Thr Gln
195 200 205
cag agg ttc atc tac ccc tag 645
Gln Arg Phe Ile Tyr Pro
210 215
6
214
PRT
rhodopseudomonas sphaeroides
6
Val Pro Arg Gln Gln Asp Arg Ile Lys Glu Ala Val Leu Ser Arg Phe
1 5 10 15
Asp Asp Tyr Leu Thr Glu Val Gln Gln Arg Met Gly Leu Val Pro Ile
20 25 30
Asn Leu Ile Arg Thr Trp Thr Ala Ala Glu Ile Thr Ser Val Glu Leu
35 40 45
Ala Ile Arg Thr Ala Val Ala Ala Ser Gln Ile Val Gly Met Val Ile
50 55 60
Pro Asn Phe Val Gly Thr Asn Gln Ala Lys Gly Asn Lys Ala Ala Asp
65 70 75 80
Phe Phe Ile Ala Thr Ile Pro Pro His Leu Pro Ala Asn Asn Ser Ile
85 90 95
Val Ala Ala Arg Gly Ala Gly Tyr Pro Asp Arg Leu Phe Val Ser Gly
100 105 110
Ala Thr Arg His Cys Met Glu Phe Lys Ala Thr Ser Asn Trp Gln Asp
115 120 125
Gly Asp Pro Asn Arg Arg Val Leu Thr Ser Ala Pro Thr Lys Met Ile
130 135 140
Arg Leu Val Asn Ser Arg Gln Val Gly Val Ala Pro Asn His Val Pro
145 150 155 160
Ala His Leu Ile Cys Thr Val Leu Tyr Ser Glu Gln Gln Ser Ser Val
165 170 175
Gln Gly Val Arg Leu Asp Phe Leu Glu Pro Asp Ser Glu Val Asn Ile
180 185 190
Arg Leu Glu Ala Ser Thr Ser Gln Arg Leu Leu Ala Met Gly Thr Gln
195 200 205
Gln Arg Phe Ile Tyr Pro
210
7
23
PRT
rhodopseudomonas sphaeroides
7
Met Glu Arg Arg Phe Pro Leu Arg Trp Asp Glu Glu Glu Leu Ala Arg
1 5 10 15
Ala Phe Lys Val Thr Thr Lys
20
8
26
PRT
rhodopseudomonas sphaeroides
8
Met Ala Arg Glu Ile Pro Asp Leu Gln Ala Val Val Arg Thr Gly Thr
1 5 10 15
Gly Lys Gly Ala Ala Arg Gln Ala Arg Xaa
20 25
9
36
DNA
rhodopseudomonas sphaeroides
9
aggtccggat ccatcggatt gttttgttgc agcggc 36
10
36
DNA
rhodopseudomonas sphaeroides
10
aggtccctgc agttggtgcc tttggagccg ttatcc 36
11
36
DNA
rhodopseudomonas sphaeroides
11
aggtccctgc agttggtgcc tttggagccg ttatcc 36
12
24
DNA
rhodopseudomonas sphaeroides
12
tgcgcgcgcc ttcaaggtca cgac 24
13
60
DNA
rhodopseudomonas sphaeroides
13
cggggtaccg catgcaagga ggtttaaaat atgaaccagc tctccatgtt tgaccgagtc 60
14
45
DNA
rhodopseudomonas sphaeroides
14
tggcggccgg gatcctcact agtgccgctg caacaaaaca atccg 45
15
51
DNA
rhodopseudomonas sphaeroides
15
gttggatccg taattaagga ggtaattcat atggagataa ataaaatcta c 51
16
33
DNA
rhodopseudomonas sphaeroides
16
gttgaatccg tcgactattt aaataaatgc atc 33
17
54
DNA
rhodopseudomonas sphaeroides
17
ttgttctgca gtaaggaggt ttaaaatatg gaaagacgtt ttcaacttcg gtgg 54
18
36
DNA
rhodopseudomonas sphaeroides
18
ttgggatcct cagtgccgaa tgtcccggac catgtc 36
19
62
DNA
rhodopseudomonas sphaeroides
19
tggggtctag aggaggtaac atatggaaag acgttttcaa cttcggtggg atgaggagga 60
gc 62
20
42
DNA
rhodopseudomonas sphaeroides
20
ttgggtctcg agtcagtgcc gaatgtcccg gaccatgtca cg 42
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RsaI, a restriction enzyme from the bacterium Rhodopseudomonas sphaeroides, recognizes the DNA sequence 5′-GTAC-3′. Because RsaI is commercially valuable, we sought to overproduce it by cloning the genes for RsaI and its accompanying, modification, enzyme. The ‘methylase-selection’ method, the customary procedure for cloning restriction and modification genes, was applied to RsaI. The method yielded clones containing the methylase gene (rsaIM), but none containing both the methylase gene and the restriction gene (rsaIR). Inverse-PCR was then used to recover sections of the DNA downstream of rsaIM. These sections were sequenced, and the sequences were joined in silico to reveal the gene organization of the RsaI R-M system. By comparing the coding potential of the DNA with the N-terminal amino acid sequence of the purified RsaI restriction enzyme, we discovered that the RsaI R and M genes, rather than being adjacent-the situation that pertains in most R-M systems-are separated by an intervening gene of unknown function. Based on this information, the rsaIR gene was cloned by PCR instead of methylase-selection. These new clones proved to be highly unstable, however, even in the presence of the rsaIM gene. Various attempts were made to stabilize the gene, but most met with failure. Stability was finally achieved by introducing a second methylase gene, mjaVM, to augment the protection provided by rsaIM, and by tightly controlling the expression of rsaIR using a special two-promoter, anti-sense transcription, expression vector.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. provisional patent application Ser. No. 60/514,435, filed Oct. 24, 2003, all of which is incorporated herein in entirety by this reference thereto.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to methods for locating and accessing Internet resources and to methods for linking offline advertising, directory listings, and other published information to associated Internet resources, particularly in instances where a linking element comprises a telephone number. As well, the invention relates to graphic display methods as applied in printed publications and in associated replica interactive versions of printed publications which may be made available as Internet resources or in multimedia formats, such as CD-ROM and DVD disks.
2. Discussion of Related Art
Rapid adoption of the Internet for commerce has provided an electronically connected venue of networked computers ideally suited to support many types of commerce. Fundamental Internet technology is well understood by people schooled in the field and need not be further elaborated.
To exploit the commercial opportunities of this electronic venue, businesses and other entities have created a vast networked array of publicly accessible digital resources encompassing data formats for text, graphics, audio, and video. Further, a system of standards has been established and is enforced within the network to insure homogeneity in the various electronic processes and data interchange methods that are possible between Internet-connected devices.
The hypertext linking and addressing protocol facilitates one process whereby any client computer connected to the Internet may directly request and have returned any resource that is accessible from any resource server computer within the network. One requirement of the hypertext protocol is that there is a discrete relationship between one URL and one associated available resource, and this one-to-one relationship is necessary to enforce within the totality of all computers connected to the Internet. A network of registries has been established to enforce this requirement as new resources are created. Thus, creators of new web resources such as web sites often have difficulty, as a practical matter, in finding a unique character sequence not previously assigned which can be used as sub-domain reference.
From a commercial perspective, it is generally held that the subdomain URL, or domain name selected to identify a company's top-level domain, or home page, can influence a company's level of success in its efforts to exploit the commercial opportunities afforded by the Internet. For example, URL's with fewer characters and those with memorable word associations are generally held to be more desirable because they are more apt to be remembered by prospective customers, and are easier to enter into a browser address box. Given the sheer volume of individual resources that have already been assigned URLs, creators of new web resources now typically find it is increasingly difficult to secure URLs that meet these criteria.
As well, many resource URL assignments are established via automatic programmed processes within a resource server computer without regard to semantic association with spoken language, length, or other considerations. Typically, these automatic processes result in the creation of lengthy nonsensical URL character strings with multiple pathname layers that are extremely difficult for a client user to enter into browser address field by manual means using a keyboard.
To address this problem, various methods of simplified addressing have been introduced which enable a simplified alias URL to be established and associated with an actual URL. Typically, these methods make it possible to request an internet resource on the basis of an associated telephone number, zip code, email address, and on the basis of association with other alphanumeric coding schemes.
Relative to the invention herein, Gifford (U.S. Pat. No. 5,812,776) anticipated the desirability of simplified references to web resources and teaches a method enabling client systems to locate Internet resources with simplified addressing based on telephone numbers. Gifford implies the method could be used as the basis to enable a service.
In Gifford, a client system sends a first resource request comprising a phone number element to an intermediary redirection server system holding a translation database of telephone numbers mapped to corresponding Internet resources. Using the translation database, the intermediary system uses the phone number element of the received request to determine the associated URL, which is returned to the client system and used by the client system in a second resource request to locate the actual resource.
Successful resolution of a telephone number-based resource request using the method requires the receiver system to be in receipt of a client system resource request, and that said resource request include at least one pathname element comprising a phone number, typically written as www.subdomainofreceivingserver/phonenumber. By implication this imposes a requirement that a client user system, either by client user manual entry or by some other means, must be provided with both the subdomain address of the computer which is to receive the resource request and the telephone number associated with the actual requested resource.
To satisfy this requirement, Gifford in a first method implies the possibility (see column 6, line 4) of an acceptable manual entry method whereby a client user enters a conforming URL request in a conventional browser address entry box. This first method, in turn, implies a requirement that the client user must have knowledge of the subdomain address of the receiver server that is to receive the resource request, the telephone number that is associated with the resource, and also knowledge of how to format a conforming resource request. Gifford also teaches in a preferred embodiment a second method (see column 7, line 50) which implies a modified browser which can be caused by a client user to generate a conforming URL request to a specified receiver server upon manual entry by the user of only a phone number element into a modified address entry box, though further details are not provided. Gifford also teaches a third method (see column 7, line 60) in which a client user is first provided access by a directory server to a form page, and through implication teaches that a user may enter only a phone number element into a prompt box on the form page which by some means causes a conforming URL request to be received by the designated receiver server.
This first method of Gifford, while imposing additional knowledge requirements on a client user, is nonetheless in practice preferred, as this method most conforms to current client user practice, does not require a user to download and install special browser software, and does not consistently require a client user to perform the intermediary step of locating and requesting a separate forms page. Because this method imposes the additional knowledge requirements upon the client user as discussed above, two additional requirements are therefore introduced by implication that must be satisfied to insure widespread adoption of telephone number-based Internet addressing. The first requirement is that there must be in place a simple means readily and widely available to prospective client users for determining which telephone numbers have been registered with a designated receiving server system. The second requirement being that instructions for using the service must be readily available to a prospective client user, which would include the subdomain address of the receiver server which is to receive the resource.
Printed telephone number directories are ideally suited as a means to make available this information, if properly enabled for this purpose. Telephone directory publishing is a well-developed art, and published directories are now constructed on the basis of much cumulative research on how to organize telephone-listing data for optimal utility. They are also widely distributed and available on a vast scale. In the U.S., over 600,000,000 individual copies of 7,500 different directories are distributed annually. Printed directories are virtually ubiquitous and consulted frequently by all strata of society, which is another reason these directories are ideally suited as a means to speed market acceptance for telephone-number Internet addressing.
Further, the telephone directory publishing business has become increasingly competitive due to proliferation and fragmentation of local media, and most recently by Internet competitors, such as search engines and web portal sites which are seeking to attract advertising revenue from local advertisers. As well, usage of directories by the general public is no longer growing as some people have begun to migrate to online sources. As well, the base of businesses using telephone directory advertising has also been negatively affected by business consolidation and other factors.
Telephone directory publishers therefore need and are seeking ways to enhance the value of their directories to attract advertisers, and also ways to make telephone directories more useful to the general public, thereby increasing usage. By establishing an advertising charge to designate numbers that have been registered for Internet addressing, publishers are afforded a significant new revenue opportunity that also has the advantage of making a directory more valuable to both its users and advertisers.
Particularly relevant to the invention herein, directory publishers have recently begun offering advertisers the opportunity to include their homepage URL in an expanded listing format for a fee. In directories that have implemented this format, the URL line typically appears on an additional line, typically immediately under the lines containing the traditional name, address, and telephone number information. In some directories, the URL information is displayed in a color shade that is different from the color used to display the name, address, and telephone number information. In these instances, the differentiated color is not used to designate that the telephone number itself has been established to serve as linking element to online resources in a network, but serves the purpose of attracting increased reader attention to the included URL information.
This offering has had some limited success in attracting paying advertisers, but has several drawbacks for publishers. A first drawback is that the providing of an extra line to accommodate the addition of URL listings, if provided in volume, would significantly increase publisher costs for paper, ink, printing, and shipping. A second drawback is that this method necessitates a thicker directory, which published research has shown to affect customer usage. A third drawback is that many URL's are simply too lengthy to fit within the space of a typical directory layout. Thus, many potential advertising customers are automatically excluded as sales prospects. A fourth drawback is that URL's, especially those established as homepage URLs for smaller businesses, are highly subject to frequent modification, yet directories are updated only once a year. Telephone number-based addressing may provide a means for an advertiser to reassign the URL that is associated with his telephone number at any time, so the directory is more apt to remain current. For these and other reasons, it is in the interest of publishers to open their directories to serve as directories for telephone-number based Internet addressing.
Another drawback relates to the production of facsimile versions of printed directories which publishers may make available as Internet resources, or in interactive multimedia versions, which may be distributed in CD-ROMs or by other means. In some forms of these multimedia versions, URL's which appear in the printed version of the directory are enabled as an active hypertext link, such that a user who is connected to the Internet may click on said URL link and thus call up the associated website. However, production of this multimedia using this method creates difficulties in the production process as follows. To enable the active hypertext link with a URL, a computer application is used that accesses the URL from the record database that was used to print the printed version of the directory. For each directory listing in which a URL is to be enabled as a hypertext link, a special software tool, typically custom programmed, is used to extract the URL from the database, and in conjunction with a graphics application, automatically apply a graphic to the multimedia version of the URL which in the distributed multimedia version, indicates to users that the URL information is a clickable live link. However, variability in the length of URLs complicates this process significantly because it is difficult to program this application of the graphic to be fully automatic, and typically graphics must be manually applied using other software tools. This adds significant labor expense to the process of enabling live URL links in the multimedia replica versions. By implementing telephone-number based Internet addressing in telephone directories, the telephone number may be enabled as a hypertext link, and because of higher consistency in the number of characters typically occurring in phone numbers within a directory, the multimedia production process is simplified, thus, lowering cost.
The opportunity to use telephone directories as directories for telephone-number based addressing was first tried in 2001 by the Internet Number Corporation (INC) of Tokyo, Japan, which established a service to provide telephone-based Internet addressing based on the Gifford method, and conducted a test program in conjunction with Yellow Page publisher NDC Yellow in 2001. The implementation by NDC/INC failed to win marketplace adoption and is no longer offered. This implementation was deficient in at least three ways, and it is an object of the invention herein to correct the deficiencies and teach an improved method of implementing telephone-number based Internet addressing within a printed telephone directory.
The first deficiency in the NDC/INC implementation was that although a graphic method was used within the directory to designate which numbers had been registered for telephone-number based Internet addressing, the method used was completely ineffective. A small graphic logo appeared in the same color ink as that which was used for the balance of the textual information in the number listing that was placed adjacently in proximity to the telephone number. This graphic designation method failed in practice to provide adequate visual differentiation between registered numbers and unregistered numbers. A second deficiency was that the insertion of the graphic indicia within a line of text caused variable registration and wraparound problems, which complicated the production process. A third deficiency was that NDC/INC did not provide instructions for Gifford's first method of manual entry method whereby a client user constructs a conforming URL request written as www.subdomainofreceivingserver/phonenumber in the format in a conventional browser address entry box. Thus, a prospective user either had to download special browser plug-in software, or use a provided URL of a forms page, where a phone number could be entered and sent to the telephone number-based addressing service server.
A need therefore exists for an improved method for implementing telephone number-based Internet addressing using printed telephone directories as directories, in particular in a method that would make readily available to prospective users the instructions for how to construct a conforming URL request, which would include the subdomain address of the telephone number-based addressing service receiver server which is to receive a conforming URL sent by a client system. A need also exists for an improved graphic method for designating telephone numbers within a printed directory, which numbers have been registered with a telephone-number based Internet addressing service and in associated replica multimedia versions. A need also exists to have said method such that it does not contribute to registration and wraparound problems in the printing process. A need also exists to for a method of enabling live hypertext links within multimedia replica versions of printed versions that better facilitate the use of software tools in the application of graphics in a multimedia version.
SUMMARY OF THE INVENTION
The invention comprises a graphic designation method for visually differentiating each number individually for a set of telephone numbers within a printed telephone directory. In a particular instance, the invention is applied in cases in which each said telephone number in the set has been established as a link element for linking to online digital resources associated with said telephone number.
The invention also teaches a method for establishing a printed telephone number directory simultaneously as a directory for a telephone number directory service.
The invention also teaches a method for displaying instructions for Internet addressing within a printed directory.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block schematic diagram showing an overview of a preferred embodiment of the invention as applied to a telephone directory;
FIG. 2 is a block schematic diagram that shows variants of a graphic method used to differentiate printed telephone numbers, as implemented in a printed telephone directory, and separately in a newspaper classified advertisement, in accordance with the invention; and
FIG. 3 shows a page from a white page business listings section of a printed telephone directory illustrating visually differentiated registered telephone number elements in accordance with the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the preferred embodiment shown in FIG. 1 , a telephone number based-Internet addressing service 108 is established. The service is comprised at a minimum of an Internet-connected receiving server at the service having a subdomain address, e.g. www.subdomain, and a translation database comprised of a set of first telephone number elements 106 . Each telephone number element is in one-to-one correspondence with a second element comprised of an actual URL element 109 . The URL element is associated with a predetermined Internet resource 110 . A telephone number is established as an entry in a service translation database. The telephone number is also mapped within a translation database to an associated predetermined URL element that is deemed as having been registered with the service. Multiple URL elements may be associated with a telephone number element.
A printed telephone directory 102 is established containing printed listings 103 , in which one or more listings comprise registered telephone number elements 114 . A set of registered telephone number elements within the directory are visually differentiated uniformly within the directory by use of an enforced graphic designation method which is uniquely applied to each of the registered numbers within the set. A directory may contain at a minimum an alternate set of registered phone number elements, if the alternate registered set is established as registered with a different service, and provided that no registered number element is contained in multiple registered sets within the same directory.
Adapted versions of the printed directory containing any replica portion of the printed directory, which adapted versions may have been established as Internet resources and as multimedia versions on CD-ROMs and DVD-ROMs, may also be used.
It is enforced that at least one instruction element 105 be displayed within the directory which contains at a minimum an example alias URL in the format www.subdomain/exampletelephonenumber, where the www.subdomain portion is the URL of the service receiving server and the exampletelephonenumber pathname portion is an example of a registered telephone number element. It is preferred that the instruction element is displayed on multiple pages within the printed directory, as shown for example, at top of example directory page 103 .
The enforced graphic designation method is applied uniformly to each registered number within a set of registered numbers. The graphic designation requires at least one permitted graphic treatment 201 to be applied to each registered number within a set of registered numbers. The graphic treatment must be applied with a generally rectangular shaped area that extends slightly around and aligned vertically and horizontally with the generally rectangular area bounding a registered number within the set. Also enforced is that said graphic treatment must be a permitted graphic treatment. Multiple permitted graphic treatments may be applied if applied uniformly to all registered numbers within a set. Multiple permitted graphic treatment are available as shown in FIG. 2 , which may include a registered telephone number being displayed in bold type face in any color; the registered telephone number being displayed in plain type face type in any color; the slightly extended generally rectangular area being displayed as outlined in any color; and the extended generally rectangular area being displayed as shaded using any halftone shade of any color.
A client user consults a directory 102 to find a listing 114 differentiated on basis of graphic designation method that contains a registered telephone number element.
FIG. 3 illustrates a directory page in which the herein disclosed method is implemented.
In a combination step (see FIG. 1 ), the client user combines a found telephone number element with the service receiving server URL element extracted from instruction element to construct an alias resource request 107 in the format www.subdomain/telephonenumberelement, where the www.subdomain portion is the service receiving server URL extracted from instruction element and the telephonenumberelement pathname portion is the found registered telephone number element. The client user enters the constructed alias URL into an Internet browser address field on an Internet-connected client system. Access is made 111 via a simultaneous Internet connection to the connected service-receiving server 108 . The pathname portion may include multiple pathname directory levels as long as at least one, and only one pathname directory level includes a phone number element. A parsing means may be integrated into receiving server system to extract the telephone number element to accommodate use of variant entry formats of the telephone number element. A programmed means may be provided, such that registered number elements comprising different country codes may be registered with and be recognized by service. Another means may be provided so that multiple country codes may be accommodated by the service enforcing that a unique receiving server with a unique subdomain address must be assigned only to receive alias URL's constructed of a set of phone number element, all of which are contained within a set of telephone numbers within one country code.
Service receiving server at 108 receives an alias resource request from the client system and extracts the telephone number element in a service translation process at 108 . The service translation process uses a translation database in a connecting process to connect the client system with a predetermined Internet resource. Both the service translation process and the connecting process at 108 may be by means of method taught by Gifford, or by some other method.
Number registrations may be promoted by directory publishers, newspaper publishers, other authorized publishers of printed media, and others. A means may be provided such that publishers, newspaper publishers, domain registrars, and others may be established as registrars for the service. A means may be provided such that a portion of established registrars may have direct connected access to the service server system and a means to create and modify new registrant entries. Registrars may charge a registration fee to registrants.
An authorization means may be provided for verifying that an entity requesting a registration is the bona fide owner of a telephone number being registered, such that only a bona fide owner entity of a telephone number may be allowed to register a telephone number with service. A telephone directory publisher may have means to authorize a registrant, and also a newspaper publisher, and others. Other authorization methods may be required to insure that a requesting entity registrant is a bona fide owner of a telephone number being registered. One such means is to require that a registrant call the service registry system from the telephone number being registered as verification of that telephone number.
A more elaborate means may include a first step of a prospective registrant registering at a service registration web page and entering at least a registrant telephone number and email address, a second step of a service sending email to a registrant email address which includes a service telephone number and at least a one-use password uniquely assigned to said user, a third step of a registrant calling the telephone number provided in the email, a fourth step of the service answering the registrant call and prompting the user to enter a password, and a final step of the user entering a password received in a service email.
The service may also provide the registrant with means to access a web page and view reports quantifying linking activity associated with registrant's registered number. The registrant may also be provided with a means to log into a web page and directly modify a predetermined URL associated with a registrant telephone number.
A parsing means may also be provided, such that the format of the telephone number informational element may vary in format. A means may be provided such that an international telephone number is used by a client searcher as the telephone number informational element. A means may be provided such that if there is duplication between one or more international telephone numbers and a local number, multiple website links are displayed to the searcher, such that a client searcher could select a correct link.
The service may provide a checking means such that registered predesignated URLs are periodically verified as valid active links, and further means may be provided such that a registrant and, as well the registrar of a registrant, may be automatically notified by email and other means upon a predesignated ULR becoming an inactive link, e.g. as discovered though a testing process.
In an alternate embodiment, the method may be to applied classified sections of newspapers, as illustrated by the drawing element 202 .
Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention. Accordingly, the invention should only be limited by the claims included below.
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The invention comprises a graphic designation method for visually differentiating each number individually for a set of telephone numbers within a printed telephone directory. In a particular instance, the invention is applied in cases in which each said telephone number in the set has been established as a link element for linking to online digital resources associated with said telephone number. The invention also teaches a method for establishing a printed telephone number directory simultaneously as a directory for a telephone number directory service. The invention also teaches a method for displaying instructions for Internet addressing within a printed directory.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to hydrocracking processes, and in particular to hydrocracking processes adapted to receive multiple feedstreams.
2. Description of Related Art
Hydrocracking processes are used commercially in a large number of petroleum refineries. They are used to process a variety of feeds boiling in the range of 370° C. to 520° C. in conventional hydrocracking units and boiling at 520° C. and above in the residue hydrocracking units. In general, hydrocracking processes split the molecules of the feed into smaller, i.e., lighter, molecules having higher average volatility and economic value. Additionally, hydrocracking processes typically improve the quality of the hydrocarbon feedstock by increasing the hydrogen to carbon ratio and by removing organosulfur and organonitrogen compounds. The significant economic benefit derived from hydrocracking processes has resulted in substantial development of process improvements and more active catalysts.
In addition to sulfur-containing and nitrogen-containing compounds, a typical hydrocracking feedstream, such as vacuum gas oil (VGO), contains small amount of poly nuclear aromatic (PNA) compounds, i.e., those containing less than seven fused benzene rings. As the feedstream is subjected to hydroprocessing at elevated temperature and pressure, heavy poly nuclear aromatic (HPNA) compounds, i.e., those containing seven or more fused benzene rings, tend to form and are present in high concentration in the unconverted hydrocracker bottoms.
Heavy feedstreams such as de-metalized oil (DMO) or de-asphalted oil (DAO) have much higher concentration of nitrogen, sulfur and PNA compounds than VGO feedstreams. These impurities can lower the overall efficiency of hydrocracking unit by requiring higher operating temperature, higher hydrogen partial pressure or additional reactor/catalyst volume. In addition, high concentrations of impurities can accelerate catalyst deactivation.
Three major hydrocracking process schemes include single-stage once through hydrocracking, series-flow hydrocracking with or without recycle, and two-stage recycle hydrocracking. Single-stage once through hydrocracking is the simplest of the hydrocracker configuration and typically occurs at operating conditions that are more severe than hydrotreating processes, and less severe than conventional full pressure hydrocracking processes. It uses one or more reactors for both treating steps and cracking reaction, so the catalyst must be capable of both hydrotreating and hydrocracking. This configuration is cost effective, but typically results in relatively low product yields (e.g., a maximum conversion rate of about 60%). Single stage hydrocracking is often designed to maximize mid-distillate yield over a single or dual catalyst systems. Dual catalyst systems are used in a stacked-bed configuration or in two different reactors. The effluents are passed to a fractionator column to separate the H 2 S, NH 3 , light gases (C 1 -C 4 ), naphtha and diesel products boiling in the temperature range of 36-370° C. The hydrocarbons boiling above 370° C. are unconverted bottoms that, in single stage systems, are passed to other refinery operations.
Series-flow hydrocracking with or without recycle is one of the most commonly used configuration. It uses one reactor (containing both treating and cracking catalysts) or two or more reactors for both treating and cracking reaction steps. Unconverted bottoms from the fractionator column are recycled back into the first reactor for further cracking. This configuration converts heavy crude oil fractions, i.e., vacuum gas oil, into light products and has the potential to maximize the yield of naphtha, jet fuel, or diesel, depending on the recycle cut point used in the distillation section.
Two-stage recycle hydrocracking uses two reactors and unconverted bottoms from the fractionation column are recycled back into the second reactor for further cracking. Since the first reactor accomplishes both hydrotreating and hydrocracking, the feed to second reactor is virtually free of ammonia and hydrogen sulfide. This permits the use of high performance zeolite catalysts which are susceptible to poisoning by sulfur or nitrogen compounds.
A typical hydrocracking feedstock is vacuum gas oils boiling in the nominal range of 370° C. to 520° C. DMO or DAO can be blended with vacuum gas oil or used as is and processed in a hydrocracking unit. For instance, a typical hydrocracking unit processes vacuum gas oils that contain from 10V % to 25V % of DMO or DAO for optimum operation. 100% DMO or DAO can also be processed for difficult operations. However, the DMO or DAO stream contains significantly more nitrogen compounds (2,000 ppmw vs. 1,000 ppmw) and a higher micro carbon residue (MCR) content than the VGO stream (10W % vs. <1W %).
The DMO or DAO in the blended feedstock to the hydrocracking unit can have the effect of lowering the overall efficiency of the unit, i.e., by causing higher operating temperature or reactor/catalyst volume requirements for existing units or higher hydrogen partial pressure requirements or additional reactor/catalyst volume for the grass-roots units. These impurities can also reduce the quality of the desired intermediate hydrocarbon products in the hydrocracking effluent. When DMO or DAO are processed in a hydrocracker, further processing of hydrocracking reactor effluents may be required to meet the refinery fuel specifications, depending upon the refinery configuration. When the hydrocracking unit is operating in its desired mode, that is to say, producing products in good quality, its effluent can be utilized in blending and to produce gasoline, kerosene and diesel fuel to meet established fuel specifications.
In addition, formation of HPNA compounds is an undesirable side reaction that occurs in recycle hydrocrackers. The HPNA molecules form by dehydrogenation of larger hydro-aromatic molecules or cyclization of side chains onto existing HPNAs followed by dehydrogenation, which is favored as the reaction temperature increases. HPNA formation depends on many known factors including the type of feedstock, catalyst selection, process configuration, and operating conditions. Since HPNAs accumulate in the recycle system and then cause equipment fouling, HPNA formation must be controlled in the hydrocracking process.
Lamb, et al. U.S. Pat. No. 4,447,315 discloses a single-stage recycle hydrocracking process in which unconverted bottoms are contacted with an adsorbent to remove PNA compounds. Unconverted bottoms having a reduced concentration of PNA compounds are recycled to the hydrocracking reactor.
Gruia U.S. Pat. No. 4,954,242 describes a single-stage recycle hydrocracking process in which an HPNA containing heavy fraction from a vapor-liquid separator downstream of a hydrocracking reactor is contacted with an adsorbent in an adsorption zone. The reduced HPNA heavy fraction is then either recycled to the hydrotreating zone or introduced directly into the fractionation zone.
Commonly-owned U.S. Pat. No. 7,763,163 discloses adsorption of a DMO or DA0 feedstream to a hydrocracker unit to remove nitrogen-containing compounds, sulfur-containing compounds and PNA compounds. This process is effective for removal of impurities including nitrogen-containing compounds, sulfur-containing compounds and PNA compounds from the DMO or DAO feedstock to the hydrocracker unit. A separate VGO feedstock is also shown as a feed to the hydrocracker reactor along with the cleaned DMO or DAO feed. However, a relatively high concentration of HPNA compounds remains in unconverted hydrocracker bottoms.
While the above-mentioned references are suitable for their intended purposes, a need remains for improved process and apparatus for efficient and efficacious hydrocracking of heavy oil fraction feedstocks.
SUMMARY OF THE INVENTION
In accordance with one or more embodiments, a hydrocracking process is provided for treating a first heavy hydrocarbon feedstream and a second heavy hydrocarbon feedstream, in which the first heavy hydrocarbon feedstream contains undesired nitrogen-containing compounds, sulfur-containing compounds and PNA compounds. The process includes the following steps:
a. contacting the first heavy hydrocarbon feedstream with an effective amount of adsorbent material to produce an adsorbent-treated heavy hydrocarbon stream having a reduced content of nitrogen-containing, sulfur-containing compounds and PNA compounds;
b. combining the second heavy hydrocarbon feedstream with the adsorbent-treated heavy hydrocarbon stream;
c. introducing the combined stream and an effective amount of hydrogen into a hydrocracking reaction unit that contains an effective amount of hydrocracking catalyst to produce a hydrocracked effluent stream;
d. fractionating the hydrocracked effluent stream to recover hydrocracked products and a bottoms stream containing HPNA compounds;
e. contacting the fractionator bottoms stream with an effective amount of adsorbent material to produce an adsorbent-treated fractionator bottoms stream having a reduced content of heavy poly-nuclear aromatic compounds;
f. integrating the adsorbent-treated fractionator bottoms stream with the combined stream of steps (b); and g. introducing the combined stream into the hydrocracking unit.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary as well as the following detailed description of preferred embodiments of the invention will be best understood when read in conjunction with the attached drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and apparatus shown, in the drawings, in which:
FIG. 1 is a process flow diagram of an integrated hydrocracking process with feed/bottoms pretreatment;
FIG. 2 is a process flow diagram of an embodiment of a desorption apparatus; and
FIG. 3 is a process flow diagram of an integrated hydrocracking process with separate feed and bottoms treatments.
DETAILED DESCRIPTION OF THE INVENTION
Integrated processes and apparatus are provided for hydrocracking hydrocarbon feeds, such as a combined feed of VGO and DMO and/or DAO, in an efficient manner and resulting in improved product quality. The presence of nitrogen-containing compounds, sulfur-containing compounds and PNA compounds in DMO or DAO feedstreams, and the presence of HPNA compounds in hydrocracker bottoms, have detrimental effects on the performance of hydrocracking unit. The integrated processes and apparatus provided herein remove or reduce the concentration of nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and HPNA compounds to thereby improve process efficiency and the effluent product quality.
In general, the processes for improved cracking includes contacting a first heavy hydrocarbon feedstream and a hydrocracking reaction bottoms stream, with an effective quantity of adsorbent material in which nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and HPNA compounds are removed. The adsorbent effluent, which generally contains about 85 V % to about 95 V % of the first heavy hydrocarbon feedstream and about 10 V % to about 60 V %, in certain embodiments about 20 V % to about 50 V %, and in further embodiments about 30 V % to about 40 V % of the hydrocracking reaction bottoms stream (i.e., the recycle stream), is combined with a second hydrocarbon feedstream and cracked in the presence of hydrogen in a hydrocracking reaction zone. Excess hydrogen is separated from hydrocracking effluent and recycled back to the hydrocracking reaction zone. The remainder of the hydrocracking effluent is fractionated, and the hydrocracking reaction bottoms stream is contacted with adsorbent material as noted above.
In particular, and referring to FIG. 1 , a process flow diagram of an integrated hydrocracking apparatus 100 including feed/bottoms treatment is provided. Apparatus 100 includes an adsorption zone 110 , a hydrocracking reaction zone 130 containing hydrocracking catalysts, an optional high-pressure separation zone 150 , and a fractionating zone 160 .
Adsorption zone 110 includes an inlet 114 in fluid communication with a source of a first heavy hydrocarbon feedstream via a conduit 102 , and hydrocracking reaction product fractionator bottoms via a conduit 164 , which is in fluid communication with an unconverted/partially converted fractionator bottoms outlet 162 of fractionating zone 160 . Optionally, inlet 114 of adsorption zone 110 is also in fluid communication with a source of elution solvent via conduit 104 , for instance, straight run naphtha which can be derived from the product collected from the fractionating zone 160 or from another source of solvent. In addition, adsorption zone 110 includes a cleaned feedstream outlet 116 in fluid communication with an inlet 136 of hydrocracking reaction zone 130 via a conduit 120 . In embodiments in which a solvent elution stream is employed, the solvent can be distilled off, for instance, at an optional fractionator 118 between the cleaned feedstream outlet 116 and the inlet 136 of hydrocracking reaction zone 130 .
Feed inlet 136 of hydrocracking zone 130 is also in fluid communication a source of second heavy hydrocarbon feedstream via a conduit 132 . In addition, inlet 136 is in fluid communication with a source of hydrogen via a conduit 134 and optionally a hydrogen recycle stream from outlet 154 of high-pressure separation zone 150 via a conduit 156 , e.g., if there is an excess of hydrogen to be recovered. An outlet 138 of hydrocracking reaction zone 130 is in fluid communication with an inlet 140 of high-pressure separation zone 150 . In embodiments in which there is not an excess of hydrogen to be recovered, i.e., stoichiometric or near-stoichiometric hydrogen feed is provided, high pressure separation zone 150 can be bypasses or eliminated, and outlet 138 of hydrocracking reaction zone 130 is in fluid communication with inlet 158 of the fractionating zone 160 .
High-pressure separation zone 150 includes an outlet 152 in fluid communication with an inlet 158 of the fractionating zone 160 for conveying cracked, partially cracked and unconverted hydrocarbons, and an outlet 154 in fluid communication with inlet 136 of the hydrocracking reaction zone 130 for conveying recycle hydrogen. Fractionating zone 160 further includes outlet 162 in fluid communication with inlet 114 of adsorption zone 110 and a bleed outlet 163 , and an outlet 166 to discharge cracked product.
In operation of the system 100 , a combined stream including a first heavy hydrocarbon feedstream via conduit 102 and a hydrocracking reaction bottoms stream via conduit 164 , and optionally solvent via conduit 104 from fractionating zone 160 or from another source, are introduced into the adsorption zone 110 via inlet 114 . Solvent can be optionally used to facilitate elution of the feedstock mixture over the adsorbent. The concentrations of nitrogen-containing compounds, sulfur-containing compounds and PNA compounds present in the in the first heavy hydrocarbon feedstream, and HPNA compounds from the hydrocracking reaction bottoms stream, are reduced in the adsorption zone 110 by contact with adsorbent 112 .
An adsorbent-treated hydrocracking feedstream is discharged from adsorption zone 110 via outlet 116 and conveyed to inlet 136 of hydrocracking reaction zone 130 via and conduit 120 , along with the second hydrocarbon feedstream which is introduced into inlet 136 of hydrocracking reaction zone 130 via conduit 132 . In embodiments in which elution solvent is utilized, it is distilled and recovered in fractionator 118 .
An effective quantity of hydrogen for hydrocracking reactions is provided via conduits 134 and optionally recycle hydrogen conduit 156 . Hydrocracking reaction effluents are discharged from outlet 138 of hydrocracking reaction zone 130 . When an excess of hydrogen is used, the hydrocracking reaction effluents are conveyed to inlet 140 of high-pressure separation zone 150 . A gas stream, which mainly contains hydrogen, is separated from the converted, partially converted and unconverted hydrocarbons in the high-pressure separation zone 150 , and is discharged via outlet 154 and recycled to hydrocracking reaction zone 130 via conduit 156 . Converted, partially converted and unconverted hydrocarbons, which includes HPNA compounds formed in the hydrocracking reaction zone 130 , are discharged via outlet 152 to inlet 158 of fractionating zone 160 . A cracked product stream is discharged via outlet 166 and can be further processed and/or blended in downstream refinery operations to produce gasoline, kerosene and/or diesel fuel. At least a portion of the fractionator bottoms from the hydrocracking reaction effluent, including HPNA compounds formed in the hydrocracking reaction zone 130 , are discharged from outlet 162 and are recycled to adsorption zone 110 via conduit 164 . A portion of the fractionator bottoms from the hydrocracking reaction effluent is removed from bleed outlet 163 to remove a portion of the HPNA compounds, which could causes equipment fouling. The concentration of HPNA compounds in the hydrocracking effluent fractionator bottoms is reduced in adsorption zone 110 . In particular, in system 100 , both the hydrocracking reaction fractionator bottoms and the first heavy hydrocarbon feedstream are combined and contacted with adsorbent material 112 in adsorption zone 110 . The adsorbent-treated hydrocracking feed is combined with the second heavy hydrocarbon feedstream for cracking in the hydrocracking reaction zone 130 .
In certain embodiments, the adsorption zone includes columns that are operated in swing mode so that production of the cleaned feedstock is continuous. When the adsorbent material 112 in column 110 a or 110 b becomes saturated with adsorbed nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and/or HPNA compounds, the flow of the combined feedstream is directed to the other column. The adsorbed compounds are desorbed by heat or solvent treatment.
In case of heat desorption, heat is applied, for instance, with an inert nitrogen gas flow to adsorption zone 110 . The desorbed compounds are removed from the adsorption columns 110 a , 110 b via a suitable outlet (not shown) and can be conveyed to downstream refinery processes, such as residue upgrading facilities, or is used directly in fuel oil blending.
Referring to FIG. 2 , a flow diagram of a solvent desorption apparatus 100 a is provided. A solvent inlet 174 of adsorption zone 110 is in fluid communication with a source of fresh solvent via a conduit 172 and recycled solvent via a conduit 186 .
Adsorption zone 110 further includes an outlet 176 in fluid communication with an inlet 182 of a desorption fractionating zone 180 via a conduit 178 . A solvent outlet 184 of desorption fractionating zone 180 is in fluid communication with the adsorption zone inlet 174 via a conduit 186 , and a bottoms outlet 188 is provided to discharge the desorbed nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and/or HPNA compounds.
In one embodiment, fresh solvent is introduced to the adsorption zone 110 via conduit 172 and inlet 174 . The solvent stream containing removed nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and/or HPNA compounds is discharged from adsorption zone 110 via outlet 176 and conveyed via conduit 178 to inlet 182 of fractionation unit 180 . The recovered solvent stream is recycled back to adsorption zone 110 via outlet 184 and conduit 186 . The bottoms stream from the fractionation unit 180 containing the previously adsorbed nitrogen-containing compounds, sulfur-containing compounds, PNA compounds and/or HPNA compounds is discharged via outlet 188 and can be conveyed to downstream refinery processes, such as residue upgrading facilities, or is used directly in fuel oil blending.
Referring to FIG. 3 , a process flow diagram of an integrated hydrocracking apparatus 200 including feed pretreatment and bottoms treatment is provided. Apparatus 200 includes a first adsorption zone 210 , a hydrocracking reaction zone 230 containing hydrocracking catalysts, a high-pressure separation zone 250 , a fractionating zone 260 , and a second adsorption zone 290 .
First adsorption zone 210 includes an inlet 214 in fluid communication with a source of first heavy hydrocarbon feedstream via a conduit 202 (and optionally a source of solvent as described with respect to FIG. 1 , not shown in FIG. 3 ), and a cleaned feedstream outlet 216 in fluid communication with an inlet 236 of hydrocracking reaction zone 230 via a conduit 217 .
Feed inlet 236 of hydrocracking reaction zone 230 is also in fluid communication with a source of second hydrocarbon feedstream via a conduit 232 . In addition, inlet 236 is in fluid communication with a source of hydrogen via a conduit 234 and hydrogen recycle stream from outlet 254 of high-pressure separation zone 250 via a conduit 256 . As noted with respect to the discussion of apparatus 100 in FIG. 1 , the high pressure separation zone can be bypasses or eliminated, for instance, if there is little or no excess hydrogen. Hydrocracking reaction zone 230 includes an outlet 238 in fluid communication with an inlet 240 of high-pressure separation zone 250 .
High-pressure separation zone 250 also includes an outlet 252 in fluid communication with an inlet 258 of fractionating zone 260 for conveying cracked, partially cracked and unconverted hydrocarbons, and an outlet 254 in fluid communication with the hydrocracking reaction zone 230 for conveying recycle hydrogen. Fractionating zone 260 further includes outlet 262 in fluid communication with inlet 292 of second adsorption zone 290 , and an outlet 264 to discharge cracked product.
Second adsorption zone 290 includes inlet 292 in fluid communication with fractionating zone outlet 262 (and optionally a source of solvent as described with respect to FIG. 1 , not shown in FIG. 3 ), and an outlet 294 in fluid communication with inlet 236 of hydrocracking reaction zone 230 via a conduit 296 .
In operation of the system 200 , a first heavy hydrocarbon feedstream is conveyed via conduit 202 to inlet 214 of first adsorption zone 210 . The concentrations of nitrogen-containing compounds, sulfur-containing compounds and PNA compounds in the first heavy hydrocarbon feedstream are reduced in first adsorption zone 210 .
An adsorbent-treated first heavy hydrocarbon feedstream is discharged from outlet 216 of adsorption zone 210 and conveyed to inlet 236 of hydrocracking reaction zone 230 via conduit 217 . A second hydrocarbon feedstream is also introduced into the hydrocracking reaction zone 230 via conduit 232 . An effective quantity of hydrogen for hydrocracking reactions is provided via conduits 234 , 256 . Hydrocracked effluents are discharged via outlet 238 to inlet 240 of high-pressure separation zone 250 . A gas stream, which primarily contains hydrogen, is separated from the converted, partially converted and unconverted hydrocarbons in the high-pressure separation zone 250 , and is discharged via outlet 254 and recycled to hydrocracking reaction zone 230 via conduit 256 . Converted, partially converted and unconverted hydrocarbons, including HPNA compounds formed in the hydrocracking reaction zone 230 , are discharged via outlet 252 to inlet 258 of fractionating zone 260 . A cracked product stream is discharged via outlet 264 and can be further processed and/or blended in downstream refinery operations to produce gasoline, kerosene and/or diesel fuel. Unconverted and partially cracked fractionator bottoms, including HPNA compounds formed in the hydrocracking reaction zone 230 , are discharged from outlet 262 and at least a portion thereof is conveyed to inlet 292 of second adsorption zone 290 , with the remainder removed via a bleed outlet 263 . The concentration of HPNA compounds in the unconverted fractionator bottoms is reduced in the second adsorption zone 290 , therefore improving the quality of the recycle stream. Adsorbent-treated unconverted fractionator bottoms are sent to the hydrocracking reaction zone 230 via outlet 294 in fluid communication with inlet 236 for further cracking.
By employing distinct adsorption zones 210 , 290 , the content of the individual feeds to these adsorption zones can be specifically targeted. That is, nitrogen-containing compounds, sulfur-containing compounds and PNA compounds from the initial feed can be removed in the first adsorption zone 210 under a first set of operating conditions and using a first adsorbent material, and HPNA compounds formed during the hydrocracking process can be removed in the second adsorption zone 290 under a second set of operating conditions and using a second adsorbent material.
The feedstreams for use in above-described system and process can be a partially refined oil product obtained from various sources. In general, the first heavy feedstream is one or more of DMO from a solvent demetalizing operations or DAO from a solvent deasphalting operations, coker gas oils from coker operations, heavy cycle oils from fluid catalytic cracking operations, and visbroken oils from visbreaking operations. The first heavy feedstream generally has a boiling point of from about 450° C. to about 800° C., and in certain embodiments of from about 500° C. to about 700° C.
The second heavy hydrocarbon feedstream is generally VGO from a vacuum distillation operation, and contains hydrocarbons having a boiling point of from about 350° C. to about 600° C., and in certain embodiments from about 350° C. to about 570° C.
Suitable reaction apparatus for the hydrocracking reaction zone include fixed bed reactors, moving bed reactor, ebullated bed reactors, baffle-equipped slurry bath reactors, stirring bath reactors, rotary tube reactors, slurry bed reactors, or other suitable reaction apparatus as appreciated by one of ordinary skill in the art. In certain embodiments, and in particular for VGO and similar feedstreams, fixed bed reactors are utilized. In additional embodiments, and in particular for heavier feedstreams and other difficult to crack feedstreams, ebullated bed reactors are utilized.
In general, the operating conditions for the reactor of a hydrocracking zone include: reaction temperature of about 300° C. to about 500° C., in certain embodiments about 330° C. to about 475° C., and in further embodiments about 330° C. to about 450° C.; hydrogen partial pressure of about 60 Kg/cm 2 to about 300 Kg/cm 2 , in certain embodiments about 100 Kg/cm 2 to about 200 Kg/cm 2 , and in further embodiments about 130 Kg/cm 2 to about 180 Kg/cm 2 ; liquid hourly space velocity of about 0.1 h −1 to about 10 h −1 , in certain embodiments about 0.25 h −1 to about 5 h −1 , and in further embodiments about 0.5 h −1 to about 2 h −1 ; hydrogen/oil ratio of about 500 normalized m 3 per m 3 (Nm 3 /m 3 ) to about 2500 Nm 3 /m 3 , in certain embodiments about 800 Nm 3 /m 3 to about 2000 Nm 3 /m 3 , and in further embodiments about 1000 Nm 3 /m 3 to about 1500 Nm 3 /m 3 .
In certain embodiments, the hydrocracking catalyst includes any one of or combination including amorphous alumina catalysts, amorphous silica alumina catalysts, natural or synthetic zeolite based catalyst, or a combination thereof. The hydrocracking catalyst can possess an active phase material including, in certain embodiments, any one of or combination including Ni, W, Mo, or Co. In certain embodiments in which an objective is hydrodenitrogenation, acidic alumina or silica alumina based catalysts loaded with Ni—Mo or Ni—W active metals, or combinations thereof, are used. In embodiments in which the objective is to remove all nitrogen and to increase the conversion of hydrocarbons, silica alumina, zeolite or combination thereof are used as catalysts, with active metals including Ni—Mo, Ni—W or combinations thereof.
The adsorption zone(s) used in the process and apparatus described herein is, in certain embodiments, at least two packed bed columns which are gravity fed or pressure force-fed sequentially in order to permit continuous operation when one bed is being regenerated, i.e., swing mode operation. The columns contain an effective quantity of absorbent material, such as attapulgus clay, alumina, silica gel silica-alumina, fresh or spent catalysts, or activated carbon. The packing can be in the form of pellets, spheres, extrudates or natural shapes, having a size of about 4 mesh to about 60 mesh, and in certain embodiments about 4 mesh to about 20 mesh, based on United States Standard Sieve Series.
The packed columns are generally operated at a pressure in the range of from about 1 kg/cm 2 to about 30 kg/cm 2 , in certain embodiments about 1 kg/cm 2 to about 20 kg/cm 2 , and in further embodiments about 1 kg/cm 2 to about 10 kg/cm 2 , a temperature in the range of from about 20° C. to about 250° C., in certain embodiments about 20° C. to about 150° C., and in further embodiments about 20° C. to about 100° C.; and a liquid hourly space velocity of about 0.1 h −1 to about 10 h −1 , in certain embodiments about 0.25 h −1 to about 5 h −1 , and in further embodiments about 0.5 h −1 to about 2 h −1 . The adsorbent can be desorbed by applying heat via inert nitrogen gas flow introduced at a pressure of from about 1 kg/cm 2 to about 30 kg/cm 2 , in certain embodiments about 1 kg/cm 2 to about 20 kg/cm 2 , and in further embodiments about 1 kg/cm 2 to about 10 kg/cm 2 .
In embodiments in which the adsorbent is desorbed by solvent desorption, solvents can be selected based on their Hildebrand solubility factors or by their two-dimensional solubility factors. Solvents can be introduced at a solvent to oil volume ratio of about 1:1 to about 10:1.
The overall Hildebrand solubility parameter is a well-known measure of polarity and has been calculated for numerous compounds. See The Journal of Paint Technology , Vol. 39, No. 505 (February 1967). The solvents can also be described by their two-dimensional solubility parameter. See, for example, I. A. Wiehe, Ind . & Eng. Res., 34(1995), 661. The complexing solubility parameter component, which describes the hydrogen bonding and electron donor acceptor interactions, measures the interaction energy that requires a specific orientation between an atom of one molecule and a second atom of a different molecule. The field force solubility parameter, which describes the van der Waals and dipole interactions, measures the interaction energy of the liquid that is not destroyed by changes in the orientation of the molecules.
In accordance with the desportion operations using a non-polar solvent or solvents (if more than one is employed) preferably have an overall Hildebrand solubility parameter of less than about 8.0 or the complexing solubility parameter of less than 0.5 and a field force parameter of less than 7.5. Suitable non-polar solvents include, e.g., saturated aliphatic hydrocarbons such as pentanes, hexanes, heptanes, paraffinic naphtha, C 5 -C 11 , kerosene C 12 -C 15 diesel C 16 -C 20 , normal and branched paraffins, mixtures or any of these solvents. The preferred solvents are C 5 -C 7 paraffins and C 5 -C 11 paraffinic naphtha.
In accordance with the desportion operations using polar solvent(s), solvents are selected having an overall solubility parameter greater than about 8.5, or a complexing solubility parameter of greater than 1 and field force parameter of greater than 8. Examples of polar solvents meeting the desired minimum solubility parameter are toluene (8.91), benzene (9.15), xylenes (8.85), and tetrahydrofuran (9.52).
Advantageously, the present invention reduces the concentrations of nitrogen-containing compounds, sulfur-containing compounds and PNA compounds in a heavy feedstream to a hydrocracking unit such as a DMO or DAO feedstream. In addition, in recycle hydrocracking operations, the concentration of HPNA compounds that are formed in the unconverted fractionator bottoms is reduced. Accordingly, the overall efficiency of operation of the hydrocracking unit is improved along with the effluent product quality.
EXAMPLE
Attapulgus clay having the properties set forth in Table 1 was used as an adsorbent to treat a blend of de-metalized oil stream and unconverted hydrocracker bottoms (1:2 ratio). The virgin DMO contained 2.9 W % sulfur and 2150 ppmw nitrogen, 7.32 W % MCR, 6.7 W % tetra plus aromatics as measured by a UV method. The unconverted hydrocracker bottoms was almost free of sulfur (<10 ppmw), nitrogen (<2 ppmw) and contained >3000 ppmw coronene and its derivatives and about 50 ppmw of ovalene. The mid-boiling point of the DMO stream was 614° C. as measured by the ASTM D-2887 method. The unconverted hydrocracker bottoms had much lower mid boiling point (442° C.). The de-metalized oil and HPNA blend was mixed with a straight run naphtha stream boiling in the range of 36° C. to 180° C. containing 97 W % paraffins, the remainder being aromatics and naphthenes at 1:10 V:V % ratio and passed to the adsorption column containing attapulgus clay at 20° C. The contact time for the mixture was 30 minutes.
The naphtha fraction was distilled off and 94.7 W % of adsorbent treated DMO/unconverted hydrocracker bottoms mixture was collected. The molecules adsorbed on the adsorbent material, was desorbed in two steps. A first desorption step was conducted with toluene, and after distilling the first desorption solvent, the yield was 3.6 W % based on the total weight of the blend feed. A second desorption step was conducted with tetrahydrofuran, and after distilling the second desorption solvent, the yield was 2.3 W % based on the initial feed. After the treatment process, 75 W % of nitrogen-containing compounds, 44 W % of MCR and 2 W % of sulfur-containing compounds were removed from the blend sample. 95 W % of the HPNA was also removed from the blend.
The treated de-metalized oil and unconverted hydrocracker bottoms were hydrocracked using a stacked-bed reactor. Using the treated de-metalized oil and unconverted hydrocracker bottoms according to the process herein, the hydrocracking reactions occurred with a decrease in 10° C. in reactivity temperature as compared to untreated oil as shown in Table 2, thereby indicating the effectiveness of the feedstream treatment process of the invention. Table 3 shows product yields for both configurations
The reactivity, which can be translated into longer cycle length for the catalyst, can result in at least one year of additional cycle length for the hydrocracking operations, processing of a larger quantity of feedstream, or processing of heavier feedstreams by increasing the de-metalized oil content of the total hydrocracker feedstream. In addition, the treatment of unconverted hydrocracker bottoms stream resulted in clean recycle stream and eliminated the indirect recycle to the vacuum tower or other separation units such as solvent de-asphalting.
TABLE 1
Property
Unit
Attapulgus Clay
Surface Area
m 2 /g
108
Pore Size
°A
146
Pore Size Distribution
°A-cc/g
97.1
Pore Volume
cc/g
0.392
Carbon
W %
0.24
Sulfur
W %
0.1
Arsenic
ppmw
55
Iron
ppmw
10
Nickel
W %
0.1
Sodium
ppmw
1000
Loss of Ignition @500° C.
W %
4.59
TABLE 2
VGO/DMO
VGO/DMO
Blend With
Blend No
treated DMO
Feedstream
Treatment
Treatment
VGO/DMO Ratio
85:15
85:15
Temperature
398° C.
388° C.
Pressure
115 Kg/cm2
115 Kg/cm2
Hydrogen to Oil Ratio
1,500
1,500
LSHV
0.70 h−1
0.70 h−1
Catalyst 1
Ni—W on
Ni—W on
Silica Alumina
Silica Alumina
Catalyst 2
Ni—W on Zeolite
Ni—W on Zeolite
Catalyst 1/Catalyst 2 V:V %
3:1
3:1
Overall Conversion of 370° C.+
95
95
Hydrocarbons, W %
Recycle of 370° C.+, W %
15
15
Bleed of 370° C.+ Hydrocarbons,
0
0
W %
TABLE 3
VGO/DMO
Blend No
VGO/DMO Blend With
Feedstream
Treatment
treated DMO Treatment
Light Naphtha
20.01
22.02
Heavy Naphtha 85-185° C.
39.64
37.34
Kerosene 185-240° C.
8.68
8.58
Light Diesel Oil 240-315° C.
6.41
6.42
Heavy Diesel Oil 315-375° C.
4.42
4.56
Bottoms 375-FBP ° C.
20.84
21.07
The method and system of the present invention have been described above and in the attached drawings; however, modifications will be apparent to those of ordinary skill in the art and the scope of protection for the invention is to be defined by the claims that follow.
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A hydrocracking process for treating a first and a second heavy hydrocarbon feedstream, in which the first heavy hydrocarbon feedstream contains undesired nitrogen-containing compounds, sulfur-containing compounds and poly-nuclear aromatic compounds. The process includes contacting the first heavy hydrocarbon feedstream with adsorbent material to produce a hydrocarbon stream having a reduced content of nitrogen-containing, sulfur-containing compounds and poly-nuclear aromatic compounds. The second heavy hydrocarbon feedstream is combined with the adsorbent-treated heavy hydrocarbon stream. The combined stream is charged to a hydrocracking reaction unit. The hydrocracked effluent is fractioned to recover hydrocracked products and a bottoms stream containing heavy poly-nuclear aromatic compounds, and bottoms are contacted with adsorbent material to produce an adsorbent-treated fractionator bottoms stream having a reduced content of heavy poly-nuclear aromatic compounds, and are recycled to the hydrocracking reaction unit.
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FIELD OF THE INVENTION
The invention relates to a mobile communication device being connectable to a memory device comprising a plurality of memory sectors, wherein at least one application is stored in at least one memory sector, wherein the memory sectors are protected against unauthorized access by sector keys.
The invention further relates to a method for disabling applications in a mobile communication device that is connected to a memory device comprising a plurality of memory sectors wherein the sectors are protected against unauthorized access by sector keys, wherein each application is stored in at least one memory sector.
The invention further relates to a computer program product being directly loadable into the memory of a mobile communication device being connectable to a memory device comprising a plurality of memory sectors wherein at least one application is stored in at least one memory sector, wherein the memory sectors are protected against unauthorized access by sector keys.
The invention further relates to a telecommunication system comprising a Mobile Network Operator, a plurality of mobile communication devices and a Trusted Service Manager.
BACKGROUND OF THE INVENTION
The MIFARE® classic family, developed by NXP Semiconductors is the pioneer and front runner in contactless smart card ICs operating in the 13.56 MHz frequency range with read/write capability. MIFARE® is a trademark of NXP Semiconductors. MIFARE complies with IS014443 A, which is used in more than 80% of all contactless smart cards today. The technology is embodied in both cards and card reader devices. MIFARE cards are being used in an increasingly broad range of applications (including transport ticketing, access control, e-payment, road tolling, and loyalty applications). MIFARE Standard (or Classic) cards employ a proprietary high-level protocol with a proprietary security protocol for authentication and ciphering. MIFARE® technology has become a standard for memory devices with key-protected memory sectors. One example for a published product specification of MIFARE® technology is the data sheet “MIFARE®Standard Card IC MF1 IC S50-Functional Specification” (1998) which is herein incorporated by reference. MIFARE® technology is also discussed in: Klaus Finkenzeller, “RFID Handbuch”, HANSER, 3 rd edition (2002).
The MIFARE Classic cards are fundamentally just memory storage devices, where the memory is divided into sectors and blocks with simple security mechanisms for access control. Each device has a unique serial number. Anticollision is provided so that several cards in the field may be selected and operated in sequence.
The MIFARE Standard 1 k offers about 768 bytes of data storage, split into 16 sectors with 4 blocks of 16 bytes each (one block consists of 16 byte); each sector is protected by two different keys, called A and B. They can be programmed for operations like reading, writing, increasing value blocks, etc. The last block of each sector is called “trailer”, which contains two secret keys (A and B) and programmable access conditions for each block in this sector. In order to support multi-application with key hierarchy an individual set of two keys (A and B) per sector (per application) is provided.
The memory organization of a MIFARE Standard 1 k card is shown in FIG. 1 . The 1024×8 bit EEPROM memory is organized in 16 sectors with 4 blocks of 16 bytes each. The first data block (block 0 ) of the first sector (sector 0 ) is the manufacturer block which is shown in detail in FIG. 2 . It contains the serial number of the MIFARE card that has a length of four bytes (bytes 0 to 3), a check byte (byte 4) and eleven bytes of IC manufacturer data (bytes 5 to 15). The serial number is sometimes called MIFARE User IDentification (MUID) and is a unique number. Due to security and system requirements the manufacturer block is write protected after having been programmed by the IC manufacturer at production. However, the MIFARE specification allows to change the serial number during operation of the MIFARE card, which is particularly useful for MIFARE emulation cards like SmartMX cards.
SmartMX (Memory eXtension) is a family of smart cards that have been designed by NXP Semiconductors for high-security smart card applications requiring highly reliable solutions, with or without multiple interface options. Key applications are e-government, banking/finance, mobile communications and advanced public transportation.
The ability to run the MIFARE protocol concurrently with other contactless transmission protocols implemented by the User Operating System enables the combination of new services and existing applications based on MIFARE (e.g. ticketing) on a single Dual Interface controller based smart card. SmartMX cards are able to emulate MIFARE Classic devices and thereby makes this interface compatible with any installed MIFARE Classic infrastructure. The contactless interface can be used to communicate via any protocol, particularly the MIFARE protocol and self defined contactless transmission protocols. SmartMX enables the easy implementation of state-of-the-art operating systems and open platform solutions including JCOP (the Java Card Operating System) and offers an optimized feature set together with the highest levels of security. SmartMX incorporates a range of security features to counter measure side channel attacks like DPA, SPA etc. A true anticollision method (acc. ISO/IEC 14443-3), enables multiple cards to be handled simultaneously.
Building on the huge installed base of the MIFARE® interface platform, SmartMX enables e.g. Service Providers to introduce even more convenient ticketing systems and payment concepts. The high security (PKI and 3-DES) and the extended functionality of SmartMX allows for the integration of loyalty concepts, access to vending machines, or using an e-purse to pay fares instead of pre-paid electronic ticketing. The essential features of SmartMX cards are the following:
Contact interface UART according to ISO 7816. Contactless interface UART according to ISO 14443. Exception sensors for voltage, frequency and temperature. Memory management unit. MIFARE® classic emulation. JavaCard Operating System. DES and/or RSA engine. Up to 72 kilobyte EEPROM memory space.
It should be noted that the emulation of MIFARE Classic cards is not only restricted to SmartMX cards, but there may also exist other present or future smartcards being able to emulate MIFARE Classic cards.
Recently, mobile communication devices have been developed which contain or are connectable to memory devices comprising a plurality of memory sectors, wherein the memory sectors are protected against unauthorized access by sector keys. Examples of such memory devices comprise MIFARE Classic cards or emulated MIFARE Classic devices like SmartMX cards. These mobile communication devices are e.g. configured as mobile phones with Near Field Communication (NFC) capabilities. Mobile communication devices that are equipped with the above explained memory devices can be used for multi-application purposes. I.e. it is possible to install a plurality of applications, like tickets, coupons, access controls and so on in one memory device. Each application is stored in one or more separate sector(s) of the memory device such that terminal readers are only able to read those applications that are stored in sectors with the sector keys being known by the terminal readers.
While this protection concept works well as long as the owner of the mobile communication device is in possession of the same there is a potential security risk if the mobile communication device is stolen. Let us assume that the mobile communication device that has been stolen is a mobile phone. In this case the user when becoming aware of the theft will immediately inform the Mobile Network Operator that his mobile phone has been lost or stolen, whereupon the Mobile Network Operator can remotely block its basic network services for this mobile phone. However, the applications stored in the memory device are still available for use at the terminal readers since these terminal readers do not identify the actual user of the mobile phone. This represents an important security issue that needs to be addressed before NFC value-added services are deployed by Mobile Network Operators.
OBJECT AND SUMMARY OF THE INVENTION
It is an object of the invention to provide a mobile communication device of the type defined in the opening paragraph and a method of the type defined in the second paragraph, in which the problems mentioned above are overcome.
In order to achieve the object defined above, with a mobile communication device according to the invention characteristic features are provided so that such a mobile communication device can be characterized in the way defined below, that is:
A mobile communication device ( 1 ) being connectable to a memory device (MIF) comprising a plurality of memory sectors ( 0 -F), wherein at least one application is stored in at least one memory sector, wherein the memory sectors are protected against unauthorized access by sector keys (key A, key B, 4 ), wherein the mobile communication device ( 1 ) comprises an applications manager (MAM) being adapted to disable the stored applications (TK 1 , AC 1 , AC 2 , TR 2 , TR 3 , CP 1 , TR 4 , AC 3 , TK 3 ) when triggered by an external trigger event.
A mobile communication device comprising a classic or emulated MIFARE memory, a swap memory and a MIFARE applications manager being adapted to swap MIFARE applications between the MIFARE memory and the swap memory.
In order to achieve the object defined above, with a method according to the invention characteristic features are provided so that a method according to the invention can be characterized in the way defined below, that is:
A method for disabling applications in a mobile communication device ( 1 ) that is connected to a memory device (MIF) comprising a plurality of memory sectors ( 0 -F) wherein the sectors are protected against unauthorized access by sector keys (key A, key B, 4 ), wherein each application is stored in at least one memory sector ( 0 -F), wherein the method comprises disabling the stored applications (TK 1 , AC 1 , AC 2 , TR 2 , TR 3 , CP 1 , TR 4 , AC 3 , TK 3 ) when triggered by an external trigger event.
In order to achieve the object defined above, a computer program product being directly loadable into the memory of a mobile communication device being connectable to a memory device comprising a plurality of memory sectors wherein at least one application is stored in at least one memory sector, wherein the memory sectors are protected against unauthorized access by sector keys, comprises software code portions for performing—when running on the mobile communication device—the steps of the method according to the above paragraph.
In order to achieve the object defined above, a telecommunication system comprises a Mobile Network Operator, a plurality of mobile communication devices as defined above and a Trusted Service Manager, wherein the Trusted Service Manager is adapted to establish communication with a mobile communication device by request of the Mobile Network Operator and to instruct the mobile communication device to disable applications being stored in a memory device that is connected to the mobile communication device.
The present invention provides a mechanism to remotely disable all applications stored in said memory with protected memory sectors and thereby closes a potential security hole in using such value-added applications. The present invention is particularly useful in conjunction with memory devices being implemented as MIFARE Classic cards or emulated MIFARE Classic devices and the applications being implemented as MIFARE applications such as tickets, coupons, access controls, etc.
The invention allows to trigger application disabling from external sources, e.g. the Mobile Network Operators. However, in order to provide improved security levels it is preferred that a Trusted Service Manager establishes a communication link to the mobile communication device and instructs it to disable the stored applications.
According to the present invention there are three alternative approaches how to disable the stored applications. In a first embodiment disabling the stored applications comprises erasing the applications from the memory device. Erasing can be done by rewriting the respective sectors of the memory device with empty information or random data. While this solution provides high security and all application will be disabled without any possibility for restoring them, the speed of this erasing procedure can be a potential problem, if the new user (in case of a stolen mobile phone the thief) quickly interrupts the disabling routine by removing the battery from the mobile phone, for example, thereby keeping some of the stored applications “alive”. Hence, the conclusion is that the disabling routine should work as fast as possible.
Another embodiment of the present invention provides a faster disabling routine compared with the first one. This second disabling approach comprises disabling the stored applications by scrambling the applications in the memory device, preferably by writing random information at random locations of the respective sectors of the memory device. This disabling method is very fast but is not 100% secure. Some important data could remain in the memory device since the applications are only left in an unusable state, but are not completely removed from the memory device.
A third embodiment of the invention combines both high processing speed and security by disabling the stored applications by means of changing the sector keys of the memory device. This disabling method is fast, since just the sector keys have to be re-written (if MIFARE memory devices are used the sector trailer), and 100% secure because all the sectors of the memory device will be un-accessible by Terminal Readers.
The present invention is perfectly suited for mobile phones with NFC capabilities that can be equipped with memory devices having multiple memory sectors protected by sector keys, such as (emulated) MIFARE devices, like SmartMX cards.
The aspects defined above and further aspects of the invention are apparent from the exemplary embodiments to be described hereinafter and are explained with reference to these exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail hereinafter with reference to exemplary embodiments. However, the invention is not limited to them. The exemplary embodiments comprise memory devices being configured as MIFARE devices.
FIG. 1 shows the memory organization of a MIFARE Standard 1 k EEPROM.
FIG. 2 shows the manufacturer block of a MIFARE memory.
FIG. 3 shows the sector trailer of a sector of MIFARE memory.
FIG. 4 shows a telecommunication system in which the present invention is implemented.
FIG. 5 shows a scheme of a first embodiment of the present invention.
FIG. 6 shows a scheme of a second embodiment of the present invention.
FIG. 7 shows a scheme of a third embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
Referring to FIG. 4 a telecommunication system according to the present invention is explained. This system comprises a Mobile Network Operator MNO providing the full range mobile services to customers, particularly providing UICC and NFC terminals plus Over The Air (OTA) transport services. In FIG. 4 one user 5 is shown who is the owner of a mobile communication device 1 being configured as a NFC mobile phone. The customer uses the mobile communication device 1 for mobile communications and Mobile NFC services. In order to use the Mobile NFC services reader terminals 2 are necessary being adapted to wirelessly communicating with the mobile communication device 1 . reader terminals 2 are operated under the influence of Service Providers. The customer subscribes to a MNO and uses Mobile NFC services. Mobile NFC is defined as the combination of contactless services with mobile telephony, based on NFC technology. The mobile phone with a hardware-based secure identity token (the UICC) can provide the ideal environment for NFC applications. The UICC can replace the physical card thus optimising costs for so called Service Provider, and offering users a more convenient service. The Mobile Network Operator MNO communicates with a Trusted Service Manager TSM who securely distributes and manages services to the MNO customer base. Also shown in FIG. 4 is a Service Provider (SP) who provides contactless services to the user 5 (SPs are e.g. banks, public transport companies, loyalty programs owners etc.). The Trusted Service Manager TSM will also securely distribute and manage the Service Providers' services to the MNO customer base. For the explanation of the present invention it is convenient to assume that the Mobile Network Operator MNO also acts as a Service Provider. The role of the Trusted Service Manager TSM is to provide the single point of contact for the Service Providers SP (herein also the Mobile Network Operator MNO) to access their customer base through the MNOs. The Trusted Service Manager TSM further manages the secure download and life-cycle management of Mobile NFC applications on behalf of the Service Providers. The Trusted Service Manager TSM does not participate in the transaction stage of the service, thus ensuring that the Service Providers' existing business models are not disrupted. Depending on the national market needs and situations, the Trusted Service Manager TSM can be managed by one or a consortium of Mobile Network Operators MNO, or by independent Trusted Third Parties.
According to the present invention the mobile communication device 1 is equipped with a memory device MIF that comprises a plurality of memory sectors ( 0 -F), each memory sector being protected against unauthorized access by sector keys (see Key A and Key B in FIG. 3 , or numeral 4 in FIG. 7 ). In the present embodiment of the invention the memory device MIF is a MIFARE Classic card (as shown in FIGS. 1 to 3 ) or an emulated MIFARE Classic device such as a SmartMX card. The Service Provider SP and the Mobile Network Operator MNO, respectively, provide NFC services requiring to download applications, here MIFARE applications, into the memory device MIF of the mobile communication device 1 . As has been explained above download of applications is exclusively handled by the Trusted Service Manager TSM who receives the applications from the Service Provider SP and the Mobile Network Operator MNO and forwards them to the mobile communication device 1 . It is the Trusted Service Manager who decides in which sectors of the memory device MIF the applications have to be written. The mobile communication device 1 comprises a software-implemented Trusted Service Manager Applet (not shown in the drawing) being responsible to carry out all instructions of the Trusted Service Manager. Particularly the Trusted Service Manager Applet writes the applications into the prescribed sectors of the memory device MIF. The applications comprise e.g. tickets, access controls and transit applications, but are not limited to said types of applications. Having a closer look at the memory device MIF it currently comprises the following applications:
Ticket 1 (TK1) in sector 0
Access Control 1 (AC1) in sector 1
Access Control 2 (AC2) in sector 2
Transit 2 (TR2) in sector 3
Transit 3 (TR3) in sector 4
Coupon 1 (CP1) in sector 5
Transit 4 (TR4) in sector 6
Access Control 3 (AC31) in sector 7
Ticket 3 (TK3) in sectors 8, 9 and A
sectors B, C, D, E, F remain empty.
For the explanation of the present invention it is assumed that the user 5 has realized that his mobile communication device 1 has been stolen. He reports the theft of his mobile communication device 1 to the Mobile Network Operator MNO (see arrow MSG). The Mobile Network Operator MNO block all basic network services for this mobile communication device 1 . Further, the Mobile Network Operator MNO sends a request (arrow REQ) to the Trusted Service Manager TSM to discard all applications stored in the memory device MIF of the mobile communication device 1 . Upon receipt of this request REQ the Trusted Service Manager establishes a connection with the mobile communication device 1 and especially with an application manager MAM residing as a software implementation within the mobile communication device 1 . Preferably, the application manager MAM is located in a secure memory element (for instance the SIM card). The Trusted Service Manager TSM instructs (see arrow INS) the application manager MAM to disable all applications (TK 1 , AC 1 , AC 2 , TR 2 , TR 3 , CP 1 , TR 4 , AC 3 , TK 3 ) that are stored in the memory device MIF being connected to the mobile communication device 1 .
The application manager MAM can handle this disabling instruction INS in a plurality of alternative ways being discussed below.
A first application disabling procedure carried out by the application manager MAM is schematically shown in FIG. 5 . This disabling method consists in physically erasing (symbolized by arrow ERS) all applications from the memory device MIF. This task can be accomplished by writing empty information into all the sectors of the memory device MIF. Application disabling by this erasing method is secure, since all the applications will be removed from the memory device MIF, but performance issues might arise. The new user of the mobile communication device 1 (i.e. in case of a stolen mobile the thief) could interrupt the erasing procedure by removing the battery of the device for example. Hence it is important to carry out disabling as fast as possible, in order to exclude interruption of the disabling procedure.
FIG. 6 shows another way how the application manager MAM accomplishes disabling of the applications stored in the memory device MIF. This second disabling approach comprises disabling the stored applications by scrambling (symbolized by arrows SCR) the applications in the memory device MIF, preferably by writing random information 3 at random locations of the respective sectors of the memory device. In FIG. 6 the random information 3 is symbolized by spots being located within the applications. This disabling method is very fast but has the drawback that it is not completely safe. Some important data within the applications could remain in the memory device MIF since the applications are not completely removed from the memory device, although they are left in an unusable state after the disabling routine.
FIG. 7 shows a third disabling approach that combines both high processing speed and security. In this embodiment of the invention the application manager MAM disables the applications stored in the memory device MIF by means of changing (symbolized by arrow CHG) the sector keys 4 of the memory device MIF. This disabling method is fast, since just the sector keys have to be re-written (if MIFARE memory devices are used: the sector trailer), and 100% secure because all the sectors of the memory device will be un-accessible by terminal readers 2 (see FIG. 4 ) which only know the previous sector keys 4 .
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim. The indefinite article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
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A mobile communication device ( 1 ) is connectable to a memory device (MIF) that comprises a plurality of memorysectors ( 0 -F), wherein at least one application is stored in at least one memory sector. the memory sectors are protected against unauthorized access 5 by sector keys (key A, key B, 4 ). The mobile communication device ( 1 ) comprises an applications manager (MAM) being adapted to disable the stored applications (TK 1 , AC 1 , AC 2 , TR 2 , TR 3 , CP 1 , TR 4 , AC 3 , TK 3 ) when triggered by an external trigger event.
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TECHNICAL FIELD
The present invention relates to a cooking device for cooking of foodstuffs.
BACKGROUND ART
Large scale cooking, such as industrial cooking of foodstuffs, is of a growing interest, particularly as the demand for products such as pre-cooked dishes is increasing. In industrial cooking, it is often desired that certain properties of the products, such as shape and surface structure, are controlled and that products with little variation over time with regards to the desired properties can be delivered.
It is known to cook foodstuffs positioned between surfaces. In the American patent with number U.S. Pat. No. 6,745,671, cooking in oil of meat products positioned on a feed belt with a top belt preventing the products from floating in the oil is disclosed. There is, however, a need for of cooking equipment efficiently handling shape-controlled cooking and non-shape-controlled cooking of foodstuffs.
SUMMARY OF THE INVENTION
It is an object of the present invention to make available an efficient cooking device for shape-controlled cooking of foodstuffs, as well as non-shape-controlled cooking of foodstuffs.
According to a first aspect of the invention the object is achieved by means of a cooking device for cooking of foodstuffs, comprising a cooking chamber, a product conveyor, a shape-controlling belt, and a lifting member, the product conveyor being arranged to convey said foodstuffs through said cooking chamber, the shape-controlling belt being an endless belt extending along an upper return path, and a lower work path, the lifting member being arranged to shift a part of the lower work path between a first position in which the belt extending along said part is slacking and is adopted to contact said foodstuffs on the product conveyor, and a second position in which the belt extending along said part is adapted to be separated from said foodstuffs on the product conveyor.
The cooking chamber can be a chamber which can be heated, such as an oven. Thereby, several different types of cooking is possible with the cooking device, such as baking, frying, grilling, toasting, surface treatment, or steam cooking, or combinations thereof.
The product conveyor conveys the foodstuffs through the cooking chamber, and the foodstuffs are being cooked as they are inside the cooking chamber. The product conveyor thus enables continuous cooking of foodstuffs, but also batch cooking. The product conveyor also enables transport of foodstuffs through the cooking chamber.
The shape-controlling belt according to the invention is an endless belt.
The shape-controlling belt according to the invention, can be in contact with the foodstuffs on the product conveyor. When the shape-controlling belt is in contact with the foodstuffs on the product conveyor, the shape-controlling belt may control the shape of the product. Controlling the shape may comprise providing the surface of the foodstuffs being in contact with the shape-controlling belt, a flat, smooth or patterned appearance, and/or restricting or controlling the height, thickness or size of the foodstuffs. For example, controlling the shape may comprise making or keeping foodstuffs flat. Furthermore, controlling the shape may comprise limiting or preventing the rising of the foodstuffs, for example in case of baking of dough, for example, into breads.
The shape-controlling belt may be made of metal, such as steel or stainless steel, or any other material being suitable for the purpose of controlling the shape of foodstuffs during cooking according to the invention.
The lifting member according to the invention, allows the shape-controlling belt to be shifted between a first position and a second position, wherein the shape-controlling belt in the first position is closer to the product conveyor compared to the shape-controlling belt in the second position. Thus, the first position may allow the shape-controlling belt to contact foodstuffs on the product conveyor, while the second position may allow the belt not to contact foodstuffs on the product conveyor. Thus, the lifting member can be used to shift the shape-controlling belt between controlling the shape of the foodstuffs being cooked, or not controlling the shape of the foodstuffs being cooked. In the first position, the shape-controlling belt may be in contact with the product conveyor.
Thus, the device according to the invention can be used efficiently for shape-controlled cooking and/or for non-shape-controlled cooking.
The lifting member may further be used for increasing the space between the product conveyor and the shape-controlling belt, thereby giving better access, for example for inspections or maintenance to the device.
Said slacking enables the lifting member to shift the shape-controlling belt between said first position and said second position.
Said slacking further enables the lifting member to shift the shape-controlling belt, between said first position and said second position, without shifting the whole of the shape-controlling belt, as simply the slack of the belt has to be shifted. Thus the shifting is easy and efficient.
Cooking according to the invention can for example be baking, frying, grilling, toasting, surface treatment, or steam cooking, or combinations thereof. According to the invention, the surfaces of the product conveyor and of the lower work path of the shape-controlling belt, being in contact with foodstuffs may be essentially parallel.
The lifting member according to the invention may comprise a structure supported on at least one lateral side of the shape-controlling belt, said structure being insertable between the shape-controlling belt and the product conveyor such that the structure engage the shape-controlling belt in order to shift said part of the work path from said first position to said second position.
A structure being insertable between the shape-controlling belt and the product conveyor is an easy, reliable and efficient way for the structure to engage the shape-controlling belt, and thus for the structure to shift said part of the lower work path between said first position and said second position. Thus the structure may be used to allow the device according to the invention to be used efficiently for shape-controlled cooking and/or for non-shape-controlled cooking, and the device may efficiently be shifted between shape-controlled cooking and/or for non-shape-controlled cooking. Thus the device may be used by users desiring shape-controlled cooking according to the invention, by users desiring non-shape-controlled cooking, and by users desiring to be able to alter between shape-controlled and non-shape-controlled cooking.
Non-shape-controlled cooking, as discussed herein, can be regarded as cooking without the shape-controlling belt being in contact with the foodstuffs on the product conveyor, and thus cooking without the shape-controlling belt effecting the foodstuffs.
The structure being supported on at least one lateral side of the shape-controlling belt is an efficient way of controlling the structure. It may be more efficient to support the structure on both lateral sides of the shape-controlling belt.
The lifting member according to the invention may comprise a lateral supporting means arranged on at least one lateral side of the shape-controlling belt, wherein said lateral supporting means is supporting said structure.
A lateral supporting means arranged on at least one lateral side of the shape-controlling belt is an efficient means for supporting the structure and allowing the structure to be moved in the elongated direction of the shape-controlling belt.
The structure according to the invention may be transversal spaced apart rods being movable in the longitudinal extension of the product conveyor. Such rods may be cost-effective, require little space, and be rolled up on rolls.
The lateral supporting means of said lifting member according to the invention may comprise two support lines, such as chains or wires, one support line being arranged on each lateral side of the shape-controlling belt, wherein said lateral supporting means supports transversal spaced apart rods being movable in the longitudinal extension of the product conveyor.
Such support lines being arranged on each lateral side of the shape-controlling belt allows for stable support of said spaced apart rods, and allows for easy and efficient movement in the longitudinal extension of the product conveyor. Said support lines further makes it possible and easy to insert said rods between the shape-controlling belt and the product conveyor such that the structure engage the shape-controlling belt in order to shift said part of the work path from said first position to said second position.
Said rods may be rotatably attached to the support lines. Such rotatably attached rods may be beneficial for supporting the shape-controlling belt, when the shape-controlling belt is moving. Such rotatably attached rods may prevent undesired scraping off of residues of foodstuffs or material from the shape-controlling belt.
The support lines may be, for example, chains, wires, ropes, belts, or any other suitable objects.
The two support lines may at each end be engaged with a moving member arranged to move the support lines in the longitudinal extension of the product conveyor. Thus, the support lines can be moved back and/or forth. Thus, said structure or transversal spaced apart rods can be moved in the longitudinal extension of the product conveyor and inserted between the shape-controlling belt and the product conveyor, such that said part of the work path is shifted from said first position to said second position. It is realised that the process may be reversed such that said part of the work path may be shifted from said second position to said first position.
The moving member may be, for example, a roll, a reel, or a wheel. The moving member may be incorporated with a means for turning or rotating the moving member. Said turning or rotating can be clock-wise or anti-clock-wise. For example a gear unit powered by an electric motor or a hydraulic motor may be used for said turning or rotating.
The rods are transversal in relation to the elongation of the belt.
The supporting means may comprise one section supporting transversal spaced apart rods and one section without transversal spaced apart rods. The supporting means may also comprise at least one section supporting transversal spaced apart rods and at least one section without transversal spaced apart rods.
The support lines according to the invention may be supported on support rails, one rail for each support line, with elongation in the direction of the support lines. Such rails may be beneficial for keeping the support lines at a suitable and/or predetermined level in relation to the product conveyor and/or the shape-controlling belt. Furthermore, the support rails may be efficient for keeping the support lines essentially parallel to the product conveyor and/or the lower work path of the shape-controlling belt.
The rails may be mounted to inside walls of the cooking chamber. The rails may be adjustably mounted to the inside walls of the cooking chamber such that the height of the rails above the product belt may be adjusted, and thus the height to which the lower work path of the shape-controlling belt may be elevated above the product belt may be adjusted.
The lower work path of the shape-controlling belt in the second position is at a distance from the product conveyor. Said distance may be, for example, 1-20, 2-10, 3-9, or 4-8 cm. For example, the distance may be 7.5 cm.
The shape-controlling belt may be slacking between the rods, according to the invention, when the lower work path is in said second position.
Said part according to the invention is a portion of the lower work path or the whole of the lower work path. Thus, a portion or the whole of the lower work path may be engaged in shape-controlled cooking, or a portion or the whole of the lower work path may be engaged in non-shape-controlled cooking. The cooking device according to the invention may thus be used, for example, such that the foodstuffs are cooked with shape-control in the first part of the cooking chamber and with non-shape-controlled cooking in the last part of the cooking chamber, or vice versa.
Each of the product conveyor, the shape-controlling belt, and the lifting member may have an extension outside of the cooking chamber. Thus, for example, the foodstuffs may be positioned on the product conveyor outside of the cooking chamber, after which the foodstuffs are conveyed into the cooking chamber in which the food stuffs are subjected to shape-controlled cooking or non-shape-controlled cooking, after which the cooked foodstuffs are conveyed out of the cooking chamber for possible further treatment.
The product conveyor according to the invention may be a conveyor belt. The product conveyor according to the invention may further be an endless conveyor belt. A conveyor belt, or an endless conveyor belt, is an efficient means of conveying foodstuffs according to the invention.
The product conveyor, such as an endless conveyor belt, may be made of metal, such as steel or stainless steel. Such a material lends the product conveyor suitable properties for baking at high temperatures and suitable properties, for example, with regards to cleaning and strength.
The shape-controlling belt according to the invention may be movable.
The shape-controlling belt may be movable such that when the shape-controlling belt is extending along said lower work path, the shape-controlling belt presents a velocity which corresponds to the velocity with which the foodstuffs are transported.
The first position of said part of the lower work path may result in shape-controlled cooking of foodstuffs, and the second position of said part of the lower work path may result in non-shape-controlled cooking. Thus, it is possible to use the cooking device according to the invention both for shape-controlled cooking and for non-shape-controlled cooking. The lifting member enables switching between shape-controlled cooking and for non-shape-controlled cooking.
According to a second aspect of the invention, a method is proposed for switching a cooking device between being adapted for shape-controlled cooking and non-shape-controlled cooking of foodstuffs, using the cooking device according to the invention, comprising the step of shifting a part of the lower work path between a first position in which the belt extending along said part is slacking and is adopted to contact said foodstuffs and shape-controlled cooking, and a second position in which the belt extending along said part is adopted to be separated from said foodstuffs on the product conveyor and non-shape-controlled cooking.
Thus, said method allows a single device to be used for shape-controlled cooking as well as non-shape-controlled cooking. Such a method allows different foodstuffs to be cooked using the same cooking device, without the necessity of having two cooking devices or one cooking device which has to be rebuilt.
According to a third aspect of the invention, a use of the cooking device according to the invention, is proposed for cooking of foodstuffs.
The foodstuffs according to the invention may be, for example, bread, rolls, buns, pies, pizzas, pitta bread, pizza bases, tortilla chips, sausages, burgers, or bacon. The cooking may be, for example, baking, grilling, frying, toasting, surface treatment, or steam cooking, or combinations thereof.
The foodstuffs may be positioned directly on the belt, or, for example, on trays.
The shape-controlled cooking may be used to control the flatness and the thickness of foodstuffs being cooked. For example with bacon, shape-controlled cooking may be used to obtain flat bacon, while non-shape-controlled cooking typically results in wavy bacon. With some foodstuffs, for example bread, it is sometimes desired that the bread is baked with shape-control, for example if a flat surface is desired on the bread which may be the case, for example, with loafs to be used for toasts or pizza bases; while it is sometimes desired that the bread has a natural uneven crust, which may make the bread look more natural and appetising. The use of the cooking device according to the invention allows for easy and efficient switching between shape-controlled cooking and non-shape-controlled cooking.
The use of the cooking device according to the invention may be for shape-controlled cooking.
The use of the cooking device according to the invention may be for non-shape-controlled cooking.
The use of the cooking device according to the invention may be for baking of bacon.
The use of the cooking device according to the invention may be for cooking, wherein the cooking is a combination of shape-controlled cooking and non-shape-controlled cooking.
Relevant parts of the explanations given above with regard to the device are also applicable to the method and use of the device. Reference is hereby made to these explanations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 a illustrates the cooking device according to the invention, as viewed from the side, wherein a part of the lower work path is in the first position.
FIG. 1 b illustrates the cooking device according to the invention, as viewed from above, wherein a part of the lower work path is in the first position.
FIG. 2 a illustrates the cooking device according to the invention, as viewed from the side, wherein a part of the lower work path is in the second position.
FIG. 2 b illustrates the cooking device according to the invention, as viewed from above, wherein a part of the lower work path is in the second position.
FIG. 3 illustrates a perspective view of the cooking device according to the invention, during baking of bacon.
DETAILED DESCRIPTION
The invention will now be explained in more detail, and specific preferred embodiments, and variations of these, will be shown. The explanations are intended for illustrative and explanatory purposes and are not to be seen in any way as limiting the scope of the invention. The illustrations are schematic and all details are not illustrated, and all illustrated details may not be necessary for the invention.
A specific embodiment of the invention will now be discussed with reference to FIGS. 1 a and 1 b.
A cooking device 1 according to the invention is illustrated in FIGS. 1 a and 1 b . The product conveyor 2 is horizontally mounted and runs through a cooking chamber 3 (illustrated as a see-through box for improving the clarity). A shape-controlling belt 4 is positioned on top of the product conveyor. The shape-controlling belt 4 is an endless belt made of stain-less steel, and the belt 4 has a slack 5 which makes it hang down towards the product conveyor 2 . A lifting member 7 comprising two support lines, in this example being chains 8 a and 8 b , supporting a structure comprising transversal spaced apart rods 9 (of which only one rod is pointed out in the figure). Although the chains 8 a and 8 b are illustrated as lines, for improved clarity, it should be realised that the chains may comprise links. In this example there are nine rods 9 , but there may be fewer or more rods 9 . For example there may be 28 rods. The number of rods may vary depending on the length of the shape controlling belt. Each one of the chains 8 a and 8 b is supported on a rail (not illustrated) which is mounted on an inside wall of the cooking chamber 3 . In this example, the chains 8 a and 8 b are further positioned and stretched by shafts comprising cogs 12 a , 12 b , 12 c and 12 d (only illustrated in FIG. 1 a ), running transversal to the elongation of the product conveyor 2 . Other means may be used for positioning and stretching the chains 8 a and 8 b , such as cog wheels, shafts without cogs, loops, or other suitable means. It may also be possible to operate the device according to the invention without any such means for positioning and stretching the support lines. The lifting member further comprises moving members in the form of two rolls 6 a , 6 b . The rolls 6 a and 6 b comprise an axis 11 a and 11 b , respectively. In FIGS. 1 a and 1 b , the spaced apart rods are illustrated positioned rolled up on the rolls, and not inserted between the shape-controlling belt and the product conveyor. As a result of this, combined with the fact that the chains 8 a and 8 b are positioned at a distance from the side of the shape-controlling belt, the shape-controlling belt is slacking and is in the first position. Thus, the device, as illustrated in FIGS. 1 a and 1 b , is adapted for shape-controlled cooking.
Shifting a part of the lower work path from a first position to a second position, thus shifting the cooking device from being adapted for shape-controlled cooking to non-shape-controlled cooking will now be discussed with references to FIGS. 1 a and 1 b . The rolls 6 a and 6 b are rotatable according to this example, for example by means of an electric motor and a gear unit (not illustrated), and when the rolls 6 a , 6 b are rotated anti-clockwise, the roll 6 a is unwinding the chains 8 a and 8 b and the rods 9 , while simultaneously roll 6 b is winding the chains 8 a and 8 b . Thus, the chains 6 a and 6 b and the rods will be motioned in a direction from left to right in the illustration. It is realised that the rotating can be turning. The chains 8 a and 8 b and the rods 9 are arranged at a distance above the product conveyor 2 . When the rods 9 reaches the nip 13 formed between the shape-controlling belt 4 and the product conveyor 2 , the rods 9 will enter the nip transversal to the elongation of the product conveyor 2 , and as a result of said distance above the product conveyor 2 , the rods 9 will force or lift the slack 5 of the shape-controlling belt 4 upwards and the work-path of the shape-controlling belt 4 will thus be elevated to a higher distance above the product conveyor 2 , corresponding to shifting of the lower work-path from the first position to the second position. In FIGS. 1 a and 1 b the first position is illustrated. The rods 9 , which in this example are rotatably attached to the chains 8 a and 8 b , will rotate and thereby decreasing the friction between the rods 9 and the lower work path, allowing for smoother operation, a longer lasting cooking device, and reduced risk of scraping off foodstuff residues or material from the shape-controlling belt. The second position is described below with references to FIG. 2 a or 2 b.
FIGS. 2 a and 2 b illustrate the same cooking device as is illustrated in FIGS. 1 a and 1 b , and the difference between FIGS. 1 a and 1 b on one hand and 2 a and 2 b on the other hand, is that FIGS. 1 a and 1 b illustrate the cooking device with the lower work-path in the first position; and FIGS. 2 a and 2 b illustrate the lower work-path in the second position.
In FIGS. 2 a and 2 b , the chains 8 a and 8 b and the rods 9 have been motioned in a direction from left to right in the illustration, as compared with FIGS. 1 a and 1 b , and the rods 9 , thus, have been moved from being wound on the roll 6 a to being positioned between the product conveyor 2 and the shape-controlling belt 4 , where the rods 9 are engaged with a part of the lower work path of the shape-controlling belt, such that it is lifted and is in the second position. The cooking device is thus adapted for non-shape-controlled cooking. As can be seen from the inset, the lower work path of the shape-controlling belt 4 , according to this example, may be hanging down between the rods 9 . During non-shape-controlled cooking according to the invention, the chains 8 a and 8 b and the rods 9 will be held essentially motionless in the illustrated positions, but the product conveyor will be moving. The shape-controlling belt may be moving or not moving.
If the rolls 6 a and 6 b are rotated in clock-wise direction, the chains 8 a and 8 b and the rods 9 would be motioned to the left in the illustration. The rods 9 would leave their position between the product conveyor 2 and the lower work path of the shape-controlling belt 4 . Thus, the lower work path of the shape-controlling belt 4 would not be elevated by the rods 9 and, as a result would slack and shift from the second position to the first position. Thus, the cooking device would shift from being adapted for non-shape-controlled cooking to shape-controlled cooking.
With reference to FIG. 3 , shape-controlled baking of bacon is being discussed below. Shape-controlled baking of bacon, using the device according to the invention, results in bacon which has a flat appearance, in contrast to the wavy appearance typical to bacon being baked without shape-control. FIG. 3 illustrates a cooking device 1 according to the invention with the lower work path in the first position, and thus a slack 5 of the lower work path of the shape-controlling belt. The lower work path is in the first position as a result of the rods 9 not being positioned between the product conveyor 2 and the lower work path of the shape controlling belt 4 . Several rods 9 can be seen rolled up on roll 6 a , and two rods 9 being outside the roll 6 a . It is realised that all rods 9 could have been rolled up on roll 6 a , but that, for this example, it is important that the rods are not positioned between the shape-controlling belt 4 and the product belt 2 . The chains 8 a and 8 b are illustrated running alongside, but at a distance from, the shape controlling belt 4 . The foodstuffs in this example are slices of bacon 10 (of which only one slice is pointed out in the figure). The slices of bacon 10 are positioned on the product conveyor 2 . The product conveyor 2 is motioned such that the slices of bacon 10 are moved to the right in the illustration. The lower work path of the shape-controlling belt 4 is moving at the same speed as the product conveyor 2 and the slices of bacon 10 . The slices of bacon 10 will before entering the cooking chamber 3 enter between the product conveyor 2 and the shape-controlling belt 4 and be sandwiched between the two, and the slices of bacon 10 will be in contact with the shape-controlling belt. The slices of bacon 10 are conveyed into the cooking chamber 3 where they are heated and baked. The slices of bacon 10 are limited upwards by the shape-controlling belt and the shape of the slices of bacon 10 are thus controlled, and the slices of bacon 10 are thus not becoming wavy during the baking. Slices of bacon 10 appearing flat are of interest, for example, when positioned on top of hamburgers. For some purposes the slices of bacon 10 are visible when eaten and it is desired that they have a wavy appearance to look appetising. The device according to the invention can be used for efficient baking of both flat and wavy bacon. After flat bacon has been cooked as discussed above, the lower work path may, according to the invention, efficiently be shifted from the first position to the second position (not illustrated) and bacon may be baked such that the slices of bacon 10 obtain a wavy appearance.
In the example discussed directly above, there exists a continues movement of the product conveyor and the shape-controlling belt, and thus a continuous movement of slices of bacon 10 through the cooking chamber 3 , and the cooking process may be regarded as a continuous cooking process. New slices of bacon 10 are positioned on the product conveyor at the same pace as the slices of bacon 10 are conveyed into the cooking chamber 3 . The cooking device 1 can also be used for batch cooking, in which a batch of slices of bacon 10 would be positioned on the product conveyor and conveyed into the cooking chamber 3 where they are baked. During this baking the movement of the product conveyor 2 and the shape-controlling belt 4 may be stopped during the baking, and started again when the baking is finished, or nearly finished, to convey the slices of bacon 10 out from the cooking chamber 3 , while at the same time possibly conveying other, un-cooked, slices of bacon 10 positioned upstream the cooking chamber 3 into the cooking chamber 3 . After being conveyed out of the cooking chamber 3 , the slices of bacon 10 may be subjected to further treatment, for example seasoning or packing.
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The present invention relates to a cooking device for cooking of foodstuffs, comprising a cooking chamber, a product conveyor, a shape-controlling belt, and a lifting member, the product conveyor being arranged to convey said foodstuffs through said cooking chamber, the shape-controlling belt being an endless belt extending along an upper return path, and a lower work path, the lifting member being arranged to shift a part of the lower work path between a first position in which the belt extending along said part is slacking and is adopted to contact said foodstuffs on the product conveyor, and a second position in which the belt extending along said part is adopted to be separated from said foodstuffs on the product conveyor. The invention further relates to a method for switching a cooking device between being adapted for shape-controlled cooking and non-shape-controlled cooking of foodstuffs, and use of the cooking device.
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RELATED U.S. APPLICATION DATA:
This application claims the benefit of and is a continuation in part of U.S. Provisional Application Ser. No. 60/039,125, filed Feb. 25, 1997, for IREC METHODOLOGY.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to systems and methods for measuring volume and rate of gas well flow by electrical means using differential pressure with time integration. More specifically it relates to an improved methodology for resolving measurement slippage associated with intermittent or erratic flow conditions in order to enhance accurate gas well flow measurement. In addition it relates to a method for improving gas flow control, and concomitant to that, optimum gas reservoir recovery.
2. Description of the Related Art
Because the majority of gas wells are in a decline stage, and therefore flow intermittently, the conventional mechanical chart recording and electronic flow measurement inventions are inaccurate. The gas industry acknowledges that as much as 20 percent of natural gas production is not accounted for, and therefore not paid for, because of the inadequacies of the existing measurement systems. These inadequacies are primarily due to the fact that the majority of gas wells flow intermittently, while existing flow measuring mechanical circular chart recording and electric computer systems are designed to measure continuous flow. Currently, these mistakes cannot be corrected because the existing measurement systems do not provide raw data for an audit-trail for use in recalculating possible errors due to interpretations nor do they in any other way reproduce the actual flow results. Furthermore, in both of the state-of-the-art measurement systems, the recorded data which is available can be manipulated by either the gas producers or the gas purchasers in their favor. As is further detailed below, these measurement errors and the inability to fairly and reliably audit or correct them, are the main cause of disputes between gas producers and gas purchasers. In addition, the lack of audit-trail or analytical quality gas flow trending data which could provide historical profiles of gas reservoir and gas flow performance for each well prevents the gas producer from achieving effective control and optimization of the gas well. The lack of analytical quality trending data leads to faulty gas production practices, and as a result, most gas well reservoirs are poorly managed, and fail to allow for well production optimization.
The most commonly used gas flow measurement system is the mechanical multi-pen chart recorder system. It adequately meets the gas industry's flow measurement needs for accounting purposes if the well flows at a stable, constant rate. However, this situation is rare, due for example, to intermittent gas flow, line surging, and mechanical vibration at the chart, each of which can cause a solid band of ink on the chart, thereby obscuring the actual gas flow, and resulting in gas flow measurement slippage, i.e. improperly measured gas flow. Even in the absence of those conditions, the thickness of the ink track on the chart may cause errors of as much as 30 minutes. Furthermore, because of their lack of adequate detail, and because each person who integrates a chart will do it differently, since no raw data is available, circular charts are incapable of providing a reliable audit-trail. These and other short comings make chart recorders inadequate to provide accurate gas !low data, especially for wells with erratic gas flow, plus they provide no well control options.
With the recent advancements of computer technology, electronic flow measurement (EFM) systems which are capable of frequent sampling and flow integration have begone to be used to replace the circular chart and mechanical flow integration systems. However, the on-site EFM systems introduce different problems that may result in gas flow measurement slippage. First, it must be understood that EFM systems calculate gas flow based on data generated by transducers that convert line pressure, differential pressure and the temperature of the gas flow into electrical signals of about 1 to about 5 volts. These three variables are then converted to engineering numbers and are the basic gas flow variables used to determine gas flow volume using the industry wide accepted formula of the American Gas Association (AGA-3). These basic variables which are used in EFM systems at an on-site, i.e., remote, calculating computer provide some improvement in overall accuracy and timeliness of gas flow measurement, as compared to mechanical multi-pen chart recorder systems, but they create a new set of problems in accurately measuring intermittent gas flow. These problems include the total reliance on the signal from the differential transducer to determine the flow/no-flow condition of the well for gas pressure, because 0 inches differential pressure does not necessarily mean that there is "zero" or "no gas flow" without actual knowledge or determination of actual gas flow. Without going into excessive details herein, an EFM system calculates and accumulates an hourly average flow volume so long as both the line pressure and differential pressure are positive. In addition, for the EFM system to be accurate in flow integration of erratic or intermittent flow, the transducer must be unconditionally infallible, and the gas flow in an ideal condition of no turbulence. This ideal condition does not exist in nature, because, as the gas flow rate approaches or falls below a predetermined level, say 10 inches (of water pressure) of differential pressure, the relationship between the differential pressure and the actual flow becomes erratic. At that point, these systems are not reliable because they rely on a preset moving differential pressure zero (zero cut-off) reference to establish the integration or flow period. For reasons set forth in the STELA™ METHODOLOGY brochure, the accuracy of the typical EFM transducer can be in error by about 0.25% because of total accuracy and transducer drift. Typically, an EFM system sets the calibration of the transducer at, say exactly 1 volt for 0 inches of differential pressure, and the transducer reading can be in error by as much as say about 0.5 inches. Since the flow calculation is reliant on a differential pressure reading to establish a flow condition, this error causes problems. As a result, the gas flow could be shut off, while the EFM system continues to compute about 50,000 cubic feet of gas per day, and conversely, the flow could actually be 50,000 cubic feet per day, yet the transducer might indicate 0 inches of differential pressure, with the result that the EFM system would calculate no flow.
Furthermore, the current, but misguided, logic says that the accuracy of the flow computing system is based on the accuracy of the EFM flow transducers which measure line pressure, differential pressure, and temperature and the frequency and speed of the calculations. However, accuracy really depends on precise awareness of the integration period, that is, knowing when true flow/no-flow conditions occur and knowing the true differential pressure based on a dynamically adjusted true zero. Currently, it is a common practice of the pipeline operator to assume that the no-flow point must be established at a certain positive differential pressure value, which incidently ensures that any slippage is in favor of the purchaser. However, the imposition of such a zero cut-off prematurely cuts off flow calculation while the well is still flowing. This is the major cause of measurement slippage in EFM systems. Under other conditions, the zero base flow could also shift positively, and without a zero cut-off, show a difference of 20%.
The EFM systems convert all engineering values of flow variables, calculate, and store hourly flow volumes at the well head location, which is usually remote from the central operations office. Typically the raw data of the basic flow parameters are discarded during integration, thereby eliminating the audit trail capability of this system. Consequently, the raw data needed for reintegration is unavailable. As a result, recalculation of the local hourly averaged data will not match the average of the integrated flow result because of the square-root effect in the flow formula of the American Gas Association (AGA-3). That is, the sum of the square-root will equal the square root of the sum only if the line pressure and differential pressure remain constant, but in nature these pressures are not (constant in most wells. This lack of audit trail requires the field personnel to enter all of the calibration factors arid all data needed for the AGA-3 flow calculation before activation of the on-site EFM systems. This information along with the transducer readings allows the on-site computer to calculate flow. The result is an average hourly flow, even if the well was only open 30 minutes, that cannot be recalculated because the raw data has not been stored. Erroneous integrated results due to incorrect entry of the above data, are found to be very difficult to correct.
Not only is unintentional human error likely with the EFM systems, but, as set forth in the STELA™ METHODOLOGY brochure, the possibility of intentional manipulation exists. The hourly managed data provided by the EFM system further obscures the analytical quality data needed by the producer to operate and manage the production of the well.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide a method and system which is specifically designed to solve the gas flow measurement and control problems of the prior art chart and EFM systems.
It is another object of the present invention to provide to meet the two main objectives for gas well flow measurement and control of providing analytical quality data and event logs for production optimization, also to provide analytical quality data and event logs for accurate gas flow integration with complete audit-trail, and to leave gas well operational control to the field personnel and keep the accounting procedures in a central office.
The present invention specifically overcomes the disadvantages in the prior art discussed above. The method in accordance with the present invention basically includes at least a "remote component system" and a "host component system". The remote component system is located at the well head location, and is usually remote from the central operations office at which the host component system is located. The remote component system basically includes some form of electronic computer data logger, such as an electronic chart recording system. The electronic data logger of the remote component system is connected to transducers which measure and transmit line pressure, flow differential pressure, and temperature, all as analog data. In preferred embodiments, the remote component system is also connected to transducers which measure and transmit the gas well casing pressure and the pressure of the tubing immediately adjacent to the well head, also as analog data. The remote component system electronic data logger includes software to trend the analog data accurately, and a memory system to store in a retrievable format, as a function of time, the analog data so collected. To maintain measurement integrity the memory system also stores and logs digital data of precise events, such as valve positions, to indicate the actual period of gas flow, all as a function of time. The remote component system also includes a mechanism for transmitting, using a data compression technique, both analog trending and event log digital data to the host component system, which is normally located at the central operations office, upon request.
The system and method of the present invention is designed to specifically address the needs of the intermittently flowing well. It has no time span limitations. The well can be scanned from the host component system location in seconds for its current flow parameters, and, as a set of specific conditions are met, a control program can be caused to react to those conditions, for example under conditions of low flow pressure, by shutting down the well until certain pressure criteria are met, and then allowing the well to flow again. A computer program assists in the calibration of the sensors that monitor the vital temperatures and pressures of the well, thereby also minimizing maintenance cost. The auto-calibration and reintegration features in the system of the present invention methodology eliminate the problems due to the failure to accurately measure slippage gas, and can thereby either eliminate or provide data for use in settling disputes as to gas volume between the gas producer and the pipeline operator. The host software can also be loaded into a notebook computer and allows the user the portability of using the system in the field.
These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings, showing the contemplated novel construction, combination, and elements as herein described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and form a part of this specification illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which:
FIG. 1 is a schematic representation of gas well head incorporating transducer elements of the remote component system.
FIG. 2 is a simplified flow-chart of the remote component system of the present invention.
FIG. 3 is a simplified flow-chart of the host component system of the present invention.
FIG. 4 is an example of the system of the present invention Trend screen.
FIG. 5 is a flow-chart of an alternative embodiment of the remote component system of the present invention.
FIG. 6 is a flow-chart of an alternative embodiment of the host component system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
For the purposes of promoting an understanding of the principles of the present invention, reference will now be made to the embodiments and alternatives illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present invention is thereby intended. The embodiments illustrated and explained are exemplary only. Like reference numerals are used to designate similar structures in the views of the various figures. Alterations and modifications of the illustrated apparatus and methods, and such further applications of the principles of the present invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present invention relates are intended to be within the scope of the present invention.
Referring first to FIG. 1, a schematic representation of gas well head, generally 10, incorporating various transducer elements of the remote component system, and from which the typical blow down and separator elements have been removed for simplicity of exposition. Various pressure and temperature data is shown for representative purposes only. When the well is closed by valve 12, plunger 14 is normally at the bottom of the well tubing, not shown, but when valve 12 is opened, plunger 14 rises through the well tubing to the plunger arrival location 16 to push water, salt water, hydrocarbons and mixtures thereof from the tubing for disposal at blow down and separator elements, not shown. Gas can then flow through tubing 18 through to orifice 20 to provide a differential pressure reading at transducer 22, in the manner which is well known in the art. Downstream of orifice 20 are standard temperature transducer 24 and standard static line transducer 26. In addition, a casing pressure transducer 28 is connected to the well head at the top of the casing, not shown, and tubing pressure transducer 30 is located downstream of well head 10, but upstream of orifice 20.
Now referring to the simplified flow-chart of FIG. 2, the operation of the remote component system, generally 32, of the present invention will be explained. Analog and digital data is transmitted from transducers 22 (differential pressure reading), 24 (temperature transducer), 26 (static line transducer), 28 (casing pressure transducer) and 30 (tubing pressure transducer) are electrically connected to input device 34, and thence transmitted to data logging manager 36 for storage on any media, and for further transmission to memory archiving data compression and data management system 38. The compressed data is then transmitted to the host component system, generally 40, see FIG. 3. Transmission may be by remote telemetry system 42, as shown, or by direct wiring, which is normally not practical in view of the vast distance between the gas wells and the central operations office. Remote telemetry system 42 may most efficiently operate by means of a wireless or conventional phone line system, although other state-of-the-art transmission means, such as satellite transmission, may be used.
In preferred embodiments the data management system 38 can be programmed to activate control modules 44 to activate control outputs 46 to, for example, open and close valves in real time to optimize well output. The activation of control module 44 and control output 46 may be remotely controlled by telemetry from host component system 40.
Referring again to flow-chart FIG. 2, the remote component system of the present invention will continue to scan and save all active analog data received from transducers 22, 24, 26, 28 and 30 at a preset interval. As explained above, the data will be compressed and stored both in short term memory archiving data compression and data management system 38, for say about a one month duration, and optionally, in preferred embodiments, in a mass storage system 48, using state-of-the-art storage devices may be used to store data from the remote component system for the life of the well. One such preferred mass storage device is a PCMCIA card with up to 100 MB capacity or about 50 years of data storage. Event logs of digital status changes or software status changes will be time stamped and stored in Event log files. Referring now to flow-chart FIG. 3, the host component system of the present invention includes a telemetry driver 48 for receiving data from and sending data to telemetry driver 42. this data is then processed through memory archiving data compression AGA-3 flow calculation processor 50 from which it can be evaluated, for example in preferred embodiments by displaying it as a graphic display on graphic display user interface report generation monitor/input device 52. A representative example of the trend screen of the system of the present invention is shown in FIG. 4, and is discussed in additional detail below. As explained above, the data will be stored both in short term memory in module 50, again for say about a one month duration, and optionally, in preferred embodiments, in a host mass storage system 54, again using state-of-the-art storage devices.
In preferred embodiments, the system of the present invention host component system 40 includes a computer, say a personal computer running, for example Windows software, say versions 3.1 and higher, capable of uploading data from the system of the present invention remote component system 32, as well as downloading control strategies back to the remote component system 32, again by means of a wireless or conventional phone line system, for example. Specifically designed computer software, a sample of which is submitted with this application as computer microfiche, allows the host component system to splice the trending data seamlessly for the life of the well. The latest versions of AGA-3 and AGA-8 may be loaded along with software to handle flow calculation to determine gas flow volume. This provides an effective way to recalculate the gas volume for any time period using modified parameters or scaling factors, thereby providing a means which can be used to settle volume disputes between producers and pipeline operators. The system of the present invention host component system is essentially an electronic chart integrator with no retracing or human intervention required, thereby having high reproducibility, and no opportunity for human error. The raw database is maintained as a permanent record or audit-trail of the well.
The flow integration software is based on the event logging of the positions of valve 12, which controls the gas flow based on downloaded control strategy from the host component system 40 to determine when to start and stop flow calculation. The zero differential pressure, i.e. the millivolt reading of raw data before the valve is open, is used to scale the differential pressure values of the cycle. The differential pressure span uses the latest calibrated or manually input value as it displays on the event log of the calibration table. This application of the event logs to determine the flow period and the establishment of the actual differential pressure zero base of each flow cycle constitutes a system that eliminates gas measurement slippage caused by differential pressure zero shifting. Also the software allows insertion of the new parameters of scaling factors, gas composition, and basic flow data, thereby providing another invention that effectively expedites the reintegration process to settle any disputes between the producer and the pipeline operator.
The trend screen of FIG. 4, displays both analog data or process variable trends and the digital event logs along with records of calibration and control-strategy changes, provides critical historical data to effect production optimization. Time bars located at both the top and bottom of the screen can be scrolled to display data for the desired period. The top time bar displays the event logs by means of data blocks. Data blocks can be color coded for easy recognition. If more than a single event occurs at the remote location at the same time, the number of events which have occurred are displayed on a data block, i.e. "2" and "3" as shown at the top time bar. Icons to expand and contract the time scales are provided for the user to analyze and diagnose all the process variables on the trend screen.
Markers can be inserted on the screen, and the time span thus marked can be scrolled. Analog data is shown to be displayed beneath the bottom time bar, and event data is shown to be displayed along the top time bar. The display feature with the dual time bars to correlate the process variable and the event logs constitute an invention. The well control program will be activated only after the applicable control software and all configurable control parameters are downloaded from the host component system. The remote component system is equipped with control capability to modify a motorized choke, not shown, or to operate a bi-stable form of a solenoid valve 12 to control the flow of gas delivered to the pipeline. A motorized choke can be used to control a gas well production above 200 MCFD and bi-stable solenoid valve 12 is more effective for controlling a gas well with less than 200 MCFD. Also an alarm software package, allowing the remote component system to initiate transmission of an alarm message to the host component system 40 is a built in feature of the system. A state-of-the-art telemetry package is also provided to allow data exchange with a host component system computer loaded with the system of the present invention host component system software package.
Referring again to FIG. 4, when a gas well 10 is initially open to production, an inrush of gas will produce a sharp rise of the differential pressure 60, but static line pressure will remain unchanged. An immediate drop of both the tubing pressure 62 and casing pressure 64 will then be noted. After a flowing period, the casing pressure will slowly rise in response to liquid moving up through the tubing. A wide variation between the tubing pressure 62 and casing pressure 64 shows continued liquid build up. When the differential pressure 60 reaches a predetermined control limit valve 12 is closed to stop the gas flow. After valve 12 is closed and kept close, both the tubing pressure 62 and casing pressure 64 will increase until they reach stable points.
Referring again to FIG. 4, to the time upstream just before 12th hour, process variables differential pressure 60, tubing pressure 62. and casing pressure 64, show a characterization or signature of an pre-optimized well. After the 12th hour control parameter was downloaded to the remote system the characteristic of 60, 62, and 64 show the characteristic of the well trying to stabilize after a new control parameter was installed. The well characteristic after 16th hour, shows a stabilization of differential pressure 60, tubing pressure 62, and casing pressure 64 and this will become an optimized signature of the well. This optimized characterization will remain for a period of several months or longer.
Tubing pressure 62 can be used to diagnose leakage between the well head 10, separator (not shown) and line pressure 26. If leakage occurs, the tubing pressure profile will show a decline after the well is shut.
The above control strategies allow the well to produce gas at a rate that matches the ability of the reservoir and the line 18 or head 10 pressure. The event logs of the control strategies and the presentation of the process variable give the operator an effective tool to determine the optimum production control strategy for each well. The trending data produced by the process of the present invention shows if the well is optimized. Most wells, if properly optimized will remain optimized for at least several months. Since most wells have their own unique signature or trending profile, a trained operator can quickly diagnose any problem well through visual inspection of its trending profile.
FIGS. 5 and 6 are flow-charts of an alternative embodiment of the remote component system and the host component system of the present invention.
In the operation of the present invention, at a gas well head 10 at a remote well site transducers, and more specifically at least a differential pressure transducer 22, a temperature transducer 24 and a static pressure line transducer 26 are placed in analog electric signal transmission connection with a remote component system 32 installed at that remote well site. In preferred embodiments, casing pressure transducer 28 and tubing pressure transducer 30 are also placed in analog electric signal connection with the same remote component system 32. Remote component system 32 is commissioned with all of the calibration, gas flow parameters, and control configurations needed to operate the process of the present invention, for example in the form of the STELA software listing submitted herewith and incorporated herein, as though set forth in its entirety. The input device 34 scans, monitors and receives analog electric data signals from at least the differential pressure transducer 22, temperature transducer 24 and static pressure line transducer 26, as well any other transducers associated with the well head area 10 and linked to the remote component system 32. The remote component system 32 also receives digital electric event data signals from associated not shown end-devices such as a state-of-the-art tank level sensor, not shown, a state-of-the-art valve position sensor, a state-of-the-art plunger arrival sensor, and the like.
This data is then electrically sent to input device 34, and thence transmitted to data logging manager 36 both for short term storage, and in preferred embodiments, for further transmission to memory archiving data compression and data management system 38. As detailed below, the compressed data is then transmitted to the host component system 40, see FIG. 3, for example by remote telemetry system 42 for further processing. In preferred embodiments data management system 38 is programmed to activate control modules 44 to activate control outputs 46 to, for example, open and close gas head 10 well valve 12 in real time, rather than on an arbitrary schedule, thereby optimizing gas output from the well, and thereby, increasing both well efficiency and well life. In preferred embodiments the activation of control module 44 and control output 46 is also managed remotely by telemetry from host component system 40. In addition to these functions, In preferred embodiments the remote component system 32 continuously scans, at a preset interval, and saves all active analog data received from transducers 22, 24, 26, 28 and 30, and all digital data received from digital electric event data signal transducers 12 and 16. That data is then compressed and stored both in short term memory archiving data compression and data management system 38, for say about a one month duration, and in preferred embodiments stored in mass storage system 48 for the life of the well. Event data is stored in event logs as retrievable digital data which is time stamped. The data stored in the event log is then used to build up the trend files for both the process variables and event logs, as shown in FIG. 4. Remote component system 32 is in electronic communication with host component system 40. However, it should be noted that the remote component system 32 is fully capable of stand-alone operation. It does not rely op the host to function, and is a typical distributed architecture system design.
Referring again to flow-chart FIG. 3, the telemetry driver 48 of host component system 40 receives data from and sends data to remote telemetry driver 42. Data communication between the host component system 40 and the remote component systems 32 is in serial format, for example via the serial data port of an off the shelf computer and modem device, similar to the Internet system. Since most gas well sites do not have conventional phone outlets, wireless telemetry data is the preferred communication device. This data is then processed through memory archiving data compression AGA-3 flow calculation processor 50 where it is be evaluated, for example, by displaying it as a graphic display on graphic display user interface report generation monitor/input device 52, as shown in FIG. 4, and discussed in detail above. The data is then stored both in short term memory in module 50, and in preferred embodiments, in a host mass storage system 54. Host component system 40 includes a computer which is capable of uploading data from the system of the present invention remote component system 32, as well as downloading control strategies back to the remote component system 32. The specifically designed computer software, again for example in the form of the STELA software listing submitted herewith and incorporated herein, as though set forth in its entirety allows the host component system 40 to splice the trending data seamlessly for the life of the well. The latest versions of AGA-3 and AGA-8 are also loaded along with software to handle flow calculation to determine gas flow volume. This allows the recalculation of gas volume for any time period using modified parameters or scaling factors, and also provides a means which may be used to settle volume disputes between producers and pipeline operators. The system of the present invention host component system is essentially an electronic chart integrator with no retracing or human intervention required, thereby having high reproducibility, and no opportunity for human error. The raw database is maintained as a permanent record or audit-trail of the well.
The flow integration software is based on the event logging of the positions of valve 12 to determine when to start and stop flow calculation. The zero differential pressure, i.e. the millivolt reading of raw data before the valve is open, is used to scale the differential pressure values of the cycle. The differential pressure span uses the latest calibrated or manually input value as it displays on the event log of the calibration table. This application of the event logs to determine the flow period and the establishment of the actual differential pressure zero base of each flow cycle constitutes an invention that eliminates gas measurement slippage caused by differential pressure zero shifting. Also the software allows insertion of the new parameters of scaling factors, gas composition, and basic flow data, thereby providing another invention that effectively expedites the reintegration process to settle any disputes between the producer and the pipeline operator.
In preferred embodiments, communication from with the remote component system 32 to the host component system 40 is on an interrupted mode. But, for example, any alarm at the remote component system 32 is automatically reported to the host component system 40 immediately on a "report-by-exception" basis. The host component system 40 is normally located in a central operating office at which field personnel are present. The host component system 40 is programmed to scan a plurality, or effectively, all of the remote component systems 32 in the field that it is designed to control, to update the trending files of each well, to generate a field wide report of daily gas flow production data, all the related process variables, and any alarm events. This report, normally schedule to print each morning, may be quickly reviewed by the responsible field personnel to identify wells with abnormal conditions, such as alarm situations and unusual production. Analysis of the trends of these abnormal wells allows the responsible field personnel to quickly develop a corrective action plan. For example, some wells may need modified control strategies from the host component system 40 to the remote component system 32. Others may require on site visitation to correct the problems. The trending analysis provide by the system of the present invention also allows the responsible field personnel to take action on a preventive maintenance basis in order to prevent damaging events, such as liquid spillage or freezing pipe from occurring has been proven to be a very beneficial operating tool. In addition, the trending profile also provides diagnostic data to determine if the correct orifice meter size is in use.
Both the producer and the pipeline operator can share the raw database produced by the process of the present invention. The host component system 40 is capable of archiving the raw and integrated flow data for the accounting system of both the producer and tile pipeline operator. To optimize productivity of the gas well, reservoir trending of tubing and casing pressure profiles via casing pressure transducer 28 and tubing pressure transducer 30 are vital data for proper control strategy. To open the well, casing pressure must be allowed to build to a level where it must overcome the line pressure and liquid loading of the vertical tubing, not shown, to induce measurable gas flow. For a high volume gas well, say of over 200 MCFD, a variable choke valve 12 may be used to control the over ranging of the differential pressure and use the energy to extend the gas flow volume. For wells under 200 MCFD, an on-off valve 12 controlled by a state-of-the-art bi-stable solenoid is more effective in unloading the well at a cost of over ranging the differential pressure limit in the initial opening period. Once the differential pressure is detected to fall below about 10 or 15 inches, the remote system may be programmed to stop the gas flow by shutting valve 12. The ability to stop the flow of the well at a high differential value results in more accurate gas flow measurements, and also maintains a healthier gas reservoir pressure.
Accordingly, it is seen that several objects and advantages of the system of the present invention have been achieved:
a) Accuracy. With event logging of the position of the valves and the control software's action, the system of the present invention can pinpoint the exact flow period and, consequently, knows when to integrate data. FIG. 4 shows the display of event-logging of both the analog and digital data. The digital data including open and/or closed valve positions, the arrival time of the plunger, and the time-stamped record of the digital inputs are displayed along with the analog data. Unlike other solutions, this eliminates dependence on differential pressure data to determine on/off or flow/no-flow conditions. The system of the present invention avoids zero-shifting errors by simply stopping the flow calculation when the valve is shut-off. Therefore, the system of the present invention solves the zero shifting problem.
b) Calibration economy. The system of the present invention eliminates the costly calibration procedure of the flow measurement transducers. The system of the present invention achieves software calibration from the PC keyboard instead of on-site adjustment.
c) Data storage capacity. The system of the present invention eliminates storage and archiving limitations of the mechanical chart systems. The system of the present invention can store data for the life of the well. Archiving or searching the raw data trend can be easily accomplished by clicking the appropriate icons or buttons on the computer to select the desired data on the screen.
d) Does not rely on transducers for flow/no-flow determination. In systems that rely on transducers for flow/no-flow determination, the transducer must be absolutely infallible, and the gas flow must be in an ideal condition with no turbulence at the low end, i.e. below 10 inches of differential pressure. These conditions cannot exist because as the gas flow rate approaches or falls below 10 inches differential pressure, the data becomes erratic and unreliable. Also, transducers may lose accuracy over time. Therefore, since the system of the present invention does not rely on transducers, but rather on event logging to indicate precisely when valves are open or closed and the exact time of flow/no-flow periods the data is neither erratic nor unreliable.
e) Zero-shift correction. Unlike the electronic flow measurement systems that rely on the differential pressure sensor for no-flow cutoff, this invention provides computer software written to automatically and dynamically establish the true zero base, and therefore true differential pressure base, before opening the well to production on each intermittent cycle.
f) Retention of raw data. The system of the present invention logs raw analog data of the well's flow variables of line pressure, differential pressure, and temperature. The data are retained in original unscaled millivolt values. Therefore, reintegration with a modified scaling factor and zero base, as well as conversion to engineering values can be easily achieved with software. Measurement disputes can be resolved fairly because the original data can be retrieved and used for recalculation by both parties using the established AGA formulas.
g) Uncompromised audit trail Unlike the currently used chart recorders, the system of the present invention does not need to retrace or manipulate data. The original, raw data are available for the life of the well. Any need for recalculation can be met because the raw databases of line pressure, differential pressure, and temperature are easily accessible.
h) Programmed control instructions. Programmed instructions can shut in the well, in real time, when it falls below the accurate differential pressure range at about 10 inches and/or when other parameters (i.e.liquid loading problems) exist. These control actions maintain the flow at accurate ranges while maintaining a high bottom hole pressure. Exerting control over the principles of gas extraction can extend the life of the reserve while keeping the differential pressure at an accurate flowing rate.
k) Event logging. The event log is a time-stamped record of the digital inputs; for example, the valve open and closed positions or the plunger arrival status. This eliminates the dependence on differential pressure data alone to determine the on-off or flow-no-flow conditions.
l) Full graphical presentation of all vital analog and digital readings on a single screen. The trend screen, for example as shown in FIG. 4, displays color-coded temperature and pressure readings as a graph along the analytical time bar at the bottom of the screen. Corresponding values display in fields below the time bar. This data display provides the vital information needed for flow analysis.
Along the digital time bar at top of the screen, color-coded blocks identify specific well events. Each block marks an event that is logged on the bar at the time it occurs; if multiple events occur at a single time point, the block indicates the number of events. Examples of well events include plunger arrival, changes in valve position, changes in the level of the storage tank that stores produced water and distillate, changes in control parameters, application of AGA-3 parameters, calibration, and others. A message box can be opened at an event block on the trend screen which itemizes each well event in detail. For example, the message for a selected event block might inform the user that the well was shut-in on a specific date and time.
Should data require reintegration, the operator can specify the time span to be reintegrated by using a hairline marker available on the button bar. Data not visible on the screen can be accessed by a scroll button.
The graphical presentation of temperature and pressure data and the digital information available through event log detail provide both optimum flow analysis and indisputable measurement of continuous and intermittent flow.
Unlike the state-of-the-art circular chart recording which covers only eight days, the system of the present invention trend screen, such as in FIG. 5, has no such time limitation and seamlessly displays all process variables, including tubing and casing pressure trending profiles which yield valuable information about the reservoir performance. This invention allows the operator to analyze the well's behavior to determine the best strategy for flow control and elimination of slippage. With the precise stamping of the on-off valve position, the operator does not have to rely on arbitrarily assigned timing periods of opening and closing the well to flow.
Referring again to FIG. 4, this basic version of the trend screen, which is integral to the system of the present invention methodology and software package is used with software which is designed to duplicate the actual characteristics of analog and digital data with respect to time. By means of time stamping, the system of the present invention records the high and low peak values of the analog data for real time analysis. The system of the present invention methodology combines flow parameters of static line pressure, differential pressure, and temperature analog data, and shut-in tubing valve status as digital data, and software control operation to provide an auditable electronic flow measurement system for custody transfer of natural gas. The system of the present invention is capable of resolving measurement slippage associated with intermittent or erratic flow conditions. The system of the present invention also simplifies calibration procedure of the analog instruments because it retains the raw database for software calibration.
In preferred embodiments, the system of the present invention Trend screen provides easy to interpret and analyze color-coded well data. The user selects the analog data to display data such as casing pressure, tubing pressure, line pressure, or differential pressure, line or glycol temperatures, and so on, on the time line at the lower edge of the screen. The user can also select well events to be time stamped, i.e. records of digital inputs such as open and closed positions of the value or plunger arrival status, which are displayed on the time line at the upper edge of screen. With the two displays of analog data and digital data, the user of the system of the present invention methodology has precise measurements of flow, precise knowledge of the exact flow period, the ability to auto-calibrate analog instruments, and the ability to reintegrate raw data when corrections are needed, as for example, calculations based on the wrong size orifice plate or calculations based on erroneous gas parameters, could be easily corrected with this invention.
It is therefore seen that the present invention provides a highly reliable, more accurate, and more economical methodology that can be used to precisely measure flow volume without time span limitations, accurately pinpoint flow and no-flow situations, and retain raw data to ensure accurate reintegration. As a result, producers will benefit because production efficiency relies on the analytical quality of the flow and pressure trending of the well to diagnose production problems and optimize the liquid removal process, producers will benefit by having a tool to effectively plan a preventive maintenance schedule for the well and control the gas reserve. In addition, both the seller and purchaser benefit by being able to resolve disputes over unaccounted-for gas volumes through the reintegration process with full graphical presentation of all vital analog and digital components of the measurement system and a common raw database. The event logging of the digital data of on-and-off conditions of the valve or shut-in end-devices and trending of the flow parameters (static pressure, differential pressure, and temperature analog data) completely eliminate the measurement slippage problem. Because the trending data are unscaled or in the original raw format (millivolt values), reintegration, as well as rescaling flow or other parameters, is accomplished with software. Therefore, any disputes of the calculated flow data of any period can be quickly and easily resolved to the satisfaction of the seller and purchaser.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the host component system 40 of the present invention may be loaded into a notebook computer having a modem and will allow direct connection with the system of the present invention remote component system from any phone line or cell phone to interrogate or upload-download control strategies from or to the remote component system 32.
The foregoing exemplary descriptions and the illustrative preferred embodiments of the present invention have been explained in the drawings and described in detail, with varying modifications and alternative embodiments being taught. While the invention has been so shown, described and illustrated, it should be understood by those skilled in the art that equivalent changes in form and detail may be made therein without departing from the true spirit and scope of the invention, and that the scope of the present invention is to be limited only to the claims except as precluded by the prior art. Moreover, the invention as disclosed herein, may be suitably practiced in the absence of the specific elements which are disclosed herein. Accordingly, the teaching of the present invention is intended to embrace all such changes, modifications, and variations that fall within the spirit and broad scope of the appended claims.
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This system and Method serve as both a raw data logger for well operation analysis and a well event logger for well performance analysis. An improved methodology of remote event and process variable logging and data retention designed specifically to address the needs of intermittently flowing gas wells is useful for eliminating gas slippage associated with intermittent or erratic gas flow conditions, eliminating measurement errors, and lowering operating costs. The well data can be scanned in seconds for its current flow situation, and as a set of specific conditions are met, a built-in control program reacts to those conditions by shutting down the well until certain pressure criteria are met to allow the well to flow again. To maintain measurement integrity, precise event logging of the valve positions to indicate the actual flowing period are included in the flow integration. There are auto-calibration and reintegration features in the system methodology for eliminating slippage gas and eliminating settling disputes between the producer and the pipeline operator. Graphical presentation of event logs and process variable data allows the user to quickly and effectively diagnose and correct gas well problem. The same graphical presentation provides visual inspection and analysis to optimize gas well production.
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This is a continuation in part of a application filed Jul. 20, 1999, entitled Electron Bombarded Active Pixel Sensor, Ser. No. 09/356,800, invented by Aebi et al., and now issued as U.S. Pat. No. 6,285,018 B1.
FIELD OF THE INVENTION
This invention relates to devices and methods to image or detect useful images at low light levels utilizing passive pixel sensors in an electron bombarded mode using a photocathode for detection or imaging at low light levels.
BACKGROUND OF THE INVENTION
The copending parent application is directed to the use of active pixel sensors in creating images, particularly of low light level subjects. Active pixel sensor devices comprise a structure or system in which there is gain associated with each pixel in the production of viewable images. Although the use of active pixel sensors enables the production of images from very low light sources or the production of image frames at speeds extending present day capabilities of imaging at low light levels, the use of passive pixel sensors improves upon the sensitivity of certain active pixel sensor systems and thus can produce improved performance in certain low light level conditions. In imaging in which electrons strike the front surface of the pixel, those striking the surface of an active pixel sensor must pass through more transistors to be recognized as compared to the number of transistors encountered in a passive system. This is meaningless if the losses that occur are not important. However, in those systems where each electron is important to the final result and bombardment occurs at the front surface, then a passive system is likely to show less loss as compared to an active one. On the other hand if the amplification of the incoming bombarding electrons is more important to the results than the losses that may be incurred, then an active pixel sensor is to be preferred.
Additionally the use of passive pixel sensors simplifies the making or manufacture of the resulting system. These advantages will become more apparent as this invention is fully discussed hereinafter. For a complete understanding and discussion of the use of active pixel sensor systems, there is incorporated herein by reference the disclosure appearing in Ser. No. 09/356,800, the parent of this application.
Cameras that operate at low light levels have a number of significant applications in diverse areas. These include, among others, photographic, night vision, surveillance, and scientific uses. Modern night vision systems, for example, are rapidly transforming presently used direct view systems to camera based arrangements. These are driven by the continued advances in video display and processing. Video based systems allow remote display and viewing, recording, and image processing including fusion with other imagery such as from a forward looking infra-red sensor. Surveillance applications are also becoming predominately video based where camera size, performance, and low light level sensitivity are often critical. Scientific applications require cameras with good photon sensitivity over a large spectral range and high frame rates. These applications, and others, are driving the need for improved low light level sensors with the capability of a direct video output.
Image sensing devices which incorporate an array of image sensing pixels are commonly used in electronic cameras. Each pixel produces an output signal in response to incident light. The signals are read out, typically one row at a time, to form an image. Cameras in the art have utilized Charge Coupled Devices (CCD) as the image sensor. Image sensors which incorporate an amplifier into each pixel for increased sensitivity are known as active pixel sensors (sometimes referred to herein as APS). Image sensors without an amplifier incorporated in each pixel are known as passive pixel sensors (sometimes referred to herein as PPS). Both APS and PPS imagers belong to the general family of image sensing devices known as CMOS imagers. Active pixel sensors are disclosed, for example in U.S. Pat. No. 5,789,774 issued Aug. 4, 1998 to Merrill; U.S.Pat. No. 5,631,704 issued May 20, 1997 to Dickinson et al; U.S. Pat. No. 5,521,639 issued May 28, 1996 to Tomura et al; U.S. Pat. No. 5,721,425 issued Feb. 24, 1998 to Merrill; U.S. Pat. No. 5,625,210 issued Apr. 29,1997 to Lee et al; U.S. Pat. No. 5,614,744 issued Mar. 25, 1997 to Merrill; and U.S. Pat. No. 5,739,562 issued Apr. 14, 1998 to Ackland et al. Passive pixel sensors are disclosed, for example in U.S. Pat. No. 3,465,293 to Weckler; U.S. Pat. No. 4,631,417 to Brilman; and U.S. Pat. No. 5,345,266 to Denyer. Extensive background on passive and active pixel sensor devices is contained in the paper by Fossum, “CMOS Image Sensors: Electronic Camera-On-A-Chip”, IEEE Transactions on Electron Devices, Vol. 44, No. 10, pp. 1689-1698, (1997) and the references therein.
In general, it is desirable to provide cameras which generate high quality images over a wide range of light levels including extremely low light levels such as those encountered under starlight and lower illumination levels. In addition, the camera should have a small physical size and low electrical power requirements, thereby making portable, head-mounted, and other battery-operated applications practical. CMOS image sensor cameras (both APS and PPS) meet the small size and low power requirements, but have poor low light level sensitivity with performance limited to conditions with 0.1 lux (twilight) or higher light levels. Generally APS image sensors have greater sensitivity than PPS image sensors due to the inclusion of amplification in each pixel but amplification, as discussed above requires more transistors per pixel which in turn can result in more photon losses for optical imagers and electron losses for electron sensitive CMOS imagers, which can destroy utility for some applications.
Night vision cameras which operate under extremely low light levels are known in the art. The standard low light level cameras in use today are based on a Generation-III (GaAs photocathode) or Generation-II (multi-alkali photocathode) image intensifier fiber optically coupled to a CCD to form an Image Intensified CCD or ICCD camera. The scene to be imaged is focused by the input lens onto the photocathode faceplate assembly. The impinging light energy liberates photoelectrons from the photocathode to form an electron image. The electron image may, for example, be proximity focused onto the input of the microchannel plate (MCP) electron multiplier, which intensifies the electron image by secondary multiplication while maintaining the geometric integrity of the image. The intensified electron image may also be proximity focused onto a phosphor screen, which converts the electron image back to a visible image, which typically is viewed through a fiber optic output window. A fiber optic taper or transfer lens then transfers this amplified visual image to a standard CCD sensor, which converts the light image into electrons which form a video signal. In these existing prior art ICCD cameras, there are five interfaces at which the image is sampled, and each interface degrades the resolution and adds noise to the signal of the ICCD camera. This image degradation which has heretofore not been avoidable, is a significant disadvantage in systems requiring high quality output. The ICCD sensor tends also to be large and heavy due to the fused fiber optic components. A surveillance system having a Generation-III MCP image intensifier tube is described, for example, in U.S. Pat. No. 5,373,320 issued Dec. 13, 1994 to Johnson et al. A camera attachment described in this patent converts a standard daylight video camera into a day/night video camera.
In addition to image degradation resulting from multiple optical interfaces in the ICCD camera a further disadvantage is that the MCP is a relatively noisy amplifier. This added noise in the gain process further degrades the low light level image quality. The noise characteristics of the MCP can be characterized by the excess noise factor, Kf. Kf is defined as the ratio of the Signal-to-Noise power ratio at the input of the MCP divided by the Signal-to-Noise power ratio at the output of the MCP after amplification. Thus Kf is a measure of the degradation of the image Signal-to-Noise ratio due to the MCP gain process. Typical values for Kf are 4.0 for a Generation-III image intensifier. A low noise, high gain, MCP for use in Generation-III image intensifiers is disclosed in U.S. Pat. No. 5,268,612 issued Dec. 7, 1993 to Aebi et al.
An alternate gain mechanism is achieved by the electron-bombarded semiconductor (sometimes referred to herein as EBS) gain process. In this gain process, gain is achieved by electron multiplication resulting when the high velocity electron beam dissipates its energy in a semiconductor. The dissipated energy creates electron-hole pairs. For the semiconductor silicon one electron-hole pair is created for approximately every 3.6 electron-volt (eV) of incident energy. This is a very low noise gain process with Kf values close to 1. A Kf value of 1 would indicate a gain process with no added noise.
The electron-bombarded semiconductor gain process has been utilized in a focused electron bombarded hybrid photomultiplier tube comprising a photocathode, focusing electrodes and a collection anode comprising a semiconductor diode disposed in a detector body as disclosed in U.S. Pat. No. 5,374,826 issued Dec. 20, 1994 to LaRue et al. and U.S. Pat. No. 5,475,227 issued Dec. 12, 1995 to LaRue. The disclosed hybrid photomultiplier tubes are highly sensitive but do not sense images.
The electron-bombarded semiconductor gain process has been used to address image degradation in the ICCD low light level camera. A back illuminated CCD is used as an anode in proximity focus with the photocathode to form an Electron Bombarded CCD (EBCCD). Photoelectrons from the photocathode are accelerated to and imaged in the back illuminated CCD directly. Gain is achieved by the low noise electron-bombarded semiconductor gain process. The EBCCD eliminates the MCP, phosphor screen, and fiber optics, and as a result both improved image quality and increased sensitivity can be obtained in a smaller sized camera. Significant improvement of the degraded resolution and high noise of the conventional image transfer chain has been realized with the EBCCD. An EBCCD is disclosed in U.S. Pat. No. 4,687,922 issued Aug. 18, 1987 to Lemonier. Extensive background on EBCCDs is contained in the paper by Aebi, et al, “Gallium Arsenide Electron Bombarded CCD Technology”, SPIE Vol. 3434, pp. 37-44, (1998) and references cited therein.
Optimum low light level EBCCD performance requires a specialized CCD. The CCD is required to be backside thinned to allow high electron-bombarded semiconductor gain. The CCD cannot be used in a frontside bombarded mode as used in a standard CCD camera as the gate structures would block the photoelectrons from reaching the semiconductor and low electron-bombarded semiconductor gains would be obtained at moderate acceleration voltages. High acceleration voltages required to penetrate the gate structures would cause radiation damage to the CCD and shorten CCD operating life. Also a frame transfer format is required where the CCD has both an imaging region and a store region on the chip. The image and store regions are of approximately the same size. A frame transfer format is required for two reasons. First it is essential that the CCD imaging area have high fill factor (minimum dead area) if possible. The frame transfer CCD architecture satisfies this requirement. The interline transfer CCD architecture would result in substantial dead area (of order 70-80%). Any reduction in active area will result in lost photoelectrons. This is equivalent to a reduction in photocathode quantum efficiency or sensitivity. At the lowest light levels (starlight or overcast starlight), low light level camera performance is dictated by the photon statistics. It is essential that the maximum number of photons be detected by the imager for adequate low light level resolution and performance. Second a frame transfer format allows signal integration to occur during the readout of the store region in addition to any integration period. This allows charge to be integrated almost continuously maximizing the collected signal.
EBCCD cameras have several disadvantages. The frame transfer CCD architecture has the serious disadvantage for the EBCCD application of essentially doubling the size of the required vacuum envelope due to the requirement for image and store regions on the CCD. This requirement also means that the frame transfer CCD chip is more than twice the size of the image area. This substantially increases the cost of the CCD relative to interline transfer CCDs or active or passive pixel sensor chips as fewer chips can be fabricated per silicon wafer. EBCCD based cameras also have the disadvantage of backside illumination of the CCD which necessitates specialized processing to thin the semiconductor and passivate the back surface for high electron-bombarded semiconductor gain. This processing is not standard in the silicon industry and substantially increases the EBCCD manufacturing cost. The EBCCD cameras consume several watts of power due to the CCD clocking requirements and require external electronics for a complete camera. The size of the external camera electronics presents an obstacle to applications that would benefit from miniaturization of the camera. Finally CCDs require specialized semiconductor processing lines which are not compatible with mainstream CMOS semiconductor fabrication technology. This further increases the cost of CCD based cameras.
SUMMARY OF THE INVENTION
It is the object of the present invention to further improve upon these various disadvantages in the prior art and provide improved low light level imaging systems and corresponding processes using a passive pixel sensor. This may be achieved by utilizing a passive pixel sensor CMOS imager in an electron bombarded mode in a vacuum envelope with a photocathode sensor. The electron bombarded passive pixel sensor constitutes a complete low light level camera with the addition of a lens, housing, power, and a control interface.
It is accordingly another object of this invention to describe an improved low light level camera which makes use of a passive pixel sensor CMOS imager and direct electron bombardment.
It is yet another object of this invention to describe a novel chip or imaging circuit to facilitate the creation of light-weight structures when this imaging circuit employing passive pixel sensors is used which considerably reduces power requirements and enables improved devices for various and select low light level imaging applications.
Further features and embodiments 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 a schematic illustration of the architecture of a CMOS image sensor chip;
FIG. 2 is a schematic illustration of the architecture of a typical passive pixel sensor;
FIG. 3 is a schematic illustration showing an electron bombarded passive pixel sensor in a vacuum tube arrangement in accordance with the present invention.
FIG. 4 is a cross sectional view of a photodiode pixel structure;
FIG. 5 is a schematic illustration of a passive pixel sensor with an overlying light conversion layer; and,
FIG. 6 is an showing of an imaging system or camera illustrating an application of this invention.
DETAILED DESCRIPTION OF THE INVENTION
A CMOS image chip is illustrated in FIG. 1 . The architecture of a passive pixel sensor is shown in FIG. 2 .
Referring now to FIG. 1, there is shown a pixel array 11 controlled by a logic timing and control circuit 12 . The pixel array is, in this instance, comprised of an array of passive pixel sensors. Signals are processed by signal processors 13 which may comprise an analog signal processor and analog to digital converters. A column select control circuit is illustrated as 15 and the output signal is shown feeding from the pixel sensor array by an arrow designated 16 . The output at 16 may comprise a digital or analog signal depending on the system in which the pixel sensor is being used or to which the signal is being fed.
The pixel architecture used to form the individual pixels in pixel array 11 comprises a passive pixel structure discussed more fully in connection with FIG. 2 .
In FIG. 2 there is illustrated a passive pixel structure. The photoelectrons generated by the incident photon flux are collected on photodiode 200 . Photodiode 200 has been reverse biased by the voltage source 240 applied to column bus 230 which is applied when gate 210 of the normally off pass transistor 220 is pulsed by a voltage source to turn the transistor on and set the photodiode bias to the column bus voltage. The photogenerated charge is also sensed when the pass transistor 220 is turned on by applying a voltage pulse to transistor gate 210 . Timing and control of the voltage source is performed by a logic timing and control circuit 12 as is illustrated in FIG. 1 . The charge is amplified and the signal converted to a voltage by a charge integrating amplifier connected to column bus 230 as part of the analog signal processing circuit 13 (see FIG. 1) connected to the column bus 230 .
CMOS image sensor based cameras have significant advantages over charge coupled device based cameras. These advantages include: substantially higher levels of electronics integration with the majority of the required camera electronics integrated on the CMOS image sensor (either APS or PPS) chip where the electronics include integrated timing and control electronics; an order of magnitude or greater reduction in power requirements; use of low cost standard CMOS fabrication technology; substantial overall reduction in camera volume; and versatile image readout. Image readout modes can include window readout of subregions of the overall array or skip readout where every n th pixel is readout (n being an integer). In both of these modes only a fraction of the pixels are readout enabling higher frame rates.
Referring now to FIG. 3, there is shown an electron bombarded CMOS image sensor vacuum system or tube 33 in accordance with this invention. This system may comprise photocathode 31 (preferably a III-V semiconductor photocathode such as GaAs or an InP/lnGaAs Transferred Electron photocathode for high performance applications or a multi-alkali photocathode for lower cost and performance applications) in proximity focus with a specialized CMOS image sensor chip 32 which forms the anode of tube 33 . Photoelectrons 35 are emitted from photocathode 31 in response to incident light illustrated as arrows designated 36 . These electrons are transferred by an applied voltage. Typically the acceleration voltage 37 applied to photocathode 31 is negative with respect to the chip. This permits biasing of the chip to near ground potential for easy interfacing with other components. Control signals and bias voltages 38 are applied to the CMOS image sensor chip 32 and a video output signal 40 may be taken off sensor 32 . The base of tube 33 in FIG. 3 is a transparent faceplate 41 and tube sidewalls 39 extend between the transparent faceplate 41 on which the photocathode 31 is positioned and header assembly 34 , on which the CMOS imager chip is positioned. The header assembly 34 , also provides means for electrical feedthroughs for applying voltage 38 to the CMOS imager chip and for video output signals 40 from the chip.
The CMOS image sensor for this application is modified for electron sensitivity using the electron-bombarded semiconductor mechanism. The preferred embodiment is a front side electron bombarded mode to eliminate the requirement for backside thinning and passivation of the CMOS image sensor chip. The front side electron bombarded approach will result in the lowest cost electron bombarded CMOS image sensor component. However, it is important that low light level performance not be significantly compromised with this approach. This implies that the photodiode occupies a substantial percentage of the pixel area to allow a high pixel fill factor. Fill factors in excess of 50% are desirable for good low light level performance. A 50% fill factor would result in an equivalent low noise sensitivity for the electron bombarded CMOS image sensor to an image intensifier CCD system using a Generation-IlIl image intensifier.
A front side electron bombarded CMOS imager preferably uses a passive pixel structure as this results in the highest fill factor for a given CMOS process as only one transistor is required per pixel. This large fill factor allows potentially greater sensitivity in a CMOS image sensor with this approach versus the active pixel sensor designs. Also for a given required sensitivity level the passive pixel sensor system can obtain this with a smaller pixel size than if the active pixel sensor approach were followed. This enables a higher resolution CMOS Imager to be fabricated. This is not realized in practice for direct detection of photons as the passive pixel structure results in much higher read noise (two to three times higher) than is obtained in an active pixel design where amplification of the detected signal occurs in each pixel. This high read noise with the passive pixel design has resulted in use of this approach in low performance applications only. The situation is much different in the electron bombarded CMOS image sensor application. In this case the addition of low noise EBS gain prior to the CMOS readout noise mitigates the greater read noise with the passive pixel approach. Overall electron bombarded CMOS image sensor performance is now dominated by the photodiode fill factor.
This advantage can be directly evaluated by examining the signal-to-noise ratio (SNR) performance of the electron bombarded CMOS imager as a function of fill factor (ff), photocathode quantum efficiency (QE), photon flux incident on the photocathode (ø), EBS gain (G), and CMOS imager read noise (σ). The per pixel SNR of the electron bombarded CMOS imager is given by the following equation:
SNR=ff×QE×ø/sqrt (ff×QE×ø+σ{circumflex over ( )}2/G{circumflex over ( )}2)
It can be seen by examination of the equation that large EBS gain mitigates the CMOS imager read noise. SNR is proportional to the square root of the fill factor. Larger fill factor directly increases SNR allowing the passive pixel design with its larger fill factor to result in higher SNR performance than can be obtained with a front side bombarded active pixel sensor CMOS imager as only one transistor is required per pixel. This large fill factor allows potentially greater sensitivity in a CMOS image sensor with this approach versus one using active pixel sensor designs.
The photodiode as illustrated in FIG. 2 is desired to have high electron-bombarded semiconductor gain at relatively low electron acceleration voltages (preferably less than 2,000 volts). This minimizes radiation damage to the CMOS imager due to x-rays generated by electron bombardment of the silicon or overlying structures on the CMOS image sensor chip. Low voltage operation is also desirable to enable easy gating of the tube by control of the applied voltage. Furthermore it is desirable to shield adjacent CMOS circuitry from the electron bombardment by providing an overlying protective layer with conductivity to allow any charge accumulation to be drained, preventing damage due to electrostatic discharge. The shielding also reduces x-ray dose to the underlying CMOS circuitry.
High electron-bombarded semiconductor gain at low electron acceleration voltages requires elimination of any overlayers from the photodiode surface and good passivation of the semiconductor surface to minimize carrier recombination at the surface. This passivation can be achieved by a number of techniques known to the art. One standard technique is to form a thin doped region at the semiconductor surface. The thickness of this doped region is desired to be less than or equal to the electron range in the solid, preferably substantially less, at the desired operating voltage. For operation at 2,000 volts the electron range is approximately 600 Å for silicon. The approximate electron range in a solid is given by R G the Gruen range where
R G =400 E b 1.75 /ρ
R G is in angstroms, E b is in keV and ρ is in gm/cm 3 . For silicon the bulk density, ρ is 2.33 g/cm 3 .
The doped region is doped to have a greater free carrier concentration of the same carrier type than the underlying region. This increase in doping concentration forms a potential barrier which prevents the desired minority carriers from reaching the surface where they could recombine and not be collected by the reverse biased photodiode. Other techniques to form a potential barrier to prevent minority carriers from reaching the surface are known in the art. Passivation techniques are disclosed, for example, in U.S. Pat. No. 4,822,748 issued Apr. 18, 1989 to Janesick et al; and in U.S. Pat. No. 4,760,031 issued Jul. 26, 1988 to Janesick.
An alternate embodiment of this invention utilizes a backside bombarded CMOS image sensor chip. In this embodiment the CMOS imager chip is mounted face down and the silicon substrate is mechanically and chemically removed leaving a thinned CMOS image sensor chip.
A disclosure of how to thin the substrate in connection with CCDs appears in U.S. Pat. No. 4,687,922. This described method may also be used to thin the backside of a CMOS image chip structure and is incorporated herein by reference. In general back-thinning may be accomplished by thinning the substrate under sensitive areas.
A cross section of a photodiode pixel structure is illustrated in FIG. 4 prior to thinning of the substrate. The photodiode, 200 in FIG. 2, is indicated as region 55 in FIG. 4 . The CMOS circuitry composed of the associated pass transistor in the pixel (transistor 220 in FIG. 2) is contained in region 53 . First a rapid isotropic etching step is performed to remove a major portion of substrate 51 . For example, if the substrate is approximately 400 μm initially, this etch step will proceed until approximately 380 μm of the substrate layer 51 has been etched away leaving a thin layer of approximately 20 μm of substrate material. This etch step is performed with the aid of a solution of nitric acid, acetic acid and hydrofluoric acid in proportions of 5:3:3 or through the use of similar solutions known in the art. By rotating the substrate during this etch a final thickness of good consistency will be produced. A slow etch is then carried out in order to remove the remaining substrate material, stopping the etch in layer 57 . This leaves a layer which is on the order of 5 μm thick. This etch is done with the aid of a solution of nitric acid, acetic acid and hydrofluoric acid in proportions of 3:8:1, in the presence of hydrogen peroxide in the ratio of 5 ml per 350 ml of acid solution or using similar solutions known in the art. Doping differences between layers 57 and 51 are utilized to obtain etch selectivity. Etching is performed to assure good uniformity in thickness. After thinning of the CMOS image sensor the back surface is passivated to reduce the surface recombination velocity and ensure high electron bombarded gain at low operation voltages (<2 kV).
Substrate removal and backside passivation enables the photons and photoelectrons to be absorbed at a point sufficiently close to the source of potential and charge collection which in this embodiment is performed with a reverse biased photodiode to allow charges created to reach their destinations without bulk or surface recombination or lateral diffusion.
In the exposure mode, electrons from the photocathode are incident on the back face of the chip, similar to the case for the previously described EBCCD. Although this approach requires additional processing to mount and thin the PPS chip, advantages are that 100% fill factor may be obtained as no intervening structures are on the electron bombarded surface and potentially all of the incident photoelectrons may be detected by building in the appropriate electrostatic potential distribution into the solid by manipulation of doping profiles in ways known in the art. The potential distribution in layer 57 can be structured to deflect the generated electrons away from the CMOS circuitry to the photodiode. This allows the ultimate in low light level sensitivity.
An alternate embodiment of this invention utilizes a frontside bombarded CMOS image sensor chip coated with an electron-to-light conversion layer. This is now discussed in connection with FIG. 5 hereof.
This approach has the advantage of utilizing standard chips which have not been modified for direct electron sensitivity. A CMOS image sensor of this type is shown in FIG. 5 . Referring now to FIG. 5, there is shown a cross section of a passive pixel sensor with a front side electron-to-light conversion layer. The photodiode ( 200 in FIG. 2) is indicated as region 85 in FIG. 5 . The CMOS circuitry comprising the associated pass transistor in the pixel (transistor 220 in FIG. 2) is contained in region 83 . These structures are contained in substrate 81 . An optical shield layer 86 , is used to block light generated in electron-to-light conversion layer 84 from entering region 83 . Layer 86 may be fabricated from aluminum or other highly reflective metal to allow generated light to be reflected back into the light conversion layer where further reflections may result in the light reaching region 85 where it will be detected by the photodiode structure. The light conversion layer, 84 , is coated with an optically reflective, electrically conductive layer 82 . Layer 82 forms a conductive anode layer for the electron bombarded pixel sensor and allows the incident electrons to be collected and to drain off to the tube bias voltage supply. Layer 82 also blocks light generated in layer 84 from reaching the photocathode. If light from this layer reached the photocathode it would result in optical feedback and would add excess noise to the detected image. Typically layer 82 must attenuate light reaching the photocathode from layer 84 by at least three orders of magnitude or more to minimize optical feedback effects.
In this embodiment a standard CMOS image sensor chip may be used with application of the electron-to-light conversion layer and associated structure shown in FIG. 5 . Electrons accelerated from the cathode to anode are converted to photons by the conversion layer which are detected by the CMOS image sensor pixel. This screen would be deposited directly on the CMOS image sensor chip. In this approach layer 82 would be fabricated using aluminum which has the properties of good optical reflectivity and good electron transmission at relatively low incident electron energies. Optical reflectivity is important to allow more of the generated light to reach the photodiode for greater sensitivity. In this case light which strikes layer 82 may be reflected back to the pixel and be detected, increasing screen efficiency. Layer 84 may be fabricated using high efficiency phosphors such as P20 or P43, which emit in the green. Further optimization may be done by choosing a phosphor that emits light with a wavelength which matches the peak sensitvity wavelength of the CMOS image sensor. The conversion layer may comprise a standard metallized phosphor screen of the type known in the art.
Disadvantages of the approach using a conversion layer at the surface are lower resolution and higher noise as compared to the direct detection of electrons by the CMOS image sensor chip. Lower resolution results from light scattering in the light conversion layer which will result in pixel-to-pixel cross talk, reducing the modulation transfer function. Higher noise results from degradation in the excess noise factor due to the additional conversion step now incorporated with the light conversion screen. Higher noise will also result as the electron acceleration voltage will need to be substantially higher to achieve good overall conversion gain. This is due to inefficiency in the light conversion layer which typically requires voltages greater than 4 kV for good conversion efficiency. The high acceleration voltage will greatly increase the x-ray generation rate. X-rays detected by the photocathode will result in large noise pulses. The x-rays may also significantly shorten the pixel sensor chip lifetime due to radiation damage effects. Optimizing the light conversion structure for maximum efficiency, allowing lower voltage operation by using the techniques previously described can reduce noise effects.
Referring now to FIG. 6 there is shown an illustration of a camera in accordance with this invention intended to be illustrative of any number of different imaging systems. In this figure, 140 represents an image which is focused through lens 141 onto photocathode 142 . There is connected to photocathode 142 a voltage lead 143 from voltage source 145 . Voltage source 145 is also connected through lead 146 to CMOS image sensor 147 . A vacuum chamber 148 separates photocathode 142 from CMOS image sensor 147 . Walls 150 indicate the outer sealed walls of the chamber.
The camera arrangement shown in this figure is intended to illustrate a system useful in connection with this invention. What should be readily appreciated is the camera system may take many forms and may be modified as is known in the art for a particular application. Thus in a surveillance system, the image being captured may comprise the inside or the outside of a building area with the camera lens focusing images onto the photocathode which in turn in space wise configuration transfers the image to the CMOS image sensor which in turn may feed an output cathode ray system or alternate display for viewing of the image. As will be readily apparent, the image 140 may be viewed at a remote location or on a display integrated in the system to which the output of the passive pixel sensor is fed. Such a screen may located as shown at 154 as the output of the system.
A camera of the type illustrated is capable of imaging and reproducing images working at light levels as low as starlight but typically and preferably will be operated in brighter surroundings but such surroundings may be without adequate light for normal passage of persons at nighttime. This generally is more than adequate for most systems and needs and thus permits the setting of lower standards for certain components used in the system. In the case of applications demanding the full capability of low light level imaging such as for night vision purposes such as for helicopter applications where flying may be very low and concern may exist about accidents with either high buildings or trees or power wires, the system would be designed as illustrated and may include some of the unique approaches followed for night vision devices such as battery operations, helmet arrangements and the like.
In some scientific applications it is necessary to work in extremely dark conditions. Yet it is necessary for personnel to handle items without breakage. Night vision adjusted systems are most useful for these purposes. Other scientific applications require the ability to image light emission at very low levels or even to detect single photons. The described system is suitable for these applications.
While this invention has been described in terms of specific embodiments, it should be understood that there are various alternatives that may be employed in practicing this invention which will be apparent to those skilled in the art. It is therefore intended to broadly define this invention in terms of the following claims.
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A low light level image directed to a photocathode in a vacuum causes release of electron which bombard a CMOS imager including passive pixel sensors which in turn generates an electronic image which is fed out of the vacuum and is used to create useful images corresponding to the low level input image. A camera and other low light imaging devices are described.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a textile element for protecting a plastic support.
2. Description of the Related Art
It relates more particularly to a textile element intended to protect plastic pipes, of the polyamide pipe type, from abrasion.
This type of plastic pipe is used in particular in motor vehicles for transporting fuel from the tank to the engine.
In general, protective textile elements take the form of a textile sheath forming a sleeve around the plastic pipe. However, textile sheaths have a tendency to slide along their support, especially when the latter is made of polyamide, a particularly slippery material.
SUMMARY OF THE INVENTION
The present invention aims to solve the above problem and provides a protective textile element that can be immobilized on a plastic support.
For this purpose, the present invention relates to a textile element for protecting a plastic support.
According to the invention the textile is a knit and at least one portion of the textile element comprises a heat-bonding textile yarn.
Thanks to the use of a heat-bonding textile yarn, it is possible, by subjecting that portion of the textile element to the action of heat, to cause the heat-bonding yarn to melt and bond the portion of the textile element to the plastic support.
Thus, the textile element can be immobilized on the plastic support.
Furthermore, the knitted structure of the textile makes it possible, owing to its natural radial elasticity, for the textile to be applied perfectly on the plastic support and thus for effective bonding to be achieved when the textile yarn melts.
Preferably, the heat-bonding yarn melts at a temperature between 60 and 140° C. Furthermore, since the protective textile elements are generally exposed in use to temperatures of around 125-150° C., the heat-bonding yarn is preferably made of a thermosetting material, thus exhibiting good temperature behavior even when the textile element is raised to temperatures above the melting point of the heat-bonding yarn.
For example, the heat-bonding yarn is of the polyester and/or polyamide type, conventionally used in weaving to produce pieces of heat-bonding fabric for labels or welts.
Advantageously, the textile element takes the form of a tubular sheath, this being particularly well suited for protecting a plastic pipe.
To ensure that this tubular sheath bonds optimally, the heat-bonding yarn is preferably interlaced in the textile structure over at least one transverse portion of the tubular sheath. The heat-bonding portion of the textile element thus extends over a circular band of the tubular sheath.
In one particularly practical embodiment, the textile is a jersey knit or a rib knit.
Preferably, the heat-bonding yarn is a molleton yarn, allowing the heat-bonding yarn to be placed perfectly on one side of the knitted textile structure.
Other features and advantages of the invention will become clearer in the description below.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
In the appended drawings, given as non-limiting examples:
FIGS. 1 to 3 illustrate schematically a knitted textile structure suitable for being used in the textile element according to one embodiment of the invention; and
FIGS. 4 and 5 illustrate schematically, in longitudinal section, a textile sheath for protecting a plastic pipe, before and after bonding the sheath.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the invention will now be described with reference to the figures.
In this example, the protective textile element is a tubular sheath.
Of course, this protective textile element could have any shape provided that it can be obtained by a knitting manufacturing process.
In this embodiment, the textile element providing mechanical protection is produced by knitting, of the jersey knit type.
Other types of knitting could be used, for example rib knitting.
By using a knitted structure it is possible to improve the effectiveness of the meltable yarn. This is because the knitted textile element has a certain radial elasticity, unlike for example a woven structure that has no radial elasticity. Thanks to this elasticity, the meltable yarn is held in contact with the plastic while this meltable yarn melts, thus improving the bonding and the fastening of the protective textile element to the plastic support.
Furthermore, knitting techniques make it possible, unlike a braided structure for example, to position most of the meltable yarn on the inside of the textile element, that is to say on the side intended to come into contact with the plastic support.
In this embodiment, the function of the textile sheath is to provide mechanical protection for a plastic support.
This textile sheath for mechanical protection must therefore have a number of characteristics owing to its application as mechanical protection.
When this sheath is intended to protect a fuel pipe in a motor vehicle, it must have good abrasion resistance, a temperature resistance of around 125 to 150° C., and good resistance to the automotive fluid, which is liable to migrate through the plastic pipe.
For this purpose, the textile sheath comprises polyester or polyamide monofilaments. The diameter of the monofilaments used in the textile structure is determined according to the desired mechanical properties for the textile element, and especially the desired abrasion resistance.
These polyester and polyamide monofilaments furthermore have the advantage of shrinking slightly when they are heated.
As will be explained later, this temperature shrinkage makes it easier to mount the tubular sheath on the plastic pipe and to immobilize it by bonding.
Moreover, when acoustic properties are also sought for the protective textile element, the textile sheath may furthermore include PET (polyethylene terephthalate) multifilaments.
According to the invention a heat-bonding textile yarn is also used over at least one portion of the textile sheath.
For example, it is possible to use heat-bonding yarns, commonly used in weaving to make labels, pieces of heat-bonding fabric, welts, etc.
Given that the plastic support on which the protective textile sheath is intended to be applied is generally made of a polyamide, it is preferable for the heat-bonding yarn to melt at a temperature between 60 and 140° C.
To give an example, it is possible to use a heat-bonding yarn made of a thermosetting material, of the polyester and/or polyamide type.
A heat-bonding yarn of the polyester/copolyamide type is for example sold under the name GRILON®.
Of course, other heat-bonding yarns may be used by assembling a heat-bonding yarn with a non-heat-bonding yarn in various proportions.
In particular, it is possible to use a yarn sold under the name FILIX® composed of:
6% elastane; 40.5% GRILON® heat-bonding yarn; and 53.5% textured polyamide.
The heat-bonding yarn is interlaced in the textile structure of the sheath over at least one transverse portion of the tubular sheath so that at least one annular portion of this sheath has a heat-bonding textile structure.
Preferably, when only one portion of the tubular sheath includes a heat-bonding textile yarn, a heat-bonding yarn of the FILIX® type is used.
This FILIX® yarn comprises only 50% of meltable material, so that the other components of FILIX® do not melt at the temperatures used. Thus, after bonding, a certain mechanical strength is retained and the FILIX® yarn may be knitted on its own for a portion of the sheath.
However, when the tubular sheath comprises a heat-bonding textile yarn over its entire length, it is advantageous to use a heat-bonding yarn of the GRILON® type.
This GRILON® yarn is entirely meltable. Consequently, it must be knitted at the same time as another, non-meltable yarn.
In this embodiment, the textile used by the tubular sheath is a jersey knit. In order to add a heat-bonding textile yarn into the textile structure knitted from polyester or polyamide monofilaments, and possibly multifilaments, several knitting techniques may be used.
In particular when the heat-bonding textile yarn extends over the entire length of the sheath, the heat-bonding yarn is a molleton yarn. The heat-bonding yarn is used in circular knitting, inserted right through it, and does not mesh with the knitted textile structure.
An example of molleton is described in FIGS. 1 to 3 .
In these examples, the monofilament used for knitting the textile structure bears the reference 1 and the heat-bonding textile yarn bears the reference 2 .
This a 1/2 molleton in which there is an alternation of one interlocked stitch 10 and two float stitches 20 .
A jersey circular knitting process has the advantage of obtaining a seamless tubular product. The molleton yarn principle allows ideal deposition of the heat-bonding yarn inside the textile sheath.
In the illustrative embodiment, the molleton float is produced on two needles. Of course, it could also be produced on one or three needles. These are then referred to as a 1/1 or 1/3 molleton.
This molleton float process makes it possible to make a substantial saving of heat-bonding yarn used in the textile structure.
Various types of two-needle float are illustrated in FIGS. 2 and 3 . In FIG. 2 , the interlocked stitch is always produced on the same needle, whereas in FIG. 3 the interlocked stitch is shifted by one needle on each course of the knit. Preferably, the latter method of knitting, called two-needle float, is used in “diamond” fashion, allowing the visible surface of the heat-bonding yarn to be distributed over the inside of the textile sheath.
Of course, other processes could be used, of the plating type, allowing the fabric to be obtained with two different sides, each with one type of yarn, for example one side with a heat-bonding yarn and the other side with a monofilament.
Preferably, the gauge of the knitting machine cylinder, the needles and the closeness setting will be chosen so as to obtain a dense loop structure.
A dense knitted structure provides better abrasion resistance and a relatively rigid cylindrical sheath, thus making it easier to fit it onto a cylindrical pipe.
Furthermore, it is advantageous to knit a textile sheath with a diameter slightly greater than that of the plastic support so as to make it easier to fit the sheath onto its support.
This type of knitted sheath exhibits little longitudinal elasticity, while still containing a slight diametral expansion capability.
Other types of knitting may be used to produce a tubular sheath, in particular when only one or both end portions of the tubular sheath comprise a heat-bonding textile yarn.
It is then possible to use a circular jersey knitting process using a striper, allowing the knitted yarn to be automatically changed.
In practice, a certain length corresponding to a first end portion of the tubular sheath is knitted in a monofilament heat-bonding yarn of the polyester or polyamide type.
This first portion is followed by a length of jersey knit produced only from monofilaments, and possibly from multifilaments, in order to obtain a tubular sheath having mechanical protection properties.
This length of sheath is itself followed again by a length of jersey knit using a heat-bonding yarn along a portion that may correspond either to the first end of a second tubular sheath to be knitted, or to the second end of the first tubular sheath already knitted. A single portion using a heat-bonding yarn may be knitted so as thereafter to form, after the knitted sheath has been cut at this portion, both the second end of a first tubular sheath and the first end of a second tubular sheath.
This knitting process is most particularly valid for long sheaths, since the change of yarn for producing each of the portions requires the knitting machine to be stopped.
However, compared with the first process described, employing a molleton knit, this second knitting method makes it possible to achieve a not insignificant saving of heat-bonding yarn.
Or course, only illustrative examples of a sheath using circular knitting machines have been described here.
However, the tubular sheath could also be produced flat and then closed up by a seam along its longitudinal edges.
Furthermore, the invention is not limited to the production of a tubular sheath but may also apply to any other type of textile structure for mechanical protection.
An example of the use of a textile tubular sheath according to the invention will be described with reference to FIGS. 4 and 5 .
In this embodiment, the textile sheath 30 is of tubular form, including two end portions 31 , 32 produced from a heat-bonding textile yarn either using a molleton yarn or knitting the heat-bonding yarn using a tubular jersey process or a rib knitting process.
As already explained above, to make it easier to fit the sheath 30 onto a plastic pipe 33 , the inside diameter of the sheath 30 is slightly greater than the outside diameter of the pipe 33 .
Thanks to the action of the heat, illustrated by the arrows T in FIG. 5 at the end portion 31 , 32 of the sheath 30 , the heat-bonding yarn melts so as to allow it to bond onto the plastic pipe 33 .
Preferably, the monofilaments chosen exhibit a slight shrinkage with temperature during the bonding process. The monofilaments used in the end portions 31 , 32 shrink in such a way that sufficient pressure is applied by the tubular sheath 30 on the plastic pipe 33 , making it easier for bonding to take place.
This shrinkage effect is illustrated in FIGS. 4 and 5 , with the shrinkage of the end portions 31 , 32 being exaggerated compared within the main central portion 34 of the tubular sheath, so as to make it easier to understand the invention.
Preferably, the heat-bonding yarns used have a color that changes when the yarn melts in such a way that the operator carrying out the bonding operation can see with the naked eye that the heat-bonding yarn has melted and that the tubular sheath has bonded properly to the plastic support.
For example, the heat-bonding yarn may be white and becomes black or transparent after melting.
A textile sheath is thus obtained that can be immobilized on a plastic pipe of the type made of a relatively slippery polyamide.
Furthermore, when the tubular sheath according to the invention is used in a pipe conveying fuel between a tank and the engine of a motor vehicle, the operation of bonding the protective textile sheath may be incorporated during a pipe-forming cycle.
Of course, many modifications may be made to the exemplary embodiments described above without departing from the scope of the invention.
In particular, the tubular sheath could include only a single portion comprising a heat-bonding textile yarn, for example at one of its ends, or possibly in the middle of the sheath.
The textile sheath could also perform a thermal protection role.
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The invention relates to a textile protection element ( 30 ) for a plastic support ( 33 ) of knitted embodiment, comprising at least one section ( 31, 32 ) with a thermosealing textile thread ( 2 ). The above is particularly of use for protection of a plastic hose.
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TECHNICAL FIELD
This description relates to fault protection, and more particularly to traveling wave based relay protection.
BACKGROUND
Power transmission lines can carry alternating current (AC). When a fault occurs on a line, it is useful to rapidly determine the existence and location of the fault, so that protective measures can be taken before components connected to the line are damaged. The location of the fault also may be used in fixing the cause of the fault.
SUMMARY
In one general aspect, an apparatus includes at least one Rogowski coil and a processor. The at least one Rogowski coil is positioned within an electrical power distribution network to detect a first traveling wave current caused by a fault on an electrical power transmission line of the network, generate a first signal indicative of detection of the first traveling wave, detect a second traveling wave current caused by the fault on the transmission line, and generate a second signal indicative of detection of the second traveling wave. The processor is adapted to receive the first signal and the second signal and to determine, based on the first signal and the second signal, where on the transmission line the fault occurred.
Implementations may include one or more of the following features. For example, the apparatus can include a single Rogowski coil that generates the first and second signals, or a first Rogowski coil that generates the first signal and a second Rogowski coil that generates the second signal. The processor can be further operable to receive a timing synchronization signal. When a bus electrically connected to the transmission line, the second traveling wave current can be caused by the fault on the electrical power transmission line and can be reflected by the bus.
In another general aspect, an electrical protection apparatus includes a first Rogowski coil, a second Rogowski coil, and a protection device. The first Rogowski coil is positioned to detect a first traveling wave current on a first transmission line of a power distribution network and to generate a first signal indicative of a polarity of the first traveling wave caused by a fault within the network. The second Rogowski coil is positioned to detect a second traveling wave current on a second transmission line of the network and to generate a second signal indicative of a polarity of the second traveling wave caused by the fault within the network. The protection device is adapted to receive the first signal and the second signal and is operable to determine, based on the first signal and the second signal, where in the network the fault occurred.
Implementations may include one or more of the following features. For example, the protection device can include a relay and a processor. The apparatus can further include a circuit breaker operable to open in response to a signal from the protection device, where the signal is generated by the protection device upon the determination by the protection device of where the fault in the network occurred. The apparatus can further include a first circuit breaker positioned on the first transmission line and a second circuit breaker positioned on the first transmission line, where the protection device is further operable to cause the first circuit breaker, the second circuit breaker, or both circuit breakers to open in response to a determination by the protection device of where the fault in the network occurred. The apparatus can further include a busbar, to which the first transmission line and the second transmission line are electrically connected.
In another general aspect, determining the location of a fault on an electrical power transmission line includes receiving a first signal from a Rogowski coil positioned to detect a first traveling wave current caused by the fault, where the first signal is indicative of a time at which the first traveling wave is detected, receiving a second signal from a Rogowski coil positioned to detect a second traveling wave current caused by the fault, where the second signal is indicative of a time at which the second traveling wave is detected, and determining, based on the first signal and the second signal, where on the transmission line the fault occurred.
Implementations may include one or more of the following features. For example, the first signal and the second signal can be received from the same Rogowski coil, or the first signal can be received from a first Rogowski coil and the second signal can be received from a second Rogowski coil. A timing synchronization signal may be received, and, based on the timing synchronization signal, the first signal, and the second signal, a determination may be made as to where on the line the fault occurred.
The transmission line can include a bus electrically connected to the transmission line. At least one of the Rogowski coils can be adapted for detecting a traveling wave current caused by a fault on the electrical power transmission line that is reflected by the bus and can be adapted for generating a third timing signal indicative of a time at which the reflected traveling wave is detected.
In another general aspect, protecting a power apparatus from a fault in a power distribution network includes receiving a first signal from a first Rogowski coil positioned to detect a first traveling wave current on a first transmission line of the network, where the first signal is indicative of a polarity of the first traveling wave; and receiving a second signal from a second Rogowski coil positioned to detect a second traveling wave current on a second transmission line of the network, where the second signal is indicative of a polarity of the second traveling wave. The location of the fault in the network is determined based on the first signal and the second signal, and a current flow on a transmission line of the network is halted based on the determination of the fault location. The transmission line upon which the current flow is halted can be the first or second transmission line, or can be a transmission line in the network other than the first transmission line or the second transmission line. A first tracking pulse having a predetermined amplitude and width may be generated in response to a first detected traveling wave current that exceeds a predetermined threshold value, and a second tracking pulse having a predetermined amplitude and width can be generated in response to a second detected traveling wave current that exceeds a predetermined threshold value. Based on the first tracking pulse and the second tracking pulse, a determination may be made as to where the fault in the network occurred.
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 is a diagram of the temporal relations between the generation of traveling waves on a transmission line at a fault location and reflections of the traveling waves at points of impedance changes on the line.
FIG. 2 is a graph of instantaneous current on a transmission line shortly before and shortly after a fault in the line occurs.
FIG. 3 is a schematic view of a transmission line and two Rogowski coils used to measure current changes on the line.
FIGS. 4 and 5 are graphs of the instantaneous current and the instantaneous change in current on a transmission line on opposite sides of a fault in the line shortly before and shortly after the fault occurs.
FIG. 6 is a schematic diagram of a power network protection system.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
A fault in a power system causes traveling waves (TWs) that propagate through the system away from the fault location at velocities close to the speed of light. The TWs reflect at points where the impedance of the system changes. TWs can totally reflect, or can partially reflect and partially refract, with the refracted portion continuing to travel in the same direction. TWs have a fast rising front and a slower decaying tail, and have magnitudes that decrease with time. When TWs are generated, then both traveling wave voltages (TWVs) and traveling wave currents (TWCs) exist. TWCs can be used for fast relay protection and accurate determination of fault locations in power systems.
The surge impedance Z S of a transmission line is given by
Z s =√{square root over (L/C)} (1)
where L is the line inductance in Henries per unit length, and C is the line capacitance in Farads per unit length. Faults in power lines cause traveling waves that propagate along the line away from the fault. The velocity of a traveling wave, C TW , is given by
C TW =1 /√{square root over (LC)} (2)
and is approximately equal to the speed of light for most transmission lines. The traveling wave emitted from a fault has a traveling wave voltage (TWV or V TW ) and a traveling wave current (TWC or i TW ). At the instant of the fault, the TWV and the TWC are related by
V TW =Z s ×i TW , (3)
where V TW is the instantaneous voltage on the line, and i TW is the instantaneous current in the line.
After a traveling wave is emitted from the fault location, the wave propagates along the line until the wave reaches a point on the line where the impedance changes (e.g., a transformer or a bus). Because of the impedance change, the wave is reflected back along the line or is partially reflected and partially transmitted. The time at which individual reflections and transmissions occur on the line can be used to determine the location of the fault on the line.
For example, as shown in FIG. 1 , a transmission line 102 is connected to a first bus 104 , to a second bus 106 , and to two sources 108 and 110 . When a fault occurs at a location 112 on the line, traveling waves propagate away from the fault location 112 on the line 102 towards the buses 104 and 106 at a speed given by equation (2). When a traveling wave reaches a point of changing impedance on the line 102 (e.g., a bus 104 or 106 ), the wave is either reflected or partially reflected and partially transmitted. The amplitude, v r , of the reflected wave is
v r = Z b - Z s Z b + Z s v i , ( 4 )
where v i is the amplitude of the incident traveling wave, Z b is the impedance of the bus 104 or 106 , and Z S , as noted above, is the surge impedance. The amplitude, v t , of the transmitted wave is
v t = 2 Z b Z b + Z s v i . ( 5 )
When the impedance of the bus 104 or 106 is much smaller than the surge impedance (Z b <<Z s ), the reflected wave amplitude may be approximated as being equal to the incident wave amplitude (|v r |=|v i |), and the transmitted wave amplitude may be approximated as being zero (v t =0).
Because the ionized fault resistance at fault location 112 is usually much less than the surge impedance Zs, the traveling wave that reflects off bus 104 is totally reflected at fault location 112 and travels back to bus 104 , with a reversal of the polarity of the pulse. If the fault resistance has a higher value that is comparable to the value of the surge resistance, the TWC will not totally reflect at the fault location 112 , and, instead, will also be partially transmitted through the fault location 112 toward the bus 106 with a reduced magnitude as given in equation (5). The energy of the first incoming traveling wave to arrive at bus 104 is significantly larger than the energy of the wave that arrives at bus 104 after being reflected from bus 106 and transmitted through fault location 112 . This enables reliable differentiation between the reflected and transmitted waves. Similarly, the TWC that reflects off bus 106 will be partially reflected and partially transmitted by the ionized fault resistance at fault location 112 .
The arrival times of the TWCs at buses 104 and 106 are shown in the lower portion of FIG. 1 , where distance is measured on the horizontal axis and time is measured on the vertical axis. For example, the TWC emitted from fault location 112 at time t=t o in the direction of bus 104 (i.e., the first direct wave) travels at speed C TW =1/√{square root over (LC)} over a distance A and arrives at bus 104 at time t A1 =t o +Δt A . The speed, distance, and time are related by Δt A =A√{square root over (LC)}. The first TWC that is reflected from bus 106 and transmitted through fault location 112 arrives at bus 104 at time t A2 , which is defined as:
t A2 =t o Δt A +2 Δt B =t o +( A +2 B ) √{square root over (LC)},
where B is the distance from the fault location 112 to bus 106 . The first TWC that is reflected from bus 104 and from fault location 112 arrives at bus 104 at time t A3 , which is defined as:
t A3 =t o +3 Δt A =t o +3 A√{square root over (LC)}.
The second TWC that is reflected from bus 106 and transmitted through fault location 112 arrives at bus 104 at time t A4 , which is defined as:
t A4 =t o +Δt A +4 Δt B =t o +( A +4 B ) √{square root over (LC)}.
The initial TWC emitted from fault location 112 arrives at bus 106 at time t B1 , which is defined as:
t B1 =t o +Δt B +2Δ t B =t o +B√{square root over (LC)}.
The first TWC that is reflected from bus 106 and from fault location 112 arrives at bus 106 at time t B2 , which is defined as:
t B2 =t o +3 Δt B =t o +3 B√{square root over (LC)}.
The first TWC that is reflected from bus 104 and transmitted through fault location 112 arrives at bus 106 at time t B3 , which is defined as:
t B3 =t o +2 Δt A +Δt 3 =t o +(2 A+B ) √{square root over (LC)}.
The second TWC that is reflected from bus 106 and from fault location 112 arrives at bus 106 at time t B4 , which is defined as:
t B4 =t o +5 Δt B =t o +5 B√{square root over (LC)}.
FIG. 2 shows current waveforms recorded at buses 104 and 106 due to a fault at location 112 on an 80-mile long transmission line 102 (as shown in FIG. 1 ). The arrival of TWCs at bus 104 (referred to as “Bus A” in FIG. 2 ) and bus 106 (referred to as “Bus B” in FIG. 2 ) is also evident in the current waveforms shown in FIG. 2 . The fault simulated in FIG. 2 is a single-phase-to-ground fault in the A-phase of the AC transmission line that occurs at t o =0.5 ms at a distance of 50 miles from bus 104 near the voltage peak (at 500 μs, 79°) of an AC cycle. For simplicity, FIG. 2 shows only the currents measured on the A-phase line and omits representation of the currents on the B-phase line and the C-phase line.
The lower trace of FIG. 2 shows the current at bus 106 . The first incoming TWC pulse reaches bus 106 at t B1 =660 μs and produces an approximately 218 A positive step change in the line current. The first TWC pulse to be reflected by bus 106 and by fault location 112 reaches bus 106 at t B2 =980 μs. The first TWC pulse that is reflected from bus 104 and transmitted through fault location 112 arrives at bus 106 at t B3 =1199 μs and produces an approximately 75 A negative step change in the line current.
The third TWC pulse reflected from the fault location 112 reaches bus 106 at t B4 =1300 μs and produces an approximately 43 A positive step change in the line current.
The upper trace of FIG. 2 shows the current at bus 104 . The first incoming TWC pulse reaches bus 104 at t A1 =767 μs, and produces an approximately 206 A positive step change in the line current. The first TWC pulse to be reflected by bus 106 and transmitted through fault location 112 reaches bus 106 at t A2 =1090 μs and produces an approximately 88 A negative step change in line current. The second TWC pulse to arrive at bus 104 after being reflected from bus 104 and reflected by the fault location 112 produces an approximately 77 A positive step change in line current and reaches bus 104 at t A3 =1300 μs. The second TWC pulse to be reflected by bus 106 and transmitted through fault location 112 reaches bus 106 at t A4 =1413 μs and produces an approximately 23 A negative step change in line current.
The fault location 112 on the line 102 can be determined by measuring the time difference between the time at which the initial pulse is received at bus 104 and the time at which the second pulse, which is reflected from the bus 104 and then from the fault, is received at bus 104 . The distance, D, from the bus 104 to the fault location 112 is given by:
D
=
c
TW
×
(
t
A
3
-
t
A
1
)
2
.
(
6
)
In the similar way, the fault location 112 on the line 102 can be determined by measuring the time difference between the time at which the initial pulse is received at bus 106 and the time at which the second pulse, which is reflected from the bus 106 and then from the fault, is received at bus 106 . The distance, D, from the bus 106 to the fault location 112 is given by:
D
=
c
TW
×
(
t
B
2
-
t
B
1
)
2
.
(
7
)
The fault location can also be determined using synchronized measurements of the arrival times of pulses that reach buses 104 and 106 at the two ends of the transmission line 102 . The times can be synchronized by a GPS reference time signal available at each bus. Using arrival times of pulses at the two ends of the line 102 , the distance, D, from the bus 104 to the fault location 112 is given by
D = l - c TW × ( t A 1 - t B 1 ) 2 , ( 8 )
where l is the line length.
To reliably detect and time tag the arrival of a traveling wave, the TWC pulse must be filtered out from the current component corresponding to the fundamental power frequency (e.g., 60 Hz). The arrival of a TWC at a location on the line 102 (e.g., at bus 104 or 106 ) can be detected by a coil positioned on the transmission line 102 just before the bus 104 or 106 . The coil can be, for example, a Rogowski coil. Generally speaking, a Rogowski coil includes a conductive element that is wound around a non-magnetic core. The conductive element may be, for example, a metal wire or a metal deposit. The non-magnetic core may be made of any material that has a magnetic permeability that is substantially equal to the permeability of free space, such as, for example, an air core or a printed circuit board (PCB) on which the conductive element is traced.
The output voltage of a Rogowski coil is proportional to the rate of change of measured current (di/dt) enclosed by the coil. Thus, Rogowski coils are particularly sensitive to high-frequency components, and are able to amplify high-frequency signal components without using special filters. This unique feature of Rogowski coils makes them particularly suitable for measuring rapid current changes and for detecting TWCs.
As shown in FIG. 3 , a transmission line 302 is connected to power sources 304 and 306 and to buses 308 and 310 . Rogowski coils 320 and 322 are located on the transmission line 302 in close proximity to the buses 308 and 310 , respectively. The coils 320 and 322 can be constructed according to various techniques. Examples of such techniques are discussed in, for example, U.S. Pat. No. 6,313,623, titled “High Precision Rogowski Coil,” and U.S. Pat. No. 6,680,608, titled “Measuring Current Through An Electrical Conductor,” both of which are incorporated by reference. For example, the coils 320 and 322 can include two or more arms that form a main loop (or loops) of the coils 320 and 322 when coupled together. Various winding techniques for winding the conductive element may be used in constructing the coils 320 and 322 , and the coils 320 and 322 can include multiple coils that are associated with one another in various ways. These and other construction details related to the coils 320 and 322 may be selected so as to ensure high levels of sensitivity and accuracy in determining the current changes on the transmission line 302 .
The output signal from the Rogowski coils 320 and 322 , which can be located at a high voltage potential near the transmission line 302 , can be passed to electrical-to-optical converters 324 and 326 , respectively, and then transmitted by optical fibers 328 and 330 to optical-to-electrical converters 332 and 334 , respectively, which can be located close to electrical ground. Once the Rogowski coil signals have been re-converted to electrical signals, they can be further processed by processors 336 and 338 . Processors 336 and 338 can communicate with each other through a data transmission line 340 to compare the signals that they receive and generate.
Although the communications line 340 may communicate information between the processors 333 and 338 , there may nonetheless be some amount of delay in transmitting the various signals. When comparing current signals from the coils 308 and 310 , relative timing information for the current signals may be required in order to account for this delay (as well as other delays that may occur) so as to make a meaningful comparison of the current signals.
Such timing information can be obtained from various sources. For example, an external synchronizing network 342 (e.g., a network that provides a GPS clock) may be set up to provide timing information. Processors 336 and 338 can receive timing information from the synchronizing network, so that the arrival times of TWCs at Rogowski coils 320 and 322 can be compared to an absolute reference standard. As another example, the processors 336 and 338 may time stamp their respective current measurements before transmission of the measurements.
FIG. 4 shows an instantaneous current measurement 400 at a bus 308 at one end of an 80-mile long transmission line 302 along with the change in current 405 measured by the Rogowski coil 320 located close to the bus 308 . FIG. 5 shows the instantaneous current measurement 500 at a bus 310 at the other end of the transmission line 302 and the change in current measured by the Rogowski coil 322 located close to the bus 310 . When a fault occurs at a time t=500 μs, high-frequency transients are superimposed on the 60 Hz fundamental frequency in the current traces. The Rogowski coils 320 and 322 detect the changes in current and register signals that are proportional to the temporal derivative of the current. When the output signal of a Rogowski coil 320 or 322 exceeds a threshold value, processor 336 or 338 , respectively, generates a standard amplitude and width tracking pulse that can be used by timing logic within the processor 336 or 338 to determine the location of the fault on the transmission line according to equations (6) (7), or (8).
To achieve reliable fault detection, an instantaneous current level detector (ICLD), which can be implemented in hardware or software, provides a supervisory function by monitoring the instantaneous value of the current. Whenever a TWC having an amplitude within predetermined threshold values is detected by a processor 336 or 338 , the processor generates a standard amplitude and width tracking pulse. A relay that is operated in response to the detection of a TWC will not issue a trip command until the ICLD asserts and latches.
As discussed above, Rogowski coils may be used as the current sensing coils of FIGS. 3-5 . Rogowski coils are very sensitive to even low-level current changes, and, thus, are capable of, for example, detecting and initiating clearing of sustained arcing fault currents. Such fault currents generally are at a small fraction of the maximum available fault current, and are not much higher than the load currents themselves.
The ability to detect small current changes means that fault detection levels may be set relatively low, thereby reducing stress on (or damage to) equipment and speeding fault response times without sacrificing reliability. Moreover, a risk of fire propagation is reduced, and faster response times (including a faster restoration of service) may be provided.
Rogowski coils do not saturate, and, therefore, are capable of handling large currents and avoiding false tripping of circuit breakers in response to faults outside the protected zone. The ability of a particular Rogowski coil to avoid saturation may allow a-single Rogowski coil to provide current measurements over a wide measurement range, such as, for example, from several amps to several hundred thousand amps. As a result, such coils may be used to measure currents having a large DC component. Also, Rogowski coils may operate over a wide frequency range, such as, for example, from approximately 0.1 Hz to over 1 MHz. Rogowski coils also may be designed to provide a bandpass frequency response of up to approximately 200 MHz or more. Additionally, Rogowski coils are generally immune to external magnetic fields, and, therefore, may avoid any effects of such fields on current measurements. Moreover, Rogowski coils are relatively inexpensive and typically do not require substantial space or wiring. Finally, a Rogowski coil is easily installed by, for example, simply placing the relevant conductor through the coil (or by placing the coil around the conductor).
Because Rogowski coils are sensitive to changes in current, they can be used to detect a fault in less than one full 60 Hz cycle (i.e., 16.67 ms). As is evident from the example described above, because TWCs produced by a fault 112 propagate on the transmission line 102 at close to the speed of light, and Rogowski coils can detect a TWC with sub-millisecond accuracy, a Rogowski coil can detect a TWC indicating a fault in far less time than the time period of a 60 Hz cycle (i.e., 16.67 ms). Thus, one or more Rogowski coils can quickly identify a fault in a power transmission system and respond to the fault to protect the system (as explained in further detail below).
A differential busbar protection system using Rogowski coils is illustrated with reference to FIG. 6 . As shown, an electrical power system includes a busbar 602 electrically connected to a first power system 604 (e.g., a source or a load) by a first transmission line 614 and to a second power system 606 (e.g., a source or a load) by a second transmission line 616 and a third transmission line 618 . Thus, current can flow into the busbar 602 on line 614 and out of busbar 602 on lines 616 and 618 . During normal operation, the sum of currents flowing into the busbar 602 is equal to the sum of currents flowing out of the busbar 602 .
Rogowski coils 624 , 626 , and 628 are located close to busbar 602 and sense current and current changes in lines 614 , 616 , and 618 , respectively. A relay 630 electrically connected to the Rogowski coils 624 , 626 , and 628 and to circuit breakers 644 , 646 , and 648 located on respective lines 614 , 616 , and 618 serves to provide integrated protection against short circuits and other system malfunctions and/or failures, as described in more detail below. As such, the relay 630 may be programmed or otherwise associated with a predetermined algorithm for automatically implementing the integrated protection scheme. For example, the relay 630 can include an ICLD to monitor the instantaneous level of the current and to generate a standard amplitude and width tracking pulse whenever a TWC having an amplitude within predetermined threshold values is detected by Rogowski coils 624 , 626 , and 628 . The tracking pulses can be used to make logical decisions for protecting the network (as explained in more detail below). Although only one relay 630 is shown, two or more relays in communication with each other can be used in the system. For example, a separate relay can be associated with an individual Rogowski coil 624 , 626 , or 628 .
With regard to the protection system 600 , the relay 630 is capable of providing multiple types of protection against electrical or mechanical malfunctions and failures, and of integrating these types of protection into a cohesive protection scheme. Moreover, the relay 630 is capable of interacting with other relays and/or other coils in order to provide further options for constructing an integrated electrical protection system.
One type of protection afforded by the relay 630 is differential protection. In a differential protection scheme, the relay 630 operates to compare the currents on lines 614 , 616 , and 618 to check if the currents have some predetermined relationship to one another. As one example, when a fault occurs at busbar 602 or otherwise between coils 624 , 626 , and 628 , a transient current pulse is created on each of the lines 614 , 616 , and 618 . Because the fault occurs within the zone between coils 624 , 626 , and 628 , the transient pulses on each of the lines has the same polarity. In such a case, the relay 630 can determine that the fault is located within the zone and can trip each circuit breaker 644 , 646 , and 648 to protect the busbar 602 from overload due to power supplied from power system 604 or 606 .
As another example, when a fault occurs outside the busbar 602 , such as, for example, on transmission line 616 , the polarity of the transient pulse moving toward the busbar 602 (e.g., on line 616 ) will be opposite to the polarity of the transient pulse moving away from the busbar 602 (e.g., on lines 614 and 618 ). In such a case, the relay 630 can determine that the fault is located on line 616 because the polarity of the pulse detected by Rogowski coil 626 is different from the polarity of the pulses detected by coils 624 and 628 . Thus, relay 630 can trip circuit breaker 646 to protect the busbar 602 from the fault on line 616 but can allow power to continue to flow to/from power system 604 to busbar 602 on line 614 and to/from power system 606 on line 618 . Similarly, when a fault occurs on line 618 , relay 630 can determine that the polarity of the pulse measured by coil 628 is different from the polarity measured by coils 624 and 626 and, in response, can trip circuit breaker 648 while leaving breakers 644 and 646 closed.
As a further example, when a fault occurs upstream of coil 624 , the polarity of the pulse measured by coil 624 is different from the polarity measured by coils 626 and 628 . Based on this information, relay 630 can determine the location of the fault but need not trip any of the circuit breakers.
The relay 630 may be, for example, a microprocessor-controlled, multi-function relay, such as a three-phase relay having multiple voltage and/or current inputs. As discussed above, the relay 630 may be in communication with circuit breakers 644 , 646 , and 648 , companion relays (not shown), control equipment (not shown), and other circuit elements. For example, the relay 630 may be connected to a network switch/hub that supports having the relay 630 communicate with other relays in implementing an electrical protection system.
Using these and related techniques, electrical equipment may be protected from damage due to fault currents. Moreover, by placing the coils 624 , 626 , and 628 around selected pieces of circuitry/equipment, and thereby establishing the protection zones, a location as well as an existence of a fault current may be accurately detected. Additionally, a number of current sensors (coils) and relays may be minimized (relative to other electrical protection systems) so as to increase an ease of installation.
A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. Accordingly, other implementations are within the scope of the following claims.
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An apparatus includes at least one Rogowski coil and a processor. The at least one Rogowski coil is positioned within an electrical power distribution network to detect a first traveling wave current caused by a fault on an electrical power transmission line of the network, generate a first signal indicative of detection of the first traveling wave, detect a second traveling wave current caused by the fault on the transmission line, and generate a second signal indicative of detection of the second traveling wave. The processor is adapted to receive the first signal and the second signal and to determine, based on the first signal and the second signal, where on the transmission line the fault occurred.
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FIELD OF THE INVENTION
[0001] The field of the invention is multi-zone subterranean completions and more particularly those that are performed in a single trip where the gravel itself rather than an external packer provides zonal isolation.
BACKGROUND OF THE INVENTION
[0002] Producing zone completions involve insertion of a screen assembly that can be as long as several pay zones with long non-producing formations in between the producing zones. The surrounding annulus around the screens is filled with gravel using a tool called a crossover tool that takes the gravel slurry coming down the tubing string from the surface and redirects it out to the annular space below an isolation packer and outside the screen. The gravel remains in the annular space outside the screens while the carrier fluid goes through the screen and into a wash pipe connected to the crossover. The crossover allows the returning fluid to get through the isolation packer and back to the surface through the upper annular space above the isolation packer.
[0003] If the producing zones are far apart, the length of borehole between them is spanned by blank pipe and a packer that allows the screen sections to be properly located at the various producing locations. Typically the delivered gravel goes to the furthest (lowest) screen downhole and fills the annulus around it. When that screen is covered, the crossover tool and wash pipe are shifted to allow the setting of a packer in the annulus (between the two zones) to fully isolate the lower zone before further gravel deposition fills the non-producing zone. After the packer is set, pumping of the slurry is resumed, and gravel is deposited on top of the packer, while the returning fluid finds another path of least resistance and starts going through the next higher production screen as the lowermost screen now fully surrounded by gravel is said to “screen out” or resist flow to an extent that sends the returns to the next higher screen. This technique is illustrated in IACC/SPE 77214 by Corbett and Vickery entitled Multiple Zone Open Hole Gravel Packing Techniques with Zonal Isolation. It is limited to separating two zones with a packer in a single trip but is impractical for more than two zones.
[0004] US Publication 2008/0164026 shows a method of gravel packing multiple zones together and then setting packers into the gravel pack to isolate the producing zones.
[0005] What is needed and not available is a way to more economically perform a gravel pack of multiple zones that are spaced apart and get a good pack in an intervening non-producing zone while getting effective zonal isolation in the pack between the producing zones without employing packers. Those skilled in the art will appreciate each of the aspects of the present invention, some of which are individually listed above, from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be found in the appended claims.
SUMMARY OF THE INVENTION
[0006] Multiple producing zones separated by a non-producing zone are gravel packed together. The non-producing zone has locations to take returns so as to get a consistent pack in the non-producing zone. The production string features external seals and/or an internal plug so that no matter which producing zone is aligned to produce, the screens in the non-producing zone are selectively isolated so that the producing zone that is not intended to be produced has only the path through the gravel pack to get to the actual zone being produced. Since the annulus can be long and full of gravel this path will make flow from the zone that is not of interest minimal into the flow from the zone of interest without using a packer between pairs of spaced apart producing zones.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows two producing zones with a non-producing zone in between where the annulus is fully gravel packed;
[0008] FIG. 2 is the lower part of the production string that fits into the completion in FIG. 2 to isolate the screens in the non-producing zone and to make access between zones A and C possible only through the gravel pack in the annulus;
[0009] FIG. 3 shows the start of the gravel pack in zone C;
[0010] FIG. 4 is the view of FIG. 3 with the zone C gravel pack finished;
[0011] FIG. 5 is the view of FIG. 4 with the start of gravel packing zone B with returns coming through the screen in location 7 ;
[0012] FIG. 6 is the view of FIG. 5 with the gravel pack advanced beyond the screen in zone 7 ;
[0013] FIG. 7 is the view of FIG. 6 with the gravel pack advanced beyond the screen in zone 5 ;
[0014] FIG. 8 is the view of FIG. 7 with the gravel pack advanced into the producing zone A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 shows producing zone A separated from producing zone C by non-producing zone B. The entire illustrated wellbore is divided into regions 1 - 10 to simplify the discussion of how the gravel packing will proceed. It should be noted that while two producing zones A and C are shown separated by a non-producing zone B, the pattern can repeat and the distance between producing zones can vary and can be many meters down to a very small gap. The basic idea is to limit cross flow between zones A and C when only one is desired to be produced without using barriers in the annulus 12 below the production packer 14 . The annulus 12 is filled with gravel 16 . If only one of zones A and C are aligned to produce such as, for example if zone A is aligned to produce as indicated by arrows 18 and 20 , any flow from zone C indicated by arrows 22 and 24 will only be able to reach zone A through the annulus 12 , as indicated by arrows 26 . Zone C will not flow into producing screen 28 because the production string 30 can have a plug 32 at its lower end 34 when the string 30 has its lower end shown in FIG. 2 inserted into a sealing relationship with the production packer 14 shown in FIG. 1 . The string 30 has a sliding sleeve 38 to selectively cover port 40 . The sleeve 38 can be initially in the desired position and can be shifted with a known shifting tool either initially to open it as well as subsequently to close it to isolate any desired zone for a variety of reasons, such as when it produces excess water, for example. When the string 30 is inside packer 14 , the ported sub 36 is opposite screen 42 in zone A. If it is known from the beginning that zone A is to be produced first, the port 40 can be run in open and the plug 32 in position at the lower end 34 of the string 30 . While attaining a no flow condition from zone C to zone A when producing only from zone A would be ideal, there may be some minimal amount of infiltration from zone C to zone A through the gravel 16 in annulus 12 . The flow resistance between the producing formations A and C depends on many variables such as the distance between them, the density of the packed gravel, the fluid viscosity and the gravel particle size and void volume, to name a few variables.
[0016] One of the features of the invention is to get a good gravel pack in the zone B. Normally, there is just blank pipe and a packer between producing screens 28 and 42 in prior systems. This mean that when the gravel gets to the point of causing screen 28 to screen out, the slurry fluid that carries the gravel has to return to the surface from screen 42 as it then becomes the path of least fluid resistance. What this means is that gravel and carrier fluid separate at screen 42 and the gravel has only gravity to carry it down the annulus 12 below the producing screen 42 . As a result the pack density of the gravel 16 between screens 42 and 28 is not optimally high.
[0017] In the present invention, there are completion screens such as 44 , 46 and 48 located respectively at regions 7 , 5 and 3 . The spacing of these screens and their individual length can vary as can the number of such non-producing zone B seal bores 2 , 4 , 6 , and 8 . The screens 44 , 46 and 48 should be shorter than the production screens 28 and 42 due to their limited service during gravel packing but they can also be the same size or larger. The objective is that after screen 28 is covered by gravel 16 and the gravel packing continues, that there are enough return locations for the fluid carrying the gravel to return to the surface at different locations so as to continue to use the fluid velocity to carry the gravel 16 into the non-producing zone B as it fills the annulus 12 in a direction from screen 28 to screen 42 .This is shown graphically in FIGS. 3-8 . In FIG. 3 , the gravel covers about half of screen 28 and fluid represented by arrow 50 that carried the gravel in annulus 12 passes through the screen 28 and returns to the surface through the packer 14 and a crossover (not shown) through the annulus above the packer 14 . In FIG. 4 the screen 28 has screened out and the returns represented by arrow 52 enter screen 44 as the gravel 16 builds above the level of screen 28 and into the non-producing zone B. In FIG. 5 the gravel 16 has reached screen 44 . In FIG. 6 , screen 44 has screened out and returns represented by arrow now pass through screen 46 . In FIG. 7 , screen 46 has screened out and returns represented by arrow 56 go through screen 48 . In FIG. 8 , screen 48 has screened out and returns represented by arrow 58 enter through screen 42 . Continuing the gravel packing until screen 42 screens out will produce a fully gravel packed annulus 12 with gravel 16 over the top of screen 42 .
[0018] With the gravel pack complete as shown in FIG. 1 the crossover and any wash pipe attached (not shown) are removed and the production string of FIG. 2 is inserted into the packer 14 . When that happens, seal assemblies 60 , 62 , 64 and 66 are placed respectively in regions 2 , 4 , 6 and 8 so that every screen 44 , 46 , and 48 is straddled so that no flow can come through it. It essentially converts the portion of the completion in FIG. 1 between screens 28 and 42 into blank pipe. It also provides flow access into the string 30 through its lower end 34 if there is no plug 32 there so that flow can occur into screen 28 from zone C. Alternatively, the port 40 can be put into or already be in the open position to allow flow from zone A while shutting the lower end 34 with plug 32 to block flow from zone C into screen 28 .
[0019] The seal assemblies 60 , 62 , 64 and 66 can have one or more external seals to the string 30 . The seal type can vary as long as the objective of isolating the screens 44 , 46 , and 48 from flow is accomplished after the gravel packing is completed. Screens 44 , 46 , and 48 can be small openings of any shape size and number so as to prevent gravel from getting through during gravel packing. These screens are spaced apart so that the seal assemblies 60 , 62 , 64 and 66 can land on blank pipe to seal in regions 2 , 4 , 6 and 8 . The lower end 34 is in region 9 inside the screen 34 . If plug 32 is used it can be subsequently removed in a variety of ways. If desired, the zone A and C can be produced together. Any number of producing zones can be completed in this manner and produced in any desired order by manipulating sliding sleeves such as 38 in ported subs 36 that can be positioned in any of the producing zones. The lowermost zone is preferably produced through an opening at the bottom of the string 30 .
[0020] When the annulus 12 is tightly packed due to the presence in the non-producing zone of return screens 44 , 46 , and 48 the migration flow between adjacent producing formations can be as low as a few barrels per day or with optimal low pressure differentials between adjacent formations and long spacing between them it is conceivable to effectively get to a no cross flow situation between adjacent producing zones. Clearly, the longer the spacing and the smaller the open hole annulus and the tighter the gravel pack, the amount of cross flow between producing formations is minimized if not eliminated.
[0021] While production is mentioned through screens 28 and 42 , the term “production” encompasses flow in the reverse direction is contemplated such as in a fracturing mode or in an injection mode such as with steam, for example.
[0022] The above description is illustrative of the preferred embodiment and various alternatives and is not intended to embody the broadest scope of the invention, which is determined from the claims appended below, and properly given their full scope literally and equivalently.
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Multiple producing zones separated by a non-producing zone are gravel packed together. The non-producing zone has locations to take returns so as to get a consistent pack in the non-producing zone. The production string features external seals and/or an internal plug so that no matter which producing zone is aligned to produce, the screens in the non-producing zone are selectively isolated so that the producing zone that is not intended to be produced has only the path through the gravel pack to get to the actual zone being produced. Since the annulus can be long and full of gravel this path will make flow from the zone that is not of interest minimal into the flow from the zone of interest without using a packer between pairs of spaced apart producing zones.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 10/081,876, entitled: “Power Management for Wireless Peripheral Device with Force Feedback,” filed on the same day as the current application, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
The present invention relates to wireless peripheral devices, and in particular to wireless peripheral devices in communication with an intelligent host. More particularly the present invention is related to the establishment of the connection between the peripheral device and the intelligent host as well as the power management aspects of the wireless peripheral device.
Many peripheral device vendors have decided to cut the cord that connects the peripheral device with its host. For example, many vendors presently offer wireless peripheral devices such as wireless keyboards and computer input devices such as computer mice. Some have also provided wireless game controllers. The wireless game controllers typically communicate over a fixed 900 MHz band or via an infrared link. Infrared links require the device to be in the line of sight of its host to properly interface with the host, and thus is prone to losing connectivity. While the 900 MHz devices are an improvement over the infrared-type wireless devices, these devices have several shortcomings. For example, the prior art peripheral devices typically come prematched with a receiver, exchange data over a predefined and fixed frequency band and require the manual activation of a connect button to establish a wireless link between the peripheral device and its host. The fixed frequency operation of the devices, especially at the lower 900 MHz band are prone to interference problems from other consumer devices operating in the same frequency range.
Furthermore, these wireless devices typically require alkaline or rechargeable batteries as their power source. In addition, the ongoing incorporation of force feedback technology places bigger demands on battery life, by requiring power for the motors which play back the force effects. Efficient use of battery power, prolonged and predictable battery life and predictable device performance, while providing the user with sufficient feedback feel are essential features of any wireless peripheral device. Superior delivery of these features is likely to provide a peripheral device provider with the competitive edge needed to compete commercially with other competing products.
There is therefore a need for an improved and energy efficient wireless peripheral device.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a system and methods for the automatic establishment of a connection between a human interface device and a host transceiver unit, wherein the system includes a host transceiver unit configured to be connected with a host via a bus, and configured to wirelessly exchange data with a human interface device; a human interface device configured to wirelessly exchange data with a host transceiver; and a computer readable media having instructions thereon, wherein the instructions include routines for synchronizing the host transceiver unit and the human interface device for wirelessly exchanging data between the host transceiver unit and the human interface device at a spread spectrum modulation pattern which is determined by the host transceiver after the host transceiver unit and the human interface device have acknowledged each other's presence.
In one embodiment of the present invention, the routines for synchronizing the host transceiver and the human interface device include the broadcasting of a first signal at a first broadcasting pattern by the host transceiver unit in response to powering up the host transceiver unit, wherein this first signal is intended to be received by a human interface device. Additionally, the routines for synchronizing the host transceiver unit and the human interface device include routines for causing the human interface device to switch to broadcasting at a broadcast spread spectrum pattern matching that of the host transceiver unit after a receipt of a signal transmitted by the host transceiver unit by the human interface device, thus synchronizing said host transceiver unit and said human interface device.
Furthermore, embodiments of the present invention provide a method and a system wherein the host transceiver unit is configured to broadcast at one of a plurality of host spread spectrum broadcast patterns, each of which is a function of the host communication state; and wherein the human interface device is configured to broadcasts at one of a plurality of device spread spectrum broadcast patterns, which are a function of the device communication state; and wherein the host transceiver unit and the human interface device broadcast at a same spread spectrum broadcast pattern after the host receiver and the human interface device have acknowledged each other's presence.
For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the cordless Human Interface Device (HID) (“slave”) and the host receiver (“master”) incorporating the present invention.
FIG. 2 is a state diagram for the master device (host end of RF link) showing the communications states within which the master device operates.
FIG. 3 is a state diagram for the slave device (HID) showing the communications states within which the slave device operates.
FIG. 4 is a diagram illustrating an embodiment of the channel hopping sequences during various communications states for the master and the slave devices.
DETAILED DESCRIPTION OF THE INVENTION
Basic System
FIG. 1 is a block diagram 100 of the cordless Human Interface Device (HID) (“slave”) 106 and the host transceiver (“master”) unit 104 incorporating the present invention. The wireless HID slave device 106 communicates in a bi-directional manner with the host transceiver unit 104 via a wireless radio frequency (RF) link. In an exemplary embodiment, the wireless communication is carried over a 900 MHz frequency range and preferably over a 2.4 GHz frequency range. In other embodiments, the wireless communication is carried over other alternate or regionally available frequency ranges. The host transceiver 104 is connected via a communication bus 103 with an intelligent host 102 . The intelligent host 102 is enabled to execute an application program, which is configured to exchange data with various input and interaction devices, including the HID 106 . Data sent over the RF link may include HID input data for incorporation by a host application program (not shown) executing at the intelligent host 102 . Furthermore, data sent over the RF link may include commands originating at the host 102 for execution by the HID 106 . The various embodiments of the host 102 may include a personal computer, an interactive game console, a television set top box, a network computer, a workstation, a server, a router, a switch, a hub, a bridge, a network appliance, or any other intelligent host device where images, audio and data are displayed, further processed locally or over a network. The HID 106 includes a keyboard, a computer mouse, a computer trackball, an interactive gaming controller such as a joy stick, a wheel or a gamepad. The HID 106 includes an electronic camera or may optionally include actuation devices such as motors, magnets, linkages, and such for the imparting of force feedback feel effects to the operator holding the HID 106 . The bus 103 , may be a universal serial bus (USB), or an IEEE 1394 bus, or a parallel port, or other suitable communication link.
The host transceiver unit 104 includes a data serializer 108 such as an UART or other equivalent hardware or firmware enabled-device to convert the data stream being exchanged with the host 102 into a serial data stream. The data serializer 108 is coupled to a processor 110 , such as a microcontroller. The microcontroller 110 or alternately microprocessor processes all data being exchanged between the host 102 and the transceiver module 112 . In one embodiment, the transceiver module 112 is a commercially available 2.4 GHz transmit/receive module. Alternately, the transceiver module 112 is a commercially available 900 MHz transmit/receive module. Further alternate embodiments, use other commercially available transceiver modules communicating over other available frequency ranges. The transceiver module 112 prepares data for wireless exchange between the host transceiver unit 104 and the HID 106 via transceiver antenna 114 . Memory (not shown) is provided to enable the storage of data for use in conjunction with the microcontroller 110 and transceiver module 112 . One embodiment of the memory includes read and write memory (e.g., RAM). This memory stores data and program instructions for execution by the processor 110 , and stores temporary or other intermediate information during the operation of the processor. An embodiment of the memory also includes a read only memory (ROM) for storing information and instructions for the processor 110 . ROM memory also stores the firmware instructions necessary for the operation of the host transceiver unit 104 . In addition to the RAM and the ROM memory devices, FLASH, EEPROM and other memory arrays as deemed suitable may also be used.
Data being sent or received by transceiver antenna 114 is received or sent by the HID antenna 116 on the HID module 106 . In the description that follows the HID module includes a gamepad enabled to play back force-feedback effects issued from an application program being executed by the host. This gamepad embodiment is used for the description herein, since it includes input buttons 124 , a mini joy stick 122 , as well as motors 130 and associated linkages (not shown) and thus allows for a more comprehensive description of the functionality of a wireless HID in accordance with the embodiments of the present invention. This is for exemplary purposes only and is not meant to limit the scope of the claimed invention to only such an HID as other HIDs are within the scope of the present claimed invention. The HID antenna 116 is in turn coupled with the HID transceiver 118 . HID transceiver 118 prepares data for transmission from the HID 106 , and also prepares data received from the host transceiver unit 104 for further processing by the HID microcontroller 120 . Alternately, an HID microprocessor 120 may be used in place of the HID microcontroller 120 . HID microcontroller 120 is enabled to receive various inputs. HID microcontroller 120 receives input from an operator manipulating a mini joy stick. An operator's input using the mini joy stick is provided to the HID microcontroller 120 via the gamepad analog axis matrix 122 . The analog signal provided by the gamepad analog axis matrix is converted to digital by the analog to digital converter 123 . The HID microcontroller 120 also received operator input from various push button operations. The push button input data is provided to the HID microcontroller 120 via the gamepad button/switch matrix 124 . Data is read in from the gamepad button switch matrix via the general purpose input output (GPIO) interface 125 of the HID microcontroller 120 . Optionally, an appropriate analog to digital converter is used to convert analog push button inputs to digital signals. HID microcontroller 120 also sends drive commands to motors 130 via the same GPIO interface 125 for the playback of force-feedback effects. Battery module 128 is coupled with the power management circuit 126 which is configured to provide regulated power for the operation of the HID 106 . The power management aspects of the HID are described in further detail below. A memory device (not shown) is provided to enable the storage of information for use in conjunction with the microcontroller 120 and transceiver module 118 . One embodiment of the memory device includes read and write memory (e.g., RAM). This memory stores data and program instructions for execution by the processor 120 , and stores temporary or other intermediate information during the operation of the processor. An embodiment of the memory also includes a read only memory (ROM) for storing information and instructions for the processor 120 . ROM memory also stores the firmware instructions necessary for the operation of the HID 106 . In addition to the RAM and the ROM memory devices, FLASH, EEPROM and other memory arrays as deemed suitable may also be used.
Communication Protocol
The communication protocol for the HID in accordance with the present invention supports communication between a single host transceiver (“master”) and a single HID (“slave”), and is designed to allow multiple master/slave pairs to operate in close proximity on a single host.
In one embodiment of the present invention, transceivers are spread spectrum transceivers. Spread spectrum transceivers utilize spread spectrum modulation to modulate signals. Spread spectrum modulation spreads a relatively narrow band of transmitted frequency over a broad band with lower energy content to minimize noise and interference. More specifically, spread spectrum transceivers utilize a form of radio transmission in which the signal is distributed over a broad frequency range. This distribution pattern is based on either direct sequence coding or frequency hopping. In direct sequence coding, the information to be transmitted is modified by multi-bit binary codes, which spreads the signal out over a broader frequency range. The receiver knows the codes and thus it can decode the receiver signal. Alternately, in frequency hopping, a transmitter transmits at a particular frequency for a short time interval, then switches to another frequency for another short interval, and so on. The random frequency selection sequencing is determined by one of the transmitter or receiver and both transceivers follow the same sequencing.
In one embodiment, the communication is enabled between two 2.4 GHz transceivers—a master (host system end transceiver) and a slave (HID end), and the transmission is conducted via FSK modulation over the 2.4 GHz band, using a commercially available transceiver module using a channel-hopping algorithm. This communication protocol is adaptable to any method of data serialization that can be sent and received. With appropriate adjustments to the time division multiplexing “slot” length and the number of hopping channels (or no hopping at all), the communication protocol is useable with any microcontroller and in different RF bands. Alternately, the transmissions are carried out over a 900 MHz band using a commercially available transceiver module, or other frequency bands that may be available.
In one embodiment, the one-to-one master/slave relationship is maintained by requiring that each master “marry” an individual slave by sharing a random 8-bit “Marriage ID” and, once married, only communicate with that one slave. Alternately, other embodiments use a Marriage ID having more or less data bits. RF interference between different master/slave pairs is eliminated or minimized by the fact that all master/slave pairs are channel hopping, with different pairs using different hopping patterns, because the hop pattern is calculated using the unique “Marriage ID.” Bi-directional communication is enabled by the use of synchronized time slots during which the master and slave each have an opportunity to transmit for up to half of the slot period for time division multiplexing. This bi-directional communication is described in further detail below in conjunction with FIG. 4 .
Communications States
Masters and slaves start operation in the “Scan” state, with the goal of finding and synchronizing with an appropriate “mate.” Synchronization is achieved when the slave receives multiple master pings and responds to the pings, over a slave frequency hopping pattern which is the same as the master's. The term ping as used herein is as it is understood by those of skill in the art, where a ping is program that bounces a request off of another device to see if another device is still responding. If the master is not currently married or the user presses the “Connect” button on the master, it tries to synchronize using the reserved Proposal ID. Once synched, a master device generates and assigns a MID to the slave device for subsequent communication between the master and slave devices. If the master is currently married, it will attempt to synchronize using the MID of its mate.
In the Scan state the slave listens for a master that is pinging with an appropriate ID (e.g., proposal ID). To ensure that only the correct devices synchronize, a slave with a MID other than the Proposal ID will only respond to the Proposal ID if it sees the Proposal ID a certain number of times (e.g., three) without seeing its own MID. This ensures that a slave device that has previously been married can still connect with a master whose connect button has been pressed. Scanning devices that share a MID (including the Proposal ID) move to the Connected state.
In the case of a successful proposal connection (i.e., successful synchronization), the master generates a random 8-bit marriage token, or MID which is passed to the slave in a “Request” and stored in non-volatile memory on both the master and slave, completing the wedding.
FIG. 2 is a state diagram 200 for the master device (host end of RF link) showing the communications states within which the master operates. The master device moves between states as shown on FIG. 2 . Initially, the master device is connected with a host. In this initial state the host is powered off, and hence the master device is in the off state ( 202 ). Once the master device is powered on (e.g., the host device is turned on) ( 203 ), the master device moves to the scan state ( 204 ). In the scan state, the master device is frequency hopping in a scan hop mode, sending a proposal ID (or the MID of its mate) and attempting to marry or synch with a slave device. If a slave device acknowledges the pinging of the master device, the master (and slave) move (e.g., connect [ 205 ]) to the connected state ( 206 ). In the connected state ( 206 ), the master device broadcasts in the normal hop mode. Once a master has moved to the connected state it then moves to the reporting state ( 208 ), wherein the reporting state is a sub-state of the connected state ( 206 ). In the reporting state ( 208 ), the master device is frequency hopping in the normal mode. The transmittal of a “StartReport” packet ( 210 ) by the master device, starts the exchange of data between the master and the slave devices for sending and receiving position/button and motor data reports, and thus moves the slave and the master device to the Reporting state ( 208 ) from the connected state ( 206 ). StartReports ( 210 ) packets are sent by the master to tell the slave to go from the Connected state ( 206 ) to the Reporting state ( 208 ). StartReports packets ( 210 ) are valid only in the Connected state ( 206 ). Request packets ( 212 ) serve the same function as the Setup phase of USB Control transfers. They are sent only by the master, and are valid only in the Connected state (receipt of a Request by a slave in the Reporting state causes the slave to stop reporting and revert to the Connected state). When the devices are Connected and there is no request activity, the slave echoes periodically (e.g., every fourth Tick packet) back to the master. The periodic echo rate is a variable and can be more or less that every fourth packet, in different embodiments. This allows the master to detect and act on any loss of synchronization without excessive delay. “Lost synch” ( 214 ) is a condition defined by a predefined number of (e.g., five) consecutive attempts at communication with no response. In other words, if either device (i.e., master or slave) expects a packet from the other and that packet is not detected at the expected time (e.g., in five consecutive occasions) the device will revert to the Scan state ( 204 ). The expected packet and time depends on the current state and protocol stage. Lastly, the shutting down or powering off the host ( 216 ), will return the master to the off state ( 202 ).
FIG. 3 is a state diagram 300 for the slave device (HID) showing the communications states within which the slave device operates. The slave device moves between states as shown on FIG. 3 . The move from the Scan state ( 304 ) to the Connected state ( 306 ) occurs in conjunction with the master device, as described above. Initially, the slave device is in a Sleep state ( 302 ) where the slave device is off. The pressing of any button on the slave device ( 303 ) will move the slave device to the Scan state ( 304 ). In the scan state, the slave device is frequency hopping in a scan hop mode, and attempting to synchronize with the master by listening for the master's pings and acknowledging the master's pings. If a slave device acknowledges the pinging of the master device, the master (and slave) move (e.g., connect [ 305 ]) to the connected state ( 306 ). In the connected state ( 306 ), the slave device broadcasts in the normal hop mode. Once a slave has moved to the connected state it then moves to the reporting state ( 308 ), which is a subset of the connected state ( 306 ). In the reporting state ( 308 ), the slave device is frequency hopping in the normal mode. The transmittal of a StartReport packet ( 310 ) by the master device, starts the exchange of data between the master and the slave devices for sending and receiving position/button and motor data reports, and thus moves the slave and the master device to the Reporting state ( 308 ) from the connected state ( 306 ). StartReports ( 310 ) packets are sent by the master to tell the slave to go from the Connected state ( 306 ) to the Reporting state ( 308 ). StartReports packets ( 310 ) are valid only in the Connected state ( 306 ). Request packets ( 312 ) serve the same function as the Setup phase of USB Control transfers. They are sent only by the master, and are valid only in the Connected state (receipt of a Request by a slave in the Reporting state causes the slave to stop reporting and revert to the Connected state). When the devices are Connected and there is no request activity, the slave echoes periodically (e.g., every fourth Tick packet) back to the master. This allows the master to detect and act on any loss of synchronization without excessive delay. “Lost synch” ( 314 ) is a condition defined as a predefined number of (e.g., five) consecutive attempts at communication with no response. In other words, if either device (i.e., master or slave) expects a packet from the other and that packet is not detected at the expected time (e.g., in five consecutive occasions) the device will revert to the Scan state ( 304 ). The expected packet and time depends on the current state and protocol stage. Lastly, if the slave device is inactive for a specified time period, the slave device times out ( 312 ) and the slave device reverts back to the Sleep state ( 302 ). In one embodiment, “timeout” is defined as 10 seconds in the Scan state without detecting a master (pinging with either the device's MID or the Proposal ID) or 45 seconds in the Reporting state with no user activity (button presses or axis motion). Alternate embodiments, use different time periods to define a timeout event when in Scan or a Reporting states.
FIG. 4 is a diagram 400 illustrating an embodiment of the channel hopping sequences during various communications states for the master and the slave devices. Transmit periods are shaded, while receive periods are not. Note that a device is not necessarily transmitting for any or all of its entire transmit period, and may “listen” for longer than the receive period. “F(i)” indicates the transmit/receive frequency for the period. In one 2.4 GHz implementation, there are 79 channels (0 . . . 78), wherein each channel is 1 MHz apart. The master and slave distribute their communications among these channels by “hopping” from channel to channel in a random sequence of time slots that depends upon the current state (e.g., scanning, synchronizing or Connected and Reporting states) and the Marriage ID. For convenience, all hopping/slot times in the remainder of this description are specified in milliseconds, but they are actually implemented as multiples of 1024 μs. In other words, a “4 ms” slot is actually 4096 μs long. Initial connection and synchronization ( 402 ) (Scan state) is achieved using short slots of 2 ms (Scan Hop) on the master ( 404 ). The slave changes frequency every 8 ms ( 406 ) until it has found or synchronized with its master ( 408 ), at which point it hops together with the master at every 2 ms ( 410 ) slot until they arrange to move to the Connected state ( 412 ). The start of each packet from the master serves as the synchronization reference for the slave. In one embodiment, once synchronized, the slots are lengthened to 4 ms (Connected and Reporting states, or Normal Hop), which allows the use of longer packets.
Alternately (not shown), initial connection and synchronization (Scan state) is achieved using short 4 ms (Scan Hop) slots on the master. The slave changes frequency every 8 ms until it has found its master, at which point it hops together with the master every 4 ms until they arrange to move to the Connected state. The start of each packet from the master serves as the synchronization reference for the slave. In this alternate embodiment, once synchronized, the slots remain at 4 ms (Connected and Reporting states, or Normal Hop), which allows the use of longer packets. In addition to the time slots described above, other time slot configurations can be envisioned by those having the necessary skill in art of implementing a communication protocol, in accordance with the embodiments of the present invention.
Channel Hopping—Scan Hop: Scanning to Synchronizing
In one embodiment, when scanning, the master uses a 4 ms slot time, pinging in the first half and listening for a response in the second half, and then changing to the next frequency in the sequence, as shown in FIG. 4 . The slave also hops channels in the same sequence, but changes frequency every 8 ms. The difference in hop rates assures that the master and slave will be using the same frequency roughly every 105 ms. This time can be reduced by scanning on only a subset of the total available frequencies. As set forth above, in addition to the time slots described above, other time slot configurations can be envisioned by those having the necessary skill in art of implementing a communication protocol, in accordance with the embodiments of the present invention.
If the master is pinging with the slave's MID (or with the Proposal ID, and the slave does not detect its own MID), the slave will adjust its hopping clock and slot size to match the master slots, and then acknowledge (“ACK”} the master's ping, as illustrated in the “Synchronizing” diagram, as shown in FIG. 4 ( 410 ).
As shown in FIG. 4 , the F(j+6) ping is the first master transmission captured by the slave. The F(j+6) ping is the first frequency in this particular example where the master and the slave are respectively sending and receiving at the same time, and the ping is detected by the slave. At F(j+5) the master and the slave are also both on the same frequency at the same time, but the ping packet is not detected by the slave (e.g. due to interference, which is not shown). The slave will not transmit an acknowledgment until it has successfully received at least a certain number of (e.g., two/three) consecutive master pings. After a brief exchange using the 2 ms slot size (starting at t′+13), the master and slave move together to the Connected state and the Normal Hop mode.
Scan Hop Sequence
In one embodiment, the scan state channel hopping sequence is not randomized and both devices just cycle through the channel table (i.e., 0, 1, 2, 3, . . . , 78, 0, 1, 2, 3, . . . ).
Normal Hop
Once synchronization is achieved, the master and slave switch to the Normal Hop 4 ms slot time, as illustrated in the “Connected & Reporting” ( 412 ) diagram, shown in FIG. 4 .
Normal Hop Sequence
The normal hop sequence is determined by the master device and is dependent on the Marriage ID established by the master device. In one embodiment, the Normal Hop sequence is determined using the low 6 bits of the Marriage ID, such that:
Channel (next)=Channel ((current+HopSkip) MOD 79), where:
(HopSkip=Marriage_ID AND 0x3F), meaning that only the last 6 significant bits of the MID are used.
In addition, in certain embodiments, to improve spread spectrum performance, the firmware also checks to make sure that the HopSkip value is no less than 16, to reduce the probability of losing synchronization between the master and slave devices. Some forms of interference will affect multiple adjacent 1 MHz bands (e.g., devices using direct sequence coding), so forcing HopSkip to be greater than a particular value (e.g., 16) helps the master and slave devices to hop away from affected frequencies faster, which reduces the probability of losing synchronization between the master and slave devices.
In one embodiment, the master device always transmits at intervals of 4 milliseconds. The slave device uses the start of the first byte of each host packet as its slot reference time and calculates all other slot-synchronous times from this reference. In the reporting state, the master and slave do not necessarily transmit and/or receive in every slot, which reduces the power consumption of both devices. Other power management aspects of the present invention are described below.
While the communication protocols as set forth above describe exemplary embodiments where the host transceiver unit acts as the broadcaster in initiating a communication link with the human interface device, other embodiments of the present invention include those where the device that initiates the communication link is the human interface device and the initially responding device is the host transceiver unit. In other words, the master device can alternately be the human interface device and the slave device can alternately be the host transceiver unit. These alternate embodiments are also within the scope of the presently claimed invention.
Power Management
Various embodiments of the present invention are directed to the power management features of the wireless peripheral device (slave device). Since the device is wireless, and power is provided by batteries, maximizing battery life is a desired feature, which will provide for a prolonged use between battery replacements and thus enhance usability and hence operator acceptability. The power management aspects are directed to the communication protocol, the power supply and the force feedback devices (e.g., motors) used in the peripheral device.
In one embodiment, the wireless communication protocol is configured to transmit and receive as little as possible in order to conserve battery power. For example, information is sent from the slave device in short bursts instead of using a continuously transmitting protocol, thus having transmission active only for a portion of the time slot available for transmitting from the slave to the master device. In another embodiment, there is a power-down feature between information exchange bursts, wherein the power down feature, which is a power saving feature, is meant to include reducing device power down to a lowered power level such that the device is in a low power or standby mode. In yet another embodiment, a time-out feature automatically switches the device to a sleep mode after an extended period of inactivity. These as well as other power management features are described below in further detail.
Communication Protocol
The communication protocol is designed to transmit and receive as little as possible in order to conserve battery power. As described above, when the master and the slave device are in the connected and reporting mode, information is exchanged between the master and the slave at a periodic rate. For example, in one embodiment where the master and slave are frequency hopping at 8 msec time slots, the host system is sent an updated report from the slave device every 16 msec (the device is bi-directional having 8 msec for transmit and 8 msec for receive). Alternate embodiments use different time slot lengths for communications between the slave and the master devices. For each such reporting the device has a maximum amount of information to send, which in one embodiment includes approximately 200 bits of information. If this information was to be streamed at a rate of 200 bits every 8 msec, this would correspond to a baud rate of 25 kb/sec. However, the transmission rate of the device is designed to be much faster than this rate, and in one embodiment, is set to 250 kb/sec (instead of the 25 kb/sec). Having a transmit rate be approximately 10 times faster than a required data exchange rate means that the transmitter (and the corresponding receiver) need only turn on approximately 1/10 of the time per each update report. The remainder of the time, the transmitter and receiver are configured to be off or at a reduced power level (e.g. standby or low-power mode), thus resulting in substantial power savings.
In addition to the periodic updating (e.g., at 16 msec) of information from the device to the master, the device is configured to only transmit at the periodic rate only if the device has new information to send. Such new information typically includes button clicks, mini joy stick position information and other operator input actions. If the device has no new information to send, it will transmit at a reduced rate, which is enough to maintain the synchronized frequency hopping link with the host master. For example, the device instead of transmitting information to the host once every 16 msec, it will transmit to the host and receive an “acknowledge” signal from the host once at multiples of the time slot (e.g., every 5 timeslots). This reduced communication rate results in a further reduction in the transmit/receive duty cycle (by another multiplier, e.g., 5 times) during idle periods. The product of the reduced duty cycle and the powering off of the transmitter and receiver during non transmit/receive provides for even more substantial power savings.
In addition to the periodic updating, the short bursts of information exchange and the reduced update rate for idle periods, if the (slave) device is in an idle state for a predetermined time period (e.g., 2 minutes) the processor (e.g., microprocessor or microcontroller) will put the device in a sleep mode. In this mode, the transceiver (transmitter and receiver) and the processor are completely powered down such that the device is using a negligible amount of power from the batteries. For example, in the sleep mode, power is negligibly consumed to monitor the switch matrix for any button input activity. If there is activity, the processor will power itself up completely, power up the transceiver and re-establish the link (i.e., scan and connect) with the master and send the information (that caused the device to “wake up”) to the master device. Once awake, the slave device continues to send information at the periodic rates described above, or go back to sleep if the period of inactivity exceeds a predetermined time period, which in one embodiment is set at approximately 2 minutes.
The communication protocol also enables the transmission and reception of information in less than ideal circumstances, such as when for example, information that is transmitted is not fully received due to bad reception conditions. As in any wireless communication, bad reception can be caused by interference, a device going out of range and other known reception problems. The communication protocol is configured for the retransmission of bad data. These retransmissions take place in the “empty” time slots that are ordinarily not used to send data, since information is sent in short bursts at higher rates, yet the device is still in the time slot set aside for transmission. So, instead of sending one packet of information in each direction (to and from the host master) every say 16 msec, there may be anywhere from 1 to more depending on the severity of the interference.
Power Supply
In order to maximize the battery life of the device, certain embodiments of the present invention are specifically directed toward the power supply circuit of the slave device. In one embodiment, the device uses a processor that uses 4.5 Volts to operate. In the same embodiment, the device is powered with a battery pack comprising four AA cells, which when new provide 6 Volts. The battery pack is connected to a voltage regulator to provide a stable voltage as required by the processor, which in this embodiment requires 4.5 Volts. This way, excess battery power in not unnecessarily wasted, thus resulting in power savings and extended battery life. However, once the batteries are depleted to less than 4.5 Volts, they would ordinarily be considered spent. However, the device in accordance with the embodiments of the present invention uses a secondary power supply circuit that boosts a lower voltage (e.g., less than 4.5 Volts) up to a higher voltage level, thus enabling the continued use of the batteries for a much longer period of time; one that would not be possible without the secondary power supply circuit. In one embodiment, the secondary power supply circuit includes a “step-up converter.” In the embodiment having a 4.5 Volts microprocessor (or microcontroller) and a 6 Volts power supply, the use of the secondary power supply circuit enables the device to maximize the energy depletion of the batteries, until they are depleted to a much lower level, which is approximately 3 Volts in this embodiment. Thus, the combined use of the voltage regulator and the secondary power supply circuit enable a more efficient and prolonged usage of the device.
Force Feedback Device
Certain embodiments of the device in accordance with the present invention incorporate a force feedback feature. The force feedback enabled device “plays back” or provides a force, vibration or rumble effect to the operator of the device depending on the commands issued by an application or operating system program. Most typically, the force effect is provided by one or more DC motors. As described above, one embodiment of the device uses a power supply circuit providing a voltage range to the device which is between 3V and 6V, where 3V is the point at which the batteries can be considered completely used. Accordingly, the one or more motors are designed to operate over the same voltage range as that provided by the power supply circuit, which is 3V to 6V in an embodiment.
An essential factor in providing an operator with force feedback is to provide a sufficient level of feel to the user. This sufficient level of feel is a rather subjective criterion and one that may be different for different operators. The inventors herein having a high level of knowledge in the design and manufacture of force feedback enabled devices, have determined what a sufficient force level is and have designed the motors so that they generate a force level that is sufficiently satisfactory to the user, while only requiring a minimum available voltage level to generate such a force, which in an exemplary device is a 3V voltage level. This means that for this exemplary device, at 6V, when the batteries are new, they will generate more force than is required, which is a waste of energy. So, to conserve power and extend the useful life of the device between battery replacements, the device firmware is configured to monitor the battery voltage level and scale the drive to the motors to provide just the required force regardless of the battery level. So, for example, when the batteries are fresh and provide a 6V output, while the motors only require a 3V input, the scaling applied to the drive to the motors is approximately 50%. On the other hand, when the batteries are depleted to their minimum (e.g., 3V), the scaling applied is 100%. This combination of monitoring battery level and applying appropriate scaling will result in a substantially constant feeling for the user from the motors as battery voltage decreases over time. So not only, is the battery power not unnecessarily wasted, the force feedback feel that is provided to an operator is sufficiently adequate even when the batteries are nearly maximally depleted.
The scaling back of the power to the motors is enabled by a look up table stored in memory (firmware) that applies an appropriate scaling factor to the motor drives based on the battery level. The use of the firmware as opposed to a voltage regulator to step down the battery power before applying it to the motor drives itself provides additional power savings since a voltage regulator itself is not a 100 percent efficient and thus would undesirably deplete battery life.
In addition to providing the user with a sufficient level of feel at the most reduced battery level, it is also highly desirable to provide the user with sufficient warning when the battery level gets too low, so the user is enabled to stop the application program (or game) at a convenient place before completely losing device functionality due to a low battery level. This diagnostic feedback is provided to the user by way of activating appropriate visual indicators (e.g. LEDs) on the device. Since the firmware is monitoring battery level as described above, and hence knows the state of the batteries, the firmware will cause a warning to be flashed to the user, for example by using a visual indicator (e.g. an LED), when the battery level reaches a predefined level. In addition, the warning flash (e.g., “low battery”) may be another signal sent by the device to the host, which may be displayed to the user on the host's display device. If the user then continues to use the device in this “low battery” state, the firmware will at another lower predefined state disable the force feedback devices (e.g., motors). This powering off of the motors is done since the motors are one of the largest power users in the device. The powering off of the motors will give the user an extended period of time during which the user can continue to operate the device to save or stop the application program at a convenient location in the application program; but of course without motor functionality. These diagnostic features provide functionality to the user which is clearly advantageous to simply losing device functionality once the batteries are depleted to too low of a level.
Visual Indicator Behavior
In addition to the power savings embodiments described above, the device's visual indicator(s) (e.g. LEDs) are also designed to enhance the overall power management of the device. In an exemplary embodiment, the device incorporates LEDs to display various status information. Any change in device status (i.e., scanning, synchronizing, connected, sleep, wake, low power, etc.) is communicated to the user by way of briefly turning on a relevant LED and then turning it off again a few seconds later to conserve power.
As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, the slave device may include a computer mouse, a joy stick, a gamepad or other human interface device. Furthermore, the particular range of frequencies over which the slave and master devices hop or the particular channel hopping patterns may be different from those specifically described above. These other embodiments are intended to be included within the scope of the present invention, which is set forth in the following claims.
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A system and method for the automatic establishment of a connection between a human interface device and a host transceiver unit, wherein the system includes a host transceiver unit configured to be connected with a host via a bus, and configured to wirelessly exchange data with a human interface device; a human interface device configured to wirelessly exchange data with a host transceiver; and a computer readable media having instructions thereon, wherein said instruction include routines for synchronizing the host transceiver unit and the human interface device for wirelessly exchanging data between the host transceiver unit and the human interface device at a spread spectrum modulation pattern which is determined by the host transceiver after the host transceiver unit and the human interface device have acknowledged each other's presence.
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FIELD OF THE INVENTION
[0001] The present invention relates to a drill pipe connector and method and more particularly to a drill pipe connector and method that connects without rotation of the drill pipe and without requiring high make-up torque.
BACKGROUND OF THE INVENTION
[0002] In the exploration and production of oil and gas, drill pipe or a column of drill pipe (e.g., a drill pipe string) may be employed for a variety of purposes. On a drilling rig, the drill string is made up on the rig's platform. The drill string is run downhole and into the well bore. The drill string transmits drilling fluid (via mud pumps) and rotational power (via a Kelly or top drive) to the drill bit, which is part of a bottom hole assembly positioned at the end of the drill string. The drilling fluid is pumped down through the internal bore in the drill string, exits at or near the drill bit, and circulates back up the well annulus (void between the drill string and the well bore). The drill pipe string may also run casing, a liner, or a landing string downhole. The drill pipe string may also be used to work-over a hydrocarbon well. Drill strings can reach a length of 30,000 feet for a vertically drilled well and 35,000 feet for a deviated or horizontal drilled well.
[0003] The drill string includes a column of individual joints or segments of drill pipe threadedly connected together by threaded ends. A joint or segment of drill pipe may vary in length. Typically, the length of a drill pipe joint ranges from 30 feet to 33 feet. A joint or segment of drill pipe has a box member secured at one end and a pin member secured at the other end. The box member is internally threaded and adapted to receive the pin member of another drill pipe joint, which has external threads. Mating joints of drill pipe are interconnected via the threads to make up the drill string. The joints of drill pipe must be securely made up to prevent leakage, wobbling, or unscrewing. Typically, power tongs are used to transmit sufficient rotational torque to the pipe joints to ensure that the pin end is tightly threaded in the box end; this is called make-up torque. The amount of torque required depends in part on the specific frictional properties of the threaded connections. A higher friction coefficient means increased torque transmitting ability thereby lessening instances of tool joints unscrewing and having to be made up downhole. A lower friction coefficient with less torque transmitting ability may cause too much torque to be applied when making up the joints. Excessive torque could stretch or burst the box member or crack or break the pin member. This is undesired as drill pipe is expensive.
[0004] Pipe “dope” may be applied to the threaded connections of the joints to maintain a high coefficient of friction. The dope permits easier breaking down of the tool joints and helps prevent excessive make up. Despite the application of pipe dope, excessive make up and joint damage remains a problem. Moreover, the use of power tongs to make up pipe increases operational costs as additional equipment and personnel are required. The need exists for equipment and methods to connect drill pipe joints without rotating the drill pipe into itself.
SUMMARY OF THE INVENTION
[0005] It is an object of the present invention to provide a drill pipe connector and method that does not require rotation to make up the drill pipe.
[0006] It is a further object of the present invention to provide a drill pipe connector and method that eliminates the need for power tongs.
[0007] It is a further object of the present invention to provide a drill pipe connector and method that imparts tensile strengths.
[0008] It is a further object of the present invention to provide a drill pipe connector and method that achieves pressure integrity.
[0009] It is a further object of the invention to provide a drill pipe connector and method that is capable of transferring rotational torque.
[0010] These and other objects and advantages are achieved by the novel drill pipe connector assembly described herein, which may include a first drill pipe segment. The first drill pipe segment may include an outer surface and an inner surface. The inner surface may form a first bore. The first drill pipe segment may have a pin end. The assembly may also include a second drill pipe segment having an outer surface and an inner surface. The inner surface may form a second bore. The second drill pipe segment may have a connector end, which is adapted to receive the pin end of the first drill pipe segment within the second bore. The assembly may also include a connector nut interconnecting the first drill pipe segment with the second drill pipe segment. Such interconnection achieves fluid communication between the first bore and the second bore. The connector nut may also include an outer surface, an inner surface, an upper section, and a lower section. The lower section of the connector nut may be detachably affixed to the connector end of the second drill pipe segment. The upper section of the connector nut may operatively retain the pin end of the first drill pipe segment.
[0011] The inner surface of the lower section of the connector nut may include a first set of threads. The outer surface of the connector end of the second drill pipe segment may include a second set of threads. The lower section of the connector nut may be threadedly affixed to the connector end of the second drill pipe segment via mating engagement of the first set of threads with the second set of threads. In one embodiment, the first and second set of threads may each be wicker-type threads. In another embodiment, the first and second set of threads may each be breech lock-type threads.
[0012] The inner surface of the upper section of the connector nut may include a retaining shoulder. The outer surface of the pin end of the first drill pipe segment may include a beveled shoulder. The retaining shoulder may cooperatively engage the beveled shoulder to operatively retain the pin end of the first drill pipe segment.
[0013] In another embodiment, the drill pipe connector assembly may include seal means. For example, the outer surface of the pin end of the first drill pipe segment may include one or more seal means forming a pressure seal between the outer surface of the pin end of the first drill pipe segment and the inner surface of the connector end of the second drill pipe segment.
[0014] In a further embodiment, the pin end of the first drill pipe segment may include a first rotational torque transfer profile. The inner surface of the connector end of the second drill pipe segment may include a second rotational torque transfer profile. The first and second rotational torque transfer profiles may operatively engage each other to transfer torque from the first drill pipe segment to the second drill pipe segment via the interconnection provided by the connector nut. In another embodiment, the pin end of the first drill pipe segment includes a distal end. The distal end may contain the first rotational torque transfer profile. In a further embodiment, the first rotational torque profile may include a first lateral surface and a tapered surface. The second rotational torque profile may include a second lateral surface and a second tapered surface. The first and second lateral surfaces and the first and second tapered surfaces may cooperatively engage each other to transfer the rotational torque through the drill string as a result of drilling or other operations.
[0015] The present invention is also directed to a method of making up drill pipe. The method may comprise providing a drill pipe connector assembly as previously described herein. The method may further include the step of stabbing the pin end of the first drill pipe segment into the connector end of the second drill pipe segment so that the first bore and the second bore are placed in fluid communication. The method may further include the step of detachably affixing the lower section of the connector nut to the connector end of the second drill pipe segment. The method may further include the step of causing the upper section of the connector nut to operatively retain the pin end of the first drill pipe segment. The method may further include the step of causing the seal means or plurality of seals to operatively seal the assembly to prevent leaking of a pressurized fluid flowing through the first and second bores.
[0016] In a further embodiment of the method of the present invention, the step of detachably affixing the lower section of the connector nut to the connector end of the second drill pipe segment may be accomplished by threadedly affixing the lower section of the connector nut to the connector nut end of the second drill pipe segment via mating engagement of the first set of threads with the second set of threads. Alternatively, the detachably affixing step may be accomplished by snap locking the lower section of the connector nut to the connector end of the second drill pipe segment via mating engagement of the first set of wicker-type threads with the second set of wicker-type threads. Alternatively, the detachably affixing step may be accomplished by rotating the lower section of the connector nut to the connector end of the second drill pipe segment via mating engagement of the first set of breech lock-type threads with the second set of breech lock-type threads via ½ turn of the connector nut.
[0017] In a further embodiment, the step of causing the upper section of the connector nut to operatively retain the pin end of the first drill pipe segment may be accomplished by positioning the retaining shoulder of the connector nut in cooperative engagement with the beveled shoulder of the first drill pipe segment to operatively retain the pin end of the first drill pipe segment.
[0018] In yet a further embodiment, the step of causing the seal means to operatively seal the assembly to prevent leaking of the pressurized fluid flowing through the first and second bores may be accomplished by causing the plurality of seals to form a pressure seal between the outer surface of the pin end of the first drill pipe segment and the inner surface of the connector end of the second drill pipe segment.
[0019] In an alternative embodiment, the method may include the step of causing the first and second rotational torque transfer profiles to operatively engage in order to transfer rotational torque from the first drill pipe segment to the second drill pipe segment via the interconnection provided by the connector nut.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of the connector assembly of the present invention.
[0021] FIG. 2 is a cross-sectional view of the connector assembly of FIG. 1 .
[0022] FIG. 3 is a partial cross-sectional view of the holding means of the connector assembly of the present invention shown as a set screw.
[0023] FIG. 4 is a partial cross-sectional view of the holding means of the connector assembly of the present invention shown as a snap latch.
[0024] FIG. 5 is a cross-sectional view of an alternative embodiment of the connector assembly of the present invention.
[0025] FIG. 6 is an exploded, partial cut-away, perspective view of a further alternative embodiment of the connector assembly of the present invention.
[0026] FIG. 7 is a schematic of a platform with a drill string composed of a plurality of connector assemblies of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] With reference to the figures where like elements have been given like numerical designation to facilitate an understanding of the present invention, and in particular with reference to the embodiment of the present invention illustrated in FIG. 1 , connector assembly 10 may include first drill pipe 12 , second drill pipe 14 and connector nut 16 .
[0028] FIG. 2 shows that first drill pipe 12 may include pin end 18 . Pin end 18 may include outer surface 20 and inner surface 22 . Outer surface 20 of pin end 18 may include beveled shoulder 24 . Shoulder 24 may include retaining face 26 , holding face 28 , and stop face 30 . Shoulder 24 may also include one or more recesses 32 in holding face 28 for receiving a holding device 34 (not shown). Lower section 36 of pin end 18 may have one or more seals 38 positioned in outer surface 20 . Seals 38 may be pressure seals formed of rubber, urethane, steel, plastic or other material capable of forming a seal that is leak resistant. Lower section 36 may include distal end 40 . Distal end 40 may have torque transfer profile 42 . Profile 42 may include lateral surface 96 and tapered surface 98 .
[0029] With reference to FIG. 2 , second drill pipe 14 may have connector end 44 . Connector end 44 may have outer surface 46 and inner surface 48 . Outer surface 46 may contain shoulder 50 . Connector end 44 may also include upper section 52 . Outer surface 46 of upper section 52 may include connector nut means 54 . Connector nut means 54 may be any device capable of detachably affixing connector nut 16 to upper section 52 of connector end 44 of second drill pipe 14 . Connector nut means 54 may be threads 56 . Upper section 52 may include support surface 57 . Inner surface 48 of connector end 44 may have torque transfer profile 58 . Profile 58 may include lateral surface 100 and tapered surface 102 .
[0030] Again with reference to FIG. 2 , connector nut 16 may be a tubular device having outer surface 60 and inner surface 62 . Connector nut 16 may also include upper section 64 and lower section 66 . Lower section 66 may include distal surface 67 . Inner surface 62 of upper section 64 may have shoulder 68 . Inner surface 62 of lower section 66 may contain connector end means 70 . Connector end means 70 may be any device capable of cooperating with connector nut means 54 to detachably affix connector nut 16 to upper section 52 of connector end 44 of second drill pipe 14 . Connector end means 70 may be threads 72 that cooperatively engage and disengage from threads 56 . Threads 72 may also threadedly engage and disengage from threads 56 . Connector nut 16 may contain one or more thru holes 74 . Each hole 74 may house or contain holding device 34 (not shown). Each hole 74 may align with recess 32 in holding face 28 of pin end 18 of first drill pipe 12 . Holding device 34 (not shown) may be positioned within aligned hole 74 and recess 32 .
[0031] To make up or connect first drill pipe 12 to second drill pipe 14 , pin end 18 of first drill pipe 12 is stung into connector end 44 of second drill pipe 14 . Stop face 30 of beveled shoulder 24 acts as a stop for pin end 18 by contacting support surface 57 of upper section 52 of second drill pipe 14 . Connector nut 16 is secured to upper section 52 of second drill pipe 14 by rotating connector nut 16 so that connector nut 16 is threadedly connected to upper section 52 via threaded engagement of threads 54 and threads 70 . Shoulder 50 of connector end 44 of second drill pipe 14 acts as a stop for connector nut 16 by contacting lower section 66 of connector nut 16 at distal surface 67 . The detachable affixation of connector nut 16 to second drill pipe 14 compresses first drill pipe 12 and second drill pipe 14 together into operative connection. First drill pipe 12 is operatively connected to second drill pipe 14 via connector nut 16 . Shoulder 68 of connector nut 16 cooperates with or engages beveled shoulder 24 of first drill pipe 12 , and in particular, retaining face 26 of beveled should 24 , to hold or maintain first drill pipe 12 in position and operatively connected to second drill pipe 14 . The operative connection of first and second drill pipes 12 , 14 forms bore 75 through which pressurized fluid (e.g., drilling mud) may be pumped. Seals 38 form a seal between outer surface 20 of first drill pipe 12 and inner surface 48 of second drill pipe 14 to maintain pressure within first and second drill pipes 12 , 14 and to prevent leaking of the drilling fluid. The operative connection of first and second drill pipes 12 , 14 also causes operative engagement of torque transfer profile 42 of pin end 18 of first drill pipe 12 and torque transfer profile 58 of connector end 44 of second drill pipe 14 . For example, lateral surface 96 cooperatively engages lateral surface 100 and tapered surface 98 cooperatively engages tapered surface 102 . The operative engagement of torque transfer profiles 42 , 58 permits rotational torque to be transferred from first drill pipe 12 to second drill pipe 14 through connector nut 16 (and in like fashion to any other drill pipe segments made up and comprising the drill pipe strand) during exploration or production operations such as drilling of a well.
[0032] To ensure that connector nut 16 remains secured about first and second drill pipes 12 , 14 , holding device 34 may be employed to retain connector nut 16 in a fixed or stationary position relative to first and second drill pipes 12 , 14 . Holding device 34 ensures that connector nut 16 , namely connector end means 70 or threads 72 , do not detach or threadedly detach from connector nut means or threads 56 of second drill pipe 14 while connector assembly 10 rotates during operation of the drill string incorporating connector assembly 10 . Holding device 34 may be any type of device capable of maintaining connector nut 16 in fixed position about first drill pipe 12 . One or more holding devices 34 may be used, as for example, two, three, or four holding devices 34 . Preferably, holding device 34 fixedly connects connector nut 16 to beveled shoulder 24 of pin end 18 of first drill pipe 12 . For example, holding device 34 may be set screw 76 as show in FIG. 3 . Screw 76 may be inserted into thru hole 74 of connector nut 16 and into recess 32 of beveled shoulder 24 to thereby fixedly attach connector nut 16 to beveled shoulder 24 of first drill pipe 12 . Removal of screw 76 from recess 32 disengages the direct fixed connection between connector nut 16 and beveled shoulder 24 of first drill pipe 12 .
[0033] As seen in FIG. 4 , holding device 34 may also be snap latch 78 . Latch 78 may be inserted into thru hole 74 and into recess 32 to affix connector nut 16 to beveled shoulder 24 of first drill pipe 12 . Latch 78 may also be made integral with connector nut 16 or fixed to inner surface 62 (e.g., via welding) and extend outward from inner surface 62 . Latch 78 would snap into recess 32 when connector nut 16 is connected to connector end 44 of second drill pipe 14 and disengage from recess 32 when connector nut 16 is detached from connector end 44 of second drill pipe 14 .
[0034] FIG. 5 shows an alternative embodiment of connector assembly 10 . Connector nut means 54 of second drill pipe 14 are formed as wicker-type threads 80 . Connector end means 70 of connector nut 16 are formed as wicker-type threads 82 . Rather than threadedly connecting connector nut 16 to connector end 44 of second drill pipe 14 , in the alternative embodiment of assembly 10 , wicker-type threads 82 of connector nut 16 and wicker-type threads 80 of second drill pipe 14 operatively engage when pin end 18 of drill pipe 12 is stabbed into connector end 44 of second drill pipe 14 to thereby make up first and second drill pipes 12 , 14 . Connector nut 16 may be disengaged from connector end 44 of second drill pipe 14 by rotating connector nut 16 of wicker-type threads 80 of second drill pipe 14 . Alternative assembly 10 may include or not include one or more holding devices 34 . If one or more holding devices 34 are included with alternative assembly 10 , one or more holding devices 34 may be set screw 76 or snap latch 78 to prevent connector nut 16 from rotating off and disengaging from second drill pipe 14 during rotation of alternative assembly 10 as would occur, for example, during drilling operations. FIG. 5 shows assembly 10 with set screws 76 .
[0035] FIG. 6 reveals a further alternative assembly 10 . In the further alternative assembly 10 , connector nut means 54 of second drill pipe 14 are formed as breech lock-type threads 104 . Breech lock-type threads 104 are interrupted helically threads that contain thread-sections 106 and gaps 108 . Connector end means 70 of connector nut 16 are formed as breech lock-type threads 110 . Breech lock-type threads 110 are interrupted helically threads that contain thread-sections 112 and gaps 114 . Connector nut 16 is connected to connector end 44 of second drill pipe 14 by positioning each of thread-sections 112 of connector nut 16 within respective gaps 108 of second drill pipe 14 and rotating connector nut 16 in a first direction by a ½ turn causing mating engagement of each thread-section 106 of second drill pipe 14 with a corresponding thread-section 112 of connector nut 16 . Thus, drill pipe 12 (operatively engaged within connector nut 16 ) and drill pipe 14 are made up. Drill pipes 12 , 14 may be disengaged by rotating connector nut 16 in the opposite direction by a ½ turn and removing connector nut 16 (and associated drill pipe 12 ) from connector end 44 of second drill pipe 14 . If one or more holding devices 34 are included with further alternative assembly 10 , one or more holding devices 34 may be set screw 76 or snap latch 78 to prevent connector nut 16 from rotating off and disengaging from second drill pipe 14 during rotation of further alternative assembly 10 as would occur, for example, during drilling operations. FIG. 6 shows assembly 10 with set screws 76 .
[0036] FIG. 7 shows a schematic of floating platform 84 containing drilling rig 86 . Drilling rig 86 contains hoisting system 88 that is used to make up drill string 90 that is run down through marine riser 92 and into well 94 . Drill string 90 comprises a series of first and second drill pipes 12 , 14 connected together via connector assemblies 10 .
[0037] While preferred embodiments of the present invention have been described, it is to be understood that the embodiments described are illustrative only and that the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalents, many variations and modifications naturally occurring to those skilled in the art from a perusal hereof.
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A drill pipe connector assembly capable of connecting drill pipe segments without rotation. The assembly includes the pin end of a first drill pipe stabbed within the connector end of a second drill pipe. A connector nut is threadedly connected or snap locked to the connector end of the second drill pipe. The connector nut includes a retaining shoulder cooperating with a beveled shoulder on the pin end of the first drill pipe to retain the first drill pipe. The assembly includes seals to provide pressure integrity and prevent leaking. Cooperating rotational torque transfer profiles in the first and second drill pipes enable operational rotation of the drill string.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation of U.S. patent application Ser. No. 11/101,033, filed on Apr. 6, 2005, which claims priority from U.S. Provisional Patent Application No. 60/560,047, filed Apr. 6, 2004, and Canadian Application No. 2,463,354, filed Apr. 6, 2004, which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to a telemetry system, and in particular to a measurement while drilling (MWD) system. More particularly, the present invention relates to a servo-actuator for a downhole mud pulser for sending information from downhole to surface.
BACKGROUND OF THE INVENTION
The desirability and effectiveness of well logging systems where information is sensed in the well hole and transmitted to the surface through mud pulse telemetry has long been recognized. Mud pulse telemetry systems provide the driller at the surface with means for quickly determining various kinds of downhole information, most particularly information about the location, orientation and direction of the drill string at the bottom of the well in a directional drilling operation. During normal drilling operations, a continuous column of mud is circulating within the drill string from the surface of the well to the drilling bit at the bottom of the well and then back to the surface. Mud pulse telemetry repeatedly restricts the flow of mud to propagate signals through the mud upward to the surface, thereby providing a very fast communication link between the drill bit and the surface. Depending on the type of drilling fluid used, the velocity may vary between approximately 3000 and 5000 feet per second.
A telemetry system may be lowered on a wireline located within the drill string, but is usually formed as an integral part of a special drill collar inserted into the drill string near the drilling bit. The basic operational concept of mud pulse telemetry is to intermittently restrict the flow of mud as it passes through a downhole telemetry valve, thereby creating a pressure pulse in the mud stream that travels to the surface of the well. The information sensed by instrumentation in the vicinity of the drilling bit is encoded into a digital formatted signal and is transmitted by instructions to pulse the mud by intermittently actuating the telemetry valve, which restricts the mud flow in the drill string, thereby transmitting pulses to the well surface where the pulses are detected and transformed into electrical signals which can be decoded and processed to reveal transmitted information.
Representative examples of previous mud pulse telemetry systems may be found in U.S. Pat. Nos. 3,949,354; 3,958,217; 4,216,536; 4,401,134; and 4,515,225.
Representative samples of mud pulse generators may be found in U.S. Pat. Nos. 4,386,422; 4,699,352; 5,103,420; and 5,787,052.
A telemetry system capable of performing the desired function with minimal control energy is desirable, since the systems are typically powered by finite-storage batteries. One such example is found in U.S. Pat. No. 5,333,686, which describes a mud pulser having a main valve biased against a narrowed portion of the mud flowpath to restrict the flow of mud, with periodic actuation of the main valve to allow mud to temporarily flow freely within the flowpath. The main valve is actuated by a pilot valve that can be moved with minimal force. The pilot valve additionally provides for pressure equalization, thereby increasing the life of downhole batteries.
Another example of an energy efficient mud pulser is described in U.S. Pat. No. 6,016,288, the mud pulser having a DC motor electrically powered to drive a planetary gear which in turn powers a threaded drive shaft, mounted in a bearing assembly to rotate a ball nut lead screw. The rotating threaded shaft lifts the lead screw, which is attached to the pilot valve.
Solenoid-type pulser actuators have also been used to actuate the main pulser valve, however, there are many problems with such a system. The use of a spring to bias the solenoid requires the actuator (servo) valve to overcome the force of the spring (about 6 pounds) and of the mud prior to actuating the main valve. A typical solenoid driven actuator valve is capable of exerting only 11 pounds of pressure, leaving only 5 pounds of pressure to actuate the pulser assembly. Under drilling conditions requiring higher than normal mud flow, the limited pressures exerted by the solenoid may be unable to overcome both the pressure of the return spring and the increased pressure of the flowing mud, resulting in a failure to open the servo-valve, resulting in the main valve remaining in a position in which mud flow is not restricted, and therefore failing to communicate useful information to the surface.
A further problem with the use of a solenoid to actuate the pulser assembly is the limited speed of response and recovery that is typical of solenoid systems. Following application of a current to a solenoid, there is a recovery period during which the magnetic field decays to a point at which it can be overcome by the force of the solenoid's own return spring to close the servo-valve. This delay results in a maximum data rate (pulse width) of approximately 0.8 seconds/pulse, limiting the application of the technology.
Moreover, the linear alignment of the solenoid must be exactly tuned (i.e. the magnetic shaft must be precisely positioned within the coil) in order to keep the actuator's power characteristics within a reliable operating range. Therefore, inclusion of a solenoid within the tool adds complexity to the process of assembling and repairing the pulser actuator, and impairs the overall operability and reliability of the system.
Existing tools are also prone to jamming due to accumulation of debris, reducing the range of motion of the pilot valve. Particularly when combined with conditions of high mud flow, the power of the solenoid is unable to clear the jam, and the tool is rendered non-functional. The tool must then be brought to the surface for service.
Stepper motors have been used in mud pulsing systems, specifically, in negative pulse systems (see for example U.S. Pat. No. 5,115,415). The use of a stepper motor to directly control the main pulse valve, however, requires a large amount of electrical power, possibly requiring a turbine generator to supply adequate power to operate the system for any length of time downhole.
Repair of previous pursers has been an as yet unresolved difficulty. Typically, the entire tool has been contained within one housing, making access and replacement of small parts difficult and time-consuming. Furthermore, a bellows seal within the servo-poppet has typically been the only barrier between the mud flowing past the pilot valve's poppet and the pressurized oil contained within the servo-valve actuating tool, which is required to equalize the hydrostatic pressure of the downhole mud with the tool's internal spaces. Therefore, in order to dissemble the tool for repair, the bellows seal had to be removed, causing the integrity of the pressurized oil chamber to be lost at each repair.
Furthermore, a key area of failure of MWD pulser drivers has been the failure of the bellows seal around the servo-valve activating shaft, which separates the drilling mud from the internal oil. In existing systems, the addition of a second seal is not feasible, particularly in servo-drivers in which the servo-valve is closed by a spring due to the limited force which may be exerted by the spring, which is in turn limited by the available force of the solenoid, and cannot overcome the friction or drag of an additional static/dynamic linear seal.
It remains desirable within the art to provide a pulse generator that has an energy efficiency sufficient to operate reliably and to adapt to a variety of hostile downhole conditions, has reduced susceptibility to jamming by debris, and is simpler to repair than previous systems.
SUMMARY OF THE INVENTION
It is an object of the present invention to obviate or mitigate at least one disadvantage of previous mud pulsers and pulse generators.
In a first aspect, the present invention provides a downhole measurement-while-drilling pulser actuator comprising a servo valve movable between an open position which permits mud flow through a servo-orifice and a restricted position which restricts mud flow through the servo-orifice, the servo-valve powered to the open position and powered to the closed position by a reversible electric motor.
In one embodiment, the servo valve includes a servo-poppet powered by the motor in reciprocating linear movement towards and away from the servo-orifice.
In a further embodiment, the actuator may include a rotary to linear conversion system for converting rotary motion of the reversible electric motor into linear reciprocating movement of the poppet. The rotary to linear conversion system may include a threaded lead screw held stationary and driven in rotation by a rotary motor. In this embodiment, the lead screw may be threadably attached to a ball nut from which the poppet depends, whereby the rotary motion of the motor causes rotation of the screw to result in driven linear movement of the ball nut and the poppet in either direction.
In a further embodiment, there is provided a servo-controller for controlling the powering of the servo-valve by the electric motor. The servo-controller may further be capable of sensing the position of the poppet with respect to the servo-orifice, such that the poppet position is sensed when mud flow through the servo-orifice is restricted or unrestricted, and wherein the amount and direction of rotation of the motor from the sensed poppet position is counted and stored by the controller.
In another embodiment, the sensed position of the orifice restriction is calibrated as the fully closed position of the poppet. The poppet's travel is thereby monitored and controlled during operation to avoid unneeded collision or frictional wear between the poppet and the servo-orifice. The servo controller may sense the position of the poppet by sensing whether movement of the poppet is impeded, and the servo-controller counts the number of rotations of the motor until the poppet is impeded and compares the number of rotations to an expected number of rotations to determine the position of the poppet with respect to the servo-orifice. The expected number of rotations can be preset to allow a predetermined rate of mud flow past the servo-orifice when the poppet is moved away from the servo-orifice by the preset expected number of rotations.
In a still further embodiment, the servo-controller may include a debris clearing command that is initiated when the number of rotations counted is not equal to the expected number of rotations. The debris clearing command may cause the motor to rapidly reciprocate the poppet to dislodge any debris present between the poppet and the servo-orifice.
In another embodiment, the attachment between the poppet and the motor comprises a dynamic seal to isolate the motor, rotary to linear conversion system and related drive components from the drilling mud in which the poppet and orifice are immersed when in operation.
In a further aspect, the present invention provides a method for causing the generation of a mud pulse by a controlled pulser's main pulse valve comprising the steps of: powering a pulser servo-valve in a first direction using a rotary motor such that mud is permitted to flow past a servo-orifice to activate a main mud pulse valve; and powering the servo-valve in a second direction using the rotary motor such that mud flow past the servo-orifice is restricted to deactivate the main mud pulse valve.
In one embodiment, the method further comprises the step of cutting power to the motor to hold the servo-valve in a particular position within its range of motion to tailor the actuator's effect on the main pulse valve and thereby tailor the pressure and duration characteristics of a mud pulse.
In another aspect, the invention provides a servo-controller for use with a downhole measurement-while-drilling pulser actuator, the servo-controller comprising a sensor, memory, control circuitry, and an operator interface.
In one embodiment, the sensor is a mudflow sensor, pressure sensor, temperature sensor, rotation-step counter, position sensor, velocity sensor, current level sensor, battery voltage sensor, timer, or an error monitor.
In another embodiment, the memory stores time-stamped or counted sensed events together with an event-type indication. The servo-controller may be programmable to cause an action within the actuator responsive to a sensed event, a time, an elapsed time, a series of sensed events, or any combination thereof.
In a further embodiment, the user interface provides information from memory to the operator, and may allow an operator to alter the programming of the control circuitry.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
FIGS. 1A and B are a longitudinal cross sectional view of the upper and lower portions of an embodiment of the mud pulser during mud flow through the servo orifice; and
FIGS. 2A and 2B are a longitudinal cross sectional view of the upper and lower portions of an embodiment of the mud pulser during mud flow restriction by the poppet.
DETAILED DESCRIPTION
The present invention relates to an apparatus and method for actuating a mud pulser telemetry system used during well-drilling operations. The present apparatus allows a servo-valve to be powered both in opening and closing to activate a main mud pulser valve, and does not rely on a solenoid system. The powered opening and closing of the servo-valve results in various functional and economic advantages, including the ability to clear debris from the restricted portion of the mud flowpath, and faster data rates due to elimination of inherent operating delays in the solenoid systems of previous tools, with the end result of providing a pulser driver which consumes a minimal amount of DC power while providing more force with which to drive the servo-valve's poppet in each direction. Therefore, the actuator remains functional at a comprehensive range of downhole drilling conditions.
Furthermore, in the embodiment shown in the Figures, the present device is designed to have several independent, interconnected housings, and employs a double seal between the oil compartment and the drilling mud, which simplifies assembly and repair of the tool. The assembly/disassembly is simplified to reduce repair turnaround time by using modular components.
Additionally, the use of a stepper motor, electric load sensors, and control circuitry in a powered-both-directions servo-valve system will allow for self-calibration of the tool and self-diagnosis and error correction unavailable in other systems. In an embodiment of the invention, as shown in FIGS. 1A and 1B , a three-phase stepper rotary motor 1 is monitored and controlled by a servo-controller 10 , the rotary movement of the motor 1 being converted into linear movement of a poppet 21 , thereby opening and closing a servo-valve 20 to actuate a mud pulser main valve (not shown). Communication of information to the well surface is accomplished by encoded signals, which are translated to produce pressure surges in the downward flow of the pressurized mud. It is recognized that although the drilling fluid is generally referred to as mud, other drilling fluids are also suitable for use with the present invention, as is well known in the art.
With reference to the Figures, the mud pulser actuator is lowered downhole and, in the embodiment shown, generally includes a plurality of serially interconnected housings 2 , 3 , 4 , 5 , 6 , 7 , and 8 , an electrical connector 9 , a servo-controller 10 for controlling the operation of a rotary motor 1 , and a servo-valve assembly 20 that is driven in linear motion by the rotary motor 1 . The servo-valve assembly includes a poppet 21 capable of linear reciprocating movement to and from a seal surface 22 of a servo orifice 23 , thereby opening and closing the servo orifice 23 to allow or prevent the passage of pressurized mud and thereby actuate a pulser (not shown, connected to the lower end 2 a of the lowermost housing 2 ) to generate a pressure pulse for telemetric purposes.
Mechanical System
A rotary-to-linear coupling system 30 a , 30 b (hereinafter referred to as coupling system 30 ) is used to translate the torque from the rotary motor 1 into linear movement of the servo-valve shaft 24 , which is preferably a series of connected shafts for transferring linear movement from the coupling system 30 to the servo poppet 21 . Preferably, the servo shaft includes a spline shaft 24 a , which passes through a spline coupling 24 b that can be used to prevent rotation of the shaft 24 a when necessary. The coupling system 30 also includes seals which serve to isolate the rotating mechanism from the downhole mud.
In the embodiment pictured in FIGS. 1A and 1B , the rotary motor 1 , is electrically powered through an electrical connection 9 , by a power source (not shown). When activated, the motor 1 rotates a lead screw 31 that is mounted within a bearing support 32 , causing a ball nut 33 to move threadably along the lead screw 31 . Linear movement of the ball nut 33 results in dependent linear movement of the servo shaft 24 , and servo poppet 21 . When driven in the forward direction, the rotary motor 1 will cause linear movement of the poppet 21 away from the servo-valve seat 22 , to allow passage of pressurized mud through the servo-orifice 23 to activate the main mud pulser valve to close. When the motor 1 drives the lead screw 31 in the reverse direction, poppet 21 is urged towards the seal surface 22 to cover the servo orifice 23 , as shown in FIG. 2B , and mud is therefore prevented from passing through the servo orifice 23 to actuate the mud pulser main valve to open.
The spline shaft 24 is surrounded by lubricating fluid, which must be pressurized against the downhole hydrostatic pressure. As shown, a pressure compensator in the form of a membrane or bellows 42 allows reservoir fluid to substantially equalize the pressure via a part 43 . The pressure compensator be a membrane, bellows, piston type or other type known in the industry. In addition to a bellows seal 40 , an additional seal 41 may be added to hold oil inside the chamber of the tool, with the bellows seal 40 preventing mud from reaching the additional seal 41 . The dual seal 40 , 41 maintains the integrity of the lubrication chamber during operation and during replacement of the bellows seal 40 during maintenance. The addition of this seal 41 does not negatively impact performance of the actuator due to the improved power characteristics of the system, as will be discussed below.
In a preferred embodiment, the construction of the device allows most downhole clogs, where debris in the mud may stop the poppet 21 from sealing with the seal surface 22 , to be easily cleared as will be described below, and the serially interconnected housing design allows simple and rapid repair of the tool when necessary.
The valve assembly 20 is preferably composed of a wear resistant material such as tungsten carbide or ceramic to maximize the efficiency of the tool and to minimize maintenance of the tool, and is preferably replaceable.
Operation
When restriction of mud flow by the main valve is desired, the rotary motor 1 will be activated by the servo-controller 10 in the forward direction. As shown in FIG. 1B , forward powering of the rotary motor 1 will cause the lead screw 31 to turn in the forward (for example, clockwise) direction, thereby raising the ball nut 33 and lifting the servo poppet 21 from the servo-valve seat 22 . This will allow mud flow to pass unrestricted through the servo-orifice 23 to actuate the main mud pulse valve, restricting mud flow to generate a pulse that is transmitted to the surface. The current-consuming portion of the circuit is then shut down until a further signal is received from the servo-controller 10 . The lack of current to the motor 1 results in the motor 1 being immovable and therefore acting as a brake to prevent further movement of the poppet 21 until further activation of the motor 1 .
Subsequently, when the servo-controller 10 initiates reverse motion by the motor 1 , the lead screw 31 is rotated in the reverse direction (in the example, counterclockwise) by the motor 1 , causing the ball nut 33 and servo shaft 24 to move towards the servo-valve seat 22 as shown in FIG. 2B . Closure of the servo-valve 20 causes opening of the main mud pulser valve to allow mud to flow unrestricted to the surface. The current-consuming portion of the circuit is then shut down until a further signal is received from the servo-controller 10 . The motor again acts as a brake until further power is applied (by shorting its coils together).
The lead screw 31 and ball nut 33 may be replaced by an alternate system of rotary to linear conversion, however a lead screw 31 and ball nut 33 are advantageous as they are relatively small in size and may be provided with bearings to provide a low-friction mechanism with high load capacity, durability, and low backlash tolerance. The lead screw 31 may be held in contact with the motor 1 by a bearing support 32 or any other suitable means.
The presently described system of using a stepper motor 1 to drive a servo-valve has several advantages. The powering of the servo-valve 20 in both directions allows greater direct control of the servo-valve 20 , avoids the previous necessity of using a return spring in the servo assembly, and therefore the energy required is similar to that of the force of the downhole mud flow. This results in an energy efficient system, and results to date indicate that the presently described system can supply a force of 100 pounds of pressure for less energy than previous systems, particularly than those which employ a solenoid activator. Thus, the present system can overcome higher pressures on the poppet valve 21 , allowing the system to clear itself of debris, and permitting use in a wide range of downhole conditions, including conditions of higher pressure and higher volume mud flow, and in conditions when the mud is contaminated or is very dense.
Use of a rotary motor powering the servo-valve in both directions also allows the system to be more responsive than solenoid systems, resulting in a faster data rate with more accurate or precise pulse-edge timing. Experimental results indicate that data rates of 0.25 seconds/pulse are possible with this system, as compared to 0.8 to 1.5 seconds/pulse in solenoid systems.
Flow Detection & Diagnostic Software
The servo controller detects the position of the poppet 21 against the servo-valve seal 22 by counting the number of rotations made by the motor until further movement of the poppet is impeded. For example, if the poppet 21 is generally programmed to attain an unseated position that is three forward motor rotations away from the seated position, upon seating activation by the servo-controller 10 , the motor will turn three reverse rotations, at which point further rotation will be impeded due to seating of the poppet 21 on the seal 23 . On unseating activation by the servo controller 10 , the motor will turn three complete forward rotations to return the poppet to its pre-programmed unseated position. Seating can be sensed by an increase in current drawn by the motor, from which a large opposing force (like stopped motion due to valve seating) is inferred. The control circuitry also senses rotation of the motors and can count rotations and direction of rotation.
Debris may enter the device with the mud, potentially causing jamming of the poppet. The servo controller 10 can be programmed to detect and clear jams from the servo-valve 20 . For example, debris may become lodged at the servo-valve seal 22 , preventing the poppet from fully sealing against the valve seal 22 . In such a situation, the motor would be prevented from completing its three reverse rotations. This is sensed by the servo-controller 10 , which will then attempt to dislodge the debris. The dislodging sequence may include rapid reciprocation of the poppet 21 towards and away from the seal 22 , or may include further reverse rotations on the subsequent reverse rotation. For example, if the motor was able to turn only two reverse rotations, the servo-controller 10 will recognize that the valve did not properly close, and will adjust one or more subsequent forward and/or reverse rotations to ensure that the poppet 21 is able to seat against the valve seal 22 . Similarly, debris may cause the poppet to not fully open, resulting in appropriate corrective action by the servo-controller on the next motor 1 activation. In either case, a processor provides a report of measurements recorded and controls the following cycle of the brushless motor's rotation accordingly.
The ability to detect and clear most jams within the tool allows a more robust design of the tool in other respects. For example, as the tool can easily clear particulate matter from the servo-valve assembly, the tool can be provided with larger and fewer mud ports, and may include reduced amounts of screening. Screening is susceptible to clogging, and so reducing screening leads to longer mean time between operation failure of the device in-hole; and will reduce the velocity of any mud flow through the tool, reducing wear on the bladder and other parts. Further, the removal of several previously necessary components (such as the return spring, transformer, and solenoid and related electronics) contributes to a tool of smaller size (in both length and diameter) that is more versatile in a variety of situations. For example, embodiments with outside diameter less than 1⅜″ (approaching 1″) or length less than four feet have been achieved, although these dimensions are not by way of limitation, but by example only.
Custom software also has the ability to track downhole conditions, and also uses a sensor to detect mudflow. When mudflow is detected, a signal is sent to the Directional Module Unit (not shown), to activate the overall system. The system also has the ability to time stamp events such as start or end of mudflow, incomplete cycles or system errors, low voltages, current, and the like, as well as accumulated run-time, number of pulses, number of errors, running totals of rotations or motor pulses. Wires or conductors may also be easily passed by the pulser section to service additional near-bit sensors or other devices. The software that detects the mudflow can be configured for different time delays to enable it to operate under a larger variety of downhole drilling conditions than its predecessors. The mudflow detection capability can also be used to calibrate or confirm the closed position of the poppet.
In addition, a user may monitor such data as well as any downhole sensors using a user interface attachable to the tool. Such sensors may include pressure or temperature sensors, rotation step-counters, travel or depth sensors, current levels, battery voltage, or timers. The user could monitor each component of the actuator to determine when the tool must be removed from downhole for repair. A user may, in turn, program an activity to cause an action or correction in response to a sensed event.
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
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An improved energy efficient intelligent pulser driver used for generating a mud pulse in a MWD (measurement while drilling) application. In the pulser driver, a direct current (DC) powered control circuit activates a three-phase DC brushless motor that operates a servo-valve. Opening of the servo-valve equalizes pressure in a plenum causing the operation of a main valve reducing flow area and causing a pressure spike in the mud column. Closing of the servo-valve creates a reduction in mud pressure that operates the main valve and increases the flow area causing an end to the pressure spike. The servo-valve is powered both in opening and closing operations by the motor.
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TECHNICAL FIELD OF THE INVENTION
The present invention relates to method and apparatus for activating a probe and, in particular, for activating a probe used with an ultrasound imaging system.
BACKGROUND OF THE INVENTION
As is well known in the art, ultrasound imaging systems have one or more probes. In systems having more than one probe, there must be a technique for providing an indication that a particular probe will be used by a sonographer. One existing technique for providing an indication uses switch activated control circuits, which circuits are activated manually by, for example, pressing a button on a console, to indicate that a particular probe is in use. Then, in response to the indication generated when the user presses the button, the ultrasound system activates the indicated probe in a manner which is well known in the art. Aother existing technique for providing an indication uses probe holders which contain switches that are activated when a probe is removed from its holder. When a switch is activated, an indication is provided which causes the ultrasound system to activate the probe. Still another existing technique for providing an indication uses switch activated control circuits, which circuits are activated manually by, for example, pressing a button disposed on the probe to indicate that a particular probe is in use.
There are disadvantages associated with each of the above-described techniques. The first technique is disadvantageous because it requires a user to press a button to indicate that a particular probe is to be activated. The second technique is disadvantageous in that it requires a probe to be returned to its holder before another probe can be used. In addition, for proper activation using the second technique, probes must be returned to specific holders, otherwise the wrong probe will be activated. The third technique is disadvantageous in that it requires the user to remember to press the button to turn the probe on and off.
In light of the above, there is a need in the art for method and apparatus for activating a probe which overcomes the above-described problems.
SUMMARY OF THE INVENTION
Advantageously, embodiments of the present invention are method and apparatus for activating a probe automatically. In particular, an embodiment of the present invention is an ultrasound imaging system providing automatic activation of a probe, which ultrasound system comprises: (a) motion sensor means for detecting motion of the probe and for generating a signal in response to the motion; (b) signal detecting means for detecting the signal; and (c) probe activating means, in response to a detection signal from the detecting means, for activating the probe. In a preferred embodiment of the present invention, the motion sensor means is an accelerometer which is affixed to the probe.
BRIEF DESCRIPTION OF THE FIGURE
FIG. 1 shows, in pictorial form, an ultrasound imaging system which automatically activates an ultrasound probe in accordance with the present invention; and
FIG. 2 shows, in graphical form, signals produced by various parts of the ultrasound imaging system shown in FIG, 1.
DETAILED DESCRIPTION
FIG. 1 shows ultrasound imaging system 300 which automatically activates ultrasound probes 101 and 102 in accordance with the present invention. As shown in FIG. 1: (a) ultrasound probes 101 and 102 are connected to main control station 210 of ultrasound imaging system 300 by cables 151 and 152, respectively; (b) sensors 161 and 162 are affixed to ultrasound probes 101 and 102, respectively; (c) ultrasound transducers 121 and 122 are disposed within ultrasound probes 101 and 102, respectively; (d) communications channel 171 extends from sensor 161, through cable 15 1, to signal detector 180 in main control station 210; (e) communications channel 172 extends from sensor 162, through cable 152, to signal detector 180 in main control station 210; (f) sensor 163 is affixed to main control station 210; and (g) communications channel 173 extends from sensor 163 to signal detector 180. Lastly, signal detector 180 is connected to activation switch 190 by communications link 185 and activation switch 190 interconnects ultrasound transducers 121 or 122 with imaging channel 205 by means of communications links 181 and 182, respectively.
In accordance with the present invention, sensor 161 detects motion of probe 101 and sensor 162 detects motion of probe 102. For example, in response to movement of probe 101, sensor 161 transmits a signal over communications channel 171 to signal detector 180. In response to the signal received from sensor 161, in a manner which will be explained in detail below, signal detector 180 determines that probe 101 is to be activated. Then, signal detector 180 transmits such information over communications link 185 to activation switch 190. Finally, in response to the information received from signal detector 180, activation switch 190 activates probe 101 by connecting probe 101 with imaging channel 205 in accordance with methods which are well known to those of ordinary skill in the art, such as, for example, by use of relay switches.
In a preferred embodiment of the present invention, sensors 161 and 162 are accelerometers which are placed, for example, within the handle of probes 101 and 102. Thus, for example, whenever a user picks up probe 101, sensor 161 (accelerometer 161) generates a signal which is transmitted to signal detector 180, all of which takes place in a manner which is well known to those of ordinary skill in the art.
In embodiments of the present invention wherein ultrasound imaging system 300 has several probes, signal detector 180 is fabricated to distinguish among signals coming from the probes. This ability to distinguish arises, in part, by: (a) routing signals arriving from different probes to different hardware appearances; (b) requiring signals from different probes to be different; or (c) requiring signals to contain identifying information which is embedded within the signals. This information is then used, in the manner which will be described in detail below, to determine which probe is to be activated. This information is then transmitted to activation switch 190. In response, activation switch 190 connects the identified probe to imaging channel 205 to activate the identified probe.
In a preferred embodiment of the present invention, sensor 163 is affixed to main control station 210 to enable the system to identify motion of probes which is caused by motion of the main control station when the probes are attached thereto. Further, in accordance with the preferred embodiment, signal detector 180 is fabricated to identify other events which are not caused by a user. FIG. 2 shows, in graphical form, signals produced by various parts of ultrasound imaging system 300 shown in FIG. 1. Line 401 shows signals generated by sensor 161, line 402 shows signals generated by sensor 162, and line 403 shows signals generated by sensor 163--all as a function of time.
The following describes the operation of the preferred embodiment of the present invention in conjunction with FIG. 2. Assume that imaging system 300 is turned on at time 601 and that probe 101 is selected for activation as a default condition. Thus, in the default condition, activation switch 190 is set at position 192 (see FIG. 1) so that probe 101 is connected to imaging channel 205. During time interval 510, sensor 161 generates signal 701 when probe 101 is picked up by a user and is moved during subsequent use. Signal 701 is sent through communications channel 171 to signal detector 180. In response to signal 701, signal detector 180 identifies the user-selected probe to be probe 101. Since this matches the probe used for the default condition, signal detector 180 sends no action command to activation switch 190. During time interval 510 probe 101 is always activated and is the only probe which is connected to imaging channel 205.
Time interval 510 ends at time 602 when the user picks up probe 102. At that moment, sensor 162 in probe 102 generates signal 702 which is sent through communications channel 172 to signal detector 180. In response to signal 702, signal detector 180 identifies the user-selected probe to be probe 102 and signal detector 180 sends an action command through communications link 185 to activation switch 190. In response to this action command, activation switch 190 changes the position of the switch from position 192 to position 194 so that probe 102 is now connected to imaging channel 205. Note that typical probe-in-motion signals, such as signals 701 and 703, have relatively large amplitude and relatively long duration.
Time interval 520 starts at time 602 and probe 102 is the only probe which is connected to imaging channel 205 during this time interval. During time interval 520, probe 102 may be picked up and put down and picked up again several times. This will cause sensor 162 to generate and send multiple signals, like signal 703, to signal detector 180. However, as long as such signals are associated with the current probe selection, signal detector 180 will not send action commands to activation switch 190.
While probe 102 is in use during interval 520, sensor 161 in probe 101 may generate some short spike signals like signal 704 and low-level signals like signal 705. Such signals may be generated for unintentional reasons such as, for example, the user accidentally touching the probe or small vibrations in the area where the probe rests. As can be seen in FIG. 2, these signals have significantly different characteristics from probe-in-motion signals 701,702, and 703 which are generated when a probe is in use by an operator. In the preferred embodiment, signals such as 704 and 705 are filtered by signal detector 180.
During interval 520, unused probe 101 may be placed in a probe holder on main control station 210. Further, the user may adjust the position of main control station 210 while using probe 102. In such an event, movement of main control station 210 causes sensor 161 in probe 101 to generate signal 706 which is similar to signals 701,702 and 703 which indicate use of a probe by an operator. Sensor 163 is installed on main control station 210 to prevent false probe activation in this case as follows. During motion of main control station 210, sensor 163 generates signal 707, which signal 707 is sent to signal detector 180. Signal detector 180 identifies the coincidence of signals 706 and 707 as being caused by motion of main control station 210 and sends no activation command to activation switch 190. As a result, signal detector 180 ignores signals caused by motion of main control station 210.
Time interval 520 ends and time interval 530 begins at time 630 when the user picks up probe 101 again. During time interval 530, sensor 161 generates signal 708 which indicates that probe 101 is in use. In response, signal detector 180 sends an action command to activation switch 190 to change the switch position from 194 back to 192. Now probe 101 is back in use in time interval 530. As one can readily appreciate from the above, the automatic probe activation process repeats itself by switching back and forth between probes 101 and 102 as the user operates ultrasound imaging system 300.
In summary, in accordance with the preferred embodiment of the present invention, signal detector 180 utilizes the following rules in analyzing signals generated by sensors 161-163 to determine which probe is to activated: (a) if a probe is activated, maintain it in that state until a motion signal is received from another probe; (b) if a motion signal is received from a probe and from sensor 163, do not activate the probe since the main control station has moved, thereby causing the motion signal from the probe; and (c) ignore short, transient signals and low-level signals from an inactive probe. Signal detector 180 is fabricated utilizing a microprocessor or logic for implementing the above-identified rules in a manner which is well known to those of ordinary skill in the art.
As one can readily appreciate, embodiments of the present invention solve the above-identified disadvantages of prior art systems in that a user does not have to press a button to activate or deactivate a probe; a user does not have to place a probe in a holder before picking up another probe; and a user does not have to place a probe in a pre-defined holder.
Note that the present invention is not limited to the embodiment described above. For example, signals generated by motion detectors 161 and 162 to indicate movement of probes 101 and 102, respectively, need not be transmitted by communications channels 171 and 172, respectively, which pass through cables 151 and 152, respectively. In other embodiments of the present invention such signals may be transmitted by broadcast methods of cordless transmission, much like the manner in which information is transmitted by a cordless telephone. In such a mode, the signal would also transmit information which identifies the probe being used.
Although various minor modifications may be suggested by those versed in the art, it should be understood that we wish to embody within the scope of the patent granted hereon all such modification as reasonably and properly come within the scope of our contribution to the art.
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Ultrasound imaging system providing automatic activation of a probe, which ultrasound system includes: (a) a motion sensor for detecting motion of the probe and for generating a signal in response to the motion; (b) a signal detector for detecting the signal; and (c) a probe activator, in response to a detector signal from the detector, for activating the probe. In a preferred embodiment of the present invention, the motion sensor is an accelerometer which is affixed to the probe.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This patent application claims priority under 35 USC §119(e) to U.S. Provisional Patent Application Ser. No. 62/302,120 filed on Mar. 1, 2016.
TECHNICAL FIELD
[0002] This disclosure relates generally to clutches, and in particular to clutches having multiple modes of engagement with a rotating element for selectively locking the element against rotation and allowing the element to rotate freely in one or both directions.
BACKGROUND
[0003] An automotive vehicle typically includes an internal combustion engine containing a rotary crankshaft configured to transfer motive power from the engine through a driveshaft to turn the wheels. A transmission is interposed between engine and driveshaft components to selectively control torque and speed ratios between the crankshaft and driveshaft. In a manually operated transmission, a corresponding manually operated clutch may be interposed between the engine and transmission to selectively engage and disengage the crankshaft from the driveshaft to facilitate manual shifting among available transmission gear ratios.
[0004] On the other hand, if the transmission is automatic, the transmission will normally include an internal plurality of automatically actuated clutch units adapted to dynamically shift among variously available gear ratios without requiring driver intervention. Pluralities of such clutch units, also called clutch modules, are incorporated within such transmissions to facilitate the automatic gear ratio changes.
[0005] In an automatic transmission for an automobile, anywhere from three to ten forward gear ratios may be available, not including a reverse gear. The various gears may be structurally comprised of inner gears, intermediate gears such as planet or pinion gears supported by carriers, and outer ring gears. Specific transmission clutches may be associated with specific sets of the selectable gears within the transmission to facilitate the desired ratio changes.
[0006] Because automatic transmissions include pluralities of gear sets to accommodate multiple gear ratios, the reliability of actuators used for automatically switching clutch modules between and/or among various available operating modes is a consistent design concern. It is also desirable to provide smooth transitions between the operating modes when the clutch modules engage and disengage from the gears. These considerations are also important in other operating environments where selectable clutch modules may be implemented to selectively allow and restrict the rotation of rotating components such as gears, shafts, torque converter components and the like. Therefore, much effort has been directed to finding ways to assure actuator reliability and seamless performance at competitive costs.
SUMMARY OF THE DISCLOSURE
[0007] In one aspect of the present disclosure, an actuator device for a selectable clutch having a plurality of mode positions for controlling relative rotation between two components connected by the selectable clutch is disclosed. The actuator device may include a piston housing having an exterior surface, a piston housing longitudinal bore extending longitudinally there through, a first fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a first bore end, and a second fluid passage extending inwardly from the exterior surface and intersecting the piston housing longitudinal bore proximate a second bore end, and a piston having a piston body disposed within the piston housing longitudinal bore for longitudinal motion therein. A first pressure force acting on the piston body toward the second bore end is equal to a first pressure supplied at the first fluid passage multiplied by a first area equal to a first piston body cross-sectional area of the piston body, and a second pressure force acting on the piston body toward the first bore end is equal to a second pressure supplied at the second fluid passage multiplied by a second area equal to a second piston body cross-sectional area of the piston body.
[0008] In another aspect of the present disclosure, a selectable clutch is disclosed. The selectable clutch may include an outer race, an inner race rotatable relative to the outer race, a selective locking mechanism having a plurality of locking modes for controlling relative rotation between two components connected by the selectable clutch, actuator cam that is rotatable between a plurality of mode positions each causing the selective locking mechanism to engage one of the plurality of locking modes, and an actuator device such as that described in the preceding paragraph operatively connected to the actuator cam to move the selective locking mechanism between the plurality of mode positions as the main piston moves longitudinally within the piston housing longitudinal bore.
[0009] Additional aspects are defined by the claims of this patent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is both a perspective and a cross-sectional view of a portion of one possible embodiment of a selectable in the form of a multimode clutch module that may be implemented in vehicles;
[0011] FIG. 2 is an enlarged side view of a portion of one possible embodiment of the multimode clutch module of FIG. 1 with the near inner race plate removed to reveal the internal components, and with an actuator cam in a one-way locked, one-way unlocked position;
[0012] FIG. 3 is the enlarge view of one possible embodiment of the multimode clutch module of FIG. 1 with the actuator cam in a two-way unlocked position;
[0013] FIG. 4 is the enlarge view of the multimode clutch module of FIG. 1 with the actuator cam in a two-way locked position;
[0014] FIG. 5 is a cross-sectional view taken through line 5 - 5 of FIG. 2 of an embodiment of an actuator device in accordance with the present disclosure in position to place the actuator cam in the one-way locked, one-way unlocked position;
[0015] FIG. 6 is a cross-sectional view taken through line 6 - 6 of FIG. 3 of the embodiment of the actuator device in position to place the actuator cam in the two-way unlocked position;
[0016] FIG. 7 is a cross-sectional view taken through line 7 - 7 of FIG. 4 of the embodiment of the actuator device in position to place the actuator cam in the one-way locked, one-way unlocked position; and
[0017] FIG. 8 is a cross-sectional view taken through line 5 - 5 of FIG. 2 of an alternative embodiment of an actuator device in accordance with the present disclosure in position to place the actuator cam in the one-way locked, one-way unlocked position;
[0018] FIG. 9 is a cross-sectional view taken through line 6 - 6 of FIG. 3 of the alternative embodiment of the actuator device in position to place the actuator cam in the two-way unlocked position; and
[0019] FIG. 10 is a cross-sectional view taken through line 7 - 7 of FIG. 4 of the alternative embodiment of the actuator device in position to place the actuator cam in the one-way locked, one-way unlocked position.
DETAILED DESCRIPTION
[0020] In accordance with the present disclosure, a selectable clutch, such as a multimode clutch module may be implemented at various locations of a vehicle (not shown) to provide multiple modes for connecting and disconnecting rotatable components to prevent or allow, respectively, relative rotation between two components. Referring to FIG. 1 , a multimode clutch 10 of a vehicle may be of the type illustrated and described in Intl. Publ. No. WO 2014/120595 A1, published on Aug. 7, 2014, by Papania, entitled “Multi-Mode Clutch Module,” which is expressly incorporated by reference herein. While the multimode clutch 10 is illustrated and described herein, those skilled in art will understand that actuator devices in accordance with the present disclosure may be implemented with other types of selectable clutches providing multiple modes for connecting and disconnecting rotatable components to prevent or allow, respectively, relative rotation between two components, and the use of the actuator device with such selectable clutches is contemplated by the inventors. In the illustrated embodiment, the multimode clutch 10 may incorporate an interior driven hub 50 and an outer housing 52 that may be locked for rotation together in some modes of the multimode clutch 10 and may be unlocked for independent rotation with respect to each other in other modes of the multimode clutch 10 as will be described more fully below. The driven hub 50 may contain an array of circumferentially spaced cogs 54 adapted to secure an inner race 56 to the driven hub 50 for rotation therewith. As disclosed, the inner race 56 is comprised of first and second spaced plates 56 A and 56 B. An outer race 58 sandwiched between the pair of inner race plates 56 A, 56 B, is situated so as to allow for relative rotation between inner race 56 and the outer race 58 , and with the outer race 58 being operatively coupled to the outer housing 52 for rotation therewith.
[0021] In the present design of the multimode clutch 10 , an actuator cam 60 is interposed between one of the race plates 56 A, 56 B and the outer race 58 for rotation over a predetermined angle about a common axis of the driven hub 50 and the outer housing 52 to control movements of pairs of opposed pawls 62 , 64 as will be described further hereinafter. The sets of pawls 62 , 64 are trapped, and hence retained, between the inner race plates 56 A, 56 B to allow limited angular movements of the pawls 62 , 64 held within bowtie shaped apertures 66 , 68 , respectively, subject to the control of the actuator cam 60 . In each set, the combined pawl 62 and corresponding aperture 66 is similar to but oppositely oriented to the combined pawl 64 and corresponding aperture 68 . The elements of the multimode clutch 10 are contained within the outer housing 52 . A plurality of spaced apertures 70 are adapted to accommodate rivets (not shown) for providing fixed and rigid securement of each of the two inner race plates 56 A and 56 B relative to the other.
[0022] The operational components of the multimode clutch 10 are illustrated in FIGS. 2-4 that illustrate the various operational modes of the multimode clutch 10 for controlling the relative rotation between the components attached to the driven hub 50 and the outer housing 52 . Referring first to FIG. 2 , the outer race 58 is configured to accommodate interactions with the pawls 62 , 64 by providing the inner circumference of the outer race 58 with circumferentially spaced notches 72 , each defined by and positioned between pairs of radially inwardly projecting cogs 74 . The notches 72 and cogs 74 are configured so that, in the absence of the actuator cam 60 , a toe end 76 of each pawl 62 enters one of the notches 72 and is engaged by the corresponding cog 74 when the driven hub 50 and the inner race 56 rotate in a clockwise direction as viewed in FIG. 2 relative to the outer housing 52 and the outer race 58 to cause the connected components to rotate together. Similarly, a toe end 78 of each pawl 64 enters one of the notches 72 and is engaged by the corresponding cog 74 when the driven hub 50 and the inner race 56 rotate in a counterclockwise direction relative to the outer housing 52 and the outer race 58 to cause the connected components to rotate together.
[0023] Within its interior periphery, the actuator cam 60 incorporates a strategically situated array of circumferentially spaced recesses, herein called slots 80 , defined by and situated between projections, herein called cam teeth 82 . The slots 80 and cam teeth 82 are adapted to interact with the pawls 62 , 64 to control their movement within the apertures 66 , 68 , respectively, and disposition within the notches 72 and engagement by the cogs 74 as will be described. The actuator cam 60 may further include an actuator tab 84 or other appropriate member or surface that may be engaged by an actuator device 100 that is capable of causing the actuator cam 60 to move through its rotational range to the positions shown in FIGS. 2-4 . The actuator device 100 may be any appropriate actuation mechanism capable of moving the actuator cam 60 , such as a hydraulic actuator as illustrated and described below operatively coupled to the actuator cam 60 and capable of rotating the actuator cam 60 to multiple positions. The actuator tab 84 may include a radially extending slot 85 that receives a cam actuator bar 102 extending from a longitudinally extending slot 104 of the actuator device 100 . The cam actuator bar 102 may transmit forces from the actuator device 100 to rotate the actuator cam 60 in the clockwise and counterclockwise directions. The interconnection between the actuator cam 60 and the actuator device 100 is illustrative, and alternative arrangements and linkages facilitating conversion of translational motion of the actuator device 100 into rotational motion of the actuator cam 60 to shift between a plurality of available clutch modes are contemplated and will be apparent to those skilled in the art. In the illustrated embodiment, the actuator tab 84 may be disposed within a slot 86 through the outer race and the rotation of the actuator cam 60 may be limited by a first limit surface 88 engaging the actuator tab 84 at the position shown in FIG. 2 and a second limit surface 90 engaging the actuator tab 84 at the position shown in FIG. 4 .
[0024] The pawls 62 , 64 are asymmetrically shaped, and reversely identical. Each of the opposed pawls 62 , 64 is movably retained within its own bowtie-shaped pawl aperture 66 , 68 , respectively, of the inner race plates 56 A and 56 B. The toe end 76 , 78 of each individual pawl 62 , 64 , respectively, is urged radially outwardly via a spring 92 . Each spring 92 has a base 94 , and a pair of spring arms 96 and 98 . The spring arms 96 bear against the bottoms of the pawls 62 , while the spring arms 98 bear against the bottoms of the pawls 64 , each to urge respective toe ends 76 , 78 into engagement with the cogs 74 of the outer race 58 when not obstructed by the cam teeth 82 of the actuator cam 60 . It will be appreciated from FIG. 2 that axially extending rivets 99 are used to secure the inner race plates 56 A, 56 B together. The rivets 99 extend through the apertures 70 in each of the plates 56 A, 56 B to hold the two plates 56 A, 56 B rigidly together, and to thus assure against any relative rotation with respect to the plates 56 A, 56 B. In lieu of the rivets 99 , other structural fasteners may be employed within the scope of this disclosure to secure the inner race plates 56 A, 56 B.
[0025] It will be appreciated that the actuator device 100 ultimately controls the actuator tab 84 which, in turn, moves the actuator cam 60 between multiple distinct angular positions. Thus, the positioning of the pawls 62 , 64 as axially retained between the riveted inner race plates 56 A, 56 B is directly controlled by the actuator cam 60 against forces of springs 92 . In FIG. 2 , the actuator tab 84 is shown positioned by the actuator device 100 in a first, angularly rightward selectable position, representative of a first, one-way locked, one-way unlocked or open mode. In this position, the slots 80 and cam teeth 82 of the actuator cam 60 are positioned so that the toe ends 76 of the pawls 62 are blocked by cam teeth 82 from engagement with notches 72 , and hence with the cogs 74 on the interior of the outer race 58 . As such, the inner race 56 is enabled to freewheel relative to the outer race 58 , and to thus provide for an overrunning condition when the inner race 56 and the driven hub 50 are rotating clockwise relative to the outer race 58 and the outer housing 52 . Conversely, however, the position of the actuator cam 60 allows of the toe ends 78 of the pawls 64 to enter the slots 80 of the actuator cam 60 due to the biasing force of the spring arms 98 , and to thereby directly engage the cogs 74 of the outer race 58 to lock the inner race 56 and the outer race 58 together whenever the inner race 56 and the driven hub 50 undergo a driving, or counterclockwise rotational movement, thereby causing the driven hub 50 and the outer housing 52 to rotate together.
[0026] FIG. 3 illustrates the actuator tab 84 placed by the actuator device 100 in a second, intermediate selectable position, representative of a two-way unlocked or open mode of the multimode clutch 10 . In this position, the slots 80 and the cam teeth 82 of the actuator cam 60 are positioned to prevent the toe ends 76 , 78 of both pawls 62 , 64 from entering the slots 80 of the actuator cam 60 , and to maintain disengagement from the cogs 74 of the outer race 58 . With the pawls 62 , 64 blocked from engagement with the cogs 74 , the inner race 56 and the driven hub 50 are enabled to freewheel relative to the outer race 58 and the outer housing 52 during relative rotation in either the clockwise or the counterclockwise direction.
[0027] In FIG. 4 , the actuator tab 84 is shown in a third, angularly leftward selectable position, representative of a two-way locked mode of the multimode clutch 10 . In this configuration, the actuator cam 60 is positioned so that the toe ends 76 , 78 of both pawls 62 , 64 enter the slots 80 of the actuator cam 60 under the biasing forces of the spring arms 96 , 98 , respectively, and are engaged by the cogs 74 of the outer race 58 as described above to lock the inner race 56 and the driven hub 50 to the outer race 58 and the outer housing 52 for rotation therewith, irrespective of the rotational direction of the inner race 56 and the driven hub 50 .
[0028] Even though one specific embodiment of the multimode clutch 10 is illustrated and described herein, those skilled in the art will understand that alternative configurations of multimode clutches and other selectable clutches are possible that provide operational modes or positions as alternatives or in addition to two-way unlocked and two-way locked modes ( FIGS. 3 and 4 ), and the one-way locked, one-way unlocked mode ( FIG. 2 ). For example, an additional one-way locked, one-way unlocked mode that may provide for an overrunning condition when the inner race 56 and the driven hub 50 are rotating counter clockwise relative to the outer race 58 and the outer housing 52 , and to lock the inner race 56 and the outer race 58 together whenever the inner race 56 and the driven hub 50 undergo a clockwise rotational movement so the driven hub 50 and the outer housing 52 rotate together. Moreover, alternate structures providing some or all of the modes discuss herein for selectable clutches may be implemented in a similar manner in vehicles, such as that illustrated and described in U.S. Pat. No. 8,079,453, published on Dec. 20, 2011, by Kimes, entitled “Controllable Overrunning Coupling Assembly.” The implementation of such alternative selectable clutches in vehicles and controlling the mode switching using such clutches with actuator devices in accordance with the present disclosure would be within the capabilities of those skilled in the art and is contemplated by the inventors.
[0029] FIG. 5 illustrates one embodiment of the actuator device 100 shown in a cross-sectional view taken through line 5 - 5 of FIG. 2 . The actuator device 100 may include a piston housing 110 having a longitudinal bore 112 extending inwardly into the piston housing 110 from an open end 114 to a closed end 116 disposed opposite the open end 114 . The longitudinal bore 112 may have a generally constant inner diameter as the longitudinal bore 112 extends inwardly to accommodate various internal components of the actuator device 100 . However, the longitudinal bore 112 may include a cap bore portion 118 proximate the open end 114 that transitions to a main bore portion 120 having a constant inner diameter. The longitudinal bore 112 may further define a cap snap ring annular groove 122 in the cap bore portion 118 having a larger inner diameter than the cap bore portion 118 , and a cap engagement surface 124 configured to receive and engage a cap 126 inserted through the open end 114 of the longitudinal bore 112 to retain the internal components within the actuator device 100 . The cap 126 may be held in place by a cap snap ring 128 . The cap snap ring 128 may be annular and have an outer diameter that is greater than the inner diameter of the cap bore portion 118 , and may be pressed into the cap snap ring annular groove 122 to lock the cap 126 in place.
[0030] Additional passages may be defined in the piston housing 110 . The longitudinal slot 104 may extend inwardly from an exterior surface 130 of the piston housing 110 and intersect the longitudinal bore 112 approximately midway between the open end 114 and the closed end 116 . A first fluid passage 132 may extend inwardly from the exterior surface 130 and intersect the main bore portion 120 proximate the open end 114 . A second fluid passage 134 may extend inwardly from the exterior surface 130 and intersect the main bore portion 120 proximate the closed end 116 . The first fluid passage 132 and the second fluid passage 134 may be configured for connection to conduits (not shown) from fluid sources (not shown) of the vehicle for provision hydraulic fluid to opposite ends of the main bore portion 120 . As discussed further below, one or both of the fluid passages 132 , 134 may be connected to pressurized fluid sources providing hydraulic fluid with varying pressures to control the operation of the actuator device 100 and, correspondingly, the multimode clutch 10 .
[0031] The actuator device 100 may include a piston 140 disposed within the longitudinal bore 112 and slidable back and forth in the longitudinal direction within the longitudinal bore 112 . The piston 140 may include a piston body 142 having a first piston stop 144 and a second piston stop 146 extending outwardly longitudinally from opposite sides of the piston body 142 . The first piston stop 144 may engage the cap 126 and the second piston stop 146 may engage a closed end wall 148 to ensure that the piston body 142 is maintained between the first fluid passage 132 and the second fluid passage 134 . The piston body 142 may have a piston body outer diameter that is less than the inner diameter of the main bore portion 120 so that the piston 140 may slide therein without leakage of hydraulic fluid there between. If necessary, appropriate seals (not shown) may be provided at the interface between the main bore portion 120 and the piston body 142 to further prevent leakage of hydraulic fluid. The cam actuator bar 102 may have an end operatively connected to the piston body 152 and extend outwardly through the longitudinal slot 104 to the exterior of the piston housing 110 .
[0032] A piston spring 150 may be disposed within the main bore portion 120 of the longitudinal bore 112 to provide a biasing force on the piston 140 . In the illustrated embodiment, the piston spring 150 may be compressed between the cap 126 and the piston 140 to provide a force biasing the piston 140 toward the closed open end 116 of the longitudinal bore 112 . Absent other forces acting on the piston 140 , the piston spring 150 will move the piston 140 to the right as shown in FIGS. 5-7 until the second piston stop 146 is engaged by the closed end wall 148 . With this arrangement, the actuator device 100 may default to the mode position shown in FIG. 7 . The piston spring 150 may be placed on the opposite side of the piston 140 if it is desired to cause the actuator device 100 to default to the mode position shown in FIG. 5 . If the middle mode position shown in FIG. 6 is the default mode position, a second piston spring 150 may be provided opposite the first piston spring 150 to apply spring forces to the piston 140 in opposite directions. Depending on the particular implementation, the spring constants k of the piston springs 150 may be varied to default the actuator device 100 to any position between the end positions shown in FIGS. 5 and 7 . In still further embodiments, the piston spring 150 may be omitted and the actuator device 100 will not have a default mode position.
[0033] In the illustrated embodiment, the position of the piston 140 , the cam actuator bar 102 and, correspondingly, the actuator cam 60 will be dictated by a first pressure P 1 at the first fluid passage 132 , a second pressure P 1 at the second fluid passage 134 , and the amount of compression of the piston spring 150 . The first pressure P 1 acts on the piston body 142 to exert a first pressure force F 1 to the right in as seen in FIG. 5 , and has a magnitude equal to P 1 ×A 1 , where A 1 is the cross-sectional area of the right side of the piston body 142 . The second pressure P 2 acts on the opposite side of the piston body 142 to exert a second pressure force F 2 on the piston 140 to the left. The second pressure force F 2 has a magnitude equal to P 2 ×A 2 , where A 2 is the cross-sectional area of the left side of the piston body 142 . In the illustrated embodiment, the area A 1 is equal to the area A 2 . In other implementations, the area A 1 and the area A 2 may be different depending on the configuration of the piston 140 and its connection to the piston housing 110 . In either configuration, the equations and relationships discussed hereinafter will have equal applicability. Finally, the piston spring 150 exerts a spring force FS on the piston 140 to the right having a magnitude equal to kX, where k is the spring constant for the piston spring 150 and X is the amount of compression of the piston spring 150 . It is contemplated that the spring constant k will have a constant value over the operating range of the actuator device 100 .
[0034] In the present example, the first pressure P 1 may have a value that is approximately constant and equal to a system pressure of the vehicle that is known to the control system causing changes in the position of the actuator device 100 and the mode of the multimode clutch 10 . The second pressure P 2 may be a control pressure that may be varied by controlling an output pressure of a pressurized hydraulic fluid source (not shown) in fluid communication with the second fluid passage 134 . As a result, the second pressure P 2 is controlled and varied to move the piston 140 and the cam actuator bar 102 .
[0035] As seen in FIG. 5 , the piston 140 is moved to the left with the first piston stop 144 engaged by cap 126 . In this position, the cam actuator bar 102 has moved the actuator cam 60 to the first mode position shown in FIG. 2 . The force equation for this position may be expressed as F 1 +FS≦F 2 , or P 1 *A 1 +kX≦P 2 *A 2 . Holding the second pressure P 2 constant, or increasing the second pressure P 2 , will maintain the piston 140 at the left limit position and keep the multimode clutch 10 in the first mode.
[0036] When a controller (not shown) of the vehicle detects that the multimode clutch 10 should move to a second mode such as that shown in FIG. 3 , the controller may cause the pressurized hydraulic fluid source to reduce the second pressure P 2 . When the force equation changes to F 1 +FS>F 2 , or P 1 *A 1 +kX>P 2 *A 2 , the first pressure force F 1 and the spring force FS may overcome the second pressure force F 2 and cause the piston 140 to begin to move to the right toward the second mode position shown in FIG. 6 . As the piston 140 moves toward the second mode position, the controller may receive position sensor signals from a position sensor (not shown) containing values indicating a sensed position of a component of the multimode clutch 100 , the actuator device 100 or other component that is indicative of the state of the actuator cam 60 in transitioning from the first mode position to the second mode position. For example, the position sensor may be operatively connected to the actuator cam 60 , the actuator tab 84 or the cam actuator bar 102 . Upon receiving the position sensor signals, the controller may further adjust the second pressure P 2 as necessary arrive at and maintain the piston 140 at the second mode position of FIG. 6 .
[0037] Once the piston 140 and, correspondingly, the actuator cam 60 arrive at the second mode position, the controller may set the second pressure P 2 at a value that restores the force equation to equilibrium such that F 1 +FS=F 2 , or P 1 *A 1 +kX=P 2 *A 2 . It will be apparent that the spring force FS is less at the second mode position due to the elongation of the piston spring 150 . Correspondingly, the second pressure P 2 and the second pressure force F 2 will be less than at the first mode position of FIG. 5 . From the second mode position, the second pressure P 2 may be decreased to cause the piston 140 to move to the right toward the third mode position of FIG. 7 , or increased to cause the piston 140 to move to the left and return to the first mode position of FIG. 5 .
[0038] FIGS. 8-10 illustrate an alternative embodiment of the actuator device 100 configured to be operatively connected to a multimode clutch 10 having an actuator cam 160 with an actuator tab 184 extending therefrom. The actuator cam 160 may operate in a similar manner as the actuator cam 60 to switch the multimode clutch 10 between mode positions as the actuator cam 160 is rotated about a rotational axis of the multimode clutch 10 . The piston housing 110 may have a similar configuration as described above. A piston 190 may be disposed within the longitudinal bore 112 and slidable back and forth in the longitudinal direction within the longitudinal bore 112 . The piston 190 may have generally the same configuration as the piston 140 described above, and may include a piston body 192 having a first piston stop 194 and a second piston stop 196 extending outwardly longitudinally from opposite sides of the piston body 192 to limit the travel of the piston 190 in each direction in the manner described above. The piston body 192 may have a piston body outer diameter that is less than the inner diameter of the main bore portion 120 so that the piston 190 may slide therein without leakage of hydraulic fluid there between. If necessary, appropriate seals (not shown) may be provided at the interface between the main bore portion 120 and the piston body 192 to further prevent leakage of hydraulic fluid.
[0039] The piston 190 may be configured to engage the actuator tab 184 by providing an annular groove 198 at approximately the longitudinal center of the piston body 192 . The annular groove 198 may be sufficiently wide and deep so that the actuator tab 184 may be inserted through the longitudinal slot 104 and received by the annular groove 198 . The actuator tab 184 may be rounded to facilitate rotation of the actuator tab 184 within the annular groove 198 , and rotation of the actuator cam 160 about the rotational axis of the multimode clutch 10 , as the piston 190 moves from the first mode position of FIG. 8 , past the second mode position of FIG. 9 and to the third mode position of FIG. 10 .
[0040] The embodiment of FIGS. 8-10 further illustrates the use of piston springs 150 on both sides of the piston 190 so that the actuator device 100 may have a default mode position that is between the first mode position and the third mode position. The second piston spring 150 may be taken into accounted in the control strategy by adding a second spring force FS 2 to the force equation acting in the same direction as the second pressure force F 2 . In other respects, the control strategy for the multimode clutch 10 and the actuator device 100 may perform substantially as described above.
INDUSTRIAL APPLICABILITY
[0041] The illustrated configuration of the actuator device 100 and the control strategy for changing the position of the actuator device 100 discussed herein may be advantageous in applications where a selectable clutch has four or more clutch modes. The actuator device 100 provides infinite mode positions that will be dictated by the pressures, the cross-sectional areas of the pistons 140 , 190 , and the spring forces applied by the piston spring(s) 150 . Those skilled in the art will understand that the control strategy for the actuator device 100 may be configured stop the pistons 140 , 190 at additional intermediate mode positions at which a different engagement mode will be provide between the components connected by the selectable clutch. By creating an actuator device 100 wherein the pistons 140 , 190 can be positioned using differential pressures within the piston housing 110 , three or more modes for the multimode clutch 10 can be achieved by changing the pressure differential acting on the single piston 140 , 190 .
[0042] Those skilled in the art will further understand that the configuration of the actuator device 100 and the control strategy described herein are exemplary, and modifications of the design are contemplated. For example, in alternative embodiments, the second pressure P 2 may be held constant and the first pressure P 1 may be controlled to move the piston 140 to the right (increase the first pressure P 1 ) and to the left (decrease the first pressure P 1 ). In further alternatives, both pressures P 1 , P 2 may be controlled so that a pressure differential is varied to move the piston 140 . Such variations are contemplated by the inventors as having use in actuator devices in accordance with the present disclosure.
[0043] The design may be further varied in terms of the location and presence of the piston spring(s) 150 . The piston spring 150 may be moved to other locations in and around the actuator device 100 while still having an effect on the response and control of the pistons 140 , 190 . For example, the piston spring 150 in FIGS. 5-7 could be moved to the opposite side of the piston 140 and positioned between the piston 140 and the closed end wall 148 . In this position, the piston spring 150 would bias the piston 140 toward the one-way locked, one-way unlocked position of FIG. 5 . In these embodiments, the spring force FS would be subtracted from the first pressure force F 1 in the equations discussed above. With the spring force FS assisting the second pressure force F 2 in moving the piston 140 to the left, lower second pressures P 2 will need to be generated to move the piston 140 between the locking positions.
[0044] In other embodiments, the piston spring 150 may be located external to the piston housing 110 , and still be operatively connected to the cam actuator bar 102 ( FIGS. 5-7 ) to provide the spring force FS to the piston 140 . For example, the piston spring 150 may be coupled between a stationary portion of the vehicle, such as the vehicle frame, and the cam actuator bar 102 . Alternatively, the piston spring 150 may be connected between the stationary structure and the cam actuator 60 , 160 that will transfer the spring force FS of the piston spring 150 to the pistons 140 , 190 through the intervening connection provided by the cam actuator bar 102 ( FIGS. 5-7 ) or the actuator tab 184 and the annular groove 198 ( FIGS. 8-10 ). Such external arrangements of the piston spring 150 can function to apply the spring force FS in either direction to either work against or assist the second pressure force F 2 in moving the pistons 140 , 190 between the locking positions, or in both directions to bias the pistons 140 , 190 toward an intermediate locking position.
[0045] As discussed above, in further alternative embodiments, the piston spring 180 may be omitted so that no spring force FS acts on the piston 150 . In such embodiments, the controlled first pressure P 1 will be adjusted accordingly to reflect the absence of the spring force FS from the force balancing equations discussed above. With the spring force FS omitted, the curve of the graph 190 will move downward by an amount that is less than in the situation above where the spring force FS is shifted to assisting the first pressure force F 1 , but removal of the piston spring 180 will still lower first pressures P 1 required to move the piston 150 between the locking positions.
[0046] While the preceding text sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of protection is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the scope of protection.
[0047] It should also be understood that, unless a term was expressly defined herein, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to herein in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning.
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An actuation device having a piston is used to actuate a mechanical or friction clutch by means of differential pressure. Two sides of a piston are pressurized, and the relative pressure between the two sides is decreased or increased to move the piston in either direction. The position of the piston may be determined using position feedback, or with springs of known spring rates, two piston areas, and knowing the pressures of the two areas. The actuation device may be used with a selectable clutch to actuate an actuation cam, and may also have application with other clutches requiring the ability to achieve multiple positions and clutch modes.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to information processing systems and in particular to an open network system and the management of system communication, therein. More particularly, it relates to fault management for the system and the protocols for exchanging network management information relating to tests for faults between system management and agent devices.
2. Description of the Prior Art
Systems management is the science of providing mechanisms and methods for the monitoring, control and co-ordination of the devices and resources within a network system. More simply, for an expansive computer system comprised of many elements, it concerns the ways that must be devised so that the elements can work together and communicate. The elements of the system are typically made by a number of different manufacturers so if the elements are to work together they must have a common means, accepted by the manufacturers, for communication and cooperation. The standards appropriate to the management of open communications and operations in a network are generally referred to as "Open Systems Interconnection" (OSI) standards.
The International Organization for Standardization (ISO) has been striving to set such common standards. These include specified procedures for carrying out necessary systems management activities. Such activities are generally grouped into five areas: fault management, configuration management, accounting management, performance management and security management. The subject matter of this invention generally concerns the activity of fault management.
The ISO has generally described systems management standards in a project paper entitled Information Processing Systems--Open Systems Interconnection--Systems Management: Overview, ISO/IEC JTC1/SC21/WG4 N571, July 1988. As described therein, the management functions of a conventional network management system are divided into managing processes and agent processes. The object of management is referred to as a "managed object." A managed object is a system resource that is subject to management, such as a layer entity, a connection or an item of physical communications equipment. A managing process has responsibility for a management activity. An agent process manages, at the request of a managing process, the associated managed objects. It is important to note that network management information relating to the managed object is exchanged between the managing process and the agent process.
For simplification purposes, hereafter a network managing apparatus performing a managing process will be referred to as a "manager" and a network managing apparatus performing an agent process will be referred to as an "agent".
The ISO has also generally described a protocol for fault management in a paper entitled Information Processing Systems--Open Systems Interconnection--Systems Management: Fault Management Working Document ISO/IEC JTC1/SC21 N3312, January, 1989. Much of the information necessary for fault management is derived from a systems function identified as confidence and diagnostic testing which provides for one user to direct another user to perform a test on a managed object to determine if it is capable of performing its service or to assist in diagnosis of a fault. This paper provides a model for the OSI environment in the operation of a test. The initiator of a test is referred to as a test conductor. It requests the execution of a test. A test performer executes the test. Test performers are considered to be managed objects and are sometimes referred to as "test objects." In a test whose execution is dispersed to involve more than one open system, separate test performers exist in each system. The test performer with whom the test conductor communicates is referred to as the primary test performer. The test performer with whom the primary test performer communicates is called the secondary test performer. The primary test performer includes a test request receiver which receives a test request from the test conductor, a test object comprising the test itself and the testing equipment, and a resource under test as the resource which is utilized in the test.
Problems to be Solved by the Invention
The OSI standards described above merely specify an abstract test model but do not at all prescribe any definite techniques for performing the test such as protocols or their timings. When considering a network management system for concentrated managing of a large network including a large number of sub-networks, ultra high speed and performance levels are required. It is more effective to dispose agents for managing the individual sub-networks in order to divide functionally the management function of the manager as described in the OSI document cited above (N3312). However, no technical solution at all has been proposed or defined on how to divide functionally the management function of the manager for suitable management of the network. Each agent that manages a sub-network operates in any one of a plurality of test operation modes (idle state, initiation state, test state, etc., as identified in the OSI paper, N3312) and it becomes an important technical problem for the distribution of the network management function whether the switch of these test operation modes should be made by the agent itself or by the manager.
The present invention contemplates new and improved methods and systems which overcome the foregoing problems to provide a high quality network management system with high speed fault management protocols that require reduced manager obligations for the fault management and test protocols.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with the present invention, a network management method is provided wherein the agent apparatus autonomously notifies the manager apparatus of the subject and content of a test made for the sub-network, executes the test in accordance with the test content, reports sequentially the test result to the manager apparatus, autonomously terminates the test and sends the termination report of the test to the manager apparatus. The manager apparatus is equipped with timer means capable of setting arbitrarily the period from the execution till timeout, and executes or suspends the timer means (TIMER #1) in accordance with the report or the report content from the agent apparatus. The manager apparatus further initiates the termination process of the test for the agent apparatus when the timer means comes to timeout.
In a network system equipped with a test mode in which a test for an arbitrary sub-network is autonomously executed and another test mode in which the test described above is executed by the manager apparatus, the manager apparatus, operating in a second test mode, is equipped with timer means (TIMER #2) capable of setting arbitrarily the period from the start till timeout, gives the test content for an arbitrary sub-network or the instruction relating to the execution or suspension of the test operation to the agent apparatus which manages this subnetwork, starts the timer means (Timer #2) , suspends the timer means (Timer #2) in accordance with a predetermined response content sent from the agent apparatus in response to the instruction described above and issues the termination instruction of the test in accordance with timeout of the timer means or the last report of the test result made by the agent apparatus. Further, the manager apparatus is equipped with timer means (Timer #3) capable of setting arbitrarily the period from the start till timeout, starts the timer means (Timer #3) in accordance with a predetermined response content from the agent apparatus, suspends this timer means in accordance with the last test report sent from the agent apparatus and makes the termination instruction of the test irrespective of the existence of the last report of the test result when this timer means comes to timeout.
The agent also is equipped with timer means capable of setting arbitrarily the period from the start till timeout, executes the timer means in accordance with the response content delivered in response to each instruction from the manager, suspends the timer means in accordance with a predetermined instruction content from the manager and makes autonomously the test termination irrespective of the termination instruction of the test from the manager when the timer means comes to timeout.
In accordance with another aspect of the present invention, the function of executing, reporting and terminating autonomously a test for a sub-network is provided to the agent and the manager performs the switch instruction of the test operation mode in accordance with timeout of its built-in timer. Therefore, the functions of the manager can be reduced, and it is possible to prevent the uncontrolled state of the testing for a long time without termination of the test, and the erroneous operation due to the continuance of the test object without disappearing for a long time. In the network system equipped with a test mode in which the test for an arbitrary sub-network is executed autonomously and another test mode in which the test described above is executed by the manager apparatus, if the test is interrupted due to a failure or the like, the manager and the agent give the switch instruction of the test operation mode or execute the switch in accordance with the timer operations of their built-in timer means.
Accordingly, it is possible to prevent the uncontrolled state of the test for a long time without terminating and the erroneous operation due to the continuance of the test object without disappearing for a long time. Thus, a network system and a network management method both suitable for the network management can be accomplished.
It is an object of the present invention to provide a network system and a network management method both suitable for network management having concrete protocols between a plurality of agents that individually manage the sub-networks and a manager in communication with each agent for managing the network as a whole.
It is another object of the present invention to provide a network system and a network management method suitable for network management by providing the agent with an autonomous test function for the sub-network or letting the manager or the agent bear the switch function of the test operation modes in accordance with a protocol.
For ease of understanding, assume a model wherein the test model of the N3312 paper is made to correspond to the test model of the N551 paper as shown in FIG. 6. In the model, a test conductor and a managing process, and a test request receiver of a primary test performance and an agent process may be considered to correspond to one another, respectively, as shown in FIG. 6.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow diagram showing a protocol sequence when an agent reports the result of an autonomous test to a manager;
FIG. 2 is a flow diagram showing the protocol sequence of a test having an implicit reporting mechanism and an implicit termination mechanism between the manager and the agent in accordance with the present invention;
FIG. 3 is a flow diagram showing the protocol sequence of a test having an explicit reporting mechanism and an implicit termination mechanism between the manager and the agent in accordance with the present invention;
FIG. 4 is a flow diagram showing the protocol sequence of a test having an explicit reporting mechanism and an implicit termination mechanism between the manager and the agent in accordance with the present invention;
FIG. 5 is a flow diagram showing the protocol sequence of a test having an explicit reporting mechanism and an explicit termination mechanism between the manager and the agent in accordance with the present invention;
FIG. 6 is a comparative diagram showing a correspondence table of the concepts of a test model in accordance with ISO Paper No. N3312 and a management model in accordance with ISO Paper No. N517;
FIG. 7 is a table showing the test states which a test object of the present invention can take;
FIG. 8 is a table showing the services of the present invention;
FIG. 9 is a logical structural view of a manager in accordance with the present invention;
FIG. 10 is a logical structural view of an agent in accordance with the present invention;
FIG. 11 is a table showing the parameters which are provided by the primitive of the request and indication of a TEST-ENROL service;
FIG. 12 is a table showing the parameters which are provided by the primitive of the request and indication of a TEST-DEENROL service;
FIG. 13 is a table showing the parameters which are provided by the primitive of the request and indication of a TEST-CREATE service;
FIG. 14 is a table showing the parameters which are provided by the primitive of the response and confirm of a TEST-CREATE service;
FIG. 15 is a table showing the parameters which are provided by the primitive of the request and indication of a TEST-DELETE service;
FIG. 16 is a table showing the parameters which are provided by the primitive of the response and confirm of a TEST-DELETE service;
FIG. 17 is a table showing the parameters which are provided by the primitive of the request and indication of a CHANGE-STATE service;
FIG. 18 is a table showing the parameters which are provided by the primitive of the response and confirm of a CHANGE-STATE service;
FIG. 19 is a table showing the parameters which are provided by the primitive of the request and indication of a TEST-GET service;
FIG. 20 is a table showing the parameters which are provided by the primitive of the response and confirm of a CONNECTIVITY-TEST-GET service;
FIG. 21 is a table showing the parameters which are provided by the primitive of the request and indication of a CONNECTIVITY-TEST-REPORT service;
FIG. 22 is a table showing the parameters which are provided by the primitive of the request and indication of a LOOPBACK-TEST-REPORT service;
FIG. 23 is a table showing the parameters which are provided by the primitive of the request and indication of a DATA-INTEGRITY-TEST-REPORT service;
FIG. 24 is a table showing the parameters which are provided by the primitive of the request and indication of a FUNCTION-TEST-REPORT service;
FIG. 25 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the TEST-ENROL service, to parameters which are provided by the primitive of the request and indication of an m-Event-Report service provided by the CMISE;
FIG. 26 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the TEST-DEENROL service, to the parameters which are provided by the primitive of the request and indication of the m-Event-Report service provided by the CMISE;
FIG. 27 is a diagram showing mapping of the parameters which are provided by the primitive of the request and indication of the TEST-CREATE service, to parameters which are provided by the primitive of the request and indication of an m-Create service provided by the CMISE;
FIG. 28 is a diagram showing the mapping of the parameters which are provided by the primitive of the response and confirm of the TEST-CREATE service, to parameters which are provided by the primitive of the response and confirm of the m-Create service provided by the CMISE;
FIG. 29 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the TEST-DELETE service, to parameters which are provided by the primitive of the request and indication of an m-Delete service provided by the CMISE:
FIG. 30 is a diagram showing the mapping of the parameters which are provided by the primitive of the response and confirm of the TEST-DELETE service, to parameters which are provided by the primitive of the response and confirm of the m-Delete service provided by the CMISE;
FIG. 31 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the CHANGE-STATE service, to parameters which are provided by the primitive of the request and indication of an m-Set service provided by the CMISE;
FIG. 32 is a diagram showing the mapping of the parameters which are provided by the primitive of the response and confirm of CHANGE-STATE service, to parameters which the primitive of the response and confirm of an m-Set service provided by the CMISE;
FIG. 33 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of TEST-GET service, to the parameters which are provided by the primitive of the request and indication of an m-Get service provided by the CMISE;
FIG. 34 is a diagram showing the mapping of the parameters which are provided by the response and confirm of the TEST-GET service, to the parameters which are provided by the primitive of the response and confirm of the m-Get service provided by the CMISE;
FIG. 35 is a diagram showing the mapping of the parameters which are provided by the request and indication of the CONNECTIVITY-TEST-REPORT service, to the parameters which are provided by the primitive Of the request and indication of an m-Event-Report service provided by the CMISE;
FIG. 36 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the LOOPBACK-TESTREPORT service to the parameters which are provided by the primitive of the request and indication of the m-Event-Report service provided by the CMISE;
FIG. 37 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the DATA-INTEGRITY-TEST-REPORT service to the parameters which are provided by the primitive of the request and indication of the m-Event-Report service provided by the CMISE;
FIG. 38 is a diagram showing the mapping of the parameters which are provided by the primitive of the request and indication of the FUNCTION-TEST-REPORT service, to the parameters which are provided by the primitive of the request and indication of the m-Event-Report service provided by the CMISE:
FIG. 39 is a table showing the attributes of the Connectivity Test Class in accordance with the present invention;
FIG. 40 is a table showing the attributes of the Loopback Test Class in accordance with the present invention;
FIG. 41 is a table showing the attributes of the Data Integrity Test Class in accordance with the present invention;
FIG. 42 is a table showing the attributes of the Function Test Class in accordance with the present invention;
FIG. 43 is a schematic view of a network system comprising an integrated network management system, subnetwork management system and information processing and communication equipment (subnetwork) assembled in accordance with the present invention;
FIG. 44 is a block diagram of the integrated network management system of FIG. 43; and,
FIG. 45 is a block diagram of the subnetwork management system of FIG. 43.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings where the showings are for purposes of illustrating preferred embodiments of the invention only and not for purposes of limitation, the Figures show a network management system and method useful for implementation of fault management in an open information processing system.
The logical construction of the manager and the agent is best explained before the particular system configuration and operation are described.
As described in the ISO Paper No. N3312 cited above, a test is conducted to the test object. The test object has various test states such as an idle state, an initiation state, a testing state, a reporting state and a termination state, as are shown and described in FIG. 7. A failure state may also exist but is not necessary for the description of the present invention. Transition through the test states will determine the sequence the test.
The present invention provides the stipulated services tabulated in FIG. 8. FIG. 9 is a logical block diagram of the configuration of a manager for executing these services and FIG. 10 is a logical block diagram of the configuration of an agent for executing the services. The services are ones which the test function invoker functional unit (FIG. 9) and the test function performer functional unit (FIG. 10) of the Specific Management Information Service Entity ("SMISE") 210 provide to the test applications 200, 205, respectively, by utilizing the Common Management Information Service Entity ("CMISE") 220, 225. (Common elements to both assemblies are identified by like numerals.)
The manager and the agent are modelled by an OSI7 hierarchical model, i.e., a seven layer Basic Reference Model (note ISO Paper No. N571 at pg. 1). FIGS. 9 and 10 show the configuration of the application layers of the manager and agent, respectively. The application layer consists of an Association Control Service Element 230, a Remote Operation Service Element 240, CMISE 220, 225, SMISE 210 and test applications 200, 205.
The services and protocols provided by the Association Control Service Element 230 are prescribed in ISO/IEC 8649 Information Processing Systems Open Systems Interconnection--Service Definition for the Association Control Service Element and ISO/IEC 8650 Information Processing Systems--Open Systems Interconnection--Protocol Specification for the Association Control Service Element.
The services and protocols provided by the Remote Operation Service Element 240 are prescribed in ISO/IEC 9072-1 Information Processing Systems Text Communication--Remote Operations--Part 1: Model, Notation and Service Definition and in ISO/ IEC 9072-2 Information Processing Systems--Text Communication--Remote Operations--Part 2: Protocol Specification.
The services and protocols provided by the CMISE are prescribed in ISO/IEC DIS 9595-2 Information Processing Systems--Open Systems Interconnection Management Information Service Definition--Part 2: Common Management Information Service and in ISO/IEC DIS 9596-2 Information Processing Systems--Open Systems Interconnection--Management Information Protocol Specification--Part 2: Common Management Information Protocol.
Each CMISE 220, 225 consists of several functional units. The present invention includes, in the configuration of the manager CMISE 220, an event report performer functional unit, confirmed get invoker functional unit, confirmed set invoker functional unit, confirmed create invoker functional unit, and confirmed delete invoker functional unit.
Included in the configuration of CMISE 225 of the agent, are an event report invoker functional unit, confirmed get performer functional unit, confirmed set performer functional unit, confirmed create performer functional unit, and confirmed delete performer functional unit.
Next, each of the services defined in the present invention will be explained. Generally, a service consists of four primitives, that is, request, indication, response and confirm.
A TEST-ENROL service is the service which reports to the manager that the agent has generated the test object. This service consists of the primitives of request and indication and has parameters as shown in FIG. 11. The parameters are mapped to the primitives of request and indication of an m-Event-Report service of CMISE 220, 225 as shown in FIG. 25, respectively.
It is possible by use of this TEST-ENROL service to report to the manager that the agent has autonomously started the test. It is also possible to report to the manager which test the agent executes, by use of the Test Object Class which is the parameter of the primitive of the request and indication of the TESTENROL service shown in FIG. 11. The tests can be recognized by the Test Object Class parameter and the Test Object Instance parameter. The time at which the agent starts the test and the condition under which the test is started can be known by use of the other parameters shown in FIG. 11.
The TEST-DEENROL service is the service which reports to the manager that the agent has deleted the test. This service consists of the primitives of request and indication and has the parameters shown in FIG. 12. The parameters are mapped to the primitives of request and indication of the m-Event Report service of CMISE 220, 225 as shown in FIG. 26, respectively.
It is possible by use of this TEST-DEENROL service to report to the manager that the agent terminates the test which it has started autonomously. The finished tests can be distinguished by the Test Object Class parameter and Test Object Instance parameter as the parameters of the primitive of the request and indication of the TEST-DEENROL service shown in FIG. 12. It is possible to know the time at which the agent terminates the test, by use of the Deenrol Time parameter.
The TEST-CREATE service is the service by which the manager requests the agent to create the test object. This service consists of primitives of request, indication, response and confirm and the primitives of the request and indication of this service have the parameters shown in FIG. 13. The primitives of the confirm and response for this service has the parameters shown in FIG. 14. As shown in FIG. 27, respectively, the parameters of the request and indication of this service are mapped to the primitives of the request and indication of the m-Create service of the CMIS 220, 225. The parameters of the response and confirm of this service are mapped to the primitives of the response and confirm of the m-Create service of the CMISE 220, 225 as shown in FIG. 28, respectively.
The manager can request the agent to execute the test by use of this TEST-CREATE service. The manager can let the agent know which kind of test is to be executed by use of the Test Object Class parameters as the parameters of the primitives of the request and indication of the TEST-CREATE service shown in FIG. 13. The manager can set the condition of the test by use of the Attribute List parameters.
The manager can know which test is started, by use of the Test Object Class parameter and the Test Object Instance parameter as the parameters of the primitives of the response and confirm of the TEST-CREATE service shown in FIG. 14. Further, the manager can know the time of the start of the test by use of the Create Time parameter, and can know the cause why the start of the test has failed, by use of the Errors parameter.
The TEST-DELETE service is the service by which the manager requests the agent to delete the test object. This service consists of the primitives of request, indication, response and confirm, and the primitives of the request and indication of this service have the parameters shown in FIG. 15. The primitives of the response and confirm of this service have the parameters shown in FIG. 16. The parameters of the primitives of the request and indication of this service are mapped to the primitives of the request and indication of the m-Delete service of the CMISE 220, 225 as shown in FIG. 29, respectively. The parameters of the primitives of the response and confirm of this service are mapped to the primitives of the response and confirm of the m-Delete service of CMISE 220, 225 as shown in FIG. 30.
The manager can instruct the end of the test to the agent by use of this Test-Delete service. The manager can instruct which test should be terminated, by use of the Test Object Class parameter and Test Object Instance parameter as the parameters of the primitives of the request and indication of the TEST-DELETE service shown in FIG. 15.
The manager can know which test has been terminated by use of the Test Object Class parameter and Test Object Instance parameter as the parameters of the primitives of the response and confirm of the TEST-DELETE service shown in FIG. 16. The manager can know the termination time of the test by use of the Delete Time parameter. Further, the manager can know the cause of the failure of the termination of the test, by use of the Errors parameter.
The CHANGE-STATE service is the service by which the manager requests the agent to change the test state of the test object. This service consists of the primitives of request, indication, response and confirm and the primitives of the request and indication of this service have the parameters shown in FIG. 17. The primitives of the response and confirm of this service have the parameters shown in FIG. 18. The parameters of the primitives of the request and indication of this service are mapped to the request and indication of the m-Set service of the CMISE 220, 225 as shown in FIG. 31, respectively. The parameters of the primitives of the response and confirm of this service are mapped to the primitives of the response and confirm of the m-Set service of the CMISE 220, 225 as shown in FIG. 32, respectively.
The execution control of the test can be made by use of this CHANGE-STATE service. In other words, the test can be executed by changing the test state to the initiation state, or the test can be suspended by changing the test state to the idle state.
The test whose execution is to be controlled can be designated by use of the Test Object Class parameter and the Test Object Instance parameter as the parameters of the primitives of the request and indication of the CHANGE-STATE service shown in FIG. 17. The test can be executed by setting a value representing the initiation state to the Test State parameter or can be suspended by setting a value representing the idle state.
The manager can know to which test the execution control is made, by use of the Test Object Class parameter and Test Object Instance parameter as the parameters of the primitives of the response and confirm of the CHANGE-STATE service shown in FIG. 18. The manager can know the time of the execution control for the test, by use of the Change Time parameter. Furthermore, the manager can know the cause of the failure of the execution control for the test, by use of the Errors parameter.
The TEST-GET service is the one by which the manager requests the agent to collect the test result that the test object has. This service consists of the primitives of request, indication, response and confirm, and the primitives of the request and indication of this service have the parameters shown in FIG. 19. The primitives of the response and confirm of this service have the parameters shown in FIG. 20. The parameters of the primitives of the request and indication of this service are mapped to the primitives of the request and indication of the m-Get service of CMISE 220, 225 shown in FIG. 33, respectively. The parameters of the primitives of the response and confirm of this service are mapped to the primitives of the response and confirm of the m-Get service of CMISE 220, 225 as shown in FIG. 34, respectively.
The test result can be collected by use of this Test-Get service. It is possible to designate the test result of which test should be collected, by use of the Test Object Class parameter and Test Object Instance parameter as the parameters of the primitives of the request and indication of the TEST-GET service shown in FIG. 19. The kind of the test result to be collected can be designated by use of the Attribute Identifier List parameter.
It is possible to distinguish to which test the collected test result belongs, by use of the Test Object Class parameter and the Test Object Instance parameter as the parameters of the primitives of the response and confirm of the TEST-GET service shown in FIG. 20. The time of collection of the test result can be known by use of the Get Time parameter, and the test result can be known by use of the Attribute List parameter. Further, the reason why the test information cannot be collected can be known by use of the Errors parameter.
The CONNECTIVITY-TEST-REPORT service is the one by which the agent reports the test result of the connectivity test to the manager. This service consists of the primitives of request and indication and has the parameters shown in FIG. 21. The parameters are mapped to the primitives of the request and indication of the m-Event-Report service of CMISE 220, 225 as shown in FIG. 35, respectively.
The agent can report the test result of the connectivity test to the manager by use of this CONNECTIVITY-TEST-REPORT service. It is possible to know which result of connectivity test has been reported, by use of the Test Object Class parameter and the Test Object Instance parameter as the parameters of the primitives of the request and indication of the CONNECTIVITY-TEST-REPORT service shown in FIG. 21 The time when the test result is reported can be known by use of the Report Time parameter. The result of the connectivity test can be known by use of the Test Result parameter. Whether or not the reported test result is the last report can be known by use of the Last Report parameter. The information other than the test result can be known by use of the Other Information parameter.
The LOOPBACK-TEST-REPORT service is the one by which the agent reports the test result of the loopback test to the manager. This service consists of the primitives of the request and indication and has the parameters, as shown in FIG. 22. These parameters are mapped to the primitives of the request and indication of the m-Event-Report service of CMISE 220, 225 as shown in FIG. 36, respectively.
The agent can report the test result of the loopback test to the manager by use of this LOOPBACK-TEST-REPORT service. It is possible to know which result of loopback test has been reported, by use of the parameter of the primitive of the indication as the request of the LOOPBACK-TEST-REPORT service shown in FIG. 22, the Test Object Class parameter and the Test Object Instance parameter. The time when the test result has been reported can be known by use of the Report Time parameter. The test result of the loopback test can be known by use of the Test Result parameter. Whether or not the reported test result is the last report can be known by use of the Last Report parameter. The information other than the test result of the loopback test can be known by use of the Other Information parameter.
The DATA-INTEGRITY-TEST-REPORT service is the one by which the agent reports the test result of the data integrity test to the manager. This service consists of the primitives of the request and indication and has the parameters shown in FIG. 23. These parameters are mapped to the primitives of the request and indication of the m-Event-Report service as shown in FIG. 37, respectively.
The agent can report the test result of the data integrity test to the manager by use of this DATA-INTEGRITY-TEST-REPORT service. It is possible to know the test result of which data integrity test is reported by use of the Test Object Class parameter and the Test Object Instance parameter the parameters of the primitives of the request and indication of the DATA-INTEGRITY-TEST-REPORT service. The time when the test result is reported can be known by use of the Report Time parameter. The test result of the data integrity test can be known by use of the Test Result parameter. Whether or not the reported test result is the last one can be known by use of the Last Report parameter. The information other than the test result of the data integrity test can be known by use of the Other Information parameter.
The FUNCTION-TEST-REPORT service is the one by which the agent reports the test result of the function test to the manager. This service consists of the primitives of the request and indication and has the parameters shown in FIG. 24. These parameters are mapped to the primitives of the request and indication of the m-Event-Report service of CMISE 220, 225 as shown in FIG. 38, respectively.
The agent can report the test result of the function test to the manager by use of this FUNCTION-TEST-REPORT service. It is possible to know the test result of which function test is reported by use of the Test Object Class parameter and the Test Object Instance parameter as the parameters of the primitives of the request and indication of the FUNCTION-TEST-REPORT service shown in FIG. 24. The time at which the test result is reported can be known by use of the Report Time parameter. The test result of the function test can be known by use of the test result parameter. Whether or not the reported test result is the last one can be known by use of the Last Report parameter. The information other than the test result of the function test can be known by use of the Other Information parameter.
In FIGS. 11 through 24, the mandatory degree of each parameter means the following.
(1) M . . . Mandatory:
This means the parameter which becomes mandatory irrespective of the condition, state, etc.
(2) U . . . User Option:
This means the parameter which is used in accordance with the application utilizing the services described above.
(3) C . . . Conditional:
This means the parameter which is used in accordance with the condition in which the services are used. Next, the meaning of each parameter shown in FIGS. 11 to 24 will be explained.
Invoke Identifier:
This is a parameter for making the primitives of the request and confirm of the service correspond to the primitives of the indication and response one-to-one.
Test Object Class:
This is a parameter for distinguishing the object classes of the test object.
Test Object Instance:
This is a parameter for distinguishing the object instances of the test object.
Enrol Time & Create Time:
They are parameters representing the creation time of the test object.
Attribute List:
This is a list of the attribute values of the test object, for example, a location or identification number.
Deenrol Time and Delete Time:
They are parameters representing the time of deletion of the test object.
Errors:
This is a parameter representing the cause of failure if the service fails.
Test State:
This is a parameter which represents the test state of the test object.
Change Time:
This is a parameter which represents the time at which the test state of the test object is changed.
Attribute Identifier List:
This is a list of identifiers which represent the attributes of the test object.
Get Time:
This is a parameter which represents the time at which the attribute values of the test object are collected.
Report Time:
This is a parameter which presents the time at which the test result is reported, and which is kind of the attribute values of the test object.
Test Result:
This is a parameter which represents the test result of the test object.
Last Report:
This is a parameter which represents whether the report of the test result of the test object is the last one or still continues.
Other Information:
This is the parameter which represents the attribute value other than the test result of the test object. It can be a future option.
Next, each object class of the test object will be explained. The test objects are classified into four kinds, that is, Connectivity Test Class, Loopback Test Class, Data Integrity Test Class and Function Test Class, in accordance with the kinds of tests described in the ISO Paper No. N3312.
The Connectivity Test Class is a test for confirming whether or not connection can be established between two entities. The Connectivity Test Class has the attributes shown in FIG. 39. The attributes have the following means.
Test State:
This represents the test state of the test object.
Timeout Period:
This represent the maximum time which can be used for establishing connection between the entities.
Tested Object:
This represents the entity which transmits the connection establishment request among the entities.
Pair Object:
This represents the entity which receives the connection establishment request among the entities.
Established Time:
This represents the time which is required for the establishment of connection.
Report Time:
This represents the time at which the test result of the test object is reported.
Last Report:
This represents whether the report of the test result of the test object is the last report or still continues.
Test Result:
This represents the test result of the test object.
Effective Time:
This represents the maximum value of the time in which the test object is not deleted, when the operation is not executed for the test object or an event does not occur for the test object.
The Loopback Test Class is a test for confirming the state of the line till a loopback point by looping back suitable test data to the suitable loopback point. The Loopback Test Class has the attributes shown in FIG. 40. The attributes have the following meaning.
Test State, Report Time, Last Report, Test Result and Effective Time have the same meaning as those of the Connectively Test Class described already.
Source Object:
This represents a managed object which transmits the test data of the loopback test.
Destination Object:
This represents a managed object which receives the test data of the loopback test.
Intermediate Object:
This represents the loopback point of the test data of the loopback test.
Timeout Period:
This represents the maximum time which can be used for the execution of the loopback test.
The Data Integrity Test Class is a test for confirming that no change exists in the data exchanged between the two entities. The Data Integrity Test Class has the attributes shown in FIG. 41. The attributes have the following meaning.
Test State, Report Time, Last Report, Test Result and Effective Time have the same meaning as those of the attributes of the Connectivity Test Class.
Timeout Period:
This represents the maximum time which can be used for the execution of the Data Integrity Test.
Tested Object:
This represents the entity which transmits the test data of the Data Integrity Test among the entities.
Pair Object:
This represents the entity which receives the test data of the Data Integrity Test.
Test Data:
This represents the test data of the data integrity test which is exchanged between the entities.
Failure Cause:
This represents the cause of failure when the data integrity test fails.
The Function Test Class described above is a test for confirming the function of the managed object. The Function Test Class has the attributes shown in FIG. 42. The attributes have the following meaning.
Test State, Report Time, Last Report, Test Result and Effective Time have the same meaning as that of the attributes of the Connectivity Test Class described already.
Tested Object:
This represents the managed object.
Timeout Period:
This represents the maximum time which can be used for the execution of the function test.
Next, the definite protocols between the manager and the agent that comprise the subject invention will be explained.
FIG. 43 is a diagram showing the connection relation between the integrated network management system 10, the subnetwork management systems 20-1 to 20-3 and information processing equipment and communication equipment 30-1 to 30-3 which comprise the managed objects. The integrated network management system 10 functions as the manager and the subnetwork management system 20 functions as the agent.
The integrated network management system 10 is connected to the subnetwork management systems 20-1 to 20-3 by the communication line 70 between the integrated network management system and the subnetwork management systems and exchanges the network management information between it and the subnetwork management systems 20-1 to 20-3.
The information processing equipment and communication equipment 40, 42, 44, 46, 48 are connected by the communication lines 50, 51, 52, 53, 54, 55 and constitute the subnetworks. The subnetwork management system 20-1 is directly connected to the information processing equipment and communication equipment 40 by the communication line 60 between the subnetwork management system and the information processing equipment and communication equipment, and is connected indirectly to the information processing equipment and communication equipment 42, 44, 46, 48 through the information processing equipment and communication equipment 40, and thereby exchanges the network management information. The subnetwork management system 20 may be connected directly to the information processing equipment and communication equipment 42, 44, 46, 48 through the communication line.
The configuration of the integrated network management system 10 and subnetwork management system 20 will be explained with reference to FIGS. 44 and 45. FIG. 44 is a block structural view of the integrated network management system 10. A CPU 100 executes the test protocol in accordance with the present invention by use of the test application program stored in a memory 110. A communication control driver 120 also utilizes the test protocol of the present invention. The network management information that is exchanged between the integrated network management system 10 and the subnetwork management system is stored in external storage equipment 135. A console control driver 150 provides an interface with a network manager through a console 152. The CPU 100, the memory 110, the communication control driver 120, the external storage equipment driver 130 and the console control driver 150 are connected through a common bus 140.
FIG. 45 is a block structural view of the subnetwork management system 20. The function of each block is substantially the same as that of the integrated network management system 10 described above, but is different in that the communication control driver 120 makes the communication control with the information processing equipment and communication equipment 40, 42, 44, 46, and 48.
It is a feature of this embodiment, that the integrated network management system 10 and the subnetwork management system 20 use three kinds of timers for the test protocol. These timers have the following functions.
(1) Timer #1:
This is a timer for deleting the test object when no operation is made for the created test object. It is designated by the Effective Time of the test object.
(2) Timer #2:
This is a timer for confirming that confirm exists for the request transmitted in the case of the confirm type service.
(3) Timer #3:
This is a timer for judging whether or not the test exceeds the maximum time within which the test is executable. It is designated by the Timeout Period of the test object.
When the Timer #1 times out, the agent has caused a timeout and therefore deletes the test object and suspends the test. The manager recognizes that the test object is deleted and the test is suspended.
When the Timer #2 times out, the manager tries again for a predetermined number of times the service that has timed out.
When the Timer #3 times out, the agent suspends the test. The manager recognizes that the test is suspended.
Hereinafter, the CONNECTIVITY-TEST-REPORT service, the LOOPBACK-TEST-REPORT service, the DATA-INTEGRITY-TEST service and the FUNCTION-TEST-REPORT service will be generically referred to as the "TEST-REPORT services".
With reference to FIG. 1, the protocol (the first protocol) will be explained between the test function invoker functional unit and the test function performer functional unit when the subnetwork management system 20 reports autonomously the result of the test conducted for the information processing equipment and communication equipment to the integrated network management system 10.
When the subnetwork management system 20 executes the test autonomously, it creates the test object of the object class corresponding to the kind or "class" of test executed in this subnetwork management system 20. The subnetwork management system 20 reports to the integrated network management system 10 that the test object is created, by use of the request (400) of the TEST-ENROL service, and then executes the test. The TEST-ENROL service request/indication parameter list is shown in FIG. 11.
Being informed of the creation of the test object by the indication (400) of the TEST-ENROL service, the integrated network management system 10 recognizes that the test object described above is created in the subnetwork management system 20, and starts the internal Timer #1.
The subnetwork management system 20 sequentially reports to the integrated network management system 10 the test results of the test which the subnetwork management system 20 executes autonomously, by use of the request (500) of the TEST-REPORT service. As noted above, all the different test reporting services have been grouped together for simplicity in this description but are more particularly shown in FIGS. 21-24. If it is the last report of the test results, it terminates the test by interpreting the value of the parameter of the Last Report parameter of the request (510) of the TEST-REPORT service as "True".
On each receiving of the indications (500, 510) of the TEST-REPORT services, the integrated network management system 10 stops the Timer #1, conducts processing such as the display of the test result, and again starts the Timer #1.
The subnetwork management system 20 reports to the integrated network management system 10 the suspension of the test which the subnetwork management system 20 executes autonomously, by utilizing the request (600) of the TEST-DEENROL service (FIG. 12). Thereafter, the subnetwork management system 20 deletes the test object and the integrated network management system 20 deletes the test object.
Receiving the indication (600) of the TEST-DEENROL service, the integrated network management system 10 suspends the Time #1 and recognizes deletion of the test object in the subnetwork management system 20.
With reference to FIG. 2, the sequence of a second protocol is explained between the test function invoker functional unit and test function performer functional unit having an implicit reporting mechanism and an implicit termination mechanism.
When the integrated network management system 10 instructs the subnetwork management system to execute the test, it generates a request (700) of the TEST-CREATE service to the subnetwork management system 20, which requests the creation of the test object of the object class corresponding to the kind of the test to be executed and at the same time, starts the Timer #2 inside the integrated network management system 10.
Receiving the indication (700) of the TEST-CREATE service (FIG. 13), the subnetwork management system 20 creates the test object and gives the object instance name to it. This object instance name is given in such a manner as not to overlap with other object instance names of other management objects which the subnetwork management system 20 manages at the point of reception of the indication (700) of the TEST-CREATE service. It reports this object instance name to the integrated network management system 10 as the value of the Test Object Instance parameter of the response (710) of the TEST-CREATE service. The Timer #1 of the subnetwork management system 20 is also started simultaneously.
Receiving the confirm (710) (FIG. 14) of the Test-Create Service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10. Then, it requests the subnetwork management system 10 to change the test state of the test object to the initiation state by the request (800) (FIG. 17) of the CHANGE-STATE service, and instructs the subnetwork management system to execute the test.
When requested to change the test state of the test object to the initiation state by the indication (800) of the CHANGE-STATE service, the subnetwork management system 20 suspends the Timer #1 in the subnetwork management system 20 and executes the test as described above. When the execution of this test proves successful, the subnetwork management system 20 returns the response (810) of the CHANGE-STATE service to the integrated network management system 10.
Receiving the confirm (810) (FIG. 18) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 in the integrated network management system 10 and starts the Timer #3 in the integrated network management system 10.
The subnetwork management system 20 reports the test results of the test it has executed to the integrated network management system 10 by the request (500) of the TEST-REPORT service, just as in the first protocol. In the case of the request (510) of the last TEST-REPORT service which reports the test results, the subnetwork management system 20 starts the Timer #1 of the subnetwork management system 20 and changes the test state of the test object to the idle state. In other words, this test is terminated automatically.
Receiving the indication (500) of the TEST-REPORT service, the integrated network management system 10 conducts processing such as the display of the test result. Particularly when the indication is the indication (510) of the last TEST-REPORT service, it suspends the Timer #3 of the integrated network management system 10.
when the test is suspended, the integrated network management system 10 requests the subnetwork management system 20 to delete the test object by the request (900) of the TEST-DELETE service (FIG. 15). At the same time, the integrated network management system 20 starts the timer #2.
Receiving the indication (900) of the TESTDELETE service, the subnetwork management system 20 suspends the Timer #1 of the subnetwork management system 20 and deletes the test object. Thereafter it sends the response to the integrated network management system 10 by the response (910) of the TEST-DELETE service (FIG. 16).
Receiving the confirm (910) of the TEST-DELETE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
With reference to FIG. 3, a third protocol sequence will be explained between the test function invoker functional unit and test function performer functional unit having an implicit reporting mechanism and an explicit termination mechanism.
When the test is executed, the integrated network management system 10 creates the request (700) of the TEST-CREATE service and requests the creation of the test object for the subnetwork management system 20, and at the same time, the integrated network management system 10 executes the Timer #2, just as in the second protocol.
Receiving the indication (700) of the TEST-CREATE service, the subnetwork management system 20 creates the test object and gives the object instance name to it. This object instance name is given in such a manner as not to be the same as any one of the object instance names of other managed objects which are managed by the subnetwork management system 20 at that point. This object instance name is reported as the value of the parameter of the Test Object Instance of the response (710) of the TEST-CREATE service to the integrated network management system 10. In the subnetwork management system 20, the Timer #1 is also executed simultaneously.
Receiving the confirm (710) of the TEST-CREATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10. It requests to change the test state of the test object to the initiation state by the request (800) of the CHANGE-STATE service and instructs the execution of the test.
When requested to change the test state of the test object to the initiation state by the indication (800) of the CHANGE-STATE service, the subnetwork management system 20 suspends the Timer #1 in the subnetwork management system 20 and executes the test described above. When the execution of this test proves successful, it returns the response (810) of the CHANGE-STATE service to the integrated network management system 10.
Receiving the confirm (810) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
The subnetwork management system 20 reports the test result of the executed test to the integrated network management system 10 by the request (500) of the TEST-REPORT service.
Receiving the indication (500) of the TEST-REPORT service, the integrated network management system 10 conducts processing such as the display of the test result.
It is a particular feature of the third protocol that to terminate the test, the integrated network management system 10 requests the subnetwork management system 20 to change the test state of the test object to the idle state by the request (820) of the CHANGE-STATE service (FIG. 17) and executes the Timer #2 of the integrated network management system 10.
When the subnetwork management system 20 is requested to change the test state of the test object to the idle state by the indication (820) of the CHANGE-STATE service, the test is terminated. After the test is terminated, the subnetwork management system 20 sends the response to the integrated network management system 10 by utilizing the response (830) (FIG. 18) of the CHANGE-STATE service. At the same time, the subnetwork management system 20 starts the Timer #1.
Receiving the confirm (830) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
To suspend the test, the integrated network management system 10 requests the subnetwork management system 20 to delete the test object by use of the request (900) of the TEST-DELETE service. At the same time, the integrated network management system 10 starts the Timer #2.
Receiving the indication (900) of the TEST-DELETE service, the subnetwork management system 20 suspends the Timer #1 of the subnetwork management system 20 and deletes the test object. Thereafter, it sends the response to the integrated network management system 10 by the response (910) of the TEST-DELETE service.
Receiving the confirm (910) of the TEST-DELETE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
With reference to FIG. 4, the fourth protocol sequence will be explained between the test function invoker functional unit and test function performer functional unit having an explicit reporting mechanism and an implicit termination mechanism.
To execute the test having an explicit reporting mechanism and implicit termination mechanism, the integrated network management system 10 creates the request (700) of the TEST-CREATE service and requests the subnetwork management system 20 to create the test object in accordance with the kind of the test to be executed, just as in the second protocol. At the same time, the integrated network management system starts the Timer #2.
Receiving the indication (700) of the TEST-CREATE service, the subnetwork management system 20 creates the test object and gives the object instance name to it. This object instance name must be given in such a manner as not to be the same as any one of the object instance names of other managed objects which the subnetwork management system 20 manages at that point. The object instance name is reported to the integrated network management system 10 as the value of the parameter of the Test Object Instance of the response (710) of the TEST-CREATE service. At the same time, the Timer #1 of the subnetwork management system is started.
Receiving the confirm (710) of the TEST-CREATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10. It requests the subnetwork management system 20 to change the test state of the test object to the initiation state by the request (800) of the CHANGE-STATE service and instructs the latter to execute the test.
When the subnetwork management system 20 receives the indication (800) of the CHANGE-STATE service from the integrated network management system 10 and is requested to change the test state of the test object to the initiation state, the subnetwork management system 20 suspends the Timer #1 and executes the test. When the execution of the test proves successful, it returns the response (810) of the CHANGE-STATE service to the integrated network management system 10 and starts the Timer #3. The subnetwork management system 20 executes the test until the internal Timer #3 comes to timeout.
Receiving the confirm (810) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10 and starts the Timer #3 of the integrated network management system 10.
When the time of the Timer #3 has run out in the subnetwork management system 20, the subnetwork management system 20 terminates (automatically) the test, changes the test state of the test object to the idle state and starts the Timer #1 of the subnetwork management system 20.
It is a particular feature of the fourth protocol that when the time of the Timer #3 has run out in the integrated network management system 10, the integrated network management system 10 creates the request (1000) (FIG. 19) of the TEST-GET service and requests the subnetwork management system 20 to report the test result of the test object. At the same time, the integrated network management system 10 starts the Timer #2.
Receiving the indication (1000) of the TEST-GET service, the subnetwork management system 20 suspends the Timer #1 of the subnetwork management system 20 and returns the test result of the test as the value of the parameter of the Attribute List parameter of the response (1010) (FIG. 20) of the TEST-GET service to the integrated network management system 10. It changes the test state of the test object to the idle state and starts the Timer #1 of the subnetwork management system 20.
Receiving the confirm (1010) of the TEST-GET service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10 and conducts processing such as the display of the test result of the test.
To suspend the test executed in the subnetwork management system, the integrated network management system 10 requests the subnetwork management system 20 to delete the test object by use of the request (900) of the TEST-DELETE service and starts the Timer #2 of the integrated network management system 10.
Receiving the indication (900) of the TEST-DELETE service, the subnetwork management system 20 suspends the internal Timer #1 and deletes the test object. Thereafter, it makes response to the integrated network management system 10 by the response (910) of the TEST-DELETE service.
Receiving the confirm (910) of the TEST-DELETE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
With reference to FIG. 5, the sequence of the fifth protocol will be explained between the test function invoker functional unit and the test function performer functional unit having an explicit reporting mechanism and an explicit termination mechanism.
To execute the test, the integrated network management system 10 creates the request (700) of the TEST-CREATE service and requests the subnetwork management system 20 to create the test object of the object class corresponding to the kind of the test. In the integrated network management system 10, the Timer #2 is started simultaneously.
Receiving the indication (700) of the TESTCREATE service, the subnetwork management system 20 creates the test object and gives the object instance name to it. This name is given in such a manner as not to be the same as any one of the object instance names of other managed objects which the subnetwork management system 20 manages at that point. The subnetwork management system 20 reports the object instance name to the integrated network management system 10 by the value of the parameter of the Test Object Instance parameter of the response (710) of the TEST-CREATE service. The subnetwork management system 20 starts simultaneously the Timer #1.
Receiving the confirm (710) of the TEST-CREATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10. Then, it requests to change the test state of the test object to the initiation state by the request (800) of the CHANGE-STATE service and instructs subnetwork management system 20 to execute the test.
When the subnetwork management system 20 is requested to change the test state of the test object to the initiation state by the indication (800) of the CHANGE-TEST service, it suspends the internal Timer #1 and executes the test. When the execution of the test proves successful, it returns the response (810) of the CHANGE-STATE service to the integrated network management system 10.
Receiving the confirm (810) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
In the subnetwork management system 20, the test result obtained by the execution of the test is held as the attribute of the test object. The execution of the test is continued until the indication is given from the integrated network management system 10 to change the test state to the idle state by the indication (820) of the CHANGE-STATE service.
To terminate the test, the integrated network management system 10 instructs the subnetwork management system 20 to change the test state of the test object to the idle state by utilizing the request (820) of the CHANGE-STATE service. The integrated network management system 10 starts simultaneously the Timer #2.
It is a particular feature of the fifth protocol that when the subnetwork management system 20 is requested to change the test state of the test object to the idle state by the indication (820) of the CHANGE-TEST service, it terminates the test, changes the test state of the test object to the idle state and then makes response to the integrated network management system 10 by utilizing the response (830) of the CHANGE-STATE service. At the same time, it starts the Timer #1 of the subnetwork management system 20.
Receiving the confirm (830) of the CHANGE-STATE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
When the integrated network management system 10 collects the test result of the test executed in the subnetwork management system 20, it requests the subnetwork management system 20 to report the test result of the test object by the indication (1000) of the TEST-GET service. At the same time, it starts the Timer #2 of the integrated network system 10.
Receiving the indication (1000) of the TEST-GET service, the subnetwork management system 20 suspends the Timer #1 of the subnetwork management system 20 and reports the test result of the test object as the value of the parameter of the Attribute List of the response (1010) of the TEST-GET service. The subnetwork management system 20 again starts the Timer #1.
Receiving the confirm (1010) of the TEST-GET service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10 and makes processes such as the display of the test result.
To suspend the test, the integrated network management system 10 requests the subnetwork management system 20 to delete the test object, by use of the request (900) of the TEST-DELETE service. At the same time, the integrated network management system 10 starts the Timer #2.
Receiving the indication (900) of the TEST-DELETE service, the subnetwork system 20 suspends the Timer #1 and deletes the test object. Thereafter, it sends a response to the integrated network management system 10 by the response (910) of the TEST-DELETE service.
Receiving the confirm (910) of the TEST-DELETE service, the integrated network management system 10 suspends the Timer #2 of the integrated network management system 10.
It is a particular operational advantage of the present invention that even if communication failure occurs and any of the primitives of the services of the invention disappear, a state cannot occur where the test object remains longer than its proper period so that the test does not properly terminate.
A protocol processor for processing exclusively at least one of the foregoing first to fifth protocols provides a network management method and system suitable for improved network management.
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A system and method are provided for a network communication protocol specifically directed to implementation of fault management between managers, agents and test objects in the network. Timers for limiting the available times for implicit and explicit reports and instructions are provided to avoid excessive waits for instructions, responses or execution of the overall test. Agents can autonomously report test results to reduce manager responsibilities for improved operating efficiency.
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RELATED APPLICATIONS
[0001] The present application claims priority to Korean Patent Application Serial Number 10-2008-0123484, filed on Dec. 5, 2008 and Korean Patent Application Serial Number 10-2009-0109611, filed on Nov. 13, 2009, the entirety of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an SCA (Software Communications Architecture) based SDR (Software Defined Radio) terminal, and in particular, to a method of vertical handover for an SDR terminal.
[0004] 2. Description of the Related Art
[0005] An SDR (Software Defined Radio) is a technology that can use various wireless communication services by executing software in one wireless device. To this end, in an SDR terminal, all or a part of components that perform functions related to communication are implemented by software, unlike a hardware based terminal such as an application specific integrated circuit (ASIC). The SDR terminal should execute waveform applications in order to provide communication services. Generally, since the waveform application is first loaded and then executed, the SDR terminal requires longer service standby time than a hardware based terminal such as ASIC, etc., such that it may be difficult to quickly provide services when the services are changed.
[0006] In the viewpoint of the SDR terminal, vertical handover means changing from currently used waveform applications to other waveform applications. Therefore, for the vertical handover, the SDR terminal should change the waveform application, such that the existing waveform applications should be uninstalled and new waveform applications should be installed. However, a considerable time is consumed in this process and therefore, the seamless vertical handover cannot be easily made in the SDR terminal.
[0007] An SCA (Software Communications Architecture) is standardized communication software architecture proposed in order to largely improve interoperability between communication systems and reduce development and disposition expense. The SCA adopts COBRA (Common Object Request Architecture), which is an industrial standard of a real-time operating system, and a distributed object model as middleware, to provide an integrated environment having different kinds of hardware and software. The SDR system adopts the SCA as a standard of a software framework.
[0008] FIG. 1 is a block diagram of an SCA based SDR terminal according to the related art.
[0009] Referring to FIG. 1 , an SDR terminal 100 includes a domain manager 110 , a device manager 120 , a file manager 130 , an application factory 140 , various devices 1450 , a file system 160 , and a waveform application 170 .
[0010] The domain manager 110 generally manages the operations of the SDR terminal 100 .
[0011] The device manager 120 controls various devices 150 .
[0012] The various devices 150 may include a DSP device, an FPGA device, a GPP device, etc., as shown in FIG. 1 .
[0013] The file manager 130 manages the file system 160 in the SDR terminal 100 .
[0014] The application factory 140 controls the waveform application 170 of the SDR terminal 100 . In other words, the application factory 140 can perform the install and uninstall of the waveform application 170 .
[0015] The waveform application 170 is executed in order to provide the communication services of the SDR terminal 100 . When the vertical handover is generated, the waveform application 170 should be updated into a new waveform application.
[0016] A media independent handover (MIH), in which research is actively being pursued at the IEEE (Institute of Electrical and Electronics Engineers) (802.21 standard), is a technology that provides seamless handover to terminals so that the terminals having multi wireless interfaces such as wireless LAN of IEEE 802.11 standard, Wibro of IEEE 802.16 standard, WCDMA (Wideband Code Division Multiple Access), CDMA-2000 (Code Division Multiple Access 2000), etc., can cross between different media, thereby making it possible to receive various application services such as voice, data, multimedia, etc. The media independent handover is realized by performing information exchange for handover between the terminal and the base station by using an event service, a command service, and an information service.
[0017] Consequently, a need exists for a new method of seamless vertical handover for the SDR terminal, which can quickly change the waveform application in the SDR terminal in order to perform the seamless vertical handover while ensuring compatibility with the IEEE 802.21 standard.
SUMMARY OF THE INVENTION
[0018] The present invention proposes to solve the above-mentioned problems of the related art. It is an object of the present invention to perform seamless vertical handover by reducing time consumed to reconfigure waveform applications of an SDR terminal in the vertical handover.
[0019] In addition, it is another object of the present invention to provide a method of seamless vertical handover for an SDR terminal having better expandability by being compatible with the IEEE 802.21 standard.
[0020] Further, it is yet another object of the present invention to reduce power consumption while performing seamless vertical handover by quickly performing the install of new applications and the uninstall of existing applications upon performing the vertical handover to minimize a multi mode operation time.
[0021] A method of seamless vertical handover for an SDR terminal according to one embodiment of the present invention includes: determining whether a download of a waveform application related to a peripheral access network is needed by collecting peripheral access network information prior to requesting vertical handover; if it is determined that the download is needed, downloading and storing the waveform application; and performing the seamless vertical handover using the pre-stored waveform application upon requesting the vertical handover.
[0022] At this time, the peripheral access network information is collected using a media independent information service (MIIS) and the vertical handover request can be identified using a media independent event service (MIES) or a media independent command service (MICS).
[0023] At this time, the media independent information service provides information element that represents the connection information of a waveform application repository server and the downloading and storing the waveform application can download the waveform applications by connecting to the waveform application repository server using the information elements.
[0024] At this time, the waveform application related to the peripheral access network may be the waveform application usable in the access network corresponding to a network type information element provided by the media independent information service.
[0025] In addition, an SCA based SDR terminal according to one embodiment of the present invention includes: a media independent handover resource that provides functions of a media independent information service (MIIS), a media independent command service (MICS), and a media independent event service (MIES); a waveform application manager that downloads and stores a waveform application required prior to a vertical handover request and installs the pre-stored waveform application upon request of the vertical handover; and a media independent handover manager that controls the waveform application manager based on the media independent information service and the media independent event service.
[0026] At this time, the media independent information service provides information elements that represent connection information of a waveform application repository server and the waveform application manager downloads the waveform applications by connecting to the waveform application repository server using the information element.
[0027] At this time, the media independent handover manager can control the waveform application manager to identify the vertical handover request based on event and commands provided by the media independent event service or the media independent command service and to install the pre-stored waveform application upon request of the vertical handover.
[0028] At this time, the media independent handover manager can control the waveform application manager that identifies whether the vertical handover completes based on a link events or commands provided by the media independent event service or the media independent command service and if it is determined that the vertical handover is completes, uninstalls the existing waveform application.
[0029] The following effects can be obtained by the present invention.
[0030] With the present invention, it can reduce the time consumed to reconfigure the waveform applications upon performing the vertical handover for the SDR terminal to perform the seamless vertical handover.
[0031] In addition, the present invention can provide the method of seamless vertical handover for the SDR terminal having better expandability by being compatible with IEEE 802.21 standard.
[0032] Further, the present invention can reduce power consumption while performing the seamless vertical handover by quickly performing the install of the new applications and the uninstall of the existing applications upon performing the vertical handover to minimize the multi mode operation time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a block diagram of an SCA based SDR terminal according to the related art;
[0034] FIG. 2 is a block diagram of an SCA based SDR terminal according to one embodiment of the present invention;
[0035] FIG. 3 is a block diagram showing the waveform application download operation of the SCA based SDR terminal shown in FIG. 2 ;
[0036] FIG. 4 is a diagram showing one example of information elements according to one embodiment of the present invention;
[0037] FIG. 5 is a block diagram showing the multi mode operations of the SCA based SDR terminal according to one embodiment of the present invention;
[0038] FIG. 6 is an operational flowchart showing a method of seamless vertical handover for the SDR terminal according to one embodiment of the present invention; and
[0039] FIG. 7 is an operational flowchart showing one example of the vertical handover steps shown in FIG. 6 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] The present invention will be described below with reference to the accompanying drawings. Herein, the detailed description of a related known function or configuration that may make the purpose of the present invention unnecessarily ambiguous in describing the present invention will be omitted. Exemplary embodiments of the present invention are provided so that those skilled in the art may more completely understand the present invention. Accordingly, the shape, the size, etc., of elements in the drawings may be exaggerated for explicit comprehension.
[0041] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0042] FIG. 2 is a block diagram of an SCA based SDR terminal according to one embodiment of the present invention.
[0043] Referring to FIG. 2 , the SCA based SDR terminal according to one embodiment of the present invention includes a domain manager 210 , a media independent handover manager 220 , a file manager 230 , an application factory 240 , a waveform application manager 250 , a file system 260 , a waveform application 270 , and a waveform application repository 280 .
[0044] The domain manager 210 generally manages the operation of the SCA based SDR terminal 200 . Although not shown in FIG. 2 , the domain manager 210 can transmit and receive the signal from and to the waveform application manager 250 and the application factory 240 , etc.
[0045] In particular, when the domain manager 210 receives an install request of a new waveform application from the waveform application manager 250 , it can generate a new application factory to generate the new waveform application.
[0046] In addition, when the domain manager 210 receives an uninstall request of the waveform application from the waveform application manager 250 , it can transmit the request to the application factory 240 .
[0047] The media independent handover manager 220 corresponds to a media independent handover (MIH) user in MIH architecture and receives access network information through media independent information service (MIIS) of a media independent handover (MIH) function and transmits it to the waveform application manager 250 , such that the waveform application manager 250 searches whether the waveform application for using the corresponding network is stored in the waveform application repository 280 in the SDR terminal 200 and if it is determined that the waveform application for using the corresponding network is not stored in the waveform application repository 280 , accesses a waveform application repository server defined by an information element of the MIIS to download a new waveform application file and is stored in the waveform application repository 280 .
[0048] In addition, when the media independent handover manager 220 receives a media independent event service (MIES), it selects the waveform application to be newly installed and transmits commands regarding the install of the new waveform application to the waveform application manager 250 .
[0049] When the media independent handover manager 220 receives a specific MIH link event or an MIH command, it is determined that the handover is completed and can request the waveform application manager 250 to uninstall the existing waveform application.
[0050] The file manager 230 manages the file system 260 in the SCA based SDR terminal 200 .
[0051] The file system 260 manages the waveform application file that is stored in the waveform application repository 280 .
[0052] In particular, when the file manager 230 requires the generation of the new application, the waveform application file in the waveform application repository 280 can be provided to the application factory 240 , etc.
[0053] The application factory 240 controls the waveform application 270 of the SCA based SDR terminal 200 . In other words, the application factory 240 can perform the install and uninstall of the waveform application 270 .
[0054] The waveform application manager 250 receives the specific information elements of the MIIS or the signals generated using the information element through the media independent handover manager 220 and analyzes them, thereby confirming whether the waveform application usable in a peripheral access network is stored in the waveform application repository 280 .
[0055] When the waveform application manager 250 does not store the necessary waveform application, it receives the necessary waveform application and stores it in the waveform application repository 280 , in a waveform application repository server that is described in the information elements (waveform application server specific information elements) that represents the connection information of the waveform application repository server of the MIIS.
[0056] Further, the waveform application manager 250 confirms whether the corresponding waveform application exists in the waveform application repository 280 when the vertical handover request is identified by the MIES or MICS, and then requests the domain manager 210 to install the new waveform application.
[0057] Moreover, when the waveform application manager 250 requests the uninstall of the waveform application from the media independent handover manager 220 , it can transmit the request to the domain manager 210 .
[0058] The waveform application 270 is executed to provide communication services of the SCA based SDR terminal 200 . When the vertical handover is generated, the new waveform application 270 should be also updated into the waveform application.
[0059] In particular, the waveform application 270 includes the media independent handover resource 271 . At this time, the media independent handover resource 271 corresponds to the media independent handover (MIH) function.
[0060] The media independent handover resource 271 provides the MIIS and MIES functions and when it receives the MIIS or MIES, transmits the MIIS or MIES to the media independent handover manager 220 .
[0061] At this time, the media independent handover resource 271 can receive the MIH event related to the handover such as MIH_Link_Detected, MIH_Link_UP, MIH_Link_Down, or MIH_Link_Handover_Complete, etc., and MIH command such as MIH_N2N_HO_Commit, MIH_MN_HO_Commit, MIH_Net_HO_Complete, MIH_N2N_HO_Complete, etc., which are defined by the IEEE 802.21 standard, to transmit them to the media independent handover manager 220 . The process for MIH user to receive the MIH event follows a scheme defined in an IEEE 802.21 technical standard.
[0062] The MIH user, MIH function, MIIS, MIES, and MICS, etc., is described in detail in a web document such as a submission tree page, etc., of IEEE 802.21 technical standard discussion group website (http://www.ieee802.org/21/).
[0063] FIG. 3 is a block diagram showing the waveform application download operation of the SCA based SDR terminal shown in FIG. 2 .
[0064] Referring to FIG. 3 , the SCA based SDR terminal 300 receives the peripheral access network information through the MIIS (s 1 ).
[0065] At this time, the MIIS can be transmitted through the access network 301 from a server 303 having the MIH function.
[0066] The media independent handover resource 371 transmits the received MIIS to the media independent handover manager 320 (S 2 ).
[0067] The media independent handover manager 320 transmits the information elements, which represents the network type in the MIIS, to the waveform application manager 350 (s 3 ). At this time, the information element representing the network type is the information element, which can uniquely identify the waveform application such as IE_NETWORK_TYPE, IE_SERVICE_PROVIDER_ID, etc., which is defined by the IEEE 802.21 standard.
[0068] The waveform application manager 350 searches the waveform application repository 380 to confirm whether the useable waveform application is stored in the access network corresponding to the information element that represents the network type. At this time, the waveform application repository 380 can search the waveform application repository 380 through the file manager 330 .
[0069] When the necessary waveform application is not stored, it can obtain the connection information of the waveform application repository server 302 using the information element that represents the connection information of the waveform application repository server provided through the MIIS. At this time, the connection information may be an IP address.
[0070] The waveform application downloaded from the waveform application repository server 302 is stored in the waveform application repository 380 . At this time, the downloaded waveform application may be stored in the waveform application repository 380 through any one of the application factory 340 , the waveform application manager 350 , the file manager 330 , and the file system 360 (S 4 , S 5 , and S 6 ).
[0071] FIG. 4 is a diagram showing one example of the information element according to one embodiment of the present invention.
[0072] Referring to FIG. 4 , the information element representing the connection information of the waveform application repository server according to one embodiment of the present invention is added to the MIIS.
[0073] This information element may include a first field 410 that represents a name of the information element, a second field 420 that represents a description about the information element, and a third field 430 that represents the connection information such as the IP address, etc., of the waveform application repository server.
[0074] FIG. 5 is a block diagram of a multi-mode operation of the SCA based SDR terminal according to one embodiment of the present invention.
[0075] At this time, the multi-mode may mean the operation mode that the SDR terminal simultaneously has two or more waveform applications.
[0076] Referring to FIG. 5 , an SCA based SDR terminal 500 receives the vertical handover request through the media independent event service (MIES) or the media independent command service (MICS) (S 1 ).
[0077] At this time, the MIES can be provided through the access network 503 from the server 501 having the MIH function at the remote place.
[0078] The media independent handover resource 572 transmits the event corresponding to the received vertical handover request to the media independent handover manager 520 (S 2 ).
[0079] The media independent handover manager 520 selects the waveform application to be newly installed based on the MIIS information and transmits the command regarding the install of the new waveform application to the waveform application manager 550 (S 3 ).
[0080] The waveform application manager 550 confirms whether the corresponding waveform application exists in the waveform application repository 580 and then, requests the domain manager 510 to install the new waveform application (S 4 ).
[0081] The domain manager 510 generates the new application factory 542 for generating the new waveform application (S 5 ).
[0082] In order to generate the new waveform application, the file of the waveform application requests the file manager 530 and the corresponding file is provided from the waveform application repository 580 (S 6 ).
[0083] The application factory 542 receiving the file generates the new waveform application 573 (S 7 ).
[0084] When receiving the MIH link event such as MIH_Link_Detected, MIH_Link_UP, etc., that are defined by the IEEE 802.21 standard in the media independent handover resource 574 of the new waveform application 573 , this is transmitted to the media independent handover manager 520 (S 8 ).
[0085] When receiving the MIH link events such as MIH_Link_Down, MIH_Link_Handover_Complete, etc., that are defined by the IEEE 802.21 standard in the media independent handover resource 572 of the existing waveform application 571 or the MIH commands such as MIH_N2N_HO_Commit, MIH_MN_HO_Commit, MIH_Net_HO_Complete, MIH_N2N_HO_Complete, etc., this is transmitted to the media independent handover manager 520 (S 9 ).
[0086] When the media independent handover manager 520 receives the specific MIH link event such as MIH_Link_Detected, MIH_Link_UP, MIH_Link_Down, MIH_Link_Handover_Complete, etc., that are defined through IEEE 802.21 or when receiving the MIH commands such as MIH_N2N_HO_Commit, MIH_MN_HO_Commit, MIH_Net_HO_Complete, MIH_N2N_HO_Complete, etc., it is determined that the handover is completed and requests the application manager 550 to uninstall the existing waveform application 571 (S 10 ).
[0087] The waveform application manager 550 requests the domain manager 510 to uninstall the waveform application 571 (S 11 ).
[0088] The domain manager 510 requests the application factory 541 to uninstall the waveform application 571 (S 12 ).
[0089] The application factory 541 uninstalls the waveform application 571 (S 13 ).
[0090] Thereafter, the domain manager 510 uninstalls the application factory 541 .
[0091] Therefore, the SCA based SDR terminal is operated as a multi-mode during the vertical handover process and then operated as a single mode terminal after the handover is completed. Further, the latency generated upon reconfiguring the waveform application of the SDR terminal can be reduced and thus, the seamless vertical handover can be achieved.
[0092] Consequently, this is possible since the SDR obtains the information related to the vertical handover using the IEEE 802.21 standard to prepare procedures regarding the handover beforehand by using a proactive scheme. In other words, a process required to reconfigure the waveform application using the MIIS is previously performed and when the process waits until the MIES event or the MICS command is received and then, receives the MIES event or the MICS command, it quickly starts the new waveform application in order to perform the vertical handover. Since the time consumed to change the waveform application in this scheme is minimized, the seamless vertical handover can be performed.
[0093] FIG. 6 is an operational flowchart showing the method for seamless vertical handover for the SDR terminal according to one embodiment of the present invention.
[0094] Referring to FIG. 6 , the method for seamless vertical handover for the SDR terminal according to one embodiment of the present invention first collects the peripheral access network information prior to the vertical handover request (S 610 ).
[0095] At this time, the peripheral access network information is collected using a media independent information service (MIIS) and the vertical handover request can be identified using a media independent event service (MIES) or a media independent command service (MICS).
[0096] In addition, the method for seamless vertical handover for the SDR terminal uses the collected peripheral access network information to confirm whether the waveform application corresponding to the peripheral access network is stored in the SDR terminal (S 620 ). At this time, when the corresponding waveform application is not stored in the SDR terminal, it can be determined that the download is required.
[0097] At this time, the waveform application corresponding to the peripheral access network may be the waveform application usable in the access network corresponding to a network type information element provided by the media independent information service. At this time, the network type information elements may be IE_NETWORK_TYPE defined by the IEEE 802.21 standard.
[0098] When it is determined that the download is required, the method for seamless vertical handover for the SDR terminal downloads the corresponding waveform application in the waveform application repository server and stores it in the SDR terminal (S 630 ).
[0099] At this time, the information element, which represents the connection information of the waveform application repository server, can be provided by the media independent information service. At this time, step (S 630 ) uses the information element to access the waveform application repository server, thereby making it possible to download the waveform application.
[0100] In this case, the connection information of the waveform application repository server may be an IP address.
[0101] In addition, the method of seamless vertical handover for the SDR terminal uses the stored waveform application to perform the seamless vertical handover (S 640 ).
[0102] FIG. 7 is an operational flowchart showing one example of the vertical handover step (S 640 ) shown in FIG. 6 .
[0103] Referring to FIG. 7 , step (S 640 ), which performs the seamless vertical handover using the stored waveform application shown in FIG. 6 , first identifies the vertical handover request (S 710 ).
[0104] At this time, the vertical handover request can be identified based on the events provided by the media independent event service (MIES).
[0105] The step of performing the seamless vertical handover does not progress the next step if it is determined that there is no vertical handover request. At this time, if it is determined that there is no vertical handover request, the step of performing the seamless vertical handover may progress to the step (S 610 ) of collecting the peripheral network information shown in FIG. 6 .
[0106] If it is determined that there is the vertical handover request, the step of performing the seamless vertical handover selects the necessary waveform application within the waveform application repository in the SDR terminal (S 720 ).
[0107] In addition, the step of performing the seamless vertical handover newly installs the selected waveform application (S 730 ).
[0108] Further, the step of performing the seamless vertical handover uninstalls the existing waveform application (S 740 ).
[0109] At this time, the uninstall of the existing waveform application may be performed according to the completion or not of the vertical handover identified based on the link event provided by the media independent event service.
[0110] The waveform application download operation and the multi-mode operation of the SCA based SDR terminal, which are described through FIGS. 3 to 5 , can be applied to the method for seamless vertical handover of the SDR terminal shown in FIGS. 6 and 7 and in order to avoid the repeated description, the description thereof will be omitted.
[0111] Each step shown in FIGS. 6 and 7 can be performed in an order shown in FIGS. 6 and 7 , and vice versa or simultaneously.
[0112] Some steps of the present invention can be implemented as a computer-readable code in a computer-readable recording medium. The computer-readable recording media include all types of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording media may include a ROM, a RAM, a CD-ROM, a CD-RW, a magnetic tape, a floppy disk, an HDD, an optical disk, an optical magnetic storage, etc., and in addition, can be implemented in the form of a carrier wave (for example, transmission through the Internet). Further, the computer-readable recording media are distributed on computer systems connected through the network, and thus may be stored and executed as the computer-readable code by a distribution scheme.
[0113] As described above, the preferred embodiments have been described and illustrated in the drawings and the description. Herein, specific terms have been used, but are just used for the purpose of describing the present invention and are not used for qualifying the meaning or limiting the scope of the present invention, which is disclosed in the appended claims. Therefore, it will be appreciated to those skilled in the art that various modifications are made and other equivalent embodiments are available. Accordingly, the actual technical protection scope of the present invention must be determined by the spirit of the appended claims.
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The present invention provides a method of seamless vertical handover for an SDR terminal and an SCA based SDR terminal for the same. A method of seamless vertical handover for an SDR terminal of the present invention includes: determining whether a download of a waveform application related to a peripheral access network is needed by collecting peripheral access network information prior to requesting vertical handover; if it is determined that the download is needed, downloading and storing the waveform application; and performing the seamless vertical handover using the pre-stored waveform application upon request the vertical handover. Therefore, the seamless vertical handover for the SDR terminal can be efficiently performed.
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BACKGROUND OF THE INVENTION
This invention relates to a process for the stabilization of certain poly(ether ketone ketones), which contain units derived from diphenyl ether as well as 1,4-benzenedicarbonyl and 1,3-benzenedicarbonyl units.
Poly(ether ketone ketones), hereinafter sometimes referred to as PEKK's, especially those having the above chemical structure, are well known engineering polymers, which find wide use in certain high value applications such as, for example, in fabricating panels for aircraft interiors. They have high melting points, yet are melt processable and are reasonably well resistant to ignition.
PEKK's are made industrially by Friedel-Crafts catalyzed condensation of diphenyl ether with terephthalyl chloride and isophthalyl chloride in an inert solvent such as, e.g., o-dichlorobenzene, nitromethane, or ethylene chloride. The most commonly used catalyst is aluminum chloride, which always is employed in a large excess. The so-produced PEKK's usually have xanthydrol end groups which result from acylation in the ortho position of diphenyl ether. Those xanthydrol groups are thermally unstable and decompose on heating with the liberation of xanthone and formation of a phenyl free radical, which reacts with the polymer, causing crosslinking and degradation by hydrogen abstraction.
This thermal degradation is illustrated below in the following equation: ##STR1##
While this elimination of xanthone can be retarded by heating the polymer with formic acid, and thus reducing the xanthydrol groups to xanthene groups, exposure of the polymer to oxygen regenerates xanthydrol, which then rearranges to xanthone. Thus, the formic acid treatment simply slows down the degradation process but does not eliminate it.
It thus is very important to be able to permanently thermally stabilize PEKK's.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, there is provided a process for thermally stabilizing poly(ether ketone ketones), wherein a poly(ether ketone ketone) swollen with an organic liquid is contacted for a period of at least about 15 minutes above its glass transition temperature with an organic hydroperoxide having a boiling point above about 130° C., thermally degradable between about 130° C. and the contacting temperature, containing at least 0.1 mg of active oxygen per gram, and made from a precursor comprising at least one benzylic or allylic hydrogen in its molecule, and separating the so-treated poly(ether ketone ketone) from the liquid.
DETAILED DESCRIPTION OF THE INVENTION
Organic hydroperoxides are well known and some are commercially available. Usually, they can be made in situ by a reaction of an appropriate precursor with a source of active oxygen, for example, hydrogen peroxide. Preferred hydroperoxides contain more than 0.5 mg/g of active oxygen. Those hydroperoxides are made from a variety of precursors. Those having a benzylic hydrogen may be represented, for example, by the following formula: ##STR2##
where R 1 and R 2 are lower alkyl groups, especially methyl groups, and the benzene ring may be further substituted, especially with alkyl groups. Precursors containing allylic hydrogen include, for example, limonene, tetralin, and undecene-1. The preferred precursor is 1,3,5-triisopropylbenzene (1,3,5-TIB). Chiyoda et al. U.S. Pat. No. 4,455,440 describes one of the processes suitable for making TIB trihydroperoxides. TIB can be purchased from Aldrich Chemical Co. The hydrogen of each isopropyl group of TIB can be oxidized to a hydroperoxy group, --O--OH, using a hydrogen peroxide solution or another suitable peroxide or by passing a stream of oxygen through a solution of TIB in a suitable solvent. All such procedures are well known to those skilled in the art. Hydrogen peroxide itself cannot be used as a stabilizing compound because it decomposes below the temperature at which stabilization is required. Poly(ether ketone ketones) of interest in the present invention have glass transition temperatures in the neighborhood of 130°-110° C. and must be stabilized at temperatures above that range. However, hydrogen peroxide decomposes below 130° C.
The amount of active oxygen in the stabilizing hydroperoxide can be determined, for example, by gas chromatography, calibrating the system for the monohydroperoxide and noting the hydroperoxide peak's appearance and disappearance. In the case of the hydroperoxides from TIB, all three hydroperoxides are quite stable, but the monohydroperoxide is sufficient to effect complete PEKK stabilization, so that the presence of the other two hydroperoxides would indicate only the degree of oxidation of the precursor but not the degree of stabilization that will occur. Further, active oxygen can be determined in a known manner by a reaction with sodium or potassium iodide in an acidic medium and titration of liberated iodine.
PEKK, which is to be stabilized, is always prepared in a solvent, as explained above. In the industrial practice, the original solvent normally is removed by washing with a lower-boiling organic liquid, such as, for example, methanol, in which it is insoluble. The organic liquid swelling this PEKK thus may be methanol, or a mixture of methanol with the original reaction solvent, or any other suitable organic liquid or combination of organic liquids.
This invention is now illustrated by examples of certain representative embodiments thereof, where all parts, proportions, and percentages are by weight, unless otherwise indicated.
EXAMPLE 1
Preparation of Polymer
A stirred 3-liter glass reactor was charged with 87.60 g (0.515 mole) of diphenyl ether (99.9% purity, Dow Chemical Co.), 70.70 g (0.35 mole) of terephthalyl chloride (Du Pont Technical grade), 30.30 g (0.15 mole) of isophthalyl chloride (Du Pont Technical grade), 1.30 g (0.005 mole) of 1,3,5-benzenetricarboxylic acid chloride (trimesyl chloride), and 2200 ml of o-dichlorobenzene. The mixture was cooled to 0°-5° C. and 202 g (1.51 moles) of anhydrous aluminum chloride (Witco ACL-0008) was added while the temperature was maintained between 0° and 5° C. Upon completion of the aluminum chloride addition, the reaction temperature was increased to 100° C. at a rate of approximately 10° C./min. The reaction was held at 100° C. for 30 minutes and then allowed to cool to room temperature. Once at room temperature, the agitation was stopped and the o-dichlorobenzene was removed by means of a vacuum filter stick. Methanol (1200 ml) was added slowly with agitation, keeping the temperature below 45° C. The mixture was stirred for 30 minutes and filtered. The polymer product was washed two times with methanol and dried in vacuum for 12 hours at 180° °C. The polymer exhibited a melt index, with 5 minutes preheating at 360° C., of 0 g/10 minutes, which indicated a high degree of crosslinking.
COMPARATIVE EXAMPLE 1
Stabilization by Formic Acid Treatment
Approximately 100 ml of the wet, methanol washed, particulate polymer from Example 1 was mixed with 10 ml of formic acid. The mixture was dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index, with 5 minutes preheating at 360° C. of 250 g/10 minutes. The polymer thus was not excessively crosslinked.
COMPARATIVE EXAMPLE 2
1,3,5-TIB Containing Less than 0.1 mg/g of Active Oxygen
Approximately 100 ml of the wet, methanol washed, particulate polymer from Example 1 was placed in a 500-ml, 3-neck, round bottom flask fitted with a condenser, thermowell, and nitrogen purge. Two hundred fifty ml of oxidized 1,3,5-TIB (containing less than 0.1 mg/g of active oxygen) was added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed twice with 500 ml of acetone, and dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index, with 5 minutes preheating at 360° C., of 0 g/10 minutes. This polymer thus was highly crosslinked.
EXAMPLE 2
1,3,5-TIB Containing More than 0.1 mg/g Active Oxygen
Approximately 100 ml of the wet, methanol washed, particulate polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell, and nitrogen purge. Two hundred fifty ml of oxidized 1,3,5-TIB (Aldrich Chemical Co., containing more than 0.1 mg/g of active oxygen as determined by gas chromatography) was added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed twice with 500 ml of acetone, and dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index, with 5 minutes preheating at 360° C., of 243 g/10 minutes. This polymer obviously was not excessively crosslinked.
EXAMPLE 3
Stabilization with TIB/3% Hydrogen Peroxide Solution
Approximately 100 ml of the methanol washed polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell and nitrogen purge. Two hundred fifty ml of 1,3,5-TIB (Aldrich Chemical Co., containing less than 0.1 mg/gm of active oxygen as determined by gas chromatography) and 100 ml of 3% hydrogen peroxide solution were added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed two times with 500 ml of acetone and dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index, with 5 minutes preheating at 360° C., of 360 g/10 minutes.
EXAMPLE 4
Stabilization with 1,3,5-TIB/30% Hydrogen Peroxide Solution
Approximately 100 ml of the methanol washed polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell and nitrogen purge. Two hundred fifty ml of 1,3,5-TIB (Aldrich Chemical Co., containing less than 0.1 mg/gm of active oxygen as determined by gas chromatography) and 10 ml of 30% hydrogen peroxide solution were added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed two times with 500 ml of acetone and dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index with 5 minutes preheating at 360° C., of 373 g/10 minutes.
Examples 3 and 4 thus show that a hydrogen peroxide solution can generate 1,3,5-TIB hydroperoxide in situ, and this 1,3,5-TIB hydroperoxide stabilizes PEKK. If hydrogen peroxide decomposed before it had a chance to oxidize 1,3,5-TIB to the corresponding hydroperoxide, proper stabilization of PEKK would not have been observed.
EXAMPLE 5
Oxidation of 1,3,5,-TIB
Five hundred ml of 1,3,5-TIB and 500 ml of water were placed in a 2 liter, 3-neck, flask fitted with a condenser, thermowell and air purge. The mixture was heated to 80°-90° C. while air was continuously passed through the solution. The active oxygen content of the TIB phase was monitored by gas chromatography on a 30-m capillary glass column coated with methylsilicone. The column was programmed to equilibrate for 5 minutes at 35° C. and then was heated to 100° C. at the rate of 10° C./min. An internal standard was used. When the active oxygen content reached 1 mg/g, approximately 4-8 hours, the mixture was cooled to room temperature. The TIB layer was decanted from the water layer and stored for further use.
EXAMPLE 6
Stabilization with Oxidized 1,3,5-TIB
Approximately 100 ml of the methanol washed polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell and nitrogen purge. Two hundred fifty ml of 1,3,5-TIB from Example 5 (containing 1.1 mg/g active oxygen, as determined by gas chromatography) was added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed two times with 500 ml of acetone and dried in a vacuum oven at 180° C. for 12 hours. The polymer exhibited a melt index, with 5 minutes preheating at 360° C., of 250 g/10 minutes.
EXAMPLE 7
Additional Compounds Suitable for Stabilizing PEKK
Approximately 100 ml of the methanol-washed polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell and nitrogen purge. Two hundred fifty ml of one of the compounds from Table I (containing less than 0.1 mg/g of active oxygen as determined by gas chromatography) and 100 ml of 3% hydrogen peroxide solution were added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed two times with 500 ml of acetone and dried in a vacuum oven at 180° C. for 12 hours. The melt indices for each compound are shown in Table I.
TABLE I______________________________________Examples 7-12 Melt IndexExample Hydroperoxide Precursor (g/10 min)______________________________________ 7 1,3-Diisopropylbenzene 61 8 Tetralin 392 9 1-Phenylnonane 19110 1,4-Diisopropylbenzene 8911 Limonene 52212 Undecene 237______________________________________
COMPARATIVE EXAMPLES 3-5
Similar Compounds Unsuitable as Stabilizing Agents
Approximately 100 ml of the methanol-washed polymer from Example 1 was placed in a 500 ml, 3-neck, round bottom flask fitted with a condenser, thermowell and nitrogen purge. Two hundred fifty ml of one of the compounds from Table II (containing less than 0.1 mg/gm of active oxygen as determined by gas chromatography) and 100 ml of 3% hydrogen peroxide solution were added. The mixture was heated at 180°-200° C. for 2 hours and cooled to room temperature. The polymer was filtered from the solution, washed two times with 500 ml of acetone and dried in a vacuum oven at 180° C. for 12 hours. The melt indices for each compound are shown on Table II.
TABLE II______________________________________Comparative Examples 3-6 Melt IndexExample Hydroperoxide Precursor (g/10 min)______________________________________3 2-Ethylhexanol 04 Phenol 05 1,3,5-Tri-t-butylbenzene 06 o-Dichlorobenzene 0______________________________________
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Poly(ether ketone ketones), which are important engineering resins, are thermally stabilized by being contacted for at least 15 minutes above their glass transition temperature with an organic hydroperoxide containing at least 0.1 mg of active oxygen per gram, having a boiling point above about 130° C., and degradable between 130° C. and the contacting temperature, the hydroperoxide being made from a precursor comprising at least one benzylic or allylic hydrogen in its molecule.
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FIELD OF THE INVENTION
The present invention relates to a cuff link, and more particularly to a cuff link with interchangeable insert members and the components of such cuff links.
BACKGROUND OF THE INVENTION
All conventional shirt cuffs fully encircle the wrist of the wearer so that they may be fastened. Shirts for men's use are largely classified into two types depending on the fastener used. In one type, the overlapped cuff ends are fastened usually by a button. In the other type, often called “French cuff”, the overlapped cuff ends are fastened by a cuff link instead of a button. Some cuffs of the former type are made to be “convertible” so that, if desired, they may be fastened with a cuff link instead of a button.
Conventional shirt cuffs and cuff links often have a uniformity of appearance. Thus, someone who desires to change the look of their cuff links would need to have a number of sets of cuff links with various styles, which can be expensive.
Attempts have been made to solve this problem by providing cuff links with interchangeable parts. For example, JP Patent No.10276806 to Super Planning:KK discloses a cuff link with two different types of ornament pieces. The first piece includes a spring member rotatably connected to a holder for retaining a pattern part. The spring member is releasably connectable to a base A with the pattern part in the open position. Once the spring member is connected to the base, the pattern part covers a base plate. The second piece includes a holder for retaining a pattern part. The holder further includes projections that releasably connect the second piece by snapping the projections about a base plate.
Another example is disclosed in U.S. Pat. No. 3,535,747 to Benn. This patent discloses a cuff link, which in one embodiment, includes a head with a pivotal spring clip connected thereto. The spring clip is received in slot of the link post to secure the head to the post.
Although both of these patents disclose interchangeable cuff links these assemblies may be difficult or costly to manufacture or difficult to use. Therefore, there remains a need for an improved cuff link that has interchangeable members but is easy and inexpensive to manufacture and user friendly.
SUMMARY OF THE INVENTION
The present invention is directed to a cuff link comprising an insert member and a holder. The insert member includes an insert coupled to a catch member. The holder includes a base and a post. The base defines a slot for selectively receiving the catch member, and the base includes a latch member pivotally coupled thereto. The latch member cooperates with the catch member in a closed position to secure the insert member to the holder.
In one embodiment, the latch member is coupled to a bottom surface of the base.
According to one aspect of the present invention, the insert may be made from materials such as onyx, sterling silver, pearl, gold, platinum, bronze, sterling silver, a base material covered by another material, fabric, skins such a leather, wood, coins, precious gems, or simulated gems, among others. These materials can be of various colors.
According to one embodiment, the holder further includes a cup member with the base and a sidewall that extends upwardly from the base to define a cavity for receiving the insert member.
According to yet another embodiment, the insert member further includes a cup member with a base and a sidewall that extends upwardly from the base to define a cavity for receiving the insert.
According to one aspect of the present invention, the post may further include a toggle member rotatably connected to the post and rotatable between a first position and a second position.
Preferably, at least two insert members are provided for each cuff link. The first insert member has the first insert, and the second insert member has the second insert, wherein the first and second inserts have different material properties. In such a cuff link, the material properties may be based on color, material type, and material composition.
The present invention is also directed to a cuff link holder that can be sold separately from the insert members. The cuff link holder comprises base and a post. The base includes a latch member pivotally coupled thereto for cooperating with an insert member in a closed position to secure the insert member to the holder.
The present invention is also directed to an insert member that can be sold separately from the cuff link holder. These insert members can be sold in pairs, individually or in sets with any number of pairs of matching insert members. Each insert member comprises an insert and a cup member configured and designed to receive the insert.
According to one aspect of the present invention, the insert may be made from materials such as onyx, sterling silver, pearl, gold, platinum, bronze, sterling silver, a base material covered by another material, fabric, skins such a leather, wood, coins, precious gems, or simulated gems, among others. These materials can be of various colors.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
FIG. 1 is a perspective view of an assembled cuff link of the present invention;
FIG. 2 is an exploded, perspective view of the cuff link of FIG. 1, wherein the cuff link is partially disassembled;
FIG. 3 is a bottom, perspective view of with the cuff link of FIG. 1, wherein a latch a member is in a closed position;
FIG. 4 is an enlarged, cross-sectional view of the cuff link of FIG. 1, with various portions such as a post and latch member removed for clarity;
FIG. 5 is an enlarged, top view of the latch member shown in FIG. 3;
FIG. 6 is an enlarged, bottom view of the cuff link of FIG. 1 showing the latch member in the closed position in solid lines and in an open position in phantom lines; and
FIG. 7 is a top, perspective view of a set of various insert members for use with the cuff link of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
As shown generally in FIGS. 1-2 where like numbers designate like parts, reference number 10 broadly designates a cuff link of the present invention. The cuff link 10 includes a cuff link holder 12 and at least one insert member 14 a.
The holder 12 includes a cup member 16 with a base 18 and an upwardly extending circular sidewall 20 thereabout. The sidewall 20 is optional. The base 18 and sidewall 20 are configured to define a cavity 22 within the cup member 16 . The base 18 defines a rectangular slot 24 there through. Referring to FIGS. 3-4, the base 18 further includes two spaced apart posts 26 and 28 extending from the bottom surface thereof.
Referring to FIG. 2, the thickness of the sidewall 20 is designated by arrows labeled t H and the diameter of the cavity 22 is designated by arrows labeled D H . In this embodiment, the preferred thickness t H of the sidewall 20 is between about 0.5 mm and about 2 mm. More preferably, the thickness t H of the sidewall 20 is about 1.0 mm. In this embodiment, the preferred diameter D H of the cavity 22 is between about 10 mm and about 20 mm. More preferably, diameter D H of the cavity 22 is about 16.5 mm.
In other embodiments, the cup member 16 can have various other shapes such as octagonal, trianglar, rectangular, or the sidewall 20 can be surrounded by various ornaments such as a simulated rope or numerous balls. In these embodiments, the dimensions of the cup member 16 may vary from the dimensions above.
Referring to FIGS. 3-5, the holder 12 further includes a latch member 30 with a first end 32 and a second end 34 . The first end 32 of the latch member 30 defines a bore 36 for receiving post 28 . The latch member 30 and post 28 being configured and dimensioned to allow latch member 30 to pivot about post 28 .
Referring again to FIGS. 3 and 5, the second end 34 of the latch member 30 includes an upwardly extending wall 38 for use by a user in moving the latch member 30 . The free end of the wall in this embodiment includes serrations 40 for allowing a user's finger to move latch member 30 . The second end 34 of the latch member 30 also includes a first projection 42 , which may be used by a user in moving the latch member 30 .
Between the first end 32 and the second end 34 , the latch member 30 further includes first and second cutouts 44 and 46 on opposite sides of a second projection 48 , and a third cutout 50 . As shown in FIG. 6, the third cutout 50 in conjunction with first projection 42 is configured and dimension to receive post 26 with a snap fit when the latch member 30 is in the closed position as shown. Referring again to FIG. 3, the holder 12 further includes an outwardly extending post 52 . The post 52 is centrally disposed on the base 18 . The slot 24 is eccentrically located on the base 18 so that it is spaced from the central post 52 (as shown in FIGS. 4 and 6 ). The post 52 is connected to the base 18 at a first end 54 and bifurcates toward the free ends 56 . The free ends 56 , however, are joined by a bar 58 (as shown in FIG. 2 ).
Referring to FIG. 3, the holder 12 further includes a toggle member 60 . As shown in FIG. 2, the toggle member 60 includes first and second spring members 62 and 64 and a housing 66 . When assembled, the bar 58 is sandwiched between the first and second spring members 62 and 64 . The housing 66 receives the second spring member 64 therein and the ends of the housing 66 are bent to retain the spring members 62 and 64 therein. The components of the toggle member 60 are commercially available from various suppliers.
The bar 58 , spring members 62 , 64 , and housing 66 are configured and dimensioned to allow the toggle member 60 to rotate between first and second positions. In the first position, the toggle member 60 is aligned with the post 52 . In the second position (as shown in FIG. 3 ), the toggle member 60 is unaligned with the post 52 . The components 58 , 62 , 64 and 66 are further configured and dimensioned so that when the toggle member 60 does not freely rotate between the first and second positions, and within an angle of about 15 degrees of the second position, the spring members 62 and 64 bias the toggle member 60 toward the second position.
In the first position of the toggle member 60 , the cuff link holder can be inserted into a buttonhole of a shirt. In the second position of the toggle member 60 , the cuff link holder is retained within the buttonhole.
Alternative arrangements and components, as know by those of ordinary skill in the art, can be used to allow the toggle member to operate as discussed above. For example, a swivel member can also be used that is commercially available.
Referring to FIG. 2, the holder 12 in this embodiment is formed of sterling silver, which has the necessary strength, finish and manufacturability characteristics desired. In other embodiments, the holder 12 can be formed of any other materials, such as gold, platinum, stainless steel, and the like that have the necessary characteristics. The holder can also be formed of a base material, such as stainless steel, and covered by techniques, such as electroplating with another metal. The coating metal can be, for example, gold, nickel, or silver.
The holder 12 is preferably produced by casting but it can be formed by other methods such as stamping or the die-stroke method. Referring to FIGS. 2 and 3, cup member 16 and latch member 30 are formed each as separate cast pieces. The cup member 16 and post 52 are joined together by methods such as soldering or welding and the like. The cup member is formed as a single piece with the base, sidewall, slot 24 , and posts 26 , 28 . The post 52 is stamped with the bi-frication and bar 58 as one piece. The post 52 is a commercially available component. However, in another embodiment, these pieces can be formed differently and joined by methods such as soldering or welding and the like. After the latch member 30 is disposed on post 28 , the free end of post 28 is formed into a wider-flattened shaped by riveting. This wider shape of the post end secures the latch member 30 thereto. The toggle member 60 is preferably formed about the bar 58 after the post 52 is coupled to the cup member 16 .
Referring to FIG. 2, the insert member 14 a includes a cup member 68 and an insert 70 . Referring to FIGS. 2 and 4, the cup member 68 includes a base 72 and an upwardly extending circular sidewall 74 thereabout. The sidewall 74 is optional. The base 72 and sidewall 74 are configured to define a cavity 76 within the cup member 68 . The base 72 further includes a catch member 78 extending from the bottom surface thereof. The catch member 78 defines a rectangular slot 80 there through. Referring to FIGS. 4 and 5, the slot 80 of the catch member 78 and the second projection 48 of the latch member 30 are configured and dimensioned so that the projection 48 can be received within the slot 80 to hold the insert member 14 a in place.
Referring to FIG. 2, the outer diameter of the insert member 68 is designated by arrows labeled D IM1 the diameter of the cavity 78 is designated by arrows labeled D IM2 , and the thickness of the sidewall 74 is designated by arrows labeled t IM . In this embodiment, the preferred outer diameter D IM1 of the insert member 68 is between about 12 mm and about 20 mm. More preferably, diameter D IM1 is about 16.8 mm. In this embodiment, the preferred diameter D IM2 of the cavity 78 is between about 10 mm and about 20 mm. More preferably, diameter D IM1 of the cavity 78 is about 16.45 mm. In this embodiment, the preferred thickness t IM of the sidewall 74 is between about 0.5 mm and about 2 mm. More preferably, the thickness t IM of the sidewall 74 is about 1.0 mm. These dimensions are exemplary and the present invention is not limited thereto.
Referring to FIGS. 2 and 4, the insert 70 in this embodiment is a colored stone. The insert 70 is in the shape of a disk. The height of the insert 70 is designated by arrows labeled H I and the diameter of the insert 70 is designated by arrows labeled D I . In this embodiment, the preferred height H I of the insert 70 is between about 1.5 mm and about 2.5 mm. More preferably, the height H I of the insert 70 is about 2 mm. In this embodiment, the preferred diameter D I of the insert 70 is between about 12 mm and about 20 mm. More preferably, diameter D I of the insert 70 is about 15 mm. These inserts are commercially available from Zarlene located in Fort Lauderdale, Fla. under the name onyx.
In this embodiment, the clearance between the insert 70 and the cup member 68 allow a press fit between these components to retain the insert 70 within the cavity 76 . However, in another embodiment, the insert 70 can be glued or bonded to the cup member 68 . For example an adhesive, such as epoxy, can be used.
In this embodiment, the height H I of the insert 70 and the depth of the cavity 76 in cup member 68 are such that the top surface of the insert is above the top surface of the sidewall 74 . The present invention is not limited to this configuration and these dimensions can be varied so that the insert is flush with or below the top surface of the sidewall 74 .
Furthermore, as shown in FIG. 4, the depth of the holder 12 cup member and the height of the insert member 14 a are such that the cup member 68 and insert 70 are above the height of the holder 12 sidewall 20 . The present invention is not limited to this configuration and these dimensions can be varied so that the insert member and/or insert are flush with or below the top surface of the sidewall 20 .
The insert cup member 68 in this embodiment is preferably formed of sterling silver, which has the necessary strength, finish and manufacturability characteristics desired. In other embodiments, the insert cup member 68 can be formed of any other materials, similar to those discussed above for the holder 12 .
Referring to FIG. 4, the insert cup member 68 is preferably made by casting, but it can be formed by other methods such as stamping or the die-stroke method. The catch member 78 is preferably formed with the cup member 68 as one piece. However in another embodiment, these pieces can be formed separately and joined by methods such as soldering or welding and the like. In this embodiment, the slot 80 is formed into the catch member 78 during casting of the cup member 68 .
Referring to FIG. 7, various insert members 14 b-e can be formed and used with the holder 12 (as shown in FIG. 2 ). The insert member 14 b-e are formed similarly to insert member 14 a . The insert member 14 b includes for example a brown tiger's eye insert 70 b in a sterling silver cup member 68 b . The insert member 14 c includes a black onyx insert 70 c in a sterling silver cup member 68 b . The insert member 14 d includes a blue onyx insert 70 d with indicia I thereon in a gold cup member 68 d . The indicia I in this embodiment, is a geometric pattern. In other embodiments, however, the indicia can be any pattern, symbol, alphanumeric character or the like. The indicia can be formed by precious gems, gold leaf, silver leaf, paint, printing or the like. The insert member 14 e includes a sterling silver insert 70 e in a sterling silver cup member 68 e.
In alternative embodiments, the insert can be formed of various other minerals, gems and/or metals such as diamonds, rubies, sapphire, turquoise, opal, mother-of-pearl, gold, platinum or bronze, sterling silver, a base material covered by another material, fabric, skins such a leather, wood, coins, precious gems, or simulated gems, among others. These materials can have various colors. An example of a fabric that can be used is a woven wool that may or may not match the material of a user's suit. The fabric may form at least the upper surface of the insert. Other fabrics that are woven or non-woven can also be used. These materials can have various colors.
Moreover, the cuff link can be provided with at least two insert members. The first insert member having a first insert, and the second insert member having a second insert. The first and second inserts may have different material properties. The material properties can be selected based on color, material type, texture, and material composition, among others.
Referring to FIGS. 3 and 7, a user is supplied with at least two cuff link holders 12 and at least two insert members 14 a-e . Preferably, the insert members 14 a-e are provided in matching pairs and additional pairs of matching insert members can be purchased as the user desires. As shown in FIGS. 4 and 6, with the latch member 30 in an open position as shown in phantom, the user takes one insert member, such as insert member 14 a , and places it within the cavity 22 (as shown in FIG. 2) of the holder cup member 20 so that the catch member 78 is disposed within the slot 24 in the cup member 20 . The user then pivots the latch member 30 , as shown by arrow P 1 in a first direction, from the opened position (shown in phantom) to the closed position (shown in solid). In a closed position, the second projection 48 of the latch member 30 extends through the slot 80 (as shown in FIG. 4) of the insert member 14 a to retain the insert member 14 a to the holder 12 . The third cutout 50 receives the post 26 to secure the latch member 30 in the closed position. To change the insert member, the user pivots the latch member 30 , as shown by arrow P 2 in a second opposite direction, from the closed position to the opened position (shown in phantom). In the open position, the second projection 48 of the latch member 30 is spaced from the slot 80 (as shown in FIG. 4) of the insert member 14 a to allow the insert member 14 a to be removed from the holder 12 . The user can then select another insert member, such as insert members 14 b-e , as shown in FIG. 7, and secure the selected one in the holder as discussed above.
While various descriptions of the present invention are described above, it is understood that the various features of the present invention can be used singly or in combination thereof. Furthermore, in the present invention, the holder cup member, insert cup member and insert are all circular. In an alternative embodiment, these components can have various shapes such as rectangular, oval, and the like. In addition, the insert, insert cup member and holder cup member can have different shapes from one another so long as they are configured to cooperate together as discussed above. The sidewalls on insert and holder cup members are optional. Therefore this invention is not to be limited to the specifically preferred embodiments depicted therein.
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The present invention is directed to a cuff link for attaching to a shirtsleeve. The cuff link includes a holder and at least one insert member. The insert member is relesably retained in the holder by a pivotal latch member of the holder. The insert member can include an insert of various materials such as gems or precious metals.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for fabricating a semiconductor device, more specifically to a method for fabricating a semiconductor device comprising gate insulation films having different film thicknesses from each other.
[0002] In recent semiconductor devices, gate insulation films have different film thicknesses from each other for improved device characteristics, etc. In DRAM, for example, it is preferable for improved operation speed to form, as the peripheral circuit transistors, transistors having the gate insulation film made thinner. On the other hand, it is preferable that the memory cell transistors have the gate insulation film made thicker than the peripheral circuit transistors, because the memory cell transistors having the gate insulation film made as thin as the peripheral circuit transistors have too low threshold voltage, which deteriorates controllability and refresh characteristics. In non-volatile semiconductor devices, such as EEPROM, flash EEPROM, etc., in addition to the above-described requirement for the peripheral circuit transistors and the memory cell transistors, transistors having the gate insulation film which is thicker than the transistors forming the memory cell transistors and logics of the peripheral circuits are required as high breakdown voltage transistors used in writing/erasing.
[0003] Conventional techniques for forming gate insulation films having different film thickness from each other are a technique wherein a silicon oxide film is formed uniformly on an entire surface and removed in a region, and then additionally oxidized to thereby provide a difference in film thickness between the region for the silicon oxide film removed and the rest region, and techniques using enhanced oxidation and retarded oxidation by ion implantation. It is preferable from the viewpoint of throughputs to use the techniques using enhanced oxidation and retarded oxidation by ion implantation.
[0004] In the techniques using ion implantation, it has been proposed that nitrogen ions are implanted in a silicon substrate before a gate insulation film is formed to thereby suppress the following oxidation (retarded oxidation), and argon ions are implanted in a silicon substrate before a gate insulation film is formed to thereby enhance the following oxidation (enhanced oxidation). In the specification of laid-open Japanese Patent Application No. Hei 11-260813/1999 and the specification of Japanese Patent No. 2950101, a technique wherein fluorine ions are implanted in a silicon substrate before a gate insulation film is formed to thereby enhance the following oxidation is proposed. Such ion implantation is performed selectively in a specific region, whereby a gate insulation film of silicon oxide film which is thicker or thinner in an ion-implanted region than in the rest region can be formed.
[0005] Thus, by the conventional method for fabricating a semiconductor device, wherein the gate insulation film is formed by using the enhanced oxidation or retarded oxidation by ion implantation, the gate insulation films having different film thicknesses from each other can be formed by one thermal oxidation step.
[0006] However, the conventional semiconductor device fabrication method using the retarded oxidation by nitrogen ion implantation has often degraded reliability of the gate insulation film. The conventional semiconductor device fabrication method using the enhanced oxidation by argon ion implantation has often increased gate leak current. The conventional semiconductor device fabrication method using argon ion implantation produces a relatively small film thickness difference of about 10% between a region with ions implanted and a region without the ion implantation. A technique for ensuring larger film thickness differences has been required.
[0007] Usually, wet oxidation film is more reliable than dry oxidation film, and the oxidation technique for forming a gate insulation film is preferably wet oxidation. However, in a case that the above-described method uses wet oxidation, the effect of the enhanced oxidation by ion implantation is much suppressed, and the merit of the ion implantation has not been produced. Accordingly, dry oxidation has been used for the oxidation for the enhanced oxidation, and the gate insulation film of high quality which is comparable to that of the wet oxidation film has not been produced.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide a semiconductor device fabrication method which can form gate insulation films having different film thicknesses from each other while retaining sufficient reliability and sufficient film thickness difference.
[0009] A first method for fabricating a semiconductor device according to the present invention is characterized mainly in that halogen ions are implanted before the thermal oxidation for forming a gate insulation film, and is also characterized in that wet oxidation under low pressure is applied to forming the gate insulation film.
[0010] Fluorine, which is one of VII-group elements (halogen), is added to a silicon oxide film in a suitable amount to thereby improve reliability thereof. Accordingly, the oxidation is enhanced by fluorine ion implantation, whereby reliability of the gate insulation film can be improved, and the gate insulation films having different film thicknesses from each other can be formed by one oxidation step. However, as described above, dry oxidation is used for the oxidation for the enhanced oxidation, and no silicon oxide film of good quality which is comparable to wet oxidation film can be formed.
[0011] In such circumstances, the inventors of the present application have made earnest studies and found for the first time that wet oxidation under low pressure or in an atmosphere of nitrogen or diluted with rare gas applied to forming a gate insulation film is very effectively for producing the effect of the enhanced oxidation.
[0012] The effect of the enhanced oxidation by the ion implantation is conspicuous in dry oxidation but is not in wet oxidation. This will be due to oxidizability difference between the two. That is, wet oxidation, which is more oxidizable than dry oxidation, advances the oxidation reaction so rapidly that an implanted element cannot affect the mechanism. Then, the inventors of the present application had an idea that oxidizability of wet oxidation is reduced so as to delay the oxidation reaction, whereby the enhanced oxidation effect by the ion implantation is allowed to be sufficiently exerted, and tested wet oxidation under low pressure or in an atmosphere of nitrogen or diluted with rare gas.
[0013] As a result, wet oxidation film could be formed without much suppressing the effect of the enhanced oxidation by fluorine ion implantation. Especially by suitably controlling conditions for the fluorine ion implantation, silicon oxide film can be made more reliable than that formed without the fluorine ion implantation.
[0014] It is preferable that the wet oxidation is conducted in an ambient atmosphere which an H 2 O partial pressure is less than 1 atm. A low pressure oxidation and a dilute oxidation may be applicable to such the wet oxidation. The low pressure wet oxidation used in this specification is wet oxidation made under low pressure, and a pressure in a film forming chamber is set to be, e.g., 1-400 Torr. The same effect can be produced by dilution with nitrogen, rare gas, such as argon, etc., or inactive gas so that an H 2 O partial pressure becomes less than 1 atm to prepare a steam partial pressure equivalent to the low pressure. It is possible that nitrogen, rare gas, such as argon, etc., or inactive gas is used under low pressure so as to use the synergetic effect. The diluent gases are not limited to rare gas or inactive gas. It is possible that oxygen or hydrogen may be also used as diluent gas. These gases have an effect of lowering the oxidation rate. It is possible that other additives, e.g., hydrogen chloride (HCl) may be incorporated in the atmosphere for the end of improving film quality of silicon oxide film, and other ends.
[0015] Wet oxidation film of good quality can be formed, producing the effect of the enhanced oxidation by the ion implantation, for example, at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, at a 3 liters oxygen flow rate, at 20 liters nitrogen flow rate, and a 5% hydrogen chloride flow rate.
[0016] Then, the first method for fabricating a semiconductor device according to the present invention will be detailed below.
[0017] [0017]FIG. 1 is a graph of dose dependency of silicon oxide film thickness of samples each with a silicon oxide film formed by implanting fluorine ions at 5 keV acceleration energy through a 6 nm-thick sacrificial oxidation film and removing the sacrificial oxidation film and forming the silicon oxide film by low pressure wet oxidation or dry oxidation. In FIG. 1, the circles indicate the formation of the silicon oxide film by low pressure wet oxidation, and the squares indicate the formation of the silicon oxide film by dry oxidation.
[0018] As shown, both in the low pressure wet oxidation and the dry oxidation, the silicon oxide films increase thickness as the doses are increased. It is found that the enhanced oxidation is caused by the fluorine ions implantation. At below an about 1×10 14 cm −2 dose, the enhanced oxidation is below about 4%, and the effect is not conspicuous. At a 5×10 14 cm −2 dose, a film thickness increase is about 20% for the dry oxidation and about 15% for the low pressure wet oxidation. At a 1×10 15 cm −2 dose, the film thickness is further increased, and a film thickness increase is about 35% for the dry oxidation and about 20% for the low pressure wet oxidation.
[0019] [0019]FIG. 2 is a graph of acceleration energy dependency of silicon oxide film thickness of samples each with a silicon oxide film formed by implanting fluorine ions at a 5×10 14 cm −2 dose through a 6 nm-thick sacrificial oxidation film, removing the sacrificial oxidation film and forming the silicon oxide film by low pressure wet oxidation.
[0020] As shown, a film thickness of the formed silicon oxide film increases as the acceleration energy increases and decreases when the acceleration energy exceeds about 10 keV. This is because when the acceleration energy is too low, nitrogen is mostly incorporated into the sacrificial oxidation film and cannot contribute to the oxidation reaction, and when the acceleration energy is too high, nitrogen is incorporated deep into a region of the substrate, which does not contribute to the oxidation reaction. Accordingly, it is preferable that conditions for the acceleration energy are selected so that many nitrogen atoms are incorporated into a region of the substrate, which contributes to the oxidation reaction. For example, when nitrogen ions are implanted with the sacrificial oxidation film of an about 6 nm-thick, it is preferable in FIG. 2 that the acceleration energy is set at about 5-10 keV.
[0021] From this viewpoint, a film thickness of the sacrificial oxidation film is set to be thinner than a projected range R p of nitrogen ions. Specifically, it is preferable that the acceleration energy of nitrogen ions are set so that a projected range R p of nitrogen ions is positioned at a depth of less than 10 nm from the interface between the sacrificial oxidation film and the silicon substrate. The sacrificial oxidation film is formed for the prevention of the substrate from being contaminated when the ions are implanted. Accordingly, when the ions can be implanted in a clean environment, the sacrificial oxidation film is not essential.
[0022] [0022]FIG. 3 is a graph of dose dependency of etching rates of a silicon oxide film with nitrogen ions implanted at 5 keV acceleration energy. The shown etched film thicknesses are equivalent to the etching amounts when the samples are etched by the etching condition of 10 nm-thick thermal oxidation film without nitrogen ions implanted.
[0023] As shown, as the dose of nitrogen ions increases, the etching rate of silicon oxide film much increases. The etching step of removing the sacrificial oxidation film is necessary after the nitrogen ion implantation and before the gate insulation film formation. In the etching step, the device isolation film as well as the sacrificial oxidation film is exposed to the etching. Accordingly, unpreferably for device isolation characteristics and surface planarity the device isolation film is etched at the high etching rate shown in FIG. 3. Accordingly, it is preferable that the sacrificial oxidation film is made as thin as possible so as to expose the device isolation film to the etching for a shorter period of time.
[0024] [0024]FIG. 4 is a graph of results of damage measured by thermal wave method, which was incorporated in the silicon substrate when fluorine ions are implanted in a 5×10 14 cm −2 dose. As shown, the damage in the substrate increases as the acceleration energy for the fluorine ions is increased. Accordingly, it is preferable from the viewpoint of less damage in the silicon substrate that the acceleration energy is set as low as possible.
[0025] [0025]FIG. 5 is a graph of reliability of silicon oxide films of samples measured by constant voltage TDDB (time dependent dielectric breakdown) method, each of which was formed by implanting fluorine ions at 5 keV acceleration energy and forming a 5 nm-thick silicon oxide film by low pressure wet oxidation. In FIG. 5, mark indicates the sample which fluorine ions are implanted at a dose of 1×10 14 cm −2 , □ mark indicates the sample which fluorine ions are implanted at a dose of 2×10 14 cm −2 , ▪ mark indicates the sample which fluorine ions are implanted at a dose of 5×10 14 cm −2 , and Δ mark indicates the sample which fluorine ions are implanted at a dose of 1×10 15 cm −2 . As a control, the reliability of a wet oxidation film formed without fluorine ion implantation is indicated by ο mark. Oxidation conditions were controlled so that all the samples have a 5 nm-thick for the end of expelling influences due to differences in the film thickness. The MOS capacitor used for the measurement has an N + gate electrode formed on a p-type substrate interposing a silicon oxide film therebetween.
[0026] As shown, it is found that as the fluorine dose is increased from 1×10 14 cm −2 to 2×10 14 cm −2 dose and further to 5×10 14 cm −2 , the silicon oxide films have longer lifetimes. However, when the dose is increased to 1×10 15 cm −2 , the lifetime is shortened by about one digit, and the silicon oxide film has poor quality than that of the sample without fluorine ions implanted. A detailed mechanism for implanted fluorine ions making a lifetime of silicon oxide film longer is not clear, but it will be a cause that suitable incorporation of fluorine in the interface between a silicon substrate and silicon oxide film improves interface characteristics. Accordingly, it is preferable that a dose of fluorine ions is set to be not less than 1×10 14 cm −2 and less than 1×10 15 cm −2 .
[0027] [0027]FIG. 6 is a graph showing damages in the substrates measured by thermal wave method. The measurements are conducted before and after the silicon oxide film formation. In FIG. 6, ∇ mark indicates the damage incorporated immediately after the implantation, ο mark indicates the damage after the 3 nm-thick silicon oxide film formation by the dry oxidation, □ mark indicates the damage after the 4 nm-thick silicon oxide film formation by the dry oxidation, Δ mark indicates the damage after the 4.5 nm-thick silicon oxide film formation by the low pressure wet oxidation. As shown, the damage incorporated by the fluorine ion implantation has been substantially removed during the formation of the silicon oxide film. Considering that the residual damage in the sample, which the silicon oxide film is formed after the nitrogen ion implantation at the dose of 5×10 14 cm −2 dose, is typically about 2000 [TW unit], the enhanced oxidation by fluorine ion implantation is more effective than that by nitrogen ion implantation.
[0028] [0028]FIG. 7 is a graph of fluorine distributions in the silicon substrates before and after the silicon oxide films were formed. FIG. 8 is a graph of fluorine distributions in the silicon oxide films before and after the silicon oxide films were formed. As shown in FIG. 7, by either of the dry oxidation and the low pressure wet oxidation, fluorine concentrations in the silicon substrates are lowered to below the detection limit as the silicon oxide films were formed. On the other hand, as shown in FIG. 8, fluorine remains in the dry oxidation film by about {fraction (1/100)} of the implanted doses, while fluorine remains in the low pressure wet oxidation film by about {fraction (1/1000)} of the implanted doses. Accordingly, the low pressure wet oxidation film is less affected by fluorine in comparison with the dry oxidation film.
[0029] The mechanism for fluorine contributing to the enhanced oxidation in the wet oxidation process, and the mechanism for fluorine in the silicon oxide film vanishing are not clear. The inventors of the present invention consider as follows. That is, fluorine contributes to the enhanced oxidation in the wet oxidation process because fluorine atoms bonded with silicon atoms in the interface between the silicon oxide film and the silicon substrate attract electrons, thereby weakening bonds of back bonds of the silicon (FIG. 9A). The mechanism for fluorine in the silicon oxide film vanishing will be that OH − acts on bonding between the silicon and the fluorine in the silicon oxide film to bond the oxygen of the OH − with the silicon while the fluorine bonded with the silicon is evaporated in HF (FIG. 9B to 9 D).
[0030] [0030]FIG. 10 is a graph of J-E characteristics of a sample with a silicon oxide film formed by the low pressure wet oxidation after fluorine ions were implanted at 5 keV acceleration energy and at a 5×10 14 cm −2 dose, and J-E characteristics of a sample with a silicon oxide film formed by the low pressure wet oxidation without fluorine ion implantation. FIG. 11 is a graph of high frequency C-V characteristics of a sample with silicon oxide films formed by the low pressure wet oxidation after fluorine ions were implanted at 5 keV acceleration energy and a sample with a silicon oxide film formed by the low pressure wet oxidation without fluorine ion implantation. A MOS capacitor used in the measurement had an N + gate electrode formed on a p-type substrate interposing the silicon oxide film therebetween and had a 0.1 mm 2 electrode area. As shown in FIG. 10, the sample with fluorine ions implanted, and the sample without fluorine ions implanted have substantially equal J-E characteristics. As shown in FIG. 11, the sample with fluorine ions implanted in a 1×10 15 cm −2 dose has the large flat band voltage shift, but the samples with fluorine ions implanted in doses of not more than 5×10 14 cm −2 could have the flat band voltage shifts suppressed small. Thus, it is considered that the fluorine implantation in doses which are less than 1×10 15 cm −2 does not affect the electric characteristics of the silicon oxide film.
[0031] As described above, silicon oxide film is formed by the low pressure wet oxidation after fluorine ions are implanted, whereby the silicon oxide film can have higher reliability than wet oxidation film formed without the fluorine ion implantation. In addition, the effect of the enhanced oxidation can be enhanced in comparison with that produced by the conventional method using argon ion implantation.
[0032] Iodine (I), which is a halogen element, as is fluorine, has the same properties as fluorine, and has the atomic weight, which is larger than that of fluorine. Iodine ions are used as a dopant to be implanted before the silicon oxide film is formed to produce the same effect described above as produced by implanting fluorine ions, and the enhanced oxidation is more effective than that produced by fluorine ion implantation.
[0033] [0033]FIG. 12 is a graph of film thickness differences of silicon oxide films of samples prepared by implanting iodine ions at 10-20 keV acceleration energy and in 0−1×10 15 cm −2 doses through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide films by thermal oxidation.
[0034] As shown, by the iodine ion implantation as well as the fluorine ion implantation, the film thicknesses of the silicon oxide films increase as the doses increase. The film thickness increases of the silicon oxide films are much larger in comparison with those by the fluorine ion implantation. At 10 keV acceleration energy, a film thickness increase was about 10% for a 1×10 13 cm −2 dose; about 20-40%, for a 1×10 14 cm −2 dose; about 50-80% for a 3×10 14 cm −2 dose; about 60-120% for a 5×10 14 cm −2 dose; and about 150-240% for a 1×10 15 cm −2 dose. At 20 keV acceleration energy, a film thickness increase was about 30-60% for a 5×10 14 cm −2 dose. The iodine ion implantation as well as the fluorine ion implantation makes the effect of the enhanced oxidation higher in the dry oxidation film than in the low pressure wet oxidation film. In comparison with the fluorine ion implantation, the iodine ion implantation can make the effect of the enhanced oxidation higher also in the low pressure wet oxidation film.
[0035] [0035]FIG. 13 is a graph of reliability of silicon oxide films of samples measured by constant voltage TDDB, each of which was formed by implanting iodine ions at 10 keV acceleration energy and forming a 5 nm-thick silicon oxide film by low pressure wet oxidation. In FIG. 13, □ mark indicates the reliability for the silicon oxide film formed at a 1×10 13 cm −2 dose, Δ mark indicates the reliability for the silicon oxide film formed at a 1×10 14 cm −2 dose. As a control, the reliability of a sample without iodine ions implanted is indicated by ο mark. Oxidation conditions were controlled so that all the samples have a 5 nm-thickness for the end of expelling influences due to differences in the film thickness.
[0036] As shown, all the samples with iodine ions implanted could have the oxide film lifetimes equal to or longer than the oxide film lifetime of the sample without iodine ions implanted.
[0037] As described above, by the iodine ion implantation as well, the effect of the enhanced oxidation can be enhanced without deteriorating film quality of silicon oxide film. Especially by using iodine, a much higher rate of the enhanced oxidation can be obtained in comparison with that obtained by using fluorine. Accordingly, by using iodine, the atmospheric wet oxidation can provide sufficient effect of the enhanced oxidation.
[0038] Although the inventors of the present application have not tested, chlorine (Cl) and bromine (Br), which belong to VII group, are expected to produce the same effect.
[0039] A second method for fabricating a semiconductor device according to the present invention is characterized mainly in that ions of rare gas, such as xenon (Xe) or krypton (Kr) are implanted before the thermal oxidation for forming the gate insulation film.
[0040] Xenon and krypton as well as argon are elements belonging to the rare gas, and are elements having larger atomic weights than argon. Accordingly, it is considered that implanted xenon and krypton are little influential and have higher effect of the enhanced oxidation. From this viewpoint, the inventors of the present invention have made earnest studies and found that xenon ions and krypton ions are used as ion species to be implanted before a silicon oxide film is formed, whereby the effect of the enhanced oxidation can be much enhanced. Especially by using xenon good effect of the enhanced oxidation can be produced not only in the dry oxidation, but also in the low pressure wet oxidation and the atmospheric wet oxidation. By using even argon, which does not produce sufficient effect of the enhanced oxidation in the atmospheric wet oxidation, sufficient effect of the enhanced oxidation could be produced in the low pressure wet oxidation.
[0041] [0041]FIG. 14 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films which were formed by implanting xenon ions at 10-20 keV acceleration energy and in 0−5×10 14 cm −2 does through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide film by thermal oxidation. In FIG. 14, ο mark indicates film thickness for the dry oxidation. □ mark indicates film thickness for the low pressure wet oxidation. Δ mark indicates film thickness for the low pressure wet oxidation following annealing at 600° C.
[0042] As shown, as the dose increases, the thickness of the silicon oxide films increases. At 10 keV acceleration energy, the film thickness increases by about 4-8% for a 1×10 13 cm −2 dose, by about 10-20% for a 1×10 14 cm −2 dose, by about 30-45% for a 3×10 14 cm −2 dose, and by about 50-60% for a 5×10 14 cm −2 dose. At 20 keV acceleration energy, the increases of the film thickness is a little smaller, and the increase of the film thickness is about 30-50% at a 5×10 14 cm −2 dose.
[0043] In comparison between the dry oxidation and the low pressure wet oxidation, the film thickness increase is larger in the dry oxidation, as in the case of using halogen. In the low pressure wet oxidation, however, an about 50% film thickness at maximum could be obtained.
[0044] A characteristic of the use of xenon is that the effect of the enhanced oxidation can be produced even with the annealing after the ion implantation and before the oxidation. In the case of the argon ion implantation, the annealing makes the enhanced oxidation less effective. The annealing before the oxidation is effective to recover damage incorporated in a silicon substrate. Accordingly, the silicon oxide film after the annealing, and the silicon substrate can have improved reliability.
[0045] It is preferable that a film thickness of the sacrificial oxidation film, and acceleration energy for the ions are set to be the same as those for using halogen.
[0046] A third method for fabricating a semiconductor according to the present invention is characterized in that nitrogen ions are implanted before thermal oxidation for forming a gate insulation film, and then using oxidation combining the dry oxidation and the low pressure wet oxidation for forming the gate insulation film.
[0047] [0047]FIG. 15 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films which were formed by implanting nitrogen ions (N + ) at 5 keV acceleration energy and in 0−4×10 14 cm −2 does through 6 nm-thick sacrificial oxidation films, removing the sacrificial oxidation films and forming the silicon oxide film by the low pressure wet oxidation.
[0048] As shown, combining the nitrogen ion implantation and the low pressure wet oxidation, the effects of retarded oxidation can be obtained. However, the film thickness decrease is only about 7% for implanting nitrogen ions at 5 keV acceleration energy and in a 4×10 14 cm −2 dose. In comparison with the dry oxidation which has the film thickness decrease of about 20%, the film thickness decrease in the low pressure wet oxidation is low.
[0049] From this viewpoint, the inventors of the present invention have made earnest studies to find the oxidation method which can obtain the effects of the retarded oxidation and the merit of the wet oxidation, and found for the first time that implanting nitrogen ions before forming the gate insulation film by the thermal oxidation and forming the gate insulation film by combining dry oxidation and low pressure wet oxidation is very effectively for producing the effect of the enhanced oxidation.
[0050] [0050]FIG. 16 is a graph of film thickness differences of silicon oxide films of samples with the silicon oxide films formed each by implanting nitrogen ions through a 6 nm-thick sacrificial oxidation film, removing the sacrificial oxidation film and forming the silicon oxide film by various oxidation methods. In FIG. 16, ο mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation at 750° C. mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation after nitrogen annealing at 600° C. for 1 hour. □ mark indicates a 4 nm-thick silicon oxide film formed by the dry oxidation at 750° C. ▪ mark indicates a 4 nm-thick silicon oxide film formed by the dry oxidation after nitrogen annealing at 600° C. for 1 hour. Δ mark indicates a 3 nm-thick silicon oxide film formed by the dry oxidation at 900° C. ∇ mark indicates a sample which is oxidized by the dry oxidation at 750° C. to form a 4 nm-thick silicon oxide film and processed for 30 minutes under a low pressure wet oxidation atmosphere. ▾ mark indicates a sample which is annealed at 1015° C. for 10 seconds in nitrogen atmosphere, oxidized by the dry oxidation at 750° C. to form a 4 nm-thick silicon oxidation film and processed for 30 minutes under a low pressure wet oxidation atmosphere.
[0051] As seen in FIG. 16, in forming a 4 nm-thick silicon oxide film by the dry oxidation at 750° C., the oxidation is retarded by about 20% (see the □ marks). The rate of the retarded oxidation can be enhanced to about 30% by the nitrogen annealing before the oxidation, at 600° C. for 1 hour (see the ▪ marks).
[0052] In forming the 3 nm-thick silicon oxide film by the dry oxidation (see the ο marks and marks), the retarded oxidation can be found, but the rate is lower than that for forming the 4 nm-thick silicon oxide film. This will be because the implanted nitrogen do not sufficiently contribute to the oxidation reaction in the oxidation for the 3 nm-thick silicon oxide film. Accordingly, in order to make the retarded oxidation sufficiently effective, it is effective to form silicon oxide film of an above 4 nm-thick.
[0053] In forming a silicon oxide film of an about 5.5 nm-total thickness by forming a 4 nm-thick silicon oxide film by the dry oxidation and then processing in a low pressure wet oxidation atmosphere for 30 minutes (see the ▾ marks), the retarded oxidation of about 30% is observed. Especially, under these conditions, the dry oxidation is followed by the wet oxidation, and reliability equal to the wet oxidation film can be obtained. However, when the nitrogen annealing is made at 1015° C. for 10 seconds before the dry oxidation, the effect of the retarded oxidation is not observed.
[0054] In comparing between N + ion implantation and N 2 + ion implantation in the retarded oxidation effect, the retarded oxidation effect is higher in the former. This will be because N 2 + has the larger atomic weight than N + and more damages the substrate with a result that the enhanced oxidation effect is exhibited. For nitrogen ion implantation for the purpose of the retarded oxidation the use of N + ions will be effective.
[0055] As described above, in order to form silicon oxide film of good quality by the retarded oxidation using nitrogen ions, it is effective to perform the oxidation combining the dry oxidation and the low pressure wet oxidation after nitrogen ions are implanted.
[0056] In a fourth method for fabricating a semiconductor device according to the present invention, in place of the ion implantation in the above-described first method for fabricating the semiconductor device, a semiconductor substrate with a sacrificial oxidation film formed on is exposed to a plasma atmosphere containing a halogen element to incorporate the halogen element in the semiconductor substrate.
[0057] The present method is the same as the methods using the ion implantation in that an element is incorporated for the purpose of enhancing the enhanced oxidation, and the effect produced by the present method is the same as that produced by the above-described first method for fabricating the semiconductor device.
[0058] As a method for incorporating a halogen element by using plasma, for example, a gas, as of F 2 , ArF, KrF, XeF, Cl 2 , ArCl, KrCl, XeCl, Br 2 , ArBr, KrBr, XeBr, I 2 , ArI, KrI, XeI, or others, is incorporated in a vacuum system for magnetron plasma processing.
[0059] For example, a halogen element can be incorporated in a silicon substrate by introducing one of these gases into a vacuum system, applying a substrate bias to the back side of the silicon substrate under a 0.01-10 Pa to establish a negative voltage within 1 kV, concurrently therewith introducing electromagnetic waves of 200-2000 W of rf (e.g. 13.56 MHz) or microwaves to parallel plate electrodes to cause discharges and expose the substrate to the plasma for about 10 seconds—about 3 minutes. In place of applying rf or microwaves, electron beams may be applied to ionize a halogen element to apply the halogen ions to the silicon substrate. An ion source, such as ECR, is used to apply ionized halogen ions to the silicon substrate.
[0060] A distribution of a halogen element in the silicon substrate can be controlled by gas partial pressure control, discharge voltage control, and a thickness of a protection film on the surface of a silicon substrate. By controlling these parameters, a concentration of the surface of the silicon substrate can be changed to about 1×10 19 cm −2 -10 22 cm −2 .
[0061] A halogen element is distributed, decreasing a concentration from the surface of the substrate toward the inside thereof. A distribution width is about 5-10 nm and is about 20-30 nm at maximum.
[0062] In exposing the silicon substrate to the plasma, it is important to cover the surface of the silicon substrate with a protection film, and an about 5-10 nm thick silicon oxide film, for example, is formed. In setting high a concentration of halogen to be incorporated, a material of the protection film may be changed corresponding to a gas to be used.
[0063] If necessary, a gas, such as a rare gas, may be added to the halogen gas to prepare a mixed gas.
[0064] The above-described object is achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or argon into a first region of a silicon substrate; and wet oxidizing the silicon substrate in an ambient atmosphere which an H2O partial pressure is less than 1 atm to thereby form a first silicon oxide film in the first region of the silicon substrate, and a second silicon oxide film thinner than the first silicon oxide film in a second region of the silicon substrate different from the first region.
[0065] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing iodine, krypton or xenon into a first region of a silicon substrate; and oxidizing the silicon substrate to thereby form a first silicon oxide film in the first region, and a second silicon oxide film thinner than the first silicon oxide film in a second region of the silicon substrate different from the first region.
[0066] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing nitrogen into a first region of a silicon substrate; and wet oxidizing the silicon substrate after dry oxidation to thereby form a first silicon oxide film in the first region, and a second silicon oxide film thicker than the first silicon oxide film in a second region of the silicon substrate different from the first region.
[0067] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or a rare gas at a first concentration into a first region of a silicon substrate; selectively introducing a halogen element or a rare gas at a second concentration higher than the first concentration into a second region of the silicon substrate different from the first region; and wet-oxidizing the silicon substrate to thereby form a first silicon oxide film in the first region, a second silicon oxide film thicker than the first silicon oxide film in the second region, and a third silicon oxide film thinner than the first silicon oxide film in a third region of the silicon substrate different from the first region and the second region.
[0068] The above-described object is also achieved by a method for fabricating the semiconductor device comprising the steps of: selectively introducing a halogen element or a rare gas into a first region of a silicon substrate; selectively introducing nitrogen in a second region of the silicon substrate different from the first region; and wet-oxidizing the silicon substrate after dry oxidation to thereby form a first silicon oxide film in the first region, a second silicon oxide film thinner than the first silicon oxide film in the second region, and a third silicon oxide film thinner than the first silicon oxide film and thicker than the second silicon oxide film in a third region of the silicon substrate different from the first region and the second region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] [0069]FIG. 1 is a graph of relationships between doses of fluorine ions and enhanced oxidation film thickness.
[0070] [0070]FIG. 2 is a graph of relationship between acceleration energy of fluorine ions and enhanced oxidation film thickness.
[0071] [0071]FIG. 3 is a graph of dose dependency of etching rates of silicon oxide film with nitrogen ions implanted.
[0072] [0072]FIG. 4 is a graph of relationships between acceleration energy of fluorine ions and damage incorporated in the silicon substrate.
[0073] [0073]FIG. 5 is a graph of relationship between doses of fluorine ions and the silicon oxide film reliability.
[0074] [0074]FIG. 6 is a graph of relationship between doses of fluorine ions and damage in the silicon substrates before and after silicon oxide films were formed.
[0075] [0075]FIG. 7 is a graph of fluorine distributions in the silicon substrates before and after the silicon oxide films were formed.
[0076] [0076]FIG. 8 is a graph of fluorine distributions in the silicon oxide films after the silicon oxide films were formed.
[0077] FIGS. 9 A- 9 D are views showing the mechanism for fluorine contributing to the enhanced oxidation in the wet oxidation process, and the mechanism for fluorine in the silicon oxide film vanishing.
[0078] [0078]FIG. 10 is a graph of J-E characteristics of silicon oxide films formed after fluorine ion implantation.
[0079] [0079]FIG. 11 is a graph of high frequency C-V characteristics of silicon oxide films formed after fluorine ion implantation.
[0080] [0080]FIG. 12 is a graph of relationships between iodine ion doses and acceleration energy, and enhanced oxidation film thickness.
[0081] [0081]FIG. 13 is a graph of relationships between iodine ion doses and the silicon oxide film reliability.
[0082] [0082]FIG. 14 is a graph of relationships between xenon ion doses and acceleration energy, and enhanced oxidation film thickness.
[0083] [0083]FIG. 15 is a graph of relationships between nitrogen ion doses and retarded oxidation film thickness.
[0084] [0084]FIG. 16 is a graph of oxidation method dependency of retarded oxidation film thickness formed by thermal oxidation following nitrogen ion implantation.
[0085] FIGS. 17 A- 17 D and 18 A- 18 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a first embodiment of the present invention, which show the method.
[0086] FIGS. 19 A- 19 C and 20 A- 20 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a second embodiment of the present invention, which show the method.
[0087] FIGS. 21 A- 21 C and 22 A- 22 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a third embodiment of the present invention, which show the method.
[0088] FIGS. 23 A- 23 C and 24 A- 24 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a fourth embodiment of the present invention, which show the method.
[0089] FIGS. 25 A- 25 D are sectional views of a semiconductor device in the steps of the method for fabricating the same according to a fifth embodiment of the present invention, which show the method.
DETAILED DESCRIPTION OF THE INVENTION
[0090] A First Embodiment
[0091] A method for fabricating the semiconductor device according to a first embodiment of the present invention will be explained with reference to FIGS. 17 A- 17 D and 18 A- 18 C.
[0092] FIGS. 17 A- 17 D and 18 A- 18 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method.
[0093] A device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines a device region 14 and a device region 16 (FIG. 17A). In the present embodiment, the device region 14 is a region where a thick gate insulation film is to be formed, and the device region 16 is a region where a thin gate insulation film is formed. In a DRAM, for example, the device region 14 can be a memory cell region and the device region 16 can be a peripheral circuit region.
[0094] Then, a sacrificial oxidation film 18 is formed, by thermal oxidation, of, e.g., an about 6 nm-thick silicon oxide film on the device regions 14 , 16 defined by the device isolation film 12 (FIG. 17B).
[0095] Next, a photoresist film 20 exposing the device region 14 and covering the device region 16 is formed by the usual photolithography techniques.
[0096] Then, fluorine ions are implanted in the silicon substrate 10 with the photoresist film 20 as a mask. The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 17C).
[0097] Next, after the photoresist film 20 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution. After the sacrificial oxidation film 18 is removed, chemical oxide film may be formed on the surface of the substrate 10 by processing using a chemical liquid, such as SC- 1 , SC- 2 or others.
[0098] Then, the silicon substrate 10 is thermally oxidized by low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 and a gate insulation film 24 of silicon oxide film on the device region 16 . At this time, the enhanced oxidation takes place in the device region 14 , where fluorine ions have been incorporated in. Accordingly, the gate insulation film 22 is formed thick in the device region 14 , and in the device region 16 , the gate insulation film 24 is formed thin (FIG. 17D). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine ions implanted set at 4.5 nm, the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.1 nm-thick, and the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited.
[0099] Next, annealing is performed at 900° C. for 30 minutes to incorporate the nitrogen into the interface between the gate insulation films 22 , 24 and the silicon substrate 10 , whereby the gate insulation films 22 , 24 are formed of silicon oxynitride film. An annealing temperature may be a temperature suitable to incorporate the nitrogen into the interface and can be typically 700-1100° C.
[0100] It is preferable from the viewpoint of improving reliability of the gate insulation films to form the gate insulation films of the silicon oxynitride film. Because fluorine enhances diffusion of boron, the gate insulation films 22 , 24 are formed of silicon oxynitride film, whereby the effect of suppressing increase of gate resistance and source/drain resistance of P-type transistors can be produced. In the method for fabricating the semiconductor device according to the present embodiment, wherein fluorine ions are implanted for the purpose of the enhanced oxidation, it is preferable from the viewpoint of suppressing diffusion of boron to form the gate insulation films 22 , 24 of silicon oxynitride film.
[0101] Gate electrodes 26 are formed on the gate insulation films 22 , 24 . Polycrystalline silicon film and tungsten silicide film are deposited by, e.g., CVD method and then are patterned by the usual photolithography and etching to form the gate electrodes 26 of the polycide structure of the layer film of the polycrystalline silicon film and the tungsten silicide film.
[0102] Next, ions are implanted in the device regions 14 , 16 with the gate electrodes 26 as a mask to form a source/drain diffused layer 28 for memory cell transistors in the device region 14 and an extension region 30 of the source/drain diffused layer for peripheral circuit transistors in the device region 16 (FIG. 18A). For example, in the n-type transistor forming region, arsenic (As) ions are implanted at 10 keV acceleration energy and a 5×10 14 cm −2 , and, in the p-type transistor forming region, BF 2 ions are implanted at 10 keV acceleration energy 5×10 14 cm −2 .
[0103] Next, silicon oxide film is deposited on the entire surface by, e.g., CVD method, and then etched back to form a sidewall insulation film 32 on the side walls of the gate electrodes 26 (FIG. 18B).
[0104] Then, ions are implantation in the device region 16 with the gate electrodes 26 and the sidewall insulation film 32 as a mask to form the source/drain diffused layer 34 for the peripheral circuit transistors. For example, in the n-type transistor forming region, arsenic ions are implanted at 50 keV acceleration energy and 3×10 15 cm −2 dose, and in the p-type transistor forming region, BF 2 ions are implanted at 40 keV acceleration energy and 3×10 15 cm −2 dose.
[0105] Thus, the memory cell transistors having the thin gate insulation film 22 are formed in the device region 14 , and the peripheral circuit transistors having the thick gate insulation film are formed in the device region 16 (FIG. 18C).
[0106] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is made after fluorine ions have been selectively implanted, whereby the gate insulation film in the region where the fluorine ions have been implanted can be made selectively thicker. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have improved reliability than those formed by the dry oxidation.
[0107] In the present embodiment, an ion species for enhancing the oxidation is fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, or xenon ions may be used.
[0108] Iodine ions are implanted, e.g., at 10 keV acceleration energy and 5×10 14 cm −2 dose to form the gate insulation film 22 of an about 7.8 nm-thick silicon oxide film in the device region 14 and the gate insulation film 24 of an about 4.5 nm-thick silicon oxide film in the device region 16 (see FIG. 12).
[0109] Xenon ions are implanted, e.g., at 10 keV acceleration energy and 5×10 14 cm −2 dose to form the gate insulation film 22 of an about 6.5 nm-thick silicon oxide film in the device region 14 and the gate insulation film 24 of an about 4.5 nm-thick silicon oxide film in the device region 16 (see FIG. 14). In the case that xenon ion are used, annealing of, e.g., 600° C. for 1 hour may be performed before the oxidation.
[0110] Fluorine ions may be implanted together with other ions, such as iodine ions, xenon ions, krypton (Kr) ions, argon ions, germanium (Ge) ions, silicon ions, etc., whereby the effect of the enhanced oxidation can be further enhanced. Fluorine, which has the effect of improving reliability of the insulation films, is implanted together with such ions to thereby more improve damage in the substrate than singly implanted.
[0111] A Second Embodiment
[0112] The method for fabricating the semiconductor device according to a second embodiment of the present invention will be explained with reference to FIGS. 19 A- 19 C and 20 A- 20 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first embodiment are represented by the same reference numbers not to repeat or simplify their explanation.
[0113] FIGS. 19 A- 19 C and 20 A- 20 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the second embodiment of the present invention, which show the method.
[0114] A device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines a device region 36 , a device region 14 and a device region 16 (FIG. 19A). In the present embodiment, the device region 14 is a region where a thick gate insulation film is to be formed, the device region 16 is a region where a thin gate insulation film is to be formed, and the device region 36 is a region where a gate insulation film thinner than the gate insulation film in the device region 14 but thicker than the gate insulation film in the device region 16 is to be formed. In a DRAM, for example, the device region 14 can a memory cell region, the device region 16 can be a peripheral circuit region, and the device region 36 can be a region for high breakdown voltage transistors, such as input/output transistors, etc. to be formed in.
[0115] Then, a sacrificial oxidation film 18 is formed, by thermal oxidation, of, e.g., an about 6 nm-thick silicon oxide film on the device regions 14 , 16 , 36 defined by the device isolation film 12 (FIG. 19B)
[0116] Next, a photoresist film 38 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography.
[0117] Then, fluorine ions are implanted in the silicon substrate 10 with the photoresist film 38 as a mask. The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 4×10 14 cm −2 dose (FIG. 19C).
[0118] Next, after the photoresist film 38 is removed, a photoresist film 40 exposing the device regions 36 , 14 and covering the device region 16 is formed by the usual photolithography.
[0119] Then, with the photoresist film 40 as a mask, fluorine ions are implanted in the silicon substrate 10 . Fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 1×10 14 cm −2 dose (FIG. 20A).
[0120] The twice ion implantation incorporates a 5×10 14 cm −2 dose of fluorine in the device region 36 and a 1×10 14 cm −2 dose of fluorine in the device region 14 .
[0121] Next, the photoresist film 40 is removed, and then the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution.
[0122] Then, the silicon substrate 10 is thermally oxidized by low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 , a gate insulation film 24 of the silicon oxide film on the device region 16 , and a gate insulation film 42 of the silicon oxide film on the device region 36 . At this time, the enhanced oxidation takes place in the device regions 36 , 14 , where fluorine ions have been incorporated in. The enhanced oxidation is more enhanced in the device region 36 , where more fluorine ions are incorporated than in the device region 14 . Accordingly, the thick gate insulation film 42 is formed in the device region 36 , the thin gate insulation film 24 is formed in the device region 16 , and the gate insulation film 22 having the thickness thinner than the gate insulation film 42 but thicker than the gate insulation film 24 is formed in the device region 14 (FIG. 20B). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 5.1 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 4.7 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited.
[0123] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 20C).
[0124] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is performed after fluorine ions are selective implanted, whereby the gate insulation films in the regions with the fluorine ions implanted can be thick. Different doses of fluorine ions are implanted in the regions, whereby the gate insulation films can be different in thickness among the regions. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have improved reliability than that formed by the dry oxidation.
[0125] In the present embodiment, an ion species for enhancing the enhanced oxidation is provided by fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, etc., or xenon ions may be used.
[0126] In the present embodiment, three gate insulation films which have different thicknesses from each other are formed, but four or more gate insulation films having different thicknesses from one another may be formed.
[0127] A Third Embodiment
[0128] The method for fabricating the semiconductor device according to a third embodiment of the present invention will be explained with reference to FIGS. 21 A- 21 C and 22 A- 22 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first and the second embodiments are represented by the same reference numbers not to repeat or to simplify their explanation,
[0129] FIGS. 21 A- 21 C and 22 A- 22 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method.
[0130] First a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 36 , 14 , 16 (FIG. 21A).
[0131] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is formed on the device regions 14 , 16 , 36 defined by the device isolation film 12 (FIG. 21B).
[0132] Next, a photoresist film 46 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography.
[0133] Then, with the photoresist film 46 as a mask, xenon ions are implanted in the silicon substrate 10 . The xenon ions are implanted, e.g., at 10 keV acceleration energy and a 5×10 14 cm −3 dose (FIG. 21C).
[0134] Next, after the photoresist film 46 is removed, a photoresist film 48 exposing the device region 14 and covering the device regions 16 , 36 is formed by the usual photolithography.
[0135] Then, with the photoresist film 48 as a mask, fluorine ions are implanted in the silicon substrate 10 . Fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 22A).
[0136] Next, after the photoresist film 48 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution.
[0137] Then, the silicon substrate 10 is thermally oxidized by the low pressure wet oxidation to form a gate insulation film 22 of silicon oxide film on the device region 14 , a gate insulation film 24 of the silicon oxide film on the device region 16 and a gate insulation film 42 of the silicon oxide film on the device region 36 . At this time, xenon ions are implanted in the device region 36 , and fluorine ions are implanted in the device region 14 , and the enhanced oxidation takes place in the device regions 36 , 14 . The enhanced oxidation is more enhanced in the device region 36 than in the device region 14 , whereby the gate insulation film 42 in the device region 36 is formed thick, the gate insulation film 24 in the device region 16 is formed thin, and the gate insulation film 22 in the device region 14 is formed thinner than the gate insulation film 42 but thicker than the gate insulation film 24 (FIG. 22B). For example, when the thermal oxidation is performed at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine or xenon ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 6.5 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.5 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.1 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited.
[0138] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 22C).
[0139] As described above, according to the present embodiment, the thermal oxidation for forming the gate insulation films is performed after xenon ions and fluorine ions are selectively implanted, whereby film thicknesses of the gate insulation films in the regions with the ions implanted can be selectively increased. Xenon ions and fluorine ions, which are different in the enhanced oxidation effect, are implanted in the different regions, whereby film thicknesses of the enhanced oxidation films in the regions can be made different from one another. The gate insulation films, which are formed by the wet oxidation, can have improved reliability than those formed by the dry oxidation.
[0140] In the present embodiment, an ion species for enhancing the enhanced oxidation is provided by fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions, may be used.
[0141] In the present embodiment, the gate insulation films of three different film thicknesses are formed, but the gate insulation film of four or more different film thicknesses may be formed.
[0142] A Fourth Embodiment
[0143] The method for fabricating the semiconductor device according to a fourth embodiment of the present invention will be explained with reference to FIGS. 23 A- 23 C and 24 A- 24 C. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first to the third embodiments are represented by the same reference numbers not to repeat or to simplify their explanation.
[0144] FIGS. 23 A- 23 C and 24 A- 24 C are sectional views of a semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method.
[0145] First, a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 36 , 14 , 16 (FIG. 23A).
[0146] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is formed in the device regions 36 , 14 , 16 (FIG. 23B).
[0147] Then, a photoresist film 46 exposing the device region 36 and covering the device regions 14 , 16 is formed by the usual photolithography.
[0148] Next, with the photoresist film 46 as a mask, fluorine ions are implanted in the silicon substrate 10 . The fluorine ions are implanted, e.g., at 5 keV acceleration energy and a 5×10 14 cm −2 dose (FIG. 23C).
[0149] Then, after the photoresist film 46 is removed, a photoresist film 44 exposing the device region 16 and covering the device regions 36 , 14 is formed by the usual photolithography.
[0150] Next, with the photoresist film 44 as a mask, nitrogen ions are implanted in the silicon substrate 10 . The nitrogen ions (N + ) are implanted, e.g., at 5 keV acceleration energy and at a 4×10 14 cm −2 dose (FIG. 24A).
[0151] Next, after the photoresist film 44 is removed, the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution.
[0152] Then, the silicon substrate 10 is thermally oxidized by thermal oxidation combing the dry oxidation and the low pressure wet oxidation to form a gate insulation film 22 of the silicon oxide film in the device region 14 , a gate insulation film 24 of the silicon oxide film in the device region 16 and a gate insulation film 42 of the silicon oxide film in the device region 36 . At this time, fluorine ions are incorporated in the device region 36 , and nitrogen ions are incorporated in the device region 16 , whereby the enhanced oxidation takes place in the device region 36 , and the retarded oxidation takes place in the device region 16 . Accordingly, the gate insulation film 42 in the device region 36 is formed thick, the gate insulation film 24 in the device region 16 is formed thin, and the gate insulation film in the device region 14 is formed thinner than the gate insulation film 42 but thicker than the gate insulation film 22 (FIG. 24B). For example, when the dry oxidation for forming a 4 nm-thick silicon oxide film at 750° C. is followed by the low pressure wet oxidation at a 750° C. oxidation temperature, under a 40 Torr film forming chamber pressure, at a 3 liters hydrogen flow rate, a 3 liters oxygen flow rate, a 20 liters nitrogen flow rate and a 5% hydrochloric acid flow rate, and with a target film thickness of the silicon substrate without fluorine or nitrogen ions implanted set at 4.5 nm, the gate insulation film 42 in the device region 36 is formed of the silicon oxide film of about 6.8 nm-thick, the gate insulation film 24 in the device region 16 is formed of the silicon oxide film of about 4.0 nm-thick, and the gate insulation film 22 in the device region 14 is formed of the silicon oxide film of about 5.5 nm-thick. Thus, wet oxidation film of good quality can be formed while the effect of the enhanced oxidation owing to the ion implantation being exhibited.
[0153] Next, gate electrodes 26 , source/drain diffused layers 28 , 34 , etc. are formed in the same way as in the method for fabricating the semiconductor device according to the first embodiment (FIG. 24C).
[0154] As described above, according to the present embodiment, after fluorine ions and nitrogen ions are selectively implanted, the thermal oxidation combining the dry oxidation and the low pressure wet oxidation is performed as the thermal oxidation for forming the gate insulation film, whereby film thicknesses of the gate insulation films in the ion implanted regions can be selectively increased or decreased. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can have higher reliability than those formed by the dry oxidation.
[0155] In the present embodiment, an ion species for enhancing the enhanced oxidation is fluorine ions, but in place of fluorine ions, halogen ions, such as iodine ions or others, may be used.
[0156] In the present embodiment, by the oxidation in which the dry oxidation is followed by the wet oxidation, the gate insulation films are formed, but the gate insulation films may be formed by the low pressure wet oxidation in a case that the retarded oxidation by nitrogen can be less.
[0157] In the present embodiment, the gate insulation films of three different film thicknesses are formed, but gate insulation film of four or more different film thicknesses may be formed.
[0158] A Fifth Embodiment
[0159] The method for fabricating the semiconductor device according to a fifth embodiment of the present invention will be explained with reference to FIG. 25A- 25 D. The same members of the present embodiment as those of the method for fabricating the semiconductor device according to the first to the fourth embodiments of the present invention shown in FIGS. 7A to 24 C are represented by the same reference numbers not to repeat or to simplify their explanation.
[0160] FIGS. 25 A- 25 D are sectional views of the semiconductor device in the steps of the method for fabricating the same according to the present embodiment, which show the method.
[0161] First, a device isolation film 12 buried in a silicon substrate 10 is formed by, e.g., shallow trench technique. The device isolation film 12 defines device regions 14 , 16 (FIG. 25A).
[0162] Next, a sacrificial oxidation film 18 of, e.g., about 6 nm-thick silicon oxide film is form by thermal oxidation in the device regions 14 , 16 defined by the device isolation film 12 (FIG. 25B)
[0163] Next, a photoresist film 20 exposing the device region 14 and covering the device region 16 is formed by the usual photolithography. The photoresist film 20 is formed of a material which has etching resistance to a gas containing a halogen element.
[0164] Next, the silicon substrate with the photoresist 20 formed on is exposed to fluorine plasma to incorporate fluorine selectively in the device region 14 of the silicon substrate 10 .
[0165] For example, the silicon substrate 10 is introduced in to a vacuum system for magnetron plasma processing, and then a fluorine content gas, e.g., F 2 gas, is introduced into the vacuum system. Then, a substrate bias is applied to the back side of the silicon substrate 10 under a 0.01-10 Pa pressure to establish a negative voltage within 1 kV. Concurrently therewith, introducing electromagnetic waves of 200-2000 W of rf (e.g. 13.56 MHz) or microwaves are introduced into parallel plate electrodes to cause discharges, and the silicon substrate 10 is exposed to the plasma for about 10 seconds—about 3 minutes. Thus fluorine is incorporated in the silicon substrate 10 .
[0166] Next, the photoresist film 20 is removed, and then the sacrificial oxidation film 18 is removed by wet etching using a hydrofluoric acid based aqueous solution.
[0167] Next, the silicon substrate is thermally oxidized by the low pressure wet oxidation to form a gate insulation film 22 of the silicon oxide film in the device region 14 and a gate insulation film 24 of the silicon oxide film in the device region 16 . At this time, in the device region 14 , where fluorine ions are incorporated, the enhanced oxidation takes place. Thus, the gate insulation film 22 in the device region 14 is formed thick, and the gate insulation film in the device region 16 is formed thin (FIG. 25D). Thus, while the enhanced oxidation effect owing to the fluorine plasma processing is exhibited, wet oxidation film of good quality can be formed.
[0168] Then, in the same way as in the method for fabricating the semiconductor device according to, e.g., the first embodiment shown in FIGS. 18A to 18 C, transistors including the gate insulation films 22 , 24 having different film thicknesses from each other are formed in the device regions 14 , 16 .
[0169] As described above, according to the present embodiment, after the fluorine plasma processing is selectively performed, the thermal oxidation for forming the gate insulation films is performed, whereby a film thickness of the gate insulation film in the region subjected to the fluorine plasma processing can be selectively increased. The gate insulation films, which are formed by the wet oxidation, can have higher reliability than those formed by the dry oxidation.
[0170] In the present embodiment, in place of applying rf or microwaves, electron beams may be applied to ionize fluorine to apply the fluorine ions to the silicon substrate 10 .
[0171] In the present embodiment, as a fluorine content gas, F 2 gas is used, but, for example, ArF, KrF, XeF or other gases may be used. In place of fluorine, iodine or chlorine (Cl) or bromine (Br) may be incorporated, and, in this case, for example, a gas of Cl 2 , ArCl, KrCl, XeCl, Br 2 , ArBr, KrBr, XeBr, I 2 , ArI, KrI, XeI, or others can be used.
[0172] In the same way as in the second to the fourth embodiments, gate insulation films of 3 or more different film thicknesses may be formed.
[0173] Modifications
[0174] The present invention is not limited to the above-described embodiments and can cover other various modifications.
[0175] For example, in the above-described embodiments, the region for the thick gate insulation film to be formed in and the region for the thin gate insulation film to be formed in are the memory cell region and the peripheral circuit region, but are not essentially the memory cell region and the peripheral circuit region. For example, the memory cell region may be a region for the thin gate insulation film to be formed, and the peripheral circuit region is a region for the thick gate insulation film to be formed in. A region for high breakdown voltage input/output transistors to be formed in may have a thicker gate insulation film than other regions. It is preferable that regions for gate insulation films of different film thicknesses are selected suitably for device structures.
[0176] In the above-described embodiments, the present invention are explained by means of fabricating n-type transistors, but the present invention may be applied to forming the gate insulation films of p-type transistors. It is possible that gate insulation films are different in film thickness between n-type transistors and p-type transistors.
[0177] In the above-described embodiments, the present invention is applied to forming the gate insulation films but is applicable widely to forming insulation films of different film thicknesses by a single oxidation step. For example, for non-volatile memories, such as flash EEPROM, etc., it is necessary that a thin device isolation film is formed in the memory cell regions for the purpose of micronization, and a thick device isolation film is formed in the peripheral circuit region because peripheral circuits require high breakdown voltage units, such as charge pump circuits. Accordingly, the present invention is applied to a thermal oxidation step for forming the device isolation films, whereby the device isolation films of different film thicknesses can be simultaneously formed by a single thermal oxidation step.
[0178] As described above, according to the present invention, after halogen ions are selectively implanted, the thermal oxidation for forming gate insulation films is performed, whereby the gate insulation film in a region with the halogen ions implanted can be selectively formed thick. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation. Especially by using fluorine as halogen ions, the silicon oxide film can have higher reliability than that formed without ion implantation.
[0179] After xenon ions are selectively implanted, the thermal oxidation for forming gate insulation films is performed, whereby the gate insulation film in the ion-implanted region can be selectively formed thick.
[0180] After nitrogen ions are selectively implanted, thermal oxidation combining the dry oxidation and low pressure wet oxidation is performed as the thermal oxidation for forming gate insulation films, whereby the gate insulation film in the ion implanted region can be selectively formed thin. The gate insulation films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation.
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A semiconductor device is fabricated by a method comprising the steps of: selectively introducing a halogen element or argon into a device region 14 of a silicon substrate 10; and wet oxidizing the silicon substrate 10 in an ambient atmosphere which an H 2 O partial pressure is less than 1 atm to thereby form a silicon oxide film 22 in the device region 14 of the silicon substrate 10, and a silicon oxide film 24 thinner than the silicon oxide film 22 in a device region 16 of the silicon substrate 10. Whereby the silicon oxide film in a device region 14 with the halogen element or argon introduced can be selectively formed thick. The silicon oxide films are formed by the wet oxidation, whereby the gate insulation films can be more reliable than those formed by the dry oxidation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a photographic film supply and threading assembly for use in a high speed camera.
2. Description of the Prior Art
In the past it has been common practice to use open reels of film in high speed microfilm cameras used to photograph financial documents. In order to install the film in the camera, a supply reel would be mounted on a suitable spindle. A portion of the film would then be unwound from the supply reel and be carefully fed through a system of film advance rollers and idler rolls and over a capstan followed by more rollers before being attached to a suitable take-up reel. This was a very time-consuming and intricate task since it had to be done within the confines of the camera body. Great care had to be exercised in positioning the film so that it would feed properly at high speed and not jam or come off any of the pulleys or rollers in the feed path. Also, care had to be taken to not move or damage any portion of the lens system of the camera.
The film transport assembly of the present invention allows the supply reel of film to be put in place and the film to be fed around spaced guide rollers to the take-up reel while the assembly is outside of the camera body. After loading, the film transport assembly can be put into position in the camera where the film is brought to the image plane and automatically tensioned and prepared for movement in the camera without the film having to be handled again by the operator.
The field in which the present invention is expected to be employed, that of high speed microfilming of documents as in a check processing environment, will benefit by enhanced speed of film movement and greater simplicity of film loading and unloading. In this area, representative of prior art relating to film transport motor controls, in the applicant's opinion is the U.S. Pat. No. 4,058,266, granted Nov. 15, 1977 to Jack Beery. Jack Beery is also the inventor of U.S. Pat. No. 4,087,173 granted May 2, 1978, relating to a document photography system which has been incorporated in earlier devices sold by Unisys Corporation and its predecessors. Other patents of interest might include U.S. Pat. No. 4,175,719 granted Nov. 27, 1979 to Speckman (illustrating a cartridge which may be used in connection with the present invention); U.S. Pat. No. 3,209,644 granted Oct. 5, 1965 to Simmon et al relating to reeling and unreeling of a different device; and U.S. Pat. No. 3,478,985 granted Nov. 18, 1969 to Richard Tobey relating to a still different tape transport. A less desirable device is illustrated by U.S. Pat. No. 4,037,239 of July 19, 1977 to Jamieson et al. The invention of this application represents a novel and significant improvement in light of such prior devices.
SUMMARY OF THE INVENTION
The present invention is an improved system for loading and moving film in a high speed camera. The system includes a support base which is separable from the camera and upon which can be mounted supply and take-up reels for the film. Each reel has an associated drive motor which is mounted on the support base or which may be mounted in the camera and which may be suitably brought into operating contact with the reels when the support base is inserted into the camera. Between the supply and take-up reels are mounted film guide rollers which define a first film path. Also mounted on the support base is a motor driven capstan drive roller which is not in the first film path.
It is a feature of the present invention that separate reels or cartridge held reels can quickly be mounted by placing the stretched film between reels over rollers which will subsequently define film movement and then move the film on the support base to enable engagement with the activating capstan rollers and film tension control mechanisms.
Within the body of the camera is the image plane of the lens system at which point the image is focused onto the film. Disposed on either side of the image plane are a pair of pivoted spring biased control arms which have a film roller mounted at one end and a switch contacting surface at the opposite end. A control switch for controlling the electrical power to the supply and take-up reel motors is positioned to be activated by the surface on the control arms.
After the supply reel of film is mounted on its support and the film led about the film rollers to a take-up reel, the base assembly is ready to be mounted in the camera. The loading of the film along the first film Path can be done outside of the camera with very little skill. The film does not have to be threaded through a complex of rollers and around idler rollers or spring loaded arms within the body of a camera as is the usual practice. The support base is then placed into the camera and advanced toward the image plane. The rollers on the spring biased control arms contact the film. As the assembly continues to move forward, the control arms are moved causing the switch contact portion to activate the motor control switches When the motors are energized during the film loading process both motors turn to release film from the supply and take-up reels. When sufficient film is released, the switch activating surfaces at the ends of the film tension arms move off of the switches, turning off the power to the motors. The film is now held under tension by the springs that bias the control arms. The control arms and associated film rollers hold the film in a second film path where the film is wrapped about a major portion of the surface of the capstan roller. The film is now ready to be advanced through the camera under control of the capstan roller with the tensioning arms performing the usual function as inertia buffers during high speed incremental film advance. The tensioning arms and associated elements are made of lightweight materials to enable the tensioning arms to act as low inertia elements to enable the film to be moved from one frame to the next in three milliseconds as is required for processing film for capture of documents in a high speed check and document processing environment. The film is exposed for 40 milliseconds and in that interval the control arms recycle as will be described in the detailed description. During the 40 millisecond and 3 millisecond time intervals, the control switches and reversible DC motors act in concert to enable at low cost and effectively the substantially instantaneous film advance when required without breaking the film, in the embodiment described herein as the most preferred embodiment.
It should again be noted that the film has been threaded into position in the camera without having to be fed through rollers or wrapping on the capstan. The mere movement of the film supply assembly into position completed the final steps necessary to prepare the camera for operation. All of the film loading steps have been easily performed outside of the camera with plenty of space to work and without danger of damaging the lens system of the camera.
The invention, both as to its organization and method of operation, together with further advantages thereof, will best be understood by reference to the following Detailed Description of the Invention taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the elements of the film transport assembly before the support base and film are loaded into the camera.
FIG. 2 is a schematic view of the elements of the film transport assembly as the support base and film are being loaded into the camera.
FIG. 2A is a schematic view of the elements of the film transport assembly after the support base and film have been fully loaded into the camera.
FIG. 3 is a schematic view of the elements of the film transport assembly with the film tensioned and moving in the camera from left to right as shown.
FIG. 3A is a schematic view of the elements of the film transport assembly at the instant when the film is not moving but is being exposed at the image plane.
FIG. 4 represents a schematic of the central logic governing the motor controls during film movement.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the film transport assembly is made up of two major subassemblies. The first part is the film supply assembly indicated generally by the number 10 and the second is the film control assembly indicated generally by the number 12.
The film supply assembly 10 has a support or base plate 14 upon which the several parts of the film supply assembly are mounted. The support plate 14 can be made of metal such as a steel or aluminum alloy. It can also be made of any of the well known sheet plastic materials of sufficient strength and rigidity to support the several components.
The support plate 14 has a leading edge 16 and a trailing edge 18. Adjacent to the trailing edge and near the left corner as shown in FIG. 1 is mounted a rotatable shaft or carrier 20 for supporting film supply reel 22. The shaft 20 is driven by a suitable electric motor, not shown. The motor is preferably driven by direct current or D.C. power so that its direction of rotation can be reversed. An alternating current or A.C. motor can also be used, if it is adapted to drive the shaft 20 in either direction.
Near the right rear corner, as shown in FIG. 1, is mounted a second rotatable shaft or carrier 24 for supporting a film take-up reel 26. The shaft 24 is driven by a suitable electric motor, not shown.
The motor is preferably driven by direct current or D.C. so that its direction of rotation can easily be reversed. An alternating current or A.C. motor can also be used if it is adapted to rotate the shaft 24 in either direction.
On the top surface of the support base 14 near the left front corner are mounted a pair of film transfer rollers 28 and 30. A similar pair of transfer rollers 32 and 34 are mounted near the right front corner of the support plate. Each of the film transfer rollers are substantially identical having a rubber or elastomer covering to control the vertical movement of the film. The diameter of the rollers is not critical. It is preferred that they be of sufficient width so that the film will bend at a wide angle to avoid sharp bends in the film with resultant possible breakage.
The photographic film 36 is fed from the supply reel 22 about the film transfer rollers 28, 30, 32 and 34 to the film take-up reel 26. The film is easily loaded into what is referred to herein as the first film path while the film supply assembly is outside of the body of the camera. The film can be loaded either in a darkened room or in a suitable glove box by merely placing the film s supply on its support spindle and then unwinding sufficient film to follow the path about the film transport rollers to the take-up reel.
A film transport roller 38 is mounted on the top of the support plate to the left of center near the forward edge and adjacent to the first film path. A capstan drive shaft 40 carrying a capstan or film advance roller 42 is mounted on the support plate to the right of center and spaced from the film transport roller 38 along a line parallel to the leading edge of the support plate. Both the film transport roller 38 and the capstan 42 are located within the area bounded by the first film path. The capstan drive shaft 40 is driven by a suitable motor, not shown, which is attached to the bottom of the support plate. The motor is preferably of the stepping type for moving the film in incremental steps.
The motors to drive the reels and the capstan may also be mounted in the camera with drive connection established by suitable spindles in the support plate engaging shafts on the motors.
After the film supply assembly is loaded with photographic film, it is placed into the body of the camera to bring the film into contact with the image plane 44. At the image plane there is a shutter 45 which is open at all times during the movement of film across the image plane. When the shutter is open, it may expose a slit opening behind which a rotating mirror may reflect the image from the document to be copied onto the film moving across the image plane.
Since FIGS. 1, 2, 2A, 3 and 3A are schematic views, only those components which form part of the present invention are illustrated. The remaining portions of the camera generally indicated by 47 are well known and conventional and form no part of the present invention.
Within the camera body a pair of film transport rollers 46 and 48 similar to those earlier described, are mounted along the direction of film travel on either side of the image plane 44. These rollers assist in flattening the film and in providing a smooth passage for the film across the image plane of the camera.
To the left of the image plane 44, as seen in FIG. 1, is pivot shaft 50 upon which is mounted a film tension and control arm 52. The control arm 52 is biased by spring 54 against a stop 56 where it is held when no film is in the camera. At the end of the film tension and control arm 52 closest to the image plane of the camera is mounted a film transfer roller 58 which is adapted to contact and roll along the surface of the film as it moves through the camera. The end 59 of the control arm remote from the film transfer roll is used to actuate a control switch 60 which is used to control the electrical power to the motor that drives the film supply reel 22.
To the right of the image plane 44, there is mounted a second pivot shaft 62. The pivots 50 and 62 are preferably equidistant from the image plane and disposed at either end of an imaginary line behind and parallel to the image plane. The pivot 62 is used to support a film tension and control arm 64 which is substantially identical to the arm 52. The control arm 64 is biased by a spring 66 against a stop 68 where it is held when no film is in the camera. At the end of the film tension and control arm 64 closest to the image plane of the camera is mounted a film transfer roller 70 which is adapted to contact and roll along the film as it moves through the camera. The end 71 of the control arm remote from the film transfer roll is used to activate a control switch 72 which is used to control the electrical power to the motor that drives the film take-up reel 26.
A switch 74 is shown schematically in FIGS. 1, 2, 2A, 3 and 3A. This switch is a part of the control circuit and is used to detect the presence of the film supply assembly 10 in the camera body. The operation of the switch will be more fully described in relation to FIGS. 3 and 3A.
Referring to FIG. 2, the film supply assembly 10 is shown partially inserted into the film control assembly 12 within the camera body. The motors which drive film supply reel 22 and film take-up reel 26 do not appreciably rotate as pressure is applied against film 36. The rotation of the motors can be resisted by clutches, ratchets, gear boxes, etc., as is well known in the art. As the film supply assembly 10 is moved into the camera, the film 36 pushes against film transfer rollers and 58 and 70 at the ends of film tension and control arms 52 and 64, respectively. The pressure of the film causes arms 52 and 64 to pivot bringing the switch activating surfaces 59 and 71 at the ends of the arms into contact with switches 60 and 72, respectively. While pressure activated switches are shown, these could be replaced by optical switches with the switch contacting portion of the control arm functioning as a shutter to interrupt a beam of light thereby activating a switch or gating circuit. When switch 60 is activated, the film supply reel motor is caused to rotate in a counter-clockwise direction releasing film from the supply reel 22. When switch 72 is activated, the film take-up reel motor rotates in a clockwise direction releasing film from the reel 26.
As the film supply assembly 10 continues to move into the camera, the above described process is continued until the condition illustrated in FIG. 2A is attained. At this point, the film supply is fully inserted. The switch support plate 14 is in contact with switch 74 but activating surfaces 59 and 71 on control arms 52 and 64 are not in contact with switches 60 and 72, respectively. The film 36 is also in contact with a substantial portion of the capstan roller 42 and the film transfer or idler roller 38. The film is now in the second film path and is ready to be moved across the image plane of the camera.
It is worth repeating again that the film does not have to be manipulated by the camera operator after the film supply 10 is loaded outside the camera. The film is placed in proper position at the image plane of the camera and is put under tension about the face of the capstan roller and is ready for controlled movement all by merely inserting the film supply 10 into the body of the camera. During the early portion of the movement of the base plate 14 into the camera, the film 36 causes the film tension arms to pivot about their respective supports bringing the switch contacting portion of each arm into contact with its associated switch or sensor. When the sensor 74 is not activated, the closing of switches 60 and 72 causes the corresponding drive motors for film reels 22 and 26 to rotate so as to release film from each reel. The process of releasing film from the reels continues as long as switches 60 and 72 are closed until the release of the film creates enough slack to allow the springs 54 and 66 to pull the arm sensors 52 and 64 so as to open switches 60 and 72 and stop the drive motors. This position is shown in FIG. 2A. The base plate 14 is then fully seated in the camera and the plate sensor switch 74 is closed.
From the above, it can be seen that if the plate sensor 74 is not activated and if switches 60 and 72 are not closed, the reel motors are off. On the other hand, if the plate sensor 74 is not activated but either arm sensor switch is activated, the corresponding reel motor is turned on so that film is fed from the reel. When the plate sensor 74 is closed and both arm sensor switches 60 and 72 are open, the film is correctly threaded around the rollers and the reel motors are turned off. The film is now ready to be moved by the capstan or drive roller 42.
When the camera control circuit advances film by means of the capstan 42, the reel motors are turned on and off by appropriate logic circuitry depending on the status of the film tension arms.
Referring to FIG. 3, if the capstan or drive roller 42 is driven in a clockwise direction to take up film from the loop buffered by arm 59, and to advance it past the image plane 44 (see FIG. 1) the reversible DC servo motor 24 (shown by shaft 24) driving take-up reel 26 is driven in a counter-clockwise direction while switch 72 is open. When switch 60 closes it cause motor 20 to turn counter-clockwise as described below. Also while switch 72 is open, the tension arm 64 and spring 66 act as an inertial buffer to control high speed film advance quickly creating a loop. The movement of the film by the clockwise motion of capstan 42 which is the direction of feed causes tension arm 52 to rotate counterclockwise as the loop of film is taken up by the capstan, and the cam control surface 59 on arm 52 acts to close switch 60 which then activates the reversible DC servo motor 20 (shown by shaft 20) of supply reel 22 to turn it on a counterclockwise direction to release additional film.
FIG. 3A shows the result o: the motion of motor 20 moving counterclockwise (caused by opening of switch 60) and letting out film. This capstan movement opens switch 72, which caused motor 24 to turn counterclockwise to take up the loop which had been fed during the 3 millisecond film advance whenever switch 72 is closed as shown. This action may occur while the film at the image plane is stationary (approximately 40 milliseconds) during which time the capstan 42 is stopped, as shown in FIG. 3A, out this is not necessary. The motor can be breaked and dependent upon the size of the film reel switch 60 may be open or closed as dependent upon the amount of film in the loop. During the time the motor 24 moves counterclockwise it takes up film increasing the tension on the film and thus the action of the reversible motor 24 has caused tension arm 64 to rotate clockwise until switch 72 is closed. Then the cycle repeats itself with the clockwise rotation of capstan 42.
The preferred embodiment of the invention has been described with the use of the low inertia arms, biased to open the related switches by springs, 54, 66. These control switches and the reversible DC servo motors are part of the preferred embodiment, because the simple control switch, and the reversible motors allow control within the time frame of 3 milliseconds.
In an alternative embodiment, now shown, the control of the motors could be achieved with the use of optical encoders for each motor and the capstan, but this is a much more expensive embodiment.
FIG. 4 illustrates schematically the control circuit. As shown, the film advance direction is determined by film advance direction logic 83 which is related to the motion of the capstan. Inputs to direction determining logic 84, 85 are associated with the plate sensor 74 and the respective arm sensor control switches 60 and 72 respectively. The output of this direction determination logic is a servo motor control signal which is amplified by amplifiers 81 and 82 respectively to cause the reel motors and their associated shafts 20, 24 to rotate in the appropriate direction.
The logic for the motor control functions can be implemented using semiconductor devices or integrated circuits and may be implemented by servo motor drivers, such as those available from Compumotor Division of Parker Hannifin, or other similar suppliers, or made by those skilled in this art from available components.
Similarly, the wiring for the several motors and switches is not shown as this is also well within the skill of the art and would only serve to clutter the drawings used to illustrate the invention.
It is within the scope of the disclosure that the film cartridge can be either separate reels locked together with a snap fit with the film extending therebetween as illustrated by U.S. Pat. No. 4,175,719 previously cited which is preferred, or reels mounted in a integral housing made to match the spacing of the particular shaft and insertion film supply base plate in the form of a cartridge, which would be an acceptable alternative embodiment.
While a particular embodiment of the invention has been described, it will be understood that the invention is not limited thereto since modifications may be made. It is therefore contemplated by the appended claims to cover any such modifications as fall within the true spirit and scope of the invention.
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An improved photographic film supply and threading mechanism which enables a person to prepare a document record camera 44,45 for use without having to feed the film 36 through a complex system of guides and rollers 38, 42 within the body of the camera where the lens and shutter system are exposed to possible displacement and damage. The film 36 is simply fed around a pattern of rollers 38, 42 from a supply reel 22 to a take-up reel 26 mounted on a suitable support assembly 10,14. The assembly is then placed into the body of the camera 44,45 where a combination of film tension arms 59,71 and associated motor control switches act 60,72 together to position the film 36 along a path crossing the image plane 44 of the camera where when the assembly is in position as sensed by a switch 74 it may be exposed as the camera control circuit FIG. 4 advances the film.
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RELATED CASES
I claim priority from my earlier-filed applications U.S. Ser. No. 61/007,117 filed Dec. 11, 2007 and U.S. Ser. No. 60/887,657 filed Feb. 1, 2007, each of which is hereby incorporated by reference in its entirety.
REFERENCE TO FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was funded at least in part by NIH grant R03AA014644. The government has certain rights in this invention.
TECHNICAL FIELD
this invention relates to treating alcohol and/or other substance abuse or dependence, and to compositions used for such treatment.
BACKGROUND
Substance use disorder (i.e., substance abuse or substance dependence) occurs commonly in patients with schizophrenia and worsens its clinical course. Commonly abused substances include alcohol, cannabis and cocaine, and such abuse occurs at a rate of greater than 3 times the rate seen in the general population. Moreover, tobacco smoking occurs in over 75% of the patients with schizophrenia. The standard or typical antipsychotic medications commonly used to treat schizophrenia do not appear to be helpful in lessening the use of substances in this population. Data from our group and others, however, suggest that the atypical antipsychotic clozapine appears to limit alcohol, cannabis and cocaine abuse in this population, but its toxicity limits widespread use 1 . 1 Green, A. I., et al., Clozapine for comorbid substance use disorder and schizophrenia: do patients with schizophrenia have a reward-deficiency syndrome that can be ameliorated by clozapine? Harv Rev Psychiatry, 1999. 6(6): p. 287-96; Green, A. I., et al., Substance abuse and schizophrenia: Pharmacotherapeutic intervention. J Subst Abuse Treat, 2008. 34(1): p. 61-71; Brunette, M. F., et al., Clozapine use and relapses of substance use disorder among patients with co-occurring schizophrenia and substance use disorders. Schizophr Bull, 2006. 32(4): p. 637-43. Drake, R. E., et al., The effects of clozapine on alcohol and drug use disorders among patients with schizophrenia. Schizophr Bull, 2000. 26(2): p. 441-9; Green, A. I., et al., Alcohol and cannabis use in schizophrenia: effects of clozapine vs. risperidone. Schizophr Res, 2003. 60(1): p. 81-5; Zimmet, S. V., et al., Effects of clozapine on substance use in patients with schizophrenia and schizoaffective disorder: a retrospective survey. J Clin Psychopharmacol, 2000. 20(1): p. 94-8; US 2006-0189599.
SUMMARY
We have discovered, based on a series of experiments in animals, that medications exhibiting a combination of dopamine D2 receptor blockade (typically a weak blockade) with norepinephrine reuptake inhibition (i.e., inhibition of the norepinephrine transporter) are useful treatments for patients with, or at risk for, alcohol and/or other substance abuse/dependence (including those patients who have both alcohol and/or other substance abuse/dependence with a co-occurring psychiatric disorder such as schizophrenia or bipolar disorder). The presence of a norepinephrine alpha 2 receptor blockade (also a property of clozapine) in such a medication (in combination with the other effects, i.e., dopamine D2 receptor blockade and norepinephrine reuptake inhibition) may also be helpful in limiting alcohol (or other substance) abuse in such individuals. Substances of abuse in this context include not only alcohol but also opioids, including heroin and oxyContin®, cannabis, cocaine, amphetamines, tobacco and others.
Another aspect of the invention features combinations of medications exhibiting the above-described activities. The combinations include: a) for the dopamine D2 receptor antagonist activity, risperidone, paliperidone, haloperidol, olanzapine, quetiapine, ziprasidone, aripiprazole, fluphenazine or other drugs with D2 receptor blockade (antagonistic) properties; b) for norepinephrine reuptake blockade (inhibition), desipramine or reboxetine, or other drugs with norepinephrine reuptake inhibition properties; c) for alpha 2 antagonist activity, idazoxan and yohimbine, or other drugs with norepinephrine alpha 2 receptor antagonistic effects.
Compositions having combinations of medications, as well as methods of therapy using combinations of medications, are featured, in which the multiple activities of the medication are provided by more than one specific medicinal compound.
Accordingly, the invention generally features methods of treating and or preventing substance abuse/dependence, and alcohol abuse/dependence in particular. The medications used in the invention are described above. The patients to be treated according to the invention are those with a history or a risk of alcohol or substance abuse/dependence.
The compounds to be administered can be formulated into a suitable pharmaceutical preparation by known techniques, for example well known tablet and capsule formulations. Such formulations typically comprise the active agent (or the agent in a salt form) and a pharmaceutically acceptable carrier. As used herein the language “pharmaceutically acceptable carrier” is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the compositions is contemplated. Supplementary active compounds can also be incorporated into the compositions.
A pharmaceutical composition of the invention is formulated to be compatible with its intended route of administration. Examples of routes of administration include oral, intravenous, intradermal, subcutaneous, transdermal (topical), transmucosal (e.g. intranasal), and rectal.
By far the most convenient route of administration is oral (ingestion). Oral compositions generally include an inert diluent or an edible carrier. They can be enclosed in gelatin capsules or compressed into tablets. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules. Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.
In one embodiment, the active compounds are prepared with carriers that will protect the compound against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Methods for preparation of such formulations will be apparent to those skilled in the art. The materials can also be obtained commercially from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art.
It is especially advantageous to formulate oral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the subject to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on the unique characteristics of the active compound and the particular therapeutic effect to be achieved, and the limitations inherent in the art of compounding such an active compound for the treatment of individuals.
The pharmaceutical compositions can be included in a container, pack, or dispenser together with instructions for administration.
DESCRIPTION OF DRAWINGS
FIG. 1 (PRIOR ART) is a graph depicting the results of the experiment reported in Example 1: Clozapine and Halperidol on Alcohol Drinking in Hamsters, taken from Green, A. I., et al., Clozapine reduces alcohol drinking in Syrian golden hamsters. Psychiatry Res, 2004. 128(1): p. 9-20.
FIG. 2 is a graph depicting the results of the experiment reported in Example 2: Chronic Clozapine on Alcohol Drinking in Hamsters.
FIG. 3 is a graph depicting the results of the experiment reported in Example 3: Clozapine and Haloperidol on Initiation of Alcohol Drinking in P-rats.
FIG. 4 is a graph depicting the results of the experiment reported in Example 4: Clozapine and Haloperidol on Initiation of Alcohol Drinking in P-Rats.
FIG. 5 is a graph depicting the results of the experiment reported in Example 5: Clozapine and Raclopride on Initiation of Alcohol Drinking in Hamsters.
FIG. 6 is a graph depicting the results of the experiment reported in Example 6: Haloperidol and Desipramine on Alcohol Drinking Hamsters.
FIG. 7 is a graph depicting the results of the experiment reported in Example 7: Haloperidol, Desipramine and Idazoxan on Initiation of Alcohol Drinking in P-Rats.
FIG. 8 is a graph depicting the results of the experiment reported in Example 8: Haloperidol, Desipramine and Idazoxan on Initiation of Alcohol Drinking in P rats.
FIG. 9 is a graph depicting the results of the experiment reported in Example 9: Risperidone and Desipramine on Alcohol Drinking in Hamsters.
FIG. 10 is a graph depicting the results of the experiment reported in Example 10: Risperidone and Desipramine on Alcohol Drinking in Hamsters.
FIG. 11 is a graph depicting the results of the experiment reported in Example 11: Risperidone and Desipramine on Initiation of Alcohol Drinking in P-rats.
DETAILED DESCRIPTION
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
The following Examples provide a detailed description of the invention.
General Methods
The animal models that we have used in our experiments include the Syrian golden hamster (Mesocricetus auratus, Harlan Inc.) and the alcohol preferring P rat (Indiana University). Both animals prefer an alcohol solution over water when given a choice between the two fluids and they consume large quantities of alcohol on a daily basis. However, while the hamster is an out-bred rodent, which has a natural preference for alcohol, the P rat has been bred over multiple generations through the selective mating of rats with high alcohol preference. Both the hamster and the P rat have been used by alcohol researchers to screen medications for treatment of alcoholism. Keung, W. M. and B. L. Vallee, Daidzin and daidzein suppress free-choice ethanol intake by Syrian golden hamsters. Proc Natl Acad Sci USA, 1993. 90(21): p. 10008-12; McBride, W. J. and T. K. Li, Animal models of alcoholism: neurobiology of high alcohol-drinking behavior in rodents. Crit Rev Neurobiol, 1998. 12(4): p. 339-69.
Two types of studies were conducted in hamsters and P rats. The first type of study assessed the ability of drugs (or drug combinations) to decrease chronic alcohol drinking in these animals. In these studies, drug treatment began after the animals had been drinking alcohol for several weeks. The second type of study assessed the effects of drugs (or drug combinations) on the ability of the animals to initiate alcohol drinking. The animals in the latter type of study received drug treatment several days prior to and during the initial weeks of exposure to alcohol. All animals were given 24 hours/day access to 10-15% alcohol and water in two separate drinking bottles. Groups of animals (n=6-10/group) received daily injections of the specific drug or drug combination or vehicle for up to 4 weeks.
Examples 1 (Prior Art) and 2
In one study, we demonstrated that clozapine (CLOZ), but not the typical antipsychotic drug haloperidol (HAL), dramatically decreased chronic alcohol drinking in the Syrian golden hamster more than vehicle (VEH) ( FIG. 1 ). Green, A. I., et al., Clozapine reduces alcohol drinking in Syrian golden hamsters. Psychiatry Res, 2004. 128(1): p. 9-20. No dose of haloperidol tested had an effect on alcohol drinking in the hamster. Moreover, in another study with unpublished data, as seen in FIG. 2 , we demonstrated that this effect of clozapine is chronic, lasting at least 1 month.
Examples 3 and 4
In another study, we demonstrated that clozapine (CLOZ) also decreases the initiation of alcohol drinking in the alcohol-preferring P rat, as compared to vehicle (VEH) and haloperidol (HAL) ( FIG. 3 ). This can be seen most dramatically by looking at alcohol preference (the % of liquid consumed that comes from the alcohol bottle)— FIG. 4 . Clozapine dramatically decreases alcohol preference during the initiation of alcohol drinking.
Example 5
In Example 5 ( FIG. 5 ), we have demonstrated that clozapine (in this case a low dose) also blunts the initiation of alcohol drinking in the hamster. We have also demonstrated in FIG. 5 that by adding raclopride (RACL, a potent D2/D3 receptor antagonist) to a low dose of clozapine, this effect of clozapine on the initiation of alcohol drinking by the hamster is lost. This finding is consistent with our proposition that clozapine's effect on alcohol drinking is at least partially related to its weak D2 receptor blocking ability.
Example 6
In the hamster, as noted above, haloperidol has very little effect on chronic alcohol drinking. However, if the norepinephrine reuptake inhibitor desipramine (DMI) is added to low dose haloperidol (HAL), it decreases the alcohol drinking more than does desipramine alone ( FIG. 6 ). This supports our proposition that a weak dopamine D2 receptor blocker plus a norephinephrine reuptake inhibitor decreases alcohol drinking.
Examples 7 and 8
Low dose haloperidol has minimal ability to blunt the initiation of alcohol drinking by the P rat. However, adding the alpha 2 receptor blocker idazoxan (IDAZ) to low-dose haloperidol modestly increases the ability of haloperidol to blunt the initiation of alcohol drinking. However, if the norepinephrine reuptake inhibitor desipramine (DMI) is added these two drugs, it dramatically increases the ability of them to decrease alcohol drinking and alcohol preference ( FIGS. 7 and 8 ). This effect is consistent with our proposition that a weak dopamine D2 receptor blocking effect coupled with a potent norepinephrine alpha 2 receptor blocker and a norepinephrine reuptake inhibitor will decrease alcohol drinking.
Examples 9-11
Lastly, we have demonstrated that a low dose of risperidone (RISP), a drug with a potent dopamine D2 receptor blocking ability, has only a modest effect on alcohol drinking in both the hamster (on chronic drinking) and the P rat (on the initiation of alcohol drinking). We have further shown that the addition of the norepinephrine reuptake inhibitor desipramine (DMI) to risperidone causes risperidone to limit alcohol drinking. Moreover, this effect, which we have seen in both the hamster and the P rat, is more dramatic than with desipramine alone ( FIGS. 9 , 10 , and 11 ). This effect is consistent with our proposition that a weak D2 receptor blocker (weak because of the low dose of risperidone) coupled with a norepinephrine reuptake inhibitor will decrease alcohol drinking. Moreover, since risperidone is also a blocker of the norepinephrine alpha 2 receptor (as well as the D2 receptor), its blockade of the alpha 2 receptor (in combination with its D2 receptor blockade) may contribute to allowing the norephinephrine reuptake inhibitor desipramine to convert risperidone into a drug that decreases alcohol drinking.
We conclude that the combination of a weak dopamine dopamine D2 receptor blocker (antagonist) and a potent norepinephrine reuptake inhibitor may produce a drug that shares with clozapine the ability to limit alcohol drinking. We further conclude that addition of a norepinephrine alpha 2 receptor blocker (antagonist) may contribute to the ability of a composition with these characteristics to limit alcohol drinking. Our findings suggest medications containing these properties as a therapeutic agent in patients with schizophrenia and alcohol or substance abuse/dependence. Since the medications that we have tested limit alcohol drinking in animal models of alcoholism, and since, moreover, patients with alcohol use disorder and substance use disorder may share some biologic characteristics (i.e., disordered brain reward circuitry) of patients with schizophrenia, we conclude that a medication with these characteristics should be effective as well in patients with alcohol use disorder and/or substance use disorder who do not have schizophrenia.
A number of embodiments 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 embodiments are within the scope of the following claims.
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Methods of treating and or preventing substance abuse/dependence, and alcohol abuse/dependence in particular. Combinations of medications are also disclosed.
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This is a continuation-in-part of Application Ser. No. 06/455,260 filed on Jan. 3, 1983 by the same applicant and bearing the same title now abandoned.
CROSS-REFERENCE TO RELATED PRIOR ART
______________________________________U.S. Pat. No. Date Patentee(s)______________________________________ 657,199 9/1900 Lawton1,589,576 6/1926 Thompson1,604,873 10/1926 Barnhart2,563,473 8/1951 Levinson3,209,192 9/1965 Decker3,309,274 3/1967 Brilliant3,711,700 1/1973 Westlund, et al3,950,649 4/1976 Yonekubo4,040,727 8/1977 Ketchpel4,184,196 1/1980 Moret, et al4,195,329 3/1980 Woog4,199,686 4/1980 Brunsting, et al______________________________________
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a device for use with a fluorescent material, such as a fluorescent dye, so that upon application of the fluorescent material to selected areas of the body, the device of the instant invention may be used to cast filtered light directed through the device upon those areas, whereby to cause the dye or other fluorescent material to fluoresce and differentiate diseased and healthy portions of the area, while also providing a mirror for the user to view those portions. Particular applications of the instant invention are in the areas of dental diagnosis and dental hygiene, such that one may selfdiagnose the oral cavity for lesions, and for foreign matter such as bacterial plaque, microcosms, tartar materia alba and the like.
As indicated in the above-referenced U.S. Pat. No. 3,309,274, an appropriate dye or disclosing material (in the form of solution, paste, powder, or the like) for use with the instant invention, contains a normally-invisible constituent that fluoresces and becomes easily visible when activated by a proper light source. The disclosures of this patent are hereby incorporated herein by reference.
In order to provide light of the proper wavelength range, the device of the instant invention incorporates a light-filtering portion in combination with a reflecting-surface portion, so that the device may be used with a high-intensity beam of light from a generally conventional light source, such as typically found in a dental operatory room, to fluoresce the disclosing dye solution or other fluorescent material, and to make readily visible to the user a sharp delineation between healthy and diseased portions of the area treated by the fluorescent material.
In some areas of the human body, when the fluorescent material is applied and properly illuminated, skin lesions and the like are differentially identified by virtue of the fact that the healthy tissues surrounding the diseased areas are caused to glow, while in other areas of the human body the diseased portions of these areas are caused to glow rather than the healthy portions. The reasons why the fluorescent materials will associate with only diseased areas in the one instance, and with only healthy areas in other cases, are not known. However, and in any event, the diseased or adulterated areas are sharply differentiated by such a fluorescent material. Through the use of the device of the instant invention, such a differentiation between healthy and diseased portions of a treated area, particularly an area of the oral cavity, may be made by the user with respect to his or her own person. The degree of fluorescence exhibited will vary with the types of fluorescent material, light source, and light filter which are employed for the purpose.
Sources of light suitable for providing the focused beam of light with which the device is to be employed range from the common incandescent and fluorescent lamps to the quartz or mercury vapor types, and include the hydrogen bulb which is filled with argon. The high-intensity examination light typically found and used in the conventional dental operatory room is a particularly suitable light source for use with the device of the instant invention. Various color filters or diffraction-type filters may be used to convert any of the various light-beam sources to the proper wavelength of light which will excite and flouresce the specific dye or other fluorescent material chosen. The wavelength range for light which will excite and fluoresce the dye or other fluorescent material will depend upon the particular fluorescent material employed, and can be readily determined from published literature sources. Besides its ability to cause excitation or fluorescence of the fluorescent disclosing solution or other fluorescent material employed, the only other requirement of the filtered light is that its wavelength not mask the fluorescent material's fluorescence with its own color. In other words, the filtered light must be capable of exciting the fluorescent material to cause it to glow, while avoiding masking that material's fluorescence. This can be accomplished by means of selective and substantial filtration of any unreactive wavelengths of light.
When selecting a suitable color filter, i.e., a filter through which will pass only light which will excite a particular fluorescent material or dye, almost any transparent of translucent substance may be used, such as, for example, the more or less flexible films made and sold by the E. I. duPont de Nemours and Company under the trademark, "MYLAR", and the rigid "PLEXIGLAS" acrylic sheets made and sold by Rohm and Haas Company. Even colored glass may be employed in certain instances. In one particular application of the device of the instant invention, a user can positively determine and treat teeth and mouth hygiene problems in the nature of plaque deposits or the like, and can brush his teeth and rinse his mouth while observing, first-hand, the results thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of one, preferred embodiment of the instant invention;
FIG. 2 is a partial, cross-sectional view of the device of FIG. 1, as viewed in the direction of arrows 2--2; and
FIG. 3 is a partial, cross-sectional view of an alternate embodiment of the instant invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 illustrate a combination mirror and light filter supported by a frame 20 having handle 22. Frame 20 and handle 22 conveniently can be fabricated from a rigid material such as plastic or wood. Transparent members 10 and 12, fabricated from a material such as glass, plastic or the like, are mounted in opposed but separated corresponding positions within frame 20, and corresponding lower portions of their inner surfaces are each coated or otherwise provided with reflective means 14 and 16, conveniently consisting of the coventional reflective silver coating material typically employed in the construction of a mirror, in order that a portion of each external surface of the device will act as a mirror. In the remaining portions, i.e., the upper portions, of the inner surfaces, of transparent members 10 and 12, the reflective material has been omitted or removed and a light-filtering material 18, coveniently consisting of a thin, bluish film of "MYLAR" material, has been inserted therebetween so that these portions allow light to enter from either side of the device and to exit from the other side as filtered light. Additionally, one or both of the mirror portions 14 and 16 of the device may be adapted to magnify as well as reflect images incident thereon.
Referring to FIG. 3, an alternate embodiment of the instant invention comprises transparent material 30, such as plastic, glass or the like, and a layer 32 which is coated on or otherwise applied to one side of transparent member 30 such that, as viewed in FIG. 3, light which is incident upon layer 32 is passed therethrough and exists as filtered light, whereas light incident upon layer 32 from the other side is reflected therefrom.
As a simple method of manufacture of the device of FIGS. 1 and 2, two conventional mirrors may have their reflective coating removed from corresponding portions thereof and a light-filtering member may be sandwiched between the two mirrors such that light passing through these portions of the mirrors which had their reflective coatings removed will filter light of a particular portion of the light spectrum.
A possibly preferred method of manufacture of the device would be to start with a transparent optical blank made of glass or plastic, cover a portion of the blank's surface with a substantially non-porous material such as metal, ceramic, wood, paper, wax or another piece of glass or plastic, and then apply to the blank's non-covered portion a reflecting coating of silver or aluminum. If desired, a 1/4 wave length coating of magnesium fluoride can be superimposed over the reflecting coating to harden the silver or aluminum in situ. Such coatings can conveniently be applied by any of a number of conventional means such as vacuum or electro-deposition techniques, spraying, dipping in baths of the coating material, et al.
After the reflecting coating is applied the covering material could be removed and it or another cover can be positioned over the reflecting surface to prevent any additional reflecting material from depositing on that surface. A suitable light-filtering substance then is applied to a portion of the blank's surface which is devoid of the reflecting material, thereby enabling that blank portion to filter light of a particular portion of the light spectrum.
Another option is to use more than one glass or plastic optical blank, for example two of glass, or two of plastic, or one of each of glass and of plastic. In a two-membered construction one member can be coated with a reflecting substance, and the other member can be coated with a light filtering substance. The two such coated members are then placed in a uni-planar relationship, preferably in a contiguous juxtaposition similar to that depicted in the drawings by the elements identified by reference characters 10 and 18, and maintained in that position by a suitable frame or holder such as is represented by reference character 20.
In use, a person may support and minipulate the device between himself and a light source such that light filtered through the filtering portion of the device is focused on a particular area of the body, e.g., the oral cavity, and a reflection of the oral cavity may be viewed by the user in the mirror portion of the device. This is particularly useful when areas of the oral cavity have been treated by a fluorescent dye or other suitable fluorescent material as disclosed in U.S. Pat. No. 3,309,274, such that diseased and healthy portions of the area are readily differentiated by impingement of the filtered light into the dye field to cause the dye to fluoresce. It thus can be seen that the reflecting and light-filtering portions of the device cooperate so as to permit the simultaneous delineation and observation by the user of foreign matter, such as plaque, or other undesirable conditions on his or her own person, including his or her own oral cavity.
It thus will be seen that the objects set forth above, including those made apparent from the preceding description, are efficiently attained.
Modifications to the device of the instant invention will be readily apparent to those skilled in the arts. Since these and other changes may be made in carrying out the above method, and in the constructions specifically set forth herein, without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It also is to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements on the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A device is provided for a user to self-diagnose areas of the human body when those areas are treated with a disclosing material which is invisible to the naked eye, but which fluoresces when subjected to appropriately filtered light. In particular the device provides mirror and light-filtering portions such that the user may diagnose areas of his or her oral cavity when treated with and differentiated by the disclosing fluorescent material.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to the use of O-ring seals, typically formed from elastomer, as shear members. In particular aspects, the invention relates to devices that utilize O-rings as shear members to resist the movement of an axially sliding sleeve.
[0003] 2. Description of the Related Art
[0004] There is a variety of tools and devices used within a wellbore that incorporate sliding sleeves, or arrangements where one tubular member is slidably moved with respect to another tubular member to accomplish some function, such as actuation of a valve or a releasable disconnect. Traditionally, shear pins or other frangible members have been used to releasably secure these components together until it is desired to cause them to slide.
[0005] However, the use of frangible members to hold sleeve components together is problematic where the components are subject to high vibration. Vibration can rupture a frangible pin, thereby prematurely releasing the connection that holds the sleeve members together. This results in an undesired activation of the tool. One example of a tool that is normally subjected to high vibration during use is a coiled tubing shear release joint. These tools are used to provide a selective separation point in a continuous length of coiled tubing. The release joint may be activated by shearing of a shearable member, such as a frangible shear pin, to allow separation of release joint components. However, substantial vibration occurs during normal operation of coiled tubing production, and this vibration might cause the shear pin to fail prematurely, thus undesirably activating the release joint.
[0006] The present invention addresses the problems of the prior art.
SUMMARY OF THE INVENTION
[0007] The invention provides devices and methods for releasably securing components of a device having a sliding sleeve arrangement to prevent premature actuation due to vibration. In a currently preferred embodiment, the invention utilizes standard elastomeric O-rings as shear members. The O-ring shear members reside within spaces formed between two slidable sleeve members. The O-rings are sheared cross-sectionally to allow the sleeve members to move axially with respect to one another. An exemplary coiled tubing shear release joint is described that incorporates a shear disconnect assembly which uses elastomeric O-rings as shear members. Multiple O-ring seals can be used as shear members to increase the shear value of the device. The use of O-rings as shear members helps prevent premature sliding of sleeve components in response to high vibration. Because the O-rings are resilient, they absorb vibration and do not shear during vibration, the connection between the two sleeve components will not be released prematurely.
[0008] To the inventors' knowledge, elastomeric O-rings have not been heretofore utilized as shear members for the releasable securing of sliding sleeve arrangements. The conventional intended use for elastomeric O-ring members has been as fluid seals. As a result, it has been desired that O-ring members remain intact to provide for good fluid sealing rather than to deliberately destroy them.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts an exemplary sliding sleeve arrangement that incorporates O-ring seals as shear members.
[0010] FIG. 2 illustrates the sliding sleeve arrangement shown in FIG. 1 now with the O-ring seals sheared.
[0011] FIG. 3 is a side, cross-sectional view depicting an exemplary coiled tubing shear release joint that incorporates O-ring seal shear members, in accordance with the present invention.
[0012] FIG. 4 is an enlarged view of shear disconnect assembly portions of the release joint shown in FIG. 3 .
[0013] FIG. 5 is an enlarged view of the shear disconnect assembly portions shown in FIG. 4 , now with the shear members having been sheared.
[0014] FIG. 6 is a further enlarged view depicting details of an exemplary shear collar and O-ring shear member.
[0015] FIG. 7 is a side, cross-sectional view of the coiled tubing shear release joint shown in FIG. 3 , with the release now activated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present invention relates broadly to the use of typical O-ring seals as shear members in tools and devices that feature axially sliding sleeves. Many devices that incorporate axially sliding sleeves are used in oil wells.
[0017] FIGS. 1 and 2 illustrate an exemplary the general instance of a sliding sleeve apparatus 10 that incorporates elastomeric O-ring seals as a shear mechanism. The sliding sleeve apparatus 10 includes a radially outer sleeve 12 that partially surrounds a radially inner piston 14 . The outer sleeve 12 defines a series of annular grooves 16 inscribed upon its interior surface 18 . The inner piston 14 also defines a series of annular grooves 20 upon its outer surface 22 . In the initial secured position, shown in FIG. 1 , the grooves 20 on the inner piston 14 are aligned with the grooves 16 on the outer sleeve 12 . O-ring members 24 reside within the spaces created by the alignment of grooves 16 and 20 . While there are five O-ring members 24 shown, it will be understood that there may be more or fewer depending upon the amount of shear resistance desired. Each of the exemplary O-ring shear members 24 presents a substantially rounded cross-section, as shown, although other cross-sectional shapes may be utilized (i.e., square, rectangular, or other). In the position shown in FIG. 1 , the inner piston 14 is secured in place with respect to the outer sleeve 12 by the O-rings 24 , which prevent axial movement. In the case of vibration of the apparatus 10 , the O-rings 24 are not ruptured.
[0018] The inner piston 14 may be moved with respect to the outer sleeve 12 by hydraulic actuation, a mechanical shifting tool, or in other ways known in the art. In order to move the inner piston 14 with respect to the outer sleeve 12 , it is necessary to impart an axial force to the inner piston 14 that is greater than the shear resistance provided by the O-rings 24 . When this amount of force is applied, the O-rings 24 split into ring portions 24 a , 24 b , as shown in FIG. 2 , and the inner piston 14 is freed to move with respect to the outer sleeve 12 . Ring portions 24 a remain within the grooves 20 while ring portions 24 b remain inside the grooves 16 . Thus, it can be seen that a O-ring 24 will shear or be separated into two substantially annular pieces, as the ring 24 is separated along its cross-sectional area.
[0019] FIGS. 3-7 depict an exemplary coiled tubing shear release joint 30 that is constructed in accordance with the present invention. The shear release joint 30 is typically used within a wellbore (not shown) to create a separation point in coiled tubing. Thus, the shear release joint 30 includes an upper mandrel 32 with a box-type threaded connection 34 at its upper end 36 to be affixed to an upper section 38 of coiled tubing. The upper section 38 of coiled tubing typically extends to the surface of the wellbore. The mandrel 32 defines an axial flowbore 40 along its length. In addition, several lateral windows 42 (one shown) are disposed through the body of the mandrel 32 .
[0020] A tubular housing 44 radially surrounds the mandrel 32 . The upper end of the housing 44 provides a fishing neck 45 . The inner surface 46 of the housing 44 includes several annular recesses 48 . Dogs 50 , reside loosely within the windows 42 of the mandrel 32 . Although there is only one dog 50 visible in FIG. 4 , it will be understood by those of skill in the art that there is typically two to four such dogs 50 —one for each window 42 . Each of the dogs 50 presents a radially outer face 52 that is shaped to provide teeth 54 that rest within the recesses 48 of the housing 44 . As a result, the housing 44 and the mandrel 32 are secured to one another.
[0021] A shear sleeve 56 is disposed within the bore 40 of the mandrel 32 and abuts the inner surfaces 58 of the dogs 50 , thereby holding them firmly in place so that the teeth 54 of the dogs 50 engage the recesses 48 . The shear sleeve 56 has a ball seat 59 at its upper end. The lower end of the shear sleeve 56 is retained in place within the mandrel 32 by a shear disconnect assembly, generally shown at 60 in FIG. 3 . The structure and function of the shear disconnect assembly 60 is more clearly understood by reference to FIGS. 4 and 5 , and will be described in detail shortly.
[0022] Referring once again to FIG. 3 , the lower end of the housing 44 is connected by threaded connection 62 to a bottom sub 64 . The bottom sub 64 , in turn, has a lower end with a pin-type threaded connection 66 by which the bottom sub 64 is secured to a lower section 68 of coiled tubing. An axial flowbore 70 is defined along the length of the bottom sub 64 .
[0023] With reference to FIGS. 4 and 5 , the shear disconnect assembly 60 includes an inner collar 72 that surrounds a lower portion of the shear sleeve 56 . An outer collar, or shear pin retaining ring, 74 radially surrounds the inner collar 72 . One or more standard frangible shear pins 76 are preferably disposed tangentially through the outer collar 74 and inner collar 72 to releasably secure those components together.
[0024] Below the outer collar 74 are three metallic, annular shear collars 78 , 80 , 82 . Each of the three shear collars 78 , 80 , 82 has a similar configuration, which is illustrated in the further enlarged view provided by FIG. 6 . Each shear collar 78 , 80 , 82 surrounds an elastomeric O-ring shear member 84 , 86 , 88 , respectively, and each of the O-ring shear members 84 , 86 , 88 resides within a groove 90 , 92 , 94 , respectively, that is formed within the outer surface of the shear sleeve 56 . It is noted that the radially outer surface of each of the shear collars 78 , 80 , 82 is interengaged with the mandrel 32 via a toothed or threaded surface 96 . As a result of this interengagement, the shear collars 78 , 80 , 82 will move in concert with the mandrel 32 .
[0025] FIG. 6 depicts in closer detail the single shear collar 82 surrounding O-ring shear member 88 and groove 94 . The structural features shown in detail here apply equally to the shear collars 78 and 80 . It is noted that the shear collar 82 has a substantially flat inner side 98 that abuts the outer surface of the mandrel 56 . An arcuately curved inner surface 100 extends upwardly and outwardly from the leading, cutting edge 102 of the inner side 98 . The O-ring member 88 is trapped within the groove 94 by the curved inner surface 100 . It is noted that the inner surface 100 might alternatively be angled rather than curved. In either case, the currently preferred angle of departure for the surface 100 is approximately 5°.
[0026] To activate the release joint 30 , a ball 104 (shown in FIG. 7 ) is dropped through the upper coiled tubing section 38 and comes to rest on ball seat 59 of the shear sleeve 56 . Fluid pressure is then increased behind the ball 104 until the force upon the shear sleeve 56 exceeds the shear value of the O-ring shear members 84 , 86 , 88 . At that point, the shear sleeve 56 moves axially downwardly with respect to the mandrel 32 as the shear members 84 , 86 , 88 within the shear disconnect assembly 60 are sheared. Downward movement of the shear sleeve 56 with respect to the mandrel 32 causes the leading edge 102 of each of the shear collars 78 , 80 , 82 to engage each of the respective O-ring shear members 84 , 86 , 88 and cut them through their annular cross-sections, in a manner similar to the O-rings 24 described earlier (i.e., each of the shear members 84 , 86 , 88 is divided into two ring portions). Additionally, the standard frangible shear pin 76 is sheared by movement of the inner collar 72 with respect to the outer collar 74 . The elastomeric shear members 84 , 86 , 88 absorb vibration of the components during operation and prevents premature axial movement of the shear sleeve 56 with respect to the mandrel 32 via an unintended rupture of the shear pin 76 .
[0027] As the shear sleeve 56 is moved downwardly to the position shown in FIG. 7 , the dogs 50 are freed to move radially inwardly, and no longer engage the recesses 48 of the housing 44 . The housing 44 becomes disconnected from the mandrel 32 . The mandrel 32 and shear sleeve 56 can now be withdrawn from the wellbore, leaving the housing 44 and bottom sub 64 in the hole. The fishing neck 45 of the housing 44 remains available for later engagement by a fishing tool.
[0028] The shear disconnect assembly 60 may be assembled by first placing the mandrel 32 inside of the housing 44 . The dogs 50 are then slid into place within the windows 42 of the mandrel 32 . The outer collar 74 is slid over the shear sleeve 56 and the shear pin 76 is inserted through the outer collar 74 and inner collar 72 . Next, the first O-ring shear member 84 is disposed into groove 90 . The first shear collar 78 is then disposed over the shear sleeve 56 to trap the O-ring shear member 84 within its groove 90 . The second O-ring shear member 86 is then disposed within groove 92 . The second shear collar 80 is disposed over the shear sleeve 56 and brought into abutting relation to the first shear collar 78 to trap member 86 within the groove 92 . The third O-ring shear member 88 is then disposed within groove 94 , and the third shear collar 82 is slid over the shear sleeve 56 and brought into an abutting relation to the second shear collar 80 . This action traps O-ring shear member 88 within groove 94 . This, then completes the assembly of the shear disconnect assembly 60 . Next, the shear sleeve 56 , with affixed O-rings 84 , 86 , 88 and shear collars 78 , 80 , 82 , is slid into the mandrel 32 so that the shear sleeve 56 is disposed beneath (i.e., radially within) the dogs 50 , thereby holding them in place to secure the mandrel 32 to the housing 44 . A spanning wrench may be used to tighten threaded connections and to axially preload the O-ring shear members 84 , 86 , 88 . The bottom sub 64 is then secured to the housing 44 .
[0029] It is noted that one can use additional O-ring seal members as shear members to increase the shear value of a connection or reduce the number of shear members in order to reduce the shear value of a connection. However, the shear value achieved by the use of additional shear members is not uniformly cumulative, as might have been expected. In practice, it has been observed, for example, that a single elastomeric shear element might provide a total shear resistance of about 1000 psi. The addition of a second, similar shear member will provide a total shear resistance of about 1,950 psi. The addition of a third shear member will provide a total shear resistance of about 2,750. Thus, the additional shear resistance resulting from the addition of a shear member is less than additive, indeed, only about 95% additional resistance is added. In determining the number of shear members to use for a given connection, one should take account of the conditions within the well in which the connection is expected to operate. Higher temperatures will make the O-rings easier to shear, and thus, the use of additional O-rings is desirable.
[0030] Those of skill in the art will recognize that elastomeric shear members might be used in many different types of devices that incorporate sliding sleeves that must be releasably secured to one another and released upon the application of a predetermined amount of axial force. Examples of wellbore tools that might make use of elastomeric shear members are sliding sleeve production valves and actuating tubes used to open a subsurface safety valve. It is further noted that the shear release joint 30 , described above, might be used to provide a releasable disconnect joint for tubular members other than coiled tubing. For example, the release joint might be adapted for use with standard production tubing rather than coiled tubing.
[0031] It is noted that relatively pliable or substantially elastic materials other than elastomers can be used to form the shear members 24 , 84 , 86 , 88 . Suitable alternative materials would have to be suitably pliable and non-brittle in order to absorb expected vibratory energy from the device into which they are incorporated. Yet, these materials must still be able to provide the shear resistance necessary to retain the components in place until a predetermined amount of axial force is applied to the components to overcome that shear resistance. For example, annular members fashioned of plastics, polymers, resins, TEFLON®, or KEVLAR® would provide vibration resistance as well as provide suitable shear resistance for use as a shear member in a sliding sleeve device. A currently preferred type of material is standard N-butyl nitrile elastomer, of the type used to form conventional O-ring seals. These type of O-rings generally come in two hardnesses: 70 durometer and 90 durometer, both of which are suitable for use as a shear member. It is further noted that the shear member need not be annular in shape either, although that shape presently appears to be quite advantageous in use and is currently preferred.
[0032] The inventors have found that annular elastomeric shear members provide an unexpectedly high degree of shear resistance. It is believed that this significant shear resistance is due to the fact that the annular shear member must be sheared through its cross-section along its entire annular structure. In the above-described examples, the O-ring shear members 24 , 84 , 86 , 86 are sheared by the action of a cutting edge that is incorporated into one or both of the sleeve members that enclose the shear members. In the case of the sliding sleeve assembly 10 , the O-ring shear members 24 are sheared, or annularly divided, by the edges of the grooves 16 , which are formed on the outer sleeve 18 , and the edges of the grooves 20 that are formed on the inner piston 14 . In the instance of the coiled tubing release joint 30 , each O-ring shear member, such as 88 , is sheared or divided by the forward cutting edge 102 of the radially outlying shear collar.
[0033] Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof.
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Devices and methods for releasably securing components of a device having a sliding sleeve arrangement to prevent premature actuation due to vibration. In a currently preferred embodiment, the invention utilizes standard elastomeric O-rings as shear members. The O-ring shear members reside within spaces formed between two slidable sleeve members. The O-rings are sheared cross-sectionally to allow the sleeve members to move axially with respect to one another. An exemplary coiled tubing shear release joint is described that incorporates a shear disconnect assembly which uses elastomeric O-rings as shear members. Multiple O-ring seals can be used as shear members to increase the shear value of the device. The use of O-rings as shear members helps prevent premature sliding of sleeve components in response to high vibration. Because the O-rings are resilient, they absorb vibration and do not shear during vibration, the connection between the two sleeve components will not be released prematurely.
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TECHNICAL FIELD
[0001] This invention relates to improvements in electronic circuitry used in moving read/write heads in a memory disc system for use with computers, and, more particularly, to improvements in such circuitry for providing drive signals to a voice coil motor for such a system.
BACKGROUND OF THE INVENTION
[0002] Voice-coil motors are linear actuators that are widely used for moving heads and their support assemblies across discs in computer system disc drives in order to read data from or write data to the disc and in activating or deactivating disc drives. The heads float across the disc surface on a cushion of air resulting from rotation of the discs. In a conventional disc drive, the disc is roughened on at least portions of the disc surface to obviate sticking of the head to the disc surface as the disc is spun from a stop to an operating speed.
[0003] As data densities on the discs have increased, need for greater precision and accuracy in head positioning has also increased. Additionally, spacings between the heads and the discs have decreased to a point where roughening of the disc surface is impractical. As a result of these changes, a prior art practice of “parking” the head in the innermost data track in an area removed from areas of the disc that store data no longer provides adequate safeguarding of the head or of the disc when the computer system is not in use and particularly when the head is deployed from the parked position.
[0004] In increasing numbers of disc drives, the head is parked by causing the head support assembly to traverse a ramp to remove the head from proximity to the disc when the disc drive is deactivated as the system is shut down. When the head support assembly reaches the end of the ramp, the head support assembly is latched into a storage position. The head then cannot collide with the disc if the disc drive is jarred or bumped, avoiding one potential source of damage to the head or to the disc.
[0005] As the system is reactivated, the head is unparked by releasing the head support assembly from the latch. The head support assembly then traverses the ramp towards the disc in response to signals delivered to the voice coil motor from a controller. The head must be moving with the correct speed when the head support assembly reaches the end of the ramp in order to maintain the head in proximity to the disc without collision between the head and the disc. As a result, the controller must provide the proper drive signals to the voice coil motor resulting in the correct speed for the head when the head support assembly exits the ramp.
[0006] One method for driving the voice coil motor is to apply a constant voltage to a voice coil in the voice coil motor. However, the voice coil motor generates a back electromotive force (BEMF) because the voice coil is moving in a magnetic field. The actual voltage driving the voice coil motor thus is the sum of the resistive voltage (I.R.) and the BEMF, which varies with voice coil motor velocity v M. As a result, the applied voltage is not the actual BEMF of the voice coil motor.
[0007] Some conventional voice coil motor controller circuits employ a digital to analog converter circuit for providing analog control signals to the voice coil motor controller in response to digitally preprogrammed profiles. However, these conventional controller circuits have limited ability to compensate for wearing of the ramp and of the portions of the head supporting assembly that are in contact with the ramp. Additionally, conventional controller circuits have limited capability for providing control signals responsive to head velocity variations originating from other sources, such as motion of the disc drive.
[0008] In prior art approaches to driving voice coil motors and compensating for the BEMF, as described in U.S. Pat. Nos. 5,566,369 and 5,297,024, both issued to F. Carobolante, a current sensing resistor is coupled in series with the voice coil motor. A differential buffer amplifier has inputs coupled to the terminals of the current sensing resistor and provides an output signal that is proportional to a current through the voice coil motor. A comparison circuit then allows the current through the voice coil motor to be corrected to a desired value. However, the effective resistance of the voice coil motor causes some of the energy from the current through the voice coil motor to be lost as heat. As a result, this form of feedback, while providing improved performance for the voice coil motor, does not result in optimal performance, especially as voice coil motor characteristics change with age, temperature and the like.
SUMMARY OF THE INVENTION
[0009] In several aspects, the present invention includes circuits and methods for providing feedback from the motion of a head to a voice coil motor controller circuit to correct head velocity during ramp loading of the head from a disc into a storage position and particularly during ramp unloading from the storage position into proximity to the disc. As a result, voice coil motor velocity may be monitored and corrected to compensate for temperature-induced mechanical changes and also for wear of moving components that are in contact with other components.
[0010] In one aspect, the present invention includes a power supply circuit coupled to the voice coil motor that in turn is coupled to the head. A controller provides signals to the voice coil motor to correct voice coil motor velocity in response to signals from a feedback network. The feedback network includes a sample and hold circuit that is coupled to the voice coil motor during intervals when the power supply circuit is not providing drive signals to the voice coil motor.
[0011] In another aspect, the present invention includes a method for driving a voice coil motor in response to signals from a feedback network that senses voice coil motor velocity. The method includes steps of providing a drive signal to an H-bridge for a first interval. At the end of the first interval, the H-bridge is placed in a high impedance state. Following a pause during a second interval while transient voltages extinguish, a sample and hold circuit is coupled to the voice coil motor. The sample and hold circuit measures a voltage from the voice coil motor that is directly proportional to voice coil motor velocity and thus is directly related to head velocity. After the sample and hold circuit measures the voice coil motor voltage, the input to the sample and hold circuit is disabled. An output signal from the sample and hold circuit is coupled to the feedback network and thus to the H-bridge. As a result, head velocity is more accurately controlled, reducing probability of collision between the heads and the discs and thereby increasing reliability of the disc drive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a simplified block diagram of a voice coil motor driving circuit, in accordance with embodiments of the present invention.
[0013] [0013]FIG. 2 is a simplified schematic diagram of the feedback network of FIG. 1, in accordance with embodiments of the present invention.
[0014] [0014]FIG. 3 is a simplified block diagram of a disc drive, in accordance with embodiments of the present invention.
[0015] [0015]FIG. 4 is a simplified flow chart of a process for inactivating and activating a head for a disc drive, in accordance with embodiments of the present invention.
[0016] [0016]FIG. 5 is a graph showing voice coil motor current (top trace) and voltage (bottom trace) during the process of FIG. 4, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] [0017]FIG. 1 is a simplified block diagram of a voice coil motor driving circuit 10 , in accordance with embodiments of the present invention. The driving circuit 10 includes a controller 12 having a first input 14 coupled to a computer system and a second input 16 coupled to an output of a feedback network 18 . The feedback network 18 has an input 20 coupled to the output of a sample and hold circuit 21 .
[0018] The sample and hold circuit 21 includes a high input impedance amplifier 22 having a first input 24 and a second input 26 . In one embodiment, the high input impedance amplifier may be a FET input operational amplifier 22 . A capacitor 27 is coupled across the first 24 and second 26 inputs. Switches 28 and 30 , which may be solid state switches such as pass gates or FET switches, or other devices that act to couple or decouple a voice coil 31 from the capacitor 27 in response to sampling signals from an output 34 of the controller 12 . In one embodiment, the switches 28 and 30 are formed from a pair of isolation FETs in the sample and hold circuit 21 .
[0019] Outputs 36 , 38 , 40 and 42 of the controller 12 are coupled to a power supply circuit 45 . A preferred power supply circuit 45 includes FETs 44 , 46 , 48 and 50 having their respective outputs coupled via lines 33 , 35 to the voice coil 31 and that are coupled in a conventional “H-bridge” configuration. The transistors are all N-channel type in one design or, if desired, transistors 48 and 50 are P-channel in an alternative design. In one embodiment, the FETs 44 , 46 , 48 and 50 are constructed such that they could be modeled as an FET having an integral diode with an anode coupled so a source of the FET and having a cathode coupled to a drain of the FET. As a result, signals on the lines 33 and 35 cannot have voltage excursions greater than one forward-biased diode voltage above the power supply voltage or below ground. In one embodiment, the controller 12 provides analog control signals to pairs 44 , 48 or 46 , 50 of the FETs to provide current to the voice coil 31 to drive the head (shown in FIG. 3) in a first or a second direction, or turn OFF all of the FETs 40 , 44 , 48 and 50 to decouple external power sources from the terminals of the voice coil 31 .
[0020] It will be appreciated that other arrangements may be used to implement the connection to sample and hold circuit 21 . For example, the controller 12 could cause one side of the other of the voice coil 31 to be grounded through the transistor 44 or 46 , with another side of the voice coil 31 being coupled to one side of the capacitor 27 and the other side of the capacitor 27 being coupled to ground. In this embodiment, the amplifier 22 may be implemented as a one-sided voltage follower, e.g., an operational amplifier 22 configured to provide, for example, unity gain.
[0021] [0021]FIG. 2 is a simplified schematic diagram of the feedback network 18 of FIG. 1, in accordance with embodiments of the present invention. A feedback signal at the input 20 is added to an analog control signal V IN and the resulting voltage is then compared to a reference voltage V REF by an amplifier 55 having a gain A E that is set by a ratio of resistors 57 and 59 . As a result, when the comparison between the voltage V REF and the sum of V IN and the output voltage from the sample and hold circuit 21 indicates that the heads are moving too slowly, a larger drive signal is generated by the controller 12 in response to the output signal from the feedback network 18 in order to speed the voice coil motor up. Conversely, when the comparison between the voltage V REF and the sum of V IN and the output voltage from the sample and hold circuit 21 indicates that the head is moving too fast, a reduced drive signal is generated by the controller 12 in response to the output signal from the feedback network 18 in order to slow the voice coil motor down. An output signal from the amplifier 55 is then applied to the input 16 to the controller 12 .
[0022] Conventional voice coil motor controller circuits employ a digital to analog converter circuit (not shown) that outputs an analog control signal V IN in response to digitally preprogrammed profiles. However, these voice coil motor controller circuits have limited ability to compensate for effects due to wearing of the ramp and of those portions of the head supporting assembly that are in contact with the ramp. Additionally, the feedback provided by the driving circuit 10 does not compensate for voltage errors in the voltage actually present in the voice coil 31 that result from a dc resistance R MOTOR of the voice coil 31 .
[0023] In one embodiment, the sample and hold circuit 21 , the feedback network 18 and the controller 12 are integrated into a single integrated circuit. The capacitor 27 may be external to the integrated circuit. In one embodiment, the H-bridge is also external to the integrated circuit, while in another embodiment, the FETs 44 - 50 in the H-bridge are included in the integrated circuit. The integrated circuit may be formed using known processes, such as full CMOS or BiCMOS that combines complementary metal-oxide-semiconductor transistors with bipolar transistors.
[0024] [0024]FIG. 3 is a simplified block diagram of a disc drive 66 , in accordance with embodiments of the present invention. The disc drive 66 is coupled to a host computer 68 through a controller 70 that provides instructions to a disc drive microprocessor 72 . The disc drive microprocessor 72 , in turn, provides commands to control logic 74 , which decodes the commands into control signals. Some of these control signals are coupled to the voice coil motor drivers 10 . A voice coil motor 75 that includes the voice coil 31 of FIG. 1 moves in response to the control signals, causing a head support system 76 to move heads 78 across discs 80 , or to park or unpark the heads 78 . A spindle motor and spindle motor drive circuit 82 cause the discs 80 to rotate in response to control signals from the control logic 74 . Read/write head electronics 84 are also responsive to control signals from the control logic 74 . The read/write head electronics 84 deliver read data from the discs 80 to the control logic 74 to read data from the discs 80 and write data from the control logic 74 to the heads 78 to write data to the discs 80 .
[0025] [0025]FIG. 4 is a simplified flow chart of a process 100 for inactivating and parking, or activating and unparking, the heads 78 of FIG. 3 for the disc drive 66 , and FIG. 5 is a graph showing voice coil 31 (FIG. 1) current 120 (top trace) and voltage 128 or 130 (bottom trace) during the process 100 of FIG. 4, in accordance with embodiments of the present invention. In a step 102 , the voice coil motor driving circuit 10 of FIGS. 1 and 3 supplies drive signals to one of the pairs of FETs 44 , 48 or 46 , 50 to move and park the heads 78 of FIG. 3 when the disc drive 66 is to be deactivated as part of a normal system shutdown, or to move and unpark the heads 78 when the system is to be reactivated as part of a normal system boot operation. In a step 104 , the drive signals from the voice coil motor driving circuit 10 are maintained during a first interval having a first predetermined length. In one embodiment, the first predetermined length is about one millisecond, although longer or shorter intervals may be used. The top trace 120 of FIG. 5 has a first segment 122 corresponding to a portion of the drive signal of the step 102 during the inferral of the step 104 .
[0026] In a step 106 , the voice coil motor driving circuit 10 supplies a control signal to set all of the FETs 44 , 46 , 48 and 50 of FIG. 1 to a high impedance condition, i.e., turns OFF all of the FETs 44 , 46 , 48 and 50 , at a time corresponding to the end of the first segment 122 and the beginning of a second segment 124 of FIG. 5. This creates an open circuit on both ends of the voice coil 31 . In one embodiment, the current formerly passing through the inductive voice coil 31 is shunted through the integral diodes in the FETs 44 , 46 , 48 and 50 , causing the voltage to be clamped to the power supply or ground, as shown in FIG. 5. During the second segment 124 , the voice coil 31 of FIG. 1 exhibits a voltage (lower trace, FIG. 5) 128 or 130 given by Ldi/dt, where L represents an inductance of the voice coil 31 and di/dt represents the change in current through the voice coil 31 per unit time.
[0027] In a step 108 , the process 100 pauses for a second interval lasting for a second predetermined length that is longer than the length of the second segment 124 of FIG. 5 in order to allow the Ldi/dt voltage 128 or 130 during the second segment 124 to extinguish. In a step 110 , during a time represented in part by a segment 126 of the top trace of FIG. 5, the process 100 triggers the sample and hold circuit 21 of FIG. 1 to measure the BEMF across the voice coil 31 of the voice coil motor 75 of FIG. 3. The BEMF is directly related to the velocity of the voice coil motor 75 because it is due to relative motion of the voice coil 31 and a magnet (not shown) in the voice coil motor 75 . The BEMF is equal to K e V M, where K e is readily calculated. The segments 124 and 126 together represent a pause of between 50 and 200 microseconds, although longer or shorter intervals could be used, depending on the inductance L of the voice coil 31 in the voice coil motor 75 , parasitic resistance R MOTOR in the voice coil 31 , friction and other factors. During the segments 124 and 126 , the head 78 continues to move. Therefore, the BEMF generated by the motion of the head 78 can be used to calculate the velocity V M of the voice coil motor 75 . In one embodiment, the voice coil motor driving circuit 10 includes nonvolatile memory (not shown) coupled to the disc drive microprocessor 72 for storing delay parameters for different voice coils 31 employed in different disc drives 66 .
[0028] In a step 112 , an output signal from the sample and hold circuit 21 is supplied to the feedback network 18 of FIGS. 1 and 2. In a query task 114 , the process 100 determines if the heads 78 (FIG. 3) have reached a terminal position, either latched and parked, or unparked and deployed on the disc 80 . When the query task 114 determines that the heads 78 have not yet reached a terminal position, control passes back to the step 102 and a revised drive signal incorporating feedback from the feedback network 18 is sent to the FETs 44 , 48 or 46 , 50 . The steps 102 - 114 iterate until the query task 114 determines that the heads 78 have reached a terminal position, i.e., are either parked or unparked. Typically, this iteration has a periodicity of between 800 microseconds and two milliseconds. When the query task 114 determines that the heads 78 have reached a terminal position, the process 100 ends.
[0029] Disc drives 66 including the head unparking and control circuitry for such applications may provide significant advantages over other types of disc drives, including reduced head and disc wear and increased data storage density leading to increased storage capacity. The present invention also allows increased overall disc drive reliability due to reduced probability of collision between the heads and the disc. The circuits of the present invention may be implemented in an integrated circuit, with the improvements of the present invention resulting in very little additional silicon area being needed. The methods and apparatus of the present invention compensate for effects of wear in head deployment apparatus. Programmable delays may allow a variety of different types of disc drives to be improved with a single integrated circuit. Disc drives find application in most computers where, for example, operating systems as well as programs and data are stored and may be modified.
[0030] Improved disc head parking and unparking control circuits and methods have been described. Although the present invention has been described with reference to specific embodiments, the invention is not limited to these embodiments. Rather, the invention is limited only by the appended claims, which include within their scope all equivalent devices or methods which operate according to the principles of the invention as described.
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An embodiment of the present invention includes a method for driving a voice coil motor in response to signals from a feedback network that senses voice coil motor velocity. The method includes steps of providing a drive signal to an H-bridge for a first interval. At the end of the first interval, the H-bridge is placed in a high impedance state. Following a pause for a second interval during which transient voltages extinguish, a sample and hold circuit is coupled to the voice coil motor. The sample and hold circuit measures a voltage from the voice coil motor that is directly proportional to voice coil motor velocity and thus is directly related to head velocity. After the sample and hold circuit measures the voice coil motor voltage, the input to the sample and hold circuit is disabled. An output signal from the sample and hold circuit is coupled to the feedback network and thus to the H-bridge. As a result, voice coil motor and head velocity is more accurately controlled, reducing probability of collision between heads and discs in a disc drive and thereby increasing reliability of the disc drive.
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates generally to heating systems primarily adapted to providing heated air to a space to be heated, such as a building or on enclosed portion thereof. More specifically, the invention relates to such a heating system fueled by a gaseous fuel.
Previous conventional forced-air heating systems for residential or commercial buildings, or for enclosed portions thereof, have included furnaces that burn a mixture of fuel and air in order to produce heat. Heat exchangers are included for transferring the heat from such combustion to an air flow system that is circulated through the heated space and then returned to the heat exchanger. Such conventional furnace systems have been found, however, to be wasteful in terms of their use of the thermal energy available from the combustion process, largely because exhaust gases are discharged into the atmosphere at considerably high temperatures, frequently in excess of 300 F. (149 C.), which is well in excess of the desired room temperature in the space to be heated.
Even the best of the above-described conventional furnace systems are estimated to waste at least fifteen percent to twenty percent of the gross heating value of the fuel consumed when operating at steady state conditions. Such waste of thermal energy is further compounded by the fact that when the furnace and the circulating fan of such a conventional heating systems are shut off in response to a signal from a thermostat in the heated space, the typical draft-type chimney continues to draw warm air from the furnace and from inside the building and then discharges such warm air to the atmosphere. Then when the thermostat again calls for heat, the system must restart and warm up before being capable of supplying heated air. In the northern states of the United States, this on/off cycling operation is estimated to occur over twenty thousand times per year in a typical forced-air heating system, thus resulting in an overall loss or waste of thermal energy estimated to be approximately forty percent of the available heating value of the fuel consumed.
In addition to the above disadvantages, such conventional heating systems have become economically unfeasible in large residential or commercial structures requiring very high draft-type chimneys. Because of the low cost effectiveness of the construction and maintenance of such large chimneys, such heating systems have frequently been constructed and installed on the roof of such buildings, therefore complicating their installation and increasing their cost. Alternately, especially in multi-tenant or multi-dwelling residential or commercial buildings, electric heating systems have been installed in order to reduce the initial construction cost, allow individual heating control for multiple units of the building, and eliminate the need for the building management to account for, and separately re-bill, the cost of each unit's share of the overall cost of operating a centralized heating system. Such alternate electric heating systems have included electric resistance-type heating units or heat pumps, for example, but suffer the disadvantage of being relatively expensive to operate in comparison with heating systems fueled by gaseous fuels, such as natural gas.
Because of the above-discussed disadvantages and shortcomings of conventional forced-air heating system and of typical electric heating systems, one of the primary objects of the present invention is to provide a forced air heating system, preferably fueled by a gaseous fuel, that effectively uses a much higher percentage of the available heating value of the fuel being consumed and that more effectively recovers a high percentage of the thermal energy present in the exhaust gases discharged to the atmosphere.
Another object of the present invention is to provide such a heating system that does not require a conventional chimney or other draft-type exhaust gas discharge conduit.
Another object of the present invention is to provide a heating system that maximizes the control over the function of the heating system and operates at a lower thermal energy input, but that operates for longer periods of time, thereby minimizing the number of on/off cycles required to maintain a desired temperature in the heated space, thereby maximizing the efficiency of the heating system.
Still another object of the present invention is to provide a heating system that employs a separate system for air circulating at a relatively low velocity to and from the heated space and separate high-velocity air system for transferring the heat of combustion to the air supplied to the heated space, as well as providing separate pressurized combustion air and fuel supply systems that forcibly convey combustion exhaust gases out of the heating system.
In accordance with one aspect of the present invention, a heating system for heating a space generally includes an air heating sub-system with a relatively compact combustion chamber adapted for burning a mixture of combustion air and fuel in order to produce heat, a separate cold air supply sub-system for conveying cold air from the heated space to the air heating sub-system, a combustion chamber heat exchanger in fluid communication with the cold air supply sub-system for transferring heat from the combustion chamber to the cold air withdrawn from the heated space by the cold air supply sub-system, and a separate air circulating sub-system for withdrawing cold circulating air from the heated space. The heating system also preferably includes an air mixing chamber in fluid communication with both the combustion chamber heat exchanger and the air circulating sub-system for mixing heated air with cold circulating air in order to provide heated circulating air to the heated space.
In accordance with another aspect of the present invention, the heating system includes a combustion air supply sub-system having a combustion air compressor for supplying the combustion air to the combustion chamber at an elevated pressure, a gaseous fuel supply sub-system having a gaseous fuel compressor for conveying gaseous fuel from a gaseous fuel source to the combustion chamber at an elevated pressure substantially equal to the elevated pressure of the combustion air, with the pressure of the combustion air and the gaseous fuel being sufficient to forcibly convey the mixture of combustion air and gaseous fuel into the combustion chamber and to forcibly convey the products of combustion through a relatively small exhaust discharge conduit without the need for a draft-type chimney or conduit.
In accordance with still another aspect of the present invention, the combustion air supply sub-system for a heating system includes a separator device, such as a vortex-type separator, that separates combustion air above a predetermined temperature from combustion air that is below such predetermined temperature. Such higher temperature combustion air is conveyed to the combustion chamber of the heating system, and the relatively lower temperature combustion air is conveyed to an exhaust gas heat exchanger for transferring heat from the exhaust gas to such relatively lower temperature combustion air. The combustion air that has been heated in the exhaust gas heat exchanger is then conveyed back to the heated space in order to effectively recover thermal energy that would otherwise have been wasted as the exhaust gas from the combustion chamber is discharged to the atmosphere.
A further aspect of the present invention is the provision of combustion air and gaseous fuel bypass systems, including automatic bypass valves, for bypassing quantities of combustion air and gaseous fuel from the discharges to the intakes of the respective combustion air and gaseous fuel compressors. The bypass systems allow for selective control of the quantities of fuel and air being supplied to the combustion chamber in order to control the heat being supplied to the heated space without the need for the wasteful frequent on/off cycling operation mentioned above in connection with conventional heating systems. In addition, the heating system of the present invention preferably includes a mircoprocessor control system that operates and controls the above bypass systems and other components of the heating system in response to temperature input signals from both the heated space and the exterior surroundings.
Additional objects, advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of an exemplary heating system according to the present invention.
FIG. 2 is a detailed schematic flow diagram of one preferred exhaust gas heat exchanger of the heating system shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 depict in diagrammatic form one preferred exemplary heating system for heating an enclosed space according to the present invention. As will become apparent from the following discussion, however, the principles of the present invention are not limited to the particular space heating application depicted diagrammatically in the drawings, and that the principles of the present invention are equally applicable to heating system arrangements other than that shown in the drawings.
Referring primarily to FIG. 1, an examplary heating system 10 according to the present invention generally includes an air heating sub-system 12, a cold air supply sub-system 14, an air circulating sub-system 16, a combustion air supply sub-system 18, a gaseous fuel supply sub-system 20, and a control sub-system 22.
The air heating sub-system 12 includes a combustion chamber 30 adapted for combustion of a mixture of combustion air and a gaseous fuel respectively supplied to the combustion chamber 30 from the combustion air supply sub-system 18 and the gaseous fuel supply sub-system 20 described below. The combustion air and the gaseous fuel are preferably mixed in adjustable and preselected proportions in an adjustable venturi device 32, which is in fluid communication with the combustion chamber 30 by way of an intake conduit 42. The mixture of gaseous fuel and combustion air is preferably ignited by an electronic ignition device 40, or other known ignition devices, disposed for fluid communication in the intake conduit 42, and injected into the combustion chamber 30. The combustion chamber 30 is preferably relatively small, preferably very close to the size of the flame of the burning fuel and air mixture itself, in order to minimize wasted energy in unnecessarily heating an empty space around the flame.
The adjustable venturi device 32 preferably includes a generally annular gas chamber 34 with a pair of externally-threaded inspirator tubes 36 threadably and adjustably engaged with peripheral portions of the gas chamber 34. The inspirator tubes are spaced apart within the gas chamber 34 to form an opening 38, the size of which is preselectively adjustable by threadably moving the inspirator tubes 36 toward or away from one another. Thus, for a particular application, the proportions of gaseous fuel and combustion air mixed together in the ajustable venturi device 32 can be preselectively adjusted in order to provide a range of fuel-to-air ratios that are consistent with the desired operating conditions in the particular application.
The air heating sub-system 12 also includes a small exhaust conduit 44 in fluid communication with the interior of the combustion chamber 30 for conveying the products of combustion from the combustion chamber 30 to the exterior or ambient surroundings 46 of the heated space 48. A combustion chamber heat exchanger 50 is also associated with the combustion chamber 30 and is adapted to transfer heat produced in the combustion chamber 30 to cold air supplied from the cold air supply sub-system 14 (described below) in order to produce heated air that is in turn conveyed through a heated air discharge conduit 52 to an air mixing chamber 54, which is part of the air circulating sub-system 16 described below.
The air circulating sub-system 16 generally includes a cold air return conduit 56 and a return air fan 58 for withdrawing cold air from the heated space 48 and conveying such cold air to the air mixing chamber 54 by way of a cold air conduit 59. The cold air from the air circulating sub-system 16 is mixed in the air mixing chamber 54 with heated air from the combustion chamber heat exchanger 50 and from an exhaust gas heat exchanger 94 (described below). Such mixing in the air mixing chamber 54 produces a heated air mixture that is conveyed, under the force of the return air fan 58, outwardly from the air mixing chamber 54 to the heated space 48 by way of one or more heated air supply conduits 60.
Cold air is supplied to the combustion air heat exchanger 30 from the heated space 48 by the cold air supply sub-system 14. Such cold air is withdrawn from the heated space by a cold air supply fan 74 and conveyed to the combustion chamber heat exchanger 30 by way of a cold air conduit 76.
In order to effectively transfer a very high percentage of the thermal energy produced in the combustion chamber 30 to the air that is introduced into the air mixing chamber 54, the combustion chamber heat exchanger 50 is preferably of a configuration that substantially fully envelopes the combustion chamber 30. The combustion chamber 30 is enclosed by a combustion chamber enclosure wall 64 composed of a heat-transmissive material having a high thermal conductivity. The enclosure wall 64 is generally surrounded or enveloped by an inner cold air chamber 66, which is in turn surrounded or enveloped by an outer cold air chamber 68, with one or more intermediate cold air chambers 70 disposed therebetween. The inner cold air chamber 66, the outer cold air chamber 68, and the intermediate cold air chambers 70 are separated by het transmissive chamber walls 72 having high thermal conductivity.
The cold air chambers 66, 68, and 70 of the combustion chamber heat exchanger 50 are serially disposed outwardly with respect to one another, with each of the chambers being in fluid communication with its inwardly adjacent chamber such tht cold air from the cold air supply sub-system 14 (described above) flows serially therethrough from the outer cold air chamber 68, through the intermediate cold air chambers 70, and into the inner cold air chamber 66. The heat produced by the combustion process in the combustion chamber 30 is thus transferred through the heat transmissive combustion chamber enclosure wall 64 and serially through the inner cold air chamber 66, through the intermediate cold air chambers 70, and to the outer cold air chamber 68, thus serially heating the air as it serially flows through the combustion chamber heat exchanger 50. The number of cold air chambers surrounding or enveloping the combustion chamber 30 is readily determined by one skilled in the art from the desired cold air inlet and heated air outlet temperatures for a given air flow in a particular application. Optionally, the outer cold air chamber 68 can be covered or surrounded by any of a number of well-known suitable heat insulating materials in order to further minimize thermal energy loss.
The combustion air supply sub-system 18 shown in FIG. 1 preferably includes a combustion air cleaner or filter device 80, which can comprise any of a number of well-known suitable air cleaner or air filter intake devices known to those skilled in the art. Combustion air is withdrawn from the heated space 48 through the combustion air cleaner device 80, and conveyed through an air conduit 82 to the intake or suction side 83 of a combustion air compressor 84. The combustion air compressor 84 raises the pressure of the combustion air to a predetermined pressure level and discharges the compressed combustion air through its discharge side 85 to the air heating sub-system 12 by way of an air conduit 86.
Prior to being introduced into the adjustable venturi device 32, the compressed combustion air preferably passes through a separator device 88. The separator device 88 is preferably a vortex-type separator device, such as those well-known to persons skilled in the art, preferably equipped with a noise-reducing muffler 89. The separator device 88 functions to separate combustion air that is above a predetermined temperature from combustion air that is below such predetermined temperature by separating the relatively heavy, cooler air molecules from the relatively light, higher temperature air molecules. The separated combustion air that is above such predetermined temperature is conveyed through a hot separated air conduit 90 to the adjustable venturi device 32, described above, to be intermixed with gaseous fuel from the gaseous fuel supply sub-system 20 described below.
The separated combustion air that is below the above-discussed predetermined temperature is separated in the separator device 88 and conveyed by way of a cold separated air conduit 92 to an exhaust gas heat exchanger 94 shown generally in FIG. 1, and diagrammatically depicted in more detail in FIG. 2.
As shown in FIG. 2, the exhaust gas heat exchanger 94 preferably includes a plurality of exhaust gas baffles 95 disposed within an inner housing 93. The inner housing 93 is generally surrounded or enveloped by an outer housing 91, which is spaced outwardly apart from the inner housing 93 to allow air from the cold separated air conduit 92 to flow therebetween and to be discharged through an air conduit 96 to the air mixing chamber 54 described above. Preferably, a number of air baffles 97 are disposed in the space between the inner and outer housings 93 and 91, respectively, in order to cause the air flowing therethrough to flow evenly over substantially all of the inner housing 93, thereby effectively transferring heat from the exhaust gas, which may be in the range of approximately 300 F. (149 C.) to approximately 360 F. (182 C.) in many operating conditions, to the air flowing through the exhaust gas heat exchanger 94. By such an arrangement, and by choosing an appropriately-sized exhaust gas heat exchanger 94, as is well within the capabilities of one skilled in the art, a substantial portion of the thermal energy contained in the exhaust gas can be recovered such that the exhaust gas discharged to the exterior ambient surroundings 46 is at a very low temperature, preferably below the temperature desired in the heated space 48, such as at or below 60 F. (16 C.), for example, in many applications. Furthermore, because of the relatively low temperature of the exhaust gas, the exhaust gas conduit 44 can advantageously be constructed of relatively common conduit materials, including common copper tubing, for example, in many applications.
The gaseous fuel supply sub-system 20 as illustrated in FIG. 1, wherein a gaseous fuel is withdrawn from a gas source 102, which can consist of a conventional natural gas supply system or other gaseous fuel sources well-known in the art. The gaseous fuel is conveyed through a safety valve 104, which is preferably adapted to be automatically closed or to automatically fail in a closed condition in the event of a malfunction in the heating system 10. The gaseous fuel is then conveyed through the gas conduit 103 into the intake or suction side 106 of a gaseous fuel compressor 108, which raises the pressure of the incoming gaseous fuel to a predetermined pressure level substantially equal to that of the compressed combustion air described above. The compressed gaseous fuel is then expelled through the discharge side 110 of the gaseous fuel compressor 108 and conveyed by way of a gas conduit 112 to the above-described adjustable venturi device 32, wherein it is intermixed at predetermined proportions with the compressed combustion air before being ignited by the ignition device 40 and injected into the combustion chamber 30.
Because of the elevated pressure of the combustion air and the gaseous fuel, the exhaust gases are also pressurized and thus forcibly conveyed through the exhaust gas conduit 44. Therefore, the exhaust gas conduit 44 does not have to be connected to a draft-type chimney or other conduit and can be relatively small, perhaps as small as a 1/2 inch (1.3 cm.) or (0.95 cm.) copper tubing, or even smaller, in certain applications.
In order to control the flow rates of the combustion air and gaseous fuel being supplied to the air heating sub-system 12 by the combustion air supply sub-system 18 and the gaseous fuel supply sub-system 20, bypass systems are included in association with the combustion air compressor 84 and the gaseous fuel air compressor 108, respectively. In the combustion air supply sub-system 18, a bypass conduit 116 is connected in fluid communication with the air conduits 86 and 82 in order to allow bypass air flow from the discharge side 85 to the suction or intake side 83 of the combustion air compressor 84. The flow rate of the combustion air flowing through the bypass conduit 116, and thus the discharge flow rate through the air conduit 86, are controlled by modulating an air control valve 118 provided in the bypass conduit 116. Similarly, a bypass conduit 120 is provided in fluid communication with the gaseous conduits 112 and 103 in order to allow gaseous fuel bypass flow from the discharge side 110 to the intake or suction side 106 of the gaseous fuel compressor 108, with the gaseous fuel bypass flow rate being controlled by modulation of a gas control valve 122. Thus, the respective pressures and flow rates of both the combustion air flow and the gaseous fuel flow can be preselectively regulated by modulating the combustion air control valve 118 and the gaseous fuel control valve 122, respectively. Further regulation of these flow rates can optionally be accomplished by regulating the speeds of variable-speed gas and air compressors in addition to, or in lieu of, the bypass systems described above. Regulation of the combustion air supply and the gaseous fuel supply is accomplished by the control sub-system 22 described below.
The control sub-system 22 includes an air temperature sensor 126 located in the heated space 48 and can consist of a conventional thermostat device such as that well-known in the art. The air temperature sensor 126 is operatively connected by way of a suitable conductor 128 with a preferably programmable central microprocessor 130 and is adapted to transmit signals to the central microprocessor 130 in response to varying air temperatures in the heated space 48. The central microprocessor 130 is in turn operatively connected by way of suitable conductors 133 and 135 to the combustion air control valve 118 and the gaseous fuel control valve 122, respectively, in order to transmit appropriate signals for actuating, deactuating, or modulating the respective air and gas bypass systems. The central microprocessor 130 is also in turn operatively connected with the combustion air compressor 84 and the gaseous ful compressor 108 by suitable conductors 132 and 134, respectively, in order to transmit appropriate signals thereto for purposes of actuating, deactuating, or regulating the speed of, the combustion air compressor 84 and the gaseous fuel compressor 108. The central microprocessor 130 is also operatively connected with the electronic ignition device 40 by way of a suitable conductor 136 in order to transmit actuating or deactuating signals thereto for purposes of igniting the mixture of combustion air and gaseous fuel during start-up of the heating system 10, and with the safety valve 104, by way of conductor 105 in order to shut down the system in the event of an emergency or a malfunction.
The control sub-system 22 also includes suitable conductors 150 and 152 for electrically interconnecting the central microprocessor 130 with the cold air supply fan 74 of the cold air supply sub-system 14 and the return air fan 58 of the air circulating sub-system 16. The control sub-system 22 is thus adapted to transmit actuating and deactuating signals, or modulating signals, to both the cold air supply sub-system 14 and the air circulating sub-system 16. By way of this control arrangement, as well as the control arrangement discussed above in connection with the combustion air supply and the gaseous fuel supply, the central microprocessor 130 is adapted to control the heating system 10 in response to sensed air temperatures in the heated space 48 and thereby maintain the air temperature in the heated space 48 at any of a number of preselected temperatures.
Because the ambient temperatures and conditions in the surroundings or exterior 46 of the heated space 48 can have a dramatic effect upon the air temperature in the heated space 48 by way of heat loss or heat gain, it is desirable to also control the operation of the heating system 10 in response to outside temperatures. Therefore, the control sub-system 22 optionally, but preferably, includes an outside air temperature sensor 140 operatively and electrically connected by way of a suitable conductor 142 with the central microprocessor 130. In response to sensed outside temperatures, the outside air temperature sensor 140 can therefore transmit appropriate signals to the central microprocessor 130, which in turn can preferably be programmable to control the heating system 10 in response to signal inputs relating to both the internal air temperature of the heated space 48 and the outside temperature of the exterior surroundings 46. For example, the central microprocessor 130 can preferably be programmed to respond appropriately in a situation where the heated space air temperature sensor 126 calls for heated air but the outside temperature is concurrently increasing, thereby avoiding the duplicative effect of adding heat to the heated space 48 by the heating system 10 while the heated space 48 is also experiencing a heat gain as a result of increasing outside temperatures. Likewise, for example, the central microprocessor 130 can be programmed to respond to decreasing outside temperature in order to cause the heating system 10 to supply additional heated air to the heated space 48 somewhat before the internal air temperature sensor 126 actually calls for more heat. Furthermore, by maintaining close control of the operation of the heating system 10, by way of the above-described control sub-system 22, the heating system 10 can be operated for longer periods of time, but at variable heat output levels, thereby decreasing the number of on/off operating cycles and thus decreasing the opportunity for wasteful heat loss as compared with conventional furnaces and other conventional heating systems.
It should be noted that the central microprocessor 130 can consist of any of a number of conventional, and preferably programmable, microprocessor units well-known to those skilled in the art and adaptable for performing the functions described above. In this regard, it should also be noted that although the control sub-system 22 is schematically depicted in the drawings as an electric control system, one skilled in the art will readily recognize that pneumatic, hydraulic or other control systems for actuating and deactuating the various components described above can readily be substituted for the electric control sub-system 22 depicted for purposes of illustration in the drawings.
The foregoing discussion discloses and describes exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion that various changes, modifications and variations may be made therein without departing from the spirit and scope of the invention as defined in the following claims.
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An improved heating system is disclosed for providing heated air to a heated space, preferably using a gaseous fuel as the energy source. The system preferably includes an air heating sub-system, a compact combustion chamber, a separate cold air supply sub-system for conveying cold air from the heated space to the air heating sub-system, a combustion chamber heat exchanger in fluid with the cold air supply sub-system for transferring heat thereto, and a separate air circulating sub-system for withdrawing cold circulating air from the heated space. A mixing chamber is provided for mixing heated air from the air heating sub-system with the cold circulating air to provide heated air to the space. The system also preferably includes separate sub-systems for supplying pressurized combustion air and pressurized gaseous fuel to the air heating sub-system and for forcibly conveying exhaust gases therefrom without the need for a draft-type chimney or stack. In another preferred embodiment, a vortex-type air separator separates higher temperature and lower temperature combustion air, with the higher temperature air being used for combustion and the lower temperature air being heated in an exhaust gas heat exchanger before being conveyed to the heated space. A novel control sub-system is also provided for controlling the system, preferably in response to both indoor and outdoor temperatures, and for minimizing the number of energy wasting on/off cycles in operating the system.
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BACKGROUND OF THE INVENTION
This invention relates to a process for producing an aqueous solution of a particulate material having a fine particle size, typically a polymeric particulate material, which is difficult-to-dissolve in water.
The polymeric particulate materials of this invention, such as polyacrylamide, which have a small particle size are very slippery when wetted. This is even more pronounced in materials which have an extremely fine particle size (50 micron or less). Therefore, any spillage or airborne dry polymeric dust due to the use of an "open" system migrates onto areas such as floors, stairways and handrails of a manufacturing facility potentially becoming a great hazard to workers when they become wetted.
Since there are no closed systems for producing solutions of fine micron size versions of the above-described polymers, coarser polymeric particulate materials having much higher relative particle size (250 microns or more) are instead employed in producing solutions of these hard-to-dissolve polymers. A problem associated with these coarser polymeric particulate materials is, however, the length of time it takes them to dissolve them and form a solution. In the formation of polyacrylamide solutions, for example, the intertwined higher molecular weight polymeric chains of the coarser polymeric materials become untangled over time, upon "aging" in water, as the solution reaches its full potency. This aging process requires large tanks for mixing and storing polymer solutions before they can actually be used. Accordingly, the need for including the above-described aging step in the overall solution formation process results in the need for a more costly and a more time consuming manufacturing system in order to produce an aqueous solution in which the polyacrylamide particulate material is substantially completely dissolved.
Complex formation apparatus for forming solutions of the coarser subject materials has also been produced. In U.S. Pat. No. 3,738,534, a vortex chamber is used to provide a hollow cylindrical rapidly flowing film of fluid onto the inner surface of which the polymeric material is introduced. The apparatus of U.S. Pat. No. 3,893,655 includes a vertically mounted wetted wall funnel having a throat of reduced cross-section at the bottom. The particulate solid material is distributed onto the interior surface of the wetted wall funnel and the solids-liquid mixture withdrawn from the funnel and admixed into the liquid flowing past the throat of the funnel. In U.S. Pat. No. 4,518,261, the vessel 201 and the water supply pipe 202 are so constituted that water is whirled within the vessel about the discharge pipe. The water whirled within the circular division plate 205 and discharged from a funnel-shaped discharge pipe 204. The energy and flowing conditions of the water which is whirled while generating negative pressure and discharged from the discharge pipe 204 is normally sufficient to disperse the polymer powder in the water. A particle size reduction apparatus is shown in U.S. Pat. No. 4,529,794, in which a suspension of polymer particles is formed and subjected to conditions of high shear in order to force the particles into solution. The pumping action of an impeller rotating at 10,000 to 13,000 rpm reduces the size of, and dissolves, the polymer particles. In another high shear apparatus described in U.S. Pat. No. 4,603,156, the polymer particles are first comminuted, and the comminuted material and water are fed to a mechanical dispersion means 16. The dispersion means comprises a boxlike housing having an open bottom side, and impeller/stator assembly mounted in the housing. In U.S. Pat. No. 4,778,280, a mixing apparatus is provided having a first centrifugal pump including a casing and an impeller located therein. The casing has an axially extending tubular inlet located centrally on its end wall. The discharge comprises a tubular projection on the sidewall's casing. A second centrifugal pump includes a casing which is substantially identical to the casing of the first pump. The second casing has a tubular projection on its end wall. The water is delivered to one end wall of the second casing. The polymer is directed to the other end wall of the second casing. The swirling water in the second casing creates a lower pressure at its discharge to draw the polymer downwardly and into the first casing where it is mixed with the incoming water.
Therefore a need exists for a process for producing an aqueous solution of a difficult-to-dissolve, fine particle size particulate material, typically a polymeric particulate material, wherein aging time is substantially reduced and in which spillage or airborne dry polymeric dust is eliminated.
SUMMARY OF THE INVENTION
The above-described existing needs have been met by the present invention which provides a process for producing an aqueous solution of a difficult-to-dissolve, fine particle size particulate material, typically a polymeric particulate material, such as polyacrylamide, wherein aging time is substantially reduced and in which spillage or airborne dry polymeric dust is eliminated.
More specifically, a process is provided for producing an aqueous solution of a low solubility, substantially dry particulate material. This is accomplished in a substantially reduced time period and without releasing substantial amounts of particulate dust to the surrounding atmosphere. The aqueous solution produced also contains substantially no undissolved visible particles of said low solubility particulate material.
The process comprises first forming a non-homogeneous aqueous mixture of the low solubility particulate material in a closed aqueous solution formation area by combining the low solubility particulate material and water. The prior art systems for producing homogeneous aqueous mixtures form low solubility particulate material requires the particle size of that material to be 250 microns or greater. The low solubility particulate material preferably has a low particle size of not more than about 150 microns, more preferably a low particle size of not more than about 100 microns, and most preferably a low particle size of not more than about 50 microns.
Next, low shear forces are imparted to the non-homogeneous aqueous mixture of the low solubility particulate material. In this way, homogeneous aqueous solution of the low solubility particulate material are produced containing substantially no undissolved visible particles of the low solubility particulate material. This is accomplished without substantially reducing the particle size of the particulate material beyond the level set forth above.
The aqueous solution of the low solubility particulate material and substantially all of the particulate material dust associated therewith are removed from within the closed aqueous solution formation area. This is done by exerting a partial vacuum on the aqueous solution of the low solubility particulate material from outside the formation area.
The process can also be conducted in a substantially reduced amount of time measured from the formation of the non-homogeneous aqueous mixture of the low solubility particulate material. Typically this reduced amount of time is not more than about 25%, and preferably not more than about 50%, of time period for producing an aqueous solution of low solubility particulate material from a homogeneous aqueous suspension which does not impart the high speed, low shear forces.
The process of claim can also include the step of imparting the high shear forces to the non-homogeneous aqueous mixture of the low solubility particulate material which both particularizes and conveys at constant volume the low solubility particulate material. Preferably, the high shear forces are imparted to the non-homogeneous aqueous mixture of the low solubility particulate material employing a constant volume positive displacement pump. The high shear forces which are imparted to the non-homogeneous aqueous mixture of the low solubility particulate material, are preferably at a rate of at least about 500 rpm. The process of the present invention can also include the step of agitating the aqueous suspension of the low solubility particulate material, without introducing any further amounts of the low solubility particulate material or water, to form the aqueous solution of the low solubility particulate material containing substantially no undissolved visible particles of the low solubility particulate material.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment which proceeds with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a preferred process for producing a solution of a fine particle size low solubility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the feed system 10 of this invention substantially eliminates the aforementioned particulate dust which emanates into the atmosphere from the dry, fine particle size particulate material of the present invention when a feed system open to the atmosphere is employed. The particulate material is typically a polymeric material which has a low degree of solubility in water. Particulate materials for which this process is useful includes polyacrylamide, carboxymethylcellulose, guar gum, carbopol, and various other final particle size particulate materials used in cosmetics, papermaking, and pharmeceuticals, the polyacrylamide particulate material being the preferred composition. This polyacrylamide material can be of an anionic, cationic or nonionic type, having a charge level ranging from very low to very highly, and having a molecular weight ranging from a relatively low molecular weight (about three million) to a very high molecular weight material (greater than 15 million). This material can expand upon aging in water. A typical viscosity for a 5% by weight solution of the material, measured with a Brookfield viscometer using a #2 spindle rotating at 20 rpm and 70° F., is up to about 30,000 to 50,000 cps. An example of this type of material is an polyacrylamide resin manufactured by Allied Colloids of Sulfolk, Va. under the trademark PERCOL. The average particle size of the low solubility particulate material employed herein is in general not more than about 250 microns, preferably not more than about 100 microns, and more preferably not more than about 50 microns.
The solution make-up unit of the present invention is closed to avoid the introduction of the particulate dust into the atmosphere surrounding the equipment. Therefore, the dry, fine particle size particulate material is poured and weighed in a closed system without releasing particulate dust to the atmosphere. In this case, metering of the particulate material is provided using an auger feeder system which delivers a predetermined amount of the material, from about 1-20 lbs/minute, over a set amount of time, about 3-20 minutes/batch. This auger feeder system can be one of a number of units such as the Model No. 602 or 610 manufactured by Accurate Corporation of Whitewater, Wis. A linear adjustment feature in the auger feeder system permits the user to deliver accurately predetermined amounts of the particulate material from the auger feeder.
The particulate material is introduced into the auger feeder from a large (800 to 2400 pounds) sealed bag 14 using a special hopper top accessory 11 assembly available from Accurate Corporation. The special hopper top assessory 11 includes a lifting cross, connected to the bag 14, which is attached to a hoist 15. Hoist 15 is attached to trolley 17 which is movable along I-beam 19. The sealed bag is never directly open to the atmosphere. The bag used is available from companies such as TAY, Inc of Plasticiel, SA, of Monterey, Mexico. The large sealed bag includes a tube 16 which unfolds and extends from beneath the lower portion of the bag. The tube 16 is tied about its end portion to prevent the particulate material from flowing out of the lower end of the tube into the atmosphere. The tube is 8 inches in diameter and fits into a "hoper adaptor" 18 available from Accurate Corporation. The lower end of the tube 16 is inserted into the hopper adaptor 18 and the cord is untied from about the tube. This allows the particulate material to flow from within the bag 14, out of the lower end of the tube, and into the auger feeder 12 through the hopper adaptor 18. When a bag has been emptied, the cord is retied to prevent any residual polymer from spilling out of the tube end, or from dust getting into the air. The empty big bag is disposed of at a landfill or by incineration.
The particulate material exits the lower end of the auger feeder 12 and enters a mixing vessel including a hollow central mixing chamber 20. A stream of water flow 21 (see arrows) is also introduced to the confines of the mixing chamber 20, and a non-homogeneous, aqueous mixture of the low solubility, particulate material. The water stream moves in a swirling manner within the confines of the mixing chamber. This swirling action is facilitated by a high speed, low shear mixing pump 22 operating as hereinafter described. The weight % of the particulate material in the non-homogeneous, aqueous mixture of the low solubility, particulate material is generally from about 0.5 to 10 weight %, preferably from about 1 to 5 weight %. The mixing vessel is covered to provide assistance in preventing particulate dust from escaping into the atmosphere. The material is subsequently further diluted with water in an agitated mixing tank to a solution from about 0.1 to 0.5 weight %.
A significant feature of this invention is the manner in which the system is configured to remove particulate material from within the mixing vessel, including any dust formed within the confines of the mixing chamber 20. More specifically, a high speed, low shear mixing pump 22 is connected at the exit portion of the mixing vessel, in communication with the mixing chamber 20 and the stream of a non-homogeneous, aqueous mixture of the low solubility, particulate material flowing therewith. The stream of a non-homogeneous, aqueous mixture of the low solubility, particulate material is drawn from within the mixing chamber 20 by the high speed mixing pump 22. The mixing pump 22 creates a partial vacuum by operating at a higher throughput rate than operating rate of the respective particulate material and water stream entering the mixing chamber. Any dust located within the confines of the mixing vessel is removed from the mixing chamber and through the mixing pump by exerting a partial vacuum thereon.
The high speed mixing pump described above preferably comprises a gear pump, such as a gear pump manufactured by Bowie Evaporation, or the Model No. H124 or HL125 gear pumps manufactured by Viking Corporation. Some of the particulate materials can be corrosive to the surface areas of the pump. Therefore, fabricating the pump out of hardened steel is the preferred product for greatest longevity. It has also been found that in the Viking pumps the bushing and pin on which it rotates fail in less than 100 hours of operation unless tungsten carbid parts are used. It has also been discovered that the Bowie pump with its greater sized tolerances and lower rpm will achieve over 1,000 hours of operation without need of repair or replacement. The Bowie pump, however, requires the system to have lower agitation and production time prior to using the product than required by the Viking pump. One can expect no more than 500 hours of operation from the Viking pump even with hardened steel gears and tungsten carbide bushings, before replacement parts are needed. It was also discovered that motorized valves as opposed to check valves extend the life of the gear pumps used as no back pressure is created.
The high speed mixing pump is operated at an rpm level which will create a partial vacuum on the mixing chamber, and at the same time will thoroughly mix the water and particulate material. Generally, the high speed mixing pump is operated at a level of at least about 500 rpm. This high relative pump speed mixes the water and particulate material thoroughly so that it is virtually a solution when leaving the pump, and is at full potency and fully aged within minutes. The rpm of the pump during the mixing operation is therefore maintained at a level which does not result in substantial further particularization of the particulate material. For example, if the particulate material is a polymer, the mixing pump is operated so as to avoid substantial shearing of any long chain polymeric materials which would decrease molecular weight, and significantly reduce effectiveness, of the final solution.
The solution of particulate material is pumped from a high speed, low shear mixing pump to holding tank 24. A solution of the polymer at a total solids of between 2-6% active polymer by weight can be formulated in a holding tank. Alternatively, a batch tank can be used to ensure that an exact amount of water is added to the known amount of polymer (from timer on auger) so that a solution strength is constant. This solution strength is ensured because the auger works on a timer and a fixed amount of water is added. In batching situations, solutions between 0.1 to 0.5 weight % are generally produced.
An alternative procedure for an automatic solution formation process is as follows:
If the polymer in the feed tank 24 is consumed so its level falls below a predetermined minimum level point, it is sensed by a probe. One probe which can be which is Model #2470 manufactured by Princo Instrument Corporation of Southampton, Pa. When a signal from the probe is sent to a controller on the mix tank, a batch of polymer is transferred to the feed tank. When a predetermined low level is sensed in the mix tank, an electrical signal is transmitted to a control box which initiates the following series of operations.
1. The transfer pump 26 to the feed tank is shut off.
2. A solenoid valve is opened and water is introduced into the batch tank.
3. Water enters and is moved through a mix cone.
4. The agitator starts to turn in the batch tank.
This process continues until the water level in the batch tank reaches the next sensing level called "polymer level". At this point an auger starts to turn and polymer is delivered to the mix cone. The auger continues to run for a predetermined period of time. This is accomplished by presetting the desired number of minutes on a timer to deliver the desired amount of polymer which is transferred to the batch tank at a known feed rate. Water continues to be introduced into the batch tank from two sources (1) the mix cone (with polymer) and (2) a separate fill line.
After the timer has run for its preset length of time, it shuts off the auger and polymer and, after a 3 second delay, it shuts off the water to the mix chamber and mix pump. Water continues to fill the batch tank from the fill line until the water reaches the fill level on the probe where it sends a signal to the control panel which:
1. Shuts off the solenoid valve sending water through the fill line, and
2. Shuts off the agitator after a short time delay.
The polymer will remain in the batch tank until the probe in the feed tank again signals the control panel for another batch of polymer to be sent. The amount of water required to fill the batch tank and the amount of polymer delivered by the auger over the preset time period, allows for a polymer solution to be produced at between 0.01% to 5% polymer total solids.
In the case of the polymer going directly to the truck-solution strength is determined by water flow (pressure gage through fixed orifice or water meter). In this system constant human monitoring of polymer make up is performed to ensure there is no drop or rise) in water pressure which would change polymer concentration. With batch make up human monitoring is not necessary because a drop in water pressure simply means batch tank takes longer to fill. An agitator 28 on the batch tank blends water and polymer solution so that there is no stratification. Agitation is not needed for mixing. As soon as all water is in batch tank agitator shuts off.
Throughout the system the automatic probes not only turn on and off pumps, valves and mixers, they also alert operators of problems through alarms.
Having illustrated and described the principles of my invention in a preferred embodiment thereof, it should be readily apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. I claim all modifications coming within the spirit and scope of the accompanying claims.
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The process comprises first forming a non-homogeneous aqueous mixture of the low solubility particulate material in a closed aqueous solution formation area by combining the low solubility particulate material and water. Next, low shear forces are imparted to the non-homogeneous aqueous mixture of the low solubility particulate material. The aqueous solution of the low solubility particulate material and substantially all of the particulate material dust associated therewith are removed from within the closed aqueous solution formation area by exerting a partial vacuum on the aqueous solution of the low solubility particulate material from outside the formation area. The process can also include the step of imparting the high shear forces to the non-homogeneous aqueous mixture of the low solubility particulate material which both particularizes and conveys at constant volume the low solubility particulate material. In the process of this invention, the aqueous solution of the low solubility particulate material typically contains substantially no undissolved visible particles of the low solubility particulate material.
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This application is a division, of application Ser. No. 357,376, filed Mar. 12, 1982 now U.S. Pat. No. 4,467,507 granted Aug. 28, 1984.
DESCRIPTION
1. Field of Invention
This invention relates to an improved apparatus and method for making continuous variable texture yarn by commingling two or more differently textured filaments.
2. Background Art
Variable texture yarn has been made by co-bulking a first continuous filament, which is commingled with a second continuous filament, in a hot fluid jet process. This technique produces co-bulked yarn with flecks of various colors randomly distributed throughout. U.S. Pat. No. 4,295,329 teaches one co-bulking technique for producing a composite yarn, and notes that the toughness and the tenacity of some of the filaments is reduced by co-bulking.
SUMMARY OF INVENTION
The present invention provides a method and an apparatus whereby continuous filaments are crimped, and then commingled to form a variable textured yarn. The toughness and tenacity of the various filaments in the variable textured yarn are not reduced by the commingling step. Thus, a yarn with greater resiliency than yarn co-bulked in the prior art hot fluid jet process is obtained.
The apparatus of the present invention has at least two moving chambers with different volumes that advance at the same speed and are in thermal equilibrium. Each chamber has an inlet opening for receiving continuous filaments. A movable perforated filament-receiving means is at least partially disposed in each chamber and adjacent to the inlet opening. Each chamber has an energy tube for directing a stream of compressed fluid containing the filaments onto the filament-receiving means. The angle made between the energy tube and the filament-receiving means ranges from about 15° to 75°. Processing the continuous filaments through the chamber produces crimped or textured filaments.
Means are provided for commingling the textured filaments from each of the chambers to form a variable texture yarn.
A method for production of a variable texture yarn is described. A first group of continuous filaments is textured in a first chamber of a multi-chamber moving cavity texturing apparatus, while a second group of continuous filaments is textured in a second chamber of the same texturing apparatus. Thermal communication is maintained between the first chamber and the second chamber.
The geometry of the chambers is selected so as to assure that the difference in the skein shrinkage levels between the first group of textured filaments, and the second group of textured filaments differs by at least thirty percent (30%). The first group of textured filaments and the second group of textured filaments are commingled.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a prior art single chamber moving cavity texturing apparatus.
FIG. 2 is a representation of a section taken along line 2--2 of the apparatus shown in FIG. 1.
FIG. 3 is a schematic representation of a dual chamber moving cavity texturing apparatus of the present invention in which the chambers have different lengths.
FIG. 4 is a schematic representation of the dual chamber texturing apparatus of the present invention in which the chambers have different cross sectional areas.
FIG. 5 is a schematic representation of a commingling apparatus for employment with the dual chamber texturing apparatus of FIG. 3 or FIG. 4 for producing a variable texture yarn.
FIG. 6 is a schematic representation of a second commingling apparatus for employment with the dual chamber texturing apparatus of FIG. 3 or FIG. 4 for producing a variable texture yarn.
BEST MODE FOR CARRYING THE INVENTION INTO PRACTICE
FIG. 1 is a schematic representation of the prior art single chamber moving cavity texturing apparatus described in U.S. Pat. No. 4,074,405. The apparatus has a chamber 12 including an inlet opening 14 for receiving a group of filaments 16 to be crimped, and an outlet opening 18 for withdrawal of the filaments 16 therefrom after the filaments have been crimped on a moving perforated filament-receiving means 20 which is a screen. FIG. 2 shows the section 2--2. The perforated filament-receiving means 20 is held in place by sidewalls 22, 23. The chamber 12 is completed by a shoe 24. A group of filaments 16 is fed through an energy tube 26 by a heated compressed fluid entering through the opening 28. Advancing heated compressed fluid brings the group of filaments 16 into contact with the screen 20 which deflects the group of filaments 16, and sets a crimp in the filaments 16. The group of crimped filaments 16 are advanced in the chamber 12 by the moving perforated filament-receiving means 20 and by the residual fluid pressure and secondary crimps are introduced as the group of filaments advance into the chamber forming a plug 30. The plug 30 is advanced towards the outlet 18 by the moving perforated-filament receiving means 20. The crimped filaments are then withdrawn from the plug 30 through the outlet 18 of the chamber 12.
While the prior art provides a highly effective means for crimping filaments, the output from the prior art apparatus depends on many process parameters; such as dwell time of the plug 30 in the chamber 12, the processing temperature, the speed of the screen 20, and the angle of impact θ between the energy tube 26 and the filament-receiving means 20. The dwell time of the plug 30 will be controlled by the velocity of the screen 20, as well as, the cross section of the chamber 12. Local variations in these variables can effect the resulting crimping of the filaments 16, and can hinder subsequent commingling.
FIG. 3 is a schematic representation of a two chamber crimping device having the two chambers on a common drum 34. The first chamber 36 and the second chamber 38 have equal cross sectional areas A 1 and A 2 , but different lengths L 1 and L 2 . The first chamber 36, and the second chamber 38 thermally communicate, and advance at the same rate. In view of this coupling of the two chambers, any systematic variation of the average crimp density in the first chamber 36 will be reflected in the second chamber 38, however, since the length of the two chambers differ there is a difference in the average crimp set for the first chamber 36, and the second chamber 38.
The first chamber 36 is as depicted for the chamber 12 in FIG. 1, the second chamber 38 shares a common sidewall 40 with the first chamber 36. The second shoe 44 of the second chamber 38 is substantially longer than the first shoe 24 of the first chamber 36. It is preferred that the second shoe 44 be at least about 50% longer than the first shoe 24. To optimize the consistency of the output from the first chamber 36 and the second chamber 38, it is preferred that the angle of impact, θ for the filaments 16 in both chambers be the same, and be between about 50° and 70°. Both the first chamber 36, and the second chamber 38 exhaust to a common exhaust chamber 46.
FIG. 4 is a schematic representation of another two chamber crimping device, where the first chamber 36 has a cross sectional area A 1 , which is less than the cross sectional area A 2 of the second chamber 38. It is preferred that the difference in the cross sectional areas between the two chambers be at least 50%.
Both the first chamber 36, and the second chamber 38 exhaust to a common exhaust chamber 46. The two chambers because of their different geometry will produce plugs 30 with different geometry. When the input parameters for the group of filaments 16, such as fluid temperature, fluid pressure, and angle of impact of the filaments 16 with the filament-receiving means 20, are the same for both chambers, the dwell time within the chambers will be different for the two plugs. For example, dwell times greater than about 2 seconds will be ineffective in increasing the skein shrinkage for a polyethylene terephthalate yarn of 150 denier, 34 filaments. Thus, the length of the shorter chamber should be maintained such that the dwell time of the plug in the chamber will be less than 2 seconds (ie about 0.5 seconds).
FIG. 5 illustrates the commingling of the filaments produced by the present invention. The groups of textured filaments are withdrawn from a moving multicavity texturing apparatus. A first group of filaments 62 is withdrawn from one of the cavities and is aspirated by a high velocity jet 60. The jet 60 propels the first group of filaments 62 down the aspirator tube 64. An inlet 66 is provided for the introduction of a second group of filaments 68. These filaments are withdrawn at the same rate as the first group of filaments 62 were withdrawn from the multicavity texturing apparatus. The groups of filament are impacted against a wall 70 to commingle the filaments and produce a yarn 71 of uniform texture. Further details of this commingling technique is discussed in U.S. Pat. No. 3,874,044. The uniform texture yarn produced by this technique is easily woven, and upon subsequent dyeing and shrinking, the woven material has an appearance similar to that of natural fibers, such as wool or cotton.
FIG. 6 illustrates another commingling technique. Groups of texture filaments 62 and 68 are fed at the same rate into a tube 72. The tube 72 has a first jet inlet 74 which directs a fluid into the tube 72, and a second jet inlet 76 which also directs fluid into the tube 72. The two jet inlets 72, 76 are off center and provide turbulent flow in the tube 72. The turbulent flow causes commingling of the filaments, and thereby a uniform yarn 71 to be produced. This yarn can be easily woven, and upon subsequent processing will produce a woven material with a textured appearance similar to that of natural fibers.
Other commingling techniques are described in U.S. Pat. No. 2,985,995.
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The present invention discloses a moving multicavity texturing method for simultaneously texturing filaments which are commingled to form a yarn. The yarn readily knits producing a fabric which upon subsequent dyeing and shrinking produces a variable textured fabric similar in appearance to fabrics knit from natural fibers.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a divisional of co-pending application Ser. No. 09/205,082, filed on Dec. 4, 1998. The priority of the prior application is expressly claimed, and the disclosure of each of this prior application is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to dietary supplements containing lecithin, antioxidants and/or a vitamin B complex to treat liver disease. A preferred embodiment is a composition and the use thereof of a dietary supplement comprising lecithin, at least one antioxidant, and a vitamin B complex administered orally to treat or alleviate nonalcoholic steatohepatitis.
BACKGROUND OF THE INVENTION
[0003] The liver is the largest organ in the human body, located in the superior portion of the right upper abdomen. This organ is highly complex and specialized and performs many crucial biochemical functions. The liver is critically involved in the removal of toxins from the body and in the manufacture of proteins including energy storage and blood clotting factors. The liver is also involved in storing minerals, vitamins and glucose in the form of glycogen, which is metabolized in large quantities to provide energy. The liver also plays a role in red blood cell metabolism and the break-down of certain metabolic byproducts in the blood stream.
[0004] Nonalcoholic steatohepatitis (NASH) is a liver disease that is frequently reported in both men and women, although it most often appears in women and is especially prevalent in the obese. Although the disease has been observed to be accompanied by several other pathological conditions, including diabetes mellitus, hyperlipidemia and hyperglycemia, the cause and progression of the disease, as well as the causal or temporal relation to these conditions, is not well understood. However, in patients suffering from NASH, certain characteristics of liver tissue and abnormalities of function are typical. Specifically, fatty deposits, tissue degeneration, inflammation, cell degeneration, cirrhosis, elevation of free fatty acids and other such abnormalities have come to be associated with nonalcoholic steatohepatitis and are frequently seen in patients suffering from NASH.
[0005] Steatohepatitis, excess fat in the liver, is a condition often observed in cases of starvation, overloading of carbohydrates, absence of energy in the form of proteins, obesity, and cortico steroid therapy. It has been hypothesized that the accumulation of fat in the liver may be the result of increased accumulation of free-fatty acids, increased manufacture of fatty acids in the liver, decreased oxidation of free fatty acids, or the synthesis or secretion of LDL cholesterol. The increased level of free fatty acids in some cases of steatohepatitis may implicate the reactivity of free fatty acids with biological membranes. NASH patients exhibit increased asparate aminotransferase and/or alanine aminotransferase activity, characteristically at least 150% of normal. To confirm the clinical diagnosis of NASH, evidence of zero to low alcohol consumption is required and confirmation of the absence of a previous infection with hepatitis B virus or hepatitis C. The specific diagnosis of nonalcoholic steatohepatitis may also depend on detailed analysis of liver biopsy specimens. The histological features identified may include macrovesicular fat, cirrhosis, inflammation of the parenchyma and the presence of Mallory hyaline bodies.
[0006] Approximately 8% of patients who undergo liver biopsies will show histological evidence of NASH. The physiological condition that most commonly accompanies NASH is obesity, with approximately 70% and above of NASH sufferers also displaying clinically diagnosed obesity. NASH is particularly prevalent in obese patients who have undergone jejunal bypass to treat the obesity. In NASH patients, the extent of obesity tends to be generally correlated with the amount of steatosis and to be unrelated to non-insulin-dependent diabetes mellitis. However, non-insulin-dependent diabetes mellitis increases the prevalence of steatohepatitis especially in patients requiring insulin. Weight loss in patients before death does not appear to alleviate the steatosis and, somewhat paradoxically, obese patients who lost weight before death may actually have a higher incidence of steatohepatitis. The disease rarely occurs in any patient under the age of 30, but is particularly prevalent in patients in their 50s and 60s.
[0007] Even in NASH patients who do not consume any alcohol at all, liver biopsy specimens tend to mimic those seen in patients suffering from alcoholic hepatitis. However, a comparison of the two conditions reveals a higher incidence of vacuolation (indicative of diabetes) and steatosis in NASH as compared to alcoholic hepatitis. Patients suffering from alcoholic hepatitis also have a higher incidence of periportal and pericellular fibrosis and proliferation of the bioduct. Overall, the symptoms and histological damage observed in alcoholic hepatitis patients are more severe than in NASH.
[0008] Many experimental studies have been conducted to better understand NASH. For example, Susumu Itoh et al. studied 16 nonalcoholic steatohepatitis patients and 22 alcoholic hepatitis patients and discovered various differences between these two similar liver diseases. Susumu Itoh et al., Comparison between Nonalcoholic Steatohepatitis and Alcoholic Hepatitis, 82 The American Journal of Gastroenterology 650 (July 1987). Other examples include Ian R. Wanless & John S. Lentz, Fatty Liver Hepatitis ( Steatohepatitis ) and Obesity: An Autopsy Study with Analysis of Risk Factors, 12 Hepatology 5:1106 (1990)(concluding that fatty acids have a role in the hepatocellular necrosis found in some obese individuals) and Bruce R. Bacon et al., Nonalcoholic Steatohepatitis: An Expanded Clinical Entity, 107 Gastroenterology 1103 (1994)(concluding that NASH should not only be considered as a disease predominantly seen in obese women with diabetes).
[0009] Choline deficiency has been known to cause fatty infiltration of the liver in animals such as rats, hamsters, pigs and dogs. Thus, a deficiency in choline may result in the inability of the liver to transport fatty acids such as triglycerides. Indeed, one recent study has shown that hepatic steatosis in many long-term total parenteral nutrition patients may be caused by a deficiency in plasma-free choline, and that such deficiency may be reversed with lecithin (phosphatidylcholine) supplementation. Alan Buchman et al., Lecithin Increases Plasma Free Choline and Decreases Hepatic Steatosis in Long - Term Total Parenteral Nutrition Patients, 102 Gastroenterology 1363 (1992).
[0010] Although nonalcoholic steatohepatitis is generally viewed as a progressive liver disease, the condition tends to be stable over at least a few years in patients exhibiting the most common clinical manifestations of the disease. A majority of patients who have undergone repeated biopsies over a multi-year period have, for the most part, revealed no significant morphological changes over this period. To date, scientists have not discovered any biochemical, clinical or histological measurements that can distinguish between patients that will suffer comparatively stable NASH with those for whom NASH is a precursor to a more serious liver ailment, and even death.
[0011] Currently, an established therapy for patients suffering from NASH does not exist. Weight loss is a common prescription, simply because obesity is frequently found in patients suffering from NASH. The effect of a reduction in weight loss on NASH cannot be determined with certainty, however, because obese patients seldom maintain significant weight reduction.
SUMMARY OF THE INVENTION
[0012] The present invention is comprised of methods and compositions for the treatment or alleviation of nonalcoholic steatohepatitis, specifically, pharmaceutical formulations and methods for their administration to a human suffering from NASH as part of a treatment regimen to alleviate, or at least manage, the disease. Preferably, the composition is comprised of a dietary lecithin, antioxidant compounds, and/or B vitamin complexes. The pharmaceutical compositions are preferably formulated for oral administration in a dosage range that results in a decrease in hepatic steatosis indicated by increased liver density. In a preferred clinical application of the invention, a well-tolerated oral dosage is taken regularly by NASH patients whose liver function and histology is monitored for response to the formulation.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention is a pharmaceutically acceptable composition, usually administered as a dietary supplement, to treat or alleviate nonalcoholic steatohepatitis, with a principal aim to reduce hepatic steatosis. In a preferred embodiment, the composition comprises of a dietary lecithin supplement and a dietary supplement containing antioxidants and a vitamin B complex. The dietary lecithin supplement is preferably prepared in powder form. The antioxidant compounds and vitamin B complex may be combined into a single dosage and are preferably prepared together in tablet form. Preferably, a dosage in the range of 15 to 50 grams of the dietary lecithin supplement and 675 to 4050 milligrams (1 to 6 tablets) of the antioxidant/vitamin B complex supplement should be administered daily. Most preferably, however, 20 grams of the dietary lecithin supplement and 1350 milligrams (2 tablets) of the antioxidant/vitamin B complex supplement should be taken twice daily.
[0014] As used herein, the term “lecithin” includes choline and choline phospholipids such as phosphatidylcholine, and naturally occurring choline containing compounds in general, including derivatives of lecithin such as phosphatidylserine. “Lecithin” is primarily comprised of choline and inositol, two compounds that are used by the body in the break-down of cholesterol and dietary fats. Once lecithin is reduced to these two components, choline is converted into acetyl choline, a compound used in neurological activity including brain and muscle function. Lecithin may also function to help the body absorb Vitamin A, Vitamin D, and Thiamin in the digestive tract. Typically, dietary lecithin supplements contain lecithin/phosphatidylcholine/choline in a ratio of 1.1:10:50 and are sometimes ingested to reduce triglycerides and serum cholesterol. Additionally, lecithin has been investigated as an agent for the treatment of a wide variety of liver ailments, ranging from alcoholism to radiation exposure to exposure to toxic chemicals.
[0015] Phosphatidylserine is a phosphylipid that is implicated in the structural integrity and chemical function of cell membranes. Phosphatidylserine may also be taken as a supplement and is indicated in patients suffering from a deficiency of methyl donors, i.e., folic acid, Vitamin B12, and essential fatty acids that reduce the capacity of the brain to synthesize this compound.
[0016] Although, as noted above, dietary lecithin has been investigated as a remedy for certain liver ailments, sources of lecithin in the diet tend to be found in high-fat, high-cholesterol foods such as meat, liver and eggs which should be avoided by the typical NASH patient who tends to be obese. Therefore, pursuant to the present invention, dietary lecithin is preferably ingested orally as a supplement. The dietary lecithin supplement is available from commercial sources or may be manufactured by techniques known in the art. In the preferred embodiment, a granulated phospholipid fraction from soya lecithin enriched with phosphatidylcholine is used. This supplement comprises of phosphatidylcholine (minimum 50%), phosphatidylethanolamine (maximum 30%), lyso-phosphatidylcholine (maximum 5%), and other phospholipids (maximum 9%).
[0017] The “vitamin B complex” of the invention is a combination of two or more of the compounds that form the group of water soluble vitamins generally recognized as B vitamins, including vitamin B-1, B-2, B-3, B-5, B-6, B-7, B-12, and folic acid. As will be readily appreciated by those in the art, the invention also includes analogues, precursors, pro-drugs and functional metabolic by-products of these compounds. In addition, these vitamins contained in natural extracts, yeast compounds, and concentrations of natural products may be administered pursuant to the invention.
[0018] Like all vitamins, B vitamins are essential to metabolism and other necessary biological functioning in higher organisms. As noted, B vitamins are water soluble and typically function as co-enzymes that interact with metabolic enzymes to complete certain, specific biochemical functions. Vitamin B-1, thiamine, functions to release energy from carbohydrates, alcohol, and fat. A biochemically active form of B-1, thiamine pyrophosphate, is a co-enzyme in certain metabolic processes including the citric acid cycle and the conversion of alanine to acetyl co-enzyme. Thiamine forms a co-enzyme following phosphorolation by ATP-dependent pyrophosphorylase. Thiamine pyrophosphate contains a substituted pyrimidine nitrogen heterocyclic ring and a thiazole nitrogen-sulfur heterocycle. The thiazole moitey provides the activity in the metabolism of pyruvate to provide a non-oxidative decarboxylation.
[0019] Vitamin B-2, riboflavin, is metabolized to form the flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) co-enzymes. Both co-enzymes have an isoalooxazine ring that accepts two electrons in enzymatic reactions. Biochemically, vitamin B-2 releases energy from protein, fats, and carbohydrates. Vitamin B-3, niacin or nicotinamide, is involved in the synthesis of pyridine nucleotides. Niacin reacts with adenosine to form nicotinamide adenine dinucleotide (NAD), which performs a critical function as an electron carrier in certain biochemical processes. Niacin is also reported to play an important role in digestive functions and in maintaining serum cholesterol levels. Biochemically, vitamin B-3 is involved in the oxidative metabolism of ingested food and appears to play a role in maintaining the circulatory system. Vitamin B-6, pyridoxine, is structurally similar to pyridine but features a hydroxymethyl group in the para position. Biochemically, the para-hydroxymethyl group is oxidized to form an aldehyde and the hydroxymethyl group in the meta position undergoes phosphorylation to yield a pyridoxal phosphate. Vitamin B-6 is metabolically involved in transaminations, decarboxylations, and chemical modifications to amino acids. Vitamin B-6 also appears to promote blood cell and hemoglobin formation and assists in carbohydrate protein and fat metabolism.
[0020] Vitamin B-12, cyanocobalamin, contains a monovilent cobalt metal centrally located in a porphyrin-like structure of tetrapyrrole rings. Biochemically, vitamin B-12 contributes a methyl group to the synthesis of certain compounds in numerous biochemical reactions, including specifically, a synthesis of choline and methionine. Vitamin B-9, folic acid, functions as a methyl donor following enzymatic reduction to tetrahydrofolate by reaction with the enzyme dihydrofolate reductase. Vitamin B-9 is reported to promote the formation of erythrocytes and to play a role in the maintenance of the neurological system.
[0021] The antioxidants of the present invention include at least one of vitamins C or E and preferably include other known antioxidants such as vitamin A and certain forms of selenium. Selenium is preferably administered in a selenium yeast composition that improves the bioavailability of the selenium. Such compositions are commercially available (Viva America Marketing, Inc., Costa Mesa, Calif.). As with the B vitamin complex, analogues, precursors, functional metabolics, concentrations of natural products and other substitutes for the isolated vitamin composition may be used. In the preferred embodiment of the invention, wherein the compositions are administered orally, the compositions may be administered in pill or liquid form. The pill form may be comprised of traditional pharmaceutically acceptable carriers and formulations such as preservatives, fillers, gums, stabilizers, and other functionally inert substances, such as sodium or calcium carbonate, calcium phosphate, lactose, and solidifying or binding agents such as gelatin, acacia, and pharmaceutically acceptable lubricants. A pharmaceutically acceptable formulation pursuant to the present invention meets the pharmaceutical industry standards for toxicity, mutagenicity, sterility, non-pyrogenicity, shelf-life stability, and overall standards of biocompatibility.
[0022] Pursuant to the present invention, antioxidants and a vitamin B complex are preferably administered together as part of a dietary supplement also containing lecithin. The contents of a suitable composition containing a combined antioxidant/vitamin B complex supplement are shown below in Table 1.
TABLE 1 Description Unit (mg) per tablet Thiamine Mononitrate (Vitamin B-1) 1.500 Riboflavin (Vitamin B-2) 1.753 Niacinamide (Vitamin B-3) 20.101 Pyridoxine HCL (Vitamin B-6) 2.062 Cyanocobalamin (Vitamin B-12) 0.600 D-Calcium Pantothenate 10.870 Folic Acid (Vitamin B-9) 0.408 D-Biotin (Vitamin H) 30.000 Barley Juice Powder 215.154 Wheat Spout Powder 100.000 Beta Carotene 5.000 Ascorbic Acid 50.000 Vitamin E Acetate 71.429 Selenium Yeast 1,600 MCG/GM 15.625 Stearic Acid Powder 3.250 Sylox (Silicon dioxide) 9.750 Magnesium Stearate 6.500 MCC (Methyl crystalline cellulose) 131.202 Total 675.200
[0023] All of the other components of the antioxidant/vitamin B complex compositions are available from commercial sources.
[0024] Having generally described the present invention, a further understanding may be acquired by reference to the following Example, an experimental study conducted to investigate the effects of dietary supplementation with lecithin, antioxidants and a vitamin B complex in NASH patients.
EXAMPLE I
[0025] Four patients, one male and three female, were recruited who had increased aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT), at least one and a half times the upper limits of normal, and a liver biopsy which demonstrated NASH within three months prior to entering the study. These patients did not have other chronic liver disease, and were not on total parenteral nutrition or lipid lowering agents. Each patient was given 20 grams of dietary lecithin supplement with antioxidants (vitamins A, C, and E and selenium) and vitamin B complex 300 percent of the RDA daily level twice a day for a total of 12 weeks.
[0026] Serum levels of AST, ALT, GGT (gamma-glutamyltranspeptidase), alkaline phospatase, total bilirubin, lipid profile, free choline and phospholipid bound choline of plasma and red blood cell were measured at entry, week 4, week 8, and week 12. A computed tomography (CT) scan of liver was obtained at entry and week 12. Another liver biopsy was performed after the treatment to confirm the change of fatty infiltration measured by the CT scan. Portal inflammation, lobular activity, steatosis, and fibrosis were graded from 0 to 4. The Average CT tissue density in Hounsfield Units (HU) for liver and spleen was generated from multiple representative sections. Liver density was determined by the liver-spleen differential, with 0 to 8 HU representing borderline fatty changes and negative HU values corresponding to marked fatty infiltration.
[0027] The study was completed by all four patients without adverse drug reaction. Furthermore, all four patients showed a statistically significant decrease in hepatic steatosis indicated by increased liver density as measured by CT scans (4.97±4.65 HU before treatment vs. −5.21±8.07 HU after treatment; p<0.05). On histology, two out of four patients had a reduction in steatosis. No change in portal inflammation was observed, however, two out of four patients had mildly increased lobular activity. Although a small increase in fibrosis was observed, it cannot be concluded whether this is a positive or negative effect. Increased fibrosis may result from focal sampling bias, moreover, fibrosis has been observed to correlate with a degree of obesity and the existence or development of fibrosis is not known to be directly correlated with the development or progression of NASH. Detailed biopsy results are shown below in TABLE 2.
TABLE 2 Patent Portal Lobular Glycogenated Number Inflammation Activity Steatosis Fibrosis Iron Nuclei #1 Pre- 1 0 2 2 1 1 treatment Post- 1 1 1 3 1 1 treatment #2 Pre- 2 1 2 2 0 0 treatment Post- 2 2 1 2 0 0 treatment #3 Pre- 0 2 3 0 0 0 treatment Post- 0 2 3 2 0 0 treatment #4 Pre- 0 1 1 0 0 1 treatment Post- 0 1 1 1 0 0 treatment
[0028] There will be various modifications, improvements, and applications of the disclosed invention that will be apparent to those of skill in the art, and the present application encompasses such embodiments to the extent allowed by law. Although the present invention has been described in the context of certain preferred embodiments, the full scope of the invention is not so limited, but is in accord with the scope of the following claims.
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Nonalcoholic steatohepatitis (NASH) is a disease of the liver characterized by inflammation and damage to the liver cells. Typically, steatohepatitis involves inflammation of the liver related to fat accumulation, and mimics alcoholic hepatitis but is observed in patients who seldom or never consume alcohol. Nonalcoholic steatohepatitis can lead to serious liver damage, and ultimately cirrhosis. The present invention provides methods and compositions useful for the treatment or alleviation of nonalcoholic steatohepatitis and the pharmaceutical formulations for their administration to a human. Specifically, compositions comprised of lecithin, antioxidants and vitamin B complex are administered parenterally, most preferably by oral administration. Specific therapeutic formulations include admixtures of these compounds and specific dosage formulations include daily oral administrations of these compounds in tablet or powder forms.
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FIELD OF THE INVENTION
[0001] The invention relates generally to pipe handling systems and in particular to an apparatus for providing drill pipe to, and receiving drill pipe from, the work floor of a derrick or rig.
BACKGROUND OF THE INVENTION
[0002] Drill strings of pipe for oil and gas wells are assembled or disassembled vertically on a derrick one joint at a time, and are stored horizontally on pipe racks situated on the ground adjacent the rig. The work floor of the rig is typically elevated substantially above the pipe rack such that transferring sections of pipe to and from the work floor and the racks is necessary and requires careful handling of the heavy pipe to protect the workers and the pipe.
[0003] Conventional systems based on a boom having a pipe receiving trough in which pipe may be placed typically also include some way to eject sections of pipe out of such trough.
[0004] A variety of ejection mechanisms are known for removing pipe from a trough. For example U.S. Pat. No. 4,371,302 to Frias et al (‘302’) teaches a means for tilting an entire trough in a boom assembly that does not itself rise to the derrick work floor but merely feeds a second boom one end of which is pivotally coupled to the work floor. Disadvantageously, tilting an entire trough or boom requires significantly more power and compromises the potential rigidity of the boom more than is necessary when a short kicker member or section of trough is tilted to the same effect.
[0005] U.S. Pat. No. 3,143,221 to Blackmon (‘221’) teaches a pipe car pulled and released by a cable and having 2 sets of side-mounted wheels each set having a common axle and running in a channel in a fixed track, with a v-shaped carriage member that tilts to either side of the pipe car in a manner similar to the tilting car of US 24,907 to Maydew (‘907’). Disadvantageously all known car designs run in a stationary track and require separate power and trigger assemblies.
[0006] U.S. Pat. No. 4,235,566 to Beeman (‘566’) teaches a dump arm pivotally connected to a boom and fastened to an hydraulic ram that is connected to the boom, such configuration disadvantageously adds weight and complexity to the boom.
[0007] Applicant's Canadian application CA 2224638 teaches a number of embodiments of a kicker together with a kicker rod. However, such design necessarily uses power and trigger assemblies that are separate from the boom.
[0008] The prior art in the oil-field service industry has concentrated on teaching variations on power driven tilting troughs and hydraulically powered kickers mounted on the boom or on the base and relying on a separate source of the power needed to cause ejection. None of the prior art, however, teaches an ejector that uses passive actuator members and is operable without a separate trigger and source of power to cause the ejecting motion.
SUMMARY OF THE INVENTION
[0009] The apparatus of the present invention provides passive means for ejecting pipe from the trough of a boom by using the weight of the boom itself as the source of ejection force. This efficient implementation of an integrated “kicker” ejection apparatus may be combined with conventional hydraulic or pneumatic technologies for increased flexibility of operation.
[0010] Accordingly, in a broad aspect of the present invention there is provided a pipe handling apparatus capable of laterally ejecting pipe, the apparatus having a base, the base having a longitudinally extending cavity therein, the apparatus further having longitudinally extending boom having a distal end and a proximal end, a first side and a second opposing side, and a longitudinally extending trough for receiving at least one section of pipe, further comprising: a first ejector pivotally coupled to the first side of the boom; a second ejector, longitudinally separated along the boom from the first ejector and pivotally coupled to the first side of the boom; an actuator shaft assembly situate below and substantially parallel to the boom movably coupled to the base, the actuator shaft assembly has an actuated position and means for moving the actuator shaft assembly to its actuated position in order to enable substantially simultaneous activation of the first and second ejectors so as to cause the pipe to be ejected from the first side of the boom.
[0011] In a refinement of the present invention there is further provided: a third ejector, situate proximate the first ejector, pivotally coupled to the second opposing side of the boom, the first and second ejectors forming a first ejector pair; and a fourth ejector, situate proximate the second ejector, pivotally coupled to the second side of the boom, the third and fourth ejectors forming a second ejector pair; the actuator shaft assembly having a first actuated position and a second actuated position, together with means for moving the actuator shaft assembly between the first and second actuated positions; wherein the actuator shaft assembly may be moved to the first actuated position to activate the first ejector pair so as to eject pipe from the first side of the boom and may be moved to the second actuated position to activate the second ejector pair so as to eject pipe from the second side of the boom.
[0012] The invention comprises a number of configurations for the actuator shaft assembly.
[0013] In a first embodiment, the actuator shaft assembly comprises: an elongate shaft member; a first actuator member extending radially from the shaft member and the first actuator member is substantially in longitudinal alignment with the first ejector; and a second actuator member extending radially from the shaft member and the second actuator member is substantially in longitudinal alignment with the second ejector; whereby, when the actuator shaft assembly is operated to the actuated position the first actuator member can engage the first ejector and substantially simultaneously the second actuator member can engage the second ejector.
[0014] According to an alternate implementation, the actuator shaft assembly comprises: an elongate shaft member; a pair of first actuator members extending radially from the shaft member and substantially in alignment respectively with the first and second ejectors of the first ejector pair; and a pair of second actuator members extending radially from the shaft member and substantially in alignment respectively with the first and second ejectors of the second ejector pair; wherein the elongate shaft member may be moved to a position whereby the pair of first actuator members engage respectively the first and second ejectors of the first ejector pair so as to eject pipe from the first side of the boom, and the elongate shaft member may be moved to a position whereby the pair of second actuator members engage respectively the first and second ejectors of the second ejector pair so as to eject the pipe from the second side of the boom.
[0015] According to an alternate implementation, the actuator shaft assembly comprises: an elongate shaft member; a pair of first actuator members extending radially from the shaft member and substantially in alignment respectively with the first and second ejectors of the first ejector pair; and a pair of second actuator members extending radially from the shaft member and substantially in alignment respectively with the first and second ejectors of the second ejector pair; wherein the elongate shaft member may be moved to a position whereby the pair of first actuator members engages respectively the first and second ejectors of the first ejector pair so as to, when the boom is lowered into the cavity, eject pipe from the first side of the boom, and the elongate shaft member may be moved to a position whereby the pair of second actuator members engages respectively the first and second ejectors of the second ejector pair so as to, when the boom is lowered into the cavity, eject the pipe from the second side of the boom.
[0016] In yet a further, alternate embodiment, the actuator shaft assembly comprises: a first elongate shaft member having a first actuator member extending radially therefrom and substantially in longitudinal alignment with the first ejector; a second actuator member extending radially from the first elongate shaft member and substantially in longitudinal alignment with the second ejector; a second elongate shaft member having a third actuator member extending radially therefrom and substantially in longitudinal alignment with the third ejector; and a fourth actuator member extending radially from the second elongate shaft member and substantially in longitudinal alignment with the fourth ejector; wherein the first elongate shaft member may be moved to a position whereby the first actuator member engages the first ejector and substantially simultaneously the second actuator member engages the second ejector, so as to eject pipe from the first side of the boom, and alternatively the second elongate shaft member may be moved to a position whereby the third actuator member engages the third ejector and substantially simultaneously the fourth actuator member engages the fourth ejector, so as to eject pipe from the second side of the boom.
[0017] According to yet a further alternate implementation, the actuator shaft assembly comprises: a first elongate shaft member having a first actuator member extending radially therefrom and substantially in longitudinal alignment with the first ejector; a second actuator member extending radially from the first elongate shaft member and substantially in longitudinal alignment with the second ejector; a second elongate shaft member having a third actuator member extending radially therefrom and substantially in longitudinal alignment with the third ejector; and a fourth actuator member extending radially from the second elongate shaft member and substantially in longitudinal alignment with the fourth ejector; wherein the first elongate shaft member may be moved to a position whereby the first actuator member engages the first ejector and substantially simultaneously the second actuator member engages the second ejector, so as to, when the boom is lowered into the cavity, eject pipe from the first side of the boom, and alternatively the second elongate shaft member may be moved to a position whereby the third actuator member engages the third ejector and substantially simultaneously the fourth actuator member engages the fourth ejector, so as to, when the boom is lowered into the cavity, eject pipe from the second side of the boom.
[0018] In a further refinement of the apparatus as a whole having a first ejector pair, the first and second ejector of the first ejector pair comprises: pivot means for pivotally coupling the first ejector pair to the first side of the boom; and a receiver assembly coupled to the cradle for engaging one actuator member of the pair of first actuator members; wherein each receiver assembly of the first ejector pair is positioned, shaped, and sized so as to enable the pair of first actuator members to substantially simultaneously activate the first and second ejectors of the first ejector pair.
[0019] In an alternate embodiment of the apparatus having a first and second ejector pair, each of the first and second ejector of the second ejector pair comprises: pivot means for pivotally coupling the ejector to the second side of the boom; and a receiver assembly coupled to the cradle for engaging one actuator member of the pair of second actuator members; wherein each receiver assembly of the second ejector pair is positioned, shaped, and sized so as to enable the pair of second actuator members to substantially simultaneously activate the first and second ejectors of the second ejector pair.
[0020] In a further aspect of the present invention, a cradle member is provided, each cradle member having a generally v-shaped cross-section further having a cradle surface situated co-planar with and conforming to the trough, the cradle member laterally extending across an opening in the trough between first and second sides thereof, the cradle member having a first edge and a second edge respectively substantially coincident with the first and second sides of the boom, the cradle member pivotally coupled, by the pivot fastened on one of the first or second edges of the cradle member, to one side of the boom for permitting the ejector to pivot about one side of the boom so as to allow pipe contacting the cradle surface to exit the trough when the ejector pair is activated.
[0021] In a further refinement, each pivot for pivotally coupling an ejector to the boom comprises: a pivot tube connected to one of the first or second edges of the cradle member; at least one fixed tube fastened to one side of the boom situate proximate to and axially aligned with but longitudinally displaced from the pivot tube, and a pivot pin positioned on a common axis so as to releasably couple the pivot tube to the at least one fixed tube, about which pin the attached ejector can pivot transversely relative to the boom.
[0022] Each receiver assembly, in a preferred embodiment, comprises a rigid surface against which a respective actuator member may be engaged so as to permit the application of force to the rigid surface in order to cause the first and second ejector to respectively pivot transversely relative to the boom, each rigid surface being situated, oriented, shaped, and sized so as to enable the pair of first actuator members to substantially simultaneously pivot the first and second ejectors of the first ejector pair.
[0023] In a preferred embodiment of the invention, the actuator member comprises an elongate cam relatively situated, oriented, shaped, and sized so as to transmit force against a receiver assembly for the purpose of substantially simultaneously activating a pair of ejectors. Each elongate cam comprises a coupling end and an opposing striking end having there between a retractably telescoping member for moving the striking end radially towards and away from the actuator shaft member, for the purpose of enabling the activation of ejectors while the boom is nested in the cavity.
[0024] According to different implementations of the apparatus of the present invention the movement of an actuator shaft member may be rotational or longitudinally slidably. Further, the means to assist the movement of an actuator shaft member include but are not limited to any suitable manual crank or power (e.g. electric, hydraulic, pneumatic) driven ram or gearing assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention, in order to be easily understood and practised, is set out in the following non-limiting examples shown in the accompanying drawings, in which:
[0026] [0026]FIG. 1 is a side view of a mobile version of the apparatus of the present invention;
[0027] [0027]FIG. 2 is a top view of select elements of the apparatus shown in FIG. 1;
[0028] [0028]FIG. 3 is an enlarged view of an ejector of the apparatus of the present invention;
[0029] [0029]FIG. 4 is a perspective view of one embodiment of an actuator shaft and actuator members of the ejection apparatus of the present invention;
[0030] [0030]FIG. 5 is an isometric view of one embodiment of a distal ejector of the present invention;
[0031] [0031]FIG. 6 is an isometric view of one embodiment of a proximal ejector of the present invention;
[0032] [0032]FIG. 7 is a perspective view of one embodiment of a receiver assembly of an ejector of the present invention;
[0033] [0033]FIG. 8 is a perspective view of one embodiment of an actuator member element;
[0034] [0034]FIG. 9 is a side view of one embodiment of a distal arm assembly of the apparatus of the present invention; and
[0035] [0035]FIG. 10 is a close-up side view of one embodiment an assembly of interdigitating slots and rods of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] Reference is to be had to FIGS. 1-10 in which identical reference numbers identify similar components.
[0037] Referring to FIG. 1 there is illustrated one embodiment of a pipe handling system, denoted generally as 100 shown having base 110 mounted on undercarriage assembly 105 stabilized by legs 112 when in operation. Boom 120 is shown with proximal end 121 in a raised position moving toward a derrick work floor (not shown) with distal end 122 gliding along cavity 115 guided by track means (not shown), as actuating means 130 raises boom 120 out of cavity 115 . Trough 140 , having pipe 148 therein, extends longitudinally along boom 120 and may be formed therein or fastened thereon, but in either case trough 140 is adapted for having ejectors 160 , 165 , 170 , and 175 mounted therein, as well as for receiving carriage assembly 150 adapted to be driven bi-directionally between the distal end 122 and the proximal end 121 of boom 120 . As shown, carriage assembly 150 carries the distal end of pipe 148 . The proximal end 121 of boom 120 is raised by any suitable actuating means 130 , one embodiment of which comprises pivoting arm 131 and suitable linkage 132 actuated by hydraulic ram 133 , for the purpose of receiving pipe 148 into trough 140 from the rig floor for further handling, typically returning same to the racks. To return from the rig floor to ground, pipe 148 is lowered into receiving area 215 (see FIG. 2) of carriage assembly 150 (while positioned at proximal end 121 of boom 120 at the level of the rig floor) until pipe 148 comes to rest against pipe engaging member 220 on carriage assembly 150 . Actuating means 130 then lowers boom 120 with pipe 148 therein, such that in its fully lowered or “laid down” position boom 120 nests inside cavity 115 in base 110 . Depending upon the position of actuator shaft 310 (see FIG. 3), as boom 120 nests in cavity 115 ejectors 160 and 165 can engage actuator members 350 and 355 respectively or ejectors 170 and 175 can engage actuator members 370 and 375 (see FIG. 4) respectively. Although base 110 is shown in a mobile embodiment having any suitable undercarriage assembly 105 , a person of skill in the art would understand that base 110 may also be of the stationary variety.
[0038] It is further contemplated that the distal end 122 of boom 120 may be also raised to the level of work floor 16 by any suitable actuating means similar to actuating means 130 (one embodiment of which comprises pivoting arm 131 and suitable linkage 132 actuated by hydraulic ram 133 ) for the purpose of better leveling trough 140 during either a pickup or lay down sequence. For example, according to the embodiment of the present invention illustrated in FIG. 9 pivoting leg assembly 10 comprises a leg member 104 having one end adapted for releasable coupled engagement with distal end 122 of boom 120 , and an opposing end pivotally connected to stationary base 12 at any suitable location by any suitable connection means 103 . Releasable coupled engagement between leg member 104 and the distal end 122 of boom 120 is achieved in a preferred embodiment by complementary engaging means 102 a and 102 b (seen in a sequence of close-up side views in FIG. 10) that each comprise an assembly of interdigitating slots and rods, but numerous other configurations permitting releasable coupleable engagement, whereby the end of the leg member 104 is releasably coupled to distal end 122 of boom 120 , will be readily apparent to those skilled in the art. Engaging means 102 a is situate on one end of leg member 104 an opposing end thereof pivotally connected by connection means 103 to stationary base 12 . Complementary engaging means 102 b is situate on the distal end 122 of boom 120 in longitudinal axial alignment with engaging means 102 a for the purpose of permitting engaging means 102 a to releasably engage engaging means 102 b as boom 120 moves proximally towards leg member 104 , such that as boom 120 moves longitudinally in response to operation of lift means 106 , leg member 104 either engages or disengages (depending upon direction) the distal end 122 of boom 120 in releasable coupled engagement.
[0039] Referring to FIG. 10, once releasable coupled engagement occurs between engaging means 102 a and 102 b (ref. FIG. 9), according to a preferred embodiment they further lockingly engage as their mating assemblies of interdigitating slots and rods rotate relative to one another, which rotation occurs upon the pivoting motion of leg member 104 about connection 103 , thereby causing engaging means 102 a in association with leg member 104 to lockingly engage engaging means 102 b in association with the distal end 122 of boom 120 . The pivoting motion of leg member 104 about connection 103 results because leg member 104 is responsive to operation of lift means 106 , having the further advantage that no independent vertical assist means is necessary to lift distal end 122 , which results from the longitudinal and vertical movement of boom 120 causing pivoting motion of leg member 104 so as to raise the distal end 122 of boom 120 .
[0040] A person of skill in the art of machine design would understand that stationary base 12 may be replaced by base 110 to implement a mobile version of system 10 .
[0041] Referring to FIG. 2 there is illustrated a top view of boom 120 including first ejector pair 160 and 165 each adapted to pivot about a pivot 180 relative to one side of boom 120 . Further included is the second ejector pair 170 and 175 each ejector adapted to pivot about a pivot 180 relative to an opposing side of boom 120 . As at ejector 160 , each pivot 180 may comprise any suitable assembly, however according to one embodiment a thick-walled tube is attached to or formed in cradle member 161 (see FIG. 3) permitting the use of any suitable pin to hingedly attach ejector 160 to a side of boom 120 . As carriage assembly 150 moves distally from proximal end 121 having pipe 148 (not shown) carried in receiving area 215 , once carriage assembly 150 nears distal end 122 of boom 120 substantially all of pipe 148 will lay in trough 140 across both ejector pair 160 and 165 and ejector pair 170 and 175 , whereupon if ejector pair 160 and 165 activates, then pipe 148 will be ejected from trough 140 to one side of boom 120 and if instead ejector pair 170 and 175 activates, then pipe 148 will be ejected from trough 140 to an opposing side of boom 120 . All pivots 180 are adapted to permit carriage assembly 150 to pass thereover without interfering with the motion of carriage assembly 150 . A person of skill in the art of machine assembly would understand that according to a preferred embodiment of system 100 cradle member 161 (see FIG. 3) of ejector 160 may be cut from trough 140 after trough 140 has been formed and fastened to boom 120 , thereby ensuring that the cross-sections of cradle member 161 and trough 140 substantially conform to one another in order to reduce the risk of interference (at the joints there between) with the passage of carriage assembly 150 over ejector 160 enroute to either proximal end 121 or distal end 122 .
[0042] Referring to FIG. 3 there is illustrated a cut-away end-view of ejector 160 partially activated by actuation means 300 wherein actuator shaft 310 has been moved to an activated position such that actuator member 350 and striker 351 thereon can contact receiver assembly 162 (fastened to the underside of cradle member 161 ) as boom 120 lowers into cavity 115 (not shown) the interference of actuator member 350 and striker 351 with receiver assembly 162 forces cradle member 161 to pivot about pivot 180 ejecting pipe 148 from trough 140 . A person of skill in the art of machine design would understand that the size, shape and position of each of receiver assembly 162 and actuator member 350 with striker 351 are relative to one another as well as to the distance between first ejector 160 and second ejector 165 . There are many sizes, shapes, and relative positionings of ejectors and actuators that will work on the principle of a passive actuator member interfering with a suitably positioned, pivotally connected ejector so as to cause such ejector to pivot about such connection. Optional striker 352 limits the radial motion of actuator member 350 and reduces wear against base 120 .
[0043] According to one embodiment of actuation means 300 , actuator shaft 310 is rotated into its activated position prior to ejector 160 being lowered into the zone in which ejector 160 can be interfered with by actuator member 350 . According to an alternate embodiment of actuation means 300 , actuator shaft 310 may slide longitudinally into position prior to ejector 160 being lowered into the zone in which it can be interfered with by actuator member 350 . According to a further alternate embodiment of actuation means 300 , actuator shaft 310 may rotate laterally into position after ejector 160 has been lowered into the zone in which it can be interfered with by actuator member 350 . According to a further alternate embodiment of actuation means 300 , actuator shaft 310 may slide longitudinally into position after ejector 160 has been lowered into the zone in which it can be interfered with by actuator member 350 . According to a further alternate embodiment of actuation means 300 , actuator shaft 310 may be moved either slidingly or rotatingly causing actuator member 350 to be positioned either prior or after ejector 160 has been lowered into a zone in which it is both laterally and longitudinally aligned with actuator member 350 , and actuator member 350 comprises a telescoping member such that striker 351 is moved, toward receiver assembly 162 on ejector 160 , when actuator member 350 extends by any suitable (e.g. hydraulic ram, electrically driven worm gear) telescoping action a distance that permits ejector 160 to activate substantially simultaneously with ejector 165 in order that ejector pair 160 and 165 eject pipe 148 from trough 140 in a manner that allows pipe 148 to roll safely onto base 110 or to any suitable integrated dumping assembly included therein.
[0044] Advantageously, trough 140 has a substantially v-shaped cross-section that tolerates a “pitch and roll” of approximately 30 degrees at the same time as facilitating pipe 148 “finding center” and resting stably in trough 140 rather than rocking back and forth (before coming to rest) as it would tend to do in a conventional trough having a substantially circular cross-section.
[0045] Referring to FIG. 4 there is illustrated a perspective view of one bidirectional embodiment of actuation means 300 comprising a single actuator shaft 310 to which actuator members 350 and 355 are fastened for the purpose of interfering with ejectors 160 and 165 respectively for ejecting pipe 148 from trough 140 to one side of boom 120 . Further comprising actuator members 370 and 375 fastened to actuator shaft 310 for the purpose of interfering with ejectors 170 and 175 respectively, for ejecting pipe 148 to an opposing side of boom 120 . A person of skill in the art would understand that actuator members 350 , 355 , 370 and 375 may be reoriented and/or reshaped to operate with their respective ejectors adapted to activation resulting from either the rotational or longitudinal sliding movement of actuator shaft 310 .
[0046] Referring to FIG. 5 there is illustrated an embodiment of ejector 165 being the ejector paired with and situate distally of and longitudinally isolated from ejector 160 shown in FIG. 6. As shown, ejectors 160 and 165 each have pivots 180 for any suitable pin coupling to boom 120 at their respective locations. Ejectors 160 and 165 further have respectively cradle members 161 and 166 that according to a preferred embodiment are the same size and shape. However a person of skill in the art of machine design would understand that receiver assembly 162 although directly related to receiver assembly 167 will differ therefrom in a manner and to an extent that depends upon the relative positions of ejectors 160 and 165 as well as the absolute size of one or the other of the operationally matched ejector pair, since although ejectors 160 and 165 must be longitudinally isolated from one another, their activation is synchronized in order to ensure the safe ejection of pipe 148 from trough 140 .
[0047] Referring to FIG. 7 there is illustrated a perspective view of the underside of ejector 160 showing one embodiment of receiver assembly 162 fastened typically by welding to the underside of cradle member 161 , that conforms to trough 140 , further having one embodiment of pivot 180 shown as a thick-walled tube through which a pivot pin (not shown) may be inserted for the purpose of coupling ejector 160 to boom 120 . A person of skill in the art of machine design would understand that receiver assembly 162 may comprise a flat plate 163 , across which striker 351 rolls as actuator member 350 engages ejector 160 , or it may comprise a pocket (not shown) formed by receiver sides 164 into which a portion of actuator member 350 is inserted—in either case to cause ejector 160 to activate. Although as shown receiver assembly 162 is configured for longitudinal alignment with and lateral engagement by actuator member 350 , it is contemplated that by repositioning and reshaping plate 163 , across the bottoms of sides 164 , to permit engagement of actuator member 350 with receiver assembly 162 in order to cause the activation of ejector 160 by either rotating or sliding actuator shaft 310 . A person of skill in the art would further understand the need to suitably reinforce pivot 180 and to orient plate 163 such that ejector 160 can pivot nearly perpendicular to the activating motion.
[0048] Referring to FIG. 8 there is illustrated a perspective view of one embodiment of actuator member 350 fastened at its base 311 to actuator shaft 310 . According to one embodiment actuator member 350 comprises a rigid elongate member of any suitable dimension and material. Strikers 351 and 352 may each be of either the fixed or rolling variety and sized according to the ejector and base that they are respectively designed to engage. A person of skill in the art would understand that all actuator members may be of the same specifications while all ejectors have specifications that are unique to their locations, or vice versa, all ejectors may be of substantially the same specifications while each actuator member is customized to its particular location and relative to the location of its mate. According to an alternate embodiment actuator member 350 may comprise an hydraulic ram permitting striker 351 to telescopically extend radially away from actuator shaft 310 for the purpose of permitting ejector 160 to be activated in the laid down position even if boom 120 has not been raised to permit the movement of actuator shaft 310 to an activated position.
[0049] The terms and expressions employed in this specification are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions to exclude any equivalents of the features shown and described or portions thereof, and it is recognized that various modifications are possible within the scope of the invention claimed. Although the disclosure describes and illustrates various embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications will now occur to those skilled in the art of machine design and drill pipe handling. For full definition of the scope of the invention, reference is to be made to the appended claims.
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A pipe handling apparatus for raising and lowering pipe to and from a raised derrick work floor. The apparatus comprises a longitudinally-extending base, with a longitudinally-extending cavity therein. An elongate, longitudinally-extending boom member is provided, which is adapted for raising out of and nestable positioning in such cavity. The boom member has a longitudinally-extending trough therein on an upperside surface thereof, adapted to receive at least one section of pipe. At least one arm member is coupled to the boom member for raising a proximal end of such boom member. A pipe ejection assembly, integrated into said boom, is operable as the boom lowers into the cavity for the purpose of laterally ejecting pipe from the trough. The ejection assembly is adaptable for unidirectional or bidirectional ejection. Motive means are provided to permit powered movement of the ejector members when the boom is nested.
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TECHNICAL FIELD
This invention refers to a process and a device for applying fluids, especially particle material, on an area to be coated in accordance with the preamble of claims 1 and 6 . Furthermore the invention also concerns the application of a device and a process like this.
BACKGROUND OF THE INVENTION
The PCT publication script WO 35/18715 states to use a coater for the particle material, designed in form of a downward opening funnel, in a process for manufacturing three-dimensional objects out of particle material, such as a rapid prototyping process. This funnel vibrates during the coating process at right angles to the coater's direction of movement and parallel to the coating level. With a coater, as described in this document, an unimpeded emission of the particle material during coating can be guaranteed and densification can be achieved.
But this type of coating has a disadvantage. The particle emission cannot be switched, which means that when the vibration mechanism is deactivated, powder escapes the coater, unless this is closed from below.
It is also known from DE 102 16 013 A1 that in the case of a process to manufacture three-dimensional objects from particle material for the application of particle material, one container opened from the base, connected with a vibrating leveling element is used.
SUMMARY OF THE INVENTION
A significant advantage of this device is that the powder emission is controlled. The width of the gap is set so that when the coater is inactive, the powder is prevented from emission due to the particle bridges formed over the gap and the particle material only leaves the gap when the coater oscillates.
For very fine or/and very free flowing (fluid) powder materials, for example fluids with a particle size <150 μm or powder, which mostly consists of round particles, this coating proves itself to be very complex because the gap has to be chosen very fine in order to achieve a spread of the particle material when the coater is inactive, because such materials are less likely to form particle bridges.
This requires an accurate alignment of the gap width to achieve the effect of the named invention. Moreover a constant gap width is necessary over the entire width of a coater. This requires a very precise alignment. For production reasons this is either barely possible or very costly.
This invention is challenged with providing a process, a device as well as a use of the device with which a controlled metering and application of any and therefore also fine and/or free flowing powder is possible.
According to the invention this challenge is solved with a process to apply fluids, especially particle material, on an area to be coated, this being viewed in a forward moving direction of the coater, that fluid is applied on the area to be coated and then a leveling element is run over the applied fluid, whereby the fluid is led from a metering system provided with an opening, which at least performs an oscillation during application of the fluid. The opening is closed when the metering system is at a standstill by the fluid forming an angle of repose in the opening.
The metering system features an oscillating container provided with an opening, in which the opening is designed in such a way that no material flows out when the metering system is inactive as an angle of repose is formed in the opening and when the vibration mechanism is activated the angle of repose breaks downs and the particle material is emitted.
The leveling element can be designed as a blade, which is either run only fixed over the fluid or also oscillates, if necessary, with the metering system.
Under the forward motion of the blade the direction of the coater shall be recognized in the coating stage. If coating is possible in two or more directions of the coater, the forward motion can also be possible in several directions.
As a leveling element a roller with an axle parallel to the surface area to be coated and vertical to the coating direction is also suited. The roller can be fixed, or rotate around its own axle. The direction of rotation is set in the opposite direction to the forward motion direction of the coater, in order to emit the fluid from the gap between roller and powder bed surface.
The fluid is coated according to this invention from a metering system provided with an opening, whereby the opening, described in the illustration, is designed in a vertical direction to the area to be coated seen with an angle α. In colloquial speech it is a type of “side” opening. No vertical application is made on the area to be coated.
The opening is blocked from particle material when the container is inactive due to the formation of an angle of repose in the opening. It no longer flows uncontrolled, as in processes of prior art, when the coater is at a standstill. Instead it is retained by the design of the opening according to the invention when the coater is at a standstill.
The opening can have any width adapted to the process. If a component essentially spans across the entire width of the area to be coated, the coater and the opening also span over their entire width favorably. One and/or several smaller openings would also be possible.
The oscillation of the metering system can be horizontal or/and vertical according to this invention. Especially good results could be achieved if the oscillation contains vertical as well as horizontal components. In particular an oscillation proved itself to be beneficial according to the type of rotation.
Especially good coating results could be achieved with a process in line with the invention, if the leveling element also oscillates when the applied fluid runs over. In the case of an especially preferred the embodiment of this invention the leveling element resonates with the metering system.
In such an embodiment of this invention the densification of the fluid can be achieved by two effects.
By means of the oscillation or vibrations of the container and the fluid, the particles of the material to be coated are graded to a higher packing density. In addition if the leveling element oscillates horizontally and/or vertically, a densification of the fluid under the leveling element is also achieved through movement.
However, it must be observed that too strong a densification of the particle material achieved this way can lead to movement in the powder bed over the actual layer and thus lead to a deterioration of the structure printed.
According to this invention, the particle material is compacted by the oscillation prior to coating in the metering system, so before laying the coat, the densification can be carried out gently by the leveling element. Damage to the area to be coated is therefore avoided.
The densification of the powder bed is essentially homogenous over the area to be coated and not dependent on the direction of the coater, as this Is the case In the process of the prior art. It is possible therefore to achieve an adequately good coating result in one coat. This leads to a time saving compared to the process of prior art, with which an adequately homogenous coating result only can be achieved typically after a second coat.
If it requires further definition of the rapid prototyping equipment, the coater and as the case may be, the metering system can be led back over the powder bed into the starting position after running over the area to be coated once, at increased speed and without oscillation and therefore without particle emission. The coating result achieved previously is thus not affected.
According to a favored embodiment of this patent a metering quantity of fluid required for the coating should always be smaller than residual volume of the fluid present in the container.
By means of oscillation of the metering system, and the container if the case may be, the fluid can be metered on the area to be coated. When activating the oscillation mechanism of the container the fluid, and if the case may be the particle material, is fluidized in the container and flows out of the opening of the metering system in front of the leveling element. If the oscillation mechanism stops, when an angle or repose is formed in the opening the particle material remains in the container.
The rotary motion of the coater's oscillation, the metering system and/or the leveling element is preferably achieved over the eccentric for the process in line with the invention, which are attached torque proof to the drive motor shaft.
The transmission of power from the eccentric to the coater, the metering system or/and the leveling element can be for example, form-fit, therefore illustrated by directly applying a ball bearing on the eccentric.
This process in line with the invention can be carried out preferably with a device to apply fluids on an area to be coated, whereby a leveling element and a metering device viewed in forward direction of the leveling element is provided, via the fluid to be applied on the area to be coated. The blade can be run over the fluid applied, whereby the metering device is provided with an opening and an oscillation can be performed. The opening is designed in line with this device, in such a way that when the metering system is at a standstill it is closed by means of the fluid forming an angle of repose.
In accordance with the preferred embodiment the device is designed in such a way that the metering system, and the container respectively is connected to the leveling element.
With such a preferred embodiment of the invention it is possible to place the emission of particle material as close as possible on the leveling element. Furthermore it is also possible that the oscillation mechanism as well as the metering system also drives the leveling element.
In line with an especially preferred embodiment the container of the metering system is essentially designed as a funnel.
In activating the oscillation mechanism of the container, so the funnel here, the particle material fluidizes in the funnel and flows out of the side opening, which can be designed as a gap, in front of the leveling element.
In another case the particle material stays in the container, if the gap (length and height) is set accordingly, so that due to the formation of an angle of repose in the opening other material is prevented from emission. The funnel can therefore convey a significantly larger quantity of material than is necessary for the actual coat.
On the one hand the result is a significantly lower quantity of waste material. On the other hand the requirements of the feed system, which meters the particle material Into the funnel, are reduced. An equal distribution of quantity in the container over the coater width or the width of the opening has to be ensured.
A possible over-filling or if the supply is lowered too heavily into the funnel could be monitored preferably with a fill level sensor and if necessary, it would be possible to top up the funnel from the feed system. This is possible after one coat.
The coating unit shall be designed as rigid as possible In order to be able to transfer the oscillations exactly.
The container opening, preferably a gap, shall be dimensioned in height and length so that when the coater is inactive no particle material flows out of the container or funnel and when the vibration mechanism is activated just as much material is emitted as is necessary for coating. The emission quantity is preferably regulated via the gap height and oscillation amplitude of the metering system.
It has thus emerged that a longer gap has to be chosen higher, in order to achieve the same material emission as a shorter gap. In order to achieve an equal emission over the entire coating width, it is useful to choose a long and high gap. In this way the metering system is easier to set, more tolerant compared to variations in the gap dimension and more unsusceptible to blockage of the gap.
If the gap is set too large, particle material is accrued in front of the blade during operation of the coater. In order to obtain a good coating result the quantity in front of the leveling element should remain constant during the entire coating process.
In a preferred embodiment this is therefore achieved so that the gap is fixed as close as possible over the surface area to be coated directly with the leveling element. The gap can be dimensioned in a way that when the vibration mechanism is activated relatively a great deal of particle material is emitted. In the coating the particle material is accrued until it reaches the metering opening. Through the accrued particle material now further material is prevented from escaping the supply through the opening. In this way a constant quantity of powder can be achieved in front of the leveling element without adjustment works on the gap height.
A self-regulating system like this has a significant advantage compared to well-known coating process, as no exact alignment of the opening is necessary. This is very complex particularly with very wide openings.
The leveling element smoothes and condenses the applied material. A changeable blade is preferably chosen with a specific support length, via the incline of the support area to the coating surface area the densification of the layer can set well.
The blade has rounded edges in accordance with a preferred embodiment. This prevents damage to the applied coating surface area. The round forms preferably have a radius of 0.2 to 1 mm.
The coater, which at least consists of a metering system and the leveling element, is activated to oscillate. One advantage is that the oscillation occurs mainly in the coating direction. However it is also possible to let the system oscillate with an additional vertical component, in order to achieve a higher densification of the particle material. But is must be observed that too strong a densification of the particle material can lead to a movement in the powder bed over the actual layer and thus lead to a deterioration of the structure printed.
Via the frequency and amplitudes (horizontal and vertical) of the oscillator, on the one hand the densification and on the other hand the emission quantity of the metering system can be set.
As already discussed the coating equipment in line with the invention is especially suited for the use of very fine particle materials (particle sizes <150 μm), as they are used in the current rapid prototyping processes, like 3D printing or selective laser sintering established for example from the EP 0 431 924. In these processes the grain size of the particle material determines the possible layer thickness and therefore the accuracy and resolution of the printed parts.
Unlike the processes of prior art particle materials with rounded grain sizes and therefore high flow capability as well as powder with square-edged particles and lower flow capability can be processed. By means of fluidization of the particle material in the metering system the outcome in both cases is a homogenous coating result.
With the process according to the invention plastic particle materials such as PMMA, PA or PS, the most diverse forms of metal powder as well as form sands such as silica sand, zircon sand, magnetite or chromerz sand can be processed. The selection of material grade depends solely on the selected layer build method and the properties of the target material grade.
The particle materials can be homogenous or as particle mix or coated powder. It is also possible that other substances in the form of fluids are added to the particle material before the coating process.
Other powder mixes contain for example fiber materials for later strengthening of the component.
Other beneficial embodiments of this invention result from the sub claims as well as the description.
For a more detailed illustrated the invention is described in more detail below based on favored design examples with reference to the diagram.
BRIEF DESCRIPTION OF THE DRAWINGS
The diagram shows:
FIG. 1 the sequence of a process in line with the invention according to a preferred embodiment; and
FIG. 2 the device as per the invention in accordance with a preferred embodiment.
DETAILED DESCRIPTION OF THE INVENTION
For example, below the process and the device according to the invention for use in layer design of cast models from particle material and binding agent in rapid prototyping process are explained.
In particular it can be assumed from very fine and flow-capable particle materials that a rapid prototyping process is used.
Referring to FIG. 1 the sequence of the coating is described below according to the preferred, embodiment of the process in line with the invention.
In a set up process of a component, such as for example a cast model, a construction platform 4 on which the model is to be built, is lowered around a layer strength of the particle material 5 . Then the particle material 5 , for example very fine plastic powder is applied to the construction platform 4 . This has a required layer strength from the container, here a funnel 3 . Then the selective application of binding agent Is attached to one hardened areas. This can be carried out using a drop-on-demand-drop generator, depending on the type of ink-jet printer. These application steps are repeated, until the finished component, embedded into the loose particle material 5 , is obtained.
At the start coater 1 is in the starting position, which is represented in FIG. 1 a . It Is first filled via a filling device, if the fill level sensor has recognized a sub level In a container, which is designed here as a funnel 3 .
As illustrated in FIG. 1 b , the construction platform 4 is lowered to more than one layer.
Then the coater 1 , as shown in FIG. 1 c , without oscillation movement and thus without feed effect in the position compared to the filling device 2 , until it is over the edge of the construction platform 4 .
Now the build platform 4 is raised exactly to the layer height, as FIG. 1 d shows. This means that the build platform 4 is now accurately lowered to the layer height.
Now the coater 1 begins to oscillate and goes in a constant run over the build platform 4 . Thus it emits particle material 5 in exactly the right quantity and coats the build platform 4 . This is shown in FIG. 1 e.
The running speed of the coating is between 10 and 200 mm/s. The selectable coating speed depends on the emitted particle quantity and the movement of the individual particle. If the run speed is selected too great compared to the particle emission, imperfections (surface detects) are formed in the powder bed, which can lead to delaminating of the component in the worst case. Generally for reasons of productivity higher coating speeds are beneficial.
An unfavorable conformation of run speed in oscillation movement of the leveling element leads to so-called chatter marks on the powder bed surface. These have a negative effect on the component quality. Generally, the higher the coating speed chosen, the higher the oscillation frequency on the moved leveling element.
The coater 1 runs after the coating run without oscillation movement, which means as quick as possible, back to the starting position and can be refilled as required via the filling device 2 . This is shown in FIG. 1 f , which corresponds to 1 a.
In order to balance an unequal filling of the coater 1 via its length, after a specific time the funnel 3 can be emptied via the waster container 6 by means of oscillation of the funnel 3 and subsequently refilled.
The printing process, or illumination process to harden the particle material provided with binding agent 1 can take place during or after the coating.
FIG. 2 shows a device In line with the invention according to a favored embodiment.
In particular also for carrying out the process according to the invention a device is suitable according to the demonstrated favored embodiment.
In line with FIG. 2 particle material 5 is applied to an area to be coated, whereby a rocker 7 , which contains a metering device 3 , viewed in a forward direction 16 of the blade 14 particle material 5 on the build platform 4 . Furthermore a blade 14 is provided as a leveling element, which condenses, smoothes the applied material, and ensures a constant layer thickness H s of the applied particle material 5 .
The rocker 7 is applied to the coater main bracket 10 according to the preferred embodiment in such a way that it can perform an oscillation depending on the type of rotary motion indicated by arrow 8 . The coater main bracket 10 spans over the entire width of the build platform 4 in accordance with the preferred embodiment. The rotary axis 9 of the rocker 7 is vertical to the running movement represented by arrow 16 in accordance with the preferred embodiment and parallel to the longitudinal axis of the rocker 7 .
In this case the metering device 3 contains a container, a funnel-shaped particle device, which is formed via the rocker 7 and a corresponding sheet 17 , and features a metering gap, located in the container, which resembles the shape of a funnel, sideways, which means vertical to the coating direction viewed with an angle α and In running direction in front and above the stripper blade 14 . In accordance with the diagram this is about 90°. This shall only serve as an example.
The sheet 17 and the blade 14 are arranged in such a way that the gap height H and gap length L of the opening 11 designed as a gap is measured so that when the vibration mechanism is deactivated no particle material 5 leaves the supply and when the vibration mechanism is activated more particle material 5 is emitted than is necessary for dimension of the compressed layer. The height of the gap 11 can be set by means of the locking bolt 18 .
The surplus material is collected in front of the blade 14 . If the surplus particle material 5 reaches the opening 11 in front of the blade 14 , which is formed here as a gap, further particle material 5 is prevented from leaving the opening 11 . This way in the coating run along the blade 14 an equally large accumulation of particle material 5 is set in front of the blade. This leads to a uniform coating result over the entire width of the coater and over the entire length of the section 4 .
The rocker 7 with the firmly connected or contained metering unit and blade 14 oscillates according to arrow 8 around the rotary axis 9 . By means of another arrangement of the rotary axis 9 a movement can be realized with an additional vertical share, in order to achieve an additional compression effect of the applied layer through an extra vertical movement of the blade 14 .
The oscillation of the rocker 7 can be set by the size of the eccentric 12 and its juncture 19 with the rocker 7 , so that the amplitude of movement of the blade 14 lies between 0.05 and 1 mm.
The amplitude and frequency of the oscillation are adapted so that there is a sufficient compression of the particle layer and adequate particle material 5 is supplied by the metering system. The amplitude and the oscillation direction shall be chosen so that no damage to the area below the layer occurs.
The device is designed according to the embodiment in a way that a propulsion of the coater 4 is made over at least a fast running electro motor, which brings the wave 7 to oscillation via an eccentric.
The motor used for driving the eccentric 12 has for example a nominal rotation speed at 12V of 3000 U/min, the hub of the eccentric 12 amounts to 0.15 mm, which corresponds to an amplitude on the top of the blade 14 of 0.20 mm according to the example described. At 15 V a rotational speed of 4050 U/min was measured. This value corresponds to 67.5 Hz. Depending on the width of the blade 7 It can be necessary, to provide several pivotal points.
The blade 14 features rounded edges 13 . This prevents damage to the applied coating surface area. The round forms preferably have a radius of 0.2 to 1 mm.
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This document describes a process and a device for applying fluids, specifically particle material, on an area to be coated, which is viewed in forward moving direction of the coater, that fluid is applied on the area to be coated and then a leveling element is run over the applied fluid, whereby the fluid is led from a metering system provided with an opening, which oscillates when applying the fluid. The opening shall be designed in such a way that when the metering system is at a standstill this is closed by forming an angle of repose of the fluid.
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TECHNICAL FIELD
The present invention relates to fiber reinforced skis in general and in particular to skis formed by the wet wrap or torsion box process wherein a wooden or foamed plastic core is wrapped in a fiber reinforced sheet impregnated with resin, "cooked" and cured under pressure in a mold with a base assembly. The invention comprises a unique braided fiber reinforced "sock" covering for a ski core which includes strands of reinforcement oriented at an angle to the longitudinal direction of the core and braided directly thereon. Longitudinally extending strands of reinforcement may be intertwined with the braided strands and other longitudinal strands of material may be positioned on the top or bottom surface of the ski core between the core and the braided reinforcement. The term "fiber reinforcement" is meant to include any highmodulus fibrous material such as glass, aramid fibers such as "Kevlar", carbon, metal wire, polyester, etc. suitable for the production of skis. A method and apparatus for manufacturing the fiber reinforced braided ski core is also disclosed.
BACKGROUND OF THE INVENTION
In the past, "wet wrap" or "torsion box" skis have typically been formed by impregnating a sheet of unidirectional fiberglass with epoxy resin. The core and any other internal components of the ski, such as fiberglass mat or a bias-ply precured fiberglass strip, are placed in the center of the unidirectional glass, again with resin applied. The unidirectional glass is then wrapped tightly around the core on all four sides. This unit is then placed in a mold, the base assembly set on top, and the mold closed. The unit is "cooked" under fairly high pressure for a period of time and, after the cure cycle, is removed from the mold. At this point, the ski is basically complete structurally and the rest of the production process is devoted to sanding, topping, finishing and other cosmetic operations. Ski cores have typically been wrapped or "laid up" by hand and this is a labor intensive and time-consuming process.
It is known that unidirectional fiberglass is a material of great longitudinal tensile strength but little lateral strength. Thus, the torsional rigidity of skis was typically increased through the addition of randomly oriented fiberglass mat or angularly biased, precured fiberglass strips to the "sock" unit prior to wrapping. The longitudinally oriented unidirectional fiberglass imparted longitudinal rigidity to the ski. It is known that the orientation of fiberglass at a 45 degree angle to the longitudinal dimension of the ski core imparts the highest torsional rigidity to the ski. Of necessity, the use of a randomly oriented mat to increase torsional rigidity also resulted in unnecessarily increasing ski weight and expense since only a small percentage of the mat fibers were oriented at angles which enhanced torsional stiffness.
The placement of 45 degree biased, precured fiberglass strips in the "sock" was an improvement in that it represented a more effective use of the strength characteristics of fiberglass in controlling torsional rigidity, but was undesirable in that it required additional lay-up and curing steps for the strips themselves. Further, the biased fiberglass was not wrapped around the core and thus did not obtain the benefits of strength and durability provided thereby.
Another problem of the prior construction technique was that variations in lay-up from ski-to-ski created differences in torsional and longitudinal rigidity, thus making it difficult to produce a truly matched pair of skis. Further the known wrap process involves wrapping a rectangular sheet of fiberglass around the ski core which has a varying cross section along its length. This creates a large overlap of the sheet at the narrow waist of the ski and a small overlap at the wide tip. This adversely affects molded tolerances in the ski.
The problems of hand lay-up have been attempted to be overcome in the past through the use of prebraided bias fiberglass socks which were slipped over a ski core prior to resin impregnation. Such socks were formed of multiple strands of fiberglass oriented at angles with respect to each other such that when the finished sock was slipped over the ski core, the strands were also oriented at angles, preferably 45 degree angles, to the ski core. Such prebraided fiberglass socks were difficult to use in that the braid tended to become loosened and unbraided while being slipped onto the ski core. In addition, the sock invariably fit loosely upon the ski core, thus creating difficulties in manufacture as well as quality control. The technique was also labor intensive and inflexible in design and still required premade contoured strips of longitudinal fiberglass.
Prebraided fiberglass socks including longitudinally extending strands of fiberglass, as well as the angularly biased strands, were successful in overcoming the tendency of the solely angularly biased strand prebraided socks to become unbraided. Such three strand socks, however, had such little ability to expand that it was extremely difficult to slip them onto a ski core and they could not be effectively used in a production process.
The present invention provides a unique ski core covering whereby strands of fiberglass are braided at preselected angles directly onto the core as the core is moved through a braiding machine. In addition, longitudinally directed strands of fiberglass may also be intertwined with the angularly biased strands during braiding. Other strands of longitudinally extending fiberglass or other desired materials may be positioned on the ski core while it is being passed through the braiding machine to allow for additional strengthing and tailoring of the flex characteristics of the ski.
The present invention makes possible a lighter and yet stronger ski in that the use of randomly oriented fiberglass is eliminated and all strands which are used are oriented longitudinally such that the best use can be made of their tensile strength characteristics.
The amount of fiberglass braided onto the ski core, as well as the angle of the braided fiberglass strands with respect to the ski core, can be varied by increasing or decreasing the speed of movement of the ski core through the braiding machine or the speed of the braiding machine itself. The equipment may be operated to allow the angle of the braided fiberglass strands with respect to the longitudinal dimension of the ski core to be varied along the ski core to separately control the torsional rigidity characteristics of the shovel or tail of a ski as desired. The braiding of the fiberglass onto the ski core under slight tension prevents unbraiding and holds the orientation of the fiberglass with respect to the ski after it is removed from the braiding machine and prior to its impregnation with epoxy and placement into a mold.
SUMMARY OF THE INVENTION
A wrapped core for a fiberglass ski is formed by passing a foamed plastic, wood or other suitable type of ski core through a braiding machine whereby angularly biased strands of fiberglass are braided directly onto the ski core to cover it from one end to the other. Prior to braiding, other strands of fiberglass, or other suitable material, may be fed onto either or both the top and bottom surfaces of the ski core as it passes into the braiding machine, such that the longitudinal strands are captured and held by the overlying braid. The apparatus for feeding the longitudinal fibers onto the top and bottom surfaces of the ski core includes means for contouring the fibers to the varying widths of the ski. Longitudinal strands of fiberglass may also be intertwined directly into the braid to increase the longitudinal rigidity of the ski.
Means are provided for varying either the speed of the braiding machine or the speed of travel of the ski core through the braiding machine to vary the angle at which the braided fibers are laid on the longitudinally extending ski core. This allows for easy control of the torsional stiffness characteristics of the ski and, thus, would allow different types of ski handling characteristics for different levels or styles of skiing to be manufactured on a single machine by simply varying the speed of movement of the ski core, the speed of the braiding machine, or modifying the amounts or types of longitudinal fibers or other materials which are laid upon the surfaces of the ski core prior to braiding.
A unique, lightweight ski is provided which makes efficient use of the high tensile strength characteristics of fiberglass by orienting all strands of fiberglass longitudinally along preselected lines to produce a ski having a maximum strength-to-weight ratio. It provides a method and apparatus for producing uniform, lightweight skis having preselected torsional and longitudinal flex characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
The details of a typical embodiment of the present invention will be described in connection with the accompanying drawings in which:
FIG. 1 is a side elevation view of one embodiment of an apparatus for producing the wrapped core of the present invention;
FIG. 2 is a partial perspective view of the apparatus of FIG. 1;
FIG. 3 is an enlarged partial perspective view of the braiding nip portion of the apparatus of the present invention;
FIG. 4 is a side elevation view of the braiding nip portion of the present invention;
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 4;
FIG. 6 is a top, plan view of the apparatus of FIG. 4;
FIG. 7 is a plan view of a portion of a ski core showing angularly biased braid positioned thereon;
FIG. 8 is a top, plan view of a portion of a ski core showing angularly biased braid including longitudinally extending fibers intertwined therewith;
FIG. 9 is a plan view of a portion of a ski core showing angularly biased braid overlying longitudinally extending fibers positioned on the top surface of a ski core; and
FIG. 10 is a plan view of a portion of a ski core showing angularly biased braid including intertwined longitudinally extending fibers overlying longitudinally extending fibers positioned on the top surface of a ski core.
DETAILED DESCRIPTION
FIG. 1 illustrates an apparatus 10 made according to the present invention for producing a wrapped ski core. The apparatus includes a conventional braiding machine indicated generally at 12 for producing tubular braid. Such machines are commonly known as "maypole" braiders, and one source for such a machine is Mossberg Industries, Inc., 160 Bear Hill Road, Cumberland, R.I. 02864. As is best seen in FIG. 2, the braiding machine includes a plurality of spools 14 positioned on a circular peripheral track 16. The spools carry strands of fiberglass and are adapted to move over and under each other as they travel around the periphery of the track 16. The strands of fiberglass 18 extending from the spools are directed through a guide ring 20 to a braiding nip area 22 where the movement of the spools causes the strands of yarn to be wrapped in opposing helixes to produce a braid about a ski core 24 passing longitudinally through guide 20.
As illustrated, the strands of yarn initially pass over a larger outer guide ring 26, whose purpose, like that of guide ring 20, is to guide and direct the strands of fiberglass such that they are directed to the braiding nip at similar angles to allow braiding to easily occur.
Referring again to FIG. 1, it will be seen that horizontal and vertical guide rollers 28 and 30 are positioned immediately adjacent the braiding nip area to guide the braid covered ski core from the braiding knit to the haul-off apparatus 32. Haul-off apparatus 32 comprises a pair of endless belts 34 running around the pairs of rollers 36 and 38. Rollers 38 are rotatably driven. At least one pair of rollers 36 and 38 are also mounted on pneumatic cylinders or the like to allow the pairs of cylinders and overlying belts 34 to be moved toward each other to press against and grip the braid covered ski core to haul it through the braiding machine. A conventional cutting mechanism 40 is positioned outwardly of haul-off 32 to separate braid covered cores from each other. The location of the cut-off mechanism outward of the haul-off apparatus 32 and rollers 28 and 30 allow the braiding machine to braid on a continual basis by maintaining tension in the strands running from the bobbins on the braiding machine. The tension at which the strands are removed from the spools for braiding is about 0.25 pounds but may be any reasonably larger or smaller number so long as the machine braids effectively and the orientation of the strands on the core is maintained.
Operation of the braiding machine 12 to braid angularly biased strands of fiberglass about ski core 24 produces a ski core covered in angularly biased braid, such as that shown in FIG. 7. The fiberglass strands may be oriented at a variety of angles with respect to the longitudinal direction of the ski core with it being understood that maximum torsional stiffness occurs when the braid fibers are oriented at a 45 degree angle to the ski core.
It will be understood that the thickness or thinness of the foamed plastic or wooden core over which the braid is laid grossly controls both the longitudinal and torsional flex of a ski at any point along its length. The thinner a ski core at any point, the less stiff it is. The ability to control the angle at which the braided fibers are placed on the ski by the apparatus of the present invention allows, for the first time, separate control of the longitudinal and torsional flex characteristics of a ski. For example, as the speed of movement of a ski core through the braiding machine 12 is increased, the angle at which the knitted fibers are laid on the ski core with respect to the longitudinal dimension of the ski core is lowered, i.e., the braided strands move toward longitudinal alignment with the ski core and, thus, the longitudinal stiffness of the ski increases while the torsional rigidity is reduced. Such independent control of these two flex characteristics was not possible by simply making the ski core thinner or thicker.
Referring again to FIG. 1, it will be seen that rack 42 holding a plurality of spools 44 of fiberglass roving is also disclosed. Fiberglass strands 46, which are drawn from each of the spools 44, are directed over guide ring 48 through openings 51 in circular track 16 of the braiding machine 12 (FIG. 2), over circular guide ring 26, through circular guide ring 20 and into the braiding nip area 22. It will be understood that the openings 51 on track 16 of the braiding machine do not move and, thus, strands 46 are not truly braided in braiding nip 22, but rather are merely intertwined with braided strands 18. Fiberglass strands 46, while intertwined with strands 18, maintain their longitudinal direction along the ski core 24 and, thus, add to the longitudinal stiffness of the completed ski.
Referring to FIG. 8, the longitudinal strands 46 are shown intertwined with the angularly biased braided strands 18. This three-strand fiberglass sock is tightly woven onto the ski core and conforms closely to its outer dimensions. It will be understood that the braided strands 18 of the three-strand braided sock of FIG. 8 may still be varied in angular orientation by speeding or slowing the movement of the ski core through the braiding machine, or the speeding or slowing of the braiding machine itself.
Referring again to FIG. 1, it will be noted that racks 42 hold other spools 50 of fiberglass material, the strands 52 of which are led to fiber guide 54 which is best shown in FIGS. 3 and 4. Fiber guide 54 includes a strand receiving screen 56 comprising a metal plate having a plurality of holes 57 positioned above and below opening 58 through which ski core 24 passes. Holes 57 direct strands 52 toward springs 60 positioned above and below the ski core near the opposite end of fiber guide 54. As best shown in FIG. 5, springs 60 are end mounted in vertically oriented posts 66 and spiral about pins 62, which may be conventional bolts and nuts and which are, in turn, mounted in openings 64 in posts 66.
Fiberglass strands 52 are locked in springs 60 by removing pins 62 therefrom, pulling the fiberglass upwardly or downwardly through springs 60 and then reinserting locking pins 62. As shown in FIG. 5, fiber strands 52 are then locked beween springs 60 and pins 62.
Strands 52 then extend through guide ring 20 and onto the top and bottom surfaces of the ski core in nip area 22 where they are covered and held by braided strands 18 and intertwined longitudinal strands 46.
It will be understood that strands 52 may be formed of fiberglass similar to longitudinal strands 46, or may be fiberglass roving, or any other material having a characteristic useful in ski manufacture such as carbon, kevlar, polyester, metal wire or the like.
It will also be understood that unequal amounts of fiber material may be deposited on the top or bottom surface of the ski core as desired by varying the number of spools of material feeding fiber strands to the upper or lower guide holes 57 of plate 56. While only a pair of spools have been shown feeding strands of material to the fiber guide in FIG. 1, it will be understood that many more spools will actually be used during ski production.
Referring additionally to FIG. 6, it will be seen that vertical posts 66 are mounted on pivoting arms 68. The distal ends of arms 68 are mounted upon pivotal vertical shafts 70 which extend downwardly through fiber guide support plate 72. Meshing toothed gears 74 are fixedly mounted to the bottom of each shaft 70 such that the angular rotation of one shaft 70 caused by the inward or outward movement of the distal end of arms 68 as a ski core 24 moves therebetween is equally imparted to the other shaft 70 through gears 74.
A conventional cylinder and piston arrangment 76 is mounted to the periphery of one of the toothed gears 74 to angularly bias the gear, interconnected arms 68 and posts 66 against the lateral side of ski core 24. In this way, as the width of the ski core narrows or widens as it passes between posts 66, arms 68 are continuously biased against the sides of the ski core and move inwardly and outwardly therewith.
Since, as best shown in FIG. 5, the ends of springs 60 are fixedly mounted in posts 66, the lateral movement of posts 66 as ski core of varying width passes therebetween causes springs 60 to flex inwardly and outwardly. Since fiberglass strands 52 are captured beneath the turns of springs 60, the strands are also moved inwardly and outwardly as springs 60 flex and, in this way, fiberglass strands 52 are variably spaced or contoured with respect to the upper and lower surfaces of ski core 24 on which they are deposited as the width of the ski core varies.
As is best shown in FIG. 4, upper and lower guide rollers 78 are also mounted on the arms 68 of fiber guide 54 and at least the upper roller is biased downwardly against the top of ski core 24 by means of a conventional spring 80 mounted on the side of arm 68.
Referring to FIG. 9, strands of longitudinal material positioned on the top surface of ski core 24 and captured by angularly biased braid 18 are disclosed.
Referring to FIG. 10, longitudinally extending strands 52 extending beneath and captured by angularly biased strands 18 and intertwined longitudinally extending strands 46 are disclosed. It will be understood that any of the braided fiberglass covered ski core constructions shown in FIGS. 7-10 are considered to be novel products of the present invention. These fibers are braided and placed directly on a moving ski core in a continuous fashion to produce structures having improved characteristics not heretofore available in the art.
The above-described apparatus and the method of manufacturing these and other unique braided ski cores are also considered to be novel features of this invention.
It is contemplated that varying the speed of movement of a ski core through the braiding machine, or varying the speed of the braiding machine as a ski core moves therethrough, will allow the impartation of differing flex patterns along the length of a single ski core. It is also contemplated that the speed of travel of the ski core or the speed of the braiding machine may be automatically controlled in a known manner to allow ski cores of a preselected flex pattern to be repeatedly and uniformly produced.
As will be apparent to those skilled in the art to which the invention is addressed, the present invention may be embodied in forms other than those specifically disclosed above without departing from the spirit or essential characteristics of the invention. The particular embodiment of the apparatus, method and product described above is therefore to be considered in all respects as being merely illustrative of one form of apparatus, method and product capable of carrying out the present invention.
The scope of the invention is as set forth in the appended claims, rather than in the foregoing description.
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A wrapped core for a ski comprising a wood or foamed plastic longitudinally extending core having first longitudinal strands of material positioned on the top and or bottom surfaces of the core and second strands of fiber reinforcement braided thereover to surround the core and capture said first strands. Third longitudinally extending strands of fiber reinforcement are intertwined with said second braided strands. The method and apparatus for forming the wrapped ski core.
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FIELD OF THE INVENTION
This invention relates to a nonvolatile memory used for counting and the method of counting using such a memory.
BACKGROUND OF THE INVENTION
Electronic odometers for automotive vehicles are generally required to store input pulses for the life of the vehicle operation. To assure a permanent record of vehicle usage, even in the event of power loss to the odometer, nonvolatile memories are used. In addition, high resolution is necessary. For example it is desired to store data representing each 0.1 mile of travel. Thus very large numbers of input pulses must be counted and retained without danger of loss. Standard binary counters are able to efficiently store large numbers but such counters utilizing nonvolatile memories are subject to wearing out through repeated erase and write operations.
A traditional scheme for avoiding the high incidence of erase and write operations is to use a volatile memory counter for normal operation and to write the counter contents to a nonvolatile memory only when a loss of power is impending. This requires circuits to detect such power loss, to interrupt normal counting, and to carry out the storage activity. Alternatively, only volatile counters are used for low order registers but battery back-up for the volatile counters is expensive and can drain vehicle batteries over extended periods of nonuse.
Another way of using nonvolatile memories in odometers is to provide a large number of redundant memories for the low order register to distribute the wear caused by the frequent updating of the low order data. The redundant locations are swapped with each other to provide a longer effective life. For example, if 24 bits of data (3 eight bit words) are to be stored in a conventional binary format it can record 128,000 miles with a resolution of 0.1 mile if the second word is limited to 10,000 writes or erasures. It is assumed that 10,000 writes or erasures can be made to the memories yielding an acceptable life span. The two higher order 8 bit words do not require any redundancy since they will not be written to more than 10,000 times. However the lower word will undergo 1.28 million erase/write sequences. To insure that no location is written or erased more than 10,000 times, 128 redundant banks of 8 bit memory or 1024 bits are required to share the load. In addition to the storage locations, logic must be provided to perform read, write and erase operations in individual banks as well as logic to select which banks are to be currently used.
It has further been proposed, as described in the U.S. Pat. No. 4,682,287 to Mizuno et al., to use nonvolatile memories which are linearly arranged to be written to bit by bit in sequence. A first memory has 256 cells and the second memory has 32 cells. Each input pulse represents 1 km and causes a "1" to be written to one of the cells so that the first memory can accumulate 256 km, while each cell is written only once, thereby reducing the frequency of erase/write operations. When the first memory is full it is erased and the second memory is incremented by placing a "1" in one of its cells so that each digit in the second memory represents 256 km. The total memory capacity is (256×32)+256 so that only 8448 km can be stored with the recommended memory sizes and only a resolution of 1 km is offered. In addition, the control of the memory requires a microcomputer or other complex logic circuits.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a memory using a relatively small number of nonvolatile memory (NVM) cells and limited erase/write requirements for each cell while yielding large capacity and fine resolution. For example, the memory is smaller than that of Mizuno et al. and its capacity and resolution are vastly superior.
Another object of the invention is to provide such a memory having simple inexpensive support circuitry for control purposes. A microcomputer is not needed.
A further object of the invention is to provide a method of counting events which requires a low number of read/write operations on a particular cell and yet provides a large counting capacity for the small number of memory cells so that it is particularly useful for NVM applications.
The invention is carried out by the method of counting events in a nonvolatile memory comprising the steps of; setting a first plurality of memory locations to a first state in serial fashion in response to an equal plurality of input events, when a preset number of memory locations have been set to the first state, changing the states of the same memory locations to a second state in serial fashion in response to further input events, so that the preset number of memory locations effectively count two times the preset number of input events, and counting in binary fashion in another plurality of memory locations the number of times the said preset number of memory locations have all been set to the first and then the second state, whereby each binary count represents two times the preset number.
The invention is further carried out by a nonvolatile counter incorporating memory cells having a limited tolerance to repeated erasures comprising; input means for supplying event pulses, a linear array of nonvolatile memory cells, each cell being capable of holding either of first and second states, means coupled to the input means and responsive to event signals for changing the state of each cell, in turn, to a first state for each event pulse and then effective when all the cells have attained the first state to change the state of each cell, in turn, to the second state for each event pulse, means for generating an output signal when all cells have attained the second state, and nonvolatile binary register means for counting the output signals whereby the nonvolatile memory cells have minimal requirements to change state.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other advantages of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings wherein like references refer to like parts and wherein:
FIG. 1 is a memory state diagram illustrating the method of counting data serially in a linear array for low order data and in a binary register for higher order data, according to the invention,
FIGS. 2A, 2B, 2C, and 2D are memory state diagrams illustrating different stages in a counting sequence for the linear array of FIG. 1,
FIG. 3 is a block diagram of the counter according to the invention,
FIG. 4 is a circuit diagram of an inverter used in the shift register of FIG. 3, and
FIG. 5 is a schematic diagram of one memory cell and associated shift register stage and support circuitry for the counter of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Although the ensuing description is directed to a counter and a counting method especially suitable for vehicle odometers, it is expected that other applications for this technology will be apparent.
The improved NVM counter uses a linear array 10 of memory cells in which cells are written serially for low order data and a conventional binary register 12 for storing high order data, as shown in FIG. 1. Starting with a reset array 10 (all cells in 0 state, as shown in FIG. 2A), the array 10 is incremented by changing the first, second, and third cells in order to the 1 state as the first, second and third input pulses are received (FIG. 2B). This process continues until all the cells of the array 10 are at the 1 state, the most significant digit being the last cell to change (FIG. 2C). Succeeding pulses repeat the process but the cells are serially changed from 1 to 0 (FIG. 2D). The general rule is that the changing cell always changes to the state opposite that of the most significant digit. Finally, when the number of pulses equals two times the number of cells in the array 10, all the cells will have been set to 0. Then the binary register 12 is incremented by 1 and the process repeats for succeeding input pulses.
Applying this arrangement to an odometer, it is appropriate to use 128 cells in the linear array 10 and two 8 bit words in the binary register 12. If an input pulse is applied to the counter for each 0.1 mile traveled, the array will produce an output pulse to the binary register 12 at each 25.6 miles. During that period the array cells will be written once and erased once. After 10,000 output pulses the limit of 10,000 write/erase sequences will be reached in the linear array and the total recorded mileage will be 256,000 miles.
To read the data stored in the memory the cell contents are read out serially and converted to a parallel format like that of the binary register and the sum of the array and register contents is displayed. When the most significant digit of the array is 0 the value of the contents is the number of 1's in the array. When the most significant digit is 1 the number of 0's plus 128 is the value of the contents.
The success of the method of counting depends on the ability to implement an integrated circuit for carrying out the method at a low cost. The circuit to be described is easily implemented as an IC and the support circuitry is relatively simple, requiring a reasonable number of transistors. As shown in FIG. 3, the NVM array 10 is coupled to a dynamic shift register 14 such that a shift register stage is coupled to a corresponding NVM cell. The purpose of the shift register 14 is to read the contents of the array 10 and serially shift the data out to a counter 16 or other circuit for conversion to the parallel format. The contents of the counter 16 is combined with the contents of the binary register 12 and displayed by display 18. Data is incremented in the NVM array 10 by increment logic 20 associated with each NVM cell. A secondary usage of the shift register 14 is that an inverter in each register stage is used in conjunction with the increment logic, but the shifting capability, per se, of the shift register 14 is not involved in the array incrementing process. Both the shift register and the increment logic are controlled by a logic controller 22 which supplies control voltages to each transistor in the circuit. The controller 22 is a relatively simple circuit using only a few hundred transistors to manage the repetitive reading and writing functions of the counter. The event input 24 to the counter is connected to the logic controller 22 to initiate counter incrementing. If the circuit is used as an odometer the event input may be a prescaler responsive to speedometer pulses to generate an input pulse to the controller 22 for each 0.1 mile of travel.
The circuitry requires nonvolatile memory (NVM) transistors which are well known in the art. The NVM transistor may be, for example, an EEPROM cell such as a type described in Shiner et al. "Characterization and Screening of SiO 2 Defects in EEPROM Structures," 1983 Proceedings of the 21st Annual Reliability Physics Symposium, p 248-256. Such a transistor requires a high voltage (20 v) for erase and write operations and 5 v and ground for outputting logic 1 and 0, respectively. The transistor is programmed to a reset condition (erased) by placing a high voltage on the drain and ground on the gate. The transistor is programmed to a set state by applying a high voltage to the gate while grounding the drain. In both cases the source is maintained at ground voltage. To read data out of the transistor, a current source is applied to the drain and a logic 1 is applied to the gate. The transistor will conduct the drain current to the source terminal if the transistor is erased and will not conduct if programmed to a set state.
The circuit also requires MOS FETs of both the n-channel and the p-channel type. The n-channel FET requires the gate to be at logic 1 for conduction while the p-channel FET requires the gate to be at logic 0 for conduction. To form an inverter as shown in FIG. 4 a p-channel FET 30 and an n-channel FET 34 are serially connected between +5 v and ground. The gates are tied together to form the input and the node between the two FETs is the output. When the input is low the FET 30 conducts to yield a high output and when the input is high the FET 34 conducts to take the output to ground. The gate capacitances of the FETs provide a memory for a signal impressed on the gates provided the gates are otherwise isolated to prevent current drain.
FIG. 5 shows the schematic circuit for one stage 36 of the dynamic shift register 14 and the logic associated with a single NVM cell 38. That logic comprises an increment circuit 40 which compares the state of the cell 38 to that of the previous stage, and read/write circuitry 42. The various circuit terminals identified in FIG. 5 are present in each such stage; corresponding terminals of each stage are bused together for control by the logic controller 22.
The shift register stage 36 comprises a FET 44 with its drain forming the stage input A N-1 and having a gate terminal 46 and the source coupled to the input of an inverter 48. The inverter output is connected to the drain of FET 50 which has its source connected to the input of an inverter 52. The inverter 52 output forms the output A N of the stage 36. The FET 50 has a gate terminal 54. By suitably controlling the gate terminal signals data can be shifted through the stage 36 from the input to the output. By holding gate 46 high and gate 54 low, the input is passed to the inverter 48. Then gate 46 is taken low and the voltage is maintained on the inverter 48 input and the inverted voltage is held at the inverter output independently of any further change at the stage input. The gate 54 is then taken high to pass the voltage to the inverter 52 which produces the signal to its output which is the same as the original input. By connecting the stages 36 end to end, data may be passed from one stage to the next in bucket brigade fashion, thus forming a shift register.
The NVM cell 38 is connected between ground and the input of the inverter 52 in the register stage 36. The gate is connected to control voltages via FETs 56 and 58 in the read/write control 42 and the drain is connected to control voltages through FET 60 in the control 42. As indicated above, terminals 57 and 59 of FET 56 as well as terminals 62 and 64 of FETs 58 and 60 are controlled by the controller 22. The gates of FETs 58 and 60 are connected to FET 66, having control terminals 68 and 70 which are also controlled by the controller 22.
Several steps are required to read data from the NVM cell 38. Terminal 54 and 74 are taken low to isolate the cell 38 from inverter 48 and increment circuit 40; terminals 62 and 64 are taken low and high, respectively, to establish the read voltages for cell 38; and terminals 68 and 70 are taken high and low, respectively, for applying the read voltages to cell 38 via FETs 58 and 60. During such operation, the FET 60 acts as a load for the cell 38, and the high voltage at the drain of FET 60 is stored on the input of inverter 52. Then, terminal 70 of FET 66 is taken high to hold FETs 58 and 60 off, isolating the drain of the NVM cell 38. Then, terminals 57 and 59 of FET 56 are taken high to turn on cell 38. If the cell 38 is at a zero state, it will conduct to pull the input of inverter 52 low; if the cell 38 is at a 1 state, the inverter input will remain high. Thus, the data is loaded from the cell 38 to the stage 36 and appears in inverted form at the stage output. The data is then read out of the linear array of NVM cells by simultaneously loading the data from all the cells to the shift register and serially shifting the data out, in inverted form, to counter 16 where it is counted in binary fashion for compatibility with the contents of the binary register 12.
The increment circuit 40 is an exclusive OR logic circuit which compares the state of the cell 38 to the previous NVM cell in the array, and enables the circuit 42 to change the cell state if it is different from the previous one. An FET 72 having a gate 74 (which is connected to the controller 22) forms an output switch for the circuit 40. FETs 76 and 78 are connected in series between the FET 72 to ground. The gates 80 and 82 of FETs 76 and 78 are connected to lines A N-1 and B N respectively which represent the state of the cell 38 and the inverted state of the previous cell. If both are high, indicating the cells are in different states, the FET 72 is connected to ground. Similarly FETs 84 and 86 are serially connected between the FET 72 and ground and their gates 88 and 90 are connected to lines A N and B N-1 respectively which represent the state of the previous cell and the inverted state of cell 38. If both are high, indicating the cells are in different states, the FET 72 is connected to ground.
In operation, the incrementing is initiated in response to an input signal to the controller 22 which determine a sequence of control signals. First, terminal 74 of FET 72 is taken low to isolate circuits 40 and 42, and then the data is loaded from the NVM cells as described above so that the lines A N , B N , etc. will be charged to the appropriate states. Further, the controller 22 will sense the state of the last NVM cell in the array and prepare to program the opposite state to the next cell to be changed by applying suitable voltages to the terminals 62 and 64 of FETs 58 and 60, the FETs 58 and 60 being biased off by a high voltage stored on their gates via terminal 70 of FET 66, and then FET 66 is turned off to isolate the gates. All the cells in the array are simultaneously prepared in this manner. Then the gate 74 of FET 72 is taken high to allow the FET 72 to conduct. Only one NVM cell in the array will have a state different from its lower order neighbor and its incrementing circuit 40 will ground the gates of FETs 58 and 60 via FET 72 to allow the programming voltages to be applied to that one NVM cell 38.
The entire NVM linear array can be set or reset. Each NVM cell 38 is isolated by turning off FETs 44, 50, 56 and 72 while terminals 68 and 70 are taken high. To bank erase, terminal 64 is taken high (20 v), and terminals 62 and 70 are taken low for sufficient time for the cell to erase. To bank set, the same operation applies but with terminal 64 taken low and terminal 62 taken high.
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A nonvolatile memory has a linear array of memory cells to serially store counts by setting the cells one by one in correspondence with input pulses and when the array is full by resetting the cells one by one for successive pulses. When all the cells are reset a conventional binary counter is incremented and the serial count is repeated for further inputs. This procedure minimizes the erase/write sequences required to count a series of pulses. A shift register having a stage corresponding to each memory cell is used to read out the data from the linear array. Data is loaded from the array into the shift register and shifted out in a serial pulse train to a binary counter.
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TECHNICAL FIELD
The invention concerns an activating pin for a valve connector for connecting to inflation valves, the connector comprising a housing to be connected to a pressure source, within the housing a coupling hole having a central axis and an inner diameter approximately corresponding to the outer diameter of the inflation valve to which the valve connector is to be connected, and a cylinder and means for conducting gaseous media between the cylinder and the pressure source, and which activating pin is arranged for engaging with a central spring-force operated core pin of the inflation valve, is arranged to be situated within the housing in continuation of the coupling hole coaxially with the central axis thereof and comprises a piston part with a piston, which piston is to be positioned in the cylinder movably between a first piston position and a second piston position.
BACKGROUND OF THE INVENTION
It is well-known from PCT/DK96/00055, now U.S. patent application Ser. No. 08/837,505, herein incorporated by reference, that an activating pin located within the coupling house can be designed as a piston equipped with a suitable seal and a piston rod that is slidable in the cylinder-shaped coupling house. The piston can be held in a longitudinal position against the cylinder valve without applying physical force so that the piston automatically slides, after the valve connector is placed on the inflation valve, by means of compressed air. This compressed air comes from the pressure source such that the piston, in the proximal position to the valve, (1) opens up the inner valve, (2) opens the air passage to the valve and, (3) tightens less than 100% against the cylinder wall while in the distal position from the valve.
FIG. 14 in PCT/DK96/00055 shows a valve (360) which must be closed against the piston control. The disadvantage is that the above-mentioned two seals must be operational at a certain section of the sliding. This requires very accurate calibration of the cylinder wall and the piston movement. Furthermore, the piston has a precisely defined opening zone and can thus only adjust itself to a minor extent to the tolerances of the pump valve in question.
FIGS. 8, 9, 10, 14, and 15 in PCT/DK96/00055 show various activating pins equipped with a center blind drilling or a center drilling, side drillings and a V-shaped milling at the bottom which is perpendicular to the center axial drilling of the piston. The effect of this is that more force than necessary has to be applied when pumping, especially at high air velocities.
FIG. 9 in PCT/DK96/00055 shows an activating pin which has a center drilling, side drillings and a V-shaped milling at the bottom. When the coupling is connected to e.g. a high pressure pump with a built-in check valve, the spring keeps the valve of the activating pin in a closed position after uncoupling of a Schrader valve. If a tire with a Sclaverand valve has to be pumped immediately afterwards, one has to apply a large force to slide the activating pin which opens the inner valve of the Sclaverand valve. Air will escape and consequently the pumping time will be substantially longer if the tire has already been partly pumped. This last-mentioned problem also exists in the embodiments shown in FIGS. 10 and 15 in PCT/DK96/00055.
THE OBJECT OF THE INVENTION
The purpose of the present invention is to produce a reliable activating pin which is: (1) inexpensive, (2) has low aerodynamic drag making it comfortable to use for pumping purposes, and (3) provides the shortest possible pumping time.
These tasks are solved by the invention where the activating pin further comprises a valve part, the piston part comprises within it a channel, the cross-section of said channel is, at least one part of said piston part, consisting of sectors, wherein in each sector the distance between the center point of the channel cross-section and the outermost limiting surface of the channel is larger than the corresponding distance measured along the line separating the sector from an adjacent sector, and said valve part is positioned movably with respect to said piston part between a first valve position and a second valve position for enabling the conduction of gaseous and/or liquid media through said channel when said valve part is in said first valve position, and inhibiting the conduction of gaseous and/or liquid media through said channel when said valve part is in said second valve position.
The channels are positioned in a mainly longitudinal direction in relation to the center axis of the housing, and can be defined by at least one cross section which approximately can be defined by at least one curve. The curve is closed and can be defined by two unique modular parametrisation Fourier Series expansions, one for each co-ordinate function: f ( x ) = c 0 2 + ∑ p = 1 ∞ c p cos ( px ) + ∑ p = 1 ∞ d p sin ( px ) where c p = 2 π ∫ 0 π f ( x ) cos ( px ) x d p = 2 π ∫ 0 π f ( x ) sin ( px ) x 0 ≦x≦ 2π, xεR
p≧ 0 ,pεN
c p =cos-weighted average values of f(x),
d p =sin-weighted average values of f(x),
p=representing the order of trigonometrical fineness
thereby resulting in a large flow cross section area. All kinds of closed curves can be described with this formula, e.g. a C-curve. One characteristic of these curves is that when a line is drawn from the mathematical pole which lies in the section plane it will intersect the curve at least one time. A regular curve bounding a region which is symmetric with reference to at least one line which lies in the section plane through the mathematical pole can be defined by a single Fourier Series expansion: f ( x ) = c 0 2 + ∑ p = 1 ∞ c p cos ( px ) where c p = 2 π ∫ 0 π f ( x ) cos ( px ) x 0≦ x≦ 2 π,xεR
p≧ 0, pεN
c p =weighted average values of f(x),
p=representing the order of trigonometrical fineness.
When a line is drawn from the mathematical pole it will always intersect the curve only one time. In order to minimize the aerodynamic friction the channels are positioned mainly parallel to the centerline of the activating pin.
When the curves are approximately defined by the following formula, the cross section area of the channels is optimized by a certain given cross section: e.g. a section which combines approximately laminar flow and which can guide a central piston valve rod. It is then also possible to obtain a contact area for a Schrader valve core. This means that a bridge is unnecessary. In the following description, curves defined by the formula have been given the name “flower-shaped”. The formula is: f ( x ) = c 0 2 + ∑ p = 1 ∞ c p cos ( 3 px ) where f ( x ) = r 0 + a · sin 2 ( n 2 ) x 2 m c p = 6 π ∫ 0 π 3 f ( x ) cos ( 3 px ) x 0 ≦x≦ 2 π,xεR
p≦ 0 ,pεN
c p =weighted average values of f(x),
p=representing the order of trigonometrical fineness
and where this cross-section in polar co-ordinates approximately is represented by the following formula: r = r 0 + a · sin ( n 2 ϕ ) m
where
r 0 ≧0,
a≧0,
m≧0, mεR,
n≧0, nεR,
0≦φ≦2π,
and where
r=the limit of the “petals” in the circular cross section of the activating pin,
r 0 =the radius of the circular cross section around the axis of the activating pin,
a=the scale factor for the length of the “petals”,
r max =r 0 +a,
m=the parameter for definition of the “petal” width,
n=the parameter for definition of the number of “petals”,
φ=the angle which bounds the curve.
Pursuant to the invention, an activating pin ensures a large flow cross section which, by means of radial fins, also produces an approximately laminar flow which contributes to a reduced pressure drop during the flow. Similarly, the radial fins can control any centrally positioned valve without blocking the air passage.
In a first embodiment of the invention, the piston rod is equipped with two blind drillings parallel to the center axis that reaches the activating pin at both ends of the activating pin. The piston rod is also equipped with a concentric valve made of an elastic material, e.g. a valve rubber used on a Dunlop-Woods valve and squeezed onto the piston rod between e.g. its upper and lower part covering the radial drilling proximal to the pressure source. The radial drilling has an azimuth angle ∝ larger than or equal to 90° to the center axis of the piston, seen in the flow direction of the air at flow from the side of the pressure source. Furthermore, the distal radial drilling has an azimuth angle β larger than or equal to 90° to the distal center drilling of the piston, seen in the flow direction of the air at flow from the side of the pressure source. To ensure an interaction between the piston and the inner valve in a Schrader valve, the radius r 0 in the distal blind drilling is smaller than the radius r 0 of the proximal part of the center drilling. Due to evident arrangements in dimensioning the by-pass, the piston control is proximally equipped with longitudinal air ducts and/or having a bigger diameter. Moreover, the side of the piston is chamfered. If connected to e.g. a pump with a built-in check-valve, the connector needs to have an airing valve or a similar solution for providing the shortest pumping time. This results in a reliable activating pin because the pin valve works independently of the piston control fit and tolerances of the pump valves in question. It also results in a pin with low aerodynamic drag, which is comfortable for pumping purposes and which is inexpensive to produce.
A second embodiment is an improvement of the first embodiment where the coupling is connected to e.g. a high-pressure pump with a built-in non-return valve. A spring force being produced by means of the combination of compressed air and the valve lever passing through the piston in a eccentric position ensures the lowest possible pumping time. The effect of the eccentric valve lever is that the air pressure in the space between the non-return valve of the pump and the activating pin becomes equal to the pressure of the surroundings as the valve lever opens the above-mentioned space if a Schrader valve is disconnected. It is thus always possible to couple a Sclaverand valve without air escaping from the tire. Alternatively, an airing valve which is constantly shut could be established in the above-mentioned space when the connector is coupled to the valves or when the activating pin touches the core of the Schrader valve. This can take place if, for example, the airing is shaped as a narrow channel at the pressurized side of the activating pin relative to the distal end of it. In a special embodiment, it is proposed that the eccentric valve lever is integrated in the piston valve which makes the activating pin inexpensive to produce. The activating pin works independently of the piston control fit.
A third embodiment comprises a similar combination to the one described in the second embodiment, except here the activating pin has a center drilling. It is appropriate if the center drilling at each end expands gradually by a circular cross section and has an angle γ or δ, respectively, with the center axis of the activating pin and each angle is larger than 0° and smaller than 20° (usually in the interval between 6° and 12°). In an appropriate embodiment, the top of the piston of the activating pin forms a valve seat for the valve ( 304 ). This results in a large opening area created by a small movement of the eccentric valve lever. In a special embodiment it is suggested that the eccentric valve pin is loose in the piston and a stop device is used to stop its movement. The stop device is an integrated part of the piston valve and is resilient in relation to it. The piston valve rod has e.g. a “flower-shaped” cross section and the piston rod e.g. a circular cross section, resulting in channels ( 321 ). The activating pin is very reliable and inexpensive to produce. The air flow in the valve connector is approximately laminar which ensures low aerodynamic drag so that it is comfortable when pumping even with (low pressure) pumps without an integrated non-return valve. The improvement over the activating pin shown in FIG. 9 in PCT/DK96/00055 is considerable regarding reduction in pumping force and pumping time and is as good as e.g. the valve connector of FIGS. 5 a, 5 b, 6 and 7 .
A fourth embodiment is an alternative to the third embodiment. As the piston valve is rotating at an angle θ in relation to the top of the piston, if activated by the eccentric valve pin, the rotation is limited with a stop device. The cross section of the piston rod can have two main forms, according the specific formula each being “flower-shaped” with different parameters, both resulting in an approximately laminar flow. In a special embodiment, the radius r 0 is smaller than the radius of the core of a Schrader valve while the air is flowing through the distals of the “flower shaped” cross section. The eccentric valve lever is similar to the loose type of FIG. 5 d, with the difference being that the top is rounded off. The characteristics of this model are almost in accordance with those of the third embodiment.
In a fifth embodiment of the invention, the activating pin is designed as a piston with a piston rod that is slidable in the cylinder-shaped coupling house. The activating pin has a center drilling with an axially slidable valve in the center drilling that is kept closed by a spring where the center drilling of the activating pin has e.g. a “flower-shaped” cross section (FIG. 8.1) and the piston valve rod has a circular one resulting in a reliable control and efficient air passage. The center drilling at each end expands gradually by a circular cross section. The walls of the gradual expansions form an angle ρ or φ, respectively, between 0° and 20° (usually in the interval between 6° and 12°). The wall of the gradual expansion by the piston part of the center drilling forms a valve seat for the seal face of the valve. The seal face of the valve is pressed into the correct position by a spring, e.g. an elastic band. In a special embodiment, the sealing surface is a small area with an angle Ψ, in relation to the center axis, of approximately 90°-150° (incl.) as seen in the flow direction of the air at flow from the side of the pressure source. This enables improved sealing. In a special embodiment, the valve is equipped with at least one fin or a similar device, which fits on the top of the edge of a Dunlop-Woods inner valve. It also fits either the top of the core of a Schrader valve, or the bridge of a Schrader valve without fitting the top of its core, as the activating pin does. In the last mentioned embodiment, the fin is equipped with a device perpendicular to the fin. Furthermore, the center drilling in the last-mentioned embodiment can also be designed in a way that provides a favorable flow in the area around the fin of the piston part. If e.g. combined with a pump with a built-in check-valve, the space between the connector and the check-valve need to have an airing or a similar solution. The activating pin is reliable, as it works independent of the piston rod fit and the tolerances of the pump valves. It is inexpensive to produce and it gives a low pump force, specifically with pumps without a check-valve. It works independent of piston control fit or pump valve tolerances.
In a sixth embodiment of the invention, the activating pin has a center axial drilling with a valve that is axially slidable in the drilling and is kept closed by means of a spring. The valve and the spring are made of one piece of deformable material. The axially slidable valve and the spring are partly formed by a conic section, with an apex angle (2ε), and partly formed by an approximately cylindrical section with a mainly circular cross section. The spring is attached to the piston part of the activating pin by means of a securing device. This is expedient if the wall of the center drilling in the activating pin is gradually expanded and has an angle η or ν, respectively, in relation to the center axis of the activating pin. Each angle is larger than 0° and smaller than 20° (usually in the interval between 6° and 12°). The wall of the gradual expansion of the center drilling thus forms a valve seat for the seal face of the valve. The valve is pulled to the tightening position by the spring. In a special embodiment of the invention, the piston part is equipped with at least one fin or a similar device which fits on top of the core of a Schrader valve.
In another embodiment of the activating pin, the slidable valve has two cones resting upon each other. This turns the air flow around the valve and in the grooves into an approximately laminar flow. The piston valve rod and the piston rod define e.g. a cylindrical channel, while the rest of the piston rod has a “flower-shaped” cross section. The embodiment of the flow ensures low aerodynamic drag so that it is comfortable when pumping even with low pressure pumps without an integrated non-return valve. In addition, the invention is inexpensive. It works independently of piston control fit and pump valve tolerances. In a special embodiment, the sealing surface of the cones is a small area with an angle ξ in relation to the center axis of approximately 90°-150° (incl.) with the center axis as seen in the flow direction of the air at flow from the side of the pressure source. This enables improved sealing. In the case of combining this embodiment with pumps with an built-in check-valve, the space between the connector and the check-valve needs to be equipped with airing or the like. Instead of air, (mixes of) gasses and/or liquids of any kind can activate and flow through and around the embodiments of the activating pin. The invention can be used in all types of valve connectors, where at least a Schrader valve or any valve with a spring operated core can be coupled, irrespective of the method of coupling or the amount of coupling holes in the connector. Further, the invention can be coupled to any pressure source irrespective of whether or not there is a securing means in the valve connector. Any possible combination of the embodiments shown in the specification fall into the scope of the present invention. The various embodiments described above are provided by way of illustration and should not be constructed to limit the invention. Those skilled in the art will readily recognize various modifications and changes which may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention.
DESCRIPTION OF THE DRAWINGS
In the following, the invention is described in detail by means of the preferred embodiments of which the main construction elements are shown on the drawings. The following is shown on the drawing:
FIG. 1 a shows an illustration of a channel's curve which is defined by two unique modular parametrisation Fourier Series expansions.
FIG. 1 b shows an illustration of the mathematical model of the “flower-shaped” cross section.
FIG. 2 shows a first embodiment of the activating pin shown in a distal position relative to the pressure source for a valve connector that can be squeezed onto valves.
FIG. 2.1 shows an enlargement of the piston valve according to FIG. 2 . The broken line drawing shows the valve when it is open.
FIG. 2.2 shows an enlargement of the embodiment of FIG. 2 where the side drilling is positioned distally in the piston rod together with a center blind drilling.
FIG. 3 a shows an enlargement of a further development of the second embodiment of the activating pin where the valve in the activating pin is activated by the eccentric valve lever.
FIG. 3 b shows the activating pin according to FIG. 3 a where the valve in the activating pin is kept closed by air pressure.
FIG. 3.1 shows section 3 . 1 — 3 . 1 of FIG. 3 a.
FIG. 3 d shows the top of the piston and valve of the activating pin according to FIG. 3 a.
FIG. 4 shows a third embodiment of the activating pin in a distal position relative to the pressure source for a valve connector that can be squeezed onto valves.
FIG. 5 a shows an enlargement of the activating pin according to FIG. 4 . The valve of the activating pin is activated by the eccentric valve lever.
FIG. 5 b shows the activating pin shown in FIG. 5 a where the valve is shut by gas and/or liquid mix pressure.
FIG. 5.1 shows section 5 . 1 — 5 . 1 of FIG. 5 a (the piston is not shown).
FIG. 5 d shows an eccentric valve pin that is freely movable in the piston of the activating pin.
FIG. 6 a shows the fourth embodiment of an activating pin similar to FIG. 5 a, with a rotatable piston valve which is activated by the eccentric valve pin.
FIG. 6 b shows the activating pin according FIG. 6 a, where the piston valve is closed by gas and/or liquid mix pressure.
FIG. 6.1 shows an end view 6 . 1 — 6 . 1 of FIG. 6 a.
FIG. 6.2 shows cross section 6 . 2 — 6 . 2 of FIG. 6 b.
FIG. 7 shows a fifth embodiment of the invention in a distal position relative to the pressure source for a valve connector that can be squeezed onto valves.
FIG. 8 a shows an enlargement of the invention according to FIG. 7 where the valve in the activating pin is activated.
FIG. 8.1 shows section 8 . 1 — 8 . 1 of FIG. 8 a.
FIG. 8 c shows an enlargement of the invention according to FIG. 7 where the valve in the activating pin is kept closed by the spring.
FIG. 8 d shows the embodiment according to FIG. 8 c, with a different sealing surface.
FIG. 9 shows the sixth embodiment of the invention in a distal position relative to the pressure source for a valve connector that can be squeezed onto valves.
FIG. 10 a shows an enlargement of the embodiment of FIG. 9 where the valve in the activating pin is in a closed position or activated position (broken lines).
FIG. 10.3 shows the top view 10 . 3 — 10 . 3 of the activating pin according to FIG. 10 a with spring suspension and intake.
FIG. 10.1 shows a section after the line 10 . 1 — 10 . 1 in FIG. 10 a.
FIG. 10.2 shows a section after the line 10 . 2 — 10 . 2 in FIG. 10 a.
FIG. 11 a shows the embodiment according to FIG. 10 a, with a different sealing surface.
FIG. 11 b shows an enlargement of the sealing surface of the embodiment of FIG. 11 a.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 a shows a cross section of e.g. a piston rod 801 with a channel 802 . Its curve is defined by two unique modular parametrisation Fourier Series expansion.
FIG. 1 b shows a mathematical model of the “flower-shaped” cross section that provides a suitable approximation. The general formula for this cross section is found above. In the model shown is:
r 0 ≈0.4r max , m= 4 and n= 6.
The change from a center drilling 303,410,533,653 to the circle section of expansions 312,313,411,412,538,539,658 can mathematically be expressed by
r
0
→r
max
under retention of the other parameters.
FIG. 2 shows the first embodiment with the piston 121 in its distal position relative to the pressure source for a valve connector that is squeezed onto valves. The piston 121 has a piston rod 122 and is equipped with a center blind drilling 123 which branches into at least one radial drilling 124 . Both blind drillings 123 , 128 have e.g. a “flower-shaped” cross section, of which the radius r 0 of blind drilling 123 is larger than radius r 0 of blind drilling 128 . The proximal part of drilling 123 and the distal part of drilling 128 can be provided with gradual expansions (not shown), seen from the pressure source. Also shown is the piston ring 131 .
FIG. 2.1 shows the radial drilling 124 which has an azimuth angle α to the center axis 125 of the piston 121 . The angle α is shown larger than 90°. The radial drilling 124 leads to the underside of the valve 126 . The valve 126 is shown in its open position by means of a broken line 126 a. The valve 126 is fastened by being squeezed between e.g. the upper and lower part (not shown) of the piston rod.
FIG. 2.1 shows the radial drilling 127 which is open at an angle β to the blind drilling 128 . The angle β is shown larger than 90°. The radial drilling 127 leads to e.g. a center blind drilling 128 at a distal position on the piston rod 122 .
FIG. 3 a shows a further development of the activating pin shown in FIG. 2 . The axially movable piston valve 225 is shown in an activated position by operation of the eccentric valve lever 226 which is integrated in the piston valve 225 . The piston valve rod 227 has a sealing surface 228 which is positioned at the end. This ensures that the piston valve 225 always opens up to make air flow possible, e.g. from the space between the non-return valve of a pump and the activating pin to the surroundings, when a Schrader valve is uncoupled. The piston rod 223 has a sealing 229 with a sealing surface 230 . The piston valve 225 has a sealing 238 with sealing surface 239 and the top of the piston 222 has a sealing surface 240 . The radius r 0 of drilling 248 is smaller than radius r 0 of drilling 224 . The air flows through the center drilling 224 , which has a “flower-shaped” section, and around the piston rod 227 which has a circular cross section resulting in channels 234 (section 3 . 1 — 3 . 1 ) which form the center drilling 224 . A stop device 231 prevents the piston valve from being pulled out of the activating pin as it strokes against the piston rod 223 . A radial drilling 247 is positioned distally. The center axis 237 of the activating pin is also shown. The piston valve can have a gradual expansion (not shown) proximal to the pressure source.
FIG. 3 b shows the activating pin according to FIG. 3 a where the piston valve 225 is kept shut by air pressure. The valve function is fulfilled by the sealing 236 in full accordance with FIG. 2 . The stop device 231 has a stop surface 232 and the piston rod 223 has a stop surface 233 .
FIG. 3.1 shows section 3 . 1 — 3 . 1 of the piston valve 223 , which has a “flower-shaped” section, and the piston valve rod 227 which has a circular cross section resulting in air channel 234 in order to enable a suitable flow through the section with reliable guidance of the piston valve rod 227 .
FIG. 3 d shows a top view of the activating pin where the piston valve rod 227 is hung in the shackle 235 . The figure also shows the eccentric valve pin 226 which is integrated into the piston valve 225 and which is a section of a cylinder surface. In an appropriate embodiment not shown the valve pin is made by means of at least two legs that can be arranged rotationally symmetric around the center axis 237 of the activating pin. The embodiments described in FIG. 3 d are, of course, applicable in connection with the other embodiments. Channel 242 is located between the shackle 235 , the piston valve 225 .
FIG. 4 shows the third embodiment of the activating pin with the piston 301 in its distal position relative to the pressure source in a coupling house of a valve connector that can be squeezed onto tire valves. The piston 301 has a piston rod 302 and a center drilling 303 . The activating pin has a piston valve 304 and an eccentric valve pin 305 . Also shown are the center axis 337 and piston ring 338 .
FIG. 5 a shows an enlargement of the activating pin of FIG. 4 . The axially movable piston valve 304 is in activated position by the eccentric valve lever 305 and has a sealing 306 with a sealing surface 307 . The piston 301 has a sealing surface 309 . The air flows through the proximally gradual expansion 310 of the center drilling 303 which e.g has a “flower-shaped” section to the distally gradual expansion 311 . The wall 312 , 313 forms an angle γ or δ, respectively, with the center axis 337 of the center drilling 303 . These angles are each larger than 0° and smaller than 20° and are usually in the interval between 6° and 12°. Both expansions 310 , 311 have an approximately circular section. Together, the “flower-shaped” cross-section of the piston valve rod 322 defines air channels 321 which e.g. four can be used in order to get an approximately laminar air flow. The stop 315 prevents the piston valve 304 from being pulled out of the activating pin in cases where the coupling is connected to a piston pump without a non-return valve. The stop 315 is resiliently mounted by means of the bar 316 in the bottom 317 of the piston valve rod 322 . The cross section of this channel changes constantly over its length. The activating pin has distally at least one fin or a shackle 318 which is optimally shaped in terms of air flow. Channel 324 is defined by partly the inside and outside (see section B-B) of the piston rod 302 , and partly by bar 316 . Channel 325 is defined by piston rod 304 , sealing 306 and the eccentric valve pin 305 .
FIG. 5 b shows the activating pin according to FIG. 5 a where the piston valve 304 is kept shut by air pressure. The stop device 315 has a stop surface 319 and the stop surface 320 is a part of the piston rod 302 .
FIG. 5. 1 shows a section 5 . 1 — 5 . 1 with the air channel 311 which has a suitable flow through the section area. Moreover, the stop device 315 and the fin 318 are shown.
FIG. 5 d shows the activating pin in an activated position with an eccentric valve pin 350 which is freely movable in the piston 301 of the activating pin and on which the piston valve 353 presses at the top 351 . The stop device 352 ensures that the valve pin does not fall through the piston 301 . In an appropriate embodiment not shown, the valve pin has at least two legs which can be positioned rotationally and symmetrically around the center axis 337 of the activating pin. The valve pin can also be designed as the valve pin 226 shown in FIG. 3 a. Embodiments described in FIG. 5 d are, of course, also applicable in connection with the other embodiments.
FIG. 6 a shows a fourth embodiment of the activating pin, which is similar to the third embodiment, in a position where the piston valve 401 is opened by the activated eccentric valve pin 402 . The piston valve 401 rotates over an angle θ from the center axis 403 of the activating pin. The piston valve 401 rotates around an axis 404 which is perpendicular to the center axis 403 . The rotation of the piston valve 401 is limited by the stop device 405 . The piston valve 401 has a sealing 414 with a sealing surface 406 , while the piston 407 has a sealing surface 408 . The rest of the activating pin is similar to FIG. 5 a, except for the piston rod 420 and the eccentric valve pin 402 which has a rounded top 421 as shown in FIG. 5 d. The channel 422 is defined by the piston valve 401 , the sealing 414 , the piston 407 and the eccentric valve pin 402 . The channel 423 is defined by the piston 407 and the piston valve 401 .
FIG. 6 b shows the activating pin similar to FIG. 6 a with the piston valve 401 shut. The piston rod 409 has different parameters for the “flower-shaped” cross section of the center drilling 418 . Also here are two gradual expansions 410 , 419 and walls 411 , 412 , respectively, with characteristics according to those of FIG. 5 a: angles μ and κ in relation to the center axis 403 . The contact area 413 (see also FIG. 6 b ) of the activating pin with a Schrader valve has a cone shape. No bridge is necessary, as r 0 is smaller than the diameter of the core of a Schrader valve.
FIG. 6.1 shows section 6 . 1 — 6 . 1 of FIG. 6 a with fin 415 and opening 416 .
FIG. 6.2 shows cross section 6 . 2 — 6 . 2 of FIG. 6 b with the “flower-shaped” cross section of the piston rod 409 defining air channel 417 . Also shown is a contact area 413 for engaging with the core of a Schrader valve.
FIG. 7 shows a fifth embodiment with the piston 531 in its distal position relative to the pressure source in the coupling house of a valve connector that can be squeezed onto valves. The piston 531 has a piston rod 532 and is equipped with a center drilling 533 .
FIG. 8 a shows the activating pin in activated position where an axially slidable valve 534 has a seal face 535 . The air flows through a proximal (to the pressure source) gradual expansion 536 of the center drilling 533 and through the latter to the distal gradual expansion 537 . The wall 538 , 539 forms an angle ρ or φ, respectively, to the wall 540 of the center drilling 533 . These are larger than 0° and smaller than 20° (usually in the interval between 6° and 12°). Both expansions 536 , 537 have an approximately circular cross section distally from the connection to the center drilling 533 . Also shown are the center axis 543 and the piston valve rod 544 .
FIG. 8.1 shows the section 8 . 1 — 8 . 1 from FIG. 8 a where the channel 533 is defined by a “flower-shaped” cross section of the piston rod 532 and a circular cross section of the valve rod 544 . Furthermore, a fin 542 is shown.
FIG. 8 c shows the activating pin with a closed valve. The spring 541 secured in the piston 531 is an elastic band which presses the axially slidable valve 534 down so that the seal face 535 of the valve is pressed against the wall 538 of the expansion 536 . The seal face 535 can have a similar sealing (not showed) with the wall 538 as showed in FIG. 11 a, 11 b.
FIG. 8 d shows an improved sealing surface arrangement: sealing 550 with surface 551 and piston rod 553 with sealing surface 552 . Angle Ψ is between 90°-150° (incl.). The channel 546 is defined by the sealing surfaces 551 and 552 , when these are separated from each other.
FIG. 9 shows a sixth embodiment with the piston 651 in its distal position relative to the pressure source in a coupling house of a valve connector that can be squeezed onto valves. The piston 651 has a piston rod 652 and is equipped with a center drilling 653 .
FIG. 10 a shows the activating pin in its closed position and its activated position (broken lines) where the axially slidable valve 654 has a seal face 655 . The air flows through the expansion 656 of the center drilling 653 and through the latter to the distal gradual expansion 657 and the distal part of the piston rod with a “flower-shaped” cross section. The wall 658 , 659 forms an angle η or ν, respectively, to the wall 660 of the center drilling 653 . These angles are each larger than 0° and smaller than 20° (usually in the interval between 6° and 12°). Both expansions 656 , 657 have an approximately circular cross section. The valve 654 has a spring part 661 secured in a brace 662 . Distally, the activating pin has at least one fin or brace 663 . Furthermore, a cone 664 is shown.
FIG. 10.3 shows the top of the activating pin shown in FIG. 10 a with the three expansions 656 and braces 662 . The braces serve as a securing device for the valve spring and the expansions 656 ensure a suitable flow cross section.
FIG. 10.1 shows the section 10 . 1 — 10 . 1 in FIG. 10 a resulting in a cylindrical air channel 653 . A suitable flow cross section is also ensured here.
FIG. 10.2 shows the section 10 . 2 — 10 . 2 in FIG. 10 a. Internally, this section of the piston rod 652 is “flower-shaped” to ensure a suitable flow cross section. Furthermore, a fin designed as a brace 663 is shown. Also shown is the channel 666 between the brace 663 and the piston rod 652 .
FIG. 11 a shows an activating pin similar to the one of FIG. 10 a, with the sealing surface 704 of the cone 702 and the corresponding surface 703 for the piston rod 701 having an angle ξ equal to or larger than 90° and less than approximately 150° with the center axis 665 seen in the direction of the flow of the air at flow from the pressure source. Channel 705 is defined by the sealing surface 703 and 704 , when these are separated from each other.
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An activating pin which comprises a valve part, the piston part comprises within it a channel, the cross-section of said channel is, at least one part of said piston part, consisting of sectors, wherein in each sector the distance between the center point of the channel cross-section and the outermost limiting surface of the channel is larger than the corresponding distance measured along the line separating the sector from an adjacent sector, and said valve part is positioned movably with respect to said piston part between a first valve position and a second valve position for enabling the conduction of gaseous and/or liquid media through said channel when said valve part is in said first valve position, and inhibiting the conduction of gaseous and/or liquid media through said channel when said valve part is in said second valve position.
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RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/695,288, which application was filed on Jun. 30, 2005, which application is incorporated by reference in its entirety herein.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates generally to the field of culinary arts and more particularly to the field of prepackaged foodstuffs.
[0004] 2. Background Art
[0005] The world today is a place of ever-increasing hustle and confusion. The demands of everyday life and the hectic pace of living for most individuals and families allow for very little “down time” and other opportunities to “stop and smell the roses.” In days gone by, many meals would be painstakingly prepared with great care and the expenditure of a significant amount of time. No more. Today, most people simply don't have the luxery of spending as much time as they might like in the preparation of food. The advent of fast foods and prepackaged foods are but a few indicators of the ever-increasing growth of time-saving approaches to providing busy people with eating options that fit their hectic lifestyles.
[0006] Another casualty of the busy lifestyle so prevelant today is the near demise of breakfast as a meal. Instead of a nourishing breakfast with a variety of healthy choices, many people simply grab a bowl of prepared, sweetened breakfast cereal. While this may be a quick meal, it is hardly nourishing or even appetizing. Alternatively, some people may opt to grap a slice of bread or a bagel to supplement their morning meal. However, while a bagel may be a more nutritious choice than sugery cereal, it is also nutritionaly deficient in some respects. For example, while most bagels provide an adequate amount of carbohydrates, little protein is contained in a standard bagel. Additionally, the taste of a plain bagel is not acceptable to some individuals. In order to address these various shortcomings, it is common practice to slice a bagel in two halves and add various toppings to bagel, sandwich style. This is typically done to both enhance the nutritional value and to enhance the taste experience when consumed. Alternatively, the bagel may be eaten “open-faced” with a topping placed on the split bagel half.
[0007] While the addition of foodstuffs to bagels is well known, there are few prepared bagel toppings that can be quickly and easily added to a bagle without some effort. For example, while cream cheese is a popular addition to a bagel, it takes time to get the cream cheese out of the refrigerator and then to spread the cream cheese on the surface of the bagel. Some people also find it difficult to quickly and evenly distribute the cream cheese over the surface of the bagel and, accordingly, may not be satisfied with the uneven results. Further, the cold cream cheese is often somewhat difficult to spread and may damage the surface of the bagel when spread too quickly.
[0008] Additionally, while other types of prepared, pre-sliced toppings such as ham and american cheese may be placed, sandwich style, on a split bagel, the typical pre-sliced topping is generally square or rectangular in shape. These ill-fitting shapes are obviously aesthetically and practically mismatched when placed on the open face of a round bagel. The excess topping material hanging over the edge of the bagel must be painstakingly trimmed or consumed without consuming a corresponding amount of bagel. While these various toppings have been employed for years, they are obviously not well suited for the express purpose of topping a bagel. Accordingly, while these various known solutions are not without merit, all fall short of the desired goal for quickly and easily topping a bagel for enhanced nutrition and eating pleasure.
[0009] As shown by the previous discussion, without additional improvements in the form, content, packaging and shape of bagel toppings, the efficiency and enjoyment of eating bagels will continue to be suboptimal.
BRIEF SUMMARY OF THE INVENTION
[0010] A substantially flat and circular bagel topping, sized to fit a bagel, is disclosed. The bagel topping may be manufactured from a variety of foodstuffs, including various cheeses and the like. Certain embodiments of the present invention will further incorporate an aperture in the center of the substantially circular bagel topping, thereby conforming to bagels with a center hole as well. The most preferred embodiments of the present invention will be thin, circular slices, with each slice being individually pre-packaged within a plastic-like material to facilitate quick and easy dispensing and application of the bagel topping on the bagel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The preferred embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements and:
[0012] FIG. 1 is an exploded view of a bagel and bagel topping in accordance with a preferred exemplary embodiment of the present invention;
[0013] FIG. 2 is a plan view of a bagel topping in accordance with a preferred embodiment of the present invention;
[0014] FIG. 3 is a side view of a bagel topping in accordance with a preferred embodiment of the present invention;
[0015] FIG. 4 is a plan view of a bagel topping enclosed in a plastic wrapper in accordance with a preferred exemplary embodiment of the present invention; and
[0016] FIG. 5 is a flow chart for a method of implementing bagel toppings in accordance with a preferred exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0017] Referring now to FIG. 1 , an exploded view of a bagel 100 and a bagel topping 120 in accordance with a preferred embodiment of the present invention is shown. As shown in FIG. 1 , bagel 100 can be separated into two halves, half 110 and half 130 . Bagel topping 120 may be manufactured from any appropriate foodstuff but in the most preferred embodiments of the present invention is manufactured from cream cheese. Depending on the manufacturer of bagel 100 , bagel 100 may also have an optional indentation in the top or bottom and/or and aperture 105 that extends through the body of bagel 100 . Those skilled in the art will recognize that bagel 100 may be provided in many different sizes, with varying diameters.
[0018] Bagel topping 120 most preferrably has a flat, substantially circular form with a diameter sized to be substantially equal to the diameter of bagel 100 . Given that bagel 100 may be manufactured with a plurality of diameters, it is considered within the scope of the invention to provide bagel toppings 120 with the same or substantially similar diameters as the standard range of diameters for any and all commercially available bagels 100 . In this fashion, an appropriately sized bagel topping 120 will be available for use with a wide range of bagels 100 . As shown in FIG. 1 , bagel 100 and bagel topping 120 are typically assembled in “sandwich” fashion with bagel topping 120 being placed between the halves 110 and 130 .
[0019] One simple process for making cream cheese is set is set forth herein. This process is for a relatively small batch of cream cheese but may be adapted for larger quantities, if desired. Typically, 2 or 3 litres of skim or whole milk (cow or goat's milk, for example), or cream or raw milk will be combined with other ingredients.
[0020] The process is most preferrably conducted at room temperature, in the range of 20-24 degrees C. (68-75 degrees F.). Typically, 2 or 3 litres of skim or whole milk (cow or goat's milk, for example), or cream or raw milk will be combined with 200 ml mesophilic culture (10% by volume). In a clean pot, the milk mixture is pasteurized at 62 degrees C. or 145 F and held for approximately 20 minutes, if using raw milk. After pasteurization, the milk mixture is allowed to cool down to 20-24 degrees C. in a cool water bath. Next, 200 ml of mesophilic culture (10% by volume) is added to the milk. Alternatively, it would be possible to use ¼ tsp of mesophilic powder culture for 2 litres of milk, or V 2 tsp of mesophilic powder culture for 3 litres of milk, or even ¼ tsp mesophilic pellets. Next, 2-3 drops of liquid Rennet is added to the milk mixture and the mixture is stirred well to combine the ingredients.
[0021] Next, the pot containing the milk mixture is covered and the milk mixture is allowed to set at room temperature until a firm curd forms. This will typically take approximately 14-16 hrs. Once a firm curd has formed and some clear whey has been formed on the top of the curd, the entire curd is poured into a cheesecloth draining bag and drips for approximately 8-12 hours until the bag feels slightly damp. The cream cheese may then be removed from the bag and stored in a clean container. If desired, salt and/or fresh or dry herbs may be added to provide additional flavor for the cream cheese. Once formed, this cream cheese product will keep for approximately two weeks if refrigerated. If a longer shelf life is necessary, then preservatives may be added as well. Using the process set forth herein, the yield for the cream cheese would be approximately 20% by volume. Accordingly, starting with 3 litres of whole milk, it would be possible to produce approximately 600 grams of cheese (approximate 1⅓ pounds). Typically, the resulting cream cheese yield goes down as the fat content of the milk drops.
[0022] Those skilled in the art will recognize that other processes for making cream cheese may be utilized as well. These processes may be adapted for use in conjunction with the present invention wihthout undue experimentation. After the cream cheese has been obtained, it is necessary to form it into the desired shape for use in the preferred embodiments of the present invention. The most common form of cream cheese known is most likely the “block” form. Another common form of cream cheese is a spreadable paste stored in “tubs.” As previously explained, these existing options are at least somewhat deficient in certain ways.
[0023] In one preferred embodiment of the present invention, a cylindrical or “log-shaped” piece of cream cheese may be formed with the desired circumference (approximately equal to the circumference of a standard bagel) and then thin slices of cream cheese in the desired thickness may be sliced from the cylindrical piece of cream cheese, thereby forming the circular slices of the present invention. Depending on the application, an aperture may be formed in the cream cheese slice to more closely match the shape of the bagel.
[0024] In yet another preferred embodiment of the present invention, the cream cheese will be pressed flat into thin sheets of the desired thickness. Once the thin sheets of cream cheese have been formed, the desired circular shape set forth in the various preferred embodiments of the present invention can be formed by using a stamping process or other process suitable for the purposes of the present invention. Regardless of the process used to obtain the cream cheese slices, once the relatively thin, circular slices of cream cheese or other bagel topping have been manufactured, they are most preferrably wrapped in individual plastic wrappers to preserve the freshness of the product and to provide for convenient distribution and use.
[0025] Referring now to FIG. 2 , a plan view of bagel topping 120 from FIG. 1 is shown. As shown in FIG. 2 , bagel topping 120 has an outer diameter 210 and, optionally, an inner diameter 220 . If bagel 100 of FIG. 1 has an aperture 105 formed in the middle of bagel 100 , it may be desirable to remove a substantially circular portion of bagel topping 120 , thereby forming an aperture, with the apertue having a diameter equal to inner diameter 220 . This aperture may be as large or small as desired, thereby providing a method for optimizing the ratio or amount of bagel topping for the bagel. For example, if inner diameter 220 is very small, then more of bagel topping 120 will be provided. Conversely, if inner diameter 220 is increased, then less of bagel topping 120 will be provided for consumption. In the most preferred embodiments of the present invention, inner diameter 220 will be equal to approximately ⅕-⅙ of outer diameter 210 .
[0026] Referring now to FIG. 3 , a side view of bagel topping 120 from FIG. 1 is shown. As shown in FIG. 3 , bagel topping 120 has a thickness 310 . Thickness 310 may be adjusted to provide the appropriate and desired ratio of bagel topping 120 to bagel 100 for maximum enjoyment during consumption. For example, if more bagel topping 120 is desired for each bite of bagel 100 , then thickness 310 will be increased during the manufacturing process. Conversely, if less of bagel topping 120 is desired for each bite of bagel 100 , then thickness 310 will be decreased during the manufacturing process. In this fashion, bagel topping 120 can be provided at the desired thickness. In the most preferred embodiments of the present invention, thickness 310 will be in a range between 1/16 of an inch and ½ inch
[0027] Referring now FIG. 4 , a plan view of a bagel topping 120 enclosed in a plastic wrapper 410 in accordance with a preferred exemplary embodiment of the present invention is shown. As shown in FIG. 4 , bagel topping 120 is enclosed within plastic wrapper 410 and repositionable flap portion 420 may be used to seal bagel topping 120 inside plastic wrapper 410 . The use of plastic wrappers with repositionable flap portions to enclose individual portions of ready-to-serve foodstuffs, particularly cheese slices, is well known to those skilled in the art. In the most preferred embodiments of the present invention, plastic wrapper 410 is manufactured from a thin, transparent plastic film of the type typically used to preserve and distribute similar types of foodstuffs. Additionally, it is anticipated that certain preferred embodiments of the present invention, such as packaging for point-of-sale purchases at grocery stores, etc., will include a plurality of individually wrapped bagel toppings 120 in a cardboard container, allowing for the purchase of a plurality of individually wrapped bagel toppings in a single container.
[0028] Referring now to FIG. 5 , a flow chart for a method 500 of implementing a bagel topping in accordance with a preferred exemplary embodiment of the present invention is depicted. As shown in FIG. 5 , a bulk version of the desired bagel topping is obtained (step 510 ). As previously explained, the desired bagel topping may be any type of bagel topping including cheese, meats, etc.
[0029] Next, the bagel topping is formed into subtantially circular slices (step 520 ) with a circumference that is approximately equal to a standard bagel. Once the slices have been prepared, the individual slices are packaged (step 530 ) and the slices are grouped together in the desired packaging units (step 540 ) and made available to consumers via any appropriate distribution methodology (step 550 ). Once the slices have been received by the consumer, the slices can be removed from the packaging, placed on bagels (step 560 ) and consumed (step 570 ).
[0030] In summary, the present invention provides for the quick and easy application of certain desired bagel toppings to bagels. By implementing one or more of the preferred embodiments disclosed herein, the consumption of bagels can be enhanced from both the nutritioal perspective and taste perspective. Lastly, it should be appreciated that the illustrated embodiments disclosed herein are preferred exemplary embodiments only, and are not intended to limit the scope, applicability, or configuration of the present invention in any way. Rather the foregoing detailed description provides those skilled in the art with a convenient roadmap for implementing the preferred exemplary embodiments of the present invention. Accordingly, it should be understood that various changes may be made in the function and arrangement of elements decribed in the various preferred embodiments without departing from the spirit and scope of the present invention as set forth in the appended claims.
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A substantially flat and circular bagel topping, sized to fit a bagel, is disclosed. The bagel topping may be manufactured from a variety of foodstuffs, including various cheeses and the like. Certain embodiments of the present invention will further incorporate an aperture in the center of the substantially circular bagel topping, thereby conforming to bagels with a center hole as well. The most preferred embodiments of the present invention will be thin, circular slices, with each slice being individually pre-packaged within a plastic-like material to facilitate quick and easy dispensing and application of the bagel topping on the bagel.
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BACKGROUND OF THE INVENTION
Hub joints used for joining space frames typically include multiple assembly parts, and require significant time to assemble or disassemble using special tools. Conventional hub joints may only be assembled into a specific structure. The cost of conventional hub joints is typically high, due to components requiring machining or custom fabrication.
Space frames have increased in popularity in the last decades. This is due to better materials and computer aided design tools. Indeed, complex space frame and truss structures may be seen in many applications including amusement parks, commercial buildings, complexes, hangers, space stations, playgrounds, road signs, towers, and tents, for example.
A key component of any space frame structure is the connector or joint. The type of joint depends on the connection method (welding, bolting, etc.), the size of the joining members, and the role the space frame has in the application. Many types of joints are used for space frame structures. For example, Leung in U.S. Pat. No. 5,056,291 describes a modular system for space frame structures, in which a crystal-like hub is used to connect struts in a variety of configurations. The hub joins struts having ends equipped with C-shaped grips, which engage trunnions. The C-shaped end grips may rotate about an axis of the trunnions. A disadvantage of the Leung invention is that it requires custom manufactured components and special tooling. The Leung invention is also limited in the number of struts that may be attached to the hub. Furthermore, although the end grips snap into place, they are not locked and, hence, may unexpectedly be unsnapped.
Grimm in U.S. Pat. No. 4,676,043 describes a hub joint having elements arranged concentrically to one another. The Grimm invention forms a strong, complex, durable space frame structure. However, the Grimm invention requires custom manufactured components and special tooling, including multiple bolts and pins that have high non-recurring setup and manufacturing costs.
Some popular conventional joints include: (1) the MERO connector, (2) the UNISTRUT system, (3) the Space Deck system, (4) the Triodetic system, (5) the UNIBAT system, and (6) the NODUS system
The MERO connector, introduced in 1942, includes tubular members with threaded ends connected to a steel sphere node. The sphere node is drilled and tapped to accept the tubular members. The MERO connector is a popular connector due to its strength, elegance of assembly, and improvements including a cylindrical joint (type ZK), a plate-disc joint (type TK), a hollow semi-spherical joint (type NK), and a block joint (type BK).
The UNISTRUT system, introduced in 1955, includes a connector consisting of a pressed steel plate formed in a special tooling machine. The UNISTRUT system, which includes four components, is self aligning and self-leveling.
The Space Deck system was introduced in the United Kingdom during the 1960s as an industrialized space frame system which, when assembled at the site, produces a double-layer square-on-offset square configuration. The basic unit is an inverted square based pyramid consisting of an angle top tray and four diagonal or bracing members. Connection requires bolting top layer members and interconnecting them using tie bars. A turnbuckle is used to adjust the center camber of the structure.
A Canadian firm of F. Fentiman developed the Triodetic system, which is a popular hub joint system. This system uses an extruded aluminum hub for inserting members of any cross-section, after a deforming process to shape the ends of the members. This hub joint system effectively substitutes for welding, bolting or riveting.
S. du Chateau introduced the UNIBAT system in France in 1977. Its modular pyramidal skeletal units are bolted at their corners to adjacent units with bolts. A lower layer is formed by tubular members, which are flattened and joined by only one vertical bolt. The UNIBAT system may be used for double-layered or multi-layered structures.
The Tubes Division of the British Steel Corporation introduced the NODUS system in 1972. The joint of the NODUS system consists of two casings, with chord and fork connectors used as diagonals. The casings are held together by a center bolt. Although the NODUS system has been used in the construction of horizontal double-layer grids, it may be adapted to vertical, inclined or multi-layer grids. This system has been used throughout the world.
Common to all of the above mentioned hub joints are multiple components requiring custom manufacturing, complex assembly, and/or specialized tools. Hence, the cost of manufacturing, assembling, reconfiguring, and disassembling the aforementioned systems is high, when used in large or complex structures. Furthermore, they may only be used in specific structures for which they were originally intended. Joints and members cannot be removed after a structure is partially or fully assembled.
As will be explained, the present invention provides a simple, low cost, lightweight, strong, and durable hub joint for rapidly assembling, reconfiguring, or disassembling a frame structure. The present invention joins and secures tubular members at a vertex or a node using a low cost hub joint that requires minimal manufacturing costs with common off the shelf materials and components.
As will be explained, the present invention includes a hub joint that may be easily scaled using any size and number of tubular members, and may be used in any type of space frame structure including geodesic domes, trusses, slabs, 4-sided pyramids, 5-sided pyramids, and circular structures.
SUMMARY OF THE INVENTION
To meet this and other needs, and in view of its purposes, the present invention provides a joint for attaching a plurality of longitudinal members. The joint includes:
(a) at least two members, each including a circumferential wall forming a longitudinal core,
(b) a transverse slot formed through the circumferential wall for communication with the longitudinal core of each member,
(c) a rod for insertion into the transverse slots of the at least two members, and
(d) a respective locking pin for insertion into the longitudinal core of a respective member for clasping the rod. The rod is inserted through the transverse slot of the at least two members, and the respective locking pin clasps the rod.
The rod is curved and ends of the rod are in contact to form a ring. The locking pin includes two arms biased by a spring, and the two arms are configured to clasp the rod. The members are rotatable about the rod. The rod is inserted substantially parallel to the transverse slot of each member. The locking pin is inserted substantially parallel to the longitudinal core of each member. The rod forms a hinge, about which each member is rotatable.
The transverse slot is formed at a first longitudinal end of each member, and the rod is transversely inserted into the slot at the first longitudinal end of each member. At least one member includes an additional transverse slot formed at a second longitudinal end of the one member. An additional rod and an additional locking pin are configured for insertion into the second longitudinal end of the one member and the additional transverse slot, respectively. A cap is provided for sealing an end of the longitudinal core of the respective member, after the locking pin is inserted to clasp the rod. The rod is shaped to form a polygon with the ends of the rod abutted to each other.
Another embodiment of the present invention is at least one joint for attaching longitudinal members. The joint includes:
(a) a rod curved to form a ring or a polygon,
(b) a longitudinal bore extending between first and second end portions of each longitudinal member,
(c) a slot formed transversely at the first end portion of each longitudinal member, wherein the transverse slot is in communication with the longitudinal bore, and
(d) a clasp provided for each transverse slot.
The transverse slot of each member is configured to receive a section of the rod for orienting the first end portions of the longitudinal members adjacent to each other, and the second end portions of the longitudinal members extending radially away from the rod. The clasp is configured for insertion into the longitudinal bore to lock the rod within the transverse slot. The clasp includes two arms biased by a spring, and the two arms extend into the longitudinal bore and through the transverse slot to envelop the rod and form a hinge about which the longitudinal members are rotatable.
The at least one joint may further include:
(e) another transverse slot formed at the second end portion of one of the longitudinal members,
(f) another rod, and
(g) another clasp.
The other rod is inserted in the other transverse slot formed at the second end portion of the one longitudinal member. The other clasp is configured for insertion into the longitudinal bore to lock the other rod within the other transverse slot.
The at least one joint may further include:
(h) still another transverse slot formed at the second end portion of another one of the longitudinal members,
(i) still another rod, and
(j) still another clasp.
The still other rod is inserted in the still other transverse slot formed at the second end portion of the other one longitudinal member. The still other clasp is configured for insertion into the longitudinal bore to lock the still other rod within the still other transverse slot.
The at least one joint may further include: a plurality of transverse slots formed in a plurality of longitudinal members wherein two of the slots are formed in each of the plurality of longitudinal members; a plurality of rods; and a plurality of clasps. The plurality of longitudinal members, the plurality of rods and the plurality of clasps are configured to form a space frame structure.
The longitudinal members are rotatable about a hinge formed by the rod inserted in the transverse slots of the longitudinal members. The longitudinal members are formed from either hollow PVC tubing, hollow steel tubing, or hollow aluminum tubing.
Yet another embodiment of the present invention is a method of forming a space frame structure. The method includes the steps of:
(a) forming a transverse slot at each end portion of a circumferential wall of each of a plurality of longitudinal members;
(b) inserting a first circular or polygonal rod into a first set of multiple transverse slots to form a first joint;
(c) clasping the first set in the first rod to form a first hinge for rotating the longitudinal members about the first hinge;
(d) inserting a second circular or polygonal rod into a second set of multiple transverse slots to form a second joint; and
(e) clasping the second set in the second rod to form a second hinge for rotating the longitudinal members about the second hinge.
The first and the second joints are configured to form a portion of a three-dimensional frame structure. The first and second hinges are oriented at different points in the three-dimensional frame structure.
The method may further include the step of covering the longitudinal members with a skirt.
The step of clasping may be performed by hand. The method may include the step of separating the first and second hinges from the longitudinal members by hand.
BRIEF DESCRIPTION OF THE FIGURES
The invention may be understood from the following detailed description when read in connection with the accompanying figures:
FIG. 1 shows a notched tubular member, a ring, a locking pin, and an end cap, in accordance with an embodiment of the invention;
FIG. 2 is an assembled notched tubular member, ring, and locking pin with an end cap, in accordance with an embodiment of the invention;
FIG. 3 is a cross section of an assembled notched member, ring, and locking pin, in accordance with an embodiment of the invention;
FIG. 4 is an assembled member, ring, pin, and end cap, in accordance with an embodiment of the invention;
FIG. 5 is an assembled member having a notch at each end, with each end including a ring, a pin, and end cap, in accordance with an embodiment of the invention;
FIG. 6 is another view of the tubular member shown in FIG. 5 ;
FIG. 7 is an eight-sided ring, in accordance with an embodiment of the invention;
FIG. 8 is a twelve-sided ring, in accordance with an embodiment of the invention;
FIG. 9 is an elongated eight-sided ring, in accordance with an embodiment of the invention;
FIG. 10 is a truncated six-sided ring, in accordance with an embodiment of the invention;
FIG. 11 is a dual ring having four spacers, in accordance with an embodiment of the invention;
FIG. 12 is a dual ring having eight spacers, in accordance with an embodiment of the invention;
FIG. 13 is a dual ring having twelve spacers, in accordance with an embodiment of the invention;
FIG. 14 is a top view of a six-tube ring assembly, in accordance with an embodiment of the invention;
FIG. 15 is a top view of an eight-tube ring assembly, in accordance with an embodiment of the invention;
FIG. 16 is a top view of a twelve-tube ring assembly, in accordance with an embodiment of the invention;
FIG. 17 is a top view of a six-tube ring assembly with one tube shown oriented perpendicularly to the other tubes, in accordance with an embodiment of the invention;
FIG. 18 is a top view of a four tube truncated ring assembly, in accordance with an embodiment of the invention;
FIG. 19 is an assembled geodesic dome that uses hub joints of the present invention;
FIG. 20 is an assembled truss composed of pentahedron units that uses hub joints of the present invention;
FIG. 21 is an assembled Howe truss that uses hub joints of the present invention;
FIG. 22 is an assembled space frame that uses hub joints of the present invention;
FIG. 23 is an assembled space frame with vertical supports that uses hub joints of the present invention;
FIG. 24 is the assembled space frame of FIG. 23 including a canopy;
FIG. 25 is the assembled space frame of FIG. 23 including a canopy and skirt;
FIG. 26 is a custom fit space frame with vertical supports that uses hub joints of the present invention;
FIG. 27 is the custom fit space frame of FIG. 26 with vertical supports and a canopy;
FIG. 28 is the custom fit space frame of FIG. 26 with vertical supports, canopy and skirt;
FIG. 29 is an assembled four-story space frame structure composed of tetrahedron units, in accordance with an embodiment of the invention; and
FIG. 30 is the assembled four-story space frame structure if FIG. 29 with accessory panels.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a longitudinal tubular member 1 , with a transverse slot or notch 2 , cut through a circumferential wall of the member, which is adjacent to the end of the member. The figure also shows ring 3 , pin 4 , and end cap 5 . The components in FIG. 1 are assembled by inserting ring 3 into slot 2 . The pin 4 is then inserted through the open end of the tubular member for enveloping the ring segment inserted through notch 2 . The pin 4 thus prevents the ring from falling out of the notch. End cap 5 is fitted into the end of the tubular member, after the pin is inserted. This provides a covering for the open end of the member. The end cap 5 is shown inserted into the tube end; however, an outside end cap may be used with a slightly larger end cap and ring diameter.
The notch 2 may be formed at one end or both ends of the tubular member, for example, one half inch from each end. The tubular member 1 is free to pivot almost 360 degrees about its ring segment while still retaining its integrity and strength. This freedom of motion is a key advantage to the flexibility and diverse construction forms that may be formed with the invention.
The length of notch 2 may be cut through no more than one third the circumference of the tube, for example, so that pin 4 may fit easily about the exposed ring segment in the slot or notch 2 . The width of notch 2 may be the same as the thickness of the ring, for example, 5/32″, 3/16″, etc. The notch may be cut, for example, parallel to the end of the member or parallel to the ring radius providing any ring diameter. Inserting and removing pin 4 may be performed by hand as it requires neither tools, nor special equipment.
The diameter of ring 3 may be considered to be a function of the outer diameter of the tubular member, the distance of notch 2 from the end of the tubular member, and the number of tubular members connected to the ring. For example, for 1.5″ schedule 40 PVC, the PVC tubular outer diameter is 1.9″, or approximately 2″. If twelve 1.5″ PVC tubes converge at the same ring, then the ring circumference is at least equal to 12×2″=24″. The circumference, c, of a circle is equal to the diameter d times π. Therefore, the diameter is at least c divided by π or 7.6″. If notch 2 is cut ½″ from the end of the tube, then twice that distance may be added (2×½″=1″), to 7.6″ or 7.6″+1″=8.6″. Therefore, the diameter of ring 3 may be at least 8.6″ for receiving twelve 1.5″ schedule 40 PVC tubular members.
The tubular member 1 and end cap 5 may be fabricated, for example, from polyvinylchloride (PVC), aluminum, or steel to prevent bending or breaking under heavy loads. Furniture grade PVC is available in many sizes and colors and may be fabricated with an ultraviolet (UV) inhibitor for outdoor use. The ring may be fabricated, for example, from 5/32″ or 3/16″ 1080 steel or 304 stainless steel rod stock and may be butt-welded at the joined ends of the ring. The pin may be, for example, a hitch pin or bow tie cotter pin, and may be made of steel or stainless steel, so that it easily locks around or envelops the ring and does not break, shear, or separate from the ring. The pin fits easily inside the end of the member and locks about the ring and may easily be removed by hand, if necessary.
The present invention provides a joint that is as strong as or stronger than the tubular members, while still allowing quick assembly, reconfiguration, and disassembly of any space frame structure, without use of tools or specialized equipment. The present invention allows tubular members to be quickly assembled with only two components: ring 3 and pin 4 . The present invention also allows tubular members to be easily added or removed from a structure that has already been assembled. This is possible without distorting adjacent members or requiring any special tools or equipment. The tubular members may easily be slid into or out of place, once the locking pin is removed. This is true for all tubular members in any orientation in the structure. An assembled structure may easily be expanded in size, by simply inserting additional tubular members with locking pins and end caps.
Typical schedule 40 PVC diameter dimensions for the tubular members are:
PVC Size
O.D.
I.D.
1″
1.215″
1.029″
1.25″
1.66″
1.36″
1.5″
1.9″
1.59″
2″
2.375″
2.047″
While typical schedule 80 PVC dimensions for the tubular members may be:
PVC Size
O.D.
I.D.
1″
1.315″
0.936″
1.25″
1.66″
1.255″
1.5″
1.476″
1.476″
2″
2.375″
1.913″
FIG. 2 shows an embodiment of the present invention in assembled form at one end of tubular member 1 . Of course, both ends of tubular member 1 may be similarly notched. As shown, ring 3 fits easily into notch 2 and pin 4 may be inserted by hand through the core of the tubular member (also referred to herein as the tube) at one end and locked about the exposed ring segment inside the tube. End cap 5 may be inserted into the end of the tube after pin 4 is placed on the ring segment. The tube 1 is free to pivot almost 360 degrees about the ring segment, while maintaining the strength and integrity of the joint.
FIG. 3 shows a cross section of an embodiment of the present invention including ring 3 , tube 1 and pin 4 . Notch 2 may be cut a minimum of ½″ from the end of the tube and its depth may extend to no more than approximately ⅓ of the outer circumference of the tube. The width of the notch may be equal to the thickness of the ring. The straight portion of the pin section, shown parallel to the length of the tubular member, fits between a segment of ring 1 and the inner surface of the tube. The straight portion of the pin may be visible from the opening of notch 2 . Both tube ends may be assembled in the same manner using a ring and a pin combination.
FIG. 4 shows an assembled embodiment of the present invention, including tube 1 , ring 3 and end cap 5 . Although not shown, both ends of tube 1 may include a notch and may be similarly assembled. The combination of tube 1 , ring 3 and end cap 5 should include compatible materials that provide sufficient strength and durability for the intended structure. The end cap prevents tampering with the pin and provides an aesthetically pleasing appearance. As such, it may not be necessary and may be considered as optional.
FIG. 5 shows an assembly of an embodiment of the present invention, designated as 9 . It includes tubular member 1 , ring 3 at each end of the tubular member, and end caps 5 , one for each end. The assembly order is not critical, since tubular members may be easily added or removed, even after a structure is fully assembled. The assembly 9 is lightweight, since each component is lightweight, yet provides high strength and durability.
FIG. 6 shows an assembled tube 1 , rings 3 , and end caps 5 in accordance with the present invention. The pins are not visible in the figure with the end caps in place. The rings 3 in the figure are shown perpendicular to tubular member 1 and may be rotated about ring 3 to almost any angle with respect to tubular member 1 . The freedom of rotation of tubular member 1 relative to a plane of ring 3 advantageously allows many different structures to be assembled, reconfigured, and disassembled, while providing a strong, durable, and aesthetically attractive joint.
FIG. 7 shows another embodiment of the present invention, in which the ring is not circular in shape, but is polygonal in shape. The eight-sided ring 11 will support up to eight tubular members with individual pins and end caps. The diameter of the eight-sided ring 11 is dependent upon the outer diameters of the attached tubular members. The ring 11 may be fabricated, for example, from steel or stainless steel. The thickness of the ring may be, for example, 5/32″ or 3/16. The ring may be lightweight and provide significant strength.
FIG. 8 shows yet another embodiment of the present invention using a twelve-sided ring 12 . The twelve-sided ring 12 will support up to twelve tubular members with respective pins and end caps. The diameter and thickness of the twelve-sided ring 12 may be similar to the eight-sided ring.
FIGS. 9 and 10 show still other embodiments of the present invention. FIG. 9 shows an eight-sided elongated ring, designated as 13 , which will support up to ten tubular members with respective pins and end caps. The diameter of the eight-sided ring 13 is dependent upon the outer diameter of attached tubular members, as describe earlier. FIG. 10 shows a six-sided ring, designated as 14 , which will support up to seven tubular members with respective pins and end caps. This embodiment may be used, for example, at the outer periphery, or border of a space frame, such as a geodesic dome or a truss, because the ring orientation may be vertical with respect to the ground and two horizontally oriented tubular members may be attached to the longer segment of the six-sided ring 14 .
FIG. 11 shows another embodiment of the present invention, designated as 16 . As shown, two rings 3 are fabricated parallel to one another with the addition of four perpendicular spacers 15 joining the two rings 3 . The distance between the parallel rings 3 may be, for example, ½″ to 1″ depending on the tube size. This embodiment may be used for providing four sections for joining tubular members. The assembly 16 , for example, may be used for tubular members having one size for attachment to the lower ring 3 and another size for attachment to the upper ring 3 . This embodiment may be used, for example, when multiple tubular members are positioned in the same plane, but need to be perpendicular to the ring plane. This ring structure 16 provides additional stability in complex space frame structures. The spacers 15 provide both positioning indices, as well as structural support.
FIGS. 12 and 13 show two more embodiments of ring structures, designated as 17 and 18 , respectively. As shown in FIG. 12 , two rings 3 are fabricated parallel to one another with the addition of eight spacers 15 providing eight sections for tube placements. The ring structure may support, for example, eight tubes depending on the ratio of the outer tube diameter and ring diameter. FIG. 13 shows two rings 3 fabricated parallel to one another with the addition of twelve spacers 15 providing twelve sections for tube placements. The ring structure 18 may support, for example, twelve tubes depending on the ratio of the outer tube diameter and ring diameter.
FIG. 14 shows an assembled joint in accordance with the present invention. As shown, joint assembly 19 includes six tubular members with end caps 5 assembled on a circular ring 3 . The pins are not visible since the end caps are covering them. The tubular members 1 are assembled the same way at each respective end and are free to rotate about the plane of ring 3 over almost 360 degrees. The joints may be assembled, reconfigured, or disassembled rapidly. The ring may be fabricated, for example, from steel or stainless steel and tubes 1 may be fabricated, for example, from PVC, steel, or stainless steel. The joint assembly 19 may be repeated numerous times in order to assemble complex space frame structures, as described later.
FIG. 15 is another assembled joint in accordance with the present invention. The joint assembly 20 includes eight tubular members assembled on circular ring 3 and includes end caps 5 . The tubular members 1 may be assembled in the same manner at each respective end, and are free to rotate about the plane of ring 3 over almost 360 degrees.
FIG. 16 shows yet another assembled joint, designated as 21 , in accordance with the present invention. As shown, the joint assembly includes twelve tubular members assembled on a circular ring 3 and includes end caps 5 . Each joint 21 may be assembled, reconfigured, or disassembled rapidly using the present invention.
FIG. 17 shows an assembled joint 22 in accordance with the present invention. The assembled joint 22 shows the versatility of the present invention. As shown, 5 tubular members 1 are oriented in the plane of circular ring 3 and one tubular member 1 is oriented perpendicularly to the plane of circular ring 3 . The joint assembly 22 may be used, for example, in trusses, where the plane of ring 3 may be oriented perpendicularly rather than horizontally to the ground.
FIG. 18 shows another assembled joint in accordance with the present invention. Tubular members 1 may be added or removed easily from the polygonal ring 14 in any complex space frame structure. The assembled joint 23 in FIG. 18 may be ideal, as an example, for the bottom edge of a geodesic dome, where vertical rings may come in contact with the ground.
FIG. 19 shows an exemplary assembled space frame structure that uses an embodiment of the present invention. As shown, space frame structure 24 is a geodesic dome, and uses hub joints including multiple tubular members 1 and multiple rings 3 and multiple rings 14 . The bottom row of the frame structure showing rings 14 includes the polygonal rings 14 shown in FIG. 10 , which may be oriented vertically with respect to the ground or a surface upon which the frame structure may be assembled. All the other rings, designated as 3 , may be, for example, any other ring assembly in accordance with the aforementioned embodiments, previously described. The structure 24 in FIG. 19 is strong, lightweight, low cost, and may be scaled to almost any desired size. Furthermore, frame structure 24 may be reconfigured into many different space frame designs using similar components. For the sake of clarity, the pins and the end caps have been omitted from FIG. 19 (and the other later described figures).
FIG. 20 shows an assembled truss, designated as 26 , that uses embodiments of the present invention. The assembled truss structure 26 may be assembled using multiple tetrahedron units 25 . The hub joints include rings 3 and/or 14 that are used for joining multiple tubular members 1 . As shown, the top tubular members 1 b connect the tetrahedron units at strategic locations and provide strength. These tubular members 1 b also allow a long truss to be rapidly assembled, reconfigured, or disassembled. This truss structure 26 may be employed for different applications by positioning the truss structure in any attitude, including a horizontal or a vertical attitude with respect to a ground plane. Long trusses may be used as load bearing structures spanning long distances. The truss structure may also be positioned perpendicular to the ground and may be used as an antenna support frame, or as one of many vertical column structures for a single level or multi-level building structure. In addition, this so called modified Warren truss shown in FIG. 20 may be seamlessly expanded into similar or different space frame structures in any dimension.
FIG. 21 shows an assembled Howe truss structure that uses embodiments of the present invention. The Howe truss is strong enough to be used in steel bridges. Its impressive strength over long spans also contributed to its overwhelming popularity as a railroad bridge. The structure 27 may be assembled using rings 3 and/or 14 placed vertically at joint locations receiving the multiple tubular members 1 . The rings in FIG. 21 may also be positioned perpendicular to the ground plane of the structure, rather than parallel to the ground plane. (Rings positioned parallel to the ground plane may violate the position requirements of the tubular members required to assemble a Howe truss.) The truss frame 27 may easily be reconfigured into a Pratt truss, a modified Warren truss, or other popular trusses that exhibit strength with minimal number of members used to span long distances.
FIG. 22 shows an assembled space frame structure in accordance with another embodiment of the present invention. The assembled structure 28 may be assembled from multiple pentahedron units, designated as 25 . The pentahedron unit 25 may be assembled in any direction with tubular members 1 b added to provide a strong, rigid, and expandable space frame structure. The length of the tubular members 1 and 1 b may be scaled without degradation or loss of integrity of the overall structure. Hence, the overall size of the space frame structure 28 may be sufficient to cover a large area and may be easily and rapidly assembled, reconfigured, or disassembled, without any special tools.
FIG. 23 shows an assembled space frame structure that uses an embodiment of the present invention. The assembled structure 29 includes support legs 30 comprised of tubular members that are joined at multiple ring hubs. The ring hubs may include any configuration shown in the aforementioned hub assembly figures, such as rings 3 , 13 , 14 and/or 16 .
FIG. 24 shows an assembled space frame structure 31 that includes vertical support members 30 and a canopy, the latter designated as 32 . FIG. 25 shows another assembled space frame structure 34 that includes vertical support members 30 , canopy 32 , and a skirt 33
FIG. 26 shows an assembled custom space frame structure using an embodiment of the present invention. The assembled structure 35 may be assembled from pentahedron units 25 , and may be connected at the top layer with horizontal tubular members 1 b. This structure provides a high degree of strength and stability, while using low cost lightweight materials. The joints may be assembled using rings 3 , 13 , 14 , and/or 16 , as needed to form a repeatable and lightweight structure. These custom structures may be rapidly assembled to fit into any area and around any type of obstacles. Furthermore, these custom structures may be assembled over large areas with vertical members placed strategically for maximum strength and stability.
FIG. 27 shows yet another assembled custom space frame structure in accordance with the present invention. The assembled structure 36 includes a plurality of vertical support members 30 that are connected as previously described. Hub joints that include rings 3 , 13 , 14 and/or 16 may also be used. A canopy 32 may also be included to map onto any layout of the assembled space frame. FIG. 28 shows the same assembled custom space frame structure and includes a skirt 33 . This configuration may be ideal for strong durable tents or shelters.
FIG. 29 shows still another assembled space frame structure, which uses the present invention. The structure 39 may be assembled from multiple tetrahedron units 38 , by connecting these units horizontally and vertically with the many rings of the present invention. Large three dimensional space frame structures may be easily and rapidly assembled using low cost common off-the-shelf tubular members 1 and rings 3 , for example. In addition, unique custom structures may be assembled or added, such as trusses, towers, and larger tetrahedrons to create a “city” of unique custom space frame structures.
FIG. 30 shows the same assembled space frame structure with the addition of accessories. The shown accessories are custom fitted panels 41 that may be assembled to create three dimensional mazes and may be partitioned into areas for games or for therapeutic applications.
While the invention has been described with respect to particular embodiments shown and discussed above, numerous alternatives, modifications and variations will occur to those who read and understand this specification. It is intended that all such alternatives, modifications and variations be included within the spirit and scope of the following claims:
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A hub joint includes a metal rod and pin for joining tubular members in three-dimensional space for assembling a frame structure. The hub joint enables rapid assembly, rapid reconfiguration, and rapid disassembly without using any specialized tools. Multiple hub joints may be used to form geodesic domes, freestanding trusses, space frame slabs, tetrahedrons, and pentahedrons. The hub joints allow different frame configurations that are lightweight, strong, durable, scalable, expandable, and portable.
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BACKGROUND OF THE INVENTION
The invention relates to a continuous casting mold having mold side walls supported on an oscillating lifting table and having a stirrer comprising a magnetic circuit with a yoke at least partly surrounding the mold side walls and the yoke has at least two cores that are directed against mold side walls which are arranged opposite each other.
In continuous casting, the melt is caused to flow into the continuous casting mold from a tundish either directly or through a casting tube. Due to its kinetic energy, the pouring stream exiting from the tundish or exiting from the casting tube, respectively, penetrates deeply into the liquid core of the strand forming in the continuous casting mold. In this process, entrainment of slag particles, casting powder or other impurities may occur, which entrainment leads to inclusions in the strand if these impurities penetrate very far inside, since separation or flowing upward of the slag etc. to the meniscus of the strand can hardly occur any longer.
To enable control of the flow behavior of the pouring stream inside the continuous casting mold, particularly to prevent the pouring stream from penetrating too far into the liquid core of the strand, it is known to provide a stirrer directly at the continuous casting mold, which stirrer or creates causes a magnetic field that slows down the velocity of the pouring stream and, in addition, advantageously divides the pouring stream. The operation of such a stirrer is comparable to that of an electromagnetic brake.
Continuous casting molds with electromagnetic stirrers of the initially described kind are known for example from EP-B -0 265 796, EP-A - 0 401 504, EP-B - 0 286 935 and WO 92/12814. In accordance with the prior art, the yokes, which constitute a considerable mass, are arranged stationarily to avoid loading the oscillation drives for the mold side walls with these masses. Mostly, the iron cores likewise have been stationarily arranged, in order to avoid loading the oscillation drives with these masses as well. The yoke that has to be additionally provided at the continuous casting mold not only causes substantial structural expenditures (in that additional neon in the very confined space of the continuous casting mold room has to be made for this yoke), but also renders mold construction more expensive due to the additional expenditures incurred for the material.
To enable perfect oscillation of the mold side walls relative to the stationarily arranged stirrer, an air gap is provided between each of the cores of the stirrer and the mold side walls. As a consequence, considerable magnetic forces arise during the operation of the stirrer, which act on the mold side walls and cause a deformation of the mold side walls in the direction toward the core or the yoke. With continuous casting molds for casting a strand having a slab cross section, the molds are constructed as plate molds having broad side walls and narrow side walls clamped between the broad side walls. The narrow side walls either will be clamped only to an unsatisfactory degree by the broad side walls which are acted upon by the magnetic forces, or the forces acting from the stirrer will have to be compensated for by the clamping forces. In the latter case, excessive clamping forces exist between the broad and n arrow side walls when the stirrer is de-engized or put out of action.
It is internally known to rigidly arrange the iron core in the broad side walls of a mold provided for casting a strand having a slab cross section, and the yoke in this case is arranged at a certain distance from the iron cores which are integrated into the broad side walls of the continuous casting mold. Here too, deformations result during the operation of the stirrer, due to the air gap between yoke and core and due to the forces drawing the broad side walls toward the yoke.
A further disadvantage of this construction has to be seen in that for each mold there has to be provided a separate stirrer, which also has to be exchanged whenever the mold side walls are exchanged (for instance in order to change the strand format, etc.).
A continuous casting mold of the initially described kind in which the lifting table that imparts an oscillating movement to the mold side walls is constructed as a yoke, is known from WO-A -94/16844. However, this document does not disclose how the cores are arranged.
SUMMARY OF THE INVENTION
The invention aims at avoiding these disadvantages and difficulties and has as its object to create a continuous casting mold of the initially described kind, in which the expenditures for material are only negligibly higher as compared to a continuous casting mold without a stirrer, in which the spatial conditions as compared to a continuous casting mold without a stirrer are only negligibly confined and in which, during operation of the stirrer, the forces that are caused by the stirrer and act on the mold side walls can be avoided. A further essential criterion is that the slight masses to be moved by the oscillation drive for the mold side walls.
In accordance with the invention, this object is achieved in that the lifting table, which imparts an oscillating movement to the mold side walls, is constructed as a yoke and each core is arranged at a console rising up from the lifting table. With this construction, the separate arrangement of a yoke at the continuous casting mold becomes unnecessary, and therefore, the structural expenditures are very low. It is merely necessary to adjust the lifting table to the magnetic requirements in terms of the iron cross sections and to provide it with consoles that carry the cores. As the lifting table naturally moves synchronously with the mold side walls supported on it, it is not necessary to provide air gaps between the lifting table, i.e. the yoke, the cores and the mold side walls in order to enable relative motion between these parts. In accordance with the invention, direct contact is provided between these parts, so that deformations caused by magnetic forces can no longer occur.
To enable particularly simple replacement of the mold for casting strands of different cross-sectional formats, particularly of different thicknesses, one and the same stirrer can be utilized for continuous casting molds having different cross-sectional formats. To be able to exchange the continuous casting mold in the shortest time possible, without any delays being caused by the stirrer, in accordance with a preferred embodiment, the cores are adjustable relative to the lifting table and the consoles in a direction roughly perpendicular to the mold side walls. Preferably openings in the consoles are provided for receiving the cores. From JP-1-289550 it is known to arrange cores in electromagnetic devices of continuous casting molds within the electromagnetic device in such a manner that they are movable in the horizontal direction and, the direction of adjustment is oriented perpendicular to the side walls of the continuous casting mold.
Due to the movability of the cores relative to the yoke, the cores during the operation of the stirrer can be adjusted against the mold side walls until they are in contact with the same, leaving no vertical air gap between the cores and the mold side walls. The cores are automatically drawn to the mold side walls by the magnetic forces caused by the stirrer.
Preferably, the cores are constructed such as to be divided in a direction roughly parallel to the extension of the mold side walls, against which they are directed, wherein suitably one part of each of the cores is rigidly attached to a mold side wall and one part is adjustably mounted on the lifting table. Hereby it becomes feasible to make the cores project from the copper plates of the mold side walls, hence making them project through the supporting structure of the mold side walls that reinforces the copper plates without having to provide for very large dimensions for the path of adjustment of the cores during mold replacement.
For simple adjustment of the adjustable part of the core, the latter is movable relative to the part of the cores that is attached to the mold side wall and vice versa by an adjusting means, wherein advantageously, via brackets, the adjusting means is on the one hand connected with the lifting table and on the other hand with the movable part of the core.
Preferably, the parts of the cores that are adjustable relative to the lifting table carry one coil each, such that when exchanging the continuous casting mold it is feasible for the coils to remain in the continuous casting plant. Advantageously the adjustable part carries the coil at its one end that is directed against the mold side wall.
According to a preferred embodiment, the path of adjustment of the cores is dimensioned such that strand guiding means, such as a bending zone, that are arranged below the continuous casting mold can be removed and inserted through the lifting table carrying the cores.
A structurally simple variant is characterized in that the cores are arranged so as to be stationary relative to the lifting table.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic top plan view with portions broken away of a continuous casting mold of the present invention; and
FIG. 2 is a partial cross sectional view taken on line II--II of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the exemplary embodiment illustrated in FIGS. 1 and 2, a lifting table 2 constructed in a frame-like manner is supported on the frame 1, which is stationary, i.e. which rests on the foundation, by an oscillation drive 3. The oscillation drive 3 is provided with eccentric shafts 4 extending along the short sides 5 of the rectangular lifting table 2 and imparting a vertical lifting and lowering motion to the lifting table 2 via brackets 6 hinged to the lifting table 2. To guide the lifting table 2 in the vertical direction, guide elements not illustrated in detail are provided between the lifting table 2 and the stationary frame 1. The two eccentric shafts 4 are driven synchronously by a driving motor 7 connected with the eccentric shafts 4 via spacer shafts 8 and corner gears 9.
The mold side walls 10, 11, 12, 13 of the continuous casting mold, which is constructed as a plate mold, are supported on the lifting table 2. All mold side walls 10 to 13 are constructed as individual plates and are formed by copper plates 14, 15 arranged on the inside and supporting plates 16, 17 supporting the same. The continuous casting mold illustrated in FIGS. 1 and 2 serves for casting a strand having a slab cross section, preferably for casting a strand having a thin slab cross section. Its broad side walls 10, 11 are supported directly on the lifting table 2; the narrow side walls 12, 13 are clamped between the broad side walls 10, 11 by the schematically illustrated clamping means 18.
A stirrer 19 which comprises a magnetic circuit is formed by the lifting table 2 being constructed as the yoke of the stirrer 19, i.e. the wall cross sections of the table 2 are adjusted in accordance with the magnetic requirements concerning the necessary cross-sectional area. At the frame parts 20 of the lifting table 2, which parts 20 are disposed parallel to the broad side walls 10, 11, consoles or brackets 21 are arranged, which consoles 21 rise vertically upward and are provided with one opening 22 each for receiving one iron core 23.
Each of the iron cores 23 extends roughly horizontally and perpendicular to the planes formed by the broad side walls 10, 11 as far as the copper plates 14 of the latter, which plates 14 are arranged on the inside. Each of the cores 23 is constructed so that it is divided into two parts 23', 23", with the dividing plane 24 extending roughly parallel to the planes formed by the broad side walls 10, 11. One of the parts 23', 23" of each core 23, namely part 23', is stationarily mounted within the supporting plate 16, projects as far as the copper plate 14 and terminates approximately flush with the exterior of the supporting plate 16. The other part 23" of each of the cores 23 is inserted in the opening 22 of the console 21 and is adjustable in a direction roughly perpendicular to the planes formed by the broad side walls 10, 11, namely by adjusting means 25. Each adjusting means 25 is connected on the one hand with the lifting table 2, i.e. at the consoles 21, via brackets 26 and on the other hand with the movable part 23" of the cores 23 via brackets 27. At their ends 28, which are directed against the core parts 23' stationarily inserted in the supporting plates 16, the movable parts 23" of the cores 23 carry electric coils 29. Instead of as electric coils 29, the cores 23 can also be constructed as permanent magnets.
Due to the occurrence of magnetic forces during the operation of the stirrer, the movable part 23" of the core 23 is automatically drawn to the part 23' that is immovable, i.e. to the part 23' of the core 23 that is inserted in the broad side walls 10, 11, and thus reliably avoids an air gap which is capable of causing the broad side walls 10, 11 to be deformed by these magnetic forces. The exchange of the mold side walls 10 to 13 is very easy to accomplish; by means of the adjusting means 25, and the part 23", which is adjustably supported on the lifting table 2, simply has to be moved to a position where it occupies a space located at a certain distance from the part 23' of the core 23 that is integrated into the broad side walls 10, 11. The broad side walls 10, 11 can then be conveniently removed along with the narrow side walls 12, 13 and replaced with intact ones or with ones of a different format, etc.
It can be seen that the new broad side walls 10, 11 just have to be provided with a part 23' of the core 23 that is integrated in the supporting plates 10, 11 and that the remaining parts of the stirrer 19, namely the yoke (lifting table 2) and the adjustable core part 23" plus coil 29 are suitable for all mold side walls 10 to 13 that can be inserted on the lifting table 2, and that it is therefore not necessary to exchange these parts of the device. This not only results in a very short mold exchange time but also in cost-advantageous construction.
Herein, the adjustability of the adjustable parts 23" of the cores 23 is dimensioned such that--if necessary--even strand guiding elements arranged below the continuous casting mold--such as for instance a bending zone--can be removed through the lifting table 2 without having to remove the lifting table 2 or the parts 23" of the cores 23 from the continuous casting plant. The parts 23" of the cores 23 can be formed by two or several parts which are rigidly connected with each other, for instance are flanged to each other, for example for easier production of these parts or for their easier removal and insertion.
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A continuous-casting mold has walls resting on an oscillating lifting platform and is provided with a stirrer which incorporates a magnetic circuit. The stirrer has a yoke which at least partially surrounds the walls of the mold and which has at least two cores facing opposite sides of the mold. In order to prevent the magnetic force of the stirrer from deforming the walls of the mold, the lifting platform, which sets the walls of the mold into oscillation, is designed as the yoke and each core is located on a bracket projecting out of the lifting platform.
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This is a continuation of application Ser. No. 006,425, filed Jan. 23, 1987, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a method of compiling a program written in a logic programming language for computers represented by PROLOG and intends high speed execution of artificial intelligence (AI) programs by a pipelined vector processor or a parallel vector processor.
Representation of a program by a logic programming language is first explained.
In the logic programming language, a proposition in predicate logic (called clause in the logic programming language) is described as follows.
bird (swallow). 1
fly(X):-bird(X). 2
The clause 1 means "A swallow is a bird." The clause 2 means "If X is a bird, X flies in the sky." The head name in the clause (bird in 1, and fly in 2) is called a procedure name or predicate name. The set of clauses having the same predicate name is called a procedure or predicate. If the program consists of only the clauses 1 and 2, each of the clauses 1 and 2 is a procedure by itself.
A name whose initial letter is uppercase (X in the above example) represents a logical variable and it represents an unspecified object. On the other hand, a name whose initial letter is lowercase (swallow in the above example) is called a constant and it represents a specific object or number. Unlike a variable in a programming language such as FORTRAN, the value of the logical variable, once it is set, cannot be changed unless failure takes place. That is, assignment in a conventional sense is not allowed.
Assuming that 1 and 2 are given to a logic programming language system as a program, and assuming that the following question 3 is made. The concept "question" corresponds to "main program" in FORTRAN language.
?-fly (swallow). 3
The result of question 3 is true. The question means "Does a swallow fly in the sky?".
The program may be used as follows.
?-fly (Y). 4
The result is Y=swallow. The question 4 means "What flies in the sky?" and fly (swallow) means a swallow flies in the sky" or "It is a swallow that flies in the sky".
The fly (swallow) in the question 3 and the fly(Y) in the question 4 are called procedure calls of procedure "fly". Similarly, the bird (X) in the clause 2 is a procedure call of procedure "bird". The procedure call corresponds to a subroutine call in FORTORAN language.
The attribute that the program whose input and output are exchanged is executable as in question 3 and the question 4 is called bidirectionality (An argument for "fly" is an input in the question 3 and an output in the question 4.) The bidirectionality is one of the characteristics of the logic programming language program.
If the following program 5 is added to 1 and 2, the solution of the question 4 is Y=swallow and Y=hen. (In this case, the procedure "bird" comprises two clauses.)
bird (hen). 5
Such a plurality of solutions is also a characteristic of the logic programming language program.
Before the question "?-fly(Y)" is executed, the logical variable Y is unspecified, but it is bound to a constant "swallow" during the execution. When the logical variable is bound to a specific object, it is said "instantiated" and when it is not bound to a specific object, it is said "uninstantiated".
Sequential execution of the logic programming language is now explained.
As an example, a program 200 shown in FIG. 2 is used. The meaning of the program 200 is first explained. Clauses 201-205 mean as follows.
Clause 202 "A swallow is a bird."
Clause 203 "A hen is a bird."
Clause 204 "A penguin cannot fly in the sky."
Clause 205 "A hen cannot fly in the sky."
Procedure bird consists of clauses 201, 202 and 203 and procedure cannot Fly consists of clauses 204 and 205.
Question 206 means "Output all those birds which cannot fly in the sky." More exactly, it means "Output all possible solutions of a logical variable X which meets bird(X) and cannot Fly(X), and if there is no more solution, output "false". The question 206 comprises four procedure calls, "bird(X)", "cannot Fly(X)", "write (X)" and "fail".
FIG. 3 illustrates the sequential execution of question 206. The sequential execution of the logic programming language is explained with reference to FIG. 3. While procedure call "bird" 301 is executed, the logical variable X is uninstantiated. There are three clauses 201-203 which match (unify) "bird(X)" and the first one, clause 201 is selected. As a result, the logical variable X is instantiated to "penguin". Then, the procedure call "cannot Fly" 302 is executed. Since the logical variable X has been instantiated to "penguin", only the clause 204 in the clauses 204-205 matches. Then, the procedure call "write" 303 is executed. Since the logical variable X has been instantiated to the constant "penguin", one solution "penguin" is displayed on an output device. Then, the procedure call "fail" 304 is executed.
Since the procedure "fail" means "Search another solution", another solution of the procedure call "cannot Fly" is searched. This step is called retrial of the procedure "cannot Fly". Since there is no other solution so long as X is instantiated to the constant "penguin", the procedure "cannot Fly" does not return a result to the argument X by the retrial. Accordingly, the state of the logical variable X is restored to that prior to 301, that is, to an uninstantiated state and the procedure "bird" is retrial (305). That is, other solution of the procedure call "bird" is searched. The step to restore the logical variable to its previous value and retry the procedure call is called "backtrack". In the step 305, a solution is found and the logical variable X is instantiated to the constant "swallow". Then, the procedure call "cannot Fly" 306 is executed. Since the logical variable X has been instantiated to the constant "swallow", there is no matchable clause in clauses 204-205. Accordingly, the trial fails, X is reset to the uninstantiated state and the procedure call "bird" is again retried (307).
The steps 307-310 are executed in the same manner as the steps 301-304 and the explanation thereof is omitted. Finally, X is again reset to the uninstantiated state and the procedure "bird" is retried (311). Since there is no other solution, the result to the question 206 is false and the execution is terminated.
A compiling method for generating a program which is sequentially executed is disclosed in "Implementing PROLOG--Compiling Predicate Logic Programs", D.A.I. Research Report No. 39, Department of Artificial Intelligence, University of Edinburgh.
As described in the Japanese Patent Application document 61-65337 (filed on Sept. 7, 1984), in order to materially increase a speed of execution of the logic programming language, a high speed vector operation mechanism of a pipelined vector processor or a parallel vector processor can be used. The vector operation means an operation of the same type to each of vectors or data comprising plural elements of the same type. In a vector operation, a data structure (or array) in which elements are arranged in a continuous area at a constant stride is usually a target of operation. Here, an operation of the same type to each element of a list is also called the vector operation. The vector processor means a processor having vector instructions.
An example of the vector processor is Hitachi S-810. The processor of S-810 is explained with reference to FIG. 4. In S-810, an array data can be processed at a high speed by a pipeline mechanism shown in FIG. 4. For example, data contained in array data 401 on a main memory 421 are sequentially loaded to a vector register 403 by a load pipeline 402. The load pipeline means a hardware for processing the array data which can load the entire array data (or a portion thereof) at a short pitch. The vector register means a large capacity register which can hold the entire array data (or a portion thereof). Data contained in array data 404 are loaded to the vector register 406 by a load pipeline 405, in the same manner as that for 401-403.
When a first element is written into the vector register, it can be immediately read. Accordingly, when first data are written into the vector registers 403 and 406, the processing by a processor 407 is immediately started and the processing is sequentially carried out. A result of the processing is written into a vector register 408. The processor is a pipelined processor designed for array processing and it can process at the same pitch as the vector registers 403 and 406. When a first data is written into the vector register 408, the storing into the array data 410 is immediately started by a store pipeline 409 and the data are sequentially stored.
Since the array data are loaded, processed and stored in the pipeline fashion in the vector processor, the array data can be processed much faster than by a general purpose computer.
The execution method of the logic programming language program in the vector processor is shown in the above JP-A and "High Speed Execution of PROLOG by A Supercomputer" 26th Programming, Symposium Report, pages 47-56, 1985 in Japanese. A method for executing the above example in the vector processor is explained with reference to FIG. 5.
FIG. 5 shows a method for executing the program of FIG. 2 by the vector processor. A procedure call "bird" 501 obtains all the solutions which meet a procedure "bird" to form array data 502. The processing corresponding to the steps 301, 305, 307 and 311 of FIG. 3 is carried out by vector operation, and resulting X is given by array data 502. Accordingly, the array data 502 comprises three constants, "penguin", "swallow" and "hen". The number of elements, "3", is stored at the top of the array data 502. The number of elements is stored at the top of each array data. This data is not regarded as an element of the array. This is also true for the embodiments to be described later. For example, the first element of the array data 502 is not "3" but "penguin", the second element is "swallow" and the third element is "hen".
A procedure call "cannot Fly" 503 reads in the array data 502 and detects all solutions which meet the procedure "cannot Fly" to form array data 504. The step 302 of FIG. 3 is carried out for the element "penguin" of the array data 502, the step 306 of FIG. 3 is carried out for the element "swallow", and the step 308 of FIG. 3 is carried out for the element "hen". Thus, it is determined that X which meets "cannot Fly(X)" is "penguin" and "hen". Array data 504 comprising those two elements is defined. Accordingly, the array data 504 comprises two constants, "penguin" and "hen".
A procedure call "write" 505 reads in the array data 504 and displays all elements thereof on an output device. That is, the steps 303 and 309 of FIG. 3 are carried out. Thus, "penguin" and "hen" are displayed on the output device.
Finally, a procedure call 506 is executed. Since all solutions have been obtained for "bird" 501 and "cannot Fly" 503, the result for the question 201 is false and the execution is terminated.
Prior to the explanation of the problem, a program 600 shown in FIG. 6 is explained.
The program 600 determines square numbers between 0 and 3, inclusive. The square number means a number whose root is an integer. Because 0=0 2 and 1=1 2 , the solution is "0" and "1", respectively. The program in FIG. 6 consists of three portions, a question 601, a procedure "root" 602 and a procedure "digit" 603.
In the question 601, the procedure "root" 602 and the procedure "digit" 603 are called to calculate a root and it is printed out. The question 601 comprises four portions, "digit (B)", "root (B, A)", "write (B)" and "fail". The "digit (B)" calls the procedure "digit" by using a logical variable B as an argument. The "root (B, A)" calls the procedure "root" by using the logical variables B and A as arguments. The "write (B)" calls a built-in procedure "write" to print out the value of the logical variable B. The built-in procedure means a procedure which is previously prepared in the logic programming language system and can be used without supplying a processing method by the user. The procedure "fail" is the built-in procedure. In the procedure "fail", the procedures "root (B, A)" and "digit (B)" are retried until all solutions are obtained and "digit (B)", "root (B, A)" and "Write (B)" are repeatedly executed.
The procedure "root" 602 comprises only one clause. The clause 602 comprises a head "root (Y, X)", a body "digit (X), Y is X * X" and an operator ":-". The head indicates a procedure name and an argument. The procedure "root" 602 receives arguments Y and X. In the call of "root" in the query 601, Y=B and X =A. The body of the procedure root 602 comprises two portions, "digit (X)" and "Y is X * X". The portion "digit (X)" calls the procedure "digit" by using the logical variable X as an argument. "Y is X * X" is a built-in procedure in which square of the logical variable X is compared with Y. The portion "digit (X)" is retried when a retry is caused by the procedure call "fail" of the query 601, and different values of arguments are produced.
The procedure "digit" 603 comprises four clauses. After the first clause "digit (1)" has been executed, an argument in the call of "digit" is set to "1". The same is true for the second to the fourth clauses. The program 600 of FIG. 4 has thus been explained.
A problem encountered in executing the program 600 of FIG. 6 in a prior art vector processor is explained, with comparison to the program 200 of FIG. 2.
In the program 200 of FIG. 2, the procedure "bird" produces a different argument for each call and each retry. Thus, the procedure call "cannot Fly (X)" is called plural times (N times). However, in no case, the retrial of the procedure "cannot Fly" successes nor the value is returned to the argument. (In the call, the trial is successed and the value is returned to the argument, or it is failed.) In the execution method of FIG. 5, plural values, that is, "penguin", "swallow" and "hen" are given to array data 502 corresponding to the logical variable X by the execution of "bird" 501, and the elements "penguin" and "hen" produces one solution, respectively, and "swallow" produces no solution. As a result, array data 504 is produced. When each array element before processing corresponds to one or zero array element after processing, the method shown in the above JP-A may be used. It may be readily implemented by combining vector instructions of the vector processor such as S-810.
This is not true for the program 600 of FIG. 6. Because the procedure call "digit (Y)" produces a different argument data by each call and each retrial, the procedure call "digit (X)" is called plural times (N times). Thus, unlike the program 200, a different argument data is produced by each call and each retrial. Accordingly, the second array data having elements of logical variables Y before processing does not match to first array data having elements of argument data X after processing. However, in the conventional vector processor, there is no vector instruction which processes the non-corresponding elements. Accordingly, the program 600 cannot be executed by the method shown in the above JP-A. In the above article (2), procedure "select" in a program which solves a puzzle called N queens problem is cited as an example of generation of plural array elements from each element of the array data, and input data and output data therefor are explained. However, a program for computation is not given.
SUMMARY OF THE INVENTION
The above problems are resolved in a compiler which converts a source program in a logic programming language to an object program, by converting a program which comprises
(1) a first source program portion which is executed by call or retrial and carries out first processing for each execution to produce argument data; and
(2) a second source program portion which (a) indicates call and plural times of retrial of the first source program .portion, (b) carries out second processing to a plurality of argument data produced from the first source program portion by the call and the retrial, and (c) repeats the steps (a) and (b) N times; into
(3) a first object program portion which (a) sequentially executes the first processing by a number of times designated by input data, N data at a time and (b) generates first array data having argument data obtained by the processing as respective elements, and
(4) a second object code portion which (c) executes the first object program by designating the number N of times of repetition and (d) sequentially executing second processing for the elements of the first array data outputted by the first object program portion.
The method of the present invention accomplishes the above objects by providing a method for controlling a vector processor to detect whether a value of each data signal among a first set of data has a specific relation with a value of one of a second set of data signals. The vector processor includes an operation unit for performing arithmetical and logical operations in a pipeline manner on vector data. First vector data is formed from the first set of data signals including groups of data signals wherein the groups respectively correspond to the data signals of the first set and the data signals of each group are equal to one data signal corresponding to a group among the data signals belonging to the firs set. A total number of data signals of the groups is equal to a total of the data signals belonging to the second set of data signals. Second vector data is also formed from the second set of data signals including groups of data signals wherein data signals in each group are respectively equal to the data signals belonging to the second set of data signals. The number of the groups is equal to the number of data signals belonging to the first set of data signals. The operation of the operation unit is controlled so that the operation unit detects whether the a data of each data signal of the first vector data has a specified relation with a value of a corresponding data signal of the second vector data which is equal in vector element number to each data signal of the first vector data. Thereby, the operation unit is caused to provide third vector data including result data signals each indicative of a result of the detection.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an object program generated by inputting a logic programming language program shown in FIG. 6 to an compiler of the present invention,
FIG. 2 shows a logic programming language program used to explain prior art technique,
FIG. 3 shows a flow chart of an execution procedure of the program shown in FIG. 2 in a general purpose computer,
FIG. 4 shows a block diagram of a vector processor for executing the object program of FIG. 1,
FIG. 5 shows a flow chart of an execution procedure of the program shown in FIG. 2 in the vector processor,
FIG. 6 shows a logic programming language program in an embodiment of the present invention,
FIG. 7 illustrates an operation of a vector equality compare instruction,
FIG. 8 illustrates an operation of a vector compression instruction,
FIGS. 9A-9G show an execution procedure of the object program of FIG. 1 in the vector processor,
FIG. 10 shows a flow chart of a compiler which converts a logic programming language program to the object program,
FIG. 11 shows a flow chart of step 1102 of FIG. 10, and
FIG. 12 shows a flow chart of step 1103 of FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(a) Description of Vector Compare Instruction and Vector Compress Instruction
As preparation for explanation of the execution method, a vector equality compare instruction and a vector compress instruction which are vector operation instruction used in the execution are explained.
FIG. 7 shows an operation of the vector equality compare instruction. The vector equality compare instruction compares the elements of array data 801 and 802 contained in vector register 801 specified by an operand, and stores the result in vector mask register 803. The vector mask register stores array data whose elements are single-bit logical values. In FIG. 7, the logical value is represented by "1" or "0". The element of the vector mask register 803 corresponding to the equal elements is set to "1", and the element corresponding to unequal elements is set to "0". In FIG. 7, since the first elements of both vector registers 801 and 802 are "1", the first element of the vector mask register 803 is "1". Since the second elements of the vector registers 801 and 802 are "6" and "4" and are not equal, the second element of the vector mask register 803 is "0". The same rule applies to the subsequent elements.
The vector processor S-810 is provided with the vector equality compare instruction VCEQ.
FIG. 8 shows an operation of the vector compress instruction. The vector compress instruction compresses a content of vector register 901 specified by an operand in accordance with a content of a vector mask register 902 and stores the result into a vector register 903. In FIG. 8, since the first element of the vector mask register 902 is "1", the first element of the vector register 901 is stored into main storage 421 or the vector register 903. Since the second element of the vector mask register 902 is "0", the second element of the vector register 901 is not stored. Since the third element of the vector mask register 902 is "1", the third element, of the vector register 901 is stored contiguously. That is, it is stored into the area of the main storage 421 or the vector register 903 corresponding to the second element. The same rule applies to the subsequent elements.
The vector processor S-810 is provided with vector compress instructions VSTC and VSTDC for storing into the main storage 421.
(b) Object Program
The compiler compiles the program 600 of FIG. 6 to the object program 100 of FIG. 1 in a method to be described later. The compiling may be done on a general purpose computer.
A construction of the object program 100 shown in FIG. 1 is first explained. The object program 100 comprises the following three portions.
(1) An object program 101 of a question resulting from compiling of the question 601.
(2) An object program 102 of a procedure "root" resulting from compiling of the procedure "root" 602.
(3) An object program 103 of a procedure "digit" resulting from compiling of the procedure "digit" 603.
Of those, only the procedure "digit" generates, during processing, plural array elements from one element of array data which is present before processing. The object programs 101-103 comprise the following portions.
(1) Object program 101 of the question resulting from compiling of the question 601
(1.1) A question initialization portion 109 having no directly corresponding portion in the logic programming language program of FIG. 6.
(1.2) A "digit (B)" call portion 110 resulting from compiling of the procedure call "digit (B)" in the question 601.
(1.3) A "root (B, A)" call portion 111 resulting from compiling of the procedure call "root (B, A)" in the question 601.
(1.4) A question built-in procedure processing portion 112 resulting from compiling the built-in procedure "write" in the question 601.
(2) Object program 102 of the procedure "root" resulting from compiling the procedure "root" 602.
(2.1) A "root" initiatization portion 114 having no directly corresponding portion in the logic programming language program of FIG. 6.
(2.2) A "digit (X)" call portion 115 resulting from compiling the procedure call "digit (X)" in a body of the procedure "root" 602.
(2.3) "Root" built-in procedure processing portion 116 resulting from the built-in procedure "Y is X * X" in a body of the procedure "root" 602.
In compiling the logic programming language program which contains a structure such as a list in a temporary argument, argument unification processing for pattern-matching of the argument is necessary in addition to the portions 115-116. In the program in FIG. 6, the temporary argument (Y, X at the top of the clause 602) is not a logical variable and hence the argument unification processing portion is not necessary. Since the argument unification processing portion may be handled in the same manner as the "root" built-in procedure processing portion 116, an embodiment thereof is not shown.
(3) Object program 103 of the procedure "digit" resulting from compiling of the procedure "digit" 603.
(3.1) A "digit" initialization portion 119 having no directly corresponding portion in the logic programming language program of FIG. 6.
(3.2) A copy portion 120 for copying as many data on the main storage 421 as the number of clauses.
(3.3) A first clause portion 121 corresponding to the first clause of the procedure "digit" 603, a second clause portion 122 corresponding to the second clause, a third clause portion 123 corresponding to the third clause, and a fourth clause portion 124 corresponding to the fourth clause.
(3.4) A merge portion 125 for merging the array data copied by the copy portion 120. (c) Execution procedure of the object program 100
The execution procedure of the object program 100 of FIG. 1 is explained with reference to FIGS. 9A-9G.
The question initialization portion 109 is first executed to generate data 1001. All variable data areas used in the object program 101 of the question, that is, a pointer area 1020A of array data corresponding to a variable A and a pointer area 1020B of array data corresponding to a logical variable B, are allocated to the main storage 421. Array data areas 1021 and 1022 both of which have one element are allocated to the main storage 421 and start addresses thereof are stored in a variable area 1020. The number of element "1" is stored at the top 1023 of the array data area 1021. The same is true for the array data area 1022. A value "U" indicating "undefined" is stored in each element of the array data 1021 and 1022.
The "digit (B)" call portion 110 and the object program 103 of the called procedure "digit" are then executed. The object program 103 of the procedure "digit" is started and executed by using the array data pointer 1020B as an argument. As a result, the data 1002 is generated. Since the processing is done in the same manner as the "digit (X)" call processing 1003-1006, detail thereof is omitted. The following data are obtained. The elements allocated to the main storage 421 from the pointer areas 1020A and 1020B in the procedure "digit" designate array data 1024 and 1025 both of which have four elements. The array data 1024 contains the number of elements, "4", at the top and all elements are "U". That is, all elements are undefined. The array data 1025 contains the number of elements, "4", at the top, and the elements are "1", "2", "3" and "0".
Then, the "root (B, A)" call portion 111 is executed. The object program 102 of the procedure "root" is called by using the array data pointer 1020B and 1020A as an argument. When the execution of object program 102 of the procedure root is started, the "root" initialization portion 112 is first executed and then the "digit (X)" call portion 115 is executed. When the "digit (X)" call portion 115 is started, the "digit" initialization portion 119 is first executed. After the above processing, data 1003 is generated on the main storage 421. The data 1002 remains unchanged in the data 1003, and areas 1031 and 1032 have been added. The area 1032 is a pointer area allocated by the "root" initialization portion 114, and the area 1031 is a pointer area allocated by the "digit" initialization portion 119.
The copy portion 120 is executed in the following manner. A series of data 1020, 1031, 1032 and 1024 on the main storage 421 are copied to generate four sets of data of the same structure. That is, as many copy data as the number of clauses in the original procedure "digit" 603 are made. The result is shown by 1004. Of the copy data, a first set is the original data 1070, a second set is 1071, a third set is 1072 and a fourth set is 1073. The copying is carried out in the following manner. Three areas 1036, 1040 and 1044 of the same size as that of the array data 1024 are allocated on the main storage 421, and the content of the array data 1024 is copied into those areas. Three areas of the same size as those of the array data 1020, 1032 and 1031, respectively, are allocated for each of the array data. That is, the areas 1033, 1037, 1041, 1034, 1038, 1042, 1035, 1039 and 1043 are allocated. The start addresses of 1035, 1040 and 1044 are stored in those areas as shown by 1004. The array data 1025 is copied to generate array data 1080, 1081 and 1082.
After the execution of the copy portion 120, the first clause portion 121, second clause portion 122, third clause portion 123 and fourth clause portion 124 are executed. The sequence of execution of those portions may be arbitrary, and they may be executed in parallel. In the present embodiment, they are executed orderly. After the execution of 121-124, data 1005 is generated on the main storage 421. The first clause portion 121 receives the first copy 1070 of the data 1004 and outputs the first copy 1070 of the data 1005. The second clause portion 122 receives the second copy data 1071 of the data 1004 and outputs the second copy data 1071 of the data 1005. The third clause portion 123 receives the third copy data 1072 of the data 1004 and outputs the third copy data 1072 of the data 1005. The fourth clause portion 124 receives the fourth copy data 1073 of the data 1004 and outputs the fourth copy data 1073 of the data 1005. The array data 1025, 1080, 1031 and 1081 do not change through the execution of 121-124.
The first clause portion 121 is executed in the following manner. "1" is stored in each element of the array data designated by the area 1031 corresponding to the argument of the procedure "digit" 603. The same is true for the second clause portion 122, third clause portion 123 and fourth clause portion 124. Thus, "2", "3" and "0" are stored in respective elements of the array data 1036, 1040 and 1044 designated by 1033, 1037 and 1041, respectively. The above processing may be done by using a general purpose (scalar) instruction, but high speed processing is attained when a vector instruction is used.
The merge portion 125 merges the array data 1024, 1036, 1040 and 1044, and merges the array data 1025, 1080, 1081 and 1082. The array data 1024 is merged in the following manner. The numbers of elements of the array data 1024, 1036, 1040 and 1044 are added together and an array data area 1046 having the number of elements equal to the above sum, 16, is allocated on the main storage 421. The number of elements of the array data 1024, 1036, 1040 and 1044 are stored in the top areas of the respective array data. The first to fourth elements of the array data 1046 are equal to the elements of the array data 1024, the fifth to eighth elements are equal to the elements of the array data 1036, the ninth to twelveth elements are equal to the elements of the array data 1040, and the thirteenth to sixteenth elements are equal to the elements of the array data 1044. The merging may be done by using a general purpose (scalar) instruction but high speed merging is attained when a vector instruction is used.
Merging of the array data 1025, 1080, 1081 and 1082 is carried out in the same manner. The array data 1025 in 1003 and the three copy data 1080, 1081 and 1082 are merged to generate array data 1047 having 16 elements. The array data 1046 and 1047 occupy 1006 only partially, and they fully occupy 1007.
After the execution of the merge portion 125, the process returns to the object program 102 of the procedure "root" through "digit" and processing 126, and the "root" built-in procedure processing 116 is executed. The "root" built-in procedure processing 116 is executed by using the vector instruction. Numerals 1007-1009 denote data in the course of vector operation in the "root" built-in procedure processing 116. Numerals 1050, 1051 and 1053 denote vector registers. Numeral 1054 denotes a vector mask register. Numerals 1055 and 1056 denote areas on the main storage 421.
In the "root" built-in procedure processing 116, the content of the array data 1046 is loaded to the vector register 1050. The number of elements stored at the top of the array data 1050 is not loaded. All values of the array data 1046 are stored in the vector register 1050. Similarly, the content of the array data 1047 is loaded to the vector register 1051.
Then, each elements of the vector register 1050 is squared to create an array data, which is stored into the vector register 1053. For example, the fourth element of the vector register 1050 is 2, and hence the fourth element of the vector register 1053 is 2 2 =4. The elements of the vector registers 1051 and 1053 are compared and the result is stored in the vector mask register 1054. The comparison is made by using the vector equality compare instruction explained with reference to FIG. 7. The first and sixteenth elements of the vector registers 1051 and 1053 are equal and other elements are not equal. Accordingly, the first and sixteenth elements of the vector mask register 1054 are "1" and the other elements are "0".
The contents of the vector registers 1050 and 1051 are compressed in accordance with the content of the vector mask register 1054 and the results are stored into the newly allocated areas 1055 and 1056 on the main storage 421, respectively. The elements "1" and "0" of the vector register 1050 which correspond to the first and sixteenth elements "1" of the vector mask register 1054 are stored into 1055. Similarly, the first element "1" and the sixteenth element "0" of the vector register 1051 are stored into the area 1056 on the main storage 421. The compression may be done by using the vector compress instruction.
Numeral 1010 denotes data on the main storage 421 after the last step of the "root" built-in procedure processing 116. In the processing, the number of elements, "2", is stored at the top of the main storage areas 1055 and 1056 and the start addresses are stored into 1020A, 1020B, 1031X and 1031Y.
After the above processing, the process returns to the object program of the question through the "root" end processing 117, and the elements of the array data designated by 1020B in the question built-in procedure processing 112, that is, "1" and "0", are printed out. Then, the execution is terminated.
(d) Compiling method
A compiling method for compiling the logic programming language program of FIG. 6 to the object program of FIG. 1 is explained with reference to FIG. 11.
All the procedures are compiled repeatedly as shown by 1100. A question is considered as one procedure. In the program of FIG. 6, processing 1101-1106 are carried out for the question 601, procedure 602 and procedure "digit" 603, respectively.
An initialization portion is first generated. A question initialization portion 109 is generated for the question 601, a "root" initialization portion 114 is generated for the procedure "root" 602, and a "digit" initialization portion 119 is generated for the procedure "digit" 603.
Solution check processing 1102 for checking whether there is a possibility that the procedure before compiling produces argument data through retrial (that is, the retrial successes) is carried out. The content of the processing is further explained with reference to FIG. 11. If the processing 1102 determines that the argument data is not produced by the retrial, only processing 1103 is carried out. Otherwise, processing 1104, 1103 and 1106 are carried out in this order.
The processing 1104, 1103 and 1106 are executed for the procedure "digit" 603. In the processing 1104, the copy portion 120 is generated. In the processing 1105, the first to fourth clause portions 121-124 of the procedure "digit" 603 are generated. In the processing 1106, the merge portion 125 is generated. On the other hand, the processing 1103 is executed for the question and the procedure "root" 602. A question first clause portion 140 is generated for the question 601. A "root" first clause portion 141 is generated for the procedure 602. The question first clause portion 140 comprises program portions 110-112, and the "root" first clause portion 141 comprises program portions 115-116. The generation of those program portions is explained with reference to FIG. 12.
Thus, all portions of the program 100 of FIG. 1 have been generated, and the compiling is terminated.
The solution check processing 1102 is explained with reference to FIG. 11. Whether the program under execution is question or not is checked (processing 1201), and if it is a question, the decision of the solution check processing 1102 is rendered NO. If it is not a question, whether the procedure under execution comprises a plurality of clauses or not, and if so, the result of the solution check processing 1102 is rendered YES. If it is not, the result is rendered NO. Since the procedure "root" comprises only one clause, the result of the solution check processing 1102 for the procedure "root" 602 is NO. Since the procedure "digit" 603 comprises a plurality of clauses, the result is YES.
In this check method, the result may be YES even if an argument data will not be produced by the retrial (the retrial does not success). In this case, unnecessary copy portion and merge portion are generated and unnecessary copying and merging are carried out in the execution, although the execution result is not changed from the case of not YES.
The first to n-th clause portion generation processing 1103 is explained with reference to FIG. 12. In the processing 1103, the following processing 1301 is executed for each of the clauses of the procedure under processing, in the order of the clauses. In the program 600 of FIG. 6, the processing 1301 is executed for the question 601, the single clause of the procedure "root" 602 and each clause of the procedure "digit" 603.
In the processing 1301, the following processing 1302-1304 are sequentially executed for all procedure calls of the clauses under processing. In the program 600, the processing 1302-1304 are executed for each of "digit (B)", "root (B, A)", "write (B)" and "fail" for the question 601. For the single clause of the procedure "root" 602, the processing 1302-1304 are executed for each of "digit (X)" and "Y is X * X". Since the procedure "digit" 603 contains no procedure call, the processing 1302-1304 are not executed.
The processing 1302 checks if the procedure call under processing is the call of the built-in procedure or not. In the program 600, "write (B)", "fail" and "Y is X * X" are determined to be the calls of the built-in procedure, and "digit (B)", "root (B, A)" and "digit (X)" are determined not to be the built-in procedure.
If the built-in procedure is detected in the processing 1302, the processing 1303 is executed. The object program portion corresponding to the built-in procedure under processing is generated. In the program 600, question built-in procedure processing 112 is generated for "write (B)". Nothing is generated for "fail". (An empty object program is generated.) Root built-in procedure processing 116 is generated for "Y is X * X".
If the processing 1302 determines that it is not a built-in procedure, the processing 1304 is executed. An object program portion for starting the object program corresponding to the procedure call under processing is generated. In the program 600, a "digit (B)" call portion 110 is generated for "digit (B)", a "root (B, A)" call portion 111 is generated for "root (B, A)", and a "digit (X)" call portion 115 is generated for "digit (X)".
In accordance with the present invention, the logic programming language procedure having a plurality of solutions is partially executed by using the vector instruction and the execution speed is improved.
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A method for controlling a vector processor so as to detect whether or not a value of each data signal among a first set of data signals has a specific relation with a value of one of a second set of data signals. The vector processor includes an operation unit for performing an arithmetical or logical operation in a pipeline manner on vector data. First and second vector data are formed each including groups of data signals related to the first and second set of data signals. The operation of the operation unit is controlled such that the operation unit detects whether or not a value of each data signal of the first vector data has a specific relation with a value of a corresponding data signal of the second vector data. Third vector data including result data signals is generated thereby which indicate the result of the operation.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to implants, and in particular to a porous implant system and treatment methodology for both orthopedic and soft tissue applications, which promotes tissue interdigitation and healing.
2. Description of the Prior Art
In the medical, dental and veterinary fields, implants are in widespread use for treating a variety of patient conditions. For example, in the field of orthopedics, joints are commonly replaced with implants after the original joints fail through degeneration, trauma and other causes. Such implants are typically designed to promote bone induction, bone replacement and soft tissue anchoring. Porous materials have been extensively used in the manufacture of joint prostheses for this purpose. Their open-lattice configurations tend to promote interdigitation, tissue ingrowth and tissue outgrowth whereby integration with the patients' living tissues can occur.
Trabecular metal comprises a type of porous material, which is commonly used in orthopedic procedures. An example of such an implant is described in U.S. Pat. No. 5,456,723 entitled “Metallic Implant Anchorable to Bone Tissue for Replacing a Broken or Diseased Bone”. Porous thermoplastic materials have also been used for orthopedic implants. Examples are described in U.S. Pat. No. 4,164,794 and No. 4,756,862, both of which are entitled “Prosthetic Devices Having Coatings of Selected Porous Bioengineering Thermoplastics”. U.S. Pat. No. 5,443,512 for “Orthopedic Implant Device” and No. 6,087,553 for “Implantable Metallic Open-Celled Lattice/Polyethylene Composite Material and Devices” both describe orthopedic implants with metal and plastic composite constructions. All of these patents are incorporated herein by reference.
Trabecular metal and other porous implant materials, including thermoplastics, can promote tissue ingrowth under certain conditions. However, the depth of penetration of bone and soft tissue ingrowth may be limited by various biological factors. Moreover, depth and quality of tissue penetration, and the physical properties of the host/prosthesis interface, may be limited by both pathological and physiological host factors.
Another persistent problem with such implants relates to the potential for infection. Porous materials tend to encourage tissue ingrowth, but they can also accommodate microbes and metabolic agents. Digitization and integration can be hindered by the presence of toxins, wound drainage fluid and other substances, particularly when they are trapped in the porous material and closed within a surgery site after a medical procedure.
Artificial joints, implants and other prostheses are further susceptible to persistent problems with secure bonding to patients' living tissue. Macro and micro motion in such connections can compromise replacement joints and cause their premature failure. In order to strengthen such connections, adhesives and cements have been developed for bone-to-implant bonds. Such adhesives and cements can be combined with antibiotic and antimicrobial agents. For example, ALAC identifies an acrylic cement loaded with antibiotic or antimicrobial agents (ABX). Polymethylenemethacralate (PMMA) cement is also used for this purpose. However, problems can be encountered with inducing such cements into the voids and latticework formed in the porous implant materials.
In the related fields of chronic wound care and post-operative incision healing, gradients of various kinds have been utilized. For example, thermodynamic (temperature) gradients can stimulate cell growth. Electrical, gravitational and magnetic fields have also been utilized for this purpose. Considerable research is currently being directed toward the use of biologics in various medical applications. Gradients can be established with biological agents for enhancing healing and countering infection. Pressure differentials and gradients have been applied to close separated tissue portions and promote their healing. Negative pressure gradients have been used to apply suction forces for draining bodily fluids and exudates. Positive pressure gradients have been used to irrigate wound sites and infuse them with pharmacological agents, such as antibiotics, growth factors, etc.
The present invention combines concepts from the porous implant field with gradient formation equipment and treatment protocols to promote tissue ingrowth for anchoring implants. Forming a gradient at a situs also facilitates drainage and the application of biologics, such as antibiotics, growth factors and other fluids for controlling infection and promoting healing.
The design criteria for implants include secure connections with living tissue, facilitating tissue ingrowth, infection resistance and permanency. Another design objective is applicability to a wide range of procedures, including prosthetic fixation, cosmetic and structural bone substitution, treatment of failed bone unions, bone defects, composite tissue defects and other conditions. Heretofore there has not been available a porous implant system and treatment method with the advantages and features of the present invention.
SUMMARY OF THE INVENTION
In the practice of the present invention, a porous implant system and treatment method are provided for various conditions, including orthopedic procedures such as total joint replacement (TJR). The system and method involves the application of a gradient to a porous implant material. The gradient can be formed with a wide variety of different forces and influences. A negative pressure differential creates a suction force across the implant whereby tissue ingrowth is encouraged. The negative pressure differential/suction mode of operation also functions to drain the implant situs and remove toxins, microbes and metabolic agents. In a positive pressure/infusion mode, various biologic and pharmacological agents can be infused throughout the implant and the patient situs for countering infection, promoting tissue growth, etc. An interface, such as a tube, a sponge or a membrane, is provided for connecting the porous material of the implant to a pressure differential source.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the porous implant system embodying the present invention.
FIG. 2 a is a perspective view of a total hip replacement (THR) procedure.
FIG. 2 b is a cross-sectional view of a porous acetabular cup for the THR procedure.
FIG. 3 is a flowchart of a porous implant treatment procedure according to the method of the present invention.
FIG. 4 is an outline of a subprocedure of the treatment method, which subprocedure involves patient situs parameters.
FIG. 5 is an outline of a subprocedure of the treatment method, which subprocedure involves selecting a porous material type.
FIG. 6 is an outline of a subprocedure of the treatment method, which subprocedure involves selecting a gradient source.
FIG. 7 is an outline of a subprocedure of the treatment method, which subprocedure involves selecting a patient interface.
FIG. 8 is an outline of a subprocedure of the treatment method, which subprocedure involves selecting inputs/pharmacological agents/biologics.
FIG. 9 is a flowchart showing a treatment subprocedure.
FIG. 10 a is a front, right side perspective view of a knee joint.
FIG. 10 b is a cross-sectional view of the knee joint, showing the porous implant system applied to the patella.
FIG. 11 is a cross-sectional view of the porous implant system applied to a tibia.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction and Environment.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of a similar import.
Referring to the drawings in more detail, the reference numeral 2 generally designates a porous implant pressure differential system embodying the present invention. The system 2 interacts with a patient situs 4 through a porous implant 9 , which is connected to an interface 6 . The interface 6 is connected to a gradient source 5 through a gradient transfer 8 . The gradient source 5 is controlled by a controller 10 , which provides output to a monitor/display 12 and is powered by a power source 13 . Inputs 14 communicate with the patient situs 4 through the interface 6 , and exudate 16 is drawn therefrom to a collection receptacle 18 . Reperfusion of the patient's bodily fluids can occur along dashed line 20 .
Without limitation on the generality of useful applications of the system 2 , it can be applied to both human and animal patients and subjects in connection with a wide variety of medical, dental and veterinary conditions and treatments. For example, total joint replacements (TJRs) typically involve several procedures, which can benefit from the system 2 . It will be appreciated that the system and treatment method of the present invention are applicable to a wide range of medical, dental and veterinary procedures and conditions.
A total hip replacement (THR) 22 is shown in FIGS. 2 a , 2 b and includes an acetabular cup assembly 24 and a femoral prosthesis 26 . As shown in FIG. 2 b , the acetabular cup assembly 24 includes a porous component 28 and a bearing or wear component 30 , which can comprise a material such as polyethylene. Composite metal and plastic acetabular cups of this type are available from the Implex Corporation of Allendale, N.J.
The porous component 28 functions to distribute the pressure differential from the gradient source 5 through input and output lines (e.g., tubes, wires, etc.) 14 a , 16 a connected to an interface 6 . The lines 14 a , 16 a function as gradient transfers ( 8 in FIG. 1 ). In a negative pressure/suction mode, the porous implant system 2 facilitates tissue interdigitation for enhancing and expediting bonding with the patient. Preferably, both tissue ingrowth into the porous component 28 and outgrowth onto same are enhanced. Moreover, in a negative pressure mode, various pharmacological agents and biologics, such as antibiotics, growth factors, etc., can be drawn into the porous component 28 for expediting healing, reducing infection, etc. In a negative pressure gradient (suction) mode, fluid, toxins, microbes and metabolic products can be drained from the situs 4 . The risks of infection can thus be reduced and healing promoted by applying a pressure differential or other gradient to the porous component 28 . Interdigitized tissue and pharmacological agents drawn and/or injected into the situs 4 by a negative and/or positive pressure differential across same will tend to displace bodily fluids and toxins occupying the interstitial spaces in the porous implant, thus reducing or eliminating an environment in which microbes and metabolic products can develop and infect the situs 4 .
In a positive pressure/input mode the porous material 28 acts as a manifold to distribute the fluid input throughout the situs 4 . It will be appreciated that the controller 10 can be programmed to alternate between these functions. Moreover, they can occur simultaneously as the system 2 provides a fluid input at one side of the porous component 28 and exudate is drained from the other side thereof.
The gradient source 5 and the interface 6 can comprise, for example, components of a vacuum assisted closure (VAC) system and interface from Kinetic Concepts, Inc. of San Antonio, Tex. For example, the interface 6 can comprise various suitable sponge materials, or can comprise a length of tubing attached to the porous component 28 .
FIG. 3 is a flowchart showing an overview of a treatment method 50 of the present invention, utilizing the system 2 embodying the present invention. The process starts at 52 and proceeds to a patient situs parameters subprocedure 54 . A porous material type is selected at 56 , a gradient is selected at 58 , a patient interface is selected at 60 and inputs/pharmacological agents/biologics are selected at 62 . A treatment subprocedure occurs at 64 whereafter the methodology ends at 66 . These subprocedures will be discussed below.
FIG. 4 is an outline of the patient situs parameter considerations 54 . For soft tissue applications 68 , the system 2 is adapted for connecting tendons and joining separated tissue at the subcutaneous (SQ) layer of the patient at 70 , 72 respectively. For example, a pair of porous material components 28 can be placed against soft tissue portions and bonded to same with tissue interdigitation. The porous material components 28 can then be mechanically drawn together for closure of the separated tissue portions. In an orthopedic interface 74 , such as the hip replacement discussed above, different considerations are taken into account if the situs is load bearing or not ( 76 ), and depending upon whether it includes wear surfaces ( 78 ), for example, in connection with a joint prosthesis. The situs 4 can comprise a diseased or damaged tissue location whereat a revision or reconstruction is performed at 80 . In orthopedic medicine, previous implants and prostheses are commonly replaced due to their failure, infection, ineffectiveness, etc. The system and method of the present invention can be used to advantage in such implant extraction and replacement procedures.
The interface 6 can comprise either permanent ( 82 ) or temporary components ( 84 ), or both. For example, biocompatible and absorbable components are designed to dissolve within the patient at 86 . By encouraging living tissue interdigitation, the system 2 can enhance the absorption of the interface 6 components. Their components are designed for removal. For example, the interface 6 can include tubing adapted for placement upon installation of the system 2 . After the system 2 has accomplished its purpose, such as draining a wound, applying and distributing biologics, etc., removable components can be extracted at 88 .
FIG. 5 shows the subprocedure 56 for selecting a porous material. Trabecular metal is shown at 90 . Porous thermoplastic materials ( 92 ) are also suitable for receiving tissue ingrowth and would benefit from a pressure differential. Moreover, biodegradable and absorbable porous materials ( 94 ) can be utilized for eventual absorption into the patient through replacement by the patient's living tissue. A composite material composition can be selected at 96 .
FIG. 6 shows the subprocedure 58 for selecting the gradient. As shown, biologic 98 , temperature 100 , electrical 102 , magnetic 104 and chemical 106 gradients can be utilized. A negative/suction pressure differential 108 can be utilized to drain the situs 4 and a positive/infusion pressure differential 110 functions to input various fluids and agents to the situs 4 . Drainage and infusion can be combined at 112 . These functions and operational modes can be sequenced for constant/intermittent operation ( 114 ) and can operate simultaneously. They can also be preprogrammed ( 116 ) with the controller 10 . For example, the gradient source 8 can pause in its operation and provide a substantially static pressure or other condition across the interface 6 .
FIG. 7 shows a subprocedure 60 for selecting the patient interface 6 . A hydrophilic or hydrophobic sponge 118 can be placed on the implant porous material portion 28 . Alternatively, it can directly receive a tube connected to the gradient source 5 ( 120 ). Membranes of porous, semi-permeable and impervious material can be utilized ( 122 ). As discussed above, the interface 6 can comprise multiple materials in a composite construction ( 124 ). Some or all the components of the interface 6 can be biodegradable and absorbable ( 126 ). The ALAC acronym identifies antibiotic or antimicrobial (ABX) loaded acrylic cement, which can also be utilized for installing the patient interface 6 ( 128 ). Polymethylmethacralate (PMMA) is another adhesive adapted for orthopedic applications, and can be used for adhering one or more of the components of the system 2 to a patient ( 130 ).
FIG. 8 shows the subprocedure 62 for selecting inputs/pharmacological agents/biologics, which are chosen to enhance healing, counter infection, etc. They can include antibacterial/antimicrobial agents (ABX) 132 , growth factors 134 , irrigation 136 (i.e., in conjunction with drainage of the situs 4 ) and reperfusion 138 of the patient's fluids and biologics.
FIG. 9 shows a treatment subprocedure 64 starting at 140 and including a diagnosis and prescription of a treatment protocol ( 142 ). Following suitable preparations at 144 , the implant is installed at 146 and the patient interface is installed at 148 . A gradient source(s) is connected at 150 and a gradient is applied at 152 . In a negative pressure differential/extraction mode, exudate is extracted at 154 . The negative pressure differential/extraction mode also encourages tissue interdigitation ( 158 ) for biointegration of the interface 6 into the patient's tissue. In a positive pressure differential input/supply mode, input substances are infused at 156 into the patient interface 6 for distribution by the porous component 28 . Various treatments and pharmacologicals are available for countering patient rejection of tissue transplants, and can be used in conjunction with the system 2 at 160 . The treatment results can be monitored at 162 through various sensors 11 associated with the monitor/display 12 , and through conventional medical inspections and observations. Components of the system 2 can be changed if additional treatment is indicated at 164 , and treatment parameters can be adjusted as indicated for optimum healing at 170 and components can be changed at 168 . Finally, non-permanent components can be extracted at 166 and the treatment ends at 172 .
FIG. 10 a shows a knee joint 102 , a femur 104 and a tibia 106 . A patella 108 (kneecap) is connected to a quadriceps tendon 110 and and a patella tendon 112 . FIG. 10 b shows an implant 114 , which includes a porous, outer layer 116 . The implant 114 can comprise trabecular metal, porous thermoplastic and other porous materials, as described above. The implant 114 also includes an ultra high molecular weight plastic (UHMWP) inner layer 118 adapted for sliding with respect to the components of the knee joint 102 and providing a relatively low coefficient of friction. The implant 114 is temporarily secured to the tendons 110 , 112 by sutures 120 , which can be absorbable. The porous outer layer 116 of the implant 114 receives tissue ingrowth, as described above, for permanent bonding. A gradient source 122 is connected to the implant 114 via first and second interfaces 124 , 126 . The resulting system 128 provides drainage, irrigation, biologic application and other functions, as discussed above.
FIG. 11 shows a system 132 for reconstructing a tibia 134 . Damaged tibia tend to have high risks of infection, whereby drainage and the application of various antibiotics, antimicrobials and other biologics comprise important aspects of effective treatment. The system 132 includes a porous implant 136 connected to a gradient source 138 by first and second interfaces 140 , 142 .
It will be appreciated that various other medical, dental and veterinary applications of the porous implant system and treatment methodology fall within the scope of the present invention. While certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.
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A porous implant system includes a gradient source adapted for transferring a gradient to an interface connected to an implant at a patient situs. The gradient source is controlled by a programmable controller. The implant is bonded to the patient by tissue ingrowth, which is facilitated by the gradient formed across the porous portion of the implant. A treatment method and includes the steps of providing a porous implant, connecting same to a gradient source through an interface, forming a gradient across the implant and controlling the operation of the gradient source according to a predetermined and preprogrammed treatment protocol.
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This application is a continuation-in-part of application Ser. No. 08/111,189 filed Aug. 24, 1993, which is a continuation of application Ser. No. 07/894,084 filed Jun. 5, 1992, abandoned.
BACKGROUND OF THE INVENTION
This invention pertains to a method and apparatus for applying resilient surfaces to be used for running tracks, tennis courts, playgrounds, jogging paths, ballfield warning tracks and other activity areas requiring resilience.
Many materials and methods of application have been used to produce all-weather surfaces for the aforementioned uses, including pre-manufactured and in situ types. These systems typically involve a mixture of rubber granules, which provide resilience and traction, and a liquid binder, which hardens or cures and thereby holds the rubber particles in a solid matrix.
Pre-manufactured products are expensive and difficult to install. Indeed, the installation of pre-manufactured products inevitably results in many seams or joints which can fail in outdoor use. Accordingly, most installations of all-weather surfaces have been of the in situ (formed on site) type. Currently, there are two basic methods of in situ installation, commonly referred to as "dry" and "wet" applied.
The wet application process involves mixing rubber particulate with liquid binder in a mixer at specific ratios and batch sizes (usually at a ratio, by weight, of 60% binder, 40% rubber). The resulting slurry is spread onto the area to be surfaced by hand or mechanical means. This application is usually done in multiple layers when using latex binder and in one mechanically paved layer when using urethane binders. With respect to the latter, the application is typically accomplished by means of a track driven paving machine with an oscillating oil heated screed. This installation method creates paving joints or seams approximately every eight feet, as well as transverse joints approximately every 100 to 200 feet. These joints are not only aesthetically objectionable, they also create weak links in the system which are subject to premature failure. To cover these joints and seams, multiple structural sprays are usually applied to paved base mat polyurethanes. However, this method is limited to a maximum particle size of approximately 2 mm, and requires a high ratio of binder. Attempts have been made to use this method with latex binders, however there is a tendency for the rubber to separate from the liquid and clog the hose. Moreover, even with latex binders the particle size is limited to a maximum of 2 mm. With rubber particle sizes larger than 2 mm, the velocity of the rubber exiting the tip of the spray nozzle was such that the rubber "bounced" when impacting the substrate, thereby separating the rubber from the liquid binder. Moreover, such small particle sizes means that surface thickness cannot be built up to typically required depths without intolerable cost in terms of time and materials, and without un acceptable loss of resilience and porosity in the resulting surface. Stated differently, one could spray apply a track surface to typical thickness (3/8 or 1/2") using rubber particles of less than 2 mm, but such a process would not be economically feasible. Hence, this method is inappropriate for surfaces with greater than 2 mm in depth because of the man-hours required for application of thicker surfaces. In addition, the rubber and binder are mixed in a hopper, and unless conveyed to the site of application promptly, may set prematurely either in the hopper, the hose, or the spray nozzle.
The structural spray coats are the standard method of adding color to this type of track surface. Structural spray coats consist of 0.5 to 1.5 mm EPDM rubber, polyurethane binder and color pigmentations. However, this surface traditionally shows premature shadowing (signs of "black through"). This shadowing occurs because the structural spray can only be applied in limited thicknesses or it will choke the surface creating problems of adhesion and delamination. Thus, these structural sprays are generally applied to a maximum of 2 mm thickness with 0.5 to 1.5 mm rubber.
Conventionally the most common method for applying latex tracks is called the "rake and spray" or "dry" method. This process involves simply evenly raking out a layer of dry rubber granules onto the track base and then spraying over the granulate with a latex binder. This process is repeated with successive layers of rubber until a desired thickness is reached.
Although this method provides a more affordable athletic surface than polyurethane surfaces, is seamless, and does not require heavy investment in equipment, it is flawed in several major respects:
1. The method depends totally on the applicator to assume that a uniform ratio of rubber to binder is maintained. This is extremely difficult, since it requires the applicators to spread rubber by hand at the same poundage per unit area at all points on the surface, and then requires that the sprayer of the liquid binder applies exactly the same volume of liquid to each unit area. Improper application renders surfaces installed by this method prone to inconsistent results which are manifested in weak or easily abraded areas of the surface.
2. The method relies on migration by gravity of the liquid binder through the rubber granules in order to accomplish encapsulation of all the rubber particles. The ability or extent of migration can vary significantly, however, with the poundage of rubber applied per unit area and with the sizing or gradation of the rubber. For example, the presence of more fines will greatly inhibit migration. Since the recycled ground rubbers used in a running track surface vary dramatically from load to load or even from bag to bag, migration and therefore encapsulation can vary greatly.
3. Latex binder does not have the same physical properties as polyurethane binder. Its resilience is more effected by temperature, which means the majority of latex track surfaces are very hard during track season (February through mid May). In addition, latex binder is very susceptible to moisture during curing, which causes unraveling and delamination.
This "rake and spray" method of the prior art tends to pack the rubber tightly, which means more rubber and therefore more binder is necessary for a given thickness.
The wet and dry methods of application each have the further disadvantage of being labor intensive and time consuming.
In view of the added difficulties associated with the dry application method, various attempts have been made to devise continuous wet application methods rather than batch for both latex and urethane binder systems.
SUMMARY OF THE INVENTION
The problems of the prior art have been solved by the instant invention, which provides a method and apparatus for coating particulate material such as rubber with liquid binder and applying the same to a substrate in a continuous mix operation without the need to mix individual batches of rubber and binder. Total encapsulation of the rubber particulate with the liquid binder is accomplished prior to applying the mix to the substrate. In addition, the method of delivery of the rubber and binder maintains the ratios thereof uniform; thus, the system is not prone to mechanical problems such as clogging.
In its method aspects, the instant invention involves separately introducing a stream of particulate and a stream of binder into a spray nozzle, where they are combined and delivered to the substrate.
The apparatus of the instant invention includes a nozzle assembly having a central lumen and an elongated tip, the lumen being formed so as to force the rubber particulate introduced therein to follow a circuitous or indirect path therethrough and thereby decrease its velocity prior to being ejected from the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial diagrammatic view of the apparatus used in accordance with the present invention;
FIG. 2 is a side view of the nozzle assembly used in accordance with the present invention; and
FIG. 3 is a cross-sectional view of the dispersing ring of the nozzle assembly along lines A--A of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
One suitable rubber utilized in the instant invention is a terpolymer elastomer made from ethylene-propylene diene monomer (referred to hereinafter as "EPDM"), typically used when colored surfaces are desired. It will be understood by those skilled in the art that any suitable rubber or resilient particulate can be used, depending on the application. For example, other particulate material suitable for use in the present invention includes ground tire rubber (SBR) and resilient plastics. Where multiple layers are applied, each layer need not be comprised of the same particulate material.
The binder system also depends on the application, and can be any liquid system capable of forming a bond with the particulate, such as an asphalt emulsion, urethane system, latex system, or any combination thereof. For example, suitable binders include carboxylated styrene butadiene latex, styrene-acrylic copolymer latex, acrylic latex, vinyl acrylic latex, water-borne urethane (aromatic and aliphatic), diphenylmethane diisocyanate-urethane (MDI), and toluene diisocyanate (TDI). Suitable surfaces which are a combination of particulate and binder are exemplified by those commercially available from Sprintrax under the Sprint 200®EA (a carboxylated styrene butadiene latex based surface), Sprint 200®E, Sprint 200® (an acrylic co-polymer based surface), Sprint 300™ (MDI) and Sprint 400™, Sprint 2000 Supreme (water-borne urethane) and Sprintcote series.
The surface to be constructed in accordance with the present invention is typically applied to an existing asphalt or concrete base.
Turning now to FIG. 1, there is shown apparatus to be used in accordance with the instant invention. The apparatus is a modification of conventional equipment typically used for the application of GUNITE, such as the GRH 600 Rotary Gun commercially available from Allentown Pneumatic Gun, Inc.
Liquid binder is stored in holding tank 10 of suitable size. Suitable liquid binder feed hose, such as 3/4" I.D. rubber hose 12 is connected to tank 10 and is in communication with the nozzle 30 (FIG. 2). Pump 14, which can be any suitable type typically available for the purpose of pumping the type of liquid binder being used, such as an air actuated or motor driven pump, is attached to the hose 12 and produces sufficient pressure to convey the liquid binder to the nozzle 30. In the case of an air actuated pump, a compressor 16 of suitable capacity (185 cfm as been found to be appropriate) and an air line 18 associated therewith and with the pump 14 is used.
The compressor 16 also can be used to drive and provide transport air for the rotary gun/hopper assembly 20. The hopper 22 is of suitable capacity to hold sufficient rubber particulate, preferably in excess of 250 pounds of rubber particulate. The hopper 22 preferably includes a bag breaker, as the rubber material is typically packaged in a paper bag. A spider 24 comprising a vertical rod (not shown) with small horizontal or angled arms 47 projecting into the hopper chamber is attached perpendicular to the feed hole 48 and is caused to rotate within the hopper 22 by a rotor 26 driven by motor 29 in the rotary gun. Operation of the spider 24 helps prevent bridging, blocking and/or agglomeration of the rubber in the hopper 22 and breaks up any agglomerations of particulate than may have formed. The spider 24 also helps in continuously feeding the rubber particulate through a rotating manifold or rotor 26 which distributes the particulate evenly into an air stream. The air stream may be produced by any suitable means, such as by a blower or air compressor. Where an air compressor is used, it can be the same compressor used to actuate air pump 14. The particulate is transported by the air stream through a hose 28 to the nozzle 30. A hose having an internal diameter of 1.25 inches has been found to be suitable for transporting the rubber particulate in the air stream to the nozzle 30.
Turning now to FIG. 2, there is shown a nozzle 30 which includes a conduit portion 45 and a nozzle head 32 at a distal end of the conduit portion 45, the head 32 being positioned at about a 45° angle with respect to the conduit portion. A suitable internal diameter of the conduit portion 45 is 1.25 inches. A dispersing ring 34 (best seen in FIG. 3) is located at the proximal end of the nozzle 30. A plurality of circumferential orifices 36a-36n are formed in the dispersing ring 34, with eight evenly spaced orifices each having a diameter of 1/4" being preferred, although it should be understood by those skilled in the art that the size and number of the orifices depends on the viscosity of the liquid binder being used. The hose 28 is coupled to the proximal end of the nozzle 30, and the air stream conveying the rubber is introduced into the nozzle 30 and flows through the central lumen 38 of the dispersing ring 34. The liquid binder is pumped via feed hose 12 into the circular chamber 40 housing the dispersing ring 34 (FIG. 3). Pressure developed by the pump 14 forces the liquid binder through orifices 36a-36n in the dispersing ring 34, causing the binder to enter into the air stream carrying the rubber particulate. As the air stream carrying the particulate and binder flows toward the distal end of the nozzle 30, the binder becomes uniformly dispersed in the air stream and ultimately the particulate becomes encapsulated by the binder.
Other means of introducing the binder into the rubber include the use of multiple spray heads (not shown) through which the binder is sprayed into the air stream carrying the rubber.
In order to reduce the velocity of the binder-coated rubber particulate exiting the nozzle head 32, and thereby reduce or prevent the particulate from bouncing when it impacts the substrate, the length of the nozzle 30 between the dispersing ring 34 and the end of the nozzle head 32 should exceed twelve inches. Preferably the length of the nozzle 30 is about 20 to about 32 inches long, most preferably at least about 24 inches long. The elongated nozzle 30 also results in additional contact and wetting of the particulate with the liquid binder, which in turn causes further encapsulation of the rubber particulate by the binder. In addition, in order to create a circuitous or indirect flow path as the air stream travels from the dispersing ring 34 to the nozzle head 32, crimps or pinches 42a-42n are formed in the wall of the nozzle 30 at various intervals along its length (three shown), which cause the particulate to bounce against the inner walls of the nozzle 30 and decelerate. In the embodiment where the conduit portion is 1.25 inches in diameter, crimps which extend 1/2" into the central lumen of the nozzle 30 defined by the conduit portion 45 have been found to be suitable.
The ratio of binder to rubber particulate can be regulated as desired by any suitable means, such as by increasing or decreasing the rate at which particulate is fed from the hopper 22 by increasing or decreasing the rotation speed of the feed manifold and spider. In addition, the rate of flow of the liquid binder can be regulated by any suitable means, such as by a ball or needle valve 44 located just before the proximal end of the nozzle 30. By properly setting these flow rates, the operator can spray a specified mixture of rubber and binder onto a substrate in a continuous fashion. Depending upon the curing characteristics of the binder being used, a surface can be applied by this method in one, two or more passes. Since the flow of liquid and rubber can be independently controlled, the ratio of rubber and binder therefore can be controlled at a constant rate. Those skilled in the art will recognize that the ratio of binder to rubber desired depends upon the desired characteristics of the surface. For latex-based surfaces, the preferred ratio is about 40% latex and 60% rubber. For urethane-based surfaces, the preferred ratio is about 22% urethane and about 78% rubber.
The regulation of each stream also allows other methods of application with the same machinery. For example, after the surface mat has been installed, it can be over-sprayed with binder alone (i.e., no rubber particulate) by simply turning off the particulate material feed mechanism. For example, a urethane overspray of about 1 lb/yard can be applied for added strength. Similarly, a surface could be installed by spraying binder with no rubber and then blowing rubber with no (or a small proportion of) binder into the wet or uncured binder, allowing each course to cure, and then repeating the process until enough courses are applied to achieve the desired thickness.
The instant method and apparatus also is not limited to any specific size of rubber particulate. This is so because the rubber particulate passes through the central lumen of the dispersing ring 34, not through small orifices. Only the liquid binder flows through small orifices. In addition, the particular rheology of the liquid is not critical to the transport of the rubber particulate, since the binder and particulate are transported to the nozzle 30 separately. Suitable particulate material has average particulate diameters ranging from about 0.5 to about 7 mm. More specifically, particulate material having average diameters in the range of 0.5-1.5 mm, 1-3 mm, 1-4 mm, 1-5 mm, 2-6 mm and 4-7 mm have all been found to be functional. In view of the relatively large particle diameter that can be used in the present invention, the required surface thickness can be achieved with a minimal number of layers (2 to 5) and with sufficient void ratios to allow for much greater yield of materials and significant improvements in resilience and porosity.
Since the binder and rubber particulate are not combined until the separate streams reach the nozzle, premature curing is eliminated. Since the rubber particulate in the hopper is not mixed with the binder therein, it can be stored in the hopper 22 without problematic premature curing.
An added benefit of the present invention is the ability to build surface thickness with lower density of rubber. The "rake and spray" method of the prior art tends to pack the rubber more tightly, which means more rubber and therefore more binder is necessary for a given thickness (about 15% more). Not only does a less dense mat yield greater resilience in the surface, it also reduces the cost of materials.
In a preferred embodiment of the present invention wherein urethane is the binder, in order to obtain a smoother surface, the surface is bullfloated after each layer is applied. Best results are obtained when the bullfloating is carried out within about 0.5 hours after spray application. The system can be successfully installed by bullfloating the last layer of rubber applied, the last two layers, the last three layers, or all of the layers of rubber. The best combination of aesthetic results and manpower efficiency is attained when the last three layers of rubber applied are bullfloated within 0.5 hours of spraying.
The primary reason that bullfloating is needed with the urethane binder and not when using latex binder is that the urethane binder is much more viscous, which tends to allow the rubber to form small "piles", wherein one rubber particle will set on top of another, or where small pyramid groupings of particles would form high points. This does not occur with low viscosity latex binders. The bullfloating breaks up these undesirable groupings or high spots and forces the rubber particles into the mat by the weight of the bullfloat.
Preferably the bullfloat employed is a 4 or 5 foot wide by 6 inch deep bullfloat with a 24 to 30 foot adjustable angle handle, commercially available from Allen Engineering Corporation and sold under the RAZORBACK name.
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A method and apparatus for continuously coating particulate such as rubber with liquid binder and applying the same to a substrate to form resilient athletic surfaces. Total encapsulation of the particulate with the liquid binder is accomplished prior to applying the mix to the substrate. In addition, the method of delivery of the particulate and binder maintains the ratios thereof uniform. In its method aspects, the instant invention involves separately introducing a stream of particulate and a stream of binder into a spray nozzle, where they are combined and delivered to the substrate. The apparatus includes a nozzle assembly having a central lumen and an elongated tip, the lumen being formed so as to force the particulate introduced therein to follow a circuitous or indirect path therethrough and thereby decrease its velocity prior to being ejected from the nozzle.
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The present invention is broadly concerned with improved clamp assemblies adapted for application to the joint between welded-together pipe sections in order to prevent full separation of the pipes. More particularly, the invention pertains to clamp assemblies of this character having self-tightening capabilities, i.e., the clamp assemblies exert an increasing gripping force on the engaged pipes in the event of relative separation movement between the pipes.
BACKGROUND OF THE INVENTION
Piping systems in refinery and other oil and gas plants make use of welded pipe sections of various sizes. Such pipe sections are subject to varying temperature and pressure conditions which can lead to failures, particularly at the welded pipe joints. One such failure mechanism is referred to as carbonate stress corrosion cracking, which is a common problem within fluid catalytic cracking units, especially in the main fractionator overhead condensing and reflux systems, the downstream wet gas compression systems, and the sour water systems emanating from the foregoing. Carbonate stress corrosion cracking results in leakage and cracking in carbon steel and low alloy steel piping weldments if appropriate post-weld heat treatment is not adequately performed.
When a cracking indication is detected in these systems at the weld locations, a temporary repair in the form of an external clamp is normally applied. The clamp is designed to protect the pipe against full separation while the plant is still in operation.
A variety of clamps have been proposed in the past for the temporary repair of refinery piping systems. U.S. Pat. Nos. 4,049,296, 4,171,142, and 4,709,729 illustrate such clamps having divided clamp bodies which can be installed around continuous piping in bridging relationship to a joint. These types of clamp are deficient, however, inasmuch as they do not provide any self-tightening feature which causes the clamp to effect a tighter gripping relationship with the pipe sections as the latter tend to separate. U.S. Pat. Nos. 4,127,289 and 4,832,379 and Published Application 2005/0052023 disclose pipe couplings having toothed pipe-engaging segments. However, these units do not include separable clamp bodies, and thus cannot be applied to continuous piping around existing joints.
There is accordingly a real and unresolved need in the art for improved clamp assemblies which can be installed on interconnected ends of opposed pipe sections in bridging relationship to connection joints, and which afford a self-tightening feature such that the clamp assemblies exert an increased gripping force in the event that the interconnected pipes begin to separate.
SUMMARY OF THE INVENTION
It is, therefore, an object of the invention to provide improved clamp assemblies and clamping methods designed for application to the joint between pipe sections, in order to provide a more effective clamping action even in the event of relative separation movement between the pipes.
A further object of the invention is to provide clamp assemblies and methods having self-tightening capabilities so that an increased gripping force is exerted upon clamped pipe ends in the event of separation thereof.
It is yet another object of the invention to provide improved clamp assemblies and methods wherein the assemblies are equipped with pipe-engaging teeth oriented against separation movement of the engaged pipes and further having mechanical advantage geometries which create increased gripping forces as a result of relative separation movement between clamped pipes.
One aspect of the invention concerns self-tightening clamping assemblies adapted for installation on the adjacent ends of a pair of opposed pipe sections having a joint therebetween. The clamping assembly comprises a plurality of clamp bodies configured to be placed about the adjacent pipe section ends in spanning relationship to the joint, wherein the clamp bodies have a plurality of teeth oriented for engaging both of said pipe section ends. The assemblies further include clamping mechanisms operably coupled with the clamp bodies in order to cause the teeth to grippingly engage both of the pipe section ends. The teeth are oriented relative to the adjacent gripped pipe section ends so as to exert an increasing gripping force thereon in the event of relative separation movement between the adjacent gripped pipe section ends.
In preferred forms, a pair of clamp bodies are utilized to cooperatively surround the adjacent pipe ends, wherein each of the clamp bodies has a plurality of segments carrying teeth members oriented for engagement of the pipe ends. The clamping mechanism advantageously includes a plurality of links surrounding the segments and pressing the teeth members into gripping engagement with the pipe ends.
Another aspect of the invention concerns the combination comprising a pair of opposed pipe sections having adjacent ends with a joint therebetween, together with a clamping assembly operably engaging the pipe ends in spanning relationship to the joint. The clamping assembly comprises a plurality of clamp bodies configured to be placed about the adjacent pipe section ends, wherein the clamp bodies have a plurality of teeth oriented for engaging both of the pipe section ends. The assembly further includes clamping mechanisms operably coupled with the clamp bodies in order to cause the teeth to grippingly engage both of the pipe section ends. The teeth are oriented relative to the adjacent gripped pipe section ends so as to exert an increasing gripping force thereon in the event of relative separation movement between the adjacent gripped pipe section ends.
A still further aspect of the invention relates to methods for preventing full separation of a pair of opposed pipe sections having a joint therebetween. The methods comprise the steps of applying a plurality of clamp bodies about adjacent pipe section ends in spanning relationship to the joint, with the clamp bodies carrying a plurality of teeth. The bodies are clamped to the pipe sections in order to cause said teeth to grippingly engage both of the pipe section ends. In the event of relative separation movement between the adjacent pipe section ends, the teeth are caused to exert an increasing gripping force on the gripped pipe section ends. Preferably, the teeth are oriented at an angle relative to the adjacent gripped portions of the pipe section ends, so as to create the desired enhanced gripping properties.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a clamp assembly in accordance with the invention, shown operatively coupled to the ends of a pair of interconnected pipe sections for preventing separation thereof.
FIG. 2 is an end view of the assembly depicted in FIG. 1 .
FIG. 3 is a perspective exploded view of the clamp assembly of FIG. 1 .
FIG. 4 is a fragmentary view illustrating one of the toothed segments forming a part of the FIG. 1 clamp assembly.
FIG. 5 is a vertical sectional view taken along line 5 - 5 of FIG. 1 and illustrating the initial clamping orientation of the clamp assembly disposed about the pipe section ends.
FIG. 6 is a sectional view taken along line 6 - 6 of FIG. 1 and illustrating the fastener connection of the toothed segments.
FIG. 7 is a sectional view similar to that of FIG. 6 , but illustrating the operation of the clamping assembly for preventing full separation of the interconnected pipe section ends.
FIG. 8 is a perspective exploded view of another clamp assembly embodiment of the invention.
FIG. 9 is a vertical sectional view similar to that of FIG. 5 , but showing the FIG. 8 clamp assembly embodiment.
FIG. 10 is a view similar to that of FIG. 6 , but again showing the FIG. 8 embodiment.
FIG. 11 is a perspective view of another clamp assembly of the invention, shown operatively mounted on the interconnected ends of opposed pipe sections.
FIG. 12 is a perspective view of one of the toothed segments carried by the FIG. 11 clamp assembly adjacent one of the butt ends thereof.
FIG. 13 is a perspective view of one of the toothed segments carried by the FIG. 11 clamp assembly adjacent the opposite butt end thereof.
FIG. 14 is a sectional view of the clamp assembly shown in FIG. 11 .
FIG. 15 is a sectional view of part of the clamp assembly shown in FIG. 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, particularly FIGS. 1-7 , a self-tightening clamp assembly 20 is depicted. The assembly 20 is designed for installation about the adjacent ends 22 , 24 of a pair of elongated pipe sections 26 , 28 , and specifically in bridging relationship to the weld joint 30 between the ends 22 , 24 . Broadly speaking, the assembly 20 includes a pair of clamp bodies 32 , 34 designed to cooperatively surround the ends 22 , 24 , as well as a clamping mechanism 36 operably coupled with the clamp bodies 32 , 34 in order to draw the latter into tight gripping engagement with the ends 22 , 24 .
In more detail, the bodies 32 , 34 are each formed of malleable metal and are substantially semi-circular in configuration and are designed for mating interconnection. Referring first to the body 32 , it will be seen that it has a central body section 38 ( FIG. 3 ) as well as side peripheral sections 40 , 42 . The central section 38 is essentially imperforate and has endmost, external flange couplers 44 with through-apertures 45 . Internally, the central section 38 has a pair of laterally spaced apart, inwardly extending walls 46 , 48 cooperatively defining a channel 50 . A single fill port 52 extends through the section 38 and communicates with channel 50 . As explained below, the opposed clamping section 34 also has a port 52 .
The peripheral sections 40 , 42 are each formed into eight individual segments 54 by means of seven spaced joints or cut lines 56 . Each segment 54 has a pair of spaced apart, inwardly extending walls 58 , 60 which define a recess 62 having an oblique, sloped inner wall 63 . A pair of spaced apart fastener holes 64 extend through each segment 54 and communicate with the corresponding recess 62 . As best seen in FIG. 4 , a toothed member 66 having threaded connection bores 67 is disposed within each of the recesses 62 and is maintained therein by means of screws 68 extending through the holes 64 and into the bores 67 . The internal face of each of the members 66 presents a plurality of elongated, hardened metal teeth 70 which are slightly inclined towards joint 30 (see FIG. 5 ) and are designed to engage and grip a corresponding pipe section end 22 , 24 . It will further be seen that the width of each member 66 is less than the distance between side walls 58 , 60 ; the significance of this feature will be described below.
The body 34 is substantially identical to body 32 , and accordingly like reference numerals will be applied to the parts of body 34 which correspond to those of body 32 . As best seen in FIG. 3 , the central body section 38 is equipped with flange couplers 44 , and bolts 74 extend through the apertures 45 in order to interconnect the sections 32 , 34 ; nuts 76 and washers 78 are employed to complete the connection of the clamp bodies 32 , 34 . It will be appreciated that when the sections 32 , 34 are interconnected, the channel 50 is continuous throughout the entirety of the clamped assembly and that the segments 54 are uniformly spaced about the peripheral sections 40 , 42 .
The clamping mechanism 36 is made up of two circumferential, substantially identical clamps 80 , 82 which are respectively disposed about the segments 54 of the peripheral sections 40 , 42 . Thus, the clamp 80 is made up of a pair of complemental clamp halves 84 which cooperatively surround and engage the segments 54 of peripheral section 40 . Each half 84 has a pair of apertured end blocks 86 with a total of five interconnected links 88 which are secured to the blocks 86 and to each other by means of lateral pin couplers 90 . The inner faces 86 a of the blocks 86 , and the inner faces 88 a of the intermediate links 88 , are configured to closely conform with the outer faces of the segments 54 , i.e., each of these inner faces engages one of the segment outer faces. Interconnection of the halves 84 is effected by means of bolts 92 extending through the opposed blocks 86 and secured with nuts 94 and washers 96 .
The clamp 82 is identical with clamp 80 , save for the fact that the clamp 82 is disposed about the segments 54 of side section 42 . Therefore, like reference numerals are used throughout and no further description is warranted.
In use, the clamp bodies 32 , 34 are disposed about the pipe sections 26 , 28 in spanning relationship to joint 30 , with teeth 70 of the individual members 66 in engagement with the outer surfaces of the section ends 22 , 24 . The bodies 32 , 34 are then bolted together using the couplers 44 and bolts 74 . The clamps 80 , 82 are next secured to the peripheral sections 38 , 40 , with the inner surfaces 86 a , 88 a in alignment with corresponding segments 54 , as best illustrated in FIG. 2 . The clamp halves 84 are then interconnected and drawn in to tight engagement with the segments 54 by means of the bolts 92 and nuts 94 . Tightening of the bolts 94 serves to slightly deflect (either permanently or temporarily) the segments 54 inwardly so as to insure a tight gripping engagement of the teeth 70 with the outer surfaces of the pipe ends 22 , 24 . The soft steel segments 54 allow the segments to deflect and yield as necessary so that the clamp conforms to irregular pipe surfaces, e.g., the pipes may not be precisely round or flat-sided as the case may be.
Finally, an injectable polymer resilient fill material 98 is inserted into the continuous channel 50 so that the fill material engages and spans the joint 30 . This material preferably hardens but will retain a degree of resiliency for sealing purposes. It may be advisable to block the port 52 of one half of the clamping mechanism in order to effect a seal without a “leaking” of the injected material. Additionally, at the region where the clamp bodies 32 , 34 come together there will be a gap. It may be advisable to use a labyrinth seal or some other type of gasket to keep the injected filler material from leaking out of the clamping arrangement before it hardens.
It will be appreciated that the teeth 70 are driven into the pipe walls by the elastic response of the preloaded clamp arrangement. When the clamping bolts are preloaded initially, there is a stretching of the clamp elements and a consequent elastic compression the pipe sections.
In the event of relative separation movement between the pipe ends 22 , 24 as depicted in FIG. 7 , the self-tightening feature of the invention comes into play. Specifically, in such an instance, the relatively large forces generated by such separation serves to shear the screws 68 holding the members 66 . At the same time, owing to the oblique orientation of the surfaces 63 , an increased gripping force is generated between the teeth 70 and the pipe ends 22 , 24 , thereby serving to minimize the separation between the pipe ends within the width of the fill material 98 . This effect is augmented owing to the elasticity of the preloaded clamp/pipe section arrangement. The small motion between the teeth and pipe does not significantly reduce the preload force. The dimensions of recess 62 are a significant factor in controlling the gap 30 ( FIG. 7 ), i.e., the amount of gripping force can be controlled by the recess dimensions, and are selected to provide enough self-tightening to grip the pipe sections but not to allow the clamping ring to become overloaded or deform the pipe sections. As such, complete failure of the pipe arrangement is avoided, thereby permitting continued operation until the separation can be permanently repaired.
FIGS. 8-10 illustrate a modified clamp assembly 100 which is in many respects identical with assembly 20 . Accordingly, like reference numerals will be used in the description of the assembly 100 , and only the differences between assembly 100 and assembly 20 will be particularly discussed.
Thus, the assembly 100 is broadly made up of clamp bodies 32 a , 34 a which differ from the previously described bodies 32 , 34 only in the specific construction of the individual segments 54 a . In particular, these segments include inwardly directed walls 58 a , 60 a defining recesses 62 a . The latter receive toothed members 66 a having inwardly directed, angularly oriented hardened teeth 70 a . In this case, however, the members 66 a are in a tight fitting relationship with the recesses 62 a . In all other respects, the bodies 32 a , 34 a are identical with the clamp bodies of the first embodiment. Similarly, the clamping mechanism 36 , including the clamps 80 , 82 , are identical to those of the first embodiment and need not be further described.
The use of assembly 100 is the same as that described with reference to assembly 20 . However, upon relative separation movement between the pipe ends 22 , 24 , the assembly 24 creates an increased gripping power owing simply to the orientation of the teeth 70 a ; the mechanical advantage derived in the assembly 20 from the use of the frangible screws 68 and the oblique surfaces 63 is not present in assembly 100 .
A still further embodiment of the invention is illustrated in FIGS. 11-15 , in the form of clamp assembly 102 which includes a pair of opposed clamp bodies 104 , 106 adapted to be mounted in spanning relationship to the joint 30 between pipe ends 22 , 24 of pipes 26 , 28 . Additionally, the overall assembly 102 includes a clamping mechanism 108 applied over the bodies 104 , 106 .
In more detail, the clamp body 104 is generally semicircular in configuration and includes a central section 110 as well as outwardly extending side sections 112 , 114 . The central section 110 has a pair of laterally spaced apart, inwardly projecting walls 116 , 118 which cooperatively defines a channel 120 . A fill port 122 communicates with the channel 120 . Each of the side sections 112 , 114 extends outwardly from the section 110 and is spaced above the inner faces of the walls 116 , 118 , thereby defining respective side recesses 124 , 126 . As best seen in FIGS. 14 and 15 , the inner surface of each side section 112 , 114 includes a surface 128 , 130 which is substantially parallel with the underlying pipe surface, and a sloped surface 132 , 134 , and a terminal butt end surface 136 , 138 ; locating bores 139 are provided in these end surfaces as illustrated in FIG. 11 . Thus, the sections 112 , 114 effectively define restricted throats 140 , 142 adjacent the outboard ends thereof. The outer surface of the body 104 presents a series of concavities 144 which are important for purposes to be described.
The opposed clamp body 106 mates with body 104 and is likewise arcuate so as to mate with the pipe ends 22 , 24 . Specifically, the section 106 is essentially a mirror image of section 104 , and accordingly like reference numerals are used throughout. As shown, the two bodies 104 , 106 cooperatively surround the ends 22 , 24 of the pipes 26 , 28 .
The clamping mechanism 108 includes a pair of yokes 146 , 148 having apertured, endmost connection blocks 150 , 152 . The yokes 146 , 148 are designed to overlie the respective side sections 112 , 114 as depicted in FIG. 14 . The yokes 146 , 148 are secured in place by means of a plurality of integral, continuous U-bolts 154 which seat within the concavities 144 of body 104 and extend through the apertures of the blocks 150 , 152 . Nuts 156 are used to tighten the mechanism 108 and thus secure the bodies 104 , 106 in place.
The overall assembly 102 further includes a plurality of tooth members 158 secured to the side sections 112 , 114 . Referring to FIGS. 12 and 13 , it will be seen that each of the members 158 includes an inboard gripping section 160 having lowermost pipe-gripping teeth 162 . The sections 160 also have an inclined upper surface 164 which is complemental with the surfaces 132 , 134 of the side sections 112 , 114 . In addition, each of the members 158 has a relatively thin neck section 166 which is designed to fit within restricted throats 140 , 142 previously described. Finally, each member 158 includes an upstanding flange section 168 having a pair of threaded bores respectively carrying spaced connection screws 170 .
The members 158 are secured to the side sections 112 , 114 by positioning the screws 170 within the bores 139 . These would be initially loosely installed on the butt ends of the sections 112 , 114 , followed by application of the latter to the pipe ends 22 , 24 using mechanism 108 . After the latter is installed over the bodies 104 , 106 , the screws 170 are used to preload the respective members 158 and create a tight gripping engagement between teeth 162 and the pipe ends. The surfaces 164 of the members 158 are thereby brought into tight complemental engagement with the surfaces 132 , 134 of the side sections 112 , 114 .
The final step in the attachment of assembly 102 involves filling the continuous channel 120 with resilient sealing fill material 172 .
The use of assembly 102 involves initial attachment thereof to the pipe ends 22 , 24 as previously described. In the event of relative separation movement between the end sections, the preloaded members 158 , because of the angularly oriented teeth 162 and the mechanical advantage gained by the mating oblique surfaces 164 and 132 , 134 , causes the gripping force exerted on the pipe end sections to be increased. This prevents catastrophic failure of the pipe assembly and permits continued use thereof until a permanent repair can be made.
The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.
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Improved self-tightening clamp assemblies are designed for application to the adjacent ends of connected pipe sections in spanning relationship to the joint therebetween. The assemblies include a plurality of clamp bodies configured for placement about the adjacent pipe section ends and carrying a plurality of pipe-engaging teeth; a clamping mechanism is operably coupled with the clamp bodies to cause the teeth to grippingly engage the pipe section ends. The teeth are oriented so as to exert an increasing gripping force on the pipe sections ends in the event of relative separation movement between the ends.
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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with United States Government support under Government Contract/Purchase Order No. DE-FC26-02NT41246. The Government has certain rights in this invention.
TECHNICAL FIELD
The present invention relates to solid oxide fuel cells (SOFCs); more particularly, to materials for forming the cathode in an SOFC; and most particularly, to improved perovskite-type materials (known in the SOFC art as “LSCF” compositions) having enhanced ionic and electronic conductivity, improved thermal properties, and capability for yielding higher SOFC power densities.
BACKGROUND OF THE INVENTION
Solid oxide fuel cell (SOFC) technology is being developed for automotive and stationary applications. It is known that mixed ionic and electronic conducting (MIEC) perovskite-type ABO 3 oxides are promising cathode materials for solid oxide fuel cells and oxygen semi-permeable membranes.
The general chemical formula for perovskite compounds is ABX 3 , wherein ‘A’ and ‘B’ are two cations of very different sizes, and X is an anion that bonds to both. (The native titanium mineral perovskite itself is of the formula CaTiO 3 ). The ‘A’ atoms are larger than the ‘B’ atoms. The ideal cubic-symmetry structure has the B cation in 6-fold coordination, surrounded by an octahedron of anions, and the A cation in 12-fold cuboctahedral coordination. The relative ion size requirements for stability of the cubic structure are quite stringent, so slight buckling and distortion can produce several lower-symmetry distorted versions, in which the coordination numbers of A cations, B cations, or both are reduced.
In the LSCF pervoskite crystal lattice, the A-sites are occupied by La and Sr ions, and the B-sites are occupied by Co and Fe ions that surround oxygen ions. In these materials, the cathode oxygen exchange reaction in an SOFC is not limited only to the triple-phase boundary line between electrolyte, cathode, and gas phase, but extends over a large three-dimensional area within the cathode.
Compositions of the general formula La 1−x Sr x Co 1−y Fe y O 3−δ have been proposed in the prior art as materials for SOFC cathodes due to their high catalytic activity for the oxygen exchange reaction and a high electronic conductivity for current collection. The physical and chemical properties of this class of materials, such as electrical conductivity, electronic structure, catalytic activity, stability, and thermal expansion coefficient (TEC), have been studied in detail. Generally, electronic and ionic conductivities and catalytic activity are enhanced with increasing values of x and decreasing values of y, whereas there is an opposite tendency for chemical stability.
Further, it is known that these properties are strongly affected by a change in the combination of La and Co oxide concentrations. Electronic conductivity for La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (also known in the art as “LSCF 6428”) is sufficient (>250 S/cm at 1073° K) for the above-mentioned applications. However, ionic conductivity is rather low (˜10 −2 S/cm at 1273° K). It has been suggested that increasing Sr-deficiency in LSCF 6428 is a way to improve its oxide ionic conductivity and catalytic property for oxygen reduction.
Another investigation on A-site deficiency has reported significant decrease in electronic conductivity in the order La 0.6 Sr 0.4−z >(La 0.6 Sr 0.4 ) 1−z >La 0.6−z Sr 0.4 . In yet an another investigation, it has been concluded that the TEC decreases with decreasing A-site stoichiometry, and that electronic conductivity of the perovskites has a weak dependence on the A-site stoichiometry. As a result, (La 0.6 Sr 0.4 ) 1−z Co 0.2 Fe 0.8 O 3−δ materials are commonly used for SOFC cathodes and are available commercially.
From the above discussion it is clear that while A-site deficiency is desirable, both ionic and electronic conductivities need to be high to drive performance in terms of fuel cell power density (W/cm 2 ) and to reduce the cost. This is because cathode polarization, or resistance associated with the low rate of chemical and electrochemical reactions occurring in the cathode, is still the major source of voltage loss in SOFCs. Control of cathode microstructure (pore size, shape, and porosity) helps, but supply of electrons (electronic conductivity) and oxygen (oxide ion conductivity) deep into the cathode is the key to reducing cathode losses.
The supply of oxygen ions to the electrolyte is a function of ionic conductivity on one hand and the supply of electrons on the other hand and depends on the electronic resistivity of the cathode material. What is desired is a cathode material that has high electronic and ionic conductivities along with high catalytic activity. Further, cathode polarization resistance, mechanical properties, and cost are major concerns in the development of a practical SOFC.
Still further, reducing cost of manufacture requires a reduction in fuel cell operating temperature to around 750° C. or below so that less expensive interconnect and sealing materials can be used. The degradation of these materials is reduced at lower operating temperature, and thus reliability and long-term stability of a fuel cell stack is improved. Development of such materials can help in attaining higher power density (W/cm 2 ) at lower cost from SOFC stacks.
What is needed in the art is improved LSCF perovskite materials having enhanced ionic and electronic conductivity, improved thermal properties, and capability for yielding higher SOFC power densities and at lower operating temperatures.
It is a principal object of the present invention to reduce the cost of manufacture and improve performance and stability of a solid oxide fuel cell.
SUMMARY OF THE INVENTION
Briefly described, the present invention comprises an improved LSCF 6428 perovskite material for use as a cathode in an SOFC and a method for forming the material. By creating deficiency on the A-site of the pervoskite lattice by reducing La or Sr or La+Sr in the LSCF 6428 material, electrical conductivity is reduced. Sr deficiency in LSCF material increases conductivity of the oxide ion.
LSCF 6428 materials in accordance with the present invention of the type La 1−x−2z. Sr x+z Co 0.2+a Fe 0.8+b O 3−δ where preferably x=0.4, z=(0-0.1), a=(0.01-0.04), and b=(0.05-0.15) exhibit enhanced ionic and electronic conductivity. These materials are La-deficient but Sr-rich with respect to prior art LSCF 6428 materials. The general formula is similar to the prior art formulae (La 0.6 Sr 0.4 ) 1−z Co 0.2 Fe 0.8 O 3−δ and La 0.06 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ but applies the z term to La and Sr independently as well as reducing the overall content of La and increasing slightly the amount of Fe. Further, by adding a small amount of extra Co ions beyond the above stoichiometry, catalytic activity, conductivity, and sinterability may further enhanced.
Still further, adding small amounts of Fe and/or Fe and Co moderates the thermal expansion coefficient with no adverse effect on crystal structure or fuel cell performance.
Finally, improved sinterability, microstructure, and reduced film cracking from these compositions result in high power density and stability of fuel cells having these compositions as cathodes. While these pervoskites can be synthesized by various methods, a currently-preferred inherently low-cost solid state reaction method is described.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is an isometric drawing of a prior art perovskite lattice structure used in the present invention;
FIG. 2 is a prior art graph showing the adverse effect on electronic conductivity of reducing the molar amount of La, Sr, and La+Sr by various molar amounts z;
FIG. 3 is a table showing comparative manufacturing conditions and resulting specific surface areas for two commercially-available LSCF compositions and three exemplary LSCF compositions in accordance with the present invention;
FIG. 4 is a graph of sheet resistivity as a function of temperature, showing reduced resistivity and hence improved conductivity of LSCF compositions in accordance with the present invention;
FIG. 5 is a graph of polarization curves showing a comparison of cell voltage and power density for a prior art LSCF composition and an LSCF composition in accordance with the present invention;
FIG. 6 is a graph of AC impedance spectra for the five LSCF compositions shown in FIG. 3 , obtained at 650° C.; and
FIG. 7 is a graph of power density as a function of time for SOFCs having cathodes formed of LSCF compositions 1 , 3 , and 4 .
The exemplifications set out herein illustrates currently preferred embodiments of the present invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 , prior art perovskite lattice structure 10 comprises a central B-site cation 12 surrounded by a square double pyramid lattice of six oxygen ions 14 in turn surrounded by a cubic lattice of eight A-site cations 16 . As noted above, the A-sites are occupied by La and Sr ions, and the B-sites are occupied by Co and Fe ions that surround oxygen ions 14 .
In the present invention as well as in the prior art, in forming a suitable LSCF 6428 material some of the cubic A-sites, such as site 16 ′, which would otherwise contain La or Sr, are left vacant. As is known in the prior art, when Sr is omitted from some A-sites 16 ′ ionic conductivity σ ion of LSCF is increased. However, such omission unfortunately causes a concomitant reduction in electronic conductivity σ e . FIG. 2 is a prior art graph showing the effect on σ e of reducing the molar amount of La, Sr, and La+Sr by various molar amounts z.
Considering factors such as chemical stability, TEC, electrochemical activity, and ease of manufacturing A-site deficient LSCF perovskites, La 1−x−2z Sr x+z Co 0.2+a Fe 0.8+b O 3−δ , with z about 0.05, three such novel perovskites as shown in FIG. 3 were synthesized by solid-state reaction of cationic salts. Compositions 1 and 2 were two commercially-available LSCF 6428 compositions manufactured by a prior art combustion spray process and a solid state reaction process, respectively. Note that compositions 3 , 4 , 5 in accordance with the present invention are deficient in La and enriched in Sr with respect to prior art compositions 1 , 2 .
For the three novel compositions 3 , 4 , 5 in accordance with the present invention, appropriate amounts of La 2 O 3 , SrCO 3 , CoCO 3 , and Fe 2 O 3 salts were mixed and ball-milled for 12 hours using aqueous or isopropyl alcohol as a medium. The wet slurries were then heated to 105° C.-120° C. and dried. The resultant mixtures were each calcined at about 800° C. for 1 hour. Next, the resulting powders were ground by ball milling for several hours until a mean particle size (d 50 ) of about 1.0 μm was achieved. A small amount (composition 3 a ) of La 0.5 Sr 0.45 Co 0.2 Fe 0.8 O 3−δ 3 was calcined at 1400° C. for 1 hour. All the powders were then calcined at 1250° C. for 1 hour (range 1100° C.-1400° C., 0.5-3 h) and were remilled for several hours until a mean particle size (d 50 ) of about 0.8 μm was achieved. Heating and cooling rates were controlled at 5° C./min. After calcination, all powders were wet milled using alcohol and stainless steel balls as the media. A small amount of one of the compositions (composition 5 a ) was also wet milled using ceramic balls formed of yttrium-stabilized zirconia (YSZ) as the media. Although solid-state reaction was used to prepare these pervoskites, alternative known methods such as EDTA or citrate pyrolysis, flame or combustion spray, sol-gel, dissolution of metal nitrates, glycine nitrate, and the like, may be employed as well.
X-ray diffraction patterns were taken of all the FIG. 3 LSCF powders, represented by La 1−x−2z. Sr x+z Co 0.2+a Fe 0.8+b O 3−δ and synthesized by solid-state reaction method, using a Siemens D500 equipped with a monochromated Cu Kα radiation source. A comparison with (La 0.6 Sr 0.4 ) 0.95 Co 0.2 Fe 0.8 O 3−δ prepared by combustion spray process (commercial composition 1 ) revealed that all the X-ray diffraction patterns of LSCF-powders were single perovskite type structures and were indistinguishable from each other. With about 5% A-site deficiency and additional Co and Fe in two of the compositions (compositions 4 , 5 ) traces of (Co,Fe) 3 O 4 were possible (while not observed) and were not considered to be detrimental for use as an SOFC cathode.
Sheet resistivity of La 0.5 Sr 0.45 Co 0.2 Fe 0.8 O 3−δ (composition 3 ) was compared with commercial materials 1 , 2 . For this purpose, three strip cells with respective cathode materials (2.5 cm 2 area) on anode-supported electrolytes were prepared. The cathodes included a 5 μm thick samarium doped ceria (SDC) layer and a 30 μm thick LSCF layer. The SDC layer was sintered at 1200° C. with particle size about 0.3 μm while the LSCF layer was sintered at 1050° C. with particle size about 1.0 μm. Two Ag/Pd strips (containing 15 wt. % Pd) were coated on each cathode 0.45 cm apart. A platinum wire, spot welded to a silver screen, was used as a current lead. Two such screens were then pasted on the Ag/Pd strips with an Ag/Pd thick film ink. The strip cell was placed inside a furnace and tested in air using an AC impedance technique. During the measurement, the temperature of the strip cell was set between 550 and 750° C. In this measurement, electrons were laterally transferred from one Ag/Pd strip into a sheet of the cathode material and then transferred out through the other Ag/Pd strip. After subtracting the resistance of the Pt leads, the sheet resistivities for the LSCF cathode materials were calculated as shown in FIG. 4 . In this calculation, the contact resistance existing between the silver screen and the Ag/Pd strip was not excluded.
FIG. 4 shows that as compared to combustion sprayed commercial composition 1 , and solid state reaction commercial composition 2 , material in accordance with the present invention and represented by composition 3 had the lowest sheet resistance (highest sheet conductivity). Further, and referring now to FIG. 5 , a higher power density was measured at a variety of cell voltages for improved LSCF composition 3 in comparison to prior art LSCF composition 1 .
To determine the effect of LSCF compositions on the cathode resistance, button cells with symmetrical cathodes were prepared on YSZ electrolyte (0.42 mm thick, as support) for each of the five LSCF materials shown in FIG. 3 . Each cell had two symmetrical cathodes (2.5 cm 2 ). The construction of button cells was similar to that of strip cells described above except that there were cathodes on both sides of the electrolyte. The resistance of the cathodes was measured using an AC impedance technique. During the measurement, a sinusoidal voltage (20 mV peak) was applied to the electrodes. The frequency of the sinusoidal voltage was scanned from 1 to 10 kHz. The sinusoidal current response of the system was then measured. From the voltage/current ratio, an AC impedance spectrum was obtained. In the spectrum, the width of the opening corresponded to the resistance of the cathode. The AC impedance spectra obtained at 650° C. are shown in FIG. 6 .
FIG. 6 shows that La 1−x−2z. Sr x+z Co 0.2+a Fe 0.8+b O 3−δ materials 3 , 4 , 5 obtained via solid state reaction have spectra with smaller opening than commercial material 2 . This implies a higher rate of oxygen ion conversion, as the width of the opening is inversely proportional to the rate of the cathodic reactions. Further, material 4 with slight excess of cobalt possesses high electronic and ionic conductivities along with high catalytic activity. Still further, milling of La 0.5 Sr 0.45 Co 0.2+0.025 Fe 0.8+0.12 O 3−δ 5 material with metallic beads (composition 5 ) or ceramic beads (composition 5 a ) shows that ceramic beads (YSZ, alumina, ZrO 2 ) degrade the material. Finally, materials formed in accordance with the present invention yield films that have few cracks and high mechanical strength after sintering.
Based on results shown in FIG. 6 , three 1-inch diameter cells were prepared to evaluate power density performance with time. These cells were built on a 12 micron thick YSZ electrolyte supported on a 0.45 mm Ni/YSZ substrate acting as an anode. All the layers were screen printed using a paste obtained by mixing about 60 wt % of a solid phase with an organic binder. First, the electrolyte surfaces of these cells were covered with a Sm 0.2 Ce 0.8 O 2 with 2 wt % Fe 2 O 3 . The thickness of the layer was 4-5 μm after sintering at 1200° C. Next, the LSCF cathodes were screen printed to produce cathodes with active area of 2.5 cm 2 . After sintering at 1050° C., the thickness of the cathodes were about 30 μm. Silver and nickel meshes with platinum lead wires and pastes were used to establish the current collectors. The air and fuel sides of the cells were isolated using a glass sealing material. The NiO/YSZ composite anode was reduced, in situ, at 800° C. for 1 hour in a hydrogen gas atmosphere (50% H 2 in N 2 ). During testing, the cathode side of the cell was exposed to flowing air at a rate of 2.3 L/min and the anode side was exposed to a flowing stream of 50% hydrogen at a rate of 2.3 L/min. The electrochemical measurements were conducted at 750° C. using a potentiostat/galvanostat (PARSTAT® 2273) and power-generating characteristics as a function of time were measured at a polarization potential of 0.7V.
FIG. 7 shows power generation characteristics of compositions 3 , 4 in accordance with the present invention, and prior art composition 1 . Under these conditions, at 750° C. the La 1−x−2z. Sr x+z Co 0.2+a Fe 0.8+b O 3−δ materials produce stable and high power, implying high catalytic activity with improved ionic and electronic conductivities. Further, the solid state reaction manufacturing method described above is suitable for low-cost volume production of such LSCF materials.
While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
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An improved LSCF 6428 perovskite material of the type La 12z Sr x+z Co 0.2+a Fe 0.8+b O 3−δ wherein x=0.4, z=(0-0.1), a=(0.01-0.04), and b=(0.05-0.15) for use as an SOFC cathode having increased electronic and ionic conductivity. The general formula is similar to the prior art formulae (La 0.6 Sr 0.4 ) 1−z Co 0.2 Fe 0.8 O 3−δ and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ but applies the z term to La and Sr independently as well as reducing the overall content of La. Further, by adding a small amount (a) of extra Co ions, catalytic activity, conductivity, and sinterability are further enhanced. Adding small amounts (b) of Fe and/or Fe and Co moderates the thermal expansion coefficient with no adverse effect on crystal structure or fuel cell performance. Improved sinterability, microstructure, and reduced film cracking result in high power density of fuel cells. An inherently low-cost solid state reaction method is described.
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TECHNICAL FIELD
[0001] This invention relates to a process for producing hydrolysed whey protein products which are free of bitter flavours and which contain bioactive peptides. The products of the process have high digestibility and good organoleptic properties. The products may have either a bland or slightly sweet taste and are free of soapy or brothy flavours. The hydrolysed whey protein products may optionally contain oligosaccharides and are useful sources of bioactive peptides for incorporation into functional foods.
BACKGROUND ART
[0002] A number of food ingredients and foodstuffs have been produced from the hydrolysis of a protein source such as the milk proteins, casein and whey proteins.
[0003] Hydrolysed protein foodstuffs may have advantages over non-hydrolysed protein foodstuffs in a number of areas of health care. For example, it is known that enzymatically hydrolysed proteins are less allergenic. They are also more rapidly digested and absorbed than whole proteins. Foodstuffs containing hydrolysed proteins are also useful in the alimentation of hospital patients with digestive diseases for example.
[0004] Hydrolysis of whey proteins and caseins is known to release bioactive peptides that can exhibit a number of physiological effects (Maubois et al, 1991; EP 475506). A number of publications describe such bioactive peptides, for example, ACE inhibiting peptides which have antihypertensive properties have been released through an enzymatic treatment of bovine β-lactoglobulin and whey protein concentrates (Mullally et al, 1997). ACE inhibitory peptides are also found in sour milk and in hydrolysates of α s and β casein (JP 4282400; Nakamura et al 1994, Yamamoto et al 1994).
[0005] EP 4745506 discloses the hydrolysis of the milk protein lactoferrin in whey to release lactoferricin which acts as an antimicrobial agent useful for treating diarrhoea, athlete's foot, eye infections, mastitis etc in humans and animals.
[0006] However, the hydrolysis of most food proteins, especially the hydrolysis of whey and casein containing products, is known to generate bitterness. This causes palatability problems particularly when attempting to formulate orally ingestible products incorporating milk protein hydrolysates as a source of bioactive peptides.
[0007] In the field of protein hydrolysis one or both of two approaches are commonly used for controlling or removing bitterness in protein hydrolysates to increase palatability of the products.
[0008] The extensive hydrolysis of the protein substrate is known to reduce bitterness in milk protein hydrolysates (EP 065663; EP 117047; U.S. Pat. No. 3,970,520). Less bitter products are produced relatively easily and cheaply in this way. However, extensive hydrolysis reduces the chain lengths of all peptides, including the bioactive peptides of interest. Extensive hydrolysis of the protein substrate destroys the functional and biological activity of the peptide of interest. In addition soapy and brothy off-flavours often develop, with the consequence that the palatability of the final product remains poor compared to the original bland tasting protein substrate. A final disadvantage is that for some hydrolysates the bitterness is only partially removed (Roy 1992 and 1997).
[0009] A second common method for the control of bitterness in protein hydrolysates is to use debittering enzymnes, in particular those sourced from Aspergillus oryzae.
[0010] “Bitterness” generation in protein hydrolysis is thought to be due to the presence of large hydrophobic ‘bitter’ peptides. Debittering enzymes selectively hydrolyse bitter peptides present in the protein hydrolysates. A worker skilled in the art can—by the judicious selection of debittering enzymes and the conditions of treatment—effectively debitter milk protein hydrolysates leaving intact the particular bioactive peptides of interest. However, use of debittering enzymes makes the process more expensive, and preservation of some of the bioactive peptide is not easily or sucessfully achieved. A further disadvantage is that debittering enzymes treatments have a tendency to release free amino acids into the final product and, as a consequence, the hydrolysates develop unpleasant brothy or soapy flavours (Roy 1992 and 1997).
[0011] The various methods of debittering the protein hydrolysates result in additional process steps and add costs to the manufacture of the final product. In addition the final product also becomes overbalanced in its supply of free amino acids.
[0012] It would be most advantageous if a process for hydrolysing protein could be developed which releases bioactive peptides of interest and which limits the formation of bitter peptides and free amino acids, thereby allowing the original bland taste of the milk proteins substrates to be retained.
[0013] Some bioactive peptides—in particular the antihypertensive peptides—are relatively stable during protein hydrolysis and are released very early during the hydrolysis of the milk protein substrate as shown in FIG. 1 .
[0014] The bitter flavours of milk protein hydrolysates can be improved by adding sugars or by hydrolysing natural sugars, such as lactose, already present in the milk protein substrate (Bernal and Jelen, 1989). For example sour wheys and cheese wheys are made more palatable when they have been sweetened by β-galactosidase and lactase hydrolysis of lactose (FR 2309154; U.S. Pat. No. 4,358,464; JP 8056568).
[0015] In order to achieve a high flavour acceptability for a hydrolysed protein product which contains bioactive peptides, precise control of hydrolysis is required to prevent bitterness occurring.
[0016] A common method of termination of hydrolysis is by deactivation of the enzymes, usually by thermal deactivation at high temperatures, typically >90-100° C. for an extended period of time. However, this method cannot be used to stop the hydrolysis of whey proteins as any intact unhydrolysed whey proteins remaining in the mixture would denature and precipitate making the final product less soluble and less acceptable for the use as a food ingredient.
[0017] It would be advantageous if a process of hydrolysing whey protein could be controlled so that it directly produced a hydrolysate comprising bioactive peptides for incorporation into functional foods which did not taste bitter and where the enzyme inactivation steps did not compromise the integrity of the intact proteins in the final product.
[0018] It is an object of the invention to go some way towards achieving these desiderata or at least to offer the public a useful choice.
SUMMARY OF THE INVENTION
[0019] Accordingly the invention may be said broadly to consist in a process for preparing a whey protein hydrolysate containing bioactive peptides which comprises the following steps:
(i) treating a whey protein containing substrate with one or more enzymes capable of hydrolysing whey proteins, to produce a whey protein hydrolysate containing bioactive peptides; and (ii) terminating the hydrolysis before substantial production of bitter flavours.
[0022] Preferably the hydrolysis is terminated under conditions which cause no more than partial denaturation of the whey proteins and which maintain or improve their organoleptic properties.
[0023] More preferably the hydrolysis is terminated under conditions which partially denature the whey proteins and thereby improve their organoleptic properties.
[0024] Preferably the enzyme capable of hydrolysing the whey proteins is selected from the group consisting of Protease P6, Protease A, Protease M, Peptidase, Neutrase, Validase and AFP 2000 (all as herein defined).
[0025] Preferably the hydrolysis is terminated by heat treatment, preferably for a period of about 1 to 10 seconds at a temperature of about 85° C. to 100° C.
[0026] Preferably the degree of hydrolysis of the substrate before termination of hydrolysis is up to 10%.
[0027] More preferably the degree of hydrolysis is from about 3% to about 5%.
[0028] Preferably the substrate also contains lactose, in an amount of up to 50% by weight.
[0029] Alternatively, the substrate also contains lactose in an amount of up to 30% by weight.
[0030] Preferably the substrate is also treated with lactase and/or β-galactosidase, either before or during the whey protein hydrolysis, to hydrolyse the lactose to galactose and glucose and synthesize galacto-oligosaccharides.
[0031] In another embodiment the invention consists in a whey protein hydrolysate containing one or more bioactive peptides selected from the group consisting of AFE, LFSH, ILKEKH, LIVTQ, MKG, LDIQK, VF, ALPMH, VTSTAV, LHLPLP, LVYPFPGPIPNSLPQNIPP and LFRQ.
[0032] The enzyme hydrolysis step may be carried out under conditions which are suitable for the particular enzyme used as would be understood by a person skilled in the art.
[0033] The whey protein substrates are hydrolysed at a concentration in the range from 5-50% solids and the enzyme or enzyme mixtures are added to give an enzyme to substrate ratio between 0.01% and 3% w/w total solids, preferably between 0.01% and 1.0% w/w total solids.
[0034] Protein substrates treated with acid proteases may be hydrolysed at pH between 2.5 and 6.0, preferably between pH 3.0 and 5.0.
[0035] Protein substrates treated with neutral proteases may be hydrolysed at pH between 3.5 and 9.0, preferably between pH 6.0 and 8.0.
[0036] Protein substrates treated with alkaline proteases may be hydrolysed at pH range between 5 and 10.0, preferably between pH 6.0 and 8.0.
[0037] The protein hydrolysis may be carried out at a temperature range of from 20-65° C., preferably from 50-60° C.
[0038] The hydrolysis of lactose may be carried out at a prior stage to the whey protein hydrolysis, concurrently therewith or subsequently. The enzymes used for lactose hydrolysis may comprise lactase and/or β-galactosidase and may be selected from yeast or fungal sources eg Klyvermyces lactis, Saccharomyces lactis, Saccharomyces fragillis, eg Aspergillus niger, Aspergillus oryzae such as Maxilact (Gist Brocades) and Novolact (Novo Nordisk). The lactose hydrolysis is carried out under conditions which would be known to persons skilled in the art.
[0039] In one embodiment termination of the hydrolysis is achieved by deactivating the one or more whey protein hydrolysis enzymes (and/or the lactose hydrolysing enzymes added previously) by firstly changing the pH of the reaction mixture to a pH in which the enzyme(s) is either inactive or less active, and/or heating the reaction mixture to a comparatively mild temperature using a heat exchanger to denature the enzyme but not the intact whey proteins in the substrate. A suitable temperature range which would denature the enzymes is in the order of 55-70° C., preferable 65° C.
[0040] According to one option, depending on the enzyme(s) used, the enzyme or enzyme mixture may also be deactivated by the evaporation and drying procedures.
[0041] According to another option the enzyme or enzyme mixture may also be deactivated with or without a prior pH change.
[0042] Alternatively, the one or more enzymes used to selectively hydrolyse the whey protein may be immobilised on an inert support such as Roehm Eupergit, Carrageenan particles, chitosan particles or any other suitable material and then used in a stirred tank or fixed bed reactor or on a membrane or on a hollow fiber reactor.
[0043] Alternatively, the enzyme(s) to be used for the hydrolysis could be cross linked to suitable inert support prior to the hydrolysis reaction and subsequently separated out of the hydrolysis reaction with the use of a microfiltration membrane.
[0044] Alternatively, the enzyme can be separated away from the hydrolysis mixture with the use of an ultrafiltration membrane with a nominal molecular weight cutoff in the range 10-500 kDa once hydrolysis is complete.
[0045] After hydrolysis and optional deactivation or removal of enzymes, the hydrolysate may optionally be subjected to reverse osmosis under conditions whereby salt and water are removed from the hydrolysate. The purified desalted hydrolysate comprising whey proteins and bioactive peptides is then recovered. If lactose hydrolysis is also chosen then the hydrolysate will also contain glucose, galactose and/or galacto-oligosaccharides.
[0046] Optionally the hydrolysed whey proteins containing the bioactive peptide fraction can be separated with a UF membrane of 5-200 kDa cut off, preferably 10-50 kDa cut off. The bioactive peptides, other peptides and, optionally, hydrolysed lactose is recovered in the permeate.
[0047] According to another option ion exchange or hydrophobic adsorption or hydrophobic interaction chromatography or combinations of these processes may be used to recover the hydrolysed bioactive fraction from the hydrolysates in an enriched form.
[0048] In addition, lactase and β-galactosidase hydrolysis of lactose produces galacto-oligosaccharides which are known to stimulate the growth of beneficial gut flora thereby adding to the bioactive properties of the hydrolysates.
[0049] Hydrolysates which have been treated to further hydrolyse lactose are useful as food additives for consumers who are lactose intolerant.
[0050] The hydrolysed whey protein product of the invention has one or more of the following features:
antihypertensive ACE-I activity bifidus growth promoting activity non-gluey, non-bitter flavour pleasant to slightly sweet taste good organoleptic properties.
[0056] The invention consists in the foregoing and also envisages constructions of which the following gives examples.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] The present invention will now be described with reference to the accompanying drawings in which:
[0058] FIG. 1 is a plot of bitterness and bioactivity on the ordinant against the degree of hydrolysis on the abscissa. The ‘opportunity window’ of obtaining a product according to the present invention containing bioactive peptides and having acceptable flavours before the hydrolysis reaction produces bitter peptides is between the lines x 1 and x 2 .
[0059] FIG. 2 is a plot of systolic blood pressure of four groups of hypertensive rats fed different diets over a period of eight weeks.
[0060] FIG. 3 is a plot of a least squares means analysis of rats fed with a control of commercial rat chow against groups of rats fed with hydrolysate at two different concentrations per day.
DETAILED DESCRIPTION OF THE INVENTION
[0061] As discussed above, the present invention provides a process for producing a hydrolysed whey protein product containing bioactive peptides, whereby the hydrolysis is carried out under a high degree of control to prevent undesirable flavours developing during hydrolysis (eg bitter, soapy and brothy). The hydrolysis is terminated within the “opportunity window”, ie before the emergence of substantial bitterness—as shown in FIG. 1 —to provide hydrolysates having good organoleptic properties and maximum bioactive peptides. In FIG. 1 the degree of hydrolysis is represented qualitatively on the x axis. The window of opportunity is between the points x 1 and x 2 which will vary depending on the enzyme which is used. The optimum conditions sought are a maximum bioactivity with an acceptable level of bitterness.
[0062] In particularly preferred embodiments of the process of the invention, the enzyme which hydrolyses the whey proteins is selected from the group consisting of Protease P6, Protease A, Protease M, Peptidase, Neutrase, Validase and AFP 2000 (all as herein defined) and the hydrolysis of the whey proteins is terminated by heat treatment for a short time at a high temperature (about 85-100° C. for 1-10 seconds). The applicants have surprisingly found that the above enzymes (1) are able to produce a whey protein hydrolysate containing a good level of bioactive peptides, and (2) can be inactivated by a short time, high temperature treatment which causes only partial denaturation of the whey proteins in the hydrolysate, and surprisingly improves the organoleptic properties of the whey proteins, in terms of providing a product which is creamy in texture (has a relatively small particle size) and substantially white in appearance.
[0063] The present invention is now exemplified by the following examples:
EXAMPLE 1
[0064] A 10% solution of a sweet whey protein concentrate with 80% protein content (ALACEN™ 392, 2 L) was hydrolysed at 50° C. with the commercially available enzyme Neutrase sourced from Bacillus subtilis (Novo Nordisk, Denmark). A pH of 7.0 and an enzyme substrate ratio of 0.3% w/w was used for the hydrolysis. The hydrolysate was adjusted to pH 5.0 and heated at 65° C. for 30 min to inactivate the enzyme. The hydrolysate (DH of 4.5%) was spray dried and tested for angiotensin-converting enzyme inhibitor (ACE-I) activity and flavour. ACE-I activity in the dried product was determined using FAPGG as a substrate (Product 305-10 ex Sigma Chemical Corporation, St Louis, Mo., USA) according of the method of D W Cushman & H S Cheung (1971). ACE-I activities are expressed as the amount of material (g/L) needed to reduce the activity of the ACE-I enzyme by 50%. IC 50 ACE-I activity in the hydrolysate was 0.44 g/L and flavour acceptability score, as determined by a taste panel, was very high.
EXAMPLE 2
[0065] A 50% solution of ALACEN™ 421 whey protein concentrate (56% protein content, 10 L) was treated with commercial lactase sourced from Kluveromyces lactis (Lactozyme 3000L ex Novo Nordisk) at an enzyme to substrate ratio of 0.3% at 50° C. for 2 hours. The lactase treated solution was hydrolysed with Neutrase (Novo Nordisk, Denmark) for 1 hour at 50° C. at an enzyme substrate ratio of 0.3%. Active enzymes were inactivated by UHT treatment (5 sec at 95° C.) after a five fold dilution of the mixture. The hydrolysate was spray dried. The dry powder (DH 2.8%) contained no traces of active enzyme and had an ACE-I activity of 2.18 g/L. The flavour score was exceptionally high due to the introduction of a low level of sweetening into the product. ACE-I measurements and flavour acceptability scoring were determined as for Example 1.
EXAMPLE 3
[0066] A 500 L hydrolysate, made from ALACEN™ 392 in a similar way to that in example 1, was cooled to 10° C. after enzyme inactivation. A sub-sample of the original hydrolysate was dried. The remaining hydrolysate was subjected to ultrafiltration at 10° C. with a 10,000 dalton nominal molecular weight cutoff membrane (HFK 131, Koch Membrane Systems, USA). The hydrolysate (at a DH between 3.8% and 4.2%) was concentrated to a VCF 10 and the retentate was dried directly. The permeate was concentrated by evaporation to approx 25% solids and dried. ACE-I measurement and flavour acceptability scoring were determined as for Example 1. The ACE-I activity was enriched in the permeate powder (IC 50 of the permeate powder was 0.15 g/L). ACE-I activity in the sub-sample of the dried hydrolysate before ultrafiltration was 0.43 g/L. The flavour acceptability scores on the retentate powder and the spray dried powder of the feed were both high.
EXAMPLE 4
[0067] Three different solutions from ALACEN™ 392, ALACEN™ 421 and a mixture of ALACEN™ 392 and lactose were made up at 15% solids to yield 150 L. The solution was treated with a commercial protease from Bacillus subtilis Neutrase (Novo, Nordisk Denmark) and a commercial lactase from Klyvermyces lactis (Lactozyme 3000L ex Novo Nordisk). The addition rate of enzyme was 0.3% w/w (on protein basis) for Neutrase and 1.2% w/w (on lactase basis) for Lactozyme. The reaction continued for 2 h at 50° C. at a pH of 7.0. Samples of 35 L were taken every 0.5 h inactivated at 88° C. for 3 seconds and subsequently spray dried. The ACE-I activity as specified in example 1 yielded 0.424 g/L, 0.336 g/L and 0.432 g/L for the three mixtures on a protein basis. The bitterness of the samples from ALACEN™ 392 was formally evaluated against two standard hydrolysates. The scores for bitterness on a scale of 1 to 10, 10 being most bitter were 1.9 for a sample after 0.5 h hydrolysis, 2.3 for the 2 h hydrolysis compared to 5 and 7 for the standard hydrolysis samples of greater degrees of hydrolysis.
[0068] The samples of ALACEN™ 421 and a mixture of ALACEN™ 392 and lactose taken after 2 h had a mean particle size of 3 μm or 2 μm respectively. The sample of ALACEN™ 392 had a mean particle size of 6 μm after 2 h hydrolysis and inactivation as specified. Less grittiness and chalkiness was attributed to the smaller particle size samples.
[0069] The solubility of the hydrolysed ALACEN™ 392/lactose mixture was the highest with approximately 85% across the pH range. The ALACEN™ 392, ALACEN™ 421 samples are soluble to about 70% with a slight drop in solubility to 65% at pH 3.5.
EXAMPLE 5
[0070] Three different solutions from ALACEN™ 392, ALACEN™ 421 and a mixture of ALACEN™ 392 and lactose were made up of 30% solids to yield 75 L. The enzyme treatment was done using the same conditions as example 4. The samples taken at half hourly intervals were diluted to 15% solids. Otherwise the heat treatment was done as in example 4. The ACE-I activity measured as specified in example 1 was 0.560 g/L, 0.440 g/L and 0.728 g/L.
[0071] Samples from example 4 and 5 were added in a concentration of 0.1% to the standard growth media of Bifidobacterium lactis and resulted in a faster cell growth and higher final cell density of the strain than the control without any supplement.
[0072] The oligosaccharide level (trisaccharides and higher) of those three hydrolysed samples was 0.2%, 2.1% and 7.0% in ALACEN™ 392, ALACEN™ 421 and the mixture of ALACEN™ 392 and lactose, respectively.
EXAMPLE 6
[0073] Hydrolysate powders prepared in example 5 were used as a supplement for yoghurts in addition rates from 2.5% and 5% of the final yoghurt and resulted in an increased creaminess and improved the texture compared to the control.
EXAMPLE 7
[0074] The hydrolysate powders prepared in example 5 were used as the protein source in a muesli bar recipe on a 6% and 12% w/w addition rate. All tasters preferred the hydrolysate bars over the unhydrolysed WPC control. The best results were achieved with hydrolysed ALACEN™ 421 and a mixture of ALACEN™ 392 and lactose prepared in example 5.
EXAMPLE 8
[0075] The hydrolysate powder prepared in example 5 was used as an ingredient in a meal replacer concept sample. ALACEN™ 421 hydrolysed in lactose and protein was added at a rate of 45% w/w to whole milk powder, malto dextrin, sucrose and milk calcium (ALAMIN™) to result in a powder meal replacer prototype. In comparison with a control sample without hydrolysed whey protein, hydrolysed whey protein prepared in example 5 was found to be more acceptable.
EXAMPLE 9
[0076] A nutritional whey protein drink was formulated containing 8% w/w of ALACEN™ 392 or ALACEN™ 421 or a mixture of ALACEN™ 392 and lactose hydrolysed as specified in example 5. The drink also contained sucrose, citric acid, flavouring and colouring agents. The pH of the drink was adjusted to 4.3. The drink combined the nutritional and health advantages of whey protein with the refreshing taste of a soft drink. Compared to a drink containing untreated whey protein control the pH stability was improved and the drink had a more milk like appearance than the control.
EXAMPLE 10
[0077] A further nutritional protein drink was formulated containing 12.5% w/w of ALACEN™ 421 hydrolysed as in example 5 in water mixed with pasteurised whole milk. Sucrose was added to yield 6% of the final formulation as well as stabiliser. The drink was flavoured when desired with banana, vanilla or similar flavours. To achieve an extended shelf life the drink was ultra high heated to 140° C. for 3 seconds. The mean particle size remains at 3 microns after the additional UHT heat treatment.
EXAMPLE 11
[0078] The hydrolysis was carried out as specified in example 5 but instead of reconstituting ALACEN™ 421 powder a fresh retentate of ALACEN™ was concentrated to 30% solids in the solution. The neutrase addition rate was varied to 0.9% w/w (on a protein base), the lactase level as specified. The reaction mixture was inactivated at 15% solids after 2 h. The ACE-I activity yielded 0.480 g/L. The organoleptic properties, particle size and food application were very similar to example 4 and 5.
EXAMPLE 12
[0079] The hydrolysis was carried out as specified in example 4 with ALACEN™ 421 powder. The Neutrase addition rate was varied to 0.9% w/w (on a protein basis). The lactose was converted with a lactase from Aspergillus oryzae (Fungal lactase 30,000, Kyowa Enzymes Co. Ltd. Japan) on an addition rate of 0.4% w/w (on lactose base). The reaction mixture was inactivated after 1.5 h with direct steam injection to achieve a temperature of 88° C. for either 1.5 seconds or 3 seconds.
[0080] The particle size was 2.3 microns. Organoleptic properties and food application were very similar to the product of example 4.
EXAMPLE 13
[0081] A 10% w/w solution of ALACEN™ 392 was hydrolysed with a commercial protease from Bacillus subtilis Neutrase (Novo, Nordisk Denmark) at an enzyme concentration of 0.9% w/w. The reaction continued for 6 h at 50° C. Samples of 200 ml were taken every 1 h, inactivated at 88° C. for 8 seconds and subsequently freeze dried.
[0082] ACE-I activity, degree of hydrolysis, pH of solution and bitterness developed over time as follows. The higher the bitterness score the more bitter is the taste. The smaller the level measured, the higher is the ACE-I activity.
TABLE 1 Hydrolysis of ALACEN ™ 392 WPC Degree of Bitterness Hydrolysis ACE-I activity hydrolysis pH of score time [h] [g/L] (IC 50 ) [%] solution [informal, 0-10] 1 0.420 3.86 7.01 0 2 0.280 3.78 6.96 1 3 0.230 4.53 6.92 1 4 0.220 4.89 6.89 3.5 5 0.210 5.20 6.87 2 6 0.190 5.37 6.87 4.5
EXAMPLE 14
[0083] A 10% w/w solution of ALACEN™ 392 was hydrolysed with the following commercial proteases at 1% w/w, 50° C. for 1 h. The reaction was inactivated at 88° C. for 8 seconds and subsequently the hydrolysate was freeze dried.
TABLE 2 Hydrolysis with Different Enzymes ACE-I Degree of activity hydrolysis Enzyme [g/L] (IC 50 ) pH [%] Protease P6, neutral protease, Aspergillus 0.274 7.0 8.9 strains, Amano Enzymes Protease A, neutral protease, Aspergillus 0.443 7.0 9.2 oryzae , Amano Enzymes Protease M, acid protease, Aspergillus 0.450 4.0 7.4 oryzae , Amano Enzymes Peptidase, neutral peptidase, Aspergillus 0.540 7.0 6.9 oryzae , Amano Enzymes Neutrase, neutral bacterial protease, 0.510 7.0 4.3 Bacillus subtillis , Novo Nordisk DK Validase (Genancor), acid fungal protease, 0.510 4.0 5.6 Aspergillus niger , Enzyme Services Ltd. NZ AFP 2000 (Genancor), acid fungal 0.550 4.0 3.9 protese, Aspergillus niger , Enzyme Services Ltd. NZ
EXAMPLE 15
[0000] Identification of ACEI-Peptides and Measuring their Activities
[0084] 200 mg of permeate from example 3 was dissolved in 0.1% trifluoroacetic acid (TFA) and applied to a Jupiter preparative reverse-phase HPLC column (10 micron, C18, 22×250 mm [Phenomenex NZ]) equilibrated with solvent A (0.1% TFA) and connected to an FPLC system (Pharmacia). Peptides were sequentially eluted from the column with a gradient of 0 to 43% solvent B (0.08% TFA in acetonitrile) in 245 min at a flow rate of 10 mL/min. Peptides eluting from the column were detected by monitoring the absorbance of the eluate at 214 nm. The eluate was collected by an automatic fraction collector set to collect 3 min fractions.
[0085] Each fraction was lyophilised and the amount of peptide material present was measured gravimetrically. Fractions were assayed for ACE-I activity using an in vitro assay system (reagents from Sigma product 305-10) consisting of rabbit lung ACE and the colorimetric ACE substrate furylacryloylphenylalanylglycylglycine (FAPGG); ACE hydrolyses FAPGG to give the products FAP and GG which results in a decrease in absorbance at 340 mm. If a peptide inhibits ACE, the change in absorbance at 340 nm is reduced. Fractions containing the highest ACE inhibitory activity per mg peptide material were re-applied to the preparative reverse-phase HPLC column and eluted using a shallow gradient of solvent B i.e. 0.09% increase in solvent B concentration/min. The eluate was collected using the fraction collector set to collect 0.5 min fractions.
[0086] Samples from each fraction were analysed using an analytical reverse-phase HPLC column, and those fractions containing a single, identical peptide were pooled. Each pooled fraction was lyophilised and the weight of the peptide present was determined gravimetrically. The purified peptides were assayed for ACE-I activity as before and the IC 50 was calculated for each individual peptide.
[0087] The molecular weight of each peptide was determined by Electrospray lonisation Mass Spectrometry (Sciex API 300 triple quadrupole mass spectrometer). Tandem mass spectrometry was also done for each peptide to generate CAD spectra using MSMS experiment scans. Each peptide was also analysed by an automated N-terminal sequencer (ABI model 476A protein sequencer). Data collected from all three techniques was used to deduce the sequence of all of the peptides possessing ACE-I activity. The origin of each of the active peptides was determined by searching a database containing the known sequences of all bovine milk proteins.
[0088] The peptides, their origins, activities and known similarities are set out in table 3. Although the last three peptides are of a casein origin they were from a whey protein hydrolysate. The rennet used to precipitate casein did not precipitate these casein fractions and they remained with the whey proteins.
TABLE 3 ACE-I Peptides and their Activities Similarity Activity b to known (IC 50 in ACE-I Peptide Sequence a Origin mg L −1 ) Peptides AFE PP d 3(129-131) 20 (Ala-Phe-Glu) LFSH PP3(125-128) 30 (Leu-Phe-Ser-His) ILKEKH PP3(71-76) 20 (Ile-Leu-Lys-Glu-Lys-His) LIVTQ β-LG e (1-5) 17 (Leu-Ile-Val-Thr-Gln) MKG β-LG(7-9) 24 (Met-Lys-Gly) LDIQK c β-LG(10-14) 17 β-LG(9-14) (Leu-Asp-Ile-Gln-Lys) VF β-LG(81-82) 19 (Val-Phe) ALPMH β-LG(142-146) 12 β-LG (Ala-Leu-Pro-Met-His) (142-148) VTSTAV GMP f (59-64) 30 (Val-Thr-Ser-Thr-Ala-Val) LHLPLP β-CN g (133-138) 7 (Leu-His-Leu-Pro-Leu-Pro) LVYPFPGPIPNSLPQNIPP β-CN(58-76) 19 β-CN (Leu-Val-Tyr-Pro-Phe-Pro- (74-76) Gly-Pro-Ile-Pro-Asn-Ser- Leu-Pro-Gln-Asn-Ile-Pro- Pro) LFRQ α s1 -CN(136-139) 17 h (Leu-Phe-Arg-Glu) a sequence given using the single-letter amino acid code with the corresponding three-letter code in brackets b using the colorimetric substrate FAPGG c most abundant ACE-I in hydrolysate d protease peptone e β-lactoglobulin f glycomacropeptide g β-casein h activity measured with that of another peptide of unknown origin
EXAMPLE 16
[0089] The effect of the hydrolysate powder prepared in example 3 (without ultrafiltration) on in vivo blood pressure was tested using spontaneously hypertensive rats (SHR/N). The rat strain has been specifically selected for their development of high blood pressure on maturing, and is used extensively to monitor the effect of blood pressure lowering agents. They were purchased from Animal Resources Centre, P O Box 1180 Canning Vale, Western Australia 6155.
[0090] Eight week old rats were individually housed in plastic rat cages and kept in temperature controlled facilities throughout the trial. They had unlimited access to water and were fed commercial rat chow ad libitum. The test products were given orally as a single daily dose for 8 weeks during which time changes in blood pressure were monitored. Their blood pressure was measured using a specially designed tail cuff and blood pressure monitoring apparatus (IITC Inc., Life Science Instruments, 23924 Victory Blvd, Woodland Hilld, Calif. 91367). The experimental design was approved by the Massey University Animal Ethics Committee, protocol number 98/141.
[0091] The changes in the systolic blood pressures of each group of animals over the eight weeks are plotted in FIG. 2 (as least squares means). The hydrolysate at both 2 g/Kg bodyweight/day and 4 g/Kg bodyweight/day significantly lowered the systolic blood pressure of SHRs compared to animals fed commercial rat chow only (p<0.004 by least-squares means analysis, see FIG. 3 ). The effect of the hydrolysate was not as great as that of captopril, a known ACE-I inhibitory drug administered at 30 mg/Kg bodyweight/day, but was a significant improvement for animals fed commercial rat chow only.
REFERENCES
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Roy G (1992). Bitterness: reduction and inhibition. Trends in Food Science and Technology 3: 85-91
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Yamamoto N (1997). Antihypertensive peptides derived from food proteins. Biopolymers 43: 129-134.
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The invention relates to a partial hydrolysate of when protein which contains bioactive peptides but does not have a bitter flavour. The hydrolysate is carried out using selective enzymes which produce the active peptides and is terminated at a degree of hydrolysis before substantial bitter flavours are created. There are also described novel peptides and a method of reducing systolic blood pressure through the administration of the peptides.
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